Resin encapsulated semiconductor device and the production method

Abstract

A semiconductor device having both high strength and high thermal radiation that is capable of being applied to mounting on automobiles experiencing many thermal cycles, and a manufacturing method thereof are provided. A circuit boardfor a resin encapsulated semiconductor module device has a configuration where a silicon nitride platewith a thickness of 0.635 mm has copper plates of 1.0 mm and 0.8 mm bonded to both sides thereof via active metal. A copper plateis bonded to the surface side of the silicon nitride plateand a prescribed circuit pattern is formed on the copper plateTin-silver-copper cream solder layersandwith a thickness of 200 μm are formed at a prescribed location on the circuit patternon which a semiconductor elementis mounted and at a prescribed location of a base plateon which the circuit boardis disposed. Nickel particleshaving a maximum particle size of 100 μm and an average particle size of 70 μm are dispersed in the solderon the base plateof good thermal conductivity. A semiconductor element (chip)the circuit boardand the base plateare disposed on predetermined locations. Thereafter, they are set in a reflow oven (not shown in the drawings) for reflow soldering. After the inside of the reflow oven is replaced by a nitrogen atmosphere, the reflow oven is heated to 280° C. At the time when solder is melted, the inside of the oven is decompressed to 1 Pa, nitrogen is introduced, and the reflow oven is cooled to about room temperature, thereby completing the solder bonding step. After flux is washed, an outer casewith an insert-molded outlet terminalis adhered to the base plateand a predetermined connection is conducted via an aluminum bonding wireThen, silicone gelis injected into a package delimited via the base plateand the outer caseand the silicone gelis heat-hardened, thereby completing a resin encapsulated semiconductor device A.