Why do so many PCB designers choose copper plating? Is it necessary?
2024-12-11
After all PCB design content is completed, the last critical step is usually carried out-copper laying.
Copper laying is to cover the unused space on the PCB with copper surface. Various PCB design software provide intelligent copper laying function. Usually the area where copper is laid will turn red, indicating that this area is covered with copper.
So, why is copper laid at the end? Isn’t it possible not to pave it?
For PCB, laying copper has many functions, such as reducing the impedance of the ground wire and improving the anti-interference ability; connecting to the ground wire to reduce the loop area; and helping to dissipate heat, etc.
1. Copper laying can reduce the ground impedance and provide shielding protection and noise suppression.
There are a lot of spike currents in digital circuits, so it is more necessary to reduce the ground impedance. Copper laying is a common method to reduce the ground impedance.
Copper laying can reduce the resistance of the ground wire by increasing the conductive cross-sectional area of the ground wire; or shorten the length of the ground wire and reduce the inductance of the ground wire, thereby reducing the impedance of the ground wire; it can also control the capacitance of the ground wire so that the ground wire can be The capacitance value of the line is appropriately increased, thereby improving the conductive performance of the ground wire and reducing the impedance of the ground wire.
A large area of ground or power supply copper can also play a shielding role, helping to reduce electromagnetic interference, improve the anti-interference ability of the circuit, and meet EMC requirements.
In addition, for high-frequency circuits, copper laying provides a complete return path for high-frequency digital signals, reducing DC network wiring, thereby improving the stability and reliability of signal transmission.
2. Copper laying can improve the heat dissipation capacity of PCB. In addition to reducing the ground wire impedance in PCB design, copper laying can also be used for heat dissipation.
As we all know, metal is a material that is easy to conduct electricity and heat. Therefore, if the PCB is covered with copper, the gaps in the board and other blank areas will have more metal components, and the heat dissipation surface area will increase, so it is easier for the overall heat dissipation of the PCB board. Copper paving can also help distribute heat evenly and prevent the creation of localized hot areas.
By evenly distributing heat to the entire PCB board, local heat concentration can be reduced, the temperature gradient of the heat source can be reduced, and heat dissipation efficiency can be improved.
Therefore, in PCB design, copper laying can be used to dissipate heat in the following ways:
Design the heat dissipation area: According to the heat source distribution on the PCB board, reasonably design the heat dissipation area, and lay enough copper foil in these areas to increase the heat dissipation surface area and heat conduction path.
Increase the thickness of copper foil: Increasing the thickness of copper foil in the heat dissipation area can increase the heat conduction path and improve heat dissipation efficiency.
Design heat dissipation through holes: Design heat dissipation through holes in the heat dissipation area to conduct heat to the other side of the PCB board through the through holes, increasing the heat dissipation path and improving heat dissipation efficiency.
Add heat sinks: Add heat sinks to the heat dissipation area to conduct heat to the heat sink, and then dissipate heat through natural convection or fan radiators to improve heat dissipation efficiency.
3. Copper laying can reduce deformation and improve PCB manufacturing quality.
Copper laying can help ensure the uniformity of electroplating, reduce the deformation of the board during the lamination process, especially for double-sided or multi-layer PCBs, and improve the manufacturing quality of PCBs.
If there is too much copper foil in some areas and too little in some areas, it will lead to uneven distribution of the entire board. Copper laying can effectively reduce this gap.
4. Meet the installation needs of special devices.
For some special devices, such as those that require grounding or special installation requirements, copper laying can provide additional connection points and fixed support to enhance the stability and reliability of the device. Therefore, based on the above advantages, in most cases, electronic designers will lay copper on the PCB board. However, copper laying is not a necessary part of PCB design.
In some cases, copper routing may not be appropriate or feasible. The following are some situations where copper laying is not appropriate:
① High-frequency signal lines: For high-frequency signal lines, copper laying may introduce additional capacitance and inductance, affecting signal transmission performance. In high-frequency circuits, it is usually necessary to control the routing of the ground wire to reduce the return path of the ground wire instead of over-laying copper. For example, copper plating will affect the signal of the antenna part. Laying copper in the area around the antenna part can easily cause the signal collected by weak signals to receive relatively large interference. The antenna signal is very strict for the amplification circuit parameter settings, and the impedance of the copper layer will affect the performance of the amplification circuit. Therefore, the area around the antenna part is generally not covered with copper.
