Ukuthembeka kwe-HDI PCB: Ukuqonda Izindlela Zokuhluleka kanye Namasu Okuvimbela

Isingeniso: Kungani Ukuthembeka Kwe-HDI PCB Kubalulekile

Amabhodi wesekethe aphrintiwe e-High Density Interconnect abe yinto ebalulekile kuma-electronics anamuhla adinga ukwenziwa kube lula kanye nokusebenza okuthuthukisiwe. Lawa mabhodi athuthukile asekela ukwakheka kwamadivayisi okuyinkimbinkimbi ngokwengeziwe ngokusebenzisa imikhondo emincane, ama-microvia ahlanganisiwe, kanye nokwakhiwa kwezingqimba eziningi. Kodwa-ke, izinqubo zokukhiqiza eziyinkimbinkimbi kanye nezimo zokusebenza ezidingayo zidala izinselele ezithile ezingalimaza ukuthembeka kwe-HDI PCB kanye nokuphila isikhathi eside komkhiqizo.

Ubunkimbinkimbi busukela ekusebenzelaneni phakathi kwezakhiwo eziminyene ze-microvia, izendlalelo ezincane ze-dielectric, kanye nengcindezi yokushisa ngesikhathi sokukhiqiza nokusebenza kwensimu. Ukuqonda lezi zindlela zokwehluleka kuba semqoka ku-aerospace, ugesi wezimoto, kanye nengqalasizinda yezokuxhumana lapho ukwehluleka kwesistimu kuba nemiphumela ebalulekile. Lokhu kuhlaziya kuhlola ukukhathazeka okuyinhloko kokwethembeka futhi kuveza amasu asebenzayo okuthuthukisa ukusebenza kwesikhathi eside.

Izindlela Ezijwayelekile Zokuhluleka Ukuthembeka kwe-HDI PCB

I-Microvia Cracking kanye Nokwehluleka

Ukwehluleka kwe-microvia kungenye yezinto ezivame kakhulu ekuthembekeni kwe-HDI PCB. Ukungafani kokukhula kokushisa phakathi kwezinto zethusi ne-resin kudala ukucindezeleka komshini esibonakalayo se-via barrel, ikakhulukazi ngesikhathi sokujikeleza kokushisa phakathi kuka--55°C kuya ku-125°C. Izinqubo zokubhoboza nge-laser zethula ukugxila okwengeziwe kokucindezeleka ngezindawo ezithintekile ekushiseni ezenza buthaka ukunamathela kwethusi.

Ukugcwaliswa kwethusi okungaphelele ngaphakathi kwesakhiwo se-microvia kwandisa inkinga ngokwakha izikhala ezingenalutho ezigxilisa ubunzima bemishini. Ukubonakaliswa ngokuvamile kubonakala njengokuhluleka kwesignali ngezikhathi ezithile noma amasekhethi avuliwe aphelele phakathi kwezendlalelo. Ukuskena i-electron microscopy ngokuvamile kwembula imifantu eyindilinga kusixhumi esibonakalayo se-via-pad noma ukuphuka kwe-longitudinal ngombhobho wethusi ngokwawo.

Ukufuduka Kwethusi kanye Nokufuduka Kwe-Electrochemical

Ukungena komswakama kuhlanganiswe nokuchema kukagesi kudala izimo zokuthutha i-ion yensimbi phakathi kwamakhondaktha aseduze. Le nqubo yokufuduka kwe-electrochemical kancane kancane yenza izindlela eziguquguqukayo ezivala izikhala ezivikelayo, okuholela kumasekhethi amafushane noma amaza avuzayo. Lesi simo sisheshisa ngaphansi kwezimo eziphakeme zokushisa kanye nomswakamo, ikakhulukazi ezithinta ukwethembeka kwe-HDI PCB ezindaweni ezinokhahlo.

Ukuhlolwa kokufaneleka okujwayelekile kusebenzisa ukuhlolwa kwe-Highly Accelerated Stress Test (HAST) ku-130°C/85%RH noma 85°C/85%RH ukuchayeka ukuze kuhlolwe ukuthambekela okuthile. Inhlanganisela yamandla enkundla kagesi, okuqukethwe umswakama, nokungcoliswa kwe-ionic kunquma izinga lokwakheka kwe-dendrite, okunomthelela ngqo ekusebenzeni kokwethembeka kwesikhathi eside.

