Ngokuthuthukiswa kwemikhiqizo yamakhasimende, kancane kancane ikhula ibheke ohlangothini lwezobunhloli, ngakho-ke izidingo zebhodi le-PCB le-impedance ziya ngokuya ziba nzima, okuphinde kukhuthaze ukuvuthwa okuqhubekayo kobuchwepheshe bomklamo we-impedance.
Kuyini impedance yesici?
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 ne-current.
Ukusetshenziswa kwesici se-impedance
1. Kusetshenziswe ekudlulisweni kwesignali yesivinini esikhulu kanye nesekhethi ye-high-frequency, ukusebenza kukagesi okunikezwa ibhodi eliphrintiwe kufanele kukwazi ukuvimbela ukubonakaliswa ngesikhathi sokudluliswa kwesignali, ukugcina isignali iqinile, ukunciphisa ukulahlekelwa kokudlulisela, nokudlala indima efanayo.Ukudluliswa kwamasignali okuphelele, okuthembekile, okunembile, okungakhathazeki, nokungenamsindo.
2. Ubukhulu be-impedance abunakuqondwa kalula njengendawo enkulu engcono noma encane engcono, ukhiye uyahambisana.
Lawula amapharamitha wesici se-impedance
I-dielectric constant yeshidi, ukujiya kongqimba lwe-dielectric, ububanzi bomugqa, ukujiya kwethusi, kanye nogqinsi lwemaski ye-solder.
Ithonya nokulawula imaski ye-solder
1. Ubukhulu be-mask solder bunomphumela omncane ku-impedance.Ubukhulu bemaski ye-solder bukhuphuka ngo-10um, futhi inani le-impedance lishintsha kuphela i-1-2 ohms.
2. Ekwakhiweni, kunomehluko omkhulu phakathi kokukhethwa kwekhava nokungabi nayo imaski ye-solder yekhava, i-single-end 2-3 ohms, kanye nokuhluka okungu-8-10 ohms.
3. Ekukhiqizeni amabhodi we-impedance, ubukhulu be-solder mask buvame ukulawulwa ngokuvumelana nezidingo zokukhiqiza.
Ukuhlolwa kwe-Impedans
Indlela eyisisekelo yindlela ye-TDR (Time Domain Reflectometry).Isimiso esiyisisekelo siwukuthi ithuluzi likhipha isignali ye-pulse, egoqwe emuva ngocezu lokuhlola lwebhodi lesifunda ukuze kulinganiswe ushintsho kusici se-impedance yokuphuma kanye nomhlane ogoqiwe.Ngemuva kokuthi ikhompuyutha ihlaziye i-impedance yesici, ukuphuma kwesici se-impedance kuyaphuma.
Ukuphatha inkinga ye-impedance
1. Ngokuphathelene nemingcele yokulawula ye-impedance, izidingo zokulawula zingafinyelelwa ngokulungiswa okuhlangene ekukhiqizeni.
2. Ngemuva kokufakwa kwe-lamination ekukhiqizeni, ibhodi liyasikwa futhi lihlaziywe.Uma ubukhulu be-medium buncishisiwe, ububanzi bomugqa bungancishiswa ukuze buhlangabezane nezidingo;uma ubukhulu bukhulu kakhulu, ithusi lingaqiniswa ukuze kuncishiswe inani le-impedance.
3. Esivivinyweni, uma kunomehluko omkhulu phakathi kwethiyori kanye neqiniso, okungenzeka kakhulu ukuthi kunenkinga ngomklamo wobunjiniyela kanye nomklamo womugqa wokuhlola.
Isikhathi sokuthumela: Nov-19-2021