Ngokumalunga nokuhlelwa kwe-PCB kunye nengxaki ye-wiring, namhlanje asiyi kuthetha ngohlalutyo lwengqibelelo yomqondiso (SI), uhlalutyo lokuhambelana kwe-electromagnetic (EMC), uhlalutyo lwentembeko yamandla (PI). Ukuthetha nje malunga nohlalutyo lwe-manufacturability (DFM), uyilo olungenangqiqo lokwenziwa kwezinto luya kubangela ukungaphumeleli koyilo lwemveliso.
I-DFM ephumeleleyo kuyilo lwePCB iqala ngokumisela imithetho yoyilo ukuze iphendule ngemiqobo ebalulekileyo ye-DFM. Imithetho ye-DFM eboniswe ngezantsi ibonisa ezinye zezakhono zoyilo lwangoku ezinokufunyanwa ngabavelisi abaninzi. Qinisekisa ukuba imida ebekwe kwimithetho yoyilo ye-PCB ayiphuli ukuze uninzi lwezithintelo zoyilo olusemgangathweni ziqinisekiswe.
Ingxaki ye-DFM yomzila we-PCB ixhomekeke kulungiselelo oluhle lwe-PCB, kunye nemigaqo yomzila inokumiselwa kwangaphambili, kuquka nenani lamaxesha okugoba omgca, inani lemingxuma yokuqhuba, inani lamanyathelo, njl. Ngokuqhelekileyo, i-wiring yokuhlola iqhutywa. ngaphandle kuqala ukudibanisa imigca emifutshane ngokukhawuleza, kwaye emva koko i-labyrinth wiring iqhutywa. Ukulungelelaniswa kweendlela zomhlaba jikelele kuqhutyelwa kwiintambo eziza kubekwa kuqala, kwaye ukuphinda kufakwe i-wiring kuzanywa ukuphucula umphumo jikelele kunye nokuveliswa kwe-DFM.
Izixhobo ze-1.SMT
Isithuba soyilo lwesixhobo siyahlangabezana neemfuno zendibano, kwaye sikhulu ngokubanzi kune-20mil yezixhobo ezinyuselwe phezulu, i-80mil yezixhobo ze-IC, kunye ne-200mi yezixhobo ze-BGA. Ukuze kuphuculwe umgangatho kunye nemveliso yenkqubo yokuvelisa, isithuba sesixhobo sinokuhlangabezana neemfuno zendibano.
Ngokubanzi, umgama phakathi kweepads ze-SMD zezikhonkwane zesixhobo kufuneka ube mkhulu kune-6mil, kunye nomthamo wokwenziwa kwebhulorho ye-solder yi-4mil. Ukuba umgama phakathi kweepads ze-SMD ungaphantsi kwe-6mil kwaye umgama phakathi kwefestile ye-solder ungaphantsi kwe-4mil, ibhuloho ye-solder ayikwazi ukugcinwa, okubangela iinqununu ezinkulu ze-solder (ingakumbi phakathi kwezikhonkwane) kwinkqubo yendibano, eya kukhokelela kwisekethe emfutshane.
Isixhobo se-2.DIP
Kufuneka kuthathelwe ingqalelo isithuba sephini, isalathiso kunye nesithuba sezixhobo ezikwinkqubo yokuthengiswa kwamaza. Isithuba esinganelanga sephini yesixhobo siya kukhokelela kwi-solder tin, eya kukhokelela kwisiphaluka esifutshane.
Abaqulunqi abaninzi banciphisa ukusetyenziswa kwezixhobo ze-in-line (THTS) okanye bazibeke kwicala elifanayo lebhodi. Nangona kunjalo, izixhobo ze-intanethi zihlala zingenakuphepheka. Kwimeko yokudibanisa, ukuba isixhobo esise-line sibekwe kumaleko angaphezulu kunye nesixhobo se-patch sibekwe kumaleko asezantsi, kwezinye iimeko, siya kuchaphazela i-soldering yecala elinye. Kule meko, iinkqubo ze-welding ezibiza kakhulu, ezifana ne-welding ekhethiweyo, zisetyenziswa.
