Interfacial reaction of a Sn‐3.0Ag‐0.5Cu thin film during solder reflow

Abstract

Purpose

The purpose of this paper is to produce and investigate the interfacial reaction between Sn‐3.0Ag‐0.5Cu (SAC305) thin films and Cu substrates by solder reflow at various temperatures and times.

Design/methodology/approach

SAC305 thin films were deposited on copper substrates using a thermal evaporation technique. The as‐deposited SAC305/Cu was then reflowed on a hot plate at temperatures of 230, 240, 250 and 260°C for 30 s. In addition, solder reflow was conducted at a constant temperature of 230°C for 5, 10, 15 and 20 s. The microstructure, phase and thickness of the intermetallic compounds (IMCs) formed were determined after cross‐sectional metallographic preparation.

Findings

Cu₆Sn₅ and Cu₃Sn were observed at the as‐reflowed SAC305/Cu interfacial region. The IMC thicknesses increased with the higher reflow temperature and longer reflow times.

Originality/value

Up to now, studies on the thin film characteristics of SAC305 lead‐free solder have been very limited. Thus, this paper presents the deposition of SAC305 thin film by a thermal evaporation technique and its characteristics after solder reflow.

Citation

Mei Lee, L., Haliman, H. and Azmin Mohamad, A. (2013), "Interfacial reaction of a Sn‐3.0Ag‐0.5Cu thin film during solder reflow", Soldering & Surface Mount Technology, Vol. 25 No. 1, pp. 15-23. https://doi.org/10.1108/09540911311294560