What is the difference between impedance PCB and non-impedance PCB?

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PCB board impedance control technology is an important link in PCB production. Impedance-controlled PCB boards can ensure the quality of signal transmission, but the cost will be relatively high. Non-impedance boards are relatively cheap, but in high-speed signal transmission environments, the signal transmission quality may decrease.

1. Definition and principles of impedance PCB and non-impedance PCB

Impedance control technology refers to controlling the impedance of electronic signals through the wiring design and manufacturing process of PCB boards to minimize distortion and reflection of signals during transmission. The impedance board uses special materials and manufacturing processes to control parameters such as line width, distance, load, etc. to ensure the stability and accuracy of signal transmission. Non-impedance boards use general PCB manufacturing processes and do not pay attention to signal impedance control.

2. Advantages and Disadvantages of  impedance PCB and non-impedance PCB

The main advantage of impedance plates is the high quality of signal transmission. The impedance-controlled PCB board can reduce signal distortion and reflection, and can also reduce signal interference and crosstalk, ensure that circuit noise is small, and improve signal transmission accuracy and stability. However, the cost of impedance control is relatively high, and the material and process requirements for PCB boards are also relatively high. In some special high-frequency and high-speed environments, impedance control may not fully meet the requirements. The main advantages of non-impedance boards are low production cost, simple production process and short manufacturing cycle. For some occasions where the transmission rate is not high and the circuit is simple, non-impedance boards can also meet the requirements. However, in some high-speed and high-frequency environments, non-impedance boards are prone to problems such as signal distortion, crosstalk, and noise, which will have a certain impact on the working stability and reliability of the circuit.

3. Applications of impedance PCB and non-impedance PCB

Impedance control technology is often used in high-speed signal transmission, high-frequency circuits, analog circuits and other fields. Usually in the design of high-speed AD, DA converters and high-speed digital signal processors, PCB boards using impedance control technology are required to ensure signal accuracy and stability. Non-impedance boards are usually used in some low-speed and low-frequency circuit designs, such as LED light bars, home appliance control boards, etc.

4. Manufacturing requirements and methods of impedance PCB and non-impedance PCB

The production of impedance-controlled PCB boards is highly demanding, requiring the use of high-precision manufacturing equipment and fine control of the materials and processes of the PCB boards. This can be achieved by using some high-impedance control design software and manufacturing processes. For example, during the design process, the upper and lower copper foils can be wired together to form a differential impedance. Use high dielectric constant dielectrics with controlled impedance greater than 1 such as FR4, ROGERS, etc. Non-impedance boards are relatively simple to make, and the process and material selection are also more flexible.

Impedance PCB and non-impedance PCB are suitable for different circuit design needs. Impedance PCB can ensure the quality of signal transmission in high-speed and high-frequency circuits, but the cost is relatively high. Non-impedance boards are suitable for the design of some low-frequency and low-speed circuits and have lower costs. Therefore, when selecting PCB board type, you need to make a reasonable choice based on the specific application environment and circuit design requirements.

What is the difference between high-frequency circuit boards and ordinary circuit boards? Comprehensive analysis of advantages and disadvantages!

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High-frequency circuit boards have higher operating frequencies and lower signal distortion rates, but their manufacturing costs are higher and manufacturing is more difficult. Ordinary circuit boards are relatively low-cost and simple to manufacture, but they cannot meet the working requirements of high-frequency circuits. This article comprehensively explains the differences and characteristics of these two circuit boards through comparisons in technical principles, material differences, design standards, manufacturing difficulty and other aspects.

1. Technical principles

The main difference between high-frequency circuit boards and ordinary circuit boards lies in the processing of electrical signals. In high-frequency circuits, the frequency of electronic signals exceeds 1MHz. At this time, the signal has extremely high frequency and transient response speed. Ordinary circuits can process low-frequency signals and process electrical signals in the range below 1MHz. Because the signal processing requirements of high-frequency circuits are more stringent, circuit boards equipped with high-frequency circuits are endowed with special capabilities such as high interconnection and low noise. Therefore, in order to ensure the normal operation of high-frequency circuit boards, high-frequency circuit boards need to have higher design and manufacturing standards.

