3. Enclosure types

Here, we divide components into two types: discrete components (one chip per package) and modules (several chips per package, forming one or more elementary functions). This distinction is explained by the internal structure of the components:

• discrete components have only two (in the case of a diode) or three (transistor, thyristor) terminals, connected directly to the chip terminals. In most cases, the heat exchange surface is not electrically insulated (it is one of the component's terminals);

• modules have a variable number of terminals connected, via a more or less direct electrical circuit, to the terminals of several chips. Because of the multiplicity of electrical potentials present in the module, the substrate (which also serves as the thermal interface) must be electrically insulating. Consequently,...