Ukuhlaziywa Kwesici kanye Nokuthuthukiswa Kwenqubo Yamajoyinti E-BGA Solder

Isingeniso

Ukupakishwa kwe-Ball Grid Array (BGA) sekuvele njengobuchwepheshe obubalulekile embonini ye-electronics, ikakhulukazi kusukela yethulwa ekuqaleni kwawo-1990. Le ndlela yokupakisha ibe yimfuneko njengoba inani lezikhonkwane zedivayisi kumaphakheji anomthofu wendabuko likhula, okubangele ukuba isikhala somthofu sehle kakhulu. Lokhu kuholele ezinseleleni ekwenziweni nasekuthembekeni ngesikhathi sokudayiswa kwedivayisi, nesikhala esincane esifinyelela ngaphansi kuka-0.3mm (12mil). Ukuze kubhekwane nalezi zinkinga, kwathuthukiswa ubuchwepheshe be-BGA, okuvumela ukuba kube nenani eliphakeme lamaphinikhodi uma kuqhathaniswa namaPhakheji e-Quad Flat (QFP) anosayizi ofanayo.

Amadivayisi e-BGA athembele kumabhola e-solder ngaphansi kwe-chip ukuze asebenze njengezikhonkwane zawo. I-pitch enkulu yalawa mabhola e-solder yenza ukuhlanganisa kube lula, kuthuthukisa ngokuphawulekayo amazinga okufaneleka kwe-solder kanye namazinga okuphumelela kokuqala.

Izinhlobo ezimbili ezivamile zokupakisha i-BGA yi-Plastic BGA (PBGA), evame ukusetshenziswa emikhiqizweni yabathengi neyokuxhumana, kanye ne-Ceramic BGA ( CBGA), esetshenziswa ezinhlotsheni zempi. Ukwakheka kwebhola le-solder kuvame ukufaka i-63% tin (Sn) kanye ne-37% lead (Pb) ye-eutectic solder kumadivayisi e-PBGA, kuyilapho amadivayisi e-CBGA esebenzisa i-solder engeyona i-eutectic eshisa kakhulu eyakhiwe yi-10% Pb kanye ne-90% Sn. Ukuvela kobuchwepheshe be-BGA kuholele nasekuthuthukisweni kwama-BGA amancane, abizwa ngokuthi ama-microBGA (μBGA) noma ama-Chip Scale Packages (CSP), anezindawo ezincane kakhulu zebhola le-solder ezingaphansi kwe-0.3mm (12mil) kanye nesikhala sebhola le-solder esingaphansi kwe-0.5mm (12mil).

Lesi sihloko sihlola indlela yokwamukela, ukusebenza kwesici, nokuthembeka kwamalunga e-BGA solder, ngokugxila ikakhulukazi endaweni eyimpikiswano - voids. Ukwengeza, sizophakamisa ukuthuthukiswa kwenqubo okuhloswe ngayo ukuthuthukisa ikhwalithi yamajoyinti e-solder e-BGA.

Ukuhlolwa kwekhwalithi ye-BGA Soldering

Ukuhlola ikhwalithi yamajoyinti e-solder e-Ball Grid Array (BGA) kuyisici esibalulekile sokuqinisekisa ukuthembeka nokusebenza kwamadivayisi kagesi. Ngenxa yemvelo eyingqayizivele yamaphakheji e-BGA, lapho amabhola e-solder ebekwe ngaphansi kwe-chip, izindlela zokuhlola ezibonakalayo zendabuko azanele. Lesi sigaba sizogxila kumasu ahlukahlukene nezinselele ezihlobene nokuhlola ikhwalithi ye-soldering ye-BGA.

