• Title, Summary, Keyword: Cu

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A Study on the Influence of Substituting Cu Eine Particle for CuO on NiCuZn Ferrite (CuO 대신 Cu 미분말 치환이 NiCuZn Ferrite에 미치는 영향에 관한 연구)

  • Kim, Jae-Sik;Koh, Jae-Gui
    • Journal of the Korean Magnetics Society
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    • v.13 no.1
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    • pp.15-20
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    • 2003
  • Diffusion speed of Cu metal fine particle is fast better than CuO, so it will promote grain growth in sintering. In this paper, the influence on substituting Cu fine particle for CuO of NiCuZn ferrite with basic composition (N $i_{0.204}$C $u_{0.204}$Z $n_{0.612}$ $O_{1.02}$)F $e_{1.98}$ $O_{2.98}$ has been investigated with varying Cu/CuO ratio. The perfect spinel structure of sintered specimen at 90$0^{\circ}C$ was confirmed by the analysis of XRD patterns. The best condition was obtained when the ratio of Cu/CuO was 60%, and the permeability was 1100 and Ms was 87 emu/g in this condition. Cu has influenced on grain growth in sintering, substituting Cu fine particle for CuO could lower sintering temperature over the 3$0^{\circ}C$. After sintering, substituting Cu performed as good as CuO.s CuO.s CuO.

Study on the Cu/polyimide interface using XPS: Initial growth of Cu sputter-deposited on the polyimide at room temperature (I) (XPS를 이용한 Cu/Polyimide 계면에 관한 연구 : 상온에서 증착한 Cu의 초기성장과정(I))

  • 이연승;황정남
    • Journal of the Korean Vacuum Society
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    • v.6 no.3
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    • pp.187-193
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    • 1997
  • We investigated the initial growth mode of Cu deposited on polyimide at room temperature using x-ray photoelectron spectroscopy. We could find that when Cu is sputter-deposited on the polymide, Cu-N-O complex of strong interaction is mainly formed first, Cu-oxide of weak interaction is formed successively, and then finally metallic Cu grow. From these results, we could conclude that Cu/polyimide interface consists of Cu-N-O complex and Cu-oxide.

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The Growth Mode of Cu Atoms on Cu(110) and Oxygen-covered Cu(110) Surfaces by Reflectance Difference Spectroscopy (RDS를 의한 Cu(110)와 산소가 흡착된 Cu(110) 표면에 Cu의 성장 모드)

  • Kim S. H.;Sun L. D.
    • Journal of the Korean Vacuum Society
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    • v.15 no.1
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    • pp.45-49
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    • 2006
  • The changes in the optical anisotropy of the clean Cu(110) and the oxygen covered Cu(110) surfaces due to Cu growth have been studied by reflectance difference spectroscopy(RDS). We have monitored the growth mode of Cu atoms on Cu(110) and Cu(110)-(2XlO surfaces at 250K and checked the surfactant effect of oxygen during the Cu growth. For Cu grow on Cu(110) and Cu(110)-(2Xl)O surface at low temperature, we observed evidence for the layer-by-layer growth mode with change of 4.25eV peak intensity.

Coupling effect of Cu(ENIG)/Sn-Ag-(Cu)/Cu(ENIG) sandwich solder joint (Cu(ENIG)/Sn-Ag-(Cu)/Cu(ENIG) sandwich solder 접합부의 Coupling 효과)

  • Yun Jeong-Won;Jeong Seung-Bu
    • Proceedings of the KWS Conference
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    • pp.33-35
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    • 2006
  • The interactions between Cu/Sn-Ag-(Cu) and Sn-Ag-(Cu)/Ni interfacial reactions were studied during isothermal aging at $150^{\circ}C$ for up to 1000h using Cu(ENIG)/Sn-3.5Ag-(0.7Cu)/Cu(ENIG) sandwich solder joints. A typical scallop-type Cu-Sn intermetallic compound (IMC) layer formed at the upper Sn-Ag/Cu interface after reflowing, whereas a $(Cu,Ni)_6Sn_5$ IMC layer was observed at the Sn-Ag/ENIG interface. The Cu in the $(Cu,Ni)_6Sn_5$ IMC layer formed on the Ni side was sourced from the dissolution of the opposite Cu metal pad or Cu-Sn IMC layer. When the dissolved Cu arrived at the interface of the Ni pad, the $(Cu,Ni)_6Sn_5$ IMC layer formed on the Ni interface, preventing the Ni pad from reacting with the solder. Although a long isothermal aging treatment was performed at $150^{\circ}C$, no Ni was detected in the Cu-Sn IMC layer formed on the Cu side. Compared to the single Sn-Ag/ENIG solder joint, the formation of the $(Cu,Ni)_6Sn_5$ IMC layer of the Cu/sn-Ag/ENIG sandwich joint effectively retarded the Ni consumption from the electroless Ni-P layer.

