SEMICONDUCTOR DEVICE

• Main Author: OGATA TOSHIICHI
• Format: Patent
• Language: English
• Published: 04.04.1988
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

PURPOSE:To obtain a semiconductor device, to which ceramics can be fixed by soldering without causing hair cracks in the ceramics, by a method wherein, as a heat- radiating fin, a copper-tungsten alloy layer is used for the upper surface for fixing the ceramics, a copper layer is fixed to its lower surface with a brazing metal and so on, and the heat-radiating fin is formed into a two-layer structure. CONSTITUTION:The upper surface, which is used for fixing ceramics 4, of a heat- radiating fin 1 is constituted of a copper-tungsten alloy layer 2 having a thermal expansion coefficient approximate to that of the ceramics 4 for preventing hair cracks from occurring due to the heat at the time of soldering, a mechanical strength necessary when the fin is mounted on a heat sink and so on is ensured by the lower surface, and two layers of the alloy layer 2 and a copper layer 3 having a specific gravity smaller than that of the copper-tungsten alloy layer 2 and a thermal conductivity larger than that of the alloy layer 2 are combined together by soldering and so on. As the upper surface of the heat-radiating fin 1 is constituted of the copper-tungsten alloy layer 2 having a thermal expansion coefficient approximate to that of the ceramics 4 in such a way, even such the comparatively large ceramics 4 as 10 mm deg. or layer can be soldered without causing hair cracks due to the thermal strain at the time of soldering.