Top-GaP 상부에 나노 크기의 Roughness 처리에 의한 AlGaInP 고휘도 LED의 휘도 향상

소순진,하헌성,박춘배,So, Soon-Jin,Ha, Hun-Sung,Park, Choon-Bae 한국전기전자재료학회 2008 전기전자재료학회논문지 Vol.21 No.1

AlGaInP high-brightness LEDs(HB-LEDs) have gained importance a variety of application operating in the red, orange, yellow and yellow-green wavelength. The light generated from inside LED chips should be emitted to the air through the surfaces of the chips. However, because of the differences between the semiconductor and air or epoxy's refractive index, some of the light was blocked so that caused lowering external quantum efficiency. In this study, nano-scale roughness on the top-GaP layer of AlGaInP epitaxial wafer was fabricated to improve' the brightness of AlGaInP LEDs. Nano-scale roughness was made by ICP dry etcher. Our AlGaInP LEDs with nano-scale roughness has higher brightness (about 28.5 %) than standard AlGaInP LEDs.

해외조림투자의 경제적 타당성 분석 - 파라과이 동부지역 Caaguazu주를 중심으로 -

소순진,김형호,이창배,김세빈 경상대학교 농업생명과학연구원 2017 농업생명과학연구 Vol.51 No.5

본 연구는 파라과이에 대한 조림투자의 경제적 타당성을 분석하기 위하여 수행되었다. 한국은 목재자 급률이 낮아 90년대 초반부터 적극적인 해외조림투자에 나서고 있으나, 그 투자의 대부분이 동남아시아 에 집중되어 있다. 이러한 상황에서 조림목 생장이 우수하고 적극적인 조림 지원 정책을 추진하고 있는 파라과이는 한국의 해외조림투자 대상지로서 훌륭한 대안이 될 수 있다. 하지만 지구 반대편이라는 지 정학적 위치에 대한 거리감으로 인하여 한국기업은 파라과이 해외조림투자에 대하여 적극적으로 검토하 지 않고 있다. 파라과이 조림투자에 대한 정보가 부족한 것도 기업의 접근을 막는 하나의 요인이며, 우 선적으로 조림사업의 수익성에 대한 자료가 요구된다. 본 연구에서는 파라과이 해외조림투자를 파라과 이 내수 시장에서의 원목 판매와 현지 위탁가공 후 한국시장으로의 제재목 수출, 두 가지 경우에 대하 여 경제적 타당성을 분석하였다. 그 결과, 두 시나리오 모두 높은 경제적 타당성을 가지고 있는 것으로 분석되었다. 원목의 내수시장 판매의 경우, IRR 9.64%, NPV U$ 2,811,888로 나타났다. 제재목 한국 수출의 경우, IRR은 17.51%로 현지원목판매 대비 7.87%p 상승하였고, NPV는 U$ 38,260,086로 현지 원목판매 대비 U$ 35,448,198 상승하였다. 본 연구는 원거리라는 점으로 인해 외면 받아온 남미, 특히 파라과이 조림 진출에 대한 가능성을 새롭게 분석한 것에 큰 의의가 있다하겠다. The purpose of this study is to analyze the economic feasibility of overseas plantation investment in Paraguay. Korea has been actively investing in overseas plantation since the early 1990s due to its low self-sufficiency rate of raw material. In this situation, Paraguay can be a promising alternative for overseas plantation investment with its excellent plantation growth and favorable reforestation support policy. However, due to the concern on the geographical distance of Paraguay located on the opposite side of the globe, there has been no active consideration of overseas plantation investment in Paraguay. Lack of information is another factor of low plantation investment in Paraguay, and data on the profitability of project is preferentially required. Therefore, this study analyzed the economic feasibility of the overseas plantation investment in Paraguay for two cases; 1) logs sale in domestic market and 2) swan wood exportation to Korean market. The results showed that both scenarios have high profitability validity. For domestic market sale of logs, IRR was 9.64% and NPV was U$ 2,811,888. In case of export of swan wood to Korea, IRR was 17.51% and NPV was U$ 38,260,086, which were higher than the logs sale in Paraguay respectively by 7.87%p and U$ 35,448,198. This study has a special significance in introducing the possibility of overseas plantation investment in South America, especially Paraguay, which has not been considered due to geographic distance.

