Kusuka ku-PCB World
Ngemishini ye-elekthronikhi, inani elithile lokushisa likhiqizwa ngesikhathi sokusebenza, ukuze izinga lokushisa langaphakathi lemishini likhuphuke ngokushesha.Uma ukushisa kungachithwa ngesikhathi, okokusebenza kuzoqhubeka nokushisa, futhi idivayisi izohluleka ngenxa yokushisa ngokweqile.Ukuthembeka kwemishini kagesi Ukusebenza kuzokwehla.
Ngakho-ke, kubaluleke kakhulu ukuqhuba ukwelashwa okuhle kokukhipha ukushisa ebhodini lesifunda.Ukukhishwa kokushisa kwebhodi lesifunda le-PCB kuyisixhumanisi esibaluleke kakhulu, ngakho-ke iyini inqubo yokukhipha ukushisa yebhodi lesifunda le-PCB, ake sikuxoxe ndawonye ngezansi.
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Ukukhipha ukushisa ngebhodi le-PCB ngokwalo Amabhodi e-PCB asetshenziswa kabanzi njengamanje ama-copper clad/epoxy glass cloth substrates noma ama-phenolic resin glass cloth substrates, kanye nenani elincane lamabhodi anezingubo zethusi asekelwe ephepheni.
Nakuba lawa ma-substrates anezakhiwo ezinhle kakhulu zikagesi kanye nezakhiwo zokucubungula, anokukhipha ukushisa okungekuhle.Njengendlela yokushisa ukushisa yezingxenye ezishisa kakhulu, cishe akunakwenzeka ukulindela ukushisa okuzokwenziwa yi-resin ye-PCB ngokwayo, kodwa ukukhipha ukushisa kusuka ebusweni bengxenye kuya emoyeni ozungezile.
Kodwa-ke, njengoba imikhiqizo ye-elekthronikhi ingene enkathini ye-miniaturization yezingxenye, ukufakwa kwe-high-density mounting, nomhlangano wokushisa okuphezulu, akwanele ukuthembela ebusweni bengxenye enendawo encane kakhulu ukuze kukhishwe ukushisa.
Ngesikhathi esifanayo, ngenxa yokusetshenziswa okubanzi kwezingxenye ze-surface mount ezifana ne-QFP ne-BGA, ukushisa okukhiqizwa yizingxenye kudluliselwa ebhodini le-PCB ngenani elikhulu.Ngakho-ke, indlela engcono kakhulu yokuxazulula ukuchithwa kokushisa ukuthuthukisa amandla okukhipha ukushisa kwe-PCB ngokwayo ethintana ngokuqondile nesici sokushisa.Kwenziwa noma kukhishwe imisebe.
Isakhiwo se-PCB
Imishini ezwelayo eshisayo ibekwe endaweni yomoya obandayo.
Idivayisi yokuthola izinga lokushisa ibekwe endaweni eshisa kakhulu.
Amadivayisi ebhodini elifanayo eliphrintiwe kufanele ahlelwe ngokusemandleni akho ngokuvumelana nenani lawo le-calorific kanye nezinga lokukhipha ukushisa.Amadivayisi anevelu ye-calorific encane noma ukumelana nokushisa okungekuhle (njengama-transistors amasignali amancane, amasekhethi ahlanganisiwe ezinga elincane, ama-electrolytic capacitor, njll.) kufanele abekwe ekugelezeni komoya okupholisayo.Ukugeleza okuphezulu kakhulu (ekungeneni), izisetshenziswa ezinokushisa okukhulu noma ukumelana nokushisa (njengama-transistors amandla, amasekhethi amakhulu ahlanganisiwe, njll.) abekwe endaweni ephansi kakhulu yokugeleza komoya okupholisa.
Esiqondisweni esivundlile, amadivaysi anamandla aphezulu abekwe eduze nomkhawulo webhodi eliphrintiwe ngangokunokwenzeka ukuze unciphise indlela yokudlulisa ukushisa;ohlangothini olume mpo, amadivaysi anamandla aphezulu abekwe eduze nangaphezulu kwebhodi eliphrintiwe ngangokunokwenzeka ukuze kuncishiswe umthelela wale mishini ekushiseni kweminye imishini lapho isebenza .
