PCB impedance yana nufin ma'auni na juriya da amsawa, wanda ke taka rawar hanawa a musanya halin yanzu. A cikin samar da allon da'ira na pcb, maganin impedance yana da mahimmanci. To, ka san dalilin da ya sa PCB kewaye allon bukatar yin impedance?

1, PCB kewaye hukumar kasa yi la'akari da shigarwa na lantarki aka gyara, lantarki watsin da kuma siginar watsa yi bayan sakawa, don haka zai bukatar da ƙananan impedance, mafi alhẽri, da resistivity kasa da 1 × 10-6 da murabba'in santimita kasa.

2, PCB kewaye hukumar a cikin samar tsari fuskanci jan karfe nutsewa, tin plating (ko electroless plating, ko zafi fesa tin), solder gidajen abinci da sauran tsari samar links, da kuma kayan amfani a cikin wadannan links dole ne tabbatar da cewa resistivity kasa, a domin tabbatar da cewa gaba ɗaya impedance na PCB kewaye hukumar ba shi da ƙasa don saduwa da ingancin samfur bukatun, iya aiki kullum.

3, tinning na PCB board shi ne mafi kusantar da matsaloli a samar da dukan kewaye hukumar, kuma shi ne mabuɗin mahada shafi impedance. Babban lahani na sinadari plating Layer shine sauƙin canza launi (duka mai sauƙin iskar oxygen ko delixing), ƙarancin brazing mara kyau, wanda zai haifar da walƙiya mai wahala na allon kewayawa, babban impedance yana haifar da ƙarancin ƙarancin wutar lantarki ko rashin kwanciyar hankali na aikin gabaɗaya.

4, PCB kewaye allon a cikin madugu zai sami nau'in watsa sigina iri-iri, lokacin da za a inganta yawan watsawa kuma dole ne ya ƙara yawan mita, layin da kansa idan etching, laminated kauri, waya nisa da sauran dalilai sun bambanta, zai haifar da impedance. yana da daraja canzawa, don haka siginar siginar, yana haifar da raguwar aikin hukumar, don haka kuna buƙatar sarrafa ƙimar impedance a cikin wani kewayon.