Archive for the ‘Special PCB’ Category

Tuesday, November 26th, 2024

What is Via in Pad?

With the improvement of the integration of electronic products, the package of components is getting smaller and smaller, and the pin spacing is also getting smaller and smaller. In complex PCB design, the signal cannot be fanned out without punching the disc hole, and the signal must be drawn from the next layer through the disc hole. Especially in the miniaturization applications of ‌BGA (Ball Grid Array) and ‌SMD (Surface Mount Device) chips, the process of disc holes has been widely used.

Via in pad is a design methodology in PCB manufacturing where vias are directly embedded in the pads of surface-mount devices (SMDs). Traditional vias are placed near the components with traces connecting them to the pads. However, in via-in-pad designs, the vias and pads are combined, which saves space and shortens trace lengths. This approach is particularly useful in HDI PCBs, where board real estate is limited, and signal integrity is critical.

What is Via-in-Pad Plating?

Via-in-pad plating refers to a specialized manufacturing process where vias embedded in pads are filled and plated over to form a smooth, conductive surface. This process involves:

Via Filling: The via hole is filled with a material, often epoxy or a conductive paste, to eliminate voids and provide structural stability.
Copper Plating: The filled via is then plated with copper to create a uniform and conductive layer.
Surface Finish: A finish such as ENIG (Electroless Nickel Immersion Gold) or HASL (Hot Air Solder Leveling) is applied to ensure solderability.

Proper via-in-pad plating prevents solder wicking, a phenomenon where solder flows into the via during reflow, causing insufficient solder on the component leads.

Is Via-in-Pad Expensive?

Via-in-pad designs are undeniably more expensive than traditional vias. The additional manufacturing steps, such as via filling, plating, and the need for precise alignment, contribute to the higher costs. Moreover, the advanced equipment and materials required for this process add to the overall expense.

However, for designs that demand high performance, such as smartphones, medical devices, and aerospace electronics, the benefits of via in pad often outweigh the cost. It allows for compact layouts, improved performance, and better thermal management, making it indispensable for cutting-edge applications.

What Size is a Via-in-Pad?

The size of a via-in-pad is influenced by the PCB’s application, layer count, and the size of the components used. In HDI PCBs, via sizes typically range from 0.15 mm to 0.4 mm in diameter. Microvias, often used in via-in-pad designs, can be as small as 0.1 mm.

The diameter must align with the pad size to avoid compromising the pad’s mechanical and electrical integrity. Designers also need to consider the PCB manufacturer’s capabilities when selecting via sizes, as extremely small vias may require advanced fabrication techniques.

What are the Drawbacks of Via in Pad?

While via in pad offers several advantages, it also comes with notable challenges:

Higher cost
Soldering defects
Complex manufacturing
Thermal stress risks
Complex manufacturing process

Can You Put Vias Under Components?

Yes, placing vias under components is common in advanced PCB designs, particularly with via in pad. This technique is often used for BGAs, QFNs, and other fine-pitch components.

However, proper design and manufacturing practices must be followed to prevent defects. Filling and plating the vias ensure they do not interfere with soldering. Additionally, simulations and testing are essential to validate the design and ensure reliability.

Traditional Vias vs. Via-in-Pad Design

Traditional vias are placed outside the component pad, with traces connecting them to the pads. While this approach is cost-effective, it consumes more space and may result in longer trace lengths, increasing parasitic effects.

Via-in-pad designs embed the vias directly within the component pads, reducing trace lengths and optimizing space. They enhance signal integrity, thermal performance, and overall board aesthetics but at a higher cost and complexity.

When to Use Via-in-Pad Design?

Via-in-pad designs are not always necessary, but they are indispensable in specific scenarios where performance, space optimization, and thermal management are critical. Below are the situations where via-in-pad designs are most appropriate:

1. High-Density Interconnect (HDI) PCBs

When designing HDI PCBs with compact layouts and high layer counts, via-in-pad is essential. This design technique optimizes the limited space available, allowing for more components and connections on the board. It is particularly useful for devices like smartphones, wearables, and IoT devices where miniaturization is key.

2. Fine-Pitch Components

Via-in-pad designs are commonly used for components with fine pitches, such as:

BGA chips: BGAs have numerous pins closely spaced, leaving minimal room for traditional routing. Via in pad provides a clean solution to connect signals directly.
QFNs: QFNs require vias under the pads for effective routing and thermal management.

3. High-Speed and RF Applications

In high-speed and RF circuits, signal integrity is paramount. Via-in-pad designs minimize trace lengths, reducing parasitic inductance and impedance mismatches. This makes them ideal for applications like:

5G communication systems
High-frequency radar systems
Advanced networking equipment

4. Improved Thermal Management Needs

For power components or heat-sensitive devices, via in pad aids in efficient thermal dissipation. By directly connecting the pads to thermal vias leading to internal or external layers, heat is transferred away from the components. This is critical for:

High-power LEDs
Voltage regulators
Power amplifiers

5. Limited PCB Real Estate

In designs with severe space constraints, via in pad maximizes usable board area. This allows for additional routing space and supports high component density without sacrificing performance. Applications like medical implants and aerospace electronics greatly benefit from this approach.

6. Double-Sided Component Placement

When components are placed on both sides of the PCB, traditional vias can interfere with the routing on the opposite side. Via in pad eliminates this issue by embedding the vias within the pads, simplifying double-sided designs.

7. High-Performance Computing Systems

For processors, GPUs, and other high-speed ICs, via in pad ensures reliable power delivery and signal integrity. It is frequently used in:

Data centers
High-performance workstations
AI hardware

Guidelines for Via-in-Pad Design

Via-in-pad designs require meticulous attention to detail to ensure reliability and performance.

1. Decide on the most suitable via type based on your design requirements:

Microvias: Ideal for high-density designs due to their small size.
Blind/Buried Vias: Useful for connecting internal layers without penetrating through the entire board.
Through-Hole Vias: Less common in via-in-pad but may be necessary for specific designs.

2. Fill the vias with appropriate materials to ensure mechanical stability and prevent solder wicking:

Non-Conductive Epoxy Fill: Provides a reliable, flat surface for soldering.
Conductive Fill: Used when electrical connectivity through the via is needed.

3. The plating over the filled vias should be smooth and flat to avoid soldering issues. Use a high-quality copper plating process to enhance electrical and thermal conductivity.

4. Collaborate with your PCB manufacturer early in the design process to align on their capabilities. This includes:

Minimum via diameter and pad size.
Spacing requirements between vias and traces.
Maximum number of vias that can be placed in pads.

5. Ensure the via size is proportionate to the pad size. A via that is too large can compromise the pad’s structural and electrical integrity, while a too-small via may not provide the necessary connectivity or thermal performance.

6. For high-power applications, incorporate thermal relief patterns or thermal vias.

7. Maintain sufficient spacing between vias and other components or traces to prevent electrical interference or thermal stress.

8. To avoid solder flowing into the via during reflow soldering:

Use filled and capped vias.
Employ surface finishes like ENIG (Electroless Nickel Immersion Gold) or OSP (Organic Solderability Preservative) for enhanced soldering reliability.

9. When using via in pad for power components or ground connections, thermal relief patterns help prevent excessive heat buildup. These are especially important in high-current designs.

Need assistance in designing via-in-pads in your PCB design? Leave your comments on below, our design experts will help to solve them.

What is Wireless PCB?

Wireless PCB is a printed circuit board specially designed to support wireless communication functions. It integrates various wireless communication modules, antennas and related electronic components, enabling electronic devices to perform data transmission, signal reception and transmission without physical cable connection. For example, the smart phones, tablets, wireless Bluetooth headsets and other devices we use in daily life all use wireless PCB technology, thus realizing convenient Wi-Fi connection, Bluetooth data transmission, NFC near-field communication and other functions.

Compared with traditional PCB, the biggest feature of wireless PCB is its wireless communication capability. Through careful layout and design, it organically integrates circuit modules with different functions such as radio frequency (RF) circuit, baseband processing circuit, power management circuit on a circuit board, and also takes into account the transmission characteristics of wireless signals, such as impedance matching, signal interference and other issues, to ensure the stability and efficiency of wireless communication.

Wireless PCB Design Guidelines | Best Technology

Advantages of wireless PCB

High flexibility

Because of the wireless PCB, devices can be moved and placed more freely, no longer restricted by the length and connection position of cables. For example, wireless smart home devices can be easily deployed in every corner of the home, and users can control them through mobile phones or other smart terminals anytime and anywhere, it greatly improves the user’s experience.

Easy to install

In some large-scale applications, such as industrial automation production lines, smart warehousing systems, etc., wireless PCBs can significantly reduce the use of cables. So that reducing material costs, installation costs, and later maintenance costs. Since there is no need to use a large number of cables, the installation process of the equipment is also simpler and faster, which can greatly shorten the lead time.

Support multi-device interconnection

Wireless PCBs can achieve seamless connection and data sharing between multiple devices. In the Internet of Things (IoT) environment, various smart devices can communicate with each other through the network built by wireless PCBs to form a large and intelligent ecosystem.

Easy to upgrade and expand

With the continuous development of wireless communication technology, new wireless standards and protocols continue to emerge. The design of wireless PCBs is relatively flexible, which is easy to upgrade and expand to adapt to new technical requirements. For example, when Wi-Fi technology is upgraded from 802.11n to 802.11ac or 802.11ax, only the relevant modules on the wireless PCB need to be updated or optimized without a large-scale redesign of the entire device.

Disadvantages of wireless PCB

Signal interference problem

Since the wireless PCB works in an open wireless environment, it is easily interfered by others, like wireless devices or electromagnetic signals around it. For example, in areas with crowded Wi-Fi frequency bands, such as offices and apartment buildings, wireless devices may experience signal interruption, slow network speed and other problems.

High power consumption

In order to realize wireless communication functions, wireless PCB needs to consume a certain amount of power to drive the wireless module and antenna to work. Especially in some devices that adopt high-performance wireless communication standards (such as 5G), the power consumption problem is more prominent. This will not only shorten the battery life of the device, but also may put higher requirements on the heat dissipation design of the device.

