Amasu Asebenzayo Okuvimbela Amasekethe Amafushane Ekuhlanganisweni kwe-SMT PCB
Ekuhlanganisweni kwe-PCB ye-SMT (Surface Mount Technology), ukuvimbela ama-short circuits kubalulekile ekuqinisekiseni ukuthembeka nokusebenza komkhiqizo wokugcina. Ama-short circuits awagcini nje ngokuphazamisa ukusebenza kodwa angaholela emikhiqizweni enephutha, izindleko zokukhiqiza ezikhuphukile, kanye nokusebenza kabusha. Lesi sihloko sihlola amasu amaningana okuvimbela ngempumelelo ama-short circuits ngesikhathi senqubo yokuhlanganiswa kwe-SMT PCB.
1. Ukukhethwa Nokuhlolwa Kwezingxenye
Ikhwalithi yezingxenye ihlobene ngqo nezinkinga zesekethe emfushane. Izinkinga ezifana nama-pad amakhulu noma angaphansi, ama-lead ezingxenye asontekile, kanye nokukhubazeka kwangaphakathi kungaholela ekungalungi kahle kwesekethe, okuholela kuma-short circuit. Ukuze kuncishiswe lezi zingozi, abakhiqizi kufanele bakhethe izingxenye kubahlinzeki abathembekile futhi benze ukuhlolwa okuqinile kokulawula ikhwalithi ezingxenyeni ezingenayo.
Hlola ukubukeka, usayizi, kanye nama-lead ezingxenye ukuqinisekisa ukuthi azinawo amaphutha.
Yenza amasampula angahleliwe ukuqinisekisa ukuthi izingxenye ziyahlangabezana nezindinganiso zekhwalithi ngaphambi kokuhlanganiswa.
Ngokuqinisekisa izingxenye zekhwalithi ephezulu, abakhiqizi bangavimbela ama-short circuits abangelwa izinto ezinephutha noma ezingaphansi kwekhwalithi.
2. Ukuthuthukisa Amasu Okubophela
Ukushiswa kwe-solder okungafanele kuyimbangela enkulu yamasekethe amafushane ekuhlanganisweni kwe-SMT. Izici ezifana nokushisa ngokweqile noma okunganele kokushiswa kwe-solder, noma isikhathi esingafanele sokushiswa kwe-solder, zingathinta kabi ikhwalithi yamajoyinti okushiswa kwe-solder, okuholela kumasekethe amafushane. Amapharamitha afanele okushiswa kwe-solder kufanele abekwe ngokwezimpawu zezingxenye ukuze kugwenywe lezi zinkinga.
Gcina amazinga okushisa okunamathela kanye nezikhathi ezihambisanayo ngokusekelwe ezicacisweni zengxenye.
Linganisa njalo futhi ulondoloze imishini yokunamathisela ukuze uqinisekise ukusebenza okuzinzile.
Sebenzisa izinto zokusoda ezisezingeni eliphezulu ukuvimbela izinkinga ezifana nokugeleza ngokweqile noma ukubopha okunganele.
Amasu okushisela alungiselelwe kahle asiza ekwakheni amajoyinti okushisela athembekile futhi aqinile, okunciphisa ingozi yamasekethe amafushane.
3. Ukulawulwa Kwenqubo Yokuhlanganisa
Ukubekwa okungalungile kwezingxenye ngesikhathi senqubo ye-SMT nakho kungaba nomthelela kuma-short circuits. Ukungalungi kahle kwezingxenye noma ukusetshenziswa okungalungile kwe-solder paste kungabangela ukuhlangana phakathi kwama-solder pads. Ezingxenyeni eziqondile ezifana nama-IC (ama-Integrated Circuits), ukubekwa okungafanele kungaholela emabhulohweni e-solder futhi kubangele ama-short circuits.
Sebenzisa imishini yokubeka enembile kakhulu ukuqinisekisa ukuthi izingxenye zibekwe ngendlela efanele.
Lawula ngokuqinile ukuphakama kokubekwa kanye nama-engeli ukuze uvimbele ukubhidlika noma ukubopha i-solder paste.
Qinisekisa ukuthi ukwakheka kwe-stencil kanye nosayizi wokuvula kuhlangabezana nezidingo zokusetshenziswa kwe-solder paste ngendlela enembile.
