Document #107-00092-001
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Create and Edit a Pump Down Schedule
A Pump Down schedule is used to evacuate gas in an oven/interchange chamber with vacuum,
and backfill the chamber with process gas to prevent contamination of the enclosure
environment. In order to completely get rid of the wet gas in an oven/interchange chamber,
multiple evacuate and backfill cycles may be needed.
The two important parameters in a Pump Down schedule are the Vacuum Set Point, which is
used in the evacuate process, and the Evacuate/Backfill Cycles. In order to effectively remove wet
gas from the oven/interchange chamber, two additional parameters are included in a pump down
schedule, namely the Backfill Hold Time and the Vacuum Hold Time. See Figure 8 for an
example of the pump down schedule.
Backfill Hold Time
– the time duration that a backfill process lasts.
Vacuum Hold Time
– the time duration from the time that the chamber vacuum level reaches
the preset vacuum set point to the time when a subsequent backfill starts.
Figure 9 Example Pump Down Schedule
Create a New Pump Down Schedule
Pump Down schedules are created and edited using a visual schedule editor (Figure 4). The visual
schedule editor is accessed by clicking the “GloveBox” main window menu, and select “Pump
Down and Oven Settings”. The user must have schedule editing “rights” to be able to change the
pump down schedule parameters or create new schedules.
To create a new pump down schedule, click the New button located on the upper half of the
Pump Down and Oven Settings USER INTERFACE SCREEN (see Figure 4). The Create New
Pump Down Schedule dialog window (Figure 9) with all default settings shows up. Enter a
schedule name, change the default parameter values as necessary and click OK to add this new
schedule to GLOVEBOX database. After the OK button is clicked, the new schedule will
displayed in the Pump Down Schedule list box on the upper-left part of the visual schedule editor
USER INTERFACE SCREEN.