Izinselelo ku-BGA Solder Joint Inspection

1. Amajoyinti e-Solder angafinyeleleki: Inselele enkulu ilele ekungafinyelelekiyo kwamajoyinti e-solder e-BGA. Ngokungafani ne- through-hole noma i-surface-mount components lapho amalunga e-solder evezwa khona, ama-BGA anamabhola e-solder afihlwe ngaphansi kwengxenye. Lokhu kwenza kube nzima ukuhlola ngokubonakalayo amalunga ngokuqondile.
2. Isikhala Esikhawulelwe: Umklamo ohlangene wama-BGA ushiya indawo encane yamathuluzi namasu okuhlola. I-pitch eqinile phakathi kwamabhola e-solder yenza kube nzima ukufinyelela nokuhlola amalunga angawodwana.
3. Ubunkimbinkimbi: Imishini kagesi ivamise ukuqukatha ama-BGA amaningi, ngalinye linamajoyinti amaningi e-solder. Ukuhlola wonke la malungu ngokucophelela nangempumelelo kungaba umsebenzi onzima.
4. Ukuhlonza iphutha: Ukuhlonza ukukhubazeka ngaphakathi kwamajoyinti e-solder e-BGA, njengokuqhekeka, i-voids, noma ukumanzisa okungaphelele, kudinga okokusebenza okukhethekile kanye nobuchwepheshe.

Ukuqinisekisa ikhwalithi kanye nokuthembeka kwamajoyinti e-BGA solder kudinga amasu okuhlola asebenzayo. Ukuze uthole ulwazi olwengeziwe, sicela ubheke i -The Need for Weld Inspection Using a Digital Microscope: Inspection Methods Explained | Active Wave Digital Microscope.

Amasu e-BGA Solder Joint Inspection

Ukuze unqobe lezi zinselele, kusungulwe amasu namathuluzi okuhlola ahlukahlukene ukuze kuhlolwe ikhwalithi yamalunga e-BGA solder. Lezi zindlela zihlanganisa:

1. Ukuhlolwa kwe-X-ray:

Ukuhlolwa kwe-X-ray kuyindlela esetshenziswa kakhulu yokuhlola ikhwalithi ehlangene ye-BGA solder. Inikeza indlela engonakali yokubona ngaphakathi kwephakheji ye-BGA futhi ihlole ubuqotho bamalunga e-solder. Kunezinhlobo ezimbili eziyinhloko zokuhlolwa kwe-X-ray:

• I-2D X-ray Radioography: Le nqubo ithwebula izithombe ze-X-ray ze-2D zomhlangano we-BGA. Ibiza kakhulu futhi ingakwazi ukukhomba izinkinga ezifana nama-voids kanye ne-solder enganele. Kodwa-ke, ingahlushwa izithunzi ze-solder ezigqagqene lapho izingxenye zikhona kuzo zombili izinhlangothi ze-PCB, okwenza kube inselele ukukhomba amaphutha ngokunembile.
• I-X-ray Tomography: I-X-ray tomography, eyaziwa nangokuthi i-3D X-ray noma i-computed tomography (CT), inikeza isisombululo esithuthuke kakhulu. Idala izithombe ezihlukene ze-BGA, okuvumela ukuhlaziya okuningiliziwe kwamajoyinti e-solder ngezilinganiso ezintathu. Le nqubo ihlinzeka ngokutholwa kokukhubazeka okuphezulu nokwenza kwasendaweni.

2. Ukuhlola Okubonakalayo:

Izindlela zokuhlola zamehlo zibandakanya ukusetshenziswa kwamakhamera, ama-microscopes, noma ama-endoscope ukuze kuhlolwe ngokubona amalunga e-solder e-BGA. Nakuba zingenamandla njengokuhlola i-X-ray, izindlela zokubonwayo zibalulekile ekuhlonzeni amaphutha nokungahambi kahle kwendawo. Kodwa-ke, bangase bangaboni ukukhubazeka okufihliwe ngaphakathi kwamalunga e-solder.

3. Ukuhlolwa kwe-Ultrasonic:

Amasu okuhlola e-Ultrasonic asebenzisa amaza omsindo ukuhlola ubuqotho besakhiwo se-BGA solder joints. Amagagasi e-Ultrasonic angangena ephaketheni futhi anikeze ulwazi mayelana nesakhiwo sangaphakathi, okuhlanganisa ukuba khona kwama-voids noma ama-delaminations. Le ndlela iwusizo ikakhulukazi ekutholeni iziphambeko ezithinta amandla emishini yamajoyinti e-solder.

4. Isithombe esishisayo:

Amakhamera ezithombe ezishisayo angathola ukuhluka kwezinga lokushisa kuyo yonke inhlangano ye-BGA ngesikhathi sokuphinda kufakwe i-solder. Okudidayo kumaphrofayili okushisa kungabonisa iziphambeko ezifana ne-solder enganele noma amajoyinti abandayo e-solder. Nakuba le ndlela isebenza ngesikhathi sokukhiqiza, ingase ingafaneleki ukuhlolwa kwe-post-solder.

