Kudzora Kusagadzikana kwePCB kweLayer 10 uye Kusimbiswa kweTDR

Kudzora kupindirana kunowanikwa nekudzora chimiro chemutsetse wekutumira, kwete nekupa upamhi hwetrace hwakajairwa kune protocol. Chinangwa chimwe chete che50 Ω chinogona kuda geometry yakasiyana kwazvo pamapuranga maviri ane layer gumi nekuti ukobvu hwe dielectric, ukobvu hwe copper, kuvakwa kwezvinhu, solder mask uye copper iri pedyo zvakasiyana. Saka dhizaini yekugadzira inofanira kutsanangura chinangwa uye chimiro chereferensi, nepo kuverenga kwe stackup ne fabricator kuchitsanangura upamhi hwekupedzisira uye nzvimbo.

Gwaro iri rinotsanangura zvinofanirwa kuverengerwa, kuti kushivirira kugadzira kunoshanda sei, uye kuti kuponi yeTDR inofanira kumiririra sei chimiro chakarongwa. Rinodzivisa nemaune kuburitsa mitemo yepasi rose yekuti "5 mil yakaenzana ne50 Ω", nekuti nhamba idzodzo dzinova dzisina kururama kana kuvaka kwachinja.

Impedance Inodzorwa Inotsanangurwa neStackup uye Maitiro

Kuvharirwa kwePCB trace kunoratidzwa nekupararira kweminda yemagetsi nemagineti yakakomberedza conductor. Zvinhu zvinonyanya kukosha zvinosanganisira chikamu checonductor chakapedzwa, daro kusvika kune imwe kana kupfuura reference planes, dielectric properties, pair spacing yemitsetse yakabatana, solder mask pazvivakwa zvepamusoro uye kuvapo kwemhangura iri pedyo. Copper roughness uye dielectric loss zvinokanganisa kupararira uye measurement yakayerwa, kunyanya sezvo edge rate ichiwedzera.

Kurongeka kweimpedance kwakadzorwa kunofanira kupindura mibvunzo miviri yakasiyana. Chekutanga, ndeapi mageometry anotarisirwa kusangana nechinangwa pane stackup yakasarudzwa? Chechipiri, kugadzirwa kuchasimbiswa sei? Kuverengera kweField-solver kunotarisa chekutanga; coupon inomiririra uye maitiro eTDR anotarisa chechipiri. Hapana chimwe chinotsiva simulation yechiteshi kana kurasikirwa kwekuisa, kuburikidza nekusagadzikana uye ma connectors zvakakosha.

Stackup ine zvidimbu gumi inofanira kuomeswa isati yaomeswa. Kana mugadziri akachinja core, prepreg, copper foil kana ukobvu hwakadzvanywa, kuverenga kwe impedance kunofanirwa kugadziriswa uye chero shanduko yeunyanzvi inofanira kutevedzera maitiro ekubvumidza akabvumiranwa.

Zvinodiwa Kuti Trace Geometry Isati Yaburitswa

Pamhando dzakasiyana dzemifananidzo, mugadziri wemifananidzo anofanira kugamuchira upamhi nenzvimbo sezvinhu zvinoshanduka pane mutemo weunyanzvi usingachinjiki kana zvinhu zvichiri kupedzwa. Dhirowa rinoburitswa rinogona kubvumidza kugadziriswa kwehupamhi hwakadzorwa mukati memiganhu yakatarwa, kana kuti rinogona kuda mvumo yemutengi usati wachinja mifananidzo.

Impedance Inopera Imwe Chete, Isinganzwisisike uye Kusiyana

Chinangwa chine magumo mamwechete chakadai se50 Ω chinotsanangura kondakita imwe chete kana tichienzanisa nechimiro chayo chekudzosa. Chinangwa chine magumo madiki chakadai se85 Ω kana 100 Ω chinotsanangura musiyano wemagetsi pakati pemakondakita maviri anofambiswa munzira dzakasiyana. Kune symmetric coupled pair, differential impedance inenge kaviri odd-mode impedance. Hazvirevi kuti hazvina kukwana kaviri single-end impedance yetrace imwe neimwe kana imwe trace isipo.

Kubatana kwakasimba kunobvumira nzvimbo shoma pakati pemapeya uye kunogona kuderedza musiyano wekuchinjana, asi zvinoitawo kuti mhedzisiro ive nyore kunzwisiswa nekusiyana kwenzvimbo uye kupatsanurwa kwemapeya emunharaunda. Mapeya akabatana zvisina kusimba anokanganiswa zvakanyanya nematanho awo ekureferensi uye zvishoma nepakati chaipo, asi anogona kushandisa upamhi hwakawanda hwenzira. Kuenzana kwakakodzera kunoenderana nehuwandu hwenzira, skew, crosstalk kune nzira dziri pedyo uye kugona kwemugadziri wenzira.

