Coating Nozzle Liquid Position Control for Drip Prevention
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Solution Overview
Problem
Conventional liquid processing apparatuses for semiconductor and FPD substrates require frequent and cumbersome operations to maintain coating nozzles in a standby state, leading to risks of liquid drip and dryness, necessitating lengthy dummy dispense procedures and inefficient process control.
Innovation Solution
A liquid processing apparatus with a nozzle transfer mechanism, dispense controller, and imaging unit that analyzes and adjusts the position of a coating solution nozzle and anti-drying liquid layer using a soft scale, allowing for precise control and reduced standby time by preventing liquid dryness and drip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If coating nozzles are moved as one body by a common driving arm, then device complexity is reduced, but reliability deteriorates due to risks of liquid drip and dryness
Solution Approach 1:
The patent divides the nozzle system into individually controllable units. Each coating nozzle can be independently moved between standby and processing positions, and each has its own drive mechanism. This segmentation allows independent control of each nozzle's liquid state, preventing the reliability issues that arise when all nozzles are moved together as one body.
2Reliability
If dummy dispense is performed for a long time, then reliability of preventing dryness is improved, but productivity deteriorates due to time consumption
Solution Approach 1:
The patent applies preliminary action by moving each coating nozzle to a processing position just before it is needed, rather than maintaining all nozzles in a standby state for extended periods. The controller manages the timing and positioning of each nozzle individually, performing dummy dispense only when necessary and for the minimum required duration. This approach maintains reliability while minimizing productivity loss.
3Adaptability or versatility
If multiple coating nozzles are used with different resist solutions, then adaptability is improved, but device complexity increases due to individual nozzle requirements
Solution Approach 1:
The patent implements universality through a common drive arm that can position multiple different coating nozzles at the same processing location. Each nozzle is designed for a specific resist solution type, but they all share the same positioning mechanism and control system. This allows the system to handle multiple resist solution types (improving adaptability) while using a unified positioning infrastructure (managing complexity).
Data Source
AI summary
A liquid processing method forms a coating film by supplying and pouring a coating solution from a coating solution nozzle onto a surface of a substrate held substantially horizontally by a substrate holder. In the liquid processing method, a process for photographing a leading end portion of a coating solution nozzle is provided. When performing a process for anti-drying of the coating solution for a long period of time in advance, a position of the coating solution and a position of an anti-drying liquid are set by using a soft scale displayed on a screen where the photographed image is displayed. Therefore, a dispense control is performed based on a set value without depending on the naked eyes and a control for suppressing the drying of the coating solution in the leading end portion of the coating solution nozzle is performed.