The Study On Preparing Single-component Flow-type EP Underfill Adhesives

Underfill adhesive not only being able to circuit dust, moisture, anti-chemical corrosion,and shock, but also being able to solve the heat problem circuit.it is crucial to the working lifeand reliability of electronic devices.So it requires that the single-component flow-type EPunderfill adhesives with good liquidity, high heat resistance, high thermal conductivity, lowdielectric propertiesWith EP(epoxy resin) as matrix resin,DCA(dicyandiamide) as curing agent and modifiedimidazole as curing accelerator,and adding fillers and other additives,a single-componentflow-type EP underfill adhesive was prepared.The curing temperature of adhesive wasdetermined by testing gelation time and DSC(differential scanning calorimety),FT-IR(infraredspectroscopy).And discussed the effects of the types and proportions on the thermalconductivity, viscosity, mechanical properties, thermal expansion properties of the underfilladhesivesThe results showed that: when m (EP): m (dicyandiamide): m (modified imidazole): m(AGE)=100:8:1:10, m (SiO2): m (Al2O3)=40:20, w (silane coupling agent)=2%, and w(dispersing agent)=0.5%(respectively in epoxy resin) and a curing process was "120℃/30min-150℃/30min ",its viscosity was7.32Pa·S,shear strength was15.33MPa and thermalconductivity was0.793W/(m·K). it shows the the glass transition temperature was106.23℃, the storage modulus of1934MPa (60℃) and1252MPa (80℃). Its water absorption ratewas0.78%(85%humidity,85℃) and0.38%(45%humidity,40℃). At85%humidity, at85℃, can maintain72.5%(11.01MPa) shear strength after aging200hours, after200-20℃-100℃high temperature cycling to maintain78.2%(11.87MPa) shear strength.