Ejection Head Immersion Standby to Prevent Clogging and Dripping
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Solution Overview
Problem
Substrate processing apparatuses face issues with outlet clogging due to drying during standby and potential liquid dripping when the ejection head is resumed for use, as existing methods do not effectively prevent drying or liquid adherence to the substrate.
Innovation Solution
The substrate processing apparatus includes a mechanism to immerse the ejection head's ejection surface in an immersion liquid during standby, with a supply part movement mechanism to position the ejection head and reservoir for immersion, and a liquid removing part to separate and remove the immersion liquid, preventing drying and dripping by continuously or intermittently ejecting processing liquid into the immersion liquid.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the ejection head is kept in standby position outside the cup part, then the processing time is reduced, but the outlets may dry and cause clogging
Solution Approach 1:
The ejection head is pre-immersed in immersion liquid within the reservoir during standby periods, ensuring outlets remain wetted before actual processing begins. This preliminary protective action prevents drying and clogging without affecting processing speed.
Solution Approach 2:
Immersion liquid serves as an intermediary substance between the ejection head outlets and the ambient air, preventing direct contact with dry air that would cause drying. The liquid layer maintains outlet moisture while allowing the head to remain in standby position.
2Reliability
If processing liquid is supplied to prevent outlet drying during standby, then outlet clogging is prevented, but liquid may drip and adhere to the substrate
Solution Approach 1:
The harmful processing liquid is extracted and replaced with immersion liquid that serves the protective function without causing dripping issues. The immersion liquid is specifically selected to have properties that prevent both drying and unwanted adhesion to substrates.
Solution Approach 2:
Immersion liquid acts as an intermediary that provides outlet protection without the harmful effects of processing liquid. It creates a protective liquid layer during standby but can be easily removed or evaporated before substrate contact, preventing dripping.
3Reliability
If the ejection head is immersed in immersion liquid during standby, then outlet drying is prevented, but the device complexity increases
Solution Approach 1:
The standby protection function is merged with the existing ejection head structure by integrating the immersion capability into the head itself. The ejection head contains an immersion liquid supply mechanism that directly wets the outlets, eliminating the need for a separate immersion reservoir and complex positioning mechanisms.
Solution Approach 2:
The ejection head serves its own protection needs by incorporating an immersion liquid supply mechanism within the head structure. The head automatically supplies immersion liquid to its own outlets during standby, eliminating the need for external immersion systems.
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 solution effectively prevents outlet clogging and liquid dripping, maintaining the substrate clean by ensuring the ejection head's outlets remain moist during standby and ensuring no liquid adheres to the substrate when resumed for processing.
Implementation Method 1
an ejection head (31) disposed inside the cup part (22) and above the substrate holding part (21) and for ejecting a processing liquid toward the substrate (9) from an outlet (314) provided in an ejection surface (311)
Implementation Method 2
a supply part movement mechanism (35) for moving the ejection head (31) from a position above the substrate holding part (21) to a standby position outside the cup part (22)
Implementation Method 3
a reservoir (44) disposed outside the cup part (22) and for retaining an immersion liquid (49) in which the ejection surface (311) of the ejection head (31) located at the standby position is immersed
Implementation Method 4
a liquid removing part (47) for removing the immersion liquid (49) from the ejection surface (311)
Data Source
AI summary
In a substrate processing apparatus, an ejection surface of an ejection head located at a standby position is immersed in an immersion liquid retained in a reservoir during standby of the ejection head. This prevents drying of a plurality of outlets provided in the ejection head and drying of processing liquid flow passages that communicate with the outlets. It is thus possible to suppress or prevent clogging of the fine outlets. When the ejection head resumes processing on a substrate, the immersion liquid in the reservoir is discharged and then a liquid removing part removes the immersion liquid adhering to the ejection surface. Accordingly, it is possible to prevent the immersion liquid remaining on the ejection surface from dropping and adhering to the substrate (so-called “liquid dripping”) when, for example, the ejection head is moved to a position above the substrate.