The ignition properties of PP (polypropylene) and HIPS (high impact polystyrene) as general use plastics, PC (polycarbonate) as an engineering plastic, and ABS (acrylonitril-styrene-butadiene copolymer) were studied. The specimens were placed at a plane view position (position in which the heat source irradiates a plane of the specimen: P-position) and at a side view position (S-position) and ignited by a burner. The critical heat flux (Hc) depended on the shape of the specimen and the excess heat (Q) depended on the kind of polymer at the P-position. On the other hand, at the S-position the Hc depended on the kind of polymer and Q depended on the shape. Thus, we see that fire risk in electrical parts is affected by not only by the kind of polymer but also by the shape of the specimen.

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An emboss patterned interface was formed between an electrode and an insulator in LTCC (Low Temperature Cofired Ceramics) . Preparing a resist film on which a micro pattern had already been formed, and inserting the resist film between a release film and specimen slurry during the green sheet formation process, the emboss pattern was produced on the green sheet. This formation was applied to a silver conducting sheet, and the sliver sheet showed excellent emboss formation. Making use of the obtained embossed silver sheet, emboss interface patterns were formed between the electrode and the insulator by coating glass ceramic slurry on the embossed structure. The embossed line was 30 μm and the height was 25 μm. Realizing this kind of fine embossed structure is quite difficult using only conventional formation methods. Also, this embossed microstructure is expected to have applications for filters or other devices that require complicated electrical interfaces.

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We have fabricated a refined copper wiring pattern with a super-connect level on insulating low-k resin, and embedded it in the same insulating resin. We made it by means of a semi-additive process, which enables a flat connection between the copper pattern and the insulating resin. The surface of the copper pattern was processed with a black-oxide treatment (adhesion-promoting copper surface treatment) . The sample was prepared both with and without “A” treatment. The aim of“A”treatment is improvement of the bonding strength between the resins. This paper aims to evaluate the ionic migration durability of the newly developed sample under high temperature and high humidity conditions. We investigated the influence of the treatment that fosters ionic migration, and adopted a mainly AC-impedance method for the analysis of the ionic migration. The impedance analysis gave the initial information for the ionic migration. This analysis method could be used for the estimation of forthcoming ionic migrations.

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