② High-density circuit boards: For circuit boards with higher density, excessive copper laying may cause short circuits or grounding problems between lines, affecting the normal operation of the circuit. When designing high-density circuit boards, you need to carefully design the copper layout to ensure sufficient spacing and insulation between lines to avoid problems.
③. Too fast heat dissipation and difficult welding: If the component pins are fully covered with copper, it may cause heat dissipation too fast, making desoldering and repair difficult. We know that copper has a high thermal conductivity. Therefore, whether it is manual soldering or reflow soldering, the copper surface will quickly conduct heat during soldering, causing the temperature of the soldering iron to lose, which will affect the welding. Therefore, the design should try to use "cross flower pads" to reduce heat dissipation and facilitate welding.
④. Special environmental requirements: In some special environments, such as high temperature, high humidity, corrosive environments, etc., the copper foil may be damaged or corroded, thus affecting the performance and reliability of the PCB board. In this case, it is necessary to select appropriate materials and processing methods according to specific environmental requirements, rather than over-plating copper.
⑤. Special-level boards: For special-level boards such as flexible circuit boards and rigid-flexible composite boards, copper laying design needs to be carried out according to specific requirements and design specifications to avoid problems with the flexible layer or rigid-flexible composite layer caused by excessive copper laying.
To sum up, in PCB design, it is necessary to make the appropriate choice of copper laying or no copper laying according to the specific circuit requirements, environmental requirements and special application scenarios.
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How much do you know about the special process of PCB - the nickel-palladium gold process?
2024-11-27
Among the surface treatment processes for printed circuit boards (PCBs), the nickel-palladium-gold process has attracted much attention for its excellent performance and wide range of applications. This process provides reliable guarantee for PCB in complex electronic application environments, ensuring the high performance and stability of electronic equipment.
I. Basic principles of nickel-palladium alloy process
The nickel-palladium-gold process is a surface treatment technology that sequentially forms a nickel layer, a palladium layer, and a gold layer on the copper surface of a PCB through chemical deposition. Its principle is based on the redox process in chemical reactions. In an electroless plating solution containing nickel salt, palladium salt and gold salt, the copper surface of PCB is used as a reducing agent. Under the action of specific temperature, pH value and additives, the metal The ions are gradually reduced and deposited on the copper surface. First, nickel ions are reduced on the copper surface to form a nickel layer. The role of the nickel layer is to provide a flat, uniform and good adhesion base, and also provide certain protection for the subsequent palladium layer and gold layer. Next, palladium ions are reduced and deposited on the nickel layer to form a palladium layer. The palladium layer has good corrosion resistance and serves as a transition layer between the gold layer and the nickel layer. It can effectively prevent the oxidation of the nickel layer and improve the quality of the gold layer. of adhesion. Finally, gold ions are reduced on the palladium layer to form a gold layer. The gold layer gives the PCB good conductivity, solderability and oxidation resistance, ensuring that the connection parts of the PCB can be stable during the assembly and use of electronic equipment. Works reliably.
II. The operation process of nickel-palladium-gold process
(1) Pre-processing.
Before proceeding with the nickel-palladium-gold process, the PCB needs to be thoroughly pre-processed. This includes steps such as degreasing, micro-etching, and pre-soaking. Degreasing is to remove oil stains and impurities on the PCB surface. Alkaline degreasers are usually used to emulsify the oil stains and separate them from the PCB surface by soaking or spraying. Micro-etching uses an acidic solution to slightly etch the copper surface to remove the oxide layer on the copper surface, activate the copper surface, and increase the bonding force with subsequent plating. The pre-soaking step is to immerse the PCB in a solution that is similar to the chemical plating solution but does not contain metal ions. The purpose is to prevent the PCB from bringing moisture or impurities into the chemical plating solution, affecting the stability of the plating solution and the quality of the coating.