3.umgama phakathi kwamacandelo kunye nomphetho wepleyiti
Ukuba umatshini ukuwelda, umgama phakathi amacandelo elektroniki kunye emphethweni webhodi ngokuqhelekileyo 7mm (abavelisi ezahlukeneyo ukuwelda kufuneka iimfuno ezahlukeneyo), kodwa oko nako kongezwa kumda wenkqubo yokuvelisa PCB, ukuze amacandelo elektroniki ibekwe emphethweni webhodi yePCB, ukuba nje ikulungele ukufakwa kweengcingo.
Nangona kunjalo, xa umphetho weplate udityanisiwe, unokuhlangana nomzila wesikhokelo somatshini kwaye wonakalise amacandelo. I-pad yesixhobo ekupheleni kweplate iya kususwa kwinkqubo yokuvelisa. Ukuba i-pad incinci, umgangatho we-welding uya kuchaphazeleka.
4.Umgama wezixhobo eziphezulu / eziphantsi
Kukho iintlobo ezininzi zezixhobo ze-elektroniki, iimilo ezahlukeneyo, kunye nemigca yelothe eyahluka-hlukeneyo, ngoko ke kukho umahluko kwindlela yokuhlanganisana kweebhodi eziprintiweyo. Uyilo olulungileyo alunakwenza kuphela umatshini wokusebenza okuzinzile, ubungqina bokuthuthumela, ukunciphisa umonakalo, kodwa unokufumana umphumo ococekileyo kunye nomhle ngaphakathi kumatshini.
Izixhobo ezincinci kufuneka zigcinwe kumgama othile malunga nezixhobo eziphezulu. Umgama wesixhobo ukuya kumlinganiselo wobude besixhobo uncinci, kukho i-wave ye-thermal engalinganiyo, enokubangela umngcipheko we-welding embi okanye ukulungiswa emva kwe-welding.
5.Isixhobo kwisithuba sesithuba
Ngokuqhelekileyo ukuqhutyelwa kwe-smt, kuyimfuneko ukuqwalasela iimpazamo ezithile ekufakweni komatshini, kwaye uthathele ingqalelo ukulungeleka kokugcinwa kunye nokuhlolwa okubonakalayo. Amacandelo amabini ameleneyo akufanele asondele kakhulu kwaye umgama othile okhuselekileyo kufuneka ushiywe.
Isithuba phakathi kwamacandelo eflake, SOT, SOIC kunye neflake components yi-1.25mm. Isithuba phakathi kwamacandelo eflake, SOT, SOIC kunye neflake components yi-1.25mm. I-2.5mm phakathi kwe-PLCC kunye ne-flake components, i-SOIC kunye ne-QFP. 4mm phakathi kwe-PLCCS. Xa uqulunqa iziseko ze-PLCC, kufuneka kuthathelwe ingqalelo ukuvumela ubungakanani besiseko se-PLCC (iphini ye-PLCC ingaphakathi kwezantsi kwesiseko).
6.Ububanzi bomgca/umgama womgca
Kubaqulunqi, kwinkqubo yoyilo, asikwazi kuphela ukuqwalasela ukuchaneka kunye nokugqibelela kweemfuno zoyilo, kukho umqobo omkhulu yinkqubo yokuvelisa. Akunakwenzeka ukuba umzi-mveliso webhodi wenze umgca omtsha wokuvelisa ukuzalwa kwemveliso elungileyo.
Ngaphantsi kweemeko eziqhelekileyo, ububanzi bomgca womgca wehla bulawulwa kwi-4 / 4mil, kwaye umngxuma ukhethwa ukuba ube yi-8mil (0.2mm). Ngokusisiseko, ngaphezu kwe-80% yabavelisi bePCB banokuvelisa, kwaye iindleko zemveliso zezona ziphantsi. Ubuncinci bobubanzi bomgca kunye nomgama womgca ungalawulwa ukuya kwi-3/3mil, kunye ne-6mil (0.15mm) inokukhethwa ngomngxuma. Ngokwesiseko, ngaphezu kwe-70% abavelisi bePCB banokuyivelisa, kodwa ixabiso liphezulu kancinci kunemeko yokuqala, alikho phezulu kakhulu.
