1、Designation: D 2739 97 (Reapproved 2004)Standard Test Method forVolume Resistivity of Conductive Adhesives1This standard is issued under the fixed designation D 2739; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、 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 test method covers the determination of the volumeresistivity of resin-based conductive adhesives in the curedcondit
3、ion. 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 This standard does not purport to address the safetyconcerns, if any, associated with its use. It
4、is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.1.3 The values stated in either SI or other units shall beregarded separately as standard. SI equivalents to screwthreads are sh
5、own in the figures.2. Referenced Documents2.1 ASTM Standards:2D 618 Practice for Conditioning Plastics for TestingD 907 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 T
6、erminology D 907.3.1.1 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. D 2864, D273.1.2 resis
7、tivity, volume, nthe ratio of the electric poten-tial gradient to the current density when the gradient is parallelto the current in the material. D 1566, D114. Summary of Test Method4.1 The volume resistivity of adhesive layers cured betweenmetal adherends is measured on a resistance bridge. Tensil
8、eadhesion 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 adhesive
9、s 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 different configurations withdifferen
10、t 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 prepare thetensile adhesion specimens.
11、NOTE 1Different 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 Speci
12、fication 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.).
13、Any size 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 April 1, 2004. Published April 2004. Originallyapproved in 1968. Last previous edition approv
14、ed in 1997 as D 2739 97.2For 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 from Standardization Docum
15、ents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-50984Detailed drawings of the assembly jig are available from ASTM International.Request Adjunct No. ADJD2739.5Plugs to accommodate banana plugNo. 192, Herman H. Smith, Inc., orequivalent.6Satisfactory resistance br
16、idges 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 Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.mm in diameter can be used wit
17、h 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 solvent, such asreagent-grade methyl ethyl ketone, immediately prior to bond-ing.7.2 Mix the adhesive
18、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 the edge of the bondedarea. Remove excess adhesive, controlling the bond thicknessas shown on an
19、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. Curing under other conditions of time andtemperature is acceptable by an agreement of the interestedpa
20、rties.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 out the top plate on the guide post before andafter application of the adhesive.8.3 After the adhes
21、ive 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 condition.9. Conditioning9.1 Condition the cured test specimens at 23 6 1C (73.4 61.8F) and 50 6 5
22、 % 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 from those given in PracticeD 618.10. Procedure10.1 Make contacts (banana-plug type) so that when
23、 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 specimen in a stress-free position, sincesemirigid and flexible formulations are very sensitive
24、 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 total resistancetaken as the resistance of the adhesive layer. The resistivity of copper,silver, an
25、d 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 resistivity of the test specimen asfollows:7Crocus cloth 452 is available from the Carborundum Co., Niag
26、ara 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 Physics Handbook, Second Edition, Gray, E. H., Ph.D.,ed., 1957.FIG. 1 Brass Tensile Adhesion Specime
27、ns with Electrical ConnectionsD 2739 97 (2004)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 the calibration of the bridge, including theresistance metallic plugs cleaned as specified inSec
28、tion 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 adhesivematerials tested, including adhesive type, source, and manu-facturers code number,12.1.2 Curing c
29、onditions 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 resistances of each test specimen,12.1.7 Volume resistivity, in ohm-centimeters, of each testspec
30、imen,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 specimen per sample isused.13. Precision and Bias13.1 Precision and bias have not been determined for
31、 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 connection with any item mentionedin this standard. Users of this standard are expressly advise
32、d 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 responsible technical committee and must be reviewed every five years andif not revised, either re
33、approved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If y
34、ou 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, 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 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 2739 97 (2004)3
