Flexible Nonstick Replica Mold for Transfer Printing of Ag Ink

Abstract

We report the fabrication of flexible replica molds for transfer printing of Ag ink on a rigid glass substrate. As mold precursors, acrylic mixtures were prepared from silsesquioxane-based materials, silicone acrylate, poly(propylene glycol) diacrylate, 3,3,4,4,5,5,6,6,7,7,8,8, 9,9,10,10,10-heptadecafluorodecyl methacrylate, and photoinitiator. By using these materials, the replica molds were fabricated from a silicon master onto a flexible substrate by means of UV-assisted molding process at room temperature. The wettability of Ag ink decreased with increase in the water contact angle of replica molds. On the other hand, the transfer rate of Ag ink onto adhesive-modified substrates increased with increase in the water contact angle of replica molds. Transferred patterns were found to be thermally stable on the photocurable adhesive layer, whereas Ag-ink patterns transferred on non-photocurable adhesives were distorted by thermal treatment. We believe that these characteristics of replica molds and adhesives offer a new strategy for the development of the transfer printing of solution-based ink materials.

Fabrication of Line & Space Structure and Wiring on 3D Surface Features with Imprinting Process

“…1. There are 3 main steps of the process; [1] The flexible intermediate molds of the groove structures called line & space (L/S) were prepared by thermal nanoimprint using the aluminum master molds (Type1: width/height/pitch = 500/100/1,000 μm/μm/μm and Type2: width/height/pitch = 50/50/250 μm/μm/μm). The intermediate mold materials used are the cyclic olefin copolymer COC (Polyplastics Co., Ltd., TOPAS 6013-s04) and polyetherimide PEI (Mitsubishi Chemical Co., SUPERIO ○ R UT Type E).…”

“…In the previous research, there was a report on the wiring technique that a replica mold is produced with the silver nano-ink and transferred to the material surfaces. 1,2 In these reports, it has been shown that Ag transferability is improved by controlling the wettability and release ability at the interface between the resin mold and the conductive ink. However, general methods are still focusing on the two-dimensionally of the flat surfaces.…”