An Accommodative Approach Designed for TCP Gold-to-Gold Inner Lead Bonding

Abstract

This paper proposes an approach that resolves the tradeoff between bond pad crack, the passivation crack, and lead lift failure modes in gold-to-gold inner lead bonding. The bonding head temperature, stage temperature, and bonding force are addressed as three critical recipes. The proposed scenario determines the bonding head temperature according to the maximum compensation flatness, followed by the corresponding stage temperature and required bonding force in sequence. The relevant gold bump hardness, chip warpage, and flatness variation in the bonding tool were evaluated using the finite-element method. The corresponding bonding force was determined using semianalytical equations with empirical factors. A gate driver IC with 280 I/O pins was adopted to conduct the experimental verification in the engineering pilot run. With the optimal recipes, the obtained results demonstrated success in diminishing these three failure modes. The feasibility of proposed approach was verified experimentally.