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The purpose of this paper is to investigate the wetting behaviors of Sn-5Sb-CuNiAg solders on copper substrates in different soldering processes and the effects of alloying elements on the wettability.

Sn-5Sb-CuNiAg solder balls (750 µm in diameter) were spread and wetted on 40 × 40 × 1 mm copper plates, in different fluxes, soldering temperatures and time. The contact angles were obtained by a home-made measuring instrument. The samples were polished and deep etched before analyzed by scanning electron microscopy. Energy dispersive X-ray spectroscopy was used to identify the composition of the joints.

The effects of different soldering processes and alloying elements on the wetting behaviors of Sn-5Sb-CuNiAg solders on copper substrates were calculated and expounded. The rosin-based flux could effectively remove oxidation layers and improve the wettability of Sn-5Sb-CuNiAg solders. Then with the increase of soldering temperature and time, the contact angles decreased gradually. The soldering processes suited for Sn-5Sb-CuNiAg solders were RMA218, 280°C and 30 s. Considered the effects of alloying elements, the wettability of Sn-5Sb-0.5Cu-0.1Ni-0.5Ag was relatively favorable on copper substrates. Besides, Ni could accumulate at the solder/Cu interface and form a jagged (Cu,Ni)6Sn5 IMC.

This work was carried out with our handmade experiment equipment and the production of the quinary lead-free solder alloy used in wetting tests belongs to us. The investigated Sn-5Sb-CuNiAg alloys exhibited higher melting point and preferable wettability, that was one of the candidates for high-temperature lead-free solders to replace high-Pb solders, and applied extremely to high temperature and frequency working environments of the third-generation semiconductors components, with a greater potential research and development value.

This paper aims to investigate the effect of the Cu, Ni and Ag addition in Sn5Sb-based alloy on the mechanical properties and its mechanism.

The micro-indentation, creeping test of the Cu/Sn5Sb–0.5Cu–0.1Ni–0.5Ag/Cu and Cu/Sn–5Sb/Cu were conducted, and its microstructure was analysed. The scanning electron microscope and the metallographic microscope characterized the microstructure of the Sn5Sb–0.5Cu–0.1Ni–0.5Ag/Cu and Sn–5Sb/Cu joints.

The microstructure of Cu/Sn5Sb–0.5Cu–0.1Ni–0.5Ag/Cu is distributed with the fine (Cu,Ni)6Sn5 and Ag3Sn intermetallic compounds (IMCs), whereas the Cu6Sn5 and Sn3Sb2 in Cu/Sn–5Sb/Cu is larger and far more less. This investigation reveals that the addition of the Cu, Ni and Ag elements reinforced mechanical properties and provided a technical basis for the development of Sn–Sb alloy with good mechanical properties.

This paper reveals that the hardness and the modulus of the bulk solder Cu/Sn–5Sb/Cu solder joints were improved with the addition of Cu, Ni and Ag trace elements. Meanwhile, the creep resistance and plasticity were also improved. This study has a great value for exploring high-performance Sn–Sb based solder alloy and has proved an example.

The purpose of this paper is to investigate the morphology evolution and the composition transformation of Au-Sn intermetallic compounds (IMCs) of the new Au/Sn-5Sb-1Cu-0.1Ni-0.1Ag/(Au)Ni solder joint during the high temperature aging.

Sn-5Sb-1Cu-0.1Ni-0.1Ag solder balls (500 µm in diameter), heat sink with structure of 7.4 µm Au layer on 5 µm Ni-plated Cu alloy and Si chip with 5.16 µm plated Au were used to fabricate micro-solder joints. The joints were performed in a furnace at 150°C for 150, 250 and 350 h aging. The samples were polished and deep etched before analyzed by metallographic microscope and scanning electron microscopy, respectively. Energy dispersive x-ray spectroscopy was used to identify the composition of the IMCs.

ß-(Au,Ni,Cu)₁₀Sn phase is formed during the soldering process. The IMCs evolution has two periods during the aging. The first is the ξ-(Au,Ni,Cu)₅Sn, ξ-(Au,Cu)₅Sn and δ-AuSn were formed and grew to form a full-compound joint after about 150 h aging. The second is the conversion of the full-compound joint. The IMCs converted to ξ′ phase when the aging time extends to 250 h, and transformed to ε-(Au,Ni,Cu)Sn₂ and η-(Au,Ni,Cu)Sn₄ after 350 h aging. The thicker gold layer and thinner solder joint can promote the growth of the IMCs. ß-(Au,Ni,Cu)₁₀Sn emerged in Au/SnSb-CuNiAg/(Au)Ni in this research, which is not usually found.

The results in this study have a significant meaning for the application of the new Sn-5Sb-1Cu-0.1Ni-0.1Ag in harsh conditions.