Printed wiring board and method for manufacturing the same

A method for manufacturing a printed wiring board, comprising:

• forming a lower layer comprising a plurality of conductor layers and a plurality of insulating layers;
• forming a conductor layer on an outermost insulating layer of the plurality of insulating layer in the lower layer;
• forming a solder resist layer on the conductor layer such that the solder resist layer covers the conductor layer formed on the outermost insulating layer of the lower layer;
• and
• forming a two-dimensional code on the lower layer comprising the conductor layer and a portion of the solder resist layer such that the portion of the solder resist layer has a plurality of openings forming a plurality of exposed portions of the conductor layer and that the plurality of openings of the solder resist layer and the plurality of exposed portions of the conductor layer form the two-dimensional code structure,
• wherein the conductor layer includes a portion corresponding to the two-dimensional code structure such that the conductor layer has a degas pattern comprising a plurality of degassing holes and formed in the plurality of exposed portions of the conductor layer and that the portion of the conductor layer has a residual copper rate that is 80% or more and allows the two-dimensional code structure to be read, where the residual copper rate is a rate of an area with the degas pattern/an area without the degas pattern in the portion of conductor layer.