Indima Yezisetshenziswa Zokuhlola Okuzenzakalelayo

Imishini yokuhlola ezenzakalelayo isibalulekile ekukhiqizeni izinto zikagesi zesimanje, ikakhulukazi lapho usebenza nemihlangano ye-BGA eyinkimbinkimbi. Le mishini ingaskena ngokushesha futhi ihlaziye ama-BGA amaningi, iqinisekise ukulawulwa kwekhwalithi okungaguquki. Izici ezibalulekile zemishini yokuhlola ye-BGA ezenzakalelayo zifaka:

• Ukuskena Ngesivinini esikhulu: Amasistimu azenzakalelayo angahlola ama-BGA amaningi ngokushesha, anciphise isikhathi sokukhiqiza nezindleko.
• Ukubonwa Kwesici: Amasistimu okubona omshini athuthukisiwe angakwazi ukukhomba futhi ahlukanise amaphutha ngokunemba okuphezulu, okuhlanganisa i-voids, imifantu, nokungahambi kahle kwebhola le-solder.
• Ukuhlaziywa Kwedatha: Imishini yokuhlola ezenzakalelayo ikhiqiza imibiko nedatha ephelele, ivumela abakhiqizi ukuthi balandelele amaphutha, bahlonze amathrendi, futhi bathuthukise izinqubo zabo zokunamathisela.
• Ukuhlanganisa kalula: Lawa masistimu angahlanganiswa kalula emigqeni yokukhiqiza, enze inqubo yokuhlola ibe lula.
• Ukuqinisekisa ikhwalithi: Ukuhlola okuzenzakalelayo kunciphisa ubungozi bephutha lomuntu futhi kuqinisekisa ikhwalithi engaguquki kuwo wonke ama-BGA.

Imibandela Yokwamukela Ye-BGA Solder Joints

Ukuhlola ikhwalithi ye-BGA solder joints ngokunembile, izindlela zokwamukela ezicacile zibalulekile. I-IPC-A-610C inikeza imihlahlandlela ethile yokwamukelwa okuhlanganyelwe kwe-solder ye-BGA. Amajoyinti e-solder e-BGA akhethwayo kufanele abonise izici ezithile: kufanele abe bushelelezi, ayindilinga, abe nemingcele ecacile, futhi angabi nama-voids. Ububanzi, ivolumu, isikali esimpunga, kanye nokungafani kwawo wonke amalunga e-solder kufanele kuhambisane, nokuma okuqondile, kungabi nama-offset, twist, noma amabhola e-solder.

Nakuba indinganiso ekhethwayo isetha ibha ephezulu, imibandela ekhululeke kancane iyasebenza kumajoyinti e-solder afanelekayo. Ukuze uthole izikhundla eziqondile, i-BGA solder joint ingase ibe ne-offset efika ku-25% ngokuhlobene nephedi. Ibhola le-solder akufanele lidlule u-25% webanga phakathi kwamabhola e-solder aseduze.

Ukukhubazeka Okujwayelekile kwamajoyinti e-BGA Solder

Naphezu kokuhambisana nenqubo yokwamukela, amalunga e-BGA solder angabonisa amaphutha ahlukahlukene. Lezi zinkinga zihlanganisa:

1. Amalungu e-Solder: Lokhu kwenzeka lapho i-solder ingahlanganisi kahle, okuholela kumasekhethi avulekile noma ukuxhumeka okubi.
2. Vula Izifunda: Qedela amakhefu ekuholeni okuhlangene kwe-solder kuma-circuits avulekile, ukuphazamisa ukuxhumana kukagesi.
3. Amabhola e-Solder angekho: Amabhola e-solder angaphelele noma angekho angabangela ukuxhumana okungathembeki.
4. Ama-Voids amakhulu: Izikhala phakathi kwejoyinti le-solder zingenza buthaka ubuqotho balo besakhiwo futhi zingaholela ekwahluleleni.
5. Amabhola amakhulu e-Solder: Amabhola amakhulu kakhulu angakha ukuxhumana okungajwayelekile futhi aphazamise izingxenye ezingomakhelwane.
6. I-Fuzzy Edges: Imingcele ehlanganisiwe ye-solder echazwe kabi ingabonisa i-solder engaphansi.

