| abstract |
1,002,845. Semi-conductor devices. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. Nov. 30, 1962 [Dec. 4, 1961], No. 45388/62. Heading H1K. An electrical conductor is joined between its extremities to a semi-conductor body by a thermo-compression bond and is then joined on both sides of the bond to a current supply member. As shown, a wafer of P-type germanium 1 is heated in the presence of antimony vapour to produce an N-type surface layer. It is then soldered, 3, to a nickel support 4, using a solder containing indium and gallium, to form an ohmic contact with the P-type wafer 1. A hemispherical piece of nylon plastic is fused on to the central part of the wafer which is then electrolytically etched to remove the N-type layer except where it is covered by the nylon. The nylon is then dissolved to leave an upstanding portion 6 capped by N-type layer 2. An aluminium wire 8 is etched and then pressed on to the wafer using a sapphire head, and the wafer is heated to form a thermo-compression bond 13 which simultaneously forms a P-type emitter region. A gold wire 9 is similarly secured to the wafer at 12 to form an ohmic contact with base layer 2. The wafer may be reheated after each bonding operation to improve the characteristics of the contact. The complete structure is mounted on a header comprising metal ring 21 with conductors 22, 23, 24 sealed into glass plug 25. Support 4 is soldered to conductor 22 and the wires 8, 9 are soldered on both sides of the thermo-compression bonds 13, 12 to the conductors 23, 24 respectively. The device is enclosed in a cap which fits over ring 21. |