• 한국분말재료학회지
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• 제8권4호
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• pp.245-252
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• 2001

Recent remarkable progress in the semiconductor industry has promoted smaller size of semiconductor chips and increased amounts of heat generation. So, the demand for a substrate material to meet both the characteristics of thermal expansion coefficient and heat radiation has been on the increase. Under such conditions, tungsten(W)-copper(Cu) has been proposed as materials to meet both of the above characteristics. In the present study, the W-10wt.%Cu powders were synthesised by the mixing and hydrogen reduction of the starting mixture materials such as W-Cu, $W-CuCl_2$and $WO_3-CuCl_2$ in order to obtain the full densification. The W-10wt.%Cu produced by hydrogen reduction showed the higher interparticle friction than the simple mixed W-10wt%Cu because of the W agglomerates. In the dilatometric analysis the W-10wt.%Cu prepared from the $W-CuCl_2$was largely shrank by heating up $1400^{\circ}C$ at the constant heating rate of $5^{\circ}C$/min. The possibility of application of metal injection molding (MIM) was also investigated for mass production of the complex shaped W-Cu parts in semiconductor devices. The relationship between the temperature of molding die and the pressure of injection molding was analyzed and the heating up stage of 120-$290^{\circ}C$ in the debinding process was controlled for the most suitable MIM condition.

• 한국주조공학회지
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• 제17권5호
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• pp.458-464
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• 1997

Mg-Cu-Si과 Mg-Cu-Ge계 3원 합금에서 비정질 생성범위와 열적, 기계적 성질을 조사하였다. Mg-Cu-Si계에서는 $15{\sim}45%Cu$, $0{\sim}10%Si$, Mg-Cu-Ge계에서는 $15{\sim}45%Cu$, $0{\sim}5%Ge$의 조성범위에서 각각 비정질 단상이 생성되었고, $15{\sim}22.5%Cu$, 2.5%Si(or Ge)의 조성범위에서 생성되는 비정질상은 180도 밀착굽힘을 하여도 파단되지 않는 양호한 인성을 가지고 있었으며, $Mg_{82.5}Cu_{15}Ge_{2.5}$비정질합금의 최대인장강도는 800 MPa로 결정질 Mg기 합금의 최대치인 300 MPa에 비해 월등히 높은 값을 나타내었다. 그러고 비정질합금의 결정화는 다음과 같은 과정으로 일어났다. 1) Si(or Ge) ${\le}$ 2.5%: 비정질 ${\to}$ 비정질+$Mg_2Cu$+Mg ${\to}$ $Mg_2Cu$+Mg+$Mg_2Si$(or Ge), 2) Si(or Ge)=5%: 비정질 ${\to}$ $Mg_2Cu$+Mg+$Mg_2Si$(or Ge), 3) Si=10%: 비정질 ${\to}$ 비정질+$Mg_2Si$ ${\to}$ $Mg_2Si$+$Mg_2Cu$+Mg.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.152-153
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• 2007

$CuInSe_2$ single crystal thin film was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the hot wall epitaxy (HWE) system. After the as-grown $CuInSe_2$ single crystal thin films was annealed in Cu-, Se-, and In-atmospheres, the origin of point defects of $CuInSe_2$ single crystal thin films has been investigated by the photoluminescence(PL) at 10 K. The native defects of $V_{Cu}$, $V_{Se}$, $Cu_{lnt}$, and $Se_{lnt}$ obtained by PL measurements were classified as a donors or acceptors type. And we concluded that the heat-treatment in the Cu-atmosphere converted $CuInSe_2$ single crystal thin films to an optical n-type. Also, we confirmed that In in $CuInSe_2$/GaAs did not form the native defects because In in $CuInSe_2$ single crystal thin films existed in the form of stable bonds.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.314.2-314.2
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• 2013

