ASTM D2442-75(2020)
(Specification)Standard Specification for Alumina Ceramics for Electrical and Electronic Applications
Standard Specification for Alumina Ceramics for Electrical and Electronic Applications
SCOPE
1.1 This specification covers the requirements for fabricated alumina parts suitable for electronic and electrical applications and ceramic-to-metal seals as used in electron devices. This specification specifies limits and methods of test for electrical, mechanical, thermal, and general properties of the bodies used for these fabricated parts, regardless of part geometry.
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.3 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
Relations
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:D2442 −75 (Reapproved 2020)
Standard Specification for
Alumina Ceramics for Electrical and Electronic
Applications
This standard is issued under the fixed designation D2442; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D116Test Methods for Vitrified Ceramic Materials for
Electrical Applications
1.1 Thisspecificationcoverstherequirementsforfabricated
D149Test Method for Dielectric Breakdown Voltage and
alumina parts suitable for electronic and electrical applications
DielectricStrengthofSolidElectricalInsulatingMaterials
and ceramic-to-metal seals as used in electron devices. This
at Commercial Power Frequencies
specification specifies limits and methods of test for electrical,
D150Test Methods forAC Loss Characteristics and Permit-
mechanical, thermal, and general properties of the bodies used
tivity (Dielectric Constant) of Solid Electrical Insulation
for these fabricated parts, regardless of part geometry.
D257Test Methods for DC Resistance or Conductance of
1.2 The values stated in SI units are to be regarded as
Insulating Materials
standard. The values given in parentheses after SI units are
D618Practice for Conditioning Plastics for Testing
provided for information only and are not considered standard.
D1711Terminology Relating to Electrical Insulation
1.3 This international standard was developed in accor-
D1829Test Method for Electrical Resistance of Ceramic
dance with internationally recognized principles on standard-
Materials at Elevated Temperatures (Withdrawn 2001)
ization established in the Decision on Principles for the
D2149Test Method for Permittivity (Dielectric Constant)
Development of International Standards, Guides and Recom-
And Dissipation Factor Of Solid Dielectrics At Frequen-
mendations issued by the World Trade Organization Technical
cies To 10 MHz And Temperatures To 500°C
Barriers to Trade (TBT) Committee.
D2520Test Methods for Complex Permittivity (Dielectric
2. Referenced Documents
Constant) of Solid Electrical Insulating Materials at Mi-
2.1 ASTM Standards: crowave Frequencies and Temperatures to 1650°C
C20Test Methods forApparent Porosity, WaterAbsorption, E6Terminology Relating to Methods of Mechanical Testing
Apparent Specific Gravity, and Bulk Density of Burned
E12Terminology Relating to Density and Specific Gravity
Refractory Brick and Shapes by Boiling Water
of Solids, Liquids, and Gases (Withdrawn 1996)
C108Symbols for Heat Transmission
E122PracticeforCalculatingSampleSizetoEstimate,With
C242Terminology of Ceramic Whitewares and Related
Specified Precision, the Average for a Characteristic of a
Products
Lot or Process
C408Test Method for Thermal Conductivity of Whiteware
E165/E165MPractice for Liquid Penetrant Testing for Gen-
Ceramics
eral Industry
C573Methods for ChemicalAnalysis of Fireclay and High-
E228Test Method for Linear Thermal Expansion of Solid
Alumina Refractories (Withdrawn 1995)
Materials With a Push-Rod Dilatometer
C623Test Method for Young’s Modulus, Shear Modulus,
F19Test Method for Tension and Vacuum Testing Metal-
and Poisson’s Ratio for Glass and Glass-Ceramics by
lized Ceramic Seals
Resonance
F77Test Method for Apparent Density of Ceramics for
Electron Device and Semiconductor Application (With-
This specification is under the jurisdiction of Committee C21 on Electrical and
drawn 2001)
Electronic Insulating Materials.
Current edition approved Nov. 1, 2020. Published December 2020. Originally F109Terminology Relating to Surface Imperfections on
approved in 1965. Last previous edition approved in 2016 as D2442–75(2016).
Ceramics
DOI: 10.1520/D2442-75R20.
F134Test Methods for Determining Hermeticity of Electron
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Devices with a Helium Mass Spectrometer Leak Detector
Standards volume information, refer to the standard’s Document Summary page on
(Withdrawn 1996)
the ASTM website.
