PCB Ukuqokelela izinto kubalulekile ekumiseleni ukusebenza kweemveliso ze-EMC. Ukubeka okuhle kunokuba luncedo kakhulu ekunciphiseni ukusasazeka kwemitha kwi-PCB loop (ukungafani kwemowudi yokwahluka), nakwizintambo ezixhumeke ebhodini (ukukhutshwa kwendlela eqhelekileyo).

Kwelinye icala, i-cascade embi inokuyonyusa kakhulu imitha yazo zombini ezi ndlela. Izinto ezine zibalulekile ekuqwalaselweni kwepakethi yokuqokelela:

1. Inani lamanqanaba;

2. Inani nohlobo lweendlela ezisetyenzisiweyo (amandla kunye / okanye umhlaba);

3. Ukulandelelana okanye ulandelelwano lweengqimba;

Isithuba esiphakathi kwamanqanaba.

Ngokwesiqhelo kuphela linani lamanqanaba aqwalaselwayo. Kwiimeko ezininzi, ezinye izinto ezintathu zibaluleke ngokulinganayo, kwaye eyesine ngamanye amaxesha ayaziwa nakweyila yePCB. Xa umisela inani leelayile, qwalasela oku kulandelayo:

1. Ubungakanani besignali kunye neendleko zokubiya;

2. Rhoqo;

3. Ngaba imveliso kufuneka ihlangabezane neemfuno zokumiliselwa zeKlasi A okanye iBakala B?

4. I-PCB ikwizindlu ezikhuselweyo okanye ezingakhuselwanga;

5. Ubungcali bobunjineli be-EMC beqela loyilo.

Ngokwesiqhelo kuphela kwikota yokuqala. Ewe zonke izinto zazibalulekile kwaye kufuneka ziqwalaselwe ngokulinganayo. Le nto yokugqibela ibaluleke kakhulu kwaye ayifanelanga ukungahoywa ukuba uyilo olufanelekileyo luya kufezekiswa ngexabiso elincinci lexesha kunye neendleko.

Iplate ye-multilayer isebenzisa umhlaba kunye / okanye inqwelomoya yamandla ibonelela ngonciphiso olukhulu ekuphumeni kwemitha xa kuthelekiswa nembasa emibini. Umgaqo oqhelekileyo wesithupha osetyenzisiweyo kukuba isitya esine-ply sivelisa i-15dB engaphantsi kwemitha kunepleyiti ezimbini, zonke ezinye izinto ziyalingana. Ibhodi enomgangatho othe tyaba ibhetele kakhulu kunebhodi engenamhlaba uthe tyaba ngezi zizathu zilandelayo:

1. Bavumela imiqondiso ukuba ihanjiswe njengemigca ye-microstrip (okanye imigca yeribhoni). Ezi zakhiwo zilawulwa yimizila yokuhambisa i-impedance ngemitha encinci kakhulu kunentambo engacwangciswanga esetyenziswe kwiibhodi ezingqimba ezimbini;

2. Inqwelomoya yomhlaba inciphisa ngokubonakalayo impedance yomhlaba (kwaye ke yingxolo yomhlaba).

Nangona iipleyiti ezimbini zisetyenziswe ngempumelelo kwiindawo ezingabiyelwanga ze-20-25mhz, la matyala ahlukile ngaphandle komgaqo. Ngaphezulu malunga ne-10-15mhz, iiphaneli ze-multilayer kufuneka ziqwalaselwe.

Kukho iinjongo ezintlanu ekufuneka uzame ukufikelela kuzo xa usebenzisa ibhodi ye-multilayer. Bazi:

1. Umaleko wophawu kufuneka usoloko ukufutshane nenqwelomoya;

2. Umaleko wophawu kufuneka uhlanganiswe ngokuqinileyo (kufutshane ne) kwindiza yayo ekufutshane;

3, inqwelomoya kunye nenqwelomoya yomhlaba kufuneka zidityaniswe ngokusondeleyo;

4, umqondiso wesantya esiphezulu kufuneka ungcwatywe emgceni phakathi kweenqwelomoya ezimbini, inqwelomoya inokudlala indima ekhuselayo, kwaye inokucinezela ukusasazeka kwemitha yomgca oprintwe ngesantya esiphezulu;

5. Iiplani zokumisa ezininzi zinamathuba amaninzi kuba ziya kunciphisa isiseko (isalathiso seenqwelomoya) impedance yebhodi kunye nokunciphisa imitha eqhelekileyo.

