FPC flexible circuit board technology development direction

With the diversification and miniaturization of applications, FPC used in electronic equipment requires high density circuits as well as high performance in a qualitative sense. Latest FPC circuit density

Change. Using the reduction method (etching) can form a conductor pitch of less than 30um single-sided circuit, conductor pitch of less than 50um double-sided PCB circuit has also been practical. The connection

The conduction aperture between the conductor layers of double-sided circuits or multi-layer circuits is also getting smaller and smaller. Now the conduction aperture of holes below 100um has reached the mass production scale.

The possible manufacturing range of high-density circuits based on the manufacturing standpoint. Based on circuit pitch and on-hole aperture, high-density circuits can be roughly divided into three types:

(1) Traditional FPC.

(2) High-density FPC.

(3) Ultra-high density FPC.

In the traditional reduction method, FPC with a pitch of 150um and a through-hole aperture of 15um has been mass-produced. Due to the improvement of the material or the processing device, it can be added even in the reduction method

30um line pitch. In addition, due to the introduction of CO2 laser or chemical etching process, can achieve 50um aperture through hole mass production processing, most of the current mass production

High density FPC is processed using these technologies.

However, if the pitch is less than 25um and the through-hole diameter is less than 50um, it is difficult to improve the pass rate even if the traditional technology is improved, and new process or new material must be introduced. now

There are various processing methods, but the half addition method using electroforming (sputtering) technology is the most suitable method, not only the basic process is different, but also the use of materials and auxiliary materials

The material is also different.

On the other hand, the progress of FPC joint technology requires FPC to have higher reliability performance. With the high density of the circuit, the performance of FPC has put forward the requirements of diversification and high performance,

These performance requirements are largely dependent on the circuit processing technology or materials used.