Power module

A power module or power electronic module provides the physical containment for several power components, usually power semiconductor devices. These power semiconductors (so-called dies) are typically soldered or sintered on a power electronic substrate that carries the power semiconductors, provides electrical and thermal contact and electrical insulation where needed. Compared to discrete power semiconductors in plastic housings as TO-247 or TO-220, power packages provide a higher power density and are in many cases more reliable.

Besides modules that contain a single power electronic switch (as MOSFET, IGBT, BJT, Thyristor, GTO or JFET) or diode, classical power modules contain multiple semiconductor dies that are connected to form an electrical circuit of a certain structure, called topology. Examples of broadly available topologies implemented in modules are:

Additional to the traditional screw contacts the electrical connection between the module and other parts of the power electronic system can also be achieved by pin contacts (soldered onto a PCB), press-fit contacts pressed into PCB vias, spring contacts that inherently press on contact areas of a PCB or by pure pressure contact where corrosion-proof surface areas are directly pressed together. Press-fit pins achieve a very high reliability and ease the mounting process without the need for soldering. Compared to press-fit connections, spring contacts have the benefit of allowing easy and non-destructive removal of the connection several times, as for inspection or replacement of an module, for instance. Both contact types have rather limited current-carrying capability due to their comparatively low cross-sectional area and small contact surface. Therefore, modules often contain multiple pins or springs for each of the electrical power connections.

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