Wetting Properties and Interfacial Reactions of Mechanically Alloyed Cu5Zn8-Bearing Pb-Free Solders on a Copper Substrate

Abstract

For enhanced wetting properties of Zn-doped solder alloys, this paper proposes Cu 5 Zn 8 -bearing solders. A mechanical alloying process with controlled milling time and rotational speed was used to successfully fabricate Cu 5 Zn 8 -bearing powders with a diameter of 50 lm to 70 lm. Their composition was identified by inductively coupled plasma atomic emission spectroscopy. After the powders were made into a paste with a rosin-activated type of flux, the wetting angles of the Cu 5 Zn 8 -bearing paste solders on a Cu substrate were compared with the wetting angles of bulk solder alloys with the same amount of Cu and Zn alloying elements. The reason for the enhanced wetting properties of Cu 5 Zn 8 -bearing solders is explained by thermodynamic calculations and differential scanning calorimetry experiments. In addition, the interfacial reactions and the shear strength with Cu substrates are also discussed.

Wettability and interfacial reactions between the molten Sn–3.0 wt%Ag–0.5 wt%Cu solder (SAC305) and Ni–Co alloys

“…Eutectic and near eutectic Sn-Ag-Cu solders are promising lead free solders [14][15][16][17][18]. Past research explores the wetting properties [5,6,[18][19][20][21][22][23][24][25][26][27][28][29][30][31] and interfacial reactions [14][15][16][17][18] between Sn-Ag-Cu solders and various substrates, but not for Sn-Ag-Cu/Ni-Co systems. In this study, the Wilhelmy type wetting balance method determines the wetting properties [32].…”