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 standard 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 the standard. The values given in parentheses are for information only.

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Publication Date
29-Jun-1975
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ASTM D2442-75(1996) - Standard Specification for Alumina Ceramics for Electrical and Electronic Applications
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NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 2442 – 75 (Reapproved 1996)
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Specification for
Alumina Ceramics for Electrical and Electronic
Applications
This standard is issued under the fixed designation D 2442; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope D 257 Test Methods for D-C Resistance or Conductance of
Insulating Materials
1.1 This specification covers the requirements for fabricated
D 618 Practice for Conditioning Plastics and Electrical
alumina parts suitable for electronic and electrical applications
Insulating Materials for Testing
and ceramic-to-metal seals as used in electron devices. This
D 1711 Terminology Relating to Electrical Insulation
standard specifies limits and methods of test for electrical,
D 1829 Test Method for Electrical Resistance of Ceramic
mechanical, thermal, and general properties of the bodies used
Materials at Elevated Temperatures
for these fabricated parts, regardless of part geometry.
D 2149 Test Method for Permittivity (Dielectric Constant)
1.2 The values stated in SI units are to be regarded as the
and Dissipation Factor of Solid Ceramic Dielectrics at
standard. The values given in parentheses are for information
Frequencies to 10 MHz and Temperatures to 500°C
only.
D 2520 Test Method for Complex Permittivity (Dielectric
2. Referenced Documents Constant) of Solid Electrical Insulating Materials at Mi-
crowave Frequencies and Temperatures to 1650°C
2.1 ASTM Standards:
E 6 Terminology Relating to Methods of Mechanical Test-
C 20 Test Methods for Apparent Porosity, Water Absorp-
ing
tion, Apparent Specific Gravity, and Bulk Density of
E 12 Terminology Relating to Density and Specific Gravity
Burned Refractory Brick and Shapes by Boiling Water
of Solids, Liquids, and Gases
C 108 Symbols for Heat Transmission
E 122 Practice for Choice of Sample Size to Estimate a
C 242 Terminology of Ceramic Whitewares and Related
Measure of Quality for a Lot or Process
Products
E 165 Practice for Liquid Penetrant Inspection Method
C 408 Test Method for Thermal Conductivity of Whiteware
E 228 Test Method for Linear Thermal Expansion of Solid
Ceramics
Materials with a Vitreous Silica Dilatometer
C 573 Methods for Chemical Analysis of Fireclay and
F 19 Test Method for Tension and Vacuum Testing Metal-
High-Alumina Refractories
ized Ceramic Seals
C 623 Test Method for Young’s Modulus, Shear Modulus,
F 77 Test Method for Apparent Density of Ceramics for
and Poisson’s Ratio for Glass and Glass-Ceramics by
Electron Device and Semiconductor Application
Resonance
F 109 Terminology Relating to Surface Imperfections on
D 116 Methods of Testing Vitrified Ceramic Materials for
Ceramics
Electrical Applications
F 134 Test Methods for Determining Hermeticity of Elec-
D 149 Test Methods for Dielectric Breakdown Voltage and
tron Devices with a Helium Mass Spectrometer Leak
Dielectric Strength of Solid Electrical Insulating Materials
Detector
at Commercial Power Frequencies
F 417 Test Method for Flexural Strength (Modulus of Rup-
D 150 Test Methods for A-C Loss Characteristics and
ture) of Electronic-Grade Ceramics
Permittivity (Dielectric Constant) of Solid Electrical Insu-
2.2 Other Standards:
lating Materials
MIL-STD-105 Sampling Procedures and Tables for Inspec-
tion by Attributes
This specification is under the jurisdiction of Committee C-21 on Ceramic
Whitewares and Related Products and is the direct responsibility of Subcommittee
C21.03 on Fundamental Properties. Annual Book of ASTM Standards, Vol 08.01.
This specification also includes material and suggestions provided by ASTM Annual Book of ASTM Standards, Vol 10.02.
Committee D-9 on Electrical and Electronic Insulating Materials. Annual Book of ASTM Standards, Vol 03.01.
Current edition approved June 30, 1975. Published August 1975. Originally
Annual Book of ASTM Standards, Vol 15.05.
published as D 2442 – 65 T. Last previous edition D 2442 – 72. Annual Book of ASTM Standards, Vol 14.02.
2 11
Annual Book of ASTM Standards, Vol 15.01. Annual Book of ASTM Standards, Vol 03.03.
3 12
Annual Book of ASTM Standards, Vol 15.02. Annual Book of ASTM Standards, Vol 10.04.
4 13
Annual Book of ASTM Standards, Vol 03.05. Available from the Superintendent of Documents, Government Printing Office,
Annual Book of ASTM Standards, Vol 10.01. Washington, D.C. 20402.