I-Conductive Anodic Filament (CAF) Ukukhula

Ukwakheka kwe-CAF kwenzeka ngokuwohloka kwe-electrochemical kusixhumi esibonakalayo sengilazi-resin ngaphakathi kwempahla ye-dielectric. Lapho umswakama ungena esakhiweni se-laminate, udala indlela ye-electrolytic eduze kwama-fiber bundles phakathi kwama-conductor ngamakhono ahlukene. Ukukhula okuwumphumela we-dendritic kulandela i-glass fibre orientation, ekugcineni kwakha izindlela ezimelana kancane ezidala ukwehluleka okuyinhlekelele.

Ukuvimbela i-CAF kudinga ukunakwa ngokucophelela ekukhethweni kwempahla kanye nemingcele yokucubungula. Ikhwalithi yesixhumi esibonakalayo phakathi kokuqiniswa kwengilazi kanye ne-resin matrix ithonya ngokuqondile ukuba sengozini ekukhuleni kwemicu. Amasistimu wesimanje we-laminate ahlanganisa ukwelashwa kokulinganisa okuthuthukisiwe kanye nokwakheka kwe-resin okuklanyelwe ngokukhethekile ukuthuthukisa ukwethembeka kwe-HDI PCB ngokumelene nale ndlela yokwehluleka.

I-Delamination kanye ne-Resin Cracks

Ukucindezeleka okushisayo phakathi nemijikelezo yokugeleza kabusha kwe-lamination noma umhlangano kungadlula amandla okunamathela phakathi kwezingqimba zethusi neze-dielectric. Lokhu kugxiliswa kwengcindezi kuholela ekudambiseni, okubonakala njengokuhlukana okubonakalayo noma ukwakheka kwamabhamuza ngaphakathi kwesitaki sesendlalelo. Inkinga ishuba ngokubala kwesendlalelo esikhuphukile kanye nezakhiwo zokunweba ezishisayo ezingahambelani.

Ukuqhekeka kwe-resin kuvame ukuhambisana ne-delamination njengomphumela wesibili wengcindezi yokushisa. Le mifantu ihlinzeka ngezindlela zokungena komswakama, okuqhubeka nokululaza izakhiwo ze-dielectric futhi kusheshise ezinye izindlela zokwehluleka. Imvelo exhumene yalezi zinqubo zokucekela phansi yenza ukuchithwa kube yinkinga ikakhulukazi ekuthembekeni okuqhubekayo kwe-HDI PCB.

Imbangela Izimbangela Ezithinta Ukwethembeka kwe-HDI PCB

Ukungafani Kwempahla Ebalulekile

Umehluko we-coefficient of thermal expansion (CTE) phakathi kwabaqhubi bethusi, izendlalelo ze-dielectric, kanye nezinto zokugcwalisa i-microvia kudala ukucindezeleka kwe-thermomechanical ngesikhathi sokuvakasha kwezinga lokushisa. Lokhu kungafani kwe-CTE kuba sobala kakhulu ekulungiselelweni kwe-HDI ngenxa yobuningi obukhulu bokuxhumana okuqondile kanye nezendlalelo ze-dielectric ezincane phakathi kwezindiza zethusi.

Amanani ajwayelekile e-CTE abonisa inselele:

• Ucwecwe lwethusi: 17 ppm/°C endizeni
• FR-4 dielectric: 14-17 ppm/°C endizeni, 50-70 ppm/°C ukushuba
• I-microvia copper egcwele: 16-18 ppm/°C

I-Laser Drilling Process Impact

I-Laser drilling yethula izindawo ezithinteke ekushiseni ezizungeze i-microvia engalimaza ukwakheka kwenhlaka futhi idale izindawo zokuhlangana ezibuthakathaka zokubekwa kwethusi okulandelayo. Amandla ashisayo adingekayo ukuze kucishwe impahla ye-dielectric ngokuvamile afinyelela ku-1000-2000°C khona manjalo. Ukwenziwa ngcono kwamapharamitha we-laser kulinganisa ukusebenza kahle kokumba ngokumelene nokonakaliswa kwempahla ukuze kugcinwe ukwethembeka kwe-microvia esikhathini sokuphila konke sokusebenza.

