Surface functionalization of micro silver flakes and their application in electrically conductive adhesives for electronic package

In this study, we used 3-aminopropyltrimethoxysilane, hexanedioic acid, 3-mercaptopropyltrimethoxysilane, and thioglycolic acid to functionalize the surface of micro silver flakes through in-situ replacements. Hexanedioic acid had the best effect on the functionalization. When the content of hexanedioic acid was 0.5–1 wt% of micro silver flakes, it could fully replace the long chain fatty acid and form a very thin molecular film on the surface of micro silver flakes. The micro silver flakes functionalized by hexanedioic acid played a significant role in the regards of improving the properties of electrically conductive adhesives, and letting the adhesives have low viscosity, e.g., 28,000 cPs, low bulk resistivity, e.g., 2.4×10−4 Ω cm, and high shear strength, e.g, 10.4 MPa.