LED Circuit Stack With Backside Electrodes and Insulation Trench

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Solution Overview

Problem

The existing manufacturing processes for optoelectronic devices with electroluminescent diodes face challenges in forming electrodes on the sides of the devices, which is a difficult step and affects the efficiency and reliability of the devices.

Innovation Solution

The proposed solution involves using a method that includes conductive studs separated by an electric insulation trench, with the second circuit featuring transistors and a metal oxide grid, and connectors on the side opposite to the first circuit for electrical connection, allowing for improved electrical insulation and connection between the circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electrodes are formed covering the sides of the optoelectronic devices, then electrical connection is achieved, but the manufacturing process becomes difficult and complex

Engineering Contradiction:
Improveelectrical connectionVSAvoidmanufacturing process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent transitions from lateral electrode formation on device sides to vertical electrode formation on the backside of substrates. This dimensional change simplifies manufacturing by enabling standard photolithography and deposition processes rather than requiring complex lateral electrode deposition and alignment.

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

Solution Approach 2:

The patent performs electrode formation on substrate backsides before device assembly and stacking. This preliminary action allows electrodes to be formed while substrates are still accessible and flat, making the process easier compared to forming electrodes after devices are assembled and stacked.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If simultaneous manufacturing of several copies on a single substrate is used, then productivity increases, but electrode formation becomes more difficult

Engineering Contradiction:
Improvemanufacturing throughputVSAvoidelectrode formation
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

By forming electrodes on the backside of substrates rather than on the sides of individual devices, the patent enables simultaneous electrode formation for multiple devices on a single substrate using planar deposition processes, maintaining high productivity while simplifying manufacturing.

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

Solution Approach 2:

The patent separates electrode formation from device side formation, allowing electrodes to be formed independently on substrate backsides. This segmentation enables parallel processing of multiple devices on a single substrate without the complexity of lateral electrode alignment.

Inventive Principle:
Principle #1Segmentation

3Reliability

If electrical insulation trench is introduced between conductive pads, then electrical insulation is improved, but device structure becomes more complex

Engineering Contradiction:
Improveelectrical insulationVSAvoidstructure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The electrical insulation trench serves multiple functions: it provides electrical isolation between conductive pads, defines active device regions, and serves as an etch stop layer. This multi-functionality reduces the need for additional separate structures, thereby limiting the increase in device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Adaptability or versatility

If connectors are located on the side opposite the first circuit, then assembly flexibility is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improveassembly flexibilityVSAvoidconnector positioning
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent locates connectors on the backside of substrates rather than on device sides, changing the spatial dimension. This allows connectors to be formed using standard planar photolithography processes with relaxed alignment requirements compared to lateral connector formation, reducing manufacturing precision requirements while maintaining assembly flexibility.

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

Data Source

PatentEP4222783B1Optoelectronic device
Publication Date: 2025.02.12 ALEDIA INC
  • EP4222783B1 patent drawingFigure 1A
  • EP4222783B1 patent drawingFigure 1B
  • EP4222783B1 patent drawingFigure 2~4

AI summary

The present description relates to an optoelectronic device (11) comprising a first circuit (13) including at least one light-emitting diode (LED) emitting from a first face (13i) of the first circuit and including first and second electrodes (23, 24); a second circuit (15) for controlling the light-emitting diode, positioned on a second face (13s) of the first circuit opposite the first face, including first and second electrically conductive pads (31); and an electrically conductive layer (17) located at the interface between the first and second circuits, the electrically conductive layer (17) being divided into first and second portions orthogonal to the stack of the first and second circuits, the first electrode being electrically connected to the first conductive pad via the first portion of the conductive layer and the second electrode being electrically connected to the second conductive pad via the second portion of the conductive layer.