Do you understand PCB insulation layer and raw material board?

The green or brown color on the PCB is the color of the solder mask layer. This layer is an insulation protection layer that can protect copper wires and prevent parts from being welded in incorrect places. The silk screen will be printed on the top of the solder mask layer. It is usually printed with text and symbols (mostly white) to indicate the position of the parts on the board. The silk screen surface is also known as the legend surface.

Single panel

On the most basic PCB, the parts are concentrated on one side, while the wires are concentrated on the other side. Because the wire only appears on one side, we call PCBS Single sided. Only early circuits used such boards because single panels had many strict restrictions on designing circuits (because they only had one side, wiring cannot be crossed, and must be routed separately).

Double-sided board

Both sides of the circuit board have wiring. But to use two wires at the same time, there must be appropriate circuit connections between the two sides. The "bridge" between circuits is called a guide hole (via). Guide holes are small holes filled or coated with metal on a PCB that can be connected to wires on both sides. Because the area of a double-sided panel is twice that of a single panel, and the wiring can be interleaved (which can be wound to the other side), it is more suitable for more complex circuits than a single panel.

Multilayer board

In order to increase the area that can be wired, multi-layer boards often use single-sided or double-sided wiring boards. Multi layer boards are made by splicing several double-sided boards, with an insulation layer placed between each layer and firmly bonded (pressed together). The number of layers of a board refers to several independent wiring layers, usually even layers, including the outermost two layers. Most motherboards are built with 4 to 8 layers, but technically close to 100 layers of PCB boards are possible. Most large supercomputers use quite a lot of host board layers, but since such machines can be replaced by ordinary computer cluster, super multi boards are no longer used. Due to the tight integration of layers in the PCB, it is not always easy to see the actual quantity, but if you carefully observe the motherboard, you may see it.