CIGS 박막의 물성은 조성에 크게 영향을 받으며, 특히 박막 내 Cu/(In+Ga) 비는 매우 중요한 변수로서 태양전지 특성에 영향을 주게 된다. Cu(In1-xGax)Se2 박막의 전하농도 및 반도체로의 성격을 가장 명확하게 결정하는 조성비는 Cu/(In+Ga) 비이다. 태양전지와 같은 소자로 작용하기 위해서는 Cu/(In+Ga) 비가 1보다 작아야 한다. 고효율의 태양전지는 Cu/(In+Ga)조성이 0.85~0.95로 slightly Cu-poor가 되어야 만들어진다. 본 연구에서는 Cu조성에 따른 CIGS 박막의 구조적, 전기적 특성과 CIGS 태양전지 효율 특성에 관하여 연구하였다. 미세구조 분석결과 Cu 조성이 증가함에 따라 큰 결정립을 가지며 결정립의 성장이 고르게 되어 접합 형성을 좋게 하는 경향을 보였다. X선 회절 분석결과, Cu 함유량 비율이 증가하면서 <112>의 우선배향성에서 <220/204>으로 변화하였다. 그러나, Cu/(In+Ga) 비율이 1이상이 첨가됨에 따라 우선배향은 다시 <112>로 변화함을 알 수 있었다. EDX 분석결과 Ga/(In+Ga) 0.31, Cu/(In+Ga) 0.86의 비율일 때, Carrier density $1.49{\times}1016$ cm-3을 나타내었다. CIGS의 태양전지의 효율 측정결과 Voc=596mV, Jsc=37.84mA/cm2, FF=72.96%로 ${\eta}$=16.47%를 달성하였다.

• 한국표면공학회지
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• 제27권5호
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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).

• 한국토양비료학회지
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• 제19권4호
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• pp.307-314
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• 1986

Sewage Sludge 를 시용하지 않은 토양(W), 6년간 시용한 토양($WS_6$), Sludge와 토양의 혼합물을 1주일동안 incubation한 토양($WS_1$), 그리고 Sewage Sludge(SS)로 부터 추출한 수용성 유기물(WSOF)이 구리(II) 이온과 어떻게 착화합물을 형성하는지를 전자스핀공명분광법(ESR)과 전위차적정법을 이용하여 규명하였다. Cu(II)-WSOF 착화합물은 ESR spectra 상에서 $g_{\perp}$ 값보다 큰 $g_{\amalg}$ 값을 가짐으로서 늘어난 팔면체(elongated octahedron) 배위결합을 하고 있음을 나타내었다. $77^{\circ}K$에서 Cu(II)-SS착물은 anisotropic ESR spectrum을 보인 반면 Cu(II)-W착물은 anisotropic spectrum을 나타내었다. 이러한 결과는 결국 W의 산소공여 리간드가 Cu(II)와 강한 착화합물을 이루는 반면에 SS의 리간드는 Cu(II)와 거의 Chelate를 이루지 않고 있음을 의미한다. 또한 Cu(II)-SS 착화합물의 ESR spectra는 평면상의 네개의 모서리 리간드(예, $COO^-$, $H_2O$, $Cl^-$ 등등)의 각각이 한자리 리간드로서 독립적으로 행동하고 있음을 암시한다. W에서는 방향족 카복실기 같은 산소공여 리간드가 주로 Cu(II)와 결합하고 있는것 같고 SS에서는 Sulfonate, 지방족 카복실기 그리고 질소를 함유하는 리간드가 주요한 결합 site인 것 같다. Cu(II)-SS착화합물과 비교할때 Cu(II)-W로 부터 Cu(II)를 치환하는데 6배정도의 Pyridine 농도가 요구되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제20권7호
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• pp.1067-1075
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• 2007

