| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent thermal fatigue breakdown of a soldering part due to the difference in thermal expansion coefficients, when resin molding is made after a component is fixed on a semiconductor substrate by soldering. SOLUTION: In an insulating board 10, a copper wiring layer 3 is selectively formed on a main surface of an aluminum plate 1 as the base material, via an epoxy insulating resin layer 2. On the insulating board 10, a semiconductor element substrate 21, a passive element composed of a chip resistor 22 and a chip capacitor 23, a terminal 24 are fixed by alloy materials 25, 25', in which one or more kinds of metals selected from among Sb, Ag, Zn, In, Bi and Cu are added to Sn as the main component. A heat dispersing member 27 is arranged between the insulating board 10 and the semiconductor substrate 21. An Al wire (diameter: 300 μm) 26 is formed between the substrate 21 and the copper wiring layer 3 by ultrasonic bonding. Through potting method, the mounting part of the substrate 21 and a passive element is covered with epoxy resin, whose thermal expansion coefficient is adjusted to be 13-21 ppm/ deg.C. The epoxy resin 31 id covered with silicone gel resin 32. A resin case 33 serving as an envelope is formed around a structure of such a constitution.</p> |
