• Journal of the Semiconductor & Display Technology
• /
• v.18 no.3
• /
• pp.72-76
• /
• 2019

A Q-switched diode-pumped neodymium-doped yttrium vanadate (YVO₄, λ =1064nm) laser was used for the direct patterning of indium tin oxide (ITO) films on glass substrate. During the laser direct patterning, the laser beam was incident on the two different directions of glass substrate and the laser ablated patterns were compared and analyzed. At a low scanning speed of laser beam, the larger laser etched lines were obtained by laser beam incident in reverse side of glass substrate. On the contrary, at a higher scanning speed, the larger etched pattern sizes were found in case of the beam incidence from front side of glass substrate. Furthermore, it was impossible to find no ablated patterns in some laser beam conditions for the laser beam from reverse side at a much higher scanning speed and repetition rate of laser beam. The laser beam is expected to be transferred and scattered through the glass substrate and the laser beam energy is thought to be also dispersed and much more influenced by the overlapping of each laser beam spot.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.34 no.1
• /
• pp.89-94
• /
• 2010

Patterning bacteria and cells on substrates has potential applications in molecular biology, antimicrobial drug screening, environmental monitoring and tissue engineering. We developed a technique to deposit two-dimensional array of bacterial cells onto an agar plate by modifying commercially available thermal inkjet printers. The concentration of the bacterial solution in the cartridge was carefully determined to ensure a single cell suspension in a droplet ejected from a nozzle. We measured quantitatively the effects of the bacterial concentration and the agar concentration on patterning performance. Bacterial patterning by inkjet printer is a low-cost and versatile technique which may replace the existing sophisticated methods.

• Journal of the Korean Magnetics Society
• /
• v.13 no.3
• /
• pp.115-120
• /
• 2003

We have developed laser micro-machining technology for fabrication of the micro thin-film inductors. After the thin layers of FM/M/FM films were coated to the silicon substrate by using the conventional sputtering method, the new laser machining was applied to the patterning process that used to be carried out by the semiconductor lithography procedure. A CW Nd:YAG laser operating in TEM$\sub$00/ mode was actively Q-switched to obtain the very short pulse of 200 ns. The laser micro-machining process with pulse energy and repetition rate have been optimized as 5 mJ/pulse and 5 kHz, respectively, to obtain the line resolution as fine as 20 $\mu\textrm{m}$.

• Optical Science and Technology
• /
• v.13 no.2
• /
• pp.11-19
• /
• 2009

• Polymer Science and Technology
• /
• v.18 no.2
• /
• pp.173-179
• /
• 2007

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.165-165
• /
• 2014

In this study, we demonstrated that the soft lithographic patterning processing of chemical vapor deposition (CVD) graphene and rGO sheets as large scale, low cost, high quality and simplicity for future industrial applications. Recently, a previous study has reported that single layer graphene grown via CVD was patterned and transferred to a target surface by controlling the surface energy of the polydimethylsiloxane (PDMS) stamp [1]. Using this approach, the surface of a relief-patterned elastomeric stamp was functionalized with hydrophilic dimethylsulfoxide (DMSO) molecules to enhance the surface energy of the stamp and to remove the graphene-based layer from the initial substrate and transfer it to a target surface [2]. Further, we developed a soft lithographic patterning process via surface energy modification for advanced graphene-based flexible devices such as transistors or simple and efficient chemical sensor consisting of reduced graphene oxide (rGO) and a metallic nanoparticle composite. A flexible graphene-based device on a biocompatible silk fibroin substrate, which is attachable to an arbitrary target surface, was also successfully fabricated.

• Journal of the Semiconductor & Display Technology
• /
• v.19 no.1
• /
• pp.79-84
• /
• 2020

Unlike a printing process, it is difficult to pattern organic thin films in the longitudinal (coating) direction using a coating process. In this paper, we have investigated the feasibility of patterning organic thin films using needles. To this end, we have slot-coated an aqueous poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) solution in the form of a fine stripe or large area and then applied the dual needle; one for discharging the main solvent of the underlying thin film and the other for sucking the dissolved thin film. We have found that the pattern width and depth increase as the moving speed of the plate decreases. However, it is observed that the sidewall slope is very gentle (the length of the slope is of the order of 200 ㎛) due to the fact that the discharged main solvent is widely spread and then isotropic etching occurs. With this scheme, we have also demonstrated that a fine stripe can be obtained by scanning the dual needle closely. To demonstrate its applicability to solution-processable organic light-emitting diodes (OLEDs), we have also fabricated OLED with the patterned PEDOT:PSS stripe and observed the insulation property in the strong light-emitting stripe.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.65 no.3
• /
• pp.224-234
• /
• 2016

This study developed the conductivity pattern of solid surface using laser direct pattern and compound polymer material technology. For development direct patterning system of solid surface, we used the laser power stabilizer, the dynamic focusing, 3D scanner S/W and the auto aligning techniques. Also For conductivity pattern, we are developed compound polymer material with additive by electro-less plating. These technologies are already used commercially. However operation and control integrated system for direct patterning of solid surface are not yet developed. The objective of this paper is to introduce the laser direct structuring for simple process improvement instead complex PCB process, and develop the operating stability and integration system. Also we implemented new application of laser direct structuring through sample manufacture.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.834-836
• /
• 2008

We demonstrated micro-scale conducting polymer patterning based on a selective surface treatment. A substrate with a patterned photoresist was immersed into OTS (Octadecyltrichlosilnae) solution. The protected substrate areas were hydrophilic after removing the PR resist, where a conducting polymer solution was coated selectively by spin-coating method.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.176.2-176.2
• /
• 2014

In this work, we demonstrated that the fabrication of flexible graphene-based chemical sensor with heaters by soft lithographic patterning method [1]. First, monolayer and multilayer graphene were prepared by thermal chemical vapor deposition transferred onto SiO2 / Si substrate in order to fabrication of patterned-sensor and -heater. Second, patterned-monolayer and multilayer graphene were detached through soft lithography process, which was transferred on top and bottom sides of PET film. Third, Au / Ti (Thickness : 100/30 nm) electrodes were deposited end of the patterned-graphene line by sputtering system. Finally, we measured sensor properties through injection of NO2 and CO2 gas on different temperature with voltage change of graphene heater.