US Patent No. 10,368,438

PRINTED WIRING BOARD AND METHOD FOR MANUFACTURING THE SAME


Patent No. 10,368,438
Issue Date July 30, 2019
Title Printed Wiring Board And Method For Manufacturing The Same
Inventorship Hiroyuki Nishioka, Ogaki (JP)
Shinsuke Ishikawa, Ogaki (JP)
Assignee IBIDEN CO., LTD., Ogaki (JP)

Claim of US Patent No. 10,368,438

1. A printed wiring board, comprising:a laminated base material comprising an insulating layer and a pad conductor layer formed on the insulating layer;
a first solder resist layer laminated on a surface of the laminated base material and comprising a photosensitive resin material; and
a second solder resist layer comprising a photosensitive resin material and forming a surface portion such that the first solder resist layer is forming a portion in contact with the laminated base material on an opposite side with respect to the surface portion,
wherein the pad conductor layer of the laminated base material has a pattern including a plurality of conductor pads in contact with the first solder resist layer such that the conductor pads are positioned in opening portions formed in the first and second solder resist layers, respectively, and the first and second solder resist layers satisfy at least one of a first condition that a chemical species derived from a photopolymerization initiator has a concentration that is higher in the first solder resist layer than a concentration in the second solder resist layer and a second condition that the chemical species derived from the photopolymerization initiator in the first solder resist layer has photopolymerization initiating ability higher than a chemical species derived from a photopolymerization initiator in the second solder resist layer.