Flexible printed circuit boards - Manufacturing

The manufacturing process for flexible printed circuit boards is very similar to that for rigid boards. The methods of hole drilling, image transfer, metallization, etching and circuit finishing are basically the same for flexible and rigid circuits. The difference between the two processes concerns the following three points:

• method of cleaning holes before metallization (for multilayer circuits and rigid-flex circuits);

• Controlling the dimensional behavior of flexible materials;

• delicate handling of thin, fragile materials.

This article describes the manufacture of flexible printed circuits using polyimide as the base material.