SMT ( Buga Majalisa Majalisar Da'ira , PCBA ) kuma ana kiranta fasahar hawan dutse.A lokacin aikin masana'antu, ana yin zafi da narkar da man narkar a cikin yanayin dumama, ta yadda PCB gammaye suna dogaro da haɗin gwiwa tare da abubuwan hawan saman saman ta hanyar abin da ake solder manna gami.Muna kiran wannan tsari sake kwarara soldering.Yawancin allunan da'irar suna da wuyar yin lankwasawa da warping lokacin da ake jurewa Reflow (sake fitarwa).A lokuta masu tsanani, yana iya haifar da abubuwa kamar siyar da babu komai da duwatsun kabari. A cikin layin haɗin kai mai sarrafa kansa, idan PCB na masana'antar allon kewayawa ba ta da fa'ida, zai haifar da matsaya mara kyau, ba za a iya shigar da abubuwan da aka haɗa a cikin ramuka da filayen ɗorawa na allon ba, har ma da injin sakawa ta atomatik zai lalace.An lanƙwasa allon tare da abubuwan da aka gyara bayan waldawa, kuma ƙafafu na ƙafa suna da wuya a yanke da kyau.Ba za a iya shigar da allon a kan chassis ko soket a cikin na'ura ba, don haka yana da matukar bacin rai ga masana'antar taron ta gamu da rikici.A halin yanzu, allunan da aka buga sun shiga zamanin hawan sama da guntu, kuma shuke-shuken taro dole ne su kasance da tsauraran buƙatu don yaƙin jirgin.
Bisa ga US IPC-6012 (1996 Edition) "Ƙayyadaddun Ƙididdiga da Ƙayyadaddun Ayyuka don Tsayayyen Allolin Bugawa ", matsakaicin yarda warpage da murdiya ga surface-saka buga allon ne 0.75%, da kuma 1.5% ga sauran allon. Idan aka kwatanta da IPC-RB-276 (1992 edition), wannan ya inganta da bukatun ga surface-saka buga allon. yanzu, da warpage yarda da daban-daban na lantarki taron shuke-shuke, ko da biyu-gefe ko Multi-Layer, 1.6mm kauri, yawanci 0.70 ~ 0.75%.
Don yawancin allon SMT da BGA, abin da ake buƙata shine 0.5%.Wasu masana'antun lantarki suna yin kira da su ƙara ma'auni na yakin zuwa 0.3%.Hanyar gwada shafin ya dace da GB4677.5-84 ko IPC-TM-650.2.4.22B.Sanya allo da aka buga akan dandamalin da aka tabbatar, saka fil ɗin gwajin zuwa wurin da matakin warpage ya fi girma, sannan a raba diamita na fil ɗin gwajin da tsayin lanƙwasa gefen allon buga don ƙididdige shafin wargin ɗin. buga allo.Karfewar ya tafi.
Don haka a cikin aiwatar da masana'antar PCB, menene dalilai na lankwashewa da tarwatsewar hukumar?
Dalilin kowane farantin lankwasa da farfaɗo na iya zama daban-daban, amma duk ya kamata a danganta shi da damuwa da aka yi wa farantin da ya fi ƙarfin da abin farantin zai iya jurewa.Lokacin da farantin yana fuskantar matsananciyar damuwa ko Lokacin da ikon kowane wuri a kan allo don tsayayya da damuwa ba daidai ba ne, sakamakon lankwasawa da allon allo zai faru.Takaitaccen bayani ne kan manyan abubuwan da ke haifar da lankwasawa da faranti.
1. Wurin da ba daidai ba na jan ƙarfe a kan allon kewayawa zai kara tsananta lanƙwasa da warping na allon
Gabaɗaya, an ƙera babban yanki na foil ɗin tagulla akan allon kewayawa don dalilai na ƙasa.Wani lokaci kuma an tsara babban yanki na foil na jan karfe akan Layer Vcc.Lokacin da ba za a iya rarraba waɗannan manyan bakunan tagulla ba daidai gwargwado a kan allon da'ira ɗaya A wannan lokacin, zai haifar da matsalar rashin daidaituwar zafin jiki da kuma zubar da zafi.Tabbas, hukumar da'irar kuma za ta fadada kuma ta kulla da zafi.Idan ba za a iya yin faɗaɗa da ƙaddamarwa a lokaci ɗaya ba, zai haifar da damuwa da lalacewa daban-daban.A wannan lokacin, idan zafin jiki na hukumar ya kai Tg Babban iyakar ƙimar, allon zai fara yin laushi, yana haifar da nakasawa na dindindin.
