Patent ID: 8232192

Claim:
A process of bonding a chip and a substrate, comprising: providing a metal bump on said chip, wherein said metal bump comprises a tin-containing portion over said chip; providing said substrate with a gold-containing layer; after said providing said substrate with said gold-containing layer, forming a polymer layer with a thickness between 5 μm and 400 μm on said substrate, wherein said metal bump has a height greater than said thickness of said polymer layer, wherein a difference between said height of said metal bump and said thickness of said polymer layer is less than 50 μm; after said forming said polymer layer, directly physically joining said tin-containing portion and said gold-containing layer at a temperature between 80° C. and 400° C., directly physically joining said polymer layer and said metal bump and directly physically joining said polymer layer and said chip; and after said directly physically joining said tin-containing portion and said gold-containing layer, cutting said substrate.