| 摘要 |
904,850. Semi-conductor devices. HUGHES AIRCRAFT CO. Nov. 30, 1960 [Dec. 22, 1959], No. 41222/60. Class 37. A junction-type semi-conductor device has parallel, flat electrodes separated by insulating material which encapsulates the semi-conductor body. A diode is manufactured by bonding an electrode 23 to an N-type silicon wafer 26 and alloying a piece of aluminium 25 to the other side of the wafer to form a PN junction. After cleaning the junction with acetic acid, nitric acid and water a small quantity of insulating material 28 which becomes plastic at or about the normal operating temperature of the device is flowed over the junction region. Suitable materials are high-purity glasses, e.g. one containing 24% As, 67% S, 9% I, with up to 25 parts per million of sodium, manganese, silicon, copper and iron; or glasses including As, S and Se; or As, S and Tl. The assembly shown in Fig. 7 is then placed in a press 31 and a quantity of insulating material 32 sufficient to cover the device is added and compressed to form a solid body. Suitable materials are fluorocarbons and polyfluorocarbons which are elastic at the normal operating temperature of the device. After compression the base 34 of the press is raised so that part of the insulating body protrudes (Fig. 9). This part is then shaved or ground away, leaving a clean surface of aluminium. Base 34 is then lowered and an upper electrode 22 is bonded to the top of the device using an epoxy material containing metallic (e.g. gold) flakes or by coating the electrode with gold and tin and heating above the gold-tin eutectic temperature. The lower electrode 23 is preferably of non-magnetic material, e.g. gold-clad molybdenum, and the upper electrode 22 of magnetic material, e.g. gold-clad iron or nickel iron, so that the orientation of the diode may be determined. A transistor (Fig. 4) may be produced in a similar manner. A mesa-type junction structure is formed on wafer 42 and leads 44, 45 attached to the mesa 46. Glass 47 and insulating material 48 are then applied as before, except that leads 44, 45 are coiled or angled upwardly through material 48 so that when the surface is shaved a relatively large area of metal will be exposed. Electrodes 51, 52 form segments of a circle and are separated by a volume of insulating material. An indexing tab of material is allowed to protrude at one side to determine the orientation of the transistor (Fig. 3, not shown). |
