Characterization of silver nanoparticle inks toward stable roll-to-roll gravure printing

Abstract

The rheological properties of silver inks are analyzed, and the printing results are presented based on the inks and roll-to-roll printing speed. The shear viscosity, shear modulus, and extensional viscosity of the inks are measured using rotational and extensional rheometers. The inks exhibit the shear thinning power law fluids because the concentration of dispersed nanoparticles in the solvent is sufficiently low, which minimizes elasticity. After the inks are printed on a flexible substrate through gravure printing, the optical images, surface profiles, and electric resistances of the printed pattern are obtained. The width and height of the printed pattern change depending on the ink viscosity, whereas the printing speed does not significantly affect the widening. The drag-out tail is reduced at high ink viscosities and fast printing speeds, thereby improving the printed pattern quality in the roll-to-roll process. Based on the results obtained, we suggest ink and printing conditions that result in high printing quality for complicated printings, such as overlay printing registration accuracy, which imposes pattern widening and drag-out tails in printed patterns.

Rapid Uniformity Analysis of Fully Printed SWCNT-Based Thin Film Transistor Arrays via Roll-to-Roll Gravure Process

“…The web tension and pressure of the impression rollers were maintained with accuracies of ±0.3 kgf and ±0.38 psi, respectively [ 15 ]. The control system for web tension and roll impression pressure from our previously reported setup was used without modification [ 15 , 16 ]. To prevent device failure from printing position errors, we incorporated a control system based on three charge-coupled-device (CCD) cameras into our R2R gravure printing system [ 13 ].…”

Fully roll-to-roll gravure printed electronics: challenges and the way to integrating logic gates

“…Any inconsistency in web tension or printing speed was found to affect the ink transfer process. 78) The ink rheology and printing process parameters influence the thickness, width, and surface roughness of the printed patterns, thereby affecting the characteristics of consequent dielectric and semiconducting layers that define the electrical characteristics of the printed TFTs. 59) However, since all printing processes are quite complex in practice, these factors comprehensively affect the printing process.…”

“…Researchers have reported that the rheology of ink and printing conditions affect the OPRA. 78) It was also observed that the deviations in V th are due to variations in capacitance, which are in turn caused by the fluctuation in OPRA, surface roughness, and ink rheology of the printed dielectric layers. 59,83)…”

Control of the Drying Patterns for Complex Colloidal Solutions and Their Applications

“…Mixtures containing silver, graphene nanoparticles, carbon nanotubes (CNTs), etc. are used in the fabrication of electronic devices due to their high conductivity, compatibility with substrates and excellent mechanical properties [ 24 , 25 , 26 , 27 , 28 ]. During the manufacturing process, the printed film displays non-uniform 3D morphology after solvent evaporation due to the coffee-ring effect, leading to low-resolution patterns and challenges in reproducing similar patterns, subsequently decreasing the performance of the device.…”