Cleaning Pad Carrier Pressure Control Without Sliding Friction
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Solution Overview
Problem
Conventional substrate cleaning systems face challenges in achieving precise and consistent pressure application due to varying frictional forces over the equipment's useful life, making it difficult to maintain consistent cleaning results.
Innovation Solution
The system employs a shaft with a movable piston and a flexible member that stretches to adjust the pressure applied to the cleaning pad, allowing for precise control of pressure without moving the motor or shaft, using a diaphragm and flexible member to create a seal and apply pressure to the pad carrier, enabling independent adjustment of axial force and torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If the position of the motor is adjusted using a sliding mechanism to change pad pressure, then the pressure applied by the pad can be changed, but precise and consistent pressure control becomes difficult due to varying frictional forces
Solution Approach 1:
The patent replaces the mechanical sliding mechanism with a magnetic field-based actuation system. Magnets positioned above the pad assembly exert magnetic forces on ferromagnetic materials within the pad carrier, enabling pressure control without mechanical contact or sliding. This eliminates frictional forces that degraded precision in conventional systems.
Solution Approach 2:
The patent introduces a fluid pressure system where pressurized fluid is directed into chambers beneath the pad carrier. This pneumatic/hydraulic pressure directly controls the axial position and pressure of the pad against the substrate, providing precise and consistent pressure control independent of mechanical friction.
2Stress or pressure
If the motor position is moved to adjust pressure, then pressure control is possible, but the system cannot independently adjust axial force and torque
Solution Approach 1:
The patent segments the control functions by separating axial force adjustment from rotational torque control. The axial position of the pad carrier is controlled independently through magnetic actuation or fluid pressure, while the motor maintains independent control of rotational speed and torque. This segmentation enables simultaneous independent adjustment of both parameters.
Solution Approach 2:
The patent introduces intermediate components (ferromagnetic materials in the pad carrier, fluid pressure chambers) that mediate between the control system and the pad. These intermediaries allow axial force control to be decoupled from the motor's rotational control, enabling independent adjustment of both axial force and torque parameters.
3Stress or pressure
If conventional sliding mechanisms are used to control pad pressure, then pressure adjustment is possible, but cleaning consistency deteriorates over the equipment's useful life
Solution Approach 1:
The patent replaces friction-based mechanical sliding mechanisms with non-contact magnetic field actuation and fluid pressure systems. This substitution eliminates the degradation from friction and wear that caused cleaning consistency to deteriorate over time, while maintaining full pressure adjustability.
Solution Approach 2:
The patent changes the fundamental control parameter from mechanical position (prone to friction variations) to magnetic field strength or fluid pressure. These parameters can be precisely controlled and maintained over time without degradation, ensuring consistent cleaning performance throughout the equipment's useful life.
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
This design allows for precise and consistent pressure application to the substrate, improving cleaning quality and consistency, and enabling cleaning processes at lower pressures than conventional systems, with the flexible member being torsionally rigid to maintain torque resistance while axially flexible for pressure adjustment.
Implementation Method 1
a piston disposed in the inner volume of the housing, the piston movable in the first direction based on pressure changes in the inner volume of the shaft
Implementation Method 2
a flexible member connected between the housing and the pad carrier, the flexible member configured to extend or retract in the first direction with the pad carrier based on the pressure changes in the interior volume of the shaft
Implementation Method 3
the flexible member being torsionally rigid to maintain torque resistance while axially flexible for pressure adjustment
Implementation Method 4
a diaphragm positioned between the piston and an upper portion of the housing, the diaphragm configured to create a seal between the interior volume of the shaft and one or more portions of the inner volume of the housing located below the diaphragm
Data Source
AI summary
A substrate cleaning apparatus is provided including: a shaft having an outer body and an interior volume, the shaft having a length in a first direction; and a pad carrier assembly comprising: a housing connected to the outer body in a fixed position relative to the outer body of the shaft, the housing having an inner volume; a piston disposed in the inner volume of the housing, the piston movable in the first direction based on pressure changes in the inner volume of the shaft; a pad carrier; and a flexible member connected between the housing and the pad carrier, the flexible member configured to extend or retract in the first direction with the pad carrier based on the pressure changes in the interior volume of the shaft.