I-Anti-interference iyikhonkco ebaluleke kakhulu kuyilo lwesekethe yanamhlanje, ebonisa ngokuthe ngqo ukusebenza kunye nokuthembeka kwenkqubo yonke. Kwiinjineli zePCB, uyilo oluchasene nokuphazamiseka yeyona nto iphambili kunye nenqaku elinzima ekufuneka wonke umntu eyinkosi.
Ubukho bokuphazamiseka kwibhodi yePCB
Kuphando lokwenyani, kufunyaniswe ukuba kukho iziphazamiso ezine eziphambili kuyilo lwePCB: ingxolo yobonelelo lwamandla, uphazamiseko lwentambo yothumelo, ukudityaniswa kunye nokuphazamiseka kwe-electromagnetic (EMI).
1. Ingxolo yokubonelela ngombane
Kwi-high-frequency circuit, ingxolo yokunikezelwa kwamandla inempembelelo ecacileyo ngokukodwa kwi-high-frequency signal. Ngoko ke, imfuno yokuqala yokunikezelwa kwamandla yingxolo ephantsi. Apha, umhlaba ococekileyo ubaluleke njengomthombo wamandla ococekileyo.
2. Umgca wothumelo
Zimbini kuphela iindidi zeentambo zothumelo ezinokwenzeka kwi-PCB: umgca wentambo kunye nomgca we-microwave. Eyona ngxaki inkulu ngeentambo zothumelo kukubonakalisa. Ukucamngca kuya kubangela iingxaki ezininzi. Ngokomzekelo, umqondiso womthwalo uya kuba yi-superposition yesiginali yasekuqaleni kunye ne-echo signal, eya kwandisa ubunzima bokuhlalutya umqondiso; ukucamngca kuya kubangela ukulahleka kokubuyisela (ukubuyisela ukulahleka), okuya kuchaphazela umqondiso. Impembelelo inobuzaza njengoko ibangelwa luphazamiseko olongezelelweyo lwengxolo.
3. Ukudibanisa
Isiginali yokuphazamiseka eveliswa ngumthombo wophazamiseko ibangela ukuphazamiseka kwe-electromagnetic kwinkqubo yolawulo lwe-elektroniki ngokusebenzisa ijelo elithile lokudibanisa. Indlela yokudibanisa yokuphazamiseka ayikho enye into ngaphandle kokusebenza kwinkqubo yokulawula i-electronic ngokusebenzisa iingcingo, izithuba, imigca eqhelekileyo, njl. Uhlalutyo lubandakanya ngokukodwa ezi ntlobo zilandelayo: ukudibanisa ngokuthe ngqo, ukudibanisa okuqhelekileyo kwe-impedance, i-capacitive coupling, i-electromagnetic induction coupling, i-radiation coupling; njl.
4. Ukuphazamiseka koMbane (EMI)
Ukuphazamiseka kwe-Electromagnetic EMI ineendidi ezimbini: uphazamiseko olwenziweyo kunye nokuphazamiseka kwemitha. Uphazamiso olwenziwayo lubhekiselele ekudibaneni (ukuphazamiseka) kwemiqondiso kuthungelwano lombane omnye ukuya komnye uthungelwano lombane ngokusebenzisa i-conductive medium. Uphazamiseko lombane lubhekiselele ekudibaneni komthombo wophazamiseko (uphazamiseko) umqondiso wayo komnye uthungelwano lombane ngokusebenzisa isithuba. Kwi-PCB enesantya esiphezulu kunye noyilo lwenkqubo, imigca yomqondiso we-high-frequency, izikhonkwane zesekethe ezidityanisiweyo, izihlanganisi ezahlukeneyo, njl.njl. inokuba yimithombo yokuphazamiseka kwemitha eneempawu ze-eriyali, ezinokukhupha amaza ombane kwaye zichaphazele ezinye iinkqubo okanye ezinye iinkqubo ezisezantsi kwinkqubo. umsebenzi oqhelekileyo.
PCB kunye nesekethe anti-ukuphazamiseka amanyathelo
Uyilo oluchasene ne-jamming yebhodi yesekethe eprintiweyo ihambelana ngokusondeleyo nesekethe ethile. Okulandelayo, siya kwenza kuphela iingcaciso kwimilinganiselo emininzi eqhelekileyo yoyilo lwe-PCB yokuchasana ne-jamming.
1. Uyilo lwentambo yamandla
Ngokobungakanani bebhodi yesekethe eprintiweyo yangoku, zama ukwandisa ububanzi bomgca wamandla ukunciphisa ukuxhathisa i-loop. Kwangaxeshanye, yenza isalathiso somgca wamandla kunye nomgca osezantsi uhambelane nesalathiso sokuhanjiswa kwedatha, nto leyo enceda ukukhulisa isakhono sokuchasana nengxolo.
