Printed wiring board and method for manufacturing printed wiring board

A method for manufacturing a printed wiring board, comprising:

• forming a conductor layer on a surface of a base insulating layer such that the conductor layer includes a first conductor pad and a second conductor pad and that the first and second conductor pads have a same thickness;
• forming a solder resist layer on the surface of the base insulating layer such that a first opening of the solder resist layer exposes the first conductor pad of the conductor layer and that a second opening of the solder resist layer has a diameter smaller than a diameter of the first opening and exposes the second conductor pad of the conductor layer;
• forming, on the first conductor pad of the conductor layer, a first bump comprising a first base plating layer in the first opening of the solder resist layer and a first top plating layer on the first base plating layer;
• and
• forming, on the second conductor pad of the conductor layer, a second bump comprising a second base plating layer in the second opening of the solder resist layer and forming a second top plating layer on the second base plating layer such that the second bump has a diameter smaller than a diameter of the first bump,
• wherein the forming of the solder resist layer comprises forming the solder resist layer such that the first opening has an aspect ratio of 0.5 or less, and that the second opening has an aspect ratio of 0.6 or greater, the forming of the first bump includes forming the first base plating layer such that the first base plating layer has a first recess having a depth of 20 μm or less in an upper central portion, and the forming of the second bump includes forming the second base plating layer such that the second base plating layer has a second recess shallower than the first recess in the upper central portion.