OSP 표면처리의 열적 열화에 따른 Cu/SnAgCu 접합부의 접합강도

홍원식,정재성,오철민,Hong, Won-Sik,Jung, Jae-Seong,Oh, Chul-Min 한국마이크로전자및패키징학회 2012 마이크로전자 및 패키징학회지 Vol.19 No.1

무연 리플로우 공정 횟수에 따른 organic solderability preservative(OSP) 표면처리 두께변화 및 열화현상을 분석하였다. 무연솔더 접합부의 접합강도에 미치는 OSP 표면처리의 열화특성을 SnPb 표면처리 경우와 비교하여 조사하였다. 또한 리플로우 pass에 따른 무연솔더 접합강도 열화분석을 위해 OSP 및 SnPb 표면처리된 FR-4 재질 PCB를 각각 1-6회 리플로우 처리하였다. 이후 각 리플로우를 거친 PCB 위에 2012 칩 저항기를 실장한 후 접합강도 변화를 측정하였다. 그 결과, 리플로우 공정 중 열 노출에 의해 OSP 코팅두께가 감소되는 것이 관찰되었고, 코팅두께의 변화 및 OSP 코팅 층의 산화를 유발함으로써, 솔더의 젖음성이 감소될 수 있음을 확인할 수 있었다. OSP 열화에 따른 솔더 접합강도는 SnPb 표리처리시 평균 62.2 N 이였으며, OSP의 경우는 약 58.1 N 이였다. 리플로우 공정 노출에 따라 OSP 코팅 층은 열분해 되지만, 솔더 접합부의 접합강도 측면에서는 산업적으로 적용 가능성을 확인할 수 있었다. Bonding strength of Sn-3.0Ag-0.5Cu solder joint due to degradation characteristic of OSP surface finish was investigated, compared with SnPb finish. The thickness variation and degradation mechanism of organic solderability preservative(OSP) coating were also analyzed with the number of reflow process. To analyze the degradation degree of solder joint strength, FR-4 PCB coated with OSP and SnPb were experienced preheat treatment as a function of reflow number from 1st to 6th pass, respectively. After 2012 chip resistors were soldered with Sn-3.0Ag-0.5Cu on the pre-heated PCB, the shear strength of solder joints was measured. The thickness of OSP increased with increase of the number of reflow pass by thermal degradation during the reflow process. It was also observed that the preservation effect of OSP decreased due to OSP degradation which led Cu pad oxidation. The mean shear strength of solder joints formed on the Cu pads finished with OSP and SnPb were 58.1 N and 62.2 N, respectively, through the pre-heating of 6 times. Although OSP was degraded with reflow process, the feasibility of its application was proven.

고해상도 위성영상을 이용한 3차원 지형자료 제작

이효성 ( Hyo-seong Lee ),정재성 ( Jae-sung Jung ),안기원 ( Ki-won Ahn ) 한국환경기술학회 2008 한국환경기술학회지 Vol.9 No.4

본 연구에서는 IKONOS 2호 고해상도 위성의 Geo레벨 흑백 입체영상과 다중분광영상을 이용하여 정확도가 향상된 정밀 3차원 지형자료 획득을 위해, 첫째, GPS 측량을 통한 지상기준점과 RPC 블럭조정 방법을 적용하여 개선된 DEM을 획득하였다. 둘째, 흑백영상과 동일시기의 다중파장대 영상(공간해상력; 4m)을 이용하여 1m해상도의 융합영상을 작성하였으며, 토지피복도 작성을 위한 참조자료로 활용하였다. 마지막으로, 흑백 입체영상으로부터 획득되어진 DEM자료와 동일시기의 토지피복도 등을 이용하여 복잡하고 다양한 지형요소를 보다 정확하게 분석할 수 있는 3차원 수치지형자료를 작성할 수 있었다. This study is to produce 3D geomorphology data, improved the 3D positioning accuracy, using the IKONOS-2 Geo stereo panchromatic and multispectral data with the high-resolution commercial imagery. For this, we perform the following three steps sequentially: Step 1: digital elevation model(DEM) accuracy is improved by block adjustment method with provided rational polynomial coefficient(RPC) and ground control points(GCPs). GCPs are acquired using the global positioning system(GPS). Where DEM is generated by the area-based matching method and space intersection principal of the adjusted RPC. Step 2: fusion image is made using the high-resolution panchromatic image and multispectral image of the IKONOS-2 satellite. It is utilized for reference data of the land cover classification. Step 3: the 3D digital geomorphology data is produced using the generated DEM and land cover classification map to analysis various topography.

도암만 수질의 부유물질 농도와 화학적 산소요구량의 시,공간적 특성 및 상관관계

장지승 ( Ji Seong Chang ),장지혜 ( Ji Hye Chang ),조미선 ( Mi Sun Cho ),강형일 ( Hyung Yeel Kahng ),정재성 ( Jae Sung Jung ),안삼영 ( Sam Young Ahn ) 한국환경과학회 2014 한국환경과학회지 Vol.23 No.5

Seasonal and stational variation of SS and COD were investigated from February 2008 to December 2010 and the relationship between them was discussed. During three years monitoring, SS decreased significantly (46% decline) possibly due to the increase of precipitation and thereby resulting salinity drop. COD on average was the highest in 2009. SS was the highest in autumn and the lowest in winter, and over 72% of SS was FSS. While SS is high in the upper sampling stations of the bay with shallow water, COD values do not show any relationship to the geomorphological characteristics. CODins, which was defined as COD after filtration, ranged 56%(winter)~44.6%(summer) and showed no correlation with SS. It indicates that high SS concentration is not necessarily related to the high CODins. The seasonal CODins/SS data, which can be interpreted as COD density in SS, shows that SS in winter contains the dense COD materials compared to the other seasons.