Limited transmission distance

Compared with wired communication, the wireless signal transmission distance of wireless PCB is usually shorter. Although the transmission distance can be extended by increasing antenna power and using repeaters, this will also increase costs and system complexity. In some application scenarios with high transmission distance requirements, such as remote industrial monitoring and large-scale wireless sensor networks, wireless PCBs may need to be combined with other wired or wireless communication technologies to meet the requirements.

Design Guidelines for Wireless PCBs

Designing a wireless PCB requires a balance between functionality, efficiency, and reliability. Engineers must consider several factors to optimize performance while addressing potential challenges.

1. Clarify Design Goals and Requirements

First, determine the specific functions that the wireless PCB needs to implement, such as Wi-Fi connection, Bluetooth communication, ZigBee networking, etc. For example, when designing a wireless PCB for a smart watch, it may be necessary to have Bluetooth communication for connecting to a mobile phone and receiving notifications, as well as low-power Wi-Fi functions for occasional software updates. Clarify the range and data transmission rate requirements of wireless communication. For short-range, low-rate applications, such as the PCB design of a wireless mouse, Bluetooth low-power technology may be sufficient; while for wireless surveillance cameras that require high-speed data transmission, Wi-Fi 6 or higher standard wireless PCB designs can meet the needs.

2. Component selection

Wireless module selection

Select the appropriate module according to the designed wireless communication standard. There are various brands and models of Wi-Fi modules, Bluetooth modules, ZigBee modules, etc. on the market. For example, for high-performance Wi-Fi applications, select modules that support Wi-Fi 6 or Wi-Fi 6E standards, which generally have higher data transmission rates and lower power consumption. Investigate the module’s integration and peripheral circuit requirements. Highly integrated modules can simplify PCB design and reduce the number of components.

Antenna selection

Determine the antenna type. Common antenna types include patch antennas, whip antennas, helical antennas, etc. Patch antennas are suitable for miniaturization and integrated designs inside the PCB; whip antennas are suitable for occasions that require higher gain and longer transmission distances. For example, in wireless vehicle communication devices, whip antennas may be used. Consider the performance parameters of the antenna. Antenna parameters such as gain, bandwidth, and directivity directly affect the effect of wireless communication. When selecting an antenna, it should be determined based on the designed communication distance, frequency range, and signal coverage requirements.

Other component selection

For power management components, select appropriate regulators, power chips, etc. Ensure that a stable power supply can be provided to the wireless module and other components, and consider the efficiency and power consumption of the power supply. For example, in low-power wireless devices, select a power management chip with low quiescent current. Select appropriate filtering components, such as capacitors and inductors, to filter out power supply noise and signal interference.

3. PCB layout

Partition circuits with different functions

Divide the wireless module, antenna, power circuit, digital circuit, etc. into different areas. For example, place the wireless module and antenna close to the edge of the PCB to reduce signal transmission loss; place the power circuit away from sensitive wireless signal areas to prevent power supply noise from interfering with wireless signals.

Set up isolation zones

Set up isolation zones between different functional areas, such as through blank copper foil or grounded vias. For example, set up isolation zones between digital circuits and analog circuits to reduce crosstalk between digital signals and analog signals, especially in the analog front-end part that processes wireless signals, where this isolation is more important.

Component placement

Place components according to the signal flow direction. For wireless communication circuits, start from the antenna input and place RF front-end components, wireless modules, etc. in sequence so that signals can be transmitted smoothly between components. Meanwhile, separate components that generate large amounts of heat from temperature-sensitive components to prevent heat transfer from affecting component performance. At the same time, keep components that may generate electromagnetic interference, such as high-frequency clock components, away from wireless modules and antennas. For example, when laying out, place the high-frequency clock crystal oscillator of the microprocessor away from the wireless module to prevent the high-frequency signal it generates from interfering with wireless communication.

4. PCB traces design

For wireless signal transmission lines, their characteristic impedance must be strictly controlled. Usually, the characteristic impedance of the transmission line of a wireless circuit is designed to be 50Ω or 75Ω. Use appropriate line width and dielectric thickness to achieve impedance matching, and try to maintain the uniformity of the transmission line to avoid impedance mutations.

5. Electromagnetic compatibility (EMC) design

A metal shielding cover can be used or a shielding layer can be formed by copper plating on the PCB. For example, for sensitive Wi-Fi modules, metal shielding covers are used to surround them. The shielding covers should be well grounded, which can effectively prevent external electromagnetic interference from entering the module and reduce the electromagnetic radiation of the module itself.

6. Signal integrity analysis

Use professional signal integrity analysis software, such as HyperLynx, to analyze the reflection and crosstalk of the signal on the wireless PCB. By simulating the transmission process of the signal on the transmission line, find out where the reflection may occur, such as the end point and branch point of the transmission line.

Wireless PCB Assembly Process

Wireless PCB assembly involves mounting and soldering components onto the board to create a functional circuit. The process demands precision due to the small size and sensitivity of components used in wireless communication. Key steps include:

1. Check the PCB board: Ensure that the PCB board is free from scratches, deformation, short circuit and other defects, and the surface of the welding pad of each component is clean and free of oxidation.

2. Check the component list: Check the part number, specification and quantity of the components to be mounted against the Bill of Materials (BOM).

3. Preparation of pick and place equipment: According to the production scale and accuracy requirements, select the appropriate mounting machine, and ensure that the working parameters of the mounting machine (such as nozzle height, mounting pressure, mounting speed, etc.) have been correctly set.

4. Component pretreatment: For some special components, such as QFP (Quad Flat Package), BGA (Ball Grid Array), etc., it may be necessary to pre-treat, such as baking to remove moisture, to improve the reliability of mounting.

5. Solder paste printing

Fixes the stencil onto PCB board to ensure stencil and PCB board is tight and there is no gap.
Evenly printing the solder paste onto the pad of the wireless PCB board. The thickness and shape of the solder paste should meet the process requirements, which are generally controlled by adjusting the pressure, speed and angle of the scraper of the printer.
After the printing is completed, use a microscope or automatic optical inspection equipment (AOI) to check the quality of the solder paste printing, such as whether the solder paste amount is uniform.

6. Pick and place assembly

In the mounting process, pay attention to the direction and position accuracy of the components, especially for some small components and small pin spacing Package forms, such as 0402, 0201 patch resistance capacitor and QFN (Quad Flat no-leads Package, square Flat No pin package). For some larger or heavier components, it may be necessary to increase mounting pressure or use special mounting methods to ensure good contact between the component and the pad.

7. Reflow welding: The PCB board with the installed components is fed into the reflow welder. The reflow welder melts the solder paste through heating, forming a good solder spot, and solidly welds the components on the PCB board.

8. Cleaning and testing: For applications that require high cleanliness, such as medical devices and aerospace, it may be necessary to clean the welded PCB board to remove residual flux and impurities. The cleaning method can be water cleaning, solvent cleaning or ultrasonic cleaning, etc. The specific cleaning process should be selected according to the material, component type and cleaning requirements of the PCB board.

9. Finally, the wireless PCB board for comprehensive functional testing and performance testing, including wireless communication function testing, electrical performance testing, reliability testing. Ensure that the wireless PCB board meets the design requirements and product standards, can work properly and operate stably and reliably.

If you want know more about wireless PCB or PCB assembly, welcome to contact us at sales@bestpcbs.com. Our technical team are always online!

What are the holes in a PCB called?

What are the holes on PCB called? What are the holes in the circuit? The holes on PCB can be roughly divided into 3 types, screw holes (mounting holes), conductive holes (vias), and plug-in holes.

Screw holes: Screw holes are used for fixing.

Conductive holes: Conductive holes (also called vias) are used for conducting electricity just like circuits.

Plug-in holes: Plug-in holes are of course used to plug in various parts, such as diodes, transistors, capacitors, inductors, etc.

What is a through hole

What is a through hole? Through holes, also known as perforations, are holes in a PCB that go all the way through the board. Their main purpose is to provide electrical connections for component pins while allowing soldering on both sides of the board.

1.A via is a special through hole whose wall is metallized to achieve electrical connection between different layers on a circuit board. This type of hole is usually used to connect component pins to internal circuits, or to achieve electrical connection between different layers in a multi-layer PCB. Vias need to be metallized during the PCB manufacturing process, which usually includes drilling, desmearing, chemical copper plating, and electroplating.

2.Non-conducting holes are the opposite of through holes. Their hole walls are not metallized, so they do not have electrical connection functions. These holes are mainly used for mechanical fixation, heat dissipation or identification purposes. Non-conducting holes are relatively simple in the PCB manufacturing process, and only drilling operations are required.

What is a blind via?

A blind via is a hole that extends from one side of a PCB to a certain internal layer without penetrating the entire board. The emergence of blind vias is mainly due to the development of HDI technology, which provides circuit designers with greater flexibility and more compact layout. Blind vias are usually used to connect surface mount components (SMD) to internal circuit layers, or to connect circuits between different internal layers.

What are buried vias?

Buried vias are holes located inside the PCB that do not penetrate any side of the board. They are completely hidden inside the board and are used to connect circuits between different internal layers. Buried vias are especially useful in HDI boards because they can reduce the overall thickness of the board while maintaining electrical connections between internal circuits.

What is a microvia?

Microvia refers to a hole with a smaller diameter, usually at the micron level. The emergence of microvia technology enables PCB designers to achieve more complex circuit layouts in a smaller space. Microvias are often used in high-density, high-reliability electronic devices such as mobile phones and tablets. The manufacture of microvias requires high-precision drilling equipment and technology to ensure the accuracy and reliability of the holes.

What are Mounting holes？

What are Mounting holes?Locking holes are auxiliary holes used in the PCB manufacturing and assembly process to accurately locate and fix the circuit board. They are usually located at the edge or specific position of the PCB to ensure that the circuit board can be accurately aligned and fixed during manufacturing, testing and assembly. The locating holes do not participate in the connection of the circuit, but are essential to ensure the quality and performance of the circuit board.

What are Mounting holes？

What are thermal vias?

