Effect of crystal rotation on springback of integrated circuit leadframes

Abstract

It is well known that crystal rotation which occurs in deformation processes may affect the mechanical and plastic properties of textured materials. In the present paper, the effect of crystal rotation on springback of a textured copper strip is examined. A model proposed previously by the authors for the prediction of springback of narrow and thin strips has been further extended to take crystal rotation into consideration. Based on the measured orientation distribution function of the strip, it is found that the influence of crystal rotation on the deformation behavior of the strip is significant. A reduction in elastic modulus, and circumferential and radial stresses are obtained. An improvement in the predicted springback angle is observed when crystal rotation is taken into consideration, though more research efforts still require to further enhance the accuracy of the model.