10 Layer AI Server PCB Engineering yeAccelerator Hardware

"AI server PCB" itsananguro yesystem, kwete kirasi yekugadzira. Izwi iri rinogona kureva baseboard, accelerator add-in card, CXL memory device, retimer card, network interface, optical-module carrier, management controller, power-distribution board kana small control board mukati me liquid-cooling subsystem. Zvigadzirwa izvi hazvina shared one layer count, laminate, impedance tolerance, HDI buildup kana reliability plan.

Kuvakwa kwemadziro gumi kunogona kukodzera mabhodhi akasarudzwa eAI-infrastructure, asi hakufanirwe kushambadzirwa sepuratifomu yepasi rose yemabhodhi epamusoro-soro e-accelerator kana masisitimu eswitch. Kuverengwa kwemadziro kwakakodzera kunobva mukubuda kwezvikamu, kuwanda kwechiteshi, zvinodiwa zvereferensi-plane, kugoverwa kwesimba, topology yekubatanidza, ukobvu hwemakanika uye zvinodiwa zvequalification. Muzviitiko zvakawanda, bhodhi remazuva ano remadziro gumi nemaviri, gumi nematanhatu kana kupfuura rine njodzi shoma pane kumanikidza ma cycles akawanda eHDI akatevedzana uye ma power planes akapatsanurwa kuita gumi.

Gwaro iri rinotsanangura kuti zvidimbu gumi zvinovimbika papi uye kuti chii chinofanira kupihwa usati wagadzira. Rinodzivisa nemaune zvirevo zvakagadzika zvakaita sekuti "Tachyon yakaenzana nemainchi matanhatu," "0.4 mm BGA inogara ichida 3+4+3," kana kuti "mabhodhi ese eAI anoda Kirasi 3." Sarudzo idzodzo ndedzemhando yechiteshi yakaburitswa, kudzidza kwekubuda kwepakeji uye magwaro ekutenga. Gwaro rekuvaka rakajairika rinowanikwa muongororo yeinjiniya yePCB yezvikamu gumi , nepo basa remagetsi rakadzama richifukidzwa negwaro rechiteshi rinomhanya kwazvo.

Apo PCB yeLayer gumi inokodzera muAI Infrastructure

Matanda gumi anonyanya kuvimbika kana bhodhi riine nzvimbo shoma dzekufambisa dzinomhanya zvakanyanya, nzvimbo ine nzira dzakati wandei dzekufambisa uye dhizaini yemagetsi isingade mapuraneti akawanda akafara, akaparadzana. Mienzaniso inosanganisira mabhodhi ekutarisira neBMC, makadhi ekuwedzera ekuwedzera kana ekuchengetedza ane nhamba inodzorwa yePCIe kana CXL lanes, makadhi eretimer, makadhi e optical-module breakout, zvishandiso zvekuwedzera memory zveCXL, ma subassemblies e network interface, ma fan ne pump controllers, ma telemetry boards uye zvigadzirwa zve power-control zvakasarudzwa.

Kuverengwa kwezvikamu zvakafanana kunova kwakaoma kana bhodhi richifanira kubuda mumapakeji akawanda akakura, kutakura nzira dzakawanda dzekurangarira, kufambisa nzira dzakawanda dze112 Gb/s kana nzira dzinobuda dze224 Gb/s, kutsigira njanji dzakawanda dzemagetsi ane simba, kana kubatanidza mezzanine yakawanda ine simba uye optical interfaces. Muzviitiko izvozvo, nzvimbo yekufambisa nendege inoshandiswa nema antipads, kuburikidza neminda uye zvitsuwa zvemagetsi zvinogona kuita kuti zvikamu gumi zvemagetsi zvive zvisina kusimba kunyangwe kana zvisaririra zvichigona kugadziriswa kuti zvikwane.

