Kugenzura impedance ni iki n'uburyo bwo kugenzura impedance kuri PCB

Mu miterere y'ibikoresho bya elegitoroniki bigezweho, PCB zigira uruhare runini. Imikorere ya PCB igira ingaruka zitaziguye ku ituze, ubwizerwe n'imikorere myiza ya sisitemu yose y'ikoranabuhanga. Muri zo, kugenzura impedance ni igice cy'ingenzi mu miterere ya PCB. Kubera ko imiyoboro ya elegitoroniki igezweho ifite igihe gito cyo kohereza ibimenyetso n'umuvuduko w'isaha uri hejuru, ibimenyetso bya PCB ntibikiri ibyoroshye guhuza, ahubwo ni imirongo yo kohereza. Kugenzura impedance ya PCB bivuga kugenzura umuvuduko wo kohereza no guhuza impedance y'ibimenyetso kuri PCB kugira ngo harebwe ireme n'ituze ry'uko kohereza ibimenyetso bihagaze.

Mu bihe bifatika, ni ngombwa kugenzura impedance y'uruhererekane rw'amashanyarazi iyo umuvuduko wa digitale uri hejuru ya 1ns cyangwa frequency ya analog irenze 300MHz. Kimwe mu bipimo by'ingenzi bya PCB trace ni impedance yayo idasanzwe (ni ukuvuga ikigereranyo cy'amashanyarazi n'amashanyarazi iyo umuraba woherejwe ku murongo wo kohereza ikimenyetso). Impedance idasanzwe y'insinga kuri PCB ni ikimenyetso cy'ingenzi cy'imiterere ya PCB. Cyane cyane mu miterere ya PCB ifite frequency nyinshi, ni ngombwa gusuzuma niba impedance idasanzwe y'insinga ihuye cyangwa ihuye n'impedance isabwa y'igikoresho cyangwa ikimenyetso. Ibi birimo ingingo 2: kugenzura impedance no guhuza impedance. Iyi ngingo yibanda ku bibazo byo kugenzura impedance no gushushanya stack.

Hari ibimenyetso bitandukanye byoherezwa mu byuma biyobora umuyoboro wa PCB. Kugira ngo wongere umuvuduko wo kohereza umuyoboro, inshuro zayo zigomba kongerwa. Agaciro k'impedansi y'urukiramende ubwarwo karatandukanye bitewe n'ibintu nko gukata, ubugari bw'urwego n'ubugari bw'insinga, nibindi, bitera kwangirika kw'ibimenyetso. Kubwibyo, agaciro k'impedansi y'ibiyobora umuyoboro kuri PCB zihuta cyane kagomba kugenzurwa mu rugero runaka, rwitwa "impedansi control".

Impedance y'ibice bya PCB iterwa n'uburyo byayo bwo gukwirakwiza no gukwirakwiza, ubushobozi bwo guhangana no gutwara ibintu. Ibintu bigira ingaruka ku kumena kw'insinga za PCB birimo ubugari n'ubugari bw'insinga y'umuringa, imiterere ya dielectric n'ubugari bw'icyuma gikoreshwa mu gukwirakwiza ibintu, ubunini bw'icyuma gikoresha insinga, inzira y'insinga yo hasi, n'insinga zikikije insinga, nibindi. Ingano ya PCB ni hagati ya ohms 25 na 120.

Mu by’ukuri, imiyoboro ya PCB isanzwe igizwe n’insinga, urwego rumwe cyangwa nyinshi z’ingenzi, n’ibikoresho byo gukingira. Urusobe n’urwego bigize impedance yo kugenzura. PCB akenshi zikoresha imiterere y’urwego rwinshi, kandi igenzura impedance rishobora no kubakwa mu buryo butandukanye. Ariko, hatitawe ku buryo bwakoreshejwe, agaciro k’impedance kazagenwa n’imiterere yayo n’imiterere y’ibikoresho byo gukingira:

Microstrip ni agace k'insinga yerekeza ku murongo wo kohereza amakuru ufite uruhande rumwe gusa rufite urwego rw'icyerekezo. Hejuru n'impande bihuzwa n'umwuka (cyangwa bitwikiriwe) kandi biherereye ku buso bwa PCB ya Er ifata ubushyuhe, hamwe n'urwego rw'ingufu cyangwa urwego rw'ubutaka nk'icyerekezo. Nkuko bigaragara ku ishusho ikurikira:

Icyitonderwa: Mu nganda za PCB, uruganda rwa PCB rukunze gusiga wino y'icyatsi kibisi ku buso bwa PCB. Kubwibyo, mu kubara impedance nyayo, icyitegererezo kigaragara ku ishusho ikurikira gikunze gukoreshwa ku mirongo ya microstrip y'ubuso.

Umurongo w'icyuma ni umurongo w'insinga ushyirwa hagati y'imirongo ibiri y'icyitegererezo, nk'uko bigaragara ku ishusho ikurikira. Imiterere ya dielectric ya dielectric igaragazwa na H1 na H2 ishobora kuba itandukanye.

Ibipimo 2 byavuzwe haruguru ni ikimenyetso gisanzwe cya microstrip na striplines, ubusanzwe bikoreshwa mu kwiga ibikoresho by’ubwenge bya IoT n’izindi sisitemu. Hari ubwoko bwinshi bwihariye bwa microstrip na striplines, nka microstrip yasizwe, bifitanye isano n’imiterere yihariye ya PCBs.

