Display Substrate Repair via Ultra-Fast Laser Ablation

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Solution Overview

Problem

Conventional methods for repairing signal lines in LCD panels, especially when a color filter is present, face difficulties due to coverage issues and the challenge of forming effective repair connections without proper contact, leading to suboptimal display quality.

Innovation Solution

The use of an ultra-fast laser to selectively remove and ablate the organic layer on the display substrate, exposing the underlying metal patterns and allowing for precise repair of electrical connections and addressing shorting issues, while also forming light-blocking portions to mitigate light leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of repair

If a conventional repairing line method is used on the protecting layer, then the electrical connection failure can be repaired, but the color filter covering the data line makes repairing difficult and the repair may not be effective

Engineering Contradiction:

Improveease of repairing signal lineVSAvoiddifficulty of accessing data line

Core Design Contradiction:

Ease of repairVSDifficulty of detecting and measuring

Solution Approach 1:

The organic layer is selectively removed from specific regions to expose the underlying data line and gate line, allowing direct access to the metal patterns for repair operations. This extraction of the organic layer in targeted areas enables the repair line to be formed in direct contact with the metal patterns without interference from the color filter.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The repair approach transitions from surface-level repair on the protecting layer to a multi-layer approach where the organic layer is removed to access the metal pattern layer below. This dimensional change allows the repair line to be formed at the appropriate layer level where direct contact with the data line can be achieved.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Ease of repair

If the organic layer is completely removed to expose the metal patterns for repair, then direct contact can be achieved, but light leakage may occur through the exposed areas

Engineering Contradiction:

Improvedirect contact with metal patternVSAvoidlight leakage

Core Design Contradiction:

Ease of repairVSObject-affected harmful factors

Solution Approach 1:

The organic layer is removed only in the specific regions where repair is needed, rather than being completely removed. The light-blocking portions are formed only at the boundaries of the repair holes, not across the entire exposed area. This localized approach maintains direct contact for repair while minimizing light leakage to only the essential boundary areas.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

Light-blocking portions are introduced as intermediary structures at the boundaries of the repair holes. These light-blocking portions act as mediators that prevent light leakage through the exposed areas while allowing the repair line to maintain direct contact with the metal patterns in the center of the repair holes.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Manufacturing precision

If precise exposure of metal patterns is achieved for accurate repair connection, then display quality can be improved, but the repair process becomes more complex and time-consuming

Engineering Contradiction:

Improveprecision of metal pattern exposureVSAvoidcomplexity of repair process

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The conventional mechanical or chemical methods of selectively removing the organic layer are replaced with laser processing. The laser can precisely remove the organic layer and form light-blocking portions in a single integrated process, achieving high precision exposure of metal patterns without the complexity of multiple sequential steps required by conventional methods.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

This method enables exquisite repair of defects in the display substrate by ensuring accurate exposure and connection of metal patterns, improving display quality by addressing disconnection and shorting issues and minimizing light leakage through the repair holes.

Implementation Method 1

irradiating an ultra-fast laser to an organic layer disposed on the data line, removing portions of the organic layer disposed over first and second areas of the data line

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

ablating side portions of the exposed data line in the first and second areas

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentUS9933675B2Method of repairing display substrate and display substrate repaired by the method

Publication Date: 2018.04.03 SAMSUNG DISPLAY CO LTD

AI summary

A display substrate includes a gate metal pattern including a gate line extending in a first direction, a gate electrode electrically connected to the gate line and a storage line, a data metal pattern including a data line extending in a second direction crossing the first direction, a source electrode electrically connected to the data line and a drain electrode spaced apart from the source electrode, an organic layer disposed on the data metal pattern, and a repair hole formed through the organic layer and exposing a portion of the gate metal pattern or a portion of the data metal pattern.