Patent ID: 6059046
Filing Date: 2000-05-09
Classification: A62C

Abstract:
A method of operating a fire detection and low pressure carbon dioxide fire suppression system in a semiconductor fabrication facility having a plurality of semiconductor fabrication tools, the method comprising the steps of:providing a source of low pressure carbon dioxide;providing at least one fire protection subsystem for each semiconductor fabrication tool that detects fire within the respective tool and subsequently discharges low pressure carbon dioxide within the tool to suppress fire detected within the tool, wherein each subsystem includes a user interface panel located at the tool and having an actuation station with a manual actuation switch, an abort station with a manual actuating mechanism, and an emergency shut-off station with a manual shut-off mechanism; andcontrolling the discharge of low pressure carbon dioxide by the fire protection subsystem in accordance with the following steps:a) starting a timer set for a time delay sufficient for evacuation of personnel from the immediate vicinity of the tool upon receiving an alarm signal from a detector monitoring the semiconductor fabrication tool for fire;b) momentarily suspending the operation of the timer to selectively delay the expiration of the evacuation time period in response to manual actuation of the subsystem abort station actuating mechanism;c) upon expiration of the evacuation time delay, automatically energizing one or more actuators to allow one or more associated selector flow control valves located in the plumbing between the source of low pressure carbon dioxide and the subsystem discharge plumbing to open for a preselected carbon dioxide discharge time period;d) selectively closing the one or more selector flow control valves to terminate carbon dioxide discharge before expiration of the preselected carbon dioxide discharge time period in response to manual actuation of the subsystem emergency shut-off mechanism; ande) automatically closing the one or more flow control valves between the source of low pressure carbon dioxide and the subsystem discharge plumbing upon expiration of the preselected carbon dioxide discharge time period.