Synthesis and electrochemical properties of an oxide electrode layer prepared by a new electroless plating technique

A lanthanum strontium manganese thin oxide layer was plated on yttria stabilized zirconia by oxidizing the lanthanum strontium manganese ions with hydrogen peroxide as the oxidant. The plated oxide layer was firmly adherent to the substrate, and its morphology was finely porous. The crystal phase of the oxide was determined by XRD to be a perovskite-type. The mechanism for the oxide layer formation by an oxide electroless plating was studied by means of ESCA. As a cathode of solid oxide fuel cell (SOFC), the electrode characteristics of an oxide plated in this way were measured by the current interruption method at 1000° C. The cathodic overpotential of this electrode was less than 40 mV at 1 A cm^–2 This small overvoltage was considered to be based on an effective large electrode reaction area.     

a-SiC:H/SiO2 Laminated Polarization Splitter for the Wavelength Region Longer Than 1.3 μm Prepared by Plasma-Enhanced Chemical Vapor Deposition

A laminated polarization splitter for the wavelength region longer than 1.3 μm is fabricated for the first time. It is composed of a-SiC:H/SiO₂ alternative multilayers prepared by plasma-enhanced chemical vapor deposition. Splitting behavior is also verified experimentally. It has low absorption loss even for the wavelength region around λ = 1.3 μm because the band-gap energy of a-Sic is larger than that of a-Si. The measured splitting angle is 13.8°, which is 2.4 times larger than the 5.7° splitting angle of rutile. The absorption loss of the multilayer is reduced to 1 × 10^-3 dB/μm at λ = 1.3 μm. The magnitude of the residual stress is 9.45 × 10⁸ dyn/cm², which is about one-third of that prepared by the rf bias sputtering equipment which is used for another project of our group. The deposition rate of SiO₂, is increased to 135 nm/min, which is 27 times larger than that prepared by the sputtering equipment.     

Chemical sensing by an electrical oscillator: Detection and quantification of cationic surfactants

A new chemical sensing system using an electrical oscillator has been developed. This sensing system measures the electrical ‘non-linearity’ at the surface of an electrode immersed in a test solution: a sinusoidal voltage is applied to the electrode and the higher harmonics of the output current are obtained by Fourier transformation. This sensing system has been used to detect and quantify surfactant molecules in solutions. The relative intensity P₂/P₁ of the peaks of the second (P₂) and first (P₁) harmonics in the output current was found to be linearly correlated with the logarithms of the concentrations of cationic surfactants such as cetylpyridium bromide (CPB) and cetyl-N,N,N-trimethylammonium bromide (CTAB), but not with those of the anionic surfactant sodium dodecyl sulfate (SDS) or the neutral surfactant Triton X-100. The reproducibility of this sensing system was shown to be excellent.     

High density packaging technology ultra thin package & new tab package

As electronic devices become more highly integrated, the demand for small, high pin count packages has been increasing. We have developed two new types of IC packages in response to this demand. One is an ultra thin small outline package (TSOP) which has been reduced in size from the standard SOP and the other, which uses Tape Automated Bonding (TAB) technology, is a super thin, high pin count TAB in cap (T.I.C.) package. In this paper, we present these packages and their features along with the technologies used to improve package reliability and TAB. Thin packages are vulnerable to high humidity exposure, especially after heat shock.1 The following items were therefore investigated in order to improve humidity resistance: (1) The molding compound thermal stress, (2) Water absorption into the molding compound and its effect on package cracking during solder dipping, (3) Chip attach pad area and its affect on package cracking, (4) Adhesion between molding resin and chip attach pad and its affect on humidity resistance. With the improvements made as a result of these investigations, the reliability of the new thin packages is similar to that of the standard thicker plastic packages.     

Large area ZnO films optimized for graded band-gap Cu(InGa)Se2-based thin-film mini-modules

In this study, two deposition methods (i.e. MOCVD and sputtering methods) to prepare n-type ZnO window layers for CIGS-based thin-film solar cells are discussed. In order to make ZnO : Al transparent conductive oxide (TCO) films prepared by DC magnetron sputtering comparable to ZnO : B TCO prepared by MOCVD, a new ZnO sputtering process is proposed by introducing a multilayer structure. Using these films, CIGS thin-film solar cells with efficiencies of greater than 14% have been fabricated with an active area of 3.2 cm². This structure was adapted to fabricate CIGS thin-film mini-modules with efficiencies around 11% having aperture area of 50 cm².     

Analysis of photoreceptor membrane turnover in a Drosophila visual mutant, rdgA, by electron microscope autoradiography

A Drosophila visual mutant, rdgA, has photoreceptor cells whose rhabdomeres degenerate in several days after eclosion. Incorporations of 3H-amino acids, and 3H-mannose and 3H-glucosamine residues into the photoreceptive membranes were studied in newly emerged rdgA mutant flies by electron microscope autoradiography. The amount of 3H-amino acids incorporated in rdgA rhabdomeres at 3 hr after the injection was about 50%, and that of 3H-sugar residues was about 20% of normal. Together with our previous finding that degradative activity is low in rdgA cell bodies at this time, these data indicate that the supply of photoreceptive membrane proteins is defective in rdgA.     

Calculation of magnetic near field generated by the contact discharge of an ESD gun

An ESD (electrostatic discharge) testing is specified in the IEC 61000‐4‐2, in which the detailed waveform of the discharge current injected by an ESD gun is prescribed. However, due to lack of understanding of the discharge process, it is difficult to confirm whether or not the IEC current waveform can be injected onto actual equipment. We thus previously proposed an equivalent circuit model for the ESD gun based on its geometrical structure, and showed decisive factors for the discharge current. In this study, in order to confirm the feasibility of the above equivalent circuit model, we measured with a 6‐GHz wide‐band digital oscilloscope the discharge current through an SMA connector and the resultant magnetic near field for the contact discharge of an ESD gun. As a result, we found that both measured waveforms approximately agree with those calculated from our equivalent circuit model. We then measured with respect to charge voltages the magnetic near fields for the contact discharge of the ESD gun to the ground, which revealed that the measured waveform around the first peak is in fair agreement with the calculated one. Furthermore, we found that the magnetic field peak increases with increasing charge voltage, whose dependence can be predicted from our equivalent model. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 153(1): 17–24, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20194     

Dehydrogenative polycondensation of telechelically bis(dimethylsilyl)functionalized oligo(dimethylsiloxane)s or aromatics and 1,3,3,5,5,7,7,7-octamethyltetrasiloxane

Telechelically bis(hydrodimethylsilyl)-functionalized oligo(dimethylsiloxane)s or aromatics were found to give polymers constituting of alternating disilylene and oligodimethylsiloxane or 4,4′-diylaromatics as repeating units by dehydrogenative coupling reaction in the presence of palladium dibenzylideneacetone complex. The same catalyst gave polysilylenes with trisiloxane pendant from 1,1-dihydro-1,3,3,5,5,7,7,7-octamethyltetrasiloxane. Received: 18 October 1996/Accepted: 31 October 1996