High temperature aging of epoxy-based molding compound and its effect on mechanical behavior of molded electronic package

Adwait Inamdar, Yu Hsiang Yang, Alexandru Prisacaru, Przemyslaw Gromala, Bongtae Han*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

20 Citations (Scopus)


Epoxy-based molding compounds (EMC) are widely used to encapsulate automotive electronics. Under high temperature operation, EMC is oxidized and undergoes degradation in mechanical properties. This can alter the thermomechanical behavior of encapsulated electronic components, and thus can affect their reliability. Three key aspects of EMC oxidation in the context of microelectronics reliability are presented in this paper – (1) degradation of EMC specimens is studied under high temperature aging at three different temperatures – 170°C, 200°C, and 230°C for up to 1500 hours and the oxidation growth is documented as a function of aging duration and temperature using a fluorescence microscope; (2) critical thermomechanical properties of oxidized EMC (viz., elastic modulus, thermal expansion coefficient, and glass transition temperature) are experimentally characterized using fully-oxidized specimens; (3) the effect of EMC oxidation on thermomechanical behavior of an electronic package is investigated by comparing the deformation of a thermally aged package with that of a pristine package under a thermal cycle. This study indicates that EMC oxidizes rapidly during early stages (≈ 24 hours) of exposure to high temperature, and the oxidized layer exhibits significantly different thermomechanical properties. Thus, thermal aging develops a much stiffer package behavior, which is crucial for an accurate reliability assessment.

Original languageEnglish
Article number109572
JournalPolymer Degradation and Stability
Publication statusPublished - 2021
Externally publishedYes


  • Coefficient of thermal expansion (CTE)
  • Elastic modulus
  • Epoxy molding compound (EMC)
  • Fluorescence microscopy
  • Glass transition temperature
  • Oxidative degradation
  • Thermal aging
  • Thermomechanical behavior of package

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