Effect of Thermal Aging and Salt Spray Testing on Reliability and Mechanical Strength of Sn–58Bi Lead-Free Solder

Abstract

Low-cost manufacturing in the electronics industry is becoming more demanding, particularly in the production of consumer electronics. Such manufacturing processes require reliable and low-cost lead-free solders. Among the low-temperature lead-free solders, eutectic Sn-Bi solder attracts a great deal of interest as it offers good reliability compared with that of Sn-Pb solders. In this paper, the reliability of eutectic 42%Sn-58%Bi (wt.%) lead-free solder is studied using combinations of environmental tests such as thermal aging (TA) at 100°C, salt spray test (SST), and a sequential combination of TA and SST. Microstructural studies on the samples are performed at different time intervals. To study the effect of salt spray and TA on the mechanical reliability, drop testing is performed on the samples. Failure analysis is conducted after different tests. Marked corrosion is seen after the SST. This also has a considerable effect on the impact strength of the solder interconnections. TA increases the thickness of the intermetallic layers, which is found to affect the drop performance.Index Terms-Corrosion, drop performance, microstructure, Sn-58Bi lead-free solder.

Environmental test and evaluation technology of control and protection device for flexible DC converter valve

“…The test results showed that the coral sand concrete with high strength had better adaptability under the salt spray corrosion environment than the coral sand concrete with low strength. Mostofizadeh et al [7] studied the reliability of eutectic 42%Sn-58%Bi (wt.%) lead-free soled using combinations of environmental tests such as thermal aging (TA) at 100°C, salt spray test (SST), and a sequential combination of TA and SST. However, concerning environmental tests and evaluation of the control and protection device of the flexible DC converter valve, there has been no relevant research at home and abroad.…”

On Mechanical Response of Aluminum Alloys in Corrosive Environment

“…To investigate the effect of corrosion on the mechanical behavior of aluminum alloys a specific corrosion technique known as the salt spray is utilized. The literature [15,17,23] reveals that corrosion significantly affects the mechanical properties of high-strength aluminum alloys. The present study aims to characterize the degradation behavior of Al7075T6 and Al6061T6 as a consequence of continuous salt spray exposure on tensile, hardness, and impact behavior.…”