Influence of Ga Content on the Microstructure and Mechanical Properties of Cadmium-Free Filler Metal

Abstract

The influence of Ga content on the melting temperature, wettability, microstructure, and mechanical properties of low-silver 12AgCuZnSn-2In-0.15Pr cadmium-free filler metal was investigated systematically by means of differential thermal analysis, X-ray diffractometer, scanning electron microscopy, energy-dispersive spectrometer, etc. The results showed that the addition of the Ga element reduced the solidus and liquidus temperatures of the novel low-silver filler metals, and effectively increased the spreading area of the filler metal on the copper and 304 stainless steel substrates. Furthermore, an appropriate amount of Ga element significantly optimized the interface morphology and improved the mechanical properties of the brazed joints. When the Ga content was 1wt.%, the shear strength of the brazed joints reached a peak value of 448 MPa, and the corresponding fracture morphology showed typical ductile characteristics with obvious dimples.

Microstructure and Phase Transition of Ag50.5Cu33.3Sn16.2-xInx Alloys through Experimental Study and Thermodynamic Calculation

“…With the speedy development of the electronics industry, there are increasing requirements for soldering and brazing technologies in the packaging of microelectronic devices [3,4]. Due to the toxicity of cadmium and lead, brazing/soldering alloys containing cadmium and lead are restricted in the applications of electrical and electronic devices [5][6][7]. Therefore, substitutes with the representation of silver-based solder have been attracted attention recently [8].…”