US 12,232,257 B2
Wiring substrate
Shunsuke Sakai, Ogaki (JP); Shuto Iwata, Ogaki (JP); Ikuya Terauchi, Ogaki (JP); and Takahiro Yamada, Ogaki (JP)
Assigned to IBIDEN CO., LTD., Ogaki (JP)
Filed by IBIDEN CO., LTD., Gifu (JP)
Filed on Nov. 24, 2021, as Appl. No. 17/456,390.
Claims priority of application No. 2020-207761 (JP), filed on Dec. 15, 2020.
Prior Publication US 2022/0192018 A1, Jun. 16, 2022
Int. Cl. H05K 1/11 (2006.01); H05K 1/18 (2006.01)
CPC H05K 1/111 (2013.01) [H05K 1/116 (2013.01); H05K 1/18 (2013.01); H05K 2201/096 (2013.01); H05K 2201/09609 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A wiring substrate, comprising:
an insulating layer;
a conductor layer formed on the insulating layer and including a conductor pad having a rectangular planar shape; and
a solder resist layer formed on the insulating layer such that the solder resist layer is covering the conductor layer formed on the insulating layer,
wherein the solder resist layer has an opening formed such that the opening is exposing 50% or more of an area of a surface of the conductor pad on an opposite side with respect to the insulating layer and that a side surface of the conductor pad and the surface of the conductor pad are entirely exposed except the side surface and surface of the conductor pad at at least one of corner portions of a peripheral edge of the conductor pad, and the solder resist layer is formed such that the solder resist layer has at least one covering portion covering the at least one of the corner portions of the conductor pad and that each of the corner portions has a curved outer edge.