• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 267
  • 105
  • 78
  • 44
  • 41
  • 32
  • 16
  • 12
  • 11
  • 6
  • 6
  • 4
  • 4
  • 3
  • 2
  • Tagged with
  • 687
  • 101
  • 91
  • 90
  • 89
  • 78
  • 70
  • 70
  • 64
  • 51
  • 51
  • 48
  • 45
  • 44
  • 42
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Contacting schemes for copper extraction

Parker, N. I. January 1987 (has links)
No description available.
2

Estudo da presença de pares de Cu+ - OCN- e Cu+ - CN- no cristal de KCl / Study of Cu+ - OCN- and Cu+ - CN- pairs in KCl crystal

Ruggiero, Lígia de Oliveira 24 August 1989 (has links)
O presente trabalho mostra um estudo sobre a presença de pares de íons de CN- - Cu+ e OCN- -Cu+, em cristais de KCl, usando técnicas de medidas de corrente de despolarização termoestimulada (I.T.C.) e Absorção óptica. A detecção destes pares foi feita através de um estudo sistemática de correlação entre as diferentes amostras aqui usadas: KCl + 1% KCN; KCl + 1% CuCl; KCl + 1% KOCN; KCl + 1% KOCN + 1% CuCl e KCl + 1% KCN + 1% CuCl. Deve ser ressaltado que a última amostra apresenta um tipo de impureza não intencional OCN- , cuja associação com o íon Cu+ também é observada. Na absorção ótica observamos bandas à temperatura ambiente em 210, 228, 242, 252, 260 e 290 nm para o cristal de KCl + 1% CuCl + 1% KCN, sendo que para o cristal de KCl + 1% KOCN + 1% CuCl não foi observado o último pico. As diferentes bandas são atribuídas às possíveis interações entre Cu+ e CN-, bem como Cu+ e OCN-. Quanto à técnica de ITC, as curvas obtidas por esta, para os três últimos cirstais citados acima, foram melhor ajustadas pela somatória de duas curvas singulares de ITC, cujas temperaturas de pico estão nas posições de 53 e 55 K; 54,3 e 56,6 K; 53,3 e 56,1 K, respectivamente. Em KCl + 1% KOCN a curva de mais baixa temperatura (curva 1) de ITC é atribuída à molécula (16O12C14N-) e a curva de mais alta temperatura (curva 2) é atribuída à molécula isotrópica (18O12C14N-). Para as amostras de KCl + 1% KOCN + 1% CuCl a curva 1 foi atribuída ao OCN- isolado e a curva 2 ao Cu+ perturbado pela presença do OCN-. Quanto ao cristal de KCl + 1% KCN + 1% CuCl, as duas técnicas propostas não foram suficientes para identificar a presença de pares Cu+ - CN-, necessitando, desta maneira, da utilização de outra técnica experimental, como por exemplo a da luminescência. A correlação dos resultados experimentais foi feita através dos parâmetros determinados do momento de dipolo (p), energia de ativação (Ea&#8727) e a temperatura de pico (Tm&#8727) / The present work gives a study on CN- - Cu+ and OCN- -Cu+ coupled pairs doped KCl single crystal, by using Ionic Thermal Current (I.T.C.) and Optical absorption techniques. These pairs were detected through a systematic correlation study between different samples: KCl + 1% KCN; KCl + 1% CuCl; KCl + 1% KOCN; KCl + 1% KOCN + 1% CuCl and KCl + 1% KCN + 1% CuCl, were the last sample shows unporposely doping OCN-, compled with Cu+. The observed optical absorption bands, at room temperature, were in 210, 228, 242, 252, 260 and 290 nm for KCl + 1% CuCl + 1% KCN crystal. Only the last absorption band was not seen in KCl + 1% KOCN + 1% CuCl samples. Diferent bands are associated with possible interactions between Cu+ and CN-, as also Cu+ with OCN-. The ITC curves for the last three crystals were better fitted with two single ITC´s curves, whose temperature peaks are at 53 and 55 K; 54,3 and 56,6 K; 53,3 and 56,1 K, respectively. The lowest temperature ITC band (curve 1) in KCl + 1% KOCN is attributed to the (16O12C14N-) molecule and the highest temperature ITC band (curve 2) is due to the (18O12C14N-) isotropic molecule. For KCl + 1% KOCN + 1% CuCl samples curve 1 was associated with isolated OCN- and curve 2 with Cu+ perturbed with OCN-. With KCl + 1% KCN + 1% CuCl, the two techniques were not good enough to identify Cu+ - CN-, compling, it should be necessary to apply another type of techniques, like luminescence. The correlations of the experimental results were done through the determination electric dipole moment (p), activation energy (Ea&#8727) and temperature peak (Tm&#8727) parameters
3

