Power Module Construction and Connection Technologies
A Pioneer in Semiconductor Packaging
Semikron Danfoss presented the world's first insulated power semiconductor module with bipolar chips in 1975. This innovation continues to present day with new packaging technologies, production techniques, and advanced electronics and semiconductors.
The first IGBT based standard module followed in 1989. Today, module construction is still related to the original innovative design. One or more DBC (Direct Bond Copper) ceramic substrates is soldered to a copper base plate, which also serves as the mounting surface to the heatsink. The DBC substrates consist of a thin ceramic layer made of Al2O3 or AlN clad with copper on top and bottom.
Soldered to the top of the DBC substrates are the back sides of the chips (IGBTs: collectors, diodes: usually cathodes). The chip fronts (IGBTs: gate and emitter, diodes: anode) are contacted by parallel aluminium bond wires to corresponding pads on the DBC substrate. Soldered onto these pads are either module terminals or, connections are made via wire bonds to terminals mechanically fixed in the module housing.
The continuous development of construction and connection technology of power modules is driven on one side by material/ production costs and ever-increasing technical demands on the other.
This involves the best possible dissipation of the heat loss in the semiconductors, both statically as well as for short-term loads. Power modules can be utilized very effectively with efficient cooling methods, which is a "must" for high power and lowest possible semiconductor cost. Thus the permissible temperatures of the IGBT and diode chips is increased from one chip generation to the next. However, high chip operating temperatures and efficient heat dissipation tighten the requirements for temperature and power cycling capability of the module designs. This requires continuous development of construction and connection technologies.
With technologies such as SKiiP, SPRiNG, SiNTER, SSS, and DSS successfully positioned in the market Semikron Danfoss is one of the pacemakers of power module development.