Patent ID: 8737087

Claim:
A printed wiring board, comprising: an insulating base; a first conductive circuit formed on a first surface of the insulating base; a second conductive circuit formed on a second surface of the insulating base on an opposite side with respect to the first surface of the insulating base; a first solder-resist layer covering the first conductive circuit and having a plurality of openings exposing a plurality of portions of the first conductive circuit such that the plurality of openings of the first solder-resist layer forms a plurality of first solder pads, respectively; and a second solder-resist layer covering the second conductive circuit and having a plurality of openings exposing a plurality of portions of the second conductive circuit such that the plurality of openings of the second solder-resist layer forms a plurality of second solder pads, respectively, wherein the plurality of first solder pads includes a plurality of pads having a plurality of surface portions, respectively, and the plurality of second solder pads includes a plurality of pads having a plurality of surface portions different from the surface portions of the plurality of pads in the plurality of first solder pads, respectively, and wherein the plurality of openings in the first solder-resist layer exposes the plurality of portions of the first conductive circuit such that the first solder-resist layer overlaps peripheral portions of the first solder pads, respectively, the plurality of openings in the second solder-resist layer exposes the plurality of portions of the second conductive circuit such that the second solder-resist layer overlaps peripheral portions of the second solder pads, respectively, the plurality of pads in the plurality of first solder pads is a plurality of corrosion resistant layer formation pads each having a corrosion resistant layer formed on one of the portions of the first conductive circuit with respect to the corrosion resistant layer formation pads, and the plurality of pads in the plurality of second solder pads is a plurality of corrosion resistant layer non-formation pads each not having a corrosion resistant layer on one of the portions of the second conductive circuit with respect to the corrosion resistant layer non-formation pads.