An Expedient Evaluation Method for Warp Deformation Behavior of Laminated Beam Consisting of Viscoelastic Materials in Cooling Process
linear viscoelastic theory
This paper is intended as a proposal for a simplified evaluation equation that simply predicts the warp deformation behavior arising when the thermal load was given to a viscoelastic laminated beam consisting of epoxy resin and FR-4 substrate. The validity of the equation was verified by comparing its solution with the exact solution based on linear viscoelastic theory and the experimental values. The proposed simplified evaluation equation is composed of the glass transition temperature, the rubber transition temperature, the elastic modulus and the linear thermal expansion coefficient of the component material. In this study, it was clarified that the warp deformation behavior of the viscoelastic laminated beam could be simply predicted by using the proposed simplified evaluation equation where the elastic modulus is divided into three regions such as glassy state, leathery state and rubbery state.