1. Field of the Invention
The present invention relates to the field of semiconductor integrated circuit manufacturing, and more specifically, to a die attach adhesive and a method of forming such an adhesive.
2. Discussion of Related Art
As the density for non-CPU chips continues to increase, the thickness of the package for the chips must be reduced to accommodate the stacking of multiple die on a single substrate form. Consequently, the bondline thickness (BLT), or thickness of the adhesive between the chip and the substrate, must also be decreased. However, the die attach material must continue to serve as a buffer layer between the chip and the substrate to relieve any stress from mismatch in the coefficient of thermal expansion (CTE) which would otherwise cause warpage, cracking, or delamination of the chip.
The latest trends in packaging also involve the elimination of Lead from solder and the raising of the reflow temperature to 260 degrees Centigrade. As a result, the die attach material must be stable at the higher temperatures and be resistant to high humidity while maintaining good adhesion between the chip and the substrate.
Thus, what is needed is a die attach adhesive and a method of forming such an adhesive.