Ngokubanzi, sijamelene nokukhetha phakathi komqondiso / wokudibanisa ukusondela kwenqwelomoya (Injongo 2) kunye namandla / ukuhlangana kwenqwelomoya kufutshane (injongo 3). Ngobuchule obuqhelekileyo bokwakha bePCB, iplate capacitance ethe tyaba phakathi konikezelo lwamandla elikufutshane kunye nenqwelomoya yomhlaba ayonelanga ukubonelela ngokudibanisa ngokwaneleyo ngaphantsi kwe-500 MHz.

Ke ngoko, ukudibanisa kufuneka kulungiswe ngezinye iindlela, kwaye kufanelekile ukuba sikhethe ukudibanisa okuqinileyo phakathi komqondiso kunye nenqwelomoya yangoku. Izinto eziluncedo zokudityaniswa okuqinileyo phakathi komaleko womqondiso kunye nenqwelomoya yangoku yokubuyela iya kuba ngaphezulu kokungalunganga okubangelwe kukulahleka okuncinci komthamo phakathi kweenqwelomoya.

Amacwecwe asibhozo lelona nani lisezantsi lezinto ezinokusetyenziselwa ukufezekisa zontlanu ezi njongo. Ezinye zezi njongo kuya kufuneka zonakaliswe kwiibhodi ezine kunye neebhodi ezintandathu. Ngaphantsi kwezi meko, kuya kufuneka unqume ukuba zeziphi iinjongo ezibaluleke kakhulu kuyilo olwenziweyo.

Lo mhlathi ungasentla akufuneki utolikwe ukuba uthetha ukuba awungekhe wenze uyilo lwe-EMC elungileyo kwibhodi enamanqanaba amane okanye amathandathu, njengoko unako. Ibonisa nje ukuba ayizizo zonke iinjongo ezinokufezekiswa ngaxeshanye kwaye uhlobo oluthile lokulalanisa luyafuneka.

Kuba zonke iinjongo ze-EMC ezinqwenelekayo zinokufezekiswa ngamanqanaba asibhozo, akukho sizathu sokusebenzisa ngaphezulu kweebhozo ezisibhozo ngaphandle kokufumana umgama owongezelelweyo wendlela.

Ukusuka kwindawo yoomatshini yokujonga, enye injongo efanelekileyo kukwenza icandelo elinqamlezayo lebhodi yePCB ilingane (okanye ilungelelanise) ukuthintela ukugoba.

Umzekelo, kwibhodi enemigangatho esibhozo, ukuba umaleko wesibini yinqwelomoya, umaleko wesixhenxe kufuneka ube yindiza.

Ke ngoko, lonke ulungiselelo olwenziweyo apha lusebenzisa ulungelelwaniso okanye ulungelelwaniso lwezakhiwo. Ukuba izinto ezingenakulinganiswa okanye ezingalinganiyo ziyavunyelwa, kunokwenzeka ukwakha ezinye iinkqubo zecascading.

Umaleko webhodi

Eyona nto ixhaphakileyo yolwakhiwo lwamacwecwe amane iboniswa kuMzobo 1 (inqwelomoya kunye nenqwelomoya yomhlaba ziyatshintshana). Inezintlu ezine ezilinganayo ezibekwe ngaphakathi kunye nenqwelomoya yamandla yangaphakathi kunye nenqwelomoya yomhlaba. Ezi zahlulo zimbini zeentambo zangaphandle zihlala zinezikhombisi ze-orthogonal.

Nangona olu lwakhiwo lungcono kuneepaneli eziphindwe kabini, inezinto ezithile ezinqwenelekayo.

