| 摘要 |
<P>PROBLEM TO BE SOLVED: To implement the ultrasonic joining between a heat-spreader and a metal foil in a semiconductor device structured such that a strap-shaped metal foil is ultrasonically joined as a connecting conductor to a heat-spreader, which is solder-joined to the upper surface electrode of a semiconductor chip, restraining a crack to be generated at a solder-joint layer between the semiconductor chip and the heat-spreader. <P>SOLUTION: A heat spreader 6 is placed on the upper surface of an IGBT (power semiconductor chip) 4 that is mounted on an insulating substrate 2, and is solder-joined to the upper-surface main electrode of the IGBT, and then, a strap-shaped metal foil 8 is superimposed and ultrasonically joined as a connecting conductor to the upper surface of the heat spreader (a square with one side length equal to A). At that time, leaving a blank space with a width of C around the heat spreader, the joint surface area between the heat spreader and the metal foil is limited to its inner surface area (a square with one side equal to B (B=A-2C)), and then, aligned with this joint surface area, an ultrasonic bonding tool 9 setting a head area size is positioned and set to the upper surface of the metal foil, thus performing ultrasonic joint. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
