I-jumper capacitors okanye i-decoupling capacitors inokusombulula ezinye iingxaki, kodwa ukunyanzeliswa okupheleleyo kwee-capacitors, ii-vias, iipads, kunye neentambo kufuneka ziqwalaselwe.

Eli nqaku liza kwazisa ii-EMC's Uyilo lwePCB iteknoloji evela kwimiba emithathu: iqhinga PCB layering, izakhono ubeko kunye nemithetho yocingo.

PCB layering iqhinga

Ubuninzi, ngenkqubo kunye nenani leeleya kuyilo lwebhodi yesekethe azikho isitshixo sokusombulula ingxaki.Ukupakishwa komgangatho ofanelekileyo kukuqinisekisa ukudlula kunye nokuqhawulwa kwebhasi yamandla kunye nokunciphisa amandla ombane odlulayo kumaleko wamandla okanye umaleko womhlaba.Isitshixo sokukhusela intsimi ye-electromagnetic yesiginali kunye nonikezelo lwamandla.

Ngokombono wokulandela umqondiso, isicwangciso esilungileyo sokubeka isicwangciso kufuneka sibe kukubeka zonke iimpawu zesignali kwenye okanye kwiileya ezininzi, kwaye ezi zingqimba zisecaleni komgangatho wamandla okanye umaleko womhlaba.Kunikezelo lwamandla, isicwangciso esilungileyo sokubeka i-layer kufuneka sibe ukuba umaleko wamandla usondele kumaleko omhlaba, kwaye umgama phakathi komgangatho wamandla kunye nomgangatho womhlaba uncinci kangangoko.Yile nto sithetha ngayo "i-layer" yeqhinga.Apha ngezantsi siza kuthetha ngokuthe ngqo ngesicwangciso esilungileyo se-PCB.

1. Iplani yeprojekti yoluhlu lwe-wiring kufuneka ibe kwindawo ye-reflow plane layer.Ukuba umaleko we-wiring awukho kwindawo yokubonisa i-reflow plane layer, kuya kubakho imigca yesignali ngaphandle kwendawo yokubonisa ngexesha le-wiring, eya kubangela iingxaki "ze-radiation edge", kwaye iya kwandisa indawo ye-loop yesignali, kubangele ukwanda kwemitha yemo yokwahlukana .

2. Zama ukunqanda ukuseta iileya zocingo ezikufutshane.Ngenxa yokuba ulandelelwano lweempawu ezihambelanayo kwiileya ze-wiring ezikufutshane zingabangela i-crosstalk yesiginali, ukuba iileya ze-wiring ezikufutshane azinakuphetshwa, isithuba somaleko phakathi kwee-wiring layers kufuneka sandiswe ngokufanelekileyo, kwaye isithuba somaleko phakathi kwe-wiring layer kunye ne-signal circuit kufuneka sincitshiswe.

3. Iingqimba zeenqwelomoya ezimeleneyo kufuneka zithintele ukugqithelana kwiinqwelomoya zazo.Kuba xa iingqikelelo zidibana, amandla okudibanisa phakathi kwamaleko aya kubangela ingxolo phakathi kweemaleko ukuba idibanise enye kwenye.

Uyilo lwebhodi ye-multilayer

Xa i-clock frequency idlula i-5MHz, okanye ixesha lokunyuka kwesignali lingaphantsi kwe-5ns, ukuze ulawule indawo ye-loop yesignali kakuhle, idizayini yebhodi eninzi iyafuneka ngokubanzi.Le migaqo ilandelayo kufuneka ithathelwe ingqalelo xa kuyilwa iibhodi ezininzi:

1. Umaleko wocingo olutshixo (umaleko apho umgca wewotshi, ibhasi, umgca wesiginali yojongano, umgca wamaza erediyo, ukuseta kwakhona umgca wesignali, itshiphu ekhethiweyo yomgca wesignali kunye nemigca yophawu yolawulo eyahlukeneyo ibekwe khona) kufuneka ibe kufuphi nenqwelomoya ephantsi epheleleyo, ngokukhethekayo. phakathi kweenqwelomoya ezimbini zomhlaba, Njengoko kubonisiwe kuMfanekiso 1.

