Composite Cover Glass Coating for Scratch Resistance and Color Stability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing glass cover plates on electronic devices like mobile phones or Slate devices suffer from scratches, which affect the aesthetics of the device, and the scratches can destroy the stress balance of the glass cover plate, reducing its impact resistance.

Innovation Solution

A housing structure with a scratch-resistant layer composed of a mixture of high and low refractive index materials, integrated with an underlayer to enhance adhesion and an optical adjustment layer to maintain optical performance, is applied to the glass cover plate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a glass cover plate is used to protect the display panel, then mechanical strength and wear resistance are improved, but scratches appear on the surface affecting aesthetics and impact resistance

Engineering Contradiction:
Improvemechanical strengthVSAvoidsurface scratches
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent applies a composite scratch-resistant layer comprising multiple materials with different refractive indexes (first material with refractive index 1.4-1.7, second material with refractive index 1.7-2.0) deposited on the glass cover plate. This composite structure provides enhanced scratch resistance while maintaining optical performance, resolving the contradiction between protection and aesthetic durability.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent optimizes the thickness of the scratch-resistant layer between 300-5000 nm and controls the refractive indexes of the constituent materials to achieve the desired balance between scratch resistance and optical transparency, preventing visible scratches while maintaining the protective function.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If a protective structure is added to improve scratch resistance, then scratch resistance is improved, but light transmittance and reflectance are affected causing appearance color changes

Engineering Contradiction:
Improvescratch resistanceVSAvoidlight transmittance
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The patent carefully selects and controls the refractive indexes of the materials (first material: 1.4-1.7, second material: 1.7-2.0) and the layer thickness (300-5000 nm) to minimize optical interference effects, ensuring that the protective structure does not significantly affect light transmittance and reflectance, thus maintaining the original appearance color.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The scratch-resistant layer is applied specifically on the outer surface of the glass cover plate where scratches occur, rather than throughout the entire structure. This localized protection maintains the optical properties of the bulk glass while providing scratch resistance only where needed.

Inventive Principle:
Principle #3Local quality

3Object-affected harmful factors

If the scratch-resistant layer thickness is increased to improve scratch resistance, then scratch resistance is improved, but the edge area appearance color is affected

Engineering Contradiction:
Improvescratch resistanceVSAvoidappearance color
Core Design Contradiction:
Object-affected harmful factorsVSShape

Solution Approach 1:

The patent optimizes the thickness parameter of the scratch-resistant layer to be between 300-5000 nm, which is sufficient to provide scratch resistance but thin enough to minimize optical interference at the edges. This parameter optimization resolves the contradiction between scratch resistance and appearance color maintenance.

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 solution provides a glass cover plate with improved scratch resistance and optical performance without affecting the appearance color, ensuring high impact resistance and maintaining the device's aesthetic appeal.

Implementation Method 1

The scratch-resistant layer includes at least one high refractive index material and at least one low refractive index material. The low refractive index material has a refractive index less than or equal to a refractive index of the substrate, and the high refractive index material has a refractive index greater than 1.6.

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

The scratch-resistant layer has a thickness greater than or equal to 300 nm and less than or equal to 5000 nm. The at least one high refractive index material and the at least one low refractive index material are mixed to form the scratch-resistant layer, so that a refractive index of the scratch-resistant layer is the same as or close to that of the substrate.

Methodology Applied
Scientific EffectOptical interference: Interference

Data Source

PatentEP4669038A1Shell structure, display module, and electronic device
Publication Date: 2025.12.24 HONOR DEVICE CO LTD
  • EP4669038A1 patent drawingFigure 1~2
  • EP4669038A1 patent drawingFigure 3~4
  • EP4669038A1 patent drawingFigure 5~7

AI summary

Embodiments of this application provide a housing structure, a display module, and an electronic device, and relate to the technical field of electronic devices. The housing structure can improve scratch resistance of cover plate glass. When the housing structure is applied to a 3D curved display panel, there is no appearance color difference in a 3D cambered display area, so that the electronic device has a good appearance. The housing structure includes a substrate and a scratch-resistant layer located on a side of the substrate. The scratch-resistant layer includes at least two materials, and the at least two materials include at least one high refractive index material and at least one low refractive index material. The scratch-resistant layer has a thickness greater than or equal to 300 nm and less than or equal to 5000 nm. The low refractive index material has a refractive index less than or equal to a refractive index of the substrate, and the high refractive index material has a refractive index greater than 1.6.