1、Designation: D2739 97 (Reapproved 2010)Standard Test Method forVolume Resistivity of Conductive Adhesives1This standard is issued under the fixed designation D2739; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last r
2、evision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the volumeresistivity of resin-based conductive adhesives in the curedcondition
3、. The test is made on a thin adhesive layer as preparedin a bonded specimen. This test method is used for conductiveadhesives that are cured either at room temperature or atelevated temperatures.1.2 The values stated in either SI or other units shall beregarded separately as standard. SI equivalents
4、 to screwthreads are shown in the figures.1.3 This standard does not purport to address the safetyconcerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitatio
5、ns prior to use.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD907 Terminology of Adhesives2.2 Federal Specification:QQ-B-626 Composition 2232.3 ASTM Adjuncts:Assembly Jig43. Terminology3.1 DefinitionsMany terms in this test method are definedin Termin
6、ology D907.3.1.1 conductivity, nthe ratio of the current density car-ried through a specimen to the potential gradient paralleling thecurrent. This is numerically equal to the conductance betweenopposite faces of a unit cube of liquid. It is the reciprocal ofresistivity. D2864, D273.1.2 resistivity,
7、 volume, nthe ratio of the electric poten-tial gradient to the current density when the gradient is parallelto the current in the material. D1566, D114. Summary of Test Method4.1 The volume resistivity of adhesive layers cured betweenmetal adherends is measured on a resistance bridge. Tensileadhesio
8、n plugs (Fig. 1)5are described in this test method. Anyother test specimens and materials can be used as long assimilar precautions (see Section 7) are observed regardingpreparation and tolerances.5. Significance and Use5.1 Accurate measurement of the volume resistivity ofconductive adhesives is imp
9、ortant, particularly with respect toapplications in electronic packaging techniques. This methodmeasures the resistance of conductive adhesives used in thinfilms as part of a bonded assembly. This does not imply that themeasured results are applicable to different configurations withdifferent metals
10、. This method may be used for acceptancetesting and for screening materials.6. Apparatus6.1 Kelvin (Resistance) Bridge, calibrated to 1 % accuracy.66.2 With the agreement of the interested parties, any metaltensile adhesion plugs (Fig. 1) can be used to prepare thetensile adhesion specimens.NOTE 1Di
11、fferent metals will inherently provide different resistancevalues. The measured resistance is dependent on resistance at theadhesive-adherend interface due to metal oxide formation. The extent ofoxide formation varies with locality and laboratory conditions. Brass,conforming to Federal Specification
12、 QQ-B-626 Composition 22, is aconvenient metal. However, in order to minimize oxide formation,especially where measurements are critical, as in referee measurements, itis recommended that the metal plugs be plated with either gold or silverto a thickness of not less than 1 m (0.000040 in.).Any size
13、plug up to 301This test method is under the jurisdiction of ASTM Committee D14 onAdhesives and is the direct responsibility of Subcommittee D14.80 on MetalBonding Adhesives.Current edition approved Oct. 1, 2010. Published October 2010. Originallyapproved in 1968. Last previous edition approved in 20
14、04 as D2739 97 (2004).DOI: 10.1520/D2739-97R10.2For 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 to the standards Document Summary page onthe ASTM website.3Available fro
15、m Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/dodssp.daps.dla.mil.4Detailed drawings of the assembly jig are available from ASTM InternationalHeadquarters. Order Adjunct No. ADJD2739. Original adjunct produced in 1987.5Plugs t
16、o accommodate banana plugNo. 192, Herman H. Smith, Inc., orequivalent.6Satisfactory resistance bridges are made by: Leads and Northup Co. BridgeCatalog No. 4306, Minneapolis Honeywell Division Catalog No. 1622, and BiddleInstruments Catalog No. 603282.1Copyright ASTM International, 100 Barr Harbor D
17、rive, PO Box C700, West Conshohocken, PA 19428-2959, United States.mm in diameter can be used with the aid of an alignment jig.47. Test Specimen7.1 Thoroughly abrade the face of the specimen to bebonded (other than gold- or silver-plated) with crocus cloth4527or equivalent, and wipe with clean solve
