Archive for the ‘Design Guide’ Category

Friday, October 25th, 2024

In the PCB design and testing, there is a common term be mentioned frequently, that is EMI and EMC. Some people may ask that “what is EMI/EMC, why is it be mentioned every time?” Today, BEST team will take you to understand what are they and how to test them. Let’s keep reading.

What are EMI and EMC in PCB?

Before diving into, we should know both EMI and EMC are important elements during the PCB design. Some new PCB projects are failed during testing, because EMI and EMC design is not reasonable.

EMC is short for electromagnetic compatibility. EMC in a PCB is the ability of the PCB to operate in its electromagnetic environment without creating unbearable electromagnetic interference to other devices around it. In general, to achieve an EMC compliant design, engineers need to consider three basic aspects:

Generating unwanted electromagnetic radiation and its propagation.
The vulnerability of designs or components to electromagnetic interference (EMI).
PCB design should not cause intolerable electromagnetic interference on its own.

EMI is short for electromagnetic interference. EMI is unwanted noise or signals generated by electronic devices, which can disrupt other nearby equipment. PCBs, being central to electronics, are often both sources and victims of EMI. Every engineer should follow EMC configuration standards to minimize the total amount of EMI and its impact.

In a word, EMI refers to the generation of electromagnetic interference, while EMC refers to electromagnetic compatibility, that is, how well a device blocks EMI. EMI originates from electromagnetic equipment, and EMC involves equipment that is both anti-interference and non-interference with other equipment.

What Is the Difference Between EMI and EMC Testing?

EMI testing focuses on measuring the interference a device generates. It aims to ensure that the PCB doesn’t emit electromagnetic waves that can interfere with other devices. EMC testing, on the other hand, checks the device’s ability to withstand electromagnetic interference from its environment without losing functionality. Both tests are essential to make sure that your PCB not only works well but also doesn’t cause problems for other systems.

The main difference between EMC tests and EMI is their purpose and method of testing. ‌

Test purpose

‌EMC testing focus on the equipment or system will function properly in an electromagnetic environment and will not cause intolerable electromagnetic disturbance to other equipment. EMC testing includes two aspects: electromagnetic immunity (the ability to resist interference) and electromagnetic emission (not to interfere with other equipment).
‌However, EMI testing focuses on unwanted electromagnetic energy emitted by a device or system that may interfere with the normal operation of other nearby equipment. The purpose of EMI testing is to identify and reduce these sources of interference to prevent interference with other equipment ‌

Testing method

‌EMC test usually includes shielding, grounding, and filtering methods. Shielding is surrounding devices or systems by using conductive materials to reduce leakage of electromagnetic radiation. Grounding is connecting the metal housing and ground to provide a safe electrical circuit loop. Filtering is to reduce unnecessary electromagnetic signal transmission through PCB circuit design.
‌EMI test mainly measuring by the conducted interference and radiation interference of the devices. Conducted interference is interference that travels through a conductive medium (such as a wire), while radiative interference refers to the interference that travels through space.

What Are the Testing Standards for EMI/EMC?

Several global standards guide the EMI/EMC testing process. These include:

IEC 61000 series: This is the most common EMC test standard, covering EMI and EMS (Electromagnetic sensitivity) test methods, limits and units of measure.

EN 55014 series: This is the EU EMC test standard, including:

EN 55014-1: Radiation from household appliances

‌EN 55014-2‌: Radiation immunity of household appliances

‌EN 55032‌ : Interference emission test for multimedia electronic products

‌EN 55035‌ : Immune immunity test for multimedia electronic products

‌GB/T17625 series ‌ : This is China’s EMC test standard, including:

GB/T17625.1-2012‌ : EMC limits Harmonic current emission limits (Input current per phase ≤16A)

‌GB/T17625.2-2007‌ : Limits on voltage variation, voltage fluctuation, and flicker (rated current of equipment per phase ≤16A)

‌GB/T17625.7-2013‌ : Harmonic current limit for conditionally connected devices with rated current ≤75A in a common low-voltage power supply system

‌GB/T17625.8-2015‌ : Harmonic current limit for devices connected to a common low-voltage system with input current greater than 16A but less than 75A per phase

‌GB/T17625.9-2016‌ : Signal transmission emission levels, frequency bands and electromagnetic disturbance levels on low-voltage electrical installations

‌GBZ17625.3-2000‌ : Limits on voltage fluctuations and flickers in low-voltage supply systems for devices with rated current >16A

‌GBZ17625.6-2003‌ : Limits on harmonic currents produced by devices with rated current >16A in low-voltage power supply systems

‌GBZ17625.13-2020‌ : Evaluation of emission limits for unbalanced installations connected to medium voltage, high voltage, and ultra-high voltage power systems

‌GBZ17625.14-2017‌ : Evaluation of emission limits for harmonics, interharmonics, voltage fluctuations and unbalance of nuisance devices connected to low voltage power systems

‌GBZ17625.15-2017‌ : Evaluation of low frequency electromagnetic immunity and emission requirements for distributed generation systems in low voltage power grids

These standards cover a wide range from household appliances to industrial equipment, you can follow one of them according to your specific applications and countries.

How to Conduct an EMI Test?

Before conduct a test, let’s know the testing method. EMI test methods mainly include the following ‌ :

1. Pre-test: EMI testing performed during the design phase to detect and resolve EMI problems early in product design and development. Pre-test can be conducted using computer simulation, or by using actual test equipment.

2. Emission test: It is a test to measure whether electromagnetic waves emitted by equipment meet EMI standards. The emission test can be carried out by field test, half-time test, full-field test and other methods. Commonly used test equipment includes spectrum analyzer, scanning receiver, antenna, etc.

3. Sensitivity test: Common sensitivity testing methods include radiation sensitivity testing and conduction sensitivity testing. radiation sensitivity testing uses a signal generator to generate an electromagnetic field of a specific frequency and intensity. And conduction sensitivity testing involves injecting simulated electromagnetic interference signals on the power or signal lines of the equipment under test.

4‌. Spectrum analysis: By measuring the spectrum of electromagnetic wave to analyze the characteristics of electromagnetic interference.

‌Above are the testing methods of EMI, and here is the steps that how to test it.

Select the right test method

First of all, select a right test method according to the specific test purpose and object. For example, if the emission characteristics of the equipment need to be evaluated, an emission test can be selected; If you need to evaluate the anti-interference capability of the equipment, you can choose sensitivity test.

Use professional equipment

Use professional test equipment, such as spectrum analyzer, signal generator, digital storage oscilloscope, etc., to ensure the accuracy of the test results.

Environment control

When performing sensitivity test, control the test environment to avoid the influence of other electromagnetic interference sources. Tests can be conducted in a shielded room to reduce outside interference.

Data analysis

Detailed analysis of the test data, identify potential sources of electromagnetic interference, and propose improvement measures. Methods such as difference method and potential zeroing method can be used to reduce the influence of interfering magnetic field on measurement results.

EMI/EMC PCB Design Guidelines

1. Ground plane

Because all circuits need to be grounded, the ground plane is the first line of defense against EMI. The following measures can be taken to reduce EMI:

Increase the ground area
Set up the ground plane
Each component should be connected to the ground plane
Each component should be connected to the ground plane or a ground point.
Decoupling capacitor
The ground plane is placed directly below the plane with the signal trace
Digital ground and analog ground should be separated
The ground wire should be as thick as possible
The length of the ground system should be kept to a minimum

2. Power supply design

Improper power supply design will result in greater noise and ultimately reduce product performance. Two main factors that lead to power supply instability:

1) Excessive transient AC current under high-speed switching

2) Inductance exists in the current loop Therefore, the integrity of the power supply should be fully considered in PCB design.

3. PCB layout

a) PCB size

PCB size must be considered. When it comes to oversized boards, the traces must go a long way as the impedance increases, the noise immunity decreases, and the manufacturing cost increases. When the board size is particularly small, it will cause heat dissipation problems and crosstalk is prone to occur between adjacent traces. The recommended PCB size is a rectangle with an aspect ratio of 3:2 or 4:3. In addition, when the board size exceeds 200mm*150mm, the mechanical strength of the board retraction should be considered.

b) Avoid right angles

This has been said many times. Avoid 45° to 90° for vias, traces, etc. When the trace reaches more than 45°, the capacitance will increase.

c) Keep signals separated

Digital circuits, analog circuits, and noise sources should be placed independently on the board, and high-frequency circuits should be isolated from low-frequency circuits. In addition, attention should be paid to the component distribution of strong and weak signals and the direction of signal transmission.

d) Increase the trace width as much as possible

e) Wider trace sizes can effectively reduce radiated emissions.

f) Make the return current path as short as possible and route along the path with the least resistance. The length of the return path should be roughly the same as or shorter than the length of the transmission trace.

4. Component placement

In general, it is best to completely separate analog and digital signals. Being too close can easily lead to problems such as crosstalk. In addition, compatible components should be placed independently to ensure that components do not interfere with each other in space.

5. PCB layer design

In terms of the number of layers, choose the appropriate number of layers. Single-layer PCBs and double-layer PCBs are suitable for medium and low-density wiring or low-integrity circuits. Based on manufacturing cost considerations, most consumer electronic products rely on single-layer PCBs or double-layer PCBs. However, due to their structural defects, they both generate a lot of EMI, and they are also sensitive to external interference. Multi-layer PCBs tend to be more used in high-density wiring and high-integrity chip circuits. Therefore, when the signal frequency is high and the electronic components are densely distributed, a PCB with at least 4 layers should be selected. In multi-layer PCB design, the power layer and the ground layer should be specially arranged, and the distance between the signal line and the ground line should be reduced.

6. EMI shielding

Shielding and filtering can minimize the impact of EMI. Some shielding and filtering options include:

Component and PCB shielding
Low-pass filtering
Cable shielding

7. Trace routing

Put the current signals with the same output but opposite directions in parallel to eliminate magnetic interference. Discontinuities in printed leads should be minimized. For example, the lead width should not change abruptly and the lead angle should not exceed 90°.

8. Routing design

The power line, ground line, and traces on the circuit board should maintain low impedance to high-frequency signals. When the frequency remains so high, the power line, ground line, and circuit board traces all become small antennas responsible for receiving and transmitting interference. To overcome this interference, it is more important to reduce the high-frequency impedance of the power line, ground line, and circuit board traces than to increase the filter capacitor. Therefore, the traces on the circuit board should be short, thick, and evenly arranged.

9. Decoupling and grounding

The proper placement of decoupling capacitors and the application of the inductor capacitor energy storage function make it possible to provide current to the device at the moment of switching. In a DC loop, load changes can cause power supply noise. The decoupling capacitor configuration can block the noise generated by load changes. For electronic equipment, grounding is a key method to control interference. If grounding is properly combined with shielding measures, most interference problems will be solved.

Above all are the key points when design pcb, hope you can take them in mind and use in your actual design phase.

What is Aerospace PCB Assembly?

Aerospace PCB assembly refers to the intricate process of manufacturing printed circuit boards (PCBs) specifically for aerospace systems, including aircraft, spacecraft, satellites, and other related avionics systems. These boards are vital for controlling critical systems in extreme environments, where traditional electronic components would fail. Aerospace PCBs are engineered with precise attention to durability, signal integrity, and longevity to ensure reliable operation over long periods, even in the most hostile conditions like extreme temperatures, vibrations, and radiation.

The assembly process includes component placement, soldering, testing, and verification to ensure the PCBs meet strict aerospace industry standards. Due to the high-stakes nature of aerospace applications, each PCB must be built with the highest degree of precision and undergo rigorous testing to ensure it can withstand the operational conditions of the specific aerospace application.

Aerospace PCB Assembly Guide | PCBA & Box Building

Why does Aerospace PCB Assembly Need High Reliability?

