• 한국기계가공학회지
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• 제2권1호
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• pp.63-68
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• 2003

The aspherical lenses are used as objective lens of optical pickup. To examine the design factor the sample product is made before manufacturing of injection mould of lens. The optimum cutting condition of PMMA lens sample with ultra precision SPDT, the roam spindle speed, the depth of cut, the feedrate are found. The demanded surface roughness 100m Ra, aspherical form error $0.5{\mu}m$ P-V for aspherical lens of optical data storage device are satisfied.

• 한국기계가공학회지
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• 제7권4호
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• pp.96-101
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• 2008

Due to improve form accuracy and surface roughness of a aspheric lens core that is made of Ni, the study is carried out on localization about a Subminiature Optics of Proximity and Wide Field of View. The required form accuracy P-V $0.2{\mu}m$ and surface roughness is Ra 10 nm. The design of experiment(DOE) is adopted to find a optimal cutting conditions which are spindle speed, depth of cut, feedrate. Finally, the effects of this study are replacing importation and strengthening competitiveness through the localization of the Subminiature Optics of Proximity and Wide Field of View.

• 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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 제6회 학술대회 논문집 일렉트렛트 및 응용기술연구회
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• pp.47-51
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• 2004

The aspherical lens are used as objective lens of optical pickup. The sample product is made before manufacturing the injection mould of lens to examine the design factor. The optimum cutting conditions of the main spindle speed, the depth of cut, the feed rate are found when we cut PMMA and PC lens sample with ultra-precision SPDT. The demanded surface roughness 10 nm Ra, aspherical form error 0.5 ${\mu}m$ P-V for aspherical lens of optical data storage device are satisfied for PMMA, but not satisfied for PC.

• 한국생산제조학회지
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• 제22권2호
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• pp.263-267
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• 2013

The continuing demand for increasingly slimmer and brighter liquid crystal display (LCD) panels has led to an increased focus on the role of light guide panels (LGPs) or optical films that are used to obtain diffuse, uniform light from the backlight unit (BLU). The most basic process in the production of such BLU components is the micromachining of V-shaped grooves. Thus, given the current trend, micromachining of V-shaped grooves is expected to play increasingly important roles in today's manufacturing technology. LCD BLUs comprise various optical elements such as a LGP, diffuser sheet, prism sheet, and protector sheet with V-shaped grooves. High-aspect-ratio patterns are required to reduce the number of sheets and enhance light efficiency, but there is a limit to the aspect ratio achievable for a given material and cutting tool. Therefore, this study comprised a series of experimental evaluations conducted to determine the machining limit in microcutting V-shaped grooves on electroless nickel plated die materials when using single-crystal diamond tools with point angles of $20^{\circ}-80^{\circ}$. Cutting performance was evaluated at various cutting speeds and depths of cut using different machining methods and machine tools. The experimental results are that V-shaped patterns with angles of $80^{\circ}$ or up can be realized regardless of the machining conditions and equipment. Moreover, the feed rate has little effect on machinability, and it is thought that the fly-cut method is more efficient for shallow patterns.

• 한국기계가공학회지
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• 제17권3호
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• pp.1-6
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• 2018

Micro prism pattern is applying in order to get increase of luminance, control the light, and so forth especially in optics and display industry. Most patterns are fabricated by lithography, planning, and EDM, but they have limitations on the productivity or the unit cost of produce. However, ultra precision mold is one of the processes able to replace it, and assure high productivity required by industries. In this investigation, micro prismatic end-milling is suggested in order to fabricate the pattern effectively. Micro prism pattern having $100{\mu}m$ of pitch and height was machined on STD-11. After machining, the flank and boundary wear on micro end mill were measured and analyzed, as well as burr formation and dimensional accuracy of fabricated pattern were evaluated. Thus the optimal cutting conditions were derived.