Sarudzo yacho inofanira kuenzanisa magadzirirwo matatu: bhodhi remazuva ano rine zvidimbu gumi, bhodhi reHDI rine zvidimbu gumi uye bhodhi remazuva ano rine zvidimbu zvepamusoro. Kuverengwa kwezvikamu zvishoma hakusi iko kunodhura zvakaderera kana kuti kwakavimbika. Kuisa simbi muzvikamu zvakatevedzana, kuboora nelaser, kuzadza mhangura uye kuderedzwa kwegoho zvinogona kupfuura mutengo wemamwe mativi maviri ezvikamu zvemazuva ose.

Ronga Bhodhi Usati Wasarudza Stackup

Stackup inofanira kusarudzwa kubva pabasa rebhodhi musystem. Kadhi rekuwedzera accelerator, CXL memory card uye optical-module carrier zvese zvinogona kunzi AI hardware, asi zvipingamupinyi zvavo zvakakosha zvakasiyana.

Mabhodhi ekutungamira nekudzora

Mabhodhi aya anowanzo shandiswa nema microcontrollers, BMC devices, power sequencing, fan kana pomp control, sensor interfaces uye moderate-speed networking. Kuisa mareference-plane-rich ten-layer stackup kunogona kupa nzira dzakachena dzekudzoka, kupatsanurwa pakati peswitching power nema measurement circuits, uye kugoverwa kwesimba kwakakwana pasina kushandisa premium low-loss material mubhodhi rese.

Midziyo yePCIe neCXL

PCI Express neCXL links dzine hwaro hwemuviri, asi kugadzirisa kunotonga uye chimiro chechimiro zvichiri kukosha. PCIe 5.0 inoshandisa 32 GT/s NRZ, PCIe 6.0 inoshandisa 64 GT/s PAM4, uye PCIe 7.0 Version 1.0 yakaburitswa pa128 GT/s PAM4. CXL 4.0 yakaburitswa muna 2025. Izvi zvinosimbisa mamiriro ekutumira masaini; hazvipe bhajeti repasi rose rekurasikirwa kwebhodhi. Tsanangudzo yebase inoshanda, add-in-card kana custom topology, connector model, retimer placement uye package allocation zvinofanirwa kuzivikanwa usati wasarudza kuvakwa kwebhodhi.

Mabhodhi ekubatanidza network uye optical

IEEE 802.3df-2024 400 Gb/s uye 800 Gb/s Ethernet zvinangwa uye physical layers. Bhodhi rinotsanangurwa se "800G" rinogona kushandisa nzira dzakasiyana dzekuverenga, ma electrical reach, connectors uye optical-module interfaces. Pakugadzirisa uku, IEEE P802.3dj ichiri kugadzira mashandiro e1.6 Tb/s uye mamwe ma physical layers e200/400/800 Gb/s; magadzirirwo anoshandisa basa iroro anofanira kudoma draft chaiyo kana zvinodiwa nevatengi. Saizvozvowo, mapurojekiti eOIF 224G-class anosiyanisa extra-short, very-short, medium and long reach pachinzvimbo chekutsanangura imwe universal PCB channel.

Kune marudzi ese matatu emabhodhi, mutengesi anoda tsananguro chaiyo yechiteshi. Chiratidzo chekushambadzira chakadai sekuti “Gen7,” “800G” kana “224G” hachina kukwana kuti chibudise nzira yekuisa laminate kana yekuboorera kumashure.

Kurongedza Accelerator, HBM nePCB Boundary

Memory yebandwidth yepamusoro inoshandiswa nema accelerator emazuva ano inowanzo batanidzwa ne processor kuburikidza ne advanced package, interposer kana package-level substrate. Saka HBM interface haiwanzo shandiswa se traditional differential bus kuburikidza ne server PCB. Bhodhi rinotakura external power ye accelerator package, PCIe/CXL, chip-to-chip, management, clock and service interfaces. Kubata HBM lanes se ordinary PCB stripline inyaya huru ye architecture.

Muganhu wepakeji unoshandura dambudziko rePCB nenzira mbiri. Chekutanga, bhodhi rinogona kunge risingatakure interface yeHBM yakafara zvakanyanya, asi rinofanira kuramba richitsigira nzira yeBGA yakamanikana uye network yemagetsi ine simba rakawanda. Chechipiri, nzira yekubvisa pakeji, socket kana land geometry uye nzvimbo yekubvisa ma "decoupling" zvinogona kutora huwandu hwe "layer" kunyangwe huwandu hwenzira dzekunze dzinomhanya zvakanyanya huri hushoma.

