The introduction of FPC
The main raw materials of FPC are: substrate, covering film, reinforcing and other auxiliary materials.
The base material is divided into glue base material and no glue base material
There are three main parts of glue base material: copper foil, glue, and PI, there are two types of single-sided base material and double-sided base material, there is a copper foil material for single-sided base material, there are two sides of copper foil material for double-sided base material.
Non-adhesive substrate is the substrate without adhesive layer, compared with ordinary adhesive substrate, less adhesive layer in the middle, only copper foil and PI two parts, than adhesive substrate has thinner, better dimensional stability, higher heat resistance, higher bending resistance, better chemical resistance and other advantages, now has been widely used.
It is mainly composed of three parts: release paper, glue and PI. However, only the glue and PI are retained on the product in the end, and the release paper will be torn off in the production process and no longer used.
Build on strength
It is a special FPC material used in a specific part of the product to increase the strength of support and make up for the "soft" characteristics of FPC. At present, the commonly used reinforcing materials are as follows:
FR4 reinforcement: The main composition is glass fiber cloth and epoxy resin glue, the same as the FR4 material used in PCB.
Steel sheet reinforcement: the composition is steel, with strong hardness and support strength;
PI reinforcement: It is the same as the covering film, composed of PI and glue release paper, but its PI layer is thicker and can be proportioned from 2MIL to 9MIL.
Other complementary material
Pure adhesive: This adhesive film is a thermosolidifying acrylic adhesive film with protective paper, release film and a layer of glue, mainly used for laminated plate, soft and hard bonding plate, and FR-4/ steel sheet reinforcement plate, play a bonding role.
Electromagnetic protective film: paste on the board surface to shield.
Pure copper foil: only copper foil composition, mainly used for hollow plate production.