2. Material differences

High-frequency circuit boards must be made of high-quality materials to meet their high-speed transmission-related properties. High-frequency circuit boards usually use silicone resin or PTFE (polytetrafluoroethylene) as the substrate material. In contrast, ordinary circuit boards generally use fiberglass, epoxy boards or multi-layer boards as the substrate materials. Among high-frequency materials, silicone and PTFE have the characteristics of lower performance loss, good high-frequency dielectric properties and excellent mechanical strength, while glass fiber and epoxy do not have such superior properties.

3. Design standards

The design standards of high-frequency circuit boards are relatively high, and it is necessary to fully consider the influence of the size of the circuit board, the position of the components and the board structure. In the PCB design of high-frequency circuit boards, design factors such as circuit trace width, line spacing, interlayer secants, no long ground and distributed capacitance need to be considered. Therefore, please note that great care must be taken during the design development of high-frequency circuit boards to ensure the reliability and quality of their functionality.

4. Manufacturing difficulty

The manufacturing of high-frequency circuit boards requires the use of more complex processing, production and testing equipment, with higher manufacturing standards and technical requirements. Factors such as narrow circuit traces and apertures, higher precision, and concise circuits make high-frequency circuit boards more difficult to manufacture and the manufacturing cost is relatively high. But once these requirements are met, more accurate results and lower signal distortion rates can be achieved.

High-frequency circuit boards have higher operating frequencies and lower signal distortion rates, so they are suitable for products in the fields of high-speed communications, wireless communications, and high-frequency applications. At the same time, the manufacturing cost of high-frequency circuit boards is relatively high, and the design is also difficult. Ordinary circuit boards are relatively low-cost and simple to manufacture, but they cannot meet the working requirements of high-frequency circuits, so they can only be used in applications with lower operating frequencies.

Learn about impedance board control technology and easily improve PCB signal transmission efficiency!

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Impedance PCB control technology can effectively improve PCB signal transmission efficiency, reduce signal interference, and ensure the reliability of data transmission.

1. The concept and function of impedance PCB

The impedance PCB refers to the geometric shape of the circuit board on the PCB, which is used to control the impedance matching of signals during PCB transmission. Impedance matching means that the impedance between the source and terminal is the same, so that neither the signal is reflected nor the signal is lost. In high-speed data transmission, the signal frequency is high, the signal waveform is seriously deformed, and signal reflection and signal loss are prone to occur, thus reducing the signal transmission efficiency. Therefore, the design of the impedance board is very important, which can help us control the impedance matching of the signal, reduce signal loss and reflection, and improve the reliability of signal transmission.

2. Design of impedance PCB

The design of the impedance PCB needs to consider board thickness, board dielectric constant, line width and distance, and the number of wiring layers. The larger the thickness of the board and the thinner the line width, the impedance of the signal will also increase; the larger the dielectric constant of the board, the impedance will also increase accordingly; the smaller the line spacing can also increase the impedance. Through the design of these parameters, the impedance of the signal can be effectively controlled and the stability of signal transmission can be improved.

3. Optimization of impedance PCB

The optimization of the impedance PCB mainly includes three aspects: trace layout, line width and line spacing optimization, and location optimization. In actual applications, the layout of the circuit board also has a great impact on impedance matching, so some optimization needs to be done. In terms of wiring layout, design principles such as focusing on route length, avoiding right-angle lines, and avoiding side-by-side lines can be adopted; for optimization of line width and line spacing, technologies such as microstrip lines and coaxial cables can be considered to make the signal impedance close to 50Ω. In addition, designers need to optimize the impedance plate through electromagnetic field simulation analysis.

4. Detection and diagnosis of impedance PCB

During the PCB manufacturing process, the impedance board also needs to be tested and diagnosed to ensure the accuracy of the impedance parameters. The main detection methods include self-test method, inter-board test method, and time domain reflection method. At the same time, once an impedance mismatch is discovered, it needs to be resolved promptly.

Impedance board control technology is an important method to improve PCB signal transmission efficiency and reduce signal interference. By designing and optimizing the impedance plate, signal loss and reflection can be reduced and the reliability of signal transmission can be improved. At the same time, the accuracy of the impedance parameters is ensured through the detection and diagnosis of the impedance PCB. Impedance plate control technology is an indispensable part of circuit design.

