Ujongana njani ne-PCB uphawu lokuwela umgca wesahluli?

Kwinkqubo yoyilo lwePCB, ulwahlulo lwendiza yamandla okanye ulwahlulo lwenqwelomoya ephantsi kuya kukhokelela kwinqwelomoya engaphelelanga. Ngale ndlela, xa umqondiso uhanjiswa, inqwelomoya yayo yereferensi iya kudlula ukusuka kwinqwelomoya yamandla ukuya kwenye inqwelomoya yamandla. Le nto ibizwa ngokuba kukwahlulwahlulwa kobude bomqondiso.

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Umzobo weSchematic of cross-segmentation phenomena
 
Ukwahlulahlula, kuba umqondiso wesantya esisezantsi unokungabi nabudlelwane, kodwa kwisantya esiphezulu senkqubo yomqondiso wedijithali, umqondiso wesantya esiphezulu uthatha indiza yereferensi njengendlela yokubuya, oko kukuthi, indlela yokubuya. Xa i-plane yereferensi ingagqibekanga, iziphumo ezibi ezilandelayo ziya kwenzeka: ukuhlukana kwe-cross-segmentation kungabi yinto efanelekileyo kwiimpawu eziphantsi kwesantya, kodwa kwiinkqubo zesignali zedijithali ezikhawulezayo, izibonakaliso zesantya esiphezulu zithatha indiza yereferensi njengendlela yokubuya, leyo. yi, indlela yokubuya. Xa inqwelo-moya yesalathiso ingagqitywanga, oku kulandelayo kuya kwenzeka:
l Ukungaqhubeki kokuphazamiseka okukhokelela ekubalekeni kocingo;
l Kulula ukwenza i-crosstalk phakathi kwemiqondiso;
l Ibangela ukubonakaliswa phakathi kwemiqondiso;
l Imveliso ye-waveform ilula i-oscillate ngokunyusa indawo ye-loop yangoku kunye ne-inductance ye-loop.
l Ukuphazamiseka kwemitha kwisithuba kuyenyuka kwaye imagnethi esesithubeni ichaphazeleka lula.
l Ukwandisa ithuba lokudibanisa magnetic kunye nezinye iisekethe ebhodini;
l Ukuhla kwamandla ombane aphezulu kwi-loop inductor kwenza umthombo wemitha yendlela eqhelekileyo, eveliswa ngentambo yangaphandle.
 
Ngoko ke, iingcingo zePCB kufuneka zibe kufutshane nenqwelomoya kangangoko kunokwenzeka, kwaye ugweme ukwahlukana. Ukuba kuyimfuneko ukuwela ulwahlulo okanye ayikwazi ukusondela kwinqwelomoya yomhlaba wamandla, le miqathango ivunyelwe kuphela kumgca wesignali yesantya esiphantsi.
 
Ukusetyenzwa kuzo zonke izahlulo kuyilo
Ukuba ulwahlulo olunqamlezayo alunakuphepheka kuyilo lwePCB, ukujongana njani nalo? Kule meko, ulwahlulo kufuneka lulungiswe ukuze lunikeze indlela emfutshane yokubuya yomqondiso. Iindlela zokucubungula eziqhelekileyo ziquka ukongeza i-capacitor yokulungisa kunye nokuwela ibhuloho yocingo.
l I-Stiching Capacitor
I-0402 okanye i-0603 i-ceramic capacitor enomthamo we-0.01uF okanye i-0.1uF idla ngokubekwa kwicandelo lomnqamlezo womqondiso. Ukuba indawo iyavuma, ezinye iicapacitors ezininzi zingongezwa.
Ngexesha elifanayo, zama ukuqinisekisa ukuba ucingo lwesignali lungaphakathi kwi-200mil yokuthunga i-capacitance, kwaye incinci umgama, ungcono; Uthungelwano kwiziphelo zombini ze-capacitor ngokulandelanayo zihambelana nothungelwano lwendiza yereferensi apho iimpawu zidlula khona. Jonga amanethiwekhi axhunyiwe kuzo zombini iziphelo ze-capacitor kumzobo ongezantsi. Iinethiwekhi ezimbini ezahlukeneyo eziphawulwe ngemibala emibini zezi:
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lIbhulorho phezu kocingo
Kuqhelekile ukuba "inkqubo yomhlaba" umqondiso unqamleze ulwahlulo kumaleko wesignali, kwaye inokuba yeminye imigca yesiginali yenethiwekhi, umgca "womhlaba" ushinyene kangangoko kunokwenzeka.

