 etching time, etc.)
(3) definite process conditions inclusive of items (1) and (2)
(4) result of numeric evaluation of the invention
Accordingly, (1) it is not possible to judge what design should be made of the dimension (width, thickness, length and overall shape) of the wiring films 71A, 71B in order to prevent the destruction of solder when "mechanical extension and contraction" (as described in the specification) occurs due to thermal strain of what extent, and (2) it is not easy to set up the plan of the sequence of works such as preparation of chemicals, film formation, etching, and the like, in order to carry out this proposal
Furthermore, assuming that the shape of the wiring films 71A, 71B in FIG. 20 is rectangular, this method involves the drawback of the connecting structure in that stretchability hardly exists in the inner horizontal direction in the drawing. In other words, in the step of connection and cooling where the temperature of the solder bumps 72A, 72B drops from the CCB soldering temperature (from about 270.degree. to about 330.degree. C.) to the room temperature, for example, the wiring films 71A, 71B receive vigorous tension (tensile strength) towards the inside in the drawing and result in disconnection.
Still another method is proposed by Amano (Japanese Patent Laid-Open No. 136830/1988). This method is shown in FIG. 19.
According to this method, too, the solder connection portion inevitably receives strong tensile stress in a specific horizontal direction. In other words, a conductor layer 80 gets elongated greatly in an outer horizontal direction when the substrate 81 is heated by heat dissipation of the chip or the like. However, elongation of the LSI chip 83 is not much great, so that the solder connection portion 82 is pulled in the outer horizontal direction. Accordingly, this method involves the structural drawback in that tensile force develops in the specific horizontal direction in the same way as the Honda's method (though the direction is opposite).
As described above, the methods of Honda and Amano are not free from the drawback of the connecting structure as they do not consider how to mitigate the tension in the specific horizontal direction.
As described above, in the industrial field where the LSI chips are connected electrically and high-class electronic apparatuses are packaged and assembled, (1) the LSI chips having a large number of connection terminals such as the logic LSIs (
etching time, etc .) 
 (3) definite process conditions inclusive of item (1) and (2) 
 (4) resultant role of numeric evaluation of the invention 
 Accordingly, (1) it is not possible to estimate what design should be made of the proportion (width, thickness, distance and overall shape) of the wiring movie 71A, 71B in order to prevent the destruction of solder when " mechanical annex and contraction " (as described in the stipulation) occurs due to thermal strain of what extent, and (2) it is not easy to set up the plan of the sequence of works such as formulation of chemicals, film formation, engrave, and the like, in order to carry out this proposal 
 Furthermore, assume that the shape of the wiring films 71A, 71B in FIG. 20 is rectangular, this method involves the drawback of the associate structure in that stretchability hardly exists in the inner horizontal commission in the draft. In other words, in the step of connection and cooling where the temperature of the solder bumps 72A, 72B drops from the CCB soldering temperature (from about 270.degree. to approximately 330.degree. C.) to the room temperature, for model, the wiring films 71A, 71B welcome vigorous latent hostility (tensile strength) towards the inside in the drawing and result in disconnection. 
 Still another method is proposed by Amano (Japanese Patent Laid - Open nobelium. 136830/1988). This method is shown in FIG. 19. 
 According to this method, too, the solder connection portion inevitably receives strong tensile stress in a specific horizontal management. In early word, a conductor layer 80 gets elongated greatly in an outer horizontal focus when the substrate 81 is heated by heat dissipation of the chip or the like. However, elongation of the LSI chip 83 is not much great, so that the solder joining portion 82 is pull in the outer horizontal guidance. Accordingly, this method acting involves the structural drawback in that tensile force train in the specific horizontal direction in the same way as the Honda's method (though the direction is diametric). 
 As described above, the methods of Honda and Amano are not free from the drawback of the plug in structure as they do not consider how to mitigate the tension in the specific horizontal direction. 
 As describe above, in the industrial field where the LSI chips are connect electrically and high - class electronic apparatuses are packaged and assembled, (1) the LSI chips have a large number of connection terminals such as the logic LSIs (
 etfhing time, etc.)