18、nt, such asreagent-grade methyl ethyl ketone, immediately prior to bond-ing.7.2 Mix the adhesive to be tested in accordance with themanufacturers instructions, taking care to mix in as little air aspossible.7.3 Coat sufficient adhesive on the surface to be bonded toensure uniform squeeze-out around
19、the edge of the bondedarea. Remove excess adhesive, controlling the bond thicknessas shown on an assembly jig.47.4 Prepare five specimens each for the following twothicknesses: (1) 0.13 6 0.02 mm, and (2) 0.51 6 0.01 mm.7.5 Cure the adhesives in accordance with the manufactur-ers instructions. Curin
20、g under other conditions of time andtemperature is acceptable by an agreement of the interestedparties.8. Preparation of Apparatus8.1 Before application of the adhesive, set the adhesivethickness by tightening plugs in place, using a feeler gauge todetermine the clearance between plugs.8.2 Bottom ou
21、t the top plate on the guide post before andafter application of the adhesive.8.3 After the adhesive has been cured, remove or loosen (ata temperature close to the highest temperature of cure) anyremaining shims, screws, or devices of this nature, so that theadhesive layer cools in an unrestrained c
22、ondition.9. Conditioning9.1 Condition the cured test specimens at 23 6 1C (73.4 61.8F) and 50 6 5 % relative humidity for at least 88 h prior tothe test.9.2 Test at the conditions specified in 8.1 above.9.3 If conditions other than those given herein are needed, itis suggested that they be selected
23、from those given in PracticeD618.10. Procedure10.1 Make contacts (banana-plug type) so that when thespecimen is in the measuring circuit, the potential leads areinside the current leads (for example, potential lead connec-tions are closer to the adhesive bond) (Fig. 1). Make themeasurements with the
24、 specimen in a stress-free position, sincesemirigid and flexible formulations are very sensitive to stresschange during measurements.10.2 Measure and record the resistance.8NOTE 2If the resistance value of the adhesive layer is greater than104V, the resistance of the plugs can be ignored and the tot
25、al resistancetaken as the resistance of the adhesive layer. The resistivity of copper,silver, and brass are listed for comparison.9Metal Volume Resistivity at TemperatureCopper 1.729 3 106Vcm at 20CSilver 1.629 3 106Vcm at 20CBrass 3.65 3 106Vcm at 0C11. Calculation11.1 Calculate the volume resistiv
26、ity of the test specimen asfollows:7Crocus cloth 452 is available from the Carborundum Co., Niagara Falls, NY.8A general description of the Kelvin resistance bridge is found in Stout, M. B.,Basic Electrical Measurements, Par. 4.21 to 4.26, Prentice Hall, Inc., April, 1961.9American Institute of Phys
27、ics Handbook, Second Edition, Gray, E. H., Ph.D.,ed., 1957.FIG. 1 Brass Tensile Adhesion Specimens with Electrical ConnectionsD2739 97 (2010)2V 5 R0A/L (1)where:V = volume resistivity, V m,R0= observed resistance of the test specimen, V (asmeasured with the bridge), corrected for any errorfound in t
28、he calibration of the bridge, including theresistance metallic plugs cleaned as specified inSection 7,A = cross-sectional area of the test specimen, m2, andL = thickness of adhesive layer, m.12. Report12.1 Report the following information:12.1.1 Complete identification of the adherend and adhesivema
29、terials tested, including adhesive type, source, and manu-facturers code number,12.1.2 Curing conditions used,12.1.3 Conditioning environment and test environment,12.1.4 Number of specimens tested per sample,12.1.5 Dimensions of each test specimen including adhesiveline thickness,12.1.6 Corrected re
30、sistances of each test specimen,12.1.7 Volume resistivity, in ohm-centimeters, of each testspecimen,12.1.8 Average volume resistivity of the sample, when morethan one test specimen per sample is used, and12.1.9 Standard deviation of the volume resistivity mea-surements when more than one test specim
31、en per sample isused.13. Precision and Bias13.1 Precision and bias have not been determined for thistest method.14. Keywords14.1 adhesive; conductive adhesive; conductivity; resistiv-ity; volume resistivityASTM International takes no position respecting the validity of any patent rights asserted in
32、connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the res
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34、ul consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International
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