(2) Electroless nickel plating.
The pre-treated PCB enters the electroless nickel plating bath. The electroless nickel plating solution contains nickel salts (such as nickel sulfate), reducing agents (such as sodium hypophosphite), buffers, stabilizers and other ingredients. Under appropriate temperature (generally 80 - 90°C) and pH (approximately 4.5 - 5.5) conditions, nickel ions are reduced and deposited on the copper surface to form a nickel layer. During the nickel plating process, parameters such as the temperature, pH value, nickel ion concentration, and stirring speed of the plating solution need to be strictly controlled. Too high a temperature may cause the plating solution to decompose, and too low a temperature will cause the deposition rate to be too slow; improper pH value will affect the nickel deposition rate and coating quality; insufficient nickel ion concentration will cause uneven coating thickness, and too fast or excessive stirring speed will affect the nickel deposition rate and coating quality. Slow will affect the uniformity of the plating solution and the flatness of the coating. The thickness of the nickel layer is generally controlled at 3 - 5 μm, which is achieved by controlling the nickel plating time.
(3) Electroless palladium plating
After completing the electroless nickel plating, the PCB enters the electroless palladium plating bath. The electroless palladium plating solution contains palladium salts (such as palladium chloride), complexing agents, reducing agents, etc. The deposition of the palladium layer also requires precise control of process parameters, such as temperature, pH value, palladium ion concentration, etc. The temperature for palladium plating is usually between 40 - 60°C and the pH is around 8 - 9. The thickness of the palladium layer is relatively thin, generally between 0.05 - 0.2μm. It plays a key role in the entire process, not only protecting the nickel layer from oxidation, but also providing a good adhesion basis for the gold layer.
(4) Chemical gold plating.
Electroless gold plating is the final step in the nickel-palladium gold plating process. The electroless gold plating liquid contains gold salts (such as potassium gold cyanide or cyanide-free gold salts), complexing agents, reducing agents and other ingredients. The gold plating process takes place at lower temperatures (approximately 25 - 35°C) and typically has a pH of 4 - 6. The thickness of the gold layer varies according to different application requirements, usually between 0.025-0.1μm. The main function of the gold layer is to provide excellent conductivity, solderability and oxidation resistance, ensuring the electrical connection performance and long-term stability of PCB in electronic equipment. During the gold plating process, special attention should be paid to the concentration of gold salt and the control of gold plating time to obtain a uniform and dense gold layer.
(5) Post-processing.
After chemical gold plating is completed, the PCB needs to be post-processed. Post-processing consists of cleaning and drying steps. Cleaning is to remove the remaining plating solution and impurities on the PCB surface. A multi-stage cleaning process is used, such as rinsing first with clean water and then with deionized water to ensure that the PCB surface is clean. Drying involves drying the cleaned PCB in a low-temperature, low-humidity environment to prevent oxidation of the coating and residual water stains.
III. Advantages of nickel-palladium-gold process
(1) Good welding performance.
The gold layer has excellent solderability. During the assembly process of electronic equipment, whether reflow soldering, wave soldering or manual soldering is used, PCBs treated with nickel-palladium gold can achieve good soldering effects. Compared with the traditional tin plating process, the nickel-palladium process can maintain stable welding performance during multiple welding processes, reduce the occurrence of welding defects such as false welding and continuous welding, and improve the production qualification rate and reliability of electronic equipment.
(2) Excellent corrosion resistance
The combination of nickel, palladium and gold layers provides the PCB with strong protection against corrosion. Under harsh environmental conditions such as humidity, high temperature, acid and alkali, nickel-palladium-gold plating can effectively prevent copper oxidation and corrosion and extend the service life of PCB. This is particularly important for some electronic equipment that is used outdoors or in industrial environments for a long time, such as communication base station equipment, industrial control panels, etc.
(3) High reliability and stability
The plating structure formed by the nickel-palladium-gold process is dense and uniform, and has strong adhesion with the copper surface. During the long-term operation of electronic equipment, it can ensure the stability of signal transmission and the reliability of electrical connections. The existence of the palladium layer effectively solves the problem of the nickel layer being easily oxidized and causing the gold layer to fall off, improves the stability of the entire coating system, and reduces electronic equipment failures caused by coating failure.
