GB850119A - Improvements in or relating to a method of connecting an electrical conductor to an electrode of a semi-conductor element - Google Patents

Abstract

850,119. Welding by pressure. SIEMENSSCHUCKERTWERKE A.G. April 18, 1958 [April 18, 1957; Dec. 13, 1957], No. 12377/58. Class 83 (4). [Also in Group XXXVI] A connecting conductor is fixed to a metallic electrode of a semi-conductor device by applying a pair of welding electrodes to closely-spaced parts of the conductor where it overlies the electrode and passing a pulse of current between them to weld the conductor to the electrode. In one embodiment, Fig. 1, a silver wire 2 is welded to a gold antimony alloy electrode 1a on a PN junction silicon or germanium body 5 by passing. current between welding electrodes 3 and 4. The two ends of the wire may afterwards be twisted together. In another embodiment a cup-shaped conductor 105 (Fig. 11) is welded over an annular region to the gold antimony electrode 104 on a silicon plate. To effect the welding, current is passed between a pair of coaxial cylindrical electrodes 107, 108 pressed against the bottom of the cup. Such a cupshaped conductor may alternatively be welded to the electrode at a series of spaced points. The points may, for instance, be arranged along the sides of or at the corners of a square, on the periphery of a circle or concentric circles, or along parallel or inter sectinglines, e.g. lines radiating from a point or lines intersecting at right-angles. The various welds may be produced singly, in groups, or all together by using a suitable number of welding electrodes. For example where the points lie on a circle, Fig. 13, the cup-shaped conductor may be provided with concentric ridges 110 notched at intervals for the purpose of locating suitably-shaped welding- electrodes 111, 112. The electrodes are moved around between pairs of adjacent notches to form the welds individually. As an alternative the conductor may be provided with suitablyplaced indentations for locating the welding electrodes, or with pin-shaped projections which co-operate with recessed welding electrodes. A tape-like conductor formed with a square or circular cup-like indentation similar to conductor 105 may be welded to the electrode of a semi-conductor device by processes similar to those described above.