2. Nauyin na'urar da'ira da kanta zai sa allon ya ɓata kuma ya lalace
Gabaɗaya, murhun wutar lantarki yana amfani da sarƙa don fitar da allon da'ira gaba a cikin tanderun da aka sake fitarwa, wato, an yi amfani da bangarorin biyu na allon a matsayin fulcrums don tallafawa dukkan allon.Idan akwai sassa masu nauyi a kan allo, ko girman allo ya yi yawa, zai nuna damuwa a tsakiya saboda yawan iri, yana sa farantin ya lanƙwasa.
3. Zurfin V-Cut da haɗin haɗin haɗin gwiwa zai shafi lalacewar jigsaw
Ainihin, V-Cut shine mai laifi wanda ke lalata tsarin allon, saboda V-Cut yana yanke tsagi mai siffar V akan babban takarda na asali, don haka V-Cut yana da saurin lalacewa.
4. Abubuwan haɗin haɗin (vias) na kowane Layer akan allon kewayawa zai iyakance haɓakawa da ƙaddamar da allon
Allolin da'ira na yau galibi allunan Layer Layer ne, kuma za a sami wuraren haɗin kai-kamar rivet (ta) tsakanin layuka.An raba wuraren haɗin kai ta hanyar ramuka, ramukan makafi da ramukan binne.Inda akwai wuraren haɗin kai, za a taƙaita allon.Tasirin faɗaɗawa da raguwa kuma zai haifar da lanƙwasawa da faranti a kaikaice.
Don haka ta yaya za mu fi dacewa don hana matsalar faɗaɗa jirgin yayin aikin masana'anta? Anan akwai ƴan ingantattun hanyoyin da nake fata za su iya taimaka muku.
1. Rage tasirin zafin jiki akan damuwa na jirgi
Tunda "zazzabi" shine babban tushen damuwa na allo, idan dai zafin tanda ya ragu ko kuma yawan dumama da sanyaya allon a cikin tanda ya ragu, faruwar lankwasa faranti da warpage na iya zama mai girma. rage.Koyaya, wasu illolin na iya faruwa, kamar gajeriyar kewayawa.
2. Yin amfani da babban Tg takardar
Tg shine yanayin canjin gilashin, wato, yanayin zafin da kayan ke canzawa daga yanayin gilashi zuwa yanayin roba.Ƙarƙashin ƙimar Tg na kayan, da sauri jirgin ya fara yin laushi bayan shigar da tanda na sake sakewa, da kuma lokacin da ake ɗauka don zama yanayin roba mai laushi Haka nan zai yi tsayi, kuma lalacewar allon zai zama mafi tsanani. .Yin amfani da takardar Tg mafi girma zai iya ƙara ƙarfinsa don tsayayya da damuwa da lalacewa, amma farashin kayan dangi kuma ya fi girma.
