• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2010년도 춘계학술발표대회 초록집
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• pp.82-82
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• 2010

표면실장 공법을 통해 CSP 패키지를 보드에 실장 하는데 있어 무연솔더 접합부의 신뢰성에 영향을 미치는 인자 중 가장 중요한 것은 접합부에 형성되는 IMC (Intermetallic compound, 금속간화합물)인 것으로 알려져 있다. 접합부의 칩 부분에는 솔더와 칩의 UBM (Under bump metalization)이 접합하여 IMC가 형성되나, 보드 부분에는 솔더와 보드의 UBM 뿐만 아니라 그 사이에 솔더 페이스트가 함께 접합되어 IMC가 형성된다. 본 연구에서는 패키지의 신뢰성 연구를 위해 솔더 페이스트의 유무 및 두께에 따른 무연 솔더 접합부의 미세조직의 변화를 분석하였다. 본 실험에서는 Sn-3.0(Wt.%)Ag-0.5Cu 조성과 본 연구진에 의해 개발된 Sn-Ag-Cu-In 조성의 직경 $450{\mu}m$ 솔더 볼을 사용하였으며, 솔더 페이스트는 상용 Sn-3.0Ag-0.5Cu (ALPHA OM-325)를 사용하였다. 칩은 ENIG (Electroless nickel immersion gold) finish pad가 형성된 CSP (Chip scale package)를, 보드는 OSP (Organic solderability preservative)/Cu finish pad가 형성된 것을 사용하였다. 실험 방법은 보드를 솔더 페이스트 없이 플라즈마 처리 한 것, 솔더 페이스트를 $30{\mu}m$ 두께로 인쇄한 것, $120{\mu}m$의 두께로 인쇄한 것, 이렇게 3가지 조건으로 준비한 후, 솔더 볼이 bumping된 칩을 mounting하여, $242^{\circ}C$의 peak 온도 조건의 oven(1809UL, Heller)에서 reflow를 실시하여 패키지를 형성하였다. 이후 시편은 정밀 연마한 후, OM(Optical Microscopic)과 SEM(scanning electron microscope) 및 EDS(energy dispersive spectroscope)를 사용하여 솔더 접합부 IMC의 미세조직을 관찰, 분석하였다.

• 한국염색가공학회지
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• 제21권1호
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• pp.1-9
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• 2009

A lot of research has been made over the recent decade to develop testing packages with antimicrobial properties to improve food safety. In this study, a new method, experimental device and technology for environmental corresponding packages of polypropylene (PP) film has been developed to provide effective temperature buffering during the transport/long-term storage of grains or foodstuffs from the supplier to the market. This quantitatively optimized mixing system enabled to produce PP films with the 700$\sim$1,400d (width;1.5$\sim$3mm, thickness;0.01$\sim$0.5mm). In the whole mixing systems, the finely-granulated inorganic illite and PP virgin chip for master batch (M/B) chip was calculated by digital measurement methods, and then the M/B chip for PP film was adapted through a air jet and PP grinding method. The prepared PP film was characterized with tensile strength and elongation, far infrared radiation (FIR) emissivity, antimicrobial activity and deodorization properties. The results revealed that the two differently grain-sized illite could be show homogeneously dispersed on PP chip surface, and as the increasing of illite content, the FIR emissivity and the anion emission rate of film was increasingly improved. In both of 325 and 1,500 mesh-sized illite contained PP chip, of course the antimicrobial activity was good. But the ultimate deodorization rate for ammonia gas of PP film were found to be approximately the same.

• 한국전기전자재료학회논문지
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• 제26권8호
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• pp.614-619
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• 2013

Recently, remote phosphor is reported for white LED enhancing of phosphor efficiency compared with conventional phosphor-based W-LED. In this study, Remote phosphor was produced by screen printing coating on glass substrate with phosphor contents rated paste and heat treatment. The paste consists of phosphor, lowest softening glass frit and organic binders. Remote phosphor can be well controlled by varying the phosphor content rated paste. After mounting remote phosphor on top of blue LED chip, CCT, CRI, and luminance efficiency were measured. The measurement results showed that CCT, CRI, and luminance efficiency were 6,645, 68, and 1,16l m/W in phosphor 80 wt.% remote phosphor sintered at $600^{\circ}C$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.36-36
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• 2007

