ASTM F105-72(2019)

Standard Specification for Type 58 Borosilicate Sealing Glass

ABSTRACT
This specification covers type 58 borosilicate sealing glass for use in electronic applications. The glass material shall conform to the chemical composition requirements prescribed. The material shall conform to the physical and electrical properties prescribed. The glass shall have a finish that ensures smooth, even surfaces and freedom from cracks, checks, bubbles, and other flaws of a character detrimental to the strength or life of the component or device for which its use is intended. The softening point and annealing point shall be tested to meet the requirements prescribed. The thermal expansion coefficient of the glass material shall be determined using the required procedure. The contracting coefficient of the glass material shall be tested to meet the requirements prescribed. The thermal contraction match between the glass and a sealing alloy may be determined by preparing and testing an assembly to meet the requirements prescribed.
SCOPE
1.1 This specification covers Type 58 borosilicate sealing glass for use in electronic applications.  
Note 1: This specification is primarily intended to consider glass as most generally used, that is, glass in its transparent form as normally encountered in fabricating electronic devices. X1.3 refers to a sealing alloy that is compatible with this glass. Type 58 glass in other forms such as powdered, crushed, sintered, fibrous, etc., are excluded. The requirements of this specification, as applied to these forms, must be established in the raw glass prior to its conversion.  
1.2 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Oct-2019
• ICS: 21.140 - Seals, glands
• Technical Committee: C14 - Glass and Glass Products
• Drafting Committee: C14.04 - Physical and Mechanical Properties

Relations

• Replaces: ASTM F105-72(2015) - Standard Specification for Type 58 Borosilicate Sealing Glass
• Effective Date: 01-Nov-2019
• Refers: ASTM C336-71(2020) - Standard Test Method for Annealing Point and Strain Point of Glass by Fiber Elongation
• Effective Date: 01-Aug-2020
• Refers: ASTM F14-80(2019) - Standard Practice for Making and Testing Reference Glass-Metal Bead-Seal
• Effective Date: 01-Nov-2019
• Refers: ASTM C598-93(2019) - Standard Test Method for Annealing Point and Strain Point of Glass by Beam Bending
• Effective Date: 01-Aug-2019
• Refers: ASTM C338-93(2019) - Standard Test Method for Softening Point of Glass
• Effective Date: 01-Aug-2019
• Refers: ASTM E228-11(2016) - Standard Test Method for Linear Thermal Expansion of Solid Materials With a Push-Rod Dilatometer
• Effective Date: 01-Sep-2016
• Refers: ASTM F144-80(2015) - Standard Practice for Making Reference Glass-Metal Sandwich Seal and Testing for Expansion Characteristics by Polarimetric Methods
• Effective Date: 01-May-2015
• Refers: ASTM F14-80(2015) - Standard Practice for Making and Testing Reference Glass-Metal Bead-Seal
• Effective Date: 01-May-2015
• Refers: ASTM C336-71(2015) - Standard Test Method for Annealing Point and Strain Point of Glass by Fiber Elongation
• Effective Date: 01-May-2015
• Refers: ASTM C338-93(2013) - Standard Test Method for Softening Point of Glass
• Effective Date: 01-Oct-2013
• Refers: ASTM C598-93(2013) - Standard Test Method for Annealing Point and Strain Point of Glass by Beam Bending
• Effective Date: 01-Oct-2013
• Refers: ASTM F15-04(2013) - Standard Specification for Iron-Nickel-Cobalt Sealing Alloy
• Effective Date: 01-May-2013
• Refers: ASTM F144-80(2010) - Standard Practice for Making Reference Glass-Metal Sandwich Seal and Testing for Expansion Characteristics by Polarimetric Methods
• Effective Date: 01-Apr-2010
• Refers: ASTM F14-80(2010) - Standard Practice for Making and Testing Reference Glass-Metal Bead-Seal
• Effective Date: 01-Apr-2010
• Refers: ASTM C336-71(2010) - Standard Test Method for Annealing Point and Strain Point of Glass by Fiber Elongation
• Effective Date: 01-Apr-2010

Overview

ASTM F105-72(2019), titled "Standard Specification for Type 58 Borosilicate Sealing Glass," defines the requirements for Type 58 borosilicate glass used in electronic applications, particularly where a reliable glass-to-metal seal is critical. Developed by ASTM International, this standard specifies the necessary chemical, physical, and electrical properties to ensure that the glass provides dependable performance in its intended environments. The document covers requirements for composition, physical finish, and compatibility with specific sealing alloys, making it a fundamental reference for manufacturers and users of electronic components.

