What is PCB Board
A printed circuit board called PCB is an assembly board that selectively processes and manufactures conductive patterns on an insulating substrate. Specifically, the electrical connection diagram is“printed” on the copper-clad laminate, the copper foil outside the circuit is removed through the corrosive solution, and the copper foil of the connection graphic part is reserved as the connecting plate for the wire and the installation component. Printed circuit boards install and connect circuit components such as miniaturized components and transistor integrated circuits. Because it is produced using electronic printing, it is also called a “printed” circuit board.

The insulating substrate that has been processed and assembled can be called a PCB, and its wide application benefits from its unique advantages such as high reliability, designability, and manufacturability. Next, let’s take a look at what are the common PCBs?

Types of PCB
The PCB, known as the “mother of electronic products”, is the key electronic interconnection of electronic products. Its main function is to make various electronic components form a predetermined circuit connection and play the role of relay transmission. Common PCB can be divided into the following 4 categories:

Single-sided printed circuit board
Single-sided printed circuit boards usually use phenolic paper-based single-sided copper-clad boards. By printing and etching, printed wires are made on the copper-clad side of the insulating substrate.

Applicable to: radios, tape recorders, televisions, instruments, and meters that do not require high electrical performance.

Single-sided PCB
Double-sided printed circuit board
double-sided printed circuit boards are printed circuit boards with printed wires on both sides. Epoxy resin glass cloth copper foil board or epoxy phenolic glass cloth copper foil board is usually used. Since there are printed wires on both sides, metalized holes are generally used to connect the printed wires on both sides.

Applicable to: communication equipment, computers, instruments, meters, etc., that require high electrical performance.

Feature: Its wiring density is higher than single-sided board, and it is more convenient.

Double-sided PCB

Multilayer printed circuit board
A multilayer printed circuit board is a printed circuit board made of more than two layers of printed wires on an insulating substrate. It is laminated and pressed by several layers of thinner single-sided or double-sided printed circuit boards (each layer’s thickness is less than 0.4mm). To lead out the printed wires sandwiched in the insulating substrate, the holes for mounting components on the multilayer printed circuit board need to be metalized to communicate with the printed wires sandwiched in the insulating substrate. Four, six, and eight layers are widely used, and more are also used.

Multi-layer PCB
Flexible printed circuit board
Flexible printed circuit board is a printed circuit board made of soft layered plastic or other soft insulating materials. It can be divided into three categories: single-sided, double-sided, and multi-layer.

Applicable to: Widely used in electronic computers, automation instruments, and communication equipment.

Feature: Besides light weight, small size, and high reliability, the most prominent feature is its flexibility, which can be folded, bent, and rolled.

Flexible PCB
The above four common PCBs have their own characteristics and scope of application, and it is precisely because different types of PCBs are made of different materials that they have different characteristics and functions. General PCBs are mostly composed of materials such as copper foil, adhesives and additives.

PCB Composition
There are many substrates used for PCB, which can be mainly divided into two categories, namely organic and inorganic. Organic substrates are made of reinforcing materials such as glass fiber cloth, which are also called copper clad laminates, while inorganic substrates are mainly ceramic plates and enamel-coated steel substrates. Subdivided PCBs are mainly composed of copper foil, reinforcing materials, adhesives and additives.

Copper foil is a thin, continuous metal foil deposited on the base layer of the circuit board. As a conductor of the PCB, it is easily bonded to the insulating layer and etched to form a circuit pattern. Reinforcement materials include glass fiber cloth (felt), fiber paper, etc.; adhesives include phenolic, epoxy, polyester, polyimide, polytetrafluoroethylene, silicone, etc.; additives include solid agents, stabilizers, flame retardants, etc.