Kupindirana kwemaitiro akafanana uye kushandurwa kwemaitiro zvinogona kukosha kunyangwe kana nhamba yeTDR yakasiyana idarika. Kupararira kweasymmetrical, kusaenzana kuburikidza nema antipads, shanduko dzakasiyana dzereferensi uye kugadzirisa kune divi rimwe chete zvinogona kushandura simba rekuchinja kuita common mode. Pahuwandu hwedata hwakakwira, modhi yekuchinja ye3D inodzidzisa zvakawanda kupfuura nhamba ye coupon imwe chete.

Zvivako zveMicrostrip, Stripline uye Coplanar

Kamuchina kekunze

Microstrip iri nyore kuongorora nekushandisa asi minda yayo inotambanukira mulaminate neair kana solder mask. Saka dielectric constant inoshanda yakaderera pane bulk laminate Drk. Solder mask, surface finish, local copper pours uye component pads zvese zvinogona kukanganisa mhedzisiro. Outer-layer plating inochinjawo ukobvu hwe conductor mushure mekunge base foil yasarudzwa.

Yakabatanidzwa microstrip uye stripline

Microstrip yakavharirwa yakafukidzwa ne dielectric kumativi ese asi inonyanya kutaurwa nezve plane imwe chete. Stripline iri pakati peplane mbiri. Symmetric stripline ine dielectric spacing yakaenzana kana kuti inenge yakaenzana; asymmetric stripline ine dominant nearer reference asi ichiri kushanda neplane dzese dziri mbiri. Field solver inofanira kutevedzera miganhu yese uye nzvimbo chaiyo yetrace mushure me lamination.

Zvivako zveCoplanar waveguide

Pasi peCoplanar panogona kudzora kupararira kwemunda uye kupa dziviriro, asi mukaha uripo padivi pemhangura unova chimwe chinhu chakakosha. Zvitsuwa zvepasi zvinofanirwa kubatanidzwa kune reference plane nepattern yakakodzera kana kuti zvinogona kuita sema conductors ane resonant. Zvivakwa zveCoplanar zvinofanirwa kutevedzera mask chaiyo uye geometry yepasi pane kuwedzerwa semutemo we "ground pour".

Kuchinja-chinja Kwekugadzira uye Bhajeti Rechokwadi Rekushivirira

Kugadziriswa kweimpedance yekugadzira kunofamba nekuti mativi akati wandei anofamba pamwe chete. Kucheka kunochinja upamhi hwepamusoro nepazasi. Kuchinja kwelamination kwakadzvanywa ukobvu hwe dielectric. Hunhu hwe resin uye kugoverwa kwegirazi zvinokanganisa mashandiro eDk. Kuputira kwekunze uye mask yekusolder zvinowedzera musiyano. Ongororo yekushivirira ine mutoro inoshandisa kugona kwemutengesi pakuvaka chaiko pane kufunga kuti zvese zvinopinda zvinogona kuchengetwa nemutengo wazvo wezita.

+/-10% ipfungwa yakajairika yekutenga, asi haisi mhedzisiro yakajairika inoiswa negwaro reIPC. Mabhandi akaomarara anogona kugoneka pazvivakwa zvakasarudzwa uye saizi dzemapaneru, nepo zvimwe zvivakwa zvine impedance yakanyanya, zvakapfava kwazvo kana zvakapetwa zvakanyanya zvingave zvisingakwanise. Usati wataura nezve +/-5% kana kuti zvakamanikana, simbisa margin ye geometry iripo, nzira ye coupon, sampling yelot uye kana kutsungirira kuri kuyerwa pa coupon kana kuti kwakavimbiswa panzvimbo yega yega inofambiswa.

Kusimbisa impedance pasina chikonzero chechikamu chechiteshi kunogona kuwedzera tsvina kana kumanikidza trace/space geometry yakakura iyo inokuvadza huwandu hwenzira. Kusiyana neizvi, kuponi ye +/-10% inogona kunge isina kukwana apo connector, package uye via discontinuities zvinosiya mukana mudiki wesystem. Kushivirira kunofanirwa kubva mubhajeti yemagetsi uye kudzidza kugona kwekugadzira.