Kuluhlu lweethagethi kwiCandelo 1, le mfumba yanelisa kuphela ithagethi (1). Ukuba iileya zahlulwe ngokulinganayo, kukho umsantsa omkhulu phakathi komaleko wesiginali kunye nenqwelo moya ebuyayo yangoku. Kukho umsantsa omkhulu phakathi kwendiza yamandla kunye nenqwelomoya yomhlaba.

Kwibhodi enezikhuselo ezine, asinakho ukuzilungisa zombini ezi mpazamo ngaxeshanye, ke kufuneka sithathe isigqibo sokuba yeyiphi eyona ibalulekileyo kuthi.

Njengoko bekutshiwo ngaphambili, amandla okudlala phakathi konikezelo lwamandla olusondeleyo kunye nenqwelomoya yomhlaba ayonelanga ukubonelela ngokudibanisa ngokwaneleyo kusetyenziswa ubuchwephesha bokuvelisa bePCB.

Ukudibanisa kufuneka kuphathwe ngezinye iindlela, kwaye kuya kufuneka sikhethe ukudibana okuqinileyo phakathi komqondiso kunye nenqwelomoya ebuyayo yangoku. Izibonelelo zokudibanisa ngokuqinileyo phakathi komaleko wesiginali kunye nenqwelomoya yangoku yokubuyela iya kuba ngaphezulu kwezithintelo zelahleko encinci yomthamo wabadlali.

Ke ngoko, eyona ndlela ilula yokuphucula ukusebenza kwe-EMC yesingqimba esine-layer kukuzisa umaleko womqondiso kufutshane nenqwelomoya kangangoko. 10mil), kwaye isebenzisa isiseko esikhulu se-dielectric phakathi komthombo wamandla kunye nenqwelomoya yomhlaba (> 40mil), njengoko kubonisiwe kumzobo 2.

Oku kunezibonelelo ezintathu kunye neziphene ezimbalwa. Indawo yeluphu yomqondiso incinci, ngenxa yoko umahluko kwimowudi yokwahluka kwemitha yenziwe. Kwimeko yexesha le-5mil phakathi kwesangqa sentsimbi kunye nocingo lwenqwelomoya, ukunciphisa i-10dB yelitha okanye nangaphezulu kunokufezekiswa kuthelekiswa nolwakhiwo olwahlulwe ngokulinganayo.

Okwesibini, ukudityaniswa okuqinisiweyo kweentambo zombane emhlabeni kunciphisa ukunganyanzeliswa kwesicwangciso (inductance), ngaloo ndlela kuncitshiswa imitha eqhelekileyo yendlela yentambo eqhagamshelwe ebhodini.

Okwesithathu, ukudityaniswa kokuqiniswa kweentambo kwinqwelomoya kuya kunciphisa i-crosstalk phakathi kweentambo. Ukwahlulahlulwa kwentambo okungagungqiyo, i-crosstalk ilingana nesikwere sokuphakama kwentambo. Le yenye yezona ndlela zilula, ezingabizi kakhulu, kwaye iindlela ezingakhathalelwanga zokunciphisa imitha evela kwi-PCB enemigangatho emine.

Ngolu lwakhiwo lwe-cascade, sanelisa zombini iinjongo (1) kunye (2).

Ngawaphi amanye amathuba anokubakho kulungelelwaniso olunemigangatho emine? Ewe, singasebenzisa isakhelo esingaqhelekanga, oko kukuthi, ukutshintsha umaleko wesiginali kunye nophahla lwenqwelomoya kuMzobo 2 ukuvelisa i-Cascade eboniswe kumzobo 3A.

Olona ncedo luphambili lolu lamination kukuba inqwelo moya engaphandle inikezela ngokhuseleko kwindlela yomqondiso kulungelelwaniso lwangaphakathi. Ukungancedi kukuba inqwelomoya yomhlaba inokusikwa kakhulu ziipads zecandelo loxinano oluphezulu kwi-PCB. Oku kunokuncitshiswa ukuya kuthi ga kwinqanaba elithile ngokubuyisela umva inqwelo moya, ukubeka inqwelo moya yamandla kwicala lezinto, kunye nokubeka inqwelomoya emhlabeni kwelinye icala lebhodi.

