As a flex circuit manufacturer, we’d like to share more information about flex printed circuit boards raw material selection and reinforcement.
A flex printed circuit boards (FPC) is a circuit that is fabricated in a flexible cut-to-surface, with or without cover lay (usually used for protection FPC circuits). As the FPC can be bent in a variety of ways, folding or repeated movement, compared with ordinary rigid board (PCB), FPC is light, thin, and flexible, etc., so there are more and more FPC application.
FPC base layer (Base Film) materials generally is polyimide (Polyimide, referred as PI), and polyester (PET). The material thickness can be 12.5 / 25/50/75 / 125um.We commonly use 12.5um and 25um. If the FPC should be soldered in high temperature, we suggest PI, and plus PCB substrate FR4.
FPC cover layer material is compact the dielectric film with adhesive or a flexible medium coating, with the avoidance of contamination, moisture, scratches and other protective effects, the main material is the same with the base material, that is Polyimide or polyester, 12.5um thickness.
We use FPC adhesive to combine each layer. Normally it is Acrylic, Modified Epoxy, Phenolic Butyrals, Reinforcing Adhesives, and Pressure Sensitive Adhesives. The single-sided FPC no need adhesion.
We use FPC adhesive to combine each layer. Normally it is Acrylic, Modified Epoxy, Phenolic Butyrals, Reinforcing Adhesives, and Pressure Sensitive Adhesives. The single-sided FPC no need adhesion.
It requires the stiffener for external support in many
It requires the stiffener for external support in many flex PCB assembly. The main materials for stiffener is PI or Polyester film, glass fiber, polymer materials, steel, and aluminum etc. PI or Polyester film is commonly used, generally the thickness is 125um. The glass fiber (FR4) reinforcing is higher hardness than that of PI or Polyester, which is used for application requires more hardness, it is difficult processing relatively.
