Uyilo lwe-laminated ikakhulu luhambelana nemithetho emibini:
1. Uluhlu lwe-wiring nganye kufuneka lube nesalathiso esisondeleyo (amandla okanye umgangatho womhlaba);
2. Umaleko oyintloko osondeleyo kunye nomgangatho womhlaba kufuneka ugcinwe kumgama omncinci ukubonelela nge-coupling capacitance enkulu;
Oku kulandelayo kudwelisa isitaki ukusuka kwibhodi enamaleko amabini ukuya kwibhodi enoluhlu olusibhozo umzekelo ingcaciso:
1. Ibhodi yePCB enecala elinye kunye nebhodi ye-PCB enamacala amabini
Kwiibhodi ezimbini zeebhodi, ngenxa yenani elincinci leengqimba, akusekho ingxaki ye-lamination. Ulawulo lwemitha ye-EMI iqwalaselwa ikakhulu kwiingcingo kunye noyilo;
Ukuhambelana kwe-electromagnetic yeebhodi ezinomgangatho omnye kunye neebhodi eziphindwe kabini ziye zabonakala ngakumbi. Esona sizathu siphambili sesi siganeko kukuba indawo ye-loop yesignali inkulu kakhulu, engavelisi kuphela i-radiation ye-electromagnetic eyomeleleyo, kodwa yenza ukuba isekethe ibonakale kukuphazamiseka kwangaphandle. Ukuphucula ukuhambelana kwe-electromagnetic yesekethe, eyona ndlela ilula kukunciphisa indawo yelophu yesiginali ephambili.
Isiginali engundoqo: Ngokwembono yokuhambelana kwe-electromagnetic, imiqondiso ephambili ibhekisa ikakhulu kwimiqondiso evelisa imitha yemitha eyomeleleyo kunye nemiqondiso enovakalelo kwilizwe langaphandle. Iimpawu ezinokuthi zivelise imitha yemitha eyomeleleyo zidla ngokuba ziimpawu zamaxesha athile, njengemiqondiso ephantsi kweewotshi okanye iidilesi. Iimpawu ezinobuthathaka ekuphazamisekeni zizibonakaliso ze-analog ezinamazinga aphantsi.
Iibhodi ezinomaleko omnye kunye neziphindwe kabini zihlala zisetyenziswa kuyilo lwe-analog ephantsi kwe-frequency engaphantsi kwe-10KHz:
I-1) Iimpawu zamandla kwinqanaba elifanayo zihanjiswa nge-radially, kwaye ubude obupheleleyo bemigca buncitshisiwe;
2) Xa uqhuba amandla kunye neengcingo zomhlaba, kufuneka zisondelelane; beka ucingo olusezantsi ecaleni kocingo lwesitshixo, kwaye olucingo lwasemhlabeni kufuneka lusondele kangangoko kwingcingo yomqondiso. Ngale ndlela, indawo encinci ye-loop yenziwa kwaye uvakalelo lwemodedi yokwahlukana kwemisebe ekuphazamisekeni kwangaphandle kuyancitshiswa. Xa ucingo olusezantsi ludityaniswe ecaleni kocingo lwesignali, i-loop eneyona ndawo incinci yenziwa, kwaye i-signal current izakuthatha ngokuqinisekileyo le loop endaweni yezinye iingcingo zomhlaba.
3) Ukuba ibhodi yesiphaluka esine-double-layer, unokubeka ucingo oluphantsi kunye nomgca wesignali kwelinye icala lebhodi yesekethe, ngokukhawuleza ngaphantsi komgca wesignali, kwaye umgca wokuqala kufuneka ube ngokubanzi ngokusemandleni. Ummandla we-loop owenziwe ngale ndlela ulingana nobukhulu bebhodi yesiphaluka ephindwe ngobude bomgca wesignali.
Iilaminates ezimbini nezine
1. SIG—GND(PWR)－PWR (GND)－SIG;
2. GND－SIG(PWR)－SIG(PWR)－GND;
Kwezi ziyilo zimbini zikhankanyiweyo, ingxaki enokubakho yeyobungqingqwa bebhodi eyi-1.6mm (62mil). Izithuba zomaleko ziya kuba zikhulu kakhulu, ezingathandekiyo kuphela ekulawuleni i-impedance, ukudityaniswa kwe-interlayer kunye nokukhusela; ngokukodwa, isithuba esikhulu phakathi kweenqwelo-moya zomhlaba zamandla kunciphisa i-capacitance yebhodi kwaye ayincedi ukuhluza ingxolo.