Ikhwalithi Yokugcwalisa Ithusi

Ikhwalithi yokugcwaliswa kwethusi kwe-electrolytic ngaphakathi kwe-microvias ithinta kakhulu ubuqotho besakhiwo sokuxhuma okuqondile. Ukugcwaliswa okungaphelele kudala izikhala ezingenalutho ezigxilisa ingcindezi futhi zinciphise umthamo wamanje wokuthwala. Ikhemikhali yokucwenga yethusi, amaphrofayili wamanje wokuminyana (imvamisa i-15-30 ASF), kanye nejiyomethri ngedizayini konke kuthonya ikhwalithi yokugcina yokugcwalisa kanye nokuthembeka kukonke kwe-HDI PCB.

Izimpawu Zokumunca Umswakama

Ukumuncwa komswakama wezinto ze-dielectric kuthinta ngokuyisisekelo ukuthembeka kokufakwa. Okuqukethwe umswakama okuphezulu kunciphisa ukumelana nokufakwa kwe-insulation, kusheshisa ukufuduka kwethusi, futhi kwandisa ukuthambekela kwe-CAF. I-FR-4 ejwayelekile imunca umswakama ongu-0.10-0.15% ngesisindo, kuyilapho izinto ezithuthukisiwe ezinomswakama ophansi zithola ngaphansi kuka-0.05%. Ukukhethwa kwezinto kufanele kulinganisele ukusebenza kukagesi ngokumelene nezakhiwo ze-hygroscopic ukuze kuthembeke okwanele ezindaweni zokusebenza ezihlosiwe.

Izindlela Zokuhlola Ukuthembeka kwe-HDI PCB

Ukuhlolwa Kwebhayisikili Elishisayo

Izifundo zamabhayisikili ashisayo zihlangana emazingeni okushisa aphindaphindiwe ukulingisa ingcindezi yokusebenza kanye nokuqinisekisa ukwethembeka kwe-HDI PCB. Izimo zokuhlola ezijwayelekile zifaka -55°C ukuya ku-125°C ukuhamba ngebhayisikili okunezikhathi zokuhlala eziyimizuzu engu-15 ekudluleleni ngakunye. Lokhu kuhlolwa okusheshisiwe kuveza ukukhathala kwe-microvia, ukuwohloka kwamalunga e-solder, kanye nokwehluleka kwengcindezi ye-laminate ngaphakathi kwezikhathi ezicindezelwe.

Inombolo yemijikelezo eya ekuhlulekeni inikeza idatha yobuningi yokuqagela ukwethembeka. Izinhlelo zokusebenza ezinokwethenjelwa okuphezulu ngokuvamile zidinga ubuncane bemijikelezo engu-500-1000, kuyilapho izicelo zezimoto nezasemoyeni zingadinga imijikelezo engu-2000 noma ngaphezulu ukuze zihlangabezane nezindinganiso zokufaneleka.

Ukuhlolwa Kwengcindezi Okusheshisiwe (HAST)

I-HAST ihlanganisa izinga lokushisa eliphakanyisiwe, umswakama, nokuchema kukagesi ukuze kuhlolwe ukuthambekela kokuhamba kwe-electrochemical kanye nokwakheka kwe-CAF. Izimo ezijwayelekile zika-130°C kanye nomswakama ohlobene ongu-85% onokuchema okusetshenzisiwe okungu-3-50V kudala izimo ezimbi kakhulu zalezi zindlela zokwehluleka. Ukuqapha ukumelana nokufakwa kwe-insulation ngesikhathi sokuchayeka kwamahora angu-96-500 kulandelela ukuqhubeka kokuwohloka futhi kuhlonze ubuthakathaka bomklamo obuthinta ukwethembeka kwe-HDI PCB.