3. Ƙara kauri na allon kewayawa Don cimma manufar mai sauƙi da sauƙi don yawancin kayan lantarki, kauri daga cikin jirgi ya bar 1.0mm, 0.8mm, ko ma 0.6mm.Irin wannan kauri dole ne ya kiyaye allon daga lalacewa bayan tanderun da aka sake fitarwa, wanda yake da wuyar gaske.Ana ba da shawarar cewa idan babu wani buƙatu don haske da siriri, kauri na allo ya kamata ya zama 1.6mm, wanda zai iya rage haɗarin lanƙwasa da nakasar allon. 4. Rage girman allon kewayawa kuma rage yawan wasan wasa Tunda yawancin tanderun da aka sake fitarwa suna amfani da sarƙoƙi don fitar da allon da'irar gaba, girman girman da'irar zai kasance saboda nauyinsa, haƙora da nakasawa a cikin tanderun da aka sake fitarwa, don haka gwada sanya dogon gefen allon kewayawa. a matsayin gefen allo.A kan sarkar tanderun da aka sake fitarwa, za a iya rage damuwa da nakasar da nauyin allon kewayawa ya haifar.Hakanan raguwar adadin bangarori yana dogara ne akan wannan dalili.Wato, lokacin wucewa tanderu, yi ƙoƙarin amfani da kunkuntar gefen don wuce hanyar tanderu gwargwadon yiwuwa.Adadin nakasar baƙin ciki. 5. Amfani da tire na murhu Idan hanyoyin da ke sama suna da wahalar cimmawa, na ƙarshe shine a yi amfani da mai ɗaukar kaya/samfuri don rage adadin nakasar.Dalilin da yasa mai ɗaukar kaya/samfurin zai iya rage lanƙwasawa na farantin shine saboda ana fatan ko haɓakawar thermal ne ko ƙanƙantar sanyi.Tire zai iya riƙe allon kewayawa kuma ya jira har sai zafin jiki na hukumar ya yi ƙasa da ƙimar Tg kuma ya fara taurare kuma, kuma yana iya kula da girman asali. Idan pallet mai Layer guda ɗaya ba zai iya rage nakasar allon kewayawa ba, dole ne a ƙara murfi don manne allon kewayawa tare da manyan pallets na sama da na ƙasa.Wannan na iya rage matsalar nakasar allon da'ira ta wutar tanderun da aka sake fitarwa.Koyaya, wannan tire ɗin tanderun yana da tsada sosai, kuma ana buƙatar aikin hannu don sanyawa da sake sarrafa tire ɗin. 6. Yi amfani da na'ura mai ba da hanya tsakanin hanyoyin sadarwa maimakon V-Cut don amfani da ƙaramin allo Tun da V-Cut zai lalata ƙarfin tsarin tsarin jirgin tsakanin allunan da'irar, yi ƙoƙarin kada ku yi amfani da ƙaramin allo na V-Cut ko rage zurfin V-Cut.
7. Maki uku da suka gudana a cikin ƙirar injiniya: A. Tsare-tsare na prepregs interlayer ya kamata ya zama mai ma'ana, alal misali, don allunan Layer shida, kauri tsakanin 1 ~ 2 da 5 ~ 6 yadudduka da adadin prepregs ya kamata ya zama iri ɗaya, in ba haka ba yana da sauƙin warp bayan lamination. B. Multi-Layer core board da prepreg yakamata suyi amfani da samfuran masu kaya iri ɗaya. C. Yankin tsarin kewayawa a gefen A da gefen B na Layer na waje ya kamata ya kasance kusa da yiwuwar.Idan gefen A babban saman jan karfe ne, kuma gefen B yana da ƴan layuka kaɗan, irin wannan allo da aka buga zai yi sauƙi bayan etching.Idan yankin layin a bangarorin biyu ya bambanta sosai, zaku iya ƙara wasu grid masu zaman kansu a gefen bakin ciki don ma'auni. 8. Latitude da longitude na prepreg: Bayan prepreg da aka laminated, warp da weft shrinkage rates sun bambanta, kuma warp da saƙa kwatance dole ne a bambanta a lokacin blanking da lamination.In ba haka ba, yana da sauƙi don haifar da katakon da aka gama don yaduwa bayan lamination, kuma yana da wuya a gyara shi ko da an matsa lamba akan allon yin burodi.Dalilai da yawa na warpage na allon multilayer shine cewa ba a bambanta prepregs a cikin warp da saƙa a lokacin lamination, kuma an tattara su ba da gangan ba. Hanyar da za a bambance bambance-bambancen warp da saƙa: jagorar jujjuyawar prepreg a cikin jujjuyawar ita ce jagorar warp, yayin da nisa jagorar saƙa;ga allon bangon