Iyini iPhakheji ye-QFN? Umhlahlandlela Ophelele Wokupakisha i-IC ye-Quad Flat No-Lead

1. Isingeniso kubuchwepheshe bephakheji ye-QFN

Ukupakishwa kwesekethe ehlanganisiwe (i-IC) kusebenza njengesixhumi esibalulekile phakathi kwama-semiconductor dies namabhodi esekethe aphrintiwe. Ukupakishwa okusebenzayo kuqinisekisa ukuxhumana kukagesi okuthembekile, ukuphathwa kokushisa okuphumelelayo, kanye nokuvikelwa okuqinile kwemishini. Phakathi kwezixazululo zokupakishwa ezifakwa ngaphezulu, iphakheji ye-QFN (i-Quad Flat No-Lead) ivele njengokukhetha okuthandwayo kwama-elekthronikhi esimanje ngenxa yendlela yayo encane yokunyathela, ukusatshalaliswa kokushisa okuhle kakhulu, kanye nokusebenza okuphezulu kakhulu kwemvamisa ephezulu.

2. Iyini iPhakheji ye-QFN

2.1 Imvelaphi Yethemu

Isifinyezo se-QFN simelela ukuthi “i-Quad Flat No-Lead,” esichaza iphakheji eyisicaba enezinhlangothi ezine ngaphandle kwezintambo ezivelele. Ngokungafani namaphakheji endabuko anezintambo, amaphakheji e-QFN asebenzisa amaphedi okuhambisa amandla phansi kwephakheji ukuze kuxhunywe okubekwe ngaphezulu. Lo mklamo uqeda isidingo samafreyimu ezintambo angaphandle adlula umzimba wephakheji.

2.2 Izici Eziyisisekelo Zephakheji ye-QFN

Amaphakheji e-QFN aqukethe ama-solder pad atholakala eceleni kwengxenye engezansi kunephiko le-gull langaphandle noma amaphini e-J-lead. Uma kuqhathaniswa ne-QFP yendabuko (i-Quad Flat Package), i-QFN inikeza ubukhulu obuncane kakhulu kanye nobukhulu obuncishisiwe. Iningi lemiklamo yamaphakheji e-QFN ifaka i-thermal pad eveziwe phansi maphakathi, okuvumela ukudluliselwa kokushisa okuqondile kusuka kudayi kuya endizeni yomhlabathi ye-PCB.

2.3 Izicelo Ezijwayelekile

Ubuchwepheshe bephakheji ye-QFN bufaneleka kahle izinqubo zokuhlanganisa ubuchwepheshe bokufaka endaweni (i-SMT) . Izinhlelo zokusebenza ezivamile zifaka phakathi ama-electronics abathengi, amamojula wokuxhumana angenantambo, amayunithi okulawula kagesi ezimoto, ama-IC okuphatha amandla, namadivayisi e-RF lapho ukulinganiselwa kwesikhala kanye nokusebenza kokushisa kuyizinto ezibalulekile zokuklama.

3. Ukwakhiwa Kwephakheji ye-QFN kanye Nezingxenye

3.1 Izinto Zokwakha Iphakheji

Isakhiwo sephakheji ye-QFN siqukethe izinto eziningana ezibalulekile. Uhlaka lwe-lead luhlinzeka ngokusekelwa kwemishini kanye nesisekelo sokuqondisa ugesi. I-semiconductor die inamathele ku-die pad futhi ixhunywe kuhlaka lwe-lead ngokusebenzisa i-wire bonding noma i-flip-chip interconnection. Lonke i-assembly lifakwe ku-plastic molding compound, enikeza ukuvikelwa kwemvelo kanye nokufakwa kogesi.

3.2 Izici Eziyinhloko Zesakhiwo

Izici ezimbili ezichazayo zichaza ukwakheka kwephakheji ye-QFN. Okokuqala, ama-solder pad angaphandle emaphethelweni angezansi asungula ukuxhumana kukagesi ngezimpawu ze-PCB . Okwesibili, i-pad eveziwe ephakathi (ebizwa nangokuthi i-thermal pad noma i-die pad) idala indlela yokushisa ephikiswa kancane ukusuka ku-die kuya ebhodini, okuthuthukisa kakhulu ikhono lokushabalalisa ukushisa.

