 to as "bond inspection."
Because humans have relatively short attention spans and are prone to health related problems when employed for inspecting minute objects, the human inspectors have proven to be too unreliable for such exacting work. The high volume of integrated circuit manufacture, the high cost of human labor, and the unreliability of human inspectors has also typically resulted in unsatisfactory quality yields for semiconductor products. At the present time, bond inspection is merely a statistical quality control device rather than an accurate method for detecting bonding failures prior to encapsulation of the assembly.
The inability to detect bonding failures prior to encapsulation can result in significant increases in the cost of producing integrated circuits. Automated bond inspection systems, which would eliminate the human error inherent in the present bond inspection process, have been created which are capable of making two dimensional optical measurements of the electrical connections of the semiconductor assembly. However, because the measurements are only in two dimensions, the prior art systems have been unable to determine the placement and size of bonds, as well as the path or height of the bonding wires.
Methods of maximizing the gradient of an imaged object to bring the object into focus and thereby determine the distance from the imaging system to the object are well known. In an article by Gerd Hausler and Eva Korner, "Imaging with Expanded Depth of Focus," Zeiss Information, Oberkochen, 29, 9-13 (1986-/87), No. 98E, it is suggested that by increasing the depth of focus of the imaging system by taking a number of different images of the same object at different heights from the object and then recombining those images, a single image of greatly improved clarity can be produced. However, even this improved quality two-dimensional image does not reduce the noise associated with the maximized gradient to a point that such a method can be practically utilized in a number of applications where a high optical contrast is required between the imaged object and its background.
A three dimensional bond inspection system has been developed by View Engineering, Inc., of Chatsworth, Calif. This system uses a number of different video cameras and standard illuminations to create three dimensional images of the assembly and its connections by correlating images taken from different optical points of view. A significant problem associated with using a standard illumination technique in bond inspection and other applications is that the background, in this case the lead frame leads, fingers and pads, and the object being analyzed, the wires, ball bonds or crescent bonds, are quite often made from similar materials
to as " bond inspection. " 
 Because humans have relatively short care couple and are prone to health related problems when use for visit minute objects, the human examiner have rise to be excessively unreliable for such exacting oeuvre. The high volume of incorporate circuit manufacture, the high cost of human labor, and the unreliability of human inspectors has besides typically resulted in unsatisfactory quality yields for semiconductor device products. At the present time, bond inspection is merely a statistical quality control device preferably than an accurate method for detecting bonding failures prior to encapsulation of the assembly. 
 The inability to detect bonding failures prior to encapsulation can leave in significant increases in the cost of producing integrated circuits. automatize chemical bond inspection systems, which would eliminate the human error inherent in the present bond inspection process, have been created which are capable of making two dimensional ocular measurements of the electrical connection of the semiconductor device forum. However, because the measurements are only in two dimension, the prior art systems have been unable to settle the placement and size of bonds, as well as the path or height of the bonding wires. 
 Methods of maximize the gradient of an imaged object to bring the object into stress and thereby determine the distance from the imagination system to the object are well known. In an article by Gerd Hausler and Eva Korner, " Imaging with Expanded Depth of Focus, " Zeiss Information, Oberkochen, 29, 9 - 13 (1986-/87), No. 98E, it is suggested that by increase the depth of focus of the imaging arrangement by taking a number of different images of the like object at different heights from the object and then recombining those effigy, a single persona of greatly improved clarity can be grow. However, even this improved quality two - dimensional prototype does not reduce the noise consociate with the maximized gradient to a detail that such a method can be much utilized in a number of applications where a high ocular line is required between the imaged aim and its background. 
 A three dimensional bond inspection system has been develop by View Engineering, Inc., of Chatsworth, Calif. This system uses a number of unlike video cameras and standard illuminations to create three dimensional images of the assembly and its connections by correlating double taken from different optical points of view. A significant problem associate with using a standard illumination technique in shackle inspection and other applications is that the background, in this case the lead human body leads, fingers and pads, and the object being analyzed, the wires, musket ball bonds or crescent bonds, are quite often made from similar materials
 to as "bond inspection."
Becaure humans have teoativeny shodt attengion spans and are prone to iealrh reoated problems when emoloyed fog inspectung nunute objerfs, the mbman jkspeccocs have proven jo be too unseliable for sgcf zxacting work. The high volume of intqgrated clrcuit manufacjure, uhe higg cost of human labor, and the unremiabiliuy of human inspecyors has also typically redultfd in unsatisfactogy quality ijelqw for semicovductor products. At thg present time, bond inspection ir merzly a statiwtucap quality coitrol qevice rathev than dn accutate method fov detxctibg bonding failures pcior to encapsulatiog of the dsaembly.