(4) Adapt to a variety of electronic applications
Due to its good comprehensive performance, the nickel-palladium process is suitable for various types of electronic equipment, including consumer electronics, communication equipment, computers, automotive electronics, medical electronics and other fields. Whether it is high-speed digital circuits, high-frequency analog circuits or high-power circuits, PCBs treated with nickel-palladium alloy can meet their strict requirements for surface treatment.
IV. Application Scenarios of Nickel-Palladium Process
(1) Consumer electronics field.
In consumer electronics products such as smartphones, tablets, and laptops, the performance and reliability of PCB directly affect the quality and user experience of the product. Nickel-palladium technology is widely used in the motherboards, small boards and PCBs of various functional modules of these products. For example, after the chip welding parts and connector interfaces on mobile phone motherboards are treated with nickel-palladium technology, high-precision welding can be achieved, ensuring fast and accurate signal transmission, and at the same time improving the corrosion resistance of the motherboard in daily use. Extends the life of the mobile phone.
(2) Communication equipment field
Communication base station equipment, 5G communication modules, optical communication equipment, etc. have extremely high requirements on PCBs. The application of nickel-palladium-based technology in these communication equipment is mainly reflected in its ability to meet the low-loss requirements of high-frequency signal transmission and the reliability requirements of long-term stable operation. On the RF module PCB of the base station equipment, the nickel-palladium-gold coating can ensure the integrity of the RF signal during transmission, reduce signal attenuation and reflection, and at the same time, effectively prevent PCB corrosion and oxidation in harsh outdoor environments, ensuring communication. Stable operation of the network.
(3) Computer field.
Computer motherboards, graphics cards, server motherboards, etc. are important application areas for the nickel-palladium process. During the high-speed operation of the computer, a large amount of data needs to be transmitted between various components on the motherboard. The PCB treated with nickel-palladium technology can provide low-impedance electrical connections to ensure efficient data transmission. At the same time, in equipment that runs continuously for a long time such as servers, the corrosion resistance and stability of nickel-palladium plating can ensure that the PCB operates reliably in high-temperature and high-humidity computer room environments, reducing equipment maintenance costs.
(4) Automotive electronics field.
With the continuous improvement of automobile electronics, PCBs in automobile electronic systems are facing more complex and harsh working environments. The application of nickel-palladium technology on PCBs such as automobile engine control units (ECUs), in-vehicle entertainment systems, and airbag control systems can improve the PCB's resistance to vibration and impact, and at the same time, it can protect the PCB from moisture and humidity encountered during automobile operation. In the environment of oil pollution, acid and alkali, etc., it maintains good electrical performance and reliability to ensure the safe driving of the car.
(5) Medical electronics field.
Medical electronic equipment such as electrocardiographs, blood glucose meters, medical monitors, etc. have extremely high requirements on the safety and reliability of PCBs. The PCB processed by the nickel-palladium-gold process can meet the requirements for use of medical equipment in sterilized and humid environments, prevent the precipitation of copper ions from causing harm to the human body, and ensure the accuracy and stability of signal transmission during long-term operation of the equipment. , providing reliable technical support for medical diagnosis and treatment.
5. Challenges and countermeasures faced by nickel-palladium-gold process
(1) High process cost.
The production cost of the nickel-palladium-gold process is relatively high due to the use of expensive chemical reagents such as nickel salts, palladium salts, and gold salts, as well as strict requirements for process equipment and environmental control. In order to reduce costs, we can start from the following aspects: first, optimize the plating solution formula, improve the utilization rate of metal ions and reduce the consumption of chemical reagents by developing new complexing agents, reducing agents and other ingredients; second, improve the process equipment , using equipment with a high degree of automation and high plating solution recycling rate to improve production efficiency and reduce equipment operating costs; third, establish long-term cooperative relationships with suppliers to strive for more favorable raw material purchase prices, while strengthening internal cost management and controlling production Various expenses incurred during the process.
