High frequency impedance board

Multilayer board

In order to increase the area that can be wired, more single or double-sided wiring boards are used for multilayer boards. A printed circuit board , alternated together by a positioning system and insulating bonding materials, and conductive patterns. Printed circuit boards that are interconnected according to design requirements become four-layer and six-layer printed circuit boards , also known as multi-layer printed circuit boards. The number of layers of the board does not mean that there are several independent wiring layers. In special cases, an empty layer will be added to control the thickness of the board. Usually, the number of layers is an even number and includes two layers outside Z. Most motherboards are 4 to 8-layer structures, but technically, nearly 100-layer PCB boards can be achieved. Most large supercomputers use fairly multi-layer motherboards, but because such computers can be replaced by clusters of many ordinary computers, ultra-multi-layer boards have gradually fallen out of use. Because the layers in the PCB are tightly combined, it is generally not easy to see the actual number, but if you look closely at the motherboard, you can still see it.