Glass-Substrate Waveguide Assembly for Low-Loss PIC Fiber Coupling
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Solution Overview
Problem
Silicon photonics packaging faces challenges due to mode field diameter mismatches and tight alignment tolerances, making fiber coupling compatibility and integration with electronic integrated circuits difficult.
Innovation Solution
Laser-based technology is used for low-loss coupling between optical fibers and photonic integrated circuits (PICs) through laser direct writing (LDW) and glass-to-glass bonding, enabling in situ waveguide formation in glass substrates to minimize coupling loss and facilitate efficient integration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If traditional packaging methods are used for silicon photonics, then manufacturing simplicity is maintained, but coupling loss increases and alignment precision deteriorates
Solution Approach 1:
The patent introduces a glass substrate as an intermediary component between the photonic integrated circuit and optical fibers. This glass substrate serves as a mediator that provides mechanical support, precise positioning, and optical coupling pathways, thereby reducing coupling loss while managing the overall packaging complexity through a dedicated intermediate structure.
Solution Approach 2:
The packaging structure is segmented into distinct functional components: the photonic integrated circuit module, the glass substrate with embedded waveguides, and the optical fiber coupling interface. This segmentation allows each component to be optimized independently for its specific function while maintaining overall system performance.
2Manufacturing precision
If mode field diameter matching is prioritized, then coupling efficiency improves, but alignment tolerance becomes tighter and manufacturing difficulty increases
Solution Approach 1:
The patent changes the physical parameters of the coupling interface by using a glass substrate with specific optical and mechanical properties. The glass substrate's refractive index, thickness, and waveguide dimensions are optimized to match the mode field diameter of both the photonic integrated circuit and optical fibers, thereby improving coupling efficiency while maintaining manufacturability through controlled parameter selection.
3Reliability
If tight alignment tolerance is enforced, then coupling efficiency improves, but manufacturing complexity and cost increase
Solution Approach 1:
The alignment features and waveguide pathways are pre-formed in the glass substrate during manufacturing, establishing precise geometric relationships before final assembly. This preliminary action of creating fixed alignment references in the glass substrate reduces the alignment tolerance requirements during assembly, thereby improving coupling reliability while reducing manufacturing complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for low-loss, high-voltage compatible silicon photonics packaging with improved data transmission capabilities and reduced misalignment issues.
Implementation Method 1
an embedded waveguide is made through laser direct writing (LDW)
Implementation Method 2
embedded waveguide is made through laser direct writing (LDW)
Implementation Method 3
laser made glass-to-glass bonds are used
Data Source
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Figure 3A~3D
AI summary
The invention relates to a semiconductor assembly (100; 200) comprising a first glass substrate (110), an electronic integrated circuit EIC (120), a photonic integrated circuit PIC (130) comprising an optical port (132), a bridge die (150) connecting the PIC and the EIC dies, wherein the bridge die is embedded in the first glass substrate; and comprising a coupling adapter (114) comprising a coupling port (144) configured for connecting to an optical fiber, and a waveguide (140) integrated with the coupling adapter. The invention further relates to a method of making a semiconductor assembly, the method comprising attaching a bridge die to a glass substrate, attaching an electronic integrated circuit die to the glass substrate and the bridge die, attaching a photonic integrated circuit die to the glass substrate and the bridge die, wherein the electronic integrated circuit die is electrically coupled to the photonic integrated circuit die through the bridge die, bonding a coupling adapter to the glass substrate, and forming a waveguide in the coupling adapter, the waveguide aligning with the photonic integrated circuit die, wherein forming the waveguide comprises a laser directed wiring.