Kwiskimu sokuqala, ngokuqhelekileyo sisetyenziswa kwimeko apho kukho ii-chips ezininzi ebhodini. Olu hlobo lwesikimu lunokufumana ukusebenza okungcono kwe-SI, akulunganga kakhulu kwintsebenzo ye-EMI, ikakhulu ngocingo kunye nezinye iinkcukacha zokulawula. Ingqwalasela ephambili: Umaleko womhlaba ubekwe kwindawo yokudibanisa yomgca wesignali kunye nomqondiso we-densest, onenzuzo ukufunxa kunye nokucinezela i-radiation; ukwandisa indawo yebhodi ukubonisa umthetho we-20H.
Ngokubhekiselele kwisisombululo sesibini, ngokuqhelekileyo sisetyenziswa xa ukuxinana kwe-chip ebhodini kuphantsi ngokwaneleyo kwaye kukho indawo eyaneleyo ejikeleze i-chip (beka amandla afunekayo umaleko wobhedu). Kwesi sicwangciso, umaleko wangaphandle wePCB ngumaleko omhlaba, kwaye imigangatho emibini ephakathi yimiqondiso/izaleko zamandla. Unikezelo lwamandla kumaleko wesiginali luhanjiswa ngomgca obanzi, onokuthi uthintele indlela yonikezelo lwamandla ephantsi ngoku, kunye nokuphazamiseka kwendlela yomqondiso we-microstrip nayo iphantsi, kunye nemitha yesignali yangaphakathi inokukhuselwa. umaleko wangaphandle. Ukusuka kwimbono yolawulo lwe-EMI, le yeyona nto ilungileyo ye-4-layer PCB ekhoyo.
Ingqwalasela ephambili: Umgama phakathi kwemigangatho emibini ephakathi yesignali kunye neengqimba zokuxuba amandla kufuneka zandiswe, kwaye isalathiso se-wiring kufuneka sime ngokuthe nkqo ukuphepha i-crosstalk; indawo yebhodi kufuneka ilawulwe ngokufanelekileyo ukubonisa umthetho we-20H; ukuba ufuna ukulawula i-wiring impedance, isisombululo esingentla kufuneka silumke kakhulu ukuhambisa iingcingo Ihlelwe phantsi kwesiqithi sobhedu ukubonelela umbane kunye nokubeka umhlaba. Ukongeza, ubhedu kunikezelo lwamandla okanye umaleko womhlaba kufuneka udityaniswe ngokusemandleni ukuqinisekisa ukuba i-DC kunye ne-low-frequency connectivity.
Isithathu, i-laminate enemigangatho emithandathu
Kuyilo olunoxinzelelo oluphezulu lwe-chip kunye nobuninzi bewotshi ephezulu, uyilo lwebhodi enemigangatho emi-6 kufuneka iqwalaselwe, kwaye indlela yokupakisha iyacetyiswa:
1. SIG—GND－SIG－PWR－GND－SIG;
Ngolu hlobo lwesikimu, olu hlobo lwesikimu se-laminated lunokufumana ingqibelelo yesignali engcono, umaleko wesignali ukufuphi nomgangatho womhlaba, umaleko wamandla kunye nomgangatho womhlaba udityaniswe, ukuxhatshazwa komgca we-wiring nganye kunokulawulwa ngcono, kwaye ezimbini. I-stratum inokufunxa imigca yemagnethi kakuhle. Kwaye xa unikezelo lwamandla kunye nomgangatho womhlaba lugqityiweyo, lunokubonelela ngendlela engcono yokubuya kwinqanaba ngalinye lesignali.
2. GND－SIG－GND－PWR－SIG－GND;
Kulolu hlobo lwesikimu, olu hlobo lwesikimu lufanelekile kuphela kwimeko yokuba ukuxinana kwesixhobo akukho phezulu kakhulu, olu hlobo lwe-lamination lunazo zonke iingenelo ze-lamination ephezulu, kunye nenqwelomoya yomhlaba ophezulu kunye nomgangatho ophantsi ngokulinganayo. epheleleyo, enokusetyenziswa njengomaleko ongcono wokukhusela Ukusebenzisa. Kufuneka kuqatshelwe ukuba uluhlu lwamandla lufanele lusondele kuluhlu olungeyona inxalenye ephambili yecandelo, kuba i-plane yomgangatho ongezantsi iya kugqitywa ngakumbi. Ke ngoko, ukusebenza kwe-EMI kungcono kunesisombululo sokuqala.
