Kodi m’lifupi mwake ndi chiyani?

Tiyeni tiyambe ndi zoyambira. Kodi m’lifupi mwake ndikutani kwenikweni? Chifukwa chiyani kuli kofunikira kutchula mtundu wakutambasula? Cholinga cha PCB Kulumikizana ndikulumikiza mtundu wina uliwonse wamagetsi (analogi, digito kapena mphamvu) kuchokera pamfundo ina kupita kwina.

Node ikhoza kukhala pini yophatikizira, nthambi yantchito yayikulu kapena ndege, kapena pedi yopanda kanthu kapena poyeserera pofufuza. Zowonjezera zazitali nthawi zambiri zimayezedwa ma mils kapena mainchesi masauzande. Kukula kwazolumikizira koyenera kwa zizolowezi wamba (palibe zofunikira zapadera) kumatha kukhala mainchesi angapo m’litali mwa 7-12 mils, koma zinthu zambiri ziyenera kuganiziridwa pofotokoza kukula ndi kutalika kwa zingwe.

Kugwiritsa ntchito kumayendetsa mulifupi ndi zingwe zamagetsi mu kapangidwe ka PCB ndipo, nthawi ina, nthawi zambiri zimayesa mtengo wopangira PCB, kuchuluka kwa bolodi / kukula, ndi magwiridwe antchito. Ngati bolodi ili ndi zofunikira pakapangidwe kake, monga kukhathamiritsa kwa liwiro, phokoso kapena kuponderezana, kapena kuthamanga kwaposachedwa / magetsi, m’lifupi mwake ndi mtundu wazomwe zitha kukhala zofunikira kwambiri kuposa kukhathamiritsa mtengo wopanga wa PCB wopanda kanthu kapena kukula kwa bolodi.

Mfundo zokhudzana ndi Kulumikizana mu kupanga PCB

Nthawi zambiri, zotsatirazi zokhudzana ndi zingwe zimayamba kukweza mtengo wopangira ma PCBS opanda kanthu.

Chifukwa cha kulolerana kokhwima kwa PCB ndi zida zapamwamba zomwe zimafunikira pakupanga, kuyendera kapena kuyesa kwa PCBS, mitengo imakhala yokwera kwambiri:

L Trace m’lifupi yochepera 5 mil (0.005 mkati.)

L Kutsetsereka pang’ono pasanathe mphindi 5

L Kudzera m’mabowo osakwana 8 mil m’mimba mwake

L Trace makulidwe ochepera kapena ofanana ndi ounce limodzi (ofanana ndi mils 1)

L Kusiyanitsa kwapawiri ndi kutalika kolamulidwa kapena kutsekemera kwa waya

Mapangidwe apamwamba kwambiri omwe amaphatikiza kutenga malo kwa PCB, monga ma BGA osakanikirana bwino kapena mabasi apamwamba owerengera ofanana, angafunike mzere wa 2.5 mil, komanso mitundu yapadera yolowera m’mabowo okhala ndi diameters mpaka 6 mil, monga laser lokumba mabowo obowerera. Mofananamo, mapangidwe amphamvu zamagetsi atha kufuna zingwe zazikulu kapena ndege zazikulu, kumangodya zigawo zonse ndikutsanulira ma ounsi omwe ndi olimba kuposa muyezo. Pogwiritsa ntchito malo ochepa, mbale zochepa kwambiri zomwe zimakhala ndi zigawo zingapo komanso mkuwa wochepa wamkuwa (0.7 mil makulidwe) angafunike.

Nthawi zina, mapangidwe olumikizirana mwachangu kuchokera kuzipangizo zina amafunika kulumikizana ndi maimidwe oyendetsedwa bwino komanso kutalika kwake ndikutalikirana pakati pawo kuti muchepetse kulumikizana komanso kulumikizana. Kapenanso kapangidwe kameneka kangafune kutalika kwakeko kuti kifanane ndi zikwangwani zina m’basi. Ntchito zamagetsi zamagetsi zimafunikira zinthu zina zachitetezo, monga kuchepetsa mtunda pakati pazizindikiro ziwiri zowonekera popewa kuyimitsidwa. Osatengera mawonekedwe kapena mawonekedwe, kutsatira matanthauzidwe ndikofunikira, chifukwa chake tiyeni tiwunikenso ntchito zosiyanasiyana.

