Ibhodi PCB ingxaki yesekethe emfutshane

Oyena nobangela mkhulu wesekethe emfutshane yePCB luyilo lwephedi olungafanelekanga. Ngeli xesha, i-pad yesetyhula ingatshintshwa ibe yi-elliptical shape ukunyusa umgama phakathi kwamanqaku, ukwenzela ukuba kuthintelwe imijikelezo emfutshane.

Uyilo olungafanelekanga lwamacandelo ebhodi ye-PCB luya kubangela isiphaluka esifutshane sebhodi yesekethe, okubangela ukungasebenzi. Ukuba i-pin ye-SOIC ihambelana ne-tin wave, kulula ukubangela ingozi yesiphaluka esifutshane. Kule meko, isalathiso senxalenye sinokuguqulwa sibe yi-perpendicular to wave tin.

Esinye isizathu kukuba ibhodi ye-PCB imfutshane, oko kukuthi, iyunithi ye-plug-in ezenzekelayo igobile. Njengoko i-IPC ichaza ukuba ubude bocingo bungaphantsi kwe-2mm, xa i-angle yokugoba inkulu kakhulu, inxalenye inkulu kakhulu kwaye kulula ukubangela isiphaluka esifutshane. I-solder joint ingaphezulu kwe-2mm kude nesekethe.

Ukongeza kwezi zizathu zintathu zingasentla, kukho ezinye izizathu ezinokubangela ukusilela kwisekethe emfutshane kwibhodi yePCB. Ngokomzekelo, umngxuma we-substrate mkhulu kakhulu, ukushisa kwesithando somlilo siphantsi kakhulu, i-solderability yendawo yebhodi ihlwempuzekileyo, imaski ye-solder ayisebenzi, kunye nebhodi. Ungcoliseko lomphezulu njlnjl. zizizathu eziqhelekileyo zokusilela. Injineli inokuphelisa kwaye ijonge ezi zizathu zingasentla kunye neempazamo nganye nganye.

Iindlela ezi-4 zokuphucula i-PCB esisigxina sesekethe emfutshane

I-short-circuit esisigxina ye-short-circuit short-circuit ye-PCB ibangelwa ikakhulu yimikrwelo kumgca wokuvelisa ifilimu okanye ukuvaleka kwenkunkuma kwiscreen esigqunyiweyo. Umaleko ogqunyiweyo wokuchasa ubhentsiswe kubhedu kwaye ubangela isekethe emfutshane kwiPCB. Uphuculo lolu lulandelayo:

Ifilimu kwifilimu akufanele ibe neengxaki ezifana ne-trachoma, imikrwelo, njl njl. Xa ibekwe, umphezulu wefilimu kufuneka ujonge phezulu kwaye akufanele uxutywe nezinye izinto. Xa ukopisha ifilimu, ifilimu ijongene nomphezulu wefilimu, kwaye ifilimu efanelekileyo ilayishwa ngexesha. Gcina kwisikhwama sefilimu.

Xa ifilimu ijongene, ijongene nomphezulu wePCB. Xa udubula ifilimu, thabatha i-diagonal ngezandla zombini. Sukuchukumisa ezinye izinto ukuphepha ukukrwela umphezulu wefilimu. Xa ipleyiti ifikelela kwinani elithile, ifilimu nganye kufuneka iyeke ukulungelelanisa. Khangela okanye ubuyisele ngesandla. Yifake kwisikhwama sefilimu esifanelekileyo kwaye uyigcine.

Abanini-zithuthi akufuneki banxibe naziphi na izinto zokuhombisa, ezifana nemisesane, izacholo, njalo njalo. Izikhonkwane kufuneka zichetywe kwaye zigcinwe egadini. Akukho nkunkuma kufuneka ibekwe phezu kwetafile, kwaye umphezulu wetafile kufuneka ucoceke kwaye ugudiswe.

Ngaphambi kokwenza uguqulelo lwesikrini, kufuneka ihlolwe ngokungqongqo ukuqinisekisa ukuba akukho ngxaki. Uguqulelo lwesikrini. Xa usebenzisa ifilimu emanzi, ngokuqhelekileyo kuyimfuneko ukujonga iphepha ukujonga ukuba kukho i-jam yephepha kwisikrini. Ukuba akukho sithuba sokushicilela, kufuneka uprinte isikrini esingenanto amaxesha amaninzi phambi kokushicilela ukuze obhityileyo kwi-inki anyibilikise ngokupheleleyo i-inki eqinileyo ukuqinisekisa ukuvuza okugudileyo kwesikrini.

PCB ibhodi indlela yokuhlola isiphaluka esifutshane

Ukuba i-welding manual, kuyimfuneko ukuphuhlisa imikhwa emihle. Okokuqala, jonga ngokubonakalayo ibhodi ye-PCB ngaphambi kokuba i-soldering, kwaye usebenzise i-multimeter ukujonga ukuba iisekethe ezibalulekileyo (ingakumbi umbane kunye nomhlaba) zifutshane. Okwesibini, thengisa i-chip ngalo lonke ixesha. Sebenzisa i-multimeter ukulinganisa ukuba unikezelo lwamandla kunye nomhlaba lufutshane. Ukongeza, musa ukuthengisa intsimbi xa udibanisa. Ukuba i-solder ithengiswa kwiinyawo ze-solder ze-chip (ingakumbi amacandelo e-mountain mount), akukho lula ukuyifumana.

Vula i-PCB ekhompyutheni, ukhanyise inethiwekhi ye-short-circuit, uze ubone ukuba ikufuphi kuyo kwaye kulula ukuyidibanisa. Nceda unike ingqwalasela eyodwa kwisekethe emfutshane yangaphakathi ye-IC.

Kwafunyanwa isiphaluka esifutshane. Thatha ibhodi ukusika umgca (ingakumbi ibhodi enye / kabini). Emva kokuqhawula, inxalenye nganye yebhloko yomsebenzi inikwe amandla ngokwahlukileyo, kwaye ezinye iindawo azibandakanyi.

Sebenzisa i-analyzer yendawo ye-short-circuit, efana ne-Singapore PROTEQ CB2000 i-short-circuit tracker, i-Hong Kong Ganoderma QT50 i-short-circuit tracker, i-British POLAR ToneOhm950 ibhodi ye-multi-layer ye-short-circuit detector.

Ukuba kukho i-chip ye-BGA, ekubeni onke amakhonkco e-solder awagqunywanga yi-chip, kwaye ibhodi ye-multi-layer (ngaphezu kwe-4 layers), kungcono ukusebenzisa amaso amagnetic okanye i-0 ohm ukwahlula amandla ngamnye. chip kuyilo. I-resistor idibaniswe ukwenzela ukuba xa umbane ufutshane-ujikelezwe emhlabeni, amaso amagnetic afunyenwe kwaye kulula ukufumana i-chip ethile. Ngenxa yokuba i-BGA inzima ukuyithengisa, ukuba ayiyiyo i-soldering ye-othomathikhi yomatshini, amandla akufutshane kunye neebhola ze-solder zomhlaba ziya kunqanyulwa ngononophelo.

Lumka xa i-soldering iiyure-enkulu kunye nencinci i-mountain mount capacitors, ngakumbi i-capacitors yamandla okucoca amandla (103 okanye i-104), inokubangela ngokulula isekethe emfutshane phakathi kombane kunye nomhlaba. Ewe, ngamanye amaxesha ngethamsanqa elibi, i-capacitor ngokwayo iya kujikeleza imfutshane, ke eyona ndlela ilungileyo kukujonga i-capacitor ngaphambi kokuba i-soldering.