PCB ibhodi i-impedance ibhekisela kumingcele yokumelana nokusabela, evimbela ukushintshashintsha kwamandla. Ekukhiqizeni amabhodi wesifunda we-PCB, ukucubungula kwe-impedance kubalulekile. Kungani amabhodi wesekethe we-PCB edinga i-impedance?

1. Isekhethi ye-PCB (ezansi kwebhodi) kufanele icabangele ukuxhuma nokufaka izingxenye ze-elekthronikhi, futhi ukusebenza nokusebenza kokudlulisa isignali kufanele kucatshangelwe ngemva kokuba isiqeshana se-SMT sakamuva sixhunyiwe. Ngakho-ke, ukwehla kwe-impedance, kungcono, ikakhulukazi isignali ye-microwave. Okokusebenza, imfuneko ye-resistivity ithi: ngaphansi kuka-1&TImes;10-6 ngesentimitha yesikwele ngasinye.

2. Enqubweni yokukhiqiza amabhodi wesekethe ye-pcb, kufanele badlule ezinqubweni ezinjengokucwiliswa kwethusi, i-tin plating (noma i-chemical plating, noma i-thermal spray tin), i-soldering yesixhumi, njll., nezinto ezisetshenziswa kulezi zixhumanisi kumele ziqinisekise. ukuthi i-resistivity iphansi, ukuze kuqinisekiswe ukuthi I-impedance yonke yebhodi lesifunda iphansi ukuze ihlangabezane nezidingo zekhwalithi yomkhiqizo futhi ingasebenza ngokujwayelekile.

Okwesithathu, i-tin Plating yamabhodi wesifunda se-pcb iyona ethambekele kakhulu ezinkingeni ekukhiqizeni ibhodi lesifunda lonke, futhi iyisixhumanisi esiyinhloko esithinta i-impedance. Isici esikhulu kunazo zonke ze-electroless tin coating ukuguquguquka okulula (kulula uku-oxidized noma i-deliquescent) kanye nokungatholakali kahle kwe-solderability, okuzoholela ekuhlanganisweni okunzima kwebhodi lesifunda, i-impedance ephezulu, ukungahambi kahle kukagesi, noma ukungazinzi kokusebenza kwebhodi jikelele.

4. Kukhona ukudluliselwa isignali ehlukahlukene ku abaqhubi yebhodi pcb wesifunda. Lapho i-frequency kufanele inyuswe ukuze kwandiswe izinga layo lokudlulisela, uma isekethe ngokwayo ihlukile ngenxa yezinto ezifana nokushumeka, ukushuba kwesitaki, ububanzi bentambo, njll., inani le-impedance lizoshintsha. , Ukuze isignali yayo ihlanekezelwe futhi ukusebenza kwebhodi lesifunda kucekelwe phansi, ngakho-ke kuyadingeka ukulawula inani le-impedance ngaphakathi kwebanga elithile.