Ngokusebenzisa izilawuli eziqinile enqubweni yokuhlanganisa, abakhiqizi banganciphisa amathuba okuthi izingxenye zingabi khona kahle kanye nokubopha i-solder, okuyizimbangela ezivamile zama-short circuits.
4. Ukuphathwa Kwemvelo Yokukhiqiza
Indawo yokukhiqiza nayo idlala indima ebalulekile ekuvimbeleni amasekethe amafushane. Izinto ezifana nomswakama ophezulu kanye nokungcola okuvela othulini noma ezinhlayiyeni zakwamanye amazwe zingabangela amaphutha enqubweni yokuhlanganisa. Isibonelo, umswakama owedlulele ungaholela ekumuncweni komswakama yizingxenye, okuholela ezinkingeni zokunamathela njengezikhala noma amabhamuza abangela amasekethe amafushane.
Lawula amazinga omswakama endaweni yokukhiqiza, okungcono kakhulu phakathi kuka-40% no-60%, ukuze uvimbele ukumuncwa komswakama yizingxenye.
Hlanza njalo imishini yokukhiqiza kanye nezindawo zokusebenza ukuze unciphise ukungcola kothuli kanye nezinhlayiya.
Qinisekisa ukuthi izinga lokushisa kanye nomswakama kuzinzile ukuze kugcinwe ikhwalithi yokunamathisela insimbi enamathelayo.
Indawo yokukhiqiza elawulwayo iyasiza ekunciphiseni ingozi yokungcola futhi iqinisekisa ukushiswa kwekhwalithi ephezulu, okungavimbela ama-short circuits.
5. Ukutholwa Kwesekethe Efushane Nokuxazulula Izinkinga
Naphezu kokuthatha izinyathelo zokuvimbela, ama-short circuits angase avele ngesikhathi sokuhlanganiswa kwe-SMT PCB. Ukusebenzisa izindlela zokuthola nokuxazulula izinkinga eziphumelelayo kubalulekile ekutholeni nasekuxazululeni ama-short circuits ngokushesha.
Ukuhlolwa Ngesandla: Ngemva kokuhlanganiswa, sebenzisa i-multimeter ukuhlola amasekethe abalulekile ukuze ubone ukuqhubeka kwawo futhi uthole amasekethe amafushane angaba khona.
Ukuxazulula Izinkinga Zokuhlukanisa: Uma kutholakala ama-short circuits emabhodini amaningi, hlukanisa izingxenye zebhodi ukuze uthole umthombo wenkinga.
Amathuluzi Okuthola Isifunda Esifushane: Sebenzisa amathuluzi okuthola isifunda esifushane ukuthola indawo eqondile yesifunda esifushane ngokulinganisa ugesi kanye ne-voltage kulo lonke isifunda.
Ukuhlola njalo nokuxazulula izinkinga kusiza ekutholeni ama-short circuits ekuqaleni kwenqubo yokukhiqiza, ukuvimbela amaphutha nokulibaziseka okwengeziwe.
6. Ukuphathwa Kwezingxenye Ezikhethekile
Kuzingxenye ezikhethekile ezifana nama-chip e-BGA (Ball Grid Array), ambozwe umzimba we-chip futhi kunzima ukuwahlola ngenxa yokwakheka kwawo kwe-PCB enezingqimba eziningi, kudingeka izinyathelo ezengeziwe zokuqapha ukuze kuvinjelwe ama-short circuits.
Esigabeni sokuklama, hlukanisa amandla kanye nezindawo eziphansi ze-chip ngayinye, usebenzisa ama-magnetic beads noma ama-zero-ohm resistors ukuze kube lula ukubona uma kwenzeka ukufinyela.
Sebenzisa ukuhlolwa kwe-X-ray okuzenzakalelayo ukuze uhlole izinkinga ezifihliwe zokunamathisela ngaphansi kwengxenye.
Ukuphathwa okukhethekile kwalezi zingxenye eziyinkimbinkimbi kuqinisekisa ukuthi amasekethe amafushane ayagwenywa ngisho nasemiklamo eyinselele, okuthuthukisa ukuthembeka okuphelele kwe-PCB.
