Electroless plating process and process for producing multilayer wiring board

An electroless plating process comprising irradiating a surface of a workpiece with a radiation energy beam to effect activation of the surface necessary for electroless plating,

• wherein irradiation of the surface of said workpiece with said radiation energy beam is effected in a solution not containing plating ions to allow activation of the surface and subsequent formation of a plating film to sequentially proceed on said surface, subsequently the activated workpiece is immersed in an electroless plating liquid to form a plating film, and
• the activation of the surface of said workpiece with said radiation energy beam is effected without a previous activation treatment with an activating liquid.

An electroless plating process comprising irradiating a plating portion of a workpiece with a radiation energy beam to effect activation of said plating portion necessary for electroless plating so as to form a damaged portion, and

• contacting said plating portion of said workpiece with an electroless plating liquid during and/or after the irradiation to selectively form a plating film on said damaged portion;
• the activation of said plating portion of said workpiece with said radiation energy beam being effected without a previous activation treatment with an activating liquid.

An electroless plating process as claimed in claim 7 or 9, wherein said plating film is formed by contacting said portion of said workpiece with an electroless plating liquid after formation of said damaged portion.

A process for producing a multilayer wiring board comprising supplying a laser beam and a plating liquid to a connector part to form a pole by plating for effecting interlayer connection between a conductor layer and another conductor layer formed thereon in a high-intensity packaging board,

• wherein the connector part is irradiated with the laser beam so as to allow activation and subsequent formation of a plating film to sequentially proceed in the plating liquid, and
• wherein the activation of the connector part with the laser beam is effected without a previous activation treatment with an activating liquid.

A process for producing a multilayer wiring board as claimed in claim 13, wherein an insulating layer is formed after the formation of said pole by plating.

A process for producing a multilayer wiring board as claimed in claim 14, wherein said pole by plating is formed in a through-hole preliminarily formed.