Laser direct imaging (LDI) technology is a process that uses lasers to expose images directly on photoresists, mainly used in the exposure process of PCB manufacturing processes. LDI is a widely used technology that can create a variety of images and is used in various industries, including electronics, automotive and medical industries.
What is laser direct imaging?
Laser direct imaging (LDI) is an advanced photolithography technology. It directly uses a laser beam to expose images on photoresists, eliminating the intermediate step of making photolithography masks in traditional photolithography technology.
In this process, the laser beam is precisely controlled according to the pre-set circuit pattern data. The laser emitted by the laser light source is processed by a series of optical components, such as beam expansion and focusing, and then the laser beam is guided by the scanning system to scan and expose the surface of the printed circuit board (PCB) coated with photoresist.
The photoresist responds to the laser energy, and according to the type of photoresist (positive or negative), the corresponding chemical changes occur in the laser irradiation area. This change will lay the foundation for subsequent development and other processes, thereby forming an accurate circuit pattern.
What is the principle of laser direct imaging?
The principle of laser direct imaging (LDI) is to expose the pattern directly on the substrate coated with photosensitive material through a computer-controlled laser beam.
Specifically, the workflow of LDI includes the following steps: First, the designed circuit pattern is converted into the image generation program of the spatial light modulator through computer-aided manufacturing (CAM) software. Then, the laser beam passes through the spatial light modulator, and the generated image is projected onto the substrate coated with photosensitive material through the optical imaging system to complete the pattern exposure. Compared with the traditional mask exposure process, LDI saves the film process in the exposure process and greatly improves the production efficiency.
The main advantages of LDI technology are its efficiency and precision. It directly uses a highly focused laser beam controlled by a computer to define the circuit pattern on the PCB copper layer covered with laser photoresist without the need for photographic tools, thus avoiding the film and printing defects in the traditional process.
In addition, LDI also optimizes the production environment, eliminates the influence of temperature and humidity on the product, and further improves the production quality and efficiency.
How does laser direct imaging (LDI) work?
Laser direct imaging (LDI) technology is a process that uses laser to directly expose and image on photoresist, and is mainly used in the exposure process in the PCB manufacturing process. Its working principle is as follows:
1. Design graphics: Design the circuit graphics to be produced through computer-aided design (CAD) software.
2. Generate images: Convert the designed circuit graphics into digital images and transmit them to the control system of the LDI equipment.
3. Laser scanning: The laser beam in the LDI equipment scans and exposes the photoresist according to the information of the digital image under the precise control of the control system.
4. Photochemical reaction: The photoresist undergoes a photochemical reaction under the irradiation of the laser, changing its solubility.
5. Development: The exposed photoresist is developed in the developer to remove the unexposed part of the photoresist, thereby forming a circuit pattern on the photoresist that is consistent with the design graphics.
6. Etching or electroplating: According to needs, the developed circuit board is etched or electroplated and other subsequent processes are performed to produce the actual circuit.
Compared with traditional exposure technology, LDI technology has higher resolution and precision, can produce finer circuit wiring and smaller line spacing, and also has higher production efficiency and flexibility.
What are the advantages of using laser direct imaging?
The main advantages of LDI (Laser Direct Image) technology include: eliminating the film process in the exposure process, saving time and cost for loading and unloading films, and reducing deviations caused by film expansion and contraction; directly imaging CAM data on PCB, eliminating CAM production process; high image resolution, fine wires can reach about 20um, suitable for fine wire production; improve PCB production yield.
The main problems of LDI technology include: high-precision lasers and optical systems are required, which increases the cost and complexity of the equipment; high environmental requirements, temperature and humidity need to be controlled to ensure imaging quality; high technical requirements for operators, and professional training is required to operate the equipment proficiently.
The advantages of LDI technology in the flexible board industry include: improving production efficiency, no need to make and replace physical masks, shortening production cycles and waiting time; high-precision imaging, capable of processing finer and more complex graphics, improving product yield and reliability; efficient use of materials, reducing material waste; environmental advantages, reducing the use of chemicals, and reducing environmental pollution.
What are the disadvantages of laser direct imaging?
The disadvantages of laser direct imaging (LDI) technology mainly include:
1. High equipment cost: LDI equipment is usually expensive and requires a large initial investment, which may be a burden for some small enterprises or projects.
2. High environmental requirements: LDI equipment needs to work in a specific environment, such as a dark room or a low-illuminance red light environment, which increases the requirements for the working environment.
3. Technical complexity: LDI technology involves multiple steps and complex process flows, with high technical requirements for operators, and long training costs and time.
4. High material cost: LDI requires the use of specific photoresists and laser diodes, which are expensive and increase production costs.
5. Speckle problem: After the laser beam is reflected or transmitted through a rough surface, it will form countless independent scattered sub-waves. These sub-waves are coherently superimposed during the spatial propagation process, forming random and irregularly distributed bright and dark spots in space, that is, speckle phenomenon, which may affect the imaging quality.
In summary, although LDI technology has the advantages of high precision and high efficiency, its disadvantages such as high equipment cost, complex technical requirements and speckle problem also need to be considered when using it.
When is laser direct imaging used?
Laser direct imaging LDI is mainly used in the exposure process in PCB manufacturing, especially when high precision and efficient production are required. This technology is particularly suitable for the production of fine-line and ultra-fine-line circuit boards, and can achieve the best imaging effect.
In addition, LDI technology is also widely used in the field of FPC soft boards, which can improve production efficiency and product quality, and support complex circuit structures and high-density layouts.
The advantages of laser direct imaging LDI technology include:
1. High precision: It can achieve high-resolution pattern exposure and improve product performance and reliability.
2. Efficient production: shorten the exposure process, speed up production and reduce costs.
3. Complex circuit structure: support the exposure of multi-layer FPC and meet the needs of high-density layout.
Laser direct imaging technology is a highly promising technology in the field of PCB manufacturing. It has many advantages in terms of precision, flexibility, production efficiency and cost-effectiveness, and plays an important role in PCB manufacturing in many fields such as high-end electronic products, automotive electronics, industrial control and communication equipment.
The thermal conductivity coefficient is a measure of how well a material conducts heat. It’s represented by the symbol k or λ, and it is measured in units of watts per meter-kelvin (W/m·K). It’s defined as the amount of heat that passes through a material 1 meter thick, with a temperature difference of 1 degree (K or °C) between its two sides, in one second, over an area of 1 square meter.
In general, the higher the thermal conductivity coefficient, the better the material is at transferring heat, so in some high power or power supply electronics, thermal conductivity value is important to transfer heat out. Materials with a high k value, like metals such as copper, allow heat to flow through them easily, which is why they are used in applications that require efficient heat dissipation. In contrast, materials with low thermal conductivity coefficients, such as insulators, are used to minimize heat transfer and preserve energy.
The thermal conductivity is only for the heat transfer form with thermal conductivity. When there are other forms of heat transfer, such as radiation, convection, mass transfer and other forms of heat transfer, the composite heat transfer relationship. The composite heat transfer relationship is often referred to as the apparent thermal conductivity, the dominant thermal conductivity, or the effective thermal transmissivity of material. In addition, the thermal conductivity is for homogeneous materials, in the actual situation, there are also porous, multi-layer, multi-structure, anisotropic materials, the thermal conductivity obtained by this material is actually a comprehensive thermal conductivity performance, also known as the average thermal conductivity.
According to Fourier’s law, the thermal conductivity is defined as
Where x is the direction of heat flow.
qx’’ is the heat flux in this direction in W/m2, and another is the temperature gradient in this direction, expressed in K/m.
For an isotropic material, the thermal conductivity is the same in all directions.
What Is the k Value of Copper?
The thermal conductivity of copper is about 401W/m.K. Copper is a transition element, pure copper is a soft metal, when it is cut on the surface, it is red-orange, and its ductility is good, thermal conductivity is relatively high, so it is a more commonly used material in cables and electronic components, can be used as building materials, and it is composed of many kinds of alloys.
Copper’s high k value meaning it can quickly absorb and distribute heat. That is why copper is used extensively in heat sinks, electrical wiring, and cooling systems. Because of this, it’s highly valued in industries that rely on rapid heat dissipation. Whether in electronics or heavy machinery, the high thermal conductivity of copper ensures that heat does not build up, preventing overheating.
Thermal Conductivity of Common Solid Materials
Here are the thermal conductivity values of some common materials:
Aluminum: 237 W/m·K at 300°C
Copper: 401 W/m·K at 100°C
Iron: 61 W/m·K at 18°C
Steel: 45 W/m·K at 18°C (for carbon steel with 1% carbon)
Silver: 412 W/m·K at 100°C
Graphite: 151 W/m·K at 0°C
These values highlight the differences in heat conduction across materials, with metals like copper and silver being among the most efficient conductors of heat, while materials like steel and graphite have comparatively lower conductivity.
