| 摘要 |
1320924 Semi-conductor devices GENERAL ELECTRIC CO 9 July 1970 [22 July 1969] 33466/70 Heading H1K Heat is transmitted from a semi-conductor device to a heat sink by an electrically insulating member comprising a unitary layer of aluminium nitride (AlN). As shown, Fig. 1, a diode chip 102 is soldered between two contacts 114, 130 having leads 116, 134 respectively. The edge of the wafer is passivated by a glass layer 138 and the lower contact 114 is soldered to one face of an AlN plate 118 to the opposite face of which is soldered a heat sink 120 having a mounting tab 126. The diode is provided with an encapsulation 140 of silicone, epoxy or phenolic resin. In a second embodiment, Fig. 2 (not shown), a thyristor (202) having a bevelled edge is mounted inside a pot shaped casing (204) forming one electrode provided with an insulating cover (222) through which two further electrodes (214, 218) extend. The casing is electrically insulated from a threaded mounting stud (224, 228) by means of a plate (230) of AlN. Other semi-conductor devices may be used in either type housing, transistors and triacs being mentioned, and other types of housing may be utilized. The AlN plate may be of hot pressed single phase powder but is preferably monocrystalline and is provided with surface layers of Cr, W, or Mo covered with Ni, which is covered with Ag by vacuum evaporation so that it can be secured to other parts using a Pb-Sn, Pb-Sn-In, Pb-Sn-Ag or Pb-Sb solder. The electrical contacts to the semi-conductor device may comprise similar structures or may be secured by thermocompression bonding. |
