1、Designation: D 6343 99 (Reapproved 2004)An American National StandardStandard Test Methods forThin Thermally Conductive Solid Materials for ElectricalInsulation and Dielectric Applications1This standard is issued under the fixed designation D 6343; the number immediately following the designation in
2、dicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This standard is a compilation of test
3、methods forevaluating properties of thermally conductive electrical insu-lation sheet materials to be used for dielectric applications.1.2 Such materials are thin, compliant sheets, typicallyproduced by mixing thermally conductive particulate fillerswith organic or silicone binders. For added physic
4、al strengththese materials are often reinforced with a woven or nonwovenfabric or a dielectric film.1.3 These test methods apply to thermally conductive sheetmaterial ranging from about 0.02 to 6-mm thickness.1.4 This standard does not purport to address all of thesafety concerns, if any, associated
5、 with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. See also 18.1.2 and19.1.2.1.5 The values stated in SI units are to be regarded asstandard.NOTE 1There is
6、no IEC publication or ISO standard equivalent to thisstandard.2. Referenced Documents2.1 ASTM Standards:2D 149 Test Method for Dielectric Breakdown Voltage andDielectric Strength of Solid Electrical Insulating Materialsat Commercial Power FrequenciesD 150 Test Methods for AC Loss Characteristics and
7、 Per-mittivity (Dielectric Constant) of Solid Electrical Insula-tionD 257 Test Methods for DC Resistance or Conductance ofInsulating MaterialsD 374M Test Methods for Thickness of Solid ElectricalInsulation MetricD 412 Test Methods for Vulcanized Rubber and Thermo-plastic ElastomersTensionD 624 Test
8、Method for Tear Strength of ConventionalVulcanized Rubber and Thermoplastic ElastomersD 792 Test Methods for Density and Specific Gravity (Rela-tive Density) of Plastics by DisplacementD 883 Terminology Relating to PlasticsD 1000 Test Methods for Pressure-Sensitive Adhesive-Coated Tapes Used for Ele
9、ctrical and Electronic Applica-tionsD 1458 Test Methods for Fully Cured Silicone Rubber-Coated Glass Fabric and Tapes for Electrical InsulationD 1711 Terminology Relating to Electrical InsulationD 2240 Test Method for Rubber PropertyDurometerHardnessD 5470 Test Method for Thermal Transmission Proper
10、tiesof Thin Thermally Conductive Solid Electrical InsulationMaterialsD 6054 Practice for Conditioning Electrical Insulating Ma-terials for Testing3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 apparent thermal conductivity, nthe time rate ofheat flow, under steady conditions,
11、 through unit area, per unittemperature gradient in the direction perpendicular to the area,for a nonhomogeneous material.3.1.1.1 See 16.1 for a discussion of the terms thermalconductivity and apparent thermal conductivity. To avoidconfusion, these test methods use apparent thermal conductiv-ity for
12、 measurements of homogeneous and nonhomogeneousmaterials.3.1.2 See Terminologies D 1711 and D 883 for definitionsof other terms used in these test methods.4. Significance and Use4.1 These test methods are useful to determine complianceof thermally conductive sheet electrical insulation with speci-fi
13、cation requirements established jointly by a producer and auser.1These test methods are under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and are the direct responsibility ofSubcommittee D09.19 on Dielectric Sheet and Roll Products.Current edition approved
14、 March 10, 1999. Published June 1999. Originallyapproved in 1998. Last previous edition approved in 1998 as D 6343 98.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer t
15、o the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.2 These test methods have been found useful for qualityassessment. Results of the test methods can be useful inapparatus desig
16、n.5. Specimen Preparation5.1 From a sample of sufficient size, prepare test specimensof the dimensions and of the quantity to meet the requirementsfor each test procedure.6. Conditioning6.1 Unless otherwise specified, condition specimens in ac-cordance with Procedure A of Practice D 6054. Perform al
17、ltests on specimens that are in equilibrium with the conditionsof ProcedureAof Practice D 6054. Make the tests in a chambermaintained at 23 6 2 C and 50 6 5 % relative humidity.6.2 When required by a test procedure, condition specimensin accordance with Procedure D of Practice D 6054 except thateith
