TFT-LCD 백라이트 유닛(BLU) 램프용 전극 미세 접합부의 강도 및 미세조직

김광수,김상덕,Kim, Gwang-Soo,Kim, Sang-Duck 한국재료학회 2009 한국재료학회지 Vol.19 No.1

TFT-LCD is the most popular type of flat display panel in the information technology field. The back light unit is a main part of the structure of a TFT-LCD panel. Occasionally, studies have shown that failures of the CCFL of the BLU occur due to the poor weld characteristics of these materials. The aim of this study was to prepare some technical data and to characterize a microjoined electrode for the CCFL. Microstructure examinations, microhardness measurements, resistance measurements and microtensile tests of the microjoined electrode were carried out. The result indicates that a large amount of grain coarsening exists in the heat-affected zone (HAZ) of the weld between the cup and the pin. This grain coarsening of the HAZ between the cup and pin is caused by the welding cycle, which may have an influence on the lowest microhardness values. Fracturing of the microjoined electrode also occurred at the HAZ close to the cup between the weld holding the cup and the pin. Additionally, no specific changes of the electrical resistance among the cup, pin, and lead wire themselves or in the microjoined electrode were observed.

페로 소재로 만들어진 고크롬계 내마모재의 미세조직과 경도

김광수,Kim, Gwang-Soo 한국재료학회 2006 한국재료학회지 Vol.16 No.1

This study was performed to investigate the characteristics of the synthesized powder type ferro materials for wear resistant hardfacing. The powder type filler materials were made from ferro Cr and ferro Mn. Those ferro materials are two types, such as high carbon and low carbon contained. The alloy composed of high carbon ferro Cr and high carbon ferro Mn exhibited the best properties in terms of microstructure and hardeness for wear characteristics. Further, the alloys produced by the synthesized powders and wire type filler, were also evaluated in terms of microstructures and microhardness measurements. The results indicated that the synthesized powders displayed reasonable properties compared to commercial grade materials. The hardness value of the alloy produced by the synthesized powders were approached about 90% of the commercial grade's hardness. The hardness values of the alloys closely depended on the amount of the dissolution of the ferro Cr, the hardness and the volume of the eutectic phase.

치과 치료학에서 적용되는 접합기술 연구 ; 스테인리스강 크라운에 접합된 직접용 콤포짓트 레진과 간접용 콤포짓트 레진의 전단결합강도 비교

김광수,백광우,Kim, Gwang-Soo,Baek, Kwang-Woo 대한용접접합학회 2011 대한용접·접합학회지 Vol.29 No.4

This study was performed to compare the shear strength of the bondings between stainless steel crown/direct type composite resin and stainless steel crown/indirect type composite resin. Four groups of bonding conditions were prepared. Two groups of bonding conditions were made by the indirect type composite resin system and the other two groups were made by the direct type composite resin system. The shear strength tests were carried out using universal testing machine, Model 4465 of Instron Co.. It was indicated that the bond strength values of the indirect type composite resins were higher than those of the direct type composite resins. TE-SE group was superior to the TE-ONE in indirect type resin system. These results were thought to be the high degree of the polymerization accompanied with temperature and pressure of the resin of indirect type resin. It was also found that indirect composite resin contains less amount of porosity in resin.

미세 용접된 BLU CCFL 전극의 유리비딩 열처리 온도에 따른 접합부 특성

김광수,김상덕,권혁동,Kim, Gwang-Soo,Kim, Sang-Duck,Kwon, Hyuk-Dong 대한용접접합학회 2009 대한용접·접합학회지 Vol.27 No.4

