关键词: 厚膜混合集成电路, 金层膜厚, 键合强度, 工艺优化, 可靠性

Abstract: In view of the reliability issues of gold wire bonding in thick-film hybrid integrated circuits caused by improper gold layer thickness, this paper systematically investigates the effects of different gold layer thicknesses on gold wire bonding strength on Al₂O₃ and dielectric layers. Through destructive tensile tests and gold ball shear tests under the initial bonding state, after 100 temperature cycles （-65-150 ℃）, and after high-temperature storage at 300 ℃, combined with surface morphology analysis via scanning electron microscopy (SEM), the correlation mechanism between gold layer thickness and bonding interface failure modes is revealed. The results show that within the thickness range of 6-12 μm, the bonding strength on the Al₂O₃ substrate increases monotonously with the rise of gold layer thickness, while the bonding strength on the new dielectric layer presents a trend of first increasing and then decreasing. Thin gold layers feature high surface porosity and weak interfacial bonding force, leading to potential hidden reliability risks after bonding. With the increase of gold layer thickness, the compactness of the gold layer is greatly improved, and the integrity of the bonding interface is enhanced. The optimal thickness process window of thick-film gold conductors for bonding application is comprehensively determined, which provides an experimental basis for the process optimization of thick-film hybrid integrated circuits.

Key words: HIC, gold layer thickness, bonding strength, process optimization, reliability