(2) High environmental pressure
Some chemical reagents used in the nickel-palladium oxidation process, such as potassium gold cyanide, etc., have certain toxicity and are potentially harmful to the environment and human health. In addition, the wastewater generated during the chemical plating process contains a large amount of metal ions and chemical agents, which require strict environmental treatment. In order to cope with environmental pressure, on the one hand, we can develop and promote cyanide-free nickel-palladium-gold processes, and use environmentally friendly materials such as cyanide-free gold salts to replace traditional toxic chemical reagents; on the other hand, we can establish a complete wastewater treatment system and use chemical precipitation, ion exchange, membrane separation and other technologies to treat wastewater, so that the treated wastewater meets the national environmental emission standards. At the same time, we will strengthen the company's environmental management, improve employees' environmental awareness, and ensure that environmental protection measures in the process are effectively implemented.
(3) Process control is difficult
The nickel-palladium-gold process involves multiple chemical deposition steps. The process parameters of each step are interrelated and have a great impact on the quality of the coating, such as temperature, pH value, metal ion concentration, stirring speed, etc. Achieving stable, high-quality coatings requires precise control of these process parameters. In order to solve the problem of difficult process control, advanced automated control systems can be used to monitor and automatically adjust the temperature, pH value, concentration and other parameters of the plating solution in real time; strengthen the monitoring and detection of the process through online testing equipment and experiments Use laboratory analysis methods to promptly discover process abnormalities and take measures to make adjustments; at the same time, improve the technical level and process management capabilities of operators, and enable operators to master the control points of process parameters and methods of coping with process problems through training and experience accumulation. . To sum up, the nickel-palladium-gold process in the special PCB process plays an irreplaceable and important role in the field of modern electronic manufacturing. Although faced with challenges such as high costs, high pressure on environmental protection, and difficult process control, with the continuous innovation and advancement of technology, through various efforts such as optimizing processes, developing new materials, strengthening environmental protection measures, and improving process management levels, chemical products have The nickel-palladium technology will continue to exert its advantages in future electronic equipment manufacturing, providing a strong guarantee for the high performance, high reliability and long life of electronic equipment.
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How much do you know about ceramic printed circuit boards?
2024-11-12
1. The development background of ceramic circuit boards.
The first-generation semiconductor technology represented by silicon (Si) and germanium (Ge) materials is mainly used in the field of data computing and lays the foundation for the microelectronics industry. Second-generation semiconductors, represented by gallium arsenide (GaAs) and indium phosphide (InP), are mainly used in the communications field to produce high-performance microwave, millimeter wave and light-emitting devices, laying the foundation for the information industry. With the continuous expansion of technological development and application needs, the limitations of the two have gradually emerged, making it difficult to meet the use requirements of high frequency, high temperature, high power, high energy efficiency, resistance to harsh environments, and lightweight and miniaturization. The third-generation semiconductor materials represented by silicon carbide (SiC) and gallium nitride (GaN) have the characteristics of large band gap, high critical breakdown voltage, high thermal conductivity, and high carrier saturation drift speed. Their production Electronic devices can work stably at temperatures of 300°C or higher, and have broad application prospects in semiconductor lighting, automotive electronics, new generation mobile communications (5G), new energy and new energy vehicles, high-speed rail transit, consumer electronics and other fields. The application prospects are expected to break through the bottleneck of traditional semiconductor technology, complement the first and second generation semiconductor technologies, and have important application value in optoelectronic devices, power electronics, automotive electronics, aerospace and other fields. With the rise and application of third-generation semiconductors, semiconductor devices are gradually developing in the direction of high power, miniaturization, integration, and multi-function, which also puts forward higher requirements for the performance of packaging substrates. Ceramic circuit boards have the characteristics of high thermal conductivity, good heat resistance, low thermal expansion coefficient, high mechanical strength, good insulation, corrosion resistance, radiation resistance, etc., and are widely used in electronic device packaging.
2. Technical Classification of Ceramic Circuit Boards Ceramic circuit boards include ceramic substrates and metal circuit layers.
