Semiconductor Optical Modulator Wiring Support
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing semiconductor optical modulators with air-bridge wiring suffer from sagging due to self-weight, leading to optical waveguide deterioration, and close electrode-waveguide positioning causes parasitic capacitance, degrading modulation characteristics.
Innovation Solution
A semiconductor optical modulator design featuring a resin layer that embeds and supports the wiring, preventing sagging and minimizing parasitic capacitance by positioning the wiring and build-up portions apart from the waveguide, with the wiring extending in intersecting directions and the build-up portions connecting them in a three-dimensional configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the air-bridge wiring is made long to connect the slot-line electrode and optical waveguide, then the wiring can be positioned apart from the waveguide, but the wiring sags down due to self-weight and pulls the optical waveguide, causing deterioration
Solution Approach 1:
The patent introduces a support structure (resin layer with recess portion) that counteracts the self-weight of the air-bridge wiring, preventing sagging. The wiring is positioned in a recess of the resin layer, creating a support mechanism that balances gravitational force on the wiring.
Solution Approach 2:
The resin layer acts as an intermediary between the wiring and the substrate, providing mechanical support and isolation. The recess portion in the resin layer specifically mediates the support function for the wiring, preventing direct contact with the optical waveguide while maintaining structural integrity.
2Length of stationary object
If the air-bridge wiring is made short to prevent sagging, then the wiring maintains its position, but the slot-line electrode and optical waveguide are positioned close to each other, causing parasitic capacitance
Solution Approach 1:
The patent utilizes vertical dimensionality by creating a recess in the resin layer at a depth that positions the wiring away from the optical waveguide plane. This three-dimensional arrangement allows sufficient separation distance to minimize parasitic capacitance while maintaining electrical connectivity.
3Productivity
If the wiring is extended to improve frequency modulation characteristics, then the modulation bandwidth increases, but the wiring becomes more prone to sagging and reliability decreases
Solution Approach 1:
The resin layer with recess portion provides continuous mechanical support along the wiring path, counteracting self-weight effects that would otherwise limit the maximum usable wiring length. This enables longer wirings to be deployed for improved bandwidth without sacrificing reliability.
Data Source
AI summary
A semiconductor optical modulator includes a substrate having a principal surface; a waveguide disposed on the principal surface of the substrate, the waveguide extending in a first direction; a first electrode disposed on the waveguide, the first electrode being in contact with an upper surface of the waveguide; a first wiring connected to the first electrode, the first wiring extending in a second direction intersecting the first direction; a build-up portion connected to the first wiring; a second wiring connected to the build-up portion, the second wiring extending in a plane parallel to the principal surface of the substrate; and a resin layer disposed on the substrate, the resin layer embedding the first wiring and the build-up portion. The build-up portion extends along a third direction, the third direction intersecting perpendicularly to the principal surface of the substrate. The second wiring is disposed on the resin layer.