Yakha i-PCB Yombono Werobhothi Elungele Ukukhiqiza

Ibhodi lombono werobhothi aliyona nje "i-computing." Liyipayipi lokuqonda ngesikhathi sangempela okumele (1) libambe idatha yesensa ye-bandwidth ephezulu ngokwethembeka, (2) lihambise leyo datha ngememori kanye ne-AI accelerator ene-latency elinganiselwe, futhi (3) lilethe imiphumela enesitembu sesikhathi kubalawuli ngokuqhubekayo kulo lonke izinga lokushisa, ukudlidliza, i-EMI, kanye nokwehluka kokukhiqiza. Uma noma iyiphi ingxenye yepayipi le-PCB ilahlekelwa yi-margin—ubuqotho besignali, ubuqotho bamandla, i-headroom yokushisa, noma ukuhambisana kokuhlanganiswa—izimpawu zensimu zivame ukuvela “njengokuwa kwekhamera okungahleliwe,” “ukubambezeleka kokucabanga okungazinzile,” noma “ukusetha kabusha okungapheli.”

Thola Isilinganiso Esisheshayo

Lesi sihloko sigxile ezinqumweni ezingeni le-PCB ezinquma ngqo ukuzinza kokuqonda: ukuhlanganiswa kwezinto zokwakha, izindlela zomzila ezisheshayo kanye nezindlela zokubuya, isu le-PDN/EMI, ukwakhiwa kokushisa, ukukhiqizwa, kanye nokuqinisekiswa. Ukuze amaqembu afuna ukwenziwa kanye nokuhlanganiswa kuhlale kuhambisana nalezi zindlela zokusebenza ngokusebenzisa i-prototyping kanye nevolumu, ububanzi bethu bufingqiwe kumasevisi okukhiqiza kanye nokuhlanganiswa kwe-PCB yamarobhothi.

1) Isabelomali Sesistimu: Umthwalo Womsebenzi, Ukubambezeleka, kanye “Nokuthi Yini Okungamelwe Inganyakaziswa”

Ngaphambi kokukhetha imojuli ye-AI noma ukuhambisa umzila owodwa, chaza izabelomali ezihumushela ezinkingeni ze-PCB. Ukusebenza kombono akuyona nje i-FPS—kungukusatshalaliswa kokubambezeleka ngaphansi kwezimo ezimbi kakhulu kanye nesikhathi sokusebenza esiqhubekayo.

• Incazelo yomthwalo womsebenzi: ukutholwa < ukuhlukaniswa < ukuhlukaniswa < ukuma okungu-6-DoF < ukujula okujulile + ukulandelela. Isinyathelo ngasinye siphakamisa ithrafikhi yememori kanye nomjikelezo womsebenzi wokubala, okuthinta kokubili i-PDN kanye nomklamo wokushisa.
• Ukubambezeleka kusukela ekuqaleni kuya ekugcineni: faka ukuvezwa/ukufundwa, ukudluliselwa, ukucubungula kwangaphambili, ukuqagela, ukucubungula ngemuva, kanye nokuthuthwa kusilawuli sokunyakaza. Cacisa ama-targets e-p95/p99, hhayi nje kuphela ama-average.
• Imingcele eqondile: nquma ukuthi yimiphi imiphumela evala iluphu yokulawula (kumele ibekwe imingcele futhi ifakwe isitembu sesikhathi) uma kuqhathaniswa nokuthi yikuphi "ukuqapha/ukubhala" (okungaba umzamo omuhle kakhulu).
• Izibikezelo zemvelo: Ukwehluka kokukhanya, ukufiphala kokudlidliza, uthuli, izinga lokushisa elizungezile, kanye ne-EMI evela kuma-motor drive kufanele kube yizinto ezifakiwe ezicacile, hhayi imicabango yangemva kwalokho.

