I-Lead vs Soldering Free and Solder Melting Points ku-PCB

indawo yokuncibilika kwe-solder

Imboni ye-elekthronikhi yomhlaba wonke ibhekene noshintsho olukhulu oluya ezindleleni ezigcina imvelo. Isici esisodwa esibalulekile salolu shintsho ukusuka ekuhlanganisweni okusekelwe kumthofu okungokwesiko ukuya ekuhlanganisweni kwamahhala komthofu ku-Printed Circuit Board Assembly (PCBA). Ukuqonda ama-nuances phakathi kwalezi zindlela ezimbili zokunamathisela kubalulekile ekuqinisekiseni ukwethembeka, ukusebenza, kanye nokuhambisana kwemvelo kwemikhiqizo ye-elekthronikhi. Lesi sihloko esibanzi sicubungula izici zobuchwepheshe, izinselele, nokucatshangelwa okungokoqobo kwawo womabili amasu okudayiswa, ehlinzeka ngemininingwane ebalulekile kochwepheshe embonini ye-PCB.

Ukubaluleka Kwamajoyinti E-Solder

Amajoyinti e-solder awumgogodla wemihlangano ye-elekthronikhi, esungula kokubili ukuxhumana kwemishini nokukagesi phakathi kwezingxenye nama-PCB. Ubuqotho bala malungu bubalulekile; ngisho nejoyinti elilodwa le-solder elinesici lingaphazamisa ukusebenza kwayo yonke idivayisi ye-elekthronikhi. Ngakho-ke, ukuqonda izakhiwo nokuziphatha kwezinhlobo ezahlukene ze-solder kubalulekile ekuzuzeni ukwethembeka okuphezulu ekukhiqizeni ngogesi.

I-Traditional Lead Soldering

Ukwakheka Nezakhiwo Zesoda Esisekelwe Umthofu

I-solder esekelwe kumthofu, ngokuvamile i-tin-lead (SnPb) alloy, bekuyindinganiso yemboni amashumi eminyaka. Ukwakhiwa okusetshenziswe kakhulu, i-Sn37Pb, inikeza izici eziningana ezinenzuzo:

• Indawo yokuphuza: Ukwakheka kwe-eutectic kwe-Sn37Pb kuncibilika ngezinga lokushisa eliphansi kakhulu lika-183°C.
• Ukubamanzi: Ukumanzisa okuhle kakhulu kuqinisekisa amalunga aqinile futhi anokwethenjelwa.
• Izici zemishini: Isoda yomthofu ithambile uma kuqhathaniswa, ihlinzeka ngokumuncwa okuhle kokushaqeka nokusabalalisa ingcindezi.

Izinzuzo zokuthungatha okusekelwe kumthofu

Izinzuzo eziyinhloko zokusebenzisa i-lead solder zifaka:

• Indawo Encibilika Ephansi: Isiza izinqubo zokudambisa ezilula nezingasebenzisi kakhulu amandla.
• I-Superior Wettability: Iqinisekisa ukunamathela okuqinile phakathi kwezingxenye nama-PCB.
• Ukusebenza Okuthembekile Komshini: Ukuthamba kwe-solder kusiza ukumunca izingcindezi zemishini, kuthuthukise ukuqina kwamalunga.

Izingozi Zezempilo Nezemvelo

Naphezu kwezinzuzo zawo zobuchwepheshe, umthofu unobuthi obukhulu, ubeka ubungozi obukhulu bezempilo kubasebenzi kanye nobungozi bemvelo. Lokhu kuholele emithethweni eqinile kanye nokuphushela umhlaba wonke ekuqedeni ukuhola emibuthanweni ye-elekthronikhi.

indawo yokuncibilika kwe-solder

I-Lead-Free Soldering

Ukwakheka Nezakhiwo Zesoda Esingenamthofu

Ama-alloys angenawo umthofu, akhiwe ngokuyinhloko nge-tin-silver-copper (SAC) amafomu afana ne-SAC305 (96.5% Sn, 3.0% Ag, 0.5% Cu), avele njengenye indlela evumelana nemvelo. Izici ezibalulekile zifaka:

• Indawo yokuphuza: I-SAC305 incibilika cishe ku-217°C, ephakeme kunesoda esekelwe kumthofu.
• Ukubamanzi: Ngokujwayelekile impofu kune-lead solder, edinga ukuguquguquka okusebenzayo.
• Izici zemishini: Amajoyinti e-solder angenawo umthofu avame ukuba nzima futhi abe brittle.