Thermal vias are holes designed specifically for heat dissipation, usually large and can run through the entire PCB or multiple layers. Their role is to reduce heat buildup on the circuit board by increasing surface area and air flow, thereby improving the stability and reliability of the device. Thermal vias are particularly important in high-performance, high-power electronic devices.

FAQ About board electronics with holes

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 routing method and the number of vias. The routing 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 capabilities of the routing engine. For example, the pushing ability of the routing, the pushing ability of the via, and even the pushing ability of the routing pair copper. Therefore, choosing a routing tool with strong routing engine capabilities is the solution.

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

As for whether it will affect the signal quality, it depends on the method of adding test points and how fast the signal is. Basically, the additional test points (not using the existing vias (via or DIP pins) as test points) may be added to the line or a small section of wire may be pulled out from the line. The former is equivalent to adding a very small capacitor to the line, while the latter is an additional branch. Both of these situations will have some impact on high-speed signals, and the extent of the impact is related to the frequency speed of the signal and the edge rate of the signal. The magnitude of the impact can be learned 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.

Can you introduce some foreign technical books and data on high-speed PCB design?

Now the application of high-speed digital circuits includes communication networks and calculators and other related fields. In the communication network, the operating frequency of PCB boards has reached around GHz, and the number of layers is as many as 40 layers as far as I know. Due to the advancement of chips, the operating frequency of calculator-related applications, whether it is a general PC or server, has reached 400MHz (such as Rambus) or above. In response to the demand for high-speed and high-density routing, the demand for blind/buried vias, mircrovias and build-up process technology is gradually increasing. These design requirements can be mass-produced by manufacturers.

Does the design of rigid-flexible boards require special design software and specifications? Where can I undertake the processing of such circuit boards in China?

Can I use general PCB design software to design flexible printed circuits (Flexible Printed Circuit). The Gerber format is also used for FPC manufacturers to produce. Since the manufacturing process is different from that of general PCBs, each manufacturer will have its own restrictions on line width, line spacing, and aperture (via) based on their manufacturing capabilities. In addition, some copper foil can be laid at the turning point of the flexible circuit board for reinforcement. As for the manufacturer, you can search for “FPC” as a keyword on the Internet and you should be able to find it.

If the size of the circuit board is fixed, if the design needs to accommodate more functions, it is often necessary to increase the routing density of the PCB, but this may lead to increased mutual interference between the routings, and at the same time, the impedance cannot be reduced if the routing is too thin. Please introduce the techniques in the design of high-speed (>100MHz) high-density PCBs?

When designing high-speed and high-density PCBs, crosstalk interference does need to be paid special attention to because it has a great impact on timing and signal integrity. Here are a few things to note:

Control the continuity and matching of the characteristic impedance of the trace.

The size of the trace spacing. The spacing commonly seen is twice the line width. Through simulation, you can know the impact of trace spacing on timing and signal integrity and find the tolerable spacing. The results of different chip signals may be different.

Choose an appropriate termination method.

Avoid the same routing direction of the upper and lower adjacent layers, or even have traces overlapped up and down, because this kind of crosstalk is greater than the case of adjacent traces on the same layer.

Use blind/buried vias to increase the trace area. However, the production cost of the PCB board will increase. It is indeed difficult to achieve complete parallelism and equal length in actual implementation, but it should be done as much as possible.

In addition, differential termination and common mode termination can be reserved to mitigate the impact on timing and signal integrity.

The RF part, IF part, and even the low-frequency circuit part of the outdoor unit are often deployed on the same PCB. What are the material requirements for such PCB? How to prevent interference between RF, IF, and even low-frequency circuits?

Hybrid circuit design is a big problem. It is difficult to have a perfect solution.

Generally, RF circuits are laid out and wired as an independent single board in the system, and there will even be a special shielding cavity. Moreover, RF circuits are generally single-sided or double-sided boards, and the circuits are relatively simple. All of these are to reduce the impact on the distributed parameters of RF circuits and improve the consistency of RF systems. Compared with general FR4 materials, RF circuit boards tend to use high-Q substrates. The dielectric constant of this material is relatively small, the distributed capacitance of the transmission line is small, the impedance is high, and the signal transmission delay is small. In hybrid circuit design, although RF and digital circuits are made on the same PCB, they are generally divided into RF circuit area and digital circuit area, and laid out and wired separately. Shielding is used between ground vias and shielding boxes.

What is High-Frequency PCBs?

What is High-Frequency PCBs? High frequency PCBs are specifically designed to operate at frequencies typically above 1GHz. These circuit boards play a crucial role in modern communication systems like satellite communications, radar, and wireless networks. The materials used in high-frequency PCBs are different from those in standard PCBs. While standard PCBs use FR4 material, high-frequency PCBs often require specialized materials like PTFE (Teflon) or Rogers material to reduce signal loss and improve overall performance.

The growing need for faster and more reliable communication across industries makes high-frequency PCBs essential for creating cutting-edge devices.

High Frequency PCB Materials

Click here to download Raw Materials of RF PCB.

Advantages of High Frequency PCB

Faster signal transmission

Better signal integrity

Enhanced thermal management

Low electromagnetic interference (EMI)

Application in emerging technologies

Improved precision in high-speed applications

What is the Frequency Limit for FR4 PCB?

FR4 is the most widely used material in standard PCBs due to its affordability and adequate performance for general applications. However, when it comes to high-frequency operations, FR4 has its limitations. The material can handle frequencies up to about 1GHz, but beyond this range, its performance starts to degrade significantly. High-frequency signals experience increased signal loss, dielectric losses, and electromagnetic interference (EMI) due to FR4’s higher dielectric constant (around 4.5) and poor thermal properties.

The limitations make FR4 unsuitable for more advanced applications like high-speed telecommunications, radar systems, and modern wireless technologies where signals operate in the gigahertz range. When designing PCBs that require frequencies beyond 1GHz, alternative materials like PTFE (Teflon) or Rogers laminates are recommended to maintain signal integrity and reduce losses.

How Do You Make High-Frequency PCB?

Creating a high-frequency PCB involves a few additional considerations compared to standard PCB designs. First, the choice of materials is critical. PTFE, Rogers, and other high-performance laminates are commonly used to ensure the PCB can handle high-frequency signals. Next, the board’s thickness, trace width, and layout need to be carefully calculated to avoid impedance issues. The key process including:

1. Material Selection

The first step is choosing materials that can handle high-frequency signals. Materials like PTFE, Rogers, or ceramic substrates are commonly used because they have lower dielectric constants, low dissipation factors, and better thermal stability. These materials ensure minimal signal degradation.

2. Controlled Impedance

High-frequency signals are sensitive to variations in impedance. Controlled impedance design ensures that the trace impedance matches the signal’s requirements, preventing reflection and signal distortion. This involves calculating the width and spacing of the traces and ensuring consistent dielectric properties across layers.

3. Multi-layer PCB

Multi-layer boards are often necessary for high-frequency applications to separate signals and reduce cross-talk. Ground planes are typically added to lower electromagnetic interference (EMI) and provide better signal grounding.

4. Short and Direct Signal Paths

Keeping signal paths as short as possible helps minimize signal loss and prevents unwanted interference. Traces that are too long or involve sharp bends can introduce delay and noise.

5. Shielding

In some cases, shielding techniques can be employed to prevent interference from other electronic components. This can include grounded planes, copper shields, or even encapsulating certain areas of the PCB.

High-frequency PCB design often requires sophisticated simulation tools. Software such as Ansys or Altium Designer helps predict how signals will behave on the board, allowing for adjustments to be made before fabrication.

What is the Highest RF Frequency?

In communication circuits, radio frequency (RF) bands cover a wide range of frequencies, typically starting from 20kHz up to 300GHz. The highest RF frequency currently used in commercial applications ranges from 100GHz to 300GHz, categorized as millimeter waves. These frequencies are essential for high-speed data transmission in technologies like 5G, radar systems, and advanced satellite communication. While developing PCBs that can efficiently handle such frequencies can be challenging, material innovations have made it possible.

What Are Some Important Considerations When Designing a PCB Layout for High-Frequency Circuits?

Designing a PCB for high-frequency circuits demands a careful approach to ensure signal integrity. The first thing to consider is the dielectric material. As previously mentioned, materials like Rogers or PTFE are preferred because they offer lower dielectric loss, which is crucial at higher frequencies. Trace layout is another critical factor. The length and width of the traces must be calculated to maintain impedance control, ensuring that signals don’t get distorted as they travel through the board.

1. Signal Integrity and Trace Layout

The layout of traces is a critical consideration in high-frequency PCB design. To maintain signal integrity, traces should be kept as short and straight as possible. Long traces can introduce delay, noise, and signal degradation. Additionally, sharp corners in trace routing should be avoided because they can lead to signal reflection and impedance discontinuities. Rounded or 45-degree bends are preferable to right-angle corners, which can cause unwanted signal interference.

2. Ground Planes and Layer Stack-Up

A solid, continuous ground plane is one of the most effective ways to reduce noise and EMI in high-frequency PCBs. Ground planes provide a low-impedance path for return currents and act as shields to prevent electromagnetic radiation from affecting other components. For multi-layer PCBs, having dedicated power and ground planes in the stack-up helps reduce noise and improves overall signal integrity.

3. Via Management

Vias introduce small inductances into the signal path, which can become problematic in high-frequency circuits. High-frequency signals are particularly sensitive to these inductances, and excessive use of vias can degrade signal quality. Designers should minimize the number of vias in high-frequency signal paths and use smaller, controlled-depth vias like microvias or buried vias to reduce parasitic effects.

4. Signal Isolation

High-frequency circuits often involve both analog and digital signals, and proper isolation between these signals is critical to prevent interference. Digital signals tend to generate high levels of noise, which can interfere with sensitive analog signals. To avoid this, analog and digital components should be physically separated on the PCB, with separate ground planes if possible.

5. Power Distribution and Decoupling

Stable power distribution is necessary to ensure that high-frequency components operate without interruptions. A decoupling capacitor should be placed near the power supply pins of each active component to filter out high-frequency noise and maintain a steady voltage. Multiple capacitors of different values (e.g., 0.1µF and 10µF) can be used in parallel to filter noise over a wide frequency range.