Aerospace PCB assembly requires exceptionally high reliability due to the mission-critical nature of the systems they support. Unlike consumer electronics, where failures might lead to inconvenience, failures in aerospace systems can be catastrophic, leading to loss of life, property, or the failure of multimillion-dollar space missions. Once a satellite, spacecraft, or aircraft is deployed, accessibility to repair faulty components is extremely limited. So that aerospace PCBs function flawlessly for years, or even decades, without failure.

In addition to inaccessibility, aerospace electronics face harsh environmental conditions such as extreme temperatures, radiation, shock, and vibration. These conditions demand that PCBs operate continuously under stress without compromising their performance. High-reliability standards ensure the PCBs’ long-term stability and functionality in these demanding environments. Aerospace components must be high quality, fail-safe, and undergo extensive testing for performance, durability, and resilience.

What Grade of IPC Standard Should Aerospace PCB Assembly Follow?

IPC standards are a widely used term in the electronics industry that covers all aspects of electronic product design, including the acceptability of printed circuit boards, material requirements, and more. IPC standards establish standards from all aspects, as long as manufacturers strictly implement the standards, product quality and reliability are naturally guaranteed.

Aerospace PCB assembly needs to meet the requirements of high reliability, high quality and high performance, so during the production process, it should comply with IPC-6012 Level 3 standards. IPC-6012 is a performance specification document that defines the default requirements and specifications for each class of PCB. Among them, Class 3 PCBs have tighter tolerances and are commonly used in military applications, medical devices, and the aerospace industry. The IPC-6012 Level 3 standard ensures that the PCB can also ensure the reliable start-up and operation of the equipment in harsh environments, such as high temperature, low temperature, vibration and other extreme conditions can still work.

In addition to IPC-6012, IPC-610 Class 3 is critical for ensuring the highest quality workmanship in aerospace electronics as well. In the IPC-610 standard, class 3 defines the acceptance criteria for high-reliability electronics, including tight tolerances, high-quality soldering, and thorough inspections.

Industry Standards for Aerospace PCB Manufacturing

Aerospace PCB manufacturing must adhere to several industry-specific standards to ensure reliability and safety.

ISO9001

It is an internationally recognized quality management system standards designed to help organizations continue to provide products or services that meet customer and applicable legal and regulatory requirements through a systematic approach. It is the code of conduct that governs our production process.

AS9100

Another essential standard is AS9100, which is a widely recognized quality management system tailored specifically for the aerospace industry. It covers every aspect of the aerospace PCB production process, from material selection to assembly, testing, and delivery.

MIL-PRF-31032

It is one of the most significant standards is MIL-PRF-31032, which governs the qualification of printed wiring boards used in military and aerospace applications.

RoHS

PCBs for aerospace applications must also comply with RoHS (Restriction of Hazardous Substances) regulations, particularly in Europe, to ensure the environmental safety of electronic components. Additionally, aerospace PCBs undergo specific testing procedures, such as thermal cycling, vibration testing, and humidity resistance, to ensure they meet operational standards.

Best Technology certificated by ISO9001, ISO13485, IATF16949, AS9001, RoHS and some other certifications about manufacture. We are dedicated to provide customers with “High mixed, low volume, fast delivery and high quality” PCB and PCBA products. At Best Technology, you get a sense of value for money!

Common PCBA Modules or Systems for Aerospace Electronics

Aerospace electronics rely on various specialized PCBA modules and systems to ensure efficient and reliable operation in mission-critical environments. These systems are essential in everything from flight control to communication, navigation, and power management in aircraft, satellites, and spacecraft. Below are some of the most common PCBA modules or systems used in aerospace electronics:

1. Avionics Control Systems

Avionics control systems are the backbone of modern aerospace technology, responsible for managing and controlling various systems in aircraft and spacecraft. They handle critical functions such as navigation, communication, and onboard sensors, providing real-time data to pilots and flight computers.

2. Power Management Systems

Power management systems in aerospace electronics regulate the distribution and control of electrical power across the aircraft or spacecraft. These PCBA modules are designed to manage the onboard electrical grid. In some subsystems, they provide a stable power supply, such as for communication equipment, control systems, and sensors.

3. Flight Control Systems

Flight control systems are responsible for managing an aircraft’s or spacecraft’s attitude, direction, and speed. The PCBA modules within these systems process data from various sensors (like gyroscopes and accelerometers) and use it to adjust control surfaces or thrusters.

4. Radio Communication Systems

It enables the communication between the aircraft and ground control. RF (Radio Frequency) modules, transceivers, and antenna control units are common PCBAs in communication systems. Aerospace communication systems are engineered to handle long-distance transmission and are resistant to environmental interference, such as radiation or electromagnetic noise.

5. Navigation Systems

Navigation systems in aerospace electronics guide aircraft and spacecraft to their destinations using data from GPS satellites, inertial navigation systems (INS), and other sources. The PCBAs in navigation systems are responsible for processing this data and providing accurate location, speed, and altitude information.

6. Radar and Sensor Systems

They are the most important parts in the aerospace applications, like collision avoidance, terrain mapping, and weather monitoring. They can process large amounts of data quickly and reliably, often using digital signal processors and field-programmable gate arrays (FPGAs) to handle real-time processing.

7. Environmental Control Systems (ECS)

Environmental control systems are responsible for maintaining optimal cabin and equipment conditions within an aircraft or spacecraft. These systems monitor and regulate air pressure, temperature, and humidity. The PCBAs used in ECS modules often featuring sensors that track environmental parameters and control systems that adjust them accordingly.

8. Data Acquisition Systems

Data acquisition systems collect and process data from various subsystems and sensors in aerospace applications. These PCBA modules are integral in spacecraft, aircraft, and satellites, enabling real-time data monitoring, analysis, and recording. Data acquisition PCBAs are designed to interface with different sensors, process data quickly, and transmit it to central control systems for further analysis. These systems must be reliable and capable of operating in high-altitude or space environments where temperatures and radiation levels can be extreme.

9. Power Distribution Units (PDUs)

Power Distribution Units (PDUs) manage the flow of electrical power to various subsystems within an aircraft or spacecraft. The PCBAs in PDUs ensure that power is efficiently distributed to essential systems, and they often include built-in protections against power surges, overloads, and short circuits.

Best materials for Aerospace PCB Assembly

Aerospace PCB mainly used high reliability and high temperature materials. Common material types are the following:

High temperature substrate

Because aerospace electronic equipment is often in a high temperature environment, it is necessary to use high temperature substrate, such as polyimide (PI) and polytetrafluoroethylene (PTFE).

Refractory materials

The aerospace field has strict fire safety requirements, so it is necessary to use good flame

retardant materials, such as polystyrene (PS) and Australian flame retardant epoxy resin.

Corrosion resistant materials

There are some corrosive substances in the aerospace environment, so it is necessary to use materials with good corrosion resistance, such as special polyamides and special coatings.

High electrical performance materials

In aerospace applications, circuit boards are required to have good electrical properties, including high impedance, low dielectric constant and low dissipation characteristics, so materials such as high frequency glass fiber cloth (FR4), polyimide (PI) and polytetraoxyethylene (PTFE) are often used.

Aerospace PCB Assembly design standards

Designing PCBs for aerospace applications requires adherence to strict design standards that ensure optimal performance under harsh conditions. These design standards focus on several critical factors:

Signal Integrity

Aerospace PCBs must be designed to minimize signal degradation, ensuring accurate data transmission. High-speed signal transmission lines must be optimized for impedance control and reduced electromagnetic interference (EMI).

Thermal Management

Effective heat dissipation is crucial to prevent overheating in aerospace PCBs. The design must incorporate features such as metal cores or heat sinks to manage thermal loads efficiently.

Vibration and Shock Resistance

Aerospace PCBs are subject to extreme vibration and shock during flight or launch. The design must include mechanical reinforcements and vibration-dampening measures to protect the integrity of components and solder joints.

EMI Shielding

Aerospace environments are susceptible to electromagnetic interference, which can disrupt signal integrity. Proper shielding techniques, such as ground planes and shielded traces, are essential to reduce EMI and ensure reliable signal performance.

Component Placement

Components must be strategically placed to ensure signal integrity, reduce noise, and improve overall PCB performance.

Best Technology is a professional PCB & PCBA manufacturers in military, aerospace and medical, over 70% of our engineers have worked in PCB industry for more than 10 years. We have mature technology and advanced testing equipment to ensure the highest quality while maintain fast delivery. Trust us, we can be your most reliable PCB supplier in China and Vietnam.

What is a Wi-Fi Module?

The Wi-Fi module, also known as the wireless module, belongs to the transmission layer of the Internet of Things (loT). It integrates a processor, memory, transceiver, and sometimes an antenna. A Wi-Fi module is to convert the serial port or TTL level into an embedded module that meets the Wi-Fi wireless network communication standards, with built-in wireless network protocol IEEE802.11b.g.n protocol stack and TCP/IP protocol stack.

Wi-Fi Module PCBA Design | Box Build Assembly Manufacturer

The module handles the task of connecting a device to a wireless router, allowing it to send and receive data over the internet. If embedded a Wi-Fi module in traditional hardware devices, then we can directly use Wi-Fi to connect to the Internet. It can be said, it is an important part of wireless smart home, M2M and other IoT applications.

Types of Wi-Fi Module

According to the different functions, Wi-Fi modules can be divided into three categories:

1. General Wi-Fi modules

Such as USB or SDIO interface modules on our mobile phones, laptops and tablets. Wi-Fi protocol stack and driver are run in Android, Windows and IOS systems, which require a very powerful CPU to complete the application.

2. Router Wi-Fi module

The most typical one is our home router, its protocol and driver has powerful Flash and Ram resources chip plus Linux operating system.

3. Embedded Wi-Fi module

Such as 32-bit MCU, built-in Wi-Fi driver and protocol, interface for the general MCU interface such as UART. Suitable for all kinds of smart home or smart hardware items.

What is the Difference Between Wi-Fi and Bluetooth Modules?

While both Wi-Fi and Bluetooth modules enable wireless communication, their usage and performance differ significantly:

1. Frequency

The frequency of Wi-Fi has 2.4G and 5G bands. Wi-Fi 2.4G band has 13 channels, 2401~2423MHz. Wi-Fi 5G frequency band is divided into 5.2G band and 5.8G band, and the 5.8G frequency band is: 149, 153, 157, 161, 165; The 5.2G band must support 11ac, and the available channels are 36, 40, 44, 48, 52, 56, 60, and 64. Under normal circumstances, it is recommended to avoid 52, 56, 60, 64 channels, because they conflict with radar channels;

Bluetooth only has 2.4G band: 2.402GHz ~ 2480GHz, a typical Bluetooth has 76 channels, each channel is 1MHz. And bluetooth BLE has 40 channels, each channel 2MHz, of which 37 channels belong to the data channel, 3 channels belong to the broadcast channel;

2. Application

Wi-Fi can directly access the network, and Bluetooth needs conversion processing. Therefore, WiFi is more suitable for 1-to-many local area networking, such as home and company Internet access environment. Compared with Wi-Fi module, bluetooth is more suitable for short-range and high-stability transmission, such as smart headphones. Additionally, bluetooth mesh networking is especially suitable for smart home wireless control and other applications.

3. Transmission Distance

The transmission distance of Wi-Fi is further than that of Bluetooth, which can reach several hundred meters, while the transmission distance of Bluetooth is generally within 100 meters;

4. Transmission Rate

Wi-Fi: 54Mbps; Bluetooth: 2Mbps;

Wi-Fi is more suitable for big data transmission.

5. Speed

Wi-Fi is generally faster than Bluetooth. It can handle large file transfers or streaming content without any issues. Bluetooth is slower but works well for smaller data transfers like audio streaming or simple file sharing.

What is the Range of a Wi-Fi Module?

