5. Interconnection techniques

5.1 Brazing

This is an assembly operation used several times during the manufacture of a power module. It is used to assemble the rear face of the chips to the substrate, and the substrate to the baseplate. In some cases, it can also be used to make the electrical connections on the top of the chips. On average, the thickness of a solder joint varies between a few tens and a hundred micrometers.

Two components are brazed as follows:

• deposition of the brazing alloy by screen printing, dispensing or as a preform between the two parts to be joined;

• remelting the assembly according to the adapted profile at a temperature at least equal to the alloy's "liquidus" temperature (temperature...