A mixed PdC1₂/SnCl₂ catalyst is widely applied as for the initiation of the electroless plating reaction on nonconductor. From the EDX analysis, we confirmed that palladium and palladium-tin alloy are formed on the nonconductor surface after mixed catalyst treatment. Adsorption amount of catalyst is greatly influenced by the treatment with the conditioning solution (conditioner) . Adsorption amount is increased with the addition of polyoxyethylene-alkylamine or polyvinyl-imidazole as the additives in the conditioner that hold cationic nature. From anodic polarization curves, it is assumed that disintegration of palladium (II) -tin (II) complex occurred on the treated substrate surface during the catalyst treatment if substrate is treated with conditioner.

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By using the maximum likelihood estimation, surface current distribution on a metal surface is estimated from magnetic fields measured near the metal surface. As a model source for the magnetic field, the authors made a metallic enclosure of a shape of rectangular paral-lelepiped with a narrow slit on one of its sides. The enclosure contains a loop antenna inside, and the electromagnetic field leaking out from the slit is measured near metallic enclosure to estimate the surface current distribution on it. The estimated surface current is found to be largest where the electromagnetic field is thought to be leaking out. In this way, it is possible to locate the vital position on the enclosure surface of an electronic equipment where electro-magnetic wave leaks out.

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The residual stress and warp deformation due to cooling in a three-layer laminated beam constructed with a LSI chip, adhesive and glass substrate were calculated by using the thermo-viscoelastic fundamental equations based on linear-viscoelastic theory. The warp deformation behavior during cooling processes depends on the constructive layered materials, and it could be achieved to design the proper constructive layered materials to prevent not only the warp deformation but the residual stress generated under cooling or heating processes. The results of this thermo-viscoelastic analysis show the necessity of the design for not only material properties but constructive layered material to achieve the higher reliable electronics devices.

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Thermosetting polyphenylene ether (PPE) resin S3100 having both high glass transition temperature (240°C) and excellent dielectric characteristics, was developed as an insulating material for multilayer printed circuit boards. Powder free prepreg was obtained by impregnating S3100 into E-glass cloth. Resin flow of S3100 prepreg was good enough to produce copper clad laminates and multilayer printed wiring boards (void free with 70μm thickness copper foil) . S3100 laminate was found to have both superior dielectric properties, such as ε=3.6, tan δ=0.002 at 1MHz, and very small thermal expansion. S3100 showed almost equal heat resistance with polyimide, for instance, durometer hardness and copper foil peel strength of S3100 laminate did not substantially decreased at 200°C . Since S3100 (with E-glass cloth) achieved sufficient dielectric properties without D-glass cloth, which might cause very rapid corrosion of drill, S3100 laminate could be drilled much easier than other low dielectric CCLs using D glass. Dielectric constant and dissipation factor of S3100 laminate at 1GHz were constant values throughout the whole temperature range between -20°C and 80°C, respectively, which is in sharp contrast with PTFE (drastic change in dielectricity around room temperature is inevitable) . Signal transmission loss for S3100 laminate was found to be less than 0.1dB/cm below 12GHz. S3100 multilayer printed wiring board was proved to have excellent durability in temperature-humidity cycle test, solder dip test, oil dip test, and thermal shock test.

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