Integrated circuit package having heat sink bonded with resinous adhesive

Claim 1

In an integrated circuit package comprising an insulating substrate, a cap and a sealing glass sealing the cap with the insulating substrate to form a hermetic casing which encloses at least one semiconductor element mounted on a front surface of the insulating substrate, lead members introduced from the outside of the casing and wires electrically connecting the semiconductor element with end portions of the lead members, and a heat sink bonded to a rear surface of the insulating substrate, the improvement wherein the cap is made of a ceramic material having a thermal expansion coefficient of 40 to 55×10 -7 /°C.; the sealing glass has a thermal expansion coefficient close to 40 to 55×10 -7 /°C.; the heat sink has a fin structure and is bonded to the rear surface of the insulating substrate by a silicone resin adhesive having a Young's modulus of 500 kg/cm 2 or less when formed into a film, said silicone resin adhesive containing 20 to 80% by volume of one or more fillers in order to increase its thermal conductivity; the thermal expansion coefficient of the insulating substrate is 35 to 40×10 -7 /°C., the insulating substrate is made of a sintered body of ceramic material having a thermal conductivity of 0.2 to 0.7 cal/cm.sec.°C. and the heat sink is made of at least one member selected from the group consisting of aluminum and alloys thereof having a thermal expansion coefficient of at least 170×10 -7 /°C., whereby the sealing glass is prevented from cracking.