1、Designation: D2739 97 (Reapproved 2017)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,health, and environmental practices and determine the appli-cability of re
5、gulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade
6、 Organization TechnicalBarriers to Trade (TBT) Committee.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 Definitions:3.1.1 Man
7、y terms in this test method are defined in Termi-nology D907.3.1.2 conductivity, nthe ratio of the current density carriedthrough 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 recipr
8、ocal ofresistivity. D2864, D273.1.3 resistivity, volume, nthe ratio of the electric potentialgradient to the current density when the gradient is parallel tothe current in the material. D1566, D114. Summary of Test Method4.1 The volume resistivity of adhesive layers cured betweenmetal adherends is m
9、easured on a resistance bridge. Tensileadhesion 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 vo
10、lume resistivity ofconductive adhesives is important, 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
11、 different configurations withdifferent metals. 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
12、prepare thetensile adhesion specimens.NOTE 1Different metals will inherently provide different resistance1This 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 Nov. 1, 20
13、17. Published November 2017. Originallyapproved in 1968. Last previous edition approved in 2010 as D2739 97 (2010).DOI: 10.1520/D2739-97R17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volum
14、e information, refer to the standards Document Summary page onthe ASTM website.3Available from DLA Document Services, Building 4/D, 700 Robbins Ave.,Philadelphia, PA 19111-5094, http:/quicksearch.dla.mil.4Detailed drawings of the assembly jig are available from ASTM InternationalHeadquarters. Order
15、Adjunct No. ADJD2739. Original adjunct produced in 1987.5Plugs to 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 Cat
16、alog No. 603282.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDeve
17、lopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1values. The measured resistance is dependent on resistance at theadhesive-adherend interface due to metal oxide formation. The extent ofoxide formation v
18、aries with locality and laboratory conditions. Brass,conforming to Federal Specification 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 plate
19、d with either gold or silverto a thickness of not less than 1 m (0.000040 in.).Any size plug up to 30mm 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 equ
20、ivalent, and wipe with clean solvent, 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 to
21、ensure uniform squeeze-out around 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
22、manufactur-ers instructions. Curing 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 cle
23、arance between plugs.8.2 Bottom out 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 theadhesiv
24、e layer cools in an unrestrained condition.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, iti
25、s suggested that they be selected 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.
26、 1). Make themeasurements with the specimen in a stress-free position, sincesemirigid and flexible formulations are very sensitive to stresschange during measurements.7Crocus cloth 452 is available from the Carborundum Co., Niagara Falls, NY.FIG. 1 Brass Tensile Adhesion Specimens with Electrical Co
27、nnectionsD2739 97 (2017)210.2 Measure and record the resistance.8NOTE 2If the resistance value of the adhesive layer is greater than104, the resistance of the plugs can be ignored and the total resistancetaken as the resistance of the adhesive layer. The resistivity of copper,silver, and brass are l
28、isted for comparison.9Metal Volume Resistivity at TemperatureCopper 1.729 106cm at 20CSilver 1.629 106cm at 20CBrass 3.65 106cm at 0C11. Calculation11.1 Calculate the volume resistivity of the test specimen asfollows:V 5 R0A/L (1)where:V = volume resistivity, m,R0= observed resistance of the test sp
29、ecimen, (as mea-sured with the bridge), corrected for any error found inthe calibration of the bridge, including the resistancemetallic plugs cleaned as specified in Section 7,A = cross-sectional area of the test specimen, m2, andL = thickness of adhesive layer, m.12. Report12.1 Report the following
30、 information:12.1.1 Complete identification of the adherend and adhesivematerials 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
31、of each test specimen including adhesiveline thickness,12.1.6 Corrected resistances 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 deviat
32、ion of the volume resistivity mea-surements when more than one test specimen 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 t
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34、responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addr
35、essed to ASTM International Headquarters. Your comments will receive careful 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
36、the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (
37、phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 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 Physics Handbook, Second Edition, Gray, E. H., Ph.D.,ed., 1957.D2739 97 (2017)3
