The development of high through-put micro-bump-bonded process with non-conductive paste (NCP)

In this study, various micro-bump-bonded structures with TCB + NCP processes were evaluated and developed. A commercial available snap-cure NCP material was applied for the joining processes study. Three types of micro bumps, Cu/Ni/Sn2.5Ag, Cu/Sn2.5Ag and Cu/Ni/Au- were fabricated and bonded to achieve joint structures of Cu/Ni/Sn2.5Ag/Ni/Cu, Cu/Ni/Sn2.5Ag/Au/Ni/Cu and Cu/Sn2.5Ag/Au/Ni/Cu. Moreover, the filler trapped and void issues which associated with the TCB+NCP process were also investigated. After the evaluation, the reliability test such as moisture sensitivity test level 3 (MSL 3), temperature cycling test (TCT) and high temperature Storage (HTS) were conducted to the bonded samples. Hereafter, the failure modes with the mentioned issues were analyzed and discussed. Based on the experimental and reliability results, the optimized TCB + NCP processes with various micro-bump-bonded structures can be established. The joints electrical and reliability performance associated with the failure mode were investigated and analyzed. Finally, the characteristics of each joint connection were defined.