Patent ID: 6332569
Filing Date: 2001-12-25
Classification: H01L,H05K

Abstract:
The method of providing bump contacts for a flip chip integrated circuit having contact pads on a surface,comprising the steps of:forming, in an approximately flat, chemical etchant responsive, transparent, glass carrier member, a distribution of contact volume quantities of solder in cavities each exposed at a surface of said carrier,said distribution corresponding to a distribution of said contact pads on said integrated circuit,said forming step of said distribution being achieved by the steps of,providing a hole in a glass etchant resistant coating on said glass carrier member at the location of each member of said distribution,etching through said hole a hemispherical cavity that undercuts said coating around said hole,aligning said distribution of pads with said distribution of exposed contact volume quantities by optically centering said pads over said contact volumes as viewed employing said carrier transparency, and,applying a heat cycle sufficient to fuse said distributions of pads and contact volume quantities.