Abstract: A printed circuit board includes an insulating layer; a metal pad disposed on one side of the insulating layer; a via hole penetrating through the insulating layer to expose at least a portion of the metal pad; and a via filling at least a portion of the via hole, wherein the via comprises a first metal layer and a second metal layer disposed on the first metal layer, and an average size of grains in the first metal layer and an average size of grains in the second metal layer are different from each other.

Abstract: A printed circuit board includes an insulating layer; a metal pad disposed on one side of the insulating layer; a via hole penetrating through the insulating layer to expose at least a portion of the metal pad; and a via filling at least a portion of the via hole, wherein the via comprises a first metal layer and a second metal layer disposed on the first metal layer, and an average size of grains in the first metal layer and an average size of grains in the second metal layer are different from each other.

Abstract: A method for plating a printed circuit board, includes placing a substrate, including a through hole, in contact with a plating solution and disposing the substrate to face an electrode; and applying a pulsed current to each surface of the substrate, including applying pulsed currents of opposite polarity to both surfaces of the substrate at least once and applying pulsed forward currents to both surfaces of the substrate at least once, to plate from a middle to an end of the through hole.

Abstract: A method for plating a printed circuit board, includes placing a substrate, including a through hole, in contact with a plating solution and disposing the substrate to face an electrode; and applying a pulsed current to each surface of the substrate, including applying pulsed currents of opposite polarity to both surfaces of the substrate at least once and applying pulsed forward currents to both surfaces of the substrate at least once, to plate from a middle to an end of the through hole.

Abstract: A method for plating a printed circuit board, includes placing a substrate, including a through hole, in contact with a plating solution and disposing the substrate to face an electrode; and applying a pulsed current to each surface of the substrate, including applying pulsed currents of opposite polarity to both surfaces of the substrate at least once and applying pulsed forward currents to both surfaces of the substrate at least once, to plate from a middle to an end of the through hole.

Abstract: A printed circuit board includes a substrate having a first surface and a second surface, opposite to the first surface, and having a through-portion penetrating between the first surface and the second surface; and a through-via disposed in at least a portion of the through-portion, wherein the through-via includes a first metal layer having a first groove portion facing an interior of the through-portion from the first surface of the substrate and a second groove portion facing the interior of the through-portion from the second surface of the substrate, and the first metal layer has a first region, and a second region, having different average grain sizes.