[en] A YBCO thick film containing 20 percent Ag2O with a T_c of 86.8 K and J_c of 108 A/sq cm was obtained. The film was fabricated by a two-step firing process, i.e., firing the film at 1000 C for 10 minutes and annealing at 970 C for 30 minutes. The two-step firing process, however, was not suitable for the multiple-lead YBCO sample due to the formation of the 211 green phase at 1000 C in the multiple-lead YBCO sample. A BSCCO thick film printed on a MgO coated MSZ substrate and fired at 845 C for 2 hours exhibited a superconducting behavior at 89 K. Because of its porous microstructure, the critical current density of the BSCCO thick film was limited. This report also includes the results of the YBCO and BSCCO materials used as oxide electrodes for ferroelectric materials. The YBCO electroded PLZT showed higher remanent polarization and coercive field than the sample electroded with silver paste. A higher Curie temperature for the PLZT was obtained from the YBCO electroded sample. The BSCCO electroded sample, however, exhibited the same Curie temperature as that of a silver electroded sample. Dissipation factors of the ferroelectric samples increased when the oxide electrode was applied

[en] In order to develop low-temperature-fired soft ferrites used for radio frequency devices, the effects of PbO-CuO glass addition on both the sintering behavior and the magnetic properties of Co₂Z hexagonal ferrite were investigated. PbO-CuO glass, which has a low melting point, can be used as a sintering aid for Co₂Z hexagonal ferrite, reducing the sintering temperature to 950-1000 deg. C. However, either excess addition of glass or too high sintering temperatures produced the secondary phase (M phase) in Co₂Z hexagonal ferrite, which causes the degradation of the magnetic properties. The 90% relative density, initial permeability of 7-8, the highest Q (40-50) at room temperature, and the resonance frequency above 1 GHz were all obtained for the sample with 2 wt% glass addition sintered at 1100 deg. C for 4 h

[en] Low Temperature Cofired Ceramics (LTCC) is a relative new thick film process and has many engineering and manufacturing advantages over both the sequential thick film process and high temperature cofired ceramic modules. Because of low firing temperature, low sheet resistance metal conductors, commercial thick film resistors, and thick film capacitors can be buried in or printed on the substrates. A 3-D multilayer ceramic substrate can be prepared via laminating and co-firing process. The packing density of the LTCC substrates can be increased by this 3-D packing technology. At Kaohsiung Polytechnic Institute (KPI), a LTCC substrate system has been developed for high density packaging applications, which had buried surface capacitors and resistors. The developed cordierite-glass ceramic substrate, which has similar thermal expansion as silicon chip, is a promising material for microelectronic packaging. When the substrates were sintered at temperatures between 850-900 degree centigrade, a relative density higher than 96 % can be obtained. The substrate had a dielectric constant between 5.5 and 6.5. Ruthenium-based resistor pastes were used for resistors purposes. The resistors fabricated in/on the LTCC substrates were strongly depended on the microstructures developed in the resistor films. Surface resistors were laser trimmed in order to obtain specific values for the resistors. Material with composition Pb(Fe_2/3W_1/3)_x(Fe_l/2Nb_l/2)_yTi₂O₃ was used as dielectric material of the capacitor in the substrate. The material can be sintered at temperatures between 850-930 degree centigrade, and has dielectric constant as high as 26000. After cofiring, good adhesion between dielectric and substrate layers was obtained. Combing the buried resistors and capacitors together with the lamination of LTCC layer, a 3-dimensional multilayered ceramic package was fabricated. (author)

[en] Estimating solid residue gross burning rate and heating value burning in a power plant furnace is essential for adequate manipulation to achieve energy conversion optimization and plant performance. A model based on conservation equations of mass and thermal energy is established in this work to calculate the instantaneous gross burning rate and lower heating value of solid residue fired in a combustion chamber. Comparing the model with incineration plant control room data indicates that satisfactory predictions of fuel burning rates and heating values can be obtained by assuming the moisture-to-carbon atomic ratio (f/a) within the typical range from 1.2 to 1.8. Agreement between mass and thermal analysis and the bed-chemistry model is acceptable. The model would be useful for furnace fuel and air control strategy programming to achieve optimum performance in energy conversion and pollutant emission reduction

[en] The electroweak corrections at one-loop level to the process H→t bar t are calculated, incorporating the top mass value announced recently by CDF. For M_H<1 TeV where a perturbative calculation is valid, the corrections themselves would gain a few to 20% increment in the decay width as the Higgs-boson mass M_H is increasing within the region, but they are in opposite direction to the QCD ones. If the electroweak and QCD corrections are considered together, the resultant decay width of the mode yields a reduction about a few percent of the tree level one

[en] The addition effects of ZnO-B₂O₃-SiO₂ (ZBS) glass on both the sintering behavior and dielectric properties of BaTiO₃ were investigated in developing low-temperature-fired BaTiO₃-based ceramics for LTCC devices. X-ray diffractometer (XRD), scanning electron microscopy (SEM), and a dilatometer were used to examine the effect of ZBS glass on BaTiO₃ densification and the chemical reaction between the glass and BaTiO₃. The results indicate that ZBS glass can be used as a sintering aid to reduce the sintering temperature of BaTiO₃ from 1300 to 900 deg. C without secondary phase formation. The dielectric properties of BaTiO₃ with ZBS glass sintered at 900 deg. C show a relative density of 95%, a high dielectric constant of 994, and a dielectric loss of 1.6%

[en] Two kinds of lead-free solders, Sn-8Zn-3Bi and Sn-9Zn-lAl, were used to mount passive components onto printed circuit boards via a re-flow soldering process. The samples were stored at 150 deg. C for 200, 400, 600, 800, and 1100 h. The microstructures of the samples after aged at 150 deg. C for various times were characterized using optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and the analyzed of solder joint shear strengths. The joint strength between Sn-8Zn-3Bi and Cu pad was about 4.0 ± 0.3 kg, while the strength between Sn-9Zn-lAl and Cu pad had values of 2.6 ± 0.1 kg. Both kinds of solder joints exhibited reduced strengths with increasing aging times. After aging at 150 deg. C for 1100 h, the joints strengths of Sn-8Zn-3Bi and Sn-9Zn-lAl were 1.8 ± 0.3 and 1.7 ± 0.3 kg, respectively. Both the Sn-8Zn-3Bi and Sn-9Zn-lAl joints showed brittle fracture behaviors. A flat layer of Cu₅Zn₈ intermetallic compound (IMC) was formed between Sn-8Zn-3Bi solder and Cu pad after reflow. When the aging time was increased to 400 h, Zn-depletion and formation of Cu₆Sn₅ IMC were observed in the solders due to the interaction between the tin and zinc compounds. The interaction between Sn-9Zn-lAl solder and Cu pad had similar behavior, however, Cu₆Sn₅ IMC formed in Sn-9Zn-lAl solder when after aging at 150 deg. C for 600 h. As the aging time increased, both types of solders generated clear IMC spalling layers with large and continuous voids. Those voids substantially decreased the joint strength