Flexible Substrate Thickness Reduction via In-Situ Copper Deposition

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Solution Overview

Problem

Existing methods for manufacturing flexible substrates result in substrates with excessive thickness, which hampers their curving and bending properties, making them unsuitable for flexible OLED display devices.

Innovation Solution

A method involving the sequential steps of pasting a heat dissipation sheet on a carrier substrate, preparing a thermal insulating layer, forming a flexible substrate layer, and separating the carrier substrate, while using techniques like laser lift-off or mechanical exfoliation, and optionally depositing materials like aluminum oxide or molybdenum alloys to reduce thickness and enhance thermal insulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If multiple layers (adhesive layers, PET layer, copper heat dissipation layer) are stacked on the flexible substrate layer, then thermal insulation and heat dissipation are improved, but the total thickness increases to 100-200 μm, worsening the curving property

Engineering Contradiction:

Improvethermal insulation and heat dissipationVSAvoidcurving property

Core Design Contradiction:

TemperatureVSShape

Solution Approach 1:

The patent combines the thermal insulation layer and heat dissipation layer into a single integrated structure. The copper heat dissipation layer is directly formed on the flexible substrate layer through in-situ deposition, eliminating the need for separate adhesive layers and PET layers. This merging reduces the total thickness from 100-200 μm to 50-80 μm while maintaining both thermal insulation and heat dissipation functions.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent uses a thin copper heat dissipation layer (50-80 μm) instead of thick stacked layers to achieve the desired thermal management. This thin film approach maintains flexibility and curving properties while providing sufficient heat dissipation capability. The flexible substrate layer itself serves as the thermal insulation barrier, eliminating the need for additional thick insulating layers.

Inventive Principle:

Principle #30Flexible shells and thin films

2Shape

If the flexible substrate layer thickness is reduced to enhance curving property, then curving property is improved, but the structural integrity and support may be compromised

Engineering Contradiction:

Improvecurving propertyVSAvoidstructural integrity

Core Design Contradiction:

ShapeVSStrength

Solution Approach 1:

The patent creates a composite structure where the flexible substrate layer (8-15 μm) is combined with the copper heat dissipation layer (50-80 μm) formed in-situ. This composite provides both the flexibility needed for curving and the structural integrity needed for support. The copper layer adheres strongly to the flexible substrate, creating a unified structure that maintains strength while enabling bending.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent replaces mechanical support from thick stacked layers with a chemically bonded composite structure. The in-situ deposition of copper creates strong metallurgical bonding with the flexible substrate, providing structural support through chemical adhesion rather than mechanical stacking. This allows the use of thinner materials while maintaining structural integrity.

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

The method achieves a thinner flexible substrate with improved bending and curving properties, suitable for OLED displays, by reducing the overall thickness and enhancing the structural integrity of the substrate.

Implementation Method 1

peeling the flexible substrate layer 2′ which on backwardly of the carrier substrate by laser lift off

Methodology Applied

Scientific EffectLaser lift-off: Laser Ablation

Implementation Method 2

copper heat dissipation layer 7′

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

pasting the first adhesive layer 4′, PET layer 5′, the second adhesive layer 6′ and the copper heat dissipation layer 7′ on the flexible substrate layer 2′ by sequentially

Methodology Applied

Scientific EffectAdhesion: Adhesive

Data Source

PatentUS10355228B2Method of manufacturing flexible substrate and flexible substrate

Publication Date: 2019.07.16 WUHAN CHINA STAR OPTOELECTRONICS SEMICONDUCTOR DISPLAY TECHNOLOGY CO LTD

AI summary

A method of manufacturing flexible substrate is provided, the method comprising following steps: pasting a heat dissipation sheet on a carrier substrate; preparing a thermal insulating layer on the heat dissipation sheet; preparing a flexible substrate layer on the thermal insulating layer; preparing a display element on the flexible substrate layer; and separating the carrier substrate and the heat dissipation sheet and obtaining a flexible substrate. The method of manufacturing flexible substrate and the flexible substrate are provided by this invention, which could reduce thickness of flexible substrate and enhances curving property.