• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.564-566
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• 2007

Synthesis of two photoactive compounds containing core imide moiety was carried out for an application to interdielectric layer in TFTLCD array. An aqueous alkaline developable polymer matrix was synthesized by free radical copolymerization. A positive photoresist formulation was developed utilizing synthesized UV monomers, photoactive compound, binder polymer, sulfactant and alkali developable polymer matrix. It was found that via-holes with good resolution, high transmittance and thermal resistance could be obtained by photolithographic process utilizing the new positive interdielectric material with high thermal stability.

• Structural Engineering and Mechanics
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• v.54 no.4
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• pp.665-691
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• 2015

This study aims at comparing the optimum design of two common types open web expanded beams: with hexagonal openings, also called castellated beams and beams with circular openings referred to as cellular beams. The minimum weights of both beams are taken as the objective functions while the design constraints are respectively implemented from The Steel Construction Institute Publication Numbers 5 and 100. The design methods adopted in these publications are consistent with BS5950 parts. The formulation of the design problem considering the limitations of the above mentioned turns out to be a discrete programming problem. Improved harmony search algorithm is suggested to compare the optimum design of mentioned web-expanded beams to analysis the performance of both beams. The design algorithms based on the technique select the optimum Universal Beam sections, dimensional properties of hexagonal and circular holes and total number of openings along the beam as design variables.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.303-303
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• 2007

Photo-imageable thick-film lithography technology was developed for the fabrication of embedded passives such as inductors and capacitors. In this study, photo-imageable dielectric and conductor pastes have apoted a negative type. Sodalime glass wafer, alumina substrate and zero-shrinkage LTCC green tapes were used as substrates. In result, The lithographic patterns were designed as lines and spaces for conductor material, or via-holes for ceramic, LTCC, materials. The scattering and reflection of UV-beam on the substrate had negative effects on fine patterning. The patterning performance was varied with the exposing and developing process conditions, and also varied with the substrate materials. Fine resolution of less then $50/50{\mu}m$ in line and space was obtained, which is difficult in screen printing method.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.29 no.3
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• pp.87-94
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• 1997

As the paper market becomes more and more competitive, more mills will want to switch to alkaline papermaking to take advantage of the Vowing demand. Many papermakers have tried to do this without success in the past much like the American papermakers did in the late 1970's. The Problem is that runnability Problems occur, drainage slows, Presses pick drying becomes more difficult and sheet quality suffers as a result Sheet holes and breaks occur, and runnability becomes a real operating problem. Converting to alkaline papermaking is not as simple as turning off the alum. We must be aware of the numerous factions that alum served at acid pH and provide alkaline alternatives. It is the purpose of this paper to discuss methods of deposit control via charge neutralization and system control at alkaline pH. This article explains the concept as well as the measurement and control. The resultant benefits are seen in runnability, quality and profitability for the papermaker.

• Journal of the Semiconductor & Display Technology
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• v.20 no.2
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• pp.103-108
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• 2021

The TCD is used as one of the indicators for determining whether TSV Hole is defective. If the TCD is not normal size, it can lead to contamination of the CMP equipment or failure to connect the upper and lower chips. We propose a deep learning model for measuring the TCD. To verify the performance of the proposed model, we compared the prediction results of the proposed model for 2461 via holes with the CD-SEM measurement data and the prediction results of the existing model. Although the number of trainable parameters in the proposed model was about one two-thousandth of the existing model, the results were comparable. The experiment showed that the correlation between CD-SEM and the prediction results of the proposed model measured 98%, the mean absolute difference was 0.051um, the standard deviation of the absolute difference was 0.045um, and the maximum absolute difference was 0.299um on average.

• Journal of Sensor Science and Technology
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• v.31 no.1
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• pp.12-15
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• 2022

In this study, we studied the effects of transfer gate on the photocurrent characteristics of gate/body-tied (GBT) metal-oxide semiconductor field-effect transistor (MOSFET)-type photodetector. The GBT MOSFET-type photodetector has high sensitivity owing to the amplifying characteristic of the photocurrent generated by light. The transfer gate controls the flow of photocurrent by controlling the barrier to holes, thereby varying the sensitivity of the photodetector. The presented GBT MOSFET-type photodetector using a built-in transfer gate was designed and fabricated via a 0.18-㎛ standard complementary metal-oxide-semiconductor (CMOS) process. Using a laser diode, the photocurrent was measured according to the wavelength of the incident light by adjusting the voltage of the transfer gate. Variable sensitivity of the presented GBT MOSFET-type photodetector was experimentally confirmed by adjusting the transfer gate voltage in the range of 405 nm to 980 nm.