How Do You Avoid High-Frequency Interference in PCB?

Interference is a common issue in high-frequency PCBs, but it can be managed with the right design techniques. The most effective way to avoid high-frequency interference is by using a dedicated ground plane. This plane acts as a shield, helping to reduce EMI and cross-talk between different parts of the circuit. Shielding can also be applied to individual traces or components that are more susceptible to interference.

Ground Planes

A continuous ground plane is one of the most effective ways to reduce high-frequency interference. It acts as a shield and prevents unwanted noise from penetrating the circuit. The use of multiple ground planes in multi-layer PCBs can also provide better signal grounding.

Signal Layer Segregation

Isolating analog and digital signals helps to reduce interference between them. Analog signals are more susceptible to noise, so they should be kept separate from high-frequency digital signals.

Shorter Traces

Keeping traces short and direct minimizes the potential for signal loss or delay, and helps maintain signal integrity. The longer the trace, the more likely it is to pick up unwanted noise.

Minimize Via Usage

Excessive use of vias can create points of discontinuity in the signal path, leading to reflections and noise. If vias are necessary, they should be placed strategically and sparingly.

EMI Shielding

In some cases, it may be necessary to use EMI shields around particularly sensitive areas of the PCB.

Decoupling Capacitors

Adding decoupling capacitors between the power supply and ground helps to filter out high-frequency noise and maintain a clean signal.

What is the Difference Between High-Speed and High-Frequency PCB?

Though they may seem similar, high-speed and high-frequency PCBs serve different purposes. High-speed PCBs are designed to handle fast data transmission speeds, often used in applications like computing and networking. These PCBs focus on minimizing delay and ensuring signals reach their destination without distortion.

On the other hand, high-frequency PCBs are specifically optimized for circuits operating at high frequencies, often in communication systems. The emphasis here is on maintaining signal integrity across a wide frequency range. While both high-speed and high-frequency PCBs share common design principles, such as controlled impedance and signal integrity, the challenges they face differ. High-speed PCBs focus more on data transmission, while high-frequency PCBs deal with RF signals and the challenges of maintaining signal strength at higher frequencies.

How Do You Fix Frequency Interference?

If your PCB is experiencing frequency interference, there are several methods to fix the problem. One common approach is to improve grounding by using a continuous ground plane. This helps shield signals from external noise and interference. You can also add shielding to specific components or traces that are particularly susceptible to interference.

Adding filters at key points in your circuit can help block unwanted frequencies. For instance, a low-pass filter allows only low-frequency signals to pass through, blocking higher-frequency interference. You can also reduce trace lengths and maintain clean, direct paths for high-frequency signals. Finally, proper isolation of analog and digital circuits is crucial to prevent noise from leaking into sensitive areas.

What is Copper Pour in PCB Design?

Copper pour, also known as copper coating, refers to filled solid copper on PCB where without trace layout area or idle space. Instead of leaving unused areas bare, copper is poured over them, connecting it to the ground or other designated signals. The main purpose of this process is to reduce the ground impedance, improve the anti-interference ability, reduce the voltage drop. Thereby improving the power supply efficiency, and connect with the ground wire to reduce the loop area. By covering large sections of the board with copper, it also minimizes signal interference and adds a layer of protection to the PCB. Copper pour are essential for designers to maintain signal integrity and reduce unwanted noise.

What is Pour Board? What is Copper Pour in PCB?

The process of copper coating is not only very important for digital circuits, because it can effectively reduce the ground impedance, which is particularly important for digital circuits with a large number of spiking pulse currents. However, for analog circuits, the ground wire loop formed by laying copper may cause electromagnetic coupling interference.

Why Use Copper Pours on Circuit Boards?

Copper pours offer several advantages that make them an essential part of circuit board design. When creating PCBs, some engineers tend to leave many copper-free areas on the board. But a high percentage of copper-free areas on the PCB can negatively affect the product, making it vulnerable to early damage, when copper pouring comes in handy.

There are some novices who think that less copper pouring means that the cost will be lower and lower, which is wrong. It is true that the plating area is small, which can save copper, but there is no way to guarantee the quality, and the appropriate amount of copper pouring can improve the quality of the product.

When the PCB board is placed in the plating tank and the appropriate current is applied, the PCB will show the physical state after dry film coverage. After passing a current, the circuit lines exposed to the outside of the dry film will be plated with copper from the plating tank. The total area of the part of the circuit exposed outside the dry film will affect the value of the current distribution during the plating process, if the bare copper area is large, the current input is uniform, and the current received is more uniform. Therefore, a large area of copper plane must be laid in the design to prevent this from happening. If the total plating area of copper is too small or the pattern distribution is very uneven, the received current will not be uniform. In this way, when powered on, the greater the current, the thicker the copper plating layer (so designed, if only 1OZ is required, then the finished copper thickness can reach 2OZ).

If the gap between current traces is too small, for example about 3mil to 3.5mil, a “clip film” will form between the traces. In other words, the dry film is caught in the middle of the gap, which causes the subsequent base to start the copper in the middle, which can lead to a short circuit if the etching process is not cleaned. In order to maintain the high quality of PCB manufacturing, independent lines must be avoided as much as possible in PCB design and layout. In addition, it is recommended to use a large amount of copper on the entire PCB, if there is a separate line that cannot be covered with copper, then the continuation between the lines must be as wide as possible.

Advantages of Copper Pour Board

1. For EMC (electromagnetic compatibility) requirements, a large area of ground or power supply needs to be covered with copper, which will play a shielding role. For some special area, such as protective ground, it plays a protective role.

2. From PCB manufacturing perspective, generally in order to ensure an uniform copper plating, or avoid lamination deformation and bending, manufacturers always pour copper for those less trace layout PCB board.

3. For signal integrity PCB, pour copper gives the high-frequency digital signal a complete return path, and reduce the wiring of the DC network. In another way, pour copper can help to heat dissipation.

Disadvantages of Copper Pour

1. If the pins of the components are fully covered with copper, the heat dissipation may be too fast, resulting in difficulties in dismantling and repairing the components. Therefore, sometimes in order to avoid this situation, cross connections are used for components (pin contact and pad contact are shown in “+”).

2. Pouring copper in the area around the antenna is easy to cause weak signal, interfered acquisition signal, and the impedance of copper will affect the performance of the amplifier circuit. So the area around the antenna section is usually not covered with copper.

Copper Pour vs Ground Plane

There’s often confusion between copper pours and ground planes. While both serve similar purposes, they are not the same. A ground plane is a layer dedicated entirely to the ground signal, covering the entire surface of a board layer. It ensures a low-impedance path for electrical signals, minimizing interference.

Copper pours, on the other hand, are not necessarily tied to the ground. Designers can connect copper pours to any net, including power lines or signal traces. The primary goal of a copper pour is to fill in empty spaces, whereas a ground plane is dedicated exclusively to providing a ground connection.

Implementation of PCB Copper Pours

When designing a PCB with copper pours, a few best practices help in optimizing its performance. Here are some useful tips:

Assign Copper Pours to Ground First

When designing, prioritize assigning continuous copper to ground layers over power planes. A solid ground plane improves overall performance, providing a reliable reference for signals and reducing noise. Every PCB should have strong, consistent ground connections.

Monitor Trace Currents

Although reducing inductance is advantageous, flooding the board with copper can sometimes interfere with circuit tuning. Be mindful of traced paths, especially in high-current areas, to maintain proper load control.

Maintain Symmetry in Copper Pours

Ensure copper pours are symmetrical on both sides of the PCB. This balance helps prevent issues like board warping due to uneven expansion or moisture absorption. Symmetrical copper distribution is essential for the board’s structural integrity.

Avoid Acute Angles

Keep copper pours free from long, narrow protrusions or angles sharper than 45 degrees. Such shapes can become weak points, breaking off or acting as antennas during vibration or shock, potentially causing functional failures.

Incorporate Relief Features

Adding slots, anti-pads, and thermal spokes can relieve stress caused by material expansion, especially for large copper pours used on power planes. These features ensure mechanical stability and ease soldering.

Carefully Review Design Masks

Automated copper pour shapes may need manual adjustments to remove artifacts or undesirable patterns around complex components. Always review and fine-tune these masks to achieve optimal results.

When copper pours are correctly connected to appropriate nets, designers can enhance both the electrical and physical properties of the circuit by distributing copper strategically across the board.

Copper Pour Clearances and Settings

When designing a PCB with copper pours, clearances and settings play a crucial role in ensuring proper functionality and avoiding issues like short circuits. Here are PCB copper pour suggestions based on standard PCB board:

1. Trace to Copper Pour Clearance

Standard clearance: 0.2 mm (200 µm) or 8 mils
High-voltage applications: 1 mm (1000 µm) or 40 mils (or more, depending on voltage levels)

2. Pad to Copper Pour Clearance

SMD pads: 0.2 mm to 0.3 mm (8-12 mils)
Through-hole pads: 0.3 mm to 0.5 mm (12-20 mils)

You can adjust these values based on the pad size and the net to which the copper pour is connected.

3. Copper Pour Width and Thickness

The width and thickness of the copper pour should be chosen based on the current-carrying capacity of the board:

Minimum width: 1.5 mm (60 mils) for low-current signals
Power lines: At least 2-3 mm (80-120 mils), depending on current
Copper thickness: 35 µm (1 oz/ft²) is standard, but for higher currents, you can use thicker copper like 70 µm (2 oz/ft²) or more.

4. Via Clearance in Copper Pours

Standard via clearance: 0.2 mm (8 mils)
High-current via clearance: 0.5 mm (20 mils)

Clearance should be adapted to the board’s layer stack-up and current needs.

5. Thermal Relief Spokes

Spoke width: 0.3 mm to 0.5 mm (12-20 mils)
Spoke count: Typically 4 thermal relief spokes per pad
Clearance to pad center: 0.5 mm (20 mils)

6. Copper Pour to Board Edge Clearance

Standard clearance: 0.5 mm (20 mils) from the board edge
High-voltage boards: 1 mm (40 mils) or more

Layer Placement of Copper Pours

Copper pours can be placed on any layer of a PCB. In multi-layer PCBs, copper pours are often added on internal layers to maximize performance. For example, ground and power pours are frequently found on internal layers to reduce noise and improve thermal dissipation.

