Prediction of Substrate Warpage by the Trace Mapping and Trace Reinforcement Method During Solder Reflow

With the trend of thinning the thickness of package, predicting warpage of substrate accurately is becoming more and more important. However, due to the complex patterns of Cu trace in multiple layers, simulation with high fidelity is extremely costly. In this paper, a novel substrate warpage simulation process using trace reinforcement method is introduced. To estimate the performance of this strategy, models based on trace mapping method are established. Comparing the simulation result of trace reinforcement method with trace mapping method, the accuracy of trace reinforcement method is compatible with trace mapping method with black/white option. With trace reinforcement method, not only the warpage of substrate can be simulated, but also the stress and strain in traces can be obtained.