Active Standard ASTM F144 | Developed by Subcommittee: C14.04
Book of Standards Volume: 15.02
Historical (view previous versions of standard)
Significance and Use
The term “reference” as employed in this practice implies that either the glass or the metal of the reference glass-metal seal will be a “standard reference material” such as those supplied for other physical tests by the National Institute of Standards and Technology, or a secondary reference material whose sealing characteristics have been determined by seals to a standard reference material (see NBS Special Publication 260). Until standard reference materials for seals are established by the NIST, secondary reference materials may be agreed upon between manufacturer and purchaser.
1.1 This practice covers the preparation and testing of a reference glass-metal sandwich seal for determining stress in the glass or for determining the degree of thermal expansion (or contraction) mismatch between the glass and metal. Tests are in accordance with Test Method F218 (Section 2).
1.2 This practice applies to all glass and metal (or alloy) combinations normally sealed together in the production of electronic components.
1.3 The practical limit of the test in deriving mismatch is approximately 300 ppm, above which the glass is likely to fracture.
1.4 This standard does not purport to address all of the safety problems, 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.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
F15 Specification for Iron-Nickel-Cobalt Sealing Alloy
F30 Specification for Iron-Nickel Sealing Alloys
F31 Specification for 42 % Nickel-6 % Chromium-Iron Sealing Alloy
F47 Test Method for Crystallographic Perfection of Silicon by Preferential Etch Techniques
F79 Specification for Type 101 Sealing Glass
F105 Specification for Type 58 Borosilicate Sealing Glass
F218 Test Method for Measuring Optical Retardation and Analyzing Stress in Glass
F256 Specification for Chromium-Iron Sealing Alloys with 18 or 28 Percent Chromium
ICS Number Code 21.140 (Seals, glands)