Okwesibini, abanye abantu abayithandi into yokuba nenqwelomoya enamandla, kwaye okwesithathu, ukungcwatywa komaleko kwenza kube nzima ukuphinda uyisebenzise ibhodi. Ikhasino iyanelisa injongo (1), (2), kwaye iyanelisa injongo (4).

Ezimbini kwezi ngxaki zintathu zinokuncitshiswa yicascade njengoko kubonisiwe kumzobo 3B, apho iinqwelomoya ezimbini zangaphandle ziziinqwelomoya kwaye unikezelo lwamandla luhanjiswa kwiplanethi yomqondiso njengocingo.Unikezelo lwamandla luya kugqitywa raster kusetyenziswa umkhondo obanzi kumaleko womqondiso.

Izibonelelo ezibini ezongezelelekileyo zala macwecwe zezi:

(1) Iiplanethi ezimbini zomhlaba zibonelela ngesithintelo esisezantsi somhlaba, ngaloo ndlela kuncitshiswa imitha yeendlela eziqhelekileyo;

(2) Iiplanethi ezimbini zomhlaba zinokuthungwa kunye kumda wepleyiti ukutywina yonke imikhondo yomqondiso kwikheji yeFaraday.

Ukusuka kwindawo yokujonga ye-EMC, olu luhlu, ukuba lwenziwe kakuhle, lunokuba lolona lubeko luhle lwe-PCB enemigangatho emine. Ngoku sifezekise iinjongo (1), (2), (4) kunye (5) nebhodi enye enemigangatho emine.

Umzobo 4 ubonakalisa into yesine enokwenzeka, ayisiyiyo eqhelekileyo, kodwa inokwenza kakuhle. Oku kuyafana noMzobo 2, kodwa inqwelomoya yomhlaba isetyenziswa endaweni yenqwelomoya, kwaye umbane usebenza njengomkhondo kumaleko wesiginali wentambo.

Le Cascade yoyisa ingxaki esele iphinde ikhankanyiwe kwaye ikwabonelela ngomhlaba ophantsi ngenxa yeenqwelomoya ezimbini zomhlaba. Nangona kunjalo, ezi moya aziboneleli nakukhusela. Oluqwalaselo luyanelisa iinjongo (1), (2), kunye (5), kodwa alonelisi iinjongo (3) okanye (4).

Ke, njengoko ubona ukuba kukho iindlela ezingaphezulu zokubeka umaleko omane kunokuba ungacinga ekuqaleni, kwaye kunokwenzeka ukuba ufezekise iinjongo zethu ezintlanu ngee-PCBS ezingqimba ezine. Ukusuka kwindawo yokujonga ye-EMC, ukubekwa kwamanani 2, 3b, kunye no-4 konke kusebenza kakuhle.

Ibhodi e-6 yomaleko

Uninzi lweebhodi ezingqimba ezintandathu ziqulathe umaleko wokubamba iintambo ezine kunye neepleyiti ezimbini zenqwelomoya, kwaye iibhodi ezingqimba ezintandathu ngokubanzi ziphakamile kwiibhodi ezingqimba ezine ngokwembono ye-EMC.

Umzobo 5 ubonakalisa isakhiwo esilahlayo esingenakusetyenziswa kwibhodi enemaleko emithandathu.

Ezi nqwelo moya aziboneleli ngokhuseleko kumaleko ophawu, kwaye iiseti ezimbini zomqondiso (1 no-6) azikho kufutshane nenqwelomoya. Olu lungiselelo lusebenza kuphela ukuba yonke imiqondiso yokuhamba rhoqo ihanjiswe kumanqanaba 2 kunye no-5, kwaye kuphela imiqondiso ephantsi kakhulu, okanye okungcono okwangoku, akukho zingcingo zomqondiso konke (iipads ze-solder) zihanjiswa kumanqanaba 1 no-6.

Ukuba isetyenzisiwe, nayiphi na indawo engasetyenziswanga kumigangatho 1 no-6 kufuneka yenziwe nge-viAS ize iqhotyoshelwe kumgangatho ophambili kwiindawo ezininzi.

