Conductive adhesives as die-bonding materials for power electric modules

Five different epoxy based silver filled adhesives have been tested with respect to their usefulness for die-bonding of power chip components. The measurements of electrical resistance and mechanical strength are reported for joints tested in high temperature ageing and in high temperature/high humidity ageing. Test structures had copper plates with either nickel or Au/Ni plating joined to thick film AgPt, Cu or Au metallizations on alumina substrate. In accelerated ageing tests the structures with Au/Ni-plated surfaces gave better results than those with Ni-plating. One of the adhesives survived the tests better than the other adhesives. The thermal resistances have been measured for silicon diodes either glued or soldered on alumina substrate. The results agree fairly well with those estimated by thermal simulations.