Dissolution and nucleation behavior of Al in Ta/Sn/Al joints during ultrasonic-assisted soldering

Publication date: Available online 24 May 2019Source: Materials LettersAuthor(s): Haifeng Yang, Qi Tan, Hongjun Ji, Zhihong Wang, Wenfu Xu, Mingyu LiAbstractUltrasonic-assisted soldering was used for Ta/Sn/Al interconnection. The effects of ultrasonic waves on the dissolution and nucleation behavior of Al in Ta/Sn/Al joints during ultrasonic-assisted soldering were investigated. The cavitation induced by ultrasound waves lead to the continuous dissolution of the Al from substrate into molten Sn and the content of Al in solder increased rapidly. When the Al content reached saturation in the ultrasonic field, Al precipitated in the solder as second phase and nucleated on the substrates at the same time that Al dissolve into molten Sn from substrate. The behavior of nucleation on the Al substrate suppressed the growth of Al content in solder. The Al content in the bond was in dynamic equilibrium due to the dissolution and nucleation of Al. The maximum shear strength and bonding ratio of the joints were approximately 16 MPa and 86%, respectively.Graphical abstract
Source: Materials Letters - Category: Materials Science Source Type: research