Characterization of the microweld CCFL electrode for the TFT-LCD backlight unit was carried out in terms of the glass beading heat treatment conditions. We evaluate the weld zone and parent metal of the microweld CCFL electrodes that were exposed to simulated glass beading heat treatment. The CCFL electrode was composed of the cup made with pure Ni, the pin made with pure Mo and the lead wire made with Ni-Mn alloy. Each part of the electrode was assembled together by micro spot welding process and then the assembled electrodes were exposed to simulated glass beading temperatures of $700^{\circ}C,\;750^{\circ}C$ and $800^{\circ}C$. The microstructures of the microweld CCFL electrode were observed by using optical microscope, scanning electron microscope and EDS. Micro-tensile and microhardness test were also carried out. The results indicated that the grain coarsening in the HAZs(heat affected zones) for both the cup-pin weld and pin-lead wire were exhibited and the grain coarsening of the HAZ for the cup and the lead wire was more obvious than the HAZ of the pin. The micro-tensile test revealed that the fracture occurred at the cup-pin weld zone for all test conditions. The fracture surface could be classified into two parts such as pin portion and cup portion including weld nugget. The failure was seemed to be initiated from the boundary between nugget and pin through the weld joint. The result of the microhardness measurement exhibited that the relatively low hardness value, about 105HV was recorded at the HAZ of the cup. This value was about 50% less than that of the original value of the cup. The reduction of the microhardness was considered as the cause of the grain coarsening due to welding process. It was also appeared that there was no change in electric resistance for the standard electrodes and heat treated electrodes.

초분광영상을 이용한 하천조류종 분류에 관한 연구

김광수(Kim, Gwang Soo),최재윤(Choi, Jae Yun),김영도(Kim, Young Do),권재현(Kwon, Jae Hyun) 대한토목학회 2022 대한토목학회 학술대회 Vol.2022 No.10

국내 이상기후 변화로 인해 하천 및 호소에 조류의 과대성장이 빈번히 발생하고 있다. 하천조류는 크게 녹조류, 남조류, 규조류로 분류되며, 이 중 남조류의 일부 종은 악취유발, 독성물질의 배출로 많은 문제를 발생시키고 있는 실정이다. 국내에서 조류경보제, 수질예보제를 시행하고 있으며, 이는 유해남조류세포수와 Chl-a농도에 따라 발령이 된다. 현재 조류 분석방법은 현장샘플을 하여 조류검경을 통해 산정하기 때문에 시간이 많이 소요되고 있는 실정이다. 조류발생시 즉각대응이 힘들고 조류 발생 현장에서 육안으로 유해남조류인지 구별하기 어렵다. 최근 원격탐사를 통한 조류연구가 활발히 진행되고 있으나, 조류의 대체인자인 Chl-a, Phycocyanin을 통해 조류농도를 분석하고 있으며, 광합성을 하는 모든 조류에는 Chl-a가 함유되어 있어 남조류와 녹조류를 정확하게 구별하는데 한계점이 있다. 따라서 본연구에서는 조류배양액을 초분광센서를 통해 조류스펙트럼을 취득하고, 남조류와 녹조류의 흡수, 방출 스펙트럼을 추출하여 남조류와 녹조류를 분류하였다.

