Electrophoretic deposition (EPD) usingpolydimethylsiloxane(PDMS)-based organic-inorganic hybrid materials as binders can be used to prepare alumina-binder composites on metal substrates. Herein, we investigated the deposition mechanism of PDMS-based polymers. The composition and porosity of EPD composites can be controlled by adjusting the EPD condition, and shape of alumina particles.

In this paper, we examined the transfer method of fluororesin as the novel formation method of polymer wall in order to realize the lattice-shaped polymer walls without patterned light irradiation using photomask. We clarified that the transfer method was effective for formation of polymer wall structure on flexible substrate.

We examined the novel aggregation control of the LC and monomer during formation of the polymer walls from a LC/monomer mixture in order to suppress the presence of the residual monomers and polymer networks in the pixel areas. The method is utilization of the differing wettabilities among LC and monomer molecules on a substrate surface. We patterned a substrate surface with a fluororesin and a polyimide film, and promoted phase separation of the LC and monomer by cooling process. This resulted in the LC and monomer aggregates primarily existing in the pixel areas and non-pixel areas, respectively. Moreover, the polymer-walls structure which was formed in this method partitioned into individual pixels in a lattice region and prevented the LC from flowing. This polymer-walls formation technique will be useful for developing high-quality flexible LCDs.

We have demonstrated the inverter operation of stacked-structure CMOS devices using pentacene and ZnO as active layers. The fabrication process of the device is as follows: A top-gate-type ZnO thin-film transistor (TFT), working as an n-channel transistor, was formed on a glass substrate. Then, a bottom-gate-type pentacene TFT, as a p-channel transistor, was fabricated on top of the ZnO TFT while sharing a common gate electrode. For both TFTs, solution-processed silicone-resin layers were used as gate dielectrics. The stacked-structure CMOS has several advantages, for example, easy patterning of active material, compact device area per stage and short interconnection length, as compared with the planar configuration in a conventional CMOS circuit.

Microwave circuits embedded in a multi-layer resin PCB are demonstrated using low loss resin materials. Resin materials for microwave frequencies were compared with conventional FR-4 with respect to dielectric and conductor loss factors, which proved that losses could be reduced drastically with the low loss material and design optimizations. Baluns, switches and BPFs were designed and fabricated to estimate microwave performances. Measured and simulated insertion losses of the circuits for 2.5 GHz band, were 0.3 dB for a switch, 0.4 dB for a balun and 2.0 dB for a 3-stage Chebyshev BPF. An integration of a switch, a BPF and two baluns was successfully implemented in a multi-layer PCB. Insertion losses of the fabricated integrated circuit were less than 3 dB with 0.1 dB additional loss compared with a sum of individual circuit losses. With estimated results of temperature characteristics and reliability as well as low loss performances, microwave circuits in resin PCBs can be considered as a viable candidate for microwave equipments.

We have developed a novel self-alignment process using the surface tension of the liquid resin for assembly of electronic and optoelectronic devices. Due to their characteristics of low surface tension, however, the parametric design guidelines are necessary for resin self-alignment capability. In this paper, a shape prediction mathematical model and a numerical method are developed. The developed system is capable of achieving the liquid joint geometry and the parametric design for self-alignment capability. The influences of geometric parameters such as liquid volume, component weight, pad radius, liquid surface tension on the shape of liquid joint are investigated. Furthermore, the parametric design guidelines considered the process-related practical matters of misalignment level, distribution of the supplied liquid volumes and coplanarity deviation includes difference of the height between the pads are provided.

We have developed a novel self-alignment process using the surface tension of the liquid resin for assembly of electronic or optoelectronic devices. Though the liquid resins have a characteristics as low as one tenth of the surface tension of solder in general, restoring forces for self-alignment capability can be produced by making it constrained on the 3-dimensional pads on chip and substrate. In this paper, its principle and characteristics are described and the relationship between process parameters and joint geometry were examined. And the possibility of self-alignment process was verified by analytic numerical method and scaled-up experiment. A self-alignment accuracy was examined experimentally and show that it became less than 0.4 µm. It can provide a useful information on various parameters involved in joint geometry and optimal design guideline to generate the proper profiles.

