METHOD FOR ADHERING PARTS FOR SEMICONDUCTOR DEVICE

PURPOSE:To enable gap such as a void, etc., of a soldered part to be minimized and obtain a semiconductor device with improved thermal characteristics by adhering an insulation substrate and a heat sink and the insulation substrate and a semiconductor chip, etc., with a solder which does not include flux and a cream-shaped solder which includes flux. CONSTITUTION:When a soldered joint or an entire semiconductor device is heated by a heater, etc., flux within a cream solder 12 gradually reaches the melting point, is spread onto an upper surface of a heat sink 1 or a conductor 3 which is placed on an insulation substrate 2, and wetting properties of solder are improved by eliminating these oxide films. As heating proceeds further, solder 11 is melted, it is spread to a part where the oxide film is eliminated by flux, the soldered joint is filled with the solder, thus forming a compound between metals and completing soldering. In this soldering process, flux which generates gap of void, etc., at the soldered joint is adjusted to an optimum quantity by mixing the solder 11 and the cream solder 12, thus enabling the void to be minimized.