Ball-Type Abrasive Grinding Wheel for Wafer Planarization
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Solution Overview
Problem
The existing grinding operations for silicon wafers often result in surface damage and edge cracks due to diamond-shaped grits, leading to potential leakage and increased manufacturing costs and processing time.
Innovation Solution
Integration of ball-type grinding abrasives with rounded perimeters into the grinding wheel and incorporation of an electrochemical etching reservoir to reduce surface damage and enhance the grinding efficiency, allowing for thinner wafer thickness without the need for edge trimming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If diamond-shaped grits are used in the grinding wheel, then the grinding speed and removal rate are improved, but the surface damage and edge cracks increase
Solution Approach 1:
The patent replaces the conventional diamond-shaped mechanical abrasives with an electrochemical etching system that uses electrical current and chemical electrolyte to remove material. This substitution eliminates the mechanical impact and scratching caused by diamond grits while maintaining efficient material removal through electrochemical reactions at the wafer surface.
Solution Approach 2:
The patent changes the fundamental mechanism of material removal from mechanical abrasion to electrochemical etching. By controlling electrical parameters (current density, voltage) and chemical parameters (electrolyte composition, temperature), the process achieves high removal rates without the surface damage associated with mechanical grinding.
2Speed
If diamond-shaped grits are used in the grinding wheel, then the grinding speed is improved, but the edge cracks and leakage risks increase
Solution Approach 1:
The patent replaces the mechanical grinding system with an electrochemical etching system that uses controlled electrical and chemical processes to remove material. This eliminates the mechanical stresses and impact forces that cause edge cracks while maintaining high processing speed through efficient electrochemical material removal.
Solution Approach 2:
The patent introduces an electrolyte solution as an intermediary medium between the power source and the wafer surface. This electrolyte enables controlled material removal through electrochemical reactions, providing a gentle yet efficient process that avoids the direct mechanical contact and associated edge damage of traditional grinding.
3Productivity
If conventional grinding operation is used, then the wafer thickness is reduced quickly, but the manufacturing cost increases due to edge trimming requirements
Solution Approach 1:
The patent replaces mechanical grinding with electrochemical etching, which produces a cleaner, more precise surface finish that eliminates the need for subsequent edge trimming operations. This substitution maintains rapid thickness reduction while reducing overall manufacturing complexity and cost by removing the edge trimming step.
Solution Approach 2:
The patent extracts and eliminates the edge trimming operation from the manufacturing process by using electrochemical etching to achieve the final dimensions directly. This removes the need for additional processing steps, reducing both time and cost while maintaining the rapid thickness reduction capability.
4Productivity
If conventional grinding operation is used, then the wafer thickness is reduced quickly, but the processing time increases due to additional edge trimming steps
Solution Approach 1:
The patent merges the thickness reduction and surface finishing operations into a single electrochemical etching process. This eliminates the need for separate edge trimming steps, consolidating multiple operations into one process that achieves both rapid thickness reduction and precise final dimensions simultaneously.
Solution Approach 2:
The patent extracts the edge trimming operation from the process sequence by using electrochemical etching to achieve the final wafer dimensions directly in one step. This eliminates the need for additional processing time associated with separate trimming operations while maintaining rapid material removal.
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 minimizes surface damage during grinding, enables thinner wafer thickness, and accelerates the removal rate, thereby reducing manufacturing costs and processing time while improving device performance.
Implementation Method 1
an electrochemical etching reservoir to implement electrochemical etching during the grinding operation
Implementation Method 2
a plurality of grinding teeth mounted on the base ring, wherein the plurality of grinding teeth includes a plurality of grinding abrasives, and the plurality of grinding abrasives is ball type
Data Source
AI summary
A planarization apparatus is provided. The planarization apparatus includes a platen, and a grinding wheel. The platen is configured to support a wafer. The grinding wheel is over the platen and configured to grind the wafer. The grinding wheel includes a base ring, and a plurality of grinding teeth mounted on the base ring. The plurality of grinding teeth includes a plurality of grinding abrasives, and the plurality of grinding abrasives is ball type.