Is Copper a Good Conductor of Heat?
Yes, copper is an exceptionally good conductor of heat. For example, in electronics, copper is often used to cool down processors by transferring heat away quickly, thus ensuring systems run smoothly without overheating. In plumbing, copper pipes help distribute hot water faster, enhancing energy efficiency. From cookware to cooling systems, copper’s outstanding ability to conduct heat makes it indispensable across many fields.
Copper vs. Aluminum PCB: Which is Better?
Both copper and aluminum are excellent conductors of heat in circuit boards manufacturing, but how do they compare? Let’s discuss them from below aspects:
1. Thermal conductivity
First, let’s take a look at the thermal conductivity of aluminum and copper, which is a key indicator of the material’s heat dissipation performance. The higher the thermal conductivity, the better the material’s ability to transfer heat.
Copper: 401W/m.k
Aluminum: 237W/m.k
It can be seen from the data that the thermal conductivity of copper is almost twice that of aluminum, which means that under the same conditions, copper can transfer heat more efficiently. For this reason, copper is often the material of choice in applications that require extremely high thermal performance.
2. Density
Aluminum: Density of about 2.7 g/cm³.
Copper: Density of about 8.96 g/cm³.
Copper is nearly three times as dense as aluminum, which makes copper much heavier than aluminum. In some weight-sensitive applications, such as portable electronic devices, heavy cooling components may affect the portability and user experience of the product. Therefore, in these scenarios, although aluminum is not as conductive as copper, it is still a very popular choice due to its lower weight.
3. Cost
The prices of aluminum materials are low, and processing costs are relatively low. At the same time, aluminum is easy to process into a variety of shapes, which makes aluminum very cost-effective in the manufacturing process. However, the cost of copper is much higher and the manufacturing process is more complex, so the overall cost is much higher than aluminum.
4. Corrosion resistance
Aluminum and copper also have significant differences in corrosion resistance. Aluminum has good oxidation resistance, and the aluminum oxide layer formed on the surface can effectively protect the internal material from further corrosion. However, the corrosion resistance of copper is relatively poor, and it is easy to generate patina (carbonate of copper) in humid environments, which not only affects the appearance but also reduces the heat dissipation performance.
Why Does Copper Have the Highest Thermal and Electrical Conductivity?
Copper’s good thermal conductivity is also related to its internal free electrons. Metal nuclei have a weak ability to bind electrons, allowing free electrons to move freely within the metal and transfer heat rapidly. When one end of a metal is heated, the electrons of atoms or molecules at that end absorb energy and begin to vibrate. These vibrations are passed on to the electrons of neighboring atoms or molecules, forming a heat flow ‌4. Copper is metal-bonded in a way that makes it easier for its electrons to transfer energy inside the metal, and thus heat faster.
Here is the end of this blog sharing, if you have other questions about copper material, welcome to e-mail us: sales@bestpcbs.com.
NRE, or Non-Recurring Engineering, refers to the upfront cost associated with developing and preparing the tools, processes, and engineering resources required for manufacturing a specific product. When it comes to PCB projects, NRE fees are vital because they cover the initial setup expenses that are incurred only once during the product development phase. These charges include design, tooling, programming, and testing requirements tailored to a particular PCB design, ensuring that the production is efficient and meets the required specifications.
Why Is It Necessary to Charge NRE Cost?
Charging an NRE cost is necessary because every PCB project is unique. The manufacturer must allocate resources to tailor the production to your specific design. The NRE fee ensures that all the necessary engineering work is done upfront to avoid delays or errors during mass production. If this fee weren’t charged, manufacturers would have to spread these costs across the entire production, making each unit more expensive, especially for small runs. This way, you can keep per-unit costs lower once production begins.
What Is the NRE Charge For?
The NRE charge is a crucial investment in ensuring that your PCB project gets off to the right start. It covers the engineering resources, setup, and processes that are required to customize the production environment specifically for your PCB design. Here are the main aspects that NRE fees typically cover:
Design Validation
Before manufacturing begins, the manufacturer must confirm that your PCB design is feasible and ready for production. This involves scrutinizing the layout for errors, verifying that it meets performance specifications, and ensuring compatibility with the chosen materials. This step can prevent expensive issues later in the process, such as defective boards or production delays.
Custom Tooling Setup
Every PCB design requires specific tools and fixtures to manufacture efficiently. NRE fees cover the creation or modification of tools that will allow your design to be assembled accurately. This might involve creating custom molds, dies, or specialized equipment that aligns with your PCB’s dimensions and complexity.
Programming and Firmware
For PCBs that require microcontrollers or other programmable components, the NRE charge often includes developing the necessary firmware or software to test and initialize these components. Manufacturers need to upload specific programs to ensure each unit functions correctly in real-world applications.
Prototype Creation
In some cases, the NRE fee also covers the cost of creating prototypes for testing. These prototypes are essential for verifying that the design works as intended before moving into full-scale production. The prototype phase allows for any last-minute adjustments and ensures that the final product will perform optimally.
How to Pay NRE Cost?
Paying the NRE cost is straightforward, but it’s important to clarify this with your manufacturer. Typically, the NRE fee is charged as a separate, one-time payment when you place your order. Depending on your arrangement with the manufacturer, it might be paid upfront or included in the first invoice along with the cost of your first production run. Payment terms can vary, but many manufacturers will expect it before starting the engineering and tooling processes. By paying this fee early, you ensure that your project can begin on time.
How to Reduce NRE Fee?
Reducing NRE costs may not always be possible, but there are ways to minimize them:
1. Reusing designs: If you’ve produced a similar PCB before, you can avoid some NRE costs by reusing or adapting the same designs.
2. Standardization: Using standard components and layouts rather than custom or unusual specifications can cut down on the design and tooling time.
3. Ordering in bulk: A larger production run can sometimes allow manufacturers to absorb some NRE costs, spreading the expense over a larger quantity of units.
4. Simplify design: A less complex design reduces the need for custom tools or special processes, leading to a lower NRE fee.
5. Choose experienced manufacturers: Partnering with a manufacturer like Best Technology who has experience in your industry can reduce the amount of custom setup needed, as they may already have processes and equipment suited to your project.
Considerations During the NRE Process
It’s important to approach the NRE process with a clear understanding of your project’s needs and goals. Communicate clearly with your manufacturer to avoid misunderstandings about what the NRE fee covers. For example, make sure you know if the fee includes changes or revisions to the design after the initial setup. You should also ask about the lead time for the engineering work. Knowing how long it will take to complete the NRE tasks helps you plan your project schedule more effectively.
Another consideration is the long-term benefits. While NRE fees may seem costly upfront, they are an investment that pays off as your project moves into full production. By ensuring that the initial design and setup are correct, you minimize the risk of costly production errors later.
When to Use Non-Recurring Engineering?
Non-Recurring Engineering is most beneficial when your PCB project involves custom designs or complex requirements. This is especially true when you need prototypes, new product development, or designs that require unique tools or processes. If you are producing a PCB that will have ongoing updates or revisions, it might also be necessary to pay an NRE fee each time the design changes. In general, the NRE fee is used whenever a manufacturer has to set up specialized processes or equipment that won’t be reused for other products.
How to Calculate NRE Cost?
NRE costs are calculated based on several factors. Manufacturers will consider the complexity of the design, the number of custom tools needed, and the extent of testing and programming required. The more custom features your PCB has, the higher the NRE cost is likely to be. Additionally, the cost of manpower to design and set up the project is included. Some manufacturers also calculate NRE based on the projected production run—larger runs may benefit from lower NRE fees as costs are spread over more units.
While it may seem daunting, NRE costs are ultimately a necessary investment for ensuring the success of your project. They allow manufacturers to deliver the best quality and avoid production errors, which can lead to greater savings in the long run.
An aluminum PCB, also known as an aluminum circuit board, is a type of metal core printed circuit board that uses aluminum as its base material. Unlike traditional PCBs, which are typically made with fiberglass, aluminum PCBs offer superior heat dissipation. This makes them ideal for high-power applications where excess heat can damage sensitive components. Aluminum PCBs are widely used in industries such as LED lighting, automotive, and power equipment because they provide better thermal management.
Aluminum PCBs are made from a combination of the following materials:
Aluminum Substrate: The base layer, responsible for mechanical support and heat dissipation.
Dielectric Layer: This layer provides insulation between the conductive layer and the aluminum base, while also helping with thermal transfer.
Conductive Layer: Made of copper, this layer is etched to form the circuit pattern and provides electrical connectivity.
Solder Mask Layer: This is a protective layer to protect the traces.
Types of Aluminum PCB
Aluminum circuit board is a kind of metal base copper clad plate with good heat dissipation function, the main types include single-sided aluminum PCB, double-sided aluminum PCB and multi-layer aluminum PCB. ‌
Single sided aluminum PCB
The single-sided aluminum substrate is composed of a conductive graphic layer and an insulating material plus aluminum plate, which is relatively simple in structure and suitable for the installation and connection of some basic electronic components.