2. Uyilo lwengcingo yomhlaba
Yahlula umhlaba wedijithali kumhlaba we-analog. Ukuba kukho zombini iisekethe ze-logic kunye neesekethe zomgca kwibhodi yesekethe, kufuneka zihlulwe kangangoko kunokwenzeka. Umhlaba wesekethe ye-low-frequency circuit kufuneka ubekwe ngokuhambelana kwindawo enye kangangoko kunokwenzeka. Xa i-wiring yokwenyani inzima, inokudityaniswa ngokuyinxenye kuthotho kwaye emva koko ibekwe ngokuhambelanayo. I-high-frequency circuit ifanele ibekwe kwiindawo ezininzi kwiichungechunge, ucingo lomhlaba kufuneka lube lufutshane kwaye lube lukhulu, kwaye i-grid-efana ne-foil yomhlaba enkulu kufuneka isetyenziswe malunga necandelo eliphezulu le-frequency.
Ucingo lomhlaba kufuneka lube ngqindilili kangangoko. Ukuba umgca omncinci kakhulu usetyenziselwa ucingo lokumisa, utshintsho olunokuthi lube nokutshintsha ngoku, okunciphisa ukuxhathisa ingxolo. Ngoko ke, ucingo lomhlaba kufuneka luqiniswe ukwenzela ukuba lugqithise kathathu umbane ovumelekileyo kwibhodi eprintiweyo. Ukuba kunokwenzeka, ucingo lomhlaba kufuneka lube ngaphezu kwe-2 ~ 3mm.
Ucingo lomhlaba lwenza i-loop evaliweyo. Kwiibhodi eziprintiweyo eziqulunqwe kuphela kwiisekethe zedijithali, uninzi lweesekethe zazo zokumisa zicwangciswe kwiilophu zokuphucula ukuxhathisa ingxolo.
3. Ukuqhawula uqwalaselo lwe-capacitor
Enye yeendlela eziqhelekileyo zoyilo lwePCB kukuqwalasela ii-capacitors ezifanelekileyo zokudibanisa kwindawo nganye ephambili yebhodi eprintiweyo.
Imigaqo yoqwalaselo jikelele ye-decoupling capacitors zezi:
① Qhagamshela i-10 ~ 100uf i-electrolytic capacitor kulo lonke igalelo lamandla. Ukuba kunokwenzeka, kungcono ukudibanisa kwi-100uF okanye ngaphezulu.
②Ngokomgaqo, i-chip nganye yesekethe edibeneyo kufuneka ixhotyiswe nge-0.01pF i-ceramic capacitor. Ukuba i-gap yebhodi eprintiweyo ayanele, i-capacitor ye-1-10pF inokulungiswa kuzo zonke ii-4 ~ 8 chips.
③ Kwizixhobo ezinobuthathaka bokuchasana nengxolo kunye notshintsho olukhulu lwamandla xa lucinyiwe, njenge-RAM kunye nezixhobo zokugcina i-ROM, i-capacitor yokudibanisa kufuneka idityaniswe ngokuthe ngqo phakathi kwentambo yamandla kunye nomgca osezantsi wetshiphu.
④I-capacitor lead ayifanele ibe yinde kakhulu, ngakumbi i-frequency bypass capacitor ayifanele ibe nelothe.
4. Iindlela zokuphelisa ukuphazamiseka kwe-electromagnetic kuyilo lwePCB
① Nciphisa iilophu: I-loop nganye ilingana ne-eriyali, ngoko ke kufuneka sinciphise inani le-loops, indawo yeluphu kunye nefuthe le-antenna yeluphu. Qinisekisa ukuba isignali inendlela enye ye-loop kuzo naziphi na iindawo ezimbini, uthintele iilophu ezenziweyo, kwaye uzame ukusebenzisa umaleko wamandla.
②Ukucoca: Ukucoca kungasetyenziselwa ukunciphisa i-EMI zombini kumgca wamandla kunye nomgca wesignali. Kukho iindlela ezintathu: i-decoupling capacitors, izihlungi ze-EMI, kunye nezixhobo zemagneti.
③Ikhaka.
④ Zama ukunciphisa isantya sezixhobo eziphezulu.
⑤ Ukwandisa i-dielectric engaguqukiyo yebhodi yePCB kunokuthintela iindawo eziphezulu zefrikhwensi ezifana nomgca wothumelo okufutshane nebhodi ukuba uphume ngaphandle; ukwandisa ubukhulu bebhodi ye-PCB kunye nokunciphisa ubukhulu bomgca we-microstrip kunokuthintela ucingo lwe-electromagnetic ukuba lungaphumi kwaye luthintele ukusasazeka kwemitha.