How does exploring the history of automotive circuit boards change our lives?

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1. Concept and development history of automotive circuit boards

Automotive circuit boards are an important part of automotive electronic components and are used to control and manage various electronic devices in vehicles. Automotive circuit boards were originally composed of some simple circuit boards that provided basic electronic control functions for the vehicle. With the continuous advancement of technology, the complex functions of automobile circuit boards have been continuously strengthened, and more intelligent versions have emerged. Modern automotive circuit boards can already control most vehicle functions, such as airbags, in-car entertainment systems and traffic navigation.

2. Automobile circuit boards improve automobile performance and functions

The emergence of automotive circuit boards provides cars with more functions and options for optimizing performance. For example, some modern car circuit boards can control engine fuel consumption and emissions, thereby improving the vehicle’s fuel efficiency and environmental protection. In addition, automotive circuit boards can also control the vehicle’s acceleration and braking systems, further improving the vehicle’s performance and handling. In addition, automotive circuit boards can also control the vehicle’s communication system, making it easier for the vehicle to communicate with other vehicles and road information.

3. Automobile circuit boards promote automobile safety and stability

Automobile circuit boards also play a great role in promoting the safety and stability of automobiles. For example, some modern electronic stability control systems can control vehicle stability and directional control by controlling the rotation speed of the car’s tires and vehicle steering. In addition, automobile circuit boards can also control safety devices such as emergency braking devices and airbags while the vehicle is running, thereby better protecting the safety of drivers and passengers.

4. Future development prospects and possible changes of automotive circuit boards

As automotive circuit board technology continues to develop, it will bring more innovations and changes in the future. For example, automotive circuit boards will become smarter and more responsive to the needs of drivers and passengers. In addition, automotive circuit boards may also bring the potential to be more environmentally friendly and energy-saving, providing a more sustainable way of travel for cars.

The emergence and development of automotive circuit boards have changed our lifestyle and transportation methods. By discussing the improvement of automobile performance and functions, the promotion of automobile safety and stability, and the discussion of future development prospects, we can see the impact and contribution of automobile circuit boards on future travel methods. With future development and technological advancement, automotive circuit boards will continue to influence our lifestyle and transportation methods, and create a more intelligent, environmentally friendly and safer travel experience for us.

Speed up your circuit design! Understand the characteristics of high-frequency and high-speed PCB!

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Circuit design is a job that requires patience and care, as one error may affect the performance and reliability of the entire circuit. In circuit design, high-frequency and high-speed boards are a very important part because its characteristics will greatly affect the performance of the circuit. This article will elaborate on the characteristics of high-frequency and high-speed boards, including signal transmission, EMI suppression, wiring planning and material selection, while also providing some practical tips and suggestions to help speed up your circuit design.

1. Signal transmission

Signal transmission of high-frequency and high-speed boards is one of its most important features. Since high-frequency signals have very high frequencies and short wavelengths, special measures are required to ensure the quality and stability of signal transmission. A common method is to improve the signal-to-noise ratio and anti-interference ability of the signal by using differential signal pairs. In addition, during high-speed signal transmission, signal echo is also a factor that needs to be considered. Because signals travel quickly, echoes can cause signal distortion and performance degradation. In order to reduce echoes, appropriate termination resistors and snubber circuits can be used.

2. EMI suppression

EMI (electromagnetic interference) refers to the electromagnetic radiation generated by electronic equipment and the electromagnetic field interference felt, which can have a negative impact on the performance and stability of circuits. In the design process of high-frequency and high-speed boards, appropriate EMI suppression measures need to be taken. One of the commonly used methods is to reduce the area of the current loop and the path that forms the loop through reasonable layout of circuit traces. This can be accomplished by using ground plans, differential lines, and reducing power and ground current loops.

3. Wiring planning

The wiring planning of high-frequency and high-speed boards is a very important step in the design process. When planning wiring, factors such as circuit layout, wiring, power lines, and ground wires need to be considered. One common approach is to use different layers for routing. For example, you can use the inner layer for routing power and ground lines, and the outer layer for routing data lines. Through this method, the length and intersection of traces can be reduced, and signal distortion and noise interference can be reduced.