‌The coverage range of the WiFi module usually depends on the specific application scenario and environmental conditions. According to the IEEE 802.11 standard, the maximum distance that wireless devices can cover is usually 300 meters, but this depends on the environment is open or not.

In the specific environment, the coverage of the WiFi module will be affected by a variety of factors. For example, in an ideal environment of accessibility and interference, the wireless transmission distance of a wireless router is 100 meters indoors and 300 meters at outdoors. In the actual home environment, the wireless signal will be attenuated when passing through obstacles such as walls, glass, doors, and furniture, affecting the transmission distance. If an external antenna is used, the transmission distance can reach 30 ~ 50 km or even more, depending on the gain of the antenna itself.

Advantages of Wi-Fi Module

1. Wide coverage

WiFi module supports ‌IEEE 802.11b/g/n and other standards to provide a wide range of wireless coverage, suitable for a variety of indoor and outdoor environments.

2. High-speed transmission

WiFi module supports a high data transmission rate, which can meet the requirements of high-speed data transmission, and is suitable for application scenarios with a large amount of data.

3. Compatibility and ecosystem

WiFi module supports a variety of communication protocols, such as ‌Wi-Fi, ‌Bluetooth, etc., has good compatibility and ecosystem, and can be integrated with a variety of devices and services.

4. Easy to install and use

WiFi modules are usually plug and play, easy to install and use, suitable for a variety of devices and system integration.

Disadvantages of a Wi-Fi Module

1. Power consumption

One downside of Wi-Fi modules is their higher power usage compared to other wireless technologies, such as Bluetooth. This can be a concern for devices running on battery power.

2. Interference

Wi-Fi operates on the same frequencies as other devices, such as microwaves and cordless phones.

3. Security

Since Wi-Fi networks are widespread, they can be vulnerable to hacking. Proper security measures, such as encryption, must be implemented to protect data.

What is a Wi-Fi Module Used For?

Wi-Fi modules have a wide range of applications across industries. Actually, it exist everywhere need networks. It can be said, it can be used in every fields. Here are some typical applications:

Smart Homes

Wi-Fi modules power smart devices like security cameras, thermostats, and lighting systems. They connect to a home Wi-Fi network, so users to control them remotely through apps.

Industrial Equipment

In manufacturing or logistics, Wi-Fi modules enable machines to communicate wirelessly.

Consumer Electronics

Devices like laptops, gaming consoles, and smart TVs rely on Wi-Fi modules for wireless internet access.

Healthcare Devices

Medical equipment, such as patient monitors or wearable devices, often use Wi-Fi modules to transmit data to a healthcare provider in real time.

IoT Devices

The IoT relies heavily on Wi-Fi modules. Devices ranging from smart refrigerators to connected doorbells use Wi-Fi to communicate with each other and with cloud-based systems.

Wi-Fi Module Price

Wi-Fi modules are available at various price points, depending on their features and intended use. For instance, the ESP8266 typically costs between $2 to $5. The ESP32, with its additional capabilities, is priced slightly higher, ranging from $5 to $10. High-end industrial Wi-Fi modules can be more expensive, ranging from $20 to $50.

The price may also vary depending on factors like antenna design, supported protocols, and whether the module is designed for mass production or individual projects.

What is the Most Common Wi-Fi Module?

The ESP8266 is one of the most popular and widely used Wi-Fi modules. It is favored in many IoT applications due to its low cost, ease of use, and compact size. Another frequently used module is the ESP32, which offers additional features such as dual-core processing, built-in Bluetooth. In addition to them, there are some other common Wi-Fi module that used in the electronics.

Wi-Fi Module	Description	Frequency Brand	Range	Price	Special Features
ESP8266	Popular for IoT applications due to low cost and ease of use.	2.4 GHz	Up to 150 feet	$2 – $5	Compact size, low power, integrated TCP/IP protocol stack.
ESP32	Offers better performance with dual-core and built-in Bluetooth.	2.4 GHz, Bluetooth	Up to 300 feet	$5 – $10	Dual-core processing, Bluetooth, multiple I/O options.
CC3200	A Texas Instruments Wi-Fi module designed for IoT and smart products.	2.4 GHz	Up to 200 feet	$8 – $15	Built-in ARM Cortex-M4 processor, low power, encryption features.
RN171	A high-performance Wi-Fi module from Microchip.	2.4 GHz	Up to 330 feet	$20 – $30	Embedded TCP/IP stack, simple serial interface.
ATWINC1500	A low-power module designed for IoT and wearable devices.	2.4 GHz	Up to 200 feet	$7 – $15	Ultra-low power, integrated network stack, supports power-saving modes.
WizFi210	A stable Wi-Fi module designed for industrial applications.	2.4 GHz	Up to 300 feet	$10 – $25	Low power, fast boot-up, secure connection.
Roving Networks RN131	Suitable for long-range industrial and commercial applications.	2.4 GHz	Up to 400 feet	$25 – $40	High-performance, robust design, supports SSL encryption.

Considerations in PCBA Design with a Wi-Fi Module

When integrating a Wi-Fi module into PCBA design, several factors need to be considered to ensure optimal performance:

Antenna Design and Placement

A key factor in wireless performance is the placement of the antenna. Ensuring there are no obstructions near the antenna can significantly improve signal strength. The module should be positioned to minimize interference from nearby components.

Power Supply

Wi-Fi modules require a stable and sufficient power supply to function effectively. Voltage fluctuations or insufficient power can result in poor connectivity or even module failure.

Thermal Management

Wi-Fi modules can generate heat, especially during heavy use. Proper heat dissipation methods, such as using heat sinks or thermal vias, should be incorporated into the PCBA design to maintain optimal performance.

EMI and EMC Compliance

Wireless communication devices must adhere to electromagnetic interference (EMI) and electromagnetic compatibility (EMC) standards. Proper shielding and circuit design can help reduce interference and improve reliability.

Firmware Integration

Many Wi-Fi modules come with firmware that handles wireless communication tasks.

One-Stop Box-Build Assembly for Wireless Communication Devices

For companies looking to develop wireless communication devices, Best Technology is your go-to choice. We offer one-stop PCBA and box-build service that can handle everything from component sourcing and PCBA design to final product assembly. By partnering with us, you can reduce much development time, and get a high quality, fast delivery, low cost PCBA with Wi-Fi modules.

With over 18 years of experience in printed circuit boards and as one of the leading PCB manufacturers, we support over 2,000 customers in different industrial areas worldwide. You can count on a PCB board manufacturer like us to meet your one-stop electronics manufacturing demands. We have an experienced engineer, production and quality team to fully understand the unique requirements of your industry, such as the particular acceptance criteria in medical, automotive, communication and aerospace industries. Contact us right now to get your PCB quotation!

What is PCB trace/line spacing?

PCB trace/line spacing refers to the minimum distance between two lines on the PCB board. This distance is usually used to avoid electrical interference and ensure the reliability of the circuit. The size of the line spacing will affect the crosstalk, electromagnetic compatibility and heat dissipation performance of the circuit.

PCB trace width and spacing Design Guide

The basic concept and importance of line spacing is that it directly affects the performance and reliability of the circuit. The size of the line spacing needs to ensure that the electrical coupling and interference between the circuits are minimized to ensure the normal operation of the circuit.

What are the rules for PCB trace spacing?

The basic rule for PCB trace spacing is that the distance from the center of the line to the center of the line should be greater than or equal to 3 times the line width (3W rule) to ensure that crosstalk between lines is reduced.

‌3W rule‌: In order to minimize the interference between lines, the distance from the center of the line to the center of the line should be greater than or equal to 3 times the line width (3W rule), which can reduce 70% of the electric field interference. If you need to achieve a higher interference reduction effect, you can use 10 times the line width (10W rule), which can reduce 95% of the interference.

‌Electrical safety spacing‌: According to the production capacity of the PCB manufacturer, the spacing between the wires and between the wires and the pads shall not be less than 4mil. Usually, the conventional spacing is set to about 10mil to ensure production quality and electrical safety.

‌Special signal lines‌: For signal lines that need to control impedance, such as RF signals, important single-ended signals, and differential signals, the line width and line spacing should be determined according to the stacking calculation to ensure stable signal transmission.

‌Other considerations‌: In PCB design, it is also necessary to pay attention to the signal lines to avoid using right angles and sharp angles. Using arcs or 135° obtuse angles can reduce reflections and standing waves.

What is the minimum line spacing in PCB?

The minimum line spacing in PCB is usually 4mil. ‌ This spacing is to avoid electrical interference and ensure the reliability of the circuit. The specific line spacing requirements depend on factors such as design specifications, application environment, and manufacturing process. ‌

In some high-precision applications, a smaller spacing may be required, but in general, the spacing should not be less than 4mil. The common spacing in conventional design is 10mil, which can ensure better production efficiency and circuit stability. ‌

What is the minimum line width for a PCB?

The minimum line width of a PCB is usually 6mil (about 0.153mm). This is because in high-density and high-precision PCB design, the line width needs to reach this value to ensure production quality and reliability. ‌

The minimum line width may vary under different design requirements. The minimum line width that can be supported may reach 3.5mil (about 0.09mm) or less, but in most common designs, the line width will be greater than this value to ensure production yield and reliability. ‌ In high-density and high-precision PCB design, the line width may be thinner. ‌

When designing a PCB, the choice of line width needs to consider the needs of signal transmission. Generally speaking, the larger the line width, the better the factory production and the higher the yield. The line width in conventional design is usually 10mil (about 0.254mm), which can meet most application scenarios. In high-speed signal transmission, the line width needs to be greater than 10mil to reduce signal loss and synchronization problems.

What is the minimum hole spacing for PCB?

The minimum hole spacing of PCB is generally 0.1mm to 0.15mm. This range is applicable to standard 6-layer PCB circuit boards, but the specific value may vary depending on the manufacturing process and design requirements.

Under different manufacturing processes, the specific value of the minimum hole spacing is different. The minimum aperture of mechanical drilling is 0.15mm, while the minimum aperture of laser drilling can reach 0.075mm. In addition, the spacing from the pad to the outline is generally 0.2mm, and the single side of the pad cannot be less than 4mil (about 0.1mm), preferably greater than 6mil (about 0.15mm). For non-metallic holes and slots, the minimum spacing is not less than 1.6mm, and the slot hole is not less than 2.0mm from the edge of the board of the outline.

Factors that affect the minimum hole spacing of PCB include manufacturing process, design requirements and drilling detection. The advancement of manufacturing process has continuously improved the accuracy of PCB boards, and the minimum hole diameter and spacing have been continuously reduced. For example, the accuracy of modern PCB boards has developed to a minimum hole diameter of 0.08 mm and a minimum hole spacing of 0.1 mm or even higher. In addition, drilling detection is also an important link to ensure the quality of PCBs, including through holes, part holes, slot holes and special-shaped holes, which all need to be strictly inspected.

Why is PCB trace spacing design so important?

PCB trace spacing design is very important because it is directly related to the reliability, performance and safety of the circuit board. By reasonably designing the trace spacing, electrical interference can be avoided, signal transmission quality can be guaranteed, and the thermal stability and reliability of the circuit board can be improved, thereby ensuring the normal operation and long-term stable operation of the circuit board.

First, the design of trace spacing can prevent electrical interference. When two traces are parallel and close to each other, parasitic capacitance and inductance will be generated between them, resulting in signal interference and attenuation. Increasing the trace spacing can reduce this coupling effect, thereby ensuring stable signal transmission.

Second, appropriate trace spacing helps to improve the thermal stability of the circuit board. Components and traces with large working current will generate heat when working. If the traces are too dense, heat is easy to accumulate, resulting in local temperature rise, which may cause failure.

In addition, the design of trace spacing also needs to consider the requirements of production process. Smaller line width and line spacing have higher requirements for production process, which may increase production difficulty and cost.

