Flexible Substrate Fabrication via Mechanical Peeling

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Solution Overview

Problem

Conventional methods for producing flexible substrate layers are complex, inefficient, and prone to material waste and defects due to the need for deposition, etching, and sacrificial layers, which also increase production costs and time.

Innovation Solution

A method involving a carrier substrate with a polyimide resin, where a curable polymer is applied and cured, allowing for easy separation of the flexible substrate layer using a physical stimulus like tension during winding, eliminating the need for sacrificial layers and laser/light irradiation, and enabling continuous roll-to-roll production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional deposition and etching techniques are used to form metal wires in plastic substrates, then metal wire patterns can be created, but the process becomes complicated and causes thermal damage to the plastic substrate

Engineering Contradiction:
Improvemetal wire pattern formationVSAvoidprocessing steps
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces thermal and chemical processing (deposition, etching, CMP) with a mechanical approach: metal wires are formed on a hard substrate, embedded in a curable polymer, and then the hard substrate is mechanically peeled away to leave clean metal wire patterns in the flexible substrate without thermal damage or complex processing

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a hard substrate as an intermediary carrier that enables metal wire formation and subsequent peeling. This intermediary allows the metal wires to be formed and transferred to the flexible substrate without directly exposing the plastic substrate to damaging thermal and chemical processes

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If a hard substrate is forcibly peeled from the metal wire embedded polymer substrate, then the flexible substrate can be separated, but damage to metal wires and polymer substrate occurs and portions of hard substrate remain as impurities

Engineering Contradiction:
Improvesubstrate separationVSAvoidproduct defects
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies preliminary action by forming a release layer between the hard substrate and the curable polymer before embedding the metal wires. This release layer is designed to facilitate clean separation, preventing damage to the metal wires and polymer substrate during peeling and ensuring complete removal of the hard substrate without leaving impurities

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If a sacrificial layer is removed by dissolution in water or organic solvent, then the flexible substrate can be separated from the carrier, but the costs associated with treatment of the solvent after use increase

Engineering Contradiction:
Improvesubstrate separationVSAvoidsolvent treatment costs
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent replaces chemical dissolution methods with a mechanical peeling approach. The release layer enables the flexible substrate to be separated from the carrier substrate through mechanical means rather than chemical dissolution, eliminating the need for solvent treatment and associated environmental costs

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 approach simplifies the production process, reduces costs and time, ensures uniform mechanical, thermal, and optical properties, and prevents defects, allowing for efficient fabrication of flexible electronic devices like solar cells and displays.

Implementation Method 1

forming a flexible substrate layer comprising a curable polymer on the carrier substrate

Methodology Applied
Scientific EffectCuring: Photopolymerisation

Implementation Method 2

separating the flexible substrate layer from the carrier substrate layer by the application of a physical stimulus without causing chemical changes in the carrier substrate and the flexible substrate layer

Methodology Applied
Scientific EffectMechanical separation: Mechanical Force

Data Source

PatentEP3327731B1Method for fabricating flexible substrate
Publication Date: 2023.04.19 LG CHEM LTD
  • EP3327731B1 patent drawingFigure 1~2
  • EP3327731B1 patent drawingFigure 3

AI summary

The present invention relates to a method for producing a flexible substrate. According to the method of the present invention, a flexible substrate layer can be easily separated from a carrier substrate even without the need for laser or light irradiation so that a device can be prevented from deterioration of reliability and occurrence of defects caused by laser or light irradiation. In addition, according to the method of the present invention, a flexible substrate can be continuously produced in an easier manner based on a roll-to-roll process.