4. Material selection

The material selection of high-frequency and high-speed boards also affects the performance and reliability of the circuit. For example, different dielectric constants and dielectric losses affect the speed and transmission quality of signals. Therefore, when selecting materials, factors such as the dielectric constant, dielectric loss, thermal expansion coefficient, and thermal conductivity of the board need to be considered. At the same time, factors such as the cost and reliability of materials also need to be considered.

High-frequency and high-speed boards are a very important part of circuit design and require special attention to factors such as signal transmission, EMI suppression, wiring planning, and material selection. By using the appropriate techniques and measures, you can improve circuit performance and reliability and speed up your circuit design.

What is the function of PCB half hole?

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1、 Strengthening connections

The connectivity between electronic components is the foundation of circuit boards. In traditional circuit board manufacturing, electronic components are usually soldered onto the surface of the circuit board, and the connection method is relatively simple, which is prone to poor connectivity or virtual soldering. The use of PCB half hole technology can improve the connectivity between electronic components, making the performance of circuit boards more stable and reliable. In PCB half hole technology, electronic components are not only connected to the surface of the circuit board, but also pass through the PCB half hole and penetrate into another layer of the circuit board. In this way, the connectivity between electronic components becomes tighter, making it easier to meet the requirements of circuit board designers and improve the performance and reliability of circuit boards.

2、 Improve signal quality

The quality of the signal has a significant impact on the performance of the circuit board. In traditional circuit board manufacturing, signal lines are often affected by wiring or environmental factors, which can easily lead to signal crosstalk or signal loss. By using PCB half hole technology, these issues can be effectively improved. The signal line can pass through the PCB half hole and penetrate into another layer of the circuit board, thereby avoiding interference from wiring or environmental factors on the signal line. Meanwhile, due to the tighter connection between signal lines and electronic components, the quality of signal transmission will also be more stable, thereby improving the operational efficiency and reliability of the circuit board.

3、 Improve mechanical strength

Mechanical strength is a very important indicator in circuit board manufacturing. In traditional circuit board manufacturing, due to loose connections between electronic components and circuit boards, the mechanical strength of circuit boards is low, making them prone to bending or breaking. By using PCB half hole technology, the mechanical strength of the circuit board can be effectively improved. Electronic components are not only connected to the surface of the circuit board, but also penetrate through PCB half holes and penetrate into another layer of the circuit board. This design can make the connections between electronic components tighter, thereby enhancing the mechanical strength of the circuit board, reducing the probability of breakage, and improving the durability of the circuit board.

4、 Implement a multi-layer board structure

The multi-layer board structure is widely used in the manufacturing of modern circuit boards. It can greatly reduce the size and weight of the circuit board, while improving its performance and reliability. By using PCB half hole technology, a multi-layer board structure can be achieved. Electronic components can penetrate through PCB half holes and penetrate into another layer of the circuit board. In this way, the circuit board can be divided into multiple layers, achieving a multi-layer board structure. Compared with traditional multi-layer board manufacturing, PCB half hole technology not only makes multi-layer boards more precise, but also saves costs and time, improving manufacturing efficiency.

PCB half hole technology is an important technology in modern circuit board manufacturing. It plays an important role in strengthening connections, improving signal quality, enhancing mechanical strength, and achieving a multi-layer board structure. The use of PCB half hole technology to manufacture circuit boards is more precise and efficient, while also improving the performance and reliability of the circuit board. With the continuous development of electronic technology, PCB half hole technology will be further improved and promoted, bringing more innovation and development to circuit board manufacturing.

Which wiring form is better for PCB design?

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In PCB design, adopting appropriate wiring forms has a significant impact on the performance and reliability of the circuit. The following are several common wiring forms, each with its own advantages. Choosing the appropriate form based on specific design requirements will be more conducive to improving circuit performance and reliability.

1. Straight line routing: Straight line routing is the simplest and most common form of routing. It has the advantage of being direct and fast, which can reduce the delay of signal transmission. In circuit design, there are often signal lines that must be connected in a straight line, so using straight line routing can better meet this requirement.

2. 45 degree bend wiring: When it is necessary to introduce or lead the signal line into or out of the board, using a 45 degree bend wiring can reduce the reflection and interference of the signal line. Compared to right angle bending, 45 degree angle bending can better maintain the integrity of the signal.

