The cyclic fatigue behaviour of ball grid arrays

This paper describes failure load analysis to predict the number of fatigue cycles required to cause adhesion failure at the thick film conductor and alumina substrate interface in ball grid array packages (BGAs). This enables prediction of the number of fatigue cycles required to lift the thick film conductor from the alumina substrate. Adhesion strength is determined by the mechanical properties of the thick-film ink bonding mechanisms, geometry and processing conditions. The investigation is intended to increase the understanding of the adhesion properties between the thick-film ink and the substrate in ball grid arrays.