Why do pcbs always have an even number of layers, but not odd number layers?
As I choose from the online pcb fab, the layers of the pcb is always even, why is that expected?
There is also odd number layers pcb,such as 3 layer boards, which are using a 2xboard, one prepreg and one copper layer all laminated. Using even number layers pcb is for saving money.
The stack-ups are made from cores with copper on two sides, separated by pre-preg insulator, so they naturally come on pairs. So the even number layers pcb are usually produced by pcb manufacturer.
Not the answer you're looking for?