해상 태양광발전 시스템을 위한 무선 헬스 모니터링

이현석(Hyeonseok Lee),정재성(Jae-seong Jung) 한국태양에너지학회 2020 한국태양에너지학회 학술대회논문집 Vol.2020 No.6

태양전지 리본와이어 열화예지를 위한 가속수명시험설계 연구

한창운(Changwoon Han),정재성(Jae-Seong Jung),박노창(Noh-Chang Park) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.5

대장균의 세포 밀도 의존 단백질의 검출

정재성,성치남 順天大學校 1989 論文集 Vol.8 No.1

대장균에서 세포 밀도에 따른 단백질 합성의 변화 양상을 SDS-Polyacrylamide Gel Electrophoresis를 이용하여 조사하였다. 그결과 세포의 밀도가 증가함에 따라 38 Kd의 단백질이 증가한 반면 36 Kd와 77Kd의 단백질의 양은 감소하였다. 단백질 합성을 억제시키는 항생제인 refampicine과 chloramphenicol을 처리한 후에도 38Kd의 단백질양은 감소하지 않았다. 따라서 38Kd의 단백질은 기존해 있던 단백질의 분해산물이 아니라 새로함성된 단백질임을 확인하였다. In E. coli, protein patterns changed according to population size at 23℃ and 37℃ were examined by SDS-PAGE. One 38Kd proteins band intensity was increased, while 36Kd and 77Kd proteins were diminished along with the increase of population size. When E. coli culture was treated prolonged time with antibiotics which block protein syntheses, there was no change on 38Kd protein band. These results suggest that 38Kd protein is not degradation product of preexistent protein but a newly synthesized protein.

순천만에 유입되는 동천과 이사천의 수질

김종홍,성치남,정재성,한상근 順天大學校 1991 論文集 Vol.10 No.1

순천만에 유입되는 동천과 이사천에 대한 생태학적 연구의 일환으로, 1990년 5월 부터 1992년 1월까지 이화학적및 생물학적 수질조사를 실시하였다. 조사항목중 이화학적 환경요인으로는 수온, pH, DO, BOD를 미생물학적 환경요인으로는 일반세균, 총대장균, 분변성 대장균을 측정하였으며, 하천의 생산성을 파악하기 위하여 엽록소 a의 함량을 분석하였다. 이화학적인 수질분석의 결과, 동천의 하류인 오천(정점 2)부근이 다른 정점에 비하여 오염도가 높았으며, 이사천에 비해 동천의 경우가, 또한 90년에 비해 91년의 오염도가 높음을 알 수 있었다. 조사기간동안 일반세균의 평균변화는 6.6×10⁴c.f.u./ml-6.1×?? c.f.u./ml로 나타났으며, 총대장균가 분변성 대장균의 분포도 일반세균의 분포양상과 밀접한 관계를 나타내었다. As a part of preㅣiminary ecological survey in Dongcheon and Isacheon inflowed into Suncheon Bay, the physicochemical and bioloical factors were investigated from May, 1990 to January, 1992. Water temperature, pH, turbidity, DO and BOD were meaured to estimate the physicochemical characteristics and annual fluctuationof total heterotrophic bacteria, total coliform and fecal coliform were investigated for microbiological analysis. In order to examine the productivities of these streams, Chlorophyll a contents were also measured. When we considered the physicochemical parameterts, water qualit of Ocheon (St. 2) which is located in lower reaches of Dongcheon was remarkably polluted throughout the investigated stations. Total heterotrophic bacteria population during investigating periods was ranged from 4.5×10² to 6.1×?? c.f.u./ml. Annual fluctuation and spatial disribution patterns of totoal coliform and fecal coliform populations were similar with that of total heterotrophic bacteria.

東川과 伊沙川의 水生 生態系에 關한 硏究

金琮鴻,鄭泳喆,成治南,趙顯旭,韓元東,鄭在成,盧景姬,韓相根 순천대학교 기초과학연구소 1992 基礎科學硏究誌 Vol.3 No.-

As a part of aquatic ecological study in Dongcheon and Isacheon which flows into Sunchoon Bay, the water quality, species composition of phytoplankton, flora and distribution of aquatic vascular plants and fish fauna were investigated on eleven stations from May,1990 to June, 1992. The physicochemical and bacteriological water quality of Ocheon(St.D-5) which is located in lower reaches of Dongcheon was remarkably polluted throughout the investigated stations. Annual fluctuation and spatial distribution patterns of total coliform and feacal coliform bacterial population were similiar to that of total heterotrophic bacteria. Phytoplankton community was composed of 5 Phyla, 6 Classes, 10 Orders, 23 families, 54 genera, 117 species, 6 varieties, 1 form, and 3 unidentified species in total 128 taxa. Through the collecting stations Melosira granulata, Melosira granulata var. angustissima, Melosira varians, Fragilaria capucina, Navicula cryptocephala, Cymbella tumida, Cymbella ventricosa and Nitzschia palea were dominant species. In this study, 13 species of hydrophytes, 31 species of hygrophyte and 36kinds of water side ruderal plants were collected. The aquatic vascular was 33 families, 59 genera, 71 species, 7 varieties in total 78 taxa. Three families, 18 genera, and 26 species of fishes were collected through the stations. Through the collecting stations, Zacco platypus and Z.temmincky were dominant species and Pseudogobia esocinus which is bottom dwelling species was also numerous.