BUMP STRUCTURAL DESIGNS TO MINIMIZE PACKAGE DEFECTS

摘要

A method of forming a chip package includes providing a chip with a plurality of first copper post bumps having a first height of copper post. The method also includes providing a substrate with a plurality of second copper post bumps having a second height of copper post. The method further includes bonding the plurality of first copper post bumps to the plurality of second copper post bumps by reflowing solder layers on the plurality of first copper post bumps and the plurality of second copper post bumps together to form a first copper post bump structure of the chip package. The first copper post bump structure has a standoff, wherein a ratio of a sum of the first height of copper post and the second height of copper post to the standoff is equal to or greater than about 0.6 and less than 1.