Fine leak test

The two principal specific license radiation sources used in semiconductor manufacturing are kr3 ton-85 gas (up to 50 curies) used in fine leak testing systems and cobalt-60 (up to 26,000 curies) used in irradiators for testing the ability of ICs to withstand exposure to gamma radiation in military and space applications. Under normal conditions, personnel exposures from these operations are t5 ically less than 500 millirems per year.0 1 Controls forthese systems include ... 

Cumulative Helium Leak Detection (CHLD) is a variation on conventional leak detection that allows for gross and fine leak testing in the same pass and the potential for helium-leak detection at leak rates several orders of magnitude lower than with conventional leak-detection methods. 

Fine and gross helium leak testing will detect any marginal or bad seals through which moisture and other contaminants can enter the package. 

Fine leak rate by belium gas of tbe packages were maintained less than 5.0 x 10 Pam /s after all reliability tests. We confirmed that the LTCC package had excellent hermeticity. 

The hermeticity of a sintered ceramic is particularly important in electronic components. Fine size, open porosity or surface cracks in sintered ceramics can be characterized by the bubble test or by dye penetration. The hermeticity of closed-porosity sintered ceramics can be characterized using the helium leak test. ... 

Topical aerosols and nasal sprays rely on pump systems to deliver the API in the form of finely dispersed mist or as coarse spray or stream of semisolid. Because of their design, aerosol and nasal products are usually under very high pressure, and this makes it difficult to obtain suitable samples for analysis. In spite of that, a number of very specialized tests which include pressure test, minimum fill, number of discharges per container defivered dose uniformity, delivery rate, leak test, spray pattern and plume geometry test, assay, and microbial enumeration test (MET) have been devised to test the integrity of the aerosol package and the device used to defiver the dose. ... 

Fine and gross leak tests should be conducted in accordance with the requirements and procedures for the specific test conditions for the device. Combinations of fine and/or gross leak testing can be conducted in sequence or at the same time. 

If the vessels are going to be charged with the resins at the site, it is better to pump a slurry solution of the resin into the vessels instead of physically dumping it through the manway. Make sure to backwash for fines after loading. Upon completion, test for resin and other leaks. 

Once you have determined that the system is leak-free, you are ready to purge the lines and replace the air, nitrogen, or helium test gas in each line with the gas for which the fine is intended. The procedure to follow depends on the gas line you are purging. For air and hydrogen as detector gases, use the simple purging... 

Mass Spectrometers Leak detectors using mass spectrometers are built to measure the flow rate of helium past the sensor. Helium is relatively rare in the air, so it registers only when there is a leak in the system being tested and when helium is being sprayed near the leak. By using a sensitive system with a very fine and slow helium probe, leaks as small as 1 X 10 ° torrL/s can be located. 

Table 6.3 shows the many standards for efficiency testing of HEPA and ULPA filters. New classifications have been defined for both types of filter according to EN 1822 and these are given in Table 6.4. The system is based on letters and figures in the same way as for coarse and fine filters according to the EUROVENT Classes, with H standing for HEPA and U for ULPA. The filters are then divided into eight classes from HIO to U17, depending on their efficiency at the most penetrating particle size (MPPS) and the size of the leaks.

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