• Journal of the Korean Society for Precision Engineering
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• v.21 no.1
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• pp.11-16
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• 2004

• Journal of the Korean Society for Precision Engineering
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• v.19 no.2
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• pp.33-40
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• 2002

• Journal of the Microelectronics and Packaging Society
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• v.29 no.2
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• pp.107-112
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• 2022

In this study, a silver paste capable of UV curing without using any solvent was developed. The viscosity and viscoelasticity of the silver paste developed as a solvent-free type were measured. And after printing the pattern by screen printing, an electrode coating film was formed by UV curing. Conductivity, pencil hardness, and adhesive force of the formed electrode coating film were evaluated. Finally, the curing characteristics of the electrode coating film were evaluated by TGA and FT-IR. Summarizing these results, in terms of conductivity, adhesion, and curing characteristics, it was found that Paste (4), that is, silver paste obtained by mixing 1.2 ㎛ spherical silver powder and 50 nm silver powder at 72:8% had the best physical properties.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.1
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• pp.17-25
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• 2004

• Journal of the Microelectronics and Packaging Society
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• v.31 no.3
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• pp.42-49
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• 2024

In the electromagnetic wave shielding material market, superior shielding performance in the high-frequency range, along with flexibility and durability, has emerged as critical requirements. The need for high-performance EMI (Electromagnetic Interference) films to address electromagnetic wave interference issues is growing, particularly in various industrial sectors such as smart electronic devices, automotive electronic systems, and communication equipment. In this study, a trimodal silver paste was developed and fabricated into an EMI film, with its performance evaluated. The developed silver paste, utilizing a modified epoxy binder, exhibited properties suitable for screen printing processes. The film demonstrated excellent shielding performance, with an average attenuation of -99 dB in the high-frequency range of the 5G spectrum (26.5 GHz to 40 GHz), and a shielding effectiveness of -90.3 dB at 33.6 GHz. Flexibility and durability tests showed that the film maintained its flexibility even at a curvature radius of 1 mm. In the bending cycle test, the resistance increased by approximately 25.5% from 0.51 Ω to 0.64 Ω after 10,000 cycles in the outer bending scenario, while in the inner bending scenario, the resistance decreased by about 3.6%, indicating reduced resistance to compressive stress.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.87-90
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• 2011

현재 의료기술의 발달로 실버 인구가 늘어남에 따라 주변의 도움이 필요한 일들이 많아지고 있다. 특히 무거운 물체를 옮기는데 도움이 필요한 경우가 많은 것이 현실이다. 그래서 사용자를 따라다니며 도움을 주는 로봇의 필요성이 인식되면서 추적로봇이 만들어지고 있다. 기존방식은 초음파를 이용하는데 이와 같은 방식은 송신기를 휴대해야 한다는 단점이 있다. 본 논문에서는 그것을 보완하기 위한방법으로 카메라를 이용하여 영상처리를 통한 방식을 제안한다. 표적을 부착함으로써 사용자를 인식 및 추적이 가능하게 됨으로써 생활에 편리한 제품으로 자리 잡을 수 있을 것으로 기대된다.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.777-779
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• 2011

현재의 컴퓨터 설문 시스템은 지필형 설문에 비해 여러 가지 이점이 있지만 처리절차 또는 규칙들이 시스템에 하드 코딩(Hard Coding)되기 때문에 설문이 변경되면 설문처리 엔진을 수정 또는 재구현해야 한다. 이러한 문제를 해결하고자 기존에 능동문서를 도입한 컴퓨터 설문 시스템인 능동문서 기반의 웹 설문 시스템(WINAD: The Web Interview System with Active Documents)을 구현하였다. 하지만 WINAD 시스템은 응답자의 참여도를 높이거나 응답률을 최대화할 수 있는 플래쉬, 플랙스, 실버라이트 등 인터렉티브한 설문지 작성 환경을 제공하지 않는다. 브라우저 상호호환성과 웹접근성 문제를 발생시키기 때문이다. 본 논문에서는 WINAD 시스템을 모바일 및 다양한 브라우저 환경에서 동작가능 하도록 HTML5 기술을 적용한 웹표준 기반 능동형 설문 시스템을 설계하였다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.4
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• pp.374-381
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• 2024

This paper delves into the application of the short-wave infrared (SWIR) region, with a focus on the synthesis and optical characteristics of silver sulfide (Ag₂S) nanostructures. SWIR offers advantages such as reduced damage to biological tissues and enhanced optical transparency, making it valuable across various domains. The study introduces three distinct synthesis methods, each showcasing the ability to obtain nanostructures with improved optical properties. These research findings open up the possibility of providing tailored solutions in detection, imaging, and other applications by controlling the size and ligands of Ag₂S nanoparticles. This paper provides new insights into the utilization of Ag₂S in the SWIR region, which is expected to foster advancements in future technologies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.382-389
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• 2019

A novel folding process is proposed using a repeated cold-die forging and annealing to form a sterling silver ring. Sterling silver plate was cut into a doughnut shape, and lattices with 0.43-mm line-width were imprinted on it. The sample was folded by forging using dies with slopes of $45^{\circ}$, $60^{\circ}$, and $75^{\circ}$ and annealing. For comparison, samples were also fabricated without annealing. Strain was identified by measuring the length of lattices. Vernier calipers, a Vickers hardness tester, an optical microscope, and a UV-VIS colorimeter were used to determine the size, hardness, microstructure, and body color. Without annealing, cracks occurred. However, successful deformation was possible when annealing was used. The results of macro strain measurements show that the outer diameter and width decreased, while the inner diameter and thickness increased after the final process. The maximum strain was increased 0.128 toward the parallel direction. The Vickers hardness decreased after annealing and increased after the folding process. The microstructure results showed that the grain size increased after annealing but decreased after folding. The color difference based on the Lab index was under 10 for all processes. Eventually, a doughnut-shaped silver plate was successfully deformed into a ring shape by the folding process.

• Progress in Superconductivity and Cryogenics
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• v.11 no.1
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• pp.1-4
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• 2009

Mechanical and electrical properties of silver stabilizer layer of coated conductor, which as prepared with nano silver paste as starting materials, have been investigated, Nano silver paste was coated on a YBCO film by dip coating process at a diping speed of 20m/min. Coated film was dried in air and heat treated at $400{\sim}700^{\circ}C$ in an oxygen atmosphere. Adhesion strength between YBCO and silver layer was measured by a tape est(ASTM D 3359). Hardness and electrical conductivity of the samples were measured by pencil hardness test (ASTM D 3363) and volume resistance test by LORESTA-GP (MITSHUBISHD, respectively. The sample heat-treated at $500^{\circ}C$ showed poor adhesion 1B, but samples heat treated at higher than $600^{\circ}C$ showed enhanced adhesion of 5B. The silver layer heat-treated at $700^{\circ}C$ showed the high hardness value larger than 9 H, low volume resistance, surface resistance value as well as superior current carrying capacity compared to sputtered silver. SEM observations showed that a dense silver layer was formed with a thickness of about $2{\mu}m$. Dip coated silver layer prepared by using nano silver paste showed superior electrical and mechanical characteristics.