Ikigereranyo gikoreshwa mu kubara impedansi iranga umuntu gisaba imibare igoye ya mibare, ubusanzwe hakoreshejwe uburyo bwo gukemura ikibazo cy’umurima, harimo no gusesengura ibintu by’imipaka. Kubwibyo, dukoresheje porogaramu yihariye yo kubara impedansi SI9000, icyo dukeneye gukora ni ukugenzura ibipimo bya impedansi iranga umuntu:

Ingano ya dielectric Er y'urwego rwa insulation, ubugari bw'insinga W1 na W2 (trapezoidal), ubunini bw'insinga T, n'ubugari bw'urwego rwa insulation H.

W - Ubugari bw'umurongo bwateguwe

A - gutakaza imiterere y'ikibyimba (reba imbonerahamwe iri hejuru)

Impamvu y'ubugari budahuza hagati y'igice cyo hejuru n'igice cyo hasi cy'umurongo ni uko mu gihe cyo gukora PCB, habaho ingese kuva hejuru kugeza hasi, bigatuma umurongo wangiritse usa n'aho uri mu shusho ya trapezoidal.

Hari isano ijyanye hagati y'ubunini bw'umurongo T n'ubunini bw'umuringa bw'uru rwego, nk'uko bikurikira:

* Bitewe n'ingaruka nke z'ubugari bwa maske ya solder kuri impedance, bivugwa ko ifite agaciro ka 0.5ml.

Dushobora kugera ku igenzura rya impedance dukoresheje kugenzura ibi bipimo. Dufashe urugero rwa PCB yo hasi ya Anwei, tuzasobanura intambwe zo kugenzura impedance n'ikoreshwa rya SI9000:

Icyiciro cya kabiri ni urwego rw'ubutaka, urwego rwa gatanu ni urwego rw'ingufu, naho ibindi bice ni urwego rw'ibimenyetso.

Ibisobanuro: Dielectric iri hagati y’ibice biri hagati ni FR-4, ifite dielectric constant ya 4.2; Ibice byo hejuru n’ibyo hasi ni ibice byambaye ubusa bihura n’umwuka, naho dielectric constant y’umwuka ni 1.

Abashushanya PCB bashobora gukoresha neza imiterere y’urwego rwa PCB kugira ngo bagere ku kugenzura impedance. Mu gushyira ibimenyetso bitandukanye mu myanya itandukanye y’urwego, ubushobozi bwo hagati y’urwego n’ubwikorezi bishobora kugenzurwa neza. Muri rusange, urwego rw’imbere rukoresha ibikoresho byinshi bya impedance naho urwego rw’inyuma rukoresha ibikoresho bike bya impedance kugira ngo bigabanye ingaruka zo kugarura no kuganira.

Imirongo yo kohereza ibimenyetso bitandukanye ishobora gutanga ubushobozi bwo kurwanya ingaruka mbi no kugabanya ibyago byo kuvugana. Imirongo yo kohereza ibimenyetso bitandukanye ni insinga ebyiri zifatanye zifite voltage zitandukanye ariko zingana, zishobora gutanga ubuziranenge bwiza bw'ibimenyetso no kurwanya ingaruka mbi. Ubusanzwe, impedance y'imirongo yo kohereza ibimenyetso bitandukanye igenzurwa no guhitamo intera iri hagati y'imirongo, ubugari n'ubutaka.

Ibipimo bya jeometrike nk'ubugari bw'umurongo wa PCB, intera n'imiterere bishobora no gukoreshwa mu kugenzura impedance. Ku mirongo isanzwe ya microstrip, ubugari bw'umurongo munini n'intera nini bishobora kugabanya impedance. Ku mirongo ya coaxial, uburebure bw'umurongo w'imbere n'uburebure bw'umurongo munini wo hanze bishobora kongera impedance. Guhitamo imiterere y'insinga bisaba kunoza hashingiwe ku bisabwa byihariye bya impedance n'umuvuduko w'ibimenyetso.

Uburyo bwo guhuza amashanyarazi mu bikoresho bya PCB nabwo bugira ingaruka ku kubuza amashanyarazi. Guhitamo ibikoresho bifite imiterere ihamye ya kubuza amashanyarazi ni kimwe mu bigize uburyo bwo kugenzura kubuza amashanyarazi. Mu bikorwa bikoresha inshuro nyinshi kandi byihuta cyane, ibikoresho bikunze gukoreshwa birimo FR-4 (ikibaho gikonjeshwa n'ibirahure), PTFE (polytetrafluoroethylene), na RF (umuvuduko wa radiyo).

Mbere yo gushushanya PCB, gukoresha ibikoresho byo gushushanya no gushushanya bishobora gufasha abashushanya kugenzura vuba kandi neza no kunoza impedance. Ibi bikoresho bishobora kwigana imyitwarire y'uruziga, igihombo cyo kohereza ibimenyetso ndetse n'imikoranire ya electromagnetic kugira ngo hamenyekane ibipimo byiza by'igishushanyo cya PCB. Bimwe mu bikoresho bisanzwe byo gushushanya birimo CST Studio Suite, HyperLynx na ADS.

Kugenzura impedansi ya PCB bigira uruhare runini mu miyoboro ya digitale na analog yihuta cyane. Binyuze mu gushushanya neza, gukoresha imirongo itandukanya ibimenyetso, kugenzura imiterere y'insinga, guhitamo ibikoresho bya PCB bikwiye, no gukoresha ibikoresho byo kwigana no gushushanya, kugenzura impedansi neza bishobora kugerwaho, bityo kunoza imikorere y'imiyoboro no kunoza ubuziranenge bw'ibimenyetso.