We investigated the relationship between adhesion and internal stress to improve the adhesion of electroless pure Ni plating on a smooth alumina substrate, focusing on the energy balance in the interface between the substrate and the film. We measured both parts for unified energy (J/m²) and found the ideal adhesion energy. In the measured results, peel energy G_p is dependent on film thickness, and thicker film reduced the G_p of the Ni plating. Since the thickness of columnar crystal pure Ni plating film is more than 0.2 μm, columnar crystal pure Ni plating is highly adhesive on smooth alumina substrates. Interfacial adhesion energy G_ad which is the ideal adhesion energy is not simply the sum of peel energy G_p (adhesion) and internal strain energy G_in (internal stress); we also must consider bending energy G_bend, elastic energy G_el, and fracture energy G_f. The gains achieved reflect the high adhesion property of columnar crystal pure Ni plating compared to nano crystalline pure Ni plating. In this study we successfully controlled both the appearance of the void for the interface between the substrate and the film to minimize internal strain energy G_in, and the strength around the interface between the substrate and the film to minimize elastic energy G_el and fracture energy G_f.

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We propose a new test method for detecting open leads on ICs. The test method is based on using the supply current of a CMOS gate as an open lead detector; the current flows when an AC voltage signal is provided to a targeted lead with a probe as a stimulus. To evaluate the test method, we examined whether it could detect open leads in SSIs and LSIs. The experimental results confirm that open leads can be detected within 1 μsec by providing an AC voltage signal with an amplitude that is 60% of the power supply voltage of the targeted IC.

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As liquid crystal displays (LCDs) become larger, the homogeneity of the LCD panel becomes very important for the quality of the image. The inhomogeneity of an LCD panel can be caused by many factors: the inhomogeneity of materials, the production process, warping of the panel due to changes in temperature and humidity, and so on. In this study, we developed a scheme of hygro-mechanical analyses to predict the warpage of LCDs. First, the diffusion coefficient, Henry's law coefficient, and the coefficient of moisture expansion (CME) of each LCD component were measured. To confirm the validity of the analyses, the hygro-mechanical deformations of the various components in an LCD were analyzed using these measured material properties. The deformations obtained from the analysis correspond with the quantitative measurement results obtained experimentally. Finally, the warpage of an LCD panel was analyzed, and the analysis corresponds with the measurements qualitatively.

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This paper reports the design of a wave absorber composed of plaster board, a common building material, and conductive paper, for IEEE 802.11b/g (2.45 GHz) and IEEE 802.11a (5.2 GHz) wireless LANs. A plaster board of standard thickness was selected for this design and the resistance of the conductive paper was changed; the total thickness is 50 mm and the resistance is 194 Ω/□. The wave absorber was fabricated based on the design, and its absorption characteristics were measured. Furthermore, an installation test of this absorber was conducted in a shielded room and improvement of speech quality was observed. Thus, we have shown that a wave absorber for two frequencies commonly used in wireless LANs can be realized.

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