AMOLED 제조공정에 사용되는 Fine Metal Mask 용 얇은 Invar 합금의 진동자를 이용한 펨토초 레이저 응용 홀 드릴링

최원석,김훈영,신영관,최준하,장원석,김재구,조성학,최두선,Choi, Won-Suk,Kim, Hoon-Young,Shin, Young-Gwan,Choi, Jun-ha,Chang, Won-Seok,Kim, Jae-Gu,Cho, Sung-Hak,Choi, Doo-Sun 한국금형공학회 2020 한국금형공학회지 Vol.14 No.3

One of display trends today is development of high pixel density. To get high PPI, a small size of pixel must be developed. RGB pixel is arranged by evaporation process which determines pixel size. Normally, a fine metal mask (FMM; Invar alloy) has been used for evaporation process and it has advantages such as good strength, and low thermal expansion coefficient at low temperature. A FMM has been manufactured by chemical etching which has limitation to controlling the pattern shape and size. One of alternative method for patterning FMM is laser micromachining. Femtosecond laser is normally considered to improve those disadvantages for laser micromachining process due to such short pulse duration. In this paper, a femtosecond laser drilling for thickness of 16 ㎛ FMM is examined. Additionally, we introduce experimental results for controlling taper angle of hole by vibration module adapted in laser system. We used Ti:Sapphire based femtosecond laser with attenuating optics, co-axial illumination, vision system, 3-axis linear stage and vibration module. By controlling vibration amplitude, entrance and exit diameters are controllable. Using vibrating objective lens, we can control taper angle when femtosecond laser hole drilling by moving focusing point. The larger amplitude of vibration we control, the smaller taper angle will be carried out.

PECVD로 합성한 다이아몬드상 카본박막의 전기적 특성

최원석,박문기,홍병유,Choi, Won-Seok,Park, Mun-Gi,Hong, Byung-You 한국전기전자재료학회 2008 전기전자재료학회논문지 Vol.21 No.11

In addition to its similarity to genuine diamond film, diamond-like carbon (DLC) film has many advantages, including its wide band gap and variable refractive index. In this study, DLC films were prepared by the RF PECVD (Plasma Enhanced Chemical Vapor Deposition) method on silicon substrates using methane ($CH_4$) and hydrogen ($H_2$) gas. We examined the effects of the RF power on the electrical properties of the DLC films. The films were deposited at several RF powers ranging from 50 to 175 W in steps of 25 W. The leakage current of DLC films increased at higher deposition RF power. And the resistivities of DLC films grown at 50 W and 175 W were $5\times10^{11}$ ${\Omega}cm$ and $2.68\times10^{10}$ ${\Omega}cm$, respectively.

Orthodontic Distal Movement of the Abutment Premolar to the Posterior Edentulous Area

최원석,Choi, Won-Seok Korean Academy of Esthetic Dentistry 2000 Journal of the Korean Academy of Esthetic Dentistr Vol.9 No.1

Thermal Aging Behavior of H-NBR/NBR Blend

최원석,김건완,도제성,유명우,류승훈,Choi, Won-Seok,Kim, Gun-Wan,Do, Je-Sung,Yoo, Myung-Ho,Ryu, Sung-Hun The Rubber Society of Korea 2011 엘라스토머 및 콤포지트 Vol. No.

본 연구는 H-NBR 함량 변화에 따른 H-NBR/NBR 블렌드의 열노화 거동에 대하여 살펴보았다. 이 때 가교제로는 dicumyl peroxide와 황 혼합물을 사용하였으며, 열노화에 따른 H-NBR/NBR 블렌드의 인장강도, 파괴신율, 경도 그리고 내마모성의 변화를 살펴보았다. H-NBR을 첨가함에 따라 인장강도는 증가하였으나 내마모성은 감소하는 현상을 나타내었다. 파괴신율과 경도는 H-NBR의 영향을 받지 않았다. 노화가 진행된 모든 시편은 초기 시편보다 낮은 인장강도, 파괴신율, 경도를 나타내었다. 그러나 H-NBR의 함량이 증가함에 따라 이러한 물성저하 속도가 감소함을 알 수 있었다. 즉 H-NBR 첨가에의해 열노화 특성이 향상됨을 알 수 있었다. 모든 NBR/H-NBR 블렌드는 노화시간이 증가함에 따라 내마모성이 감소하였으며, H-NBR을 첨가한 경우 내마모성의 저하가 상대적으로 낮음을 알 수 있었다. In the present investigation, thermal aging behavior of H-NBR/NBR blend with various H-NBR content was investigated. Mixture of dicumyl peroxide and sulfur were used as a curing agent. The influence of the thermal aging of the H-NBR/NBR blends on the solid state properties such as tensile strength, elongation at break, hardness and abrasion resistance was investigated. Tensile strength was increased with increasing H-NBR content, while abrasion resistance was decreased. Both elongation at break and hardness were not affected by the addition of H-NBR. The properties such as hardness, tensile strength and elongation at break of the aged samples were lower than unaged samples. However, the rate of deterioration of those properties was decreased by increasing the H-NBR content, which indicated that improved thermal aging behavior was obtained by the addition of H-NBR. Abrasion loss was increased with increasing aging time, but it became less by the addition of H-NBR addition.

