We mentioned before about the through hole (via), if the through hole apply on double sided PCB, the printed circuit board will be drilled through; However, in the multilayer PCB, through hole (via) will definitely waste some precious space if you just want to connect partial circuit wire. Buried hole and blind hole can effectively avoid this kind of problem since they only need to connect several layers of multilayer PCB. Blind hole can connect several internal layers to the top or bottom layer while buried hole will only connect the internal layers which we can’t see from outside.
In the multilayer PCB, the whole layers are all connected by ground line and power supply layer. So each layer has been separated artificially as signal, power supply & grounding. Two layers or above power supply layer will be designed if components mounted on this PCB need to use different power supply.
In order to increase the size of layout area, more single sided and double sided PCB will be applied on multilayer PCB. A multilayer PCB use two or even more double sided PCB as the basic component and among them use insulated prepreg to joint them together through press and laminate. The layer count stands for the number of isolated layer with circuit wire, most of them are even number and include the outer two layer. Most of the motherboards are from four to eight layer, and some advanced manufacturer can even reach a hundred layers. Large scale super computer is usually used highly multilayer PCB.
PCBA manufacturing experts can help you to get quality services no matter how many layers you want. The more layers, the more complex the PCB manufacturing will be, it is therefore important to find the best manufacturer.