본 논문에서는 SoP-L(System on Package-Laminates) 기술을 이용하여 이종의 유전율을 가진 유기물 적층 기반의 수동소자를 이용한 GSM/DCS 대역 분리용 diplexer를 설계, 제작하였고 그 특성을 고찰하였다. SoP-L 기술은 LTCC기술과 같은 타 SoP 기술과 비교해서 이종의 물질을 접합하는데 용이하고 공정비용이 저렴하다. 이러한 장점을 이용하여 캐때시터는 유전율 40의 고유전율 재료를 사이에 두고 구성하였고, 인덕터 부문에는 유전율 4률 적용, 정방혈 스파이럴 구조로 두 개 층으로 구성하여 소형화를 이룰 수 있었다. 제작 시에 구리와 유기물을 적층, patterning 하였고, 수직 via hole 을 형성하고 구리의 무전해, 전해 도금 과정을 거쳐 각 소자를 연결하였다. 이러한 과정을 거쳐 제작된 diplexer의 GSM 저역 통과 필터는 0.52 dB이하의 삽입손실과 20 dB 이상의 반사손실을 가지고 DCS 통과 대역 부근에 notch 가 존재하도록 설계함으로써 DCS 통과 대역에서 17 dB 이상의 저지특성을 나타내었다. DCS 고역 통과 필터는 1.2 dB 이하의 삽입손실과 16 dB 이상의 반사손실을 가지며 GSM 통과 대역 부근에 notch를 가지도록 설계하여 GSM 통과대역에서 32 dB 이상의 저지특성을 나타내었다.

• 한국식생활문화학회지
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• 제24권3호
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• pp.267-278
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• 2009

The purpose of this study was to examine parents' perceptions towards, and the importance and performance levels of, foodservices in child-care centers and to suggest ways to increase foodservice quality and promote efficient operations in the future. A questionnaire survey was provided to 540 parents and the return rates 82%. The survey period was from June 20 to July 27,2007. The collected data were statistically analyzed with the SAS package program using descriptive statistical analysis, t-tests, ANOVA, Duncan's multiple comparisons, factor analysis, and multiple regression analysis. The results were as follows: The parents perceived that foodservice operations promoted their children's health and helped them form desirable dietary habits. The parents also had a high level of perception toward the need for foodservice, earning greater than 4.5 points out of 5 points. Their perceptions of foodservice quality were examined by four dimensions of importance and performance levels. While the parents gave 4 points or greater of 5 points to most quality attributes of importance level, they gave 4 points of less out of 5 points to most quality attributes of performance level. As for the importance and performance levels of the quality dimensions of meal service, the parents regarded sanitation as the most important dimension. IPA showed that 'organic food materials' was included as a 'focus here' area. The overall satisfaction level for foodservice was 3.59 out of 5 points. A higher level of satisfaction was shown when a dietitian was present as well as in public childcare centers. According to multiple regression analysis, 53.51% of the variance in the respondents' overall satisfaction scores was explained by factors such as food, sanitation, environment, and foodservice effects.

• 한국식생활문화학회지
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• 제20권5호
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• pp.574-583
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• 2005

To investigate the importance and practice of well-being related dietary life pattern such as purchasing food materials, food habits and eating out, a survey was conducted by questionnaire and 5-point Likert score in Seoul and Gyeonggi-Do, September, 2004 and April, 2005. The responses of 732 housewives who were over 40 years were analyzed by SPSS package program. The results were as follows. Most of them were 40-49 years(74.4%), graduated highschool (66.6%) and their family type was nuclear family type(81.4%). Almost half of them had full-time job (37.1%) and part time job (15.4%). The average importance score of 'food habits', 'purchasing food materials' and 'eating out' were $4.15{\pm}0.91,\;4.06{\pm}0.96\;and\;3.25{\pm}1.01$ respectively. But the average practice score of 'food habits' was greater($3.58{\pm}1.06$) than 'purchasing food materials ($3.19{\pm}1.19$)' and 'eating out($2.54{\pm}1.05$)'. Among 5 types of 'food habits', the type of 'cut down on eating fast food' had the greatest score of importances ($4.31{\pm}0.97$) but the difference between importance and practice was greatest(0.94). Also 'consume home-made food rather than processed or ready to food' showed great scores in importance ($4.28{\pm}0.87$) and practice($3.87{\pm}1.04$). 'Consume fruits and vegetables rather than meats' and 'avoid heavy use of oils' had the importance score of $4.04{\sim}4.19$. But the practice score of 'avoid heavy use of oils' was the lowest($3.39{\pm}0.97$). Among four types of purchasing of food materials, 'purchase domestic agricultural food' was greatest($4.37{\pm}0.78$) and 'don't purchase genetically modified food' 'purchase organic food' and 'purchase whole grain products' were also great ($3.92{\sim}3.99$). But the practice score of 'purchase organic/low chemical foods($2.77{\pm}0.98$)' and 'don't purchase genetically modified food($2.99{\pm}1.41$)' were lowest. 'Go to well being restaurant' in three types of 'eating out' showed greatest in importance($3.35{\pm}0.96$) but the practice score($2.47{\pm}0.10$) was lower than the importance score. Also 'choose menu with comparing calories' had the lower score in practice($2.45{\pm}1.06$) rather than importance score($3.22{\pm}1.03$). In regarding to 'food habits', the importance score were significantly affected by type of food expense (p<0.05) and health status (p<0.05). The importance score of 'purchase food materials' were significantly affected by the type of food expense (p<0.001), type of residence(p<0.05), and self assessment of weight(p<0.05). Monthly income, especially more 400 million won, was the commonly significant effector in practice score of 'purchase food materials' and 'eating out'.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1253-1253
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• 2001