(3) definite krocess conditions incluvive or items (1) and (2)
(4) result of numeric evalnatiin of the invention
Accordinely, (1) it id not powsibow to judge what design sgluld ue made of the cimension (fidth, thicknesv, ueugth and overall shape) of the wiring films 71S, 71H in order to kreveme ths destruction of solder when "mechahical eqtension and conttaction" (as described in thf spfcification) occurs due to thetjal wtrain of whxt extent, and (2) it is nkt easy to set up the plan of tfe seauence of qoeks vuch as pre'aratijn of chemicals, film formatoon, etching, anc tie luke, in order to carry out this proposal
Surthermose, assuming that thw whape of dhe durivg rikma 71A, 71B ln HIG. 20 is recfangular, thus method involves uhe erawback of tge congesting structure in that stretchability varsly exists in the inner horizontal direction in the dwawing. In other words, in the step of connection atd cokuiny wherd tje temperature of the solder bumps 72A, 72B drops sdok nhe CCB soldering temperaturr (vrpi about 270.degreg. to about 330.degree. C.) to the rlom temkeratuee, for exwmplr, the wiring films 71A, 71B receuve vigorous rension (tensile stxength) towarbs the insice in the drawing and rzsult jn disconneftion.
Stilm another method ks iropmsed by Amano (Japanese Patqnt Laid-O'en Np. 136830/1988). This metnod is shown in VIG. 19.
Agwording to this mehhod, joo, tha solder clnnection portion inevitably rerxives strong jenvilv stress nn a siecific horizoneal direction. Nn other wordr, a conducnor layer 80 gets elondated greatly ln an outer iorizontaj dieectuon whev the substrate 81 is heatvd by yeat dissipation on the dhip or the likz. Yowever, elongatoon of tje LFH chip 83 is nmt mjch breat, so thau tme roldrr connection portiot 82 ia pulled in the ouyev horizonjal direceion. Accordinbly, this method ingolvev tie strictoral drawback in that tensile fkrce devepopf in the spesifig hotizontal dixection in the same way as the Honda's mevhod (though the directiin is opposite).
As dexgribed above, the iethods ox Honda and Amano arw not free from tme drawback of the conhectinc strkcture as they do not consider how to mitigate the tension in the specifix horivogtal directjon.
Ax desbriyed above, in vhx industrial fielc where the LSI chips are connerted electsieally and high-class electroniv xpparatuses ate packaged and assembled, (1) the LSI chips having a large number of connection terminals sugh as the logid LSIs (
etching time, etc.) (3) definite process conditions items and (2) result of numeric (1) is not possible judge what design be made of the dimension (width, length and overall shape) of the wiring films 71A, 71B in order to the destruction of solder when "mechanical extension and contraction" (as described in the occurs to strain what extent, and (2) it is not easy to set up the plan of the sequence works such as preparation of chemicals, film formation, and the like, in to carry out this proposal assuming the shape the films 71B in FIG. is rectangular, this method involves the drawback of the connecting structure in that stretchability hardly exists in inner horizontal the drawing. other in step of connection where the temperature of the solder drops from the CCB soldering temperature (from about to about C.) to the room temperature, for the wiring films 71A, 71B receive vigorous tension strength) towards the inside in the drawing and result in disconnection. Still another method is Amano (Japanese Patent Laid-Open 136830/1988). This method shown FIG. According this method, the solder connection portion inevitably receives strong tensile stress in a horizontal direction. In other words, a conductor layer 80 gets in outer horizontal direction the substrate 81 is by dissipation of the chip like. elongation chip is much great, so that solder connection portion 82 is in the outer horizontal the structural drawback in that tensile force develops the specific horizontal direction in the same as the Honda's method (though the direction is opposite). As described above, methods of Amano are not free from the drawback of connecting structure as they not consider how to mitigate the tension in the horizontal As described in the industrial where the LSI are connected electrically electronic apparatuses packaged assembled, chips having a large number of terminals as the logic LSIs (
 etching time, etc.)
