Optical circuit board and method for producing the same
View Patent ↗The optical circuit board includes a wiring board including a plurality of laminated insulating layers, and a wiring conductor disposed between the insulating layers; an optical waveguide including a lower clad layer, an upper clad layer and a core sandwiched between the lower clad layer and the upper clad layer, disposed on an upper surface of the wiring board, and extending in one direction; a reflection surface including an inner surface of a groove formed in a part of the core of the optical waveguide, and being perpendicular to an extending direction in a plane view and having a predetermined angle with respect to the upper surface in a cross sectional view; and a metal layer disposed on an upper surface of the insulating layer on the upper side than the wiring conductor of the wiring board, and set as a bottom surface of the groove.
1. A method for producing an optical circuit board, the method comprising:
preparing a wiring board comprising a lower insulating layer on the upper surface of which a lower-laver wiring conductor is deposited by a plating method, and an upper insulating layer on the upper surface of which an upper-laver wiring conductor is deposited by a plating method, and which is laminated on an upper surface of the lower insulating layer;
disposing an optical waveguide on an upper surface of the wiring board, and the optical waveguide comprising a lower clad laver, an upper clad layer and a core sandwiched between the lower clad layer and the upper clad layer; and
irradiating a laser beam obliquely from above the optical waveguide to divide the core, thereby forming a reflection surface to the core;
wherein in preparing the wiring board, a metal layer comprising copper and having a thickness of 10 to 15 μm is formed, simultaneously with the wiring conductor by the plating method, in a region where an irradiating axis of the laser beam and an upper surface of the upper insulating layer intersect, thereby preventing the laser beam from reaching below the upper insulating layer.
2. The method for producing an optical circuit board according to claim 1 , further comprising disposing a connection hole in the optical waveguide, the connection hole including a connection conductor electrically connected to the upper layer wiring conductor.