Momwe mungapewere bolodi kupingasa

1, Chifukwa chiyani board board amafunika kukhala mosalala kwambiri

Pamzere wodziyikiratu, ngati bolodi losindikizidwa silili lathyathyathya, limapangitsa kuti pakhale malo olakwika, zinthu zomwe sizingayikidwe m’mabowo ndi zikwangwani zapamwamba za bolodi, ngakhale kuwononga makina oyikapo. Bolodi lomwe limayikidwa ndi zida limapindika pambuyo pa kuwotcherera, ndipo gawo lazinthu zimakhala zovuta kudula mosalala. Bungweli silingakhazikitsidwe pa chassis kapena socket pamakina, motero ndizovuta kwambiri kuti fakitale ya msonkhano ikumane ndi gulu lomwe likulimbana. Pakadali pano, matabwa osindikizidwa alowa munthawi yakukhazikitsa pamwamba ndi kuyikika kwa chip, ndipo malo osonkhanitsira ayenera kukhala ndi zofunikira zowongolera.

2, Njira yoyeserera yoyeserera

Malinga ndi American ipc-6012 (edition 1996) Izi zimapangitsa kuti pakhale matabwa osindikizidwa pamwamba poyerekeza ndi ipc-rb-0.75 (1.5 edition). Pakadali pano, tsamba lovomerezeka pamtundu uliwonse wamagetsi wamagetsi, kaya akhale mbali ziwiri kapena zingapo, ndi 276mm wandiweyani, nthawi zambiri 1992 ~ 1.6%. Kwa matabwa ambiri a SMT ndi BGA, amafunika kukhala 0.70%. Mafakitale ena azamagetsi amalimbikitsa kukweza miyezo ya warpage mpaka 0.75%. Njira yoyesera warpage izitsatira gb0.5-0.3 kapena ipc-tm-4677.5b. Ikani bolodi losindikizidwa papulatifomu yotsimikizika, ikani singano yoyeserera pamalowo ndi warpage yayikulu kwambiri, ndikugawa m’mimba mwake la singano yoyeserera ndi kutalika kwa m’mphepete mwa bolodi yosindikizidwa kuti muwerenge warpage wa bolodi losindikizidwa.

3, Anti warping mbale popanga

1.Kapangidwe kaukadaulo: zodzitetezera pakupanga kwa PCB:

A. Mapangidwe amkati mwa masamba omwe amachiritsidwa pakati pa zigawo azikhala ofanana. Mwachitsanzo, makulidwe pakati pa zigawo 1 ~ 2 ndi 5 ~ 6 pazigawo zisanu ndi chimodzi zizikhala zogwirizana ndi kuchuluka kwa mapepala omwe achiritsidwa, apo ayi ndikosavuta kupota pambuyo pothira.

B. Zogulitsa za wogulitsa yemweyo zitha kugwiritsidwa ntchito popanga bolodi lamitundu ingapo ndi pepala lotsitsika.

C. Malo amtundu wa mzere padziko ndi pamwamba B pazosanjikiza azikhala pafupi kwambiri momwe zingathere. Ngati pamwamba a pali mkuwa waukulu ndipo pamwamba B amangotenga mawaya ochepa, bolodi lomwe limasindikizidwa limakhala losavuta kupindika likatha. Ngati kusiyana kwa mzere pakati pa mbali ziwirizi ndikokulirapo, ma gridi ena odziyimira pawokha amatha kuwonjezeredwa mbali yopingasa moyenera.

2. Kuyanika mbale musanatseke:

Cholinga choumitsira mkuwa wovala laminate musanatseke (150 ° C, nthawi 8 ± 2 maola) ndikuchotsa chinyezi m’mbale, kulimbitsa utomoni mu mbale ndikuchotsanso kupsinjika kotsalira mu mbale, komwe kumathandiza kupewa mbale warpage. Pakadali pano, matabwa ambiri okhala ndi mbali ziwiri komanso ma multilayer amatsatirabe gawo la kuyanika musanachitike kapena pambuyo pake. Komabe, pali zosiyana m’mafakitole ena. Pakadali pano, malamulo oyimitsa nthawi yamafakitale a PCB nawonso ndi osagwirizana, kuyambira maola 4 mpaka 10. Tikulimbikitsidwa kusankha malinga ndi kuchuluka kwa matabwa osindikizidwa opangidwa ndi zomwe makasitomala amafuna kuti agwiritse ntchito warpage. Njira ziwirizi ndizotheka. Ndibwino kuti muumitse bolodi mutadula. Mbale yamkati iyeneranso kuumitsidwa.

