Chigamba cha SMT chikutanthauza chidule cha njira zingapo zozikidwa pa PCB. PCB (Printed Circuit Board) ndi bolodi losindikizidwa.
SMT ndiye chidule cha Surface Mounted Technology, chomwe ndi ukadaulo wodziwika bwino komanso njira zamabizinesi apakompyuta. Ukadaulo wapagulu lamagetsi pamagetsi (Surface Mount Technology, SMT) umatchedwa kukwera pamwamba kapena ukadaulo wokwera pamwamba. Ndi njira yokhazikitsira zida zopanda lead kapena zotsogola zazifupi (zotchedwa SMC/SMD, zotchedwa chip components mu Chinese) pamwamba pa bolodi losindikizidwa (PCB) kapena gawo lina. Tekinoloje ya msonkhano wadera yomwe imasonkhanitsidwa ndi zitsulo pogwiritsa ntchito njira monga reflow soldering kapena dip soldering.
Mu njira yowotcherera ya SMT, nayitrogeni ndiyoyenera kwambiri ngati mpweya woteteza. Chifukwa chachikulu ndi chakuti mphamvu zake zogwirizanitsa ndizokwera kwambiri, ndipo zochitika za mankhwala zidzangochitika pansi pa kutentha kwakukulu ndi kuthamanga kwakukulu (> 500C,> 100bar) kapena ndi kuwonjezera mphamvu.
Jenereta wa nayitrogeni pakadali pano ndiye zida zoyenera kwambiri zopangira nayitrogeni zomwe zimagwiritsidwa ntchito pamakampani a SMT. Monga zida zopangira nayitrogeni pamalopo, jenereta ya nayitrogeni imakhala yodziwikiratu komanso yosayang'aniridwa, imakhala ndi moyo wautali, ndipo imakhala ndi kulephera kochepa. Ndikosavuta kupeza nayitrogeni, ndipo mtengo wake ndi wotsika kwambiri pakati pa njira zamakono zogwiritsira ntchito nayitrogeni!
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Nayitrogeni wakhala akugwiritsidwa ntchito mu reflow soldering mipweya ya inert isanagwiritsidwe ntchito pakupanga ma wave soldering. Chimodzi mwazifukwa ndichakuti makampani osakanizidwa a IC akhala akugwiritsa ntchito nayitrogeni kwanthawi yayitali pakuwotchera kwa mabwalo amtundu wosakanizidwa wa ceramic. Makampani ena ataona ubwino wa hybrid IC kupanga, anagwiritsa ntchito mfundo imeneyi PCB soldering. Mu mtundu uwu wa kuwotcherera, nayitrogeni amalowanso m'malo mwa oxygen m'dongosolo. Nayitrojeni amatha kulowetsedwa m'dera lililonse, osati kumalo obwezeretsanso, komanso kuziziritsa kwa njirayi. Makina ambiri obwezeretsanso tsopano ali okonzeka ndi nayitrogeni; machitidwe ena akhoza kusinthidwa mosavuta kuti agwiritse ntchito jekeseni wa gasi.
Kugwiritsa ntchito nayitrogeni mu reflow soldering kuli ndi zabwino izi:
‧Kunyowetsa mwachangu kwa ma terminals ndi ma pads
‧Kusintha pang'ono pakugulitsa
‧Kuwoneka bwino kwa zotsalira za flux ndi malo olumikizana a solder
‧Kuzizira kofulumira popanda okosijeni yamkuwa
Monga gasi woteteza, ntchito yayikulu ya nayitrogeni pakuwotcherera ndikuchotsa okosijeni panthawi yowotcherera, kukulitsa kuwotcherera, ndikuletsa kutulutsanso okosijeni. Kwa kuwotcherera odalirika, kuwonjezera pa kusankha solder yoyenera, mgwirizano wa flux umafunika nthawi zambiri. The flux makamaka amachotsa oxides ku kuwotcherera mbali SMA chigawo pamaso kuwotcherera ndi kupewa re-oxidation wa kuwotcherera mbali, ndi kupanga mikhalidwe yabwino nyowetsa kwa solder kusintha solderability. . Mayesero atsimikizira kuti kuwonjezera formic acid pansi pa chitetezo cha nayitrogeni kumatha kukwaniritsa zotsatirazi. Makina a nitrogen wave soldering makina omwe amatengera matanki owotcherera amtundu wa ngalande amakhala ngati thanki yowotcherera. Chivundikiro chapamwamba chimapangidwa ndi magalasi angapo otsegula kuti mpweya usalowe mu thanki yopangira. Nayitrojeni ikalowetsedwa mu kuwotcherera, pogwiritsa ntchito magawo osiyanasiyana a mpweya woteteza ndi mpweya, nayitrogeniyo imathamangitsa mpweyawo kuchoka pamalowo. Pa kuwotcherera ndondomeko, bolodi PCB mosalekeza kubweretsa mpweya m'dera kuwotcherera, kotero nayitrogeni ayenera mosalekeza jekeseni m'dera kuwotcherera kuti mpweya mosalekeza kutulutsidwa kwa kubwereketsa.
