Theoretical and Experimental Study of Warp Deformation Behavior with Chemical Reaction and Thermal Load for Viscoelastic Laminated Body
Shozo NAKAMURACTakaaki TANAKA and Tsukasa SHINOHARA
Abstract:Epoxy resin is usually used as an encapsulation of IC chips for electronic parts. As for the epoxy resin, a state changes from liquid to solid by the chemical reaction. Hereby, the residual stresses and warp deformation occure in the electronic parts. In this report, the warp deformation for two laminated bodies consisting of epoxy resin and steel, epoxy resin and printed board caused by chemical reaction and thermal load was examined by experiment and theory. In other words, the theoretical content is the thermo-viscoelastic analysis based on the linear viscoelasticity theory and simple prediction solution about the laminated bodies consisted of above-mentioned materials. As a result, it was clarified that the warp deformation for the laminated bodies generated by chemical reaction and thermal load could be predicted by using the combination of thermo-viscoelastic analysis and simple prediction solution which was derived from the bending theory of beam, and that the percentage of the warp deformation caused by chemical reaction was about 15`20% of the total warp deformation for the laminated bodies. Key Words:Viscoelasticity, Warp deformation, Numerical analysis, Chemical reaction, Epoxy resin, Laminate