• Journal of the Semiconductor & Display Technology
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• v.15 no.2
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• pp.74-80
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• 2016

This study presents a thermal device specially designed for thermal nanoimprint lithography equipments, which requires the capability of rapid heating and cooling, high temperature uniformity and the material strength to endure high stamping pressure. The proposal to meet these requirements is a planar-type hot plate extensible to a large area, in which long circular cartridge heaters and heat pipes are installed inside in parallel. The heat pipes are connected to the outside water cooling chamber. A hot plate made of stainless steel is fabricated with a dimension $240mm{\times}240mm{\times}20mm$. Laboratory experiments are conducted to examine the thermal performance of the hot plate. The results illustrate that the employment of heat pipes leads to a notable enhancement of temperature uniformity in the device and provides an efficient heat delivery from the hot plate to outside. It is verified that the suggested hot plate could be a feasible thermal tool for thermal nanoimprint lithography, satisfying the major design requirements.

• Design & Manufacturing
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• v.15 no.3
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• pp.7-12
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• 2021

Plastic injection molds used for rapid heating and cooling must minimize surface damage due to friction and maintain excellent thermal and low electrical conductivity. Accordingly, various surface treatments are being applied. The properties of Al₂O₃ coating and DLC coating were compared to find the optimal surface treatment method. Al₂O₃ coating was deposited by thermal spray method. DLC films were deposited by sputtering process in room temperature and high temperature PECVD (Plasma enhanced chemical vapor deposition) process in 723 K temperature. For the evaluation of physical properties, the electrical and thermal conductivity including surface hardness, adhesion and wear resistance were analyzed. The electrical resistance of the all coated samples was showed insulation properties of 24 MΩ/sq or more. Especially, the friction coefficient of high temp. DLC coating was the lowest at 0.134.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.2
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• pp.87-92
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• 2015

The injection molding process is widely used in the production of most plastic products. In order to make metal-colored plastic products like those found in modern luxury home alliances, metallic pigments are mixed with a basic resin material for injection molding. However, process control for metal-colored plastic products is extremely difficult due to the non-uniform melt flow of the metallic resin pigments. In this study, the effect of process parameters on the quality of a metal-colored plastic product is evaluated. A rapid mold cooling method using a compressed cryogenic fluid is also proposed to decrease the content of undesired compounds within the plastic product.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.09a
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• pp.9-12
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• 2005

The rapid thermal response (RTR) molding is a novel process developed to raise the temperature of mold surface rapidly to the polymer melt temperature prior to the injection stage and then cool rapidly to the ejection temperature. The resulting filling process is achieved inside a hot mold cavity by prohibiting formation of frozen layer so as to enable thin wall injection molding without filing difficulty. The present work covers flow simulation of thin wall injection molding using the RTR molding process. In order to take into account the effects of thermal boundary conditions of the RTR mold, coupled analysis with transient heat transfer simulation is suggested and compared with conventional isothermal analysis. The proposed coupled simulation approach based on solid elements provides reliable thin wall flow estimation fur both the conventional molding and the RTR molding processes

• Environmental Engineering Research
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• v.16 no.1
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• pp.11-18
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• 2011

The aim of this research was to introduce a new rapid analysis method (heating of the multi-layer silica gel column/alumina column) for polychlorinated biphenyls in insulating oils, and to compare our new method with the analytical method currently used in Korea. The entire pretreatment procedure was completed within 2 hr, using about only 20 mL of solvents via our rapid analytical method. Furthermore, the pretreatment procedure can always be uniformly performed, regardless of oil type (JIS 1~JIS 7 and KS 1~KS 7). The recovery rates were more than 89%, with relative standard deviations below 6.0%. In conclusion, this rapid analytical method could reduce the pretreatment time and solvent usage by 1/10 and between 1/25 and 1/50, respectively, compared to analytical method currently used in Korea.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.652-652
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• 2013

