| abstract |
PROBLEM TO BE SOLVED: To improve the adhesion between a copper conductor exposed after development of a photoselective thermosetting paint and a noble metal plated on the conductor, and to improve migration resistance, A coating with less deterioration of electrical insulation after pressure cooker is provided by the paint. SOLUTION: A photo-selective thermosetting paint, particularly preferably a paint containing a polyfunctional cyanate compound, is applied to the surface of a printed wiring board, dried, exposed to light and developed to form a coating film, and after thermosetting. A method of treating a copper foil before noble metal plating, in which a resin residue attached to the surface of a copper conductor exposed by development is removed by plasma treatment, and nickel plating and gold plating are performed. |