Patent ID: 6610559
Filing Date: 2003-08-26
Classification: H01L,H05K

Abstract:
A process for assembling a substrate and solder bumped chip, said process comprising:providing said chip having a plurality of bumps formed on the bottom side thereof, said bumps having a surface facing toward said substrate; providing said substrate having a plurality of bond pads on the top surface thereof; applying a tacky thermosettable flux only to the bumps attached to said chip or to said substrate bond pads; mounting said chip on said substrate such that each of said solder bumps resides on one of said bond pads and is adhered to said substrate by said tacky thermosettable flux, and, upon mounting, a gap is formed between said chip and said substrate due to the presence of solder bumps; dispensing an underfill material around the said sides of said chip; and subjecting said substrate and said chip to a reflow process.