Synthesis, Structure And Performance Of Silver Plating Copper-epoxy Conductive Adhesive

In the electrical and electronic fields, Pb-Sn solder which is used to connect parts in the product manufacturing process can cause environmental pollution, which has drawn increasing attention. With the increased awareness of environmental protection, people urgently need to find a new connection material to take the place of the Pb-Sn solder. The conductive adhesive makes people see the emergence of new hope, but there are many problems in practical applications for the conductive adhesive. So, it will be a focus to research the conductive adhesive with excellent performance to replace the traditional Pb-Sn solder.In order to solve the current problems in conductive adhesive, meanwhile, combined with the performance requirement of actual use, we select bisphenol A epoxy resin as a conductive adhesive matrix, TEPA as a curing agent, using silver plating copper powder as a conductive filler, silane coupling agent KH-550 as a dispersant, and fumed silicon dioxide as a reinforcing filler, which is prepared into the silver plating copper-epoxy conductive adhesive. We use Scanning Electron Microscopy (SEM) to observe the silver plating copper powder and fumed silicon dioxide powder which have been treated by silane coupling agent KH-550, DC low-resistance tester is used to measure the volume resistivity of conductive, differential scanning calorimetry to test the temperature of the curing reactions.Curing and the dispersion of filler are two important factors for the conductive adhesive. In this paper, we systematically analyzed the curing mechanism of the conductive adhesive. At the base of the theory and doing experiment, we select TEPA as the curing agent which meets the actual need, meanwhile, use the IR to make sure the required amount of curing agent. Studying the mechanism of conductive filler dispersion systematically, we use the silane coupling agent KH-550 to treat the silver plating copper powder and fumed silicon dioxide powder, meanwhile, use the electron microscope and SEM to observe the filler, by which we know the powder filler dispersion has been greatly improved, and the agglomeration has been markedly reduced. So, the selection of the curing agent and the improvement of filler dispersion powder lay a foundation for the conductive adhesive.The two major properties of the conductive adhesive are electrical and mechanical properties. For the electrical property, we study the effect of the amount of silver plating copper powder, the amount of coupling agent which treated the silver plating copper powder, the amount of curing agent, the amount of solvent, and the curing conditions on the volume resisitivity of the conductive adhesive. By the experiment, we know the best formula when it achieves the best electrical property. For the mechanical property, we study the effect of the amount of curing agent, the curing conditions, the amount of coupling agent which treated the fumed silicon dioxide powder, and the amount of the fumed silicon dioxide powder on the shear strength of the conductive adhesive. Then we know how to get the best mechanical property at the base of a best electrical performance property.