Application of the Spark Plasma Sintering Technique to Low-Temperature Copper Bonding

Planar structures, in which a power die is soldered on a substrate and wirebonds are used to connect the top of the die with the substrate, are limited in terms of thermal management and power density. 3-D packaging techniques have been proposed to overcome these limits. Here, an innovative copper-to-copper bonding solution is presented, that can be used for 3-D packaging. The bonding process is described and the effect of the bonding parameters is investigated. It is found that this technique is compatible with the requirements of power electronic packaging. A test assembly including a silicon power die and ceramic substrates is presented.