3D Stacked Optical Interconnects for Dense Low-Power Chip Links
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The limitations of electrical interconnects in chip-to-chip connections, such as high power consumption and low density, constrain the performance of advanced packaging technologies like 2.5D and 3D integrated circuits, leading to inefficiencies in high-performance computing systems.
Innovation Solution
Implementing optical interconnects using optoelectronic ICs with microLEDs and photodetectors in a 3D stacked configuration, providing high-density connections through multi-layer planar and vertical optical interfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If electrical interconnects are used for chip-to-chip connections, then the system can be manufactured with conventional processes, but the power consumption increases and density decreases
Solution Approach 1:
The patent substitutes electrical interconnects with optical interconnects using microLEDs and photodetectors. This replacement transitions from electrical signal transmission to optical signal transmission, fundamentally changing the physical mechanism of data transfer between chips. The optical interconnects achieve lower power consumption and higher density while maintaining manufacturability through integration with standard CMOS processes.
Solution Approach 2:
The patent changes the fundamental parameter of signal transmission from electrical to optical domain. By using microLEDs as light sources and photodetectors as receivers, the system operates in the optical regime, enabling higher bandwidth and lower power consumption compared to electrical interconnects, while the integration approach maintains compatibility with conventional manufacturing.
2Ease of manufacture
If electrical interconnects are used for chip-to-chip connections, then the system can be manufactured with conventional processes, but the interconnect density is low
Solution Approach 1:
The patent replaces electrical interconnect structures with optical interconnect structures using microLEDs and photodetectors. This substitution enables higher interconnect density because optical components can be packaged more densely and routed through the substrate without the physical constraints of electrical trace routing, achieving >2500 connections per mm².
Solution Approach 2:
The patent transitions from planar electrical interconnect routing to three-dimensional optical interconnect architecture. Optical fibers and waveguides can be routed through the substrate volume and stacked in multiple layers, enabling vertical and lateral connections simultaneously, thus achieving much higher density than conventional two-dimensional electrical routing.
3Quantity of substance
If optical interconnects are implemented with microLEDs and photodetectors, then interconnect density increases to >2500 connections per mm², but device complexity increases
Solution Approach 1:
The patent merges multiple functions into integrated optoelectronic modules. The microLEDs, photodetectors, and their supporting circuitry are combined into unified packages that interface with the substrate. This integration reduces the overall system complexity by consolidating components that would otherwise be separate, while maintaining the high interconnect density benefit.
Solution Approach 2:
The patent creates universal optoelectronic interface modules that can be used across different chip-to-chip connection scenarios. The same microLED-photodetector package structure serves multiple connection functions, reducing design complexity and enabling reuse of the same interface architecture for different applications, thereby managing complexity while maintaining high density.
4Productivity
If optical interconnects are implemented with microLEDs and photodetectors, then throughput density increases to >1 Pbps/cm², but manufacturing precision requirements increase
Solution Approach 1:
The patent performs preliminary packaging and alignment of microLEDs and photodetectors before substrate integration. The optoelectronic modules are pre-assembled and tested, with alignment features built in during module fabrication. This preliminary preparation reduces the precision requirements during final substrate mounting, as the critical alignments are already established in the modular components.
Solution Approach 2:
The patent uses intermediary alignment structures and bonding interfaces between the optoelectronic modules and the substrate. These intermediary elements provide mechanical registration features and tolerance compensation mechanisms that reduce the direct precision requirements between critical optical components, enabling high throughput density with relaxed manufacturing tolerances.
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
Achieves extraordinary interconnect densities of >2500 connections per mm² at 4 Gbps data rates, offering a throughput density of >1 Pbps/cm², surpassing the limitations of electrical interconnects.
Implementation Method 1
Optical emitters, for example microLEDs, are bonded to the optoelectronic IC, and driven by the optical drive circuitry
Implementation Method 2
Optical detectors, for example photodetectors, are also bonded to the optoelectronic IC, or formed in the optoelectronic IC, and coupled to the optical receive circuitry
Data Source
AI summary
An optical interconnect may include an optoelectronic IC mounted to a substrate. The optoelectronic IC may have optoelectronic devices, for example microLEDs and/or photodetectors, mounted to a surface of the optoelectronic IC away from the substrate. The optoelectronic IC may have circuitry for driving the microLEDs and/or processing electrical signals from the photodetectors. The optoelectronic IC may be interfaced to a D2D interface chip. The D2D interface chip may be mounted to the optoelectronic IC.