How is a PCB circuit board made? The substrate of the PCB board itself is made of insulating and heat insulating materials that are not easily bent. The subtle wiring material visible on the surface is copper foil. Originally, copper foil was covered over the entire PCB board, but during the manufacturing process, some of it was etched away, leaving behind a network of fine wiring. These circuits are called wires or wiring, and are used to provide circuit connections for components on the PCB board. The color of general PCB boards is green or brown, which is the color of solder mask. It is an insulating protective layer that can maintain copper wires and prevent parts from being welded to incorrect locations.

Nowadays, multi-layer boards are used on motherboards and graphics cards, greatly increasing the area for wiring. Multilayer boards use more single or double-sided wiring boards, and a layer of insulation is placed between each board and pressed together. The number of layers on a PCB board represents how many independent wiring layers there are. Generally, the number of layers is even and includes the outermost two layers. Common PCB boards have a structure of 4-8 layers. The number of layers on many PCB boards can be observed by viewing the cross-section of the PCB board. But in reality, no one has such good eyesight. So, let me teach you another method below.

The circuit connection of multi-layer boards is achieved through buried and blind hole technology. Most motherboards and display cards use 4-layer PCB boards, while some choose 6-layer, 8-layer, or even 10 layer PCB boards. To determine the number of layers in a PCB, it can be identified by investigating the conductive holes. This is because the four layers used on motherboards and graphics cards are the first and fourth layers for wiring, while the other layers serve other purposes such as grounding and power supply. So, like double-layer boards, the guide holes will penetrate the PCB board. If some guide holes appear on the front of the PCB board but cannot be found, then it must be a 6/8 layer board. If the same guide holes can be found for both positive and negative PCB boards, it is naturally a 4-layer board.

Article sourced from Jiangmen single and double-sided circuit boardhttp://www.yonghongpcb.com