What will happen if the PCB trace spacing is insufficient?

Insufficient PCB trace spacing will lead to problems such as signal attenuation, signal delay, crosstalk interference and layout difficulties. These problems will affect the performance and stability of the circuit and may even cause circuit function failure.

First, signal attenuation is a major problem of insufficient spacing. Signals will be attenuated during transmission. Too small spacing will increase the possibility of signal attenuation, resulting in signal distortion and increased noise, especially in high-frequency signals and fast signal transmission.

Second, signal delay is also a problem caused by insufficient spacing. It takes time for signals to propagate in the circuit. Too small spacing will extend the path of signal propagation, thereby increasing signal delay and affecting the real-time performance of the system.

In addition, crosstalk interference is another important issue. Insufficient spacing will increase the electromagnetic interaction between signal lines, leading to crosstalk interference, thereby introducing errors or interference and affecting the stability of the circuit.

Finally, layout difficulties are also a practical problem caused by insufficient spacing. When laying out the PCB, too small spacing will increase the complexity of the layout, making it difficult for designers to reasonably arrange the signal path, the distribution of power and ground lines, and the layout of components.

Does trace spacing affect PCB production cost?

The setting of trace spacing is directly related to the difficulty and cost of PCB production process. Although smaller line width and spacing can improve the performance of the circuit, it will increase the difficulty and cost of production.

The setting principles of trace spacing include:

The default values of line width and spacing are usually 6mil, but they can be adjusted according to design requirements. The minimum line width recommended value is 10mil, and the maximum line width can be set to 200mil.

The setting of trace spacing needs to take into account electrical safety and signal integrity. It is usually required that the line center spacing is not less than 3 times the line width to ensure that the electric field does not interfere with each other.

In the design of high-speed signal lines, using larger spacing can further reduce crosstalk and improve the stability of the circuit, but it will also increase costs.

Factors that affect the cost of PCB production also include:

‌Number of wiring layers‌: The more layers, the higher the price.

‌Via size‌: Vias smaller than 0.25mm usually require additional fees, and back drilling will increase the cost by about 10%~20%.

‌Plate selection‌: Unconventional materials such as high-frequency plates and halogen-free plates will increase procurement cycles and production costs.

In summary, the setting of trace spacing has a significant impact on the cost of PCB production. Reasonable settings can control costs while ensuring performance.

In short, PCB line width and spacing are very important parameters in electronic circuit design. They directly affect the performance, reliability and manufacturing feasibility of the circuit board. When designing a circuit board, it is necessary to reasonably select line width and spacing according to the requirements of the circuit and the actual situation.

Is PCB Design Difficult?

The difficulty of PCB design depends on the learning objectives and depth. ‌ If it is just the initial stage, do some simple circuit board design, then it is relatively easy. But if you want to go deep and get to expert level, in areas as diverse as pcb layout, signal integrity, electromagnetic compatibility, impedance design, and more, then you need to put in more work.

For beginners, choosing the right software and learning resources is very important. PADS from Protel, Altium Designer (AD) and Mentor Graphics are commonly used PCB design software. Protel software is simple and easy to learn, suitable for beginners to use; AD and PADS are powerful, but the operation is complex, suitable for the design of complex circuit boards.

What is the Basic Rule of PCB Design?

The key to good PCB design is layout organization. Keep the design simple, especially at the beginning. Here are a few basic rules to follow:

Control Trace Length

Controlling the length of traces means adhering to the rule of keeping traces as short as possible in PCB design to avoid unnecessary interference caused by long traces. This is especially crucial for important signal lines, such as clock signal traces, which should be placed very close to the oscillator. When driving multiple devices, the network should be determined based on specific circumstances.

Avoid Forming Self-Inductive Loops

In PCB design, it is important to pay attention to signal lines forming self-inductive loops between different layers, particularly in multilayer boards. The chances of forming self-inductive loops increase when routing signal lines between layers, and these loops can cause radiated interference.

Minimize Ground Loop Principle

The principle of minimizing ground loops is to keep the signal lines and their loops as small as possible. The smaller the loop area, the less external radiation and interference it experiences. When defining ground planes, consider the distribution of the ground plane and important signal lines to prevent issues caused by ground plane cuts.

In double-layer board designs, while leaving sufficient space for the power supply, the remaining areas should be filled with reference ground and include some necessary vias to effectively connect signals on both sides. Ground isolation should be used for key signals. For designs with higher frequencies, special attention should be paid to the signal loop problems of the ground plane, and multilayer boards are recommended.

High-Speed Signal Shielding Design

The relevant ground loop rules are also aimed at minimizing signal loop areas and are mainly used for important signals such as clock and synchronous signals. For particularly important and high-frequency signals, consider using a shielded structure design with copper coaxial cables. This means isolating the line from the ground on all sides while effectively grounding the shield layer and ensuring its connection with the ground plane.

Avoid the “Antenna Effect”

Generally, routing with one end suspended is not allowed to avoid the “antenna effect,” which reduces unnecessary interference radiation and reception; otherwise, it may lead to unpredictable results.

Chamfer Rule

PCB design should avoid sharp corners and right angles to prevent unnecessary radiation and poor manufacturing performance. The angle between all traces should be ≥135°.

Avoid Overlapping Different Power Layers

Different power layers should be spatially separated to reduce interference between them, especially between power supplies with significant voltage differences. Issues arising from overlapping power planes must be avoided, and if unavoidable, consider using an isolated ground layer.

Avoid Via Proximity to SMT Pads

If vias are not covered with a solder plug, they can easily be placed too close to SMT pads during layout. This can cause solder to flow through the via to the other side of the PCB during reflow, resulting in insufficient solder on the SMT pads and causing issues like cold solder joints. It is generally recommended to maintain a distance of more than 25 mils from the edge of the via to the SMT pad and to apply solder mask over the via.

Do Not Route Traces Wider than SMT Pads Directly into the Pads

If traces are wider than the pads, the window area of the SMT pads generally expands beyond the pad size. This means that if the solder paste on the pad is slightly insufficient during reflow, there is a risk of cold solder joints. Using traces that are slightly larger or slightly smaller than the pads can also help avoid excessive heat dissipation during soldering.

Do Not Place Components Too Close to the Board Edge

During the assembly and soldering stages of the PCB, the board will be transported through various processing areas, such as solder paste application and pick-and-place machines, followed by reflow soldering. Therefore, when designing the PCB, at least one side must leave enough space for a processing margin of at least 3 mm in width and 50 mm in length. There should be no interference between components and leads within the processing margin, as this could affect the normal transport of the PCB.

If the layout cannot accommodate this, consider adding an independent 3 mm processing margin or panel. (Note: SMT components cannot be placed within 5 mm of the edge on either side of the processing panel to facilitate reflow soldering.) If the components on your PCB are hand-soldered, you can disregard this requirement.

Keep Solder Mask Window Sizes Consistent

The solder mask layer needs openings for the pads. These openings prevent the solder mask from covering the pad area, protecting the PCB circuit from oxidation and short circuits during soldering. Typically, a solder mask layer covers the outer layers of the PCB. Common solder masks are green (though black, red, yellow, and blue are also used).

Solder should not be applied to pads to avoid solder paste sticking. To avoid the solder mask layer interfering with pad solderability due to process tolerances, it is common to design a solder mask opening that is larger than the pad by approximately 0.1 mm (4 mil). However, it is also acceptable to keep the solder mask opening area the same size as the pad dimensions; the factory will process it uniformly for you.

Reduce EMI Interference

Every PCB can be affected by EMI or become a source of interference. As part of the engineering design, special attention is required during PCB layout:

Increase the spacing between high-frequency traces and low-frequency or analog traces.
Minimize the return path for high-speed signals and ensure they do not cross split planes. Smaller current loops reduce EMI radiation intensity.
High-speed differential signals should be routed in parallel and have equal lengths; otherwise, they will offset the noise suppression characteristics of the differential pair.
Avoid using vias on high-speed traces, as they may lead to EMI emissions.

What Files Are Needed to Manufacture a PCB?

When you’re ready to manufacture your PCB, you will need to generate specific files for the fabrication process. The most common file format used by PCB manufacturers is the Gerber file. Here are some other important files that needed to submitted to manufacturer:

1. Gerber Files – your design files, include the design layout, detailing copper layers, solder masks, and silkscreen layers.

2. Drill Files – specify the locations and sizes of holes for vias and component leads.

3. Bill of Materials (BOM) – a list of all components required for the board, including part numbers and quantities.

4. Pick and Place File – guides the automated machines on where to place each component on the PCB.

What Software to Use for PCB Design?

Choosing the right software can make the design process much easier, especially for beginners. Here are a few commonly used PCB design tools:

KiCad: This is a free, open-source software that’s great for both beginners and professionals. It has a user-friendly interface and includes a schematic editor, PCB layout, and 3D viewer.

Eagle: Popular among hobbyists, Eagle offers a simple design process and an extensive component library. It’s free for small designs but has premium features for more advanced projects.

Altium Designer: For more complex projects, Altium Designer is an industry-standard tool with advanced features. While it’s pricier, it offers professional-grade tools for high-level PCB design.

How Do You Manufacture a PCB Board?

Manufacturing a PCB involves several steps, and understanding the process helps ensure your design is ready for production. Here’s a simplified overview:

Step 1: Designing the PCB

Using PCB design software to create the PCB layout. The design process includes defining the schematic, component placement, and trace routing. Designers must consider factors such as signal integrity, power distribution, and thermal management.

Step 2: Design Review and Engineering Questions

Once the initial design is complete, a thorough review is conducted. This includes checking for design rule violations, verifying component footprints, and ensuring all connections are correct. Engineers may raise questions about potential performance issues, manufacturability, and compliance with regulatory standards. Feedback from this review may lead to modifications to optimize the design.

Step 3: Printing the PCB Design

After finalizing the design, the PCB layout is printed onto a transparent film, which will be used as a photomask for the etching process. This film represents the layers of the PCB, including copper and solder mask layers.

Step 4: Printing the Copper for the Interior Layer

The copper layers are printed onto the laminate using a photoresist process. The photoresist is applied to the copper-clad laminate, and the printed film is exposed to UV light. The areas that are exposed to light will become soluble and can be washed away, leaving behind a copper pattern that matches the PCB design.

Step 5: Etch the Inner Layers or Core to Remove Copper

The exposed copper is etched away using a chemical process, leaving only the desired copper traces. This step must be carefully controlled to ensure the traces are of the correct width and spacing, as specified in the design. The etching process can be done using either chemical etching or laser etching.

Step 6: Layer Alignment

Once the inner layers are etched, they must be aligned correctly for lamination.

Step 7: Automated Optical Inspection (AOI)

Automated Optical Inspection is performed to check the accuracy of the printed copper layers. Any discrepancies, such as missing or misaligned traces, can be identified and corrected before proceeding to the next steps.

Step 8: Laminating the PCB Layers

The aligned layers are then laminated together using heat and pressure. It combines the different layers, including copper, dielectric, and solder mask layers, into a single, solid structure.

Step 9: Drilling

Once the layers are laminated, holes are drilled for vias and mounting holes. The drilling process requires precision, as these holes must align perfectly with the design specifications. Computer-controlled drilling machines are typically used to achieve the necessary accuracy.

Step 10: PCB Plating

After drilling, the PCB goes through an electroplating process where a conductive layer is added to the walls of the drilled holes.

Step 11: Outer Layer Imaging

Similar to the inner layers, the outer layers are prepared for imaging. A photoresist is applied, and the printed film of the outer layer design is aligned and exposed to UV light. The unwanted areas are washed away, leaving a pattern on the copper layer.

Step 12: Outer Layer Etching

The outer copper layers are then etched to remove the unprotected copper, leaving behind the desired copper traces.

