How to distinguish 4 layer PCB and 6 layer PCB

As is known to us all, printed circuit board can be divided into single-sided board, double-sided board and multilayer board. Among multilayer boards, there are 4 layers and 6 layers etc. And the price of multilayer PCB is increased by layers. That’s to say 4 layer PCB price is lower than 6 layers. Then learning to distinguish them is important for avoiding cheating by the manufacturers. Here 2 methods of distinguishing them are introduced for your reference.


4 layer PCB

4 layer PCB


1. Checking the wire on the front side

For 6 layers PCB, the layers are more than 4 layers, which lead to more space to wiring. So the wire on each layer of 6 layers PCB will be less than 4 layers PCB. By checking the wiring on front side, we can say that PCB with more wires is 6 layers PCB, otherwise it is 4 layers PCB.  


2. Checking the via on PCB

If we can find the via on the front side of PCB, while on the back side, we cannot find the same via, then we can know this is not 4 layers PCB. It is 6 or 8 layers PCB with buried via inside. Because 4 layers PCB need through hole to conduct the electricity for 4 layers. The via on it is through the whole board, which can be found on both front side and back side.  


What introduced above are two ways checking by eyes, which are easily and widely applied for many electronic hobbyist and engineers. Hope it can help you in your following contact with PCB.