• Journal of the Korean Society for Precision Engineering
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• v.23 no.8 s.185
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• pp.22-26
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• 2006

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.391-392
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• 2008

최근 나노 금속의 대량 생산에 대한 기술이 확보됨에 따라, 메탈젯을 이용한 연구가 활발히 진행되고 있다. 메탈젯의 연구 범위는 RFID, PCB, MLCC 전극, 태양전지전극, PDP 전극, EMC용재료 등 그 응용 범위를 넓혀 가고 있다. 이러한 응용 기술 대표적인 배선형성 기술인 PCB 제조에 대한 연구는 40um 이하의 고해상도 기판 개발을 요구하고 있다. 선폭은 40um 이하를 유지하면서, 두께는 10um 이상으로 CCL을 대체 하기 위한 기판 형성 기술은 응용기술은 가장 어려운 난이도의 기술이다. 메탈젯 기술은 매우 복합적인 연구분야로 나노 재료의 개발, 인쇄공정의 개발, 기재 표면처리 기술, 헤드 기술의 개발을 동시에 만족할 때 가능하다. 배선 형성을 위하여 나노 잉크를 이용하여 직접 인쇄를 진행하고, 소결하여 전도성을 얻게 된다. 본 연구에서는 미세노즐에 토출 가능한 잉크젯용 잉크 조성을 결정하고, 기판과의 신뢰성을 확보하기 위하여 접착력의 평가, 전도도의 평가, 건조 시간 조절을 통한 Crack 문제 해결, 미세 선폭의 균일성 조절에 관한 실험을 진행하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.1 s.256
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• pp.11-17
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• 2007

In this paper, we present a design, analysis, fabrication and performance test of the novel DoD metal-jet system for application to the high-density and high-temperature-melting materials. The theoretical analysis of the metal-jet nozzle system is derived by using electro-mechanical analogy. Based on the theoretical analysis results, we design the metal-jet print head system and fabricate the metal-jet system, which can eject the droplet of lead-free metal solder in high-temperature. In the experimental test, we set up the test apparatus for visualization of the droplet ejection and measure the ejected droplet volume and velocity. As a result, the diameter, volume and the velocity of the ejected droplet are about 65 $\mu$m $\sim$ 70 $\mu$m, 145p1 $\sim$ 180 pl and 4m/s, which shows quite good agreement with the theoretical analysis results of the 75 $\mu$m-diameter and 220 pl-volume of droplet. In comparison with the experimental result, the errors of diameter and volume are 7% $\sim$ 13% and 18 $\sim$ 34%, respectively.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.241-241
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• 2004

프린팅 기법은 크게 젯팅(Jetting) 기법과 코팅(Coating) 기법으로 나눌 수 있는데, 이중 젯팅 기법은 액체 상태의 재료를 노즐을 통하여 분사하는 기법을 말하며, 그 방식으로는 전하제어형, 확산형, 자성 잉크형 등의 연속 방식, 피에조형, 전기열 변환형, 방전형, 고체잉크형, 정전흡입형 등의 DOD 방식, 잉크 미스트형, 스프레이형 등의 기타 방식으로 나누어 볼 수 있다. 젯팅 공정을 이용하여 폴리머 계열을 2차원 흑은 3차원 형상으로 제작하는 것은, 기존의 잉크젯 분사시스템을 수정 보완하는 것으로도 기술적으로 가능하다.(중략)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.531-536
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• 2005

The purpose of this paper is to improve the hysteresis characteristics of a stack type piezoelectric actuator using system identification and tracking control. Recently, several printing methods that cost less and are faster than previous semiconductor processes have been developed for the production of electric paper and RFID. The system proposed in this study prints by spraying the molten metal, and consists of a nozzle, heating furnace, operating actuator, and an XYZ 3-axis stage, As an operating system, the piezoelectric(PZT) method has very valuable uses. However, the PZT actuator has a very big hysteresis characteristic due to the ferroelectric characteristics of the PZT element. This causes problems in the system position control characteristics and deteriorates the performance of the system. In this study, an investigation was conducted to improve the hysteresis characteristics of the PZT actuator that has an output displacement for the input voltage. The study proposed a inverse hysteresis model, a mathematic modeling method that can express the geometric relationship between voltage and displacement, in order to reduce the hysteresis of the PZT actuator. In addition, system identification and PID control methods were examined. Also, it was confirmed that the proposed control strategy gives good precision position control performance.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.585-586
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• 2006

In this paper, we present a design, analysis, fabrication and performance test of the novel DoD metal-jet system for application to the high-density and high-temperature-melting materials. Based on the theoretical analysis, we design the metal-jet print head system and fabricate the metal-jet system, which can eject the droplet of lead-free metal solder in the high-temperature. In the experimental test, we set up the test apparatus for visualization of the droplet ejection and measure the Ejected droplet volume and velocity. As a result, the diameter, volume and the velocity of the ejected droplet are about $65-70{\mu}m$, 145-180 pl and 4m/sec. We also fabricate vertical and inclined 3D micro column structures using the present molten metal inkjet system. The measured geometries of the micro column structures are about height of $2,100{\mu}m$, diameter of $200{\mu}m$ and aspect ratio of 10.5 for vertical micro column and $1,400{\mu}m$ of height and $150{\mu}m$ of diameter for $65^{\circ}$-inclined micro column, respectively.