Ukuhlaziywa kwe-Cross-Sectional Microsection

Ukuhlaziywa kwe-cross-sectional ngokusebenzisa i-microsectioning kunikeza ukubhekwa okuqondile kwezakhiwo zangaphakathi ze-HDI. Le ndlela yokuhlola elimazayo yembula ikhwalithi yokugcwalisa ithusi ngaphakathi kwama-microvias, ukunamathela esibonakalayo phakathi kwezendlalelo, kanye nokuba khona kokukhubazeka okufana nama-voids noma imifantu. Ukwehlukaniswa okuhlelekile ezindaweni ezibucayi okuholwa yi-IPC-TM-650 Indlela 2.1.1 kuqinisekisa isampula elimele ikhwalithi yokwakha.

Ukuhlola Ukumelana Nokufakwa Kwamanzi Okuphezulu (SIR)

Ukuhlolwa kwe-SIR kuhlola amazinga okungcola e-ionic angonakalisa ukwethembeka kwe-HDI PCB. Izilinganiso zokuhlola ukuvuza kwamanje phakathi kwamakhondaktha anezikhala ezisondelene (imvamisa isikhala esingu-0.5mm) ngaphansi kwezimo ezingu-85°C/85%RH kusetshenziswa ukuchema okungu-50V. Imiphumela ikhombisa ukusebenza kahle kwezinqubo zokuhlanza futhi ihlonze izingozi ezingaba khona zokufuduka kwe-electrochemical. Ukuthobelana nezindinganiso ze-IPC-6016 Class 3 kudinga ubuncane be-SIR yama-megohms angu-100 ngemva kokuchayeka amahora angu-168.

Amasu Okuthuthukisa Ukuthembeka kwe-HDI PCB

Ukuthuthukisa Isigaba Sokuklama

Ukucatshangelwa kwesigaba sokuklama kunethonya elikhulu emiphumeleni yokwethembeka ekugcineni. Ukulawula i-microvia aspect ratios engaphansi kuka-1:1 ye-laser-drilled vias kunciphisa ukugxila kwengcindezi futhi kuthuthukisa ikhwalithi yokugcwaliswa kwethusi. Umklamo wokupakisha ocatshangelwayo usebenzisa izinto ezinezici zokunweba ezihambisanayo zehlisa ingcindezi ye-thermomechanical ngesikhathi sokuhamba ngebhayisikili elishisayo.

Amapharamitha wedizayini angukhiye wokuthembeka okuthuthukisiwe:

• Ukubukeka kwesilinganiselo se-Microvia: Ubukhulu obungu-1:1 bokuthembeka okuphezulu
• Ngephedi yokuthwebula: Ubuncane obungu-150μm ububanzi be-laser engu-100μm nge
• Isikhala ukusuka kokudlula kuye kwezici eziseduze: Ubuncane obungu-150μm ukunciphisa ukugxilisa ingqondo
• Ukubekezelela ukubhaliswa kwesendlalelo kuya kwesendlalelo: ±75μm kwe enqwabelene ngezakhiwo

Ukukhetha Okubalulekile Kokwethenjelwa Okuthuthukisiwe

Izinga lokushisa eliphezulu lengilazi (Tg) laminates ligcina ukuqina kohlangothi ekucutshungulweni okuphezulu namazinga okushisa okusebenza. Izinto ezine-Tg ezingaphezu kuka-170°C zihlinzeka ngemajini eyanele yokucubungula ukugeleza kabusha okungenayo umthofu kumazinga okushisa aphezulu angu-260°C. Izinhlelo eziphansi zokumunca umswakama (ngaphansi kuka-0.05% ukumuncwa kwamanzi) zinciphisa ukuthambekela ekufudukeni kwe-electrochemical kanye nokukhula kwe-CAF, kuthuthukisa ngokuqondile ukwethembeka kwe-HDI PCB.

Izinto ezithuthukisiwe ze-laminate ezakhelwe ngokukhethekile izinhlelo zokusebenza ze-HDI zifaka amasistimu e-epoxy aguquliwe, ukwakhiwa kwe-polyimide, nezinto eziphansi ze-Dk/Df. Ukukhethwa kuncike ekulinganiseni izidingo zokusebenza kukagesi ngokumelene nezidingo zokuthembeka ezishisayo nezomshini zendawo ethile yohlelo lokusebenza.

