Board design issues Each layer has its own role. Power layer Primary signal layer Auxiliary signal layer Ground plane 6 The overall design of the 8 layers is the same.
The circuit connection of multilayer board is through the technology of buried hole and blind hole. The main board and display card mostly use 4-layer PCB board, and some use 6-layer, 8-layer or even 10-layer PCB board.To see how many layers a PCB has, you can tell by looking at the guide hole, because the 4 layers used on the motherboard and display card are the 1st and 4th layers wired, and the other layers have other USES (ground and power).Therefore, the same as the double - layer board, the hole will be cut through the PCB board.If some guide holes appear on the front of PCB board but cannot be found on the back, then it must be 6/8 layer board.If both sides of PCB board can find the same guide hole, it is a 4-layer board naturally.
Facing the main board or display card to the light source, if the position of the guide hole can transmit light, it means that it is 6/8 laminate;Instead, it's four layers.