Pressure-assisted low-temperature sintering for paper-based writing electronics

• Published in: Nanotechnology 2013-09, Vol.24 (35), p.355204-355204
• Main Authors: Xu, L Y, Yang, G Y, Jing, H Y, Wei, J, Han, Y D
• Format: Article
• Language: English
• Subjects: Coatings; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Electrical resistivity; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in multilayers, nanoscale materials and structures; Electronics; Exact sciences and technology; Heat treatment; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Nanostructure; Physics; Silver; Sintering; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/0957-4484/24/35/355204

With the aim of preparing paper-based writing electronics, a kind of conductive pen was made with nano-silver ink as the conductive component and a rollerball pen as the writing implement. This was used to direct-write conductive patterns on Epson photo paper. In order to decrease the sintering temperature, pressure was introduced to enhance the driving forces for sintering. Compared with hot sintering without pressure, hot-pressure can effectively improve the conductivity of silver coatings, reduce the sintering time and thus improve productivity. Importantly, pressure can achieve a more uniform and denser microstructure, which increases the connection strength of the silver coating. At the optimum hot-pressure condition (sintering temperature 120 ° C/sintering pressure 25 MPa/sintering time 15 min), a typical measured resistivity value was 1.43 × 10−7 Ω m, nine greater than that of bulk silver. This heat treatment process is compatible with paper and does not cause any damage to the paper substrates. Even after several thousand bending cycles, the resistivity values of writing tracks by hot-pressure sintering stay almost the same (from 1.43 × 10−7 to 1.57 × 10−7 Ω m). The stability and flexibility of the writing circuits are good, which demonstrates the promising future of writing electronics.