Compressively Stressed Laminated Glass via Photosensitive Cladding

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Solution Overview

Problem

Glass articles used in electronic devices require enhanced strength to withstand regular contact and incidental impacts during use and transport, as they are susceptible to damage from touch functionality and handling.

Innovation Solution

A laminated glass article is formed using a fusion lamination process with a glass core and photosensitive glass cladding layers, where the cladding layers are exposed to UV light to induce nucleation and crystallization, resulting in compressively stressed layers that strengthen the glass structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If glass articles are made robust to endure regular contact, then strength is improved, but weight and complexity increase

Engineering Contradiction:
Improveglass strengthVSAvoidglass structure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent applies composite materials by combining glass core layers with photosensitive glass cladding layers to form a laminated structure. The photosensitive glass contains silver nuclei that, when exposed to UV light, crystallize to form compressively stressed layers. This composite structure provides enhanced strength and durability while maintaining the overall glass article form, resolving the contradiction between strength improvement and complexity increase.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent utilizes parameter changes by exposing the photosensitive glass cladding layers to UV light, which induces crystallization and transforms the physical state of the glass. This phase change creates compressively stressed layers within the cladding, significantly enhancing the strength of the glass article without requiring additional structural complexity. The parameter change from amorphous glass to crystalline structure with compressive stress is the key mechanism.

Inventive Principle:
Principle #35Parameter changes

2Strength

If photosensitive glass cladding layers are added to enhance strength, then glass strength is improved, but manufacturing process complexity increases

Engineering Contradiction:
Improveglass strengthVSAvoidmanufacturing process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by incorporating silver nuclei within the photosensitive glass cladding layers during the glass manufacturing process, before the strengthening treatment. These pre-formed nuclei are positioned to become crystallization centers when the glass is later exposed to UV light. This preliminary preparation simplifies the subsequent strengthening process, as the crystallization occurs automatically upon UV exposure without requiring additional complex manufacturing steps.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If compressively stressed layers are formed through UV exposure, then glass durability is improved, but production time increases

Engineering Contradiction:
Improveglass durabilityVSAvoidproduction time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent utilizes parameter changes by exposing the photosensitive glass cladding layers to UV light, which induces crystallization and transforms the physical state of the glass. This phase change creates compressively stressed layers within the cladding, significantly enhancing the strength and durability of the glass article. The UV exposure process, while adding time, enables a direct phase transformation that would otherwise require more complex and time-consuming mechanical strengthening processes.

Inventive Principle:
Principle #35Parameter changes

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 enhances the strength and durability of the glass articles, enabling them to withstand routine contact and impacts without damage, making them suitable for use in electronic devices such as mobile phones and displays.

Implementation Method 1

the laminate structure is then exposed to UV light, sufficient to cause nucleation within the photosensitive composition, thereby growing a secondary crystal phase within that cladding layer

Methodology Applied
Scientific EffectNucleation: Nucleation

Implementation Method 2

growing a secondary crystal phase within that cladding layer which results in compressively stressing the clad layer

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Implementation Method 3

growing a secondary crystal phase within that cladding layer which results in compressively stressing the clad layer, and strengthening the laminated glass structure

Methodology Applied
Scientific EffectCompressive stress: Compression

Data Source

PatentEP2903822B1Compressively stressed laminated glass article via photosensitive glass and method of making the article
Publication Date: 2019.11.20 CORNING INC
  • EP2903822B1 patent drawingFigure 1~2

AI summary

Laminated articles comprised of glass core and clad layers, more specifically, to compressively stressed laminated articles comprising a glass core sandwiched between first and second clad layers, the clad layers being formed from photosensitive glass.