Multilayer printed wiring board and manufacturing method of the multilayer printed wiring board

A multilayer printed wiring board comprising:

• a plurality of circuit boards each having an insulating layer and a conductive circuit formed on the insulating layer, wherein interlayer connection between the conductive circuits is achieved through a via hole which includes a conductor extending between the conductive circuits;
• a solder-resist layer formed on a front face of the conductive circuit on an outermost circuit board of the plurality of circuit boards;
• a plurality of openings in the solder-resist layer, each opening exposing a respective one of a plurality of solder pads such that the solder-resist layer overlaps a peripheral part of the respective one of the plurality of solder pads;
• and
• a corrosion resistant layer formed on a front face of only a portion of the conductive circuit on the outermost circuit board such that the plurality of solder pads comprises:
• a corrosion resistant layer formation pad including the corrosion resistant layer formed on the front face of the conductive circuit, and
• a corrosion resistant layer non-formation pad not including the corrosion resistant layer formed on the front face of the conductive circuit.