Kugadzira Makuponi uye Kusimbiswa kweTDR

IPC-2141 igwara rekugadzira macircuits anodzorwa-impedance; haisi nzira yekuyedza yeTDR. Kuyerwa kwehunhu hweimpedance ne reflectometry yenguva-domain kunofukidzwa neIPC-TM-650 Method 2.5.5.7A. Odha yekutenga inofanira kutaura nzira inoshanda kana maitiro emutengi akabvumiranwa uye yobva yatsanangura coupon uye ruzivo rwekugamuchira izvo nzira yega isingasarudze.

Kuponi rinomiririra

Kuponi inofanira kushandisa layer imwe chete, reference structure, copper processing, dielectric construction uye solder-mask condition senzira inodzorwa. Differential coupon dzinofanira kuratidza upamhi hwepair uye space. Kana paine ma structure akawanda, coupon trace imwe chete haigone kuamiririra ese. Nzvimbo ye coupon pane production panel inokosha nekuti plating uye etch zvinogona kusiyana pane imwe panel.

Hwindo rekuyera uye kutanga

Kuburitswa, ma probe pads uye discontinuity yekutanga zvinofanira kuparadzaniswa nechikamu chimwe chete chinoshandiswa pakuverenga impedance. Nguva yekukwira kweTDR inofanira kukodzera chimiro chiri kuyerwa; mupendero unokurumidza zvakanyanya unogona kusimbisa discontinuity diki, nepo mupendero unononoka uchigona kuvabvisa pakati. Kurasikirwa nekupararira kunogona kugadzira trace yakatsvedza, saka hwindo rekugamuchira uye nzira yekushuma zvinofanirwa kubvumirana.

Kutora mienzaniso uye zvinyorwa

"Papaneru," "panhamba" uye "chinyorwa chekutanga chete" sarudzo dzebhizinesi uye dzemhando yepamusoro, kwete mhedzisiro yega yemhedzisiro yekushivirira. Taura huwandu nenzvimbo yemakuponi, chinzvimbo chakaparadzwa kana chakachengetwa, tsananguro yenzvimbo, mutemo wekuyedza zvakare uye kana mapuratifomu kana mhedzisiro pfupiso ichidikanwa. Kune mapurogiramu akavimbika zvakanyanya, chengetedza kurongeka pakati pemakuponi, mapaneru nemabhodhi akatumirwa.

Maitiro Ekutsanangura Impedance paDhizaini Yekugadzira

Tafura ye impedance haifanirwe kujeka zvekuti mainjiniya, maCAM nemapoka ekuongorora anoitsanangura nenzira imwe chete.

Chengetedza mitemo yekufambisa protocol pane marongerwo kana dhizaini uye ramba uchigamuchira impedance padhirowa yekugadzira. Kupatsanurwa uku kunotadzisa mutengesi kubva pakutsanangura "PCIe" sezvinodiwa zvizere zvemagetsi.

Kuti muongorore hunyanzvi, shandisai gwara re10 layer routing ; kuti muwane magadzirirwo emhando dzakasiyana uye magwaro, ona gwara remagadzirirwo ekugadzira.

Kuongorora Mhedzisiro yeImpedance Isingakwanise Kuwanikwa

Kuponi yakakundikana inofanira kukonzera kuferefeta kwakarongeka pane kuchinja kwehupamhi hwemutsetse nekukurumidza. Simbisa kuti kuponi inoenderana nechimiro chebhodhi, kugadziriswa kwakakodzera kwestackup kwakashandiswa, hwindo rekutanga uye rekuyera reTDR zvinoshanda, uye mhedzisiro yakataurwa haina kudzorwa nekurasikirwa kwakanyanya kana kusagadzikana kweprobe. Wobva waenzanisa ukobvu hwetrace cross-section uye dielectric ne solver model.

Impedance yakaderera inogona kukonzerwa ne trace yakafara, dielectric yakatetepa, higher effective Dk, thicker copper, closer coplanar ground kana imwe solder mask. High impedance inogona kukonzerwa nemamiriro akasiyana. Mhedzisiro yakasiyana inogona kufamba nekuda kwe pear spacing kunyangwe kana trace hupamhi hwega hwega hwakarurama. Microsection data uye recalculated model zvinobatsira kupfuura kuchinja imwe input nekufungidzira.

Kana kukundikana kwacho kwakarongeka, gadzirisa modhi yakarongwa nemagadzirirwo uye muripo weunyanzvi. Kana zvikagadziriswa zvichienderana nenzvimbo yepaneru, ongorora kufanana kwe etch, plating kana lamination. Chero kugadziriswazve kana kushandiswa sezvazviri kunofanirwa kufunga nezve margin yesystem, kwete chete chikamu che coupon.

