Here, we will explain the basics of Printed Circuit Boards (PCBs) and the types of PCBs as easily as possible. In this article, we plan to list the various types of boards in electronics.

　　 Part 1: What is an Electronic PCB

　　The PCB, or Printed Circuit Board, is the backbone of almost all electronic products. But it has long been more than just a carrier of conductive traces. It is an electronic component whose function goes far beyond connecting electronic components.

　　To understand the types of PCBs, you first need to understand their structure. A PCB includes copper wires, prepreg, and core material.

　　Prepreg is a substrate in which glass cloth is impregnated with resin (mostly epoxy resin) and cured to stage B. It is used for interlayer insulation when forming core materials and copper foil for multilayer boards.

　　Copper-clad laminate, also known as CCL, is the basic material for manufacturing circuit boards. Copper-clad laminate is made by impregnating glass cloth, which is woven from high-insulation glass fiber, with resin.

　　Now you have a basic understanding of PCBs and their structure. Let's look at the different types of PCBs.

　　Part 2: Three Types of PCBs - Classified by Rigidity

　　The classification of circuit board types is based on their rigidity. There are three types:

　　Rigid PCB

　　Rigid and high-strength printed circuit boards are called rigid boards. Rigid PCBs have hard materials such as fiberglass/epoxy resin (FR4), ceramic, aluminum, copper, etc. Therefore, rigid PCBs have high strength and are easy to install electronic components.

　　Flexible PCB

　　A printed circuit board using flexible plastic film (polyimide (PI) or polyester (PET)) is called a flexible PCB, also known as a "flexible printed circuit board (FPC)". Because this type of printed circuit board can be bent, it is often used in the moving parts of electronic devices.

　　Rigid-Flex PCB

　　Rigid-flex PCBs include flexible PCB and rigid PCB layers. It is not simply connecting an FPC and an FR4 PCB, but laminating the FR4 PCB onto the flexible PCB using a laser. Because rigid-flex PCBs can be bent, are small, and save on PCB connectors, they are used in compact spaces in electronic devices.

　　 Part 3: Five Types of PCBs - Classified by Structure

　　Below are five types of circuit boards classified by structure.

　　Single-sided PCB

　　In electronic circuit boards, a circuit board with electronic components printed or mounted on only one side is called a "single-sided circuit board". This type of printed circuit board only requires one surface mount circuit board component operation during circuit board assembly.

　　Double-sided PCB

　　A "double-sided board" has electronic components printed on both sides. This type of electronic PCB is more suitable for complex electronic circuits than single-sided boards, but the disadvantage is that it is more expensive.

　　Single-layer PCB

　　A single-layer PCB is a circuit board with only one circuit layer. Single-layer electronic PCBs are not suitable for forming complex electronic circuits. It has significant advantages in reducing costs.

　　Double-layer PCB

　　A double-layer PCB is a PCB with two circuit layers. These two circuit layers can be on the same side of the substrate or on both sides.

　　Multilayer PCB

　　Printed circuit boards with 4, 6, or more circuit layers are called "multilayer PCBs". Remember that the number of layers in multilayer electronic PCBs is usually even. This is for the balance of the PCB structure.

　　 Part 4: Different Types of PCBs - Classified by Substrate

　　Phenolic Paper PCB

　　Paper phenolic (FR1/FR2) boards are made by curing a paper substrate with an oily phenolic resin, and they have poor heat and moisture resistance.

　　Although their electrical properties and heat resistance are not as good as glass and epoxy resin, they are widely used in simple consumer electronics due to their low cost.

　　Glass Epoxy Resin/FR4 PCB

　　Made from glass cloth impregnated with epoxy resin, this is the most common type of PCB in modern PCB types. Glass epoxy resin (FR4) PCBs are used in circuits that require strength and insulation. They have small dimensional changes and high insulation resistance.

　　For electronic products, FR4 PCBs are a commonly used type of circuit board with high production volume. They are used in personal computers, consumer electronics, office automation equipment, etc.

　　Glass Composite Board

　　This is a printed circuit board made by impregnating the substrate with epoxy resin. It is a mixture of glass cloth and glass non-woven fabric (CEM-1 and CEM-3).

　　Its electrical properties are almost the same as glass/epoxy substrates, but its mechanical strength and dimensional stability are poor, and its usage is less than FR4 circuit boards.

　　Teflon PCB

　　Teflon is a well-known brand of PTFE material. Therefore, a Teflon PCB is a PTFE PCB. This is a printed circuit board that uses Teflon resin as the insulating material.

　　Due to its excellent high-frequency characteristics, it is used in electronic devices that handle signals from a few hundred MHz to tens of GHz.

　　We call all PCB types that can be used for high-frequency, high-speed applications "high-frequency PCBs".

　　Ceramic PCB

　　Ceramic PCB is not a type of circuit board, but a general term for different types of ceramic PCBs, including aluminum oxide PCBs and aluminum nitride (AlN) PCBs.

　　Aluminum oxide PCB is a printed circuit board using a green thin sheet made by mixing aluminum oxide and a binder and sintering it.

　　AlN PCB is a PCB using a grayish-white sheet made by mixing aluminum nitride with a binder and sintering it.

　　Ceramic PCB is an electronic PCB with excellent high-frequency characteristics.

　　The disadvantage is the higher cost, and it is applied to microwave equipment, wireless communication base stations, and occasions with high heat dissipation requirements.

　　Metal Core PCB

　　Metal core PCBs include aluminum-based PCBs and copper-based PCBs. They have metal substrates, so they have excellent physical strength and heat dissipation characteristics.