Ukulawulwa Kwenqubo Yokukhiqiza

Ukuthuthukiswa kwepharamitha yokumba i-laser kunciphisa izindawo ezithinteke ukushisa ngenkathi kugcinwa ukunemba kwejometri. Izilungiselelo ezijwayelekile ze-laser ye-UV zihlanganisa amaza okushaya angu-30-80 kHz anamazinga wamandla angu-10-30 μJ ishayela ngalinye. Izinqubo ze-Copper Plating zidinga ukulawula ngokucophelela ukwakheka kwamakhemikhali, izinga lokushisa (imvamisa engu-22-28°C), kanye nokuminyana kwamanje ukuze kufezeke ngokugcwalisa ngaphandle kokucindezeleka okukhulu kwangaphakathi.

Izindlela zokulungiselela ubuso ziqinisekisa ukunamathela okwanele phakathi kwezingqimba futhi kuvimbele i-delamination. Ukwelashwa okuhlukile kwe-oxide noma ukukhuhla ngomshini okulandelwa ukucutshungulwa kwe-desmear kudala ukuthungwa kwendawo efanele ukuze kuhlanganiswe ithusi ukuya ku-resin okuthembekile, okubalulekile ekuthembekeni kwesikhathi eside kwe-HDI PCB.

Izinqubo Zomhlangano Nokuhlola

Ukulungiswa kwephrofayela ye-reflow kulinganisa izimfuneko zokushisa eziphezulu ngokumelene nengcindezi yokushisa ezakhiweni ze-microvia. Amaphrofayli anconyiwe wemihlangano ye-HDI akhawulela izinga lokushisa eliphakeme libe ngu-245-250°C (uma kuqhathaniswa no-260°C kumabhodi ajwayelekile) futhi anciphise isikhathi esingaphezu kwe-liquidus ukuze unciphise ukuchayeka okushisayo. Izinga lerempu akufanele lidlule ku-2-3°C ngomzuzwana ukuze ulawule ukucindezelwa kwe-thermal gradient.

Izinqubo zokuhlanza kufanele zisuse ngokuphumelelayo izinsalela ze-flux ngaphandle kokulimaza izici ze-fine-pitch noma ukungenisa umswakama ku-laminate. Ikhemikhali ye-flux engahlanzekile noma ukuhlanzwa kwamanzi okulawulwa ngokucophelela ngemijikelezo yokomisa ngokuphelele kugcina izindinganiso zokwethembeka ze-HDI PCB.

I-Case Studies ye-HDI Reliability Performance

Isicelo sezimoto ze-ECU

Izinhlelo zokusebenza zeyunithi yokulawula ugesi wezimoto zibonisa ukubaluleka kokwethembeka kwe-microvia ngaphansi kwezimo zamabhayisikili ashisayo. Izinhlelo zokuhlola zalezi zinhlelo ezibucayi zokuphepha zembula ukuthi imingcele yokumba i-laser ethuthukisiwe ehlanganiswe ne-copper plating elawulwayo inciphise izinga lokuqhekeka kwe-microvia ngamaphesenti angaphezu kuka-60. Lokhu kuthuthukiswa kunikeze amandla ukufaneleka emijikelezweni yokushisa engu-2000 ukusuka ku--40°C kuya ku-125°C, ehlangabezana nezidingo ze-AEC-Q100 zeBanga loku-1 zokuthembeka kwezimoto.

Ukuhlaziywa kwezibalo kubonise ukuthi imijikelezo eshoyo kuye ekuhlulekeni inyuke isuka ku-1200 yaya kwemijikelezo engaphezu kuka-3000 ngenqubo yokwenza kahle. Lokhu kuthuthukiswa kokusebenza kuhunyushwe ngokuqondile ekuthembekeni kwenkambu okuthuthukisiwe kanye nezindleko ezincishisiwe zewaranti kumakhasimende ezimoto ze-OEM.

