关键词: 复合膜层, 键合强度, 剪切强度, SEM, 可靠性

Abstract: With the advancement of power semiconductor packaging technologies, thick-film hybrid integration achieves increasingly higher integration density accompanied by shrinking line widths and line spacings. Silver is widely adopted for thick-film conductors and bond pads. The reduction in feature sizes inevitably induces silver migration and relevant reliability risks. In existing research, photolithography and sputtering are employed to deposit diverse thin-film stacks on thick-film ceramic substrates to form composite films, improving their adaptability to microassembly scenarios and oxidation resistance. In this work, experiments are designed to investigate the bonding strength and reliability of thick-thin film composite structures. Three composite film systems combining thin films with thick films are fabricated, namely Ti/Pt/Au, WTi/Au and pure Au. Soldering tests with various solders under different dwell times and bond strength evaluations are carried out on the specimens. Soldered samples are subjected to QML group qualification tests specified by GJB 2438B—2017 General Specification for Hybrid Integrated Circuits. The results reveal that thick-film silver conductors exhibit favorable adhesion with Ti/Pt/Au thin films or pure Au thin films, which can simultaneously satisfy the requirements of soldering, wire bonding and reliability for hybrid integrated circuits. This study provides a feasible film surface treatment solution for high-density thick-film hybrid integration.

Key words: composite coatings, bond strength, shear strength, SEM, reliability