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Publication Date

Fall 2025

Degree Type

Thesis - Campus Access Only

Degree Name

Master of Science (MS)

Department

Chemical and Materials Engineering

Advisor

Christopher Lew; Katy Kao; Yanika Schneider

Abstract

This study investigated the effects of particle shape, filler loading, and surface functionalization on the mechanical, thermal, and dimensional performance of alumina–epoxy composites to provide insight for optimizing materials for electronic packaging applications. Flake and spherical alumina fillers, both untreated and APTES-treated, were incorporated at 1.0, 2.0, and 3.0 vol %. X-ray fluorescence (XRF) confirmed successful silane modification through increased SiO₂ content (~1.3 wt %), while scanning electron microscopy (SEM) revealed roughened particle surfaces, improved adhesion, and enhanced interfacial bonding in treated systems. Three-point bend testing demonstrated that the 2.0 vol % APTES-treated composites achieved the highest flexural modulus (~3.1 GPa) and strength (~132 MPa), representing increases of approximately 60% and 19%, respectively, compared to neat epoxy. Thermogravimetric analysis (TGA) showed an upward shift in maximum degradation temperature (Tₘₐₓ) to ~397–398 °C, which confirms improved thermal stability. Thermal warpage analysis indicated that flake-treated systems at 1.0–2.0 vol % exhibited the lowest curvature variation and highest dimensional stability under cyclic heating, whereas excessive filler content led to localized clustering and reduced efficiency. Ultimately, the 2.0 vol % APTES-treated flake composites exhibited the best balance of mechanical, thermal, and dimensional performance among the conditions studied.

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