Characteristics of Zn-Al-Cu Alloys for High Temperature Solder Application

Abstract

Melting range, microstructure, mechanical properties and spreadabililty of Zn-(4$6 mass%)Al-(1$6 mass%)Cu alloys were investigated. Liquidus temperature was targeted between 655 and 675 K, and solidus temperature was targeted to 645 K. The liquidus temperature of the Zn-Al-Cu solders increased with Cu contents, but it decreased with Al contents. Microstructures of the Zn-Al-Cu solders consisted of primary "-phase (CuZn 4 ), -phase (Zn matrix), -eutectic phase (Zn-Al eutectic) and "-eutectic phase (Zn-Cu eutectic), irrespective of the Al and Cu contents. Increasing the Al and Cu contents, hardness and tensile strength increased, but elongation decreased. The Al content played an important role in improving the spread ratio, the Cu content had no significant influence on the spread ratio.

Elevated-temperature shear strength and hardness of Zn–3Cu–xAl ultra-high-temperature lead-free solders

“…These alloys suffer from a comparatively low creep resistance at even moderately elevated temperatures [5]. It has been reported that the addition of 2-3 wt% copper to the Zn-Al alloys can improve their hardness and tensile strength [6]. Kang et al [4] showed that the Zn-Cu-Al solder alloys possess high hardness and tensile strength for ultra-high temperature purposes.…”

Improving the Reliability of Si Die Attachment with Zn-Sn-Based High-Temperature Pb-Free Solder Using a TiN Diffusion Barrier

“…[5][6][7][8][9][10][11][12] Although Au-based eutectic solders, such as Au-20Sn, Au-3Si, and Au-12Ge, are currently used as high-temperature solders for fluxless soldering applications, they are very expensive and exhibit poor workability and inferior wetting. [5][6][7] These serious drawbacks mean that Au-based solders are unlikely to replace high-Pbcontent solders, and also limit their application when the value of the product is high.…”

Development of High-Temperature Solders: Contribution of Transmission Electron Microscopy

“…2A (Murray, 1983), has been studied because the melting range of Zn-Al solder is similar to that of Pb-5Sn solder (so it can be used immediately in industry) (Kim et al, 2008;Kang et al, 2009). The price of zinc and aluminum is very low (they are even cheaper than lead).…”