The Study Of Heat-curing Copper Conductive Adhesives

Electronic packaging is one of most important part of modern electronic industry. In packaging, interconnect techniques of chip on substrate or chip on printed circuit board (PCB) restrict the miniaturization of electronics. For the low resolution and bad environment compatibility, Pb/Sn solder will be suitable for technical development. There has been a trend toward using anisotropical conductive adhesives (ACAs) to replace alloy solder because of its low cost and advantageousness to environment. Heat-curable ACA can meet the need of effective interconnect techniques of chip on substrate or chip on printed circuit board in the process of electronic packaging. Therefore, heat-curable conductive adhesives is a promising interconnect materials.In the present paper, heat-curable ACA was synthesized by using polyester resin as the substrate of ACA, MPDA and DDA as curing agent, copper powder modified by silane coupling agent (SCA) as conductive solder, and SiO2 nanoparticles as touchened and strengthened agent. In the paper, the influence of curing temperature, curing time, additive mass of curing agent, SCA, conductive solder and SiO2 nanoparticles on the properties of heat-curing ACA, such as curing, interconnect and conductive property. At the same time, the prepared process was optimized by IR Spectrum, SEM, XRD and DTA. And the optimal process was determined.The experimental results indicated that the process is simple, the interconnect strength is high (≥25MPa) and the conductive propertyis well. After oxidization 48 hours at 140℃ and aging test 1000 hours at room temperature, the conductive adhesives can meet the applied demand.In addition, the curing process was studied by the addition polymerization theory, and the mechanism of copper modified by SCA was analysized.