F417Test Method for Flexural Strength (Modulus of Rup-
The last approved version of this historical standard is referenced on
www.astm.org. ture) of Electronic-Grade Ceramics (Withdrawn 2001)
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2442−75 (2020)
TABLE 1 Electrical Requirements
2.2 Other Standards:
MIL-STD-105Sampling Procedures and Tables for Inspec- Type Type Type Type
Property
I II III IV
tion by Attributes
Dielectric Constant,
MIL-STD-883Test Methods and Procedures for Microelec-
max 25 °C:
tronics at 1 MHz 8.8 9.6 9.8 10.1
at 10 GHz 8.7 9.6 9.8 10.1
ANSIB46.1Surface Texture
Dissipation factor,
max 25 °C:
3. Terminology
at 1 MHz 0.002 0.001 0.0005 0.0002
at 10 GHz 0.002 0.001 0.0005 0.0002
3.1 Definitions:
Volume Resistivity,
3.1.1 The applicable definitions of terms in the following minΩ·cm:
14 14 14 14
at 25 °C 10 10 10 10
documentsshallapplytothisspecification:SymbolsC108,and
10 10 10 10
at 300 °C 1 × 10 1×10 1×10 7×10
Terminology C242, D1711, E6, E12, and F109. 7 7 7 8
at 500 °C 4 × 10 2×10 8×10 1×10
6 6 6 7
at 700 °C 4 × 10 2×10 6×10 1×10
5 5 5 6
at 900 °C 4 × 10 2×10 8×10 1×10
4. Classification
Dielectric Strength, 9.85 9.85 9.85 9.85
4.1 Ceramics covered by this specification shall be classi- 3.175 mm, minΩ·cm: (250 V/mil) (250 V/mil) (250 V/mil) (250 V/mil)
fied by alumina content as follows:
Alumina Content
Type
TABLE 2 Mechanical Requirements
Weight %, min
I82
Type Type Type Type
Property
II 93
I II III IV
III 97
Flexural strength, 240 275 275 275
IV 99 A
min avg, MPa (psi) (35 000) (40 000) (40 000) (40 000)
Modulus of elasticity, 215 275 310 345
6 6 6 6
5. Basis of Purchase min, GPa (psi) (31×10 ) (40×10 ) (45×10 ) (50×10 )
Poisson’s ratio, average 0.20–0.25 0.20–0.25 0.20–0.25 0.20–0.25
5.1 Purchase orders for ceramic parts furnished to this
A
Maximum permissible coefficient of variation is 10 %.
specification shall include the following information:
5.1.1 Type designation (see 3.1),
5.1.2 Surface finish and allowable defect limits (if required)
will be listed in the parts drawing or purchase description. For
(Terminology F109, ANSI B46.1, and Appendix X1),
definitions of the surface imperfections enumerated above, see
5.1.3 Part drawing with dimensional tolerances (Appendix
Terminology F109.
X1),
6.3.2 For hermetic seal applications at least ⁄4 of the width
5.1.4 Specific tests (if required),
of the seal surface shall remain intact at the location of any
5.1.5 Certification (if required), and
defect.
5.1.6 Packing and marking.
6.3.3 On other surfaces the limits for defects are such that
6. Requirements the dimensional tolerances of the part are not affected at the
location of the defect.
6.1 This material shall conform to the electrical,
mechanical, thermal, and general property requirements speci-
7. Test Specimens
fied in Tables 1-4.
7.1 Thepreferredspecimensfortestare,wherepossible,the
6.2 Dimensionalandsurfacefinishrequirementsoftheparts
actual part. When necessary, however, specific test specimens
shall be as agreed between the supplier and the purchaser;
shall be prepared from the same batch of material and by the
however, guidance for establishing such an agreement is
same processes as those employed in fabricating the ceramic
provided in Appendix X1.
part insofar as possible.
6.3 Visual Requirements:
8. Specimen Preparation
6.3.1 Parts shall be uniform in color and texture. Cracks,
blisters, holes, porous areas, inclusions, and adherent foreign
8.1 The specimens for tests described in 9.1 – 9.3 shall be
particles shall not be permitted. The limits of surface imper-
preconditioned in accordance with Procedure A of Test Meth-
fections such as pits, pocks, chips (open or closed), surface
ods D618.
marks, fins, ridges, and flow lines shall be set by mutual
9. Test Methods
agreement between the supplier and the purchaser. Limiting
dimensions for these defects, when required for clarification,
9.1 Dielectric Constant and Dissipation Factor—Determine
in accordance with Test Methods D150. Determine values at
higher frequencies in accordance with Test Methods D2520.
Available from U.S. Government Printing Office, Superintendent of
Determine values at higher temperatures in accordance with
Documents, 732 N. Capitol St., NW, Washington, DC 20401-0001, http://
Test Method D2149.
www.access.gpo.gov.
Available from DLA Document Services, Building 4/D, 700 Robbins Ave.,
Philadelphia, PA 19111-5094, http://quicksearch.dla.mil.
6 7
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St., For another suitable method see von Hippel,A. (ed.), Dielectric Materials and
4th Floor, New York, NY 10036, http://www.ansi.org. Applications, John Wiley and Sons, Inc., New York, NY, 1954.
D2442−75 (2020)
TABLE 3 Thermal Requirements
Type I Type II Type III Type IV
Property
min max min max min max min max
Mean coefficient of linear thermal expansion, µ m/m · °C:
25–200 °C 5.4 6.2 5.2 6.7 5.2 6.5 5.5 6.7
25–500 °C 6.5 7.0 6.6 7.4 6.7 7.5 6.8 7.6
25–800 °C 7.0 7.7 7.3 8.1 7.4 8.1 7.3 8.1
25–1000°C 7.4 8.2 7.5 8.3 7.6 8.3 7.5 8.4
Thermal conductivity, cal/s·cm·°C:
at 100 °C 0.023 0.049 0.031 0.077 0.048 0.073 0.052 0.090
at 400 °C 0.015 0.022 0.014 0.036 0.022 0.033 0.023 0.047
at 800 °C 0.009 0.018 0.009 0.021 0.014 0.021 0.014 0.025
Thermal shock resistance pass pass pass pass
Maximal deformation at 1500 °C . . 0.51 mm (0.02 in.) 0.51 mm (0.02 in.)
