Proceedings of the
9th International Conference of Asian Society for Precision Engineering and Nanotechnology (ASPEN2022)
15 – 18 November 2022, Singapore
doi:10.3850/978-981-18-6021-8_OR-12-0190
Electronic Packaging Enhancement Engineered by Enhancing the Reliability Via Rapid Cooling
1Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu Daejeion 305-701, Republic of korea
ABSTRACT
Semiconductor packaging continues to reduce in thickness following the overall thinning of electronic devices such as smartphones and tablets. As the package becomes thinner, warpage of the semiconductor package becomes more important due to the reduced bending stiffness and driven by thermal residual stresses and thermal expansion mismatch during the epoxy molding compound (EMC) curing to manufacture package. The warpage not only decreases the reliability of the semiconductor package but also lowers the production rate yield, causing the semiconductor price to rise. In this study, we developed a modified cure cycle that adds rapid cooling step to the conventional cure cycle (CCC) to enhance the reliability of the EMC molded to a copper substrate (EMC/Cu bi-layer package) by lowering the bonding temperature of the EMC/Cu bi-layer package. Analysis of package's bonding temperature via Timoshenko theory considering effective cure shrinkage allowed the rapid cooling step to be quantified and confirmed through experiments. The modified cure cycle results in reduction of residual internal strain and curvature, 26% and 27% respectively, and increase in peel strength, 40% compared to CCC.
Keywords: Semiconductor packaging, Epoxy Molding Compound (EMC), Cure shrinkage, Bonding temperature, Curvature
1Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu Daejeion 305-701, Republic of korea
ABSTRACT
Semiconductor packaging continues to reduce in thickness following the overall thinning of electronic devices such as smartphones and tablets. As the package becomes thinner, warpage of the semiconductor package becomes more important due to the reduced bending stiffness and driven by thermal residual stresses and thermal expansion mismatch during the epoxy molding compound (EMC) curing to manufacture package. The warpage not only decreases the reliability of the semiconductor package but also lowers the production rate yield, causing the semiconductor price to rise. In this study, we developed a modified cure cycle that adds rapid cooling step to the conventional cure cycle (CCC) to enhance the reliability of the EMC molded to a copper substrate (EMC/Cu bi-layer package) by lowering the bonding temperature of the EMC/Cu bi-layer package. Analysis of package's bonding temperature via Timoshenko theory considering effective cure shrinkage allowed the rapid cooling step to be quantified and confirmed through experiments. The modified cure cycle results in reduction of residual internal strain and curvature, 26% and 27% respectively, and increase in peel strength, 40% compared to CCC.
Keywords: Semiconductor packaging, Epoxy Molding Compound (EMC), Cure shrinkage, Bonding temperature, Curvature
