• 대한기계학회논문집A
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• 제27권8호
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• pp.1380-1387
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• 2003

Microsystem technology (MST) which originated from semiconductor processes has been widely spreaded into the other industry such as sensors, micro fluidics and displays. The MST, however, has been troubled in spreading with its high cost and material limitations. So, in this paper, new process for micromolding technology using silicone rubber mold was introduced. Silicone rubber mold, which was fabricated by vacuum casting, can be transferred a master pattern to a final product with the same shape but different materials. In order to verify the possibility of application of silicone rubber mold to the MST, its transferability was evaluated, and then it applied to the fabrications of polishing pad and PDP barrier ribs.

• 국제물리치료학회지
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• 제8권2호
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• pp.1142-1145
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• 2017

The purpose of this study was to examine the effect of kinematic taping on respiratory muscle strength in smokers. Twenty - five university students who smoke were involved in the study. All participants were applied to kinematic taping to breathe deeply again. Subjects sit on their backs straight up and place their hands on their thighs. Tape 1 is applied from the lower prominent neck vertebrae(seven cervical vertebra) inward and downward, past shoulder blade, around ribs to the lower tip of sternum. Tape 2 extends to the lower, outer edge of shoulder blade, around ribs to the lower tip of sternum. Respiratory muscle strength was measured with Micro Mouth Pressure Measurement before and after taping. The application of kinematic taping significantly improved the inspiratory and expiratory muscle strength (p<.05). These findings suggest that kinematic taping effective in improving respiratory muscle strength and deep breathing.

• 한국정밀공학회지
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• 제19권6호
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• pp.176-183
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• 2002

Plasma Display Panel(PDP) is a type of flat panel display utilizing the light emission produced by gas discharge. Barrier Ribs of PDP separating each sub-pixel prevents optical and electrical crosstalks from adjacent sub-pixels. The mold for forming the barrier ribs has been newly researched to overcome the disadvantages of conventional manufacturing processes such as screen printing, sand-blasting and photosensitive glass methods. The mold for PDP barrier ribs have stripes of micro grooves transferring glass-material wall. In this paper , Stripes of grooves of which width 48$\mu$m, depth 124$\mu$m , pitch 274$\mu$m was acquired by machining of single crystal silicon with dicing saw blade. Maximum roughness of the bottom of the grooves was 59.6 nm Ra in grooving Si. Barrier ribs were farmed with silicone rubber mold, which is transferred from grooved Si forming hard mold. Silicone rubber mold has the elasticity, which enable to accommodate the waviness of lower glass plate of PDP. The methods assisted by the microwave and UV was adopted for reducing the forming time of glass paste.

• 한국기계가공학회지
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• 제9권1호
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• pp.87-92
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• 2010

Micromachining technology using a ultra-precision micromachining system is widely applied in the fields of optics, biotechnology and analytical chemistry, etc. specially in microfabrication of fresnel lens, light guide panels of TFT-LED and PDP ribs with micro-patterns, machining errors have an effect on the performance of those products. The deflection of tool and tool holder is known to be one of the very important factors that is due to machining errors in micromachining. The deflections of diamond tool and tool holder used in micro-grooving are analysed by FEM. We analysed by FEM. With an linearity valuation of FEM, deflection of tool and tool holder is calculated by using the data of cutting force which is acquired from micro-V groove machining experiments in micromachining system.

• Design & Manufacturing
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• 제13권1호
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• pp.5-12
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• 2019

In this paper, we studied the micro tool deflection, micro cutting with low temperature, and deformation of micro ribs caused by cutting forces. First, we performed an integrated machining error compensation method based on captured images of tool deflection shapes in micro cutting process. In micro cutting process, micro tool deflection generates very serious problems in contrast to macro tool deflection. To get the real images of micro tool deflection, it is possible to estimate tool deflection in cutting conditions modeled and to compensate for machining errors using an iterative algorithm correcting tool path. Second, in macro cutting fields, the cryogenic cutting process has been applied to cut the refractory metal but, the serious problem may be generated in micro cutting fields by the cryogenic environment. However, if the proper low temperature is applied to micro cutting area, the cooling effect of cutting heat is expected. Such effect can make the reduction of tool wear and burr formation. For verifying this passibility, the micro cutting experiment at low temperature was performed and SEM images were analyzed. Third, the micro pattern was deformed by the cutting forces and the shape error occurred in the sidewall multi-step cutting process were minimized. As the results, the relationship between the cutting conditions and the deformation of micro-structure during micro cutting process was investigated.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.53-56
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• 2009

