LED Connection Structure for High-Resolution Display Transfer

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The challenge of improving the yield of electrical connections between LEDs and substrates in displays, particularly in enhancing resolution by transferring more LEDs as pixels, is not adequately addressed by existing technologies.

Innovation Solution

A light-emitting device with a connection structure featuring a first electrical connection portion and a protective portion surrounding a first contact electrode, where the connection portion includes an upper, lower, and neck portion, with the lower portion having a wider width, and is connected via conductive bumps or films to a carrier substrate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If more LEDs are transferred as pixels to improve resolution, then display resolution is improved, but the yield of electrical connection between LEDs and substrate deteriorates

Engineering Contradiction:
Improvedisplay resolutionVSAvoidelectrical connection yield
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The connection structure is divided into multiple functional segments: an upper portion for electrical connection, a lower portion for mechanical support, and a neck portion connecting them. This segmentation allows each part to be optimized independently - the upper portion can be designed for optimal electrical contact while the lower portion provides robust mechanical support, thereby maintaining high electrical connection yield even when transferring more LEDs

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the connection structure are given different properties: the upper portion has optimized electrical conductivity for reliable electrical connection, while the lower portion has enhanced mechanical strength for stable support. This local differentiation of properties allows the connection structure to simultaneously satisfy both electrical and mechanical requirements, improving overall connection reliability when scaling up LED transfer

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If the connection structure is simplified for easier manufacture, then ease of manufacture is improved, but the stability and reliability of electrical connection deteriorates

Engineering Contradiction:
Improveease of manufactureVSAvoidelectrical connection stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The connection structure merges multiple functions into a single integrated component: electrical conduction, mechanical support, and stress distribution are all achieved through one unified structure with varying cross-sectional areas. This merging eliminates the need for separate electrical and mechanical connection elements, simplifying the manufacturing process while maintaining reliable electrical connection stability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The connection structure utilizes parameter changes in its geometry - specifically the variation in cross-sectional area from upper to lower portion - to achieve different functional requirements at different locations. This geometric parameter variation allows a single simple structure to provide both optimal electrical connection and robust mechanical support, maintaining reliability while ease of manufacture

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3734674B1Light emitting device
Publication Date: 2025.11.19 EPISTAR CORP
  • EP3734674B1 patent drawingFigure 1A~1C
  • EP3734674B1 patent drawingFigure 2A~2C
  • EP3734674B1 patent drawingFigure 3A~3B

AI summary

A light-emitting device includes a carrier, a light-emitting element and a connection structure. The carrier includes a first electrical conduction portion. The light-emitting element includes a first light-emitting layer capable of emitting first light and a first contact electrode formed under the light-emitting layer. The first contact electrode is corresponded to the first electrical conduction portion. The connection structure includes a first electrical connection portion and a protective portion surrounding the first contact electrode and the first electrical connection portion. The first electrical connection portion includes an upper portion, a lower portion and a neck portion arranged between the upper portion and the lower portion. An edge of the upper portion is protruded beyond the neck portion, and an edge of the lower portion is protruded beyond the upper portion.