关键词: 长期湿热, Au-Al键合, 金属间化合物, 退化

Abstract: In order to evaluate the reliability of the Au-Al bonding of plastic encapsulated microelectronics (PEMs) in repeated hygrothermal environment, the resistance of the Au-Al bonding interface to repeated hygrothermal stress was tested. Two types of Au-Al bonding PEMs were selected and two groups of hygrothermal stress test conditions were set respectively to accelerate the degradation of Au-Al bonding. SEM and EDS is used to observe the morphology and composition of the bonding interface, and analyze the influence of microstructures evolution of Au-Al bonding interface on the bonding strength and reliability under the repeated hygrothermal stress. The results show that the hygrothermal environment has a apparent impact on the structure and reliability of the Au-Al interface of PEMs, the Au-Al bonding interface tends to form intermetallic compounds and grow faster. With the increase of time, cracks and holes are formed at the interface and the mechanical properties decrease.

Key words: repeatedhygrothermal, Au-Albonding, intermetalliccompound, degradation