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.Index Terms-Gold-to-gold, inner lead bonding.

An experimental and numerical investigation into the effects of the chip‐on‐film (COF) processing parameters on the Au‐Sn bonding temperature

“…In both cases, the failure is caused by an insufficient temperature during the bonding process, which leads to a poor metallurgical reaction at the Sn-Au interface and thus a poor mechanical bonding strength. However, the joint strength cannot be improved simply by increasing the bonding temperature, since a high tool tip temperature leads to a loss in tool tip co-planarity with the lead surface and causes both splotching and electrical problems (Atsumi et al, 1990;Ni et al, 2006). As a consequence, the packaging industry relies heavily on the use of trial-and-error testing methods to adjust the bonding parameters in such a way as to satisfy the design requirements.…”