Study On Preparation And Properties Of Isotropic Conductive Adhesive Filled With TIB Ceramic Powder

With the rapid development of electronic industry, the requirement on the technology ofmicroelectronic interconnection, because of the defect as low resolution, high connectiontemperature and bad environment compatibility, the development of conventional Sn/Pbsolder is conditioned. Electrically conductive adhesives (ECAs) have been more and moreextensive attention in nearly thirty years, ECAs essentially is a certain group of materials,which contain insulating polymeric matrices, conductive fillers, and it can provide electricaland mechanical interconnections between electronic components and substrates for thecorresponding curing modes. ECAs possess many advantages over conventional solderingsuch as environmental friendliness, lower temperature processing and simple interconnectionprocessing, so ECAs is an ideal substitute of Sn/Pb solder.The metal powders are widely used as conductive fillers of the traditional ECAs at thepresent time, but they have some limitations and drawbacks. In this thesis, a new epoxy resinbased on conductive adhesive is fabricated by taking Fcc-TiB conductive ceramic powder asfiller. The optimum filling amount of the additive agents in the ECAs system of conductiveceramic powder is attained through theoretical analysis and experimental design. And theresults indicate that the mass of curing agent T31is25wt.%of the mass of epoxy resin,acetone is used as nonactivated thinner and the mass is20wt.%of the mass of epoxy resin,tributyl phosphate is used as defoaming agent and the mass is0.5wt.%of the system totalweight. The mass of silane coupling agent KH550is3wt.%of the mass of TiB ceramicpowder.Through curing of ECAs for some different rates at the constant speed of warmingtemperature, differential thermal analyzer is used, according to the change of heat flow rateresponse (dH/dt) for the solidification process, showed that the theoretical initial curingtemperature of ECAs with TiB ceramic powder is86.91℃, the curing peak temperature is121.84℃and the post-processing temperature is163.58℃. Then through an experimentoptimization design method for the theoretical curing temperature, determine that the bestcuring process for ECAs with TiB ceramic powder is reaction with curing agent at150℃for about60min.The conductivity and shearing strength of ECAs with TiB ceramic powder were tested, the result of analysis indicated that ECAs changed from insulating to conductive with theincrease of the content of TiB powder, when the content up to a certain degree, the bulkresistivity tended to be stable, when the filling amount of TiB powder was75wt.%, wherethe bulk resistivity of ECAs with TiB powder was6.41×10-2cm. The shearing strengthdecreased significantly with the increase of the content of TiB powder, the shearing strengthdecreased slowly at the previous stage, when the content up to a certain degree, the shearingstrength of the system suddenly drop. But through the silane coupling agent KH550improved, the shearing strength of ECAs was capable to12.26MPa when the filling amountof TiB powder was70wt.%.Studies on the heat stability of ECAs with TiB powder on the derivativethermogravimetric analysis (TG/DTG) and analyzes the ECAs’ failure process astemperature heighten, showed that the starting decomposition temperature of ECAs is318℃.Then the TiB ceramic powder was be detected for oxidation mass gain by differentialthermal analyzer and X-ray diffractious, showed that the starting oxidation temperature ofTiB powder is400℃, the oxidation products of the different oxidation temperatures wereanalyzed, results showed that the TiB powder has good antioxidant activity below400℃, sothe TiB ceramic powder could match with epoxy resin for service temperature.The conductivity and shearing strength of ECAs with TiB ceramic powder wascompared with the traditional ECAs with Cu powder by stored under room temperature, inhigh temperature and in35wt.%nitric acid, found that the TiB powder has good anti-agingproperties and corrosion resistance, the stability of ECAs with TiB powder is far superior toECAs with Cu powder. Especially the conductivity of ECAs with TiB ceramic powder onlydropped15.6%after2000hours, and proved that in special corrosive working environment,ECAs with TiB powder has broad application foreground.