• Journal of the Semiconductor & Display Technology
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• v.21 no.1
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• pp.108-113
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• 2022

The deep-learning-based measurement method with the through-focus scanning optical microscopy (TSOM) estimated the size of the object using the classification. However, the measurement performance of the method depends on the number of subdivided classes, and it is practically difficult to prepare data at regular intervals for training each class. We propose an approach to measure the size of an object in the TSOM image using the deep-learning regression model instead of using classification. We attempted our proposed method to estimate the top critical dimension (TCD) of through silicon via (TSV) holes with 2461 TSOM images and the results were compared with the existing method. As a result of our experiment, the average measurement error of our method was within 30 nm (1σ) which is 1/13.5 of the sampling distance of the applied microscope. Measurement errors decreased by 31% compared to the classification result. This result proves that the proposed method is more effective and practical than the classification method.

• Journal of The Korean Astronomical Society
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• v.47 no.6
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• pp.235-253
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• 2014

Intensity interferometry, based on the Hanbury Brown-Twiss effect, is a simple and inexpensive method for optical interferometry at microarcsecond angular resolutions; its use in astronomy was abandoned in the 1970s because of low sensitivity. Motivated by recent technical developments, we argue that the sensitivity of large modern intensity interferometers can be improved by factors up to approximately 25 000, corresponding to 11 photometric magnitudes, compared to the pioneering Narrabri Stellar Interferometer. This is made possible by (i) using avalanche photodiodes (APD) as light detectors, (ii) distributing the light received from the source over multiple independent spectral channels, and (iii) use of arrays composed of multiple large light collectors. Our approach permits the construction of large (with baselines ranging from few kilometers to intercontinental distances) optical interferometers at the cost of (very) long-baseline radio interferometers. Realistic intensity interferometer designs are able to achieve limiting R-band magnitudes as good as $m_R{\approx}14$, sufficient for spatially resolved observations of main-sequence O-type stars in the Magellanic Clouds. Multi-channel intensity interferometers can address a wide variety of science cases: (i) linear radii, effective temperatures, and luminosities of stars, via direct measurements of stellar angular sizes; (ii) mass-radius relationships of compact stellar remnants, via direct measurements of the angular sizes of white dwarfs; (iii) stellar rotation, via observations of rotation flattening and surface gravity darkening; (iv) stellar convection and the interaction of stellar photospheres and magnetic fields, via observations of dark and bright starspots; (v) the structure and evolution of multiple stars, via mapping of the companion stars and of accretion flows in interacting binaries; (vi) direct measurements of interstellar distances, derived from angular diameters of stars or via the interferometric Baade-Wesselink method; (vii) the physics of gas accretion onto supermassive black holes, via resolved observations of the central engines of luminous active galactic nuclei; and (viii) calibration of amplitude interferometers by providing a sample of calibrator stars.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.3 s.333
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• pp.19-24
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• 2005

This paper presents design simulation, implementation, and measurement of a miniaturized GPS/K-PCS dual-band LTCC chip antenna for mobile communication handsets. The dimension of LTCC chip antenna is $9mm\times15mm\times1.2mm$. The meander type radiating patch for dual-band operation is realized by using via holes with 0.3mm height to connect upper and lower-layer antenna. The lower meander type antenna is to be tuned to the lower frequency (GPS) band. The upper meander antenna with via hole connection is to contribute the higher frequency (K-PCS) band. The resonant frequency and frequency ratio of the proposed antenna can be adjusted by changing the height of via-hole and effective path of meander radiating patch. The electrical characteristics of the meander chip antenna applied to a GPS/K-PCS are suitable for mobile communication application.

• Journal of Advanced Navigation Technology
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• v.17 no.6
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• pp.687-692
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• 2013

This paper presents a compact power divider using microstrip-slotline transition technology. By using the microstrip-slotline transition, the ${\lambda}/4$ transmission lines of the divider can be changed to two ${\lambda}/8$ transmission lines in the multilayer structure. In the microstrip-slotline transition, we have used via holes to make a short circuit at the microstrip line and embedded spiral configuration stubs to reduce the electrical length of an open circuit at the slotline end point. For validating the microstrip-slotline technique, we have simulated and implemented the power divider with embedded spiral and via hole configuration circuits at a frequency of 2 GHz. Good agreement between the simulation and the measurement results is obtained at the operating frequency.