LED Die-Bonded on the Ag/Cu Substrate by a Sn-BiZn-Sn Bonding System

• Published in: Journal of electronic materials Vol. 45; no. 12; pp. 6171 - 6176
• Main Authors: Tang, Y. K., Hsu, Y. C., Lin, E. J., Hu, Y. J., Liu, C. Y.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-12-2016; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Die casting; Electronics and Microelectronics; Instrumentation; Lead free solders; Materials Science; Optical and Electronic Materials; Solid State Physics; Studies; Die-attachment; lead-free solder; partial pressure; Sn-Bi-Zn solder; die strength
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-016-4885-7

In this study, light emitting diode (LED) chips were die-bonded on a Ag/Cu substrate by a Sn-BixZn-Sn bonding system. A high die-bonding strength is successfully achieved by using a Sn-BixZn-Sn ternary system. At the bonding interface, there is observed a Bi-segregation phenomenon. This Bi-segregation phenomenon solves the problems of the brittle layer-type Bi at the joint interface. Our shear test results show that the bonding interface with Bi-segregation enhances the shear strength of the LED die-bonding joints. The Bi-0.3Zn and Bi-0.5Zn die-bonding cases have the best shear strength among all die-bonding systems. In addition, we investigate the atomic depth profile of the deposited Bi-xZn layer by evaporating Bi-xZn E-gun alloy sources. The initial Zn content of the deposited Bi-Zn alloy layers are much higher than the average Zn content in the deposited Bi-Zn layers.