4. Izinhlobo zamaPhakheji e-QFN

4.1 Ukuhlukaniswa Ngokwendlela Yokuxhumana

I-Wire Bond QFN imelela indlela evamile, isebenzisa izibopho zensimbi zegolide noma zethusi ukuxhuma ama-die pad kwiminwe yohlaka oluphambili. I-Flip-Chip QFN isebenzisa ama-solder bumps okuxhuma ngqo kwe-die-to-substrate, iletha izindlela zesignali ezimfushane kanye nokusebenza kukagesi okuthuthukisiwe kwezinhlelo zokusebenza zesivinini esikhulu.

4.2 Ukuhlukaniswa Ngokwenqubo Yokukhiqiza

Amaphakheji e-QFN ohlobo lwe-Punch afakwa nge-single kusetshenziswa i-mechanical punching, afanele ukukhiqizwa ngobuningi obukhulu ngokulungiswa okujwayelekile kwephedi. Amaphakheji e-QFN ohlobo lwe-Sawn afakwa nge-blade saw ukuze afakwe nge-single, okunikeza ukuguquguquka okukhulu ekubalweni kwe-lead kanye nokwehluka kwe-pitch ngenkathi kugcinwa ukuqedwa okuhlanzekile komphetho.

4.3 Ukuhlukaniswa Ngokwesakhiwo Sephakheji

Amaphakheji e-Air-Cavity QFN anendawo evulekile ngaphezu kwe-die, afanelekela izinzwa ze-MEMS kanye nezingxenye ze-RF ezidinga ukuphazamiseka okuphansi kwe-dielectric. I-Plastic Molded QFN imele uhlobo oluvame kakhulu, olunikeza ukufakwa kwe-capsulation okungabizi kakhulu nokumelana okuhle nomswakama kwezicelo ezivamile.

5. Izinzuzo Eziyinhloko Zephakheji ye-QFN

5.1 Usayizi Omncane Nobuningi Obuphezulu

Ukungabikho kwama-lead angaphandle kuvumela amaphakheji e-QFN ukuthi afinyelele ubukhulu obuseduze ne-chip-scale. Lesi sici sefomu elihlanganisiwe sinciphisa izidingo ze-PCB zezindlu ngamaphesenti afinyelela ku-50 uma kuqhathaniswa namaphakheji e-QFP alinganayo, okuvumela ukuminyana kwezingxenye okuphezulu emiklamo evinjelwe isikhala.

5.2 Ukusebenza Okushisayo

Iphedi yokushisa eveziwe inikeza indlela yokuqhuba eqondile kusukela kudayi kuya ezingqimbeni zethusi ze-PCB. Uma iklanywe kahle ngama-vias okushisa ngaphansi kwephedi, amaphakheji e-QFN angafinyelela amanani okumelana nokushisa aphansi ngokuphindwe kabili kuya kathathu kunamaphakheji endabuko ane-lead, okwenza afaneleke kumadivayisi aqeda amandla.

5.3 Ukusebenza kukagesi

Izindlela ezimfushane zomqhubi ngaphakathi kwamaphakheji e-QFN zinciphisa ukuhanjiswa kwe-parasitic, ukumelana, kanye ne-capacitance. Lezi zici zigcina ubuqotho besignali kumaza aphezulu futhi zinciphisa ukulahlekelwa kokushintshana kwezicelo zamandla. I-ground pad iphinde inikeze ukuxhumana okuhle kakhulu kwendiza yomhlaba ukuze kuthuthukiswe ukuzivikela komsindo.

5.4 Ukuhambisana kwe-SMT

Amaphakheji e-QFN ahambisana ngokugcwele nemishini ejwayelekile yokuhlanganisa efakwa ngaphezulu. Iphrofayili engezansi eyisicaba iqinisekisa ukwakheka kwejoyinti le-solder elihambisanayo ngesikhathi sokugoqa kabusha, okusekela ukukhiqizwa okuzenzakalelayo okuphezulu ngokunemba kokubekwa okuthembekile.

5.5 Ukusebenza Kahle Kwezindleko

Ukwakhiwa kwephakheji okulula kuqeda imisebenzi yokwakha nokusika umthofu edingekayo kumaphakheji endabuko anomthofu. Ubukhulu bephakheji obuncane buphinde bunciphise ukusetshenziswa kwezinto kanye nezindleko zokuthumela, okunegalelo emnothweni wokukhiqiza jikelele.

