Substrateless LED Arrangement for Uniform Luminance

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Solution Overview

Problem

Existing light-emitting diode (LED) arrangements with substrate-less semiconductor layer stacks suffer from insufficient and non-uniform luminance due to gaps between individual LED chips caused by assembly inaccuracies and the presence of growth substrates or auxiliary carriers.

Innovation Solution

A light-emitting diode arrangement with substrate-less semiconductor layer stacks, each attached directly to a common carrier body without auxiliary carriers, where the distance between adjacent stacks is minimized (≤100 μm) to ensure homogeneous luminance, and electrical contact areas are optimized for series connection and reduced risk of short circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If individual LED chips with growth substrates or auxiliary carriers are used, then the mechanical stability during assembly is improved, but gaps between chips are created leading to non-uniform luminance

Engineering Contradiction:
Improvemechanical stability during assemblyVSAvoidluminance uniformity
Core Design Contradiction:
Stability of the object's compositionVSIllumination intensity

Solution Approach 1:

The invention extracts and removes the growth substrate and auxiliary carrier from the LED chip structure, attaching only the active semiconductor layer stack directly to the common carrier. This elimination of intermediate components removes the source of gaps and non-uniform luminance while maintaining mechanical stability through direct attachment.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention merges the active semiconductor layer stack directly with the common carrier by eliminating the growth substrate and auxiliary carrier. This direct integration reduces the number of interfaces and gaps, resulting in more uniform luminance distribution across the LED arrangement.

Inventive Principle:
Principle #5Merging (Combining)

2Illumination intensity

If substrate-less semiconductor layer stacks are used, then luminance uniformity is improved by minimizing gaps, but mechanical handling and assembly become more difficult

Engineering Contradiction:
Improveluminance uniformityVSAvoidassembly difficulty
Core Design Contradiction:
Illumination intensityVSEase of manufacture

Solution Approach 1:

The invention performs preliminary action by pre-attaching the substrate-less semiconductor layer stacks to a temporary carrier or organizing them in a configuration that facilitates subsequent transfer to the common carrier. This preliminary organization makes handling and assembly easier despite the reduced mechanical stability of the substrate-less structure.

Inventive Principle:
Principle #10Preliminary action

3Illumination intensity

If the distance between adjacent semiconductor layer stacks is reduced to ≤100 μm, then luminance homogeneity is improved, but the risk of electrical short circuits between adjacent stacks increases

Engineering Contradiction:
Improveluminance homogeneityVSAvoidelectrical connection reliability
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The invention applies local quality by providing electrical insulation specifically in the regions between adjacent semiconductor layer stacks where short circuits could occur. This localized insulation approach maintains the small overall pitch for luminance uniformity while preventing electrical interference between neighboring stacks.

Inventive Principle:
Principle #3Local quality

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

The solution achieves a highly uniform and enhanced luminance distribution by minimizing gaps between semiconductor layer stacks and ensuring precise electrical connections, resulting in a more efficient and reliable LED arrangement.

Implementation Method 1

Light-emitting diode arrangements are known in which several individually encapsulated LED components are arranged on a common carrier

Methodology Applied
Scientific EffectLight-emitting diode effect: Light Emitting Diode

Implementation Method 2

semiconductor chips which are intended to emit electromagnetic radiation from their front side

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP2057681B1Light-emitting diode arrangement and method for producing the same
Publication Date: 2018.11.07 OSRAM OPTO SEMICON GMBH & CO OHG
  • EP2057681B1 patent drawingFigure 1A~1C
  • EP2057681B1 patent drawingFigure 2
  • EP2057681B1 patent drawingFigure 3

AI summary

The invention relates to a light-emitting diode arrangement comprising a plurality of semiconductor chips which are provided for emitting electromagnetic radiation from their front side (101) and which are fixed by their rear side (102) - opposite the front side - on a first main area (201) of a common carrier (2), wherein the semiconductor chips are composed of a respective substrateless semiconductor layer stack (1) and are fixed to the common carrier body without an auxiliary carrier, and to a method for producing such a light-emitting diode arrangement.