Roll forming process is one of important metal processing technology because the process is simple and economical. These days, roll forming process is tried to be employed in manufacturing the circuit board, barrier ribs and solar cell plate for productivity. However, it is difficult to apply to the forming of micro scale or sub-micro scale pattern. In this study, the roll forming processing for the micro scale is designed and analyzed. In this study, the forming of micro pattern for solar cell plate by incremental roll forming process is analyzed. The solar cell plate may have thousands of patterns, and the analysis of forming considering all the patterns is impossible due to the computational costs. In this study, analyses are carried out for various numbers of patterns and the results are compared. It is shown that the analyses results with four row patterns and twelve row patterns are same. So, it is considered that the analysis can be carried out for only four rows of pattern for the design of incremental roll forming process. Also experiment is carried out process that is designed through simulation.

• 소성∙가공
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• 제19권3호
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• pp.167-172
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• 2010

Roll-to-roll forming process is one of important metal processing technology because the process is simple and economical. These days, with these merits, roll-to-roll forming process is tried to be employed in manufacturing the circuit board, barrier ribs and solar cell plate. However, it is difficult to apply to the forming of micro scale or sub-micro scale pattern. In this study, the roll forming processing for the micro scale is designed and analyzed. The forming of micro pattern for small electric device such as LCD panel by incremental roll forming process is analyzed. Firstly, the optimum analysis conditions are found by several analyses. And then, formability is analyzed for various protrusion shapes at various forming temperatures. The formability is evaluated in terms of filling ratio and damage value. The filling ratio is defined from the tool geometry and critical damage is determined from the analysis of uniaxial tensile test. Finally, optimum forming conditions that guarantee the successful forming are found.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.56-59
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• 2009

Roll forming process is one of important metal processing technology because the process is simple and economical. These days, roll forming process is tried to be employed in manufacturing the circuit board, barrier ribs and solar cell plate for productivity. However, it is difficult to apply to the forming of micro scale or sub-micro scale pattern. In this study, the roll forming processing for the micro scale is designed and analyzed. In this study, the forming of micro pattern for solar cell plate by incremental roll forming process is analyzed. The solar cell plate may have thousands of patterns, and the analysis of forming considering all the patterns is impossible due to the computational costs. In this study, analyses are carried out for various numbers of patterns and the results are compared. It is shown that the analyses results with four row patterns and twelve row patterns are same. So, it is considered that the analysis can be carried out for only four rows of pattern for the design of incremental roll forming process.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.851-856
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• 2005

The precision fabrication of aspherical lenses is increasingly required for the latest applications of compact and high resolution video-recording or camera systems. Micro-optical components, including micro-spherical or aspherical lenses and reflecting mirrors, are generally required to be manufactured with high shape accuracy, extremely low surface roughness and no surface damage. To meet the needs of the precision fabrication system, a bed which supports the micro aspherical lens fabrication machines stably and safely is required. In this study, the thickness of the ribs of the bed is optimized using the CAD integrated optimal design system, a virtual DS program.

• 우주기술과 응용
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• 제1권3호
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• pp.364-374
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• 2021

본 논문에서는 초소형 위성에 적용할 수 있는 전개형 메쉬 안테나의 Gore 특성에 따른 radio frequency (RF) 특성 변화에 관해 논한다. 메쉬 안테나의 경우 다양한 초소형위성에 탑재할 수 있으며, 통신/영상레이다/SIGINT 등 다양한 우주임무에 활용이 가능하다. 이상적인 안테나 곡면을 형성하기 위해서는 충분한 개수의 안테나 Rib 구조로 반사판을 구현해야 한다. 그러나 안테나 Rib 개수 증가에 따라 안테나 질량을 비롯해 기계적인 전개 메커니즘의 복잡도 및 전개 신뢰성 등 다양한 설계인자에 영향을 미치게 된다. 본 논문에서는 안테나의 RF 성능 열화 최소화 관점에서 적정 안테나 Rib의 개수를 도출하기 위해 메쉬 안테나의 예시 모델을 대상으로 다양한 Rib 개수에 따른 RF 시뮬레이션을 통해 비교분석을 수행하였다.