Thermomechanical and dynamic behavior of surface mounted chip components

Since SMT is a new technology, there are numerous problems at different processing stages that confront this industry. This thesis addresses the following two problems: 1) chip component movement during solder reflow and 2) thermomechanical behavior of solder joints during thermal cycling. The problem of SMC movement is predominant in passive components, such as capacitors and resistors, and hence the study was conducted on these two devices. Based on a static and dynamic model, recommendations on pad sizes, solder volume, and component dimensions were made. An elastoplastic model was developed to investigate the thermomechanical behavior of solder joints during thermal cycling. Parameters such as pad sizes, solder volume, and standoff height were varied to find their effect on the strains in the joint. Recommendations for optimal dimensions for these parameters were made based on the results of the simulations. Finally, the elastoplastic model was augmented with the inclusion of creep analysis. The effects of different PCB constraints on the strain distribution in the solder joint were studied. Finally, a methodology to predict the life of a solder joint was developed