3. Arc routing: Arc routing can reduce the radiation and crosstalk of signal lines, especially for high-frequency signals. If there are high-frequency signal lines in the design, using arc routing can reduce signal loss and distortion.

4. Node cross routing: In design, it is common to encounter situations where cross signals need to be connected. When cross routing nodes, attention should be paid to the distance between signal lines to prevent signal crosstalk. Interlayer routing, ground cutting, and other methods can be used to reduce signal interference.

5. Hard and flexible wiring: Hard and flexible wiring refers to signal transmission achieved through interlayer connections. It can improve the flexibility and reliability of design. Hard and flexible wiring is widely used in complex high-density circuit design, multi-layer board design, and so on.

6. Top/bottom wiring: In multi-layer board design, the top and bottom wiring can be used for shorter signal transmission paths, thereby reducing interlayer perforation and delay. At the same time, the top/bottom wiring can provide better shielding effect and reduce signal interference.

Although several common wiring forms are listed above, multiple factors need to be considered in actual design to choose the appropriate form. For example, the frequency characteristics of circuits, noise tolerance, power consumption requirements, and process constraints. When wiring, attention should also be paid to the separation between the signal, power supply, and ground wire, and the reasonable use of ground wire shielding technology.

In short, choosing the appropriate wiring form is crucial for the performance and reliability of the circuit. Based on specific design requirements and circuit characteristics, designers should comprehensively consider various factors and choose the optimal wiring form to optimize circuit design.

What are the protective measures and maintenance methods for PCB multi-layer circuit boards?

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（1）. Environmental protection

1. Keep the board surface dry: Excessive humidity can cause electrochemical reactions, oxidation and corrosion in multi-layer board circuits, and even cause short circuits in severe cases. Therefore, the environmental requirements for using PCB multi-layer circuit boards are relatively high, so try to keep the environment dry.

2. Pay attention to dust prevention: Dust and dirt are one of the main culprits that cause multi-layer PCB circuit board failures. Once they enter the circuit board, they will cause problems such as short circuit, discharge, leakage, etc. In serious cases, they may damage the PCB circuit board.

3. Avoid mechanical damage: Do not collide or scratch the surface of the multi-layer circuit board to avoid breaking the internal circuits and causing failure. At the same time, it is also necessary to avoid excessive force and pressure to prevent flexural damage to the board.

（2）. Manufacturing process

1. Strengthen design protection: During the design stage of PCB multi-layer circuit boards, attention should be paid to preventing possible problems and relevant protection measures should be set in advance. For example, divide high-voltage and high-current lines and low-voltage and low-current lines into different levels, and try to avoid running the lines in the same way or intersecting.

2. Strict quality control: Detailed quality control is required for each link during the manufacturing process. For example, operations in manufacturing processes such as drilling, crimping, and immersion metal need to be standardized to avoid human errors.

（3）. Transportation and installation

1. Prevent collisions: During the transportation of PCB multi-layer circuit boards, it is necessary to prevent them from being damaged by collisions with other hardware or products. Therefore, circuit boards need to be installed in special packaging boxes for transportation to avoid being affected by external forces.

2. Note on braking: When transporting multi-layer circuit boards, it is necessary to brake and slow down to avoid problems such as friction and heat caused by free sliding between the boards, resulting in line deformation and other problems.

（4）. Daily maintenance

1. Regular dust removal: In order to ensure the good working condition of the circuit board, regular dust removal is required to avoid the harm of dust to the circuit board. At the same time, you can also check the appearance of the circuit board for scratches or damage.

2. Replace capacitors regularly: Capacitors are one of the more easily damaged components in multi-layer PCB circuit boards. Once the service life expires or is affected by external factors, when problems occur, they should be replaced in time.

3. Keep dry: The working environment of multi-layer circuit boards needs to be dry. Avoid keeping circuit boards in a humid environment during daily maintenance. Pay attention to moisture-proofing during the rainy season.

When using PCB multi-layer circuit boards, you need to pay attention to protection and maintenance. Starting from four aspects: environmental protection, manufacturing technology, transportation and installation, and daily maintenance, the protective measures and maintenance methods of PCB multi-layer circuit boards are elaborated in detail. These measures play an important role in ensuring the normal operation of PCB multi-layer circuit boards during use, and are also of great significance in improving the reliability and service life of electronic products.