Ruzivo rwepakeji runodiwa pakuronga bhodhi

• mepu yebhora, pitch, dhayamita yenyika uye patani yekubviswa kwevanhu;
• kugoverwa kwesimba nebhora repasi nechitima;
• nzvimbo dzekunze dzemumugwagwa dzinomhanya zvakanyanya uye patani yebhora rekutarisa;
• nzvimbo dzekuparadzanisa dzinobvumirwa nefeni, kuburikidza nenzvimbo dzekuparadzanisa dziri mukati mepad uye kumashure;
• kuchengetedza michina, kusimbisa, kugadzika heatsink kana cold-plate;
• mamodheru epakeji uye ekuputika ekuenzanisa nzira;
• chimiro chemusangano uye zvinodiwa zve coplanarity.

Dhizaini ine zvidimbu gumi inofanira kurambwa nekukurumidza kana chidzidzo chekubuda cheBGA chikadya mareferensi, chikapwanya kugoverwa kwesimba kana kuti chikada mazinga akawanda kupfuura anogona kutsigirwa nechirongwa chekufanirwa. Gwaro reinjiniya re10 layer HDI rinotsanangura kuti nei pitch yoga isingakwanise kusarudza 1+8+1, 2+6+2 kana 3+4+3.

PCIe, CXL uye Ethernet Channel Engineering

Kugona kushanda nekukurumidza kunofanira kusimbiswa kubva pachiteshi chose: kubuda kwepakeji, kuburikidza nekuchinja, mutsetse wakarongwa, chinongedzo kana kuvhurwa kwetambo, retimer kana iripo uye receiver package. Kusarudzwa kwezvinhu kunongova chinhu chimwe chete chinoshanduka.

Kuboorera kumashure kunofanira kutsanangurwa kana stub isina kutorwa yatyora zvinodiwa nemugero uye mhinduro yekuona-kutarisa haidiwi. Chinyorwa chinofanira kutsanangura divi rekuboorera, dhayamita rechinangwa, stub yakasara yepamusoro, dhayamita yechishandiso, nzira yekubuda inobvumirwa uye nzira yekusimbisa. Chikumbiro chakasimba che "3 mil maximum" hachina kukodzera kune ese mapaneru ukobvu uye hwindo rekunyoresa.

Saizvozvowo, kufananidzana kwemapairi akasiyana-siyana uye nzvimbo yepakati penzira zvinofanirwa kubva pakushandisa nzira uye modhi yechiteshi. Mitemo yakaita se +/-1 mil intra-pair kana nzvimbo ye10W haisi zviratidzo zvepasi rose zvekutevedzera mitemo. Gwaro renzira rinotsanangura maitiro ekushandura zvinodiwa nenguva, kutaura kwakabatana uye kuchinja kuita zvirambidzo zvemarongerwo.

Sarudzo dzeStackup, Zvinhu uye Copper

Kugadziriswa kweAI-infrastructure ine zvikamu gumi kunowanzo batsira mareferensi kupfuura huwandu hwakanyanya hwemareferensi. Architecture ine zviratidzo zvina, pasi pevhu, simba mbiri inogona kupa zvikamu zviviri zvekunze zve microstrip uye zvikamu zviviri zve stripline zvakanaka uku ichichengetedza kugoverwa kwesimba kwakafara. Kurongeka kwezviratidzo zvitanhatu/pane-mana kunopa kugona kwakawanda kwekufambisa asi kunogona kugadzira zvikamu zvezviratidzo zviri pedyo kana nzvimbo isina kukwana yendege; zvinofanirwa kushandiswa chete kana nzira chaiyo yekudzoka uye chirongwa checrosstalk chichizvitsigira.

