| abstract |
1333848 Welding by pressure RCA CORPORATION 19 April 1971 [18 March 1970] 23835/71 Heading B3R In bonding a first body of gold, silver or copper to another metal body, a thin layer of nickel, iron, cobalt, magnesium, aluminium, palladium, germanium or silicon is disposed between the bodies and ultrasonic vibratory energy is applied to one of the bodies until the layer is worn away and the first metal body is adhered to the other body. A terminal wire 10 of gold, silver or copper coated by electroless plating or electroplating with the thin layer, is held in contact with a metal contact film 12 on a semi-conductor wafer and ultrasonic energy is applied to one of the bodies. The layer wears away to expose the surface of the wire which becomes welded to the layer 12. The metal layer may be between 200 and 25,000Š. In an example, gold wires plated with nickel are bonded to gold plated "Kovar" (Registered Trade Mark). |