Key Topics

• Material Specification: The standard outlines strict criteria for chemical composition, including major constituents such as silica, alumina, and boron oxide. These parameters are crucial for achieving consistency in sealing performance and long-term reliability in electronic devices.
• Performance Requirements:
  • Physical Properties: The glass must meet defined benchmarks for softening point, annealing point, and thermal expansion and contraction coefficients, supporting precise thermal matching to compatible metals.
  • Electrical Properties: Includes information about volume resistivity, dielectric constant, and dissipation factor, highlighting the glass’s suitability for use as an insulating material in electronic assemblies.
• Quality and Finish: Specifies the need for a smooth, even surface free from cracks, checks, bubbles, or other flaws that could impact the strength or service life of the final device.
• Testing Procedures: Reference to standardized ASTM test methods ensures uniform evaluation of glass properties across different manufacturers and applications.

Applications

Type 58 borosilicate sealing glass is used extensively in the electronics industry, most notably for:

• Glass-to-Metal Seals: Essential in fabricating hermetic seals for components such as vacuum tubes, transistors, diode enclosures, and connectors. The reliable bonding of glass to specialized metal alloys, such as iron-nickel-cobalt alloys (see ASTM F15), is pivotal for ensuring airtightness and longevity.
• Electrical Insulation: The electrical insulation properties make this glass ideal for dielectric applications, reducing leakage and maintaining stability under varying environmental conditions.
• Sensor and Device Encapsulation: Used to encapsulate sensitive sensors and electronic assemblies, protecting them from moisture, environmental contamination, and mechanical stress.
• Application Limitations: The standard applies to transparent glass in its raw form for fabrication. It excludes powdered, crushed, sintered, or fibrous variants unless properties are established prior to their conversion.

Related Standards

For users and manufacturers engaged with Type 58 borosilicate sealing glass, the following ASTM standards are particularly relevant and frequently referenced:

• ASTM F15 – Specification for Iron-Nickel-Cobalt Sealing Alloy: The key metal alloy compatible with Type 58 sealing glass for glass-to-metal seals.
• ASTM C336, C338, C598 – Test Methods for Annealing, Strain, and Softening Points of Glass.
• ASTM E228 – Test Method for Determining Thermal Expansion of Solid Materials.
• ASTM D150, D257 – Methods for Evaluating Electrical Properties of Solid Insulating Materials.
• ASTM F14, F140, F144 – Practices for Making and Testing Glass-Metal Seals and Evaluating Expansion Characteristics.

Practical Value

Meeting the requirements of ASTM F105 ensures consistent, high-quality performance in sealed electronic components, reducing the risk of premature failure and promoting compatibility in global manufacturing. The use of Type 58 borosilicate glass according to this standard supports stringent quality assurance, facilitates procurement, and builds confidence throughout the supply chain in critical industries such as aerospace, telecommunications, and consumer electronics.

