Cryopump Regeneration via Two-Stage Discharge Process
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Solution Overview
Problem
The regeneration of cryopumps faces challenges in efficiently discharging water, which is essential for maintaining their operational effectiveness in vacuum environments, particularly in semiconductor circuit manufacturing processes.
Innovation Solution
A cryopump regeneration method involving a control unit that alternately evacuates the cryopump housing and supplies purge gas in specific pressure ranges, with a first discharging process for vaporizing water and a second discharging process that depressurizes to a low pressure region, allowing for determination of termination and purge gas supply before assessing the need to terminate the process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If the cryopump housing is evacuated to low pressure and purge gas is supplied repeatedly, then water is discharged from the cryopump, but the regeneration time is extended
Solution Approach 1:
The control unit supplies purge gas to the cryopump housing before the first determination as to whether the second discharging process should be terminated. This preliminary action ensures that water is effectively discharged during the evacuation phase, reducing the need for prolonged repeated cycles and thereby shortening overall regeneration time while maintaining effective water removal.
2Loss of time
If the second discharging process is terminated early, then regeneration time is reduced, but water discharge may be incomplete
Solution Approach 1:
The control unit makes determinations as to whether the second discharging process should be terminated at least once in the low pressure region, and supplies purge gas prior to the first-time determination. This feedback mechanism monitors the discharge process and adjusts termination timing based on actual conditions, ensuring water is adequately discharged while avoiding unnecessary extension of regeneration time.
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 method enhances the efficient discharge of water from cryopumps, ensuring effective regeneration and reducing the time required for the process, thereby maintaining the vacuum environment necessary for semiconductor manufacturing.
Implementation Method 1
A cryopump is a vacuum pump that traps and pumps gas molecules by condensing or adsorbing them on cryopanels cooled to ultracold temperatures
Implementation Method 2
A cryopump is a vacuum pump that traps and pumps gas molecules by condensing or adsorbing them on cryopanels cooled to ultracold temperatures
Implementation Method 3
a first discharging process that includes alternately evacuating the cryopump housing and supplying the purge gas in a first pressure range
Data Source
AI summary
A method of regenerating a cryopump includes a first discharging process that includes alternately evacuating a cryopump housing and supplying a purge gas in a first pressure range, and a second discharging process that includes evacuating the cryopump housing to a low pressure region below the first pressure range. The second discharging process includes making a determination at least once in the low pressure range as to whether the second discharging process should be terminated, and supplying the purge gas to the cryopump housing prior to a first-time determination as to whether the second discharging process should be terminated.