라만 맵핑 방식을 사용한 다이아몬드상 카본박막의 미세구조변화에 관한 연구

최원석,Choi, Won-Seok 한국전기전자재료학회 2006 전기전자재료학회논문지 Vol.19 No.7

Hydrogenated Diamond-like carbon (DLC) films were prepared by the radio frequency plasma enhanced chemical vapor deposition (RF PECVD) method on silicon substrates using methane $(CH_4)$ and hydrogen $(H_2)$ gas. The wear track on the DLC films was examined after the ball-on disk (BOD) measurement with a Raman mapping method. The BOD measurement of the DLC films was performed for 1 to 3 hours with a 1-hour step time. The sliding traces on the hydrogenated DLC film after the BOD measurement were also observed using an optical microscope. The surface roughness and cross-sectional images of the wear track were obtained using an atomic force microscope (AFM). The novel Raman mapping method effectively shows the graphitization of DLC films of $300{\mu}m\times300{\mu}m$ area according to the sliding time by G-peak positions (intensities) and $I_D/I_G$ ratios.

MEMS 소자의 고체윤활박막으로 활용하기 위한 다이아몬드상 카본 박막의 트라이볼로지 특성 분석

최원석,홍병유,Choi, Won-Seok,Hong, Byung-You 한국전기전자재료학회 2006 전기전자재료학회논문지 Vol.19 No.11

Hydrogenated Diamond-like carbon (DLC) films were Prepared by the radio frequency plasma enhanced chemical vapor deposition (RF PECVD) method on silicon substrates using methane $(CH_4)$ and hydrogen $(H_2)$ gas for the application to solid lubricant of MEMS devices. We have checked the influence of varying RF power on tribological properties of DLC film. We have checked their performance as two kinds of method such as FFM (Friction Force Microscope) and BOD (Ball-on Disk) measurement. The friction coefficients and the contact number of cycles to steady state decreased as the increase of RF power with FFM and BOD measurement, respectively.

백혈구 증가증 환아의 혈장내 G-CSF와 GM-CSF의 농도 및 과립구에서의 이들 수용체의 발현

최원석,유경환,김유정,김소영,김현희,이원배,Choi, Won Seok,Ryu, Kyung Hwan,Kim, You Jeong,Kim, So Young,Kim, Hyun Hee,Lee, Wonbae 대한소아청소년과학회 2003 Clinical and Experimental Pediatrics (CEP) Vol.46 No.3