Imibuzo Evame Ukubuzwa Ehlobene Nokuvimbela I-Short Circuit Ekuhlanganisweni kwe-SMT PCB:
1. Yiziphi izimbangela ezivamile zamasekethe amafushane ekuhlanganisweni kwe-SMT PCB?
Izimbangela ezivamile zifaka phakathi ukushiswa okungafanele (ukushiswa ngokweqile noma okunganele), ukulahleka kwezingxenye, izingxenye ezisezingeni eliphansi, ukungcola endaweni yokukhiqiza, kanye nokusetshenziswa okungalungile kokunamathisela i-solder. Ukubhekana nalezi zinkinga ngamasu okushiswa athuthukisiwe, ukuhlolwa kwezingxenye, kanye nokulawulwa okunembile kokuhlanganiswa kunganciphisa kakhulu ingozi yamasekethe amafushane.
2. Umswakama uthinta kanjani ukuvimbela ukujikeleza okufushane ekuhlanganisweni kwe-PCB?
Umswakama ophezulu ungabangela ukumuncwa komswakama yizingxenye, okuholela ezinkingeni zokunamathela njengebhuloho lokunamathisela noma izikhala, okungase kuholele ezifundeni ezimfushane. Ukuze kuvinjelwe lokhu, abakhiqizi kufanele balawule amazinga omswakama endaweni yokukhiqiza futhi baqinisekise ukuthi ahlala ngaphakathi kwebanga elifanele lika-40% kuya ku-60%.
3. Kungani ukuphathwa kwezingxenye ze-BGA (Ball Grid Array) kubalulekile ekuvimbeleni ama-short circuits?
Izingxenye ze-BGA zivame ukuba nzima ukuzihlola ngoba amalunga azo e-solder afihliwe ngaphansi komzimba wengxenye. Ukuphathwa okukhethekile, njengokuhlukanisa izindiza zamandla nomhlaba kanye nokusebenzisa ama-magnetic beads noma ama-zero-ohm resistor ukuze kutholakale amaphutha kalula, kubalulekile. Ukuhlolwa kwe-X-ray okuzenzakalelayo nakho kuyanconywa ukuqinisekisa ukugoqa okufanele nokugwema ama-short circuits.
4. Yimiphi imikhuba engcono kakhulu yokwenza ngcono amasu okunamathisela ukuze kuvinjelwe ama-short circuits?
Imikhuba emihle kakhulu ihlanganisa ukugcina amazinga okushisa okunamathela kanye nezikhathi ezisekelwe ezimisweni zezingxenye, ukusebenzisa izinto zokunamathela ezisezingeni eliphezulu, kanye nokulinganisa njalo imishini yokunamathela. Ukwenza ngcono lezi zinhlaka kuqinisekisa amalunga okunamathela aqinile nathembekile ngaphandle kokugeleza ngokweqile noma ukubopha okubi okungaholela ezifundeni ezimfushane.
5. Ngingazithola kanjani iziyingi ezimfushane ekuqaleni kwenqubo yokuhlanganisa i-SMT PCB?
Amasekethe amafushane angatholakala kusetshenziswa izindlela ezihlanganisiwe: ukuhlolwa ngesandla nge-multimeter, ukuhlukanisa ibhodi ukuze kuxazululwe izinkinga, kanye nokusebenzisa amathuluzi okuthola amasekethe amafushane. Emaseshini ayinkimbinkimbi, ukuhlolwa kwe-X-ray okuzenzakalelayo noma imishini yokuhlola ekhethekile kungabona amaphutha afihliwe, okuvumela ukungenelela okusheshayo nokunciphisa amathuba emikhiqizo enephutha.
Ukuvimbela amasekethe amafushane ekuhlanganisweni kwe-SMT PCB kudinga indlela ebanzi ehlanganisa ukukhethwa kwezingxenye ngokucophelela, amasu okuhlanganisa alungiselelwe kahle, ukulawulwa kokuhlanganiswa okunembile, ukuphathwa kwemvelo, kanye nezindlela zokuthola eziqinile. Ngokusebenzisa lawa masu, abakhiqizi banganciphisa kakhulu ukwenzeka kwamasekethe amafushane, bathuthukise ikhwalithi yomkhiqizo, futhi bathuthukise ukusebenza kahle kokukhiqiza.
Ngokuthatha izinyathelo zokuqapha inqubo yokuhlanganisa, abakhiqizi bangaqinisekisa izinga eliphezulu lokuthembeka kuma-PCB abo futhi balethe imikhiqizo engcono kumakhasimende abo.