Izinselelo Zokusoda Ngaphandle Komthofu

Ukushintshela ekuhlanganisweni okungenayo umthofu kwethula izinselele ezimbalwa:

• I-Higher Melting Point: Idinga amazinga okushisa aphezulu okucubungula, okwandisa ingcindezi yokushisa ezingxenyeni nama-PCB.
• Ukuqina: Amalungu e-solder angenawo umthofu athambekele kakhulu ekuqhekekeni nasekukhathaleni, ikakhulukazi ngaphansi kwezimo ezishisayo zamabhayisikili.
• Izinkinga zokumanzisa: Ukumanzisa okungekuhle kungaholela ekuhlanganiseni okungaphelele noma okubuthakathaka, okudinga ukulawulwa okunembile kwemingcele ye-solder.

Ukuqhathanisa Okuphelele Phakathi Kokuthungatha Okuholayo Nokungena Umthofu

I-Melting Point kanye ne-Thermal Stress

Ukushintsha kusuka ekuholeni okusekelwe kumthofu kuya ekuhlanganisweni okungenayo i-lead kuhilela izinguquko eziphawulekayo kuphrofayili yokushisa yenqubo ye-solder. Amasoda angenawo umthofu, njengalawo asuselwe kuma-alloys e-tin-silver-copper (SAC), anamaphuzu ancibilikayo aphezulu (cishe ngo-217°C) uma kuqhathaniswa nesolder ye-tin-lead (SnPb) yendabuko (183°C). Leli phuzu eliphakeme lokuncibilika landisa umthwalo oshisayo ngesikhathi sokuhlanganisa, okuholela ezinkingeni eziningi ezingaba khona:

• Ukugoqa: Izinga lokushisa eliphakeme lingabangela i-substrate ye-PCB ukuthi igoqe, ikakhulukazi uma ingashisi ngendlela efanayo.
• Ukudilizwa: Izendlalelo ze-PCB zingahlukana ngaphansi kwengcindezi yamazinga okushisa aphezulu.
• Ukulimala Kwengxenye: Izingxenye ezizwelayo zingase zingamelani namazinga okushisa aphezulu okugeleza kabusha adingekayo ukuze kuhlanganiswe umthofu ongenamthofu.

Ukuze kuncishiswe lezi zingozi, ukuphathwa ngokucophelela kokushisa kubalulekile. Lokhu kuhlanganisa nokwenza kahle iphrofayela yokugeleza kabusha ukuze kuqinisekiswe ngisho nokushisisa, ukusebenzisa izigaba zokushisa ngaphambi kokunciphisa ukushaqeka okushisayo, nokukhetha izinto ezisetshenziswayo ezinokuzinza okuphezulu kwe-thermal.

Ukwethembeka Komshini

Ukuthembeka kwemishini kuyisici esibalulekile ekusebenzeni okuhlangene kwe-solder. Amajoyinti e-solder angenawo umthofu ngokuvamile aqina futhi ashwabene kakhulu uma kuqhathaniswa nozakwabo abasekelwe kumthofu. Lo mehluko wezakhiwo zemishini unemithelela eminingi:

• Ukuphamba: Ukonakala kwamasoda angenawo umthofu kuwenza athambekele kakhulu ekuqhekekeni ngaphansi kwengcindezi yemishini.
• Ukukhathala: Ukuhamba ngebhayisikili okushisayo okuphindaphindiwe, okuvamile kuma-elekthronikhi wezimoto kanye ne-aerospace, kungaholela ekuhlulekeni kokukhathala kumajoyinti e-solder angenawo umthofu.

Ukubhekana nalezi zinselele kudinga amasu athile, afana nalawa:

• Ukukhethwa kwe-alloy: Ukusebenzisa ama-alloys anezengezo ezincane zama-elementi afana ne-bismuth noma i-nickel kungathuthukisa izici zemishini zamasoda angenawo umthofu.
• Idizayini Ehlangene: Ukuklama amalunga e-solder ukusabalalisa ukucindezeleka ngokulinganayo futhi kunciphise amaphuzu okuhlushwa.
• Amasu Okuqinisa: Ukusebenzisa i-underfill noma ezinye izindlela zokuqinisa ukusekela amalunga e-solder nokuthuthukisa ukuqina kwawo.

