Mumapangidwe a Tthe EMC a PCB, chodetsa nkhawa choyamba ndikukhazikitsa kosanjikiza; Zigawo za bolodi zimapangidwa ndimagetsi, wosanjikiza pansi ndi siginolo ya ma siginolo. Pakapangidwe kazinthu za EMC, kuphatikiza pazosankha zamagawo ndi kapangidwe ka dera, kapangidwe kabwino ka PCB ndichinthu chofunikira kwambiri.

The key to the EMC design of PCB is to minimize the backflow area and make the backflow path flow in the direction we designed. Kapangidwe kameneka ndiye maziko a PCB, momwe mungagwirire ntchito yabwino ya kapangidwe ka PCB kuti EMC ikhale yoyenerera?

I. Design malingaliro a PCB wosanjikiza

The core of PCB laminated EMC planning and design is to reasonably plan signal backflow path to minimize the backflow area of signal from the board mirror layer, so as to eliminate or minimize magnetic flux.

Gulu limodzi lokhala ndi ma mirroring

Galasi losanjikiza ndi gawo lathunthu lamiyala yamagetsi yamkuwa (yosanjikiza magetsi, yosanjikiza) yozungulira mzere wosanjikiza mkati mwa PCB. Ntchito zazikulu ndi izi:

(1) Kuchepetsa phokoso lakumabwerera: galasi losanjikiza limatha kupereka njira yotsika yotsatsira mayendedwe osunthira, makamaka pakakhala kutuluka kwakukulu pakachitidwe kogawa mphamvu, gawo la magalasi osanja ndiwowonekera kwambiri.

(2) Kuchepetsa EMI: kukhalapo kwa kalilole wosanjikiza kumachepetsa malo otsekedwa otsekedwa ndi chizindikiritso ndi Reflux ndikuchepetsa EMI;

(3) kuchepetsa crosstalk: thandizani vuto la crosstalk pakati pa mizere yamagetsi pamagetsi othamanga kwambiri, sinthani kutalika kwa mzere wazizindikiro kuchokera pagalasi, mutha kuwongolera mtanda pakati pa mizere yazizindikiro, kutalika kwazing’ono, zing’onozing’ono mtanda;

(4) Kuwongolera kuyimitsidwa kuti muchepetse kuwunika kwa siginecha.

Kusankhidwa kwa kalilole wosanjikiza

(1) Mphamvu zamagetsi komanso ndege yapansi ingagwiritsidwe ntchito ngati ndege yowunikira, ndipo imakhala ndi vuto linalake poteteza waya;

(2) Kunena zowona, ndege yamagetsi ili ndi mawonekedwe amtundu wapamwamba, ndipo pali kusiyana kwakukulu komwe kungachitike ndi mulingo wofotokozera, ndipo kusokonekera kwapafupipafupi pa ndege yamagetsi ndi yayikulu;

(3) Malinga ndi momwe amatetezera, ndege yapansi nthawi zambiri imakhala pansi ndipo imagwiritsidwa ntchito ngati cholozera cha zomwe zatchulidwazo, ndipo mphamvu yake yoteteza ndiyabwino kuposa ya ndege yamphamvu;

(4) Posankha ndege yolozera, ndege yapansi iyenera kukondedwa, ndipo ndege yamagetsi iyenera kusankhidwa yachiwiri

Two, magnetic flux cancellation principle

Malinga ndi kuchuluka kwa a Maxwell, magwiridwe onse amagetsi ndi maginito pakati pamatupi osiyanasiyana kapena mafunde amafalikira kudzera pakatikati pakati pawo, kaya ndi vakuyumu kapena chinthu cholimba. In a PCB, the flux is always propagated in the transmission line. If the rf backflow path is parallel to the corresponding signal path, the flux on the backflow path is in the opposite direction to that on the signal path, then they are superimposed on each other, and the effect of flux cancellation is obtained.

Chikhalidwe cha kuletsa kwa maginito kutulutsa

Chofunika kwambiri pakuchotsa kutuluka ndi kuwongolera njira yobwerera mbendera, monga zikuwonetsedwa pachithunzichi:

Lamulo lamanja lakumanja limalongosola mphamvu yoletsa maginito kutulutsa

Momwe mungagwiritsire ntchito lamanja lamanja pofotokozera maginito otulutsa maginito pomwe gawo lazizindikiro lili pafupi ndi chingwe likufotokozedwa motere:

(1) Pakadutsa pano waya, maginito amapangidwa mozungulira waya, ndipo kuwongolera kwa maginito kumatsimikizidwa ndi lamulo lamanja.

(2) pakakhala awiri oyandikana wina ndi mnzake komanso ofanana ndi waya, monga zikuwonetsedwa pachithunzipa, m’modzi mwa oyendetsa magetsi kuti atulutse, winayo woyendetsa magetsi akuyenda, ngati magetsi akuyenda waya zilipo pakadali pano ndikubwerera kwake kwa mbendera, ndiye kuti mbali ziwirizi ndizofanana, motero maginito awo ndi ofanana, koma mbaliyo ndi yotsutsana,Chifukwa chake amaletsana.

Zitsanzo zisanu, zisanu ndi chimodzi zopanga bolodi

Kwa magawo asanu ndi limodzi, dongosolo 3 limasankhidwa

Kufufuza:

(1) Popeza mzere wosanjikiza uli pafupi ndi ndege yowunikiranso, ndipo S1, S2 ndi S3 ali pafupi ndi ndege yapansi, magwiridwe antchito abwino kwambiri a maginito amakwaniritsidwa. Chifukwa chake, S2 ndiye njira yosankhika, yotsatiridwa ndi S3 ndi S1.

(2) Ndege yamagetsi ili moyandikana ndi ndege ya GND, mtunda wapakati pa ndege ndizochepa kwambiri, ndipo ili ndi mphamvu yoletsa kutulutsa kwa maginito kwambiri komanso mphamvu yamagetsi yotsika mphamvu.

(3) Chopangira magetsi chachikulu ndi nsalu yake yofanana pansi pake pamakhala wosanjikiza 4 ndi 5. Pakakhala makulidwe osanjikiza, mipata pakati pa S2-P iyenera kukulitsidwa ndipo malo pakati pa P-G2 ayenera kuchepetsedwa (mtunda pakati pa wosanjikiza G1-S2 iyenera kuchepetsedwa chimodzimodzi), kuti muchepetse kuyimitsidwa kwa ndege yamagetsi ndi mphamvu yamagetsi pa S2.

Kwa zigawo zisanu ndi chimodzi, njira 4

Kufufuza:

Chiwembu 4 ndi choyenera kwambiri kuposa chiwembu 3 chakomweko, zochepa zofunikira, zomwe zimatha kupereka zingwe zabwino kwambiri za S2.

Zotsatira zoyipa kwambiri za EMC, dongosolo 2

Kufufuza: M’dongosolo ili, S1 ndi S2 zili pafupi, S3 ndi S4 ndizoyandikira, ndipo S3 ndi S4 sizoyandikana ndi ndege yapansi, chifukwa chake maginidwe othamangitsa maginito siabwino.

mapeto

Specific principles of PCB layer design:

(1) Pali ndege yonse yapansi (chishango) pansi pazopangira pamwamba ndikuwotcherera;

(2) Yesetsani kupewa pafupi moyandikana ndi zigawo ziwiri;

(3) Magawo onse azizindikiro ali moyandikana ndi ndege yapansi momwe angathere;

(4) Wiring wosanjikiza wamafupipafupi, kuthamanga kwambiri, wotchi ndi zizindikilo zina zazikulu ziyenera kukhala ndi ndege yoyandikana nayo.