Annular Grinding Tool for Wafer Chamfer Removal
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Solution Overview
Problem
The existing process of removing a chamfer from a wafer using a coarse grindstone followed by a fine grindstone is time-consuming and inefficient, leading to poor productivity and quality issues due to chipping and cracking.
Innovation Solution
A processing tool with an annular grinding grindstone and a polishing grindstone, where the polishing grindstone is formed on at least one side surface, and the dimensions and grain diameters of the grindstones are optimized to efficiently remove the chamfer, satisfying specific conditions to enhance productivity and surface finish.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a coarse grindstone is used to remove the chamfer, then the chamfer removal efficiency is improved, but chipping occurs at the periphery of the wafer
Solution Approach 1:
The invention combines a coarse grindstone and a fine grindstone into a single integrated processing tool. The coarse grindstone portion removes the chamfer efficiently, while the fine grindstone portion simultaneously finishes the peripheral surface to prevent chipping. This merging of two separate processing steps into one tool resolves the contradiction between removal efficiency and surface quality.
2Manufacturing precision
If a fine grindstone is used to finish the wafer peripheral surface, then the surface quality is improved, but the chamfer removal time increases
Solution Approach 1:
The processing tool integrates both coarse and fine grindstones in a single unit, allowing simultaneous chamfer removal and surface finishing. The coarse grindstone handles the bulk material removal while the fine grindstone concurrently performs the finishing operation, eliminating the need for sequential processing and thus resolving the time-quality trade-off.
Solution Approach 2:
The integrated tool enables continuous useful action by performing both chamfer removal and surface finishing in a single continuous operation. The wafer peripheral region is processed simultaneously by both grindstone portions, ensuring that the entire useful work is completed in one pass without interruption or sequential delays.
3Device complexity
If the chamfer is not removed before back surface grinding, then the grinding process is simplified, but cracks are generated from the periphery extending into the device region
Solution Approach 1:
The integrated processing tool performs preliminary chamfer removal and peripheral surface finishing before the back surface grinding operation. By removing the chamfer and finishing the peripheral surface in advance, the tool prevents the formation of sharp knife edges that would cause cracks during subsequent grinding, thus ensuring device integrity while maintaining process simplicity.
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 tool efficiently removes the chamfer region and finishes the peripheral surface, improving productivity by ensuring a smooth finish and reducing the risk of chipping and cracking.
Implementation Method 1
an annular grinding grindstone... H is a width of the grinding grindstone
Implementation Method 2
a polishing grindstone formed on at least one of the first side surface or the second side surface
Data Source
AI summary
A processing tool for removing a chamfer of a wafer that is formed on its front surface with a central region and a peripheral surplus region, the chamfer being formed in the peripheral surplus region. The processing tool includes an annular grinding grindstone with an opening into which a spindle is inserted and having first and second side surfaces and a polishing grindstone formed on at least one of the first side surface or the second side surface. The processing tool is formed in such a manner as to satisfy both the following conditions (1) and (2):H+h>L(1)L/3>h>L/100(2)where L is a length in a radial direction from a peripheral end of the chamfer to be removed, H is a width of the grinding grindstone, and h is a width of the polishing grindstone.