은계(BAg) 삽입금속으로 접합된 초경합금 업자와 탄소강 브레이징부의 특성

김광수(Kim, Gwang-Soo),김상덕(Kim, Sang-Duck) 한국산학기술학회 2008 한국산학기술학회논문지 Vol.9 No.2

초경합금입자와 탄소강사이의 브레이징 접합부 특성을 평가하였다. 선택된 두 종류의 삽입금속은 기계적 합금 공정으로 만들어졌다. 한 가지는 Cu, Zn, Ag(MIM-1) 그리고 다른 한 가지는 Cu, Zn, Ag과 Cd(MIM-2)로 구성하였다. 삽입금속들의 화학조성은 AWS BAg-20계와 BAg-2a계의 성분과 유사하였다. 그리고 상용삽입금속들(CIM-1, CIM-2) 역시 비교 평가하였다. 삽입금속들의 특성은 젖음성 시험, 전단강도 시험, 그리고 미세조직 관찰로서 나타내었다. 젖음성 시험에서 MIM-1과 CIM-1 삽입금속의 젖음각이 MIM-2와 CIM-2보다 크게 나타났고, MIM-1의 젖음각이 CIM-1보다 더 큰 값을 나타났지만 모든 경우 젖음각이 25°보다 작았다. 삽입금속, MIM-1이 가장 높은 전단강도를 나타냈고, 그 값은 2.29×10²㎫로 측정되었다. 이 값은 상용 삽입금속의 값과 같거나 높은 것으로 나타났다. 삽입 금속의 미세조직은 Cu-rich 초정영역과 Ag-rich 공정영역으로 구성되었다. MIM-1계로 만들어진 초경합금과 탄소강의 접합부는 일부 접합부 계면에 기공을 포함하지만 초정을 기지로 하는 안정적인 미세조직을 나타냈다. This study was carried out to evaluate brazing characteristics of the braze joint between superhard alloy particles and carbon steel. Two types of insert metals that made by mechanical alloying process were selected for this study. One is composed of Cu, Zn and Ag(MIM-1) and the other one is composed of Cu, Zn, Ag and Cd.(MIM-2) The chemical compositions of these insert metals were similar to AWS BAg-20 and BAg-2a system. And the commercial insert metals(CIM-1, CIM-2) were also evaluated for the comparative study. The characterization of the insert metals were conducted by wettability tests, shear tensile test and microstructural analyses. The results indicated that wettability tests displayed that MIM-1 and CIM-1 insert metals had the larger wetting angle than MIM-2 and CIM-2 and the wetting angle of the MIM-1 showed higher value than that of CIM-1. However these values are less than 25° that is recommended for standard value for usual insert metals. The highest value of shear tensile tests was obtained from the brazed joint that made by MIN-1 and the value was 2.29×10²㎫. This value is appeared to be higher or same as the commercial insert metals. The microstructures of the inserts metals were composed of Cu-rich proeutectic structure for matrix and Ag-rich eutectic structure. The braze joint between superhard alloy particles and carbon steel produced by the MIM-1(Ag-Cu-Zn) system showed sound joint showing stable microstructures. However there was also some porosities at the interface.

은행(Ginkgo biloba L.)의 세포배양에 의한 Flavonoid류의 검출

김광수(Gwang-Soo Kim),백윤웅(Yun-Woong Paek),고경민(Kyeong-Min Ko),황성진(sung-Jin Hwang),김영준(Young-Jun Kim),정상진(Sang-Jin Chung),황백(Baik Hwang) 한국생물공학회 1996 KSBB Journal Vol.11 No.1

분산객체기반 Web Server의 설계 및 구현

김광수(Gwang-Soo Kim),정연홍(Youn-Hong Jung),박규석(Kyoo-Seok Park) 한국멀티미디어학회 1999 한국멀티미디어학회 학술발표논문집 Vol.1999 No.2

분말 혼합 공정으로 만들어진 은계 삽입금속의 특성

김광수(Kim, Gwang-Soo),김상덕(Kim, Sang-Duck) 한국산학기술학회 2008 한국산학기술학회논문지 Vol.9 No.2

Ag계 분말 삽입금속을 볼 밀링법으로 제조하였다. 밀링공정의 변수들은 밀링시간을 제외하고는 일정하게 하였고 밀링 시간은 24, 48, 72시간들로 정하였다. 밀링에 의해 제조된 삽입금속들은 SEM관찰, DSC분석, 퍼짐성, 젖음성 시험을 통해 평가하였다. 삽입금속들의 브레이징부 특성은 상용금속에 비하여 우수하였다. 48시간 동안 밀링한 삽입금속이 퍼짐성과 젖음 특성이 가장 우수한 조건임을 나타냈다. 또한 브레이징부는 작은 양의 기공을 포함하고 있지만 안정적인 미세조직을 보였고 미세경도는 138VHN으로 나타났다. Powder type Ag system insert metals were manufactured by ball milling process. The variables of milling process were constant except the milling time. The milling times were selected for 24, 48 and 72 hours. The insert metals made by milling process were evaluated by performing scanning electron microscope, DSC(differential scanning calorimetry) analyses, spreading test and further in terms of wettability test. The selected insert metals that have the good characteristics compared to commercial insert metals were applied to make the brazed joints. The characterizations of those brazed joints were also conducted by microstructural observations. The results indicated that milling time of 48 hours for making powder type insert metals was the best condition showing the good spreadibility, low wetting angle. The brazed joints that applied the 48 hours milled insert metal were very sound condition indicating the stable microstructure in spite of containing small amount of porosity and the microhardness value of the joint was about 138VHN.

IPv4/IPv6에서 응용 서비스의 성능 측정 모델 설계

김광수(Gwang-soo Kim),김광현(Gwang-hyun Kim) 한국통신학회 2003 한국통신학회 학술대회논문집 Vol.2003 No.7