Copper particles/epoxy resin thermosetting conductive adhesive using polyamide resin as curing agent

Thermosetting conductive adhesive (TCA) comprised of epoxy resin E-51 as matrix, Cu microparticles and nanoparticles modified by silane coupling KH550 as con- ductive fillers, polyamide resin with low molecular weight as curing agent, and some other additives. It was reported crea- tively a new liquid curing agent, which solved successfully some difficult problems during preparation of TCA, such as limit of quantity of conductive fillers. Therefore, application of this liquid curing agent decreased greatly the resistivity of TCA under the condition of keeping enough adhesion strength. Antioxidized and mixed Cu particles were devel- oped as conductive fillers in place of expensive Ag. The results showed that optimum conditions of conductive adhe- sive composed of 16 wt % of epoxy resin E-51, 8 wt % poly- amide resin, 65 wt % of Cu microparticles and nanoparticles, 1.3 wt % of silane coupling agent, and 9 wt % of other addi- tives with curing time for 4 h at 60 � C. The adhesion strength reached 16.7 MPa and the bulk resistivity was lower than 3.7 � 10 � 4 X cm. The variation of bulk resistivity was less than 15% at high temperature (100 � C). V C 2012 Wiley Periodicals, Inc. J Appl Polym Sci 126: 815-821, 2012