Oluqwalaselo lwanelisa kuphela enye yeenjongo zethu zokuqala (iNjongo 3).

Ngamaleko amathandathu akhoyo, umgaqo wokubonelela ngamanqanaba amabini angcwatyelwe imiqondiso yesantya esiphezulu (njengoko kubonisiwe kumfanekiso 3) uphunyezwa ngokulula, njengoko kubonisiwe kumzobo 6. Oluqwalaselo lukwabonelela ngemigangatho emibini yomqondiso weempawu ezinesantya esisezantsi.

Esi sesona sixhobo sixhaphakileyo sixatyanisiweyo kwaye sinokusebenza kakuhle ekulawuleni ukukhutshwa kombane xa kwenziwe kakuhle. Oluqwalaselo luyanelisa iinjongo 1,2,4, kodwa hayi injongo 3,5. Eyona nto iphambili kukuzahlulahlula amandla omoya kunye nenqwelomoya yomhlaba.

Ngenxa yokwahlulwa, akukho kuninzi kokudibana phakathi kwenqwelomoya kunye nenqwelomoya yasemhlabeni, ke uyilo oluhle lokudibanisa kufuneka lwenziwe ukumelana nale meko. Ngolwazi oluthe kratya malunga nokudityaniswa kwezinto, jonga iingcebiso zethu zokucutha izixhobo.

Isakhiwo esiphantse silingane, siziphathe kakuhle, sinee-laminated structure sibonakalisiwe kwi-Figure 7.

I-H1 imele umda wendlela ethe tyaba yomqondiso 1, i-V1 imele umaleko wendlela ethe nkqo yomqondiso 1, H2 kunye ne-V2 imele intsingiselo efanayo yesiginali 2, kwaye uncedo lolu lwakhiwo kukuba imiqondiso yokuhamba ngomgaqo osoloko ubhekisa kwindiza enye.

Ukuqonda ukuba kutheni le nto ibalulekile, jonga icandelo leenqwelomoya zokuya kwisalathiso kwiCandelo 6. Ukungancedi kukuba umaleko 1 kunye nophawu lwe-6 azikhuselwanga.

Ke ngoko, umaleko wophawu kufuneka usondele kakhulu kwinqwelomoya ekufutshane nayo kwaye kufuneka kusetyenziswe umaleko ophakathi osisityebhe ukwenza ubungakanani beplate efunekayo. Isithuba esivaliweyo se-0.060 ye-intshi esitalatweni esinobubanzi kusenokwenzeka ukuba sibe yi-0.005 “/ 0.005” / 0.040 “/ 0.005” / 0.005 “/ 0.005”. Olu lwakhiwo lwanelisa iiNjongo 1 no-2, kodwa hayi iinjongo 3, 4 okanye 5.

Enye ipleyiti enemigangatho emithandathu enentsebenzo ebalaseleyo ibonisiwe kuMzobo 8. Inika imiqondiso emibini yokungcwatywa komqondiso kunye namandla asondeleyo kunye neenqwelomoya zomhlaba ukuhlangabezana nazo zonke iinjongo ezintlanu. Nangona kunjalo, eyona nto iphambili kuye kukuba inamacandelo amabini eentambo, ngenxa yoko ayisetyenziswa rhoqo.

Amacwecwe amathandathu alula kulula ukufumana ukuhambelana okuhle kwe-electromagnetic kuneepleyiti ezine zomaleko. Sikwanalo nolungelelwaniso lweendlela ezine zokuhambisa umda endaweni yokulinganiselwa kubini.

Njengakwimeko yebhodi yesekethe enemigangatho emine, i-PCB enemigangatho emithandathu yahlangabezana neenjongo zethu ezintlanu. Zonke iinjongo ezintlanu zinokufezekiswa ukuba sizilinganisela kumanqanaba amabini okuhambisa umqondiso. Ulwakhiwo kuMzobo 6, Umzobo 7, kunye noMzobo 8 zonke zisebenza kakuhle ngokwembono ye-EMC.