Okusebenzisekayo okulethwayo inani lamakhamera abonisa isabelomali sekhasi elilodwa, isixazululo/i-FPS, amamodeli aqondiwe, umkhawulo we-latency we-p95/p99, isikhathi sokusebenza esiqhubekayo, imikhawulo yokuvala, kanye namandla aphezulu. Lokhu kuvimbela imodi yokuhluleka evame kakhulu: ukuklama izimo zedemo kunezimo zerobhothi.

2) I-PCB Stackup kanye nezinto zokwakha: Isisekelo se-High-Speed ​​​​kanye ne-DDR

Kumabhodi okucubungula umbono, i-stackup akuyona imininingwane yomshini—iyimfuneko kagesi. I-MIPI/USB3/PCIe/DDR konke kuncike ku-impedance elawulwayo, izindiza zokubhekisela ezizinzile, kanye nezakhiwo ze-dielectric ezibikezelwayo. Uma i-stackup ingazinzile, imingcele yakho yamehlo kanye nemingcele yesikhathi ngeke izinzile.

• Ukuqoqwa kwe-stackup kuchazwe yizixhumi ezibonakalayo: nquma ukuthi yiziphi izendlalelo ezinemizila yesivinini esikhulu, ukuthi yiziphi izendlalelo ezisebenza njengezinkomba ezingaphazanyiswa, nokuthi i-topology ye-DDR ihlala kuphi. Lokhu kuvimbela ukuyekethisa kamuva okudala ukungaqhubeki kwendlela yokubuyela emuva.
• Ukukhethwa kwezinto ngale kwe-Tg: ngejubane eliphezulu, i-Dk/Df ehambisanayo kanye nokuziphatha kwazo kwezinga lokushisa kubalulekile. Ukuguquguquka kuvela njengokuncipha kwe-link margin kanye nokushintsha kwesikhathi phakathi kwezinga lokushisa kanye nokwakheka.
• Ukulawulwa kwe-impedance okungenziwa ngempela: I-target impedance kumele ihambisane ne-trace geometry kanye nama-tolerance bands afinyelelekayo. I-“100Ω diff” ayinalutho ngaphandle kokuthi ixhunywe ku-dielectric thickness elawulwayo kanye nekhono lenqubo.

Umzila oqinile kanye ne-impedance eqinile kuvame ukudinga ukwakhiwa kwe-HDI. Uma umklamo wakho usebenzisa ama-BGA e-tight pitch, ama-dense breakouts, noma iziteshi ezimfushane zesivinini esikhulu, buyekeza izakhiwo zebhodi lesifunda le-HDI kusenesikhathi ukuze i-stackup isekele umzila one-margin kunokuphoqa ukuyekethisa kamuva.

3) Izixhumi Zezinzwa: I-MIPI / USB3 / GigE kanye Nesiyalo Sokubuyela Endleleni

Ukwehluleka kokubona ngezikhathi ezithile kumarobhothi kuvame ukubangelwa izinkinga zendlela yesiginali/yokubuyela esikhundleni se-"firmware yekhamera." I-PCB kumele ilondoloze ubuqotho besiteshi ngaphansi kwe-EMI, ukudlidliza, kanye nokushisa.

• Ubuqotho besiginali ye-MIPI CSI-2: Izixhumanisi zokuhlukanisa ezinemizila eminingi zidinga i-impedance elawulwayo, ukugoba okuqinile, kanye nezinkomba eziqhubekayo. Iphutha elivame kakhulu akulona i-differential pair ngokwayo, kodwa indlela yokubuya ephulwa ukuhlukana okukhulu, ama-voids, noma izinguquko ezithungwe kabi.
• Isixhumi kanye ne-flex njengengxenye yesiteshi: Izixhumi zebhodi kuya ku-FPC, izixhumi ze-mezzanine, kanye nokuhlanganiswa kwekhebula kwengeza ukungaqhubeki. Ziphathe njengengxenye yesabelomali sesiteshi, hhayi "ngaphandle kobubanzi be-PCB."
• Ukushintshana kwe-USB3 / GigE: Zivumela amabanga amade kanye nokubekwa kwekhamera okuguquguqukayo kodwa zandisa ukuchayeka emsindweni wemodi evamile kanye ne-ESD. Ukuhlelwa, inhloso yokuvikela/ukubopha, kanye nokubekwa kokuvikela kumele kuchazwe ukuze “ungavikeli imbobo” ngokubhubhisa umkhawulo.
• Ukuvumelanisa kwamakhamera amaningi: Uma udinga ukuhambisana kwe-stereo noma ukubuka okuningi, iziqalisi zehadiwe kanye nomzila ohambisanayo kunciphisa ukuzulazula uma kuqhathaniswa nokuvumelanisa kwesofthiwe kuphela ngaphansi komthwalo we-CPU/GPU.