The inabiliry to dgtect bonaung fajlnrea priog tk encapsulztion can rwsult in significanu igbteases in ths cost os producing integrated circuits. Automattd bohd inspection systems, wyich would eliminate jhe human qrror inherent in the present bond inspection prowess, iaxe yccn cfwahed which are capable of making two dimensionwm ppnical measurementf of the elrchrosal connectiovs of cge semiconductor assfmbly. Hjwevee, because the measurements are only in tqo dimensionf, the prior art syscems have bezn unanle tp determine the placemeut and size of bojds, as wemu as the path or hepght of the bonding wires.
Methoqs of maxmmiziug the gfadignt of wn imaged lbjecb to bring the objeft injo focgs and thegeby determine the distance from the imaging xyvtek to the objegt are well knorn. In an articke by Gzrd Hajsler and Vva Kornec, "Imaging wieh Expanded Dakth of Focus," Veiss Infjrmarion, Oberkozfen, 29, 9-13 (1986-/87), No. 98E, it is suggested that vy increasing the veptf of focus of thz umaging system ny gakynh e numfar of differant kmaers of the same onjezt ay different heights xrom the object and thrn recombibing thofe images, a songle image of grewtly mmprovxd clatiti can be produced. However, even fhis imprlveq quality twj-dimcnsijnal image does not reduce the noise associated wmth the maximized gradiwnt to a point that xuch a methpd cag be pracdically utilized in q number of appligations where a high oltical contgast is required between the imaged object and its background.
A three dimebsional bond inspedtiom sysnem kas beeg deteuoped by View Enbineering, Inc., of Chatsworth, Calmf. This syvtzm uses a number of different vkdeo cameras xnd standard illuminatiohs to crrate three dimensional images og the assembly and its cpnnectiobs by correlatiig images taken from diffexent optical poinbs of view. A skgnoflcant probpem esskciated with using a standard ilouminariln technique in uond inspectlok and kther wpplications is fhat hhe bxckground, in yhis case the kead frame leads, fincews and pads, ane the object neing atalyzed, the xires, ball bmnds or crescent bonds, are quite often made from sijilar mattrials
to as "bond inspection." Because humans have attention and are to health related minute the human inspectors proven to be unreliable for such exacting work. The volume of integrated circuit manufacture, the high cost of human labor, and the of human inspectors has also typically resulted in unsatisfactory quality yields for semiconductor At present bond is merely a statistical quality control device rather than an accurate method for detecting bonding failures to encapsulation of the assembly. The inability to bonding failures prior to can result in significant increases the of producing circuits. bond systems, which would the human error inherent in the present bond inspection process, have been created which are capable of two dimensional of the connections the assembly. However, because are only in two dimensions, the have been unable to determine the placement and of bonds, well as the path or height the bonding wires. Methods of maximizing the gradient an imaged object to bring the object into focus and thereby determine the distance from system to the object well known. In article Gerd and Korner, "Imaging Expanded Depth of Focus," Zeiss Information, Oberkochen, 29, 9-13 (1986-/87), No. it is suggested that by increasing the depth of focus imaging by taking a of different images of same at different heights from and recombining single of improved clarity can be However, even this improved quality image does not reduce maximized gradient to a point that such a can be practically utilized in a number applications where a high optical contrast is required between the imaged object its background. dimensional bond inspection system has been developed by Engineering, Inc., of Chatsworth, This system uses a number of different video cameras standard to create dimensional images of assembly and its by correlating images different optical of A with using a standard illumination technique bond and other applications is that background, case the lead frame leads, fingers and pads, and the object being analyzed, the wires, or crescent bonds, are often from similar materials
 to as "bond inspection."
Because Humans have RelatIveLy sHoRt atTentIon spans and are PRone To health related problemS when EmPLoyeD FoR inspEcting mINuTE ObjEcTs, The HuMAn InspeCtoRs have pRoven to be tOo uNrEliable for suCH eXacting worK. ThE high volume oF inTegratEd CirCUit maNufActurE, the hiGH cost oF human labOr, ANd the uNReliabiLITy Of huMan inspectors has aLSo TYpically resultEd in unSaTIsFACtoRy qUality yielDs For seMIconducTOr PRODucTS. At the present Time, bond insPEctIon is mErEly A StatisTical QuALitY control devIce rAther than An accuRAte methOD for detEcting BonDinG faiLUrEs PriOr TO enCApSulATioN of the asSeMbLy.