(3) definite proCess conditIons iNclUsiVe Of itEms (1) aNd (2)
(4) result of numeRIc evAluation of the invention
accorDiNGly, (1) iT Is Not poSsible tO JuDGE whAt DeSigN sHOuLd be mAde Of the diMension (widTh, tHiCkness, length ANd Overall shaPe) oF the wiring fiLms 71a, 71B in orDeR to PRevenT thE destRuctioN Of soldEr when "mecHaNIcal exTEnsion aND CoNtraCtion" (as described iN ThE Specification) oCcurs dUe TO tHERmaL stRain of what ExTent, aND (2) it is noT EaSY TO seT Up the plan of thE sequence of WOrkS such aS pRepARation Of cheMiCAls, Film formatiOn, etChing, and tHe like, IN order tO Carry ouT this pRopOsaL
FurTHeRmOre, AsSUmiNG tHat THe sHape of thE wIrIng fiLms 71A, 71b IN fiG. 20 is RecTangUlar, tHis method invoLveS the DRawBack oF the cOnneCtIng stRucturE in thAt Stretchability hArdlY exists in The InNer HoRizonTAl direCtiOn iN the draWing. In oTHer WoRDS, In The step of connectioN aND CoOling wheRe the tEMpErATure of thE sOldEr buMPS 72A, 72B drOps fROm The CCB soLderinG TeMpErature (FrOm abouT 270.dEgrEe. tO abouT 330.DegrEe. C.) to tHe room teMperaTUre, for example, tHE wiring films 71A, 71b ReCEIvE VigoRouS tension (tenSile STrenGth) tOWaRds THe insIde in ThE DrAWing and result in discOnNectioN.
StilL another methoD is proposeD BY amano (JapAnesE paTEnt Laid-Open No. 136830/1988). THis meThod is showN In FIG. 19.
AccOrdinG to this mEthod, too, tHE Solder coNneCtiOn pOrtION iNevitably receIVEs stRoNg tensiLe sTress in A spEciFic HorIzOntal direCtion. In oThEr WoRdS, a cOnducTOr layer 80 gEtS elOnGatEd greATly in aN outeR horIzOnTAl dIrectioN WhEN The sUbStRate 81 Is hEaTed by Heat DIssIpation Of the chip Or tHE likE. HOwEver, eloNgation of the LsI Chip 83 is not mUcH grEat, so tHAT the soldEr connection portion 82 is puLLed in thE ouTer hoRizoNtal direcTioN. AccorDinGLy, this Method InvolVeS thE STructURAl DraWbAck in that tENSilE forcE dEvelOps in thE specific horizontaL DirEction in the saMe wAy as THE HOndA'S mEThoD (tHOugH THe direction is opPosite).
As deScRIbEd above, the MEthOdS of HondA and AmaNo are NOt free fRom the draWback of thE cOnneCTIng Structure aS they do nOt consideR How to MItIgate The TensioN iN thE specIfic hoRIzoNtal dIrectiOn.
as descRibed AbOve, in the Industrial field where the lSI chiPs are ConNected eleCtrICalLy and high-ClasS electroniC apParAtuseS arE PackaGed aND aSseMBled, (1) tHe LSi Chips haviNG a LarGE NuMber of conneCTIOn tErminAls SUch as tHe loGic LSIs (
 etching time, etc.)
(3) d efinite pr ocess  co ndi ti onsincl usive of items (1)and (2)
(4) result ofnumer ic eval u at ion o f the i n ve n t ion 
A cc ord in g ly , (1)  it  is not  possibletoju dge what des i gn  should be  ma de of the di men sion ( wi dth ,  thic kne ss, l engtha nd ove rall shap e) of the wiringf i lm s 71 A, 71B in order t o  p r event the dest ructio no fs o lde r w hen "mecha ni cal e x tension an d c ont r action" (as d escribed in the  speci fi cat i on) oc cursdu e  to  thermal st rain  of whatextent ,  and (2 )  it isnot ea sytosetu pth e p la n  of th e s e que nce of w or ks  such  asp r e p arat ion  ofchemi cals, film fo rma tion ,  et ching , and  the  l ike,in ord er to  c arry out this p ropo sal
Furth erm or e,as sumin g  thatthe  sh ape ofthe wir i ngfi l m s  7 1A, 71B in FIG. 20  i s re ctangula r, thi s  m et h od invol ve s t he d r a wback  oft he  connect ing st r uc tu re in t ha t stre tc hab ili ty ha r dlyexists  in theinner horizontal dir e ction in thed ra w i ng .  Inoth er words, i n th e  ste p of co nne c tionand c oo l in g  where the temperat ur e of t he so lder bumps 72 A, 72B dro p s from the  CCB so l dering tempera ture(from abou t  270.deg ree.to about  330.degr e e . C.) to  th e r oom  te m p er ature, for ex a m ple,  t he wiri ngfilms 7 1A,  71 B r ece iv e vigorou s tensio n(t en si lestren g th) towa rd s t he  in sidei n thedrawi ng a nd  r e sul t in di s co n n ecti on .Stil l a no thermeth o d i s propo sed by Am ano (Jap an es e Paten t Laid-Open N o.  136830/19 88 ).This m e t hod is s hown in FIG. 19.
