Printed wiring board and method for manufacturing the same

A method for manufacturing a printed wiring board, comprising:

• forming a penetrating hole in an interlayer resin insulation layer;
• forming a conductive circuit on a first surface of the interlayer resin insulation layer;
• forming a filled via conductor in the penetrating hole of the interlayer resin insulation layer such that the filled via conductor is connected to the conductive circuit;
• forming a first surface-treatment coating structure comprising an electroless plating structure on a first surface of the filled via conductor;
• and
• forming a second surface-treatment coating structure comprising an electroless plating structure on a second surface of the filled via conductor on an opposite side with respect to the first surface-treatment coating structure such that the first surface-treatment coating structure has a thickness which is different from a thickness of the second surface-treatment coating structure,
• wherein the filled via conductor comprises a first conductive layer formed on a side wall of the penetrating hole and a plated material filling the penetrating hole.