The ability to accurately assess wine quality is important during the wine making process, particularly when allocating batches of wines to styles determined by consumer requirements. Grape payments are often determined by the quality category of the wine that is produced from them. Wine quality, in terms of sensory characteristics, is normally a subjective measure, performed by experienced winemakers, wine competition judges or winetasting panellists. By nature, such assessments can be biased by individual preferences and may be subject to day-to-day variation. Taste and aroma compounds are often present in concentrations below the detection limit of near infrared (NIR) spectroscopy but the more abundant organic compounds offer potential for objective quality grading by this technique. Samples were drawn from one of Australia's major wine shows and from BRL Hardy's post-vintage wine quality allocation tastings. The samples were scanned in transmission mode with a FOSS NIR Systems 6500, over the wavelength range 400-2500 ㎚. Data analysis was performed with the Vision chemometrics package. With samples from the allocation tastings, the best correlations between NIR spectra and tasting data were obtained with dry red wines. These calibrations used loadings in the wavelengths related to anthocyanins, ethanol and possibly tannins. Anthocyanins are a group of compounds responsible for colour in red wines - restricting the wavelengths to those relating to anthocyanins produced calibrations of similar accuracy to those using the full wavelength range. This was particularly marked with Merlot, a variety that tends to have relatively lower anthocyanin levels than Cabernet Sauvignon and Shiraz. For dry white wines, calibrations appeared to be more dependent on ethanol characteristics of the spectrum, implying that quality correlated with fruit maturity. The correlations between NIR spectra and sensory data obtained using the wine show samples were less significant in general. This may be related to the fact that within most classes in the show, the samples may span vintages, glowing areas and winemaking styles, even though they may be made from only one grape variety. For dry red wines, the best calibrations were obtained with a class of Pinot Noir - a variety that tends to be produced in limited areas in Australia and would represent the least matrix variation. Good correlations were obtained with a tawny port class - these wines are sweet, fortified wines, that are aged for long periods in wooden barrels. During the ageing process Maillard browning compounds are formed and the water is lost through the barrels in preference to ethanol, producing “concentrated” darkly coloured wines with high alcohol content. These calibrations indicated heaviest loadings in the water regions of the spectrum, suggesting that “concentration” of the wines was important, whilst the visible and alcohol regions of the spectrum also featured as important factors. NIR calibrations based on sensory scores will always be difficult to obtain due to variation between individual winetasters. Nevertheless, these results warrant further investigation and may provide valuable Insight into the main parameters affecting wine quality.

• 한국재료학회지
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• 제12권9호
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• pp.750-760
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• 2002

In this study, three solders, Sn-37Pb, Sn-3.5Ag, and Sn-3.8Ag-0.7Cu were screen printed on both electroless Ni/Au and OSP metal finished micro-via PCBs (Printed Circuit Boards). The interfacial reaction between PCB metal pad finish materials and solder materials, and its effects on the solder bump joint mechanical reliability were investigated. The lead free solders formed a large amount of intermetallic compounds (IMC) than Sn-37Pb on both electroless Ni/Au and OSP (Organic Solderabilty Preservatives) finished PCBs during solder reflows because of the higher Sn content and higher reflow temperature. For OSP finish, scallop-like $Cu_{6}$ /$Sn_{5}$ and planar $Cu_3$Sn intermetallic compounds (IMC) were formed, and fracture occurred 100% within the solder regardless of reflow numbers and solder materials. Bump shear strength of lead free solders showed higher value than that of Sn-37Pb solder, because lead free solders are usually harder than eutectic Sn-37Pb solder. For Ni/Au finish, polygonal shaped $Ni_3$$Sn_4$ IMC and P-rich Ni layer were formed, and a brittle fracture at the Ni-Sn IMC layer or the interface between Ni-Sn intermetallic and P-rich Ni layer was observed after several reflows. Therefore, bump shear strength values of the Ni/Au finish are relatively lower than those of OSP finish. Especially, spalled IMCs at Sn-3.5Ag interface was observed after several reflow times. And, for the Sn-3.8Ag-0.7Cu solder case, the ternary Sn-Ni-Cu IMCs were observed. As a result, it was found that OSP finished PCB was a better choice for solders on PCB in terms of flip chip mechanical reliability.