Ukuchithwa kokushisa kwebhodi eliphrintiwe kumishini ngokuyinhloko kuncike ekugelezeni komoya, ngakho-ke indlela yokuhamba komoya kufanele ifundwe ngesikhathi sokuklama, futhi idivayisi noma ibhodi lesifunda eliphrintiwe kufanele lilungiselelwe ngokunengqondo.
Ngokuvamile kunzima ukufeza ukusabalalisa okufanayo okuqinile phakathi nenqubo yokuklama, kodwa izindawo ezinamandla amakhulu kakhulu kufanele zigwenywe ukuze kuvinjelwe izindawo ezishisayo ukuthi zingathinti ukusebenza okuvamile kwesifunda sonke.
Uma kunokwenzeka, kuyadingeka ukuhlaziya ukusebenza kahle kokushisa kwesifunda esiphrintiwe.Isibonelo, imojuli yesofthiwe yokuhlaziya inkomba yokusebenza kahle kwe-thermal engezwe kwenye isofthiwe yedizayini ye-PCB yobungcweti ingasiza abaklami balungiselele idizayini yesekethe.
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Izingxenye ezikhiqiza ukushisa okuphezulu kanye nama-radiator namapuleti abamba ukushisa.Uma inani elincane lezingxenye ku-PCB likhiqiza inani elikhulu lokushisa (ngaphansi kuka-3), i-heater sink noma ipayipi yokushisa ingangezwa ezingxenyeni ezikhiqiza ukushisa.Uma izinga lokushisa lingenakwehliswa, lingasetshenziswa Irediyetha enefeni ukuze kuthuthukiswe umphumela wokuqeda ukushisa.
Lapho inani lamadivayisi okushisa likhulu (ngaphezu kuka-3), isembozo esikhulu sokushabalalisa ukushisa (ibhodi) singasetshenziswa, okuwumshini wokushisa okhethekile owenziwe ngokwezifiso ngokwendawo nokuphakama kwedivayisi yokushisa ku-PCB noma iflethi elikhulu. usinki wokushisa Sika izindawo ezihlukene zobude bengxenye.Isembozo sokukhipha ukushisa siboshelwe ngokuphelele phezu kwengxenye, futhi sithinta ingxenye ngayinye ukuze sikhiphe ukushisa.
Nokho, umphumela wokukhipha ukushisa awumuhle ngenxa yokungaguquguquki okungekuhle kobude ngesikhathi sokuhlanganiswa nokushisela izingxenye.Ngokuvamile, isigaba esithambile sokushintsha i-thermal pad yengezwa phezu kwengxenye ukuze kuthuthukiswe umphumela wokulahla ukushisa.
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Okokusebenza okwamukela ukupholisa komoya we-convection wamahhala, kungcono ukuhlela amasekhethi ahlanganisiwe (noma amanye amadivaysi) aqonde ngqo noma avundlile.
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Sebenzisa idizayini yezintambo ephusile ukuze ubone ukunqanyulwa kokushisa.Ngenxa yokuthi i-resin epulatifeni ine-conductivity ephansi ye-thermal, futhi imigqa ye-foil yethusi nezimbobo ziyi-conductor enhle yokushisa, okwandisa izinga elisele le-foil yethusi nokwandisa izimbobo zokushisa ukushisa kuyindlela eyinhloko yokukhipha ukushisa.Ukuze uhlole amandla okukhipha ukushisa kwe-PCB, kuyadingeka ukubala ukuhanjiswa kwe-thermal okulingana (i-eq eyisishiyagalolunye) yezinto eziyinhlanganisela ezakhiwe ngezinto ezihlukahlukene ezinokuhanjiswa okushisayo okuhlukile-i-substrate evikelayo ye-PCB.
