4. Materials and manufacturing

The performance of an enclosure is intrinsically linked to the materials it's made of: joining two materials with very different coefficients of expansion degrades the reliability of the whole. Conversely, it's impossible to choose materials solely on the basis of their coefficient of expansion, since thermal and electrical performance must also be taken into account, as well as price. It's clear, then, that case design is all about finding the best compromise, and that this is highly dependent on the intended application.

In the rest of this paragraph, we'll list the various components of a power module, focusing on the main materials used. The same applies to discrete packages, even if they only include a subset of these elements (no insulating substrate, for example).