Accession Number : ADA194647
Title : Chemistry of Adhesion at the Polyimide-Metal Interface.
Descriptive Note : Technical rept.,
Corporate Author : MAINE UNIV AT ORONO LAB FOR SURFACE SCIENCE AND TECHNOLOGY
Personal Author(s) : Grunze, M ; Unertl, W N ; Gnanarajan, S ; French, J
PDF Url : ADA194647
Report Date : 29 Apr 1988
Pagination or Media Count : 14
Abstract : This article describes recent studies of the chemistry of adhesion between thin (d or approx. 11 A) polyimide films and silver and copper substrates, and the structural changes in the polymer when polyamic acid is imidized to polyimide. The thin polyamic acid films were formed by vapor phase deposition of 1,2,4,5-benzenetetracarboxylic anhydride (PMDA) and 4,4-oxydianiline (ODA) under high vacuum conditions and subsequent imidization by heating in vacuum. Both ODA and PMDA are at least partially dissociated upon adsorption onto clean copper and silver and with increasing film thicknesses react to form the polyimide precursor, polyamic acid. Heating to T or = 425 K leads to polymerization to form polyimide films which are thermally stable to about 700 K. Polyimide films with mean thicknesses as small as 1.1 nm have been fabricated in this way and their bonding to the substrate as determined by x ray photoemission studies is summarized. Infrared reflection absorption data gives further evidence that the polyimide bonds to the substrate via fragmented PMDA. Changes in the surface topography and molecular structure of the films during imidization are demonstrated by scanning tunneling micrographs and infrared reflection absorption data.
Descriptors : *POLYIMIDE RESINS, ABSORPTION, ADHESION, ADSORPTION, BONDED JOINTS, COPPER, INFRARED RADIATION, MEAN, MOLECULAR STRUCTURE, OPTICAL DATA, PHOTOELECTRIC EMISSION, POLYMERIZATION, SILVER, STRUCTURAL PROPERTIES, SUBSTRATES, VAPOR DEPOSITION, VAPOR PHASES, X RAYS, ADHESIVE BONDING, DIELECTRIC PROPERTIES, THERMAL STABILITY, ETHERS, ANHYDRIDES, POLYMERIC FILMS, THIN FILMS
Subject Categories : Polymer Chemistry
Distribution Statement : APPROVED FOR PUBLIC RELEASE