For electronic packaging, the packaging substrate plays a key role in connecting the previous and the next, connecting internal and external heat dissipation channels, and has functions such as electrical interconnection and mechanical support. Ceramics have the advantages of high thermal conductivity, good heat resistance, high mechanical strength, and low thermal expansion coefficient. It is a commonly used substrate material for power semiconductor device packaging. According to different preparation principles and processes, currently commonly used ceramic substrates can be divided into Thin Film Ceramic Substrate (TFC), Thick Printing Ceramic Substrate (TPC), and Direct Bonded Copper Ceramic Substrate (DBC), Direct Plated Copper Ceramic Substrate (DPC), etc. This article analyzes the physical properties of commonly used ceramic substrate materials (including Al2O3, AlN, Si3N4, BeO, SiC and BN, etc.), focusing on introducing the preparation principles, process flows and technical characteristics of various ceramic substrates.
2.1Thin-film ceramic circuit board
Thin film ceramic circuit board (TFC), also known as thin film circuit, generally uses a sputtering process to directly deposit a metal layer on the surface of the ceramic substrate, and uses photolithography, development, etching and other processes to pattern the metal layer into circuits ... Because TFC uses high-precision photoresist as the photoresist material, combined with photolithography and etching technology, TFC's distinctive feature is high pattern accuracy, such as line width/slit width less than 10 μm. TFC deposits thin film capacitors, thin film inductors, thin film resistors and distributed parameter circuit components on a ceramic substrate. It has a wide range of component parameters, high precision, and good temperature and frequency characteristics. It can work in the millimeter wave band and has a high level of integration. Due to its small size, the product is mainly used in small current devices in the field of communications. Due to the high operating frequency and the great impact of parasitic parameters on circuit performance, the TFC itself is small in size and has high component density. Therefore, there are very high precision and consistency requirements for circuit design, substrate and film patterning.
2.2 Thick film ceramic circuit board
The TPC substrate can be prepared by coating the metal slurry on the ceramic substrate through screen printing, drying and sintering at high temperature. Depending on the viscosity of the metal slurry and the size of the screen mesh, the thickness of the prepared metal circuit layer is generally 10 μm ~ 20 μm. Due to limitations of the screen printing process, TPC substrates cannot obtain high-precision lines (the minimum line width/line spacing is generally greater than 100 μm). In addition, in order to lower the sintering temperature and improve the bonding strength between the metal layer and the ceramic substrate, a small amount of glass phase is usually added to the metal slurry, which will reduce the electrical and thermal conductivity of the metal layer. Therefore, TPC substrates are only used in the packaging of electronic devices (such as automotive electronics) that do not have high requirements for circuit accuracy.
2.3 Direct bonding to ceramic substrate
To prepare the DBC ceramic substrate, oxygen element is first introduced between the copper foil (Cu) and the ceramic substrate (Al2O3 or AN), and then the CuO eutectic phase is formed at about 1065°C (the melting point of metallic copper is 1083°C), which is then combined with the ceramic substrate. The film and copper foil react to generate CuAlO2 or Cu(AO2)2, achieving eutectic bonding between copper foil and ceramics. Because ceramics and copper have good thermal conductivity, and the eutectic bonding strength between copper foil and ceramics is high, the DBC substrate has high thermal stability and has been widely used in insulated gate bipolar diodes (GBT), lasers (LD ) and focused photovoltaics (CPV) and other devices are being packaged for heat dissipation. DBC substrate copper foil has a large thickness (generally 100μm-600μm), which can meet the needs of device packaging applications in extreme environments such as high temperature and high current. Although DBC substrates have many advantages in practical applications, the eutectic temperature and oxygen content must be strictly controlled during the preparation process, which requires high equipment and process control, and the production cost is also high. In addition, due to the limitation of thick copper etching, it is impossible to prepare a high-precision circuit layer. In the DBC substrate preparation process, oxidation time and oxidation temperature are the two most important parameters. After the copper foil is pre-oxidized, the bonding interface can form enough CuxOy phase to wet the Al2O3 ceramic and copper foil, and has a high bonding strength; if the copper foil is not pre-oxidized, the CuxOy wettability is poor, and the bonding interface will be A large number of voids and defects remain, reducing bonding strength and thermal conductivity. For the preparation of DBC substrates using AlN ceramics, the ceramic substrate needs to be pre-oxidized to first form an Al2O3 film, and then react with the copper foil to produce a eutectic reaction. Xie Jianjun and others used DBC technology to prepare Cu/Al2O3 and Cu/AlN ceramic substrates. The bonding strength between copper foil and AlN ceramics exceeded 8N/mm. There was a transition layer with a thickness of 2 μm between the copper foil and AlN. Its components were mainly Al2O3 and CuAlO2. And Cu2O.
