Silicon OLED Pad Segmentation for Inline Testing

Solution Overview

Problem

Existing test methods for miniaturized OLED display panels face challenges in implementing Inline IVL tests due to layout limitations and the covering of pads by packaging materials, making it difficult to input test signals after vapor deposition and requiring multiple probes for Module Inspection Tests.

Innovation Solution

A display panel design with strategically positioned pads, including a first pad and a second pad for IVL testing, and a third pad and a fourth pad for MIT testing, which are exposed through packaging layers to allow for efficient signal input and reduced probe requirements, enabling effective testing without covering the pads with organic and inorganic materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If pads are covered by packaging materials (organic and inorganic materials) during miniaturization, then device integration is improved, but test signal input becomes difficult

Engineering Contradiction:

Improvedevice sizeVSAvoidtest signal input

Core Design Contradiction:

Volume of moving objectVSEase of operation

Solution Approach 1:

The pad structure is segmented into two functional groups: first pads (with first pad holes) for IVL testing and second pads (with second pad holes) for MIT testing. This segmentation allows different testing functions to be performed through different access paths, resolving the contradiction between miniaturization and test accessibility.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a vertical dimension to pad access by creating pad holes through packaging layers. Test signals can be input from the back side of the display panel through these vertically positioned pad holes, allowing testing without lateral access to pads that would otherwise be covered by packaging materials.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If multiple probes are used for Module Inspection Tests, then testing coverage is improved, but device complexity increases

Engineering Contradiction:

Improvetesting coverageVSAvoidprobe requirements

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The second pads are designed with second pad holes that extend through packaging layers, enabling the same pad structure to serve dual purposes: as connection points for display signals and as access points for MIT testing. This multi-functionality reduces the need for separate dedicated test probes.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The second pad holes act as intermediaries that facilitate MIT testing without requiring direct access to the pads. By creating these intermediary access channels through the packaging layers, the patent enables testing with fewer probes while maintaining comprehensive testing coverage.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of operation

If pads are positioned for easy access, then test signal input is improved, but layout flexibility deteriorates

Engineering Contradiction:

Improvepad accessibilityVSAvoidlayout flexibility

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The pad structure is segmented into two functional groups: first pads (with first pad holes) for IVL testing and second pads (with second pad holes) for MIT testing. This segmentation allows different testing functions to be performed through different access paths, resolving the contradiction between miniaturization and test accessibility.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a vertical dimension to pad access by creating pad holes through packaging layers. Test signals can be input from the back side of the display panel through these vertically positioned pad holes, allowing testing without lateral access to pads that would otherwise be covered by packaging materials.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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

Enables efficient Inline IVL testing by forming a voltage difference between electrodes and reduces the complexity and cost of Module Inspection Tests by minimizing the number of required probes and pads, accommodating the miniaturization of silicon-based OLED display panels.

Implementation Method 1

an organic light emitting layer, disposed on a side of the first electrode layer away from the driving layer

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS12004396B2Display panel and display device for IVL testing

Publication Date: 2024.06.04 BOE TECHNOLOGY GROUP CO LTD

AI summary

A display panel includes: a silicon-based substrate, a driving layer, a first electrode layer, an organic light emitting layer, a second electrode layer and a plurality of pads. Where, the display signal access pad is configured to access the display signal during a display phase, the test signal access pad at least includes a first group of test phase access pads, and the first group of test phase access pads includes a first pad and a second pad, the first pad is electrically connected with the electrode ring, and the second pad is electrically connected with the silicon-based substrate.