3. Kutalika ndi latitude la pepala lakuchiritsidwa:

Kupindika ndi kuwomba kwa pepala lokutira pambuyo poti lamination ndiosiyana, kotero ulusi ndi ma weft ziyenera kusiyanitsidwa pakumangirira ndi kupukuta. Kupanda kutero, ndikosavuta kuyambitsa tsamba lomenyera mbale itatha, ndipo zimakhala zovuta kukonza ngakhale kukakamizidwa kukugwetsa mbale. Zifukwa zambiri zopangira mapepala amitundu yambiri zimayambitsidwa chifukwa chakumapeto kwa kutalika kwa masamba omwe amachiritsidwa panthawi yopuma.

Momwe mungasiyanitsire kutalika ndi kutalika? Kuwongolera koyenda kwa pepala lokutidwa kumapeto ndiko njira yolowera, ndipo m’lifupi mwake ndikuwongolera; Kwa zojambulazo zamkuwa, mbali yayitali ili mbali yakutsogolo, ndipo mbali yayifupi ili munjira yopota. Ngati simukutsimikiza, mutha kufunsa wopanga kapena wogulitsa.

4.Kutsitsimula pambuyo pothira:

Pambuyo kukanikiza kotentha ndi kuziziritsa kozizira, tengani bolodi yama multilayer, kudula kapena kugaya burr, kenako ndikuyiyika mosanjikiza mu uvuni pa 150 ℃ kwa maola 4, kuti muchepetse nkhawa zomwe zili mgululi ndikuchiritsa utomoni wonse . Gawo ili silingachotsedwe.

5. Tsambalo liyenera kuwongoledwa pakusankha kwama electroplating:

Pamene 0.4 ~ 0.6mm kopitilira muyeso-woonda multilayer bolodi ntchito mbale pamwamba electroplating ndi dongosolo electroplating, wapadera kutsina odzigudubuza adzapangidwa. Mukamangirira mbale zing’onozing’ono pakhola louluka pamizere yamagetsi yokhayokha, gwiritsani ntchito ndodo yozungulira kuti muzimangirira ma roller oyimitsa pazitsulo zonse zouluka, kuti muwongolere mbale zonse pa roller, kuti mbale zomwe zidakulungidwa zisapunduke. Popanda izi, mbale yopyapyalayo imapindika ikasanja ma microns 20 kapena 30 amkuwa, ndipo ndizovuta kuthana nayo.

6. Wozizilitsa mbale mukatha kutentha kwa mpweya:

Bokosi losindikizidwa likamayendetsedwa ndi mpweya wotentha, limakhudzidwa ndi kutentha kwakukulu kwa malo osambira a solder (pafupifupi 250 ℃), kenako adzaikidwa pamiyala yolimba kapena chitsulo kuti kuzirala kwachilengedwe, ndi kutumizidwa ku purosesa ya positi kuyeretsa. Izi ndi zabwino kwa anti warping ya board. Pofuna kukulitsa kuwala kwa malata otsogola, mafakitale ena amaika mbale m’madzi ozizira atangotsitsimutsa mpweya wotentha, ndikuwatulutsa kuti akalandire chithandizo pambuyo pa masekondi ochepa. Kutentha kumodzi kokha ndi kuzizira kumodzi kumatha kubweretsa warpage, delamination kapena kuphulika kwamitundu ina ya mbale. Kuphatikiza apo, bedi loyandama la mpweya limatha kukhazikitsidwa pazida zoziziritsa.

7. Chithandizo cha mbale yopota:

Mufakitala woyang’aniridwa bwino, 100% kuyang’anira mosasunthika kudzachitika pakuwunika komaliza kwa matabwa osindikizidwa. Matabwa onse osayenerera adzasankhidwa, kuyikidwa mu uvuni, zouma pa 150 ℃ ndikukakamizidwa kwambiri kwa maola 3 ~ 6, ndipo utakhazikika mwachilengedwe mutapanikizika kwambiri. Kenako tengani bolodi mutapanikizika ndikuwona kusasunthika. Mwanjira iyi, matabwa ena amatha kupulumutsidwa. Matabwa ena amafunika kuyanika ndi kukanikizidwa kawiri kapena katatu kuti aimitsidwe. Makina opumira ndi kuwongolera makina opangidwa ndi pneumatic oyimilidwa ndi Shanghai Huabao agwiritsidwa ntchito ndi Shanghai Bell kukonza warpage wa board board. Ngati njira zomwe zili pamwambazi sizikukwaniritsidwa, matabwa ena alibe ntchito ndipo amangowonongeka.