90nm Cu/Low-K Phase ¡VIn and assembly process capability analysis

Hou, Chih-kun 30 July 2007 (has links)
Copper interconnects and low k dielectrics have been introduced in advanced IC technology to reduce the interconnect resistance, improve the resistance to electromigration and reduce RC delay and cross talk effects. The introduction of new materials in integrated circuits makes the root cause determination and correction action implementation more challenging. Moreover, the complexity of package structure generates additional impact on degrading the yield of assembly processing manufacture. This main purpose of this study is to investigate the influence of introducing Cu-/Low K wafer phase on actual manufacturing situation. Issues related to the failures of assembly process were analyzed for determining the root cause, in which such as die chipping issue during die sawing process, bond pad peeling/crater issues during wire bonding process and die crack / delamination issues after pre-condition and reliability test. The DOE/JMP methodology was used to achieve the optimium assembly processing condition so as to improve the quality of products, and then the mass production with stable yield could be realized.
4

Interfacial Reactions of Sn-Ag-Cu Solder Ballin BGA Package at 175¢J aging

Wang, Hsin-I 14 July 2006 (has links)
None.
5

Estudo da presença de pares de Cu+ - OCN- e Cu+ - CN- no cristal de KCl / Study of Cu+ - OCN- and Cu+ - CN- pairs in KCl crystal

Lígia de Oliveira Ruggiero 24 August 1989 (has links)
O presente trabalho mostra um estudo sobre a presença de pares de íons de CN- - Cu+ e OCN- -Cu+, em cristais de KCl, usando técnicas de medidas de corrente de despolarização termoestimulada (I.T.C.) e Absorção óptica. A detecção destes pares foi feita através de um estudo sistemática de correlação entre as diferentes amostras aqui usadas: KCl + 1% KCN; KCl + 1% CuCl; KCl + 1% KOCN; KCl + 1% KOCN + 1% CuCl e KCl + 1% KCN + 1% CuCl. Deve ser ressaltado que a última amostra apresenta um tipo de impureza não intencional OCN- , cuja associação com o íon Cu+ também é observada. Na absorção ótica observamos bandas à temperatura ambiente em 210, 228, 242, 252, 260 e 290 nm para o cristal de KCl + 1% CuCl + 1% KCN, sendo que para o cristal de KCl + 1% KOCN + 1% CuCl não foi observado o último pico. As diferentes bandas são atribuídas às possíveis interações entre Cu+ e CN-, bem como Cu+ e OCN-. Quanto à técnica de ITC, as curvas obtidas por esta, para os três últimos cirstais citados acima, foram melhor ajustadas pela somatória de duas curvas singulares de ITC, cujas temperaturas de pico estão nas posições de 53 e 55 K; 54,3 e 56,6 K; 53,3 e 56,1 K, respectivamente. Em KCl + 1% KOCN a curva de mais baixa temperatura (curva 1) de ITC é atribuída à molécula (16O12C14N-) e a curva de mais alta temperatura (curva 2) é atribuída à molécula isotrópica (18O12C14N-). Para as amostras de KCl + 1% KOCN + 1% CuCl a curva 1 foi atribuída ao OCN- isolado e a curva 2 ao Cu+ perturbado pela presença do OCN-. Quanto ao cristal de KCl + 1% KCN + 1% CuCl, as duas técnicas propostas não foram suficientes para identificar a presença de pares Cu+ - CN-, necessitando, desta maneira, da utilização de outra técnica experimental, como por exemplo a da luminescência. A correlação dos resultados experimentais foi feita através dos parâmetros determinados do momento de dipolo (p), energia de ativação (Ea&#8727) e a temperatura de pico (Tm&#8727) / The present work gives a study on CN- - Cu+ and OCN- -Cu+ coupled pairs doped KCl single crystal, by using Ionic Thermal Current (I.T.C.) and Optical absorption techniques. These pairs were detected through a systematic correlation study between different samples: KCl + 1% KCN; KCl + 1% CuCl; KCl + 1% KOCN; KCl + 1% KOCN + 1% CuCl and KCl + 1% KCN + 1% CuCl, were the last sample shows unporposely doping OCN-, compled with Cu+. The observed optical absorption bands, at room temperature, were in 210, 228, 242, 252, 260 and 290 nm for KCl + 1% CuCl + 1% KCN crystal. Only the last absorption band was not seen in KCl + 1% KOCN + 1% CuCl samples. Diferent bands are associated with possible interactions between Cu+ and CN-, as also Cu+ with OCN-. The ITC curves for the last three crystals were better fitted with two single ITC´s curves, whose temperature peaks are at 53 and 55 K; 54,3 and 56,6 K; 53,3 and 56,1 K, respectively. The lowest temperature ITC band (curve 1) in KCl + 1% KOCN is attributed to the (16O12C14N-) molecule and the highest temperature ITC band (curve 2) is due to the (18O12C14N-) isotropic molecule. For KCl + 1% KOCN + 1% CuCl samples curve 1 was associated with isolated OCN- and curve 2 with Cu+ perturbed with OCN-. With KCl + 1% KCN + 1% CuCl, the two techniques were not good enough to identify Cu+ - CN-, compling, it should be necessary to apply another type of techniques, like luminescence. The correlations of the experimental results were done through the determination electric dipole moment (p), activation energy (Ea&#8727) and temperature peak (Tm&#8727) parameters
6

Cu(I) Kompleksų vaidmuo glicinatinių ir maleatinių Cu(II) kompleksų elektrocheminės redukcijos procesuose / Role of Cu(I) complexes in the electrochemical reduction of glycinate and maleate Cu(II) complexes