Imigca yemiqondiso engundoqo idla ngokuba yimitha yemitha eyomeleleyo okanye imigca yemiqondiso ebuthathaka kakhulu.Iingcingo ezikufutshane nenqwelomoya ephantsi komhlaba zinokunciphisa indawo yesiginali yelophu, inciphise ubushushu bayo bemitha okanye iphucule isakhono sokuchasana nokuphazamiseka.

2. Inqwelomoya yombane kufuneka ihlehliswe ngokunxulumene nenqwelomoya yayo ephantsi ekufutshane (ixabiso elicetyiswayo 5H～20H).Ukuhlehliswa kwenqwelomoya yamandla xa kuthelekiswa nenqwelomoya yayo ebuyayo kunokuyicinezela ngokufanelekileyo ingxaki "yeradiation edge", njengoko kubonisiwe kuMfanekiso 2.

Ukongezelela, i-plane engundoqo yokusebenza kwamandla ebhodi (eyona nto isetyenziswa kakhulu indiza yamandla) kufuneka isondele kwinqwelo yayo yomhlaba ukuze inciphise ngokufanelekileyo indawo ye-loop yangoku yamandla, njengoko kuboniswe kuMfanekiso 3.

3. Ingaba akukho mgca wesignali ≥50MHz kwi-TOP kunye ne-BOTTOM layer yebhodi.Ukuba kunjalo, kungcono ukuhamba umqondiso wefrikhwensi ephezulu phakathi kweengqimba ezimbini zenqwelomoya ukucinezela imitha yayo esithubeni.

Ibhodi yebhodi enye kunye noyilo lwebhodi ephindwe kabini

Ukuyila iibhodi zebhodi enye kunye neebhodi eziphindwe kabini, ukuyila kwemigca yeempawu eziphambili kunye nemigca yamandla kufuneka ihlawulwe.Kufuneka kubekho ucingo olusezantsi ecaleni kunye nongqameko olunxuseneyo nomkhondo wombane ukunciphisa indawo yelophu yangoku yamandla.

"Umgca weSikhokelo soMgangatho" kufuneka ubekwe kumacala omabini omgca webhodi engundoqo webhodi enye, njengoko kuboniswe kuMzobo 4. Umgca wesiginali obalulekileyo webhodi ephindwe kabini kufuneka ube nommandla omkhulu womhlaba kwindiza yokubonisa. , okanye indlela efanayo nebhodi yomgca omnye, uyilo "Umgca weSikhokelo soMgangatho", njengoko kuboniswe kuMfanekiso 5. "I-wire ground wire" kumacala omabini omgca wesignali engundoqo inokunciphisa indawo ye-loop yesignali ngakwesinye icala, kwaye kwakhona uthintele i-crosstalk phakathi komgca wesignali kunye neminye imigca yesignali.

Izakhono zoyilo lwePCB

Xa uyila i-PCB layout, kufuneka uqaphele ngokupheleleyo umgaqo woyilo wokubeka kumgca othe tye ecaleni kwendlela yokuhamba komqondiso, kwaye uzame ukuphepha ukujikeleza emva naphambili, njengoko kubonisiwe kuMfanekiso 6. Oku kunokuphepha ukudibanisa umqondiso ngokuthe ngqo kunye nokuchaphazela umgangatho wesignali .

Ukongeza, ukuze kuthintelwe ukuphazamiseka kunye nokudibanisa phakathi kweesekethe kunye namacandelo e-elektroniki, ukubekwa kweesekethe kunye nokwakheka kwamacandelo kufuneka kulandele le migaqo ilandelayo:

1. Ukuba i-interface "yomhlaba ococekileyo" yenzelwe ebhodini, i-filtering and isolation components kufuneka ifakwe kwi-band yokuhlukanisa phakathi "komhlaba ococekileyo" kunye nomhlaba osebenzayo.Oku kunokuthintela ukucoca okanye izixhobo zokuzihlukanisa ukusuka ekudibaneni komnye nomnye ngeplani yeplani, eyenza buthathaka umphumo.Ukongezelela, "kumhlaba ococekileyo", ngaphandle kokucoca kunye nezixhobo zokukhusela, akukho zixhobo ezinokuthi zibekwe.