By adhering to ASTM F105-72(2019), manufacturers and end-users benefit from enhanced device reliability, international recognition of quality, and alignment with modern industry practices for glass-to-metal sealing in electronic applications.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:F105 −72 (Reapproved 2019)
Standard Specification for
Type 58 Borosilicate Sealing Glass
ThisstandardisissuedunderthefixeddesignationF105;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope F15 Specification for Iron-Nickel-Cobalt Sealing Alloy
F140 Practice for Making Reference Glass-Metal Butt Seals
1.1 This specification covers Type 58 borosilicate sealing
and Testing for Expansion Characteristics by Polarimetric
glass for use in electronic applications.
Methods
NOTE 1—This specification is primarily intended to consider glass as
F144 Practice for Making Reference Glass-Metal Sandwich
most generally used, that is, glass in its transparent form as normally
Seal and Testing for Expansion Characteristics by Polari-
encountered in fabricating electronic devices. X1.3 refers to a sealing
metric Methods
alloy that is compatible with this glass. Type 58 glass in other forms such
as powdered, crushed, sintered, fibrous, etc., are excluded. The require-
3. Ordering Information
ments of this specification, as applied to these forms, must be established
in the raw glass prior to its conversion.
3.1 Orders for material under this specification shall include
1.2 This international standard was developed in accor-
the following information:
dance with internationally recognized principles on standard-
3.1.1 Form,
ization established in the Decision on Principles for the 3.1.2 Type of glass,
Development of International Standards, Guides and Recom-
3.1.3 Dimensions,
mendations issued by the World Trade Organization Technical 3.1.4 Marking and packaging, and
Barriers to Trade (TBT) Committee.
3.1.5 Certification (if required).
4. Chemical Composition
2. Referenced Documents
4.1 The typical chemical composition of this glass is as
2.1 ASTM Standards:
follows (Note 2):
C336 Test Method for Annealing Point and Strain Point of
Weight %
Glass by Fiber Elongation
C338 Test Method for Softening Point of Glass
Major Constituents:
C598 Test Method for Annealing Point and Strain Point of
Silica (SiO ) 65.0
Alumina (Al O)7.5
Glass by Beam Bending
2 3
Boron oxide (B O ) 18.0
2 3
D150 Test Methods forAC Loss Characteristics and Permit-
Soda (Na O) 2.0
tivity (Dielectric Constant) of Solid Electrical Insulation
Potash (K O) 3.0
Barium oxide (BaO) 3.0
D257 Test Methods for DC Resistance or Conductance of
Minor Constituents:
Insulating Materials
Lithium oxide (Li O) 0.6
E29 Practice for Using Significant Digits in Test Data to
Fluorine (F) 0.6, max
Reducible oxides (Note 3) 0.05, max
Determine Conformance with Specifications
E228 Test Method for Linear Thermal Expansion of Solid
NOTE 2—Major constituents may be adjusted to give the desired
Materials With a Push-Rod Dilatometer electricalandphysicalpropertiestotheglass.However,nochangeshallbe
made that alters any of these properties without due notification of, and
F14 Practice for Making and Testing Reference Glass-Metal
approval by, the user.
Bead-Seal
NOTE 3—Total of arsenic trioxide (As O ), antimony trioxide (Sb O ),
2 3 2 3
and lead oxide (PbO).
5. Physical Requirements
This specification is under the jurisdiction of ASTM Committee C14 on Glass
and Glass Products and is the direct responsibility of Subcommittee C14.04 on
5.1 The material shall conform to the physical properties
Physical and Mechanical Properties.
prescribed in Table 1. For electrical properties see Table 2, and
Current edition approved Nov. 1, 2019. Published November 2019. Originally
approved in 1968. Last previous edition approved in 2015 as F105 – 72 (2015). its Footnote A.
DOI: 10.1520/F0105-72R19.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 6. Finish and Workmanship
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
6.1 The glass shall have a finish that ensures smooth, even
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. surfaces and freedom from cracks, checks, bubbles, and other
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F105−72 (2019)
TABLE 1 Physical Requirements
A
Property ASTM Test Method Condition Value
Softening point C338 see 7.1 715±10°C
Annealing point C336 or C598 see 7.2 480±10°C
Thermal expansion coefficient E228 see 7.3 4.65 ± 0.20 ppm/°C
0 to 300 °C
Contraction coefficient E228 see 7.4 5.8 ± 0.20 ppm/°C
(annealing point minus 15 to 30 °C)
A
Test methods and conditions are detailed in the appropriately referenced section of this specification.
A
TABLE 2 Electrical Properties
from1.0to1.5°C/mintoatemperaturebelow200°C.Therate
ASTM Test Condition,
of cooling from the point below 200 to 100 °C shall not exceed
Property Typical Value
Method °C
5°C/min.Therateofcoolingfrom100°Ctoroomtemperature
Volume resistivity (dc) D257 25 log R (Ω·cm)
is optional. During this cooling schedule, determine the ther-
17.0
mal contraction curve and calculate the mean coefficient of
250 log R (Ω·cm)
9.1
linear thermal contraction between a point 1
...