2.4 Direct electroplating of ceramic substrates
The DPC ceramic substrate preparation process is as follows: first, a laser is used to prepare through holes on the ceramic substrate (apertures are generally 60 μm ~ 120 μm), and then ultrasonic waves are used to clean the ceramic substrate; magnetron sputtering technology is used to deposit a metal seed layer on the surface of the ceramic substrate ( Ti/ Cu), then complete the circuit layer production through photolithography and development; use electroplating to fill holes and thicken the metal circuit layer, and improve the solderability and oxidation resistance of the substrate through surface treatment, and finally remove the dry film and etch the seed layer to complete the substrate preparation. The front end of DPC ceramic substrate preparation uses semiconductor micro-processing technology (sputtering coating, photolithography, development, etc.), and the back end uses printed circuit board (PCB) preparation technology (graphic plating, hole filling, surface grinding, etching, surface processing, etc.), the technical advantages are obvious. Specific features include: (1) Using semiconductor micro-machining technology, the metal circuits on the ceramic substrate are finer (the line width/line spacing can be as low as 30μm~50μm, related to the thickness of the circuit layer), so the DPC substrate is very suitable for applications with higher alignment accuracy requirements. High-quality microelectronic device packaging; (2) Using laser drilling and electroplating hole filling technology to achieve vertical interconnection on the upper/lower surface of the ceramic substrate, three-dimensional packaging and integration of electronic devices can be achieved, and the device volume can be reduced; (3) Electroplating growth is used to control the thickness of the circuit layer (generally 10μm~100μm), and the surface roughness of the circuit layer is reduced through grinding to meet the packaging requirements of high-temperature and high-current devices; (4) The low-temperature preparation process (below 300°C) avoids high-temperature damage to Substrate materials and metal circuit layers are adversely affected, while also reducing production costs. To sum up, the DPC substrate has the characteristics of high pattern accuracy and vertical interconnection, and is a true ceramic circuit board. The bonding strength between the metal circuit layer and the ceramic substrate is the key to affecting the reliability of the DPC ceramic substrate. Due to the large difference in thermal expansion coefficient between metal and ceramic, in order to reduce interface stress, it is necessary to add a transition layer between the copper layer and ceramic, thereby improving the interface bonding strength. Since the bonding force between the transition layer and ceramics is mainly based on diffusion adhesion and chemical bonding, metals with higher activity and good diffusivity such as Ti, Cr and Ni are often selected as the transition layer.
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In the first half of 2024, the PCB industry will see an obvious recovery trend
2024-10-09
The PCB industry is a basic industry for the manufacture of electronic information products and is greatly affected by cyclical fluctuations in the macro-economy. At present, global printed circuit board manufacturing companies are mainly distributed in mainland China, Taiwan, Japan, South Korea, the United States, Europe and Southeast Asia. my country's PCB industry has become the world's largest production base, and the impact of changes in the international political and economic environment on the domestic printed circuit board industry is becoming increasingly obvious.
The global PCB industry has recovered significantly and maintained a growth trend in the medium and long term
2023 is a challenging year for the global PCB industry. The impact of weak demand, severe backlog of inventory, oversupply and price erosion runs through the entire industry. Global PCB production fell to only US$69.5 billion in 2023, a year-on-year decrease of 15.0%.
