We investigated fluororubber metallization using atmospheric UV, which has no environmental impact caused by chemical substances. No marked change was found in the contact angle, which is one indicator of successful plating pretreatment. When FT-IR and XPS were used to assess modification, no change was observed in FT-IR measurements. Modifications were observed in XPS measurements, presumably because modification occurred on the surface layer. When plated on fluororubber that had not been UV-treated, the adhesion strength was approximately 0.5 kN/m. However, results indicated that UV treatment increased it to 1.0 kN / m or more depending on the conditions. Results show that the surface of fluororubber containing calcium carbonate filler becomes smooth and reduces the adhesion strength in conditions of strong UV irradiation intensity.
Electroless Ni（3-5 μm）/Pd/Au plating processing has been applied to various printed circuit boards（PCB）. Recently, microfabrication of Cu patterns on PCB has advanced because of demands for high-performance electronic devices. This plating process must soon be able to provide improved plated film selectivity for fine patterns. For instance, thinning of Ni films and electroless precious metal plating processing without Ni plating have been described for the metallizing of fine patterns. Our earlier reports have described investigations of relations among various surface mounting characteristics and Ni film thicknesses（0.01-5 μm）on electroless Ni/Pd/Au plated films. Results confirmed that Ni film thickness of less than 0.1 μm must be achieved to obtain a selective plated film without deposition on a resin area. However, various surface mounting properties are thereby degraded. The surface mounting property deterioration occurs because of Cu voids by a displacement reaction on plating processes and because of unevenness of the Au surface morphology. For this study, we developed an electroless ultra-thin Ni/Pd/Au plating process without Pd catalyst treatment to resolve the subjects above and to achieve good selectivity and surface mounting properties. Furthermore, the various surface mounting properties were evaluated on electroless ultra-thin Ni/Pd/Au plated films. Results suggest that ultra-thin Ni/Pd/Au plating processes are applicable as electroless precious metal plating processes for fine Cu patterns.
Compared to DC plating, Sn plating films prepared using periodic reverse current（PR）were more effective at suppressing whiskers induced by external stress. Results obtained by XRD confirmed that they had almost entirely non-oriented structures and strong oxide films. However, the strains of both DC and PR plating were similar. The internal stresses were much weaker than the external stresses.