1、Designation: B 678 86 (Reapproved 2006)Standard Test Method forSolderability of Metallic-Coated Products1This standard is issued under the fixed designation B 678; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last re
2、vision. 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 provides a procedure for evaluating thesolderability of metallic-coated products and test specimens toassur
3、e 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 broad
4、ly 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 no
5、t 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 toesta
6、blish 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 MetalD 509 Test Methods of Sampling and Grading RosinD 1193 Specification for Reagent Water3. Summary of Test
7、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
8、.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 anappr
9、opriate 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 us
10、e 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 th
11、e 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 sold
12、erability 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 caus
13、e.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 comp
14、onentsof 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 experim
15、ent.4.5 If the specimen tested is longer than 25 mm, its bottomend will be in the solder for significantly longer than thespecified time. Therefore, if the specimen is longer than 251This test method is under the jurisdiction ofASTM Committee B08 on Metallicand Inorganic Coatings and is the direct r
16、esponsibility of Subcommittee B08.10 onTest Methods.Current edition approved Nov. 1, 2006. Published December 2006. Originallyapproved in 1986. Last previous edition approved in 2001 as B 678 86 (2001).2Long, J. B., “A Critical Review of Solderability Testing,” in Properties ofElectrodeposits, Their
17、 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, orcontac
18、t ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.mm, the results obtained
19、 at the bottom end of the specimen areinvalid. This part of the specimen shall be discounted in theevaluation of the results. A second set of tests can be run onadditional specimens in which the specimens are only partlyimmersed. These would be used to evaluate the bottom ends.5. Flux5.1 The flux sh
20、all be a 25 6 5 mass % solution ofwater-white rosin, as defined by Test Methods D 509, GradeWW, dissolved in isopropyl alcohol of a minimum purity of 99mass % (Note 1). A different flux, such as mildly activated andactivated rosin fluxes, may be used if the specifying authorityrequires it. Such devi
21、ation from the standard shall be stated inthe test report.NOTE 1Suitable fluxes are commercially available. Care must betaken that the commercial flux used is nonactivated, rosin flux. Commer-cial fluxes of higher concentration may be thinned with isopropyl alcoholto give the required concentration.
22、5.2 Solder:5.2.1 The solder shall be an alloy of 60 mass % tin and 40mass % lead that conforms to alloy Grade 60A of SpecificationB32.5.2.2 The composition of molten solder will graduallychange because of oxidation. Also, the immersion of testspecimens can introduce metallic impurities into the sold
23、er. Forthese reasons, the solder shall be replaced after being moltenfor 8 h unless chemical analysis shows it to meet the require-ments of 5.2.1.5.3 WaterThe water used in the aging chamber shall bedistilled or deionized water meeting the requirements for TypeII or Type III reagent water as defined
24、 in Specification D 1193.6. Sampling6.1 The nature and the number of specimens shall be givenby the specification covering the coating or the coated productor other governing document.7. Apparatus7.1 Solder Pot, large enough that when it is filled to itsnormal capacity the mass of the solder is at l
25、east 100 times themass of the specimen that will be tested.NOTE 2If there is insufficient solder in the pot, the immersion of aroom-temperature specimen will cool the solder out of the test range.8. Procedure8.1 Do not clean the specimens. The solderability test is tobe performed on them in their as
26、-received condition. If in thenormal production process the specimens are cleaned beforethey are soldered, it may be preferred to clean the testspecimens in the same way. If such cleaning is required, it shallbe specifically called for. Avoid contaminating the specimens.Particularly do not touch the
27、 areas to be tested with bare hands.Use tweezers, forceps, cotton gloves, or other appropriatemeans.8.2 For tin and tin-lead coatings, if it is required that thespecimens be aged before solderability testing, proceed asdirected in 8.3. If the specimens are not to be aged, start thetests with 8.5.8.3
28、 Suspend the specimens in a vessel above boiling waterand leave them there with the water boiling continuously for 24h. Keep the vessel covered and assure that the specimens donot touch the side of the vessel and that the lower edges of thespecimens are from 50 to 100 mm above the surface of theboil
29、ing water. Arrange the cover of the vessel and the con-denser, if used, so that the condensed water does not drip ontothe specimens.8.4 Remove the aged specimens from the vessel and allowthem to air-dry and air-cool.8.5 Perform the remaining steps on each specimen one at atime. Dip the specimen into
30、 the flux. Remove it and allow it todrain for 30 to 60 s.8.6 Just before the next step, skim the surface of the moltensolder with a clean stainless steel scraper, stir the solder with aclean stainless steel rod, and skim the surface again. Thetemperature of the solder shall be 245 6 5C.8.7 Immerse t
31、he specimen into the solder at a speed of 25 65 mm/s, hold it in the solder for 5 6 0.5 s, and remove it fromthe solder at a speed of 25 6 5 mm/s.NOTE 3The simplicity of the test can cause a casual attitude towardthe times and rates specified. Unless the operator adheres to the times andrates, a sig
32、nificant variability in the results can occur. There are commer-cial automated dipping devices that, if used, will eliminate operatorvariability.8.8 After the solder coating solidifies, remove the fluxresidue with isopropyl alcohol or other solvent.8.9 Examine the solder coating on the specimen usin
33、g, ifnecessary, up to 103 magnification. Evaluate the adherence ofthe coating by probing or scraping it with a sharp point or asharp blade.8.10 The specimen shall be judged to have passed the test ifthe solder coating is adherent, bright, smooth, and uniformover at least 95 % of the tested surface.
34、The remaining 5 %may contain small pin holes, dewetted areas, and roughness. Ifthe specimens are flat coupons, the areas within 3 mm of theedges shall be excluded from the evaluation. It is recom-mended that tested specimens exhibiting the worst allowablecases be retained and used as acceptance stan
35、dards.9. Report9.1 The test report shall contain the following information:9.1.1 The ASTM designation, including the issue date, ofthis method,9.1.2 A description of the specimens tested,9.1.3 Whether the specimens were cleaned before testing,and, if so, the process used (see 8.1),9.1.4 Whether the
36、specimens were aged,9.1.5 Whether the test was performed manually or with anautomatic dip tester,9.1.6 Any deviations from the standard method (for ex-ample, nature of flux, nature of solder, time of immersion),9.1.7 The number of specimens tested and the number ofspecimens that failed the test, and
37、9.1.8 A description of the nature of any failed specimens.10. Precision and Bias10.1 No statement is made either on the precision or on thebias of this test method for measuring solderability because theB 678 86 (2006)2test results merely state whether there is conformance to thecriteria for success
38、 specified in the procedure.ASTM 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 advised that determination of the validity of any such patent rights, and the riskof infr
39、ingement 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 reapproved or withdrawn. Your comments are invited either for revision of this standa
40、rd 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 you feel that your comments have not received a fair hearing you shouldmake your vie
41、ws 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).B 678 86 (2006)3