tagulla, gefe mai tsayi shine alkiblar weft sannan gajeriyar gefen ita ce hanyar warp.Idan ba ku da tabbas, tuntuɓi mai ƙira Ko tambayar mai kaya. 9. Allolin yin burodi kafin yanka: Manufar yin burodin allon kafin yanke laminate na jan karfe (digiri Celsius 150, lokaci 8 ± 2 hours) shine don cire danshi a cikin jirgi, kuma a lokaci guda ya sa guduro a cikin jirgi ya ƙulla gaba ɗaya, kuma ya ƙara kawar da shi. sauran damuwa a cikin allo, wanda ke da amfani don hana hukumar daga warping.Taimakawa.A halin yanzu, yawancin alluna masu gefe biyu da masu yawa har yanzu suna manne da matakin yin burodi kafin ko bayan blanking.Koyaya, akwai keɓancewa ga wasu masana'antar faranti.Dokokin lokacin bushewa na PCB na yau da kullun na masana'antun PCB daban-daban kuma ba su da daidaituwa, kama daga awa 4 zuwa 10.Ana ba da shawarar yanke shawara bisa ga ƙimar allon buga da aka samar da buƙatun abokin ciniki don warpage.Gasa bayan an yanka a cikin jigsaw ko bargo bayan an gasa duka block.Duk hanyoyin biyu masu yiwuwa ne.Ana bada shawarar yin gasa allon bayan yankan.Hakanan ya kamata a toya allo na ciki ... 10. Baya ga damuwa bayan lamination: Bayan da alluran da aka datse mai zafi da sanyi, sai a fitar da shi, a yanke ko a niƙa daga burar, sannan a ajiye shi a cikin tanda a digiri 150 na Celsius na 4 hours, don haka damuwa a cikin jirgin ya kasance. sannu a hankali aka saki kuma resin ya warke gaba daya.Ba za a iya barin wannan matakin ba.
11. A bakin ciki farantin yana bukatar a mike a lokacin electroplating: Lokacin da 0.4 ~ 0.6mm matsananci-bakin ciki multilayer hukumar da ake amfani da surface electroplating da juna electroplating, musamman clamping rollers ya kamata a yi.Bayan da siririn farantin da aka manne a kan tashi bas a kan atomatik electroplating line, za a yi amfani da wani zagaye sanda don dakko dukan tashi bas.Ana haɗa abin nadi tare don daidaita duk farantin da ke kan rollers ɗin don kada farantin bayan plating ɗin ya lalace.Idan ba tare da wannan ma'auni ba, bayan electroplating wani Layer na tagulla na 20 zuwa 30 microns, takardar za ta lanƙwasa kuma yana da wuya a gyara shi. 12. Sanyaya allo bayan daidaita iska mai zafi: Lokacin da aka daidaita allon bugu da iska mai zafi, zafi mai zafi na wanka mai siyarwa (kimanin digiri Celsius 250) yana tasiri.Bayan an fitar da shi, sai a sanya shi a kan dutsen marmara mai laushi ko farantin karfe don sanyaya yanayi, sannan a aika zuwa injin sarrafa kayan aiki don tsaftacewa.Wannan yana da kyau don hana yaƙe-yaƙe na hukumar.A wasu ma’aikatu, don ƙara haske a saman dalma, ana sanya allunan a cikin ruwan sanyi nan da nan bayan an ɗora iska mai zafi, sannan a fitar da ita bayan ƴan daƙiƙa guda don sarrafa su.Irin wannan tasirin zafi da sanyi na iya haifar da faɗa akan wasu nau'ikan alluna.Karkatawa, lebur ko blister.Bugu da ƙari, ana iya shigar da gadon motsa jiki na iska akan kayan aiki don sanyaya. 13. Maganin allo mai karkata: A cikin masana'anta da aka sarrafa da kyau, allon buga za a bincika 100% flatness yayin dubawa na ƙarshe.Za a fitar da dukkan allunan da ba su cancanta ba, a saka a cikin tanda, a gasa a zafin jiki na Celsius 150 a ƙarƙashin matsin lamba na tsawon sa'o'i 3-6, kuma a sanyaya su a cikin yanayi mai tsanani.Daga nan sai a rage matsa lamba don fitar da allo, sannan a duba yadda ba a yi ba, domin a samu wani bangare na allo a ajiye, sannan a rika toya wasu alluna a danna sau biyu ko uku kafin a daidaita su.Idan ba a aiwatar da matakan hana yaƙin da aka ambata a sama ba, wasu allunan za su zama marasa amfani kuma za a iya soke su kawai.
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