Patent ID: 7087458

Claim:
A method for forming a flip-chip package structure comprising: providing a semiconductor device, having formed thereover one or more pillars and patterned layers of conductors each top coated with lead or lead free solder bumps wherein said pillars are formed by a method comprising: depositing a seed layer over said semiconductor device; forming a bottom metallization layer over said seed layer; forming a top metallization layer over said bottom metallization layer; and patterning said top and bottom metallization layers, using a bump-sized mask; providing a substrate having a plurality of bond pads; thereafter depositing a no flow underfill encapsulant over said bond pads exposed through bump-based size solder masks on said substrate wherein said no flow underfill encapsulated further comprises silica, aluminum oxide, aluminum nitride, or born nitride filler; and thereafter attaching said semiconductor device to said substrate by thermal compression bonding.