Taw qhia rau cov ntsiab lus paub txog EMI electromagnetic shielding

Raws li tus kws tshaj lij hluav taws xob, suab nrov thiab hluav taws xob muaj nyob txhua qhov chaw, thiab ua tus tsim hluav taws xob, yuav tsum muaj kev paub txog EMI electromagnetic shielding, thiab cov kev paub thiab kev daws teeb meem no yuav raug siv dav los txhim kho cov khoom siv los ntawm kev cuam tshuam sab nraud ntawm electromagnetic.

Maxwell qhov sib npaug qhia tau hais tias thaum twg tam sim no ntws los ntawm tus neeg xyuas pib, ib qho chaw sib nqus raug tsim, thiab qhov chaw sib nqus tsim hluav taws xob. Cov khoom hluav taws xob ntawm hluav taws xob thiab hlau nplaum yog hu ua radiative emissions. Cov hluav taws xob hluav taws xob no yuav ua rau muaj teeb meem hauv Circuit Court lossis tag nrho cov ntawv luam tawm Circuit Board (PCB). Nyob rau hauv ib qho zoo tagnrho Circuit Court, lub teeb liab tawm los ntawm Circuit Court nws tus kheej tsuas yog suav nrog tam sim no thiab voltage, tab sis nyob rau hauv lub ntiaj teb no tiag tiag, suab nrov yog ib qho teeb meem inescapable. Qhov no tshwm sim thaum muaj kev cuam tshuam rau lub teeb liab Circuit Court. Vim tias qhov xwm txheej ntawm electromagnetic signals, lub xub ntiag ntawm lub suab nrov tsis tuaj yeem zam, tab sis nws cov teebmeem tuaj yeem txo qis heev. Nws yuav tsum raug sau tseg tias lub cuab yeej yuav tsis cuam tshuam los ntawm lwm yam khoom siv thaum lub sijhawm ua haujlwm, ib yam li lub cuab yeej yuav tsis cuam tshuam los ntawm lwm yam khoom siv, electromagnetic susceptibility yog lub peev xwm ntawm lub tshuab hluav taws xob kom nyob twj ywm thaum muaj kev cuam tshuam. Qhov no rhiab heev yuav nyob ntawm seb lub suab nrov, thiab cov kev siv sib txawv, xws li tsheb, kev kho mob, tub rog, thiab lwm yam, muaj ntau qib sib nqus sib nqus. Txhua lub voj voog, cov cuab yeej, lossis cov kab ke yuav tsum tau tsim kom zoo kom txo qis cov hluav taws xob tsawg kom nws tsuas yog nkag siab rau qib siab ntawm electromagnetic teb.

EMC ntawv pov thawj

Electromagnetic Compatibility (EMC) daim ntawv pov thawj yog ib qho yuav tsum tau ua rau txhua yam khoom mus rau hauv kev lag luam, thiab txhua yam khoom yuav tsum xeem dhau EMC kuaj kom paub tseeb tias nws raug teeb tsa yam tsis muaj kev cuam tshuam rau lwm yam khoom siv (xws li kev kuaj hluav taws xob) thiab txawm tias muaj lwm lub tshuab nyob ib puag ncig. (piv txwv li, rhiab heev kuaj).

Feem ntau, cov khoom siv hluav taws xob muaj nyob hauv cov ntaub thaiv npog, thiab cov ntaub thaiv hlau yog qhov zoo ntawm kev txwv electromagnetic shielding, tab sis kuj tsis zoo. Qhov los yog qhov qhib tshwm ntawm qhov sib txuas ntawm PCB thiab cov vaj tsev, thiab cov khoom siv hluav taws xob tuaj yeem dhau los ntawm lawv. Hauv luv luv, EMI shielding yog los npog cov qhov lossis cov qhov. Tsis tas li ntawd, muaj ib qho teeb meem tshwm sim nyob rau hauv ntau yam khoom tsim: EMC ntawv pov thawj tsuas yog txiav txim siab nyob rau theem kawg ntawm lub voj voog tsim, nyob rau hauv cov ntaub ntawv tag nrho cov tsim yog khov nyob rau theem no, thiab EMC engineers tsis muaj chaw los hloov cov khoom tsim. . daws teeb meem txog electromagnetic. Yog li ntawd, tag nrho cov cuab yeej thiab ecology, tsis tas yuav hloov kho PCB dua, ua lub luag haujlwm tseem ceeb hauv EMI shielding. Miniaturization thiab kev ua haujlwm siab tau ib txwm yog lub ntiaj teb sib txawv hauv kev tsim cov khoom siv hluav taws xob, thiab PCBs muaj lub sijhawm luv thiab luv luv thiab nrawm dua thiab nrawm dua digital circuits. Lub sij hawm luv dua, qhov bandwidth loj dua, thiab tib lub sij hawm me dua qhov wavelength. Qee qhov teeb meem tshwm sim thaum lub wavelengths hauv Circuit Court yog piv rau lub cev qhov ntev ntawm PCB. Yog tias cov wavelengths me me, lawv tuaj yeem ncav cuag sab nraud thiab ua rau muaj kev cuam tshuam nrog lwm yam khoom siv. Cov qhov qhib no tuaj yeem raug kaw nrog EMI shielding (uas yog, nrog cov khoom sib nqus uas pab npog cov qhov me me thiab txhim kho Faraday tawb nyhuv ntawm cov khoom siv kaw lus).