Twenty eight 3-4 month old castrated Black Bengal kids (Capra hircus) were used to determine the effects of source and level of dietary copper (Cu) concentration on their performance and nutrient utilization. Cu was supplemented (0, 10, 20 and 30 mg/kg diet DM) as copper sulfate ($CuSO_4$, $5H_2O$) or copper proteinate (Cu-P). Kids were fed a basal diet containing maize (19.5%), soybean (17.0%), deoiled rice bran (56.5%), molasses (4.0%), di-calcium phosphate and salt (1.0% each) and mineral and vitamin mixture (0.5% each) supplements at 3.5% of body weight to meet NRC (1981) requirements for protein, energy, macro minerals and micro minerals, excluding Cu. The basal diet contained 5.7 mg Cu/kg, 122.5 mg Fe/kg, 110 mg Zn/kg, 0.26 mg Mo/kg and 0.32% S. $CuSO_4$ or Cu-P was added to the basal diet at the rate of 10, 20 and 30 mg/kg. Kids were housed in a well ventilated shed with facilities for individual feeding in aluminum plated metabolic cages. Blood samples were collected from the jugular vein on d 0, 30, 60 and 90 to determine hemoglobin (Hb), packed cell volume (PCV), total erythrocyte count (TEC), total leukocyte count (TLC) and serum enzymes (alkaline phosphatase, alanine transferase and aspertate transferase). A metabolism trial of 6 days duration was conducted after 90 days of experimental feeding. Statistical analysis revealed that source and level of Cu supplementation improved live weight gain (p<0.04) and average daily gain (p<0.01). No significant contribution of source and level of Cu to alter serum serum enzymes was evident. Goats fed Cu-P tended to have higher Hb, PCV and TEC than with $CuSO_4$ supplementation. Cu-P increased digestibility of ether extract (EE, p<0.02) and crude fiber (p<0.05) and showed an increasing trend (p<0.09) for digested crude protein (CP) and crude fiber (CF). Supplemental dose of Cu linearly improved (p<0.02) digestibilities of dry matter (DM), organic matter (OM), EE and nitrogen free extract (NFE). Though the absorption of nitrogen (N) was not affected (p>0.10) by both source and dose of Cu, N retention was affected (p<0.04) and there was a significant $Source{\times}Dose$ interaction (p<0.05). Final body weight (BW) was not influenced (p>0.10) by the source of Cu but increasing dose of Cu increased (p<0.04) the BW of kids. TDN intake (g/kg $W^{0.75}$) was higher (p<0.05) with the increased dose of Cu and there was a significant $Source{\times}Dose$ interaction. It was concluded that supplementation of Cu from different sources and varying dose level in a concentrate based diet may improve performance, nutrient utilization and plane of nutrition in castrated Black Bengal kids. The effects on performance and nutrient utilization are more pronounced with Cu-P than $CuSO_4$ supplementation. Higher dose of Cu showed better result than lower dose.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.450-455
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• 2002

Cu-cored Sn-Ag solder balls were fabricated by coating pure Sn and Ag on Cu balls. The melting behavior and the solderability of the BGA joint with the Ni/Au coated Cu pad were investigated and were compared with those of the commercial Sn-Ag and Sn-Ag-Cu balls. DSC analyses clarified the melting of Cu-cored solders to start at a rather low temperature, the eutectic temperature of Sn-Ag-Cu. It was ascribed to the diffusion of Cu and Ag into Sn plating during the heating process. After reflow soldering the microstructures of the solder and of the interfacial layer between the solder and the Cu pad were analyzed with SEM and EPMA. By EDX analysis, formation of a eutectic microstructure composing of $\beta$-Sn, Ag$_3$Sn, ad Cu$_{6}$Sn$_{5}$ phases was confirmed in the solder, and the η'-(Au, Co, Cu, Ni)$_{6}$Sn$_{5}$ reaction layer was found to form at the interface between the solder and the Cu pad. By conducting shear tests, it was found that the BGA joint using Cu-cored solder ball could prevent the degradation of joint strength during aging at 423K because of the slower growth me of η'-(Au, Co, Cu, Ni)$_{6}$Sn$_{5}$ reaction layer formed at the solder, pad interface. Furthermore, Cu-cored multi-component Sn-Ag-Bi balls were fabricated by sequentially coating the binary Sn-Ag and Sn-Bi solders on Cu balls. The reflow property of these solder balls was investigated. Melting of these solder balls was clarified to start at the almost same temperature as that of Sn-2Ag-0.75Cu-3Bi solder. A microstructure composing of (Sn), Ag$_3$Sn, Bi and Cu$_{6}$Sn$_{5}$ phases was found to form in the solder ball, and a reaction layer containing primarily η'-(Au, Co, Cu, Ni)$_{6}$Sn$_{5}$ was found at the interface with Ni/Au coated Cu pad after reflow soldering. By conducting shear test, it was found that the BGA joints using this Cu-core solder balls hardly degraded their joint shear strength during aging at 423K due to the slower growth rate of the η'-(Au, Cu, Ni)$_{6}$Sn$_{5}$ reaction layer at the solder/pad interface.he solder/pad interface.

