• Journal of Aerospace System Engineering
• /
• v.12 no.6
• /
• pp.1-8
• /
• 2018

ACF, which is used for the transparent electrode film is manufactured by the thermocompression method with conductive particles. However, the method has disadvantages since there are many wasted materials and the process is complex. To overcome the demerits of the conventional method, EHD printing technology with conductive particles ink is proposed. The line thickness of patterning is influenced by the characteristics of the inks and the printing conditions. Therefore, it is salient to find the most conducive conditions for the micro patterning. In this paper, the ink with conductive particles was manufactured, and the patterning results were obtained by varying the nozzle thickness and the flow rate. The electrical conductivity according to the ejection of the particles ink is obtained.

• Macromolecular Research
• /
• v.17 no.10
• /
• pp.791-796
• /
• 2009

An electrochemically and photochemically polymerizable monomer, 2-((2,3-dihydrothieno[3,4-b] [1,4]dioxin-2-yl)methoxy)ethyl methacrylate (EDOT-EMA), was explored for patterning of poly(3,4-ethylenedioxythiophene) (PEDOT) via side chain cross-linking. The polymer from EDOT-EMA was deposited electrochemically to produce polymeric EDOT (PEDOT-EMA), which was directly photo-patterned by UV light as the side EMA groups of PEDOT-EMA were polymerized to give cross-linked EMA (PEDOT-PEMA). Absorption and FTIR studies of the UV-exposed film (PEDOT-PEMA) indicated that the photo-patterning mainly originated from the photo cross-linking of the methacrylates in the side-chain. After irradiation of the film, the conductivity of the irradiated area decreased from $5.6{\times}10^{-3}$ S/cm to $7.2{\times}10^{-4}$ S/cm, possibly due to bending of the conductive PEDOT channel as a result of the side chain cross-linking. The patterned film was applied to a solid state electrochromic (EC) cell to obtain micro-patterned EC cells with lines up to 5 ${\mu}m$ wide.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.36 no.10
• /
• pp.1011-1017
• /
• 2012

We report the development of an optical micro-nanolithography method by using a roll-type mask. It includes phase-shift lithography and photolithography for realizing various target dimensions. For sub-wavelength resolution, a structure is achieved using the near-field exposure of a photoresist through a cylindrical phase-mask, allowing high-throughput continuous patterning. By using a film-type metal mask, continuous photolithography was achieved, and this method could be used to control the period of resultant patterns in real time by changing the rotating speed of the cylinder mask. As an application, we present the fabrication of a transparent electrode in the form of a metallic mesh by using the developed roll-type photolithography process. As a result, a transparent conductor with good properties was achieved by using a recently built cylindrical phase-shift lithography prototype, which was designed for patterning on 100-mm2 substrates.

• 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.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.15 no.4
• /
• pp.46-50
• /
• 2016

A laser head was designed for micro-scale patterning and joining applications. The target feature size of the pattern was $100{\mu}m$, and optics were designed to perform the target. Two singlet lenses were combined to minimize the chromatic aberration, and the geometry of the lenses was calculated by using the raytracing method with a commercial software program. As a restriction of lens design, the focal length was set at 100mm, and the maximum diameter of the lens or beam size was limited to 10mm for the assembly in the limited cage size. The maximum temperatures were calculated to be $1367^{\circ}C$, $1508^{\circ}C$, and $1905^{\circ}C$ for 10, 12, and 15 Watts of power, respectively. A specially designed laser head was used to compensate for the distance between the object and the lens. The detailed design mechanism and 3D data were presented. The optics design and detailed performance of the lens were analyzed by using MTF and spot diagram calculation.

