Wetting characteristics of Sn-5Sb-CuNiAg lead-free solders on the copper substrate

Abstract

Purpose 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. Design/methodology/approach 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. Findings 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. Originality/value 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.

Microstructure evolution, IMC growth, and microhardness of Cu, Ni, Ag-microalloyed Sn–5Sb/Cu solder joints under isothermal aging

“…6 a1). This finding agrees well with the investigations of previous investigations [ 29 , 31 ]. For region F, the atomic contents of Cu and Sn are 75.54% and 22.93%.…”

“…The solder pellets (760 μm) were subjected to reflow soldering process on the Cu substrate (diameter of 610 μm) of printed circuit board (PCB) coated with flux according to the DSC results of solder alloys and wetting results on the Cu substrates [ 29 ]. The reflow soldering process was achieved by a constant heating platform with a peak temperature of 280 °C for 30 s. The samples were cooled down in air and were cleaned with alcohol and ultrasound to remove redundant flux.…”

“…In our previous work [ 29 ], a comparative study was conducted on the wetting behavior and microstructure of Sn–5Sb– x CuNiAg/Cu solder joints and the initial Sn–5Sb/Cu. The Sn–5Sb– x CuNiAg/Cu joints showed excellent wettability and inhibited IMC growth relative to the Sn–5Sb/Cu joint.…”

Characterization and Electrochemical Investigation of Heterogeneous Sb-Cu Coatings

“…A Cu 2 Sb layer was tested as a sensor layer catalyzing the oxidation of antibiotic drugs [8]. Antimony-copper alloys are used as a precursor for the fabrication of ternary Cu-Sb-S and Cu-Sb-Se semiconductor layers for electronics and solar cells [9][10][11] and as additives to lead-free solders [12]. In the last ten years, they have been intensively investigated as an anode material for metal-ion batteries [13][14][15][16][17], as well as a cathode for liquid-metal batteries [18].…”