 

 

Isantya esiphezulu sezakhono ze-wiring zesignali
a)uqhagamshelo lwamaleyile amaninzi
Isantya esiphezulu somzila wesiphaluka sihlala sinokuhlanganiswa okuphezulu, ukuxinana kwe-wiring ephezulu, ukusebenzisa ibhodi ye-multilayer akuyimfuneko kuphela kwi-wiring, kodwa kunye neendlela ezisebenzayo zokunciphisa ukuphazamiseka.
 
Ukukhetha okunengqiqo kweeleyile kunokunciphisa kakhulu ubungakanani bebhodi yokushicilela, kunokusebenzisa ngokupheleleyo umaleko ophakathi ukuseta ikhaka, kunokuqonda kakuhle ukusekwa okukufutshane, kunokunciphisa ngokufanelekileyo i-parasitic inductance, inokunciphisa ngokufanelekileyo ubude bokuhanjiswa komqondiso. , inokunciphisa kakhulu ukuphazamiseka komnqamlezo phakathi kwemiqondiso, njl.
b)Okukhona igobile kancinci ilothe, kokukhona kungcono
Ukugoba okungaphantsi kwesikhokelo phakathi kwezikhonkwane zezixhobo zesekethe ezinesantya esiphezulu, kungcono.
I-wiring lead ye-high-speed signal routing circuit ithatha umgca othe ngqo opheleleyo kwaye idinga ukujika, enokusetyenziswa njenge-45 ° polyline okanye i-arc turning. Le mfuneko isetyenziselwa kuphela ukuphucula amandla okubamba i-foil yensimbi kwisiphaluka esisezantsi.
Kwiisekethe zesantya esiphezulu, ukuhlangabezana nale mfuneko kunokunciphisa ukuhanjiswa kunye nokudityaniswa kweempawu zesantya esiphezulu, kunye nokunciphisa i-radiation kunye nokubonakaliswa kwezibonakaliso.
c)Okukhona ukhokelo olufutshane, lungcono
Imfutshane isikhokelo phakathi kwezikhonkwane zesixhobo sesekethe yokuhambisa umqondiso wesantya esiphezulu, kungcono.
Ixesha elide elikhokelayo, i-inductance esasazwayo kunye nexabiso le-capacitance, eliya kuba nefuthe elikhulu kwi-high-frequency signal passing yenkqubo, kodwa iphinde iguqule i-impedance yeempawu zesekethe, okubangela ukubonakaliswa kunye nokuguqulwa kwenkqubo.
d)Ukutshintshana okuncinci phakathi kweeleya zelothe, kungcono
Ukutshintshwa kwe-interlayer encinci phakathi kwezikhonkwane zezixhobo zesekethe ezinesantya esiphezulu, kungcono.
Okubizwa ngokuba "i-interlayer encinci ye-lead alternations, ngcono" ithetha ukuba imingxuma embalwa esetyenzisiweyo ekudibaneni kwamacandelo, ingcono. Kulinganiswe ukuba umngxuma omnye unokuzisa malunga ne-0.5pf ye-capacitance esasazwayo, okubangela ukwanda okukhulu kokulibaziseka kwesekethe, ukunciphisa inani lemingxuma kunokuphucula kakhulu isantya.
e)Qaphela uphazamiseko olunqamlezayo olunxuseneyo
I-high-speed signal wiring kufuneka inikele ingqalelo "kwisiphazamiso esinqamlezileyo" esiveliswe ngumgca wesignali umgama omfutshane we-wiring ye-parallel. Ukuba ukusabalalisa okuhambelanayo akukwazi ukuphetshwa, indawo enkulu "yomhlaba" inokulungiswa kwicala elichasene nomgca wesignali ehambelanayo ukunciphisa kakhulu ukuphazamiseka.
f)Gwema amasebe kunye neziphunzi
Iingcingo zomqondiso wesantya esiphezulu kufuneka ziphephe i-branching okanye ukwenza iStub.
Iziphunzi zinempembelelo enkulu kwi-impedance kwaye zingabangela ukubonakaliswa komqondiso kunye nokugqithiswa, ngoko ke kufuneka siphephe izikhondo kunye namasebe kuyilo.
I-wiring ye-Daisy chain iya kunciphisa impembelelo kwisignali.
g)Imigca yemiqondiso iya kumgangatho ongaphakathi kangangoko kunokwenzeka
Umgca wophawu oluphezulu oluhamba phezu komhlaba kulula ukuvelisa imitha yemitha yombane enkulu, kwaye kulula nokuphazanyiswa yimitha yemitha yombane yangaphandle okanye izinto.
Umgca wesignali we-frequency ephezulu uhanjiswa phakathi konikezelo lwamandla kunye nocingo olusemhlabeni, ngokufunxwa kwamaza ombane wombane ngobonelelo lwamandla kunye nomaleko ongezantsi, ukukhutshwa kwemitha kuya kuncitshiswa kakhulu.