Step 13: Outer Layer AOI

Another round of Automated Optical Inspection is conducted on the outer layers to ensure that the copper traces and pads are correctly formed.

Step 14: Solder Mask Application

A solder mask layer is applied to protect the PCB and prevent solder from bridging between components during assembly. The solder mask is typically a green epoxy coating, but it can also be available in other colors. The areas where solder is needed are left exposed.

Step 15: Silkscreen Application

Silkscreen printing is used to apply labels, component designators, logos, and other markings onto the PCB surface.

Step 16: Finishing the PCB

The finishing process includes applying surface finishes such as HASL (Hot Air Solder Leveling), ENIG (Electroless Nickel Immersion Gold), or OSP (Organic Solderability Preservative) and so many surface treatments.

Step 17: Electrical Reliability Test (E-test)

Before packaging, the PCBs undergo electrical testing to ensure that all circuits function correctly. This may include continuity testing, insulation resistance testing, and high-voltage testing.

Step 18: Profiling and Route Out

The final PCB is profiled and routed to its specific shape, including cutting out the edges and any slots or cutouts required.

Step 19: Quality Check and Visual Inspection

A final quality check and visual inspection are performed to ensure that all specifications have been met. Examining for any physical defects, such as scratches, solder mask misalignment, or improper solder application.

Step 20: Packaging and Delivery

Once all checks are complete, the PCBs are cleaned, packaged, and prepared for delivery. Proper packaging is essential to protect the PCBs during shipping.

What Is the Cheapest PCB Finish?

The cheapest finish is HASL, which is also widely used. HASL applies a thin layer of molten solder to the surface, providing good protection and easy solderability. However, it’s not always suitable for fine-pitch components or designs requiring a flat surface. Other options, such as ENIG (Electroless Nickel Immersion Gold), are more expensive but provide a smoother, more durable finish for advanced designs.

Developing a PCB for the first time can feel like a daunting task, but by understanding the basics and using the right tools, it’s a process that anyone can learn. From following simple design rules to choosing affordable software and finishes, creating a PCB can be a good experience. Working closely with manufacturers and learning through trial and error will sharpen your skills over time.

How Much Does It Cost to Get a PCB Board Made?

The cost of producing a PCB depends on several factors, such as the size, number of layers, material used, and whether you’re doing a prototype run or full production. For a simple, single-sided board, costs can start as low as $10 to $20 per board, but more complex, multi-layer designs can cost upwards of $100 or more per board.

Additional costs may include shipping, testing, and assembly if you are having components mounted by the manufacturer. It’s always a good idea to get quotes from multiple manufacturers and consider both cost and quality.

If you don’t want to develop a PCB board by yourself, choosing a reliable EMS PCB manufacturer like Best Technology. We are engaging in PCB manufacturing over 18 years, we deeply understand every design rules and know which one is best for manufacturing. Best Team offer full turnkey PCB & PCBA service for over the world. We can help to PCB design, PCB layout, PCB manufacturing, components sourcing, PCB assembly, box building, and function testing. Give us your ideal, we can make it come true!

What is Aluminum Nitride PCB?

Aluminum nitride PCB also known as Aluminum nitride ceramic PCB or short for AlN PCB. It is a high-performance circuit board made from aluminum nitride ceramic, a material known for its exceptional thermal conductivity and electrical insulation properties. These boards are commonly used in industries where efficient heat dissipation is crucial, such as in power electronics, LED applications, and high-frequency devices. AlN PCBs are gaining popularity due to their ability to withstand extreme temperatures.

Aluminum Nitride PCB | Aluminum Nitride Ceramic PCB

Benefits of AlN PCBs

One of the key advantages of AlN PCBs is their excellent thermal conductivity, which helps prevent overheating in electronic components. With exceptional thermal conductivity of 170 W/mK, strong dielectric strength, and a low thermal expansion coefficient (CTE <4 ppm/°C), AlN is widely used in applications like high-power LEDs, lasers, high-current switches, and even ultra-low temperature vacuum electronics such as those in quantum computing. In addition to these features, AlN offers the same benefits as other ceramic materials, including rigidity, environmental and chemical resistance, and 0% water absorption.

Key reasons for choosing Aluminum Nitride over other PCB materials include:

Outstanding thermal conductivity of 170 W/mK

Excellent dielectric properties

High operating temperatures exceeding 350°C

Low thermal expansion coefficient (<4 ppm/°C)

Compact designs due to better integration

Hermetically sealed packages with 0% water absorption

Minimal to no outgassing

What is the Thermal Conductivity of Aluminum Nitride PCB?

‌The thermal conductivity of aluminum nitride PCB ranges from 170-230W/(m·K).

The high thermal conductivity of aluminum nitride PCB is due to its unique structure and chemical composition. The thermal conductivity of aluminum nitride ceramic substrate is 2-3 times higher than that of traditional alumina ceramics and silicon-based ceramics, and 10-20 times higher than that of titanium substrate. This high thermal conductivity allows them to effectively dissipate heat from high-power electronic components, preventing overheating and ensuring stable performance. The ability to manage heat efficiently makes AlN PCBs an ideal choice for applications that generate a significant amount of heat, such as power modules, LEDs, and RF components. In comparison to other materials like aluminum oxide, which has lower thermal conductivity (around 20-30 W/mK), aluminum nitride stands out as a top choice for heat-sensitive applications.

Factors affect thermal conductivity of AlN PCB

Although the theoretical thermal conductivity of AlN is extremely high, its performance in practical applications is limited by a number of factors, mainly including:

Microstructure

Phonon scattering is a key mechanism for heat conduction. Grain boundaries, interfaces, second phases, and defects can all affect the mean free path of phonons, thereby influencing thermal conductivity. High-purity, low-defect single-crystal AlN has a longer phonon mean free path and higher thermal conductivity.

Oxygen Impurity Content

AlN’s strong affinity with oxygen leads to the easy introduction of oxygen impurities, which form alumina films and lattice defects, such as aluminum vacancies. These significantly reduce the phonon mean free path, lowering thermal conductivity. When the oxygen concentration is below 0.75%, oxygen atoms primarily replace nitrogen atoms in the lattice; however, exceeding this concentration causes aluminum vacancies to disappear and results in the formation of extended defects, further affecting thermal conductivity.

Sintering Process and Additives

By selecting appropriate sintering additives (such as Y₂O₃-Li₂O, Y₂O₃-CaC₂ composite systems), densification can be achieved at lower temperatures, while reducing the formation of oxygen impurities and second phases, effectively improving the thermal conductivity of AlN ceramics. These additives help purify grain boundaries and optimize the microstructure, facilitating more efficient phonon transmission.

What is Aluminum Nitride PCB Used For?

Aluminum nitride as a stable hexagonal wurtzite covalent bond compound, has shown extensive application potential in the field of electronics and optoelectronics due to its unique physical and chemical properties. Its crystal structure takes AlN4 tetrahedron as the basic unit, space group P63mc, belongs to the hexagonal crystal system, which gives AlN a series of excellent properties and use in advanced applications.

Some common applications include:

Optical Communication

Integrated Circuits and High-Power Electronic Devices

Power Electronics

Wafer chips

Epoxy Resin Packaging

Optical Devices and Piezoelectric Devices

Industrial Materials

Acoustic Devices

Aerospace

Military

Why is Aluminum Nitride Expensive?

The high cost of aluminum nitride PCBs stems from several factors.

First of all, the raw material cost of aluminum nitride PCB is higher. The preparation of aluminum nitride powder requires high purity raw materials, synthesis methods include direct nitriding method, carbothermal reduction method, self-propagating high temperature synthesis and chemical vapor deposition method, etc. These methods have high requirements on equipment and technology, resulting in higher costs.

Secondly, the production process is complicated. The preparation process of aluminum nitride PCB is complex, including multiple steps such as molding and sintering, which has high requirements for equipment and technology and a high production threshold.

Finally, the market demand is large. Aluminum nitride PCB in power electronics, communication equipment, automotive electronics and other fields have a wide range of applications, especially in high power, high frequency and other occasions, its excellent heat dissipation and insulation performance can not be replaced, resulting in short supply in the market, the price of natural rising.

Aluminum Nitride PCB vs. Alumina Oxide PCB

Both aluminum nitride (AlN) and alumina oxide (Al2O3) are ceramic materials used in PCB manufacturing, but they differ significantly in terms of performance. AlN offers superior thermal conductivity, typically 170-230 W/mK, compared to aluminum oxide’s lower range of 20-30 W/mK. This makes AlN the better option for applications requiring efficient heat dissipation, such as high-power electronics and LED lighting.

However, aluminum oxide is more cost-effective and is often used in applications where high thermal conductivity is not as crucial. While Al2O3 provides good electrical insulation and is easier to produce, it may not perform as well in heat-sensitive environments as AlN. Therefore, the choice between AlN and Al2O3 depends on the specific thermal and budgetary requirements of the application. Here are the parameters of AlN and Al2O3 materials:

Parameter	Aluminum Nitride (AlN)	Alumina Oxide (Al2O3)
Thermal conductivity	170-230 W/m.k	24-30 W/m.k
Dielectric constant	8.8	9.2-10
Dielectric strength	15-25kV/mm	10-15kV/mm
Temperature resistance	1000-1500C	1000-1200C
CTE	4.0 ppm/K	6.5-7 ppm/K
Flexural strength	450MPa	320MPa
Dielectric breakdown voltage	14 V/m	10 V/m

AlN Ceramic PCB Design Considerations

When designing an aluminum nitride PCB, several factors need to be considered to optimize performance:

1. Trace Width

The trace width on AlN PCBs should be a minimum of 10 mils. This ensures that the conductor cross-section is sufficient to handle the current and heat dissipation needs. Given the thermal advantages of AlN, wider traces help in spreading heat more efficiently, minimizing the risk of overheating in power-dense applications.

2. Trace Clearance

Clearances between adjacent traces should be at least 8 to 10 mils. AlN PCBs often work with higher voltage levels, making spacing critical to prevent arcing or dielectric breakdown. In high-power designs, careful spacing between traces reduces the likelihood of signal interference and maintains the board’s insulation integrity.

3. Via Pads

For via pads, a minimum diameter of 16 mils is recommended. This provides sufficient area for stable soldering and ensures proper electrical connection through the via. Depending on the board’s application, larger via pads may be necessary to accommodate higher currents or thermal dissipation needs. Via sizing should also account for assembly techniques, such as reflow soldering or thermal management features, like thermal vias, which enhance heat transfer away from components.

4. Pad Geometry Adjustments

Unlike FR-4 designs, AlN PCBs often require specific adjustments in pad geometries. The mechanical and thermal properties of AlN are quite different from those of traditional PCBs. The expansion rate, hardness, and substrate fragility mean that pad designs should allow for thermal expansion and contraction without causing stress fractures. Proper pad design also ensures better solder joint reliability, particularly for components exposed to continuous thermal cycling.

5. Gold Plating for Wire Bonding Pads

In high-performance applications, wire bonding is often used, and gold plating is a preferred surface finish for wire bonding pads. The use of gold provides a stable, corrosion-resistant surface that improves bond integrity and longevity. Wire bonding is especially critical in high-frequency, high-reliability devices, where the connections must maintain integrity under thermal stress or in harsh environments.

6. Component and Solder Matching

All components and solder materials must match the electrical and mechanical properties of the AlN substrate. Mismatches in thermal expansion between the PCB material and components can lead to stress, causing cracking or delamination. It’s important to select components and solder that can withstand high temperatures and thermal cycles while maintaining compatibility with AlN’s characteristics, especially in applications like power electronics and RF circuits.

7. Hermetic Sealing and Height Restrictions

For applications requiring hermetic sealing, such as aerospace or medical devices, height restrictions may apply to the components on the PCB. Hermetic seals protect against moisture and environmental contaminants, ensuring long-term reliability in sensitive applications. The overall component height should be kept in line with the sealing requirements, and compact designs are often necessary to meet stringent packaging constraints.

