Japanese Journal of Applied Physics · 2001 · 10 citations · 1 references
EngineeringElectrical EngineeringMaterials ScienceMicroelectronicsSemiconductor DevicesSemiconductor MaterialsIntegrated Circuit DesignIntegrated Circuit FabricationSemiconductor Device MaterialsSemiconductor ReliabilitySemiconductor SurfacesSemiconductor Thin FilmsCircuit IntegrationCurrent-voltage RelationsSemiconductor Surface PreparationSolderingVoid Elimination
We have developed a new void free process for making the solder joint between the chip mounted AlN substrate and the metal substrate in large-area, high power insulated gate bipolar transistor (IGBT) modules. This new process consists of two steps. First, Ar + were used to clean the surfaces of Ni plated film on a metal and AlN substrates which were then coated with 0.5-µm-thick Ag film. Second, 50 wt% Pb–Sn solder was sandwiched between the two substrates and heated to 503 K in a vacuum for 5 min before being cooled in a N 2 atmosphere. By using this process, the area percentage of voids in a soldering area up to 130×190 mm 2 can be reduced to less than 0.1%. IGBT modules made by this process were also found to exhibit satisfactory current-voltage characteristics.
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