On outer layers, copper pours serve to enhance thermal management. They distribute heat from high-power components and help maintain an even temperature across the board. It’s important to balance the placement of copper pours with other components to ensure overall board stability and functionality.

Copper Pour PCB Design Considerations

1. The open areas in the design must be minimized and the open Spaces filled with copper.

2. It’s important to assess the current-carrying capacity. Make sure the copper pour is thick enough to handle the expected current loads, especially in power applications.

3. If there is no room for the copper, the two wires, the two pads, and the distance between the wires and the pads are designed to be 2 ounces thick with a minimum spacing of 8 mil.

4. When pouring copper, keep a certain distance from the ordinary touch pad. The distance between the track, the common plane and the drilled area should be greater than 0.5 mm. The copper must be poured as firmly as possible. Avoid pouring copper on small grids.

5. The inner layer of the gold finger must be all poured copper to avoid thinning of the board at the gold finger. Avoid choosing laminated structures with thin plates.

6. Those thin long, poorly grounded ground copper will have an antenna effect, which will cause poor EMC problems. Therefore, we should try to avoid causing broken copper when coating copper, such as causing broken copper can be removed.

7. Isolated (dead zone) copper problem, isolated copper if relatively small equivalent to broken copper can be deleted. If it is large, it can be defined as a place to add through the hole treatment, at this time there is no isolated copper.

8. Refer to the product design manual and apply copper coating near the antenna. Any interference or interference with the antenna must be avoided when pouring fake copper.

Why Use Ceramic PCB?

Ceramic PCB shows remarkable advantages in many application fields because of its unique physical and chemical properties. ‌

First of all, ceramic PCBs have excellent heat dissipation performance and low thermal expansion coefficient, which enables them to maintain stable performance in high temperature environment and effectively avoid equipment damage or performance degradation caused by temperature changes. Secondly, ceramic PCB has excellent insulation performance and high voltage resistance, which can guarantee personal safety and stable operation of equipment. In addition, the ceramic PCB has strong adhesion, and the bonding technology is adopted to ensure that the copper foil will not fall off, which improves the reliability of the product, especially in the application of high-frequency circuits. ‌

Ceramic PCB: What is it & Why should we use it?

The manufacturing process of ceramic PCB also has its own uniqueness. Usually, the bottom plate is formed by pressing ceramic powder, which ensures the flatness and surface smoothness of PCB, thus improving the quality of circuit board. Although the cost of ceramic PCB is usually higher than that of traditional materials such as FR-4, it is undoubtedly a better choice in applications requiring high performance and high reliability. ‌

To sum up, ceramic PCB is widely used in high-power power electronic modules, solar panel components, high-frequency switching power supplies, solid-state relays, automotive electronics, aerospace, military electronic products, high-power LED lighting products, communication antennas and other fields because of its excellent physical and chemical properties and high stability in high-frequency circuit applications.

What Are the Basic Components of Ceramic PCB?

The first is highly integrated circuit board, which has become an inevitable trend with the progress of electronic technology. Modern technology and electronic products integrate hundreds, thousands or even millions of transistors and resistors on a small silicon chip or integrated circuit (commonly known as IC) to form complex components.

These integrated circuits need a foundation for building tiny electronic materials and connections, usually called substrates. It also needs a structure to isolate the circuit from the external environment and turn it into a compact and solid unit, which is called packaging.

Integrated circuits need substrates and packages to maintain their reliability. Integrated circuits need insulating materials, and these two materials are born for this purpose. These packages will then be mounted on the printed circuit board.

Ceramics are famous for their insulating properties. The protective performance of this advanced ceramic material is an important factor for its use as substrate and packaging. This is why ceramic printed circuit boards or PCBs stand out from other similar products.

What are the Materials Used in Ceramic Circuit Board?

There are many kinds of materials for making ceramic PCB. When choosing ceramic materials, two basic characteristics that should be paid attention to are thermal conductivity and thermal expansion coefficient (CTE) of PCB.

Alumina (Al2O3), aluminum nitride (AlN), beryllium oxide (BeO), silicon carbide (SiC) and boron nitride (BN) are commonly used materials in ceramic PCB.

Alumina (Al2O3)

Alumina is an inorganic compound, also known as bauxite. It is an advanced material made of aluminum and oxygen. It is usually white, but it varies according to purity. The color can be pink to almost brown. This compound is tasteless and crystalline powder, but it is insoluble in water.

Among all oxide ceramics, alumina is the hardest and strongest. Because the content of alumina is higher than 95%, it is an excellent electrical insulator with a resistivity as high as about 1× 1014 Ω cm. Common purity ranges from 94% to 99%. The required color, hardness, size and shape should be easy to achieve. Because the composition can be changed, it is considered to be beneficial to engineering production.

This industrial oxide ceramic has excellent thermal stability and corrosion stability, excellent mechanical strength and dielectric strength, and can even form an airtight seal. The common 96% alumina has a thermal conductivity of 25.0 W/(m k) and a CTE of 4.5 to 10.9 x 10-6/k.. Besides being affordable and cost-effective, it has all these advantages.

It is the most commonly used substance in ceramics because it has many applications in the electronic field, including substrates and packaging. This is the preferred material when the application does not require the highest level of thermal performance. It is one of the most advanced ceramic materials with the most in-depth research and comprehensive characteristics.

Aluminum nitride (AIN)

Aluminum nitride (AIN) is a non-oxide semiconductor technology-grade ceramic material. The structure of this compound is hexagonal crystal, which is blue and white in pure state. Aluminum nitride is a synthetic ceramic compound, which is usually white or gray.

One of the best ceramic substrate materials at present is aluminum nitride (AlN). Its resistivity ranges from 10 to 1210ω-m, and its thermal conductivity is 80 to 200W/(m k), even as high as 300W/(m k). Based on these characteristics, it is undoubtedly one of the most attractive PCB substrate materials and one of the best choices.

It has electrical insulation and a low coefficient of thermal expansion (CTE) of 4 to 6× 10-6k1 (between 20 and 1000°C), which is very close to the silicon wafer. The value of this compound is much higher than that of alumina, but the cost is also higher. It is most suitable for use in high current and high temperature environment.

Beryllium oxide (BeO)

Beryllium oxide (BeO) or Beryllium oxide is also called dextran or glucose oxide in history. As the name implies, it comes from beryl or mineral beryl. It is a solid crystalline inorganic compound with white color.

In addition to good electrical insulation, its thermal conductivity is higher than that of any other nonmetal [(209 to 330 W/(m k)], and even exceeds that of some metals except diamond. There are rigid bonds between the atoms of beryllium oxide, just like diamonds. It transfers heat in the form of vibration through these strong bonds, so the energy loss is minimal.

This refractory compound has a melting point of 2506.85 °C to 2575 °C, a boiling point of 3905 °C and a CTE of 7.4 to 8.9 x 10-6/k. Beryllium oxide has these excellent characteristics, so it is widely used in electronic industry and is a valuable resource. Because of its high melting point, excellent thermal conductivity and good resistance, other industries also benefit from it.

Beryllium oxide has shown excellent chemical and thermal stability in challenging conditions and harsh environments for more than 60 years. BeO can be used to provide air or liquid cooling in applications where PCB is exposed to high temperature or high-density PCB with limited space. ‌

What are the Advantages of Ceramic PCB over Traditional PCB?

The use of ceramic printed circuit boards has several advantages, which help to significantly reduce the size and weight of the final product while improving energy efficiency. High quality surface smoothness (due to its flatness), high temperature resistance and low dielectric constant are their other significant advantages. In addition, ceramic plates are durable and wear-resistant, which means that they can be used in areas with high mechanical stress.

Because ceramic substrates are cleaner than FR-4 boards, ceramic PCBs can accommodate high component density on a single circuit board, which means that they can accommodate smaller components while still maintaining the same mass and occupying space.

The high temperature resistance of ceramic board is several times higher than that of FR4, and the thermal deformation temperature of ceramic board is much higher than that of traditional FR4, which makes the circuit board have better performance under extreme temperature conditions, thus prolonging the service life of the circuit board.

Ceramic PCB is more resistant to moisture in the air than FR4 board.

Ceramic PCB is made of ceramics, which is more durable and stronger than traditional FR4.

Ceramic board has higher density than traditional PCB, which can ensure high signal integrity. In addition, these boards are faster and more reliable than traditional boards.

Ceramic boards have high thermal resistance due to low thermal conductivity, so ceramic PCB has another advantage of fire prevention, which can make them a good choice for products that need to meet certain flammability and heat resistance criteria. Because a thin layer of ceramic fiber on the surface of PCBA can prevent heat from flowing into the circuit board, and at the same time, it can protect the conductive traces from cracking when exposed to excessive heat.

What are the Application of Ceramic PCB?

1. High power device

2. On-board chip module

3. Proximity sensor

4. Solid State Relay (SSR)

5. Solar panel array

6. Transmission/reception module

7. Multilayer Interconnect Board

8. Solar cells

9. Light emitting diodes

10. Automobile lighting system

As a high-performance electronic component, ceramic PCB‌ is playing a vital role in many fields because of its unique characteristics. This kind of printed circuit board is becoming more and more popular for various reasons. The most important factor to consider when choosing a PCB manufacturer is quality and experience. Through meticulous manufacturing technology and firm commitment to quality, BEST Technology strives to provide ceramic PCBs that can stand the test of time and meet the needs of the continuous development of modern technology. Contact us for more information!

What is Thermal-Electric Separation Copper Substrate with Flexible PCB?

The Thermal-Electric Separation Copper Substrate with Flexible PCB is a composite material that combines a rigid thermal-electric separation copper substrate with a flexible circuit board. It integrates the advantages of both, providing superior performance in high-power and high-density applications.

