Nec Corporation

Sumitomo Bakelite Corporation Limited

Eiji Maehata

Toshio Komiyatani

A fabrication method of a printed wiring board realizing high adhesion strength of a patterned conductive layer while keeping the high insulation reliability between adjacent conductive paths. First, an adhesive material is prepared, which is a mixture of a photo-setting resin as a matrix, fine particles of a photolyzable resin dispersed in the photo-setting resin, and a metal-organic compound/complex mixed with the photo-setting resin. The adhesive material is coated on an insulative base material to form an adhesive layer. The adhesive layer is then selectively exposed to light, selectively curing the photo-setting resin and selectively photolyzing the particles of the photolyzable resin. The exposed adhesive layer is developed by an alkaline developer solution, thereby transferring the pattern on the mask to the adhesive layer and removing the photolyzed particles for surface roughening of the remaining, unexposed parts of the adhesive layer. The metal-organic compound/complex in the unexposed parts of the adhesive layer is reduced for activation, causing the metal-organic compound/complex to reveal plating catalytic activity. A conductive layer is selectively formed on the unexposed parts of the adhesive layer by electroless plating performed under the plating catalytic activity of the activated metal-organic compound/complex.

Fabrication method of printed wiring board

An adhesive for a printed circuit board which consists essentially of a dispersion of a resin which is soluble in an alkaline oxidizing agent after curing in a resin matrix which is sparingly soluble in an alkaline oxidizing agent after curing, and a process for producing a printed circuit board using the above adhesive.

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Tokyo, Japan

Eiji Maehata