Ma waya osiyanasiyana ndi makulidwe osiyanasiyana

PCBS imakhala ndimizere yosiyanasiyana, chifukwa imadalira zikwangwani (onani Chithunzi 1). Zotsatira zabwino kwambiri zomwe zawonetsedwa ndizazizindikiro za TTL (transistor-transistor logic) zam’mizere ndipo zilibe zofunikira zapadera pakatetezedwe katsopano kapena phokoso.

Izi zidzakhala mitundu yolumikizidwa kwambiri ya bolodi.

Kulumikizana kocheperako kwapangidwa kuti kukhale kosakwanira pakadali pano ndipo itha kugwiritsidwa ntchito ngati zotumphukira kapena ntchito zokhudzana ndi mphamvu zomwe zimafunikira mphamvu yayikulu, monga mafani, ma mota, ndikusinthira kwamphamvu kumagawo azigawo zochepa. Gawo lakumanzere lakumanzere limawonetsanso chizindikiro chosiyanitsa (USB yothamanga kwambiri) chomwe chimafotokoza malo ndi mulifupi kuti zikwaniritse zosowa za 90 ω. Chithunzi 2 chikuwonetsa bolodi loyenda pang’ono lokhala ndi zigawo zisanu ndi chimodzi ndipo limafunikira msonkhano wa BGA (mpira grid) womwe umafunikira kulumikizana bwino.

Kodi kuwerengera PCB mzere m’lifupi?

Tiyeni tidutse pakuwunika kwakanthawi kochepa kwa chizindikiritso champhamvu chomwe chimasunthira pakadali pano kuchokera pachinthu chamagetsi kupita pachipangizo chammbali. Mu chitsanzo ichi, tiwerengera mulingo wocheperako wa njira yamagalimoto a DC. Njira yamagetsi imayambira pa fuseti, imadutsa H-mlatho (chinthu chomwe chimagwiritsidwa ntchito kuyang’anira kufalikira kwamagetsi kudutsa DC motor windings), ndipo chimathera pa cholumikizira mota. Makulidwe apakatikati opitilira omwe amafunikira ndi DC mota ndi pafupifupi 2 amperes.

Tsopano, zingwe za PCB zimakhala zotsutsana, ndipo zazitali komanso zochepetsera zingwe, kulimbana kumawonjezeredwa. Ngati zingwe sizinafotokozeredwe molondola, kuthamanga kwaposachedwa kumatha kuwononga zingwe ndi / kapena kuyambitsa kutsika kwamagetsi kwamagalimoto (kumachepetsa liwiro). NetC21_2 yomwe ikuwonetsedwa mu Chithunzi 3 ili pafupifupi mainchesi 0.8 ndipo imafunikira kunyamula ma amperes awiri. Ngati tingaganizire zina ndi zina, monga kuthira mkuwa kamodzi ndi kutentha kwa firiji nthawi zonse, tiyenera kuwerengera mulingo wocheperako komanso kupsinjika koyembekezereka kutsika m’lifupi.

Kodi kuwerengera PCB Kulumikizana kukana?

Equation yotsatirayi imagwiritsidwa ntchito pofufuza:

Dera [Mils ²] = (pakali pano [Amps] / (K * (Temp_Rise [° C]) ^ b)) ^ (1 / C), yomwe imatsata mulingo wakunja wa IPC (kapena pamwamba / pansi), k = 0.048, b = 0.44, C = 0.725. Dziwani kuti zosintha zokha zomwe tikufunikira kuyikapo ndizomwe zilipo.

Kugwiritsa ntchito dera lino mu equation yotsatirayi kutipatsa kukula kofunikira komwe kumatiuza m’lifupi mwake mzere wofunikira kunyamula zamakono popanda zovuta zilizonse:

Kutalika [Mils] = dera [Mils ^ 2] / (makulidwe [oz] * 1.378 [mils / oz]), pomwe 1.378 imagwirizana ndi mulingo woyambira 1 oz kutsanulira.

Mwa kuyika ma 2 amperes apano pakuwerengera pamwambapa, timapeza ma 30 ml osachepera a zingwe.

Koma izi sizikutiuza kuti kutsika kwamagetsi kudzakhala kotani. Izi zikukhudzidwa kwambiri chifukwa zimafunikira kuwerengera kulimba kwa waya, zomwe zitha kuchitidwa molingana ndi njira yomwe ikuwonetsedwa mu Chithunzi 4.

Mwa njirayi, ρ = resistivity yamkuwa, α = kutentha kwa mkuwa, T = kukula kwake, W = kufufuza m’lifupi, L = kutalika kwa kutalika, T = kutentha. Ngati malingaliro onse oyenera alowetsedwa mu 0.8 “kutalika kwa 30mils m’lifupi, tikuwona kuti kulumikizana kwa waya kuli pafupifupi 0.03? Ndipo imatsitsa mphamvu yamagetsi pafupifupi 26mV, yomwe ili bwino pantchitoyi. Ndizothandiza kudziwa zomwe zimakhudza izi.