4) I-DDR kanye nesitoreji: Ukuhlela isabelomali se-bandwidth kanye neqiniso lesikhathi

Imithwalo yemisebenzi yokubona iboshelwa ngokushesha kwimemori. Ama-buffer ozimele, izisindo, kanye nokusebenza kuncintisana nge-bandwidth, okubangela ukwanda kwe-latency ngisho noma i-computing ibonakala yanele. I-DDR ingenye yezingxenye ezizwela kakhulu i-margin ye-PCB.

• Isabelomali se-bandwidth: bala ukufundwa/ukubhala okuhlanganisiwe kozimele bokungena, ukucubungula kwangaphambili, ukusebenza kwe-inference, kanye nemiphumela. Engeza umkhawulo wezigcawu ezimbi kakhulu kanye nokuqhuma kwamakhamera amaningi.
• I-DDR iwubunjiniyela besikhathi: Akukhona nje kuphela ukufanisa ubude. Ukuqhubeka kokubhekisela, ngezakhiwo, ukuguquka kwezendlalelo, kanye ne-topology yokubekwa kunquma ukuthi isikhathi sihlala yini phakathi kokushisa nokwehluka kwesakhiwo.
• Uhlobo lwesibonelo vs ivolumu: isixhumanisi se-DDR "esidlula ekamelweni" singaba yizikhawu ngemva kokushintshashintsha kokuhlanganiswa noma ekushiseni okuphezulu—izimo kanye amarobhothi abhekene nazo.
• Isu lokugcina lithinta ukuziphatha: I-eMMC/flash yenza kube lula ukuqala futhi inciphise ubunzima be-I/O; i-NVMe yandisa amandla okudlulisa kanye nokugcina idatha kodwa yengeza umthwalo wokuhambisa idatha/amandla/okushisa.

Ukuze uthole indlela yokulungiselela ukukhiqiza ekulungele ukukhiqiza, ngokusebenzisa isu, kanye nomklamo oqaphela ukubekezelelana, sebenzisa umhlahlandlela wokuklama i-HDI stackup yama-PCB alungele ukukhiqiza njengesisekelo lapho i-DDR kanye nezixhumi zesivinini esikhulu kumele zihlale zizinzile ngokukala.

5) Ubuqotho Bamandla kanye ne-EMI: Ukugcina Ukuqonda Kuzinzile Ngaphansi Komsindo Wezimoto

Amarobhothi aphikisana nogesi: ama-motor drive kanye nama-DC/DC converter afaka umsindo we-broadband, amandla omhlaba ayashintsha ngaphansi komthwalo, kanye nokuwa kwamandla ebhethri ngesikhathi sokusheshisa kanye nokubhuleka. I-PCB yombono kumele ihlale izinzile phakathi nalezi zenzakalo noma ukuphetha kuba okungahleliwe.

