Pasina kudzora impedance, kuratidzira kwakanyanya kwechiratidzo uye kukanganisa kunokonzerwa, zvichikonzera kukundikana kwekugadzira. Zviratidzo zvakajairika, senge PCI bhazi, PCI-E bhazi, USB, Ethernet, DDR ndangariro, LVDS chiratidzo, nezvimwe, zvese zvinoda impedance kudzora. Impedance control pakupedzisira inoda kuzadzikiswa kuburikidza nePCB dhizaini, iyo zvakare inoisa kumberi kwepamusoro zvinodiwa Pcb bhodhi teknolojia. Mushure mekutaurirana nePCB fekitori uye inosanganiswa nekushandiswa kweESD software, iyo impedance yeiyo wiring inodzorwa zvinoenderana nezvinodiwa zvekutendeka kwechiratidzo.

Nzira dzakasiyana dzewiring dzinogona kuverengerwa kuti uwane iyo inoenderana impedance kukosha.

Microstrip mitsara

Inosanganisira tambo yetambo ine iyo yepasi ndege uye dielectric iri pakati. Kana iyo dielectric inogara iripo, hupamhi hwemutsara, uye nhambwe yayo kubva pasi pevhu inodzora, saka hunhu hwayo impedance inodzora, uye iko kurongeka kunenge kuri mukati me ± 5%.

Maitiro ekudzora PCB wiring impedance

Stripline

Ribhoni mutsetse tambo yemhangura iri pakati pe dielectric pakati pendege mbiri dzinoitisa. Kana ukobvu uye upamhi hwemutsara, dielectric inogara iri pakati nepakati, uye chinhambwe pakati penzvimbo dzepasi dzezvikamu zviviri zvinodzora, hunhu hwemutsara hunodzora, uye iko kurongeka kuri mukati me10%.

Maitiro ekudzora PCB wiring impedance

Maumbirwo emabhodhi-masenduru bhodhi:

Kuti udzore pcb impedance mushe, zvinodikanwa kuti unzwisise chimiro chePCB:

Kazhinji zvatinodaidza multilayer bhodhi inoumbwa nepakati ndiro uye semi-yakasimbiswa pepa rakamisikidzwa pamwe neumwe neumwe. Core board yakaoma, yakatarwa ukobvu, maviri chingwa chendarira ndiro, chinova chinhu chekutanga chebhodhi rakadhindwa. Uye iyo semi-yakaporeswa chidimbu chinoumba izvo zvinonzi infiltration dura, inoita basa rekubatanidza yepakati ndiro, kunyangwe paine imwe yekutanga ukobvu, asi mukuita kwekutsimbirira kukora kwayo kuchaitika shanduko.

Kazhinji iwo ekupedzisira maviri ma dielectric akaturikidzana e multilayer akanyorova matete, uye akapatsanurwa emhangura mafirita matanda anoshandiswa kunze kwemaviri aya materu sekunze mhangura foil. Iyo yepakutanga ukobvu kutaurwa kwekunze mhangura foil uye yemukati mhangura foil inowanzo kuve 0.5oz, 1OZ, 2OZ (1OZ inenge 35um kana 1.4mil), asi mushure mekuteedzana kwekurapwa kwepasirese, iyo yekupedzisira ukobvu hwekunze mhangura foil inowanzo kuwedzera ne 1OZ. Iyo yemukati yemhangura foil ndiyo yemhangura inovhara pamativi ese eplate ndiro. Kukora kwekupedzisira kwakasiyana zvishoma kubva pakukora kwepakutanga, asi kazhinji kunodzikiswa neuverengeka um nekuda kwekucheka.

Rwunze rwekunze rwe multilayer board ndeye welding resistance layer, zvinova ndizvo zvatinogara tichiti “girini mafuta”, hongu, inogona zvakare kuve yero kana mamwe mavara. Ukobvu hweiyo solder yekumanikidza dura kazhinji haisi nyore kuona nemazvo. Iyo nzvimbo isina foil foil pamusoro inenge yakati pfuurei kupfuura iyo nzvimbo ine mhangura foil, asi nekuda kwekushaikwa kwemhangura foil ukobvu, saka iyo yemhangura foil ichiri yakanyanya kuzivikanwa, patinobata yakadhindwa board board neminwe yedu inogona kunzwa.