Double sided aluminum PCB
The double-sided circuit aluminum substrate has two layers of conductive graphics layer and the insulating material plus aluminum plate superimposed together, providing a larger circuit layout space and better heat dissipation effect, which is often used in electronic devices requiring higher integration and better heat dissipation performance.
Multilayer aluminum PCB
Multi-layer printed aluminum-based circuit board consists of three or more layers of conductive graphic layer and insulating material and aluminum plate alternately laminated together, with complex circuit design and excellent heat dissipation performance, suitable for high-end applications such as LED lighting, automotive electronics ‌.
In addition, there are other special types of aluminum-based circuit boards, such as flexible aluminum substrates, mixed aluminum substrates, etc. Flexible aluminum substrate has excellent electrical insulation, flexibility and thermal conductivity, and is suitable for product design in various shapes and angles. The hybrid aluminum substrate is a multilayer component made of conventional FR-4 bonded to an aluminum substrate with a thermoelectric medium, designed to improve heat dissipation and rigidity, and used as a shield ‌.
Aluminum PCB Features
The aluminum substrate, a metal-based cooling plate (including aluminum, copper, and iron substrates), is made from a low-alloyed Al-Mg-Si series high-plastic alloy plate. This material offers excellent thermal conductivity, electrical insulation, and mechanical processing capabilities. When compared to traditional FR-4 materials, aluminum substrates of the same thickness and line width can carry higher currents. Additionally, they can withstand voltages up to 4500V and have a thermal conductivity greater than 2.0, making aluminum substrates the preferred choice in the industry.
â— Surface mount technology (SMT);
â— Very effective treatment of thermal diffusion in circuit design;
â— Reduce product operating temperature, improve product power density and reliability, extend product service life;
â— Reduce product volume, reduce hardware and assembly costs;
â— Replace fragile ceramic substrate for better mechanical durability.
Aluminum PCB vs. Copper PCB
Both aluminum and copper PCBs have their own advantages, but they cater to different applications:
1. Thermal Conductivity
In general, the higher the thermal conductivity, the more efficient the heat transfer, resulting in better heat dissipation and a longer lifespan. Among metal substrates, copper substrates offer the best thermal conductivity, outperforming aluminum substrates.
2. Electrical Conductivity
Both aluminum and copper are metals and conduct electricity, though their exact levels of conductivity differ. In terms of electrical conductivity, copper is significantly superior to aluminum. In applications that require high electrical conductivity, copper is the ideal choice.
3. Resistance
Resistance is crucial in PCB design as it affects the overall functionality and stability of the components. Given that copper has a higher density than aluminum, its resistance is generally lower. Therefore, in applications requiring thinner circuits and faster power transmission, copper is the better option.
4. Weight
Due to copper’s higher density per unit area, copper PCBs are much heavier than aluminum PCBs with the same design.
In applications where lightweight structures are critical, aluminum is the preferred material. On the other hand, applications where weight is not a major concern often favor the use of copper.
5. Applications
Aluminum substrates are somewhat specialized. They are mainly used in energy-saving lighting products such as indoor lighting, energy-efficient lighting, and street lights. Copper substrates are suitable for high-power lighting equipment like car headlights, tail lights, and some high-tech electronics.
6. Manufacturing Process
The manufacturing process for aluminum-based PCBs is simpler than that for copper-based PCBs, which also impacts their production time and delivery schedules. Below is aluminum PCB and copper core PCB that made by Best Technology:
Aluminum PCB Manufacturing Process
The manufacturing process for aluminum PCBs involves several steps to ensure high quality and performance. Here is a basic manufacturing process of aluminum PCB:
1. Substrate Selection and Preprocessing
Aluminum alloys with high thermal conductivity, such as the 5052 and 6061 series, are selected as the base material. The aluminum sheet is first cut and cleaned to remove surface grease and impurities, ensuring proper adhesion for subsequent processes.
2. Chemical Etching of Patterns
Photosensitive ink is used to form the desired circuit patterns on the aluminum surface. After exposure and development, the ink-covered areas protect the underlying aluminum from being etched by chemicals, while the unprotected areas are etched away, forming the circuit pattern.
3. Insulation Layer Deposition
To achieve electrical isolation, an insulating material, usually thermosetting resin or ceramic-filled epoxy resin, is deposited on the aluminum substrate. This step is typically completed using screen printing or inkjet printing technology to ensure a uniform and appropriately thick insulation layer.
4. Metallization
Creating conductive paths on the insulation layer is a key step. Copper foil is deposited onto the insulation layer using methods such as electroplating, sputtering, or chemical copper deposition. This copper foil serves as the conductive layer for connecting LED chips and other components.
5. Drilling and Metallization
Holes are drilled in the board according to the design to achieve electrical connections between different layers. The hole walls are then metallized to ensure good conductivity inside the holes.
6. Surface Treatment
To improve solderability and corrosion resistance, the aluminum substrate undergoes additional surface treatments, such as tin spraying, gold plating, or silver plating.
7. Assembly and Testing
LED chips, resistors, capacitors, and other components are soldered onto the circuit board to complete the assembly. Here you can see the whole manufacturing process of aluminum metal core PCB.
What Affects Aluminum PCB Circuit Board Price?
First of all, ‌ raw material cost ‌ is one of the important factors affecting the price of aluminum based circuit board. The raw materials of aluminum substrate include aluminum substrate and other auxiliary materials, such as insulating layer materials. The price fluctuation of aluminum substrate will directly affect the production cost of aluminum substrate, and then affect its market price. In addition, the cost of electricity is also a part of the production process cannot be ignored, the fluctuation of electricity price will further affect the production cost ‌.
Secondly, ‌ market supply and demand ‌ is also a key factor in determining the price of aluminum-based circuit boards. If demand increases and supply is insufficient, prices will naturally go up. On the other hand, if there is an oversupply, the price will fall. Changes in demand in the construction, automotive and other industries, as well as changes on the supply side such as the construction of new plants or the closure of old plants, will have a direct impact on the price of aluminum-based circuit boards ‌.
‌The macroeconomic environment ‌ also has an important impact on the price of aluminum-based circuit boards. When economic growth is expected to be good, the demand for aluminum substrate in related industries increases, driving up prices; The expectation of economic recession will lead to a decline in demand and pressure on aluminum substrate prices ‌.
‌Policies and regulations ‌ is also one of the factors affecting the price of aluminum-based circuit boards. The government’s environmental protection policies, trade policies and industry subsidies will have an impact on the aluminum substrate market. For example, environmental policies that limit production may reduce supply and push up prices; The establishment of trade barriers may affect the import and export of aluminum substrate, and then affect the domestic market price.
Aluminum PCB Production Capability – Best Technology
Best Technology is known for its strong production capability when it comes to aluminum PCBs. Our manufacturing facilities are equipped with the latest technology to produce high-quality aluminum PCBs that meet industry standards. We have the ability to produce single-sided, double-sided, and multi-layer aluminum PCBs, below you can see our capability of aluminum PCBs:
Applications of Aluminum PCB
Aluminum PCBs are used in a variety of applications, particularly where heat management is crucial:
LED Lighting
Automotive Electronics
Power Supplies
Consumer Electronics
Medical
Household appliance
FAQs about Aluminum PCB Circuit Board
1. What is the main advantage of aluminum PCBs?
Aluminum PCBs excel in thermal management, making them perfect for heat-sensitive applications.
2. Are aluminum PCBs expensive?
No, aluminum PCBs are generally affordable, making them a cost-effective option for many industries.
3. Can aluminum PCBs be used in consumer electronics?
Yes, aluminum PCBs are commonly used in consumer electronics, especially in devices that generate significant heat.
4. What industries commonly use aluminum PCBs?
Industries such as automotive, LED lighting, and power supplies frequently use aluminum PCBs due to their thermal properties.
5. Is aluminum PCB better than copper PCB?
It depends on the application. Aluminum is better for heat dissipation, while copper excels in electrical conductivity.
Ceramics have emerged in many fields with their unique properties, and the thermal conductivity of ceramics has become one of the focuses of attention. Ceramic PCBs have the advantages of high thermal conductivity, good insulation performance, high mechanical strength and high precision, and have been widely used in high-power LED lighting, automotive electronics, and aerospace.
The thermal conductivity of ceramic PCBs is due to the materials used, such as aluminum oxide (Al2O3) and aluminum nitride (AlN). These materials have high thermal conductivity and can effectively dissipate heat, prevent overheating, and ensure that electronic components can still work stably in high temperature environments.
