Rigid-flex PCB is a special circuit board made by pressing a rigid circuit board (PCB) and a flexible circuit board (FCB). The rigid pcb part usually choose fr4 material and the flex pcb part is polyimide. The flex-rigid board combines the advantages of the rigid characteristics of rigid PCB and the flexible characteristics of flexible PCB, so that the PCB is no longer in two-dimensional space, but is folded by three-dimensional internal wiring and arbitrary bending. In this way, the rigid-flex board can realize complex circuit layout in a small space. And it has the characteristics of light weight and small size, which is suitable for some fine electronic products.