Opto-electric hybrid board
An opto-electric hybrid board includes opto-electric module portions respectively defined on opposite end portions of an elongated insulation layer, and an interconnection portion defined on a portion of the insulation layer between the opto-electric module portions and including an optical waveguide. A metal reinforcement layer extends over the opto-electric module portions into the interconnection portion. A portion of the metal reinforcement layer present in the interconnection portion has a smaller width than portions of the metal reinforcement layer present in the opto-electric module portions, and has a discontinuity extending widthwise across the metal reinforcement layer. This arrangement makes it possible to protect the optical waveguide from the bending and the twisting of the interconnection portion, while ensuring the flexibility of the interconnection portion including the optical waveguide.
1. An opto-electric hybrid board comprising:
an elongated insulation layer;
an opto-electric module portion defined on at least one end portion of the insulation layer;
an elongated interconnection portion defined on a portion of the insulation layer extending from the opto-electric module portion; and
a metal reinforcement layer provided on a back surface of the insulation layer in the opto-electric module portion and in the interconnection portion;
wherein the opto-electric module portion includes a first electric wiring of an electrically conductive pattern provided on a front side thereof, and an optical element provided on the front side thereof;
wherein an elongated optical waveguide is provided on a back side of the interconnection portion and is optically coupled with the optical element provided on the opto-electric module portion;
wherein a portion of the metal reinforcement layer present in the interconnection portion has a smaller width than a portion of the metal reinforcement layer present in the opto-electric module portion; and
wherein the portion of the metal reinforcement layer present in the interconnection portion has a discontinuity extending widthwise across the metal reinforcement layer so as to separate the metal reinforcement layer in a longitudinal direction.
2. The opto-electric hybrid board according to claim 1 ,
wherein the discontinuity extending widthwise across the metal reinforcement layer is a discontinuity line including at least a discontinuity line portion extending longitudinally of the metal reinforcement layer or a discontinuity line portion extending obliquely with respect to a longitudinal direction of the metal reinforcement layer; and
wherein portions of the metal reinforcement layer separated widthwise of the metal reinforcement layer by the discontinuity line portion have a total width that is 0.8 to 1.2 times a width of a portion of the metal reinforcement layer which is present in the interconnection portion and which is not formed with the discontinuity.
3. The opto-electric hybrid board according to claim 1 , wherein the interconnection portion includes a second electric wiring.
4. The opto-electric hybrid board according to claim 1 , wherein the metal reinforcement layer has a rounded corner portion where the portion of the metal reinforcement layer present in the interconnection portion meets the portion of the metal reinforcement layer present in the opto-electric module portion.
5. The opto-electric hybrid board according to claim 1 , wherein an inner side of the portion of the metal reinforcement layer present in the interconnection portion has an elongated oval slit extending longitudinally.
6. The opto-electric hybrid board according to claim 1 , wherein the portion of the metal reinforcement layer present in the interconnection portion includes two elongated portions extending longitudinally.
7. The opto-electric hybrid board according to claim 1 ,
wherein the opto-electric module portion is defined on both end portions of the elongated insulation layer, and
wherein the portion of the metal reinforcement layer present in the interconnection portion includes two elongated portions extending longitudinally and disconnected in a middle portion of the interconnection portion; and an auxiliary elongated portion extending longitudinally in the middle portion of the interconnection portion.
8. The opto-electric hybrid board according to claim 1 ,
wherein the opto-electric module portion is defined on both end portions of the elongated insulation layer, and
wherein the portion of the metal reinforcement layer present in the interconnection portion includes a single elongated portion extending longitudinally and disconnected in a middle portion of the interconnection portion; and two elongated portions extending longitudinally in the middle portion of the interconnection portion so as to interpose the disconnected portion of the single elongated portion.