Power semiconductor element

摘要

Known power semiconductor elements for high current carrying capacity (permissible current loading, ampacity) have a contact layer structure of the semiconductor body which does not meet the requirement of solderable and/or pressure-bondable, mechanically stable and satisfactorily adhering contact electrodes. The metallisation, consisting of at least four sublayers, for a semiconductor body having a large active area according to the invention ensures the bonding quality required, especially for large contact areas. The metallisation consists of a first layer made of aluminium, a second layer made of chromium or titanium as an adhesive layer and as a diffusion barrier for the aluminium, a solderable third layer made of nickel, and a final protective layer made of gold or palladium or alternatively of a solderable layer containing one sublayer each made of nickel and copper, copper at the same time being the outermost layer or possibly further being covered with gold or palladium. Use in components and assemblies of high current carrying capacity in power electronics.