1、Designation: F72 17Standard Specification forGold Wire for Semiconductor Lead Bonding1This standard is issued under the fixed designation F72; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revision. A number in p
2、arentheses indicates the year of last reapproval. A superscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers round drawn/extruded goldwire for internal semiconductor device electrical connections.Four classifications of wire are
3、distinguished, (1) copper-modified wire, (2) beryllium-modified wire, (3) high-strengthwire, and (4) special purpose wire.NOTE 1Trace metallic elements have a significant effect upon themechanical properties and thermal stability of high-purity gold wire. It iscustomary in manufacturing to add contr
4、olled amounts of selectedimpurities to gold to modify or stabilize bonding wire properties, or both.This practice is known variously as “modifying,” “stabilizing,” or“doping.” The first two wire classifications denoted in this specificationrefer to wire made with either of two particular modifiers,
5、copper orberyllium, in general use. In the third and fourth wire classifications,“high-strength” and “special purpose” wire, the identity of modifyingadditives is not restricted.1.2 The values stated in SI units shall be regarded as thestandard.1.2.1 A mixed system of metric and inch-pound units is
6、inwidespread use for specifying semiconductor lead-bondingwire. SI-equivalent values of other commonly used units aredenoted by parentheses in text and tables.1.3 The following hazard caveat pertains only to the testmethod portion, Section 9, of this specification. This standarddoes not purport to a
7、ddress all of the safety, health, andenvironmental concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.4 This international stan
8、dard 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 Organization TechnicalBarriers to Trade (TBT) Committee.2. R
9、eferenced Documents2.1 ASTM Standards:2E16 Method of Free Bend Test for Ductility of Welds(Withdrawn 1978)3F205 Test Method for Measuring Diameter of Fine Wire byWeighingF219 Test Methods of Testing Fine Round and Flat Wire forElectron Devices and LampsF584 Practice for Visual Inspection of Semicond
10、uctor Lead-Bonding Wire (Withdrawn 2015)33. Ordering Information3.1 Orders for material under this specification shall includethe following information:3.1.1 Classification: copper-modified, beryllium-modified,high strength, or special purpose,3.1.2 Quantity,3.1.3 Purity (Section 4),3.1.4 Type, hard
11、, stress relieved, or annealed (Section 5),3.1.5 Breaking load and percentage elongation range (Sec-tion 5),3.1.6 Wire diameter (Section 6),3.1.7 Spool type, length of wire per spool, and type of wind(Section 11),3.1.8 Despooling, left-handed unwind or right-handed un-wind (Section 11), and,3.1.9 Pa
12、ckaging and marking (Section 12).4. Chemical Composition4.1 Beryllium-modified material shall conform to thechemical requirements specified in Table 1.4.2 High-strength material shall conform to the chemicalrequirements specified in Table 2.4.3 Special purpose material shall be in accordance withTab
13、le 3.1This specification is under the jurisdiction of ASTM Committee F01 onElectronics and is the direct responsibility of Subcommittee F01.03 on MetallicMaterials, Wire Bonding, and Flip Chip.Current edition approved Dec. 1, 2017. Published January 2018. Originallyapproved in 1966. Last previous ed
14、ition approved in 2006 as F72 06 which waswithdrawn January 2015 and reinstated in December 2017. DOI: 10.1520/F0072-17.2For 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
15、 to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in
16、 accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1NOTE 2Copper-modified wire
17、 is used on thermocompression wirebonding machines. Beryllium-modified material is often preferred onhigh-speed automated thermocompression or thermosonic bonding equip-ment. High-strength wire was developed for use on some very high speedautomated thermosonic bonders.5. Mechanical Properties5.1 Mat
18、erial specified by this standard may be either of twotypes:5.1.1 HardWire, as drawn/as extruded.5.1.2 AnnealedWire, annealed after drawing/extruding.5.2 Breaking Load and ElongationThe tension test shallbe the standard test for determining the mechanical properties,and acceptance or rejection shall
19、depend on the breaking loadand percent elongation at failure of a 254-mm (10.0-in.) lengthof wire.5.2.1 Hard wire shall conform to the requirements of Table4 for beryllium-modified gold wire.5.2.2 Stress relieved/annealed wire shall conform to therequirements of Table 5 for beryllium-modified gold w
