PCB ibhodi inkinga yesifunda esifushane

Imbangela enkulu yesekethe ye-PCB ukuklama okungalungile kwephedi. Ngalesi sikhathi, iphedi eliyindilinga lingashintshwa libe yisimo se-elliptical ukwandisa ibanga phakathi kwamaphoyinti, ukuze kuvinjwe izifunda ezimfushane.

Ukuklanywa okungalungile kwezingxenye zebhodi le-PCB kuzophinde kubangele ukujikeleza okufushane kwebhodi lesifunda, okuholela ekungasebenzini. Uma iphinikhodi ye-SOIC ihambisana ne-tin wave, kulula ukubangela ingozi yesifunda esifushane. Kulesi simo, isiqondiso sengxenye singashintshwa ukuze sibe yi-perpendicular to wave tin.

Esinye isizathu ukuthi ibhodi le-PCB lifushane, okungukuthi, iyunithi ye-plug-in ezenzakalelayo igobile. Njengoba i-IPC ibeka ukuthi ubude bocingo bungaphansi kuka-2mm, lapho i-engeli yokugoba inkulu kakhulu, ingxenye inkulu kakhulu futhi kulula ukubangela ukujikeleza okufushane. Ijoyinti ye-solder ingaphezu kuka-2mm kude nesekethe.

Ngaphezu kwezizathu ezintathu ezingenhla, kunezizathu ezithile ezingabangela ukwehluleka kwesifunda esifushane ebhodini le-PCB. Isibonelo, imbobo ye-substrate inkulu kakhulu, izinga lokushisa lesithando somlilo liphansi kakhulu, i-solderability yendawo yebhodi impofu, imaski ye-solder ayivumelekile, kanye nebhodi. Ukungcoliswa kobuso njll. kuyimbangela evamile yokwehluleka. Unjiniyela angakwazi ukuqeda futhi ahlole izimbangela namaphutha angenhla ngamunye ngamunye.

Izindlela ezi-4 zokuthuthukisa isifunda esifushane se-PCB

I-PCB ye-short circuit fixed short-circuit short-circuit ibangelwa ikakhulukazi imihuzuko kulayini wokukhiqiza ifilimu noma ukuvaleka kukadoti esikrinini esimboziwe. Ungqimba olunamekwe olumelene nokucwebezela luvezwa kukhopha futhi lubangela ukujikeleza okufushane ku-PCB. Intuthuko imi kanje:

Ifilimu ekwifilimu akumele ibe nezinkinga ezifana ne-trachoma, imihuzuko, njll. Uma ibekwe, ingaphezulu lefilimu kufanele libheke phezulu futhi akufanele lihlikihle kwezinye izinto. Lapho ukopisha ifilimu, ifilimu ibhekene nobuso befilimu, futhi ifilimu efanelekile ilayishwa ngesikhathi. Gcina esikhwameni sefilimu.

Uma ifilimu ibheke, ibheke phezulu kwe-PCB. Uma uthwebula ifilimu, thatha i-diagonal ngezandla zombili. Ungathinti ezinye izinto ukuze ugweme ukunwaya ifilimu. Lapho ipuleti lifinyelela inombolo ethile, ifilimu ngayinye kufanele iyeke ukuqondanisa. Hlola noma shintsha mathupha. Yifake esikhwameni sefilimu esifanelekile bese uyigcina.

Abasebenzi akufanele bagqoke noma yimiphi imihlobiso, njengamaringi, amasongo, njll. Izinzipho kufanele zisikwe futhi zigcinwe engadini. Awekho ama-debris okufanele abekwe phezulu kwetafula, futhi phezulu kwetafula kufanele kuhlanzeke futhi kube bushelelezi.

Ngaphambi kokwenza inguqulo yesikrini, kufanele ihlolwe ngokuqinile ukuze kuqinisekiswe ukuthi azikho izinkinga. Inguqulo yesikrini. Uma usebenzisa ifilimu emanzi, ngokuvamile kuyadingeka ukuhlola iphepha ukuze uhlole ukuthi kukhona yini i-jam yephepha esikrinini. Uma kungekho ukuphrinta kwesikhawu, kufanele uphrinte isikrini esingenalutho izikhathi ezimbalwa ngaphambi kokuphrinta ukuze okuzacile kuyinki kungancibilikisa ngokuphelele uyinki oqinisiwe ukuze uqinisekise ukuvuza okushelelayo kwesikrini.

Ibhodi le-PCB indlela yokuhlola isifunda esifushane

Uma kuyi-welding manual, kuyadingeka ukuthuthukisa imikhuba emihle. Okokuqala, hlola ibhodi le-PCB ngeso lengqondo ngaphambi kokudayiswa, bese usebenzisa i-multimeter ukuze uhlole ukuthi amasekethe abalulekile (ikakhulukazi amandla kanye nomhlabathi) ane-circuited emfushane. Okwesibili, thengisa i-chip ngaso sonke isikhathi. Sebenzisa i-multimeter ukukala ukuthi ukunikezwa kwamandla kanye nomhlabathi kune-circuited short-circuited. Ngaphezu kwalokho, musa ukuthengisa insimbi lapho u-soldering. Uma i-solder ithengiswa ezinyaweni ze-solder ze-chip (ikakhulukazi izingxenye zokubeka phezulu), akulula ukuyithola.

Vula i-PCB kukhompuyutha, khanyisa inethiwekhi yesiyingi esifushane, bese ubheka ukuthi iseduze kakhulu yini nayo futhi kulula ukuyixhuma. Sicela unake ngokukhethekile isifunda esifushane sangaphakathi se-IC.

Kwatholakala isifunda esifushane. Thatha ibhodi ukuze usike umugqa (ikakhulukazi ibhodi elilodwa/eliphindwe kabili). Ngemuva kokusika, ingxenye ngayinye yebhulokhi yomsebenzi inikwa amandla ngokuhlukana, futhi ezinye izingxenye azifakiwe.

Sebenzisa isihlaziyi sendawo yesifunda esifushane, okufana nalokhu: I-Singapore PROTEQ CB2000 i-short-circuit tracker, i-Hong Kong Ganoderma QT50 i-short-circuit tracker, i-British POLAR ToneOhm950 ibhodi yomtshina we-short-circuit detector.

Uma kukhona i-chip ye-BGA, njengoba wonke amalunga e-solder engamboziwe yi-chip, futhi ibhodi elinezingqimba eziningi (ngaphezu kwezingqimba ezi-4), kungcono ukusebenzisa ubuhlalu kazibuthe noma i-0 ohm ukuhlukanisa amandla ngamunye. chip kumklamo. I-resistor ixhunywe ukuze kuthi lapho ukunikezwa kwamandla kufinyezwa kancane phansi, kutholwa ubuhlalu kazibuthe futhi kulula ukuthola i-chip ethile. Ngenxa yokuthi i-BGA inzima ukudayiswa, uma kungeyona i-solder ezenzakalelayo yomshini, amandla aseduze namabhola e-solder aphansi azofinyezwa ngokucophelela.

Qaphela lapho u-soldering amahora-ama-mount capacitor amakhulu namancane, ikakhulukazi ama-capacitor okuhlunga amandla (103 noma 104), angabangela kalula isekethe emfushane phakathi kokunikezwa kwamandla kanye nomhlabathi. Yiqiniso, ngezinye izikhathi ngenhlanhla, i-capacitor ngokwayo izoba isikhashana, ngakho-ke indlela engcono kakhulu yokuhlola i-capacitor ngaphambi kwe-soldering.