Ingqalasizinda Yezokuxhumana

Impahla yengqalasizinda yezokuxhumana esebenza ezindaweni ezingaphandle ibhekene nezinselelo ezivela ekuchayekeni okuhlanganisiwe kwezinga lokushisa nokuswakama. Ukuhlola okusheshisiwe ku-85°C/85%RH kuhlonze ukukhula kwe-CAF njengento eyinhloko ekhathaza amabhodi e-HDI kulezi zinhlelo zokusebenza, ngamadizayini okuqala abonisa ukuwohloka kokumelana nokufakwa ngaphansi kwemikhawulo eyamukelekayo phakathi nokuchayeka kwamahora angu-500.

Ukusetshenziswa kwezinto ezithuthukisiwe ze-laminate ezithuthukisiwe zokusimama kokusebenzelana kwengilazi-resin kwandisa isikhathi sokuhluleka ngesici sokuthathu. Ukwakhiwa kwe-resin eguquliwe kanye nemijikelezo yokwelapha eyenziwe kahle etholwe ngaphezu kwamahora angu-1500 ukuchayeka kwe-HAST ngaphandle kokwakheka kwe-CAF, okuvumela ukuzibophezela kwewaranti yokuthunyelwa kwenkambu yeminyaka engu-15 kuyilapho kugcinwa izindinganiso zokwethembeka ze-HDI PCB.

Isiphetho: Ukuzuza Ukuthembeka Okuphezulu kwe-HDI PCB

Ukuthembeka kwe-HDI PCB kuvela ekusebenzisaneni okuyinkimbinkimbi phakathi kwezinqumo zokuklama, izakhiwo zezinto ezibonakalayo, nezinqubo zokukhiqiza. Izindlela zokwehluleka okubalulekile zokuqhekeka kwe-microvia, ukufuduka kwethusi, ukukhula kwe-CAF, kanye ne-delamination ngayinye iphendula ezinyathelweni ezithile zokulawula ezisetshenziswa kuwo wonke umjikelezo wokuphila womkhiqizo. Ukuqonda lezi zindlela kusiza onjiniyela ukuthi benze ukuhwebelana phakathi kwezidingo zokusebenza nezinjongo zokwethembeka.

Izakhiwo ze-Microvia, ukuphathwa kwempahla eshisayo, nokulawulwa komswakama kumelela izinsimbi eziyinhloko zokuthuthukisa ukwethembeka kwesikhathi eside. Ukuhlolwa kokufaneleka okuhlelekile kusetshenziswa izivumelwano ezisezingeni lomkhakha kunikeza ukuzethemba ekuqinisweni kwedizayini ngaphambi kokuzibophezela ekukhiqizeni.

I-Highleap Electronics iletha ukwethembeka okuqinisekisiwe kwe-HDI PCB ngokusebenzisa:

• Ukulawulwa kwenqubo ye-microvia okuthuthukisiwe ngokusebenza kwe-laser drilling kanye nokulawulwa kokugcwalisa ithusi ukuze kuncishiswe ukuqhekeka nokuqinisekisa ubuqotho besakhiwo.
• Izinhlelo zokuhlola ukwethembeka okuphelele okuhlanganisa ukuhamba ngebhayisikili elishisayo, i-HAST, nokuhlaziywa kwe-microsection eqondaniswe namazinga e-IPC-TM-650 kanye ne-IPC-6016
• Amasistimu wokufaneleka wezinto ezibonakalayo anama-laminates aphezulu e-Tg kanye nezinhlelo ze-resin ezinomswakama ophansi ezikhethelwe izicelo ezifunwa kakhulu.
• Ukulawula inqubo yezibalo ukuqapha amapharamitha abalulekile athinta ukusebenza okuthembekile kwesikhathi eside kukho konke ukukhiqiza

Bambisana ne-Highleap Electronics yokukhiqiza nokuhlanganisa i-HDI PCB esekelwa izinhlelo zekhwalithi eqinile kanye nobuchwepheshe bobunjiniyela bokuthembeka. Xhumana nethimba lethu lobunjiniyela ukuze uxoxe ngezidingo zakho zohlelo lokusebenza lokuthembeka okuphezulu futhi uthole izincomo eziningiliziwe zokuklama nokuthembeka ezilungiselelwe imigomo yakho yokusebenza ethile.