D 2442
TABLE 2 Mechanical Requirements
MIL-STD-883 Test Methods and Procedures for Microelec-
tronics Property Type I Type II Type III Type IV
ANSI B46.1 Surface Texture
Flexural strength, 240 275 275 275
A
min avg, (35 000) (40 000) (40 000) (40 000)
MPa (psi)
3. Terminology
Modulus of 215 275 310 345
6 6 6 6
3.1 Definitions:
elasticity, min, (31 3 10 ) (40 3 10 ) (45 3 10 ) (50 3 10 )
GPa (psi)
3.1.1 The applicable definitions of terms in the following
Poisson’s ratio, 0.20 to 0.25 0.20 to 0.25 0.20 to 0.25 0.20 to 0.25
documents shall apply to this specification: Symbols C108, and
average
Definitions C 242, D 1711, E 6, E 12, and F 109.
A
Maximum permissible coefficient of variation is 10 percent.
4. Classification
6.2 Dimensional and surface finish requirements of the parts
4.1 Ceramics covered by this specification shall be classi-
shall be as agreed between the supplier and the purchaser;
fied by alumina content as follows:
however, guidance for establishing such an agreement is
Alumina Content
provided in Appendix X1.
Type Weight percent, min
I82 6.3 Visual Requirements:
II 93
6.3.1 Parts shall be uniform in color and texture. Cracks,
III 97
blisters, holes, porous areas, inclusions, and adherent foreign
IV 99
particles shall not be permitted. The limits of surface imper-
5. Basis of Purchase
fections such as pits, pocks, chips (open or closed), surface
marks, fins, ridges, and flow lines shall be set by mutual
5.1 Purchase orders for ceramic parts furnished to this
agreement between the supplier and the purchaser. Limiting
specification shall include the following information:
dimensions for these defects, when required for clarification,
5.1.1 Type designation (see 3.1),
will be listed in the parts drawing or purchase description. For
5.1.2 Surface finish and allowable defect limits (if required)
definitions of the surface imperfections enumerated above, see
(Definitions F 109, ANSI B46.1, and Appendix X1),
Definitions F 109.
5.1.3 Part drawing with dimensional tolerances (Appendix
6.3.2 For hermetic seal applications at least ⁄4 of the width
X1),
of the seal surface shall remain intact at the location of any
5.1.4 Specific tests (if required),
defect.
5.1.5 Certification (if required), and
6.3.3 On other surfaces the limits for defects are such that
5.1.6 Packing and marking.
the dimensional tolerances of the part are not affected at the
6. Requirements
location of the defect.
6.1 This material shall conform to the electrical, mechani-
7. Test Specimens
cal, thermal, and general property requirements specified in
7.1 The preferred specimens for test are, where possible, the
Table 1, Table 2, Table 3, and Table 4.
actual part. When necessary, however, specific test specimens
shall be prepared from the same batch of material and by the
14 same processes as those employed in fabricating the ceramic
Available from Standardization Documents Order Desk, Bldg. 4 Section D,
700 Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS. part insofar as possible.
Available from American National Standards Institute, 11 West 42nd Street,
13th Floor, New York, NY 10036.
8. Specimen Preparation
8.1 The specimens for tests described in 9.1-9.3 shall be
TABLE 1 Electrical Requirements
preconditioned in accordance with Procedure A of Test Meth-
Property Type I Type II Type III Type IV
ods D 618.
Dielectric constant,
max 25°C: 9. Test Methods
at 1 MHz 8.8 9.6 9.8 10.1
9.1 Dielectric Constant and Dissipation Factor—
at 10 GHz 8.7 9.6 9.8 10.1
Dissipation factor,
Determine in accordance with Test Methods D 150. Determine
max 25°C:
values at higher frequencies in accordance with Test Methods
at 1 MHz 0.002 0.001 0.0005 0.0002
D 2520. Determine values at higher temperatures in accor-
at 10 GHz 0.002 0.001 0.0005 0.0002
Volume resistivity,
dance with Test Method D 2149.
min V·cm:
9.2 Volume Resistivity—Determine in accordance with Test
14 14 14 14
at 25°C 10 10 10 10
10 10 10 10
Methods D 257. For elevated temperature measurements use
at 300°C 1 3 10 1 3 10 1 3 10 7 3 10
7 7 7 8
at 500°C 4 3 10 2 3 10 8 3 10 1 3 10
Procedure A of Test Method D 1829.
