Metal Casing with Micro Arc Oxidation Ceramic Layer

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Solution Overview

Problem

Electronic device casings are prone to damage from bumps and scratches, and accumulate fingerprints and dirt due to their lightweight and slim design, lacking sufficient mechanical strength and surface protection.

Innovation Solution

A manufacturing method involving a Micro Arc Oxidation process to form an oxide ceramic layer on the metal casing body, followed by an anti-fingerprint layer with specific solvent composition, enhancing mechanical strength and preventing fingerprints and dirt accumulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If the casing is made lightweight and slim, then the electronic device becomes more portable and convenient, but the mechanical strength and surface durability of the casing deteriorates

Engineering Contradiction:
Improveweight of electronic deviceVSAvoidmechanical strength of casing
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The patent applies composite materials by forming an oxide ceramic layer on the metal casing body through Micro Arc Oxidation process. This creates a composite structure combining metal base material with ceramic coating, providing both lightweight properties and enhanced mechanical strength. The oxide ceramic layer acts as a protective composite that maintains durability while preserving the lightweight characteristic of the original metal casing.

Inventive Principle:
Principle #40Composite materials

2Shape

If the casing surface is smooth and clean, then the aesthetic appearance is improved, but the surface becomes prone to fingerprints and dirt accumulation

Engineering Contradiction:
Improvesurface smoothnessVSAvoidfingerprint and dirt accumulation
Core Design Contradiction:
ShapeVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by creating different surface properties in different regions. The oxide ceramic layer provides a base protective layer, while the anti-fingerprint layer is selectively applied to specific surface areas where fingerprint accumulation is most problematic. This localized treatment maintains overall surface smoothness for aesthetics while providing targeted protection against fingerprints and dirt in high-contact areas.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes surface parameters by applying an anti-fingerprint layer with specific chemical composition (containing solvents like xylene, toluene, and epoxy resin) that modifies the surface energy and chemical properties. This parameter change transforms the surface from one that easily attracts fingerprints to one with reduced surface energy that resists fingerprint and dirt adhesion, while maintaining the smooth aesthetic appearance.

Inventive Principle:
Principle #35Parameter changes

3Strength

If protective coatings are applied to the casing surface, then the mechanical strength and surface durability are enhanced, but the manufacturing process complexity increases

Engineering Contradiction:
Improvesurface durabilityVSAvoidmanufacturing process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by performing surface roughening treatment on the metal casing body before forming the oxide ceramic layer. This preliminary preparation of the surface creates better adhesion conditions for subsequent coating layers, ensuring enhanced durability. By preparing the surface in advance, the process ensures optimal bonding between the metal substrate, oxide ceramic layer, and anti-fingerprint layer, reducing the need for additional corrective steps and simplifying the overall manufacturing process.

Inventive Principle:
Principle #10Preliminary action

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 significantly increases the mechanical strength of the casing while providing a smooth, durable surface that resists fingerprints and dirt, enhancing both aesthetics and durability.

Implementation Method 1

An oxide ceramic layer is formed on a surface of the casing body, wherein the step of forming the oxide ceramic layer on the surface of the casing body is a Micro Arc Oxidation (MAO) process

Methodology Applied
Scientific EffectMicro Arc Oxidation: Oxidation

Implementation Method 2

an anti-fingerprint layer (AFP layer) is formed on the oxide ceramic layer... The surface of the casing body is roughend, and the oxide ceramic layer is formed on the roughened surface of the casing body

Methodology Applied
Scientific EffectHydrophobic effect: Hydrophobe

Data Source

PatentEP2644752B1Casing of electronic device and method of manufacturing the same
Publication Date: 2016.04.20 HTC CORP
  • EP2644752B1 patent drawingFigure 1
  • EP2644752B1 patent drawingFigure 2A~2B
  • EP2644752B1 patent drawingFigure 2C~3

AI summary

A manufacturing method of a casing of electronic device including the following steps: providing a casing body, whereby the material of the casing body is a metal; roughening the surface of the casing body; forming an oxide ceramic layer on a surface of the casing body, wherein the step of forming the oxide ceramic layer on the surface of the casing body is a Micro Arc Oxidation (MAO) process; forming an anti-fingerprint layer (AFP layer) on the oxide ceramic layer. A casing of electronic device including a casing body and an oxide ceramic layer is also disclosed.