The thermal conductivity of aluminum nitride reaches 170W/(mK)~220W/(mK). Such high thermal conductivity enables ceramic PCBs to effectively dissipate heat when the chip is working, ensuring that the sensor signal will not be distorted, especially in high temperature, high vibration, and corrosion environments. The signal of ceramic PCBs is still efficient, sensitive, and accurate. ‌
In addition, the manufacturing process of ceramic PCB adopts LAM technology, which is a laser rapid activation metallization technology, making ceramic PCB highly versatile and can replace the entire traditional printed circuit board with a simpler structure and enhanced performance.
In summary, ceramic PCB not only has good thermal conductivity, but also can maintain stability and reliability in harsh environments such as high temperature, high vibration, corrosion, etc., which is an ideal choice for high-performance electronic components.
The thermal performance of ceramic PCB is mainly reflected in the following aspects:
High thermal conductivity: The thermal conductivity of ceramic PCB is usually above 18W/mK, which is much higher than that of traditional ceramic materials and organic substrates. It can effectively transfer heat from the heating element to the heat sink and improve the heat dissipation efficiency.
Good insulation performance: The ceramic substrate has good insulation performance and can withstand high voltage and high current, ensuring the safety and stability of the circuit.
High mechanical strength: The ceramic substrate has high mechanical strength, can withstand large pressure and impact, and is not easy to break and deform.
‌Good chemical stability‌: Ceramic substrates have good chemical stability and can withstand corrosion from chemicals such as acids, alkalis, and salts, and are not prone to aging and deterioration‌.
‌Thin and lightweight‌: High thermal conductivity ceramic substrates can be made into thin and lightweight products to meet the needs of miniaturization and lightweight electronic devices‌.
These characteristics make ceramic PCBs the first choice for applications that generate a lot of heat and require efficient thermal management, especially in radio frequency (RF) and microwave applications, which can maintain signal integrity and minimize signal loss, making them indispensable in industries such as telecommunications, aerospace, and satellite communications‌.
In addition, ceramic PCBs’ chemical resistance and ability to withstand harsh environments make them ideal for applications that require contact with corrosive substances‌.
What material has the highest thermal conductivity?
Aluminum nitride (AlN) has the highest thermal conductivity. ‌
Aluminum nitride (AlN) is an excellent ceramic material with extremely high thermal conductivity and low expansion coefficient. Its thermal conductivity is as high as 170-230 W/mK, making it one of the ceramic substrate materials with the best thermal conductivity.
The effective heat dissipation performance of aluminum nitride makes it particularly suitable for the heat dissipation needs of high-power density electronic devices and high-frequency electronic devices. In addition, aluminum nitride also has the characteristics of high hardness, high mechanical strength, strong corrosion resistance, high biocompatibility, and a thermal expansion coefficient close to silicon, so it performs well in applications such as high-power LEDs, power modules, and laser fields.
In contrast, other common ceramic PCB materials such as aluminum oxide (Al2O3) have low thermal conductivity, generally between 18-35 W/mK. Although they have good insulation properties and mechanical strength, their thermal conductivity is not as good as aluminum nitride and cannot meet the heat dissipation needs of high-power devices. Therefore, aluminum nitride is the preferred material in applications that require efficient heat dissipation.
What is the thermal conductivity of ceramic in W mK?
Ceramic PCB, as a high thermal conductivity material, its thermal conductivity depends on the type of ceramic substrate used. The thermal conductivity of ‌alumina ceramic‌ is between 18-35 W/mK, while the thermal conductivity of ‌aluminum nitride ceramic‌ is as high as 170-230 W/mK, which shows that aluminum nitride ceramic has higher thermal conductivity than alumina ceramic.
In addition, the thermal conductivity of ceramic PCB is better than that of traditional ‌FR4 PCB‌ or ‌metal substrate‌, the latter of which usually has a thermal conductivity of less than 3W/mK. Especially in the field of products that require high heat dissipation performance, ceramic PCB is favored for its excellent thermal conductivity.
Do ceramics have good conductivity?
The conductivity of ceramic PCB (printed circuit board) is due to the ceramic substrate it uses. This substrate material has good thermal and electrical conductivity and can withstand high power density.
Ceramic substrates are usually made of materials such as alumina, aluminum oxide and silicon nitride, which give ceramic substrates excellent electrical properties and mechanical strength, making them widely used in high-frequency communications.
The thermal conductivity of ceramic PCB is between 25~230w, with very good insulation and thermal conductivity. At the same time, its dielectric constant is low, dielectric loss is small, and it has excellent high-frequency performance. These characteristics make ceramic PCB perform well in applications that require efficient thermal management and maintain signal integrity.
How good of an insulator is ceramic?
Ceramic PCB has excellent insulation performance. ‌
The insulation performance of ceramic PCB is due to its material characteristics. It is based on ceramic materials and has extremely high hardness and wear resistance. It also has good insulation performance and thermal stability. Ceramic materials themselves have excellent electrical insulation properties and can effectively prevent short circuits and current leakage.
Does ceramic have electrical resistance?
‌Ceramic PCB has resistance. ‌
Ceramic PCB, as a high-performance electronic substrate material, has excellent physical and electrical properties. In ceramic PCB, resistors are part of electronic components, used to limit current and reduce voltage, and are an indispensable component in the circuit. The resistors of ceramic PCBs are usually installed on the circuit board together with other electronic components to complete the function of the circuit together.
The thermal conductivity of ceramic is one of its important properties. Different types of ceramic materials have different thermal conductivities. In the future, with the continuous development and progress of electronic devices, the performance requirements for PCBs will become higher and higher, and ceramic PCBs will continue to develop and innovate to meet market demand.
Apex regulator PCB, as a key electronic component, plays an indispensable role in ensuring power supply stability. In today’s era of high digitalization and electronic equipment dependence, a stable power supply is essential for the normal operation of various devices.
What is a regulator PCB?
Regulator PCB (Printed Circuit Board) is a printed circuit board that integrates regulator-related circuit components. It is centered on regulator components (such as voltage, current or power regulators), supplemented by other circuit components such as capacitors, resistors, and inductors to work together.
Through specific working principles, such as linear regulators adjust the degree of conduction, switching regulators use high-frequency switching actions and related modulation methods to achieve voltage regulation, current detection and control to achieve current regulation, and power regulation based on voltage and current regulation.
At the same time, it has output stability, can maintain output stability when the input voltage fluctuates and the load changes, and has multiple protection functions such as overvoltage, overcurrent, and overheating. It has the characteristics of flexible design of circuit structure and parameters according to needs, high integration to reduce volume, and easy installation and use.
What are the three types of regulators?
There are three main types of regulators: contact regulators, transistor regulators, and integrated circuit regulators. ‌
Contact regulators are an earlier type of regulator, which are characterized by slow contact vibration frequency, mechanical inertia and electromagnetic inertia, resulting in low voltage regulation accuracy, easy sparking of contacts, large radio interference, poor reliability, and short life. They have now been eliminated.
Transistor regulators emerged with the development of semiconductor technology. Their advantages include high switching frequency of transistors, no sparking, high regulation accuracy, light weight, small size, long life, high reliability, and low radio wave interference. This type of regulator is now widely used in a variety of mid- and low-end models.
In addition to the advantages of transistor regulators, integrated circuit regulators also have the characteristics of ultra-small size. They are usually installed inside the generator (built-in regulators), reducing external wiring and improving cooling effects. This type of regulator is widely used in a variety of car models.
What is an apex regulator pcb?
Apex regulator is an electronic device that regulates the voltage, current or power of a power supply to meet the needs of a specific electronic device or system. And the Apex regulator PCB is the product of combining the Apex regulator with the printed circuit board (PCB) technology.
PCB is a substrate that carries electronic components and provides electrical connections. It is made of insulating material, usually glass fiber reinforced epoxy, covered with a conductive copper foil pattern. Electronic components are mounted on the PCB by soldering or other connection methods to form a complete electronic circuit.
Apex regulator PCB integrates the Apex regulator onto the PCB, achieving a more compact and efficient power regulation solution. This integrated design not only reduces the space occupied, but also improves the reliability and stability of the circuit.
What is the function of the apex regulator pcb?
Receive input voltage: The PCB receives the input voltage from the power supply, which may vary due to a variety of factors. This input voltage is usually higher or lower than the level required by the system components.
Regulate voltage: The voltage regulator on the PCB adjusts the input voltage to match the required output level. If the input voltage is too low, the regulator increases it to the appropriate level.
Stabilizes output voltage: Once the voltage is regulated, the PCB distributes it to the various components of the electronic system. A feedback control system continuously monitors the output voltage to ensure it remains stable, and makes real-time adjustments as needed to offset any fluctuations in the input voltage.
Ensures lifespan: By maintaining a stable voltage supply, the apex regulator PCB helps protect sensitive components from damage caused by voltage surges or voltage drops.
How does a apex regulator circuit work?