MgO 첨가에 따른 ZnO 세라믹 바리스터의 안정성 향상에 관한 연구

소순진,김영진,박춘배 한국전기전자재료학회 2002 전기전자재료학회논문지 Vol.15 No.5

The degradation characteristics of MgO additive for the ZnO ceramic devices fabricated by the standard ceramic techniques are investigated in this study. These devices were made from basic Matsuoka's composition. Especially, MgO was added to analyze the degradation characteristics and devices were sintered in air at $1200^{\circ}C$. The conditions of DC degradation test were $115\pm2^{\circ}C$ for 12h. Using XRD and SEM, the phase and microstructure of samples were analyzed, respectively. The elemental analysis in the microstructures was performed by EDS, E-J analysis was used to determine $\alpha$. Frequency analysis was accomplished to understand the relationship between $R_G$ and $R_B$ with the electric stress at the equivalent circuit.

조명용 LED 테마기획을 내면서

소순진,So, Sun-Jin 한국전기전자재료학회 2009 전기전자재료 Vol.22 No.10

분위기 소결공정에 의해 제조된 ZnO 세라믹 바리스터의 열화기구 연구

소순진,김영진,박춘배 한국전기전자재료학회 2000 전기전자재료학회논문지 Vol.13 No.5

The relationship between the DC degradation characteristics of the ZnO varistor and the ambient sintering-process is investigated in this study. ZnO varistors made o matsuoka’s composition were fabricated by standard ceramic techniques. The ambient sintering-process is performed at the extraordinary electrical-furnace which is equipped with the vacuum system. Gases used in sintering process were oxygen nitrogen argon and air. Using XRD and SEM the phase and microstructure of samples were analyzed respectively. The conditions of DC degradation tests were conducted at 115$\pm$2$^{\circ}C$ for 13 h. Current-voltage analysis is used to determine nonlinear coefficients($\alpha$). Frequency analysis are performed to understand electrical properties as DC degradation test. From above analysis it is found that the ZnO varistor sintered in oxygen atmosphere showed superior properties at the DC degradation test and degradation phenomenon of ZnO varistor is caused by the change of electrical properties in grain boundary. These results are in accordance with Gupta’s degradation model.

Undoped ZnO 박막에 Ampoule-tube 방법을 이용한 P와 As의 확산과 p형 ZnO 박막의 전기적 특성

소순진,왕민성,박춘배,So, Soon-Jin,Wang, Min-Sung,Park, Choon-Bae 한국전기전자재료학회 2005 전기전자재료학회논문지 Vol.18 No.11

To investigate the electrical properties of the ZnO films which are interested in the next generation of short wavelength LEDs and Lasers, our ZnO thin films were deposited by RF sputtering system. At sputtering process of ZnO thin films, substrate temperature, work pressure respectively is $300^{\circ}C$ and 5.2 mTorr, and the purity of target is ZnO 5N. The thickness of ZnO thin films was about $2.1\;{\mu}m$ at SEM analysis after sputtering process. Phosphorus (P) and arsenic (As) were diffused into the undoped ZnO thin films sputtered by RF magnetron sputtering system in ampoule tube which was below $5\times10^{-7}$ Torr. The dopant sources of phosphorus and arsenic were $Zn_3P_2$ and $ZnAs_2$. Those diffusion was perform at 500, 600, and $700^{\circ}C$ during 3 hr. We found the diffusion condition of the conductive ZnO films which had n- and p-type properties. Our ZnO thin film has not only very high carrier concentration of above $10^{17}/cm^3$ but also low resistivity of below $2.0\times10^{-2}\;{\Omega}cm$.

