• Journal of the Microelectronics and Packaging Society
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• v.21 no.3
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• pp.1-6
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• 2014

The demand for fine-pitch devices is increasing due to an increase in I/O pin count, a reduction in power consumption, and a miniaturization of chip and package. In addition non-scalability of Cu pillar/Sn cap or Pb-free solder structure for fine-pitch interconnection leads to the development of bumpless interconnection system. Few bumpless interconnect systems such as BBUL technology, SAB technology, SAM technology, Cu-toCu thermocompression technology, and WOW's bumpless technology using an adhesive have been reviewed in this paper: The key requirements for Cu bumpless technology are the planarization, contamination-free surface, and surface activation.

• Journal of Surface Science and Engineering
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• v.27 no.5
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• pp.261-272
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• 1994

Both Cu-Cr and Cu-Ti alloy films with different composition were prepared by dc magnetron sputtering onto polyimide substrate and their adhesion and microstructure were observed. In addition, the effect of heat treatment at $400^{\circ}C$ for 2 hours on the variation of adhesion properties and on the changess of microstructure were investigated. Cu-Cr alloy films have crystalline structure of either for or bcc phase depending on the composition of the film. However, the Cu-Ti alloy film forms fcc phase at low Ti concentration while it forms an amorphous phase as the Ti concentration in the films is increased to more than 25at.%. TEM analysis reveal that the microstructure of Cu-Cr and Cu-Ti films forms an open structure with vacant spaces. The adhesion between Cu-Cr, Cu-Ti alloy films and polyimide substrate is relatively good before the heat treatment, but is noticeably reduced after the heat treatment. In particular, the adhesion strength is significantly reduced in the Cu-Ti alloy films after the heat treatment. The reduction of adhesion strength after the heat treatment is identified to relate with the formation of oxide phases at the metal/polyimide interface by AES(Auger Electron Spectroscopy).

• Korean Journal of Materials Research
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• v.6 no.4
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• pp.412-420
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• 1996

상업용 자동차 축전지 극판재료로 각형의 초정 Pb 재료에 적은 부피 분율의 Cu상을 가지는 Pb-Cu 합금을 응고시킬 때 각형의 초정 Cu 수지상이 석출되었다. 중요한 응고변수인 냉각속도와 Cu조성의양에 따른 각형의 Cu상의 형태변화를 조사하기 위하여 Pb-1wt%Cu, pb-3wt%Cu, Pb-5wt%Cu, Pb-9wt%Cu, Pb-12wt%Cu, 등의 5가지 합금이 선택되어 노냉, 공냉, 금형냉, 수냉의 4가지 냉각방법을 이용하여 실험하였다. 일반적으로 냉각속도와 Cu성분이 증가함에 따라 Cu상의 각형정도가 감소하였으며 결국 가장 빠른 냉각인 수냉각시에는 수지상 형태가 정출되지 않고 구형의 형태가 정출 되었다.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1584-1586
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• 2002

CuIn$Se_2$ (CIS) and related compounds such as Cu($In_xGa_{1-x})Se_2$(CIGS) have been studied by their potential for use in photovoltaic devices. CIS thin film materials which have high absorption coefficient and wide bandgap, have attracted much attention as an alternative to crystalline and amorphous silicon solar cells currently in use. Cu-rich CIGS film have very low resistivity, due to coexistence of the semimetallic $Cu_{2-x}Se$. In-rich CIGS films show high resistivity, since these films are compensated films without the $Cu_{2-x}Se$ phase. Optical properties of the CIGS films also change in accordance with the resistivity for the Cu/(In+Ga) ratio. The Cu-rich films have different spectra from In-rich films in near infrared wavelengths.

