Diaphragm Valve Recirculation for Particle-Free Substrate Treatment
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Solution Overview
Problem
Existing substrate treating apparatuses suffer from particle generation due to treatment liquid remaining in the valve when closed, leading to contamination during substrate processing.
Innovation Solution
A valve assembly with a diaphragm that moves between open and closed positions, incorporating a recirculation path to prevent residual treatment liquid from stagnating, minimizing particle discharge by continuously recirculating the liquid back to the supply source.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a valve with a buffer space and diaphragm is used to control treatment liquid flow, then the valve can effectively open and close the flow path, but treatment liquid remains in the buffer space causing particle generation
Solution Approach 1:
The patent extracts the harmful stagnant treatment liquid from the buffer space through a dedicated discharge path. The discharge path includes a discharge port positioned at the bottom of the buffer space and a discharge valve that opens to remove accumulated liquid and particles, thereby eliminating the source of contamination while preserving the buffer space's flow control function.
Solution Approach 2:
The patent implements a periodic discarding mechanism where stagnant treatment liquid and generated particles are discharged from the buffer space through the discharge path. This allows the system to discard contaminated liquid and recover a cleaner state, preventing particle accumulation that would otherwise contaminate the substrate.
2Ease of operation
If the treatment liquid flows divided into opposite sides of the diaphragm in the buffer space, then the valve can control flow effectively, but the treatment liquid forms a vortex generating particles
Solution Approach 1:
The patent extracts vortex-generated particles from the buffer space before they can contaminate the treatment liquid. The discharge path positioned at the bottom of the buffer space removes particles that settle from vortex motion, while the continued flow control function of the diaphragm is preserved.
3Reliability
If the treatment liquid remains in the buffer space for a long time, then the valve maintains flow control, but particles are generated from the stagnant treatment liquid
Solution Approach 1:
The patent implements continuous recirculation of treatment liquid through a recirculation pump and path. The treatment liquid is continuously circulated from the buffer space through a filter and back to the liquid supply source, preventing stagnation and particle generation while maintaining the valve's flow control reliability.
Solution Approach 2:
The patent implements a feedback mechanism where a sensor detects particle concentration or flow conditions in the treatment liquid, and the controller adjusts the recirculation pump operation or discharge valve timing accordingly. This feedback loop maintains substrate cleanliness by actively responding to changing liquid conditions while preserving flow control functionality.
Data Source
AI summary
Disclosed is a substrate treating apparatus including a valve assembly. The valve assembly includes a body and a diagram, and the body includes an inlet port through which the treatment liquid is introduced from a liquid supply source side, an outlet port through which the treatment liquid is discharged to the liquid treating chamber side, and a recirculation port through which the treatment liquid returns to the liquid supply source side. The diaphragm opens and closes a flow path of the treatment liquid flowing toward the outlet port side. The treatment liquid introduced into the body of the valve assembly is supplied to a nozzle through the outlet port or recovered to the liquid supply source side through the recirculation port.