Selective electroless plating process for metal conductors

A method for selectively depositing an overcoat metal on a metal conductor disposed on a dielectric surface of a substrate, comprising the following steps in the sequence set forth:

• removing carbonized film from the dielectric surface;
• activating the metal conductor to allow electroless plating thereon by dipping the substrate in a metal activator solution;
• deactivating the dielectric surface to prevent electroless plating thereon without deactivating the metal conductor by dipping the substrate in a deactivator acid solution;
• and
• plating an overcoat metal on the metal conductor by dipping the substrate in an electroless plating solution, wherein the overcoat metal coats the metal conductor without plating the dielectric surface.

A method for electrolessly plating an overcoat metal on a metal conductor disposed on a dielectric surface of a substrate, comprising the following steps in the sequence set forth:

• removing carbonized film from the dielectric surface by applying a plasma discharge;
• acid treating the metal conductor by dipping the substrate in a first acid solution in order to clean the surface of the metal conductor;
• activating the metal conductor to allow electroless plating thereon by dipping the substrate in a metal activator solution;
• deactivating the dielectric surface to prevent electroless plating thereon without deactivating the metal conductor by dipping the substrate in a second acid solution;
• and
• plating an overcoat metal on the metal conductor by dipping the substrate in an electroless plating solution, wherein the overcoat metal plates on and coats the metal conductor without plating on the dielectric surface.