ASTM D6343-99

Test Methods for Thin Thermally Conductive Solid Materials for Electrical Insulation and Dielectric Applications

SCOPE
1.1 This standard is a compilation of test methods for evaluating properties of thermally conductive electrical insulation sheet materials to be used for dielectric applications.
1.2 This standard does not purport to address all of the safety concerns, 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. See also Section 1.6.
1.5 The values stated in SI units are to be regarded as the standard.
1.6 Warning-Lethal voltages are a potential hazard during the performance of this test. It is essential that the test apparatus, and all associated equipment electrically connected to it, be properly designed and installed for safe operation. Solidly ground all electrically conductive parts which it is possible for a person to contact during the test. Provide means for use at the completion of any test to ground any parts which were at high voltage during the test or have the potential for acquiring an induced charge during the test or retaining a charge even after disconnection of the voltage source. Thoroughly instruct all operators as to the correct procedures for performing tests safely. When making high voltage tests, particularly in compressed gas or in oil, it is possible for the energy released at breakdown to be sufficient to result in fire, explosion, or rupture of the test chamber. Design test equipment, test chambers, and test specimens so as to minimize the possibility of such occurrences and to eliminate the possibility of personal injury. If the potential for fire exists, have fire suppression equipment available.
Note 1- There is no IEC publication or ISO standard equivalent to this standard.

General Information

• Status: Historical
• Publication Date: 09-Mar-1999
• ICS: 29.035.99 - Other insulating materials
• Technical Committee: D09 - Electrical and Electronic Insulating Materials

Relations

• Replaced By: ASTM D6343-99(2004) - Test Methods for Thin Thermally Conductive Solid Materials for Electrical Insulation and Dielectric Applications
• Effective Date: 10-Mar-1999

