Basic knowledge of FPC circuit board
FPC is a copper circuit printed on PI Polyimide or PE Polyester film. It is flexible and thin with high precision. It can be used to make multilayer circuits, PCB paste chips or SMT chips.
1、Base material：12.5, 25, 50, 75, 125um (PIPE) substrate refers to copper foil substrate, is also one of the materials to protect the film.In terms of materials, PI (Polyamide) Film and PET (Polyester) Film are divided into two types. However, THE price of PI is higher and its fire resistance is better, while the price of PET is lower but it is not heat resistant. Therefore, PI material is mostly used when welding is required. Generally, the thickness is 1/2mil, 1mil, 2mil;
2、Copper foil：As Copper raw material, Copper foil can be divided into: ED Copper (electro-copper); Rolled Copper (RA Copper, Rolled Annealed Copper); High Density electro-deposited Copper; Copper thickness: 18um, 35um, 70um.
3、ADH：Two versions are commonly available, Acrylic and Epoxy, with the most commonly used being Epoxy. The thickness of 0.4 ~ 2mil, generally using 18um thick glue.
4、Covering film：The covering film is composed of substrate + adhesive, which is divided into PI and PET, and the thickness is from 0.5 to 1.4mil.
5、Stiffener material：PI/PET/FR4/SUS, thickness 0.1-0.3mm.