Patent ID: 6893952
Filing Date: 2005-05-17
Classification: H01L,H05K,Y02P

Abstract:
1. A method for connecting a semiconductor device having an active surface having at least one bond pad thereon, said at least one bond pad having a layer of solder on at least a portion thereof, to a substrate having a surface having at least one contact thereon, said at least one contact having a layer of solder on at least a portion thereof, said method comprising: providing at least one ball between said at least one bond pad on said active surface of said semiconductor device and said at least one contact on said surface of said substrate, said at least one ball including a core and an outer layer being solder wettable by at least a portion of said layer of solder on said at least a portion of said at least one bond pad on said active surface of said semiconductor device and said layer of solder on said at least a portion of said at least one contact on said surface of said substrate, said at least one ball having a diameter of at least approximately 50 μms, said at least one ball including a rigid non-conductive polymer, said core having a diameter in the range of 80% to 99% of said diameter of said at least one ball, said outer layer comprising one of silver and a silver alloy having a thickness of about 1 μm substantially covering an entire surface of said core; reflowing said layer of solder on said at least a portion of said at least one bond pad on said active surface of said semiconductor device and said layer of solder on said at least a portion of said at least one contact on said surface of said substrate for connecting said semiconductor device to said substrate; and curing said at least one ball so that a portion of said outer layer of said at least one ball bonds to one of said at least one bond pad on said active surface of said semiconductor device, said at least one contact on said surface of said substrate, and both said at least one bond pad of said semiconductor device and said at least one contact of said substrate.