Ukumanzisa kanye Nokwakheka Okuhlangene

Ukumanzisa kuyimpahla ebalulekile ethinta ukwakheka nokuthembeka kwamalunga e-solder. Amasoda asekelwe kumthofu abonisa ukumanzisa okuhle kakhulu, akha amalunga aqinile futhi athembekile ngomzamo omncane. Ngokuphambene, ama-solder angenawo umthofu ngokuvamile ahlushwa ukumanzisa okuphansi, okuholela ezinkingeni ezingaba khona:

• Ukumanzisa okungaphelele: Ukumanzisa okungekuhle kungabangela ukumbozwa okungaphelele kwephedi, okuholela emalungeni abuthakathaka.
• Ukuvala: Umoya oboshiwe noma izinsalela ze-flux zingadala izikhala ngaphakathi kwejoyinti le-solder, kulimaze ubuqotho bayo bemishini nogesi.

Ukuqinisekisa ukwakheka okuhlangene kwekhwalithi ephezulu ngama-solder angenawo umthofu, amasu amaningana angasetshenziswa:

• Ama-Active Fluxes: Ukusebenzisa ukwakheka kwe-flux okusebenzayo okukhuthaza ukumanzisa okungcono nokunciphisa i-oxidation.
• Kwengezwe Soldering Amapharamitha: Ukulungisa izinga lokushisa le-soldering, isikhathi, kanye nomkhathi ukuze kuthuthukiswe ukumanzisa.
• Ukulungiselela Ubuso: Ukuqinisekisa ukuthi izindawo ezizothengiswa zihlanzekile futhi azinawo ama-oxide.

Umthelela Wezemvelo Nezempilo

Isisusa esiyinhloko sokushintshela ekusongweni okungenamthofu ukwehla okukhulu kwezingozi zemvelo nezempilo ezihlobene nokuchayeka kumthofu. Umthofu uyinto enobuthi ebeka izingozi ezinkulu empilweni yabantu kanye nasemvelweni, okuholela emithethweni eqinile njengesiqondiso se-Restriction of Hazardous Substances ( RoHS ). Ukusongwa okungenamthofu kunikeza izinzuzo eziningana kulokhu:

• Ubuthi obuncishisiwe: Ukuqeda umthofu ohlelweni lokudayiswa kunciphisa kakhulu ubungozi bokuchayeka kubasebenzi futhi kunciphisa ukungcoliswa kwemvelo.
• Ukuthobela Ukulawula: Ukwamukela izinqubo zokudambisa ezingenamthofu kuqinisekisa ukuthobela imithetho yemvelo yomhlaba wonke.

Kodwa-ke, i-solder-free soldering ayinakho ukuhwebelana kwayo. Amazinga okushisa aphezulu okucutshungulwa adingekayo kuma-solder angenawo umthofu anyusa ukusetshenziswa kwamandla, okungaba nomthelela kuyo yonke indawo yemvelo. Ukulinganisa lokhu kukhathazeka, abakhiqizi bangasebenzisa imikhuba yokonga amandla, njenge:

• Ukuphatha Okushisayo Okusebenzayo: Ukulungiselela ama-ovens agelezayo nezinye izinto zokushisisa ukuze kuncishiswe ukusetshenziswa kwamandla.
• Izinto Ezithuthukisiwe: Ukuthuthukisa nokusebenzisa izinto ezivumela izinqubo zokusoda ezingaholeli izinga lokushisa eliphansi.
• Ukugaywa kabusha kanye Nokuphathwa Kwemfucuza: Ukuthuthukisa imizamo yokugaywa kabusha kanye nokuphatha imfucuza ukuze kuncishiswe umthelela wendawo.

