Hydrogen-Free DLC Coating for Touch Screen Wear Resistance
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Solution Overview
Problem
Conventional diamond-like carbon (DLC) films used in touch screens for mobile devices face challenges in achieving good bonding force, high hardness, wear resistance, hydrophobicity, oleophobicity, and high light transmittance, particularly due to hydrogen inclusion which compromises hardness and wear resistance.
Innovation Solution
A DLC-coated article is created with a substrate, a transition layer formed by magnetron sputter deposition, a hydrogen-free DLC layer formed by filtered cathodic vacuum arc, and a fluorine-doped layer formed by radio frequency chemical vapor deposition, enhancing film bonding, hardness, and hydrophobicity while maintaining high light transmittance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a thick DLC film is formed to improve wear resistance, then wear resistance is improved, but light transmittance decreases
Solution Approach 1:
The patent changes the chemical composition parameters of the DLC film by eliminating hydrogen content and controlling carbon bonding structure. This allows achieving high wear resistance with a thinner film thickness (5-20 nm), thereby resolving the contradiction between wear resistance and light transmittance
Solution Approach 2:
The patent creates a composite structure with multiple layers including transition metal oxide layers (TiO2, SiO2, Al2O3) combined with hydrogen-free DLC layers. This composite approach enables optimized wear resistance and optical properties simultaneously
2Object-affected harmful factors
If conventional CVD method is used to form DLC film, then hydrophobicity is improved, but hardness and wear resistance decrease due to hydrogen inclusion
Solution Approach 1:
The patent extracts and removes hydrogen from the DLC film composition. By using filtered cathodic vacuum arc deposition, hydrogen is excluded from the carbon film, resulting in high hardness and wear resistance while maintaining hydrophobicity through fluorine doping or surface treatment
Solution Approach 2:
The patent changes the deposition method from CVD to FCVA, fundamentally altering the chemical composition parameters by eliminating hydrogen. This parameter change resolves the contradiction by achieving both hardness and hydrophobicity without hydrogen
3Object-affected harmful factors
If DLC film is made with high hydrogen content to improve hydrophobicity, then hydrophobicity is improved, but tetrahedral amorphous carbon structure decreases leading to lower hardness
Solution Approach 1:
The patent extracts hydrogen from the system entirely by using hydrogen-free deposition methods. This eliminates the need to balance hydrogen content, allowing maximum ta-C structure formation while achieving hydrophobicity through alternative means such as fluorine doping
Solution Approach 2:
The patent introduces fluorine as an intermediary element to provide hydrophobicity without requiring hydrogen. The fluorine doping or fluorinated surface layer serves as a mediator that achieves the desired hydrophobic effect while preserving the hard ta-C structure
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 achieves excellent film bonding, high hardness, improved wear resistance, and superior hydrophobicity and oleophobicity with light transmittance exceeding 90%, outperforming conventional methods in scratch and abrasion resistance and optical clarity.
Implementation Method 1
a transition layer formed by magnetron sputter deposition
Implementation Method 2
a hydrogen-free DLC layer formed by filtered cathodic vacuum arc
Implementation Method 3
a fluorine-doped layer formed by radio frequency chemical vapor deposition
Data Source
AI summary
A method of making an article coated with DLC, includes providing a substrate; depositing a transition layer on the substrate by means of magnetron sputter deposition (MSD); depositing a DLC layer without hydrogen (H) on the transition layer by means of filtered cathodic vacuum arc (FCVA); and doping a fluorine-doping (F-doping) layer on the DLC layer. The article has good film bonding force, high hardness, good wear resistance, good hydrophobicity and oleophobicity and high light transmittance, and the DLC layer has no H included.