Tumira Tafura yeStackup neImpedance kuti Iongororwe

Kuwanda, Kurasikirwa uye Zvinoreva Nhamba yeTDR

Impedance yehunhu inowanzo kuratidzwa senhamba imwe chete, asi kubatana chaiko kunopararira uye kunorasikirwa. Hunhu hweDielectric, kushata kwemhangura uye mhedzisiro yeganda zvinochinja nekufamba kwenguva, saka TDR trace inoonekwa inogona kutsvedza ne coupon refu. Chikamu chipfupi cheyunifomu chinogona kuverenga zvakasiyana kana chikayerwa ne edge rate yakasiyana kana nzira yekubvisa embedding. Saka maitiro ekugamuchira anofanira kutsanangura kuti kukosha kunoverengwa kupi uye sei pane kuvimba ne screenshot chete.

Kuponi ye impedance inodarika hairatidzi kurasikirwa kwakaderera kwekupinza. Zviratidzo zviviri zvinogona kuyera 50 Ω nepo chimwe chichishandisa copper yakakora uye dielectric inorasikirwa zvakanyanya. Kusiyana neizvi, chiratidzo chinorasikirwa chinogona kuita kuti magumo eTDR waveform aite seakasiyana kunyangwe geometry yayo yemuviri yakafanana. Kana kurasikirwa kwechiteshi kuchikosha, shandisa kuponi yakakodzera yekurasikirwa kwechiratidzo kana kuyerwa kweS-parameter pamwe neTDR.

Misungo yekusiyanisa makuponi

Differential TDR inoda launch dzakaringana uye kureba kwemagetsi kwakaenzana nechikamu chekuyera. Kusafanana kweprobe-pad, kusaenzana kwefeniti kana kuvhurwa kwereferensi kunogona kugadzira shanduko yemode inoita sedambudziko repair-impedance. Coupon inofanira kunge iine kureba kwakakwana kupatsanura launch kubva kuhwindo rekuongorora uye inofanira kuburitsa zvakare mask chaiyo uye chimiro chereferensi. Kushuma zvese zvakasiyana uye, pazvinobatsira, maitiro ecommon-mode kunogona kuratidza kusaenzana kwakavanzika neavhareji imwe chete.

Kubatana kwekugadzirwa

Kana paiswa stackup itsva, batanidzai TDR results ne microsectioned trace width, copper thickness uye dielectric spacing. Kubatana ikoko kunogadzira process model yakavimbika kune mamwe ma lots anotevera. Kana mutengesi akachinja kuvakwa kwezvinhu, foil kana press cycle, kubatana kwacho kunofanira kuongororwa pane kufunga kuti muripo wekare uchiri kushanda.

Kukwanisa Kushivirira Zvakasimba uye Simba reMifananidzo

Nhamba yakamanikana haisiyo nguva dzose inonyanya kukosha. Kugoverwa kunogoneka kunoenderana nehupamhi hwetrace, kureba kwe dielectric, ukobvu hwemhangura, nzvimbo yepaneru, maitiro e etch uye kana chimiro chakafukidzwa pamusoro. Zviratidzo zvakamanikana zvikuru zvinogona kuratidza shanduko huru kubva pakusiyana kudiki kwe absolute etch; mitsetse yakanyanya-impedance inogona kuda upamhi kana mipata ye dielectric isingashande. Mugadziri anofanira kuongorora tolerance semubvunzo we process-ability, kwete kungoigamuchira sesarudzo yekutengesa.

Musati maburitsa, bvumiranai kuti ndiani anodzora hunyanzvi. Imwe nzira ndeyekuti mutengi ape hunyanzvi hwemhando yepamusoro uye ape mvumo kumugadziri kuti adzorere hupamhi nepakati pepakati pechinhu chakaburitswa. Imwe ndeyekuomesa hunyanzvi uye kuda kuti mupi wezvinhu aenderane nechimiro chaicho. Kusanganisa nzira mbiri idzi kunokonzera kusawirirana kana mupi wezvinhu akagadzirisa hupamhi hwemutsetse asi clearance yemufananidzo, skew kana crosstalk model yakatora chimiro chepakutanga.

Kuti uwane chigadzirwa chitsva, funga nezve kugona kwekutanga kunoitwa nemakuponi munzvimbo dzakasiyana siyana dzepaneru. Shandisa kugoverwa kwakayerwa kuti ugadzire hurongwa hwechokwadi hwekudzora kugadzirwa. Kuponi imwe chete inopasa haigone kuratidza kugona kwenguva refu, nepo maitiro akavimbika anogona kutsigira bhendi rakasimba pasina kuongororwa zvakanyanya.

