Wire Bonding: Limitations and Opportunities for High-Speed Serial Communications

This paper explores the impact of wire bonding solutions on high-speed serial links, focusing on the co-design between on-chip and off-chip parameters to achieve a boost in system bandwidth. Despite traditional limitations, wire bonding can outperform flip-chip techniques when properly designed. This study investigates various cases with different in-band ripples and describes how to optimize the on-chip and bonding parameters accordingly. Additionally, the adoption of shunt peaking techniques is examined, which allows us to achieve a bandwidth boost of up to 3.82 times. While on-chip parameters can be well controlled, the limited mechanical precision of wire bonding may lead to suboptimal wire lengths. An analysis of the variation in bandwidth boost and ripple is presented, indicating that wire length variations below 10% result in minimal impact on boosting effects and ripple. In conclusion, wire bonding offers advantages for high-speed serial links, and co-design optimizes system performance. Properly designed, wire bonding is an attractive choice for high-speed applications, outperforming flip-chip techniques in bandwidth enhancement.