Thermo-Mechanical Analysis and Design for SOD Package Based on Finite Element Method

Today´s electronic packaging products have to keep shrinking in size and achieving higher packing density. The small-outline diode (SOD) is one of the smallest and most widely used components in all electronic devices. A series of calculations and analyses were conducted based on finite element simulation to study the thermo-mechanical performance of SOD package. The residual thermal stresses accumulated during production in the cooling processes after die bonding and post-mold curing were considered as the indicator of thermo-mechanical performance of the packages. Subsequently, the impacts of the package´s material properties and geometric parameters on the residual stresses were investigated. Based on this paper, a design that achieves optimum reduction in thermal stresses has been obtained. In addition, die cracking is one of the crucial problems in electronic packaging industry that certainly influences the reliability of electronic devices. In this paper, the possibility of slanting corner cracking in silicon die during the cooling process after die bonding was taken into account, and the strain energy release rate in fracture mechanics at the crack tip was employed to evaluate the impact of several package parameters to the risk of die cracking. Similar to the previous part, parametric studies and optimal design have been conducted with the purpose of reducing the risk of die cracking.