Predictive design of flip-chip PBGA for high reliability and low cost

Base station customer application required a high reliability, low cost, surface mountable package. Predictive engineering was used to determine the package design configuration capable of meeting the customer challenge. A variety of different design configurations were evaluated using nonlinear finite element simulation. The full array design could not satisfy the reliability requirements. A new perimeter array design (solder joints depopulated from under the die) was proposed and evaluated. The influence of the package parameters was studied for both the full array and peripheral array designs. The optimum design was determined to meet or exceed the required reliability. Simulation was successfully used in the very beginning of the program to significantly reduce the design cycle time.