Ukuqhathaniswa Okuningiliziwe Kwezici Zomzimba

Ukukhombisa umehluko phakathi kwe-lead ne-lead-free soldering, nasi isiqhathaniso esiningiliziwe sezakhiwo zakho ezibonakalayo:

Ukuqhathaniswa Okuningiliziwe Kwezici Zomzimba

Izinselelo Ekuhlanganisweni Okungadingi Umthofu

Ukuxhuma

Amazinga okushisa aphezulu e-solder akhulisa ingozi ye-oxidation, enganciphisa ikhwalithi yamalunga e-solder. Le nselele idinga ukwakheka okungcono kwe-flux kanye nezimo ezilawulwayo zokunamathisela ukuze kugcinwe ubuqotho obuhlangene.

Ukuhambisana Kwengxenye

Ezinye izingxenye, ikakhulukazi lezo ezinamaphakeji epulasitiki noma ama-electrolytic capacitor, zingase zingamelani namazinga okushisa aphezulu adingekayo ukuze kufakwe umthofu ngaphandle komthofu. Ukukhetha ngokucophelela izingxenye kanye nokulungiswa komklamo okungaba khona kuyadingeka ukuze kuqinisekiswe ukuhambisana.

Ama-tin Whiskers

Amasoda angenawo umthofu, ikakhulukazi lawo anothayela ophezulu, athambekele ekukhuleni kwentshebe, okungadala izikhindi zikagesi. Amasu okunciphisa ahlanganisa ukusebenzisa izendlalelo zesithiyo njenge-nickel nokukhetha ukwakheka kwengxubevange efanele.

I-Conductive Anodic Filament (CAF)

Ukusoda okungenamthofu kungabhebhethekisa ukwakheka kwe-CAF kuma-PCB, okuholela kumasekethe amafushane kanye nokwehluleka. Izinto eziqinile nezilawuli zenqubo zibalulekile ukuze kuvinjelwe le nkinga, ikakhulukazi ezindaweni eziminyana kakhulu.

Ukucatshangelwa Okusebenzayo Kokushintshela Ekufakweni Kwe-Lead-Free Soldering

Ukulungiswa Kwenqubo

Ukushintshela ekuthengisweni okungenayo umthofu kudinga ukulungiswa kumazinga okushisa e-solder, amaphrofayili esikhathi, nokulinganiswa kwemishini ukuze kuhambisane nezindawo ezincibilikayo eziphakeme kanye nezici zokugeleza ezihlukene zama-alloys angenawo umthofu.

Ukukhetha Izinto

Ukukhetha izinto ezifanele kubalulekile. Izingxenye kufanele zikwazi ukumelana namazinga okushisa aphezulu, futhi ama-PCB kufanele abe namavelu afanelekile e-Tg (i-glass transition temperature). Lokhu kuqinisekisa ukuthi umhlangano ungabekezelela inqubo ye-solder yamahhala ngaphandle kokuyekethisa ukusebenza.

Idizayini Yokukhiqiza (I-DFM)

Izimiso ze-DFM kufanele zishintshwe ukuze kubhekwane nokuphathwa kokushisa, ukwethembeka ngokuhlanganyela, kanye nokubekwa kwengxenye. Ukuthuthukisa imiklamo yamaphedi kanye nokuqinisekisa ukukhululeka okwanele kokushisa kubalulekile ukuze kuhlanganiswe ngempumelelo ngaphandle komthofu.

Ikhwalithi yokulawula

Izindlela zokulawula ikhwalithi ezithuthukisiwe, okuhlanganisa ukuhlolwa kwe-X-ray kanye nokuhlolwa okuzenzakalelayo kwe-optical (AOI), ziyadingeka ukuthola nokulungisa amaphutha athile ekusongweni okungenalo i-lead. Lokhu kuhlolwa kusiza ukuqinisekisa ukuthembeka kwamajoyinti e-solder kanye nekhwalithi iyonke ye-assembly.