18、er distilled or deionized water may be used. In such cases,remove the specimens from the water into air maintained at 236 2 C and 50 6 5 % relative humidity, remove surface waterwith a paper towel, and begin testing within 30 s.7. Precision and Bias7.1 No evaluation of precision or bias has been est
19、ablishedfor the test methods herein as they relate to these thin thermallyconductive materials. For general guidance only, reference maybe made to Precision and Bias statements in the referenced testmethods as listed in Section 2.8. Thickness8.1 Significance and UseThe accurate determination ofthick
20、ness is essential for design purposes for both thermalconduction and electrical insulation. Thickness enters into thecalculation of thermal, electrical, and tensile properties.8.2 Procedure:8.2.1 Make thickness measurements on specimens in accor-dance with Test Methods D 374M, Method H. This test me
21、thoduses a micrometer which applies a pressure of 26 6 4 kPa onthe specimen, using a 6.25-mm diameter presser foot.8.2.2 Clean the surfaces where the measurements are to bemade. Take five randomly spaced measurements to cover thelength and width of the specimen. Take measurements at least6 mm from t
22、he edges of the specimen.NOTE 2At the compressive loads of this test method, some materialswill undergo compression or compression deflection. The buyer and theseller may wish to agree on other conditions of pressure, anvil and presserfoot geometry, and the dwell time to be used.8.3 ReportReport the
23、 thickness in millimetres as theaverage of the five measurements.9. Adhesion Strength9.1 Significance and UseMaterials covered by this testmethod are optionally coated with a pressure sensitive adhesiveon one or both sides. In some cases performance in a particularapplication can be affected by the
24、adhesion strength.9.2 ProcedureTest three specimens of 25-mm width inaccordance with Test Methods D 1000 except, clean the steelpanel with isopropyl alcohol.9.3 CalculationFrom the 3 specimens, calculate the aver-age adhesion strength.9.4 ReportReport the average adhesion strength in new-tons per me
25、tre of width.10. Breaking Strength10.1 Significance and UseBreaking strength can be asignificant limitation on methods of applying tapes. Hence itmay be important to measure the tensile force they canwithstand.10.2 Procedure:10.2.1 Prepare three specimens at least 500 mm long and 25mm wide. If the m
26、aterial contains reinforcing fibers, cut the testspecimen such that the machine direction reinforcing fibers areparallel to the long axis of the specimen. In the case ofmaterials narrower than 25 mm, test the full width as received.10.2.2 Test the breaking strength in accordance with TestMethods D 1
27、458.10.3 CalculationFrom the test measurements on the 3specimens, calculate the average breaking strength.10.4 ReportReport the average breaking strength in new-tons per metre of width.11. Tensile Strength and Elongation11.1 Significance and UseTensile test results with thesematerials will vary with
28、 specimen geometry and conditions oftesting. Hence, these tensile measurements are not alwaysreliable indicators of usefulness in a particular application.Tensile properties of glass-fiber-reinforced materials vary withthe ratio of the glass-fiber thickness to the total thickness.Measurements of ten
29、sile properties vary with the direction ofthe glass fibers with respect to the direction in which thespecimen is cut.11.2 Procedure:11.2.1 Prepare three specimens in accordance with TestMethods D 412 using Die C.11.2.2 If the material contains reinforcing fibers, cut the testspecimen such that any r
30、einforcing fibers are at 45 6 10 to thelong axis of the specimen.11.2.3 In accordance with Test Methods D 412, measure thetensile breaking strength and tensile elongation at a jawseparation rate of 500 mm/min (20 in./min).11.3 Calculation:11.3.1 Calculate the tensile strength in kilopascals using th
31、einitial thickness and width for each specimen. Calculate theaverage tensile strength from the three test measurements.11.3.2 Similarly, calculate each elongation at break as apercentage of the initial jaw separation. Calculate the averagefrom the three test measurements.11.4 ReportReport the averag
32、e tensile strength in kilopas-cals and the average elongation in percent.12. Hardness12.1 Significance and UseThis test method is empiricaland intended for control purposes only.12.2 Procedure:12.2.1 Prepare a sufficient number of specimens to form astack approximately 6 mm high.D 6343 99 (2004)212.
