Differential Adhesion Polyimide Release Layer for Flexible Substrate Peeling

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Solution Overview

Problem

Existing methods for fabricating flexible substrates, such as those used in display devices, face challenges with thermal expansion damage from laser detachment and high manufacturing costs due to the need for new intermediate layers.

Innovation Solution

A method involving a rigid support base with a polyimide release layer that includes an adhesion promoting agent and a release agent, allowing for differential adhesion strengths to enable peeling of a flexible polyimide substrate without damaging it, while the release layer remains adhered to the support base, facilitating reuse.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If laser is used for detaching the flexible substrate from the support body, then the detachment process is achieved, but thermal expansion occurs causing damage to the flexible substrate and the electric circuit

Engineering Contradiction:

Improvedamage-free detachmentVSAvoidthermal expansion damage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the laser detachment method with a mechanically peelable structure. The flexible substrate is designed with a peeling structure that allows mechanical peeling from the support body without thermal effects, thereby avoiding thermal expansion damage to the substrate and circuits.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the detachment mechanism from thermal (laser) to mechanical (peeling). By designing the flexible substrate with specific peeling structures and material properties, the detachment process transitions from thermal expansion-based to mechanical force-based, eliminating thermal damage.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If laser equipment is used for detachment, then the flexible substrate can be removed from the support body, but the manufacture cost increases significantly

Engineering Contradiction:

Improvedetachment capabilityVSAvoidmanufacture cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent employs a disposable support body or intermediate layer that can be easily removed or degraded, eliminating the need for expensive laser equipment. The support body is designed to be single-use or easily replaceable, reducing overall manufacturing costs.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent replaces expensive laser detachment equipment with simple mechanical peeling structures that can be implemented using basic manufacturing tools, significantly reducing equipment and operational costs.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of manufacture

If an intermediate layer is coated on the support body for each new flexible substrate, then the flexible substrate can be formed and detached, but the manufacture cost increases due to repeated coating processes

Engineering Contradiction:

Improveflexible substrate formationVSAvoidmanufacture cost

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The patent designs the support body or intermediate layer to be recoverable or reusable. After the flexible substrate is detached, the support body can be cleaned and reused for the next substrate, eliminating the need for repeated coating processes and reducing manufacturing costs.

Inventive Principle:

Principle #34Discarding and recovering

Solution Approach 2:

The support body is designed with universal functionality to accommodate multiple flexible substrate fabrication cycles. By making the support body reusable through cleaning and resetting processes, the system achieves multi-functionality that eliminates repeated coating requirements.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 allows for the cost-effective and damage-free fabrication of flexible substrates, enabling mechanical peeling without lasers and allowing the reuse of the support and release layers, thus reducing overall manufacturing costs.

Implementation Method 1

a peeling strength between the first and second polyimide layers being less than a peeling strength between the first polyimide layer and the support base so that the second polyimide layer is peelable from the first polyimide layer

Methodology Applied

Scientific EffectAdhesion: Adhesive

Data Source

PatentUS10334738B2Flexible substrate assembly and its application for fabricating flexible printed circuits

Publication Date: 2019.06.25 TAIMIDE TECH INC

AI summary

A method of fabricating a flexible substrate assembly includes forming a first polyimide layer on a rigid support base, wherein the step of forming the first polyimide layer includes incorporating in a polyamic acid solution, an adhesion promoting agent and a release agent for achieving different adhesion strength at two opposite sides of the first polyimide layer, and forming a flexible second polyimide layer on the first polyimide layer, the second polyimide layer being adhered in contact with the first polyimide layer, and a peeling strength between the first and second polyimide layers being less than a peeling strength between the first polyimide layer and the support base so that the second polyimide layer is peelable from the first polyimide layer while the first polyimide layer remains adhered in contact with the support base.