scholarly journals A NUMERICAL STUDY ON THERMAL DESIGN OF A LARGE-AREA HOT PLATE FOR THERMAL NANOIMPRINT LITHOGRAPHY

2016 ◽  
Vol 21 (2) ◽  
pp. 90-98
Author(s):  
G.J. Park ◽  
J.J. Lee ◽  
H.S. Kwak
Keyword(s):  
Nanoimprint Lithography ◽  
Numerical Study ◽  
Thermal Design ◽  
Large Area ◽  
Hot Plate

scholarly journals Numerical Study on Thermal Design of a Large-Area Hot Plate with Heating and Cooling Capability for Thermal Nanoimprint Lithography

2019 ◽  
Vol 9 (15) ◽  
pp. 3100
Author(s):  
Gyujin Park ◽  
Changhee Lee
Keyword(s):  
Nanoimprint Lithography ◽  
Numerical Study ◽  
Heat Pipes ◽  
Thermal Control ◽  
Thermal Design ◽  
Large Temperature ◽  
Large Area ◽  
Hot Plate ◽  
Ansys Fluent ◽  
Heating And Cooling

A numerical study is conducted on the thermal performance of a large-area hot plate specifically designed as a heating and cooling tool for thermal nanoimprint lithography processes. The hot plate has the dimensions 240 mm × 240 mm × 20 mm, in which a series of cartridge heaters and cooling holes are installed. Stainless steel has been selected to endure the high molding pressures. A numerical model based on ANSYS Fluent is employed to predict the thermal behavior of the hot plate in both the heating and cooling phases. The proportional–integral–derivative (PID) thermal control of the device is modeled by adding user defined functions. The results of the numerical computations demonstrate that the use of cartridge heaters provides sufficient heat-up performance and the active liquid cooling in the cooling holes provides the required cool-down performance. However, a crucial technical issue is raised, namely that the proposed design poses a large temperature non-uniformity in the steady heating phase and in the transient cooling phase. As a remedy, a new hot plate in which heat pipes are installed in the cooling holes is considered. The numerical results show that the installation of heat pipes could enhance the temperature uniformity both in the heating and cooling phases.

scholarly journals Experimental and Numerical Study on the Characteristics of the Thermal Design of a Large-Area Hot Plate for Nanoimprint Equipment

2019 ◽  
Vol 11 (17) ◽  
pp. 4795 ◽  
Author(s):  
Gyujin Park ◽  
Changhee Lee
Keyword(s):  
Stainless Steel ◽  
Thermal Behavior ◽  
Thermal Performance ◽  
Numerical Study ◽  
Heat Pipes ◽  
Thermal Design ◽  
Maximum Temperature ◽  
Large Area ◽  
Hot Plate ◽  
Heating And Cooling

A numerical study was conducted on the thermal performance of a large-area hot plate specifically designed as a heating and cooling tool for thermal nanoimprint lithography processes. The hot plate had the dimensions 240 mm × 240 mm × 20 mm, in which a series of cartridge heaters and cooling holes were installed. Stainless steel was selected to endure the high molding pressures. To examine the hot plate’s abnormal thermal behavior, ANSYS Fluent V15.0, which is commercial CFD code, was used to perform computational analysis. A numerical model was employed to predict the thermal behavior of the hot plate in both the heating and cooling phases. To conduct the thermal design of a large-area hot plate for nanoimprint equipment, we selected the model to be studied and proposed a cooling model using both direct and indirect cooling methods with and without heat pipes. In addition, we created a small hot plate and performed experimental and computational analyses to confirm the validity of the proposed model. This study also analyzed problems that may occur in the stage prior to the large-area expansion of the hot plate. In the case of a stainless steel (STS304) hot plate for large-area hot plate expansion, the heat pipes were inserted in the direction of the cartridge heaters to address the problems that may occur when expanding the hot plate into a large area. As a result, the heating rate was 40 °C/min and the temperature uniformity was less than 1% of the maximum working temperature of 200 °C. For cooling, when considering pressure and using air as the coolant for the ends, a cooling rate of 20 °C/min and thermal performance of less than 13.2 °C (less than 7%) based on the maximum temperature were obtained. These results were similar to the experimental results.

scholarly journals Mastering of NIL Stamps with Undercut T-Shaped Features from Single Layer to Multilayer Stamps