Isici Esiyimpikiswano - Ize

Isici esisodwa se-BGA solder joints esihlala siyisihloko senkulumompikiswano indlela yokwamukela ama-voids. I-Voids iyizikhala ezingenalutho noma izimbotshana ngaphakathi kwejoyinti le-solder. Nakuba i-voids ingahlukile kuma-BGA futhi ingathinta amalunga e-solder kwezinye izinhlobo zokupakisha, zibeka izinselelo ezithile kuma-BGA. Ngokungafani namanye amaphakheji, wonke amajoyinti e-BGA afihliwe ngaphansi kwe-chip, okwenza ukuhlolwa kwe-X-ray kube indlela eyinhloko yokuthola i-void.

Umthelela we-voids ekuthembekeni kwama-BGA yindaba yokungaqiniseki kanye nombango. Abanye baphikisa ngokuthi ama-voids amancane, angagwemeki angase akhulise ukwethembeka. Izinga le-IPC-7095, elinesihloko esithi 'Inqubo Yokuklama Nomhlangano Wokuqaphela i-BGA,' livuma izinzuzo ezingaba khona ze-voids elinganiselwe kodwa ligcizelela isidingo samazinga achaziwe ukuze kunqunywe osayizi abangenalutho abamukelekayo.

Isikhundla kanye nembangela ye-Voids

Ama-Voids kumajoyinti e-solder e-BGA angabonakala ngezigaba ezintathu eziyinhloko:

1. Isendlalelo Sengxenye: Lesi sendlalelo siseduze kakhulu nengxenye ye-BGA futhi ngokuvamile siba ne-voids ngenxa yamabhamuza omoya noma igesi eguquguqukayo eshintshashintshayo ngesikhathi sokuphinda kufakwe i-solder.
2. Isendlalelo sephedi: Izikhala ezikulesi sendlalelo zingase zibe umphumela wokushintshashintsha kokushintshashintsha kokunamathiselwe kwe-solder okufakwe kuphedi, okubangela ukuba igesi iphume futhi yenze izikhala ngemva kokupholisa.
3. I-Solder Ball Layer: Ukukhipha amabhola e-solder kungenzeka ngaphambi kokusoda, okungenzeka kungenxa yenqubo yokukhiqiza amabhola e-solder, izinkinga zempahla yokunamathisela i-solder, noma idizayini yebhodi lesifunda.

Isibonelo, uma i-via hole yakhelwe ngaphansi kwephedi, umoya ovela ngaphandle ungangena ebholeni le-solder elincibilikisiwe ngembobo ngesikhathi sokusoda. Lokhu kungadala i-void ngaphakathi kwebhola le-solder uma inqubo ye-solder isiphelile futhi i-solder ipholile.

Iphrofayili yezinga lokushisa lokugeleza kabusha phakathi ne-solder idlala indima ebalulekile ekwakhekeni okuyize. Izingoma ze-Eutectic solder ezifana no-63% Sn no-37% Pb zisengozini yokuthola i-voids, kuyilapho amabhola e-solder anephuzu lokuncibilika eliphezulu njengo-10% Pb no-90% Sn, anephoyinti elincibilikayo elingu-302°C, avamise ukukhombisa okumbalwa. ama-voids ngoba awancibiliki ngesikhathi sokugeleza kwe-soldering.

Imibandela Yokwamukela Okungenalutho

Ukuba khona okungenalutho ngaphakathi kwejoyinti ye-solder kungaholela ekucindezelekeni ngesikhathi sokuhamba ngebhayisikili okushisayo, okungase kubangele ukuncipha nokwanda. Indawo nosayizi we-voids kungaba nomthelela ekuthembekeni kwamalunga e-solder. Kodwa-ke, ama-voids nawo anganciphisa ukucindezeleka kwemishini ngokunikeza isikhala esengeziwe ngaphakathi kwejoyinti ye-solder.

