Any printed circuit board has the problem of matching and assembling with other structural parts, so the shape and size of the printed circuit board must be based on the overall structure of the product.
However, from the perspective of production technology, it should be as simple as possible, generally a rectangle with a relatively small aspect ratio, to facilitate assembly, improve production efficiency and reduce labor costs.
The number of layers must be determined according to the requirements of circuit performance, board size and the density of the circuit. For multi-layer printed circuit boards, four-layer and six-layer boards are the most widely used. Taking a four-layer board as an example, there are two wire layers (component surface and welding surface), a power supply layer and a ground layer.
The layers of the Multilayer Board should be symmetrical, and it is best to have an even number of copper layers, that is, four, six, eight layers, etc. Because of asymmetric lamination, the board surface is prone to warping, especially for surface-mounted Multilayer Boards, which should be paid more attention.