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Helium Leak Test Fixture

IP.com Disclosure Number: IPCOM000089719D
Original Publication Date: 1977-Dec-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 60K

Publishing Venue

IBM

Related People

Cadwallader, RH: AUTHOR [+5]

Abstract

Semiconductor packages can contain helium gas in order to improve the efficiency of various semiconductor cooling structures associated with the semiconductor package. An important test is determining whether there is any leakage of helium through the ceramic substrate, along the edges and through the laminated strata of suitable brazing material.

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Helium Leak Test Fixture

Semiconductor packages can contain helium gas in order to improve the efficiency of various semiconductor cooling structures associated with the semiconductor package. An important test is determining whether there is any leakage of helium through the ceramic substrate, along the edges and through the laminated strata of suitable brazing material.

This test fixture is adapted to determine whether or not there is any leakage of helium through the substrate prior to its assembly into the package structure. The fixture 10 has a lower base plate 12 provided with a recess 14 that receives the substrate 16 to be tested. Inner and outer seals 18 and 20 form a seal along the periphery of the substrate 16 and base plate 12. The material of the seal must be impervious to helium. A combination of ethylene-propylene gasket material is recommended.

An upper pressure plate 22 overlies substrate 16, which is forced against the substrate by a combination of brackets 24, a cross-bar 26 and a threaded shaft 28 connected to a nob 29. Rotation of nob 29 forces shaft 28 into biasing relation against plate 22. A cover 30 provided with seals 32 is mounted on base plate 12, forming an enclosure, part of which is formed by substrate 16.

An aperture 34 is provided for introducing helium, under a controlled pressure, within the enclosure. The helium under pressure acts on the top of substrate 16 through aperture 36, and on the sides through recesses 38. Any leakage...