• 한국재료학회지
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• 제10권7호
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• pp.482-488
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• 2000

(hfac) Cu(1,5-COD)(1,1,1,5,5,5-hexafluro-2,4-pentadionato Cu(I) 1,5-cyclooctadine) 증착원을 이용하여 MOCVD(metal organic chemical vapor deposition)로 Cu 박막을 형성시키고, MOCVD에 의한 TiN 기판 변화가 Cu 증착에 미치는 영향을 조사하였다. 공기 중에 노출시킨 기판은 MOCVD 에 의한 Cu 핵생성 및 초기성장에 영향을 미쳐 입자크기가 작고, 입자간의 연결성이 떨어졌으며, in-situ MOCVD Cu의 경우는 입자크기가 크고, 입자간의 연결성이 우수하여 1900$\AA$ 이상의 두께에서는 $2.0{\mu}{\Omega}-cm$ 정도의 낮은 비저항을 유지하였다. 또한 접착력에서는 in-situ MOCVD TiN 의 경우가 보다 우수하였다. 이와 같은 결과를 토대로 MOCVD Cu 성장단계를 제시하였다.

• Journal of Nutrition and Health
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• 제26권6호
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• pp.743-757
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• 1993

This study was undertaken to investigate the effects of dietary Fe and Cu levels on Pb accumulation of Pb poisoned rats. 80 male Sprague weaning Dawley rate weighing 80-90g were divided into 8 groups(Pb groups: LFLCPb-low Fe, low Cu and Pb group, LFACPB-low Fe, adequate Cu and Pb group, AFLCPb-adequate Fe, low Cu and Pb group, AFACPb-adequate Fe, adequate Cu and Pb group, without Pb gorups: LFLC-low Fe, low Cu and without Pb grooup, LFAC-low Fe, adequate Cu and without Pb group, AFLC-adequate Fe, low Cu and without Pb group, AFAC-adequate Fe, adequate Cu and without Pb group) according to Pb administration (0, 500ppm in drinking water) and Fe and Cu levels(Fe :6ppm, 40ppm, Cu : 0.5ppm, 0.8ppm) for 12 weeks. The food intake, body weight, gain, and FER of Pb groups were significantly lower than those of without Pb groups(p<0.01, p<0.001, p<0.001). The weights of liver in Pb groups were significantly lower than that of adequate Fe and Cu group in without Pb group(AFAC) (p<0.001). The Cu contents of liver in Pb groups were significantly lower than that of AFAC (p<0.01). The liver Pb accumulation of LFLCPb was significantly higher than those of LFACPb, AFLCPb, AFACPb(p<0.05). The serum Pb content of LFLCPb was significantly higher than those of LFACPb, AFLCPb, AFACPb(p<0.05). The levels of Hb, and Hct, of 12 weeks in Pb poisoned rats were lower than those of 8 weeks, in other words, long term Pb poisoned rats were affected more serious on hematoopoiesis. The fecal excretions of Fe and Cu in Pb groups were significantly higher than those of without Pb groups(p<0.001, p<0.001). The urinary Fe and Cu excretions were significantly higher than those of AFAC(p<0.001, p<0.001). There were significant differences between Pb groups and without Pb groups according to dietary Fe and Cu levels. So, dietary levels of adequate Fe and Cu were effective to reduce Pb accumulation in rats. It were showed that the decrease of food intake, FER, body weight gain, serum level of Fe and Cu in Pb groups than those of without Pb groups. And the increase of liver Pb accumulation, serum Pb levels, fecal and urinary Fe and Cu excretions were showed in Pb groups than those of without Pb groups by long term lead poisoning. Otherwise, adequate Fe and Cu administrations in Pb groups have preventive effects on the Pb poisoned rats.