FPC related knowledge
FPC is the abbreviation of flexible printed circuit, tft display uses fpc, usually 2layer fpc, called lcd display fpc. Each lcd display fpc is different, and it can be customized according to different lcd panels and connectors, as well as customer requirements. Generally, it takes 15 days to complete the customization.
Raw Material - CCL
CCL is the abbreviation of Copper Clad Laminates. FPC commonly used single-sided copper foil substrates and double-sided copper foil substrates. FPC relies on copper foil to form circuits.
Raw Material - CVL
Coverlay: It is composed of dielectric film and adhesive layer, which provides insulation and protection for FPC
Raw Material - STIFFENER
The main functions of the stiffeber are: 1. Reinforcing the soft board 2. Providing the required bearing strength of the parts 3. Compensating the thickness of the soft board
Material distinction: PI / PET / SUS
FPC production process
The FPC production process of single-sided copper foil and double-sided copper foil is similar to that of lamination, exposure, development and etching, and after the film is removed, punching, coating and other processes are completed.
Copper plating and gold plating are two important processes in the FPC process. Copper plating is mainly used for via holes, and gold plating is mainly used for connection positions to ensure durability and stability. There are two ways of electroplating and chemical deposition, and their advantages and disadvantages are as follows:
| item | chemical tin plating | Electroplated tin |
| Coating Uniformity | good | uneven thickness |
| Product requirements | Can be plated on individual lines | Wires need to be connected to the substrate |
| melting point | 210℃ | 210℃ |
| General coating thickness | 10-30u” | 60-100u” |
| Maximum coating thickness | 50u” | 500u” |
| item | chemical gold plating | electrolytic gold plating |
| Coating Uniformity | good | uneven thickness |
| Product requirements | Can be plated on individual lines | Wires need to be connected to the substrate |
| melting point | 890℃ | 1452℃ |
| stress | compressive stress | Tensile stress |
| General coating thickness | 1-3u” | 1-3u” |
| Maximum coating thickness | 4-8u” | 50u” |
