What is PCB?

PCB (Printed Circuit Board), also known as Printed Circuit Board (PCB) in Chinese, is an important electronic component that supports electronic components and serves as a carrier for the electrical interconnection of electronic components. It compresses layers of different materials together through heat and adhesive, and there are now over 100 practical PCBs available.

Classification and appearance of PCBs

According to the softness and hardness of the finished product, it is divided into: hard board, soft board, and soft-hard combination board

1. PCB hard board

2. PCB soft board

3. PCB soft and hard combination board

According to the number of circuit layers: divided into single panel, double-sided board, and multi-layer board.

1. Single panel is the most basic PCB, with electronic components concentrated on one side and wires concentrated on the other side. Because of this, it is called a single panel. Because it has many strict limitations in design, it is now difficult to see.

2. Double-sided board

A circuit board with wires on both sides is a double-sided board. The wires on both sides need to be connected through guide holes. Due to the ability to wire on both sides, compared to a single panel, it is more suitable for application in relatively complex circuits and has a wide range of applications.

3. Multilayer board

Multi layer board refers to placing a layer of insulation between several double layer boards and sticking them together. The number of layers of the board represents the number of independent wiring layers, which are usually even and include the outermost two layers. The common multi-layer boards are generally 4-layer and 6-layer boards, and complex multi-layer boards can reach dozens or even hundreds of layers.

Characteristics of PCB

PCB has many unique advantages:

High density: The high density of printed boards can develop with the improvement of integrated circuit integration and the advancement of installation technology

High reliability: PCB can ensure long-term reliable operation (probationary period is generally 20 years)

Designability: Various performance requirements for PCBs can be achieved through design standardization and standardization

Producibility: Able to achieve standardized, scaled, and automated production, ensuring consistency in product quality

Testability: It has complete test methods and standards, and can detect and identify the qualification and service life of PCB products through various test equipment and instruments

Assemblability: PCB products are convenient for standardized assembly of various components, and can also be used for automated and large-scale mass production. In addition, assembling a PCB as a whole with various other components can also form larger components, systems, and even the entire machine.

Maintainability: Once a system malfunctions, it can be quickly, conveniently, and flexibly replaced to quickly restore system operation.

Composition of PCB

A PCB circuit board mainly consists of solder pads, via holes, installation holes, wires, components, connectors, fillers, electrical boundaries, etc.

Solder pad: A metal hole used for soldering component pins.

Through hole: There are metal through holes and non-metal through holes, where metal through holes are used to connect component pins between layers.

Installation hole: used to fix the circuit board.

Wire: An electrical network copper film used to connect component pins.

Connector: A component used for connecting circuit boards.

Filling: Used for copper plating on ground wire networks, which can effectively reduce impedance.

Electrical boundary: used to determine the size of a circuit board, and the components on the board cannot exceed this boundary.

Application of PCB

The application fields of PCB are extremely extensive

From electronic watches, computers, Rice cooker, washing machines

From automobiles, aviation, aerospace, military weapons, etc

As long as there are electronic components such as integrated circuits

PCB is indispensable in every aspect