• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.513-516
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• 2008

We have replicated nanopillar arrays using injection molding process of active heating and cooling method by several peltier devices. The injection melding has a high accuracy ed good reproducibility that are essential for mass production at low cost. Conventional molding processes widely use the water-based mold heating and air cooling methods. However, in case of replication for nano-patterned structures, it caused several defects such as air-flow mark, non-fill, sticking and tearing. In this study, periodic nano-scale patterns are replicated by using injection molding with Peltier devices. Porous nano-scale patterns, which have pore diameter range from 120nm to 150nm, were fabricated by using anodizing process. Periodic nano-pore structures ( $20mm\;{\times}\;20mm$) were used as a mold stamp of injection molding. Finally, PMMA with nanopillar arrays was obtained by injection molding process. By using the Peltier devices, the temperature of locally adiabatic molds can be dramatically controlled and the quality of the molded patterns can be slightly improved.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.692-697
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• 2005

좋은 날개 실속특성 및 실속/스핀의 특성이 입증된 선미익형 항공기를 현재 개발중에 있다. 전에 개발된 1호기 및 2호기 시제기는 코어 샌드위치 형식으로 날개 전체가 채워지고 고정식 착륙장치로 제작되었다. 새로이 개발될 반디호는 접개식 착륙장치와 날개와 동체에 일반적인 폼 코아 샌드위치층이 장착될 예정이다. 제작을 위해 시편 시험을 포함한 복합 소재 제작 공정이 연구되었고 적층 몰드를 이용하여 유리 섬유 천으로 폼 코어 위로 상온 적충하는 방식이 채택되었으며, 복합소재 부품들은 실온과 대기압하에 경화시킨다. 일반적으로, 몰드부품들은 양산에 적합한 매끄러운 표면 조도와 표준 품질을 보여주었다. 본 연구에서는 소형 항공기 반디호 몰드 기술과 개발 상황을 기술하였다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 추계학술대회논문집
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• pp.367-370
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• 2003

In this study, application of SAM (self-assembled monolayer) to nano replication process as an anti-adhesion layer was presented to reduce the surface energy between the nano mold and the replicated polymeric nano patterns. The electron beam lithography was used for master nano patterns and the electorforming process was used to fabricate the nickel nano stamper. Alkanethiol SAM as an anti-adhesion layer was deposited on metallic nano stamper using solution deposition method. To analyze wettability and adhesion force of SAM, contact angle and LFM (Lateral Force Microscopy) were measured at the actual processing temperature and pressure for the case of nano compression molding and at the actual UV dose for the case of nano UV molding. It was found that the surface energy due to SAM deposition on the nickel nano stamper markedly decreased and the quality of SAM on the nickel stamper maintained under the actual molding environments.

• 대한치과기공학회지
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• 제9권1호
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• pp.67-72
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• 1987

This experimental study presented the study on the dimensional changes of occuring for the denture curing methods. The method is as follows: 1. The master die was made of wax. 2. The Silicon Rubber Mold was made into the same 80 casts. 3. The 80 Wax Plate were made of using the Base Plate Wax. 4. Flasking, Wax-wash, & Resin-packing were performed by the general procedures. 5. The curing method is performed through the four curing methods. (A, B, C, D). Table 2 shows the dimensional change after a day. Table 3 shows the dimensional change after soaking for 30 days in water of the degree of 36 Centigrade. As a result, the A curing method is the most denture curing.

• 소성∙가공
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• 제20권1호
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• pp.23-28
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• 2011

For the fabrication of nano patterned products manufacturing a nano patterned mold is needed in advance. The nano patterned stamper was fabricated by electroforming the AAO master with nickel. The surface of nickel-plated stamper had nano-patterned holes with the diameter of 73 nm and the depth of 83 nm. Hot embossing was used for forming P3HT sheet and the process factors of hot embossing were closer as pressure, temperature and time. In the present paper hot embossing experiments were performed to find the main process conditions to affect the replication ratio of nano patterns on surface of P3HT sheet. As a result, main contributing factors for the replication ratio of hot embossed pattern could be sequentially enumerated as pressure, temperature and time.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.169-172
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• 2000

In this paper, an OMM (On-the-Machine Measuring) system has been developed, which can perform measuring and inspection of sculptured surfaces of die and mold, by use of a scanning-type touch probe mounted into the spindle of a NC machine. The calibration procedures of a scanning prove (SP2-1, Renishaw) and an algorithm for measuring surface points by a ball-nosed stylus have been studied. The system has been developed based on commercial CAM software (Z-Master 2000), and tested through measuring a plastic injection molding-die. Also some experimental results of the calibration and measuring for given surface positions are analyzed to verify its accuracy and reliability.