1. Thermal-Electric Separation Copper Substrate

The thermal-electric separation copper substrate is designed for high-power electronic devices, providing an efficient heat dissipation solution. It separates the paths of heat and electrical signals to avoid thermal interference with electrical performance. Its structure typically includes:

Single-sided design: Electronic components are placed on one side of the copper substrate, while the other side is used for heat dissipation.
High thermal conductivity materials: Such as copper or aluminum, which can quickly conduct heat, like copper is 400W/m.k, aluminum is 237W/m.k.
Thermal vias: Vertical heat conduction paths that rapidly transfer heat to the dissipation layer.

2. Flexible PCB (FPC)

Flexible PCBs (Flexible Printed Circuits, FPC) use flexible materials like polyimide (PI) or polyester (PET) that can bend and fold to adapt to complex three-dimensional structures and dynamic application scenarios. Their advantages include:

Lightweight: Reducing the overall weight of the device.
High-density wiring: Achieving complex circuit designs in limited space.
Flexibility: Meeting diverse design needs.

Structure and Characteristics

The structure of the Thermal-Electric Separation Copper Substrate with Flexible PCB includes rigid and flexible parts, connected together using conductive adhesives or other bonding materials to form a unified whole.

1. Rigid Part

The rigid part uses the thermal-electric separation copper substrate, responsible for efficient heat dissipation and mechanical support. This part usually carries high-power components to ensure rapid heat transfer and dissipation.

2. Flexible Part

The flexible part uses the flexible PCB, which can bend and fold to fit the complex internal structure of devices. This part is typically used to connect the rigid part with other modules that require flexible connections.

3. Bonding Method

The flexible and rigid parts are bonded together using conductive adhesives, welding, or mechanical connections. The design of the bonding area ensures stable electrical connections and reliability during bending and dynamic use.

Thermal-Electric Separation Copper Substrate with Flexible PCB Advantages

1. Efficient Heat Dissipation

The thermal-electric separation copper substrate provides excellent heat dissipation, effectively conducting away the heat generated by high-power components to maintain a reasonable operating temperature range. This is especially important for applications like high-power LEDs and power semiconductor devices.

2. Flexibility

The use of the flexible PCB offers great design freedom, allowing adaptation to the complex three-dimensional structures and dynamic application needs within devices. This enables designers to achieve more complex circuit designs in limited spaces, increasing device integration and functionality.

3. Reliability

The thermal-electric separation design and high thermal conductivity materials enhance the reliability of the circuit board, reducing the impact of heat on electrical performance. The flexible part reduces the number of connection points, lowering the risk of failure.

4. Space Saving

Combining the advantages of rigid and flexible circuit boards allows for efficient heat dissipation and complex circuit in limited space. This is crucial for modern miniaturized and high-density electronic product designs.

Where Thermal-Electric Separation Copper Substrate with Flexible PCB used?

1. High-Power LED Lighting

High-power LEDs generate a significant amount of heat during operation. The thermal-electric separation copper substrate provides an efficient heat dissipation solution, ensuring the stable operation and long lifespan of LEDs. The flexible part is used to connect different LED modules, accommodating diverse design requirements.

2. Automotive Electronics

In automotive electronics, such as in-vehicle cameras and sensor modules, efficient heat dissipation and compact design are required. The thermal-electric separation copper substrate with flexible PCB can meet these demands, enhancing device reliability and performance.

3. Consumer Electronics

Devices like smartphones and tablets require lightweight and miniaturized designs. The thermal-electric separation copper substrate with flexible PCB offers efficient heat dissipation and flexible circuit, optimizing device performance and user experience.

4. Medical Devices

In applications that require flexibility and reliability, such as portable diagnostic equipment and implantable medical devices, the thermal-electric separation copper substrate with flexible PCB can help to enhancing device performance and reliability.

How does Thermal-Electric Separation Copper Substrate with Flexible PCB manufactured?

The manufacturing process for the thermal-electric separation copper substrate with flexible PCB is complex, typically including the following steps:

Material Preparation: Selecting appropriate rigid and flexible materials and performing pre-treatment.
Circuit Printing: Printing circuit patterns on both rigid and flexible materials.
Lamination and Bonding: Combining the flexible circuit board with the thermal-electric separation copper substrate, usually using conductive adhesives or other bonding materials.
Drilling and Plating: Drilling holes and electroplating to form conductive paths on the combined board.
Surface Treatment: Performing surface treatments such as pad coating on the circuit board.
Testing and Inspection: Conducting electrical and mechanical performance tests to ensure the quality and reliability of the board.

The thermal-electric separation copper substrate with flexible PCB, as an innovative composite circuit board, combines the advantages of efficient heat dissipation and flexible wiring. It is widely used in high-performance and complex design electronic products. With continuous technological advancements and growing market demand, this composite circuit board will play an important role in more fields, driving the ongoing innovation of electronic manufacturing technology. Want know more about it, just feel your free to contact us.

What is a thick film ceramic circuit board used for?

Thick film ceramic circuit board is a kind of circuit board made by thick film technology, which is widely used, mainly for electrical connection, component mounting and surface modification.

What are thick and thin film ceramic circuit boards used for?

Electrical connection

Thick film circuit board can effectively connect all parts of the circuit to ensure the smooth transmission of current.

Component mounting

It can bear and fix electronic components, and ensure the correct position and stable operation of components in the circuit.

Surface modification

Through thick film technology, the surface of the circuit board can be modified to improve its electrical performance and durability. ‌

In addition, the thick film ceramic circuit board has some specific advantages, such as its manufacturing method allows it to be manufactured independently without using a substrate, and its thickness is usually between 10 and 25 μ m. This technology can be manufactured independently without using a substrate, which provides greater design flexibility. However, there may be some limitations in the accuracy of thick-film ceramic circuit boards. For example, in the process of using screen printing technology, the line width and accuracy may be insufficient due to the problems of screen printing, which may gradually lose the accuracy advantage for heat sinks with smaller and smaller size requirements in the future.

What is a thin film ceramic circuit board used for?

Thin film ceramic circuit boards are mainly used in module components of microwave circuits, including thin film load, thin film equalizer, thin film power divider, thin film attenuator, thin film coupler and thin film bridge. ‌

1. Thin film load is often used to match the terminals of module components of microwave circuits to absorb redundant incident power. It is designed with alumina ceramic substrate, which has the advantage of high precision machining.

2. Thin-film equalizer is used to adjust the broadband power flatness of microwave circuits. By changing the square resistance of the integrated tantalum nitride film and designing different resistance values, the output waveform of the device is adjusted to achieve the balance of power signals.

3. Thin film power divider is used in multi-channel communication network system, which distributes power according to a certain proportion, and one input can be multi-output, thus avoiding the problem of unstable patch resistance welding of microstrip power divider.

4. Thin film attenuator is used for large signal attenuation or multi-gear adjustment attenuation value in microwave RF module, which realizes high attenuation value flatness of ultra-wideband and stable performance.

5. Thin-film couplers are used for power detection or signal separation, and can be designed as couplers with any weak coupling degree. tantalum nitride design is used to integrate isolated loads, which is suitable for broadband applications.

6. As a part of microwave module, thin film bridge is used for specific circuit connection and signal processing. ‌

According to these applications, we can better understand the wide application and advantages of thin-film ceramic circuit boards in the fields of high frequency, high power and high integration.

What are the advantages of thick film over thin film ceramic PCB?

Thick film ceramic circuit boards have higher mechanical strength and thermal conductivity than thin film ceramic circuit boards, and are more suitable for power electronics, automotive electronics and other occasions that require higher thermal management and mechanical strength. ‌

The main difference between thick-film ceramic circuit board and thin-film ceramic circuit board lies in their film thickness and manufacturing process. The thickness of thick film circuit board is generally greater than 10μm, while that of thin film circuit board is mostly less than 1μ m.. Thick film circuit board usually adopts screen printing process, while thin film circuit board adopts vacuum evaporation, magnetron sputtering and other process methods.

This difference in technology leads to their differences in performance and application fields. Specifically, the advantages of thick film ceramic circuit boards are mainly reflected in the following aspects:

Reliable performance

Thick film circuits are flexible in design, low in investment and cost, and are mostly used in high voltage, high current and high power occasions.

High mechanical strength

Due to the use of thick film materials, thick film ceramic circuit boards have high mechanical strength and can withstand greater physical pressure and impact.

Good thermal conductivity

Thick-film ceramic circuit boards have good thermal conductivity, which is conducive to rapid heat dissipation, and is particularly important for electronic equipment that needs good thermal management. ‌

Therefore, thick film ceramic circuit boards are more suitable for applications that require high mechanical strength and good thermal conductivity, such as power electronics, automotive electronics and other fields.

What is the difference between thick film and ceramic resistors?

There are some differences between film resistance and ceramic resistance in materials, manufacturing technology, size and shape, electrical properties and application scenarios. ‌

1. Materials and manufacturing process: Thick film resistors are usually made by screen printing process and spraying or sputtering on the circuit substrate. The commonly used substrate materials are ceramics, glass and so on. The ceramic resistor is a resistance device made of ceramic material, which is fired in a ceramic kiln. ‌

2. Size and shape: Thick film resistors are usually flat, can be made into various sizes and shapes, and are suitable for assembly on circuit boards. Ceramic resistors are usually cylindrical and have a fixed size and shape. ‌

3. Electrical performance: Thick film resistor has high resistance accuracy and stability, and small temperature coefficient. Ceramic resistors have larger power carrying capacity and higher withstand voltage. ‌

4. Application scenario: Thick film resistor is suitable for high-precision circuits because of its large resistance range and good temperature stability. Ceramic resistors are suitable for general circuits and small electronic devices because of their small size and general electrical properties. ‌

From this, we can know that thick film resistors and ceramic resistors are different in materials, manufacturing processes, sizes and shapes, electrical properties and application scenarios, which make them suitable for different electronic equipment and circuit design requirements.