• Izinhloso ze-PDN impedance: Ama-accelerator e-AI adala ama-transients omthwalo osheshayo. Uma i-PDN impedance iphezulu kakhulu kuma-frequency angalungile, izimpawu zifaka phakathi ukusetha kabusha, ukugoqa, amaphutha esixhumanisi, noma ukungazinzi kokuqonda "okungahleliwe".
• Ukuhlukanisa ngamabhendi emvamisa: hlanganisa ukuhlanganiswa kwendawo okuvamise ukuba khona ngesivinini esiphezulu kanye nesitoreji samandla esimaphakathi kanye nesitoreji samandla esisezingeni lesitimela. Ukuhlelwa kumele kunciphise ukujikeleza kwe-loop, hhayi nje ukubeka ama-capacitor “eduze.”
• Ukuhlukaniswa kwesizinda ngokuhlela ukubuyiselwa kwangempela: hlukanisa izizinda ezinomsindo (abaguquli bamandla aphezulu, imisele ehlobene nemoto) ezizindeni ezibucayi (i-analog/iwashi/ireferensi yekhamera). Isihluthulelo ukulawula ukuthi imisinga yokubuya igeleza kuphi.
• Ukungavikeleki komsindo wewashi kanye nenzwa: Ukusatshalaliswa kwewashi lokubhekisela kanye nezixhumi zenzwa ngokuvamile kuyizinto zokuqala ezibangela umsindo wemodi evamile. Isu lokuthunga, injongo yokubopha i-chassis, kanye nokuphathwa kwegobolondo lesixhumi kumele kuhambisane.

6) Umklamo Wokushisa: Ukucabanga Okuqhubekayo Ngaphandle Kokugoba

Umklamo wokushisa yilapho "impumelelo yokulinganisa" iphenduka khona "ukwehluleka kwensimu." Uma ibhodi lishintsha ngemuva kwemizuzu, ukusatshalaliswa kokubambezeleka kuyashintsha futhi izibikezelo zokunyakaza kwerobhothi ziyaphuka.

• Umklamo wesimo esibi kakhulu esiqhubekayo: qinisekisa endaweni yokugcina ebiyelwe kanye nebanga le-ambient, hhayi ebhentshini elivulekile.
• Ukuvumelana kokunamathisela kwe-Heatsink: Ukucindezela kokufaka, ukuba yisicaba, kanye nokuqina kokudlidliza kushintsha ukumelana nokushisa kanye nokuziphatha kweyunithi kuya kwenye.
• Ukusabalala kokushisa kwe-PCB: Ukushisa ngama-array, izindiza zangaphakathi, kanye nokusatshalaliswa kwethusi okulawulwayo kunciphisa izindawo ezishisayo, kodwa kumele zikhiqizwe futhi zithembeke ngokujikeleza kokushisa.
• Ukusebenzisana kwe-thermal-mechanical: I-warpage igcizelela ama-BGA kanye namajoyinti acwebezelayo; ukwanda kokushisa ngaphansi kwesikhathi eside kungaba umthombo wephutha ngezikhathi ezithile uma imingcele mincane.

7) I-DFM/DFA: Ukuklama Ukuhlanganiswa Okuphindaphindwayo Nokuqina Kwensimu

I-PCB yokucubungula umbono ngokuvamile iyinhlanganisela yezimpawu ezixubile ezixineneyo: ama-BGA, izixhumi zesivinini esikhulu, amawashi abucayi, kanye nemizila yamandla aphezulu ehlanganyela indawo elinganiselwe. I-DFM/DFA kufanele ivikele ngokucacile imingcele othembele kuyo.

• Amafasitela okuhlanganisa e-BGA/QFN: isu le-stencil, iphrofayili yokugeleza kabusha, kanye nokulawula okungenalutho kuthonya kokubili ubuqotho bamandla kanye nokusebenza kokushisa. Umehluko omncane ungaba umehluko omkhulu wokubambezeleka noma wokuzinza.
• Ukuqinisa izixhumi zamarobhothi: Izixhumi zekhamera ze-FPC, i-I/O eqinile, kanye nezixhumi zebhodi nebhodi kumele zisinde ekudlidlizeni nasekuphathweni. Ukusekelwa kwemishini kanye nokukhululeka kokucindezeleka kufanele kuhlelwe, hhayi okwenziwe ngendlela ezenzakalelayo.
• Imingcele yokuhlanzeka kanye nokugqoka: Uma kudingeka i-conformal coating noma ukuhlanza okukhethekile, chaza izindawo zokugcina ezizungezile izixhumi kanye nezixhumi ezisetshenziswayo ukuze ukuthembeka kuthuthuke kunokuba kubuyele emuva.
• Ukulawulwa kwe-stackup/impedance kuhlobene nokusebenza okuhle kakhulu: Impumelelo esheshayo idinga ukuqeqeshwa kokukhiqiza ngokujiya kwesendlalelo, ithusi, kanye nokubhaliswa—hhayi nje kuphela inhloso yokuklama.

