Malinga ndi European RoHS Directive (Directive Act of the European Parliament and the Council of the European Union pa zoletsa kugwiritsa ntchito zinthu zina zowopsa pazida zamagetsi ndi zamagetsi), Lamuloli likufuna kuletsa msika wa EU kugulitsa zamagetsi ndi zamagetsi. zida zamagetsi zomwe zili ndi zinthu zisanu ndi chimodzi zowopsa monga lead ngati "kupanga zobiriwira" zopanda lead zomwe zakhala chitukuko chosasinthika kuyambira pa Julayi 1, 2006.
Patha zaka zopitirira ziwiri kuchokera pamene ndondomeko yopanda kutsogolera inayamba kuyambira pokonzekera.Opanga zinthu zambiri zamagetsi ku China apeza zambiri zamtengo wapatali pakusintha kwachangu kuchokera ku soldering wopanda lead kupita ku soldering wopanda lead.Tsopano popeza njira yopanda chitsogozo ikukulirakulira, zomwe opanga ambiri amagwiritsa ntchito zasintha kuchoka pakutha kugwiritsa ntchito kupanga zopanda lead mpaka momwe angasinthire momveka bwino kuchuluka kwazitsulo zopanda lead kuchokera kuzinthu zosiyanasiyana monga zida. , zipangizo, khalidwe, njira ndi kugwiritsa ntchito mphamvu..
The lead-free reflow soldering process ndiye njira yofunika kwambiri yolumikizirana muukadaulo wamakono wokwera pamwamba.Zakhala zikugwiritsidwa ntchito kwambiri m'mafakitale ambiri kuphatikiza mafoni am'manja, makompyuta, zamagetsi zamagalimoto, mabwalo owongolera ndi kulumikizana.Zida zamagetsi zochulukirachulukira zimasinthidwa kuchoka pabowo kupita kumtunda, ndipo reflow soldering imalowa m'malo mwa ma wave soldering mumitundu yambiri ndizochitika zodziwikiratu pamakampani ogulitsa.
Ndiye ndi gawo lanji lomwe zida zogulitsira zowonjezera zimagwira ntchito munjira yokhwima yopanda lead ya SMT?Tiyeni tiwone momwe mungawonere mzere wonse wa SMT pamwamba:
Mzere wonse wa SMT pamwamba pa phiri nthawi zambiri umakhala ndi magawo atatu: chosindikizira chophimba, makina oyika ndi uvuni wotulukanso.Kwa makina oyika, poyerekeza ndi opanda lead, palibe chofunikira chatsopano pazida zokha;Kwa makina osindikizira a zenera, chifukwa cha kusiyana pang'ono kwa thupi la phala lopanda kutsogolo ndi lotsogola, zofunikira zina zowonjezera zimayikidwa patsogolo pazida zokha, koma palibe kusintha kwa khalidwe;Vuto la kukakamiza kopanda lead kuli ndendende pa uvuni wa reflow.
Monga mukudziwira, malo osungunuka a lead solder phala (Sn63Pb37) ndi madigiri 183.Ngati mukufuna kupanga cholumikizira chabwino cha solder, muyenera kukhala ndi makulidwe a 0.5-3.5um amitundu ya intermetallic panthawi ya soldering.Kutentha kwa mapangidwe a intermetallic mankhwala ndi madigiri 10-15 pamwamba pa malo osungunuka, omwe ndi 195-200 pazitsulo zotsogolera.digiri.Kutentha kwakukulu kwa zida zoyambira zamagetsi pa bolodi lozungulira nthawi zambiri kumakhala madigiri 240.Chifukwa chake, pazitsulo zotsogola, zenera labwino la soldering ndi 195-240 madigiri.
Kuwotcha kopanda kutsogolera kwabweretsa kusintha kwakukulu pazitsulo zazitsulo chifukwa malo osungunuka a phala la solder lopanda kutsogolera asintha.Phala la solder lomwe limagwiritsidwa ntchito kwambiri ndi Sn96Ag0.5Cu3.5 lomwe limasungunuka madigiri 217-221.Kuwotchera kwabwino kopanda kutsogolo kuyeneranso kupanga ma intermetallic okhala ndi makulidwe a 0.5-3.5um.Kutentha kwapangidwe kwa intermetallic compounds kumakhalanso madigiri 10-15 pamwamba pa malo osungunuka, omwe ndi 230-235 madigiri a soldering opanda lead.Popeza kutentha kwakukulu kwa zida zamagetsi zoyambira zopanda lead sizisintha, zenera labwino kwambiri la soldering lopanda lead ndi madigiri 230-240.
Kuchepetsa kwambiri zenera ndondomeko kwabweretsa mavuto aakulu kutsimikizira kuwotcherera khalidwe, ndipo wabweretsanso zofunika apamwamba bata ndi kudalirika kwa lead-free soldering zida.Chifukwa cha lateral kutentha kusiyana mu zipangizo palokha, ndi kusiyana matenthedwe mphamvu ya choyambirira zigawo zikuluzikulu pakompyuta pa Kutentha ndondomeko, ndi soldering kutentha ndondomeko zenera osiyanasiyana zimene zingasinthidwe mu lead-free reflow soldering ndondomeko kulamulira kumakhala kochepa kwambiri. .Uku ndiye vuto lenileni la soldering wopanda lead reflow soldering.Kufananitsa kwazenera kopanda kutsogolo komanso kosatsogolera kukuwonetsa pazithunzi 1.
Mwachidule, uvuni wa reflow umagwira ntchito yofunika kwambiri pamtundu wazinthu zomaliza kuchokera kumayendedwe onse opanda lead.Komabe, malinga ndi momwe ndalama zimakhalira mumzere wonse wopangira ma SMT, ndalama zogulira ng'anjo zopanda lead nthawi zambiri zimangotengera 10-25% ya ndalamazo mumzere wonse wa SMT.Ichi ndichifukwa chake opanga zamagetsi ambiri adasinthiratu ma uvuni awo oyambilira ndi ma ovuni apamwamba kwambiri atasinthiratu kupanga zopanda lead.
Nthawi yotumiza: Aug-10-2020