title: Roughening of Polyimide Surface for Inkjet Printing by Plasma Etching Using the Polyimide Masked with Polystyrene Nanosphere Array.
abstract: Two key conditions are required for the application of fine-line inkjet printing onto a flexible substrate such as polyimide (PI): linewidth control during the inkjetting process, and a strong adhesion of the polyimide surface to the ink after the ink solidifies. In this study, the properties of a polyimide surface that was roughened through etching in a He/SF6 plasma, using a polystyrene nanosphere array as the etch mask, were investigated. The near-atmospheric-pressure plasma system of the He/SF6 plasma that was used exhibits two notable properties in this context: similar to an atmospheric-pressure plasma system, it can easily handle inline substrate processing; and, similar to a vacuum system, it can control the process gas environment. Through the use of plasma etching, the polyimide surface masked the 120-nm-diameter polystyrene nanospheres, thereby forming a roughened nanoscale polyimide surface. This surface exhibited not only a greater hydrophobicity--with a contact angle of about 150° for water and about 30° for silver ink, indicating better silver linewidth control during the silver inkjetting process--but also a stronger adhesion to the silver ink sprayed onto it when compared with the flat polyimide surface.
authors.forename: Mu Kyeom
authors.initials: MK
authors.lastname: Mun
authors.forename: Jin Woo
authors.initials: JW
authors.lastname: Park
authors.forename: Jin Ho
authors.initials: JH
authors.lastname: Ahn
authors.forename: Ki Kang
authors.initials: KK
authors.lastname: Kim
authors.forename: Geun Young
authors.initials: GY
authors.lastname: Yeom