‌‌Thick film technology and thin film technology have certain substitutability in some fields, but thick film technology has irreplaceable role in the manufacturing and related processes of many products due to its advantages in cost, reliability, high temperature performance, etc., especially in multi-layer co-sintering processes such as LTCC and HTCC, where thin film technology cannot be applied. As a professional ceramic substrate manufacturer, Best Technology is committed to providing customers with high-quality thick film and thin film ceramic substrates to meet the needs of different applications.‌‌

What is a PCB Board?

A printed circuit board (PCB) is an electronic that uses metal conductors to create electrical connections between components. Generally, a PCB is a flat, laminated composite made of non-conductive substrate materials with conductive pathways etched or printed onto it. These pathways, also known as traces, enable the electronic components mounted on the board to communicate with each other.

PCBs are designed to support and electrically connect various components such as resistors, capacitors, diodes, and integrated circuits. The intricate network of copper tracks forms circuits that dictate the device’s functionality. PCBs can range from simple single-sided boards used in basic electronics to complex multi-layered structures found in advanced applications.

Common PCB Structure

A PCB’s structure is composed of several key layers, each serving a distinct purpose. Here is a detailed breakdown of these layers:

Substrate (Base Material)

The substrate, usually made of fiberglass (FR4), provides the board with its rigidity and thickness. It is the foundational layer upon which all other materials are built.

Copper Layer

This conductive layer is typically made of copper foil. For single-sided PCBs, the copper layer is only on one side of the substrate, whereas double-sided and multi-layer PCBs have copper layers on both sides or between multiple layers of substrate.

Solder Mask

The solder mask is a protective layer applied over the copper traces to prevent oxidation and accidental short-circuiting. It insulates the copper traces and leaves the component pads exposed for soldering. The green color commonly associated with PCBs comes from this layer, though it can also be found in other colors like red, blue, black, and white.

Silkscreen

The silkscreen layer is used to add labels, symbols, logos, and other markings to the PCB. This layer helps in identifying component locations and orientations during assembly and troubleshooting.

Components and Connectors (PCBA)

Components such as resistors, capacitors, diodes, and integrated circuits are soldered onto the PCB. Connectors allow the PCB to interface with other boards, power supplies, and external devices.

How Many Types of PCB?

Single-Sided PCBs

These are the simplest types of PCBs, with copper on only one side of the board. You’ll find them in basic, low-cost electronics like calculators, radios, and power supplies. They’re easy to design and manufacture, which keeps costs down and makes them great for straightforward applications.

Double-Sided PCBs

These boards have copper layers on both sides, allowing for more complex circuits. They’re common in more sophisticated electronics like amplifiers, power monitoring systems, and HVAC systems. With increased circuit density and flexible design options, they can handle more complex tasks.

Multi-Layer PCBs

When you need to pack in a lot of circuits, multi-layer PCBs are the way to go. They consist of three or more layers of copper, separated by insulating layers. You’ll see these in high-tech devices like computers, servers, medical equipment, and aerospace electronics. They offer high circuit density, reduced size and weight, and better signal integrity.

Rigid PCBs

Made from solid, inflexible materials like fiberglass, rigid PCBs keep their shape and provide strong support for components. They’re durable and used in everything from simple toys to complex industrial equipment.

Flexible PCBs

These are made from flexible plastic materials like polyimide, allowing them to bend and flex. Perfect for wearable electronics, flexible displays, and compact devices where space is tight. They’re lightweight, can fit into small, irregular spaces, and can handle being bent repeatedly.

Rigid-Flex PCBs

Combining the best of both rigid and flexible PCBs, these are great for devices that need both stability and flexibility, like smartphones, cameras, and medical devices. They save space, reduce the need for connectors and interconnections, and improve reliability.

High-Frequency PCBs

Designed to operate at frequencies above 1 GHz, these are used in communication systems, microwave technology, and high-speed devices. They provide low signal loss and high performance, making them crucial for advanced communication technologies.

Ceramic PCBs

Using ceramic as the substrate material, these PCBs offer excellent thermal conductivity and stability. They’re perfect for high-power applications and environments with extreme temperatures, like LED lighting, power electronics, and aerospace systems. Ceramic PCBs ensure reliable performance in harsh conditions.

Metal Core PCBs

Featuring a metal core, usually aluminum or copper, these PCBs improve heat dissipation. They’re used in high-power applications where efficient thermal management is crucial, such as LED lighting, power supplies, and automotive electronics.

Special PCBs

Bus Bar PCBs

These integrate bus bars for high-current applications, ensuring efficient power distribution and minimal voltage drop. They’re used in heavy-duty power supplies, electric vehicles, and industrial machinery. Bus bar PCBs provide robust and reliable connections for high-power systems.

Heavy Copper PCBs

With thicker copper layers, typically 3 ounces per square foot or more, these PCBs can handle higher currents and enhance thermal management. They’re used in power distribution, automotive, and industrial applications where durability and performance are critical. Heavy copper PCBs ensure reliable operation under high-stress conditions.

HDI (High-Density Interconnect) PCBs

These feature finer lines and spaces, smaller vias, and higher connection pad density. They’re used in advanced electronics like smartphones, tablets, and medical devices where space and performance are paramount. HDI PCBs enable miniaturization and improved electrical performance.

Extra Thin PCBs

Designed with minimal thickness, these PCBs are perfect for fitting into compact and lightweight devices. You’ll find them in flexible displays, wearables, and miniaturized electronic gadgets. Extra thin PCBs allow for innovative design solutions and space-saving configurations.

RF (Radio Frequency) PCBs

Optimized for high-frequency signals, these are used in communication devices, antennas, and microwave applications. They’re designed to minimize signal loss and interference, ensuring optimal performance in wireless communication systems.

High Tg PCBs

These have a high glass transition temperature, making them suitable for high-temperature environments. Used in automotive, aerospace, and industrial applications, high Tg PCBs maintain structural integrity and performance at elevated temperatures.

Impedance Control PCBs

These are designed to maintain consistent impedance for high-speed signal transmission. They’re used in communication devices, high-speed digital circuits, and advanced computing systems. Impedance control PCBs ensure signal integrity and reduce signal loss and reflection.

Why Are PCB Boards So Expensive?

Material Quality

High-grade materials like FR4 (fiberglass), ceramics, and high-quality copper foil are used to ensure durability and performance. These materials are essential for withstanding environmental stress and ensuring reliable operation, but they are expensive. For example, ceramic substrates can cost up to 10 times more than standard FR4 materials due to their superior thermal conductivity and electrical properties.

Complexity of Design

Multi-layer PCBs and advanced designs such as HDI (High-Density Interconnect) boards require complex manufacturing processes. The process involves precise alignment of layers and sophisticated techniques like laser drilling for micro-vias. The added complexity increases the production costs significantly. For instance, a standard 4-layer PCB might cost $50 per square meter, while a 12-layer HDI PCB could cost over $200 per square meter.

Precision and Technology

Manufacturing high-precision PCBs involves advanced machinery for etching, drilling, and plating. This machinery requires significant investment, and the skilled labor needed to operate it adds to the cost. The precision required in the production process ensures that the PCBs meet exacting standards, crucial for high-performance applications. A single advanced PCB drilling machine can cost upwards of $500,000.

Volume of Production

Smaller production runs generally have higher costs per unit because the setup and tooling expenses are spread over fewer units. For example, a low-volume production run of 10 PCBs might cost $100 per board, whereas a high-volume run of 10,000 boards might reduce the cost to $10 per board due to economies of scale.

Testing and Quality Assurance

Rigorous testing, including electrical, thermal, and functional tests, ensures that the PCBs meet strict performance standards. This testing process is vital to ensure reliability, especially in critical applications like medical devices and aerospace. Quality assurance processes can add 20-30% to the overall production cost, but they are essential for maintaining high standards.

What is the Difference Between PCBA and PCB Board?

The terms PCB and PCBA are often used interchangeably, but they refer to different stages of the board’s life cycle. The PCB is the bare board itself, with no electronic components attached. It consists of a non-conductive substrate, copper traces, solder mask, and silkscreen. A PCB serves as the foundation for assembling electronic components.

On the other hand, a PCBA (Printed Circuit Board Assembly) is a PCB that has undergone the assembly process, where all necessary electronic components like resistors, capacitors, diodes, and integrated circuits are soldered onto the board. Essentially, a PCBA is a functional circuit board ready for use in electronic devices. The transition from a PCB to a PCBA involves component placement, soldering, and quality testing, transforming the bare board into an operational assembly. Below is a typical PCBA product for your reference.

What is PCB Board Common Use?

PCB boards are existing in everywhere what we live, for example, the global smartphone market, which relies heavily on PCBs, was valued at approximately $520 billion in 2020. Here are some common applications that PCB used in:

Automotive Industry

In the automotive sector, PCBs are used in engine control units, infotainment systems, and advanced driver-assistance systems (ADAS). These applications enhance vehicle performance, safety, and connectivity.

Medical Devices

PCBs are integral to medical devices such as diagnostic equipment, patient monitoring systems, and implantable devices. They ensure precise and reliable operation, which is critical for patient safety and effective treatment.

Industrial Applications

PCBs are used in control systems, machinery, and power distribution units in industrial settings. They provide robust and durable solutions capable of withstanding harsh conditions and continuous operation.

Telecommunications

In telecommunications, PCBs are essential in routers, switches, and communication devices, ensuring efficient and reliable data transmission. As the demand for faster and more reliable communication networks grows, so does the need for high-quality PCBs.

Why Are Circuit Boards Green?

The characteristic green color of most PCBs comes from the solder mask, a protective layer applied over the copper traces to prevent oxidation, short-circuiting, and to protect the board during soldering.

The green color is traditional, largely due to historical reasons and practical benefits. Green solder mask provides a good contrast against the white silkscreen and the shiny copper traces, making it easier for technicians to inspect and identify components during assembly and troubleshooting. Additionally, green solder mask was one of the first colors to be developed and standardized in the industry, leading to its widespread adoption. However, PCBs are not limited to green; they can also be found in other colors such as red, blue, black, and white, depending on the specific requirements and aesthetic preferences of the project. The choice of solder mask color does not affect the performance of the PCB, but green remains popular due to its well-established manufacturing process and visual advantages.

How to Get Started with Best Technology?

