Using optical correlation to measure leak rates in sealed packages.
An optical correlation technique has been shown to accurately measure leak conduction rates from 10(-1) to 10(-6) atm cc/sec. Using hybrid microcircuit packages with glass capillary leakers, dimensional changes were detected as the packages were exposed to a small increase in external pressure. The rate at which the package returns to its original dimensions is measured and used, along with the internal free volume, to compute the leak rate. Because of its several advantages, the technique has the potential to become a useful nondestructive quality-control technique.
Wagner
J W
JW
US Food & DrugAdministration, Bureau of Medical Devices, Center for Medical Device Analysis, 8757 Georgia Avenue, Silver Spring, Maryland 20910, USA.
Phillips
L C
LC
Mueller
E P
EP
Green
R E
RE