Ukusetshenziswa kwe-nitrogen embonini ye-SMT

I-SMT patch isho isifinyezo sochungechunge lwezinqubo ezisuselwe ku-PCB. I-PCB (Printed Circuit Board) iyibhodi lesifunda eliphrintiwe.

I-SMT isifinyezo se-Surface Mounted Technology, okuwubuchwepheshe nenqubo ethandwa kakhulu embonini yokuhlanganisa i-electronic. Ubuchwepheshe be-electronic circuit surface assembly (Surface Mount Technology, SMT) bubizwa ngokuthi i-surface mount noma ubuchwepheshe bokukhweza phezulu. Kuyindlela yokufaka izingxenye ezibekwe phezu komhlaba ezingenamthofu noma ezinomthofu omfushane (okubhekiselwa kuzo njenge-SMC/SMD, ezibizwa ngama-chip components ngesiShayina) phezu kwebhodi lesekethe eliphrintiwe (PCB) noma enye i-substrate. Ubuchwepheshe bomhlangano wesifunda obuhlanganiswa ngokusoda kusetshenziswa izindlela ezifana ne-reflow soldering noma i-dip soldering.

Enqubweni yokushisela ye-SMT, i-nitrogen ifaneleka ngokwedlulele njengegesi evikelayo. Isizathu esiyinhloko ukuthi amandla ayo ahlangene aphezulu, futhi ukusabela kwamakhemikhali kuzokwenzeka kuphela ngaphansi kokushisa okuphezulu nokucindezela okukhulu (> 500C,> 100bar) noma ngokungezwa kwamandla.

Ijeneretha ye-nitrogen njengamanje iyimishini yokukhiqiza inayithrojeni efaneleke kakhulu esetshenziswa embonini ye-SMT. Njengemishini yokukhiqiza i-nitrogen esizeni, ijeneretha ye-nitrogen izenzakalela ngokuphelele futhi ayinakekelwa, inobude bempilo, futhi inezinga eliphansi lokwehluleka. Kulula kakhulu ukuthola i-nitrogen, futhi izindleko nazo ziphansi kakhulu phakathi kwezindlela zamanje zokusebenzisa i-nitrogen!

Abakhiqizi Abakhiqiza I-nitrogen - Imboni Yokukhiqiza I-Nitrogen Yase-China Nabaphakeli (xinfatools.com)

I-nitrojeni isetshenziswe ekufakweni kabusha kwe-solder ngaphambi kokuba kusetshenziswe amagesi angenayo enqubweni yokuhlanganisa amagagasi. Ingxenye yesizathu ukuthi imboni ye-IC eyingxubevange kudala isebenzisa i-nitrogen ekufakweni kabusha kwe-solder of surface-mount Ceramic hybrid circuits. Lapho ezinye izinkampani zibona izinzuzo zokukhiqiza i-IC eyingxubevange, zasebenzisa lesi simiso ekuhlanganisweni kwe-PCB. Kulolu hlobo lwe-welding, i-nitrogen iphinde ithathe indawo yomoya-mpilo ohlelweni. I-nitrogen ingafakwa kuyo yonke indawo, hhayi nje endaweni yokugeleza kabusha, kodwa futhi nokupholisa inqubo. Amasistimu amaningi okugaywa kabusha manje asekulungele i-nitrogen; ezinye izinhlelo zingathuthukiswa kalula ukuze zisebenzise umjovo wegesi.

Ukusebenzisa i-nitrogen ekufakweni kwe-reflow soldering kunezinzuzo ezilandelayo:

‧Ukumanzisa okusheshayo kwamatheminali namaphedi

‧Ushintsho oluncane ekuthengiseni

‧Ukubukeka okuthuthukisiwe kwezinsalela ze-flux kanye nendawo ehlangene ye-solder