Kana imwe hukobvu hwebhodhi rakadhindwa rikaitwa, kune rimwe divi, sarudzo inonzwisisika yezvikamu zvemidziyo inodiwa, kune rimwe divi, hukobvu hwekupedzisira hwesiti-yakaporeswa jira ichave diki pane yekutanga ukobvu. Izvi zvinotevera zvakajairwa 6-dura rakamisikidzwa chimiro:

Maitiro ekudzora PCB wiring impedance

Zvigadzirwa zvePCB:

Siyana pcb zvirimwa zvine zvishoma misiyano muPCB parameter. Kuburikidza nekutaurirana nedunhu bhodhi chirimwa technical rutsigiro, isu takawana imwe paramende data remuti wacho:

Pamusoro mhangura foil:

Kune matatu makobvu emhangura foil ayo anogona kushandiswa: 12um, 18um uye 35um. Iyo yekupedzisira ukobvu mushure mekupedza ingangoita 44um, 50um uye 67um.

Core ndiro: S1141A, yakajairwa FR-4, mahwendefa maviri emhangura ane chingwa anowanzo shandiswa. Idzo sarudzo dzekuda dzinogona kutemwa nekubata mugadziri.

Semi-yakaporeswa piritsi:

Magadzirirwo (epakutanga ukobvu) ari 7628 (0.185mm), 2116 (0.105mm), 1080 (0.075mm), 3313 (0.095mm). Ukobvu chaihwo mushure mekutsimbirira kazhinji hunowanzo kuita 10-15um pasi peiyo yekutanga kukosha. Mahwendefa matatu anokwaniswa kuita matatu anokwanisa kushandiswa kune imwechete yekupinda mukati, uye ukobvu hwemapiritsi matatu akasimbiswa haugone kufanana, chero mapiritsi akapora hafu anogona kushandiswa, asi vamwe vagadziri vanofanirwa kushandisa kanenge maviri. . Kana ukobvu hwechikamu chakarapwa chisina kukwana, chidhinda chemhangura pamativi ese eplate yepakati chinogona kubviswa, uyezve chidimbu chakarapwa chinogona kusungwa pamativi ese, kuitira kuti mukobvu wekupinda mukati kubudirira.

Nemishonga nomoto rukoko:

Ukobvu hweiyo solder inopesana neyakagadzika pane yemhangura foil ndeye C2≈8-10um. Ukobvu hweiyo solder inopesana nedenga pamusoro isina foil foil ndeye C1, iyo inosiyana nekukora kwemhangura pamusoro. Kana pakukora kwemhangura pamusoro iri 45um, C1≈13-15um, uye pakukora kwemhangura pamusoro iri 70um, C1-17-18um.

Chikamu chakayambuka:

Isu taizofunga kuti chikamu chemuchinjikwa tambo tambo, asi ichokwadi trapezoid. Kutora iyo yepamusoro TOP semuenzaniso, kana iwo hukobvu hwemhangura foil iri 1OZ, iyo yekumusoro yepasi kumucheto kwetrapezoid ndeye 1MIL ipfupi pane yepasi yepazasi kumucheto. Semuenzaniso, kana hupamhi hwehupamhi hwave 5MIL, ipapo kumusoro uye kuzasi mativi anenge 4MIL uye ezasi uye ezasi mativi anenge 5MIL. Musiyano uripo pakati pemakona ekumusoro nekuzasi kunoenderana nehurefu hwemhangura. Iyi tafura inotevera inoratidza hukama pakati pepamusoro nepasi pe trapezoid pasi pemamiriro akasiyana.

Maitiro ekudzora PCB wiring impedance

Kubvumirwa: Iko kubvumidzwa kwemashizha akasimba-akapora anoenderana nehukuru. Iyi tafura inotevera inoratidza ukobvu uye mvumo paramita yemhando dzakasiyana dzemashizha akapora.

Maitiro ekudzora PCB wiring impedance

Iyo dielectric inogara iri mundiro ine hukama neiyo resin zvinhu zvinoshandiswa. Iyo dielectric inogara iripo yeFR4 ndiro iri 4.2 – 4.7, uye inoderera pamwe nekuwedzera kwehuwandu.

