Multilayer printed wiring board and method of manufacturing the same

A method of manufacturing a multilayer printed wiring board including a plurality of layers formed on a laminate that is a lamination of an insulating substrate and a first wiring layer formed on the insulating substrate, wherein the method comprises:

• forming a first insulating layer on the laminate so as to cover the first wiring layer;
• forming a primer layer on the first insulating layer without forming a copper layer on the primer layer, the primer layer increasing adhesion between the first insulating layer and a copper electroless-plated layer;
• forming via holes penetrating the primer layer, and the first insulating layer to expose a surface of the first wiring layer;
• performing desmear treatment for removing smears generated in the via holes;
• forming the copper electroless-played layer on the surface of the primer layer and bottom surfaces and sidewall surfaces of the via holes;
• forming a resist pattern on a surface of the copper electroless-plated layer in regions where a second wiring layer is not to be formed, the resist pattern serving as a plating mask;
• forming the copper electroplated layer on a surface of the copper electroless-plated layer in regions where the resist pattern has not been formed;
• peeling the resist pattern;
• removing the copper electroless-plated layer in regions empty of the resist pattern to form a second wiring layer and expose the surface of the primer layer, the second wiring layer including the copper electroless-plated layer and the copper electroplated layer;
• forming a tin-plated layer on a surface of the second wiring layer and then forming a silane coupling layer on the surface of the tin-plated layer;
• and
• forming a second insulating layer so as to cover the primer layer and the second wiring layer where the tin-plated layer and the silane coupling layer have been formed.