What are the benefits of Immersion Gold PCB?

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1. Corrosion resistance

Immersion gold PCB has excellent corrosion resistance. Its surface metal coating can effectively prevent the PCB board from being corroded by the external environment. Compared with other surface treatment processes, immersion gold PCB can better resist oxidation, sulfuration and chemical corrosion, thereby extending the service life of the circuit board.

2. Reliability

Immersion gold PCBs are widely used in electronic product manufacturing, mainly because of its reliability. The immersion gold layer has good flatness and smoothness and can provide a good welding surface. This makes the welding process more stable and reduces the risk of poor welding. In addition, immersion gold PCB can also provide good signal transmission performance, reduce signal loss and interference, and improve circuit reliability.

3. Weldability

Immersion gold PCB has good solderability. The immersion gold layer has good wettability and solderability, and can be well combined with solder. This makes the welding process easier and more stable, greatly improving welding efficiency. At the same time, the flatness and smoothness of the immersion gold layer also help reduce welding defects and improve welding quality.

4. Conductivity

Immersion gold PCB has excellent conductive properties. The immersed gold layer has the characteristics of low resistance and low reflectivity, which can provide low noise and stable signal transmission. This is very important for high frequency and high speed circuits. In addition, the immersion gold layer also has good current carrying capacity and can meet the needs of various circuit boards.

Immersion gold PCB has many advantages such as corrosion resistance, reliability, weldability and conductivity, so it plays an important role in electronic product manufacturing, providing a stable soldering surface and reliable signal transmission. With the continuous development of electronic products, the application prospects of immersion gold PCB will be broader.

What is via hole?

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Via hole is one of the important components of multi-layer PCB, and the cost of drilling usually accounts for 30% to 40% of the PCB board manufacturing cost. Simply put, every hole on the PCB can be called a via. From a functional point of view, vias can be divided into two categories: one is used for electrical connections between layers; the other is used for fixing or positioning devices. From a process perspective, these vias are generally divided into three categories, namely blind vias, buried vias and through vias. Blind holes are located on the top and bottom surfaces of the printed circuit board and have a certain depth. They are used to connect the surface circuits and the inner circuits below. The depth of the holes usually does not exceed a certain ratio (aperture). Buried vias refer to connection holes located on the inner layer of a printed circuit board and do not extend to the surface of the circuit board. The above two types of holes are located in the inner layer of the circuit board. They are completed using the through-hole forming process before lamination. During the via-hole formation process, several inner layers may be overlapped.

The third type is called a through hole, which passes through the entire circuit board and can be used to implement internal interconnections or as mounting positioning holes for components. Because through holes are easier to implement in technology and have lower costs, most printed circuit boards use them instead of the other two via holes. The following via holes are considered as through holes unless otherwise specified.

From a design point of view, a via hole mainly consists of two parts, one is the drill hole in the middle, and the other is the pad area around the drill hole. The size of these two parts determines the size of the via. Obviously, when designing high-speed, high-density PCBs, designers always hope that the via holes should be as small as possible, so that more wiring space can be left on the board. In addition, the smaller the via holes, the smaller their own parasitic capacitance will be. The smaller it is, the more suitable it is for high-speed circuits. However, the reduction in hole size also brings about an increase in cost, and the size of the via hole cannot be reduced indefinitely. It is limited by process technologies such as drilling (drill) and electroplating (plating): the smaller the hole, the harder it is to drill. The longer the hole takes, the easier it is to deviate from the center; and when the depth of the hole exceeds 6 times the drill diameter, there is no guarantee that the hole wall will be evenly plated with copper. For example, if the thickness (through hole depth) of a normal 6-layer PCB board is 50 Mil, then under general conditions, the drilling diameter that the PCB manufacturer can provide can only reach 8 Mil. With the development of laser drilling technology, the size of drilled holes can also become smaller and smaller. Generally, vias with a diameter of less than or equal to 6 Mils are called microvias. Microvias are often used in HDI (High Density Interconnect Structure) design. Microvia technology allows vias to be drilled directly on the pad (Via-in-pad), which greatly improves circuit performance and saves wiring space.