I-IPC-7095 iveza imibandela ethile yokwamukela i-voids, kucatshangelwa kokubili isikhundla nosayizi wabo. Kungakhathalekile indawo ezikuyo ngaphakathi kwebhola le-solder, isendlalelo sephedi, noma isendlalelo sengxenye, usayizi nenani le-voids linquma umthelela wazo kukhwalithi nokuthembeka. Izikhala ezincane ngaphakathi kwamabhola e-solder zivumelekile, nesikhala se-void esihlobene nesikhala sebhola le-solder sisebenza njengesici esibalulekile. Isibonelo, isikhala esinobubanzi obungu-50% wobubanzi bebhola le-solder sithatha u-25% wendawo yebhola le-solder.

Amazinga e-IPC acacisa ukuthi izikhala kungqimba yephedi akufanele zidlule u-10% wendawo yebhola le-solder. Izikhala ezingaphezu kuka-25% zibhekwa njengeziphambeko, ezibeka ubungozi ekuthembekeni kwemishini nogesi. Ngezikhala eziwela phakathi kwebanga elingu-10% ukuya ku-25%, ukuthuthukiswa kwenqubo kunconywa ukuze kuqedwe noma kuncishiswe.

Isiphetho kanye Neziphakamiso Zokuthuthukisa Inqubo

Ukuzuza ukuthengiswa kwe-BGA okuphumelelayo kuhilela izici ezimbalwa ezibalulekile kanye nokubambelela emikhubeni ehamba phambili. Ukuze uthuthukise ikhwalithi ehlangene ye-solder futhi unciphise amaphutha, izincomo ezilandelayo kufanele zicatshangelwe:

1. Ikhwalithi yokunamathisela kwe-Solder: Qinisekisa ukusetshenziswa kokunamathisela kwe-solder okusha, okugoqizwe ngokulinganayo ngokuma okunembile kokunamathisela nezingxenye.
2. Ukulungiselela Ingxenye: Kumadivayisi e-PBGA apakishwe ngepulasitiki, ukomisa kusengaphambili ku-100 ° C amahora angu-6-8 ngaphambi kokudayiswa, okungcono kakhulu nge-nitrogen, kungaba inzuzo.
3. Iphrofayili Yezinga Lokushisa Kabusha: Yakha ngokucophelela iphrofayili yezinga lokushisa lokugeleza kabusha ukuze uqinisekise ngisho nokushisisa nokuncibilika okuphelele kwe-solder. Amaphrofayili okushisa anganele angaholela ekuhlanganiseni okubandayo kwe-solder noma ukuncibilika okungaphelele.
4. Isicelo se-Solder Namathisela: Faka inani elifanele lokunamathisela kwe-solder, ucabangela i-viscosity, ukuze uvikele idivayisi okwesikhashana futhi uvimbele ukufakwa kwe-solder.
5. I-Uniform Pad Design: Dizayina amaphedi e-PCB amaphakheji e-BGA anosayizi ofanayo futhi ugweme ukuklama izinqubo ngaphansi kwamaphedi. Ezimeni lapho izinqubo ezingaphansi kwamaphedi zidingekile, sebenzisa umkhiqizi ofanelekayo we-PCB futhi uqinisekise ngokufanele ngedizayini yembobo ukuze uvimbele umehluko enanini lethini nobude phakathi kwamaphedi amakhulu namancane.
6. Ikhwalithi Yemaski Solder: Ngaphambi kwe-BGA soldering, qinisekisa ikhwalithi ye-solder mask ezungeze ama-pads futhi uqinisekise ukuthi i-vias imbozwe ngefilimu yokuvimbela. Ukwengeza ifilimu yokumelana ne-solder ngakolunye uhlangothi lwe-PCB ngesikhathi sokukhiqiza akusebenzi futhi kungase kuholele ezinkingeni ezifana nezikhindi ezingokoqobo namasekhethi amafushane.

Ngokubhekana nalezi zincomo kanye nokulungiselela kahle ngaphambi kwe-BGA soldering, amaphutha angancishiswa, futhi izinga eliphezulu lokuphasa lingafinyelelwa. Umgomo oyinhloko ukuqeda amaphutha ngaphandle kokusebenzisa kabusha, ukuqinisekisa izinga eliphakeme kakhulu lekhwalithi nokuthembeka ku-BGA solder joints.

Uma lesi sidingo sithinta ukutholakala noma ukukhishwa komkhiqizo, siqhathanise nenqubo yokuqinisekisa ikhwalithi ye-PCB kanye nomklamo we-microvia ne-HDI ngaphambi kokuthumela amafayela okugcina ukuze abuyekezwe.