Ukucatshangelwa Okubalulekile Konjiniyela be-CAM

I-Surface Qeda Uhlobo kanye nomthelela ekudalweni kwefayela le-Gerber

Lapho beklama amabhodi anobuningi obuphezulu, onjiniyela be-CAM kudingeka bacabangele uhlobo lokuphela kobuso. Ezinqubweni zobuso obufuthwe ngethini, amanani okubhoboza nokubuyisela umzila aphezulu uma kuqhathaniswa nezinqubo zobuso obufuthwe ngethini. Lokhu kudinga ukucatshangelwa ngokucophelela inqubo yobuso, usayizi wokubhoboza, kanye nobubanzi kanye nesikhala semikhondo. Ngaphezu kwalokho, ukugoqa okungenalo i-lead, kanye nokushisa kwayo okuphezulu kokucubungula, kuthinta ukwanda kokushisa kwemikhondo. Ngakho-ke, ububanzi bemikhondo kumele buklanywe ukuze kusingathwe umthwalo wamanje olindelekile ngaphandle kokushisa ngokweqile. Isikhala esifanele phakathi kwemikhondo sibalulekile futhi ukuvimbela imikhondo emifushane, ikakhulukazi emiklamo yobuningi obuphezulu.

Ukucatshangelwa kukagesi kanye nokushisa

Uhlobo lokuqedwa kwendawo luthinta ngokuqondile ukushuba kwebhodi kanye nokuvunyelwa kwemaski ye-solder. Ukuqedwa okuhlukene kunezidingo ezihlukene zokujiya; isibonelo, ukufafaza nge-tin kudinga ukunakwa kobukhulu bebhodi elincane ukuze kuvinjwe ibhodi ukuthi liqhunyiswe phakathi nenqubo. Ukwengeza, isiphetho esingaphezulu sithinta imvume ye-mask ye-solder edingekayo. Iziqephu ezifuthwe ngothayela zinezakhiwo ezihlukile zomzimba kuneziqephu ezingafafazwe ngamathini, okudinga ukulungiswa okuqondile kokucaciswa ukuze kuqinisekiswe ukusebenza kahle nokwethembeka.

I-Solder Mask Design kanye ne-Pad Layout

Ekwakheni imaski ye-solder, kubalulekile ukuqinisekisa ukunwetshwa okufanele eduze kwamaphedi ukuze kuhlangatshezwane nokuqedwa kwendawo ekhethiwe ye-solder. Ukuqedwa okungenamthofu, okuvamise ukubandakanya amazinga okushisa aphezulu okusoda, kungase kudinge ukunwetshwa okukhulu ukuze ubhekane nengcindezi yokushisa. Ukuqondanisa okunembile kwemaski ye-solder ku-pad kubalulekile, njengoba ukungaqondi kahle kungaholela ekuhlanganisweni kwe-solder noma amajoyini e-solder ampofu. Mayelana nesakhiwo sephedi, ukugcina usayizi wephedi ongaguquki kanye nokuma kubalulekile kumajoyinti afanayo we-solder. Lokhu kubaluleke kakhulu ekuhlanganisweni okunganomthofu, lapho amalunga aqina futhi ashwabene kakhudlwana edinga ukwakheka kwephedi okunembe ukuze kuvinjelwe ukwehluleka kokusebenza. Imiklamo ye-Via-in-pad kufanele igwenywe ngaphandle kokuthi igcwaliswe kahle futhi ifakwe i-capped ukuvimbela i-solder wicking kanye ne-voiding.

Isiphetho

Ushintsho oluvela ekusongweni kwe-lead kuya ekusongweni okungenalo i-lead ku -PCBA luqhutshwa yizinto ezicatshangelwayo zemvelo nezempilo, okuletha izinselele ezinkulu zobuchwepheshe. Ukuqonda umehluko ezimpahleni zomzimba, izidingo zenqubo, kanye nezindlela zokwehluleka ezingaba khona kubalulekile ekufinyeleleni amalunga e-solder athembekile nasezingeni eliphezulu ekuhlanganisweni okungenalo i-lead.

Ngenkathi i-solder engenawo umthofu iveza izithiyo ezifana namazinga okushisa aphezulu okucubungula, ukukhuphuka kwe-oxidation, kanye nezinkinga ezingaba khona zokwethenjelwa, lokhu kungancishiswa ngokulawula inqubo ngokucophelela, ukukhethwa kwezinto ezibonakalayo, nokuzivumelanisa nedizayini. Njengoba imboni iqhubeka nokuthuthuka, ucwaningo oluqhubekayo kanye nokuthuthuka kwezobuchwepheshe kuzothuthukisa ukuthembeka nokusebenza kokudayiswa okungakhokhelwa komthofu ekukhiqizeni ngogesi.