• Journal of the Microelectronics and Packaging Society
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• v.14 no.3
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• pp.57-64
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• 2007

New Chip-on-glass technology to attach an Si chip directly on the glass substrate of LCD panel was studied with local heating method of the Si chip by using thin film heater fabricated on the Si chip. Square-shaped Cu thin film heater with the width of $150\;{\mu}m$, thickness of $0.8\;{\mu}m$, and total length of 12.15 mm was sputter-deposited on the $5\;mm{\times}5\;mm$ Si chip. With applying current of 0.9A for 60 sec to the Cu thin film heater, COG bonding of a Si chip to a glass substrate was successfully accomplished with reflowing the Sn-3.5Ag solder bumps on the Si chip.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.61-64
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• 2005

본 연구에서는 $5mm{\times}7mm$ 크기의 적층 세라믹 SMD(surface mounted device)형 PECL VCXO에 테스트지그를 이용하여 스펙트럼을 분석한다. 패키지에 PECL 칩을 장착 후 와이어결선(wire bonding)을 완료한 VCXO는 그 길이 및 패키지 내부의 패턴 등에 의하여 부유인덕턴스(stray inductance) 및 커패시턴스가 발생하고, 칩의 발진부 임피던스에 영향을 준다. 이에 칩이 패키지에 장착된 상태에서 발진부 입력임피던스 영향을 제거하고 안정한 발진기 측정을 통하여 발진기의 정확한 스펙트럼 분석 및 성능을 평가한다.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.2
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• pp.72-79
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• 2000

A new optimal tool design model which can be minimized the resultant cutting forces under the constrains of variables was developed. The resultant cutting forces are used as the objective function and tool angles are used as the variables. Cutting experiments of tool wear and chip length using the new and conventional tools wee carried out. Tool life of optimized cutter are more increased than those of conventional cutter by 2.29 times and 2.52 times at light and at heavy cutting conditions respectively. Chip length of optimized cutter are more increased than those of conventional cutter It is considered that the decrease of the resultant cutting forces is the cause that an effective rake and shear angles by the shape of optimal cutter.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.179-182
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• 2000

BWLL용 Ka-Band MMIC 저잡음 증폭기 칩을 InGaAs/GaAs 0.15um Gate 길이의 p-HEMT 공정을 이용하여 개발하였다. 칩 크기 2.5$\times$1.5$\textrm{mm}^2$의 2단으로 설계된 칩의 On-wafer 측정 결과, 24～27 GHz BWLL 주파수 대역에서 최소 19$\pm$0.2dB 이득과 최대 1.7dB의 잡음 지수와 최소 13dB의 반사손실의 특성을 얻었다.

• Korean Journal of Optics and Photonics
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• v.28 no.4
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• pp.135-140
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• 2017

In this paper, we report measured results for an all-fiber $7{\times}1$ pump combiner based on an optical fiber chip for high-power fiber lasers. An optical-fiber chip was fabricated by etching a fiber, having core and cladding diameters of 20 and $400{\mu}m$, in the longitudinal direction. To both ends of the etched chip, we spliced input and output fibers. First, we tied together seven optical fibers, having core and cladding diameters of 105 and $125{\mu}m$ respectively, in a cylindrical bundle and spliced them to the $375-{\mu}m$ end of the optical-fiber chip. Then, we attached an output DCF with core and cladding diameters of 25 and $250{\mu}m$ to the $250-{\mu}m$ end of the optical-fiber chip. Finally, the fabricated $7{\times}1$ pump combiner showed an average optical coupling efficiency of about 90.2% per port. This chip-based pump combiner may replace conventional pump combiners by massive production of fiber chips.

• Journal of the Microelectronics and Packaging Society
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• v.14 no.3
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• pp.65-71
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• 2007

For chip-stack package applications, Cu filling characteristics into trench vias of $75{\sim}10\;{\mu}m$ width and 3 mm length were investigated with variations of the electroplating current density and the speed of a rotating disc electrode (RDE). Cu filling characteristics into trench vias were improved with increasing the RDE speed. There was a Nernst relationship between half width of trench vias of Cu filling ratio higher than 95% and the minimum RDE speed, and the half width of trenches with 95% Cu filling ratio was linearly proportional to the reciprocal of root of the minimum RED speed.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06a
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• pp.271-273
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• 2012

칩을 분석하는 과정에서 게이트의 검출도 중요하지만 그와 동등하게 중요한 부분이 wire의 인식이다. 본 논문은 wire의 자동인식의 방법에 관한 것으로, 칩 내부를 전자현미경으로 촬영한 사진을 기반으로 wire를 추출한다. 사람이 수작업으로 일일이 그 wire들을 그린다면 시간과 정확성이 떨어지므로 wire 인식 과정을 자동화하는 방법을 제시한다.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.12a
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• pp.77-85
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• 2003

기 상용화되고 있는 소프트웨어/하드웨어 제품의 복제방지에 대한 강도가 부족하여 쉽게 락이 크랙될 뿐 아니라 복제방지의 기능을 수행할 수 없는 단점을 보안하여 본 논문은 세계적으로 가장 많이 사용하고 있는 암호알고리즘 중의 하나인 DES를 구조적으로 수정하고 키 길이를 확장하여 암호학적 강도를 개선한 E-DES(Extended DES)를 설계하고, 이를 하드웨어로 구현하기 위해서 시스템 설계 기술언어인 VHDL로 코딩하고, FPGA를 이용, test chip을 구현하여 성능테스트를 수행한 다음, 설계된 FPGA 칩을 ASIC으로 제작하여 강력한 암호알고리즘을 가진 보안칩을 설계한다.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.3
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• pp.141-149
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• 1996

마모된 공구로 절삭을 할 때 공구가 받는 힘은 칩을 제거할 때 받는 칩 제거력과 프랭크 면에 작용하는 공구와 공작물 사이의 마찰력으로 나눌 수 있다. 칩제거력은 그 힘이 전단선의 길이와 비례함을 이용하여 계산하였고, 프랭크면에 작용하는 마찰력은 공구에 작용하는 공작물의 탄성력을 고려하여 계산하였다. 절삭력은 이 두 힘의 합으로 구해졌으며 이 계산된 힘은 실제 절삭을 하는 동안 얻어진 실험결과와 비교되었다.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.4
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• pp.34-47
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• 2000

Since carbon fiber epoxy composite materials have excellent properties for structures due to their high specific strength, high specific modulus, high damping and low thermal expansion, the hollow shafts made of carbon fiber epoxy composites have been widely used for power transmission shafts for motor vehicles , spindles of machine tools, motor base, bearing mount for tool up and manufacturing. The molded composite machine elements are not usually accurate enough for mechanical machine elements, which require turning drilling , cutting and grinding. The experiment are surface grinding wheel GC60 to the carbon fiber epoxy composite specimen with respect to staking angle [0]nT , [45]nT, [90]nT on the CNC grinding machine. In this paper, the surface grinding characteristics of composite plate, which are surveyed experimentally and analytically with respect to the grinding force, surface roughness and wheel loading according to the variable depth of cut, wheel velocity and table feed rate are investigated.