As-Sliced Wafer Grinding and Chamfering Without Tool Changes
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Solution Overview
Problem
Conventional as-sliced wafer processing methods have low productivity due to the need for multiple steps and dedicated apparatus for grinding and chamfering before the wafer is ready for device formation.
Innovation Solution
An as-sliced wafer processing method involving a rotatable chuck table and a grinding unit with annularly arranged grinding stones for simultaneous grinding and chamfering of both surfaces of the wafer, allowing for efficient processing without changing processing tools or apparatus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional grinding and chamfering methods are used with dedicated apparatus, then processing precision is maintained, but productivity is low due to multiple steps and tool changes
Solution Approach 1:
The patent combines grinding and chamfering operations into a single processing step using one grinding wheel with multiple grinding stones arranged at different radii. The inner peripheral edge performs grinding while the outer peripheral edge performs chamfering simultaneously, eliminating the need for separate dedicated apparatus and tool changes.
Solution Approach 2:
The grinding wheel is designed with multi-functionality to perform both grinding and chamfering operations. By arranging grinding stones at different radial positions on the same wheel, a single tool can execute multiple processing functions that previously required separate dedicated tools, thereby improving productivity without sacrificing precision.
2Manufacturing precision
If multiple dedicated processing tools are used for grinding and chamfering, then processing quality is ensured, but processing time increases
Solution Approach 1:
The patent enables continuous processing by performing grinding and chamfering operations simultaneously in one continuous action. The grinding wheel rotates with both inner and outer peripheral edges engaged with the wafer surface at the same time, eliminating idle time between operations and reducing total processing time while maintaining surface quality through controlled grinding parameters.
Solution Approach 2:
The grinding stones are pre-positioned at specific radial distances from the rotation center, with inner stones positioned to perform grinding and outer stones positioned to perform chamfering. This preliminary arrangement of grinding stones at different radii allows both operations to occur simultaneously without requiring real-time tool changes or repositioning, thus reducing processing time while ensuring quality.
3Manufacturing precision
If separate grinding and chamfering steps are performed, then processing precision is maintained, but the number of tool changes increases
Solution Approach 1:
The patent merges grinding and chamfering operations into a single integrated process using one grinding wheel. The wheel simultaneously engages both operations on the wafer, eliminating the need for operators to perform multiple tool changes and reducing operational complexity while maintaining precision through controlled grinding parameters and wheel geometry.
Solution Approach 2:
The grinding wheel is designed as a universal tool that performs both grinding and chamfering functions. By configuring the wheel with grinding stones at multiple radial positions, a single tool replaces multiple dedicated tools, simplifying operations and reducing the number of tool changes required while maintaining the precision needed for accurate chamfering.
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
Enhances productivity by enabling a series of grinding and chamfering steps to be performed on both sides of the wafer without tool changes, improving efficiency and reducing processing time.
Implementation Method 1
a first grinding step of causing a grinding unit to approach the chuck table, the grinding unit having a rotatable grinding wheel that faces the holding surface and has a plurality of grinding stones arranged thereon in an annular manner, and rotating the grinding wheel such that the grinding stones pass through a rotation center of the as-sliced wafer held on the chuck table, to thereby grind a first surface of the as-sliced wafer
Implementation Method 2
a first chamfering step of chamfering an outer periphery of the first surface of the as-sliced wafer by the grinding stones after the first outer periphery positioning step is carried out. The first chamfering step positions the edge on the outer periphery of the grinding stones at the outer peripheral edge of the first surface of the as-sliced wafer and, while causing the grinding stones to approach the chuck table, moves the grinding stones in a direction toward the outer periphery of the first surface of the as-sliced wafer, to thereby grind the outer peripheral edge of the first surface to form a chamfered portion on the first surface
Data Source
AI summary
An as-sliced wafer processing method includes a grinding step of grinding a first surface of an as-sliced wafer, an outer periphery positioning step of moving a chuck table and a grinding unit relative to each other in directions parallel to a holding surface of the chuck table so as to position an edge on an outer periphery of grinding stones at an outer peripheral edge of the first surface after the grinding step is carried out, and a chamfering step of chamfering an outer periphery of the first surface of the as-sliced wafer by the grinding stones after the outer periphery positioning step is carried out.