Reliability-based design optimization for land grid array solder joints under thermo-mechanical load

This paper presents a reliability-based design optimization methodology for second level electronic package solder joints. The reliability-based design optimization aims to find the most robust as well as effective design in the possible design space. In this paper, the reliability-based design optimization is defined as a multi-objective design optimization problem: one design objective is to maximize the system performance; another is to minimize the performance variance. A differential evolution optimization algorithm has been modified to handle the multi-objective constrained problems. The response surface is generated with finite element simulations to model the output of the system in the given design space. A probability analysis of the system output is performed on the response surface using a quasi-Monte Carlo simulation method. As a test vehicle, a generic land ball array package interconnect reliability design optimization is analyzed.. By applying the reliability-based design optimization procedure the best design for the most effective and robust system performance is obtained.