Patent ID: 6593220
Filing Date: 2003-07-15
Classification: H01L

Abstract:
A method of forming solder bumps on a microelectronic device having a semiconductor substrate and a contact pad on said semiconductor substrate, wherein said contact pad has an exposed surface portion, said method comprising the steps of:providing said semiconductor substrate, the surface of said substrate having been provided with a least one contact pad having a surface; depositing a layer of passivation over the surface of said substrate including said exposed surface of said contact pad; patterning and etching said layer of passivation, partially exposing said surface of said contact pad; depositing a conductive layer over the surface of said layer of passivation, including said partially exposed surface of said contact pad; patterning and etching said conductive layer, removing said conductive layer from above said layer of passivation, partially exposing the surface of said layer of passivation, leaving said conductive layer in place above and extending from above said contact pad by a measurable amount, creating a conductive layer overlying said contact pad; depositing a layer of elastomer over said partially exposed surface of said layer of passivation, including the surface of said conductive layer overlying said contact pad; patterning and etching said layer of elastomer, creating an opening in said layer of elastomer that aligns with and exposes the surface of said conductive layer overlying said contact pad; depositing a layer of solder or solder compound over the exposed surface of said conductive layer; and performing a process of reflow, simultaneously curing said deposited layer of solder or solder compound and said patterned and etched layer of elastomer.