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 956
Author(s):  
Philipp Taus ◽  
Adrian Prinz ◽  
Heinz D. Wanzenboeck ◽  
Patrick Schuller ◽  
Anton Tsenov ◽  
...  
Keyword(s):  
Electron Beam Lithography ◽  
Nanoimprint Lithography ◽  
Silicon Oxide ◽  
Three Dimensional ◽  
Single Layer ◽  
Fabrication Technology ◽  
Large Area ◽  
Structural Colors ◽  
Biomimetic Structures ◽  
Morpho Butterfly

Biomimetic structures such as structural colors demand a fabrication technology of complex three-dimensional nanostructures on large areas. Nanoimprint lithography (NIL) is capable of large area replication of three-dimensional structures, but the master stamp fabrication is often a bottleneck. We have demonstrated different approaches allowing for the generation of sophisticated undercut T-shaped masters for NIL replication. With a layer-stack of phase transition material (PTM) on poly-Si, we have demonstrated the successful fabrication of a single layer undercut T-shaped structure. With a multilayer-stack of silicon oxide on silicon, we have shown the successful fabrication of a multilayer undercut T-shaped structures. For patterning optical lithography, electron beam lithography and nanoimprint lithography have been compared and have yielded structures from 10 µm down to 300 nm. The multilayer undercut T-shaped structures closely resemble the geometry of the surface of a Morpho butterfly, and may be used in future to replicate structural colors on artificial surfaces.

scholarly journals Experimental and numerical investigation of heat dissipation from an electronic component in a closed enclosure

2018 ◽  
Vol 144 ◽  
pp. 04010
Author(s):  
Bobin Saji George ◽  
M. Ajmal ◽  
S. R. Deepu ◽  
M. Aswin ◽  
D. Ribin ◽  
...  
Keyword(s):  
Power Dissipation ◽  
Heat Dissipation ◽  
Numerical Study ◽  
Electronic Component ◽  
Thermal Design ◽  
Electronic Systems ◽  
Computational Domain ◽  
Computational Tool ◽  
Cycle Times ◽  
Design Cycle

Intensifying electronic component power dissipation levels, shortening product design cycle times, and greater than before requirement for more compact and reliable electronic systems with greater functionality, has heightened the need for thermal design tools that enable accurate solutions to be generated and quickly assessed. The present numerical study aims at developing a computational tool in OpenFOAM that can predict the heat dissipation rate and temperature profile of any electronic component in operation. A suitable computational domain with defined aspect ratio is chosen. For analyzing, “buoyant Boussinesq Simple Foam“ solver available with OpenFOAM is used. It was modified for adapting to the investigation with specified initial and boundary conditions. The experimental setup was made with the dimensions taken up for numerical study. Thermocouples were calibrated and placed in specified locations. For different heat input, the temperatures are noted down at steady state and compared with results from the numerical study.

scholarly journals Uniform Pressing Mechanism in Large-Area Roll-to-Roll Nanoimprint Lithography Process

2021 ◽  
Vol 11 (20) ◽  
pp. 9571
Author(s):  
Ga Eul Kim ◽  
Hyuntae Kim ◽  
Kyoohee Woo ◽  
Yousung Kang ◽  
Seung-Hyun Lee ◽  
...  
Keyword(s):  
Contact Pressure ◽  
Nanoimprint Lithography ◽  
Applied Pressure ◽  
Machine Learning Techniques ◽  
Conventional System ◽  
Large Area ◽  
High Productivity ◽  
Roll To Roll ◽  
Learning Techniques ◽  
Roller Machine

We aimed to increase the processing area of the roll-to-roll (R2R) nanoimprint lithography (NIL) process for high productivity, using a long roller. It is common for a long roller to have bending deformation, geometric errors and misalignment. This causes the non-uniformity of contact pressure between the rollers, which leads to defects such as non-uniform patterning. The non-uniformity of the contact pressure of the conventional R2R NIL system was investigated through finite element (FE) analysis and experiments in the conventional system. To solve the problem, a new large-area R2R NIL uniform pressing system with five multi-backup rollers was proposed and manufactured instead of the conventional system. As a preliminary experiment, the possibility of uniform contact pressure was confirmed by using only the pressure at both ends and one backup roller in the center. A more even contact pressure was achieved by using all five backup rollers and applying an appropriate pushing force to each backup roller. Machine learning techniques were applied to find the optimal combination of the pushing forces. In the conventional pressing process, it was confirmed that pressure deviation of the contact area occurred at a level of 44%; when the improved system was applied, pressure deviation dropped to 5%.

