Particle Sizing on Non-Metallic Surfaces Through Metal-Coated Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining particle size on non-metallic surfaces, such as silicon wafers, are inadequate due to the formation of discontinuous metallic layers, leading to noise in images and inability to measure smaller particles, as they require a metallic substrate which buries smaller particles within the layer.
Innovation Solution
A method involving depositing a metal layer on non-metallic surfaces and particles, ensuring a gap between each particle and the surface layer, followed by illumination with electromagnetic rays to scatter or reflect light, which is then processed to form an image for size determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a metallic layer is provided on particles on a non-metallic surface, then the particles can be illuminated and imaged, but the metallic layer becomes discontinuous creating gaps that result in noise in the image
Solution Approach 1:
The patent changes the physical parameter of the substrate surface from metallic to non-metallic, which fundamentally alters the interaction between the electromagnetic radiation and the substrate. This allows the metallic coating on particles to remain discontinuous without creating the harmful gaps-and-noises problem that occurs on metallic substrates, as the non-metallic substrate does not create the same reflective interference patterns
Solution Approach 2:
The patent converts the potential harm of a discontinuous metallic layer (which would normally create image noise on metallic substrates) into a benefit by using a non-metallic substrate. The discontinuous nature of the coating is no longer harmful but instead allows for better particle differentiation and reduced background interference, improving overall measurement precision
2Object-affected harmful factors
If the thickness of the metallic layer is increased to ensure continuity, then fewer gaps appear in the layer, but smaller particles become completely buried within the layer and cannot be detected
Solution Approach 1:
By changing the substrate parameter from metallic to non-metallic, the patent eliminates the need for thick continuous metallic layers. The non-metallic substrate allows thin, discontinuous metallic coatings to function effectively without creating image noise, thereby preserving the visibility of small particles while maintaining layer continuity where needed
Solution Approach 2:
The patent applies partial coating action, where the metallic layer is deposited only to the extent necessary to provide sufficient signal for detection without over-coating. On non-metallic substrates, this partial coverage is sufficient and beneficial, as it prevents small particles from being buried while still providing enough metallic material to generate detectable electromagnetic signals
3Measurement precision
If existing techniques are adapted to provide metallic layer on particles on non-metallic surface, then particle size can be determined, but the method becomes impossible due to discontinuous metallic layer formation
Solution Approach 1:
The patent fundamentally changes the substrate parameter from metallic to non-metallic, which resolves the feasibility problem. This parameter change allows the metallic layer deposition process to work reliably on non-metallic surfaces, producing the desired discontinuous coating pattern that enables particle detection without the method failures experienced on metallic substrates
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
Enables accurate measurement of particle sizes on non-metallic surfaces by minimizing noise and ensuring smaller particles are visible, allowing for precise determination of both large and small particles.
Implementation Method 1
illuminating said metallic layers on particles and metallic surface of the substrate with electromagnetic rays so that said electromagnetic rays are scattered by said metallic layers on particles to produce respectively scattered electromagnetic rays
Implementation Method 2
illuminating said metallic layers on particles and metallic surface of the substrate with electromagnetic rays so that at least a portion of said electromagnetic rays are absorbed by said metallic layers on particles and another portion of said electromagnetic rays are reflected by said metallic layer on substrate to produce reflected electromagnetic rays
Implementation Method 3
at least a portion of said electromagnetic rays are absorbed by said metallic layers on particles
Data Source
AI summary
Method including providing a substrate having a non-metallic surface with particles on the surface; depositing a layer of metal on the surface and the particles, so that each particle and an area of the surface without particles has a layer of metal, wherein, each particle has a gap between metal on that particle and metal on the surface; illuminating metal with electromagnetic rays, so that rays are scattered by metal on particles to produce scattered rays; or rays are absorbed by metal on particles and another portion of rays are reflected by metal on the surface to produce reflected rays; receiving scattered or reflected rays at an array of photodiodes; forming an image as pixels corresponding to photodiodes, wherein the colour of each pixel corresponds to the intensity and/or frequency of the rays received at that pixel; processing the image to determine the size of the particles.