Michio Horiuchi

Electrochemical Power Generation Directly from Combustion Flame of Gases, Liquids, and Solids

The performance of a solid oxide fuel cell fueled with flames of combustible gases, liquids, and solids was studied. A cell structure in which cells were serially integrated within a disk was also examined. Open-circuit voltages indicated with a single cell and the integrated cell were ∼0.8 and ∼3.5 V, respectively. Maximum power density obtained with the flames of n-butane, kerosine, paraffin wax (candle), and wood were respectively 75, 65, 62, and 5 mW/cm 2 . The integrated cell gave a maximum power density of 318 mW/cm 2 with n-butane flame. Fuel to air ratio distinctly influenced the output.

Direct-Flame Solid-Oxide Fuel Cell (DFFC): A Thermally Self-Sustained, Air Self- Breathing, Hydrocarbon-Operated SOFC System in a Simple, No-Chamber Setup

We present a combined experimental and modeling study of a direct-flame type solid oxide fuel cell (DFFC). The operation principle of this system is based on the combination of a flame with an SOFC in a simple, no-chamber setup. Experiments were performed using 13-mm-diameter planar SOFCs with Ni-based anode, samaria-doped ceria electrolyte and cobaltite cathode. At the anode, a 7-mm-diameter flat-flame burner provided methane/air rich premixed flames. The cell performance reaches power densities of up to 200 mW/cm2. A detailed analysis of the electrical efficiency is carried out. Observed system efficiencies are below 0.5%. Equilibrium calculations of the flame exhaust gas were performed. From the simulations, both H2 and CO were identified as species that are available as fuel for the SOFC.

Copper-filled anodic aluminum oxide: A potential substrate material for a high density interconnection

To realize high density 3D packaging, various types of interposer including through vias are developed. Although the interposer should have a high wiring density not only horizontally but also vertically, the ability of the conventional interposers to provide high density through vias with a low cost is still quite limited. Copper-filled anodic aluminum oxide has been studied as an alternative interposer material. Stable electrical connection was confirmed with four-wiring-layer substrates. High density vias as fine as 35 μm pitch were realized as a ground-surrounded structure. This coaxial-like via structure was remarkably effective for reducing harmful noise that tends to increase with the increased via density required for high performance systems.

Mullite ceramic substrate for thin-film application

The advantages of mullite ceramic for thin-film application are examined. Using homogeneous powder, a dense mullite substrate consisting of fine mullite grains was provided without the addition of a sintering aid. The properties obtained are superior to those of the mullite presented by M. Horiuchi et al. (1988) and a conventional alumina for application to packages and substrates: low dielectric constant

Efficient Bump-Pad Geometries to Relax Design Rules Required for High Density I/O Area Array Packaging

Continuous increase in density of interconnection is demanded as a result of advances in the performance of electronic devices. Because a finer design rule is necessary in the conventional routing design to achieve the higher density, especially in the chip-to-package connection, this trend will bring various problems in both its manufacturing process and reliability. To avoid such a risk, approaches from an escape routing design standpoint might be expected to give an effective solution. This paper presents a design method efficient to relax the severe demands for an ultra-fine wiring rule that leads to a costly manufacturing process and a poor interconnection reliability. This method has been developed focusing on a bump-pad geometry that provides an efficient hybrid channel allowing a higher routability. A specific pad geometry ldquomicrovillirdquo type hybrid channel has been revealed to be applicable in both square grid and hexagonal arrays and to achieve a notable relaxing in trace width and spacing. With this hybrid channel, traces with twice the width become allowable for escape routing compared with the conventional geometry. The effects of this relaxation, not only on manufacturing cost but also on the performance and reliability of packaging, are discussed.