Microstructural and thermal characterizations of light-emitting diode employing a low-temperature die-bonding material

• Published in: Microelectronics and reliability Vol. 63; pp. 68 - 75
• Main Authors: Wang, Tzu-Hao, Lee, Hsuan, Chen, Chih-Ming, Chen, Ming-Guan, Hu, Chi-Chang, Chen, Yu-Jie, Horng, Ray-Hua
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2016
• Subjects: Die-bonding; Low-temperature; Microstructure; Optical; Thermal; Microstructure; Optical; Low-temperature; Thermal; Die-bonding
• ISSN: 0026-2714; 1872-941X
• DOI: 10.1016/j.microrel.2016.06.012

A Sn/Bi bilayer was deposited on a hot air solder leveling (HASL)-treated metal-core printed circuit board (MCPCB) using electroplating as a low-temperature die-bonding material for light-emitting diode (LED). The eutectic feature of the Sn/Bi contact enabled the die-bonding process to accomplish through a liquid/solid reaction at 185°C with a proper compression force. A high-temperature die-bonding structure composed of a Bi layer sandwiched by two intermetallic compounds (IMCs) formed after thermocompression. Employment of the Sn/Bi bilayer for low-temperature die-bonding prevented the LEDs from thermal stress problems, and the resulting high-temperature IMC/Bi/IMC die-bonding structure was capable of withstanding multiple bonding reactions and high temperature/current operation environment. Durability tests including mechanical, thermal, and optical performance were systematically performed and compared with other commercially available die-bonding materials (Ag paste and solder alloys). •A high-temperature die-bonding structure was fabricated by a low-temperature process.•Low-temperature bonding process was assisted by a eutectic reaction.•Die-bonding structure shows good mechanical, thermal, and luminous property for LED.