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Amadivayisi ebhodini elifanayo eliphrintiwe kufanele ahlelwe ngokusemandleni akho ngokuvumelana nenani le-calorific kanye nezinga lokukhipha ukushisa.Amadivayisi anevelu ye-calorific ephansi noma ukumelana nokushisa okungekuhle (njengama-transistors anesignali encane, amasekhethi ahlanganisiwe wezinga elincane, ama-electrolytic capacitor, njll.) kufanele abekwe ekugelezeni komoya okupholisa.Ukugeleza okuphezulu kakhulu (ekungeneni), izisetshenziswa ezinokushisa okukhulu noma ukumelana nokushisa (njengama-transistors amandla, amasekhethi amakhulu ahlanganisiwe, njll.) abekwe endaweni ephansi kakhulu yokugeleza komoya okupholisa.
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Esiqondisweni esivundlile, amadivaysi anamandla aphezulu ahlelwe eduze nomkhawulo webhodi eliphrintiwe ngangokunokwenzeka ukuze unciphise indlela yokudlulisa ukushisa;ohlangothini oluqondile, amadivaysi anamandla aphezulu ahlelwe ngokuseduze ngangokunokwenzeka phezulu kwebhodi eliphrintiwe ukuze kuncishiswe ithonya lale mishini ekushiseni kwamanye amadivaysi..
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Ukuchithwa kokushisa kwebhodi eliphrintiwe kumishini ngokuyinhloko kuncike ekugelezeni komoya, ngakho-ke indlela yokuhamba komoya kufanele ifundwe ngesikhathi sokuklama, futhi idivayisi noma ibhodi lesifunda eliphrintiwe kufanele lilungiselelwe ngokunengqondo.
Lapho umoya ugeleza, uvame ukugeleza ezindaweni ezinokumelana okuphansi, ngakho-ke lapho ulungiselela amadivaysi ebhodini lesifunda eliphrintiwe, gwema ukushiya indawo yomoya enkulu endaweni ethile.
Ukumiswa kwamabhodi esekethe aphrintiwe amaningi kuwo wonke umshini kufanele futhi kunake inkinga efanayo.
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Idivayisi engezwani nezinga lokushisa ibekwe kahle endaweni enezinga lokushisa eliphansi kakhulu (njengaphansi kwedivayisi).Ungalokothi uyibeke ngaphezu kwedivayisi yokushisisa.Kungcono ukunyakazisa amadivaysi amaningi endizeni evundlile.
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Beka amadivayisi asebenzisa amandla aphezulu kakhulu kanye nokukhiqiza ukushisa eduze nendawo engcono kakhulu yokukhipha ukushisa.Ungabeki amadivaysi okushisa okuphezulu emakhoneni nasemaphethelweni angaphandle ebhodi eliphrintiwe, ngaphandle uma i-heater sink ihlelwe eduze kwayo.Lapho uklama isivimbeli samandla, khetha idivayisi enkulu ngangokunokwenzeka, futhi uyenze ibe nesikhala esanele sokulahla ukushisa lapho ulungisa ukwakheka kwebhodi eliphrintiwe.
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Gwema ukugcwala kwezindawo ezishisayo ku-PCB, sabalalisa amandla ngokulinganayo ebhodini le-PCB ngangokunokwenzeka, futhi ugcine izinga lokushisa elingaphezulu le-PCB lisebenza ngokufanayo futhi lingaguquki.
Ngokuvamile kunzima ukufeza ukusabalalisa okufanayo okuqinile phakathi nenqubo yokuklama, kodwa izindawo ezinamandla amakhulu kakhulu kufanele zigwenywe ukuze kuvinjelwe izindawo ezishisayo ukuthi zingathinti ukusebenza okuvamile kwesifunda sonke.
Uma kunokwenzeka, kuyadingeka ukuhlaziya ukusebenza kahle kokushisa kwesifunda esiphrintiwe.Isibonelo, imojuli yesofthiwe yokuhlaziya inkomba yokusebenza kahle kwe-thermal engezwe kwenye isofthiwe yedizayini ye-PCB yobungcweti ingasiza abaklami balungiselele idizayini yesekethe.