1.1 These test methods cover procedures for testing devices that are sealed prior to testing, such as semiconductors, hermetically enclosed relays, pyrotechnic devices, etc., for leakage through the walls of the enclosure. They may be used with various degrees of sensitivity (depending on the internal volume, the strength of the enclosure, the time available for preparation of test, and on the sorption characteristics of the enclosure material for helium). In general practice the sensitivity limits are from 4.4 10
15
to 4.4 10
11
moles/s (10
9
standard cm
3
/s to 10
5
standard cm
3
/s at 0C) for helium, although these limits may be exceeded by several decades in either direction in some circumstances.
1.2 Two test methods are described:
1.2.1 Test Method ATest part preparation by bombing.
1.2.2 Test Method BTest part preparation by prefilling.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
====== Significance And Use ======
Methods A or B are useful in testing hermetically-sealed devices with internal volumes. Maximum acceptable leak rates have been established for microelectronic devices to assure performance characteristics will not be affected by in-leakage of air, water vapor or other contaminants over the projected life expected. Care must be taken to control the bombing pressure, bombing time and dwell time after bombing or the results can vary substantially.