• 한국전기전자재료학회논문지
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• 제19권11호
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• pp.1050-1054
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• 2006

There have been intensive and continuous efforts in the field of DLC coating process because of their feature, like high hardness, high elasticity, abrasion resistance and chemical stability and have been applied widely the industrial areas. In this research, optimal grinding condition was investigated using Microlens Process Machine for the development of aspheric glass lens which is to be used for mobile phone module with 3 mega pixel and 2.5X optical zoom, and tungsten carbide(WC) mold cote was manufactured using high performance ultra precision machining and the effects of DLC coating on the form accuracy(PV) and surface roughness(Ra) of WC mold core was evaluated.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.812-813
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• 2010

There have been intensive and continuous efforts in the field of DLC coating process because of their feature, like high hardness, high elasticity, abrasion resistance and chemical stability and have been applied widely the industrial areas. In this report, tungsten carbide(WC) mold core was manufactures using high performance precision machining and the efforts of DLC coating on the surface roughness and SEM of WC mold was evaluated.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.441-441
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• 2007

As Rhenium-Iridium{Re-Ir) coating possesses such features as, high hardness, high elasticity, abrasion resistance and chemical stability, there have been exerted continuous efforts in research works in a variety of fields, and this technology has also been applied widely to industrial areas. In this research, the optimal grinding condition was identified using Microlens Process Machine in order to contribute to the development of aspheric glass lens for mobile phone module having 3 mega pixel and 2.5X zoom, and molding core(WC) was manufactured having performed ultra-precision machining. Effects of Re-Ir coating on form accuracy (P-V) of molding core and surface roughness(Ra) were measured and evaluated.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.20-23
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• 2001

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${\mu}{\textrm}{m}$, depth 124$\mu\textrm{m}$ , pitch 274$\mu\textrm{m}$ was acquired by machining of single crystal silicon with dicing saw blade. Maximum roughness of the bottom of the grooves was 59.6nm Ra in grooving Si. Barrier ribs were formed with silicone rubber mold, which is transferred from grooved Si forming hard mold. Silicone rubber mold has the elasticity, which enable to accommodate the waveness of lower glass plate of PDP. The methods assisted by the microwave and UV was adopted for reducing the forming time of glass paste.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 춘계학술대회
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• pp.676-677
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• 2011

초경합금 성형용 코어를 이용한 고온 압축 성형방식으로 제작되기 때문에 성형용 코어의 초정밀 연산 가공 및 코어면 코팅 기술 개발이 시급한 상황이다. 따라서 본 연구에서는 성형용 초경합금 코어의 연삭가공을 수행하고, 가공 완료된 성형용 코어의 가공면에 Re-Ir 코팅을 수해, 측정을 통하여 코팅면의 마찰 계수 변화에 대한 연구를 수행하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.828-829
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• 2010

초경합금 성형용 코어를 이용한 고온 압축 성형방식으로 제작되기 때문에 성형용 코어의 초정밀 연산 가공 및 코어면 코팅 기술 개발이 시급한 상황이다. 따라서 본 연구에서는 성형용 초경합금 코어의 연삭가공을 수행하고, 가공 완료된 성형용 코어의 가공면에 Re-Ir 코팅을 수해, 측정을 통하여 코팅면이 표면 조도에 미치는 영향에 대하여 연구를 수행하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.487-488
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• 2006

As DLC coating possesses such features as, high hardness, high elasticity, abrasion resistance and chemical stability, there have been exerted continuous efforts in research works in a variety of fields, and this technology has also been applied widely to industrial areas. In this research work, the optimal grinding condition was identified using Microlens Process Machine in order to contribute to the development of aspheric glass which is to be used for mobile phone module having 2 megapixel and $2.5{\times}$ zoom, and mold core (WC) was manufactured having performed ultra-precision machining and effects of DLC coating on shape accuracy(P-V) of mold core and surface roughness(Ra) as well were measured and evaluated.

• 한국전기전자재료학회논문지
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• 제24권3호
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• pp.219-223
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• 2011

Rhenium-Iridium(Re-Ir) thin films were deposited onto the tungsten carbide(WC) molding core by sputtering system. The Re-Ir films were prepared by multi-target sputtering with iridium, rhenium and chromium as the sources. Argon and nitrogen were inlet into the chamber to be the plasma and reactive gases. The Re-Ir thin films were prepared with targets having atomic percent of 3:7 and the Re-Ir thin films were formed with 240 nm thickness. The Re-Ir thin films on tungsten carbide molding core were analyzed by scanning electron microscope(SEM) and surface roughness. Also, adhesion strength and coefficient friction of Re-Ir thin film were examined. The Re-Ir coating technique has been intensive efforts in the field of coating process because the coating technique and process have been their feature, like hardness, high elasticity, abrasion resistance and mechanical stability and also have been applied widely the industrial and biomedical areas. In this report, tungsten carbide(WC) molding core was manufactures using high performance precision machining and the efforts of Re-Ir coating on the surface roughness.

• 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.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.58.1-58.1
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• 2011

WC-Co and other similar cemented carbides have been widely used as hard materials in industrial cutting tools and as mould metals; and a number of techniques have been applied to improve its microstructural characteristics, hardness and ear resistance. Cobalt is used primarily to facilitate liquid phase sintering and acts as a matrix, i.e. a cementing phase between WC grains. A uniform distribution of metal phase in a ceramic is beneficial for improved mechanical properties of the composite. WC-Co, starting from initial powders, is vastly used for a variety of machining, cutting, drilling, and other applications because of its unique combination of high strength, high hardness, high toughness, and moderate modulus of elasticity, especially with fine grained WC and finely distributed cobalt. In this study, that started with two different compositions of initial powders, WC-7.5wt%Co and WC-12wt%Co with initial powder size being 1~3 ${\mu}m$, magnetic pulsed compaction followed by subsequent vacuum sintering were carried out to produce consolidated preforms. Magnetic Pulsed Compaction (MPC), a very short duration (~600 ${\mu}s$), high pressure (~4 Gpa), high-density preform molding method was used with varied pressure between 0.5 and 3.0 Gpa, in order to reach an initial high density that would help improve the sintering behavior. For both compositions and varied MPC pressure, before and after sintering, changes in microstructural behavior and mechanical properties were analyzed. With proper combination of MPC pressure and sintering, samples were obtained with better mechanical properties, densification and microstructural behavior, and considerably improved than other conventional processes.