‧Ukupholisa okusheshayo ngaphandle kwe-oxidation yethusi

Njengegesi evikelayo, indima eyinhloko ye-nitrogen ekushiseleni iwukuqeda umoya-mpilo phakathi nenqubo yokushisela, ukwandisa ukushisela, nokuvimbela ukuphinda kufakwe i-oxidation. Ukuze uthole i-welding ethembekile, ngaphezu kokukhetha i-solder efanelekile, ukubambisana kwe-flux ngokuvamile kuyadingeka. I-flux isusa ikakhulukazi ama-oxides engxenyeni ye-welding yengxenye ye-SMA ngaphambi kokushisela futhi ivimbele ukuphinda kufakwe i-oxidation yengxenye ye-welding, futhi yakha izimo ezinhle kakhulu zokumanzisa ukuze i-solder ithuthukise i-solderability. . Ukuhlola kufakazele ukuthi ukwengeza i-formic acid ngaphansi kokuvikelwa kwe-nitrogen kungafinyelela imiphumela engenhla. Umshini wokushisela i-nitrogen wave eyindandatho owamukela isakhiwo sethangi lokushisela uhlobo lomhubhe ikakhulukazi ithangi lokucubungula ukushisela lohlobo lomhubhe. Isembozo esingenhla sakhiwe izingcezu ezimbalwa zengilazi evulekayo ukuze kuqinisekiswe ukuthi umoya-mpilo awukwazi ukungena ethangini lokucubungula. Lapho i-nitrogen ifakwa ekushiseleni, kusetshenziswa izilinganiso ezihlukene zegesi yokuvikela nomoya, i-nitrogen izokhipha umoya ngokuzenzakalelayo endaweni yokushisela. Ngesikhathi senqubo yokushisela, ibhodi le-PCB lizolokhu liletha umoya-mpilo endaweni yokushisela, ngakho-ke i-nitrogen kufanele ifakwe ngokuqhubekayo endaweni yokushisela ukuze umoya-mpilo ukhishwe ngokuqhubekayo endaweni yokuphuma.

Ubuchwepheshe be-nitrogen kanye ne-formic acid ngokuvamile busetshenziswa ezithandweni zokugeleza kabusha zohlobo lomhubhe ngokuxubana kwe-convection okuthuthukisiwe kwe-infrared. I-inlet ne-outlet ngokuvamile yakhelwe ukuthi ivuleke, futhi kukhona amakhethini eminyango eminingi ngaphakathi anokuvalwa kahle, okungashisa kuqala futhi kushise kuqala izingxenye. Ukomisa, ukuphinda kufakwe i-solder kanye nokupholisa konke kuqediwe emhubheni. Kulesi simo esixubile, ukunamathisela kwe-solder okusetshenzisiwe akudingi ukuqukatha izicupha, futhi akukho zinsalela ezisele ku-PCB ngemva kokudayiswa. Yehlisa i-oxidation, yehlisa ukwakheka kwamabhola e-solder, futhi akukho bhuloho, okuzuzisa kakhulu ekushiseleni amadivaysi e-fine-pitch. Igcina imishini yokuhlanza futhi ivikela imvelo yomhlaba wonke. Izindleko ezengeziwe ezitholwe yi-nitrogen zitholwa kalula ekongeni kwezindleko ezitholakala ekulimaleni okuncishisiwe kanye nezidingo zabasebenzi.

I-Wave soldering kanye ne-reflow soldering ngaphansi kokuvikelwa kwe-nitrogen kuzoba ubuchwepheshe obujwayelekile ekuhlanganiseni kwendawo. Umshini wokugcwalisa i-nitrogen wave wave uhlanganiswe nobuchwepheshe be-formic acid, futhi umshini wokugcwalisa i-nitrogen reflow wendandatho uhlanganiswe nomsebenzi ophansi kakhulu we-solder paste kanye ne-formic acid, engasusa inqubo yokuhlanza. Kubuchwepheshe banamuhla bokushisela obukhula ngokushesha be-SMT, inkinga enkulu okuhlangatshezwane nayo iwukukhipha kanjani ama-oxide, ukuthola indawo ehlanzekile yezinto eziyisisekelo, nokufinyelela ukuxhumana okuthembekile. Ngokuvamile, i-flux isetshenziselwa ukususa ama-oxides, ukumanzisa ubuso ukuze kuthengiswe, ukunciphisa ukungezwani kwendawo ye-solder, nokuvimbela ukuphinda kufakwe i-oxidation. Kepha ngasikhathi sinye, i-flux izoshiya izinsalela ngemuva kokudayiswa, okubangela imiphumela emibi ezingxenyeni ze-PCB. Ngakho-ke, ibhodi lesifunda kufanele lihlanzwe kahle. Kodwa-ke, usayizi we-SMD mncane, futhi igebe phakathi kwezingxenye ezingadayisi liya liba lincane futhi libe lincane. Ukuhlanza ngokuphelele akusanakwenzeka. Okubaluleke kakhulu ukuvikela imvelo. Ama-CFC adala umonakalo ongqimbeni lwe-ozone emkhathini, futhi ama-CFC njenge-ejenti yokuhlanza eyinhloko kufanele avinjelwe. Indlela ephumelelayo yokuxazulula izinkinga ezingenhla ukusebenzisa ubuchwepheshe obungahlanzekile emkhakheni wokuhlanganisa i-electronic. Ukwengeza inani elincane nenani le-formic acid HCOOH ku-nitrogen kuye kwafakazela ukuthi kuyindlela ephumelelayo engahlanzekile engadingi noma yikuphi ukuhlanzwa ngemva kokushisela, ngaphandle kwemithelela emibi noma ukukhathazeka mayelana nezinsalela.