Notice of Retraction: Measurement of thermomechanical coupling effect in packaging structures

Digital speckle correlation method (DSCM) is used to measure the thermomechanical coupling effect in COB packaging structures. CCD camera is applied to capture the speckle patterns of CMOS chip at different temperature fields. Analyzing the speckle patterns, the in-plane deformation of the CMOS chip is obtained. Based on the trigonometrical theory, out-plane displacement can be obtained by measuring of in-plane displacement, and then the elastic thermal stress of the chip is evaluated when the application of the temperature field is repeated. Experiment results are compared with both the results of FEM simulations and the theoretical model. There results are agreed well and it can be proved that DSCM can successfully be applied to analyze the thermomechanical coupling effect. The theoretical model was also verified by result of FEM simulations and experiment testing. Experiment results provide an availability consult to the design of MEMS apparatus.