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Electronic Structures and Properties of the Charged Model Clusters Relating to High-$T_c$ Superconductor $Y{Ba_2}{Cu_3}{O_{7-x}}$

  • Paek, U-Hyon;Lee, Kee-Hag;Sung, Yong-Kiel;Lee, Wang-Ro
    • Bulletin of the Korean Chemical Society
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    • v.12 no.6
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    • pp.606-612
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    • 1991
  • We have carried out an extended Huckel calculation to rationalize the role of $CuO_3$ chains and the size effect of the charged model clusters for the following charged model culsters : ${{Cu_6}{O_{21}}^{28-},\;{{Cu_6}{O_{22}}^{30-}\;,{{Cu_9}{O_{30}}^{39-}\;,{{Cu_9}{O_{32}}^{43-}\;,{{Cu_{12}{O_{38}}^{48-}\;,{{Cu_{15}{O_{50}}^{65-}\;,{{Cu_{18}{O_{54}}^{66-}\;,{{Cu_{18}{O_{55}}^{68-}\;,{{Cu_{24}{O_{70}}^{84-}\;and\;{{Cu_{27}{O_{78}}^{93-}$ for high-$T_c$ superconductor $YBa_2Cu_3O_7$: ${{Cu_6}{O_{18}}^{22-}\;,{{Cu_9}{O_{26}}^{31-}}\;,{{Cu_{12}{O_{32}}^{36-}\;,{{Cu_{15}{O_{42}}^{49-}\;,{{Cu_{18}{O_{46}}^{50-}\;,{{Cu_{24}{O_{60}}^{64-}\;and\;{{Cu_{27}{O_{66}}^{69-}$ for insulator $YBa_2Cu_3O_6$. The results show that the electronic structures and properties of the charged model clusters relating to high-$T_c$ superconductor are very sensitive to the size change of the clusters with various environmental effects, wherease those of the charged model clusters for insulator $YBa_2Cu_3O_6$ are monotonous to the size change. The $CuO_3$ chains along the b-direction may yield cooperative electronic coupling with the $CuO_2$ layers in determining both conducting and superconducting properties of $YBa_2Cu_3O_{7-x}$ system.

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Chemical reaction at Cu/polyimide interface (Cu/polyimide 계면에서의 화학반응)

  • 이연승
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.7 no.3
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    • pp.494-503
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    • 1997
  • We investigated the initial stages of formation of the Cu/polyimide interface using another two methods by X-ray photoelectron spectroscopy. : One, in-situ measurement with increasing of Cu deposition thickness onto polyimide(PI), the other, measurement with decreasing of Cu thickness of Cu/pI film by $Ar^+$ ion etching. From these results, we find that the chemical reactions exist in Cu/PI interface. However, the measured chemical reactions were different according to experimental method.

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Heat Liberation in the Reaction of $YBa_2Cu_3O_{7-}\delta$, $Y_2BaCuO_5$, and Binary Compounds in the Ba-Cu-O System with Water ($YBa_2Cu_3O_{7-}\delta$, $Y_2BaCuO_5$ 및 Ba-Cu-O계 화합물의 수분과의 반응에 의한 열방출에 관한 연구)

  • 김배연
    • Journal of the Korean Ceramic Society
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    • v.32 no.1
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    • pp.83-89
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    • 1995
  • YBa2Cu3O7-$\delta$, Y2BaCuO5, and binary compounds in the Ba-Cu-O system with the nominal composition of Ba2CuO3, BaCuO2, Ba3Cu4O7, Ba3Cu5O8 were synthesized to investigate the heat evolutions and crystalline phases in the hydration reaction of orthorhombic YBa2Cu3O7-$\delta$ phase. The observed crystalline phases were YBa2Cu3O7-$\delta$, Y2BaCuO5, and BaCuO2, or Ba2Cu3O5+x, and some amount of noncrystalline phase in the Ba-Cu system comounds. In contact with distilled water, YBa2Cu3O7-$\delta$ and Y2BaCuO5 did not have considerable heat liberation, but in the binary compounds of the Ba-Cu-O system, the amount of total heat liberation was increased with respect to the Cu content. It might be that the reaction of high temperature superconductor YBa2Cu3O7-$\delta$ with water and/or moisture originated from the unusual oxidation state of Cu ion and the presence of amorphous Ba-Cu oxide compound. The degradation of high Tc superconductor by moisture and water could be controlled by restricting the heterogeneous distribution of Tc comlposition and the formation of second phase, such as stable Y2BaCuO5, and the resulting unstable Ba-Cu oxide compound.