scholarly journals Large-Area Subwavelength Aperture Arrays Fabricated Using Nanoimprint Lithography

2008 ◽  
Vol 7 (5) ◽  
pp. 527-531 ◽  
Author(s):  
J.L. Skinner ◽  
L.L. Hunter ◽  
A.A. Talin ◽  
J. Provine ◽  
D.A. Horsley
Keyword(s):  
Nanoimprint Lithography ◽  
Large Area ◽  
Subwavelength Aperture ◽  
Aperture Arrays

Numerical Study of Convective Heat Transfer of Multiple Internal Isolated Blocks in an Enclosure

Solar Energy ◽  
2005 ◽  
Author(s):  
Xutao Zhang ◽  
Jianing Zhao ◽  
Fusheng Gao ◽  
Jun Gao ◽  
Songling Wang
Keyword(s):  
Heat Transfer ◽  
Mixed Convection ◽  
Convective Heat Transfer ◽  
Forced Convection ◽  
Convective Heat ◽  
Numerical Study ◽  
Thermal Design ◽  
Square Enclosure ◽  
Forced Convective Heat Transfer ◽  
Low Reynolds

The treatment of Convective Heat Transfer Coefficients (CHTCs) in an enclosure has a significant impact on the thermal design of electronic appliance, especially the CHTCs in an enclosure with internal isolated blocks. The CHTCs of the isolated blocks for pure natural convection are usually used, while it may not be applicable to any practice. Combined convective heat transfer, even forced convective heat transfer, is sometime more applicable in reality. In our present work, first of all, validation of the turbulence model for CFD simulation of natural convective flows in a square enclosure is performed. The values of CHTCs for vertical walls obtained by using a low Reynolds k-ε model agree well with the existed correlations. The simulation also indicates that the distance from the first grid to the wall has a significant impact on the CHTCs. Using this low Reynolds k-ε model, computer simulations of natural and forced convective heat transfer within a square enclosure containing ten isolated blocks are performed. For both the natural and forced convection, the dimensionless Nusselt numbers are derived by the obtained results. For the case of mixed convection, the CHTCs are established by blending those for natural and forced convection using the Churchill-Usagi approach, which is a general expression combines the asymptotic solutions of independent CHTCs into the mixed convection by using a Churchill-Usagi blending coefficient.

scholarly journals A numerical study of the Plata River plume along the southeastern South American continental shelf

2005 ◽  
Vol 53 (3-4) ◽  
pp. 129-146 ◽  
Author(s):  
Felipe M. Pimenta ◽  
Edmo José Dias Campos ◽  
Jerry L. Miller ◽  
Alberto R. Piola
Keyword(s):  
South America ◽  
River Discharge ◽  
Numerical Study ◽  
South American ◽  
Southern Brazil ◽  
Large Area ◽  
Plume Dynamics ◽  
Low Salinity ◽  
River Outflow ◽  
Low Latitudes

The Rio de la Plata, one of the largest rivers on Earth, discharges into the ocean waters from basin that covers a large area of South America. Its plume extends along northern Argentina, Uruguay, and southern Brazil shelves strongly influencing the ecosystems. In spite of this, little is known about the mechanisms that control it. Here we report results of simulations with POM carried out to investigate the roles of wind and river discharge in Plata plume dynamics. Different outflows were explored, including an average climatological value and magnitudes representative of La Niña and El Niño. Forcing the model with river discharge the average plume speed was directly related to the outflow intensity. The Plata northward extension varied from 850 to 1550 km and for average discharge a band of low salinity waters formed from the estuary up to 30ºN of South Brazilian Shelf. Upwelling and downwelling winds were applied after 130 days. The distribution of low salinity waters over the shelf was more sensitive to the wind direction than to the river outflow variability. Downwelling winds were very capable of advecting the low salinity signal downshelf. Upwelling winds were efficient in eroding the plume, which was basically detached from the coast by Ekman drift. Abnormal plume intrusions toward low latitudes may be a result of the original plume position coupled with events of persistent strong downwelling favorable winds.

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