Fabrication of Aluminum Nitride Thermal Substrate and Low-Temperature Die-Bonding Process for High Power LED
- 11 Downloads
In this study, a low-cost aluminum nitride (AlN) sintering process to produce thick AlN film substrate with a high thermal conductivity is developed. The thermal conductivity of the present produced thick AlN film substrate is about 163.8 W/mK, which is very close to the reported thermal conductivity of the AlN material. Also, a Sn-Bi die-bonding system is developed to die-bond light emitting diodes (LEDs) on the present sintered AlN substrate with a relatively low die-bonding temperature (below 160°C). In this work, to enhance a better wetting at the die-bonding interface, three external forces (10 N, 15 N, and 20 N) were applied on LED chips during the die-bonding process. We found that the 15-N applied force can achieve a better die-bonding interface among three external forces (10 N, 15 N, and 20 N). The LED die-attached on the AlN substrates by 15 N normal force has the best shear strength (41.5 MPa), compared to the shear strength of 36.9 MPa and 31.5 MPa of the LED die-attached on AlN substrates by 20 N and 10 N normal force, respectively. The LED chips die-attached on the AlN substrate by 15-N normal force shows the best thermal resistance (7.3°C/W). The agreement between the thermal resistance tests and the shear strength tests implies that the better die-bonding interface produced a higher shear strength and a lower thermal resistance of the LED chips die-bonded on the AlN substrates.
KeywordsAluminum nitride (AlN) doctor blade green specimen sintered specimen thermal conductivity die-attach
Unable to display preview. Download preview PDF.
The authors would like to acknowledge C.T. Lin and J.F. Yao for sample preparation, tests and SEM observations. We would like to thank the Opto-Electrical Materials Laboratory of the National Central University (R.O.C.) for providing the equipment support. Thanks to National Chung-Shan Institute of Science & Technology (R.O.C.) for the financial support.
- 14.S. Senthilraja, K. Vijayakumar, and R. Gangadevi, Dig. J. Nanomater. Biostruct. 10, 1449 (2015).Google Scholar
- 15.E.S. Dettmer, B.M. Romenesko, H.K. Charles, B.G. Carkhuff, and D.J. Merrill, Electronic Components Conference, 1989. Proceedings, 39th IEEE, 551–556 (1989).Google Scholar