Power Module Cleaning

Cleaning IGBT modules, i.e. DCBs, is an absolute must within the power electronics industry. For one, the substrate surfaces must be prepared for wire bonding after the die attach process. In addition, cleaning is necessary after soldering the substrates onto the cooling element, i.e. “heat sink soldering.”

There are two main requirements for this cleaning process:

Complete removal of flux residues and in particular flux spatter from substrates and chips
Visually flawless and spot-free substrate surfaces and chips, i.e. free of oxide layers

Using specifically developed processes with water-based ZESTRON cleaning agents, very clean surfaces can be achieved that will significantly increase the wire bond quality. Consequently, results from shear tests as well as the qualification through power cycling will be significantly improved. This also increases the production yield.

At the same time, modern water-based cleaning processes provide optimal compatibility with chip passivations and substrates, thereby eliminating the need for subsequent plasma treatments which are usually necessary.