Effects of shear test temperatures and conditions on mechanical properties of Sn–Ag flip-chip solder bumps

• Published in: Journal of materials science. Materials in electronics Vol. 33; no. 13; pp. 10002 - 10012
• Main Authors: Heo, Min-Haeng, Lee, Dong-Hwan, Jeong, Min-Seong, Yoon, Jeong-Won
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.05.2022; Springer Nature B.V
• Subjects: Bonding; Characterization and Evaluation of Materials; Chemistry and Materials Science; Electronic devices; Flip chip soldering; Fracture surfaces; Materials Science; Mechanical properties; Optical and Electronic Materials; Reliability analysis; Shear rate; Shear strength; Shear tests; Silver; Solders; Tin
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-022-07991-7

Lately, as electronic devices are continually becoming smaller, thinner, and multifunctional, there has been a growing demand for highly integrated packaging technologies. Accordingly, the application of flip-chip bonding technology has significantly increased to meet these demands. Therefore, the reliability evaluation of the micro-sized solder bumps used in flip-chip bonding and an understanding of the relevant mechanical properties has become essential. To evaluate the properties and reliability of Sn–2.3Ag (in wt%) flip-chip bump in various environments, this study compared the results of shear tests performed under three varying conditions, viz., shear heights (10, 15, 20, and 25 μm), shear rates (50, 100, 150, 200, 300, and 500 μm/s), and shear temperatures (25, 50, 100, 125, and 150 °C). A global bond tester was used for the shear tests and scanning electron microscopy was used to observe and analyze the fracture surfaces and joint cross sections subsequent to the tests. The experimental analysis showed that the shear test conditions had a significant impact on the shear strength and joint mechanical properties of the flip-chip bumps. The shear strength tends to decrease as the shear height and temperature increase, whereas it tends to increase in correspondence with increase in the shear rate. The correlations between the results of the mechanical characterization according to these test conditions were comparatively analyzed.