摘要 |
A sacrificial material applied to a thin die prior to die attach provides stability to the thin die and inhibits warpage of the thin die as heat is applied to the die and substrate during die attach. The sacrificial material may be a material that sublimates at a temperature near the reflow temperature of interconnects on the thin die. A die attach process deposits the sacrificial material on the die, attaches the die to a substrate, and applies a first temperature to reflow the interconnects. At the first temperature, the sacrificial material maintains substantially the same thickness. A second temperature is applied to sublimate the sacrificial material leaving a clean surface for the later packaging processes. Examples of the sacrificial material include polypropylene carbonate and polyethylene carbonate. |