Pofuna kuwonetsetsa kufalikira kwa ma siginecha, kuchepetsa kusokonezedwa kwa EMI, ndikupambana mayeso oyenera a impedance, PCB makiyi ofananira ndi ma sign a impedance amafunikira. Kalozera kamangidwe kameneka kamachokera paziwerengero zodziwika bwino, mawonekedwe amtundu wazinthu zapa TV, Zofunikira za Kamangidwe ka PCB, mawerengedwe a mapulogalamu a SI9000, zambiri za PCB za othandizira ndi zina zotero, ndipo pamapeto pake bwerani pamapangidwe omwe akulimbikitsidwa. Zoyenera pamiyezo yambiri ya opanga PCB ndi mapangidwe a board a PCB okhala ndi zofunikira zowongolera.

Mmodzi. Mapangidwe a Double panel impedance

① Mapangidwe apansi: m’lifupi mwake, mipata 7/5/7mil pansi waya m’lifupi ≥20mil chizindikiro ndi mtunda wa waya pansi 6mil, dzenje lililonse 400mil; (2) Non-enveloping kapangidwe: mzere m’lifupi, danga 10/5/10mil kusiyana awiri awiri ndi mtunda pakati pa awiriwo ≥20mil (zochitika mwapadera sangakhale zosakwana 10mil) Ndi bwino kuti gulu lonse la mzere osiyana chizindikiro ntchito enveloping. kutchinga, chizindikiro chosiyanitsa ndi kutchingira mtunda wapansi ≥35mil (zochitika zapadera sizingakhale zosakwana 20mil). Mapangidwe a 90 ohm osiyanitsa akulimbikitsidwa

Line m’lifupi, katayanitsidwe 10/5/10mil Ground waya m’lifupi ≥20mil Signal ndi pansi waya mtunda wa 6mil kapena 5mil, grounding dzenje lililonse 400mil; ②Musaphatikizepo mapangidwe:

M’lifupi mwa mizere ndi mtunda wa 16/5/16mil mtunda wa pakati pa ma siginolo osiyanitsira ≥20mil tikulimbikitsidwa kuti chivundikiro chapansi chigwiritsidwe ntchito pagulu lonse la zingwe zosiyanitsira. Mtunda pakati pa chizindikiro chosiyana ndi chingwe chapansi chotetezedwa chiyenera kukhala ≥35mil (kapena ≥20mil muzochitika zapadera). Mfundo zazikuluzikulu: perekani patsogolo kugwiritsa ntchito mapangidwe ophimbidwa pansi, mzere waufupi ndi ndege yathunthu ingagwiritsidwe ntchito popanda kuyika pansi; Mawerengedwe magawo: mbale FR-4, mbale makulidwe 1.6mm+/-10%, mbale dielectric zonse 4.4+/-0.2, mkuwa makulidwe 1.0 oz (1.4mil) solder mafuta makulidwe 0.6±0.2mil, dielectric zonse 3.5+/-0.3.

Impedans mapangidwe awiri ndi anayi zigawo

100 ohm differential impedance analimbikitsa kupanga mzere m’lifupi ndi mtunda wa 5/7/5mil mtunda pakati pa awiriawiri ≥14mil(3W criterion) zindikirani: tikulimbikitsidwa kuti envelopu ya pansi igwiritsidwe ntchito pagulu lonse la zingwe zosiyanitsira. Mtunda pakati pa chizindikiro chosiyanitsa ndi chingwe chotchinga pansi chiyenera kukhala osachepera 35mil (osachepera 20mil muzochitika zapadera). 90ohm kusiyana kwa 6ohm Kulangizidwa kukula kwa mzere ndi malo 6/6/12mil Differential pair mtunda ≥3mil(6W criterion) Mfundo zazikuluzikulu: Pankhani ya chingwe chachitali chosiyanitsa, tikulimbikitsidwa kuti mtunda wapakati pa mbali ziwiri za chingwe chosiyanitsa cha USB. kulungani pansi ndi XNUMXmil kuti muchepetse chiopsezo cha EMI (kulungani pansi osati kukulunga pansi, mzere wa mzere ndi mzere wa mtunda wa mzere ndizofanana). Zowerengera zowerengera: Fr-4, mbale makulidwe 1.6mm+/-10%, mbale dielectric zonse 4.4+/-0.2, Copper makulidwe 1.0oz (1.4mil) theka-anachiritsa pepala (PP) 2116 (4.0-5.0mil), dielectric zonse 4.3+/ -0.2 solder mafuta makulidwe 0.6 ± 0.2mil, Dielectric mosalekeza 3.5+/- 0.3 laminated kapangidwe: chophimba kusindikiza wosanjikiza solder wosanjikiza mkuwa wosanjikiza theka-anachiritsidwa filimu TACHIMATA mkuwa gawo lapansi theka-ochiritsidwa filimu yamkuwa wosanjikiza solder wosanjikiza chophimba kusindikiza wosanjikiza

