SiC Power Device Packaging Technologies for 300 to 350°C Applications

Abstract:

Article Preview

The challenges of packaging SiC power devices for high temperatures include high operating temperature, wide thermal cycle range, high currents and high voltages. This paper describes ongoing research to develop suitable materials and processes for packaging SiC power devices. Ohmic and Schottky contacts must be protected from oxidation at elevated temperatures. TaSi2:N2 is an effective oxidation barrier, protecting the contacts when exposed to 350 oC in air. For package substrates, silicon nitride ceramics with a thick brazed copper foil are used. A nickel/thick gold or nickel/thick silver surface finish is plated onto the copper foil; depending on the die attach brazing process. With the nickel/thick gold finish, gold-tin eutectic has demonstrated no degradation in die shear strength after 2000 hours at 350 oC or after 500 hours at 400 oC. Work is currently underway with nickel/thick silver and gold-silicon eutectic die attach. No degradation in shear strength has been observed with this system after 100 hours at 400 oC. Gold wire (250 µm) bonding has been demonstrated on both substrate and SiC metallizations. An initial decrease in strength is observed due to annealing of the gold wire, but shear and pull strengths remain high. Polyimide has been used to increase the dc breakdown strength of a test pattern by a factor of ~3x at 300 oC compared to no passivation. The breakdown strength increased with storage in air at 300 oC through 1000 hours.

Info:

Periodical:

Materials Science Forum (Volumes 483-485)

Edited by:

Dr. Roberta Nipoti, Antonella Poggi and Andrea Scorzoni

Pages:

785-790

Citation:

R.W. Johnson and J. R. Williams, "SiC Power Device Packaging Technologies for 300 to 350°C Applications", Materials Science Forum, Vols. 483-485, pp. 785-790, 2005

Online since:

May 2005

Export:

Price:

$38.00

[1] I. Shalish, S. Gasser, E. Kolawa and M. -A. Nicolet, Stability of Schottky Contacts with Ta-Si-N Amorphous Diffusion Barriers and Au Overlayers on 6H-SiC, Proc 3rd Intl. High Temperature Electronics Conference, 1996, p.21.

[2] K. Easler, K. Sugai, T. Miyao, K. Furukuwa, and T. Hirakawa, A New Structure of Low Inductance Ceramic Substrate for Power Module, SMTA/CAVE Harsh Environment Workshop, Dearborn, MI, June 24-25, (2003).

[2] P.T. Vianco, J.J. Stephens, and C.A. Walker A Study of Potential Eutectic Braze Alloys in the Au-AgGe Ternary System, The 1997 TMS Annual Meeting, Orlando, February 9-13, (1997).

[4] Jay S. Salmon, R. Wayne Johnson, and Mike Palmer, Thick Film Hybrid Packaging Techniques for 500oC Operation, Proceedings of the 4th International High Temperature Electronics Conference, Albuquerque, NM, June 16-19, 1998, pp.103-108.

DOI: https://doi.org/10.1109/hitec.1998.676769

[5] Liang-Yu Chen and Philip G. Neudeck Thick and Thin Film Materials Based Chip Level Packaging for High Temperature SiC Sensors and Devices, Proceedings of the 5th International 2000 High Temperature Electronics Conference.

[6] G. Q. Lu and Z. Zhang, Low-Temperature Sintering of Silver paste as a Viable Die Attach Solution for High-Temperature Packaging, Proceedings of the 2004 IMAPS International Conference on High temperature Electronics, May 17-20, 2004, Santa Fe, NM. Acknowledgements. The authors would like to acknowledge the contributions of Shyam Gale, Mike Palmer, Victor Adedeji, Cai Wang and Yi Liu to this work. This work was funded in part by the US Air Force Research Laboratory, WPAFB Contract Number: F33615-01-C2188.

Fetching data from Crossref.
This may take some time to load.