7.Iengile ebukhali/iEngile yasekunene
Indlela ye-Engile ebukhali ayivumelekanga jikelele kwiingcingo, indlela yeEngile yasekunene iyafuneka ngokubanzi ukunqanda imeko kwindlela yePCB, kwaye iphantse yaba ngomnye wemigangatho yokulinganisa umgangatho wocingo. Ngenxa yokuba ingqibelelo yomqondiso ichaphazelekayo, i-wiring ye-angle-angle iya kuvelisa i-parasitic capacitance eyongezelelweyo kunye ne-inductance.
Kwinkqubo yokwenza ipleyiti ye-PCB, iingcingo ze-PCB zinqumlana kwi-Angle ebukhali, nto leyo eya kubangela ingxaki ebizwa ngokuba yi-Angle ye-asidi. Kwikhonkco le-etching yesekethe ye-pcb, ukubola okugqithisileyo kwesekethe ye-pcb kuya kubangelwa "kwi-Angle ye-asidi", okukhokelela kwingxaki yekhefu yesekethe ye-pcb. Ke ngoko, iinjineli zePCB kufuneka ziphephe ii-engile ezibukhali okanye ezingaqhelekanga kwi-wiring, kwaye zigcine i-Angle ye-45 degree kwikona ye-wiring.
8.I-Copper strip / isiqithi
Ukuba isiqithi esikhulu esaneleyo sobhedu, siya kuba yi-antenna, enokubangela ingxolo kunye nokunye ukuphazamiseka ngaphakathi kwebhodi (kuba ubhedu lwayo alusekelwanga - luya kuba ngumqokeleli wesignali).
Imicu yobhedu kunye neziqithi zininzi ezisicaba zobhedu oludadayo olukhululekileyo, olunokubangela iingxaki ezinzulu kwi-asidi. Amabala amancinci obhedu aye aziwa ukuba aphule ipaneli yePCB kwaye ahambe kwezinye iindawo ezifakwe kwipaneli, ebangela isiphaluka esifutshane.
9.Iringi yemingxuma yokugrumba
Iringi yomngxuma ibhekisa kwisangqa sobhedu esijikeleze umngxuma wokubhoboza. Ngenxa yokunyamezelana kwinkqubo yokuvelisa, emva kokugrumba, i-etching, kunye ne-copper plating, i-ring copper eseleyo ejikeleze umngxuma wokubhobhoza ayisoloko ibetha indawo esembindini ye-pad ngokugqibeleleyo, enokubangela ukuba umngxunya uphuke.
Elinye icala leringi yomngxuma kufuneka libe likhulu kune-3.5mil, kwaye ikhonkco lomngxunya leplagi kufuneka libe likhulu kune-6mil. Iringi yomngxuma incinci kakhulu. Kwinkqubo yokuvelisa kunye nokuvelisa, umgodi wokugaya unokunyamezela kunye nokulungelelaniswa komgca kunokunyamezela. Ukuphambuka kokunyamezela kuya kukhokelela kwindandatho yomngxuma eqhekeza isiphaluka esivulekileyo.
10.Ukukrazuka kwee-wiring
Ukongeza iinyembezi kwi-wiring ye-PCB kunokwenza uqhagamshelwano lwesekethe kwibhodi ye-PCB luzinzile, luthembeke kakhulu, ukuze inkqubo iya kuzinza ngakumbi, ngoko kuyimfuneko ukongeza iinyembezi kwibhodi yesekethe.
Ukongezwa kwamathontsi okukrazula kunokuphepha ukuqhawulwa kwendawo yokudibanisa phakathi kocingo kunye nephedi okanye ucingo kunye nomngxuma wokulingwa xa ibhodi yesekethe ichaphazeleka ngamandla amakhulu angaphandle. Xa ukongeza amathontsi eenyembezi kwi-welding, inokukhusela i-pad, inqande ukuwelda okuninzi ukwenza ipad iwele, kwaye unqande ukulinganisa okungalinganiyo kunye nokuqhekeka okubangelwa kukuphambuka komngxuma ngexesha lemveliso.
