Simulation and Analysis for Lead Frame Bending Impact to Assembly Singulation Process

In this paper, a transient non-linear dynamic finite element framework is built for the punch clamping process and a 3D bent lead frame geometry based on test data. The objective of this paper is to optimize the punch assembly process by modeling the complete punch clamping process through explicit finite element code LS-DYNA. Two major parts are considered: one is the lead frame bending geometry and the other is punch clamping process optimization. Modeling shows the stress impacts to the junction area between the lead frame and mold compound. The effect of different clamping tooling geometry, the different tooling movement as well as different clamping process are discussed for the impact to mold compound. The modeling results have shown that the optimized clamping tool geometry and movement can reduce clamping induced stress and therefore can eliminate package cracking and delamination even if clamping a bent lead frame