33、2.2 Determine the indentation hardness in accordancewith Test Method D 2240 with the following exception:12.2.2.1 Read the scale within 2 s after the presser foot is infirm contact with the specimen.12.3 CalculationFrom the five measurements taken atdifferent locations on the specimen, calculate the
34、 averagehardness.12.4 ReportReport the average hardness in accordancewith the Shore Hardness system.13. Specific Gravity13.1 Significance and UseSpecific gravity can be a usefultool to help verify proper filler loading and distribution. Thisvalue may also be required by designers of specific applica
35、-tions of these materials.13.2 ProcedurePrepare two specimens of at least 650mm2in area and test in accordance with Test Methods D 792,Method A-1.13.3 ReportReport the average of the two test measure-ments as the specific gravity.14. Tear Strength14.1 Significance and Use:14.1.1 In certain applicati
36、ons, these materials are stressedduring installation in such a way as to introduce tearing stresseson the material. Tear strength measurements provide a meansof comparing or specifying materials for such applications.14.1.2 The type of reinforcement, testing rate, and specimensize affect the tear re
37、sistance. The results obtained by this testmethod are predictive of performance only under certainspecific conditions of use.14.2 Procedure:14.2.1 Prepare three specimens using Die C of Test MethodD 624.14.2.2 If the material contains reinforcing fibers, cut the testspecimen such that any reinforcin
38、g fibers are at 45 6 10 to thelong axis of the specimen (the “A” dimension of Die C).14.2.3 Measure the tear strength in accordance with TestMethods D 412 using a jaw separation rate of 500 mm/min (20in./min).14.3 CalculationCalculate the tear strength for eachspecimen by dividing the maximum force
39、by the specimenthickness. Calculate the average from the three test measure-ments.14.4 ReportReport the average tear strength in newtonsper millimetre.15. Thermal Impedance15.1 Significance and UseThermal impedance measure-ments are affected by applied pressure, thickness, any surfaceirregularities,
40、 and uniformity of heat flow. Since the resultsobtained by these test methods represent thermal characteris-tics of a material under a specific set of conditions, it is notappropriate to use these results to predict performance in anapplication where conditions differ from those of the test.15.2 Pro
41、cedure:15.2.1 Prepare specimens for two determinations as re-quired by either Method A or Method B of Test MethodD 5470.15.2.2 Measure the thermal impedance in accordance withTest Method D 5470, using a pressure of 3.0 6 0.1 MPa and anaverage specimen temperature of 50 6 5C.15.3 CalculationFrom the
42、two determinations, calculatethe average thermal impedance.15.4 ReportReport the average thermal impedance in(m2K)/W and the test method used.16. Apparent Thermal Conductivity16.1 Significance and UseThermal conductivity appliesonly to homogeneous materials. Thermally conductive electri-cally insula
43、ting materials are heterogeneous since they typi-cally include ceramic fillers and elastomeric binders, and areoften reinforced with glass fiber or a layer of dielectric film.Hence the term apparent thermal conductivity is more appro-priate. Because of the multilayer nature of these products, theapp
44、arent thermal conductivity will vary with material thick-ness.16.2 Procedure:16.2.1 Prepare specimens in accordance with either MethodA or Method B of Test Method D 5470.16.2.2 In accordance with Test Methods D 5470, determinethe thermal impedance of layered stacks using 1, 2, and 3layers of specime
45、ns at 3 6 0.1-MPa pressure. Use either TestMethod A or Test Method B of Test Method D 5470.16.3 CalculationCalculate the apparent thermal conduc-tivity from the slope of a plot of thermal impedance againstspecimen stack thickness.16.4 ReportReport the apparent thermal conductivity inW/(mK) and the t
46、est method used.17. Permittivity and Dissipation Factor17.1 Significance and UseTest Methods D 150 discuss thesignificance of dielectric properties and dissipation factor.17.2 ProcedurePrepare four specimens. Use 75-mm di-ameter conducting paint opposed electrodes. Test each speci-men at 1 kHz in ac
47、cordance with Test Methods D 150 in air ata temperature of 23 6 2 C.17.3 ReportReport the electrodes used, the individualvalues, and the average value of permittivity and dissipationfactor for the four specimens.18. Volume Resistivity18.1 Significance and Use:18.1.1 Volume resistivity is important i
48、n designing an insu-lator for a specific application. Volume resistivity is affected byhumidity and temperature. The extent of change in volumeresistivity needs to be considered in developing a design for aspecific application.18.1.2 WarningLethal voltages are a potential hazardduring the performanc
49、e of this test. It is essential that the testapparatus, and all associated equipment electrically connectedto it, be properly designed and installed for safe operation.Solidly ground all electrically conductive parts which it ispossible for a person to contact during the test. Provide meansfor use at the completion of any test to ground any parts whichwere at high voltage during the test or have the potential foracquiring an induced charge during the test or retaining aD 6343 99 (2004)3charge even after disconnection of the voltage source
