Modules and power packages (packaging)

Semiconductor power components first appeared over 50 years ago. During this period, their technology has advanced extraordinarily, reaching levels that in some cases approach the theoretical limits of the material: power densities handled can be well in excess of a hundred watts per square centimetre, and a chip scarcely more than a centimetre square can withstand voltages of several kilovolts or currents of over a hundred amperes.

This being the case, it's clear that the power chip's immediate environment (its casing, or in a more generic sense, its packaging) plays a vital role in its operation. This is where the chip's electrical connections and heat dissipation take place. With the excellent performance of today's power semiconductors, it's common for the package to be the main limiting factor for the component as a whole.

At first glance, this may seem surprising: why has a totally passive element like the casing, which calls on technologies that are a priori less advanced than microelectronics, not made as much progress as chips? The answer lies in the multiplicity of packaging functions. Here, perhaps more than anywhere else, the task of design is to find a compromise between often contradictory imperatives: while it's relatively easy to design a thermally or electrically efficient package, or to find a low-cost solution, achieving all three objectives at the same time is like squaring a circle!

To fulfill its various roles, a housing must call on a multitude of different elements, materials and techniques. This is what we present to you in this dossier.