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
An American National Standard
Designation:D6343–99
Standard Test Methods for
Thin Thermally Conductive Solid Materials for Electrical
Insulation and Dielectric Applications
This standard is issued under the fixed designation D 6343; 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 374M Test Methods for Thickness of Solid Electrical
Insulation [Metric]
1.1 This standard is a compilation of test methods for
D 412 Test Methods for Vulcanized Rubber and Thermo-
evaluating properties of thermally conductive electrical insu-
plastic Rubbers and Thermoplastic Elastomers—Tension
lation sheet materials to be used for dielectric applications.
D 624 Test Method for Tear Strength of Conventional
1.2 Such materials are thin, compliant sheets, typically
Vulcanized Rubber and Thermoplastic Elastomers
produced by mixing thermally conductive particulate fillers
D 792 TestMethodsforDensityandSpecificGravity(Rela-
with organic or silicone binders. For added physical strength
tive Density) of Plastics by Displacement
these materials are often reinforced with a woven or nonwoven
D 883 Terminology Relating to Plastics
fabric or a dielectric film.
D 1000 Test Methods for Pressure-Sensitive Adhesive-
1.3 These test methods apply to thermally conductive sheet
Coated Tapes Used for Electrical and Electronic Applica-
material ranging from about 0.02 to 6-mm thickness.
tions
1.4 This standard does not purport to address all of the
D 1458 Test Methods for Fully Cured Silicone Rubber-
safety concerns, if any, associated with its use. It is the
Coated Glass Fabric and Tapes for Electrical Insulation
responsibility of the user of this standard to establish appro-
D 1711 Terminology Relating to Electrical Insulation
priate safety and health practices and determine the applica-
D 2240 Test Method for Rubber Property—Durometer
bility of regulatory limitations prior to use. See also 18.1.2 and
Hardness
19.1.2.
D 5470 Test Method for Thermal Transmission Properties
1.5 The values stated in SI units are to be regarded as
of Thin Thermally Conductive Solid Electrical Insulation
standard.
Materials
NOTE 1—There is no IEC publication or ISO standard equivalent to this
D 6054 Practice for Conditioning Electrical Insulating Ma-
standard.
terials for Testing
2. Referenced Documents
3. Terminology
2.1 ASTM Standards:
3.1 Definitions of Terms Specific to This Standard:
D 149 Test Method for Dielectric Breakdown Voltage and
3.1.1 apparent thermal conductivity, n—the time rate of
Dielectric Strength of Solid Electrical Insulating Materials
heat flow, under steady conditions, through unit area, per unit
at Commercial Power Frequencies
temperature gradient in the direction perpendicular to the area,
D 150 Test Methods for AC Loss Characteristics and Per-
for a nonhomogeneous material.
mittivity (Dielectric Constant) of Solid Electrical Insulat-
3.1.1.1 See 16.1 for a discussion of the terms thermal
ing Materials
conductivity and apparent thermal conductivity. To avoid
D 257 Test Methods for DC Resistance or Conductance of
confusion, these test methods use apparent thermal conductiv-
Insulating Materials
ity for measurements of homogeneous and nonhomogeneous
materials.
These test methods are under the jurisdiction of ASTM Committee D-9 on
Electrical and Electronic Insulating Materials and are the direct responsibility of
Subcommittee D09.19 on Dielectric Sheet and Roll Products.
Current edition approved March 10, 1999. Published June 1999. Originally Annual Book of ASTM Standards, Vol 09.01.
published as D 6343 – 98. Last previous edition D 6343 – 98. Annual Book of ASTM Standards, Vol 08.01.
2 5
Annual Book of ASTM Standards, Vol 10.01. Annual Book of ASTM Standards, Vol 10.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D6343
3.1.2 See Terminologies D 1711 and D 883 for definitions 9. Adhesion Strength
of other terms used in these test methods.
9.1 Significance and Use—Materials covered by this test
methodareoptionallycoatedwithapressuresensitiveadhesive
4. Significance and Use
on one or both sides. In some cases performance in a particular
application can be affected by the adhesion strength.
4.1 These test methods are useful to determine compliance
of thermally conductive sheet electrical insulation with speci- 9.2 Procedure—Test three specimens of 25-mm width in
accordance with Test Methods D 1000 except, clean the steel
fication requirements established jointly by a producer and a
user. panel with isopropyl alcohol.
9.3 Calculation—From the 3 specimens, calculate the aver-
4.2 These test methods have been found useful for quality
assessment. Results of the test methods can be useful in age adhesion strength.
apparatus design. 9.4 Report—Report the average adhesion strength in new-
tons per metre of width.
5. Specimen Preparation
10. Breaking Strength
5.1 From a sample of sufficient size, prepare test specimens
10.1 Significance and Use—Breaking strength can be a
of the dimensions and of the quantity to meet the requirements
significant limitation on methods of applying tapes. Hence it
for each test procedure.
may be important to measure the tensile force they can
withstand.
6. Conditioning
10.2 Procedure:
6.1 Unless otherwise specified, condition specimens in ac-
10.2.1 Prepare three specimens at least 500 mm long and 25
cordance with Procedure A of Practice D 6054. Perform all
mmwide.Ifthematerialcontainsreinforcingfibers,cutthetest
tests on specimens that are in equilibrium with the conditions
specimen such that the machine direction reinforcing fibers are
ofProcedureAofPracticeD 6054.Makethetestsinachamber
parallel to the long axis of the specimen. In the case of
maintained at 23 6 2°C and 50 6 5 % relative humidity.
materials narrower than 25 mm, test the full width as received.
6.2 When required by a test procedure, condition specimens
10.2.2 Test the breaking strength in accordance with Test
in accordance with Procedure D of Practice D 6054 except that
Methods D 1458.
either distilled or deionized water may be used. In such cases,
10.3 Calculation—From the test measurements on the 3
remove the specimens from the water into air maintained at 23
specimens, calculate the average breaking strength.
6 2°C and 50 6 5 % relative humidity, remove surface water
10.4 Report—Report the average breaking strength in new-
with a paper towel, and begin testing within 30 s.
tons per metre of width.
11. Tensile Strength and Elongation
7. Precision and Bias
11.1 Significance and Use—Tensile test results with these
7.1 No evaluation of precision or bias has been established
materials will vary with specimen geometry and conditions of
forthetestmethodshereinastheyrelatetothesethinthermally
testing. Hence, these tensile measurements are not always
conductivematerials.Forgeneralguidanceonly,referencemay
reliable indicators of usefulness in a particular application.
be made to Precision and Bias statements in the referenced test
Tensile properties of glass-fiber-reinforced materials vary with
methods as listed in Section 2.
the ratio of the glass-fiber thickness to the total thickness.
Measurements of tensile properties vary with the direction of
8. Thickness
the glass fibers with respect to the direction in which the
8.1 Significance and Use—The accurate determination of
specimen is cut.
thickness is essential for design purposes for both thermal
11.2 Procedure:
conduction and electrical insulation. Thickness enters into the
11.2.1 Prepare three specimens in accordance with Test
calculation of thermal, electrical, and tensile properties.
Methods D 412 using Die C.
8.2 Procedure:
11.2.2 If the material contains reinforcing fibers, cut the test
8.2.1 Make thickness measurements on specimens in accor-
specimen such that any reinforcing fibers are at 45 6 10° to the
dance withTest Methods D 374M, Method H.This test method
long axis of the specimen.
uses a micrometer which applies a pressure of 26 6 4 kPa on
11.2.3 In accordance with Test Methods D 412, measure the
the specimen, using a 6.25-mm diameter presser foot.
tensile breaking strength and tensile elongation at a jaw
8.2.2 Clean the surfaces where the measurements are to be
separation rate of 500 mm/min (20 in./min).
made. Take five randomly spaced measurements to cover the
11.3 Calculation:
length and width of the specimen. Take measurements at least
11.3.1 Calculate the tensile strength in kilopascals using the
6 mm from the edges of the specimen.
initial thickness and width for each specimen. Calculate the
average tensile strength from the three test measurements.
NOTE 2—At the compressive loads of this test method, some materials
will undergo compression or compression deflection. The buyer and the 11.3.2 Similarly, calculate each elongation at break as a
seller may wish to agree on other conditions of pressure, anvil and presser
percentage of the initial jaw separation. Calculate the average
foot geometry, and the dwell time to be used.
from the three test measurements.
8.3 Report—Report the thickness in millimetres as the 11.4 Report—Report the average tensile strength in kilopas-
average of the five measurements. cals and the average elongation in percent.
D6343
12. Hardness tics of a material under a specific set of conditions, it is not
appropriate to use these results to predict performance in an
12.1 Significance and Use—This test method is empirical
application where conditions differ from those of the test.
and intended for control purposes only.
15.2 Procedure:
12.2 Procedure:
15.2.1 Prepare specimens for two determinations as re-
12.2.1 Prepare a sufficient number of specimens to form a
quired by either Method A or Method B of Test Method
stack approximately 6 mm high.
D 5470.
12.2.2 Determine the indentation hardness in accordance
15.2.2 Measure the thermal impedance in accordance with
with Test Method D 2240 with the following exception:
Test Method D 5470, using a pressure of 3.0 6 0.1 MPa and an
12.2.2.1 Read the scale within 2 s after the presser foot is in
average specimen temperature of 50 6 5°C.
firm contact with the specimen.
15.3 Calculation—From the two determinations, calculate
12.3 Calculation—From the five measurements taken at
the average thermal impedance.
different locations on the specimen, calculate the average
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