The grain shape dependence of springback of integrated circuit leadframes

Anisotropy is known to be an important factor in affecting springback and deformation behaviour of cold rolled integrated circuit (IC) leadframes. Less work has been carried out to study the effect of grain shape on springback of IC leadframes, though it is considered to be a source of plastic anisotropy. In this paper, a plane stress model based on the concept of relaxed constraints has been developed to investigate the effect of grain shape on springback of a cold rolled copper alloy. Comparisons between the predictions by the relaxed constraint model and the conventional full constraints model and the experimental results have been made. It is found that significant improvement has been obtained by using the new model.