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[Display omitted] • Developed compression molding monitoring system reveals cure shrinkage behavior of epoxy molding compound in curing stages. • FEA considering viscoelastic properties and cure shrinkage accurately predicts warpage behavior of bi-material dummy package. • Optimized post-cure temperature profile reduces bi-material dummy package warpage threefold, enhancing package reliability. Warpage in semiconductor packages is a critical issue that affects their reliability and performance. This study aims to minimize the warpage of a bi-material dummy package by optimizing the post-mold curing (PMC) temperature profile. A warpage simulation model was developed considering the viscoelastic properties and cure shrinkage behavior of the epoxy molding compound (EMC). A compression molding monitoring system was also developed to analyze the cure behavior of the EMC. The gelation point of the EMC during compression molding was determined using a dielectric sensor, while cure shrinkage behaviors were analyzed using a fiber Bragg grating sensor. Viscoelastic properties were characterized through stress relaxation tests, and thermal properties were measured using three-dimensional digital image correlation. The developed simulation model was used to optimize the PMC temperature profile using a genetic algorithm. Experimental validation showed that the optimized temperature profile reduced the warpage from ∼1519 μm to 486 μm compared to a linear profile. The findings of this study have broader implications for the design and manufacturing of semiconductor packages, as the proposed approach can be applied to minimize warpage and improve package reliability. [ABSTRACT FROM AUTHOR]

Airbags are essential automotive components that protect occupants from collisions. Airbag covers made of thermoplastic olefin (TPO) material should be deployed quickly without debris under various environments. To accurately predict airbag deployment during a collision, the mechanical properties of polymer materials at high strain rates according to temperature should be considered. In this study, a quasi-static test in the range of 0.0083, 0.0083 s − 1 and a medium strain rate tensile test were performed at strain rates of 1, 10, and 100 s − 1 . Additionally, a split-Hopkinson Pressure bar test was performed to conduct a high strain rate tensile test at 1000, 1500, and 2000 s − 1 . Through this, tensile strength and failure strain were derived for each strain rate. As the polymer phase moves toward the high strain rate region, the β -transition becomes dominant, resulting in a non-linear increase in tensile strength in the Eyring plot. Based on the strain rate dependent mechanical behavior, an airbag module impact simulation was conducted to verify the effects of strain rate on airbag deployment using the LS-DYNA software. The airbag deployment analysis results showed deployment angle results similar to the actual experiment when strain rate dependent mechanical properties were applied. This is because higher strength was applied at high strain rates compared to low strain rates. Therefore, strain rate dependent mechanical properties are essential in high strain rate simulation such as collision analysis. [ABSTRACT FROM AUTHOR]