FPC boards are mainly used in the connection parts of electronic products, such as mobile phone cables and LCM, etc. Compared with rigid boards, they are smaller in dimension and lighter in weight, can achieve bending and flexing or three-dimensional assembly and other benefits. Today we will discuss the difference between FPC electromagnetic film and cover film.
Electromagnetic film which is black, is mainly used to shield external signal interference, etc.
As a connecting wire in electronic devices, FPC mainly plays the role of conducting current and transmitting signals. When the signal transmission line is distributed in the outermost layer of the FPC, in order to avoid signal distortion caused by electromagnetic interference during the signal transmission process, the FPC will press a layer of the electromagnetic film after pressing the cover film. As a conductive layer, electromagnetic film will shield the outside electromagnetic interference.
Electromagnetic film is made of mixed composite metal which has excellent OSP performance and corrosion solvent resistance. It is superior to similar products in the market in terms of shielding characteristics and winding characteristics. Electromagnetic wave film is suitable for flexible printed circuit. With high shielding, bending and heat resistance, it is suitable for electronic touch screen connecting lines and circuits and has strong protection against electromagnetic wave interference.
The electromagnetic film is generally attached to the cover film and the price of the electromagnetic film is much more expensive than cover film.
The cover film is a film that covers the surface of the substrate and is generally polyimide resin named PI, which is used for solder mask and so on, but it has little effect on signal shielding.
FPC cover film, known as CVL in the PCB industry, has a main function similar to the green paint of PCB:
1) Protect the copper foil from being exposed to the air and avoid oxidation;
2) Cover for subsequent surface treatment and cover the areas that do not need gold plating with CVL;
3)Have solder mask function in the subsequent SMT.
Victory PCB is a professional PCB manufacturer established in 2005. Adhere to being a specialized manufacturer for multiple species, small to medium series, and quick turn production, we insist to provide 3H(high quality, high precision and high density) PCBs for our customers.
Victory PCB can provide high-quality FPC, welcome to contact us and looking forward to our further communication.