Stacked LED Integrated Circuit with Lateral Isolation

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Solution Overview

Problem

Existing optoelectronic devices with light-emitting diodes face limitations in compactness, manufacturing complexity, and cost due to the limited number of connected light-emitting diodes and complex manufacturing processes, particularly when integrating these devices with control circuits.

Innovation Solution

The design incorporates two integrated circuits, where the first circuit features sets of light-emitting diodes on a semiconductor substrate with lateral electrical insulation and vertical connections, and the second circuit includes control components like transistors, allowing for a stacked configuration that reduces bulk and simplifies manufacturing by using TSVs and flip-chip bonding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If discrete optoelectronic components are connected to an integrated circuit, then the device can be powered by alternating voltage with rectification and selective LED power, but the number of LEDs is limited by component size and spacing requirements

Engineering Contradiction:
Improvevoltage adaptation capabilityVSAvoidnumber of LEDs
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent merges the optoelectronic component and control circuit into a single integrated structure where multiple LED assemblies are fabricated directly on the integrated circuit substrate. This integration eliminates the need for separate discrete components and interconnections, allowing numerous LED assemblies to be packed densely on the chip while maintaining full control circuit functionality for voltage adaptation and selective power distribution.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention transitions from a planar arrangement of discrete components to a three-dimensional integrated structure with LED assemblies positioned at different levels and orientations on the substrate. This dimensional expansion enables significantly higher LED density while maintaining electrical isolation and control circuit access through vertical and lateral interconnections within the chip architecture.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If discrete optoelectronic components are connected to an integrated circuit, then voltage control is achieved, but the manufacturing process becomes complex involving connection of each component

Engineering Contradiction:
Improvevoltage control capabilityVSAvoidmanufacturing process complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

By integrating the control circuit and LED assemblies into a single monolithic structure fabricated using standard semiconductor processes, the invention eliminates complex assembly steps involving manual or automated bonding of discrete components. The control circuit and LED interconnections are formed simultaneously during chip fabrication through photolithography, etching, and deposition processes, dramatically simplifying manufacturing while maintaining full voltage control functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention replaces mechanical assembly operations (bonding, wire bonding, mounting) with semiconductor fabrication processes (photolithography, chemical vapor deposition, sputtering). This substitution transitions the manufacturing paradigm from mechanical engineering to materials science and chemistry, enabling high-volume automated production with consistent quality and reduced process complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Volume of moving object

If multiple LED assemblies are integrated on a single circuit, then compactness is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvedevice compactnessVSAvoidalignment precision
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The invention replaces mechanical alignment and bonding operations with semiconductor fabrication techniques that inherently provide sub-micrometer precision through photolithographic patterning. All LED assemblies and control circuit interconnections are defined by lithographically patterned layers deposited and etched with precise spatial control, eliminating the need for post-fabrication alignment operations and ensuring consistent positioning across mass-produced devices.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention performs all alignment-critical operations during the fabrication process itself, before the chip is completed and packaged. Photolithographic masks define the precise positions of LED assemblies, interconnection vias, and control circuit elements in advance, ensuring that all components are automatically aligned with the required precision without subsequent manual or automated adjustment steps.

Inventive Principle:
Principle #10Preliminary action

4Adaptability or versatility

If discrete components are used, then manufacturing flexibility is maintained, but production cost increases and industrial-scale production becomes difficult

Engineering Contradiction:
Improvemanufacturing flexibilityVSAvoidindustrial-scale production capability
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The invention replaces discrete component assembly with monolithic semiconductor fabrication, enabling production methods identical to those used for standard integrated circuits. This allows utilization of existing high-volume manufacturing infrastructure, automated testing equipment, and established quality control protocols, making industrial-scale production economically viable while maintaining the flexibility to program different LED activation patterns through software control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 configuration enhances the compactness of the device, reduces manufacturing steps, and enables industrial-scale production at lower costs by allowing for a more efficient integration of light-emitting diodes and control circuits, improving the overall efficiency and cost-effectiveness of the optoelectronic device.

Implementation Method 1

Light-emitting diode (LED) optoelectronic devices are defined as devices adapted to convert an electrical signal into electromagnetic radiation

Methodology Applied
Scientific EffectLight-emitting diode (LED): Light Emitting Diode

Implementation Method 2

devices adapted to convert an electrical signal into electromagnetic radiation

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP3410482B1Optoelectronic device with light emitting diodes on a control circuit
Publication Date: 2020.11.18 ALEDIA INC
  • EP3410482B1 patent drawingFigure 1
  • EP3410482B1 patent drawingFigure 2
  • EP3410482B1 patent drawingFigure 3

AI summary

The optoelectronic device (5) comprises: an integrated circuit (6) including a substrate with opposing first and second faces, groups (G1, ...) of assemblies (D1, D2, ...) of light-emitting diodes resting on the first face, of which the first and second assemblies (D1, D2) are adapted to emit at different wavelengths. The integrated circuit further comprises, within the substrate, lateral electrical isolation elements (52) for portions of the substrate around each assembly and, on the second face, at least the first and second conductive pads connected to the terminals of each group. The device includes a second integrated circuit (7) with opposing third and fourth faces, and third conductive pads (70) on the third face electrically connected to the first and second conductive pads; the first circuit (6) being fixed to the third face of the second circuit (7).