US 12,082,338 B2
Printed wiring board
Satoru Kawai, Ogaki (JP)
Assigned to IBIDEN CO., LTD., Ogaki (JP)
Filed by IBIDEN CO., LTD., Gifu (JP)
Filed on May 13, 2022, as Appl. No. 17/744,069.
Claims priority of application No. 2021-083265 (JP), filed on May 17, 2021.
Prior Publication US 2022/0369457 A1, Nov. 17, 2022
Int. Cl. H05K 1/11 (2006.01); H05K 3/40 (2006.01); H05K 3/46 (2006.01)
CPC H05K 1/112 (2013.01) [H05K 3/4007 (2013.01); H05K 3/4644 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A printed wiring board, comprising:
a resin insulating layer;
a plurality of pads formed on the resin insulating layer;
an uppermost resin insulating layer formed on the resin insulating layer such that the uppermost resin insulating layer is covering the plurality of pads and has a plurality of openings exposing the plurality of pads, respectively;
a plurality of via conductors formed in the uppermost resin insulating layer such that the plurality of via conductors is formed on the plurality of pads exposed from the plurality of openings in the uppermost resin insulating layer, respectively;
a plurality of metal posts formed on the plurality of via conductors such that each of the metal posts has a portion on a surface of the uppermost resin insulating layer around the via conductors and a side surface having a flared bottom extending toward the uppermost resin insulating layer; and
a plurality of plating films formed on the plurality of metal posts such that the plurality of plating films is covering the plurality of metal posts and the surface of the uppermost resin insulating layer around the plurality of metal posts, respectively,
wherein the plurality of via conductors is formed such that each of the via conductors includes a seed layer and an electrolytic plating film formed on the seed layer, and the plurality of via conductors and the plurality of metal posts are integrally formed in a same process such that each of the metal posts has an integral structure with a respective one of the via conductors.