| 摘要 |
760,708. Semi-conductor device. RADIO CORPORATION OF AMERICA. Nov. 18, 1953 [Nov. 29, 1952], No. 31984/53. Class 37. A semi-conductor device comprises a body of semi-conductor material with zones of different conductivity type, with a duct of good thermalconductivity and adapted to carry a fluid coolant in heat transfer relation with one of said zones. In the Fig. 5 device, a cylinder of N- type Ge is formed by grinding or preferential etching into a spool 31. A hole 38 is formed by heating a metal rod, at the end of which is carried a body of activator material of acceptor type which is melted by the heat and dissolves the Ge so that pressure applied to the rod forces it through the body while the activator alloys with the internal surface to convert annular zone 48 to P-type. Suitable impurities are gallium, which is normally liquid, indium, aluminium, zinc or even boron which, having a higher melting point than Ge must be dissolved in a neutral or other acceptor impurity. Alternatively, a hollow tube filled with the impurity may be used. The inner surface is then chemically etched and into the hole is inserted a Cu or Ni tube 46 coated with Sn or In 47 which is heated to fuse it to the inner surface. The outer surface of the recessed part is wrapped either with an In foil which is heated to diffuse it into surface zone 50 after which cooling tubes are fused thereto or else indium coated tubes may be used. Simultaneously, tinned tubes are fused to the ends 34, 36 of the spool. The four sets of cooling tubes 46, 52, 56, 58 which are connected in parallel or series to a coolant supply serve as electrodes and 56 and 58 may be electrically connected, whereas the others, which carry insulating fluid, such as distilled water, are joined by insulating pipes. The whole assembly may be encased in insulating material such as that known by the Registered Trade Mark " Araldite." In a rectifier (Fig. 7, not shown), the central P-N junction is formed as above and a copper tube inserted, while the other electrode consists of a tinned coolant duct of elongated cross-section fused to the recessed part of the reel. In another arrangement a main semi-conductor body is bonded to a copper annulus and the electrodes which are blobs of activator material partly diffused into the main body to form P-N junctions are connected to copper discs, the discs and annulus being cooled by fluid flowing in series or parallel through tubes mounted on the peripheries thereof. In a modification, Fig. 4, one disc is replaced by a solid Cu cylinder 27 with a surrounding coil 30, which is fixable to a chassis 26 via an insulating layer 29 by an insulating bolt 28. In all the embodiments the basic body may be P-type and the N-type regions produced by diffusion of As, Sb, Bi or P. |
