Uneven-Surface Member With Carbon-Gradient Protective Coating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Polytetrafluoroethylene water-repellent coatings exhibit low adhesion to fine-uneven structures, leading to peeling during surface wiping, and conventional oxide or nitride protective coatings lack sufficient water resistance.
Innovation Solution
A protective coating with a higher carbon content at the surface layer than the inside is applied over a base with a fine-uneven structure, using atomic layer deposition (ALD) to ensure adhesion and enhance water resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a polytetrafluoroethylene water-repellent coating is formed over the fine-uneven structure, then water resistance is improved, but adhesion deteriorates causing peeling during wiping
Solution Approach 1:
The patent applies a composite coating structure consisting of an oxide or nitride layer (such as silicon oxide, aluminum oxide, titanium oxide, silicon nitride, or aluminum nitride) formed over the fine-uneven structure. This composite approach combines the adhesion benefits of oxide/nitride materials with the water-repellent properties achieved through controlled carbon content distribution, resolving the contradiction between water resistance and adhesion exhibited by polytetrafluoroethylene coatings alone.
Solution Approach 2:
The patent implements local quality by creating a carbon content gradient within the oxide or nitride coating layer. The surface layer contains higher carbon content (0.1-5.0 at%) to provide water resistance, while the inner layer contains lower carbon content (0.01-1.0 at%) to ensure adhesion to the fine-uneven structure. This spatial differentiation of carbon content allows simultaneous achievement of both water repellency and strong adhesion.
2Strength
If an oxide or nitride protective coating is formed over the fine-uneven structure, then adhesion is improved, but water resistance deteriorates
Solution Approach 1:
The patent resolves this contradiction by implementing a carbon content gradient within the oxide or nitride coating. The inner layer maintains low carbon content (0.01-1.0 at%) to ensure strong adhesion to the fine-uneven structure, while the surface layer contains higher carbon content (0.1-5.0 at%) to provide water resistance. This local differentiation of carbon content allows the coating to simultaneously achieve both adhesion and water repellency.
Solution Approach 2:
The patent applies parameter changes by controlling the carbon content distribution as a gradient parameter through the coating thickness. By adjusting carbon content from low in the inner layer to high in the surface layer, the coating transitions from an adhesive interface to a water-repellent surface, effectively resolving the contradiction between adhesion strength and water resistance.
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 coating provides improved adhesion to the base and enhances water resistance, preventing peeling and maintaining antireflection properties under environmental stress.
Implementation Method 1
using atomic layer deposition (ALD) to ensure adhesion and enhance water resistance
Implementation Method 2
The layer has a higher carbon content at a surface than on an inside... enhances water resistance
Data Source
AI summary
A member includes a base having a surface with an uneven structure, and a layer containing an oxide or a nitride over the uneven structure of the base. The layer has a higher carbon content at a surface than on an inside.