• 대한기계학회논문집 C: 기술과 교육
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• 제3권4호
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• pp.265-271
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• 2015

스마트폰을 비롯한 고성능 모바일 전자기기의 발전에 따라서 경박단소한 전자부품의 요구가 커지고 있으며 이를 위해서 새로운 패키징 방법이 탄생하고 있다. 이러한 새로운 패키징 공정에서 웨이퍼 본딩 공정이 많이 요구되고 있다. 웨이퍼 본딩에서 많이 활용되는 방법이 열 압착 방법으로 가열된 헤드로 웨이퍼에 압력을 가하여 본딩하는 방법이다. 열 압착 방법에서 요구되는 공정조건은 온도 균일성과 Uniform Press이다. 온도 균일성은 마이크로 히터와 열 해석을 통한 설계로 비교적 쉽게 요구조건을 만족 시킬 수 있지만 Uniform Press를 가공과 조립으로만 요구조건을 만족시키기 위해서는 매우 높은 정밀도가 요구된다. 열 압착 방법은 고온에서 동작되므로 열 변형에 대한 기계적인 오차를 고려하여 설계, 가공, 조립이 진행되어야하므로 많은 어려움이 따른다. 본 연구에서는 Air 스프링과 Metal Form의 자가 보정장치를 이용하여 가공, 조립, 열 변형으로 발생하는 기계적 오차를 보상하여 성능과 신뢰성을 향상시켰다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.553-556
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• 2000

The paper deals with the dynamic response of non-uniform beams subjected to a moving mass. In the dynamic analysis, the effects of inertia force, elastic force, centrifugal force, Coriolis force and self weight due to moving mass are taken into account. Galerkin's mode summation method is applied for the discretized equations of notion. Numerical results for the dynamic response of the non-uniform beam under a moving mass having various magnitudes and velocities are investigated. Experimental results have a good agrement with predictions

• 한국정밀공학회지
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• 제28권1호
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• pp.63-72
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• 2011

In recent years, hot-stamped components are more increasingly used in the automotive industry in order to reduce weight and to improve the strength of vehicles. In hot stamping process, blank is hot formed and press hardened in a tool. However, in hot stamping without cooling channel, temperature of the tool increases gradually in mass production thus cannot meet the critical cooling rate to obtain high strength over 1500MPa. Warpage occurs in the hot stamped component due to non-uniform stress state caused by unbalanced cooling. Therefore, tools should be uniformly as well as rapidly cooled down by the coolant which flows through cooling channel. In this paper, optimal design method of cooling channel to obtain uniform and high strength of the component is proposed. Optimized cooling channel is applied to the hot press V-bending process. As a result of measuring strength, hardness and microstructure of the hot formed parts, it is known that the design methodology of cooling channel is effective to the hot stamping process.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.133-134
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• 2012

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.969-970
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• 2012

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 춘계학술대회 논문집
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• pp.147-148
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• 2009

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 추계학술대회 논문집
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• pp.129-130
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• 2009

• 대한기계학회논문집B
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• 제27권11호
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• pp.1525-1533
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• 2003

In the precision hot plate for wafer processing, uniform temperature of the upper plate is one of key factors affecting the quality of wafers. The state-of-the-art precision hot plates require temperature Variations less than $\pm$0.4$^{\circ}C$ during heating to 15$0^{\circ}C$, Which is difficult to be obtained only by the improvement of manufacturing techniques alone. In this study, computer aided heat transfer analysis was carried out to obtain the temperature distribution of the currently used reference hot plate for 200mm wafer. The analysis on the reference model assuming constant heat generation rate and uniform heating area showed total variation of 0.926$^{\circ}C$ at 15$0^{\circ}C$. One of the new design approaches based on the change of heating location together with different heat generation rate resulted in total variation of 0.297$^{\circ}C$ which is a 68% improvement compared to that of the reference model.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.36-39
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• 1997

In this paper, we described an approach to design of precision optical system for visual inspection of solder joint defects of SMC(surface mount components) on PCBs(Printed Circuit Board). The illumination system, consisting of three tiered LED lamps and one main camera and four side view camera, is implemented to generated iso-contour on the solder joint according to gradient of the soldered surface. We analyze LED design parameter such as incident angle, diameter of LED ring, and so on to acquire uniform illumination.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.667-670
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• 2002

Uniform metal-droplet deposition using laser is analyzed. Using the variation principle and modeling the semi-solid phase as a non-Netwonian slurry, this model can greatly save the computational expenses that conventional numerical procedures have suffered from. The simulation results revealed that the developed model could reasonably describe the collision behavior of molten metal with solid surface. Simulations were made with variation of the falling distance and time.