Shinsuke Hagiwara

NCF for pre-applied process in higher density electronic package including 3D-package

For higher density electronic package including 3D-package, we developed a novel NCF (Non Conductive Film) support for the pre-applied process that connects and underfills a chip simultaneously. We modified the base film, filler size and others and improved the ability in lamination and BG (back grinding), transparency and dicing to get the excellent processability before the bonding. We also optimized the viscosity and added the remarkably effective flux agent (organic acid) into the NCF to improve the bondability. These properties made it possible to form the excellent Cu-solder bonding parts in short time (<;5 s) without void. For the reliability, we discovered the adequate flux agent (organic acid) which considerably can suppress the decreasing of the adhesive strength after moisture absorption treatment to the extent enough to pass the Lv2/reflow test of molded PKG. We also evaluated the processability and reliability of the pseudo 3D package using this NCF, and obtained the result of the ability to sustain the chip stack and pass the Lv2/reflow test after molding PKG. From these features, this novel NCF is expected to be a promising material for the 3D package with TSV (Through Silicon Via).