IBM Journal of Research and Development
IBM Skip to main content
  Home     Products & services     Support & downloads     My account  

  Select a country  
Journals Home  
  Systems Journal  
Journal of Research
and Development
    Current Issue  
    Recent Issues  
    Papers in Progress  
    Recent publications  
    Author's Guide  
  Contact Us  
  Related links:  
     IBM Research  

IBM Journal of Research and Development  
Volume 32, Number 5, Page 658 (1988)
Electronic Packaging
  Full article: arrowPDF   arrowCopyright info


Delocalized bonding at the metal–polymer interface

by P. S. Ho, B. D. Silverman, R. A. Haight, R. C. White, P. N. Sanda, A. R. Rossi
This paper summarizes our current understanding of the nature of the chemical bond formed at the interface between a deposited metal atom and an underlying polyimide surface. The approach in these studies is based on the use of quantum chemical calculations to interpret photoemission spectroscopy results. By focusing on the initial reaction between a chromium atom and the PMDA–ODA polyimide repeat unit, the bonding is demonstrated to be delocalized, arising from the formation of a charge-transfer complex between the metal atom and the PMDA unit of the polyimide. Stabilization of the complex involves the transfer of electronic charge from the metal d states of chromium to the lowest unoccupied molecular orbital of the π system of the PMDA unit of the polyimide. The complex proposed is energetically favored over that involving a direct local interaction between the chromium atom and one of the carbonyl functional groups. The distribution of single-particle electron energy levels deduced from molecular-orbital calculations can account for the spectroscopy results. The formation of such delocalized metal–polymer complexes is also inferred from a related study of the chromium/PMDA–PDA interface.
Related Subjects: Films, thin; Interfaces; Materials; Packaging; Polymers; Surface science