Thermal performance and mechanical stress analysis of BGA and flex-CSP using parametric FEA models

A comparative investigation of the BGA and flex-CSP designs for packaging of high-performance semiconductors is presented. Parametric finite-element models of the packages are used to study sensitivity of thermal performance, mechanical stresses and reliability on package construction and critical spreading resistances. Both the standard and enhanced BGA designs along with thermal and reliability effects of thermal balls are studied. The flex-CSP provides comparable thermal performance to the standard BGA due to a much smaller heat-injection area into the motherboard