Xam EMI tiv thaiv kev ua tau zoo thiab qhov tob ntawm daim tawv nqaij

suav tsis txheeb EMI shields tuaj nyob rau hauv cov ntaub ntawv sib txawv thiab cov duab, tab sis feem ntau lub hom phiaj yog kom kaw cov electromagnetic teb. Lub shielding caij ua raws li ib tug barrier tiv thaiv electromagnetic hluav taws xob, qhov tseeb, cov txheej txheem ntawm no shielding txoj kev muaj ib tug loj attenuation, uas yuav nyob ntawm seb lub electromagnetic yoj thiab cov khoom ntawm shielding caij. Thaum nthwv dej tsoo cov ntaub thaiv npog, ob lub nthwv dej tshiab raug tsim tawm, cuam tshuam thiab xa mus. Yog li ntawd, lub zog ntawm qhov xwm txheej nthwv dej yuav muab faib ua ob lub nthwv dej no. Cov khoom sib kis yog qhov tseem ceeb ntawm cov khoom siv, thiab cov nthwv dej yuav dhau los ntawm cov ntaub thaiv npog mus rau sab nraud. Kev ua tau zoo ntawm cov ntaub thaiv npog yuav txiav txim siab nws lub peev xwm los txo qis cov khoom siv no. Qhov tob ntawm daim tawv nqaij yog qhov kev ncua deb ntawm nthwv dej tuaj yeem taug kev ua ntej nws qhov amplitude txo qis mus rau 1 / e, ib qho kev ntsuas uas nyob ntawm cov khoom permeability, zaus thiab resistivity, thiab tuaj yeem kwv yees los ntawm cov lus hauv qab no:

Faj seeb: σ sawv cev rau conductivity, μ sawv cev rau permeability, F sawv cev rau zaus

Lub hom phiaj ntawm kev siv cov ntaub thaiv npog yog txhawm rau txo qhov amplitude ntawm nthwv dej tom qab nws dhau lawm. Yog li ntawd, nws yog ib qho tseem ceeb heev uas yuav tsum xaiv cov khoom tsim nyog thiab nws cov thickness t kom ntseeg tau tias tag nrho cov frequencies ntawm lub system yog attenuated. Cov ntaub thaiv npog ua tau zoo npaum li cas ntawm txoj haujlwm no yog nyob ntawm kev tiv thaiv kev ua tau zoo (SE) raws li hauv qab no:

Lus Cim: Thawj lub sij hawm sawv cev rau kev xav tsis zoo, thiab lub sij hawm thib ob sawv cev rau qhov tsis txaus.

Hom EMI shielding Hom EMI shielding feem ntau nyob ntawm seb hom khoom, cov khoom siv hluav taws xob thiab ib puag ncig. Cov ntaub thaiv npog EMI feem ntau yog raws li hauv qab no: - EMI gaskets - EMI shielding tapes - hlau clips - shielded txee EMI gaskets EMI gaskets yog siv los npog tsis zoo tab sis uas twb muaj lawm micro-qhov nruab nrab ntawm ob lub tshuab. Txhim kho kev sib txuas hauv av. Lawv muaj cov nplaum nplaum thiab ntau qhov profile kom lawv tuaj yeem yooj yim haum rau ntau hom kev sib koom ua ke.

EMI Shielding Daim kab xev EMC daim kab xev yog thawj qhov kev xaiv thaum koj xav kom paub tseeb tias tag nrho cov microvias raug them, tab sis tsis muaj ntau qhov chaw ntsug rau kev xaiv xws li EMI gaskets. Cov kab xev no muaj cov khoom siv hluav taws xob zoo heev (xws li npib tsib xee lossis tooj liab) nyob rau sab saum toj thiab nplaum rau sab nraud.

Hlau clips Txhua yam cuab yeej xav tau ib qho luv luv, dav, thiab ncaj-los ntawm hauv av xaim, thiab yog tias qhov kev sib txuas no tsis ua tiav, cov monopoles tsis xav tau yuav tsim, uas yuav tsim hluav taws xob electromagnetic teb. Hlau clips txhim kho qhov kev sib txuas no thiab ntxiv dag zog rau kev sib txuas ntawm cov neeg kho tshuab. Shielded Cabinets Rau cov kev cuam tshuam xws li CPUs, ICs cia, thiab xov tooj cua zaus (RF) qib, nws yog qhov kev xaiv zoo tshaj plaws los siv cov khoom siv tiv thaiv rau tus neeg tiv thaiv ntawm PCB txheej.

Xaus Tag nrho cov circuits emit electromagnetic radiation thiab yog yooj yim radiated los ntawm lwm yam circuits. Tau txais cov ntawv pov thawj xav tau los coj koj cov khoom lag luam tuaj yeem yog qhov kev sim ua rau mob. Ntau hom thiab hom kev tiv thaiv EMI yog qhov tseem ceeb los daws cov teeb meem EMI.