Polyimides (PIs) are often used as electrical insulation between levels of circuitry in the manufacture of electronic components. Copper adhesion to polyimide (PIs) is of great importance in the construction of these microsystem devices. The two polyimides, Kapton-HN (PMDA-ODA) and Upilex-S (BPDA-PDA) were studied with low pressure (253.7 nm) and medium pressure Hg lamps (broad band of radiation centered at ca. 300 nm). X-ray photoelectron spectroscopy (XPS), a highly sensitive surface analytical technique, was used to observe the surface modification within the top 2-5 nm. XPS analysis showed an increase in the O/C ratio with treatment time which appeared mostly as the carbonyl moiety (C=O). The increase in oxygen concentration was achieved faster with 253.7 nm radiation and the ratio of O/C was saturated more quickly for Upilex than Kapton. Both the materials exhibited good practical adhesion of sputter coated copper to the chemically modified PI surfaces for very short treatment time at 253.7 nm as compared to the treatment time at 300 nm. Extensive treatment resulted in cohesive failure within the modified substrates (Kapton and Upilex). Slight decrease and increase in C-O-C bonding was observed with increasing treatment times for Kapton and Upilex respectively. SEM micrographs revealed some changes but did not show any significant differences in surface morphology following photo-oxidation for PIs. The current results are in good agreement with earlier research using 184.9/253.7 nm radiation that produced ozone from the 184.9 nm photodissociation of oxygen.
Library of Congress Subject Headings
Copper plating; Adhesion; Cathode sputtering (Plating process); Polyimides
Department, Program, or Center
School of Chemistry and Materials Science (COS)
Rosenberg, L. P.
Razdan, Mayuri, "Adhesion of copper to photo-oxidized polyimides" (2008). Thesis. Rochester Institute of Technology. Accessed from
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