Microstructure and properties of AuSn20 solder ribbons prepared by rapid solidification process

The AuSn20 solder ribbons were prepared by single roll rapid solidification device and the effect of rapid solidification process parameters on the forming performance of the ribbons were studied. Microstructure, composition distribution, phase composition, melting characteristics and welding strength of the rapidly solidified AuSn20 ribbons were studied through OM, EPMA, SEM, XRD, DSC and other testing methods. AuSn20 solder ribbons prepared by single roll rapid solidification device have fine formability. The width of the strip is 6 mm and the thickness is 100 μm. The rapid solidification AuSn20 solder are composed of ζ'-Au5Sn and δ-AuSn. The quantity of primary phase ζ'-Au5Sn is reduced and the morphology is significantly refined. The eutectic (ζ'-Au5Sn+δ-AuSn) structure is small and the composition is uniformly distributed. The rapid solidification solder has a lower melting temperature and narrow melting range compared to the common solidification solder.