CCL is the key to flexible material of the flexible printed wiring board. In addition to the polyimide film itself, the various requirements, but also requires copper have good cohesiveness. So that will not happen in the processing and cracking during use or even delamination, such as a reduced portion of the folding cellular phone circuit board to be able to withstand at least tens of thousands of folds.
Flexible copper clad laminate manufacturer in two ways. The first method is now widely applied, which is a polyimide film and copper foil bonded together with an adhesive. The second is the direct coating of polyimide solution was the so-called "non-adhesive" on the copper foil of CCL. After the film should speak a performance of a better than before, but also more difficult to process.
The polyimide film substrate coated with timely, often in advance to the surface of the copper foil and the polyimide film is roughened to increase both the cohesiveness. Roughening method of ion beam etching, laser etching, rubbing method and etching with an alkali solution of an amine.