Process Development and Reliability Evaluation

The masks are intended to speed product process development and acquire realistic manufacturability data. They can also be used to test established fabrication processes and measure their performance. Mask sets are useful to evaluate vendors and extract information on the repeatability or the tolerances of their process. Bumping suppliers can also use them to check on the long range stability of their production.

Beyond process development, the masks produce dies for reliability testing: for instance, bump shear tests or temperature and humidity cycling after assembly.

Masks for Standard Bumping (no RDL)

Two masks process:

The mask set for conventional bumping consists of a mask to open contact holes on the bumping pads and a mask to define the UBM. The polymer and metallization processes determine the masks polarity. The designs can be used to evaluate the fabrication tolerances of positive or negative acting polymers, and can be used with additive or substractive metallization processes.

These masks can be built with the specific pitch and bump size required by the end user.

Masks for Wafer Level Packaging ( with RDL)

Four masks process:

Note: It is possible to build a three masks set to cut cost. This can be done at the expense of some compromises that must be acceptable to the end users.