목 적 : G-CSF와 GM-CSF는 과립구생성에 중요한 사이토카인으로서, 각각의 수용체 G-CSFr과 GM-CSFr에 결합하여 기능을 하게 되며, 이들 수용체들은 미성숙 골수 세포로부터 성숙 된 말초 과립구까지 발현된다. 일반적으로 혈중 G-CSF와 GM-CSF의 농도 및 이들 수용체의 발현은 과립구가 증가하는 감염질환에서 변화한다고 알려져 있으나, 백혈구 증가증에서 과립구수 증가와 관련된 변화에 대해서는 아직 연구된 바가 없다. 본 연구에서는 백혈구 증가증 환아와 정상아의 혈중 G-CSF와 GM-CSF의 농도를 측정하고 말초혈액의 과립구 표면에 존재하는 이들의 수용체를 정량분석하였으며, 활동성이 있는 수용체 발현 양에는 어떤 변화가 있는 지를 분석하여 백혈구 증가증 환아의 과립구 수 증가와 G-CSF와 GM-CSF 및 이들 수용체 변화의 관련성을 규명하고자 하였다. 방 법 : 정상 대조군으로서 비감염성 질환으로 입원한 같은 연령대의 아동 중 말초혈액 백혈구 수 및 중성구 수가 정상인 아동 13명과 급성기 초기의 백혈구 증가증 환아 14명, 총 27명의 혈중 G-CSF와 GM-CSF의 농도를 측정하였고 세포표면 G-CSFr와 GM-CSFr의 발현양은 각각 항 G-CSF 수용체 단 클론항체, 항 GM-CSF 수용체 단클론항체와 혼합 후 유세포 분석기를 이용하여 정량적으로 분석하였으며, 활동성 G-CSFr, GM-CSFr의 양적변화를 유세포 분석기를 이용하여 측정하였다. 결 과 : 백혈구 증가증 환아의 총 백혈구 수는 $24,100{\pm}6960/{\mu}L$로 정상 대조군 $8,680{\pm}378/{\mu}L$에 비해 유의하게 증가되었으며 중성구 수는 백혈구 증가증 환아에서 유의하게 증가되어 있었으나($20,800{\pm}2120/{\mu}L$ vs $3,360{\pm}2,120/{\mu}L$) 단구수는 차이가 없었다. 혈중 G-CSF의 농도 $164.0{\pm}187.5pg/mL$는 정상 대조군 $71.9{\pm}94.1pg/mL$과 감소된 경향을 보였으나 통계적으로 유의한 차이가 없었고(P=0.217) 혈중 GM-CSF의 농도도 유의한 차이가 없었다(P=0.968). 백혈구 증가증 환아의 중성구의 G-CSFr 발현양 $963.6{\pm}575.7$은 정상대조군 $1711.1{\pm}452.6$에 비해 유의한 감소를 보였으며(P=0.012), 백혈구 증가증 환아의 중성구의 GM-CSFr의 발현양 $471.7{\pm}217.0$은 정상 대조군의 $854.8{\pm}383.0$과 통계적으로 유의한 차이가 없었다(P=0.220). 항 G-CSFr항체는 수용체가 G-CSF와 결합하고 나면 수용체에 결합하지 못하는 epitope에 대한 항체로 보여지며, 수용체를 포화시키기에 충분한 과량의 CSF와 배양시킨 후 포화농도에도 결합하지 않은 수용체의 양을 측정하면 남은 수용체 즉, 활동성 수용체 수는 감소하게 되는데, 백혈구 증가증 환아에서 과량의 G-CSF에 배양한 후 감소된 중성구 G-CSFr의 발현양은 $407.8{\pm}405.1$로 정상 대조군의 $1,012.2{\pm}488.5$에 비해 유의한 감소를 보였고(P=0.050), 혈중 G-CSF 농도 및 혈중 GM-CSF 농도와 무관하였다(P=0.735, P=0.087). 백혈구 증가증 환아와 정상대조군에서 수용체를 포화시키기에 충분한 과량의 GM-CSF에 배양한 후 중성구의 GM-CSFr의 발현양을 분석한 결과는 발현이 증가된 소견을 보였다. 증가된 중성구의 GM-CSFr의 발현 양은 정상아 및 백혈구 증가증 환아에서 유의한 차이가 없었다(P=0.828). 결 론 : 백혈구 증가증에서는 중성구 수 증가에 의하여 총 백혈구 수가 증가되고 혈중 G-CSF의 농도는 중성구 증가의 원인으로 생각되며 G-CSFr과 결합하여 백혈구 증가증을 일으키는 것으로 보인다. GM-CSF 농도 및 GM-CSFr은 백혈구 증 Purpose : Granulocyte-colony stimulating factor(G-CSF) and granulocyte macrophage-colony stimulating factor(GM-CSF) are principal cytokines in granulopoiesis and their physiologic effects are mediated through binding to specific cell surface receptors. Although it is known that the level of serum G-CSF and GM-CSF, and presentation of the receptors are increased in infectious diseases, there have been no studies to find the correlation between the granulopoiesis and leukocytosis. This study was designed to measure G-CSF and GM-CSF in leukocytosis and in control and to demonstrate the possible pathogenesis of granulopoiesis in leukocytosis using quantitative analysis of G-CSF, GM-CSF and their CSFr. Methods : The plasma levels of G-CSF, GM-CSF of 13 children without leukocytosis and 14 children with leukocytosis were measured. Counts of cell surface G-CSFr and GM-CSFr were measured by combining anti G-CSFr and anti GM-CSFr monoclonal antibodies to their respective receptors by using quantitative flow cytometric assay. Results : There was no significant difference betweeen the plasma concentration of G-CSF and GM-CSF in acute leukocytosis and in the control group. However, levels of G-CSFr in acute leukocytosis decreased significantly compared to the control(P=0.012) and the levels of GM-CSFr in both groups revealed no significant difference. Conclusion : Increase in the number of leukocyte in leukocytosis was mediated by increasing the number of neutrophil, and increased plasma concentration of G-CSF may be the cause of neutrophilia. But GM-CSF did not have any influence on leukocytosis.