20、ire, tothe requirements of Table 6 for high-strength wire, and to therequirements of Table 7 for special purpose wire.NOTE 3Hard wire is generally used for ultrasonic wire bonding.Annealed wire is used for thermocompression and thermosonic bonding.6. Dimensions and Permissible Variations6.1 Wire dia
21、meters shall be expressed in m (or equivalentdecimal fractions of an inch). Tolerances for the various sizeranges are specified in Table 8.7. Workmanship, Finish, and Appearance7.1 The wire surface shall be clean and free of finger oilsand stains.7.2 The wire surface shall be free of drawing/extrusi
22、onlubricant residues, particulate matter and other contaminantsTABLE 1 Chemical Requirements, Beryllium-Modified GoldBonding WireElement Composition, Weight, %Gold, min 99.99Beryllium 0.00030.0010Other impurities, max each 0.003Total of all detectable impurities, max 0.01TABLE 2 Chemical Requirement
23、s, High-Strength Gold BondingWireElement Composition, Weight, %Gold, min 99.99Total of all detectable impurities, max 0.01TABLE 3 Chemical Requirements, Special Purpose Gold BondingWireElement Composition, Weight, %Gold Not restrictedOther principal elements Not restrictedTotal of all detectable ele
24、ments Not restrictedTABLE 4 Breaking Load and Elongation of Hard WireBeryllium-Modified Gold and High-Strength GoldANominal Diameter,m (in.)Breaking Load, min,N(gf)Elongation in254 mm (10.0 in.), %13 (0.00050) 0.039 (4.0) 0.5 to 2.0, incl18 (0.00070) 0.069 (7.0) 0.5 to 2.0, incl20 (0.00080) 0.088 (9
25、.0) 0.5 to 2.0, incl23 (0.00090) 0.147 (15.0) 1.0 to 2.5, incl25 (0.0010) 0.177 (18.0) 1.0 to 2.5, incl28 (0.0011) 0.216 (22.0) 1.0 to 2.5, incl30 (0.0012) 0.265 (27.0) 1.0 to 2.5, incl31.8 (0.00125) 0.284 (29.0) 1.0 to 2.5, incl33 (0.0013) 0.314 (32.0) 1.0 to 2.5, incl38 (0.0015) 0.392 (40.0) 1.0 t
26、o 2.5, incl51 (0.0020) 0.736 (75.0) 1.0 to 3.0, inclAAll modern wires are expected to have a somewhat longer shelf life, but eachmanufacturers product will be slightly different.TABLE 5 Breaking Load and Elongation of Stress Relieved/Annealed WireBeryllium-Modified GoldANominalDiameter,m (in.)Breaki
27、ng Load,min,N(gf)Elongation in254 mm (10.0 in.), %Min Max RangeB13 (0.00050) 0.020 (2.0) 0.5 3.0 218 (0.00070) 0.029 (3.0) 0.5 7.0 320 (0.00080) 0.039 (4.0) 0.5 8.0 323 (0.00090) 0.059 (6.0) 0.5 8.0 325 (0.0010) 0.069 (7.0) 0.5 10.0 328 (0.0011) 0.078 (8.0) 0.5 10.0 330 (0.0012) 0.0981 (10.0) 0.5 10
28、.0 331.8 (0.00125) 0.108 (11.0) 0.5 10.0 333 (0.0013) 0.118 (12.0) 0.5 10.0 338 (0.0015) 0.147 (15.0) 0.5 12.0 451 (0.0020) 0.245 (25.0) 0.5 15.0 4AAll modern wire are expected to have a somewhat longer shelf life, but eachmanufacturers product will be slightly different.BA range of permissible elon
29、gation of at least the number of percentage pointsshown shall be selected from within the overall range designated by the minimumand maximum values for the given diameter. For example, for wire of 25-m(0.0010-in.) diameter, permissible elongation of 4.0 to 7.0, 6.0 to 9.0, 7.0 to 10.0 %,etc., may be
30、 selected.TABLE 6 Breaking Load and Elongation of Stress Relieved/Annealed WireHigh-Strength GoldANominal Diameter,m (in.)Breaking Load, min,N(gf)Elongation in254 mm (10.0 in.), %BMin Max13 (0.00050) 0.020 (2.0) 0.5 3.018 (0.00070) 0.039 (4.0) 0.5 5.020 (0.00080) 0.040 (5.0) 0.5 6.023 (0.00090) 0.06
31、4 (6.5) 0.5 6.025 (0.0010) 0.078 (8.0) 0.5 6.028 (0.0011) 0.093 (9.5) 0.5 6.030 (0.0012) 0.113 (11.5) 0.5 6.031.8 (0.00125) 0.123 (12.5) 0.5 6.033 (0.0013) 0.132 (13.5) 0.5 6.038 (0.0015) 0.176 (18.0) 0.5 7.051 (0.0020) 0.314 (32.0) 0.5 7.0AAll modern wire are expected to have a somewhat longer shel
32、f life, but eachmanufacturers product will be slightly different.BExcept for 13 m, 38 m, and 51 m, the minimum-maximum range is usually 3percentage points, for example, 2 to 5, 3 to 6, and 4 to 7 %. For 13 m it is usually1.5 percentages points, for example, 0.5 to 2, 1 to 2.5, and 1.5 to 3 %. For 38
33、 mand 51 m it is usually 4 percentage points, for example, 0.5 to 4.5, 1 to 5, 2 to 6,and3to7%.F72172that would interfere with functional performance of the wire.The seller and the purchaser must agree upon acceptablestandard of surface cleanliness.7.3 The surface shall be free of surface contaminat
34、ion thatwould degrade service life of the device to which it is attached.The seller and the purchaser must agree upon acceptablestandard of surface cleanliness.7.4 The wire surface shall be free of nicks, dents, scratches,or other blemishes deeper than 5 % of the wire diameter. Thesurface shall be f