A
TABLE 4 General Requirements
9.8 Thermal Shock Resistance—This test is to be agreed
Type
upon between supplier and purchaser. It is suggested that the
Property
I II III IV
cold end of the cycle be ice water at 0°C. Methods of heating
B 3
Density, apparent min, g/cm 3.37 3.57 3.72 3.78
and conditions at elevated temperatures shall be negotiated.
Composition, min, weight % 82 93 97 99
Gas impermeability gas tight gas tight gas tight gas tight
The transfer from one temperature extreme to another shall be
Liquid impermeability pass pass pass pass
immediate.
A CCCC
Metallizability
A
Vendors shall, upon request, provide information on these properties as well as 9.9 Temperature Deformation—Determine deformation at
a visual standard of a typical microstructure of their specific ceramic body depicting
1500°C in accordance with Appendix X2.
its grain size and pore volume. Changes in microstructure of the ceramic are not
acceptable as they can affect the behavior of the ceramic toward a metallizing
9.10 Apparent Density—Determine in accordance with Test
process.
Method F77. For large ceramic parts not covered by this test
B
The apparent density of a ceramic body is a function of the amount and the
method, determine in accordance with Test Methods C20.
density of the primary Al O phase and the secondary phase plus the amount of
2 3
pores inherent to that body. The acceptable density limits for a specific alumina
9.11 Compositional Analysis—Use either quantitative emis-
body must be consistent with the composition and the pore volume of the ceramic
supplied by supplier and shall be agreed upon between the purchaser and the
sion spectrographic analysis of the fired ceramic with alumina
supplier. Variation in the apparent density of a specific ceramic body shall be within
content determined by difference or Test Methods C573 after
±1 % of the nominal value.
C
assuming that all determined metallic and reactive elements
Generally, very high alumina content results in increased difficulty of metallizing;
however, variations in metallizing compositions and techniques can produce
originally are present as their highest form of oxide.
excellent seals in all four types of alumina ceramics. Because of a wide variation
in materials and techniques, no specific test is recommended. A referee test for
9.12 Gas Impermeability—When air fired at 900°C for
seal strength is Test Method F19.
30minandhandledwithtweezersonly,thentestedonahelium
mass spectrometer leak detector capable of detecting a leak of
−9 3
10 atm·cm /s, the ceramic is considered impermeable if a
specimen 0.254 mm (0.010in.) thick shows no indication of
9.2 Volume Resistivity—Determine in accordance with Test
2 2
helium leakage when an area of 322.6 mm (0.5 in. ) is tested
Methods D257. For elevated temperature measurements use
for 15 s at room temperature (Method1014, Seal, of MIL-
Procedure A of Test Method D1829.
STD-883 and Test Methods F134).
9.3 Dielectric Strength—Run this test under oil in accor-
9.13 Liquid Impermeability—Determine in accordance with
dance with 6.1.1 of Test Methods D149, with a rise rate of
Test Methods D116.
1000V⁄s on a 3.175 mm (0.125-in.) thick test specimen.
9.14 Surface Imperfections—Examine visually for surface
9.4 Flexural Strength—Determine in accordance with Test
imperfections with or without the aid of a dye penetrant as in
Method F417 or D116. Somewhat lower values will result if
Practice E165/E165M. Agreement by purchaser and supplier
Test Method D116 are used. The test method to be used shall
regarding specific techniques is strongly recommended.
be agreed upon between the supplier and the purchaser.
9.15 Surface Finish—Ifsurfacefinishisspecified,itshallbe
9.5 Modulus of Elasticity and Poisson’s Ratio—Determine
determined by any appropriate method agreed upon by pur-
in accordance with Test Method C623.
chaser and supplier.
9.6 Thermal Expansion—Determine in accordance with
Test Method E228.
10. Inspection
9.7 Thermal Conductivity—Determine in accordance with
10.1 When agreed upon between the manufacturer and the
Test Method C408. For temperatures in excess of 149 °C
purchaser, the purchaser may inspect the ceramic parts and
(300°F), use a suitable method.
verify the test results at the manufacturer’s facility. Otherwise
thepurchasershallinspectandtesttheceramicpartswithinone
month of the date of receipt by the purchaser or at such other
For a suitable method see Francl, J., and Kingery, W. D., “An Apparatus for
times as may be agreed upon between the purchaser and the
Determining Conductivity by a Comparative Method,” Journal of the American
Ceramic Society, JACTA Vol 37, 1954, p. 80. manufacturer.
D2442−75 (2020)
10.2 When agreed upon between the manufacturer and the 13. Packing and Marking
purchaser, the manufacturer shall supply, prior to fabrication,
13.1
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