The working principle of an APEX regulator PCB is to convert analog signals into digital signals through an ADC conversion circuit so that electronic devices and computers can understand and process them. ‌ This process involves converting analog signals from our real world into digital signals, allowing electronic devices to recognize and process these signals‌.
Specifically, the ADC conversion circuit in the APEX regulator PCB is responsible for converting the input analog signal into a digital signal. The ADC (Analog-to-Digital Converter) circuit is responsible for converting continuously changing analog voltage or current signals into discrete digital signals that can be processed and analyzed by electronic devices.
ADC circuits usually consist of three main parts: sampling, quantization, and encoding. These steps convert analog signals into binary codes that computers can process.
What are the applications for apex regulator pcb?
Apex regulator PCB is mainly used in automation industry, industrial robots, medical inspection, precision testing instruments and other fields. ‌ These application fields have high requirements for accuracy, efficiency and stability, making Apex regulator PCB an ideal choice.
In the automation industry, Apex regulator PCB is widely used in various automation equipment, such as servo system-controlled CNC trademark printing machines, CNC pipe bending machines, etc. These equipment require high-precision speed control and stable output. Apex regulator PCB can provide precise control and reliable performance to meet the needs of automated production.
In the field of industrial robots, Apex regulator PCB is used to control various actions of the robot to ensure its precise operation in complex environments. Its high torque output and stable accuracy enable the robot to perform well in various industrial applications, improving production efficiency and product quality.
Medical inspection and precision testing instruments also require regulators with high accuracy and stability. The application of Apex regulator PCB in these fields can provide precise control signals to ensure the accuracy and reliability of test results.
Conclusion:
As an indispensable part of electronic equipment, Apex regulator PCB plays an irreplaceable role in ensuring stable operation of equipment and improving equipment performance. With the continuous development of technology, it will continue to develop in the direction of miniaturization, integration, high efficiency, intelligence, etc., and continue to play an important role.
A blank PCB is commonly referred to as a bare board. This term is used because the board has no components soldered onto it yet. It’s simply the foundation of a printed circuit board (PCB), typically made from a material like fiberglass and copper. The copper traces on the board outline where the electrical connections will eventually be made, but before any components are attached, the board remains “blank.”
A bare board is key point in the manufacturing process of electronic devices. Once components like resistors, capacitors, and integrated circuits are added, the blank PCB transforms into a fully functional circuit board. This is the stage where the blank board evolves, moving from raw material to the heart of a functioning device.
How to Use a Blank PCB Board?
Using a blank PCB starts with designing a circuit schematic. Specialized software is used to create a layout that specifies where each component will be placed and how they’ll be connected through copper traces. Once the design is finalized, the blank board serves as a canvas where components are either soldered by hand or using automated machines in mass production.
If you are working on a DIY project or prototyping, the blank PCB allows for customization and flexibility. You can use a soldering iron to manually attach your components. For large-scale production, automated machines place and solder components onto the blank board with precision. Using blank PCBs for custom designs or modifications is a cost-effective way to experiment with electronics.
Why Is PCB So Cheap?
PCBs are considered affordable due to mass production techniques. Modern manufacturing processes, such as automated assembly lines and the use of standard materials, have significantly reduced costs. The global nature of the electronics industry also plays a role, as many manufacturers source materials and labor from countries with lower production costs.
The materials used, primarily fiberglass and copper, are relatively inexpensive. Furthermore, technological advancements have optimized the process of making PCBs, allowing manufacturers to produce them quickly and in large quantities. The result is that even highly specialized PCBs can be produced at a low cost, making them accessible to hobbyists, startups, and large corporations alike. If you want to know the details about factors affect the price of PCB board, welcome to check our another blog:
How Are Blank PCBs Made?
The process of making blank PCBs is a sophisticated, multi-stage operation that ensures the boards meet high precision standards before any components are added. Here’s a detailed breakdown of the steps involved in manufacturing a blank PCB:
Material Selection and Lamination
Blank PCBs start with a substrate, typically made from fiberglass-reinforced epoxy laminate (FR4), which serves as the board’s structural foundation. This substrate is non-conductive, providing insulation for the circuit. A copper layer is then bonded to one or both sides of the substrate using heat and pressure, forming what is known as a copper-clad laminate. The thickness of this copper layer varies based on the board’s intended application, with typical copper thickness ranging from 1 oz (35 µm) to 2 oz (70 µm) per square foot. Thicker copper layers may be used for boards handling higher currents.
Photoresist Application
After lamination, the copper layer is coated with a light-sensitive material called photoresist. This step prepares the board for the next process, which is exposing the circuit pattern. The photoresist layer can be either liquid or dry film and plays a critical role in protecting certain parts of the copper during etching.
Imaging the Circuit Pattern
The desired circuit pattern, generated from PCB design software, is transferred onto the board. This is done by aligning the photoresist-coated board with a photomask (a stencil-like film) that contains the circuit layout. The board is then exposed to ultraviolet (UV) light. The areas of the photoresist not covered by the photomask are hardened, while the areas shielded by the mask remain soft and will later be removed.
Etching Process
The next step is to remove the unneeded copper from the board, a process called etching. Chemical etchants, like ferric chloride or ammonium persulfate, are used to dissolve the unprotected copper, leaving behind only the circuit traces. The areas of the copper protected by the hardened photoresist remain intact, forming the conductive pathways for the future components.
Drilling Holes for Components
After the etching process, holes need to be drilled into the board. These holes, called vias, allow for the placement of components such as resistors, capacitors, and integrated circuits, and are also used to connect different layers in multi-layer PCBs. Advanced PCB manufacturing often uses computer numerical control (CNC) drilling machines to ensure precision, especially for boards with many layers or small trace designs. Some manufacturers employ laser drilling for microvias.
Plating and Hole Metallization
Once the holes are drilled, they need to be plated to create electrical connections between the different layers of the PCB. This is done through a process called electroless copper plating, which deposits a thin layer of copper inside the drilled holes. The plating process ensures that when components are later inserted, electrical signals can flow between layers through the plated holes.
Solder Mask
After drilling and plating, the board is cleaned and coated with a layer of solder mask. This mask protects the copper traces and prevents solder from accidentally bridging across traces during assembly. The solder mask is typically green, though other colors like blue, red, black, or white can also be used. The solder mask is applied through a screen-printing process or as a dry film, and it is cured using UV light or heat.
Silkscreen Printing
Silkscreen printing is applied to the board to mark component locations, symbols, logos, or other identifiers needed during the assembly process. This layer is typically applied using a silk-screening process, similar to how images are printed onto clothing. White is the most common color used for silkscreen, as it provides high contrast against the green solder mask, but other colors can be used depending on the design.
Surface Finishing
The copper pads, where components will be soldered later, are treated with a surface finish to protect them from oxidation and ensure good solderability. Common finishes include HASL (Hot Air Solder Leveling), where the board is dipped in molten solder and excess solder is blown off with hot air, leaving a smooth surface. Another popular finish is ENIG (Electroless Nickel Immersion Gold), where a thin layer of nickel followed by gold is applied to the copper pads.
Electrical Testing and Quality Control
The final step in producing a blank PCB is electrical testing and quality control. Every trace and connection is tested to ensure there are no shorts or opens, which could render the board useless. Automated Optical Inspection (AOI) systems are used to visually inspect the board for defects, while flying probe tests and bed-of-nails tests check for electrical continuity. Any defects found at this stage are flagged for repair or, in severe cases, the board is scrapped.
What Is the Difference Between Bare PCB and PCB?
The term bare PCB refers to the unpopulated circuit board, which means it lacks any electronic components. In contrast, a PCB refers to a fully assembled board that includes all the necessary components to function.
In the bare stage, the PCB is simply the foundation for the circuit but isn’t functional. Once components are soldered onto the bare PCB, it becomes an operational printed circuit board, ready to be integrated into electronic devices.
How Do You Cut Blank PCB?
Cutting a blank PCB requires precision. Tools such as PCB shears, laser cutters, or CNC machines are commonly used to achieve clean, straight cuts without damaging the copper traces. For smaller DIY projects, a hand saw or scoring tool can be used, but these methods require a steady hand and careful planning to avoid mistakes.
Before cutting, it’s important to mark the board clearly to ensure the cuts are accurate. If the board is part of a larger project, cutting should be done after confirming that all components will fit within the intended space.
Why Are PCBs Green?
The green color on most PCBs comes from the solder mask that coats the board. While green is the most common color, the solder mask can be found in other colors such as red, blue, or black. The preference for green is largely historical, as it provided the best contrast for technicians to inspect the board visually.
Green solder masks also tend to offer better performance under different lighting conditions, which can be helpful during manufacturing and quality control processes.
Do PCBs Use AC or DC?
PCBs can handle both AC (alternating current) and DC (direct current), depending on the design and the type of components used. Some boards are designed specifically for DC circuits, while others are built to handle AC power.
