US 12,259,652 B2
Photosensitive dry film, and printed wiring board with photosensitive dry film
Ryoya Takashima, Iruma (JP); Masanobu Ishizaka, Iruma (JP); and Shinji Imai, Iruma (JP)
Assigned to TAMURA CORPORATION, Tokyo (JP)
Filed by TAMURA CORPORATION, Tokyo (JP)
Filed on Aug. 20, 2021, as Appl. No. 17/408,307.
Claims priority of application No. 2020-142991 (JP), filed on Aug. 26, 2020; and application No. 2021-127896 (JP), filed on Aug. 4, 2021.
Prior Publication US 2022/0066322 A1, Mar. 3, 2022
Int. Cl. G03F 7/11 (2006.01); G03F 7/027 (2006.01); G03F 7/033 (2006.01); G03F 7/038 (2006.01); G03F 7/30 (2006.01); H05K 3/00 (2006.01); H05K 3/28 (2006.01)
CPC G03F 7/027 (2013.01) [G03F 7/033 (2013.01); G03F 7/0385 (2013.01); G03F 7/11 (2013.01); G03F 7/30 (2013.01); H05K 3/0023 (2013.01); H05K 3/281 (2013.01); H05K 3/287 (2013.01)] 6 Claims
 
1. A photosensitive dry film comprising a support film having a first main surface and a second main surface opposite to the first main surface, and a photosensitive resin layer provided on the first main surface, wherein
the first main surface has an irregular surface formed by chemical etching, and
wherein an arithmetic average surface roughness Sa of the irregular surface of the first main surface is 0.40 μm or more and 1.00 μm or less,
wherein the photosensitive resin layer is formed from a photosensitive resin composition, and the photosensitive resin composition comprises an aliphatic-based urea compound (C), and
wherein the aliphatic-based urea compound comprises a cyclic aliphatic structure.
 
6. A method for producing a printed wiring board, comprising:
a step of bonding the photosensitive resin layer of the photosensitive dry film according to claim 1, to a printed wiring board,
a step of applying ultraviolet light from above the support film of the photosensitive dry film, to photocure the photosensitive resin layer,
a step of releasing the support film from the photosensitive dry film and developing the photosensitive resin layer photocured, to form a photocured film having a predetermined pattern, and
a step of subjecting the photocured film having a predetermined pattern to a thermal curing treatment, to form a cured film having an irregular surface section, wherein
an arithmetic average surface roughness Sa of the irregular surface section of the cured film is 0.40 μm or more and 1.00 μm or less.