US 12,216,315 B2
Protrusion dam-protected reflecting metal films in a substrate-supported optical waveguide, and optical communication device
Kazunao Yamamoto, Nagano (JP)
Assigned to SHINKO ELECTRIC INDUSTRIES CO., LTD., Nagano (JP)
Filed by SHINKO ELECTRIC INDUSTRIES CO., LTD., Nagano (JP)
Filed on Dec. 20, 2022, as Appl. No. 18/068,745.
Claims priority of application No. 2022-001649 (JP), filed on Jan. 7, 2022.
Prior Publication US 2023/0221506 A1, Jul. 13, 2023
Int. Cl. G02B 6/42 (2006.01)
CPC G02B 6/4214 (2013.01) 13 Claims
OG exemplary drawing
 
1. A substrate with optical waveguide, comprising:
a wiring substrate; and
an optical waveguide formed on the wiring substrate, wherein the optical waveguide includes
a first cladding layer,
a first metallic film forming protrusion, formed on an upper surface of the first cladding layer, and including an inclined surface that is inclined with respect to the upper surface of the first cladding layer,
a first metallic film formed on at least the inclined surface of the first metallic film forming protrusion,
a core layer formed on the upper surface of the first cladding layer so as to cover a portion of the first metallic film,
a second cladding layer formed on the upper surface of the first cladding layer, so as to cover at least an upper surface and both side surfaces of the core layer, and
a pair of first protrusions, formed on the upper surface of the first cladding layer with the core layer interposed therebetween in a plan view, and protruding from the upper surface of the first cladding layer, so as to be separated from the core layer and the first metallic film forming protrusion, wherein
the core layer and the pair of first protrusion are formed of a photosensitive resin,
the first metallic film forming protrusion includes a first central portion overlapping the core layer in the plan view, a first wide portion extending from the first central portion and protruding from one side surface of the core layer, and a second wide portion extending from the first central portion and protruding from the other side surface of the core layer, and
when the first metallic film is viewed in a direction perpendicular to an end surface of the core layer, the core layer overlaps the first metallic film formed at the first central portion, and one of the pair of first protrusions includes a portion overlapping the first metallic film formed at the first wide portion, and the other of the pair of first protrusions includes a portion overlapping the first metallic film formed at the second wide portion.