Nozzle Liquid Cut-Off Control for High-Viscosity Substrate Coating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current substrate treating apparatuses face challenges in adjusting the liquid cut-off position of treatment liquids with high viscosity, leading to poor liquid cut-off conditions that result in film thickness unevenness, coating unevenness, and nozzle contamination.
Innovation Solution
The method involves causing the suck back valve to perform suction operation in association with the closing operation of the on-off valve to adjust the liquid cut-off position, allowing for easy alignment with the nozzle tip end face and preventing poor liquid cut-off conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the on-off valve is closed at high speed to improve liquid cut-off condition, then liquid cut-off performance is improved, but pressure variation becomes excessive causing air bubble formation and coating unevenness
Solution Approach 1:
The suck back valve performs suction operation in advance during the on-off valve closing process to proactively prevent liquid cut-off deterioration before it occurs, eliminating the need for high-speed valve closing that causes pressure variation and air bubbles
Solution Approach 2:
The suck back valve acts as an intermediary mechanism between the on-off valve and the liquid column, using suction to maintain proper liquid cut-off position without requiring the on-off valve to close at excessively high speeds, thereby preventing air bubble formation
2Reliability
If the treatment liquid has high viscosity, then treatment effectiveness is improved, but liquid cut-off condition deteriorates significantly
Solution Approach 1:
The suck back valve serves as an intermediary that compensates for the poor stop performance and inertia of high viscosity liquids, using suction to maintain proper liquid cut-off position despite the liquid's resistance to flow changes
Solution Approach 2:
The system changes the operational parameters by introducing suction control that adapts to the viscosity characteristics of the treatment liquid, maintaining effective treatment while preventing liquid cut-off deterioration specific to high viscosity fluids
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 approach enables easy adjustment of the liquid cut-off position, preventing film thickness unevenness, coating unevenness, and nozzle contamination, while ensuring stable liquid cut-off performance even with high viscosity treatment liquids.
Implementation Method 1
causing the suck back valve to perform suction operation in association with the closing operation by the on-off valve
Implementation Method 2
the treatment liquid cut off below the nozzle 108 and hung down is drawn back toward the nozzle 108 by a surface tension of the treatment liquid
Implementation Method 3
an on-off valve provided on the pipe... causing the on-off valve to perform closing operation
Data Source
AI summary
The present invention relates to a treatment liquid supplying method and a substrate treating apparatus. The treatment liquid supplying method for a substrate treating apparatus provided with a nozzle configured to eject a treatment liquid, a pipe connected to the nozzle, an on-off valve provided on the pipe, and a suck back valve provided on the pipe between the nozzle and the on-off valve includes an ejection stopping step of stopping ejection of the treatment liquid from the nozzle by causing the on-off valve to perform closing operation, and a liquid cut-off position adjusting step of adjusting a liquid cut-off position as a position where the treatment liquid in a column shape ejected from the nozzle is cut off by causing the suck back valve to perform first suction operation in association with the closing operation by the on-off valve.