• 방사성폐기물학회지
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• 제17권1호
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• pp.59-73
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• 2019

원자력발전소 운영 과정에서 발생되는 폐기물인 폐수지를 원천적으로 저감하기 위해, 새로운 폐수 정화기술을 개발하고 원전 폐수처리시스템에 가상적으로 적용하여 효용성을 평가하고자 하였다. 본 기술의 기본 원리는 폐수에 존재하는 주요 핵종이온들을 생물학적 혹은 화학적 방법을 통해 무기 결정광물로 바꾸는 방식이다. 실험실에서 폐수를 대상으로 회분식실험을 통해 핵종 제거율을 측정한 결과, 생물학적 방법은 24시간 이내에 세슘을 80% 이상 제거하였고, 화학적 방법은 95% 이상 세슘을 선택적으로 제거할 수 있었다. 그리고 원전 폐수에 존재하는 다른 주요 핵종들(Co, Ni, Fe, Cr, Mn, Eu)에 대해서도 초기 99% 이상의 높은 제거율을 보여 주었다. 우리는 APR1400 원자력발전소의 폐수처리시스템 공정에서 역삼투압(R/O)과 유기 이온교환수지 모듈 사이에 가상으로 본 기술 모듈을 설치하였다. 가상의 모듈 설치를 통한 기술적 타당성 평가를 통해, 우리는 폐수의 주요 핵종들이 90% 이상 선택적으로 제거되고 폐수지의 발생량이 대폭 감소된다는 결과를 얻을 수 있었다. 이러한 결과가 의미하는 바는 본 기술이 향후 미래에 상용화되었을 경우, 폐수지 관리 비용을 크게 감소시키고 수지 수명도 대폭 연장시킬 수 있어, 결과적으로 월성 방사성폐기물 처분시설의 저장고 포화시점을 최대한 늦출 수 있는 이점이 있다.

• 한국가정과교육학회지
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• 제34권2호
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• pp.21-40
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• 2022

본 연구는 특성화고등학교 학생의 식습관 및 영양지식을 조사하여 특성화고등학교 학생의 건강한 식습관 형성을 위한 긍정적이고 실천적인 식생활교육의 기초자료를 제공하고자 하였다. 이를 위해 경상남도에 소재한 한 특성화고등학교의 학생들을 대상으로 편의표본추출법을 사용하여 설문조사를 실시하여 270부를 SPSS(Statistics Package for the Social Science, Ver. 25.0 for Window) 프로그램을 이용하여 분석하였다. 본 연구의 주요 결과를 요약하면 다음과 같다. 첫째, 조사 대상자의 생활환경은 '부모'와 동거하는 학생이 57.40%로 가장 많았고, 월 소득 수준은 '하'가 55.56%로 가장 많았다. 둘째, 조사 대상자의 식습관은 1일 '2식'을 섭취하는 학생이 64.81%로 가장 높게 나타났고, 1일 '1식'의 경우 식사 장소는 '학교 급식소'가 65.96%로 가장 높게 나타났다. 셋째, 영양지식 수준을 분류한 결과 '상'이 37.78%, '중'이 37.41%, '하'가 24.81%를 나타냈다. 영양교육에 관한 경험은 최근 12개월 동안 영양교육을 받아 본 경험이 '없다'가 64.44%로 높게 나타났으며, '영양교육을 받은 경험이 있는 학생'은 35.56%로 교육 경로는 '학교(교사)'가 72.92%로 가장 높게 나타났다. 이상의 결과로 특성화고등학교 학생에게 발생할 수 있는 청소년 식습관 문제를 예방하기 위해 가정, 학교, 지역사회가 유기적인 협조체계를 이루어야 하고, 더 나아가 정부의 아낌없는 지원이 필요하다. 또한 학생들이 알고 있는 영양지식이 올바른 식행동으로 연결될 수 있도록 실천 중심의 식생활교육을 위해 노력해야 할 것이다.