ASTM_B_678_-_86_2011.pdf

Designation:B67886(Reapproved 2011)Standard Test Method forSolderability of Metallic-Coated Products1This standard is issued under the fixed designation B678;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 provides a procedure for evaluating thesolderability of metallic-coated products and test specimens toassure satisfactory performance in manufacturing processesrequiring soldering with soft(tin-lead)solder and rosin flux.This test method is applicable only for testing coatings that arenormally readily solderable such as:tin,tin-lead alloy,silver,and gold.1.2 This test method is qualitative and broadly applicable.Itis easy to perform and requires only simple equipment.Thereare other solderability tests not covered by this test method thatare more applicable to specific situations,yield quantitativeresults,or both.Several are described in the literature.2This isa“go-no-go”test and does not grade solderability as excellent,good,fair,and so forth.1.3 This standard may involve hazardous materials,opera-tions,and equipment.This standard does not purport toaddress all of the safety concerns,if any,associated with itsuse.It is the responsibility of the user of this standard toestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:3B32 Specification for Solder MetalD509 Test Methods of Sampling and Grading RosinD1193 Specification for Reagent Water3.Summary of Test Method3.1 The specimen to be tested is coated with rosin flux,dipped briefly into molten tin-lead solder,and examined forcomplete and uniform coverage by the solder.When specifi-cally required,the specimens are artificially aged before testingby exposure to hot,humid air.4.Significance and Use4.1 In order that a sound solder joint be formed simply andquickly in a production operation,the molten solder mustreadily wet and spread over the surfaces of the products beingjoined.For this to happen,the surfaces must be clean or besoiled only with contaminants that are easily removed by anappropriate flux.It often is necessary that the flux be onlystrong enough to remove the normally occurring soils.A moreaggressive flux may corrode the product and have otherharmful effects.Nonactivated rosin in alcohol is the standardflux used in this test method;however,provision is made forthe use of other fluxes.Since rosin is a mild flux,it providesbetter discrimination between acceptable and unacceptablesolderability in marginal cases than do more active fluxes.4.2 Metallic coatings are frequently used to provide solder-able surfaces.But,an improperly produced coating may notyield the required solderability.There are many coating defectsthat cause poor solderability including porosity,codepositedimpurities,incorrect thickness,and surface contamination.Itmay be difficult or impractical to test a coating directly for eachof the undesirable conditions.In these instances solderability istested.Products that pass the solderability test can be expectedto solder satisfactorily in production.In the case of failure topass the test,the test results will not reveal the cause of theinadequate solderability,though,with experience,an operatormay be able to identify the cause.4.3 This test method measures the ability of a coatedproduct to be soldered with 60/40 tin/lead solder using anonactivated rosin flux.This solder and this flux,or anactivated form of it,are generally used in the assembly ofelectronic products.4.4 It is intended that the tested specimens be componentsof electronic products or articles with the same general shapeand mass.Articles that are much more massive than this willheat up too slowly during the solder immersion.If moremassive specimens are to be tested,a longer immersion timewill have to be used,the time to be determined by experiment.4.5 If the specimen tested is longer than 25 mm,its bottomend will be in the solder for significantly longer than the1This test method is under the jurisdiction ofASTM Committee B08 on Metallicand Inorganic Coatings and is the direct responsibility of Subcommittee B08.10 onTest Methods.Current edition approved April 1,2011.Published April 2011.Originallyapproved in 1986.Last previous edition approved in 2006 as B678 86(2006).DOI:10.1520/B0678-86R11.2Long,J.B.,“A Critical Review of Solderability Testing,”in Properties ofElectrodeposits,Their Measurement and Significance,edited by Richard Sard,Henry Leidheiser,Jr.,and Fielding Ogburn,The Electrochemical Society,1975.Harding,W.B.,“Solderability Testing,”Plating,Vol 52,No.10,October 1965,pp.971981.3For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.or