Chingwe cha PCB ndi kutalika

Pazipangidwe zadijito zokhala ndi mauthenga othamanga kwambiri, malo enaake ndi kutalika kosinthika kungafunike kuti muchepetse chopingasa, kulumikizana, ndikuwonetsa. Pachifukwa ichi, ntchito zina zodziwika bwino ndizosiyanitsa kochokera pa USB ndi zizindikiritso zofananira za RAM. Nthawi zambiri, USB 2.0 imafunikira masanjidwe oyenda pa 480Mbit / s (USB yothamanga kwambiri) kapena kupitilira apo. Izi ndichifukwa choti USB yothamanga kwambiri imagwira ntchito pama voltages otsika ndi kusiyanasiyana, kubweretsa mulingo wazizindikiro pafupi ndi phokoso lakumbuyo.

Pali zinthu zitatu zofunika kuziganizira mukamayendetsa zingwe zothamanga kwambiri za USB: kutalika kwa waya, malo otsogola, ndi kutalika kwa chingwe.

Zonsezi ndizofunikira, koma chofunikira kwambiri pa atatuwa ndikuwonetsetsa kuti kutalika kwa mizere iwiri ikufanana momwe zingathere. Monga lamulo, ngati kutalika kwa zingwe kumasiyanasiyana wina ndi mzake mopitilira 50 mils (ya USB yothamanga kwambiri), izi zimawonjezera chiopsezo chowunikira, zomwe zingayambitse kulumikizana bwino. 90 ohm ofananira ndi impedance ndikutanthauzira kwakukulu kwa ma waya awiri osiyana. Kuti mukwaniritse cholingachi, kuyendetsa bwino kuyenera kukhathamiritsidwa m’lifupi ndikutalikirana.

Chithunzi 5 chikuwonetsa chitsanzo cha mitundu iwiri yopanga ma waya othamanga kwambiri a USB omwe amakhala ndi zingwe za 12 mil mulifupi mu 15 mil.

Malo olumikizirana ndi zinthu zokumbukira zomwe zimakhala ndi mawonekedwe ofanana (monga DDR3-SDRAM) azithana kwambiri ndi kutalika kwa waya. Mapulogalamu ambiri apamwamba a PCB amakhala ndi kusintha kwakutali komwe kumakulitsa kutalika kwa mzere kuti agwirizane ndi zizindikilo zonse m’basi lofananira. Chithunzi 6 chikuwonetsa chitsanzo cha mawonekedwe a DDR3 okhala ndi zingwe zosinthira kutalika.

Zotsatira ndi ndege zodzazidwa pansi

Mapulogalamu ena okhala ndi zinthu zosamveka phokoso, monga tchipisi tating’onoting’ono kapena tinyanga, angafunikire kutetezedwa pang’ono. Kupanga zingwe ndi ndege zokhala ndi mabowo ophatikizidwa zingathandize kwambiri kuchepetsa kulumikizana kwa zingwe zapafupi kapena kunyamula ndege ndi zikwangwani zomwe zimakwera m’mbali mwa bolodi.

Chithunzi 7 chikuwonetsa chitsanzo cha gawo la Bluetooth loyikidwa pafupi ndi m’mphepete mwa mbale, ndi kanyumba kake (kudzera pazenera zosindikizidwa “ANT” zolemba) kunja kwa mzere wokulirapo wokhala ndi mabowo ophatikizidwa olumikizidwa kumtunda. Izi zimathandizira kupatula ma antenna kuchokera kuma circuits ena ndi ndege.

Njira ina yoyendetsera nthaka (pamenepa ndege ya polygonal) itha kugwiritsidwa ntchito kuteteza oyendetsa bwalo kuzizindikiro zakunja zopanda zingwe. Chithunzi 8 chikuwonetsa PCB yomvera phokoso yokhala ndi ndege yolowedwa mozungulira yomwe ili pafupi ndi bolodi.

Njira zabwino kwambiri zolumikizira PCB

Zambiri zimafotokozera mawonekedwe a gawo la PCB, chifukwa chake onetsetsani kuti mukutsata njira zabwino mukamalumikiza PCB yanu yotsatira, ndipo mupeza malire pakati pa mtengo wa PCB, kachulukidwe ka dera, ndi magwiridwe antchito onse.