• 한국정밀공학회지
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• 제30권2호
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• pp.236-240
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• 2013

In this presentation, we propose a fabrication method of PDMS stencil to apply into a localized culture of NIH/3T3 cells. PDMS stencil was fabricated by nitrogen gas blowing and soft lithography from preparing SU-8 master mold by photolithography. PDMS stencil pattern was production of the circle size 20 to $500{\mu}m$. In the culture test of PDMS stencil, a stencil was placed on a glass disk. The NIH/3T3 cells were successfully cultured into micropatterns by using the PDMS stencil. The results showed that cells could be cultured into micropatterns with precisely controlled manner at any shapes and specific size for bioscience study and bioengineering applications.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1992년도 춘계학술대회 논문집
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• pp.43-47
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• 1992

물체공간의 한점에서 출발하여 광학계에 입사한 광속은 전부 상공간의 한점에서 집속되고 물체공간의 점 과 상공간의 점은 1:1로 대응해야 하나 현실의 광학계는 필히 수차가 존재하기때문에 이상 결상을 맺지 못다. 이러한 원인으로 생기는 수차를 통상의 방법으로 제거 할 수 없을때 비구면 LENS를 사용한다. 비구 면 LENS는 축대칭성을 갖고 단면형상이 다항식으로 표현되는 곡면을 갖는 LENS로 종래의 구면체로 구성 된 광학계에서 보정될 수 없었던 수차를 근본적으로 제거한다. 또한 비구면 LENS를 사용하므로써 화질 의 향상을 기할 수 있고 LENS 매수를 줄임으로써 LENS계 전체의 COMPACT 화, COST DOWN, 중량경감이 가능한 잇점이 있다. 지금까지 이러한 장점이 있는 비구면 LENS가 사용되지 못했던 것은 설계기술보다는 생산기 술에 있었는데, 최근 비구면 LENS 가공이가능한 기계와 LASER를 이용한 측정기술, MOLD MASTER에 의한 사출기술이 발전함에따라 PLASTIC LENS의 양산이 가능하게 되었다. 본 고에서는 신 제품 개발능력 확보와 제품경쟁력 향상을 목적으로 개발한 비구면 LENS 금형의 초정밀가공 정도 (비구면 가공정도 : FORM ERROR 0.2 .mu. m 이하) 달성방법과 측정평가에 대해 논했다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.533-534
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• 2006

Micro pyramid pattern and its array are designed to enhance the brightness and its uniformity of LGP which is one of key parts in LCD. The designed micro pyramid patterns are fabricated on a Si-wafer first through MEMS process and then a Ni-stamper is electro-plated from the Si pattern master. Adopting the fabricated Ni-stamper, LGPs are injection molded at different mold temperatures and the fidelity of the pattern replication is estimated for each molding conditions and pattern locations. The replicated patterns are found to have some defect such as local short shot or micro weld line which are believed to have negative effect on the performance of the LGP.

• 한국정밀공학회지
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• 제23권9호
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• pp.174-178
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• 2006

Pyramid shape of micro pattern is applied to the light guide panel (LGP) to enhance the uniformity of the brightness of the LCD. The micro pyramids are molded in intaglio on the surface of the LGP. The size of each pyramid is 5$\mu$m $\times$ 5$\mu$m on bottom and the height is about 3.5$\mu$m. The pyramids are distributed on the LGP surface randomly to be sparser where the light comes in and denser at the opposite side as a result of a simulation using lightools$^{TM}$ Based on this design, a silicon pattern master and a nickel stamper are fabricated by MEMS process and electro plating process. Intaglio micro pyramids are fabricated on the 6' of silicon wafer from the anisotropic etching using KOH and the process time, temperature of the KOH solution, etc are optimized to obtain precise shape of the pattern. A Wi stamper is fabricated from this pattern master by electro plating process and the embossed pyramid patterns turns out to be well defined on the stamper. Adopting this stamper to the mold base with two cavities, 1.8' and 3.6' LGPs are injection molded.