• Journal of the Semiconductor & Display Technology
• /
• v.9 no.4
• /
• pp.19-23
• /
• 2010

Nanoimprint lithography (NIL) is one of the most versatile and promising technology for micro/nano-patterning due to its simplicity, high throughput and low cost. Recently, one of the major trends of NIL is large-area patterning. Especially, the research of the application of NIL to TFT-LCD field has been increasing. Technical difficulties to keep the uniformity of the residual layer, however, become severer as the imprinting area increases. In this paper we performed a numerical study for a large area NIL (the $2^nd$ generation TFT-LCD glass substrate ($370{\times}470$ mm)) by using finite element method. First, a simple model considering the surrounding wall was established in order to simulate effectively and reduce the computing time. Then, the volume of fluid (VOF) and grid deformation method were utilized to calculate the free surfaces of the resist flow based on an Eulerian grid system. From the simulation, the velocity fields and the imprinting pressure during the filling process in the NIL were analyzed, and the effect of the surrounding wall and the uniformity of residual layer were investigated.

• Korean Journal of Materials Research
• /
• v.18 no.2
• /
• pp.98-102
• /
• 2008

The ferroelectric properties of UV irradiated and non-irradiated PZT films prepared via photochemical metal-organic deposition using photosensitive precursors were characterized. Fourier transform infrared spectroscopy showed that complete removal of organic groups was possible through UV exposure of the spin-coated PZT precursor films at room temperature. The measured remnant polarization values of UV-irradiated and non-irradiated PZT films after annealing at $650^{\circ}C$ were 29 and $23\;{\mu}C/cm^2$, respectively. The UV irradiation was found to be effective for the enhancement of the <111> growth orientation and ferroelectric property of PZT film and in the direct patterning in the fabrication of micro-patterned systems without dry etching.

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.8 s.185
• /
• pp.178-184
• /
• 2006

Hot embossing is to fabricate desired pattern on the polymer substrate by pressing the patterned mold against the substrate which is heated above the glass transition temperature, and it is a high throughput fabrication method for bio chip, optical microstructure, etc. due to the simultaneous large area patterning. However, the bad pattern fidelity in large area patterning is one of the obstacles to applying the hot embossing technology for mass production. In the present study, PDMS pad was used as a cushion on the backside of the micro-patterned 4 inch Si mold to improve the pattern fidelity over the 4 inch PMMA sheet by increasing the conformal contact between the Si mold and the PMMA sheet. The pattern replicability improvement over 4 inch wafer scale was evaluated by comparing the replicated pattern height and depth for PDMS-cushioned Si mold against the rigid Si mold without PDMS cushion.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.34 no.4
• /
• pp.262-268
• /
• 2021

For the past several decades, various next-generation patterning methods have been developed to obtain well-designed nano-to-micro structures, such as imprint lithography, nanotransfer printing (nTP), directed self-assembly (DSA), E-beam lithography, and so on. Especially, nTP process has much attention due to its low processing cost, short processing time, and good compatibility with other patterning techniques in achieving the formation of high-resolution functional patterns. To transfer functional patterns onto desirable substrates, the use of soft materials is required for precise replication of master mold. Here, we introduce a simple and practical nTP method to create highly ordered structures using various polymeric replica materials. We found that polymethyl methacrylate (PMMA), polystyrene (PS), and polyvinylpyridine (PVP) are possible candidates for replica materials for reliable duplication of Si master mold based on systematic analysis of pattern visualization. Furthermore, we successfully obtained well-defined metal and oxide nanostructures with functionality on target substrates by using replica patterns, through deposition and transfer process. We expect that the several candidates of replica materials can be exploited for effective nanofabrication of complex electronic devices.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.4 no.3
• /
• pp.317-321
• /
• 2003

A conventional typewriter types letters by hammering a carbon ribbon which is attached at a paper. The laser typing process which write a micro pattern of Chrome on a silicon wafer has been developed. A glass that is coated with 100 nm Chrome (Carbon ribbon) is attached on a silicon wafer (paper). An Nd-Yag laser (hammer) is irradiated on the glass, and the Chrome is transferred on the silicon wafer. Micro patterns are made by controlling laser beam trajectory. The suggested micro pattering can be used at the high density data storage of TeraBit/in$^2$ or at the improvement of productivity of semiconductor manufacturing procedure.