35、ree of flaws protruding more than 5 % of thewire diameter above the surface.7.5 The wire shall despool without excessive curl thatwould degrade functional performance. The seller and thepurchaser must agree upon acceptable amount of curl. Curl ismeasured by the springback test (9.5).7.6 The wire mus
36、t be free of twist about the wire axis.Referring to wire twist test procedure (9.6), wire entwiningupon itself one or more complete turns (9.6.5.4) is rejectable bythe purchaser. Lesser degrees of twist may be acceptable, asagreed upon between seller and purchaser.7.7 The wire cross section must not
37、 be out-of-round to suchan extent that functional performance is impaired. The sellerand the purchaser must agree upon acceptable amount ofout-of-roundness.NOTE 4It is the intention of the directly responsible Subcommittee,F01.07, that the term “functional performance” be narrowly construed asfollow
38、s: wire imperfections denoted in 7.2, 7.5, and 7.7 must not be ofsufficient severity to excessively impair the operation of an otherwisenormally functioning wire bonding machine. In practice, standards ofadequate “functional performance” vary considerably, depending uponapplication.8. Sampling8.1 Un
39、less otherwise agreed, conformance with Section 5shall be determined by samples from each lot of wire.8.2 Lot SamplingA lot shall consist of all material fromone melt or bar in a shipment against one order description.8.3 Sampling Plan:8.3.1 A spool of wire used for testing may not be useful forprod
40、uction. Choose a sampling plan that will permit scrappingof test spools as gold wire, particularly of small diameter, iseasily damaged.8.3.2 Select the number of spools that will give a represen-tative sampling, as agreed upon between the purchaser and theseller.8.4 Number of Samples:8.4.1 Take samp
41、les from not less than 1 % of the spoolsfrom each lot.8.4.2 Take not less than three samples from each spool.9. Test Methods9.1 Chemical RequirementsPerform chemical analysis us-ing an emission spectrograph or other method having equiva-lent sensitivity. Cross-check individual constituents (forexamp
42、le, copper or beryllium) by using atomic absorptionspectrometric or other appropriate quantitative analyticalmethod. The seller and the purchaser must agree upon analyti-cal techniques to be employed.9.2 Breaking Load and ElongationApply the tension testin accordance with Test Methods F219.9.3 Wire
43、DiameterMeasure the wire diameter by one ofthe following methods:9.3.1 Measure the diameter directly with apparatus andprocedure in accordance with Test Methods E16. Becauseannealed gold wire is very soft, exercise caution when usingthe direct-measurement method to prevent deformation of thewire.9.3
44、.2 Measure the wire diameter indirectly by weighing inaccordance with Test Method F205.9.3.2.1 When the weight determination method is used, thefollowing values shall be employed: gold density19.34g/cm3; weight of a 200-mm length of wire of 25.4-m(0.00100-in.) diameter1.96 mg.9.3.2.2 Calculation of
45、Diameter from WeightWhen goldwire is weighed in 200-mm lengths, calculate the diameter asfollows:D m! 5 =W/1.96! 325.4D in! 5 =W/1.96! 30.001TABLE 7 Breaking Load and Elongation of Stress Relieved/Annealed Wire-Special PurposeANominalDiameter,m (in.)Breaking Load,min,N(gf)Elongation in254 mm (10.0 i
46、n.), %Min Max RangeB13 (0.00050) To be determinedbetween wire userand wiremanufacturer0.5 3.0 1.518 (0.00070) 0.5 7.0 2.020 (0.00080) 0.5 8.0 2.023 (0.00090) 0.5 8.0 2.025 (0.0010) 0.5 10.0 2.028 (0.0011) 0.5 10.0 2.030 (0.0012) 0.5 10.0 2.031.8 (0.00125) 0.5 10.0 2.033 (0.0013) 0.5 10.0 2.038 (0.00
47、15) 0.5 12.0 2.051 (0.0020) 0.5 15.0 2.0AAll modern wire are expected to have a somewhat longer shelf life, but eachmanufacturers product will be slightly different.BA range of permissible elongation of at least the number of percentage pointsshown shall be selected from within the overall range des
48、ignated by the minimumand maximum values for the given diameter. For example, for wire of 25-m(0.0010-in.) diameter, a permissible elongation of 4.0 to 6.0, 6.0 to 8.0, 7.0 to9.0 %, etc., may be selected.TABLE 8 Dimensional TolerancesNominalDiameter,m (in.)Standard Tolerance Special Purpose Toleranc
49、e%ofNominalDiameter%ofNominal Weight%ofNominalDiameter%ofNominal Weight13 (0.00050) 6 15 +6 2 +1 10Over 13 to 25(over 0.0005 to0.0010), incl3 10 +6 2 +1 6Over 25 to 51(over 0.0010 to0.0020)3 6 +3 0.5 +1 4F72173where:D = diameter, andW = mass, mg/200 mm.9.4 Finish:9.4.1 Visual ExaminationPerform visual examination us-ing an optical binocular microscope in accordance with Prac-tice F584.9.4.2 Use a scanning electron microscope to determine thedepth of surface blemishes.9.5 Wire Curl Test:9.5.1 This test should be regarded as
