ASTM_D_2739_-_97_2010.pdf

Designation:D273997(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 revision.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.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 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 regulatorylimitations 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 Definitions:3.1.1 Many 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 reciprocal 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 measured 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 volume 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 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 prepare thetensile adhesion specimens.NOTE1Different 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 QQ-B-626 Composition 22,is aconvenient metal.However,in order to minimize oxide formation,1This 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 2004 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 from Standardization Documents Order Desk,DODSSP,Bldg.4,SectionD,700RobbinsAve.,Philadelphia,PA19111-5098,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 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 Catalog No.603282.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 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 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 equivalent,and wipe with clean solvent,