6. Iphakheji ye-QFN vs Ezinye Izinhlobo Zephakheji

6.1 Ukuqhathaniswa kwe-QFN vs QFP

Amaphakheji e-QFP aqukethe ama-lead aphumayo ephiko le-gull, okwenza ukuhlolwa okubonakalayo kanye nokulungiswa kabusha ngesandla kube lula ukukuthola. Kodwa-ke, amaphakheji e-QFN anikeza izici zokushisa nezogesi eziphakeme kakhulu endaweni encane kakhulu. Kumadizayini aqinile futhi abalulekile ekusebenzeni, i-QFN imele ikhambi elithuthukisiwe kakhulu, kuyilapho i-QFP ihlala ibalulekile lapho kudingeka khona ikhono lokunamathisela ngesandla.

6.2 QFN vs Ukuqhathaniswa kwe-BGA

Amaphakheji e-BGA anikeza ukuminyana okuphezulu kakhulu kwe-I/O kanye nokusebenza kahle kukagesi, okulungele amadivayisi ayinkimbinkimbi, anenani eliphezulu. Ama-QFN anikeza indawo encane, ukuphakama okuphansi, kanye nokusebenza okuhle kokushisa, kuyilapho kulula ukuwahlola nokuyilungisa kabusha. I-QFN ifanelana nemiklamo ye-I/O ephakathi nendawo ebeka phambili ukuminyana kanye nezindleko, kanti i-BGA ingcono kakhulu kwizicelo eziminyene kakhulu, ezibaluleke kakhulu ekusebenzeni.

7. Izinhlelo Zokusebenza Zephakheji ye-QFN

Ubuchwepheshe bephakheji ye-QFN buhamba phambili ezinhlelweni zokusebenza ezifuna usayizi omncane, ukushabalalisa ukushisa okuphumelelayo, kanye nokusebenza okuvama kakhulu. Izindawo eziyinhloko zohlelo lokusebenza zifaka phakathi amadivayisi eselula nezinto ezigqokwayo, amamojula wokuxhumana angenantambo (i-Wi-Fi, i-Bluetooth, iselula), ama-elekthronikhi ezimoto (ama-ECU, ama-sensor, abashayeli be-LED), amasekethe ahlanganisiwe okuphathwa kwamandla, kanye namamojula we-RF front-end lapho ubude bendlela yesiginali buthinta kakhulu ukusebenza.

8. Izinto Okucatshangwayo Ngokuklama Nokukhiqiza Iphakheji ye-QFN

8.1 Ukwakhiwa Kwamaphedi Nokuthuthukiswa Kwe-Stencil

Ukuhlanganiswa kwe-QFN okuphumelelayo kudinga ukufakwa kwe-solder paste okunembile. Umklamo wokuvula nge-stencil kumele ulinganisele ivolumu eyanele ye-solder nokuvimbela i-void, ikakhulukazi kwi-thermal pad. Amaphethini okuvula nge-thermal pad anconyiwe afaka imiklamo ehlukanisiwe noma enamafasitela ukuvumela ukuphuma kwegesi nokunciphisa i-void ngesikhathi sokugeleza kabusha.

8.2 Ukuthembeka Nokulawulwa Kwenqubo

Ukulawulwa kwevolumu yokunamathisela i-solder yephedi eveziwe kuthinta ngqo ukuthembeka kwesikhathi eside ngaphansi kokucindezeleka kokujikeleza kokushisa. Ukulungiswa kwenqubo kufanele kubhekane nokufana kokumbozwa kokunamathisela, amapharamitha wephrofayili yokugeleza kabusha, kanye nezindlela zokuhlola ngemuva kokugeleza kabusha. Ukuhlolwa kwe-X-ray kuvame ukudingeka ukuqinisekisa ikhwalithi yejoyinti le-solder ngaphansi komzimba wephakheji.

9. Isiphetho

Iphakheji ye-QFN inikeza inhlanganisela efanele yobukhulu obuncane, ukuphathwa kokushisa okuhle kakhulu, kanye nokusebenza kukagesi okuphezulu. Idizayini yayo engenalo i-lead ivumela ukwakheka kwe-PCB okusebenzisa kahle isikhala kuyilapho iphedi yokushisa eveziwe ibhekana nezinselele zokushabalalisa ukushisa ezinhlelweni zokusebenza eziqaphela amandla. Njengoba amadivayisi kagesi eqhubeka nokuthambekela ekuncipheni nasekusebenzeni okuphezulu, ubuchwepheshe bephakheji ye-QFN buhlala buyisisombululo esiyisisekelo sokupakisha se-IC sokuklama nokukhiqiza ama-elekthronikhi anamuhla.