Kodi Zomwe Zimayambitsa PCB Board Deformation ndi Chiyani?

1. Kulemera kwa bolodi palokha kudzayambitsa kusokonezeka kwa bolodi

Generalreflow uvuniadzagwiritsa ntchito unyolo kuyendetsa bolodi kutsogolo, ndiko kuti, mbali ziwiri za bolodi ngati fulcrum yothandizira bolodi lonse.

Ngati pali zigawo zolemera kwambiri pa bolodi, kapena kukula kwa bolodi kuli kwakukulu kwambiri, kudzawonetsa kupsinjika kwapakati chifukwa cha kulemera kwake, zomwe zimapangitsa kuti bolodi likhale lopindika.

2. Kuzama kwa V-Cut ndi chingwe cholumikizira chidzakhudza kusinthika kwa bolodi.

Kwenikweni, V-Cut ndiyomwe imayambitsa kuwononga mapangidwe a bolodi, chifukwa V-Cut ndi kudula grooves pa pepala lalikulu la bolodi loyambirira, kotero kuti dera la V-Cut ndilosavuta kusokoneza.

Zotsatira za lamination zakuthupi, kapangidwe ndi zithunzi pa bolodi mapindikidwe.

PCB bolodi amapangidwa ndi pachimake bolodi ndi theka-anachiritsidwa pepala ndi akunja mkuwa zojambulazo mbamuikha pamodzi, pamene pachimake bolodi ndi mkuwa zojambulazo ndi olumala ndi kutentha pamene mbamuikha pamodzi, ndipo kuchuluka kwa mapindikidwe zimadalira coefficient of matenthedwe kukula (CTE) wa zida ziwiri.

Coefficient of thermal expansion (CTE) ya zojambula zamkuwa ndi pafupifupi 17X10-6;pomwe Z-directional CTE ya gawo lapansi wamba FR-4 ndi (50~70) X10-6 pansi pa Tg point;(250 ~ 350) X10-6 pamwamba pa TG point, ndipo X-directional CTE nthawi zambiri imakhala yofanana ndi zojambula zamkuwa chifukwa cha kukhalapo kwa nsalu zamagalasi. 

Kupindika chifukwa pa PCB board processing.

PCB bolodi processing ndondomeko mapindikidwe zimayambitsa zovuta kwambiri akhoza kugawidwa mu matenthedwe nkhawa ndi makina kupsyinjika chifukwa cha mitundu iwiri ya nkhawa.

Pakati pawo, nkhawa matenthedwe makamaka kwaiye m`kati kukanikiza pamodzi, makina kupsyinjika makamaka kwaiye mu bolodi stacking, akuchitira, kuphika ndondomeko.Zotsatirazi ndi kukambirana mwachidule za ndondomekoyi.

1. Laminate zinthu zomwe zikubwera.

Laminate ndi awiri mbali, symmetrical dongosolo, palibe zithunzi, zojambulazo mkuwa ndi galasi nsalu CTE si zosiyana kwambiri, kotero m`kati kukanikiza pamodzi pafupifupi palibe mapindikidwe chifukwa CTE osiyana.

Komabe, kukula kwakukulu kwa makina osindikizira a laminate ndi kusiyana kwa kutentha pakati pa madera osiyanasiyana a mbale yotentha kungayambitse kusiyana pang'ono pa liwiro ndi digiri ya machiritso a utomoni m'madera osiyanasiyana a ndondomeko ya lamination, komanso kusiyana kwakukulu kwa kukhuthala kwamphamvu. pamitundu yosiyanasiyana yotenthetsera, kotero padzakhalanso kupsinjika kwanuko chifukwa cha kusiyana kwa machiritso.

Nthawi zambiri, kupsinjika kumeneku kudzakhalabe chimodzimodzi pambuyo pa kuyanika, koma kumatulutsidwa pang'onopang'ono m'tsogolomu kuti apange mapindikidwe.

2. Lamination.

PCB lamination ndondomeko ndi njira yaikulu kupanga matenthedwe nkhawa, mofanana laminate lamination, adzatulutsanso maganizo m'deralo anabweretsa kusiyana mu ndondomeko kuchiritsa, PCB bolodi chifukwa thicker, likugawa kugawa, zambiri theka-anachiritsidwa pepala, etc. kupanikizika kwake kwa kutentha kudzakhalanso kovuta kuthetsa kusiyana ndi laminate yamkuwa.

Zopsyinjika zomwe zili mu bolodi la PCB zimatulutsidwa m'njira zotsatila monga kubowola, kuumba kapena kuwotcha, zomwe zimapangitsa kuti bolodi iwonongeke.

3. Njira zophika monga solder kukana ndi khalidwe.

Monga solder kukana inki machiritso sangathe zakhala zikuunikidwa pamwamba pa mzake, kotero PCB bolodi adzaikidwa ofukula mu choyikamo kuphika bolodi kuchiritsa, solder kukana kutentha pafupifupi 150 ℃, basi pamwamba Tg mfundo otsika Tg zakuthupi, Tg mfundo. pamwamba pa utomoni kwa mkulu zotanuka boma, bolodi n'zosavuta mapindikidwe pansi pa zotsatira za kudziona kulemera kapena amphamvu mphepo uvuni.

4. Kutentha kwa solder kwa mpweya.

Wamba bolodi otentha mpweya solder kusalaza ng'anjo kutentha 225 ℃ ~ 265 ℃, nthawi 3S-6S.kutentha mpweya kutentha 280 ℃ ~ 300 ℃.

Solder leveling bolodi kuchokera firiji kulowa mu ng'anjo, kunja kwa ng'anjo mkati mwa mphindi ziwiri ndiyeno kutentha kwa chipinda pambuyo pokonza madzi kutsuka.Yonse yotentha mpweya solder kusanja ndondomeko mwadzidzidzi kutentha ndi kuzizira ndondomeko.

Chifukwa zinthu bolodi ndi osiyana, ndi dongosolo si yunifolomu, mu yotentha ndi kuzizira ndondomeko womangidwa kupsinjika matenthedwe, chifukwa yaying'ono kupsyinjika ndi wonse mapindikidwe warpage.

5. Kusungirako.

PCB bolodi mu theka-anamaliza siteji yosungirako zambiri ofukula anaikapo mu alumali, alumali kukangana kusintha si koyenera, kapena kusunga ndondomeko stacking kuika bolodi adzapanga gulu mapindikidwe makina.Makamaka 2.0mm pansi pa bolodi woonda kwambiri zimakhudza kwambiri.

Kuwonjezera pa zinthu pamwamba, pali zinthu zambiri zimene zimakhudza PCB bolodi mapindikidwe.

YS350+N8+IN12


Nthawi yotumiza: Sep-01-2022

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