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 yokukhipha ukushisa yezingxenye zokushisa okuphezulu, cishe akunakwenzeka ukulindela ukushisa okuvela ku-resin ye-PCB ngokwayo ukuze kuqhutshwe ukushisa, kodwa ukukhipha ukushisa okuvela 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, inani elikhulu lokushisa elikhiqizwa izingxenye lidluliselwa ebhodini le-PCB. Ngakho-ke, indlela engcono kakhulu yokuxazulula inkinga yokushisa ukushisa ukuthuthukisa amandla okushisa okushisa kwe-PCB ngokwayo, ehlangene ngokuqondile nesici sokushisa, ngebhodi le-PCB. Kwenziwa noma kukhishwe imisebe.
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 yokukhipha ukushisa yezingxenye zokushisa okuphezulu, cishe akunakwenzeka ukulindela ukushisa okuvela ku-resin ye-PCB ngokwayo ukuze kuqhutshwe ukushisa, kodwa ukukhipha ukushisa okuvela 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, inani elikhulu lokushisa elikhiqizwa izingxenye lidluliselwa ebhodini le-PCB. Ngakho-ke, indlela engcono kakhulu yokuxazulula inkinga yokushisa ukushisa ukuthuthukisa amandla okushisa okushisa kwe-PCB ngokwayo, ehlangene ngokuqondile nesici sokushisa, ngebhodi le-PCB. Kwenziwa noma kukhishwe imisebe.
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.
Idivayisi ezwelayo kumazinga okushisa ibekwe kahle endaweni enezinga lokushisa eliphansi kakhulu (njengaphansi kwedivayisi). Ungalokothi uyibeke ngaphezu kwedivayisi yokushisisa. Kungcono ukunyakazisa amadivaysi amaningi endizeni evundlile.
Beka amadivayisi asebenzisa amandla aphezulu kakhulu kanye nokukhiqiza ukushisa eduze nendawo engcono kakhulu yokukhipha ukushisa. Ungabeki izinto zokushisisa okuphezulu emakhoneni nasemaphethelweni aseduze ebhodi eliphrintiwe, ngaphandle uma kuhlelwe isinki sokushisa eduze kwayo.
Lapho uklama isivimbeli samandla, khetha idivayisi enkulu ngangokunokwenzeka, futhi uyenze ibe nesikhala esanele sokulahla ukushisa lapho ulungisa ukwakheka kwebhodi eliphrintiwe.
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.
Izingxenye ebhodini elifanayo eliphrintiwe kufanele zihlelwe ngangokunokwenzeka ngokuvumelana nenani lazo le-calorific kanye nezinga lokukhipha ukushisa. Amadivayisi anevelu ye-calorific ephansi noma ukumelana nokushisa okungekuhle (njengama-transistors wesignali 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.
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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 ezwelayo kumazinga okushisa 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 izinto zokushisisa okuphezulu emakhoneni nasemaphethelweni aseduze ebhodi eliphrintiwe, ngaphandle uma kuhlelwe isinki sokushisa eduze kwayo. Lapho uklama isivimbeli samandla, khetha idivayisi enkulu ngangokunokwenzeka, futhi uyenze ibe nesikhala esanele sokulahla ukushisa lapho ulungisa ukwakheka kwebhodi eliphrintiwe.