Uljanionok, Julija 04 February 2010 (has links)
Atliktas palyginamasis dviejų kompleksinių sistemų - Cu|Cu(II), glicinas ir Cu|Cu(II), maleino rūgštis - elektrocheminių charakteristikų tyrimas. Nustatytos maleino rūgšties tirpalų pusiausvyrinės charakteristikos. Kiekybiniam titravimo kreivių aprašymui išvestos lygtys, kuriose įvertinti medžiagų bei krūvių balansai bei atsižvelgta į praskiedimo efektus. Jų taikymas pH-metrinių duomenų analizei davė tokias maleato anijonų protonizacijos konstantų reikšmes: log = 6,05, log = 7,48. Nustatyta, kad tirpaluose su 0,3 M K2SO4 priedu protonizuotų ligando formų stabilumas sumažėja (log = 5,75, log = 7,30). Cu(II) maleatinių kompleksų stabilumui nustatyti panaudotas spektrofotometrijos metodas ir pasiūlyta duomenų analizės procedūra. Ji remiasi kiekybiniu absorbcijos spektrų aprašymu, taikant lygtis, išplaukiančias iš valdomo harmoninio osciliatoriaus teorijos. Išanalizavus įvairių sudėčių tirpalų absorbcijos maksimumo dydžius, prieita išvados, kad rūgščiose terpėse vyrauja monoligandinis kompleksas, kurio koncentracinė stabilumo konstanta log b1 = 2,2. Atlikta sistemos Cu|Cu(II), maleino rūgštis pusiausvyrų termodinaminė analizė. Nustatyta, kad esant metalinio vario ir tirpalų sąlyčiui, sistemoje galimi gilūs virsmai, kurių metu iki 90 % Cu(II) transformuojasi į Cu(I). Teorines išvadas patvirtina eksperimentiniai duomenys, gauti spektrofotometrijos ir elektrocheminės kvarco kristalo mikrogravimetrijos metodais. Įvertinti Cu korozijos bei fazinių Cu2O sluoksnių susidarymo... [toliau žr. visą tekstą] / A comparative investigation of electrochemical characteristics of two complex systems, viz. Cu|Cu(II), glycine and Cu|Cu(II), maleic acid, was carried out. The equations were obtained for quantitative description of pH-metric and spectrophotometric data, which were used for determination of equilibrium characteristics in Cu(II)-maleic acid solutions. Thermodynamic analysis shows that deep changes are possible in this system resulting in 90 % transform of Cu(II) into Cu(I). The rates of Cu corrosion and Cu2O formation are estimated to be of the same order (nmol cm-2 s-1). Regularities of formal electrochemical kinetics, which account for the mass transport of chemically interacting particles and for step-wise charge transfer process, are suitable for interpretation of voltammetric data of the Cu|Cu(II), glycine system. Kinetic parameters Cu(II) glycinate complex depend on the nature of the supporting electrolyte: the exchange current density decreases and the cathodic charge transfer coefficient increases in the sequence: Li+ - Na+ - K+ - Cs+. To enhance the Cu(I) generation in maleic acid system, the pre-electrolysis procedure was applied. It was found that its effect depends on solution pH. Applied theoretical model describes satisfactorily the steady-state voltammetric characteristics of Cu|Cu(II), maleic acid system, but some contradictory results were obtained in the case of time-dependent processes. Theoretical and experimental problems to be solved are discussed.
7

Effects of Applied Loads, Effective Contact Area and Surface Roughness on the Dicing Yield of 3D Cu Bonded Interconnects

Leong, Hoi Liong, Gan, C.L., Pey, Kin Leong, Thompson, Carl V., Li, Hongyu 01 1900 (has links)
Bonded copper interconnects were created using thermo-compression bonding and the dicing yield was used as an indication of the bond quality. SEM images indicated that the Cu was plastically deformed. Our experimental and modeling results indicate that the effective contact area is directly proportional to the applied load. Furthermore, for first time, results have been obtained that indicate that the dicing yield is proportional to the measured bond strength, and the bond strength is proportional to the effective contact area. It is also shown that films with rougher surfaces (and corresponding lower effective bonding areas) have lower bond strengths and dicing yields. A quantitative model for the relationship between measured surface roughness and the corresponding dicing yield has been developed. An appropriate surface-roughness data acquisition methodology has also been developed. The maximum possible applied load and the minimum possible surface roughness are required to obtain the maximum effective contact area, and hence to achieve optimum yields (both mechanically and electrically). / Singapore-MIT Alliance (SMA)
8

Estudio de la Evolución de la Microestructura y Dureza de Aleaciones Cu-V y Cu-V-Al Durante su Fabricación por Molienda Reactiva y Extrusión

Estay Díaz, Roberto Ignacio January 2008 (has links)
No description available.
9

Studies of electrical properties of Cu/SiO thin films

Li, J. P. January 1989 (has links)
No description available.
10

The electrical conductivity and Hall coefficient of sputtered metallic glasses

Shearwood, C. January 1988 (has links)
No description available.

Page generated in 0.0305 seconds