Torque-Based Force Control for Substrate Cleaning
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Solution Overview
Problem
CMP apparatuses using load cells struggle to accurately detect and apply the desired force for substrate cleaning, leading to potential leakage or adhesion failures due to residual residues.
Innovation Solution
A substrate cleaning apparatus equipped with a cleaning member, a rotating unit, a pressing drive unit, a torque detecting unit, and a control unit that adjusts the pressing force based on torque detection to ensure accurate and consistent force application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If a load cell is used to measure and control the force applied by a roller member to clean a substrate, then the pressing force can be controlled through feedback, but the system cannot accurately detect the force applied from the load cell to the substrate
Solution Approach 1:
The patent introduces a torque detecting unit as an intermediary device that indirectly measures the cleaning force by detecting the torque applied to the roller member during rotation. This torque detection serves as a mediator between the pressing drive unit and the substrate, providing accurate measurement of the actual cleaning force without requiring direct force sensing between the roller and substrate surfaces
2Reliability
If the cleaning force is increased to improve cleaning effectiveness, then residue removal improves, but the complexity of force control increases
Solution Approach 1:
The patent implements a feedback control mechanism where the torque detecting unit continuously monitors the torque applied to the roller member, and the control unit adjusts the pressing force based on this feedback. This closed-loop system maintains optimal cleaning force by comparing detected torque values with target values and making real-time adjustments, ensuring reliable cleaning while managing system complexity through automated control
Solution Approach 2:
The patent replaces direct mechanical force measurement (using load cells) with torque detection through rotational mechanics. By measuring the torque required to rotate the roller member under cleaning conditions, the system indirectly but accurately determines the cleaning force, simplifying the measurement mechanism while maintaining precision
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 precise and reliable cleaning by accurately controlling the force applied to the substrate, preventing residue-related issues and ensuring consistent cleaning performance.
Implementation Method 1
a torque detecting unit for detecting torque applied to the member rotating unit
Implementation Method 2
a cleaning member that comes into contact with a substrate and cleans the substrate
Implementation Method 3
roller-member scrubbing or pen-member scrubbing is performed
Data Source
AI summary
A substrate cleaning apparatus comprises: a cleaning member 11,21 that comes into contact with a substrate W and cleans the substrate W; a member rotating unit 15, 25 that rotates the cleaning member 11, 21; a pressing drive unit 19, 29 that presses the cleaning member 11, 21 against the substrate W; a torque detecting unit 16, 26 for detecting torque applied to the member rotating unit 15, 25; and a control unit 50 that controls pressing force on the basis of a result of detection by the torque detecting unit 16, 26.