Grinding Apparatus with Photocatalyst Grindstone and Light Diffusion Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Grinding difficultly grindable materials like gallium nitride, silicon carbide, and metal wafers with exposed electrodes poses challenges due to excessive grindstone wear and ductility issues, leading to increased production costs and processing difficulties.
Innovation Solution
A grinding apparatus with a grinding wheel featuring abrasive grains bound by a vitrified bond and photocatalyst grains, equipped with a light applying unit that enhances the hydrophilicity of the grindstone, and a grinding water supply unit to improve cooling and swarf discharge, allowing for efficient oxidation and embrittlement of the workpiece surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional grinding is used on difficultly grindable materials like gallium nitride, silicon carbide, or gallium arsenide, then grinding can be performed, but the wearing amount of the grindstone becomes large and production cost increases
Solution Approach 1:
The patent changes the chemical state of the grindstone surface by applying light to activate photocatalyst grains, transforming the surface properties to enhance hydrophilicity and oxidation capability. This parameter change in surface chemistry reduces mechanical wear by enabling chemical embrittlement of the workpiece surface, allowing more efficient material removal with less grindstone consumption.
Solution Approach 2:
The grindstone is constructed as a composite material containing both abrasive grains and photocatalyst grains bound together. This composite structure combines the mechanical cutting action of abrasive grains with the chemical oxidation capability of photocatalyst grains, creating a synergistic effect that reduces wear while maintaining grinding efficiency on difficultly grindable materials.
2Ease of operation
If conventional grinding is used on metal wafers or wafers with exposed metallic electrodes, then grinding can be attempted, but ductility of the metal makes it difficult to perform grinding
Solution Approach 1:
The patent changes the physical state of the metal surface through light-induced photocatalytic oxidation, transforming the ductile metal surface into a more brittle oxidized layer. This parameter change in material properties enables effective grinding of metals by converting them from a ductile state that resists grinding to a brittle state that can be efficiently removed by abrasive action.
Solution Approach 2:
The photocatalyst grains generate strong oxidizing conditions through light activation, creating an accelerated oxidation environment at the grindstone-workpiece interface. This strong oxidation embrittles the metal surface, making it susceptible to grinding despite the inherent ductility of metallic materials, thereby improving ease of operation and process reliability.
3Loss of substance
If light is applied to the grindstone to enhance hydrophilicity and cooling effect, then grindstone wear is reduced and swarf discharge is improved, but light diffusion reduces the efficiency of light application
Solution Approach 1:
The diffusion preventive wall acts as an intermediary structure that controls light propagation. It prevents light diffusion while allowing the activated grindstone and cooling water to interact freely. This intermediary element ensures that light energy is concentrated where needed on the grindstone surface, maximizing the hydrophilicity enhancement and photocatalytic effects without energy waste from diffusion.
Solution Approach 2:
The diffusion preventive wall creates a localized environment where light is concentrated precisely on the grindstone surface. This local quality enhancement ensures that the photocatalyst activation and hydrophilicity improvement occur only where required, rather than diffusing uselessly into the surrounding space, thereby improving light application efficiency.
4Manufacturing precision
If grinding water is supplied to cool the grinding region, then processing quality can be maintained, but insufficient water supply leads to processing heat that lowers quality
Solution Approach 1:
The patent changes the surface properties of the grindstone through light-induced photocatalytic activation, enhancing hydrophilicity. This parameter change in surface chemistry improves the wetting and distribution of grinding water, ensuring more effective cooling and swarf removal. The modified surface properties allow grinding water to spread more uniformly and penetrate better into the grinding zone, maintaining temperature control and processing quality.
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 effectively reduces grindstone wear, enhances processing quality, and enables smooth grinding of challenging materials by making the grindstone hydrophilic, improving cooling and swarf discharge, and utilizing strong oxidizing hydroxyl radicals for oxidation, thus reducing processing time and wear.
Implementation Method 1
the grindstone has the abrasive grains and photocatalyst grains bound by the bonding agent, and the light applying unit applies the light that excites the photocatalyst grains
Implementation Method 2
a diffusion preventive wall that surrounds the light emission section and that prevents diffusion of the light
Implementation Method 3
the grinding water supply unit supplies grinding water to at least the grindstone when the workpiece held by the holding table is ground by the grinding unit
Implementation Method 4
it is ensured that the grinding water supplied exhibits an oxidizing power due to hydroxyl radicals. Therefore, even if the workpiece is a wafer formed, for example, of a difficultly grindable material, it is possible to oxidize the surface to be ground of the workpiece by the strong oxidizing power of the thus produced hydroxyl radicals, to perform grinding while embrittling the surface through the oxidation
Data Source
AI summary
A grinding apparatus includes a table that holds a workpiece, and a grinding unit including a grinding wheel mounted to a spindle. The grinding wheel has a grindstone formed by binding abrasive grains with a bonding agent. In addition, the grinding apparatus further includes: a supply unit that supplies grinding water to at least the grindstone when grinding the workpiece; and a light applying unit that is disposed adjacent to the table and that applies light to a grinding surface of the grindstone grinding the workpiece held by the table. The light applying unit includes a light emission section that emits light, and a diffusion preventive wall that surrounds the light emission section and prevents diffusion of the light.