• 한국기계가공학회지
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• 제18권7호
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• pp.56-62
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• 2019

The high-precision laser scriber carries out scribing alumina ceramic substrates for manufacturing ultra-small chip resistors. The ceramic substrates are loaded, aligned, scribed, transferred, and unloaded. The entire process is fully automated, thereby minimizing the scribing cycle time of the ceramic substrates and improving the throughput. The scriber consists of the laser optical system, pick-up module of ceramic substrates, pre-alignment module, TH axis drive work table, automation module for substrate loading / unloading, and high-speed scribing control S/W. The loader / unloader unit, which has the greatest influence on the scribing cycle time of the substrates, carries the substrates to the work table that carries out the cutting line work by driving the X and Y axes as well as by adsorbing the ceramic substrates. The loader / unloader unit consists of the magazine up / down part, X-axis drive part for conveying the substrates to the left and right direction, and the vision part for detecting the edge of the substrate for the primary pre-alignment of the substrates. In this paper, the laser scribing machining simulation is performed by applying the instrument mechanism of each component module. Through this study, the scribing machining process is first verified by analyzing the process operation and work area of each module in advance. In addition, the scribing machining process is optimized by comparing and analyzing the scribing cycle time of one ceramic substrate according to the alignment stage module speed.

• 실천공학교육논문지
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• 제15권1호
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• pp.119-126
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• 2023

오늘날 자동차의 연비 향상 과 동적 거동 향상을 위해서 자동차 부품의 경량화 및 간소화 시대가 형성되고 있다. 설계와 제작의 간소화를 위해 제품 형상을 다양한 부품의 일체화로 진행되고 있다. 예를 들어 3개의 제품을 1개의 제품화 시키기 위해서 아주 협소한 부분까지 제품 가공하는 일이 발생되고 있다. 기존의 부품의 경우 가공의 편의성을 위해 정밀 다이캐스팅 또는 주물 생산으로 가공 후 조립하는데 다중 조립체(multi-piece) 방식은 공정수가 많이 필요로 하며, 부품의 정밀도와 강도를 저하시키는 요인이 된다. 가공 공정을 단순화 시키고 부품의 강도를 확보하기 위해서 일체형으로 제작하는 것이 단점을 극복하는데 매우 유리하지만 깊고 좁은 포켓 부분을 가공 할 경우 장비 자체 스핀들로는 가공이 불가능하다. 문제점을 해결하고자 절삭가공에 대한 연구가 활발하게 진행되고 있으며, 다축 복합가공 기술은 이러한 문제점을 해결할 뿐만 아니라, 지금까지 하나의 공작기계로 여러 공정에 따른 유연한 절삭가공이 어려웠던 복합 형상에도 절삭가공이 가능하다는 등 많은 장점을 가지고 있다. 하지만 고가의 장비로 인하여 제조경비 상승과 기계를 운영할 수 있는 기술자가 부족한 것이 현실이다. 5축 절삭 가공기에서는 깊고 협소한 구간의 제품을 생산할 때 공구의 간접으로 제품 생산에 사이클 타임이 늘어남은 물론 가공상에 문제점들이 많이 발생된다. 따라서 전용 공작기계 및 다축 복합가공기를 사용해야 한다. 그 대안으로 3축 머시닝센터에서 5축 이상의 다축 복합가공을 할 수 있는 특수 공구로서의 앵글 스핀들(angle spinde)이 사용될 수 있다. 앵글 스핀들 사용함으로 가공 진동 흡수, 낮은 열 발생과 작동 안정성, 우수한 치수 안정성, 강도 확보와 같은 분야에서 다양하고 지속적인 연구가 필요하다.

• 구강회복응용과학지
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• 제38권3호
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• pp.127-137
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• 2022

지르코니아는 다양한 공정과정을 거쳐서 제작되며, 각각의 요소는 최종 보철물의 물성에 영향을 줄 수 있다. 특히 밀링과정과 소결과정이 모두 지르코니아 보철물의 최종 완성도(integrity)에 영향을 미칠 수 있다. 밀링머신은 대부분 초정밀 5축 가공방식을 채택하고 있으며 어떤 방식을 사용하고 밀링기구를 어떻게 관리하는가에 따라서도 결과가 달라진다. 밀링블록은 절삭의 효율성과 심미재현성에 따라 선택하는데 물성의 변화를 야기할 수 있음은 주의해야 한다. 소결방식은 입자성장과 광학적 특성에 영향을 미칠 수 있는데 속도를 조절하는 최근의 방식에 대해서는 추가적인 연구가 동반되어야 정확한 평가가 이루어질 수 있다. 소결온도 뿐 아니라 온도 유지시간도 최종결과물에 영향을 줄 수 있다.