Chapter 38. Effect of Substrate and Pretreatment on Copper to AIN Direct Bonds
- John B. Wachtman Jr
Published Online: 26 MAR 2008
Copyright © 1991 The American Ceramic Society, Inc.
Proceedings of the 15th Annual Conference on Composites and Advanced Ceramic Materials, Part 2 of 2: Ceramic Engineering and Science Proceedings, Volume 12, Issue 9/10
How to Cite
Chiang, W. L., Greenhut, V. A., Shanefield, D. J., Salvati, L. and Moore, R. L. (1991) Effect of Substrate and Pretreatment on Copper to AIN Direct Bonds, in Proceedings of the 15th Annual Conference on Composites and Advanced Ceramic Materials, Part 2 of 2: Ceramic Engineering and Science Proceedings, Volume 12, Issue 9/10 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470313848.ch38
- Published Online: 26 MAR 2008
- Published Print: 1 JAN 1991
Print ISBN: 9780470375105
Online ISBN: 9780470313848
It was found that copper-aluminum nitride bond strength depends on the particular source of AIN substrate and the preoxidation treatment of the substrate. Direct bonding of copper to AIN substrate was achieved through the use of the gas-metal euteclic method. A satisfactory, reliable bond could be achieved by oxidizing the surface of AIN substrate prior to bonding to copper. The strength of the bond in a peel lest ranged from 15 to 56 Nlcm depending upon substrate and pretreatment. Studies of the fracture mode for copper bonded to various pretreated AIN substrates showed that the failure interface changed with the surface oxide thickness. This could be related to a residual stress between the surface oxide and the AIN substrate resulting from thermal expansion mismatch. Using the best preoxidation treatment, the bond strength with substrates from one supplier differed by a factor of three from the bond strength with substrates from another supplier. A preliminary study showed that this might be attributed to different silicon content on the preoxidized AIN surface. This could alter the thermal expansion coefficient of the surface oxide layer and generate a smaller interfacial residual stress, which in turn results in a higher bond strength. A difference in calcium level may also enhance bond strength as found in prior studies of copper-alumina bonding.