Package delamination as indicator of ball bond lift: New diagnostic methodology

The components used in the automotive environment are subjected during their lives to various environmental combined stresses. The predominant failure mechanism at the package level due to these combined stresses is the ball bond lift. The failure is due to the combination of metallurgical effects, such as the intermetallic (IMC) Au-Al thickness growth, widening of Kirkendall voids and mechanical ones as a consequence of the delamination increase. The purpose was to detect the potential weaknesses of die to leads connections. The usual methods described by the automotive qualification standard AEC-Q100 are not sufficient to follow the temporal evolution of the degradation. For this reason, we propose, in addition to the existing methods, a new diagnosis reliability methodology, which consists to use the delamination monitoring as an indicator of potential assambly weaknesses.