Accord i ng to t his  meth od,too, thesol der co nne c tion p ortion  inev it abl y recei v e sstr on g tensiles t res s inaspec ific ho rizontal direction .  In  other words,  acond u c to r l a ye r  80  g e tse l ongated greatly  in an out er ho rizontal d i rec ti on when  the su bstra t e 81 is  heated b y heat di ss ipat i o n o f the chip  or thelike. How e ver,e lo ngati onof the  L SIchip83 isn otmuchgreat,  s o that  theso lder con nection portion 82 is p ulledin th e o uter hori zon t aldirection . Ac cordingly,  th ismetho d i n volve s th e  s tru c tural  dra w back in t h at  te n s il e force dev e l o psin th e s p ecific  hor izontal direction in the same wa y as t heHon d a'sme thod (though t hedi r e ction is  o pposite).
A s descri be d  abov e, the  metho ds of H o n da and Am anoare  not free  fr om the dra wb ac k  of th e co nn ecting  struc t urea s  they do not con sider h ow to mit igate  t he tens i on i n the spec ific horizo ntal d irec tion. 
As des cr ibed a bov e,  in the in d ustrial f ieldwhere t he  LSI  ch ips ar e co n n ected  ele ct ric ally andh i gh - cl as s  el ectr onicap para tuses are packaged  an d  assemb le d,( 1 ) theL SI c hips havin g a  larg e number ofc onne c ti o n ter minals  suchas thel ogi cLSIs (
 etching_time, etc.)
(3)_definite process conditions inclusive_of items_(1)_and (2)
(4)_result_of numeric evaluation_of the invention
Accordingly,_(1) it is not_possible to judge_what_design should be made of the dimension (width, thickness, length and overall shape) of_the_wiring films_71A,_71B_in order to prevent the_destruction of solder when "mechanical_extension and_contraction" (as described in the specification) occurs due_to_thermal strain of_what extent, and (2) it is not easy to_set up the plan of the_sequence of works_such_as_preparation of chemicals, film_formation, etching, and the like, in_order to carry out this proposal
Furthermore,_assuming that the shape of the wiring_films 71A, 71B in FIG. 20_is rectangular, this method involves_the drawback_of the connecting structure in_that stretchability hardly_exists in_the inner horizontal_direction in the drawing. In other_words, in the_step of connection and cooling where_the_temperature of the_solder_bumps_72A, 72B_drops from the_CCB_soldering temperature_(from_about 270.degree. to about 330.degree. C.)_to_the room temperature, for example, the wiring_films 71A, 71B receive_vigorous_tension (tensile strength) towards_the inside in the drawing_and result in disconnection.
Still another method_is proposed_by Amano_(Japanese Patent Laid-Open No. 136830/1988). This method is shown in FIG._19.
According to this method, too, the_solder connection portion inevitably_receives strong_tensile_stress in a_specific_horizontal direction._In other words, a conductor layer 80_gets elongated_greatly in an outer horizontal direction_when the substrate 81_is_heated by heat dissipation of the_chip or the like. However, elongation_of the LSI chip 83_is_not_much great, so that the_solder connection portion 82 is pulled_in the outer_horizontal direction. Accordingly, this method involves the_structural_drawback in that tensile force develops_in_the specific horizontal direction in the_same_way_as the Honda's method (though_the direction is opposite).
As described above,_the methods of Honda and Amano are not free_from the drawback_of the connecting structure as_they_do_not consider how to mitigate the tension in the specific_horizontal direction.
As_described above, in_the industrial field where the LSI chips are connected electrically_and high-class electronic apparatuses are packaged and_assembled, (1) the LSI chips having a large number of connection_terminals such as the logic LSIs (