| AVS 57th International Symposium & Exhibition | |
| Plasma Science and Technology | Thursday Sessions |
| Session PS-ThP |
| Session: | Plasma Science and Technology Poster Session |
| Presenter: | J.B. Park, Sungkyunkwan University, Republic of Korea |
| Authors: | J.B. Park, Sungkyunkwan University, Republic of Korea J.S. Oh, Sungkyunkwan University, Republic of Korea E.L. Gil, Sungkyunkwan University, Republic of Korea G.Y. Yeom, Sungkyunkwan University, Republic of Korea |
| Correspondent: | Click to Email |
Polyimide [(N, N′-oxydiphenylene) pyromellitimide], (PI) is one of the representative high-performance polymer films that has been widely used for the substrate in the microelectronic and flexible electronics industries because PI has desirable properties of high temperature resistance, good mechanical strength, and good dimensional stability. However, in spite of the extensive usage as well as the detailed characterization of the PIs, the poor adhesion of metals to PI, which is a consequence of its low specific surface energy, has to be overcome to render the fabricated devices reliable because the general polyimide–metal composites have limited adhesion strength. Therefore, many researchers have studied on the surface modification of PIs for adhesion improvement to metals.
In this study, the surface of PDMA-ODA PI films before and after atmospheric pressure plasma surface treatment by using remote type modified DBD module was investigated to improve the adhesion between the PI substrate and metal thin film using various gas compositions such as N2/He/SF6, N2/He/O2, N2/He/SF6/O2, N2/He/SF6/O2. Among the plasma treatments of the PI substrate surface using various gas mixtures, the plasma treatment with N2/He/SF6/O2 showed the lowest contact angle value due to the high C=O bondings formed on the PI surface while that with N2/He/SF6 showed the highest contact angle value due to the high C-Fx chemical bondings on the PI surface. Especially, when O2 gas was varied from 0 to 2.0 slm in N2(40 slm)/He(1 slm)/SF6(1.2 slm)/O2 (x slm) gas composition, the lowest contact angle value of about 9.3° could be obtained at 0.9 slm of O2 gas due to the highest oxygen radicals in the plasma, which forms the highest C=O bondings on the PI surface. When the interfacial adhesion strength between the Ag film and the PI substrate was measured after the treatment with N2(40 slm)/ He(1 slm)/SF6(1.2 slm)/O2(0.9 slm) followed by the deposition of Ag, the peel strength of 111 gf/mm which is close to the adhesion strength between metal and the PI treated by a low pressure plasma could be observed.