Multilayer Planar Waveguide Interconnects for Dense Low-Power Chip Links
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing chip-to-chip interconnects in integrated circuits face limitations in density and power consumption, falling short of intra-chip interconnects due to fundamental constraints of electrical interconnects, which hinder high-performance computing and networking applications.
Innovation Solution
Implementing a multilayer optical interconnect system using microLEDs and photodetectors with a multilayer planar waveguide that couples light between transceiver arrays, allowing for increased density and reduced power consumption through optical connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If chip-to-chip electrical interconnects are used, then connectivity between chips is achieved, but density is limited and power consumption is high
Solution Approach 1:
The patent substitutes electrical interconnects with optical interconnects using waveguides. Light propagates through dielectric waveguide structures formed by depositing layers of materials with different refractive indices (e.g., silicon nitride, silicon dioxide) on a substrate, replacing the electrical field-based transmission with optical field-based transmission to reduce power consumption and increase density.
Solution Approach 2:
The patent employs multi-layer waveguide structures where light can propagate in multiple vertical layers and be coupled between layers using grating couplers or evanescent coupling. This three-dimensional waveguide architecture increases interconnect density by utilizing the vertical dimension in addition to the horizontal plane, allowing more interconnects per chip area.
2Length of stationary object
If electrical interconnect length is increased, then connectivity distance is improved, but resistance and capacitance increase leading to performance degradation
Solution Approach 1:
The patent replaces electrical signal transmission through conductors with optical signal transmission through dielectric waveguides. Optical signals do not suffer from RC time constant limitations that constrain electrical interconnects, allowing for longer interconnect lengths without signal integrity degradation. The waveguide structure confines light through total internal reflection, maintaining signal quality over extended distances.
3Quantity of substance
If conductor width is reduced to increase density, then interconnect density improves, but resistance increases and power consumption increases
Solution Approach 1:
The patent substitutes electrical conductors with optical waveguides made of dielectric materials. Optical waveguides can be made extremely narrow (sub-micron dimensions) without suffering from the resistance increase that plagues electrical conductors. The confining dimension of the waveguide determines the mode size, and power consumption is determined by the coupling efficiency and propagation loss rather than resistive heating, enabling high-density interconnects with low power dissipation.
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
The multilayer optical interconnects achieve densities comparable to electrical interconnects while significantly reducing power consumption, enabling high-performance computing and networking by overcoming the limitations of electrical interconnects.
Implementation Method 1
a multilayer planar waveguide coupling light from the first plurality of microLEDs with the second plurality of photodetectors and coupling light from the second plurality of microLEDs with the first plurality of photodetectors
Implementation Method 2
a first plurality of microLEDs and a first plurality of photodetectors, the first plurality of microLEDs being mounted to a first substrate
Implementation Method 3
a second plurality of photodetectors, the second plurality of photodetectors being in or mounted to the second substrate
Data Source
AI summary
A multi-layer planar waveguide may be used in providing an interconnect for inter-chip and/or intra-chip signal transmission. Various embodiments to transmit optical signals are disclosed, along with designs of microLED optical assemblies, photodetector optical assemblies, waveguides, and multi-layer planar waveguides.