For example, a power supply PCB may convert AC from a wall outlet into DC, which is used by many electronic devices. The flexibility to work with either type of current makes PCBs essential for a wide range of applications.
Blank PCB Board Supplier – Best Technology
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PCB beveler is a less well-known but very important tool, but it plays a vital role in the manufacturing and assembly process of PCB (printed circuit board). It is a tool specifically used to create bevels or chamfers around the edges or holes of PCB.
What is a PCB Beveler?
PCB beveler is a device used to bevel (chamfer) the edges of printed circuit boards (PCBs). Its functions include improving the electrical performance of PCBs, dispersing the electric field through beveling, reducing the risk of electrical breakdown; enhancing the mechanical properties of PCBs, preventing stress concentration and cracking at the edges; facilitating subsequent processing and assembly work, avoiding scratching other electronic components or damaging component pins during the plug-in process.
It has the advantages of high precision, high efficiency, low noise, and low energy consumption. It is widely used in the electronics industry, especially in the production process of consumer electronic products such as smartphones and tablets, which can improve production efficiency and product quality.
What is Edge Bevel in PCB?
Edge bevel is the process of making a transition edge between two sides of a PCB, usually on the outer edge of the PCB. Bevel is often used for edge connectors to allow for smoother insertion into another circuit board socket. Edge connector pins are often called gold fingers because they are plated with gold and have multiple parallel groups together.
Why do PCB edges need to be beveled?
The main reason why PCB edges need to be beveled is to increase the contact area, reduce contact resistance, and improve the stability of electrical connections.
The bevel process increases the contact area between the gold finger and other connectors by processing the PCB edge into a bevel, thereby reducing the contact resistance and improving the stability and reliability of signal transmission.
Specifically, the bevel process has the following advantages in application:
‌Increase contact area‌: Beveled edges can increase the contact area between the gold finger and the socket, thereby increasing friction and connection stability.
‌Reduce contact resistance‌: The bevel design reduces the pressure concentration at the contact point, thereby reducing the contact resistance and reducing the loss in signal transmission.
‌Adapt to different application scenarios‌: According to the specific application scenarios and equipment requirements, the bevel angle can be adjusted between 15° and 45° to meet different spatial layouts and electrical connection requirements‌.
The use of PCB beveling machines further improves the accuracy and efficiency of the beveling process. This mechanical equipment can accurately control the bevel angle through a high-precision mechanical transmission system and an efficient grinding process to ensure processing quality and production efficiency.
What are the Benefits of PCB Edge Beveling?
The main benefits of PCB edge beveling include enhanced aesthetics, easy installation, improved electrical performance, and reduced mechanical stress. ‌
First, the beveling process can enhance the aesthetics of the circuit board. By cutting the PCB edge at a specific angle, the beveling process makes the appearance of the circuit board more refined and beautiful, which can significantly improve the overall visual effect of the product‌.
Secondly, the beveling process is easy to install. The beveling design can better adapt to the structural design of various electronic devices, making the assembly of PCB boards and other components more convenient and precise, and the design of the beveling angle can better achieve the coordination of PCB boards with other components‌.
In addition, the beveling process can also improve electrical performance. Bevel design can increase the contact area and reduce the contact resistance, thereby improving the stability and reliability of signal transmission.
Finally, bevel design can reduce mechanical stress. The design of the beveled rectangle allows the socket to slowly and gradually enter or exit the jack when plugging and unplugging, thereby reducing the mechanical stress during plugging and unplugging and extending the service life of the socket and jack.
What are the limitations of PCB edge beveling?
The main limitations of PCB edge beveling include the design of the bevel angle, the spacing requirements between the components and the board edge, and the requirements for cutting accuracy and speed. ‌
First, the design of the bevel angle needs to be determined according to the specific application scenario and equipment requirements. The common bevel angle range is between 15° and 45°.
In some devices with high requirements for plugging and unplugging force and contact stability, a smaller bevel angle may be selected to increase the contact area and friction between the gold finger and the socket to ensure the stability of signal transmission; while in some occasions with strict restrictions on spatial layout, a larger bevel angle may be used to better realize the assembly of PCB boards and other components. ‌
Finally, cutting accuracy and speed are also important limiting factors. PCB beveling machines need to have high-precision cutting capabilities and be able to accurately cut within the specified size range. The cutting accuracy directly affects the quality and reliability of the circuit board.
How Does PCB Beveling Work?
PCB beveling machines are usually composed of a frame, a transmission system, a grinding system, a positioning fixture, and a protective device.
The transmission system uses high-precision gears or screw drives to ensure processing accuracy. The grinding system consists of a grinding head and a coolant system, etc., which are used to grind PCB boards. The positioning fixture is used to fix the PCB board to ensure the accuracy and stability of the processing, while the protective device is to protect the safety of the operator.
During the operation, first check whether the beveling machine is operating normally. If there is a problem, it needs to be repaired. Then, set the beveling angle according to customer needs or the default 45° angle.
Next, adjust the angle of the gong section and the table, adjust the distance of the steel plate according to the thickness of the board, and use a copper plate of the same thickness to test the knife to ensure that the angle of the bevel of the beveled board meets the requirements.
Finally, the grinding process is carried out through the grinding system. The grinding head rotates at a high speed and applies a certain amount of pressure on the PCB board, thereby processing its edge into a bevel.
What are the Applications of PCB Beveling?
The core application of the PCB beveling process is to increase the contact area and reduce the contact resistance, thereby improving the stability and efficiency of the connection. This process is common in the beveling of gold fingers, especially on devices such as computer memory bars and graphics cards. The bevel design of gold fingers can significantly improve the data transmission speed and reliability.
‌Specific application scenarios‌ include:
‌Computer memory bars and graphics cards‌: On these components, the bevel design of gold fingers can not only increase the contact area and reduce the contact resistance, but also prevent oxidation to a certain extent and extend the service life.
‌Other communication equipment‌: In addition to computer memory bars and graphics cards, the beveling process of gold fingers is also used in various devices that communicate through digital signals, such as consumer electronics, smartphones, and smart watches.
In short, the beveler in PCB is a tool specifically used to create bevels or chamfers around the edges or holes of PCBs. It has the functions of improving the reliability of PCB, facilitating assembly and improving appearance. When using the bevel, pay attention to the correct operation method and maintenance to ensure its normal operation and service life.
PCB solder plays a vital role in the assembly and function of PCBs. Reliable solder joints must remain intact to prevent components from loosening or falling off the PCB. Solder is the material used to connect the various electronic components on the PCB. Its importance is reflected in several key aspects. Solder ensures that electronic components can be firmly attached to the PCB.
What type of solder for PCB?
The commonly used types of solder for PCB include solder paste, tin bar and tin wire. ‌
1. ‌Solder paste‌: Mainly used in reflow soldering process. Solder paste consists of tin powder, flux and other additives. Tin powder is usually an alloy of tin and other metals. According to different melting points, solder paste can be divided into three types: low temperature, medium temperature and high temperature; according to different lead content, it can be divided into lead solder paste and lead-free solder paste. Lead-free solder paste gradually replaces lead solder paste to reduce environmental pollution‌.
2. ‌Solder bar‌: Mainly used in wave soldering process. Tin bar (solder bar) has excellent antioxidant ability, good fluidity after melting, suitable for wave soldering process, and is widely used in PCBA processing due to its good fluidity and strong solderability.
3. Tin wire: Mainly used in post-soldering process. Similar to tin bar, tin wire is also a kind of welding material, mainly used for manual welding or other occasions where filament solder is required.
In addition, the selection of welding materials also involves the selection of solder alloys. Eutectic alloys are one of the preferred solder alloys because of their low melting point, low welding temperature, small crystal grains, and dense structure, which are conducive to improving the strength of solder joints.
What temperature should solder be for PCB?
The solder temperature of PCB should vary according to different types of components and welding processes. ‌‌
For lead-containing PCB boards, the temperature in the preheating stage is usually controlled at 80~120℃ for 1~3 minutes; the temperature in the insulation stage is 150~180℃ for 30~60 seconds; the temperature in the reflow stage is 210~240℃ for 20~40 seconds; the cooling stage speed should be controlled within the range of 4~6℃ per second. ‌
For lead-free PCB boards, the temperature in the preheating stage is usually controlled at 100~150℃, the insulation stage is 180~220℃, the reflow stage is 240~260℃, and the cooling speed should be controlled within the range of 3~5℃ per second. ‌
What is the best soldering temperature for PCB? ‌
The best soldering temperature range for PCB is usually between 240 and 280 degrees Celsius. This temperature range is suitable for manual soldering and can ensure the best soldering effect and component reliability. ‌
For different types of welding situations, the temperature requirements are different:
1. Wave soldering: The optimal temperature is 280 degrees Celsius, ensuring that the solder joint temperature is 50 degrees Celsius higher than the melting point of the solder to achieve reliable welding results.
