Processing Liquid Supply Apparatus Circulation Filtration
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Solution Overview
Problem
Existing processing liquid supplying apparatuses for semiconductor manufacturing face inefficiencies in filtering out micro particles and bubbles, leading to non-uniform coating and defects, and require multiple filters to achieve high filtration efficiency, which increases apparatus size and reduces throughput.
Innovation Solution
A processing liquid supplying apparatus with a circulation passage equipped with a pump and a filter, where the processing liquid is passed through the filter in the returning and replenishing steps, allowing for high capturing rates of foreign matters even with a single filter, by mixing filtered and replenished liquid, and controlling the amount returned to the source exceeds the amount ejected, optimizing filtration efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple filters are installed in the processing liquid supplying apparatus, then the filtration efficiency is improved, but the apparatus size increases and the device complexity increases
Solution Approach 1:
The patent implements a circulation system where processing liquid continuously flows from the processing liquid supply tank through the pump, filter, and back to the tank. This continuous circulation allows a single filter to repeatedly process the same liquid volume, achieving high filtration efficiency equivalent to multiple sequential filters without increasing apparatus size or complexity
Solution Approach 2:
The patent introduces a buffer tank as an intermediary component that stores processing liquid and enables the circulation system to operate independently of the coating process timing. This buffer tank allows the pump to continuously draw and filter liquid without interruption, maintaining steady filtration action while keeping the overall system compact
2Reliability
If multiple filters are installed in the processing liquid supplying apparatus, then the filtration efficiency is improved, but the productivity decreases due to elongated standby time
Solution Approach 1:
The circulation system performs preliminary filtration action continuously during the coating process. By the time coating is ready to proceed, the liquid has already been filtered multiple times through continuous circulation, eliminating the need for separate filtration standby time and maintaining high throughput
Solution Approach 2:
The pump operates continuously to circulate and filter the processing liquid throughout the coating operation. This continuous useful action ensures that filtration occurs in parallel with coating preparation and execution, not as a separate sequential step, thereby maintaining high productivity while achieving superior filtration
3Device complexity
If a single filter is used without circulation, then the apparatus complexity is reduced, but the filtration efficiency is insufficient for capturing micro particles
Solution Approach 1:
The circulation system enables a single filter to process the same liquid volume multiple times through continuous recirculation. Each circulation pass removes additional particles, achieving cumulative filtration effectiveness that would otherwise require multiple filters in series, thus maintaining simple apparatus structure while dramatically improving particle removal capability
Solution Approach 2:
The circulation system allows the processing liquid to serve itself by continuously passing through the filter without requiring external intervention or complex multi-filter arrangements. The liquid's own circulation through the pump and filter system achieves self-purification, capturing micro particles effectively while keeping the apparatus structure simple
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 enhances filtration efficiency while maintaining throughput, allowing for effective capture of micro particles and bubbles with a single filter, reducing apparatus size and operational complexity compared to multiple filter systems.
Implementation Method 1
a circulation passage which is provided thereon with a pump and a filter device connected to a secondary side of the pump
Implementation Method 2
a filter device connected to a secondary side of the pump... the processing liquid having been passed through the filter device
Data Source
AI summary
A processing liquid supplying apparatus performs an ejecting step in which a processing liquid suctioned into a pump passes through a filter device and is ejected from an ejecting part without returning the processing liquid back to the pump; a returning step in which the processing liquid suctioned into the pump is returned to a processing liquid source side of a mixing section; and a replenishing step in which the processing liquid returned to the processing liquid source side is suctioned into the pump together with the processing liquid replenished from the processing liquid source. The processing liquid passes through the filter device in at least one of the returning step and the replenishing step. The amount of the processing liquid returned to the processing liquid source side in the returning step is larger than the amount of the processing liquid ejected from the ejecting part in the ejecting step.