Zvinhu zvisinganyanyi kurasikirwa zvinofanira kuiswa panzvimbo inoratidza kuti modhi yemugero inodiwa. Chivakwa chehybrid chinogona kushandisa core isinganyanyi kurasikirwa uye sisitimu yekubatanidza yakatenderedza zvidimbu zvestripline zvinomhanya zvakanyanya uku chichishandisa imwe sisitimu inoenderana nayo kune imwe nzvimbo. Chivakwa chehybrid chinofanira kuramba chichizadzisa zvinodiwa zvekubatanidza, kuboora, kufamba kwemativi, kunamira kwemhangura uye zvinodiwa zvekupisa. Mhuri mbiri dzelaminate dziri mukirasi imwe chete yekurasikirwa kwekushambadzira hadzichinjiki otomatiki.

Zvinhu zvinoburitswa

• runyorwa rwegiredhi rakatenderwa kana runyorwa rwezvinhu zvakatenderwa;
• kuvaka kwepakati nekugadzirira, zviri mukati me resin uye magadzirirwo egirazi;
• profile yemhangura inoshandiswa mumuenzaniso wekuisa-kurasikirwa;
• dhizaini yeDk neDf source, nzira uye frequency range;
• simba rekutsiva uye nzira yekukodzera;
• nhoroondo yekupisa kubva pakutevedzana kwelamination, kuburikidza nekuzadza, kupedzisa uye kuunganidza;
• kuwanikwa, huwandu hushoma hwekutenga uye zvipingamupinyi zvenguva refu zvekuwanikwa kwezvinhu.

Gwaro rezvinhu zvine zvidimbu gumi rinofukidza zvinhu izvi zvakadzama. Kudzora kusingadzoreki kunofanirwa kuverengerwa patsva zvichienderana nekugadzirwa kunokurudzirwa, kwete kukopa kubva patafura ye5 mil/50 Ω.

HDI, BGA Escape uye Via Architecture

HDI inoruramiswa kana ikaita kuti pave ne routing access kana electrical performance iyo isingakwanise kupihwa ne conventional via field. Iyo package pin mepu, nhamba yemitsara, power-via demand uye masignal layers aripo anonyanya kukosha kupfuura pitch yega.

Pakukwidziridza, retimer uye switch packages, via-in-pad inogona kushandiswa kudzoreredza nzira dzinobuda. Dhirowa yekugadzira inofanira kusiyanisa microvia yakazara nemhangura, nonconductive fill, resin plug, planarization uye copper cap. Stacked microvias inoda humbowo hwekuvimbika kwechimiro nekuti kubatana pakati pe filled vias nenzvimbo dzakatarwa kunogona kuva nzvimbo ine kuneta kana paine kupisa kwakawanda.

Chero HDI ine layer kana multiple-buildup haifanirwe kusarudzwa nekuti iripo chete. Danho rega rega re buildup rinowedzera mifananidzo, lamination, laser drilling, metallization uye kazhinji copper fill/planarization. Dhizaini yacho inofanira kuenzanisa bhodhi repamusoro-soro nebhodhi rakaoma reHDI rine layer gumi uchishandisa routing, goho, kuvimbika uye mutengo - kwete chete nhamba ye layer.

Kuongororwa kwekuburitswa kweHDI

• ratidza zvese zvakapofumara, zvakavigwa, zvakasvetuka uye zvakapfuura nepakati patafura yekuboorera;
• tsvaga hukama hwakarongwa uye hwakarongwa nematanho nematanho;
• simbisa dhayamita ye microvia, ukobvu hwe dielectric uye bata ivhu sehwindo rekuita rimwe chete;
• tsanangura zvinodiwa pakuzadza, chivharo, dimple uye nzvimbo yekuunganidza;
• zvirevo zvechigadzirwa, kirasi, kuponi yekukodzera uye zvinodiwa zvekugamuchira zvakawanda;
• Musashandise IPC-6016 sechipimo chekugamuchirwa kweHDI chiripo; shandisai zvirevo zvechigadzirwa zviripo uye kugadziriswa kwekutenga.

