So, what are the components of FPC flexible circuit boards? In the structure of FPC flexible circuits, the materials composed of flexible copper clad laminate (FCCL), covering film, adhesive film, etc. Flexible Copper Clad Laminate (FCCL): The common film materials for flexible copper clad laminates include polyimide film (PI), polyester (PET), polyethylene naphthalate (PEN), liquid crystal display polymer (LCP), and other polymer plastic films. In FPC flexible circuit boards, copper clad boards mainly play three roles: conductivity, insulation layer, and support points.

　　Covering film: It is composed of organic chemical plastic film and adhesive, and its function is to maintain a part of the flexible power circuit electrical conductor that has already been carried out. There are different types of adhesive films and adhesive types, as well as thickness specifications and models for adhesive films.

　　Adhesive film: It is formed by pouring adhesive on two or one side of a substrate film, or a pure adhesive layer without substrate. The adhesive film has different adhesive types and thickness specifications. Adhesive film is used for interlayer bonding and insulation of multi-layer boards.

　　Ordinary FPC flexible circuit boards are mainly composed of two materials: substrate and covering film. First, let's talk about the substrate. The substrate is mainly composed of PI or PET+adhesive+copper bond synthesis. PI is a polyimide insulation resin material, characterized by high temperature resistance and good bending performance. The product produced has good reliability, which is more than twice the price of PET. It is the main material for FPC flexible circuit boards. PET is a polyester insulation resin material, which has exactly the opposite characteristics to PI. Generally, FPC manufacturers have rarely adopted it.