Skip to main content
×
×
Home

Analysis And Characterization Of Electrically Conductive Adhesives

  • Michael A. Gaynes, Luis J. Matienzo, Jeffrey A. Zimmerman and Daniel Vanhart
Abstract

Electrically conductive adhesives (ECAs) are considered an alternative to solder interconnection in microelectronic circuit packaging. In an effort to understand the performance of this class of materials, several chemical analytical techniques have been employed to characterize polymer chemistry, filler morphology and surface chemistry. These techniques include fourier transform mass spectroscopy pyrolysis (FTMS), optical microscopy, confocal laser scanning microscopy (CLSM), scanning electron microscopy with energy dispersive x‐ray analysis (SEM/EDX), auger electron spectroscopy (AES) and photo‐electron spectroscopy (XPS). Samples studied were conductive adhesive layers and deposits, plated metal surfaces, cross‐sections of bonded joints and fractured bonds. Electrical contact resistance data were also taken on bonded joints. Three commercial adhesives were studied. It was found that thermal stability varied among the three adhesives with one adhesive showing degradation at as low as 200 °C. Differences were also noted in silver flake size, morphology and apparent contact area. Excellent contact resistance stability is achieved with two formulations on a palladium‐nickel alloy surface. In contrast, a hard gold surface yielded unstable contact resistance. Fractured bond surfaces were studied for both stable and unstable joints to understand mechanisms for contact resistance degradation. The increase in contact resistance is most likely caused by oxygen ingress along an interfacial bond where the adherend surface is smooth. The matrix polymer oxidized at the interface when exposed to temperatures above the glass transition temperature. Tin surfaces cause increasing contact resistance and nickel surfaces give an initial contact resistance that is more than two orders of magnitude higher than noble metal surfaces. Oxide formation in both cases is the likely cause for the unstable and high resistances. Various analytical techniques have been used to characterize and differentiate electrically conductive adhesives. Differences among three adhesives are noted and correlated to contact resistance performance.

Copyright
References
Hide All
1 Kulwanoski, G., Gaynes, M., Smith, A. and Darrow, B., “Electrical Contact Failure Mechanisms Relevant to Electronic Packages”, Proceedings 37th IEEE Holm Conference on Electrical Contacts, 1989, pp. 184192.
2 Gaynes, Michael A., Lewis, Russell H., Saraf, Ravi and Roldan, Judith, “Evaluation of Contact Resistance for Isotropie Electrically Conductive Adhesives”, IEEE CPMT Transactions, vol. 18, no. 2, May, 1995, pp. 299304.
3 Gaynes, Michael A. and Lewis, Russell H.Evaluation of Contact Resistance for Isotropie Electrically Conductive Adhesives”, SAMPE, 1994, vol. 7, pp. 6978.
4 Wagner, C. D, Riggs, W. M., Davis, L. E. and Moulder, J. F. in Handbook of X‐Rav Photoelectron Spectroscopy. edited by Muilenberg, G. E., Perkin Elmer, Minnesota, 1979, p. 172.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

MRS Online Proceedings Library (OPL)
  • ISSN: -
  • EISSN: 1946-4274
  • URL: /core/journals/mrs-online-proceedings-library-archive
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×

Keywords

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 3 *
Loading metrics...

Abstract views

Total abstract views: 149 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 15th July 2018. This data will be updated every 24 hours.