Bondability, moldability, and reliability of very-long, multi-height Au bonding wires

In the race to meet market requirements for higher integration, miniaturization and other user demands, integrated circuits (ICs) continue to be packaged in more complex configurations, while still using wire bonding as the interconnection method of choice. While state-of-the-art wire bonding technology is capable of executing the advanced looping trajectories needed to interconnect these ICs, current Au bonding wires are only marginally capable and exhibit various linearity and mechanical failures such as shorting and breakage during the wire bond and molding processes. There is, therefore, a need to engineer new bonding wires with superior linearity and mechanical characteristics capable of supporting very long and multi-height wire bonds required in complex IC configurations. The purpose of this paper is to verify the looping capability of a new-generation bonding wire engineered to sustain very long and multi-height loops, while maintaining high quality and reliability at post-bond and post-mold conditions. This new bonding wire was designed to achieve targeted shapes and heights with reduced variation, which has been verified using standard and newly-developed loop test and measurement methods described by Calpito et al. in comparison with other bonding wires with similar claims. Realistic conditions using production materials, processes and equipment were used during these tests. In addition, high temperature storage (HTS), at 175degC for 1,000 hours using bare and molded devices, was performed to ensure robustness of results.