1、Designation: F 72 06Standard Specification forGold Wire for Semiconductor Lead Bonding1This standard is issued under the fixed designation F 72; 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
2、 parentheses indicates the year of last reapproval. A superscriptepsilon (e) 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 a
3、re 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 co
4、ntrolled 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 i
6、s 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
7、 address all of the safety concerns, if any,associated with its use. It is the responsibility of the user of thisstandard to establish appropriate safety and health practicesand determine the applicability of regulatory limitations priorto use.2. Referenced Documents2.1 ASTM Standards:2E16 Method of
8、 Free Bend Test for Ductility of Welds3F 205 Test Method for Measuring Diameter of Fine Wire byWeighingF 219 Test Methods of Testing Fine Round and Flat Wirefor Electron Devices and LampsF 584 Practice for Visual Inspection of SemiconductorLead-Bonding Wire3. Ordering Information3.1 Orders for mater
9、ial 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, stress relieved, or annealed (Section 5),3.1.5 Breaking load and percentage elonga
10、tion 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 Packaging and marking (Section 12).4. Chemical Composition4.1 Beryllium-modified mater
11、ial 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 withTable 3.NOTE 2Copper-modified wire is used on thermocompression wirebonding machines. B
12、eryllium-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.1This specification is under the jurisdiction of ASTM Committee F01 onElectronics an
13、d is the direct responsibility of Subcommittee F01.07 on WireBonding, Flip Chip, and Tape Automated Bonding.Current edition approved Jan. 1, 2006. Published March 2006. Originallyapproved in 1966. Last previous edition approved in 2001 as F 72 95 (2001).2For referenced ASTM standards, visit the ASTM
14、 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.3Withdrawn.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2
15、959, United States.5. Mechanical Properties5.1 Material 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 mechan
16、ical properties,and acceptance or rejection shall 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 thereq
17、uirements of Table 5 for beryllium-modified gold wire, 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.
18、 Dimensions and Permissible Variations6.1 Wire diameters 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
19、 The wire surface shall be free of drawing/extrusionlubricant residues, particulate matter and other contaminantsthat 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 surfac
20、e contamination 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. TheTABLE
21、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 Requirements, High-Strength Gold BondingWireElement Composition, Weight, %Gold,
22、min 99.99Total of all detectable impurities, max 0.01TABLE 3 Chemical Requirements, Special Purpose GoldBonding WireElement Composition, Weight, %Gold Not restrictedOther principal elements Not restrictedTotal of all detectable elements Not restrictedTABLE 4 Breaking Load and Elongation of Hard Wire
23、Beryllium-Modified Gold and High-Strength GoldANominal Diameter,m (in.)Breaking Load, min, N(gf)Elongation in 254 mm10.0 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 (9.0) 0.5 to 2.0, incl23 (0.00090) 0.147 (15.0) 1.0 to 2.5, incl25 (0.0
24、010) 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 to 2.5, incl51 (0.0020) 0.736 (75.0) 1.0 to 3.0, inclAAll modern wires
25、 are expected to have a somewhat longer shelf life, but eachmanufacturer;s product will be slightly different.TABLE 5 Breaking Load and Elongation of Stress Relieved/Annealed WireBeryllium-Modified GoldANominalDiameter,m (in.)Breaking Load,min,N(gf)Elongation in 254 mm(10.0 in.), %Min Max RangeB13 (
26、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 10.0 331.8 (0.00125) 0.108 (11.0) 0.5 10.0 333 (0.0013) 0.118 (12.0) 0
27、.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 elongation of at least the number of percentage pointsshown shall be sel
28、ected 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 selected.TABLE 6 Breaking Load and Elongation of Stress Relieved/An
29、nealed WireHigh-Strength GoldANominal Diameter,m (in.)Breaking Load, min,N(gf)Elongation in 254 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) 0.064 (6.5) 0.5 6.025 (0.0010) 0.078 (8.0) 0.5 6.028 (0.0011) 0.093 (9.5
30、) 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 shelf life, but eachmanufacturers product will be slightly different.BEx
31、cept for 13 m, 38 m, and 51 m, the minimum-maximum range is usually3 percentage points, for example, 2 to 5, 3 to 6, and 4 to 7 %. For 13 m it isusually 1.5 percentages points, for example, 0.5 to 2, 1 to 2.5, and 1.5 to 3 %. For38 m and 51 m it is usually 4 percentage points, for example, 0.5 to 4.
32、5, 1 to 5,2to6,and3to7%.F72062surface shall be free 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 ismeasur
33、ed by the springback test (9.5).7.6 The wire must 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 a
34、nd purchaser.7.7 The wire cross section must not 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 “functi
35、onal performance” be narrowly construed asfollows: 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 considera
36、bly, depending uponapplication.8. Sampling8.1 Unless otherwise agreed, conformance with Section 5shall be determined by samples from each lot of wire.8.2 Lot Sampling A 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 o
37、f wire used for testing may not be useful forproduction. 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 an
38、d theseller.8.4 Number of Samples:8.4.1 Take samples 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 analysisusing an emission spectrograph or other method having equiva-lent sensitivity
39、. Cross-check individual constituents (for ex-ample, 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 t
40、estin accordance with Test Methods F 219.9.3 Wire Diameter Measure the wire diameter by one ofthe following methods:9.3.1 Measure the diameter directly with apparatus andprocedure in accordance with Test Methods F 16. Becauseannealed gold wire is very soft, exercise caution when usingthe direct-meas
41、urement method to prevent deformation of thewire.9.3.2 Measure the wire diameter indirectly by weighing inaccordance with Test Method F 205.9.3.2.1 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
42、(0.00100-in.) diameter1.96 mg.9.3.2.2 Calculation of Diameter from WeightWhen goldwire is weighed in 200-mm lengths, calculate the diameter asfollows:D m! 5 =W/1.96! 3 25.4D in! 5 =W/1.96! 3 0.001where:D = diameter, andW = mass, mg/200 mm.9.4 Finish:9.4.1 Visual ExaminationPerform visual examination
43、 us-ing an optical binocular microscope in accordance with Prac-tice F 584.9.4.2 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 destructive. After thewire is despooled to perform the test, the remainder of the wi
44、reon the spool will generally be too disturbed for use.9.5.2 Test must be performed in a well-lighted work areafree of air drafts.TABLE 7 Breaking Load and Elongation of Stress Relieved/Annealed Wire-Special PurposeANominalDiameter,m (in.)Breaking Load,min,N(gf)Elongation in 254 mm(10.0 in.), %Min M
45、ax 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 (0.0015) 0.5 12.
46、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 designated by
47、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 Tolerance%ofNominal
48、Diameter%ofNominal Weight%ofNominalDiameter%ofNominal Weight13 (0.00050) 66 615 + 6/2 + 1/10Over 13 to 25(over 0.0005 to0.0010), incl63 610 + 6/2 + 1/6Over 25 to 51(over 0.0010 to0.0020)63 66 + 3/0.5 + 1/4F720639.5.3 EquipmentA fixture capable of supporting wirespool with its axis horizontal, and th
49、at permits the spool torotate freely about its axis; metre stick; fine tweezers suitablefor holding wire end (see Fig. 1).9.5.4 Arrange the equipment as indicated schematically inFig. 1. Refer to Fig. 1 in performing the steps that follow.9.5.5 Procedure:9.5.5.1 Mount spool on fixture.9.5.5.2 Using the tweezers, break the “starting end” wireend from its securing tab (Section 11). Gently pull the wireend, thus rotating the spool and dereeling the wire. Pullingforce must not exceed 30 % of the wire breaking load. Pull thefree wire end do