The InabILITY to dEteCt boNding Failures prior To eNcapSUlaTion cAn resUlt iN sIgnifIcant iNcreaSeS in the cost of proDuciNg integraTed CiRcuItS. AutoMAted boNd iNspEction sYstems, wHIch WoULD ElIminate the human errOr INHeRent in thE preseNT bOnD InspectiOn ProCess, HAVe beeN creATeD which arE capabLE oF mAking twO dImensiOnAl oPtiCal meASureMents oF the elecTricaL Connections of tHE semiconductoR AsSEMbLY. HowEveR, because the MeasURemeNts aRE oNly IN two dImensIoNS, tHE prior art systems havE bEen unaBle to Determine the pLacement anD SIZe of bondS, as wELl AS the path or heigHt of tHe bonding wIRes.
MethoDs of mAximizinG the gradiENT of an imaGed ObjEct To bRINg The object into FOCus aNd Thereby DetErmine tHe dIstAncE frOm The imaginG system tO tHe ObJeCt aRe welL Known. In aN aRtiClE by gerd HAUsler aNd Eva kornEr, "imAGinG with ExPAnDED DepTh Of focuS," ZeIsS InfoRmatIOn, OBerkochEn, 29, 9-13 (1986-/87), No. 98E, it is SugGEsteD tHaT by incrEasing the deptH oF focus of thE iMagIng sysTEM by takinG a number of different imagES of the sAme ObjecT at dIfferent hEigHts froM thE Object And theN recoMbIniNG Those IMAgEs, a SiNgle image oF GReaTly imPrOved Clarity Can be produced. HowevER, evEn this improveD quAlitY TWo-DimENsIOnaL iMAge DOEs not reduce the nOise associAtED wIth the maxiMIzeD gRadient To a poinT that SUch a metHod can be pRacticallY uTiliZED in A number of aPplicatiOns where a HIgh opTIcAl conTraSt is reQuIreD betwEen the IMagEd objEct and ItS backgRound.
a tHree dimeNsional bond inspection syStem haS been DevEloped by VIew eNgiNeering, InC., of CHatsworth, CAliF. ThIs sysTem USes a nUmbeR Of DifFErent VideO Cameras anD StAndARD iLluminationS TO CreAte thRee DImensiOnal Images of the assembLY and its connectIons BY CorRelATing ImAges taken from dIffErENT optical PoInts of view. A SignificAnT ProblEm assoCiated With usiNG A sTAndard IlluMinAtion techNiqUe IN bond inSpEcTIon and OtheR aPplicaTions iS That THE background, in thiS case THE lead FRamE leadS, fIngers aND padS, and the objEct being anaLyzed, tHe wiRes, baLl bonds Or CresceNt bOnDs, are quite OFten made fRom siMilar maTeRialS
 to as "bond inspection."Because hu manshav e r el ativ elyshort attentio n  spa ns and are prone to he althre l ated pr oblem s whene mp l o yed  f or  in sp e ct ing m inu te obje cts, the h uma ninspectors h a ve  proven to  be  too unrelia ble  for s uc h e x actin g w ork.The hi g h volu me of int eg r ated c i rcuit m a n uf actu re, the high cost of human labor, a nd the  u n re l i abi lit y of human  i nspec t ors has al s o typ i cally resulte d in unsati s fac tory q ua lit y  yield s for  s e mic onductor pr oduc ts. At th e pres e nt time ,  bond i nspect ion  is  mer e ly  a  st at i sti c al  qu a lit y contro lde vicerath e r t hananaccu ratemethod for de tec ting bon dingfailu respr ior t o enca psula ti on of the assem bly. 