We examined the creep properties and hazard rates of plastic split alignment sleeves to ensure the long-term reliablity of optical fiber connections. It required a gauge retention force Fr of more than 200 gf to suppress the fluctuation in the insertion loss of a plastic sleeve. From the fluctuation data, we estimated the time-to-failure tf at which the Fr value became 200 gf. We estimated the acceleration parameters, median lifetimes ξ, and hazard rates λ by using the tf values based on the Weibull statistics. The ξ values decreased rapidly with increasing temperature and relative humidity. Small λ values of < 0.01 FITs and of 1 FITs were expected for 20 years in a normal atmosphere (25C/50%RH) and in a more severe case of 25C/90%RH or 45C/50%RH.

We successfully fabricated split alignment sleeves for single-mode operation with the injection-molding technique using both thermosetting epoxy resin and thermoplastic polyetherimide (PEI) resin. The relationship between the surface smoothness and the connection-loss characteristics of these injection-molded plastic sleeves was investigated. We made two-dimensional contour maps of the outer and inner surfaces of the plastic sleeves using the measured surface roughness. There were many contour lines on both the outer and inner surfaces of the PEI sleeve. In contrast, the epoxy sleeves had very smooth surface profiles. An offset Δr was estimated by using the inner-surface roughness data of the sleeve-ferrule contact regions. The connection loss of the sleeve increased as the Δr value increased. The measured losses agree fairly well with the theoretical losses estimated by using the Δr values. The PEI sleeves exhibited large Δr values, and one-third of them had large connection losses of > 0.5 dB. In contrast, the epoxy sleeves had very small Δr values of < 0.6 µm, and exhibited an average loss of < 0.1 dB.

This paper describes how voltage fluctuation in the DC power supply of a digital IC can be reduced, by means of molding the package-pin in a ferrite-resin composite. The voltage fluctuation of the DC power supply, when the input terminal was driven by a 40 MHz, 5 Vp-p pulse wave, was measured using an oscilloscope. Simultaneously, the voltage spectrum of the fluctuation was measured using a spectrum analyzer. As a result, the voltage fluctuation was decreased by about 50 % when the IC package-pins were molded in a ferrite-resin composite, in which the µiac of the ferrite powder equalled 100, and the powder content was 80 weight-%. In the same IC, there was the reduction effect of the voltage spectrum of the fluctuation was recognized in the frequency range 40 MHz to 1 GHz.

We successfully fabricated plastic ferrules and split alignment sleeves for single-mode fiber-optic connectors by the injection molding process. Liquid crystalline polymer (LCP) was used as the molding material for the ferrule. We introduced an eccentricity control mechanism into the ferrule mold and realized an eccentricity of less than 1 µm. As the molding material for the sleeve, thermosetting epoxy resin was used. Suitable mechanical properties were realized by employing appropriate dimensional design and the molding process. The optical characteristics of a system combining these plastic components are compatible with single-mode SC-type connectors and are also stable under hot and humid conditions.

The static fatigue parameters of plastic sleeves are determined by dynamic fatigue and destructive tests. The failure probability and lifetime of the plastic sleeve are estimated by using these parameters. No failure is expected for 20 years if the plastic sleeve is used in a normal atmosphere (23, 60%RH) and hot water (50).

Single-crystal LiNbO3 and LiTaO3 piezo-electric resonators were developed for surface-mount technology (SMT) used in electronic equipment manufacturing. Using an energy-trapping design, a shear-mode piezoelectric resonator chip is bonded directly to the board with conductive resin and covered with a ceramic cap. The process occasionally produces nonlinear resonators, however, which led us to study the frequency characteristics of impedances for the abnormal samples. Their input impedances at the resonant frequency depended on the driving voltage. The insulator between the thin film metal electrode on the crystal strip or the thick film electrode on the ceramic base, in conjunction with silver balls in the adhesive resin, apparently caused the problem. Assuming that the insulator makes diode contacts, which show stable nonohmic phenonena or cause a discharge in a conductor causing a drastically changing in the impedance, we proposed the following corrective action：subject the nonohmic contacts to a high-voltage frequency-swept signal near the resonant frequency. The samples subjected to the high voltages recovered metalic contact and maintained even after severe thermal cycle testing.