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A Study on Solderability of Sn-Ag-Cu Solder with Plated Layers in $\mu-BGA$ ($\mu-BGA$에서 Sn-Ag-Cu 솔더의 도금층에 따른 솔더링성 연구)

  • 신규식;정석원;정재필
    • Journal of Welding and Joining
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    • v.20 no.6
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    • pp.783-788
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    • 2002
  • Sn-Ag-Cu solder is known as most competitive in many kinds of Pb-free solders. In this study, effects of solderability with plated layers such as Cu, Cu/Sn, Cu/Ni and Cu/Ni/Au were investigated. Sn-3.5Ag-0.7Cu solder balls were reflowed in commercial reflow machine (peak temp.:$250^{\circ}C$and conveyer speed:0.6m/min). In wetting test, immersion speed was 5mm/sec., immersion time 5sec., immersion depth 4mm and temperature of solder bath was $250^{\circ}C$. Wettability of Sn-3.5Ag-0.7Cu on Cu, Cu/Sn ($5\mu\textrm{m}$), Cu/Ni ($5\mu\textrm{m}$), and Cu/Ni/Au ($5\mu\textrm{m}/500{\AA}$) layers was investigated. Cu/Ni/Au layer had the best wettability as zero cross time and equilibrium force, and the measured values were 0.93 sec and 7mN, respectively. Surface tension of Sn-3.5Ag-0.7Cu solder turmed out to be 0.52N/m. The thickness of IMC is reduced in the order of Cu, Cu/Sn, Cu/Mi and Cu/Ni/Au coated layer. Shear strength of Cu/Ni, Cu/Sn and Cu was around 560gf but Cu/Ni/Au was 370gf.

Effect of Dietary Supplementation of Cu-methionine Chelate and Cu-soy Proteinate on the Performance, Small Intestinal Microflora and Immune Response in Laying Hens (사료내 Cu-methionine Chelate와 Cu-soy Proteinate가 산란계의 생산성, 소장내 미생물 균총 및 면역체계에 미치는 영향)

  • Paik, I.K.;Kim, C.H.;Park, K.W.
    • Korean Journal of Poultry Science
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    • v.35 no.3
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    • pp.303-311
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    • 2008
  • This study was conducted to investigate the effect of dietary supplementation of Cu-methionine chelate(Cu-Met) and Cu-soy proteinate(Cu-SP) on the performance, small intestinal microflora and immune response in laying hens. A total of 960 Hy-line $Brown^{(R)}$ laying hens of 39 wks old were assigned to one of the following 6 dietary treatment: control(C), antibiotic(Avilamycine 6 ppm), Cu-Met 50 and Cu-Met 100(50 and 100 ppm Cu as Cu-methionine chelate), Cu-SP 50 and Cu-SP 100(50 and 100ppm Cu as Cu-soy proteinate). Each treatment was replicated 4 times with forty birds per replication, housed in 2 birds per cages. Forty birds units were arranged according to randomized block design. Feeding trial lasted 6 wks under 16 hours lighting regimen. Hen-day and hen-house egg production of groups treated with Antibiotic and Cu supplements tended to be higher than the control with significant difference (P<0.05) shown between Cu-Me 100 and control. Egg weight was significantly (P<0.05) heavier in antibiotic and Cu-SP treatments than Cu-Met treatments but they were not significantly different from the control. Eggshell strength, egg shell thickness, egg yolk color and Haugh unit were not significantly different among treatments. There were no significant differences in leukocytes and erythrocytes in the chicken blood. But mean corpuscular hemoglobin value(MCH) was significantly (P<0.05) higher in Cu-SP 100 than antibiotic treatment. The concentrations of serum IgG and IgA were not significantly different among treatments. Copper concentration in the liver tended to increase as the level of copper supplementation increased, that of Cu-SP 100 being significantly (P<0.05) higher than those of the control and antibiotic treatment. Concentrations of iron and zinc of the liver were not significantly influenced by treatments. Populations of Cl. perfringens and Lactobacilli in the small intestinal content were significantly (P<0.05) influenced by treatments. Population of Cl. perfringens decreased and that of Lactobacilli increased in the copper supplemented groups. The result of this experiment showed that Cu-Met and Cu-SP are comparable to antibiotic in improving egg production in laying hens. Birds fed diets supplemented with Cu-SP produced heavier eggs than those fed diets with Cu-Met. There were no significant differences in the performances between 50 ppm and 100 ppm copper supplementation as organic forms.

Flip Chip Process by Using the Cu-Sn-Cu Sandwich Joint Structure of the Cu Pillar Bumps (Cu pillar 범프의 Cu-Sn-Cu 샌드위치 접속구조를 이용한 플립칩 공정)

  • Choi, Jung-Yeol;Oh, Tae-Sung
    • Journal of the Microelectronics and Packaging Society
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    • v.16 no.4
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    • pp.9-15
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    • 2009
  • Compared to the flip-chip process using solder bumps, Cu pillar bump technology can accomplish much finer pitch without compromising stand-off height. Flip-chip process with Cu pillar bumps can also be utilized in radio-frequency packages where large gap between a chip and a substrate as well as fine pitch interconnection is required. In this study, Cu pillars with and without Sn caps were electrodeposited and flip-chip-bonded together to form the Cu-Sn-Cu sandwiched joints. Contact resistances and die shear forces of the Cu-Sn-Cu sandwiched joints were evaluated with variation of the height of the Sn cap electrodeposited on the Cu pillar bump. The Cu-Sn-Cu sandwiched joints, formed with Cu pillar bumps of $25-{\mu}m$ diameter and $20-{\mu}m$ height, exhibited the gap distance of $44{\mu}m$ between the chip and the substrate and the average contact resistance of $14\;m{\Omega}$/bump without depending on the Sn cap height between 10 to $25\;{\mu}m$.

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