Printed wiring board

A printed wiring board, comprising:

• a first conductor layer;
• a resin insulating layer formed on the first conductor layer;
• a second conductor layer formed on a surface of the resin insulating layer;
• and
• a via conductor formed in the resin insulating layer such that the via conductor is connecting the first conductor layer and the second conductor layer and has a land portion extending on a boundary part of the resin insulating layer,
• wherein the via conductor is formed in a via hole formed in the resin insulating layer, and the resin insulating layer is formed such that the boundary part has a surface roughness that is larger than a surface roughness of the surface on which the second conductor layer is formed and that a surface roughness of an inner wall surface in the via hole formed in the resin insulating layer is equal to or larger than the surface roughness of the boundary part of the resin insulating layer.