Comparison study of SAC405 and SAC405+0.1%Al lead free solders

Abstract

Purpose -The purpose of this paper is to study the effect of the addition of a small amount of Al (0.1 percent) on the properties of lead-free solder type Sn-4Ag-0.5Cu (SAC 405). Design/methodology/approach -The soldering properties of wettability and spreadability on a Cu substrate were studied, and the effect of Al on the growth of intermetallic compounds (IMCs) was observed. The shear strength of soldered joints was assessed. For comparison, soldering and strength tests were carried out on SAC 405 and SAC 405 þ Al solders. Soldering was performed with an activated flux type ZnCl 2 -NH 4 Cl, with nonactivated flux (rosin), and without flux in the air. Findings -Experimental results show that Al addition slightly reduces the wettability and spreadability of SAC 405 solder. Also, the shear strength is moderately reduced, dropping by 8 MPa on average. Differential scanning calorimetry (DSC) analysis showed that the melting point of SAC 405 þ 0.1%Al solder was increased to 2218C. Originality/value -The positive effect of a small Al addition is due to the fact that it hinders the growth of IMCs formed on the contact surface with Cu substrate. The width of the transition zone of IMC was reduced by approximately 2 to 3 mm, depending on the soldering temperature.

Effect of Aluminum Addition on the Microstructure and Properties of Non-Eutectic Sn-20Bi Solder Alloys

“…The microstructure gradually coarsened with the increase of Al in Figure 2. Reference [11] also reported that particle-shaped Bi phases were found distributed in Sn-rich phase matrix. Referring to the equilibrium Sn-Bi phase diagram [28], the reaction is L(liquid)→L + primary Sn →primary Sn + Bi.…”

“…The cost of Ag was high too. Furthermore, their liquidus temperature (around 217 °C) was higher than Sn-37Pb at 183 °C [11]. The easy oxidation of Sn-Zn alloys was a fatal weakness.…”

Wetting Characteristics of Al-containing Sn-1Ag-0.5Cu Solder Alloy on Cu Substrate using Wetting Balance and Spread area Methods

“…This improvement was attributed to the interaction between Al and Cu at the solder/Cu interface. On the other hand, Kolenak et al [24] stated that the addition of 0.1 wt.% Al to the high-Ag-content Sn-4Ag-0.5Cu/Cu system slightly increased the wetting angle together with giving a slightly smaller spreading area due to the growth suppression of the Cu 6 Sn 5 IMC formed at the solder/Cu interface. Secondly, as Al is an active element, it is easier for it to accumulate at the solder/flux interface in the molten state, and subsequently, the interfacial surface energy is decreased.…”

A Review on Phase Field Modeling for Formation of η-Cu6Sn5 Intermetallic

“…Moreover, since the thickness of the IMC layer can be reduced by adding stabilizing elements such as Al [46] and nanoparticles such as CeO 2 [47] in the tin solder, future phase field simulations or calculations should consider building a multi-elements system coupling other alloying elements and additives to interpret mechanisms. Relative phase field simulation can shed light on the growth kinetics of interactions between alloying elements and IMCs, which cannot be achieved by experimental tools alone.…”