ASTM F140

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 for Standards and Technology (NIST), or a secondary reference material whose sealing characteristics have been determined by seals to a standard reference material.⁵ 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 reference glass-metal butt seals of two general configurations: one applicable to determining stress in the glass and the other to determining the degree of mismatch of thermal expansion (or contraction). Tests are in accordance with Test Method F 218 (Section 1.1).

1.2 This practice applies to all glass and metal (or alloy) combinations normally sealed together in the production of electronic components. It should not be attempted with glass-metal combinations having widely divergent thermal expansion (or contraction) properties.

2. Referenced Documents

F105 Specification for Type 58 Borosilicate Sealing Glass
F218 Test Method for Analyzing Stress in Glass
F47 Test Method for Crystallographic Perfection of Silicon by Preferential Etch Techniques
F79 Specification for Type 101 Sealing Glass

Index Terms

expansion mismatch; glass-metal seals; ICS Number Code 21.140

Citing ASTM Standards

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