FPC mainly consists of the following parts:

1. Substrate: Typically made of flexible materials such as polyimide (PI) or polyester film (PET). The substrate provides the basic structure and flexibility of FPC.

2. Conductive layer: usually a layer of copper foil, which is etched and plated to form a circuit pattern. The conductive layer is the core part of FPC, responsible for transmitting electrical signals.

3. Covering layer: Covering the conductive layer to protect the circuit pattern, prevent short circuits and oxidation. Common covering materials include polyimide and acrylic resin.

4. Adhesive: Used to bond the various layers of materials together to ensure the integrity and stability of the FPC. Common adhesives include epoxy resin and acrylic adhesive.

Function:

1. Substrate: Provides support and flexibility to enable FPC to be used in various environments.

2. Conductive layer: transmits electrical signals and realizes circuit functions.

3. Cover layer: Protect the circuit pattern and prevent external environmental influences on the circuit.

4. Adhesive: Ensure that each layer of material is tightly bonded to improve the stability and reliability of FPC.

By rational design and selection of various materials, high-performance FPCs can be manufactured to meet the needs of various electronic devices.