Molecular Approach To Enhance Thermal Conductivity in Electrically Conductive Adhesives

Abstract

Significant heat generation in modern high-speed electronic devices requires elevated thermal conductivity of electrically conductive adhesives (ECAs), but the gap between discrete filler materials significantly interrupts the pathway of heat transport. In this work, we demonstrated the 587% enhancement of thermal conductivity by adding a silver–organic complex (i.e., silver 2-ethylhexanoate) in an epoxy-based ECA with the optimal value of 4.7 W/mK at a low curing temperature of 180 °C. After the postannealing at 200 °C, the thermal conductivity can be further enhanced to 6.2 W/mK with high stability. In the presence of the silver–organic complex, the optimal die shear strength can be increased to 179% (38.06 MPa) compared to that of the blank samples. The silver–organic complex is capable of molecule-scale blending and forming ultrafine Ag particles (13–47 nm) well-distributed in the epoxy matrix, enabling gap-filling and bulky network sintering to achieve thermal conductivity enhancement.