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. Scope

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.

ASTM Standards

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

Keywords

expansion mismatch; glass-metal seals; Glass; Glass electronic seals; Electronic materials/applications; Metal electronic components/devices; Sandwich seals (for electronic devices); Seals--electronic applications; Specimen preparation (for testing)--semiconductor materials; Thermal expansion/contraction;

ICS Code

ICS Number Code 21.140 (Seals, glands)

Citing ASTM Standards

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