Atatu. Six layer board impedance design

Mapangidwe asanu ndi limodzi a lamination ndi osiyana pazochitika zosiyanasiyana. Bukuli limangolimbikitsa mapangidwe a lamination ambiri (onani FIG. 2), ndipo zotsatirazi zovomerezeka zimachokera ku deta yomwe imapezeka pansi pa lamination mu FIG. 2. Mapangidwe a impedance a mawonekedwe akunja ndi ofanana ndi a bolodi la magawo anayi. Chifukwa chakuti gawo lamkati nthawi zambiri limakhala ndi zigawo zambiri za ndege kuposa pamwamba, chilengedwe cha electromagnetic chimakhala chosiyana ndi chapamwamba. Zotsatirazi ndi malingaliro a kuwongolera kwa impedance ya gawo lachitatu la waya (laminated reference Chithunzi 4). 90 ohm differential impedance Analimbikitsa mapangidwe mzere m’lifupi, mzere mtunda 8/10/8mil Difference awiri mtunda ≥20mil(3W muyezo); Zowerengera zowerengera: Fr-4, mbale makulidwe 1.6mm+/-10%, mbale dielectric zonse 4.4+/-0.2, Copper makulidwe 1.0oz (1.4mil) theka-anachiritsa pepala (PP) 2116 (4.0-5.0mil), dielectric zonse 4.3+/ -0.2 solder mafuta makulidwe 0.6 ± 0.2mil, Dielectric mosalekeza 3.5+/- 0.3 laminated kapangidwe: pamwamba chophimba kutsekereza wosanjikiza mkuwa wosanjikiza theka-wokutidwa ndi mkuwa-wokutidwa gawo lapansi theka-wokutidwa ndi mkuwa-wokutidwa gawo lapansi theka-ochiritsa mkuwa wokutidwa wosanjikiza pansi chophimba kutsekereza wosanjikiza

Kwa magawo opitilira anayi kapena asanu ndi limodzi, chonde pangani nokha molingana ndi malamulo oyenerera kapena funsani ogwira ntchito kuti adziwe kapangidwe ka lamination ndi ma waya.

5. Ngati pali zofunikira zina zowongolera zovuta chifukwa cha zochitika zapadera, chonde werengerani nokha kapena funsani ogwira nawo ntchito kuti adziwe kapangidwe kake.

Chidziwitso: ① Pali milandu yambiri yomwe imakhudza kusokoneza. Ngati PCB ikufunika kulamulidwa ndi impedance, zofunikira za kulamulira kwa impedance ziyenera kulembedwa bwino mu data yojambula ya PCB kapena pepala lachitsanzo; (2) 100 ohm differential impedance imagwiritsidwa ntchito makamaka pa zizindikiro za HDMI ndi LVDS, momwe HDMI imayenera kudutsa chiphaso choyenera ndi chovomerezeka; ③ 90 ohm kusiyana impedance zimagwiritsa ntchito USB chizindikiro; (4) Single-terminal 50 ohm impedance imagwiritsidwa ntchito makamaka pagawo la DDR siginecha. Popeza kuti tinthu tambiri ta DDR timatengera kusinthika kwamkati kofananira ndi kapangidwe ka impedance, kapangidwe kake kamachokera pa bolodi la Demo loperekedwa ndi kampani yoyankha ngati chiwongolero, ndipo kalozera kamangidwe kameneka sikuvomerezedwa. ⑤, single-end 75-ohm impedance imagwiritsidwa ntchito makamaka pakuyika ndi kutulutsa mavidiyo a analogi. Pali kukana kwa 75-ohm kofanana ndi kukana kwapansi pamapangidwe ozungulira, kotero sikoyenera kupanga mawonekedwe ofananirako mu PCB Layout, koma ziyenera kuzindikirika kuti kukana kwa 75-ohm pamzere kuyenera kuyikidwa pafupi. ku terminal pin. Nthawi zambiri amagwiritsidwa ntchito PP.