차량용 백색 LED 패키지의 색 좌표 품질 개선

소순진,정충우,문태을,김정빈,홍성훈,So, Soon Jin,Jeoung, Choung Woo,Moon, Tae Eul,Kim, Jeong Bin,Hong, Sung Hoon 한국품질경영학회 2022 품질경영학회지 Vol.50 No.3

Purpose: The purpose of this paper is to improve the chromaticity coordinate quality of white LED packages for automobiles that require high quality and reliability. Methods: The project follows the structured methodology of the Six Sigma DMAIC Roadmap, which consists of Define, Measure, Analyze, Improve and Control phases. Results: A CTQ is determined based on COPQ analysis, and a process map and a XY matrix are utilized for selecting process input variables. Three vital Few Xs are identified through data analysis; amount to mix at one time, deviation by head pumps, and deviation by production magazines, and process improvements are performed for each of the three vital Few Xs. Conclusion: The improved process conditions for the three vital Few Xs are applied to the production line, and the results show that the percent defective of chromaticity coordinate has improved from 1.59% to 0.63% and a financial effect of about 50 million won per year is obtained.

ZnO 바리스터의 단입계면 분석을 위한 마이크로 전극 제작과 전기적 특성 해석

소순진,임근영,박춘배,So, Soon-Jin,Lim, Keun-Young,Park, Choon-Bae 한국전기전자재료학회 2005 전기전자재료학회논문지 Vol.18 No.3

To investigate the electrical properties at the single grainboundary of ZnO varistors, micro-electrodes were fabricated on the surface which was polished and thermally etched. Our micro-electrode had 2000 $\AA$ silicon nitride layer between micro-electrode and ZnO surface. This layer was deposited by PECVD and etched by RIE after photoresistor pattering process using by mask 1. The metal patterning of micro-electrodes used lift-off method. We found that the breakdown voltage of single grainboundary is about 3.5∼4.2 V at 0.1 mA on I-V curves. Also, capacitance-voltage measurement at single grainboundary gave several parameters( $N_{d}$, $N_{t}$, $\Phi$$_{b}$, t) which were related with grainboundary.ary.

ZnO 바리스터의 등가회로 분석을 통한 DC 열화특성의 향상과 진단

소순진(Soon-Jin So),김덕규(Deok-Kyu Kim),김영진(Young-Jin Kim),소병문(Byung-Moon So),박춘배(Choon-Bae Park) 대한전기학회 1999 대한전기학회 학술대회 논문집 Vol.1999 No.11

A Study on Improvement of Electrical Stability in Semi-Conducting ZnO Ceramic Varistors Sintered in Oxygen Ambient

박춘배,소순진,김영진 원광대학교 2001 論文集 Vol.26 No.-

산소, 대기, 질소 아르곤 분위기에서 각각 서로 다른 4 종류의 시편이 소결되어졌다. 이들 4 종류에 대한 열화 특성을 연구하기 위해 115℃에서 가속 DC 열화시험이 이루어졌다. 미세구조 내에서 원소들의 분석을 위해 전자현미분석기(EPMA)가 이용되어졌다. DC 열화시험 이전의 전기적 특성의 모든 시편에 대해 거의 비슷한 특성을 보였으나, 열화시험 이후에는 각각의 시편에 대해 큰 차이를 보였다. 열화시험 이후에 4 종류의 시편들 중 산소분위기에서 소결된 ZnO 바리스터가 가장 우수한 특성을 보였으며, 이들 결정립에서 Zn 원소는 가장 많이 존재하고 O원소는 가장 적게 존재함을 밝혔다. Four different samples of ZnO ceramic varistors were sintered in oxygen, air, nitrogen and argon ambient, respectively. To investigate the degradation characteristics for these four samples, an accelerated DC degradation test was performed at 115℃ , Electron Probe Microanalysis (EPMA) was used to analyze the elemental content in microstructure, The samples have very similar electrical properties before the DC degradation test. After, however, each of the samples shows significant difference. It was found that ZnO varistors sintered in oxygen ambient show superior properties after the degradation test, the their gains have the highest Zn and the lowest 0 elements content among four samples. KEYWORDS : ZnO, varistor, degradation, EPMA, ambient sintering