| 摘要 |
PURPOSE:To prevent yield of cracks in an insulating plate, by specifying the thickness of each pad, which is bonded to the insulating plate, in correspondence with whether the pad is used for pellet mounting or not and with the size of the pellets, and providing round shapes, which have the radiuses of curvatures for the shapes of the plane border lines of the pads in correspondence with the thicknesses of the pads. CONSTITUTION:On the surface of a ceramics plate 2, pads 3 and 4 for large pellets, pads 5 and 6 for small pellets and pads 7-10 for wire bonding are bonded. On the back surface, a pad 11 for bonding a heat radiating plate is bonded. The pads 3-11 are made of copper plates. The thickness of the pads 3 and 4 is relatively thick. The thickness of the other pads 5-11 is relatively thin. The shape of the plane border lines has the round shape having the large radius of curvature. The round shape having the small radius of curvature is provided at the corner parts of the pads 5-11. The pads 5-11 have the shape so that they are enclosed in the space around the pads 3 and 4. Thus the heat yielded from the pellets can be dissipated, and the space can be effectively utilized. |
