Flexible Substrate Fabrication via Photochemical Release Layer Patterning

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Solution Overview

Problem

Conventional methods for fabricating flexible display devices on plastic substrates are costly due to the need for patterned release layers, which require vacuum evaporation and can adhere to shadow masks, leading to peeling issues and increased fabrication complexity.

Innovation Solution

A flexible substrate structure and method involving a release layer with a local modification process to create bonding and release regions, using a photo-sensitive or heat-sensitive adhesive layer, where the release layer is modified through exposure or heating to form adhesion and non-adhesion areas, eliminating the need for patterned layers and reducing fabrication costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a vacuum evaporation process is used to form a patterned release layer, then the release layer can be patterned to create bonding and release regions, but the fabrication cost increases and the release layer adheres to the shadow mask causing peeling problems

Engineering Contradiction:

Improverelease layer patterningVSAvoidfabrication cost and complexity

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent replaces the mechanical vacuum evaporation process with a photochemical process. Instead of using a shadow mask and vacuum evaporation to pattern the release layer, the invention uses a photosensitive adhesive layer that is exposed to light through a mask, causing chemical changes that create the desired bonding and release regions without mechanical contact or expensive vacuum equipment

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the state of the release layer through light exposure. The photosensitive adhesive layer undergoes photochemical reactions when exposed to light, transforming from a uniform state to a differentiated state with bonding regions (exposed areas) and release regions (unexposed areas), achieving patterning through parameter change rather than mechanical removal

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If the release layer is patterned using vacuum evaporation, then bonding and release regions can be formed, but the process complexity and fabrication cost increase

Engineering Contradiction:

Improvebonding region formationVSAvoidfabrication process

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces the complex mechanical vacuum evaporation system with a simpler photochemical exposure system. The process uses standard photolithography equipment instead of expensive vacuum evaporation equipment, significantly reducing process complexity while achieving the same patterning function

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent applies the photosensitive adhesive layer uniformly across the entire release layer before exposure. This preliminary uniform coating simplifies the process by eliminating the need for selective deposition in different areas, and the subsequent light exposure automatically creates the required pattern without additional processing steps

Inventive Principle:

Principle #10Preliminary action

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 approach reduces fabrication costs, enhances yield rate and quality by allowing an intact release layer, efficient bonding, and easy separation of the flexible substrate from the carrier, while avoiding peeling issues and extra processing steps.

Implementation Method 1

performing a local exposure process with a light source to form the bonding region with adhesion property in illuminated parts of the release layer

Methodology Applied

Scientific EffectPhotochemical reaction: Photopolymerisation

Implementation Method 2

the release layer includes a heat-sensitive adhesive layer, where the release layer is modified through exposure or heating to form adhesion and non-adhesion areas

Methodology Applied

Scientific EffectThermal modification: Heating

Data Source

PatentUS9228115B2Method of fabricating flexible substrate structure

Publication Date: 2016.01.05 AU OPTRONICS CORP

AI summary

A method of fabricating a flexible substrate structure includes the following steps. A supporting carrier is provided, and a release layer is formed on the supporting carrier, where the release layer includes a photo-sensitive adhesive layer. A local modification process is performed to form a bonding region with adhesion property in modified parts of the release layer, and to form a release region without adhesion property in unmodified parts of the release layer. The local modification process includes performing a local exposure process with a light source to form the bonding region with adhesion property in illuminated parts of the release layer, and to form a release region without adhesion property in unilluminated parts of the release layer.