1,720,971 research outputs found
Study on the amorphous Ta2O5 thin film capacitors deposited by dc magnetron reactive sputtering for multichip module applications
No full textTantalum oxide (Ta2O5) thin film capacitors for multichip module (MCM) applications were investigated. Through the capacitor characterization and RBS compositional analysis, it was found that when the sputtering power and Ar flow rate is 200 W and 60 seem, respectively, the stoichiometric Ta2O5 film can be obtained at the O2 gas flow rate of 50 seem. The low temperature annealing (150°C) is useful to increase the capacitor yield, but the annelaing in oxygen atmosphere causes the leakage current to increase. When the Ta-oxide capacitors were fabricated on the polymer-laminated substrate, leakage current increased and breakdown field strength decreased. These are due to the surface roughness effects of the polymer films and also the Al bottom electrode layer. It was demonstrated that the Ta2O5 capacitors fabricated on the Upilex-S polymer film can meet the requirements of integrated capacitors for MCM applications. ？ 1999 Elsevier Science S.A. All rights reserved
Relationships between suspension formulations and the properties of BaTiO3/epoxy composite films for integral capacitors
No full textThis work was supported by Center Electronic Packaging
Materials of Korea Science and Engineering Foundation. The
authors gratefully acknowlege TPL Inc., Cabot Corp., and
Ferro Corp. for providing powders
Parametric amplification in a directly modulated semiconductor laser
No full textWe investigate the parametric amplification and its saturation characteristics in a directly modulated semiconductor laser. The parametric gain depends on the resonance frequency shift that occurs due to the pump modulation current and the bias current. Also, the parametric gain is a strong function of the phase between the signal and the pump modulation currents. The saturation characteristic of the parametric amplification occurs at a large signal modulation current due to depletion of the pump by an amplified optical signal. We explain the observed behaviors using the analytic results of the nonlinear rate equations of the semiconductor laser
Study on the epoxy/BaTiO3 embedded capacitor films newly developed for PWB applications
No full textThis work was supported by Center of Electronic
Packaging Materials of Korean Science and Engineering
Foundation
Effects of particle size on dielectric constant and leakage current of epoxy/barium titanate (BaTiO3) composite films for embedded capacitors
No full textA study on the temperature dependence of epoxy/BaTiO3 composite embedded capacitor films
No full textIn this study, the temperature dependence of capacitance, one of the most important properties of embedded capacitor films (ECFs), was investigated. The temperature dependence of the capacitance of ECFs was determined by the temperature dependence of the dielectric constant and thickness, and among these, the main factor was the dielectric constant of ECFs. The dielectric constant of ECFs was determined by that of epoxy and BaTiO3 powders. Below 130 degrees C, the dielectric constant of ECFs increased as temperature increased, and was mainly affected by an epoxy matrix. However, above 130 degrees C (the Curie temperature of BaTiO3), the increased rate of the dielectric constant of ECFs started decreasing. This was due to the fact that BaTiO3 powder undergoes a phase transition from a tetragonal to a cubic structure, and its dielectric constant decreases at 130 degrees C. The dielectric constant of BaTiO3 powder was obtained from measured dielectric constants of ECF and application of the Lichtenecker logarithmic rule
Study on the properties of Epoxy/BaTiO3 Composite Embedded Capacitor Films for Organic Substrate
No full textLimit of optical pulsewidth in the gain-switched DFB semiconductor laser
No full textWe investigate the minimum optical pulsewidth that is obtainable in the gain-switched distributed-feedback semiconductor laser. The minimum obtainable optical pulsewidth is determined by either the period doubling or the saturation of modulation efficiency, The shift of the resonance frequency to the lower frequency side with increase of the modulation current brings about these phenomena. It is predicted theoretically that the minimum obtainable pulsewidth is about 0.2 times the period of the small-signal resonance. The minimum pulsewidth after compression with a dispersion compensating fiber is also discussed. Experimental measurements are in good agreement with the theory
Comparison of theoretical predictions and experimental values of the dielectric constant of epoxy/BaTiO3 composite embedded capacitor films
No full textPolymer/ceramic composites are the most promising embedded capacitor material for organic substrates application. Predicting the effective dielectric constant of polymer/ceramic composites is very important for design of composite materials. In this paper, we measured the dielectric constant of epoxy/BaTiO3 composite embedded capacitor films with various BaTiO3 particles loading for 5 different sizes BaTiO3 powders. Experimental data were fitted to several theoretical equations to find the equation useful for the prediction of the effective dielectric constant of polymer/ceramic composites and also to estimate the dielectric constant of BaTiO3 powders. The Lichtenecker equation and the Jayasundere-Smith equation were useful for the prediction of the effective dielectric constant of epoxy/BaTiO3 composites. And calculated dielectric constants of the BaTiO3 powders were in the range of 100 to 600, which were lower than the dielectric constant of BaTiO3 bulk ceramics probably due to the presence of voids or pores. (C) 2005 Springer Science + Business Media, Inc.This work was supported by Center for electronic Packging Materials (CEPM) of Korea Science and Engineering Foundatio
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