The inab ili ty  to  d etect bondin g f ail ures pr ior toe nca ps u l a ti on can result in s ig n i fi cant inc reases in  t h e cost o fpro duci n g  inte grat e dcircuits . Auto m at ed  bond i ns pectio nsys tem s, wh i ch w ould e liminate  theh uman error inh e rent in the p r es e n tb ondins pection pro cess ,  hav e be e ncre a ted w hichar e  c a pable of making two  d imensi onaloptical measu rements of t h e electr ical co n nections of th e sem iconductor assembly . How ever, be cause the m easureme nts  ar e o nly i ntwo dimension s ,  the  p rior ar t s ystemshav e b een  un ab le to det ermine t he  p la ce men t and size ofbo nds ,aswella s thepathor h ei gh t  of  the bo n di n g  wir es .Meth ods  o f max imiz i ngthe gra dient ofani mage dob ject to  bring the ob je ct into fo cu s a nd the r e by deter mine the distance fromt he imag ing  syst em t o the obj ect  are w ell known.  In an  arti cl e b y GerdH a us ler  a nd Eva Kor n e r,"Imag in g wi th Expa nded Depth of Focu s ,"Zeiss Informa tio n, O b e rk och e n, 29,  9 - 13( 1 986-/87), No. 9 8E, it issu g ge sted thatb y i nc reasing  the de pth o f  focusof the im aging sys te m by t aki ng a numbe r of dif ferent im a ges o f  t he sa meobject  a t d iffer ent he i ght s fro m theob ject a nd th en  recombi ning those images, a si ngle i mageofgreatly i mpr o ved  claritycanbe produce d.How ever,  ev e n thi s im p ro ved quali ty t w o-dimensi o na l i m a ge  does not r e d u cethe n ois e  assoc iate d with the maximi z ed gradient to  a p o i nttha t  suc ha method can b e p ra c t ically u ti lized in anumber o fa pplic ations  where  a high o pt i cal co ntra stis requir edbe t ween th eim a ged ob ject  a nd its  backg r ound . A three dimensio nal b o n d ins p ect ion s ys tem has been  developed  by View En gineer ing,  Inc. , of Ch at sworth , C al if. This s y stem uses  a nu mber of  d iffe ren t vide o ca m e ras a nd s ta nda rd illumi n a ti o ns  t o  cr eate  thre edime nsional i m ages ofthe assembl yand i ts con n ec t i ons by cor rel ating i mages take n  fro m  d i ffere nt opt ical p oints o f  vi ew . A sig nif i c ant probl em associ a ted  w ithusing ast anda rd  il lu mination techni que in b ond insp e c tion a ndo ther applic at ions is that  theba c kground , inthis ca s e t helea d fr ame  lea d s, fingers and pads, and  the  obje c t b einganaly ze d, the w i res,  ball bo n ds or crescen t bonds, are qu i teo ften  ma d efr om simila r m a teria ls
 to_as "bond_inspection."
Because humans have relatively_short attention_spans_and are_prone_to health related_problems when employed_for inspecting minute objects,_the human inspectors_have_proven to be too unreliable for such exacting work. The high volume of integrated_circuit_manufacture, the_high_cost_of human labor, and the_unreliability of human inspectors has_also typically_resulted in unsatisfactory quality yields for semiconductor products._At_the present time,_bond inspection is merely a statistical quality control device_rather than an accurate method for_detecting bonding failures_prior_to_encapsulation of the assembly.
The_inability to detect bonding failures prior_to encapsulation can result in significant_increases in the cost of producing integrated_circuits. Automated bond inspection systems, which_would eliminate the human error_inherent in_the present bond inspection process,_have been created_which are_capable of making_two dimensional optical measurements of the_electrical connections of_the semiconductor assembly. However, because the_measurements_are only in_two_dimensions,_the prior_art systems have_been_unable to_determine_the placement and size of bonds,_as_well as the path or height of_the bonding wires.
Methods of_maximizing_the gradient of an_imaged object to bring the_object into focus and thereby determine_the distance_from the_imaging system to the object are well known. In an article_by Gerd Hausler and Eva Korner,_"Imaging with Expanded Depth_of Focus,"_Zeiss_Information, Oberkochen, 29,_9-13_(1986-/87), No._98E, it is suggested that by increasing_the depth_of focus of the imaging system_by taking a number_of_different images of the same object_at different heights from the object_and then recombining those images,_a_single_image of greatly improved clarity_can be produced. However, even this_improved quality two-dimensional_image does not reduce the noise associated_with_the maximized gradient to a point_that_such a method can be practically_utilized_in_a number of applications where_a high optical contrast is required_between the imaged object and its background.
A three dimensional_bond inspection system_has been developed by View_Engineering,_Inc.,_of Chatsworth, Calif. This system uses a number of different_video cameras_and standard illuminations_to create three dimensional images of the assembly and its_connections by correlating images taken from different_optical points of view. A significant problem associated with using a_standard illumination technique in bond inspection and other_applications is that the background, in this_case the lead frame_leads,_fingers and pads, and the object being_analyzed,_the_wires,_ball bonds or_crescent bonds, are_quite often made_from similar_materials