Ukadaulo wa nayitrogeni kuphatikiza formic acid nthawi zambiri umagwiritsidwa ntchito m'ng'anjo zamtundu wa tunnel zokhala ndi infrared enhanced convection mix. Cholowera ndi chotulukira nthawi zambiri chimapangidwa kuti chitseguke, ndipo mkati mwake muli makatani angapo osindikizira bwino, omwe amatha kutentha ndi kutenthetsa zinthu zina. Kuyanika, reflow soldering ndi kuziziritsa zonse zatsirizidwa mu ngalandeyo. M'mlengalenga wosakanikirana, phala la solder lomwe limagwiritsidwa ntchito siliyenera kukhala ndi zoyambitsa, ndipo palibe zotsalira zomwe zimasiyidwa pa PCB pambuyo pa soldering. Chepetsani makutidwe ndi okosijeni, chepetsani mapangidwe a mipira yogulitsira, ndipo palibe kutsekera, komwe kumapindulitsa kwambiri kuwotcherera kwa zida zomveka bwino. Imapulumutsa zida zoyeretsera ndikuteteza chilengedwe chapadziko lonse lapansi. Ndalama zowonjezera zomwe zinapangidwa ndi nayitrogeni zimabwezeredwa mosavuta kuchokera ku ndalama zomwe zimachokera ku zolakwika zocheperako komanso zofunikira zantchito.
Wave soldering ndi reflow soldering pansi pa chitetezo cha nayitrogeni idzakhala ukadaulo wodziwika bwino pakuphatikiza pamwamba. Makina a nitrogen wave soldering makina amaphatikizidwa ndi ukadaulo wa formic acid, ndipo makina ojambulira a nitrogen reflow amaphatikizidwa ndi phala lotsika kwambiri la solder ndi formic acid, zomwe zimatha kuchotsa Kuyeretsa. Muukadaulo wamakono wowotcherera wa SMT womwe ukukula mwachangu, vuto lalikulu lomwe timakumana nalo ndimomwe mungachotsere ma oxides, kupeza malo oyera azinthu zoyambira, ndikupeza kulumikizana kodalirika. Nthawi zambiri, flux imagwiritsidwa ntchito pochotsa ma oxides, kunyowetsa pamwamba kuti agulitsidwe, kuchepetsa kugwedezeka kwa solder, ndikuletsa kukonzanso kwa okosijeni. Koma nthawi yomweyo, flux idzasiya zotsalira pambuyo pa soldering, kuchititsa zotsatira zoipa pa zigawo za PCB. Choncho, bolodi la dera liyenera kutsukidwa bwino. Komabe, kukula kwa SMD ndi kocheperako, ndipo kusiyana pakati pa magawo osagulitsa kukucheperachepera. Kuyeretsa bwino sikungathekenso. Chofunika kwambiri ndi kuteteza chilengedwe. Ma CFC amawononga mpweya wa ozoni wa mumlengalenga, ndipo ma CFC monga chinthu chachikulu choyeretsera chiyenera kuletsedwa. Njira yabwino yothetsera mavuto omwe ali pamwambawa ndikutengera teknoloji yopanda ukhondo m'munda wa msonkhano wamagetsi. Kuonjezera kachulukidwe kakang'ono ka formic acid HCOOH ku nayitrogeni kwatsimikizira kuti ndi njira yabwino yosayeretsera yomwe sifunikira kuyeretsa pambuyo pa kuwotcherera, popanda zotsatirapo zilizonse kapena nkhawa za zotsalira.
Nthawi yotumiza: Feb-22-2024
