Printed wiring board

A method of manufacturing a printed wiring board, comprising:

• forming a connection conductor layer comprising a plurality of connection wirings;
• forming a resin insulating layer on the connection conductor layer such that the resin insulating layer has a plurality of openings;
• forming a mounting conductor layer on the resin insulating layer such that the mounting conductor layer includes a plurality of first electrodes and a plurality of second electrodes;
• and
• forming a plurality of connection via conductors including a plurality of first connection via conductors and a plurality of second connection via conductors in the resin insulating layer such that the first and second connection via conductors include a seed layer and an electrolytic plating layer formed on the seed layer, the first connection via conductors electrically connect the first electrodes and the connection wirings, and the second connection via conductors electrically connect the second electrodes and the connection wirings,
• wherein the mounting conductor layer is formed such that the plurality of first electrodes is positioned to mount a first electronic component and that the plurality of second electrodes is positioned to mount a second electronic component, and the first and second connection via conductors are formed such that the seed layer is covering an inner wall surface of each of the openings in the resin insulating layer and has a first portion and a second portion connected to the first portion and having a part of the first portion formed on the second portion.