mSAP - modified Semi Additive Process


mSAP - An innovative answer beyond the conventional printed circuit board

Miniaturization and new market requirements demand the development of innovative solutions in order to provide our customers with the best possible production technologies in the future. One of these innovations to meet the increasing demand in the field of fineline PCB’s is our activity in the development of the modified Semi Additive Process (mSAP).

The mSAP technology allows much finer structures down to 25my line / space. In addition, this process offers a significantly better conductor pattern geometry. For high-frequency applications, this offers great performance advantages. This technology can also offer decisive advantages for interposer PCBs and high-speed PCBs.


A modern micro BGA design with 30µm conductor pitch and copper filled microvias

At the conventional subtractive process, structures are created by laminating, exposing and developing a photoresist as etch protection on the copper surface. The unprotected copper is then removed by an etching medium. At Varioprint, conductor pattern of 50µm and larger can be produced by this way with high reliability.

If finer conductor patterns are to be formed, the subtractive process reaches its limits. One solution to this problem is the Semi Additive Process, which has been used in the semiconductor industry for a long time and is now becoming increasingly important in the production of printed circuit boards. Since the described variant is a modified version, this process is called modified Semi Additive Process (mSAP).

The mSAP process uses only a thin layer of copper applied to the laminate. Then a photostructurable solid resist is applied and the layout is exposed and developed inverted. The desired copper thickness is added to the exposed copper areas in the electroplating process. After removing the solid resist, the thin initial copper layer is removed by differential etching.

In recent years, Varioprint has made numerous investments in electroplating, conductor pattern etching and resist coating, which today serve as the basis for the successful introduction of the mSAP process. The process is currently undergoing validation. If everything goes according to plan, we will be able to offer you the mSAP process for larger volumes in the coming months.

This opens up countless possibilities for you as a customer to break new ground in the field of ultra-fine conductor technology and high-frequency technology.