8. Thermal Expansion Management

When attaching large dies or high-power devices, it’s crucial to model and account for thermal expansion. Even though AlN has a low thermal expansion coefficient (<4 ppm/°C), the difference in expansion rates between components and the substrate can create mechanical stress, especially during thermal cycling. Careful design, including flexible connections or underfill materials, can help mitigate these effects.

9. Thermal Vias

Thermal vias are essential for managing heat in high-power applications. By placing thermal vias directly underneath hot components, heat can be efficiently transferred away from sensitive areas, extending the lifespan of both the components and the PCB itself. In many designs, a network of thermal vias is integrated with heat sinks or spreaders to further improve heat dissipation.

10. Surface Finishes and Coatings

Aluminum nitride PCBs can benefit from surface finishes such as electroless nickel immersion gold (ENIG) or immersion silver, which protect the copper traces from oxidation and provide excellent solderability. The choice of surface finish may also depend on the specific application environment and the reliability requirements, especially in high-power or high-frequency circuits.

FAQs About AlN PCBs

1. How durable are aluminum nitride PCBs?

AlN PCBs are highly durable and can withstand extreme temperatures and harsh environments.

2. Can AlN PCBs be used in high-frequency applications?

Yes, aluminum nitride PCBs are well-suited for high-frequency and high-speed applications due to their excellent electrical insulation and low signal loss.

3. Are aluminum nitride PCBs environmentally friendly?

While the production process can be resource-intensive, AlN PCBs offer longer lifespans and higher efficiency, which can reduce the environmental impact over time.

4. How do AlN PCBs compare with metal-core PCBs?

Metal-core PCBs, such as those with an aluminum core, provide good thermal management but lack the superior electrical insulation of AlN PCBs. AlN PCBs are preferred for applications requiring both high thermal conductivity and insulation.

5. What industries typically use aluminum nitride PCBs?

Industries like power electronics, aerospace, automotive, and telecommunications commonly use AlN PCBs for their high-performance needs.

What is a 2 Layer Aluminum PCB?

A 2-layer aluminum PCB is a type of metal core circuit board that contains two conductive layers, usually copper, with an aluminum core or base material. Aluminum PCBs are used for their excellent heat dissipation properties, and always used in high-power applications like LED lighting, power supplies, and automotive systems. The aluminum base offers better thermal management than standard FR4 PCBs. In a 2-layer aluminum PCB, the two conductive copper layers allow more complex routing for electrical signals compared to single-layer boards.

2 Layer Aluminum PCB | Metal Core PCB Manufacturer

2 Layer Aluminum PCB Stack-Up

The stack-up of a 2-layer aluminum PCB consists of the following:

Top Copper Layer: This is where the signal traces and components are located. It can vary in thickness, depending on current-carrying requirements.

Dielectric Layer: A layer of insulation that separates the top copper layer from the aluminum core. It plays a key role in electrical isolation and heat transfer.

Aluminum Base: This core provides structural support and excellent heat dissipation properties. It also serves as the grounding plane in some designs.

Bottom Copper Layer: The second conductive layer allows for more advanced routing.

How Thick is a 2 Layer PCB Layer?

The thickness of a 2-layer aluminum PCB can vary depending on the specific design requirements, but typically, the copper layer is about 1 to 2 ounces (35 to 70 microns) thick. The aluminum base itself is thicker, usually between 1.0 mm and 3.0 mm, depending on the board’s required rigidity and heat dissipation needs. The overall board thickness generally ranges between 1.2 mm and 3.2 mm.

A thicker aluminum core improves heat transfer, but the board’s thickness must also align with the product’s mechanical and electrical requirements. Designers often have to balance between sufficient thermal performance and the overall board size for practical applications.

Is Thicker Aluminum PCB have Better Heat Dissipation?

Generally speaking, the thinner the thickness of the aluminum PCB, the faster the heat conduction speed. The thicker the thickness of the aluminum PCB, the slower the heat conduction rate. The thermal conductivity of aluminum-based circuit board mainly depends on its material and structure. Although thickness affects the path length of heat conduction, the more critical factors are the thermal conductivity and structural design of the material. For example, high thermal conductivity materials such as copper, silver and other high thermal conductivity materials will significantly improve the thermal conductivity of aluminum substrate. In addition, the thickness and thermal conductivity of the insulation layer will also affect the overall thermal conductivity effect ‌.

Specifically, the thermal conductivity of the aluminum-based circuit board is also related to the thickness of its insulation layer. The thicker the insulation layer, although it can withstand higher voltage, it will also reduce the heat transfer efficiency. Therefore, choosing the appropriate insulation layer thickness and materials with high thermal conductivity is the key to ensuring efficient thermal conductivity of aluminum-based circuit boards ‌.

2 Layers Aluminum PCB vs. Double Sided Aluminum PCB

Though the terms “2 layers aluminum PCB” and “double-sided aluminum PCB” might sound similar, there are slight differences.

A 2-layer aluminum PCB contains two conductive copper layers. These layers can be arranged to handle signal routing and ground planes separately. In contrast, a double-sided aluminum PCB typically has one copper layer on either side of the aluminum core, offering less flexibility in routing. Here is the stack up of double sided aluminum PCB:

How Much Does Aluminum PCB Cost?

The cost of an aluminum PCB, including a 2-layer version, depends on several factors such as the board’s thickness, copper weight, design complexity, and production volume. On average, 2-layer aluminum PCBs cost more than single-sided aluminum PCBs because of the additional copper layer and routing complexity.

For small orders, prices might range between $5 and $15 per square foot. For larger production runs, costs can decrease significantly due to economies of scale. Factors like the thickness of the aluminum base and copper layer, as well as additional features like surface finishes, can also influence the price.

While aluminum PCBs are more expensive than standard FR4 boards, their enhanced thermal performance can reduce overall system costs by improving reliability and reducing the need for additional cooling measures.

How Many Layers Should a PCB Have?

The number of layers a PCB should have depends on the complexity of the design. For simple applications like LED lighting or power conversion, a 2-layer aluminum PCB is often sufficient. It provides more routing flexibility than a single-layer board while still offering effective heat dissipation.

For more complex designs requiring high-density interconnections or additional functionality, a multi-layer PCB with three or more layers might be necessary. However, multi-layer aluminum PCBs are rare because their primary function is thermal management, which is typically solved within one or two layers. The decision to use more layers depends on the specific application, power requirements, and signal integrity needed in the design.

Aluminum PCB Design Guidelines

When designing a 2-layer aluminum PCB, several factors must be considered to maximize performance:

Thermal Management: Since aluminum PCBs are chosen for their thermal properties, optimizing heat dissipation is critical. Components that generate significant heat should be placed near the aluminum core, allowing for faster heat transfer.

Copper Thickness: The copper thickness should match the current-carrying requirements of the design. Using thicker copper can help manage higher current loads, but it also increases the cost and weight of the PCB.

Dielectric Layer: The thickness and material of the dielectric layer play a crucial role in both thermal and electrical performance. A thinner dielectric layer improves heat dissipation but may limit electrical isolation. Choosing the right dielectric material is key for balancing performance and reliability.

Via Placement: For a 2-layer design, vias must be carefully placed to connect the two copper layers. Vias should be positioned to minimize electrical interference and maintain signal integrity.

Component Placement: Heat-sensitive components should be placed away from high-power components. This minimizes thermal stress on sensitive devices and ensures reliable operation over the PCB’s lifespan.

Aluminum PCBs may come with a higher price tag compared to traditional FR4 boards, but the long-term benefits in heat management, performance, and durability make them an excellent investment for demanding applications. Whether you’re working on power electronics, automotive circuits, or lighting solutions, a 2-layer aluminum PCB can provide the right balance between complexity and thermal efficiency.

If you’re in need of high-quality, custom aluminum PCBs, Best Technology specializes in delivering tailored solutions for your specific design needs. With 18+ years of experience in PCB manufacturing, we ensure top-notch performance, quality, and reliability for all your projects. Let us help you bring your ideas to life with the right aluminum PCB solution!

How to convert Cadence17.2’s .brd file to HyperLynx9.4.1’s .hyp file

How to convert Cadence17.2’s .brd file to HyperLynx9.4.1’s .hyp file?Recently, I used Hyperlynx to simulate the signal integrity of PCBs, and I needed to convert various PCB formats into .hyp formats. In the process, I found that the PCB drawn by AD can be directly exported in .hyp format, which is very convenient, but the PCB drawn by Cadence cannot be directly exported. I need to use the built-in PCB converter of Hyperlynx to convert the .brd file of Cadence, as shown below:

But the conversion has always failed. I checked the .ERR file and found a line like this: ERROR: Cadance Allegro utility:extracta, so it is a problem with extracta.exe.

The specific solution is to add the system variable CDSROOT, and the value is D:\Cadence\Cadence_SPB_17.2-2016\tools\bin (the location of your extracta.exe). After confirming, restart the computer and the problem is solved.

Tutorial on converting Cadence17.2’s .brd file to HyperLynx9.4.1’s .hyp file

Tutorial on converting Cadence17.2’s .brd file to HyperLynx9.4.1’s .hyp file?Open the PCB file in Allegro, select ODB++inside in file–>export, select Export as ODBV6, click 1, and then click Accept….

HyperLynx’s built-in conversion function can directly convert Allegro’s .brd file for use, but for some reason the following error always occurs. I didn’t find a solution online, so I had to find another way.

Another way to import PCB into HyperLynx is to convert the file to ODB++inside format. This method requires the installation of the ODB++inside plug-in in advance.

After installing the plug-in, you can convert the .brd file.
First open the PCB file in Allegro, select ODB++inside in file–>export, the following figure appears, select Export as ODBV6, click 1, and then click Accept.

Wait for the conversion to succeed.

This file is the converted file
Open HyperLynx9.4.1, select open ODB++ in file, select the odbjob_v6 folder, and click select folder.

Wait to open.

Click ok. .

What is a .hyp file?

.hyp file is a file used to record key information such as boundary conditions, material properties, solver settings, etc. of the analysis. ‌ This file is usually associated with HyperWorks analysis software and is the basis for numerical calculation and analysis.

The specific uses of .hyp files include:

‌Geometry model file‌: represents the geometry of the product or structure.
‌Mesh file‌: shows the process of dividing the model into finite elements.
‌Simulation setting file‌: records the key setting information of the analysis.
‌Result file‌: contains the calculated engineering quantities such as strain, stress, displacement, etc.
‌Post-processing file‌: used to visualize and analyze results in tools such as HyperView.
‌Report document‌: usually in PDF or Word format, recording detailed results and conclusions of the analysis‌1.
In terms of use, for example, in PCB tool software, .hyp files can be created and edited through the BroadSim function, including setting line characteristics, editing stacking information, etc., to simulate and analyze circuit boards‌2. In addition, the Hype software also supports exporting to .hyp format files for further analysis and processing.

‌What is a high frequency pcb communication circuits

High frequency pcb communication circuits to a circuit board with an operating frequency in the high frequency band (usually greater than 300MHz or a wavelength less than 1 meter), which is mainly used to transmit high-frequency signals and data. ‌ This type of circuit board is widely used in radio frequency (RF) and microwave fields, such as communication equipment, radar systems, satellite communications, and high-speed data transmission systems.

What is a high frequency pcb communication circuits

The characteristics of high-frequency circuits include challenges such as transmission line effects, signal integrity issues, and electromagnetic interference (EMI). Due to the short wavelength of high-frequency signals, traditional low-frequency circuit design methods are no longer applicable, and special design and processing methods are required to ensure the performance and stability of the circuit.

High-frequency circuit boards are produced on microwave substrate copper-clad boards using ordinary rigid circuit board manufacturing methods or special processing methods. They need to have high-quality electrical properties and chemical stability to meet the requirements of high-frequency signal transmission.