In the first half of 2024, due to improved inventory and gradual recovery of demand, the PCB industry began to show signs of recovery. Observing the current destocking speed and rhythm, it is expected to continue to improve by the end of the year. In the second half of 2024, the inventory of most subdivided application areas will be fully normalized. 2024 is a year of recovery. According to Prismark's estimates, the PCB market as a whole will achieve positive growth, with output value expected to increase by about 5.0% year-on-year and area expected to increase by about 7.2% year-on-year. The higher growth in area relative to output value reflects the expected impact of continued price erosion.
It is normal for the PCB industry to experience a cycle from strong growth to weak growth or even contraction. In the medium and long term, artificial intelligence, HPC, communication infrastructure, automotive electronics, portable smart consumer electronic devices with advanced artificial intelligence capabilities, etc. are expected to generate incremental demand.
Based on the low base in 2023, Prismark predicts that the PCB market will grow from US$69.5 billion in 2023 to US$90.4 billion in 2028, with a five-year CAGR of about 5.4%. Southeast Asia is expected to achieve the highest growth rate in the next five years. China will continue to maintain its position as the industry's leading manufacturing center, but due to the product structure of China's PCB industry and some production transfers to Southeast Asia, Prismark predicts that China's PCB output value will grow at a compound annual growth rate of about 4.2% from 2023 to 2028, slightly lower than the global level. It is expected that China's PCB output value will reach about US$46.5 billion by 2028.
Prismark predicts that all segments of the multilayer PCB market will grow, and it is expected to grow from US$26.5 billion in 2023 to US$32.5 billion in 2028, with a five-year average annual compound growth rate of about 4.4%, among which the server/data storage field will grow the strongest, followed by military, wired infrastructure and automobiles.
Multilayer boards occupy a major market position, and high-performance products will grow faster in the future
With the innovative development of industries such as AI, data centers, VR/AR, new energy vehicles and intelligent driving, downstream application fields have put forward higher requirements for the performance of PCBs, such as high frequency, high speed, high voltage, heat resistance, and low loss. According to Prismark's forecast, the global PCB output value will grow at a compound annual growth rate of 5.4% from 2023 to 2028, reaching US$90.413 billion in 2028. Among them, 18+ multilayer boards, HDI, and package substrates will grow rapidly, with compound annual growth rates of 10%, 7.1%, and 8.8% respectively from 2023 to 2028. In terms of output value, multilayer boards are the main product category, with an output value of US$26.535 billion in 2023, accounting for 38.2% of the total output value, and a output value of US$32.483 billion in 2028, accounting for 35.9% of the total output value.
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What is the PCB industry chain like?
2024-09-27
The PCB industry plays a key role in the entire electronics industry chain.
The main raw materials required for the production of PCB include copper clad laminate, prepreg, copper foil, potassium gold cyanide, copper balls and ink.
Among them, copper clad laminate is the most important raw material. Copper clad laminate accounts for about 30%-40% of the entire PCB manufacturing cost. Copper foil is the main raw material for manufacturing copper clad laminate. The cost accounts for 30% (thin plate) and 50% (thick plate) of copper clad laminate.
The manufacturing process of copper-clad laminates is to impregnate reinforcing materials with organic resin and dry them to form a prepreg. A plate-like material made by laminating several prepregs together, covered with copper foil on one or both sides, and hot-pressed. The reason why various types of copper-clad laminates differ in performance is mainly due to the differences in fiber reinforcement materials and resins used.
According to Prismark data, in the global copper-clad laminate market share in 2023, Kingboard accounts for 14.6%, Shengyi Technology accounts for 14%, Taiwan Optoelectronics accounts for 10.3%, Nanya Plastics accounts for 9.1%, Panasonic accounts for 6.7%, and Lianmao Electronics Accounting for 6.3%, Taiyao Technology accounts for 4%, South Korea's Doosan accounts for 3.6%, Jinan Guoji accounts for 3.3%, and Nanya New Materials accounts for 3.2%.
Major copper foil manufacturers include Kingboard, Nanya Copper Foil, Copper Crown Copper Foil, Jiayuan Technology, Nord Co., Ltd., Longdianhuaxin, Changchun Chemical, Chaohua Technology, Jiangxi Copper Foil, etc.
Among downstream applications, the four major fields of communications, automotive electronics, consumer electronics, and servers account for a high proportion.
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