Effect of Support Tape on Package Delamination and Tape Adhesive Residue Study in Power QFN Assembly

In this paper, two types of support tapes (one is acrylic adhesive layer; the other is silyl adhesive layer) were selected to study tape influence on delamination in Power QFN after PMC and MSL3@260degC. C -SAM results showed the samples taped with acrylic tape (with pre-mold plasma) demonstrated better delamination performance than that taped with silyl tape both after PMC and MSL3@260degC. Some polysiloxane can be detected on the surface of leadframe taped with silyl tape by FTIR after baking at 200degC, but no organic contaminants were detected on that taped with acrylic tape. TGA results also showed silyl tape had higher out gassing than acrylic tape. The existence of organic contamination (polysiloxane) can lead to more serious delamination issues. Tape adhesive residue on the backside of leadframe and molding resin was also evaluated with acrylic tape. High wire bond temperature and long wire bond holding time can increase the risk of tape adhesive residue. Also, rapid de-taping can induce tape adhesive residue on package. After defining wire bonding temperature, wire bond holding time and de-taping method, tape residue can't be detected by visual inspection and FTIR.