• Korean Journal of Materials Research
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• v.12 no.11
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• pp.889-893
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• 2002

The reactions of $Cu/Ti/SiO_2$ structures at temperatures ranging from 200 to $700^{\circ}C$ have been studied for various Ti thicknesses. The reaction products initially formed, at around $300^{\circ}C$, were a series of Cu-Ti intermetallics ($Cu_3$Ti/CuTi) with the oxygen dissolved in the Ti moving from the compounds into the remaining unreacted Ti. At $500^{\circ}C$, the $Cu_3$Ti was converted into Cu-rich intermetallics, $Cu_4$Ti, which grew at the expense of the CuTi due to the increased oxygen content in the Ti. In addition, the outdiffusion of Ti, to the Cu surface, and the $Ti-SiO_2$ reactions, caused an abrupt increase in the oxygen content in the Ti layer, which placed thermodynamic restraints on further Ti reactions. Furthermore, thinner Ti layers showed a higher increasing rate of oxygen accumulation for the same consumption of Ti, which led to significantly reduced Ti consumption. The $SiO_2$ film under the Ti diffusion barrier was more easily destroyed with increasing Ti thickness.

• Journal of the Korean Society for Heat Treatment
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• v.4 no.2
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• pp.9-18
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• 1991

Among the many maunfactured processes of producing multi filamentary composites, in situ process is widely used owing tv its simplicity and easyness of mass production. In this study, the mechanical and electromagnetic properties of Cu-Fe composite materials was investigated. The tensile strength of the Cu-Fe wires increased as the Fe content and reduction ratio were increased. The Cu-30 wt%Fe composites had the best properties in terms of figure merits compared to the other Cu-Fe composites made in this study or the commercially manufactured 6/1 ACSR cables of Cu cable. The coercivity was decreased by increasing Fe content, but the squareness was increased greatly. As increasing reduction ratio, the coercivity and squareness increased up to the maximum points, and then decreased. For example, the maximum values were obtained at $0.09mm{\phi}$ for Cu-30 wt%Fe composites and at $0.066mm{\phi}$ for Cu-45 wt%Fe composites. The magnetic property of Cu-Fe wires produced by precipitation treatment was higher than that of Cu-Fe wires produced by thermomechanical treatment. By annealing Cu-Fe wires after drawing process, the coercivity, remanence and squareness were improved.

• Journal of Surface Science and Engineering
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• v.48 no.4
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• pp.169-173
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• 2015

$CuInSe_2$ thin films which have been widely used for thin solar cells as a light absorber were prepared by hydrazine solution processing, and their microstructural properties were investigated. Hydrazine $CuInSe_2$ precursor solutions were prepared by dissolving $Cu_2S$, S, $In_2Se_3$ and Se powder in hydrazine solvent. Multilayer $CuInSe_2$ chalcopyrite phase thin films were prepared by repeating spin-coating process using the precursor solution. Unfortunately, the presence of the interfaces between each $CuInSe_2$ layer formed by multi-layer coating impeded grain growth across the interface. Here, by doing simple interface engineering to solve the limited grain growth issue, the large grained (${\sim}1{\mu}m$) $CuInSe_2$ thin films were obtained.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.4
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• pp.538-545
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• 2017

Objective: The goal of this study was to investigate the effects of cupric citrate (CuCit) on growth performance, antioxidant indices, serum lipid metabolites, serum immune indices, and tissue residues of copper (Cu), zinc, and iron in weaned pigs. Methods: A total of 180 weaned pigs ($Duroc{\times}Landrace{\times}Large$ White) with an average body weight of $8.98{\pm}1.21kg$ were randomly assigned to a corn-soybean meal control ration, or 4 similar rations with 30, 60, 120, or 240 mg/kg Cu as CuCit. All diets contained 10 mg/kg Cu as cupric sulfate from the vitamin-mineral premix. The experiment was divided into two phases: 0 to 14 d (phase 1) and 15 to 28 d (phase 2). Results: Average daily gain (ADG; linearly, p<0.01) and average daily feed intake (ADFI; linearly and quadratically, p<0.05) were affected by an increase in CuCit during phase 2. Overall period, ADG (p<0.05) and ADFI (p<0.01) were linearly increased with increasing dietary levels of CuCit. Serum malondialdehyde concentrations (p<0.05) and glutathione peroxidase activity (p<0.01) linearly decreased and increased respectively with an increase in CuCit. Serum levels of Cu-Zn superoxide dismutase were linearly affected with an increase in CuCit (p<0.01). Hepatic malondialdehyde levels decreased with an increase in CuCit (linearly and quadratically, p<0.01). Serum total cholesterol concentrations were quadratically affected (p<0.05) and decreased in pigs fed Cu as CuCit at 60 and 120 mg/kg and increased in pigs fed 240 mg/kg Cu as CuCit. Serum high-density lipoprotein concentrations were linearly affected with an increase in CuCit (p<0.01). Serum $IL-1{\beta}$ levels were quadratically affected (p<0.05) by dietary treatment. Compared with other treatments, 240 mg/kg Cu from CuCit quadratically increased hepatic (p<0.01) and renal (p<0.05) Cu concentrations, and quadratically decreased hepatic and renal iron concentrations (p<0.05). Conclusion: Cu administered in the form of CuCit at a dosage range of 30 to 60 mg/kg, effectively enhanced the growth performance and antioxidant status of weaned pigs.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.4
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• pp.271-280
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• 2004