The conventional thermal chemical vapor deposition (CVD) setup for the graphene synthesis has mainly used convective heat transfer in order to heat a catalyst (e.g. Cu) up to $1,000^{\circ}C$. Although the conventional CVD has been so far widely accepted as the most appropriate candidate enabling mass-production of high-quality graphene, this method has stillremained under the standard for the commercialization largely due to the poor productivity arisen out of the required long processing time. Here, we introduced a fast and efficient synthetic route toward CVD-graphene. Unlike the conventional CVD using convection heat transfer, we adopted a CVD setup utilizing conduction heat transfer between Cu catalyst and rapid heating source. The high thermal conductive nature of Cu and the employed rapid heating source led to the remarkable reduction in processing timeas compared to the conventional convection based CVD (Fig. 1A), moreover, the synthesized graphene was turned out to have comparable quality to that synthesized by the conventional CVD (Fig. 1B). For the optimization of the conduction based CVD process, the parametric studies were thoroughly performed using through Raman spectroscopy and electrical sheet resistance measurement. Our approach is thought to be worth considerable in order to enhance productivity of the CVD graphene in the industry.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.4
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• pp.609-620
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• 1992

A numerical solution of temperature and thermally induced stress in a wafer during rapid thermal processing (R.T.P) is obtained, and an analysis of onset and propagation of slip is performed and compared with experiment. In order to calculate temperature distribution of a wafer in R.T.P system, heat conduction equation that incorporated with radiative and convective heat transfer model is solved, and the solution of the equation is calculated numerically using alternating direction implicit (A.D.I) method. In dealing with radiative heat transfer, a partially transparent body that absorbs the radiation energy is assumed and this transparent body undergoes multiple internal reflections and absorptions. Two dimensional (assuming plane stress) thermoelastic constitutive equation is used to calculate thermal stress induced in a wafer and finite element method is employed to solve the equation numerically. The stress resolved in the slip directions on the slip planes of silicon is compared with the yield stress of silicon in order to predict the slip. The result of the analysis shows that the wafer temperature at which slip occurs is affected by the heating rate of the R.T.P system. It is observed that once slip occurs in the wafer, the slip grows.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.54-61
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• 1999

A study was conducted to find a rapid thawing method which prevents excessive drip loss and local overheating. Effects of thawing methods (conventional thawing vs. 2,450 and 915 MHz microwave thawing) on thawing time, temperature profile, drip loss, water holding capacity, total color difference and total aerobes were investigated. Samples were thawed at 4, 28 and $50^{\circ}C$ in a refrigerator or an oven for the conventional thawing methods the convertional thawing methods. Power levels of 5, 10 and 15 kW were used for 915MHz microwave thawing. Cotreatment of 915 MHz microwave and convectional heating $(120^{\circ}C)$ was tested. 915 MHz microwave accelerated the thawing rate, and showed significant effects on penetration depth, drip loss, water holding capacity and total aerobes. Cotreatment of 915 MHz microwave and convection heating was appeared to be a suitable thawing process for the food industry.

• Korean Chemical Engineering Research
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• v.51 no.4
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• pp.455-459
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• 2013

The fuel processor for the portable fuel cell includes multi-step processes consisting of hydrogen generator, heat generator and several CO clean-up stages. One of requirements of the fuel processor for portable fuel cell system is a rapid start-up time. Especially, the warm-up time for WGS reactor is crucial factors for total start-up time. In this paper, active heating protocol, which is the heating protocol of WGS reactor supplied by the oxidation of CO rich reformate in the initial stage, is used for a rapid start-up. The air stream fed to the inlet of WGS reactor rapidly oxidize the CO rich reformate in the WGS reactor. Therefore, CO concentration in reformate quickly stabilized at the desired concentration without CO surges.

• Electrical & Electronic Materials
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• v.8 no.6
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• pp.737-743
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• 1995

Two step RTD(Rapid Thermal Diffussion) of P into silicon wafer using tungsten halogen lamp was used to fabricated very shallow n$^{+}$p junction. 1st RTD was performed in the temperature range of 800.deg. C for 60 see and the heating rate was in the 50.deg. C/sec. Phosphrous solid source was transfered on the silicon surface. 2nd RTD process was performed in the temperature range 1050.deg. C, 10sec. Using 2 step RTD we can obtain a shallow junction 0.13.mu.m in depth. After RTD, the Ti-silicide process was performed by the two step RTA(Rapid Thermal Annealing) to reduced the electric resistance and to improve the n$^{+}$p junction diode. The titanium thickness was 300.angs.. The condition of lst RTA process was 600.deg. C of 30sec and that of 2nd RTA process was varied in the range 700.deg. C, 750.deg. C, 800.deg. C for 10sec-60sec. After 2 step RTA, sheet resistance was 46.ohm../[]. Ti-silicide n+p junction diode was fabricated and I-V characteristics were measured.red.