Network yeKuendesa Magetsi uye Kugoverwa Kwazvino

Simba rekumhanyisa harigone kugadzirwa kubva pa current headline chete. PDN yebhodhi inofanira kuzadzisa kudonha kwemagetsi eDC, transient impedance, kuiswa kwe converter, kuiswa kwepakeji, connector kana busbar limits, copper temperature rinowedzera uye mechanical limits. Current inogona kuendeswa kuburikidza ne edge contacts, high-current current connectors, busbars, vertical power modules kana local regulators; architecture yega yega inoshandisa PCB zvakasiyana.

Hukama hwechinangwa-impedance Z _target = ΔV / ΔI inzvimbo yekutanga, kwete PDN specification yakakwana. Transient spectrum yakakodzera, voltage-regulator control loop, package capacitance uye allowed droop inofanira kutsanangurwa. Pamusoro pehuwandu hwema frequency apo ma capacitor akaiswa pabhodhi anoramba achishanda, package uye on-die structures ndizvo zvinonyanya kukosha.

Mibvunzo yeDC neAC inokanganisa kugadzirwa

• Ndedzipi njanji dzinoda mapurani akafara, mhangura inorema, copper inlay kana maconductor ekunze?
• Upfu hwemhangura hwakapedzwa hupi, kwete huremu hwefoil hwakatarwa?
• Nzvimbo yakakura sei yendege inorasika kubva kuma antipads, slots, thermal cutouts uye mounting hardware?
• Kupatsanurana kwemashure kunogona kuiswa kupi, uye ma-vias anozadzwa anodiwa here munzvimbo dzine zvikamu?
• Kudzikira kwevoltage nekukwira kwetembiricha kunotenderwa pamagetsi akaipisisa uye ari munzvimbo yakapoteredza mhepo?
• Bhodhi rinoda magadzirirwo emagetsi, ma "calibrated shunts" kana kuti Kelvin routing here?

IPC-2152 inopa gwara rekuti magetsi anofambisa sei magetsi uye maitiro ekupisa, asi haideredzi plane yakaoma kana via field kusvika pamuganho mumwe chete wehuwandu hwemagetsi. Shandisa simulation kana data rekuyedza rakasimbiswa remabhodhi emagetsi anomhanyisa magetsi ane simba guru. Mune zvimwe zvigadzirwa, busbar, leadframe kana power module yakakodzera pane kumanikidza mazana emaampere kuburikidza nePCB planes dzakajairika.

Kubatanidzwa kweThermal uye Mechanical

PCB chimwe chezvinhu zviri mugwara rekupisa. Mapakeji ane simba guru anowanzo ramba kupisa kwakawanda kuburikidza nechivharo chepakeji, heatsink kana mvura inotonhora pane kupfuura nepabhodhi. Mapurani emhangura nemavias zvinogona kuparadzira kupisa kwemunzvimbo uye kuderedza kurasikirwa kwemagetsi, asi kuverenga kuri nyore kwevi-count hakuratidzi kushanda kwekupisa kwepakeji.

Kutakura zvinhu nemidziyo yemagetsi kunogona kukosha sekufambisa kwemhepo. Mapakeji makuru, zvinhu zvinosimbisa, maplate anotonhora uye macage ekubatanidza zvinogadzira nguva dzekukotama dzinogona kumanikidza majoini e solder uye microvias. Mufananidzo webhodhi unofanirwa kutsanangura ukobvu, kutsetseka, kuchengetedza, kushivirira maburi ekukwirisa uye chero ukobvu hwenzvimbo hunodzorwa. Kuongorora kwekuunganidza kunofanirwa kufunga nezve warpage kuburikidza nekudzoreredza uye tembiricha yebasa.

Zvinopinda zvekuburitsa mafuta/makanika

• simba repakeji uye interface yekupisa inotenderwa;
• kusungirirwa kweheatsink kana cold-plate uye mutoro wekubatanidza;
• chikamu uye kuburikidza nekuchengetedza pasi pemidziyo yemakanika;
• rutsigiro rwebhodhi, kuomarara uye zvipingamupinyi zvechassis;
• kutenderwa kwebow/twist uye coplanarity yemuno;
• tembiricha uye kutenderera kwekupisa kunotarisirwa;
• CTE yezvinhu uye hybrid-stack symmetry.