Rondedzero Yekutarisa Kusunungurwa kweImpedance

Chinodiwa che impedance chinongopedzwa chete kana chinangwa, chimiro chemuchina wekutumira, simba rekugadzira uye hurongwa hwekusimbisa zvese zvatsanangurwa. Dhirowa ine "50 Ω" kana "100 Ω differential" isina layer, reference, tolerance uye condition ye mask inosiya mutengesi achifungidzira.

• Ziva kirasi yega yega ye impedance nechikamu chechiratidzo, ndege yekutarisa kana ndege, chinangwa, kushivirira uye rudzi rwechimiro.
• Ipa chimiro chechimiro chechimiro sechinangwa chekugadzira uye taura kana mutengesi achigona kugadzirisa hupamhi kana nzvimbo yepakati pemaviri.
• Modhi yakadzvanywa ne dielectric, mhangura ye trapezoidal yakagadzirwa, chifukidzo che solder uye mhangura iri pedyo.
• Shandisa ruzivo rwezvinhu zvakagadzirwa zvakanangana nekuvakwa kana kuti modhi yeDk yakagadzirwa nemuvaki.
• Gadzira makuponi anomiririra chimiro chaicho chekugadzira uye anotsanangura nzira yeTDR, kuwanda kwemuenzaniso uye zviri mukati memishumo.
• Chengetedza kusimbiswa kwe coupon impedance kwakasiyana nekurasikirwa nekuiswa kwechiteshi, kuburikidza nekutevedzera zvinodiwa ne connector.

Kushivirira kwakasimba kunofanira kururamiswa nekunzwa kwenzira uye kugona kwakaratidzwa kwemaitiro. Hazvisi zvinotsiva nzira yekudzoka inoenderera mberi, nzira yakanaka yekuchinja kana modhi yekurasikirwa zvachose.

Kuyera Kusava Nechokwadi uye Kubatana kweCoupon neChigadzirwa

Mhedzisiro yeTDR inokanganiswa ne coupon, launch, fixture, instrument bandwidth, reference-plane quality, calibration uye nzira inoshandiswa kusarudza nzvimbo ye impedance yakataurwa. Marabhoritari maviri anogona kuyera coupon imwe chete zvakasiyana kana mamiriro aya asina kuenderana. Saka nzira yekugamuchira inofanira kutsanangura zvinopfuura chinangwa uye kushivirira.

• Ziva nzira yekuyedza kana maitiro emutengi uye zvinotarisirwa pakushandisa mudziyo/kuongorora.
• Tsanangura hurefu hwemakuponi, nzira yekubvisa kuburitswa kana nzira yekuvhara uye nzvimbo inoshandiswa pamutengo wakataurwa.
• Chengeta kuponi iri pamadziro akafanana, layer, copper uye reference system sezvakaita chimiro chechigadzirwa.
• Nyora kana kukosha kwakataurwa kuri kweavhareji, kwepakati, kwehwindo kana chimwe chiverengero chakabvumiranwa.
• Tsanangura kuti zvinhu zvisingawanzoitiki, kuburitswa kwemakuponi akakuvara uye kuyedzwazve zvinobatwa sei.

Kubatana kwemakuponi kunewo miganhu. Kuponi refu rakatwasuka harisanganisire pedhi rega rega, mutsipa-pasi, kuburikidza, kuvhurwa kwechinongedzo kana kuvhurwa kwaro pachigadzirwa. Kusaenderera mberi ikoko kunofanirwa kunge kuri mumodhi yechiteshi kana chimiro chakatsaurirwa chekuyedza. Kusiyana neizvi, kuwedzera zvinhu zvakaoma zvechigadzirwa kuponi yeimpedance kunogona kuita kuti zviome kuparadzanisa process impedance kubva pakusaenderera mberi nemaune.

Kune mapurogiramu anoshivirira zvakanyanya, hukama hunofanira kuenzanisa geometry ye coupon yakayerwa uye data re microsection ne field-solver model. Kana impedance iri yakakwira kana yakaderera, ongororo inofanira kufunga nezve pressed dielectric, conductor hupamhi hwepamusoro/pasi, copper thickness uye kuvakwa kwezvinhu usati wachinja artwork. Kugadzirisa trace width pasina kuziva chikonzero chemuviri kunogona kuita kuti lot imwe ipfuure ukuwo kuchideredza kudzokorora.