2. Xa iisekethe zemodyuli ezininzi zibekwe kwi-PCB enye, iisekethe zedijithali kunye neesekethe ze-analog, iisekethe ezinesantya esiphezulu nezinesantya esiphantsi kufuneka zibekwe ngokwahlukeneyo ukuze kuthintelwe ukuphazamisana phakathi kweesekethe zedijithali, iisekethe ze-analog, iisekethe ezinesantya esiphezulu kunye nezisezantsi. -iisekethe zesantya.Ukongezelela, xa iisekethe eziphezulu, eziphakathi, kunye nesantya esiphantsi zikhona kwibhodi yesiphaluka ngexesha elifanayo, ukwenzela ukuba ugweme ingxolo ye-high-frequency circuit circuit ekuphumeni ngaphandle kwe-interface, umgaqo wokumisela kwi-Figure 7 kufuneka ube.

3. I-circuit filter ye-port input port yamandla ebhodi yesekethe kufuneka ibekwe kufuphi ne-interface ukuphepha ukudibanisa kwakhona i-circuit filtered.

4. Ukucoca, ukukhuselwa kunye nezixhobo zokuzihlukanisa zesekethe ye-interface zibekwe kufuphi ne-interface, njengoko kuboniswe kwi-Figure 9, enokuthi ifezekise ngokufanelekileyo imiphumo yokukhusela, ukuhluza kunye nokuzihlukanisa.Ukuba kukho zombini isihluzi kunye nesekethe yokukhusela kwi-interface, umgaqo wokukhusela kuqala kunye nokucoca kufuneka kube.Ngenxa yokuba isiphaluka sokukhusela sisetyenziselwa ukugqithiswa kwangaphandle kunye nokunyanzeliswa kwe-overcurrent, ukuba isiphaluka sokukhusela sibekwe emva kwesiphaluka sokucoca, isiphaluka sokucoca siya konakala ngokugqithisileyo kunye nokugqithisa.

Ukongeza, ekubeni igalelo kunye nemigca yemveliso yesekethe iya kwenza buthathaka ukucoca, ukwahlukaniswa okanye isiphumo sokukhusela xa zidityanisiwe, qinisekisa ukuba igalelo kunye nemigca yemveliso yesekethe yokucoca (isihluzi), ukuhlukaniswa kunye nesekethe yokukhusela ayifuni. isibini kunye nomnye ngexesha loyilo.

5. Iisekethe ezibuthathaka okanye iikhomponenti (ezifana neesekethe zokuseta ngokutsha, njl.njl.) kufuneka ubuncinane zibe yi-1000 ms kude kumphetho ngamnye webhodi, ngakumbi umda we-interface yebhodi.


6. Ukugcinwa kwamandla kunye ne-high-frequency filter capacitors kufuneka zibekwe kufuphi neesekethe zeyunithi okanye izixhobo ezineenguqu ezinkulu zangoku (ezifana neeterminal zokufaka kunye nokuphuma kwemodyuli yombane, abalandeli kunye nokuhanjiswa) ukunciphisa indawo ye-loop yangoku enkulu. iilophu.

7. Amacandelo okucoca kufuneka abekwe ecaleni ukuze athintele isekethe ehluziweyo ukuba ingaphazamiseki kwakhona.

8. Gcina izixhobo ezomeleleyo zemitha ezifana neekristale, i-crystal oscillators, ii-relays, ukutshintsha izixhobo zamandla, njl.Ngale ndlela, ukuphazamiseka kunokugqithiswa ngokuthe ngqo ngaphandle okanye umsinga unokudibaniswa nentambo ephumayo ukuze ikhuphe ngaphandle.

I-REALTER: Ibhodi yeSekethe eprintiweyo, iPCB Design, INdibano yePCB