6 6 6 7
at 700°C 4 3 10 2 3 10 6 3 10 1 3 10
9.3 Dielectric Strength—Run this test under oil in accor-
5 5 5 6
at 900°C 4 3 10 2 3 10 8 3 10 1 3 10
dance with 6.1.1 of Test Methods D 149, with a rise rate of
Dielectric
strength:
3.175 mm 9.85 9.85 9.85 9.85
(0.125 in.) (250 V/mil) (250 V/mil) (250 V/mil) (250 V/mil) 16
For another suitable method see Dielectric Materials and Applications, edited
min kV/mm
by Von Hippel, A., John Wiley and Sons, Inc., New York, N.Y., 1954.
D 2442
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 0.51 mm
(0.02 in.) (0.02 in.)
A
TABLE 4 General Requirements
and conditions at elevated temperatures shall be negotiated.
Type The transfer from one temperature extreme to another shall be
Property
I II III IV
immediate.
B
Density, apparent min 3.37 3.57 3.72 3.78
3 9.9 Temperature Deformation—Determine deformation at
g/cm
Composition, min 82 93 97 99 1500°C in accordance with Appendix X2.
weight percent
9.10 Apparent Density—Determine in accordance with Test
Gas Impermeability gas tight
Method F 77. For large ceramic parts not covered by this
Liquid Impermeability pass
method, determine in accordance with Test Methods C 20.
9.11 Compositional Analysis—Use either quantitative emis-
AC
Metallizability
sion spectrographic analysis of the fired ceramic with alumina
content determined by difference or Methods C 573 after
A
Vendors shall, upon request, provide information on these properties as well
as a visual standard of a typical microstructure of their specific ceramic body assuming that all determined metallic and reactive elements
depicting its grain size and pore volume. Changes in microstructure of the ceramic
originally are present as their highest form of oxide.
are not acceptable as they can affect the behavior of the ceramic toward a
9.12 Gas Impermeability—When air fired at 900°C for 30
metallizing process.
B
The apparent density of a ceramic body is a function of the amount and the min and handled with tweezers only, then tested on a helium
density of the primary Al O phase and the secondary phase plus the amount of
2 3
mass spectrometer leak detector capable of detecting a leak of
pores inherent to that body. The acceptable density limits for a specific alumina
−9 3
10 atm·cm /s, the ceramic is considered impermeable if a
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 specimen 0.254 mm (0.010 in.) thick shows no indication of
supplier. Variation in the apparent density of a specific ceramic body shall be within 2 2
helium leakage when an area of 322.6 mm (0.5 in. ) is tested
61 percent of the nominal value.
C for 15 s at room temperature (Method 1014, Seal, of MIL-
Generally, very high alumina content results in increased difficulty of metalliz-
ing; however, variations in metallizing compositions and techniques can produce
STD-883 and Test Methods F 134).
excellent seals in all four types of alumina ceramics. Because of a wide variation
9.13 Liquid Impermeability—Determine in accordance with
in materials and techniques, no specific test is recommended. A referee test for
Methods D 116.
seal strength is Method F 19.
9.14 Surface Imperfections—Examine visually for surface
imperfections with or without the aid of a dye penetrant as in
1000 V/s on a 3.175-mm (0.125-in.) thick test specimen.
Practice E 165. Agreement by purchaser and supplier regarding
9.4 Flexural Strength—Determine in accordance with Test
specific techniques is strongly recommended.
Method F 417 or Methods D 116. Somewhat lower values will
9.15 Surface Finish—If surface finish is specified, it shall
result if Methods D 116 are used. The method to be used shall
be determined by any appropriate method agreed upon by
be agreed upon between the supplier and the purchaser.
purchaser and supplier.
9.5 Modulus of Elasticity and Poisson’s Ratio—Determine
in accordance with Test Method C 623.
10. Inspection
9.6 Thermal Expansion—Determine in accordance with
10.1 When agreed upon between the manufacturer and the
Test Method E 228.
purchaser, the purchaser may inspect the ceramic parts and
9.7 Thermal Conductivity—Determine in accordance with
verify the test results at the manufacturer’s facility. Otherwise
Test Method C 408. For temperatures in excess of 149 C (300
the purchaser shall inspect and test the ceramic parts within one
F), use a suitable method.
month of the date of receipt by the purchaser or at such other
9.8 Thermal Shock Resistance—This test is to be agreed
times as may be agreed upon between the purchaser and the
upon between supplier and purchaser. It is suggested that the
manufacturer.
cold end of the cycle be ice water at 0°C. Methods of heating
10.2 When agreed upon between the manufacturer and the
purchaser, the manufacturer shall supply, prior to fabrication,
duplicate test specimens to the purchaser for his testing
For a suitable method see Francl, J., and Kingery, W. D., “An Apparatus for
purposes. These specimens shall be identical with those tested
Determining Conductivity by a Comparative Method,” Journal of the American
Ceramic Society, JACTA Vol 37, 1954, p. 80. by the manufacturer, insofar as it is possible.
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