| 摘要 |
1286086 Semi-conductor device WESTING- HOUSE ELECTRIC CORP 15 Oct 1969 [8 Nov 1968] 50667/69 Heading H1K A semi-conductor element has at' least' ,part of the surface thereof covered by a cured aromatic polyimide or polyamide-imide resin. A PN silicon device 102 is soldered to a silver-tungsten contact 114 by a layer of silver-lead-antimony alloy 118 and soldered to a molybdenum contact 116 by a layer of aluminium-boron alloy; The soldered assembly is sand blasted, spin etched, rinsed and dried and a layer 224 of the uncured resin in solution applied. 'The layer is cured at successive temperatures up to 250� C. The resin layer may include alizarin or a filler such as SiO 2 , Al 2 O a , BN, MgO, PTFE, quartz, mica, or glass fibre. The coated assembly is inverted and mounted on a base (202; Fig. 5, not shown) of Cu, brass, Al, Al alloy or steel with an intervening layer of Ag (208). The upper surface of the assembly has a layer of Au (218) disposed thereon which is diffused into the nickel (216) of a nickel coated molybdenum body (214). A braided conductor (220) is soldered to the body (214) by a layer of Ag + Au solder. A cup-shaped member (236) and dished-washers (232) maintain all the component parts in contact and an insulating sleeve (210) and washer (228) are provided to prevent the member (236) shorting out the rectifying stack. A ceramic cup (246) is welded to the base and forms a hermetic seal for the device. In an alternative embodiment (Fig. 2, not shown) the exposed PN junction is covered with an insulating layer of Si oxide or nitride or AI nitride and then the device is covered with the resin layer. |