Dhizimusi kurasikirwa chinhu: dielectric zvinhu pasi pechiito chekuchinjisa magetsi munda, nekuda kwekupisa uye simba rekushandisa kunodaidzwa kuti dielectric kurasikirwa, kazhinji kunoratidzwa ne dielectric kurasikirwa chinhu Tan δ. Iyo chaiyo kukosha kweS1141A ndeye 0.015.

Minimum mutsetse upamhi uye mutsetse spacing kuona machine: 4mil / 4mil.

Impedance kukarukureta chishandiso sumo:

Kana isu tikanzwisisa chimiro che multilayer bhodhi uye nekugona zvinodiwa parameter, tinogona kuverenga iyo impedance kuburikidza neESDA software. Unogona kushandisa Allegro kuita izvi, asi ini ndinokurudzira Polar SI9000, chinova chishandiso chakanaka chekuverenga hunhu impedance uye iko zvino inoshandiswa nemafekitori mazhinji ePBB.

Kana uchiverenga hunhu impedance yechiratidzo chemukati chese musiyano mutsetse uye imwechete terminal tambo, iwe unowana chete musiyano mudiki pakati pePolar SI9000 neAllegro nekuda kwemamwe ruzivo, senge chimiro chechikamu chemuchinjikwa chetambo. Nekudaro, kana iri yekuverenga hunhu impedance yeiyo Surface chiratidzo, ini ndinokurudzira kuti usarudze iyo Yakavharwa modhi pachinzvimbo cheiyo Surface modhi, nekuti mhando dzakadai dzinofunga nezve kuvepo kweiyo solder kuramba rukoko, saka mhedzisiro yacho ichave yakanyatsojeka. Iyi inotevera skrini yakasarudzika yemusiyano wepasirese mutsetse impedance yakaverengerwa nePolar SI9000 ichifunga nezve iyo solder yekupokana nedenga:

Maitiro ekudzora PCB wiring impedance

Sezvo iyo hukobvu hweiyo solder yekumisikidza rukoko isiri nyore kudzorwa, nzira yekufungidzira inogona zvakare kushandiswa, sekurudzirwa nemugadziri webhodhi: bvisa yakatarwa kukosha kubva kuSurface modhi kuverenga. Zvinokurudzirwa kuti iyo kusiyanisa impedance ive minus 8 ohms uye imwechete-yekupedzisira impedance ive minus 2 ohms.

Musiyano pcb zvinodiwa wiring

(1) Sarudza iyo wiring modhi, parameter uye impedance kuverenga. Kune maviri marudzi emisiyano modhi yemutsetse nzira: yekunze rukoko microstrip mutsara musiyano modhi uye yemukati rukoko tambo mutsara musiyano maitiro. Impedance inogona kuverengerwa neyakaenderana impedance kuverenga software (senge POLAR-SI9000) kana impedance kukaromura fomula kuburikidza zvine musoro paramende marongero.

(2) Mitsara yakafanana isometric. Sarudza upamhi hwemutsara uye nzvimbo, uye nyatsoteedzera yakaverengwa mutsetse upamhi uye nzvimbo pakati pekutenderera. Iyo nzvimbo pakati pemitsetse miviri inofanira kugara isina kuchinjika, ndiko kuti, kuti irambe yakafanana. Pane nzira mbiri dzekufananidza: imwe ndeyekuti mitsara miviri inofamba mune imwechete divi-ne-parutivi nhete, uye imwe yacho ndeyekuti mitsara miviri inofamba mune yakapfuura-pasi pechikamu. Kazhinji edza kudzivisa kushandisa musiyano chiratidzo pakati pezvikamu, zvinodaro nekuti mukugadzirisa chaiko kwePBB mukuita, nekuda kwekukanzura kwekururamisa kwakaringana kwakaderera zvakanyanya kupfuura kupihwa pakati peiyo chaiyo, uye mukuita kwekurasikirwa dielectric yekuparara, haikwanise kuvimbisa musiyano wemutsetse spacing yakaenzana nehupamhi hweiyo interlayer dielectric, inokonzeresa musiyano uripo pakati pezvikamu zve mutsauko we impedance shanduko. Inokurudzirwa kushandisa musiyano uri mukati meiyo imwecheteyo napo napo.