Definition of high frequency pcb communication circuits

High-frequency circuit board, as a special circuit board, is mainly suitable for occasions with high electromagnetic frequency, especially in the fields of high frequency (frequency greater than 300MHz or wavelength less than 1 meter) and microwave (frequency greater than 3GHz or wavelength less than 0.1 meter).

It is a circuit board made on a microwave substrate copper-clad board by adopting some manufacturing processes or special processing methods of ordinary rigid circuit boards. Generally speaking, when the frequency of the circuit board reaches above 1GHz, it can be defined as a high-frequency board.

With the rapid development of science and technology, more and more equipment designs have begun to involve microwave frequency bands (>1GHz) and even expanded to the millimeter wave field (such as 77GHz), especially in popular applications such as 77GHz millimeter wave antennas on vehicles.

This trend not only promotes the continuous increase in frequency, but also puts higher requirements on the substrate of the circuit board.

For example, the substrate material needs to have excellent electrical properties, stable chemical properties, and as the frequency of the power signal increases, the loss on the substrate must be extremely small. Therefore, the importance of high-frequency boards is becoming more and more prominent.

Advantages of high frequency pcb communication circuits

The main advantages of high frequency pcb communication circuits include efficient data transmission, strong anti-interference ability, high-frequency bandwidth and high reliability. ‌

high frequency pcb communication circuits can achieve efficient data transmission. High-frequency signals have a short cycle and can transmit more information per unit time, so they have the advantage of large-capacity transmission. In addition, high-frequency signals can achieve fast signal processing and are suitable for application scenarios that require high-speed data transmission and high real-time requirements.
high frequency pcb communication circuits have strong anti-interference capabilities. Due to the short wavelength of high-frequency signals, they can better avoid external interference and attenuation and have strong anti-interference capabilities. This makes high-frequency signals have advantages in fields such as wireless communications and radar systems, and can achieve stable signal transmission and reception. ‌
high frequency pcb communication circuits also have the advantage of high-frequency bandwidth. High-frequency signals correspond to a larger frequency range and can provide higher bandwidth than low-frequency signals. This means that more data can be transmitted, thereby supporting higher data rates and richer media content. ‌
High reliability of high frequency pcb communication circuits is also one of its advantages. The use of high-quality materials and manufacturing processes can effectively resist external interference and oxidation corrosion, ensure stable performance in high temperature environments, and thus extend the service life of the circuit board.

Classification of high frequency pcb communication circuits

Classification by material:

Organic materials: including phenolic resin, glass fiber/epoxy resin, Polyimide, BT/Epoxy (bismaleimide triazine/epoxy resin), etc.
Inorganic materials: mainly including aluminum, copper-invar-copper, ceramic, etc. These materials are mainly selected for their excellent heat dissipation function.

Classification by the hardness of the finished product:

Rigid PCB: has a solid structure and stable performance.
Flexible PCB: has flexibility and bendability, suitable for occasions requiring flexible wiring.
Rigid-Flex PCB: It combines the characteristics of rigid and flexible boards, and has higher design flexibility and wide application.

Classification by structure:

Single-sided board: A circuit board with a conductive layer on only one side.
Double-sided board: Both sides are coated with conductive layers, separated by insulating materials in the middle.
Multilayer board: It is composed of multiple conductive layers and insulating layers, and has higher circuit integration and reliability.

Classification by use:

Communication board: It is used in various communication equipment and systems.
Consumable electronic board: It is commonly found in consumer electronic products.
Military board: A circuit board that meets special requirements in the military field.
Computer board: A circuit board used in computer hardware.
Semiconductor board: A circuit board used in the manufacturing and testing process of semiconductors.
Electrical test board: A circuit board used in electronic testing and measurement equipment.

How to choose high-frequency circuit board high-speed board

When choosing PCB board, you must find a balance between meeting design requirements, mass production and cost. In short, the design requirements cover two aspects: electrical performance and structural reliability. Especially when designing ultra-high-speed PCB (frequency greater than GHz), the choice of board is particularly important. For example, the commonly used FR-4 material will have a significantly increased dielectric loss (Df, i.e., Dielectric Loss) at a frequency of several GHz, and may no longer be applicable.

Taking the 10Gb/S high-speed digital signal as an example, this signal can be regarded as the superposition of multiple sinusoidal wave signals of different frequencies. Therefore, the 10Gb/S signal contains multiple components of different frequencies: such as a 5GHz fundamental signal, a 3rd-order 15GHz signal, a 5th-order 25GHz signal, and a 7th-order 35GHz signal. In order to ensure the integrity of digital signals, maintain the steepness of the upper and lower edges of the signals, and be compatible with the low-loss, low-distortion transmission of RF microwaves (the high-frequency harmonic part of the digital signal reaches the microwave frequency band), the selection of materials for high-speed digital circuit PCBs has many similarities with the needs of RF microwave circuits.

In actual engineering operations, the selection of high-frequency boards seems simple, but the factors that need to be considered are quite complex. Through the introduction of this article, PCB design engineers or high-speed project leaders can have a deeper understanding of the characteristics and selection of boards. Understand the electrical properties, thermal properties, reliability and other characteristics of the board, and use the stacking design reasonably to create products with high reliability and excellent processability, and achieve the best balance of various factors.

Composition and key components of high frequency pcb communication circuits

High frequency pcb communication circuits are basically composed of passive components, active devices and passive networks. Passive components include resistors, capacitors and inductors, which mainly exhibit resistance characteristics at low frequencies, but also exhibit reactance characteristics at high frequencies. Active devices such as high-frequency triodes have the characteristics of high gain, high frequency response and low noise, and are widely used in television, radio communication, radar and other fields.

Application of high frequency pcb communication circuits

High frequency pcb communication circuits are widely used in long-distance communication systems, with a communication distance of up to thousands of kilometers, and are often used to maintain communication between aircraft and bases. It occupies a high-frequency band of 2~30MHz, uses skywave propagation, and can propagate over long distances. Modern airborne high-frequency communication systems usually use single-sideband communication systems, which can greatly compress the occupied frequency band and save transmission power. However, high-frequency communication is also susceptible to electrical interference such as ionospheric disturbances and lightning, generating radio background noise, and there is fading, and the signal is sometimes strong and sometimes weak.

Design Guidelines for High Frequency PCB Communication Circuits

Design Guidelines

High Frequency PCB Communication Circuits

How to avoid high-frequency interference?

The basic idea of avoiding high-frequency interference is to minimize the interference of the electromagnetic field of high-frequency signals, which is the so-called crosstalk. You can increase the distance between high-speed signals and analog signals, or add ground guard/shunt traces next to analog signals. Also pay attention to the noise interference of digital ground to analog ground.

How to solve the signal integrity problem in high-frequency communication PCB design?

Signal integrity is basically an impedance matching problem. The factors that affect impedance matching include the architecture and output impedance of the signal source, the characteristic impedance of the trace, the characteristics of the load end, and the topology of the trace. The solution is to rely on termination and adjust the topology of the trace.

How is the differential wiring method implemented?

There are two points to note when wiring differential pairs. One is that the length of the two lines should be as equal as possible, and the other is that the spacing between the two lines (this spacing is determined by the differential impedance) should remain unchanged, that is, they should be kept parallel. There are two parallel methods, one is that two lines run on the same routing layer (side-by-side), and the other is that two lines run on two adjacent layers (over-under). Generally, the former side-by-side (side by side, shoulder to shoulder) is more commonly used.

How to implement differential routing for clock signal lines with only one output end?

To use differential routing, it must be meaningful if both the signal source and the receiving end are differential signals. Therefore, differential routing cannot be used for clock signals with only one output end.

Can a matching resistor be added between the differential line pairs at the receiving end?

The matching resistor between the differential line pairs at the receiving end is usually added, and its value should be equal to the value of the differential impedance. This will improve the signal quality.

Why should the routing of differential pairs be close and parallel?

The routing method of differential pairs should be appropriately close and parallel. The so-called appropriate proximity is because this spacing will affect the value of differential impedance, which is an important parameter for designing differential pairs. Parallelism is also required because the consistency of differential impedance must be maintained. If the two lines are sometimes far away and sometimes close, the differential impedance will be inconsistent, which will affect the signal integrity and timing delay.

How to deal with some theoretical conflicts in actual wiring?

Basically, it is right to separate the analog/digital ground. It should be noted that the signal routing should try not to cross the split place (moat), and the return current path of the power supply and signal should not be too large.

The crystal oscillator is an analog positive feedback oscillation circuit. To have a stable oscillation signal, the loop gain and phase specifications must be met. The oscillation specification of this analog signal is easily interfered. Even if ground guard traces are added, it may not be possible to completely isolate the interference. Moreover, if it is too far away, the noise on the ground plane will also affect the positive feedback oscillation circuit. Therefore, the distance between the crystal oscillator and the chip must be as close as possible.

It is true that there are many conflicts between high-speed wiring and EMI requirements. But the basic principle is that the resistors, capacitors or ferrite beads added due to EMI cannot cause some electrical characteristics of the signal to not meet the specifications. Therefore, first use the techniques of arranging routing and PCB stacking to solve or reduce EMI problems, such as routing high-speed signals on the inner layer. Only then use resistors, capacitors or ferrite beads to reduce damage to the signal.

How to solve the contradiction between manual routing and automatic routing of high-speed signals?

Most of the current powerful routing software’s automatic routing tools have set constraints to control the winding method and the number of vias. The winding engine capabilities and constraint setting items of various EDA companies are sometimes very different. For example, whether there are enough constraints to control the winding method of the serpentine, whether the routing spacing of the differential pair can be controlled, etc. This will affect whether the routing method generated by automatic routing can meet the designer’s ideas. In addition, the difficulty of manually adjusting the routing is also related to the ability of the winding engine. For example, the pushing ability of the routing, the pushing ability of the via, and even the pushing ability of the routing to the copper plating, etc. Therefore, choosing a routing tool with a strong winding engine capability is the solution.

About test coupon.

The test coupon is used to measure the characteristic impedance of the produced PCB board with TDR (Time Domain Reflectometer) to see if it meets the design requirements. Generally, the impedance to be controlled is single line and differential pair. Therefore, the trace width and line spacing (when there is a differential pair) on the test coupon should be the same as the line to be controlled. The location of the ground point during measurement is important. In order to reduce the inductance of the ground lead, the grounding point of the TDR probe is usually very close to the probe tip, so the distance and method between the point where the signal is measured on the test coupon and the ground point should be consistent with the probe used.

In high-speed PCB design, the blank area of the signal layer can be copper-plated, and how should the copper of multiple signal layers be distributed in grounding and power supply?

Generally, the copper plating in the blank area is mostly grounded. However, when plating copper next to high-speed signal lines, pay attention to the distance between the copper plating and the signal line, because the copper plating will reduce the characteristic impedance of the trace a little. Also be careful not to affect the characteristic impedance of other layers, such as in the dual strip line structure.

Can the signal line on the power plane be calculated using the microstrip line model? Can the signal between the power and ground planes be calculated using the stripline model?

Yes, both the power plane and the ground plane must be considered as reference planes when calculating the characteristic impedance. For example, a four-layer board: top layer-power layer-ground layer-bottom layer. At this time, the model of the characteristic impedance of the top layer routing is a microstrip line model with the power plane as the reference plane.

Can the automatic generation of test points on high-density printed circuit boards by software generally meet the test requirements of mass production?

Whether the test points automatically generated by general software meet the test requirements depends on whether the specifications for adding test points meet the requirements of the test equipment. In addition, if the routing is too dense and the specifications for adding test points are strict, it may not be possible to automatically add test points to each line. Of course, the places to be tested need to be filled manually.

Will adding test points affect the quality of high-speed signals?

