Ngokuthuthukiswa kwemikhiqizo yamakhasimende, ikhula kancane kancane ibheke kwezobuhlakani, ngakho-ke izidingo ze-PCB board impedance ziya ngokuya ziba ziqine kakhulu, ezibuye zikhuthaze ukuvuthwa okuqhubekayo kobuchwepheshe bokuklama kwe-impedance.
Kuyini impedance isici?
1. Ukumelana okukhiqizwa ngokushintshana kwamanje ezingxenyeni kuhlobene ne-capacitance kanye ne-inductance.Uma kukhona ukudluliswa kwe-waveform yesiginali ye-elekthronikhi ku-conductor, ukumelana ekutholayo kubizwa ngokuthi i-impedance.
2. Ukumelana ukumelana okukhiqizwa amandla aqondile ezingxenyeni, okuhlobene ne-voltage, resistivity kanye namanje.
Ukusetshenziswa kwe-Characteristic Impedance
1. Izakhiwo zikagesi ezinikezwe ibhodi eliphrintiwe ezisetshenziswa ekudluliselweni kwesignali ngesivinini esikhulu kanye namasekhethi anemvamisa ephezulu kumele zibe ngendlela yokuthi kungabikho ukubonakaliswa okwenzekayo phakathi nenqubo yokudlulisa isignali, isignali ihlala injalo, ukulahlekelwa kokudlulisela kuncishisiwe, kanye nomphumela ofanayo. ingafinyelelwa.Iphelele, ithembekile, inembile, ayinakukhathazeka, isignali yokudlulisela engenamsindo.
2. Ubukhulu be-impedance abunakuqondwa kalula.Okukhulu okuba ngcono noma kuncane kungcono, ukhiye uyahambisana.
Lawula amapharamitha wesici se-impedance
I-dielectric constant yeshidi, ukujiya kongqimba lwe-dielectric, ububanzi bomugqa, ukujiya kwethusi, kanye nobukhulu bemaski ye-solder.
Ithonya nokulawula imaski ye-solder
1. Ubukhulu bemaski ye-solder bunomthelela omncane ku-impedance.Lapho ubukhulu bemaski ye-solder bukhuphuka ngo-10um, inani le-impedance lishintsha kuphela ngo-1-2 ohms.
2. Ekwakhiweni, umehluko phakathi kwemaski ye-solder yekhava kanye ne-non-cover solder imaskhi inkulu, ene-single-end 2-3 ohms, kanye nokwehluka okungu-8-10 ohms.
3. Ekukhiqizeni ibhodi le-impedance, ubukhulu be-solder mask buvame ukulawulwa ngokuvumelana nezidingo zokukhiqiza.
Ukuhlolwa kwe-Impedans
Indlela eyisisekelo yindlela ye-TDR (i-time domain reflectometry).Umgomo oyisisekelo ukuthi ithuluzi likhipha isignali ye-pulse, egoqwe emuva ngocezu lokuhlola lwebhodi lesekethe ukuze kulinganiswe ushintsho kwivelu yesici sokuphazamiseka kokuphumayo nokugoqa.Ngemuva kokuhlaziywa kwekhompyutha, i-impedance yesici iyaphuma.
Ukuxazulula inkinga ye-impedance
1. Ngemingcele yokulawula ye-impedance, izidingo zokulawula zingafinyelelwa ngokulungiswa okuhlangene ekukhiqizeni.
2. Ngemuva kokukhiqizwa kwe-lamination, ibhodi liyasikwa futhi lihlaziywe.Uma ubukhulu be-medium buncishisiwe, ububanzi bomugqa bungancishiswa ukuze buhlangabezane nezidingo;uma likhulu kakhulu, ithusi lingaqiniswa ukuze kuncishiswe inani le-impedance.
3. Esivivinyweni, uma kunomehluko omkhulu phakathi kwethiyori kanye nokwangempela, okungenzeka kakhulu ukuthi kunenkinga ngomklamo wobunjiniyela kanye nokuklanywa komugqa wokuhlola.
Isikhathi sokuthumela: Mar-15-2022