2. Small components (such as resistors and capacitors below 1206, and components with an area of ​​less than 5 mm²): The recommended temperature is 250 degrees Celsius to prevent damage to the circuit board.
3. Large components: The soldering iron temperature should be set between 350 and 370 degrees Celsius, and the maximum should not exceed 390 degrees Celsius. The welding time should be kept within a few seconds to prevent damage to the pads on the PCB.
4. SMT processing: The recommended manual soldering temperature range is 240 to 280 degrees Celsius. Try to minimize the gap between the set temperature and the actual working temperature to achieve the best welding effect and component reliability.
In addition, the precise management of temperature during the welding process is also required to ensure the quality of the solder joints and circuit performance of the PCB board.
The preheating stage is very important to reduce the thermal shock during welding. The preheating temperature is usually controlled between 80 and 120 degrees Celsius for 1 to 3 minutes.
The insulation stage is to fully melt the components and solder paste on the PCB board. The temperature is usually controlled between 150 and 180 degrees Celsius for 30 to 60 seconds.
The cooling stage is to avoid thermal stress caused by rapid cooling. The cooling rate should be controlled to drop between 4 and 6 degrees Celsius per second.
What temperature does PCB solder melt?
The melting temperature of PCB solder depends on the type of solder. The melting temperature of lead solder ranges from 183°C to 217°C, while the melting temperature of lead-free solder is usually between 217°C and 257°C.
Lead solder has a lower melting point, usually between 183°C and 217°C. During the reflow process, the preheating temperature of lead solder is controlled at 80°C to 120°C, the holding temperature is 150°C to 180°C, the reflow temperature is 210°C to 240°C, and the cooling rate decreases by 4°C to 6°C per second.
The melting point of lead-free solder is higher, usually between 217°C and 257°C. During the reflow process, the preheating temperature of lead-free solder is controlled at 100°C to 150°C, the holding temperature is 180°C to 220°C, the reflow temperature is 240°C to 260°C, and the cooling rate decreases by 3°C to 5°C per second.
What is the melting point of PCB material?
The melting point of PCB material depends on its specific composition and type, usually between 1064℃ and 900℃. For PCB substrate materials, such as FR-4, its temperature resistance is measured by the Tg value (glass transition temperature). Ordinary FR-4 sheets have lower heat resistance, while high TG FR-4 sheets have better heat resistance and can withstand higher temperatures.
Different types of PCB materials have different melting points and heat resistance. The long-term working temperature of ordinary FR-4 sheets is generally between 130℃ and 140℃, and the instantaneous temperature resistance can reach 150℃ to 260℃. In contrast, PCBs made of special materials such as polyimide can withstand higher temperatures, even up to 280℃.
In addition, the surface treatment layer material of the PCB will also affect its heat resistance. For example, the melting point of the gold plating layer depends on the composition of the metal material used.
Which solder is best for PCB?
Choosing a solder suitable for PCB requires comprehensive consideration of multiple factors. The following solders have their own advantages and disadvantages:
Tin-silver-copper (SAC) alloy: good mechanical and electrical properties, high reliability, suitable for a variety of welding processes, and environmentally friendly. But the cost is high and the welding process requirements are high.
Tin-copper (Sn-Cu) alloy: low cost, good solderability, and environmentally friendly. The disadvantage is that the mechanical properties are slightly worse in high-demand scenarios.
What type of solder should not be used with electronics?
Electronic products should not use strong alkali, rosin grease, coconut oil, and neutral flux as flux. ‌
In the soldering process of electronic products, it is very important to choose a suitable flux. The main function of the flux is to remove the oxide film, prevent oxidation, and improve the quality of soldering.
However, some substances are not suitable for use as flux. Strong alkali and rosin grease will corrode the soldering joint and affect the quality of soldering. In addition, the use of acidic flux will also corrode the soldering joint, so acidic flux should be avoided.
In order to ensure the smooth progress of the soldering process and ensure the quality of soldering, some measures can be taken.
First, choose lead-free solder materials that meet ROHS standards to reduce environmental pollution. Second, use high-brightness soldering iron tips, reduce the use of soldering oil and rosin, and reduce smoke generation. Finally, select appropriate welding materials and processes according to specific needs, such as solder wire, solder paste, solder sheet, etc., to ensure the mechanical and electrical performance of welding.
In short, solder is a key element in the PCB assembly process. Its quality is directly related to whether the electronic equipment can operate normally, and the characteristic of solder melting point plays a decisive role in the welding process. I must deeply study and understand the characteristics of solder to ensure that every solder joint can meet the highest standards.
Can you use AC in PCB?AC can be used in PCB boards. PCB boards are designed to support the use of AC, and the functions of AC can be realized through proper circuit design and component selection.
Can you use AC in PCB?
The use of AC in PCB boards requires consideration of the characteristics of AC. The current magnitude and direction of AC change continuously over time, which requires the components and layout on the PCB to adapt to such changes. For example, components such as inductors and capacitors play an important role in AC circuits, and their parameters and layout need to be carefully designed to achieve the desired circuit performance.
Specifically, AC circuit design on PCB boards includes selecting appropriate components, layout, and routing. For example, using test instruments such as LCR digital bridges can measure the parameters of components in AC circuits to ensure that the performance of the circuit meets the design requirements. In addition, reasonable ground routing and layout can reduce signal interference and ensure the stable transmission of AC.
Is the circuit board DC or AC?
Circuit boards can transmit both direct current and alternating current. In modern electronic products, we use alternating current for power supply, so most circuit boards are also designed to transmit alternating current. Of course, in some special application scenarios, some circuit boards also need to transmit direct current. Whether transmitting direct current or alternating current, the circuit board needs to meet the requirements of the transmitted current.
What is the PCB in AC?
The alternating current in PCB refers to the current whose direction changes periodically, that is, alternating current (AC). The application of alternating current in PCB is mainly reflected in power conversion and power transmission. PCB power supply usually converts AC into stable direct current (DC) output to meet the demand of electronic equipment for stable power supply. PCB power supply converts AC into the required DC through components such as transformers, rectifiers, filters and voltage regulators, and provides stable power output.
How to calculate the bandwidth of AC in PCB traces
The calculation of AC PCB trace width can be performed by the following formula: W = (I / J) * K, where W represents the trace width, I represents the current, J represents the current density, and K represents a coefficient related to materials and processes. ‌This formula shows that the trace width is related to the current, current density, and material properties‌.
AC in PCB Design Guide
Current Carrying Capacity: The width of a trace directly affects its ability to handle current without exceeding temperature limits or causing excessive voltage drop. ‌Impedance Control: In high-frequency applications, maintaining controlled impedance is critical for signal integrity. Trace width, trace spacing, and dielectric properties affect the characteristic impedance of the transmission line. ‌Heat Dissipation: Adequate trace width helps to effectively dissipate heat, preventing thermal issues such as trace delamination or solder joint failure. ‌Voltage Drop: Narrower traces exhibit higher resistance, resulting in increased voltage drop along the length of the trace. By adjusting the trace width, the voltage drop can be minimized. ‌Manufacturability: The PCB manufacturing process imposes restrictions on the minimum trace width, and designers must balance performance requirements with manufacturability constraints. ‌2. ‌Minimum Trace Width: Most manufacturers have a minimum trace width of 6mil or 0.152mm, and typically use traces of 0.254-0.3mm. ‌Material and Process Deviations: Due to the possibility of material and process deviations in the actual PCB manufacturing process, a certain margin needs to be left when calculating the line width. ‌Signal Integrity Simulation‌: Perform signal integrity simulations to ensure impedance is controlled and signal degradation due to reflections, crosstalk, or transmission line effects is minimized‌
AC in PCB wiring
The current trend is that the power supply voltage is getting lower and lower (especially for highly integrated digital devices), the space occupied is getting smaller and smaller, the weight is getting lighter and lighter, and the efficiency is getting higher and higher, which requires the precise design of the power supply circuit starting from the PCB.
Safety distance includes electrical clearance (spatial distance), creepage distance (surface distance) and insulation penetration distance…
Electrical clearance: the shortest distance between two adjacent conductors or one conductor and the adjacent motor housing surface measured along the air.
Creepage distance: the shortest distance between two adjacent conductors or one conductor and the adjacent motor housing surface measured along the insulation surface.
Determination of electrical clearance:
The distance can be determined according to the measured working voltage and insulation level
The electrical clearance size requirements of the primary side line are shown in Table 3 and Table 4
The electrical clearance size requirements of the secondary side line are shown in Table 5
But usually: Primary side AC part: L-N ≥ 2.5mm before the fuse, L.N PE (earth) ≥ 2.5mm, no requirements are made after the fuse is installed, but a certain distance should be maintained as much as possible to avoid short circuit damage to the power supply.