Isishwankathelo: Kwiskimu sebhodi yemigangatho emithandathu, umgama phakathi komgangatho wamandla kunye nomgangatho womhlaba kufuneka uncitshiswe ukufumana amandla afanelekileyo kunye nokudibanisa komhlaba. Nangona kunjalo, nangona ubukhulu bebhodi buyi-62mil kwaye isithuba somaleko sincitshisiwe, akukho lula ukulawula isithuba phakathi kombane ongundoqo kunye nomgangatho womhlaba ukuba ube mncinci. Ukuthelekisa iskimu sokuqala kunye neskimu sesibini, iindleko zeskimu sesibini ziya kunyuka kakhulu. Ngoko ke, ngokuqhelekileyo sikhetha ukhetho lokuqala xa sibeka. Xa uyila, landela umthetho we-20H kunye noyilo lomgaqo wesipili.
I-laminates ezine kunye nesibhozo
1. Le ayisiyondlela ilungileyo yokupakisha ngenxa yokungangeni kakuhle kwe-electromagnetic kunye nokuphazamiseka kombane omkhulu. Ulwakhiwo lwayo ngolu hlobo lulandelayo:
1.Isiginali ye-1 yecandelo lendawo, i-microstrip wiring layer
2. Isiginali 2 umaleko wocingo wangaphakathi we-microstrip, umaleko wocingo olungcono (ulwalathiso lwe-X)
3.Umhlaba
4. Umaleko wendlela yomgca wesi-3 we-stripline, umaleko ongcono wendlela (Y direction)
5.Signal 4 stripline routing layer
6.Amandla
7. Isiginali 5 umaleko wocingo we-microstrip wangaphakathi
8.Signal 6 microstrip trace layer
2. Kukwahluka kwendlela yesithathu yokubeka. Ngenxa yokongezwa kwereferensi yereferensi, inokusebenza okungcono kwe-EMI, kwaye i-impedance yeempawu zomaleko wesiginali nganye inokulawulwa kakuhle.
I-1.Isiginali ye-1 yecandelo lecandelo, i-microstrip wiring layer, i-wiring layer
2. Isitrato esisezantsi, isakhono esihle sokufunxa amaza ombane
3. Isiginali ye-2 stripline routing layer, umaleko olungileyo womzila
4. Umaleko wamandla ombane, wenza ukufunxa okugqwesileyo kwe-electromagnetic kunye nomaleko osemhlabeni ongaphantsi kwe-5. Umaleko ophantsi
6.Signal 3 stripline routing layer, umaleko olungileyo wokuhamba
7. Isitrato samandla, esinokuphazamiseka konikezelo lwamandla amakhulu
8.Signal 4 microstrip wiring layer, i-wiring layer elungileyo
3. Eyona ndlela igqwesileyo yokupakisha, ngenxa yokusetyenziswa kweendiza ezininzi zesalathiso zomhlaba, inomthamo we-geomagnetic wokufunxa kakuhle kakhulu.
I-1.Isiginali ye-1 yecandelo lecandelo, i-microstrip wiring layer, i-wiring layer
2. Isitrato esisezantsi, amandla angcono wokufunxa amaza e-electromagnetic
3. Isiginali ye-2 stripline routing layer, umaleko olungileyo womzila
4. Umaleko wamandla ombane, wenza ukufunxa okugqwesileyo kwe-electromagnetic kunye nomaleko wasemhlabeni ongaphantsi kwe-5.
6.Signal 3 stripline routing layer, umaleko olungileyo wokuhamba
7. Isitrato esisezantsi, amandla angcono wokufunxa amaza e-electromagnetic
8.Signal 4 microstrip wiring layer, i-wiring layer elungileyo
Indlela yokukhetha ukuba zingaphi iileya zeebhodi ezisetyenzisiweyo kuyilo kunye nendlela yokupakisha kuxhomekeke kwizinto ezininzi ezifana nenani lothungelwano lweempawu ebhodini, ukuxinana kwesixhobo, ubuninzi bePIN, ubuninzi besignali, ubungakanani bebhodi njalo njalo. Kufuneka siziqwalasele le miba ngendlela ebanzi. Ukufumana uthungelwano oluninzi lweempawu, okukhona uxinaniso lwesixhobo luphezulu, kokukhona uxinano lwePIN luphezulu kunye nobuninzi bezandi zesignali, uyilo lwebhodi yemultilayer kufuneka yamkelwe kangangoko. Ukufumana ukusebenza kakuhle kwe-EMI, kungcono ukuqinisekisa ukuba umaleko wesignali ngamnye unomaleko wereferensi yawo.