Here at Best Technology, we are experienced in designing all types of PCBs, including standard rigid PCBs, special PCBs, and irregular PCBs. We can design and develop PCBs according to customer specification and offer suggestions on the right materials for your project.

We provide the full series of PCB manufacturing, from the initial PCB design, PCB layout, to custom PCB fabricate, PCB assembly, box building and so forth. By the way, we have our own factory in Vietnam, that means we can ship out the PCBs directly from Vietnam.

Welcome to contact us when you want to get a quote!

What Does Tg Mean in PCB Manufacturing?

Tg stands for glass transition temperature. It refers to the temperature at which a polymer material, such as the resin in a PCB substrate, transitions from a hard, glassy state to a softer, rubbery state.

For the circuit board, the ‌Tg value reflects the highest temperature it can withstand. When the temperature exceeds Tg values, ‌ the molecular structure of the circuit board material will be changed, ‌ lead to changes in its physical properties. Such as mechanical strength, size stability, adhesive, water imbibition, thermal expansion, etc. ‌Therefore, the level of TG value of the PCB directly affects the stability and high temperature resistance of the circuit board.

What is Tg meaning in FR4 PCB? - Best Technology

In the high temperature environment, if the TG value of the circuit board is too low, it is easy to cause PCB deformation, fracture, cracking and other problems, affecting the reliability and life of the printed circuit board. If the TG value of the circuit board is too high, the PCB is easy to become hard and brittle, affecting the processability and flexibility of the circuit board.

How is Tg Measured in FR4 Materials?

Accurate measurement of Tg is crucial for ensuring the performance and reliability of FR4 PCBs. Knowing the exact Tg helps in selecting the appropriate material for specific applications, particularly those involving high temperatures and thermal cycling. Using materials with a Tg well above the operating temperature ensures the PCB will maintain its mechanical and electrical properties under expected conditions.

The primary method for measuring Tg in FR4 materials is by differential scanning calorimetry (DSC). It involves heating a small sample of the material at a controlled rate, typically between 10°C to 20°C/min. As the sample heats, the DSC measures the heat flow into the material and records it as a thermogram. The Tg is identified as the temperature where there is a noticeable change in heat capacity, appearing as a step or inflection point on the thermogram. DSC is widely used because it provides precise and reliable Tg measurements.

Additionally, Dynamic Mechanical Analysis (DMA) and Thermomechanical Analysis (TMA) also can be used to measure the Tg value.

Why is Glass Transition Temperature Critical in PCBs?

Glass transition temperature is critical because it affects the thermal and mechanical properties of the PCB. If a PCB operates near or above its Tg, it can experience issues like delamination, warping, and electrical failure. Here are some benefits of Tg.

Thermal stability

One of the main reasons is its role in determining thermal stability. During operation, PCBs are subjected to varying temperatures due to power dissipation from electronic components and environmental conditions. Make sure the Tg of the PCB material is well above the maximum operating temperature, it helps maintain mechanical stability and reliable performance under thermal stress.

Mechanical Strength

The Tg value also affects the mechanical strength and durability of the PCB. Below the Tg, the material is rigid and can withstand mechanical stress without significant deformation. This rigidity is essential for maintaining the structural integrity of the PCB, especially during assembly processes like soldering, where the board is subjected to mechanical and thermal stresses.

Thermal Management

Thermal management is very important to electronics, especially for those miniaturized electronic devices. If the PCB itself has good thermal management, then designers no need to install heatsink or coolers. Materials with higher Tg values exhibit lower coefficients of thermal expansion (CTE), meaning less expansion and contraction with temperature changes.

Application-specific requirements

Different applications have varying thermal and mechanical requirements. High-performance computing, automotive, aerospace, and industrial electronics often operate in environments with high temperatures and thermal cycling. For these applications, using PCB materials with appropriate Tg values is crucial.

What is the Typical Tg Value for Standard FR4 PCBs?

Standard FR4 materials generally have Tg values in the range of 130°C to 140°C. For high-performance applications, materials with higher Tg values are necessary. The table below lists some common high Tg materials used in PCB manufacturing, along with their Tg values and characteristics.

Material	Tg Value (°C)	Characteristics	Applications
ISOLA IS410	180	Excellent thermal and mechanical properties	High-reliability applications
Nanya NP-175	175	High thermal stability, good mechanical strength	Automotive, industrial electronics
Shengyi S1000H	170	Cost-effective, widely used	Consumer electronics, industrial applications
Ventec VT-47	170	High Tg and low CTE	High-density interconnect (HDI) PCBs
Rogers 4350B	280	Extremely high Tg, excellent thermal stability	RF and microwave applications

(Common used high Tg materials)

Can You Explain the Difference Between Tg and Td in PCBs?

Tg and Td (decomposition temperature) are two different thermal properties. Unlike the reversible physical change associated with Tg, decomposition is an irreversible chemical process. At Td, the polymer chains in the material break down, leading to a loss of structural integrity and release of volatile compounds. Key points about Td include:

1. Chemical Stability

Td represents the upper thermal limit of a material’s chemical stability. Exceeding Td results in the breakdown of the polymer structure, rendering the material unsuitable for further use.

2. Material Selection

Knowing the Td helps in selecting materials for high-temperature applications. A material’s Td should be well above the maximum operating temperature to prevent degradation.

3. Safety and Reliability

Operating a PCB above its Td can result in catastrophic failure, including charring, delamination, and loss of electrical performance. The operating temperature remains below Td is critical for safety and reliability.

How Do You Choose the Right Tg Value for Your PCB Design?

Choosing the right Tg value depends on the operating environment and thermal demands of your application. Consider factors such as the maximum operating temperature, the thermal cycling the PCB will undergo, and the mechanical stresses it will face. Consulting with material suppliers and using simulation tools can help make an informed decision. According to our 18 years experience in PCB, we summarized a recommend Tg value for each application. Hope this is useful for you guys.

Consumer electronics

If your PCB will be used in standard consumer electronics, just like smartphones and tablets, a Tg value of around 130°C to 140°C is typically sufficient. These devices generally do not encounter extreme temperatures or thermal cycling.

Automotive applications

Automotive PCBs are always exposed to high temperatures and significant thermal cycling. A Tg value of 170°C or higher is recommended to ensure reliability and performance under the hood. So, Rogers material is good for this kind of PCB.

Aerospace and defense

Applications in aerospace and defense require materials that can withstand extreme temperatures and harsh environments. High Tg materials with values of 180°C or more are often used to meet these stringent requirements.

Industrial Electronics

Industrial environments can vary widely, but generally, high Tg materials are preferred due to the exposure to high temperatures and mechanical stress. A Tg value of at least 150°C to 170°C is advisable.

Best Technology is a well-known PCB and PCBA assembly provider in Asia and Vietnam. We have a large facility for handling low-medium to mass production PCBs, and supporting for various kinds of custom PCBs. Some special PCBs are available here, like bus bar PCB for new energy vehicles, heavy copper PCB for high power and high current PCBs, ceramic PCBs for harsh environments, extra thin PCB, RF PCB, microwaves PCB, IC substrate PCB and so on.

For more information, please do not hesitate to contact us.

Archive for the ‘Special PCB’ Category

What is Via in Pad?

What is Via-in-Pad Plating?

Is Via-in-Pad Expensive?

What Size is a Via-in-Pad?

What are the Drawbacks of Via in Pad?

Can You Put Vias Under Components?

Traditional Vias vs. Via-in-Pad Design

When to Use Via-in-Pad Design?

Guidelines for Via-in-Pad Design

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What is Wireless PCB?

Advantages of wireless PCB

Disadvantages of wireless PCB

Design Guidelines for Wireless PCBs

Wireless PCB Assembly Process

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What are the holes in a PCB called?

What is a through hole

What is a blind via?

What are buried vias?

What is a microvia?

What are Mounting holes？

What are thermal vias?

FAQ About board electronics with holes

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What is High-Frequency PCBs?

High Frequency PCB Materials

Advantages of High Frequency PCB

What is the Frequency Limit for FR4 PCB?

How Do You Make High-Frequency PCB?

What is the Highest RF Frequency?

What Are Some Important Considerations When Designing a PCB Layout for High-Frequency Circuits?

How Do You Avoid High-Frequency Interference in PCB?

What is the Difference Between High-Speed and High-Frequency PCB?

How Do You Fix Frequency Interference?

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What is Copper Pour in PCB Design?

Why Use Copper Pours on Circuit Boards?

Advantages of Copper Pour Board

Disadvantages of Copper Pour

Copper Pour vs Ground Plane

Implementation of PCB Copper Pours

Copper Pour Clearances and Settings

Layer Placement of Copper Pours

Copper Pour PCB Design Considerations

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Why Use Ceramic PCB?

What Are the Basic Components of Ceramic PCB?

What are the Materials Used in Ceramic Circuit Board?

What are the Advantages of Ceramic PCB over Traditional PCB?

What are the Application of Ceramic PCB?

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What is Thermal-Electric Separation Copper Substrate with Flexible PCB?

Structure and Characteristics

Thermal-Electric Separation Copper Substrate with Flexible PCB Advantages

Where Thermal-Electric Separation Copper Substrate with Flexible PCB used?

How does Thermal-Electric Separation Copper Substrate with Flexible PCB manufactured?

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What is a thick film ceramic circuit board used for?

What is a thin film ceramic circuit board used for?

What are the advantages of thick film over thin film ceramic PCB?

What is the difference between thick film and ceramic resistors?

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What is a PCB Board?

Common PCB Structure

How Many Types of PCB?

Special PCBs

Why Are PCB Boards So Expensive?

What is the Difference Between PCBA and PCB Board?

What is PCB Board Common Use?

Why Are Circuit Boards Green?

How to Get Started with Best Technology?

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What Does Tg Mean in PCB Manufacturing?

How is Tg Measured in FR4 Materials?

Why is Glass Transition Temperature Critical in PCBs?

What is the Typical Tg Value for Standard FR4 PCBs?

Can You Explain the Difference Between Tg and Td in PCBs?

How Do You Choose the Right Tg Value for Your PCB Design?