Stacked Light-Emitting Modules for High-Resolution Displays

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Solution Overview

Problem

The challenge in manufacturing high-resolution organic light emitting display apparatuses lies in reducing the shadow effect and dispersion during the deposition process, which becomes increasingly difficult as the resolution increases, due to the limitations of the deposition mask used.

Innovation Solution

The solution involves a display apparatus with light-emitting device modules on different substrates, where each module has a non-emission layer and a light-emitting layer with distinct materials, positioned to minimize overlap with pixel regions, allowing for pixel penetration holes and a circuit device layer with transistors and contact holes to support high-resolution imaging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a deposition mask is used to form light-emitting layers and opposite electrodes in high-resolution displays, then the resolution increases, but the shadow effect and dispersion increase making manufacturing difficult

Engineering Contradiction:
ImproveresolutionVSAvoidshadow effect
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent transitions from planar deposition to three-dimensional stacked deposition. Multiple light-emitting devices are deposited on different substrates at different heights, allowing the deposition head to access pixel regions without shadow effects from margin regions. This vertical stacking approach eliminates the shadow effect that plagues conventional planar deposition methods when manufacturing high-resolution displays.

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

Solution Approach 2:

The display is divided into multiple independent light-emitting device modules, each on its own substrate. These modules are stacked vertically with pixel penetration holes allowing alignment across layers. This segmentation allows each layer to be deposited independently without interference from adjacent pixels, eliminating shadow effects while maintaining high resolution.

Inventive Principle:
Principle #1Segmentation

2Object-generated harmful factors

If additional pixel definition layers are added to reduce shadow effect, then the shadow effect is reduced, but the device complexity and manufacturing process become more complex

Engineering Contradiction:
Improveshadow effectVSAvoidpixel definition layers
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent removes the need for pixel definition layers entirely by using pixel penetration holes in stacked substrates. Instead of adding complex definition layers to block deposition, the invention extracts the problematic margin regions from the deposition path by stacking devices vertically, allowing direct deposition into pixel regions without any additional definition structures.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

By moving to three-dimensional stacked architecture, the patent eliminates the need for complex two-dimensional pixel definition layers. The vertical stacking with pixel penetration holes provides a simpler alternative to lateral definition structures, reducing device complexity while effectively eliminating shadow effects.

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

3Manufacturing precision

If the width of open slit of mask is decreased to increase resolution, then the resolution increases, but the dispersion of mask increases making it harder to control

Engineering Contradiction:
ImproveresolutionVSAvoidmask dispersion
Core Design Contradiction:
Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The patent eliminates the need for narrow mask slits by using vertical stacked deposition. Instead of trying to control mask dispersion through ultra-narrow slits, the invention deposits material vertically through pixel penetration holes, where the deposition width is determined by the hole diameter rather than mask slit width, providing better control over resolution.

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

Data Source

PatentEP3683840B1Display apparatus
Publication Date: 2023.05.03 SAMSUNG DISPLAY CO LTD
  • EP3683840B1 patent drawingFigure 1
  • EP3683840B1 patent drawingFigure 2
  • EP3683840B1 patent drawingFigure 3

AI summary

A display apparatus includes a substrate comprising a first pixel region and a second pixel region adjacent to the first pixel region; a circuit device layer on the substrate; a first light-emitting device module on the circuit device layer, the first light-emitting device module comprising a first light-emitting device overlapping the first pixel region to display a first color; and a second light-emitting device module on the first light-emitting device module, the second light-emitting device module having a first pixel penetration hole overlapping the first pixel region, the second light-emitting device module further comprising a second light-emitting device overlapping the second pixel region to display a second color different from the first color.