Mechanics of polymer/metal interfaces in microelectronic packaging

Abstract

Summary form only given, as follows. The loss of interfacial adhesion is mostly seen in the failure of adhesive joints. The interfacial adhesion strength is believed to highly depend on a number of parameters, such as surface topology and treatment, adhesive chemistry/structure, rheological properties of the solids, and elastic mismatch across the interface. Thermal mismatch between polymer adhesive and adherend also has considerable effect on adhesion. Surface science provides modern tools to quantify the thermodynamic work of adhesion (microscopic adhesion energy) through surface contact angle measurement, while fracture mechanics enables the measurement of the interfacial fracture toughness (macroscopic energy density) through various experimental techniques. The objectives of this work are (i) to understand how the thermodynamic work of adhesion is related to the fracture toughness, and (ii) what and how other factors (crack tip plasticity, surface roughness, residual stresses, etc.) affect the fracture toughness.