Flip chip based packaging solution for high current driver chips used in automotive applications

Abstract

In this work, flip chip is investigated as an alternative assembly technology for packaging applications requiring driving high electrical currents up to 10A and high IC power dissipation. Currently, automotive applications with components driving (temporary) high electric currents are mainly using wire bond based packaging solutions because of cost reason. However, wire bonds with standard diameters are limited in their capability of driving large currents due to the joule heating, which results in unacceptable high temperatures as shown in this paper by analytical calculations, non linear finite element model simulations and experiments on test packages. The temperature increase exponentially grows with current due to the joule heating effect. The flip chip assembly with lead-free solder interconnects, thick top metallization on the die and adapted PCB has proven to be capable to drive currents up to 10A without substantial temperature increase.