Patent ID: 6173887
Filing Date: 2001-01-16
Classification: B23K,H05K

Abstract:
A method of making at least one electrically conductive contact on a substrate, said method comprising the steps of:providing a substrate with a surface having at least one circuitized feature thereon;applying a layer of solder paste over said surface of said substrate and at least a portion of said at least one circuitized feature;selectively heating substantially only said solder paste over said at least one circuitized feature sufficiently to melt said solder paste over said at least one circuitized feature to form a substantially solid conductive solder bump on said circuitized feature while not significantly heating said solder paste over said surface of said substrate or substantially altering the configuration thereof, said applying of said layer of solder and said selectively heating occurring without using a mask; andremoving said solder paste that was not significantly heated.