훈연공정을 첨가하여 제조한 발아콩 청국장의 품질특성

최원석,박화영,최웅규,Choi, Won-Seok,Park, Hwa-Young,Choi, Ung-Kyu 한국식품영양학회 2015 韓國食品營養學會誌 Vol.28 No.3

The aim of this study is to investigate the changes in the quality characteristics of cheonggukjang made with germinated soybeans, which is produced by the addition of a smoking process. The L value of smoked cheonggukjang made with germinated soybeans (SCGS) was higher than that of non-smoked cheonggukjang made with non-germinated soybeans (NCNS) and non-smoked cheonggukjang made with germinated soybeans (NCGS). The a value of NCNS was the highest, followed by NCGS and SCGS. The b and ${\Delta}T$ values had a similar tendency compared with the L value. The amino acids in NCGS were significantly decreased compared with NCNS, whereas no remarkable difference in amino acid content was observed between NCGS and SCGS. The moisture content of NCGS ($61.9{\pm}0.9%$) was increased by more than 8% compared with that of NCNS ($53.3{\pm}0.7%$). The moisture content of SCGS was significantly decreased compared with NCGS, whereas the moisture content of SCGS was higher than that of NCNS. The pH of SCGS was significantly the highest, followed by NCGS and NCNS. The viscous substance content of NCGS was significantly increased compared with that of NCNS. No remarkable difference in viscous substance content was observed between NCGS and SCGS. The number of aerobic bacteria in SCGS was significantly decreased compared with NCGS. The levels of total isoflavone in NCNS, NCGS, and SCGS were $1,573.9{\pm}62.5$, $1,759.1{\pm}65.8$, $1,738.0{\pm}68.1mg%$, respectively.

열처리온도에 따른 다이아몬드상 카본박막의 구조적 특성변화

최원석,박문기,홍병유,Choi Won-Seok,Park Mun-Gi,Hong Byung-You 한국전기전자재료학회 2006 전기전자재료학회논문지 Vol.19 No.8

In addition to its similarity to genuine diamond film, diamond-like carbon (DLC) film has many advantages, including its wide band gap and variable refractive index. In this study, DLC films were prepared by the RF PECVD (Plasma Enhanced Chemical Vapor Deposition) method on silicon substrates using methane $(CH_4)$ and hydrogen $(H_2)$ gas. We examined the effects of the post annealing temperature on the structural variation of the DLC films. The films were annealed at temperatures ranging from 300 to $900^{\circ}C$ in steps of $200^{\circ}C$ using RTA equipment in nitrogen ambient. The thickness of the film and interface between film and substrate were observed by surface profiler, field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), respectively. Raman and X-ray photoelectron spectroscopy (XPS) analysis showed that DLC films were graphitized ($I_D/I_G$, G-peak position and $sp^2/sp^3$ increased) ratio at higher annealing temperature. The variation of surface as a function of annealing treatment was verified by a AFM and contact angle method.

장기숙성 한식간장의 숙성 기간별 품질 특성 비교

최원석,이난희,최웅규,Choi, Won-Seok,Lee, Nan-Hee,Choi, Ung-Kyu 한국식품영양학회 2019 韓國食品營養學會誌 Vol.32 No.5

In this study, the quality characteristics of 30 kinds of long-term matured soy sauce collected from all over Korea classified according to ripening period were analyzed. The longer the soy sauce had to matured, the closer the pH was to neutrality. Acidity decreased as the ripening period increased. Total nitrogen and amino nitrogen content increased as the soy sauce matured. Moisture content decreased with the increasing soy sauce ripening period, and the content of pure extracts increased in proportion to the ripening period. The numbers of bacteria, fungi, and yeast increased in proportion to the maturation period. The content of P was highest in all soy sauce analyzed, followed by K, Ca, Mg, Fe and Zn. Mg and Ca contents decreased with maturing, whereas K increased with maturing.