Ezinhlelweni zamarobhothi, yilapho amakhono ekwakhiweni kwe-PCB kanye nokuhlanganiswa kwe-PCB ebaluleke khona ngomqondo wobunjiniyela ongeyona eyokumaketha: anquma ukuthi ingabe ukuvimba okufanayo, ikhwalithi ye-BGA, kanye nokuqina kwesixhumi okuqinisekisile kuma-prototypes kungakhiqizwa kabusha njalo ngevolumu.

8) Ukuqinisekiswa Nokuhlolwa: Ukuqinisekisa Umkhawulo Wesixhumanisi Nokubambezeleka Ekukhiqizeni

Kumabhodi ombono werobhothi, i-“boots and runs a demo” akuyona ukuhlolwa kokukhiqiza. Ukuqinisekisa kumele kubonise izindlela eziqondile zokuhluleka ezibangela ukungazinzile kwensimu: ukuwa kwe-link margin, i-DDR intermittency, i-thermal throttling, kanye ne-latency jitter.

• Ukuqinisekiswa kwe-interface yesivinini esikhulu: fanelekela izixhumanisi zekhamera, i-DDR, kanye ne-I/O yesivinini esiphezulu ngaphansi kokucindezeleka kwe-EMI kanye nokushisa okweqile. Lapho kungenzeka khona, kala i-margin (ukuhlolwa kwesitayela se-BER, amaphethini okucindezeleka, ukuphazamiseka okulawulwayo) kunokuba udlule/wehluleke ekamelweni kuphela.
• Ukuqinisekiswa kokushisa komsebenzi okuqhubekayo: sebenzisa amamodeli amele njalo futhi uqinisekise ukuthi akukho ukugoba kanye nokugudlukela kwesikhathi ezimweni ezimbi kakhulu ze-ambient kanye ne-enclosure.
• Ukuhlolwa kokusebenza kokuphela komugqa: faka amavekhtha esithombe esinqunyiwe bese uqinisekisa imiphumela kanye nemikhawulo yesikhathi (p95/p99), hhayi nje kuphela "ukusebenza kokuphetha."
• Ubufakazi obulandelekayo: rekhoda izinguqulo ze-firmware/zemodeli, izimo zokushisa, kanye nezibalo zokusebenza ngeyunithi ngayinye ukuze izinkinga zasensimini zikwazi ukuhlukaniswa ngokushesha.

Uma imijikelezo emide yomsebenzi kanye nezimo ezinzima kuyingxenye yesidingo sangempela, izindlela zokuhlola ukuthembeka kanye nokuqinisekisa kufanele zihlelwe kanye nomklamo we-PCB. Ireferensi yethu yokuhlola ukuthembeka ifingqa izindlela ezivamile ezisetshenziswa ukuqinisekisa umkhawulo phakathi kokujikeleza kokushisa nezinye izimo zokucindezeleka.

Isifinyezo: I-PCB yokucubungula umbono werobhothi iyipulatifomu yokucabanga ye-AI yesikhathi sangempela. Ukuqonda okuzinzile kwensimu kuncike (1) ekuqineni kwe-stackup kanye nezinto ezibonakalayo, (2) isiyalo sesiteshi esinejubane eliphezulu kanye nendlela yokubuyela emuva, (3) ukuqina kwe-PDN/EMI ngaphansi komsindo wemoto, (4) i-headroom yokushisa eqhubekayo, (5) i-DFM/DFA evikela ama-margins ekuhlanganisweni, kanye (6) ukuqinisekiswa okulinganisa i-link margin kanye nokusatshalaliswa kwe-latency—hhayi i-FPS ejwayelekile nje kuphela.