Light Modulation Device
An object of the present invention is to provide a light modulation device capable of preventing deformation of an optical modulation element due to warpage of a TEC. The light modulation device of the present invention includes an optical modulation element that is flip-chip connected on a high-frequency wiring substrate, a temperature controller that controls a temperature of the optical modulation element, a heat spreader that is connected to the temperature controller, and a deformable adhesive layer that connects the temperature controller and the optical modulation element on a surface different from the heat spreader and is deformable in response to stress caused by deformation of the temperature controller
1 . A light modulation device, comprising:
an optical modulation element being flip-chip connected on a high-frequency wiring substrate;
a temperature controller configured to control a temperature of the optical modulation element;
a heat spreader being connected to the temperature controller; and
a deformable adhesive layer configured to connect the temperature controller and the optical modulation element on a surface different from the heat spreader, the deformable adhesive layer being deformable in response to stress caused by deformation of the temperature controller.
2 . The light modulation device according to claim 1 , wherein the temperature controller and the heat spreader are bonded by an adhesive layer, and
a viscosity of the deformable adhesive layer is lower than a viscosity of the adhesive layer between the temperature controller and the heat spreader.
3 . The light modulation device according to claim 1 , wherein a spatial distance between the optical modulation element and a heat absorbing surface of the temperature controller is at least 10 μm or more.
4 . The light modulation device according to claim 2 , wherein the adhesive layer inserted between the temperature controller, and the heat spreader is thermally cured and fixed.
5 . The light modulation device according to claim 1 , wherein a silicone resin is used for the deformable adhesive layer inserted between the temperature controller and the optical modulation element.
6 . The light modulation device according to claim 1 , wherein on the high-frequency wiring substrate, a driver IC chip is flip-chip connected.
7 . The light modulation device according to claim 1 , wherein a power supply terminal of the temperature controller is connected by a lead wire, and
power is supplied to the lead wire outside the heat spreader.
8 . The light modulation device according to claim 1 , wherein a thin-film resistance pattern is provided on the high-frequency wiring substrate, the thin-film resistance pattern being used as a termination resistor of a high-frequency signal propagated on the optical modulation element.