Heterogeneous LED-CMOS Integration via Segmented Backplane

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional color displays using red, green, and blue LEDs are complex and costly due to the need for different materials and components, and the high temperature processes for forming complementary metal oxide semiconductor (CMOS) circuit components damage LEDs, making it difficult to integrate them, especially for compact displays in virtual reality and augmented reality applications.

Innovation Solution

A display system that integrates light emitting diodes (LEDs) with CMOS components using a backplane device, where LEDs are bonded to a substrate with a dielectric layer and CMOS components are bonded to the backplane, enabling heterogeneous integration and wafer-level packaging for compact, low-power, high-resolution displays.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional color displays use separate red, green, and blue LEDs with different materials and components, then color display capability is achieved, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improvecolor display capabilityVSAvoidstructural complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple color LEDs (red, green, blue) into a single integrated LED structure with shared semiconductor layers and common electrical contacts. This merging approach maintains full color display capability while reducing the number of separate components, materials, and assembly steps required, thereby decreasing device complexity and manufacturing cost

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If high temperature processes are used to form CMOS circuit components, then circuit functionality is achieved, but LED structures are damaged

Engineering Contradiction:

Improvecircuit functionalityVSAvoidthermal damage to LEDs

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent divides the display system into two separate substrates: one substrate contains the LED structures formed at lower temperatures, while another substrate contains the CMOS circuit components formed at high temperatures. This segmentation allows each component to be manufactured under its optimal temperature conditions without interfering with the other, resolving the thermal compatibility issue

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a bonding interface or intermediary layer between the LED substrate and CMOS substrate that enables thermal decoupling. This intermediary allows the two components to be integrated into a single device while maintaining independent thermal zones, protecting the temperature-sensitive LED structures from high temperature processing

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If LEDs and CMOS components are formed on different substrates, then component integrity is maintained, but integration difficulty and device size increase

Engineering Contradiction:

Improvecomponent integrityVSAvoidintegration difficulty

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent employs a stacked configuration where the LED structure and CMOS circuit structure are vertically arranged one above the other, with the LED substrate positioned above or below the CMOS substrate. This nesting approach allows both components to maintain their structural integrity on separate substrates while achieving compact integration through vertical stacking, reducing lateral expansion and simplifying the integration process

Inventive Principle:

Principle #7Nested doll (Nesting)

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 solution facilitates the creation of cost-effective, compact, and high-resolution color displays by integrating LEDs and CMOS components, allowing for efficient interconnections and reducing manufacturing costs, while enabling low power consumption and enhanced user experience in portable devices.

Implementation Method 1

Light emitting diodes (LEDs) are widely used for various color display technologies

Methodology Applied

Scientific EffectLight emitting diode effect: Light Emitting Diode

Implementation Method 2

a plurality of light emitting diodes (LEDs) configured to emit different colors of light

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS10037981B2Integrated display system with multi-color light emitting diodes (LEDs)

Publication Date: 2018.07.31 GLOBALFOUNDRIES US INC

AI summary

A display system is disclosed. The display system comprises a light emitting diode (LED) device and a backplane (BP) device. The LED device comprises a plurality of LEDs having LED terminals. An LED bonding surface comprising a dielectric layer with LED bonding surface contact pads is coupled to diode terminals of the LEDs. The backplane (BP) device comprises a BP substrate having top and bottom surfaces. A plurality of system on chip (SoC) chips are bonded to chip pads disposed on a bottom surface of the BP device. The SoC chips are electrically coupled to the CMOS components of the BP device and LEDs of the LED device.