Mhangura inorema inochinja maetch geometry, resin fill uye maitiro ekusunga. Mari dzemhangura ne inlays zvinhu zvakakosha zvinoda saizi dzakajeka, nzira yekubatanidza, kutsetseka uye zvinodiwa zvekuongorora; hazvifanirwe kuratidzwa sesarudzo dzakajairwa pabhodhi rega rega reAI.

Kuvimbika, Kuedzwa uye Kuteverwa

Kushandiswa kwedata-center hazvirevi otomatiki IPC Kirasi 3, uye chigadzirwa cheAI chekutengeserana hachigari nhaka chitupa chemotokari, chekurapa kana chemuchadenga kubva pashoko rekuti "AI." Kirasi inoshanda yekushanda uye sisitimu yemhando yepamusoro inobva munjodzi yechigadzirwa, zvinodiwa nevatengi uye magwaro ekutenga.

Kune mabhodhi akaomarara, IPC-6012 inowanzo kuve mhuri yekushanda kwechigadzirwa; mabhodhi akaomarara anoshandisa IPC-6013, uye zvivakwa zvine frequency yakakwira zvinogona kushandisa IPC-6018 pazvinenge zvichidikanwa. IPC-A-600 inopa dudziro yekuona asi haitsivi zvirevo zvechigadzirwa. Kugadziriswazve, kirasi, addenda uye kusarudzika kwevatengi kunofanirwa kutaurwa paodha.

Humbowo hwekuvimbika hunogona kusanganisira thermal-stress microsections, interconnect stress testing, HATS, temperature cycling, reflow simulation, CAF testing, insertion-loss coupon kana product-level Environmental qualification. Nzira idzi dzinopindura mibvunzo yakasiyana. Nzira dzekuedza zvikamu zveJEDEC hadzitsananguri otomatiki kugamuchirwa kwenzvimbo isina chinhu, uye IST haisi kungotenderera kwekamuri re -40 deg C kusvika +125 deg C.

Zvinyorwa zvinowanzo fungidzirwa sezvirongwa zvine njodzi huru

• chitupa chekutevedzera zvinodiwa uye kusimbiswa kwekuyedzwa kwemagetsi;
• kuunganidzwa kwakaburitswa uye kurongeka kwezvinhu/nzvimbo;
• Mhedzisiro yeTDR yemakuponi eimpedance akatarwa;
• mhedzisiro yezvikamu zvidiki zvezvivakwa uye purani yemuenzaniso yakarairwa;
• kusimbiswa kwehudzamu hwakadzika kana kuti back-drill kana zvichidikanwa;
• mishumo yenyaya yekutanga kana yekukodzera kwezvirongwa zvitsva zveHDI;
• Kutevedzana kwezvinyorwa uye kuteverwa kwemafambiro ekufamba-famba kana zvichidikanwa nekondirakiti.

Hazvisi zvese zvinotumirwa zvinoda mushumo wega wega. Mutengo unofanirwa kusiyanisa zvinyorwa zvakajairwa, mishumo yesarudzo, bvunzo dzinoparadza uye basa rekuongorora rinoda makuponi akatsaurirwa kana mamwe mapaneru.

Kuburitswa Kwekugadzira uye Pakeji Yekukosheswa

Mashoko anobatsira haagone kunyorwa kubva ku "10 layer AI server board" uye muchidimbu. Mutengesi anoda ruzivo rwakakwana kuti asiyanise bhodhi rekutarisira kubva kune retimer inomhanyisa kana kadhi rekukurumidzira uye kuona kuti njodzi dzekuita zvinhu dzakanyanya kupi.

Mhinduro yeDFM inofanira kudzosa gadziriro yekugadzirwa yakarongwa, geometry yekupera kweimpedance, zvisizvo zvakaonekwa, fungidziro dzemaitiro akakosha uye zvinhu zvekubvumidza. Chirevo chinotsiva chinyararire zvinhu, chinochinja via architecture kana kubvisa mushumo unodiwa hachina kufanana nehunyanzvi.

Tumira AI Infrastructure PCB kuti iongororwe neUinjiniya