As for whether it will affect the signal quality, it depends on the way of adding test points and how fast the signal is. Basically, the additional test point (without using the existing via or DIP pin as the test point) may be added to the line or a short line may be pulled out from the line. The former is equivalent to adding a very small capacitor to the line, and the latter is an additional branch. Both situations will have some impact on the high-speed signal, and the degree of impact is related to the frequency speed of the signal and the edge rate of the signal. The magnitude of the impact can be known through simulation. In principle, the smaller the test point, the better (of course, it must meet the requirements of the test equipment) and the shorter the branch, the better.

How should the ground wires between the boards of a system be connected when several PCBs are connected to each other?

When the signals or power supplies between the PCB boards are in operation, for example, when the power supply or signal from board A is sent to board B, there will be an equal amount of current flowing back from the ground layer to board A (this is Kirchoff current law). The current on the ground layer will flow back to the impedance. Therefore, at each interface where the power supply or signal is connected to each other, the number of pins allocated to the ground layer should not be too small to reduce the impedance, so as to reduce the noise on the ground layer. In addition, the entire current loop can be analyzed, especially the part with larger current, and the connection method of the ground layer or ground wire can be adjusted to control the flow of current (for example, create low impedance at a certain place to let most of the current flow through this place) to reduce the impact on other more sensitive signals.

PCB Full Form

PCB stands for Printed Circuit Board, a key component in almost all electronic devices. It connects and supports electronic components using conductive tracks, pads, and other features. The design and production of PCBs require precise engineering, as they are crucial for the functionality of the final product.

What is PCB Quote Packaging?

PCB quote packaging refers to the process of gathering and organizing all the details needed to estimate the cost of producing a PCB. This includes not only the design specifications but also the materials, manufacturing processes, and other engineering considerations. It’s not just a financial calculation but a complete engineering analysis that ensures the quote is accurate, feasible, and optimized for production.

The quote must consider every detail that affects production—like material types, size, complexity, and production volume. The aim is to package all these details into a clear, comprehensive quote, ensuring the client understands what they are paying for and why.

Why is Engineering Important in PCB Quote Packaging?

Engineering plays a vital role in the PCB quoting process because it’s not just about estimating costs. It’s about understanding the technical requirements and ensuring that every aspect of the design and production is accounted for. Engineers analyze the design, materials, and manufacturing methods to ensure the quote reflects the real cost of production.

Without engineering insight, a quote could be inaccurate, leading to cost overruns or production delays. Engineers make sure that all technical details, such as layer count, trace width, and component placement, are properly considered.

What Are the Key Factors in a PCB Quote?

Several factors come into play when preparing a PCB quote:

PCB Quote Packaging is What Type of Engineering?

1. Type of manufacturing process

The technical type of PCB determines its complexity and cost. For example, simple single panels cost much less than multi-layer panels, while flexible circuits (FPC) or rigid and flexible panels require more complex manufacturing processes and naturally cost more. In addition, whether advanced technologies such as microvias, laser drilling, blind holes or buried holes are required can also have a significant impact on the quotation.

2. Material type

Materials are an important part of PCB costs. Common materials include FR4, ceramics, metal substrates, etc. FR4 is the most common base material and is suitable for most conventional applications, but for high-frequency, high-temperature environments, ceramic or metal-based materials may be more suitable, but their price is relatively high. Choosing the right material not only affects the performance, but also directly affects the cost.

3. IPC level

IPC grades reflect the quality standards of PCB manufacturing, commonly used are IPC-A-600 grades 1, 2 and 3. The higher the grade, the more stringent the manufacturing requirements, and the corresponding increase in cost. For example, grade 3 PCBS are usually used in high-demand fields such as aerospace and medical equipment, which require higher accuracy and quality control, so the price is higher.

4. Circuit design

PCB circuit design complexity directly affects manufacturing costs. Including wire width, spacing, hole size and so on, the production process has put forward different requirements. High density interconnect (HDI) boards typically require more elaborate wiring techniques and may involve the use of microvias, which will increase the difficulty and cost of manufacturing.

5. PCB size and yield

The size of the PCB directly affects the amount of material used, and the larger the board, the more material is needed. In addition, the yield is also an important factor affecting the quotation. PCB manufacturing with complex design or high density lines is prone to defects, resulting in decreased yield. That means manufacturers may need to produce more boards to meet orders, increasing costs.

6. Material thickness

Different applications require different thicknesses of PCB materials. The standard FR4 thickness is usually 1.6mm, but thinner or thicker boards are sometimes used. Changes in material thickness can affect the overall cost, especially if thicker sheets require special processing or higher strength, and manufacturing expenses will increase accordingly.

7. Copper thickness

The copper thickness in the PCB usually has a standard choice, such as 1oz, 2oz or even thicker copper layers. The higher the copper thickness, the better the conductivity of the PCB, suitable for high-current applications, but the increase in copper thickness will significantly increase the manufacturing cost, especially in the plating and etching process requires additional materials and processes.

8. Stack-up method

The stacking mode determines the number of layers and the interlayer structure of the PCB. Complex multilayer boards or HDI boards require more complex lamination processes. For example, the lamination method may involve multiple pressing, the use of prepregs or special insulation materials. Each additional layer requires more manufacturing steps, resulting in increased costs.

9. Quantity

The quantity of the order has a direct impact on the PCB quotation. High-volume production can reduce unit prices by spreading tooling and setup costs, while small-batch orders are typically more expensive due to relatively high production preparation and start-up costs.

10. Delivery date

The shorter the delivery time, the higher the quotation. Rush orders require prioritizing production, which can disrupt the plant’s production schedule and require additional resource deployment. To meet urgent delivery deadlines, manufacturers may need to work overtime or speed up production, increasing overall production costs.

These are just a few examples, but they show how engineering considerations are woven into every part of the quoting process.

PCB Manufacturing Process

How Do Engineers Calculate PCB Manufacturing Costs?

Engineers calculate PCB manufacturing costs by considering the design specifications and the production methods needed to meet those requirements. They start by analyzing the PCB’s layout and design, which determines factors like layer count, trace width, and hole size. Each of these elements has a direct impact on the materials used and the manufacturing process.

They also consider the assembly process—whether it’s surface-mount or through-hole—and what testing will be required. After evaluating these details, they calculate the costs associated with each step of the manufacturing process. This ensures the final quote is both accurate and comprehensive.

What Type of Engineer Designs PCBs?

Engineers who design PCBs typically have a bachelor’s degree or above in electrical engineering, automation, computer science, or a related field ‌ and understand the basics of electronic design, printed circuit board (PCB), and electronics manufacturing in the PCB industry. These engineers need to master PCB design software such as Altium Designer, Eagle PCB, PADS, or CAD, etc., as well as the use of related manufacturing and testing tools. At the same time, they need to have a knowledge of the PCB industry, a certain circuit design and electronic components knowledge, including digital and analog circuits, signal processing, power electronics, embedded systems, communication technology, etc. In addition, holding certificates such as IPC-2221/2222, IPC-A-600/610, and CID (Certified Interconnect Designer) can prove that they have relevant professional knowledge and skills, which can help improve their career competitiveness.

These engineers also need to have a strong sense of responsibility and team spirit, have good communication and coordination skills, and be able to work effectively with customers, manufacturers, and other team members. For junior engineers, it is recommended to study in a single point of depth, such as PCB design, SI simulation, thermal design, EMC design, product testing, etc., and then start from this advantage point to expand the scope of knowledge

What Materials Are Considered During PCB Quote Packaging?

The type of material used for a PCB is a major cost driver. Common materials include:

This is the most common material used in PCBs due to its balance of cost and performance. It’s versatile and reliable for most standard applications.

Metal Core

Metal core PCBs are used in applications where heat dissipation is a concern, such as LED lighting. These boards are more expensive due to the metal layer.

Ceramic

Ceramic materials are used for high-frequency or high-temperature applications. They are more costly but offer better performance in extreme conditions.

Each material has its own manufacturing process, which also affects the cost. For instance, metal core boards may require different drilling techniques compared to standard FR4 boards. Engineers must consider these details when preparing a quote.

How Does the Choice of PCB Manufacturing Methods Impact the Quote?

The method used to manufacture the PCB can greatly impact the final cost. Common methods include:

Surface-Mount Technology (SMT): This is the most common method for modern PCB assembly. It’s efficient and cost-effective for most applications.

Through-Hole Technology (THT): This method is used for components that require a stronger mechanical bond. It’s more labor-intensive and, therefore, more expensive.

Flexible and Rigid-Flex Manufacturing: These types of PCBs require specialized processes and materials, which can increase the cost.

Additionally, advanced techniques like laser drilling for microvias or selective soldering for complex assemblies may be necessary for high-precision designs. Each of these methods requires careful consideration, and engineers must choose the best process for both the design and the budget.

Who Designs PCB?

Since 2006, Best Technology has been the leading PCB quick turn manufacturer specializing in both PCB prototype and production quantities, initially produced single-sided and double-sided printed circuit boards for the consumer electronics market. Now, we provide not only FR4 PCB, but also some special PCB like flex circuit, metal core PCB, ceramic PCB, extra thin PCB, HDI PCB, IC substrate, busbar PCB, heavy copper PCB and so on. We can make 50 layers PCB, and it is not our limit.

Nowadays, Best Technology has grown to become a major PCB manufacturer in Asia to serve in diverse customers base such as electronics appliance, communication, educational electronics, power supplies, automations.

For more information about PCB, or to learn more about the online quote and ordering process, please visit www.bestpcbs.com

Archive for the ‘Design Guide’ Category

What are EMI and EMC in PCB?

What Is the Difference Between EMI and EMC Testing?

What Are the Testing Standards for EMI/EMC?

How to Conduct an EMI Test?

EMI/EMC PCB Design Guidelines

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Best materials for Aerospace PCB Assembly

Aerospace PCB Assembly design standards

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Wi-Fi Module Price

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Does trace spacing affect PCB production cost?

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Is PCB Design Difficult?

What is the Basic Rule of PCB Design?

What Files Are Needed to Manufacture a PCB?

What Software to Use for PCB Design?

How Do You Manufacture a PCB Board?

What Is the Cheapest PCB Finish?

How Much Does It Cost to Get a PCB Board Made?

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What is Aluminum Nitride PCB?

Benefits of AlN PCBs

What is the Thermal Conductivity of Aluminum Nitride PCB?

Factors affect thermal conductivity of AlN PCB

What is Aluminum Nitride PCB Used For?

Why is Aluminum Nitride Expensive?

Aluminum Nitride PCB vs. Alumina Oxide PCB

AlN Ceramic PCB Design Considerations

FAQs About AlN PCBs

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What is a 2 Layer Aluminum PCB?

2 Layer Aluminum PCB Stack-Up

How Thick is a 2 Layer PCB Layer?

Is Thicker Aluminum PCB have Better Heat Dissipation?

2 Layers Aluminum PCB vs. Double Sided Aluminum PCB

How Much Does Aluminum PCB Cost?

How Many Layers Should a PCB Have?

Aluminum PCB Design Guidelines

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How to convert Cadence17.2’s .brd file to HyperLynx9.4.1’s .hyp file

Tutorial on converting Cadence17.2’s .brd file to HyperLynx9.4.1’s .hyp file

What is a .hyp file?

The specific uses of .hyp files include:

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‌What is a high frequency pcb communication circuits

Definition of high frequency pcb communication circuits

Advantages of high frequency pcb communication circuits

Classification of high frequency pcb communication circuits

How to choose high-frequency circuit board high-speed board

Composition and key components of high frequency pcb communication circuits

Application of high frequency pcb communication circuits

Design Guidelines for High Frequency PCB Communication Circuits

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PCB Full Form

What is PCB Quote Packaging?

Why is Engineering Important in PCB Quote Packaging?

What is the minimum line width for a PCB?