Electrical Property Improvement of Copper Filler Conductive Adhesive with Low-Melting Point Metal Bridge

Abstract

Conductive adhesives are expected to be the solder alternative bonding materials in low temperature joining. However, the thermal resistivity and electrical resistivity are higher than those of solders. The contact resistances between the metal fillers and resin intrusion are considered to cause the high resistivity. To solve these problems, metallic cross-links are generated between the copper fillers in the conductive adhesives. Low melting point metal (SnBi) fillers which would be molten under curing temperature of the resin are mixed with copper fillers in the resin. In the curing process, the molten SnBi form the metallic bond cross-link between them. In this paper, the electrical resistivity as well as the thermal resistivity depending on the mixture ratio, size of fillers and the SnBi cross-link are investigated through the experiments.

Fig. 9 SEM images of cross section of bonding layer.