ASTM_F_584_-_87_1999.pdf

Designation:F 584 87(Reapproved 1999)Standard Practice forVisual Inspection of Semiconductor Lead-Bonding Wire1This standard is issued under the fixed designation F 584;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(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice covers conditions for nondestructive visualinspection of the surface finish of spooled aluminum and goldwire used for making internal semiconductor device connec-tions and hybrid microelectronic connections.1.2 This practice specifies the recommended lighting,mag-nification,and specimen positioning for inspecting spooledwire under an optical microscope.1.3 Photographs(Figs.X1.1-X1.5)are included in Appen-dix X1 as guides to aid the inspector in identifying particularsurface conditions.These photographs are not intended asstandards for specifying wire surface quality.1.4 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.5 This standard does not purport to address all of thesafety 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 aplicabil-ity of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2F 72 Specification for Gold Wire for Semiconductor LeadBondingF 487 Specification for Fine Aluminum-1%Silicon Wirefor Semiconductor Lead-BondingF 638 Specification for Fine Aluminum-1%MagnesiumWire for Semiconductor LeadBonding2.2Federal Standard:Fed.Std.No.209B Clean Room and Work Station Require-ments,Controlled Environment33.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 chatter marksfor the purposes of this practicerepetitive closely spaced wire surface blemishes.3.1.2 dark areafor the purposes of this practicewiresurface shadowed from direct light-source illumination.3.1.3 fingerprintfor the purposes of this practiceresidual surface contamination deposited during handling.4.Summary of Practice4.1 The wire spool to be inspected is first mounted on aholding fixture that permits rotation of the spool about its axis.The spool fixture is then placed on the stage of a binocularmicroscope.The wire surface is illuminated with light incidentat a grazing angle;the microscope and fixture are positioned sothat the microscope field shows the partially shadowed wirewrap just adjacent to the brilliantly lit surface at the top of thespool.4.2 Inspection is accomplished by slowly rotating the spoolabout its axis and moving the fixture over the microscope stageuntil the operator has viewed the entire exposed wire surfacearea under partially shadowed illumination.4.3 The defects to be identified,the manner in which theirpresence is reported,and the manner in which the wire surfacequality is to be characterized should be agreed upon by theparties to the inspection.NOTE1Viewing a wire spool in the partial shadow of glancingillumination is particularly revealing of surface flaws and soil.Theviewing arrangement amounts to dark-field illumination with imperfec-tions appearing as bright glints on the wire surface.5.Significance and Use5.1 Spooled wire viewed under bright direct lighting or indeep shadow generally exhibits a flawless appearance.Properarrangement of the viewing angle and illumination,however,permits accurate observation of wire-surface condition.This1This practice is under the jurisdiction of ASTM Committee F01 on Electronicsand is the direct responsibility of Subcommittee F01.07 on InterconnectionBonding/Carrier Bonding.Current edition approved Oct.30,1987.Published December 1987.Originallypublished as F 584 78.Last previous edition F 584 82.2For 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,Bldg.4 Section D,700Robbins Ave.,Philadelphia,PA 19111-5094,Attn:NPODS.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.practice specifies the conditions under which reliable andreproducible surface finish inspection may be achieved.Suchinspection is appropriate for evaluating surface quality withrespect to the requirements in Specifications F 72,F 487,andF 638.5.2 Surface smoothness and degree of cleanliness mayaffect the performance of wire.This practice may be used todetermine whether or not spooled wire meets performance-based surface finish criteria agreed upon between a manufac-turer or supplier and a wire purchaser.5.3 The magnification recommended may not be sufficientto permit detection of all defects on the wire surface aff