Printed wiring board

A method for manufacturing a printed wiring board, comprising:

• providing a resin insulating layer formed on a first conductor layer such that the resin insulating layer includes resin and inorganic particles;
• forming an opening in the resin insulating layer such that a portion of the inorganic particles has protruding portions protruding from an inner wall surface in the opening;
• and
• removing the protruding portions of the inorganic particles such that the inorganic particles include first inorganic particles forming the inner wall surface in the opening and second inorganic particles embedded in the resin insulating layer;
• forming a second conductor layer on the resin insulating layer such that the forming of the second conductor layer includes forming a seed layer and forming an electrolytic plating layer on the seed layer;
• and
• forming a via conductor in the opening formed in the resin insulating layer such that the via conductor connects the first conductor layer and the second conductor layer and includes the seed layer and electrolytic plating layer extending from the second conductor layer,
• wherein the second conductor layer and via conductor are formed such that the seed layer includes a first layer formed on the resin insulating layer and a second layer formed on the first layer such that the first layer comprises an alloy comprising copper, aluminum and silicon and that the second layer comprises copper, and the resin insulating layer is formed such that the inorganic particles contain oxygen and that shapes of the first inorganic particles are different from shapes of the second inorganic particles.