Primary side AC to DC part ≥2.0mm
Primary side DC ground to earth ≥2.5mm (primary side floating ground to earth)
Primary side to secondary side ≥4.0mm, components connected between primary and secondary sides
Secondary side gap ≥0.5mm
Secondary side ground to earth ≥1.0mm
Note: Before determining whether it meets the requirements, the internal parts should be applied with a force of 10N and the outer shell with a force of 30N to reduce the distance so that the space distance still meets the requirements under the worst case.
Determination of creepage distance:
Based on the working voltage and insulation level, the creepage distance can be determined by looking up Table 6
But usually: (1), primary side AC part: L-N ≥2.5mm before the fuse, L.N earth ≥2.5mm, no requirement is required after the fuse, but try to keep a certain distance to avoid short circuit damage to the power supply.
(2) Primary side AC to DC part ≥2.0mm
(3) Primary side DC ground to ground ≥4.0mm such as primary side ground to earth
(4) Primary side to secondary side ≥6.4mm, such as optocoupler, Y capacitor and other components, the foot spacing ≤6.4mm needs to be slotted.
(5) Secondary side parts ≥0.5mm
(6) Secondary side ground to earth ≥2.0mm or more
(7) Transformer two-stage ≥8.0mm or more
Insulation penetration distance:
It should meet the following requirements according to the working voltage and insulation application:
For working voltage not exceeding 50V (71V AC peak or DC value), there is no thickness requirement;
The minimum thickness of additional insulation should be 0.4mm;
When the reinforced insulation is not subjected to any mechanical stress that may cause deformation or performance degradation of the insulating material at normal temperature, the minimum thickness of the reinforced insulation should be 0.4mm. If the insulation provided is used in the protective casing of the equipment and will not be bumped or scratched during maintenance by the operator, and any of the following conditions apply, the above requirements do not apply to thin insulating materials regardless of their thickness;
For additional insulation, at least two layers of material are used, each of which can pass the dielectric strength test for additional insulation; or:
For additional insulation composed of three layers of material, any combination of two layers of material can pass the dielectric strength test for additional insulation; or:
For reinforced insulation, at least two layers of material are used, each of which can pass the dielectric strength test for reinforced insulation; or:
For reinforced insulation composed of three layers of insulating material, any combination of two layers of material can pass the dielectric strength test for reinforced insulation.
Points to note about wiring process:
Flat components such as capacitors must be flat without glue.
If the distance between two conductors can be shortened by applying a force of 10N, which is less than the safety distance requirement, glue can be used to fix the part to ensure its electrical clearance.
When laying PVC film inside some shell equipment, attention should be paid to ensuring the safety distance (pay attention to the processing technology).
When fixing the parts with glue, be careful not to leave foreign matter such as glue wire on the PCB board.
When processing parts, insulation damage should not be caused.
Requirements for flame-proof materials:
Heat shrink tubing V-1 or VTM-2 or above; PVC tubing V-1 or VTM-2 or above
Teflon tubing V-1 or VTM-2 or above; plastic materials such as silicone sheets, insulating tape V-1 or VTM-2 or above
PCB board 94V-1 or above
Regarding insulation level
(1) Working insulation: insulation required for normal operation of equipment
(2) Basic insulation: insulation that provides basic protection against electric shock
(3) Supplementary insulation: independent insulation applied in addition to basic insulation to protect against electric shock in case of basic insulation failure
(4) Double insulation: insulation consisting of basic insulation plus supplementary insulation
(5) Reinforced insulation: a single insulation structure that provides the same level of protection against electric shock as double insulation under the conditions specified in this standard
The applicable situations of various insulation are as follows:
A. Operational insulation
a. Between parts with different voltages
b. Between ELV circuits (or SELV circuits) and grounded conductive parts.
B. Basic insulation
a. Between parts with dangerous voltages and grounded conductive parts;
b. Between SELV circuits with dangerous voltages and grounding-dependent;
c. Between the primary power conductor and the grounded shield or the core of the main power transformer;
d. As part of double insulation.
C. Supplementary insulation.
a. Generally speaking, between accessible conductive parts and parts that may carry dangerous voltages after basic insulation is damaged, such as:
â… . Between the surface of handles, knobs, handles or similar objects and their ungrounded axis.
â…¡. Between the metal casing of the second category equipment and the outer skin of the power cord passing through this casing.
â…¢. Between the ELV circuit and the ungrounded metal casing.
b. As part of double insulation
D. Double insulation
Double insulation Reinforced insulation
Generally speaking, between the primary circuit and
a. between accessible ungrounded conductive parts, or
Under normal working conditions, the AC peak value between conductors or between any conductors does not exceed 42.4V or the DC value does not exceed 60V.
SELV circuit: safety extra low voltage circuit.
A properly designed and protected secondary circuit so that under normal conditions or single fault conditions, the voltage between any two accessible parts, and between any accessible parts and the protective grounding terminal of the equipment (only for Class I equipment) will not exceed the safety value.
TNV: communication network voltage circuit
Under normal working conditions, the circuit carrying communication signals
Difference between direct current and alternating current
‌The main differences between DC and AC include direction and polarity, voltage change, current loss, transformer use, and application scenarios.
‌Direction and polarity:
DC: The direction of the current remains unchanged, and the electrons flow from the positive electrode to the negative electrode.
AC: The direction of the current changes periodically, and the electrons flow back and forth between the positive and negative electrodes. ‌ ‌Voltage change:
DC: The voltage remains constant and does not change over time.
AC: The voltage magnitude and direction change periodically over time. For example, the mains is an AC with a sine waveform.
‌Current loss:
DC: Fault losses are relatively small.
AC: There is capacitive current, and there is capacitive current in the transmission line. ‌ ‌Transformer use:
DC: The voltage cannot be changed using a transformer.
AC: The voltage can be changed using a transformer, which is suitable for boosting voltage to reduce losses during long-distance transportation.
‌Application scenarios:
DC: Suitable for low-voltage electrical appliances and occasions that require stable current. ‌Alternating current‌: Suitable for household and industrial use, using transformers to change voltage to suit different needs.‌
FAQ About AC in PCB
FAQ About AC in PCB
Q: The relationship between PCB current and line width. Is the current divided into AC or DC? A: The relationship between PCB current and line width is not divided into AC or DC. In terms of the nature of the lines on the PCB, the lines are all made of copper materials, and both AC and DC can pass. However, how much current can pass depends on the cross-sectional area of ​​the line on your PCB. That is, line width x thickness of the copper foil of the line. If the cross-sectional area of ​​the line is small, only small current signals can pass, and if the cross-sectional area is large, large current signals can pass. This signal can be AC ​​or DC. Not just 1mm, any line width can pass DC or AC signals.
Q: There is a packaged device, and there are 2 pins in the device that need to be connected to the live wire and neutral wire of 220V AC respectively. So how to deal with this power line when drawing the PCB? Are there any size requirements for pads, wires, etc.? Are there any protective measures required? Is it not possible to directly add pads to connect to the pin pads of the device? A: It is best to mill a groove between the neutral wire and the live wire, and choose the thickness of the wire according to the current. When the current is large, you can put a tin layer on the wire, and the pad should be slightly larger.
Q: The grounding of the PCB circuit board design is also the negative pole. What is the difference between the grounding here and the AC grounding?
A: The concept of the circuit board ground is somewhat different from that of the power supply system. The power supply system refers to the earth, that is, the terminal with the same potential as the earth.
The ground in the circuit board is just a common terminal of a potential, which can be positive or negative, depending on the needs of the designer. It’s just that everyone is used to and assumes that the negative pole is the common terminal, that is, the ground. The circuit board ground is not necessarily connected to the earth.
But it must be connected to the earth when EMI filtering is required.
Q: Should all GNDs on the PCB board be connected? There is a terminal (screw type) with two terminals marked as V1+ and V1- on the PCB schematic. Should V1- be connected to the power supply ground? But I used a multimeter to measure why V3- is not connected to other GNDs on the board?
So how do you connect the ground and 10V of the power supply to the V1+ and V1- ends of the terminal?
A: Not all ground wires on the board are connected together. The ground wires are divided into analog ground and digital ground, just like the ground wire in DC and the ground wire in AC cannot be connected together. That is to say, there is a ground wire that is specifically used for power supply, and there is a ground wire that is specifically used for signals (shielding signal interference). These two ground wires cannot be connected together. In addition, you mentioned V1+ and V1-, and V1- should not be considered a ground wire. Generally, the signal represented by this method is a differential signal, that is, the V1 signal is differentially divided into V1+ and V1-, which can reduce external interference and transmit farther. Finally, V1+ and V1- are integrated into the V1 signal. You need to figure out whether the V1+ and V1- of the terminal are used for power supply. If they are used for power supply, then V1+ is the positive pole. V1- is the negative pole. Since you didn’t show us the picture, you can’t just connect it randomly. The circuit board needs to connect not only power but also signals, depending on how your board is made.