This pot experiment was conducted to investigate the effects of systematic variation appling of Fe, Mn, Cu, and Zn on forage performance of orchardgrass and white clover. The treatments of systematic variation were 0/100, 25/75, 50/50, 75/25, and $100/0\%$ in the Fe/Cu(trial-1), Mn/Zn(trial-2), and Fe+Cu/Mn+Zn(trial-3), respectively. The treatments of Fe/Mn/Cu/Zn(trial-4) were $70\%$ in main-element and $10\% in other 3 sub-elements, respectively. 1. Compared with orchadgrass, white clover showed relatively consistent differences in the content of micronutrients as influenced by treatments of the systematic variation. The contents of Mn and Cu in the forages were significantly influenced by the application rates of Mn and Cu, respectively. The contents of Fe and Zn in the forages, however, were not significantly different among these treatments. 2. Compared with orchardgrass in the Fe/cu trial, white clover had not only the low content of Cu but also the Cu content and yield of white clover were greatly decreased by the low rate of application of Cu. In the Mn/Zn trial, the $0/100\%$ resulted in the severe decrease of Mn-content in both forages. The low content of Mn in white clover tended to be negatively correlated to the Mn-chlorosis, inferior growth and flowering, and low yield. 3. In the Fe+Cu/Mn+Zn trial, the application with $0/100\%$ and $0/100\%$ resulted in the relatively great decrease of Cu and Mn contents, respectively. These traits in white clover tended to be negatively correlated to the inferior growth and flowering, and low yield 4. In the Fe/Mn/Cu/Zn trial, the content of every main-elements in the forages were increased especially in Mn. In addition, the contents of sub-elements were likely to be somewhat negatively influenced by the treatment of main-element respectively.

• Korean Journal of Environmental Agriculture
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• v.13 no.1
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• pp.1-9
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• 1994

To investigate differences in Cu contents in paddy soils and rices, being affected by air pollutants from the Janghang Smelter, soil samples at the different directions and surface (0-15cm) and subsurface (15-30cm) were collected in 1982 and 1990, and rice plants at the soil corresponding sampling sites in 1990 were also at separately collected from the Janghang Smelter area. Soil samples were extracted with $4M-HNO_3$ and plant samples were digested with a mixture of $HNO_3$ and $HClO_4$ for analyzing Cu, Zn, Cd and Pb by atomic absorption spectrophotometry. The Cu contents in soils ranged from 5.1 to 391.0 mg $kg^{-1}$. The average content of Cu in 1990 was higher than that in 1982. The Cu content in soils nearer to the center of the smelter was higher than that farther from the center. The Cu content was highest at the east direction, and was in order of east > north-north east = north east > north. The variation of Cu levels in soil at east sites was more considerable than other directions. The Cu level in surface soils was higher than that in subsurface soils. The Cu contaminated area was within 5 km at east, and 3 km at north-north east and north east. A significant correlation was found between Cu content in surface soils of 1982 and that in surface and subsurface soils of 1990, and between Cu content in soils and soil properties such as organic matter(OM), available phosphate, available silicate, exchangeable $Ca^{++}$ and $Na^+$ in 1982. The Cu content in brown rice ranged from 0.4 to 3.6 mg $kg^{-1}$, and was the lowest in parts of rice plant, and Cu content in a part of plant was 13.75 times higher than that in brown rice. The Cu content of leaf sheath, stem and brown rice was correlated with the levels of Cd, Zn, Cu and Pb in soils. The Cu content in soil regardless of years and soil depths was correlated with Zn and Pb in soil in the area affected by waste gas.