Browse Prior Art Database

Gas Leak Detection

IP.com Disclosure Number: IPCOM000097145D
Original Publication Date: 1962-Jun-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Kennedy, JJ: AUTHOR

Abstract

The device detects either a gross or a minute gas leak in a hermetically sealed case where a nondestructive test is desired. A semiconductor case is readily tested by first pressurizing the case with helium gas, e. g., four hours at 45 P.S.I. in a pressure chamber, not shown.

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Gas Leak Detection

The device detects either a gross or a minute gas leak in a hermetically sealed case where a nondestructive test is desired. A semiconductor case is readily tested by first pressurizing the case with helium gas, e. g., four hours at 45 P.S.I. in a pressure chamber, not shown.

Test sample chamber 10 is machined to the approximate size of the sample case so that a minimum excess volume surrounds it. In operation for gross leak detection, solenoid valves 12, 14 and 16 are initially closed. Valves 12 and 14 are then opened and the system evacuated via orifice 18. The vacuum in the system is monitored by thermocouple gauge controller 20. Orifice 18 is connected to a helium leak detector, not shown. Valves 12 and 14 are closed when a predetermined vacuum is obtained in intermediate chamber 22. Next, valve 16 is opened until a predetermined pressure is obtained in chamber 22. Finally, valve 12 is opened. The gas in the intermediate chamber is slowly metered to the helium leak detector via preset variable leak throttle valve 24. A reading by the helium leak detector is indicative of a gross leak.

For minute leak detection, the valves 12, 14 and 16 are opened and the system evacuated via orifice 18. A minute leak is determined by a reading on the helium leak detector.

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