| abstract |
PURPOSE: To prevent migration by fabricating a semiconductor device after coating the only pad surface with noble metal by ultrasonic-working and a metal wire with Cu, Ni, Sn, etc. n CONSTITUTION: The tip of the polymer of bare conductors 5 is made flat by plastic working to make pad 6. Silver bar 7 of the same diameter as pad 6, fixed to vibrator 9, is given ultrasonic vibrations of approximate 50kHz and pushed against the pad surface, so that the surface will be cleaned and then coated with silver. In this case, the noble metal bar should be softer than the pad surface. As a result, dice welding is possible on pad 6 of wire 5-C coated with silver in this way and Au or Al wires can also be connected onto pads 6 of wires 5-B and 5-C. In this way, since it is required only to providing noble metals to one part of each pad, the cost is reduced and migration is prevented. n COPYRIGHT: (C)1979,JPO&Japio |