Izixhobo zemveli zokulungisa ingxaki PCB zibandakanya: i-oscilloscope ye-time domain, i-TDR (i-time domain reflectometry) i-oscilloscope, i-logic analyzer, kunye ne-frequency domain spectrum analyzer kunye nezinye izixhobo, kodwa ezi ndlela azikwazi ukunika umboniso wolwazi olupheleleyo lwebhodi ye-PCB. idatha. Ibhodi ye-PCB ikwabizwa ngokuba yibhodi yesekethe eprintiweyo, ibhodi yesekethe eprintiweyo, ibhodi yesekethe eprintiweyo ngokufutshane, i-PCB (ibhodi yesekethe eprintiweyo) okanye i-PWB (ibhodi yocingo eprintiweyo) ngokufutshane, usebenzisa ibhodi yokugquma njengento esisiseko, isikwe kubungakanani obuthile, kwaye ubuncinci obuqhotyoshelweyo Ipatheni yokuqhuba enemingxuma (efana nemingxuma yecandelo, imingxuma yokuqinisa, imingxuma enesinyithi, njl.njl.) isetyenziselwa ukubuyisela i-chassis yamacandelo e-elektroniki yesixhobo sangaphambili kunye nokuqaphela uqhagamshelwano phakathi kwamacandelo e-elektroniki. Ngenxa yokuba le bhodi yenziwe ngokuprintwa kwe-elektroniki, ibizwa ngokuba yibhodi yesekethe “eprintiweyo”. Akulunganga ukubiza “ibhodi yesekethe eprintiweyo” njenge “printed circuit” kuba akukho “printed components” kodwa kufakwe iintambo kuphela kwibhodi yesekethe eprintiweyo.

Ulufumana njani kwaye ulusebenzise njani ulwazi lombane wePCB

Inkqubo ye-Emscan electromagnetic comppatibility scanning isebenzisa itekhnoloji ye-antenna enelungelo elilodwa lomenzi kunye neteknoloji yokutshintsha i-elektroniki, enokulinganisa i-PCB yangoku ngesantya esiphezulu. Isitshixo se-Emscan kukusetyenziswa kwe-eriyali enelungelo elilodwa lomenzi wechiza ukulinganisa i-radiation ekufutshane nebala le-PCB esebenzayo ebekwe kwiskena. Olu luhlu lwe-antenna luqukethe i-40 x 32 (1280) i-H-field probes encinci, efakwe kwibhodi yesekethe ye-8, kunye noluhlu olukhuselayo longezwa kwibhodi yesekethe ukubeka i-PCB phantsi kovavanyo. Iziphumo ze-spectrum scanning zinokusinika ukuqonda okurhabaxa kwe-spectrum eveliswa yi-EUT: zingaphi iikhomponenti zefrikhwensi ekhoyo, kunye nobungakanani obuqikelelwayo becandelo ngalinye lamaza.

Ibhendi epheleleyo scan

Uyilo lwebhodi yePCB lusekwe kumzobo wenkqubo yesekethe ukuqonda imisebenzi efunwa ngumyili wesekethe. Uyilo lwebhodi yesekethe eprintiweyo ikakhulu ibhekisa kuyilo loyilo, ekufuneka luthathele ingqalelo izinto ezahlukeneyo ezinje ngokuyilwa koqhagamshelo lwangaphandle, uyilo olulungisiweyo lwamalungu angaphakathi e-elektroniki, uyilo olulungisiweyo loqhagamshelo lwentsimbi kunye nemingxuma, ukhuseleko lwe-electromagnetic, kunye ukutshatyalaliswa kobushushu. Uyilo olugqwesileyo loyilo lunokugcina iindleko zemveliso kwaye lufezekise ukusebenza kakuhle kwesekethe kunye nokusebenza kokushisa ubushushu. Uyilo olulula loyilo lunokuqondwa ngesandla, ngelixa uyilo oluntsonkothileyo kufuneka luphunyezwe ngoncedo loyilo oluncediswa yikhompyuter.

Xa usenza isspectrum/isithuba sokuskena umsebenzi, beka iPCB esebenzayo kwiskena. I-PCB yahlulwe kwiigridi ze-7.6mm×7.6mm ngegridi yesikena (igridi nganye iqulethe i-H-field probe), kwaye iphumeze Emva kokuskena ibhendi yefrikhwensi epheleleyo yeprobe nganye (uluhlu lokuphindaphinda lunokusuka kwi-10kHz-3GHz) , U-Emscan ekugqibeleni unika imifanekiso emibini, oko kukuthi i-spectrogram edibeneyo (Umfanekiso 1) kunye nemephu yendawo edibeneyo (Umfanekiso 2).

Ulufumana njani kwaye ulusebenzise njani ulwazi lombane wePCB

I-Spectrum/spatial scanning ifumana yonke i-spectrum yedatha yeprobe nganye kuyo yonke indawo yokuskena. Emva kokwenza iskena se-spectrum/spatial, unokufumana ulwazi lwemitha ye-electromagnetic yazo zonke iifrikhwensi kuzo zonke iindawo. Unokuba nomfanekiso-ngqondweni wedatha yokuskena okubonakalayo/yesithuba kuMfanekiso 1 kunye nomfanekiso wesi-2 njengeqela ledatha yokuskena yendawo okanye iqela le-spectrum Skena idatha. Unga:

1. Jonga imephu yonikezelo lwesithuba yendawo ekhankanyiweyo yokuphindaphinda (i-frequencies enye okanye ngaphezulu) njengokujonga iziphumo zokuskena kwendawo, njengoko kubonisiwe kuMfanekiso 3.

2. Jonga ispectrogram yendawo ekhankanyiweyo yendawo echaziweyo (igridi enye okanye ngaphezulu) njengokujonga iziphumo zeskeni.

Imizobo eyahlukeneyo yonikezelo lwesithuba kumfanekiso wesi-3 yimizobo yesisu yesithuba samanqaku aphindaphindiweyo ajongwa ngamanqaku amiselweyo. Ifunyenwe ngokucacisa i-frequency point nge-× kwi-spectrogram ephezulu kumfanekiso. Ungakhankanya indawo ephindaphindayo ukujonga unikezelo lwesithuba kwindawo nganye rhoqo, okanye ungakhankanya amanqaku amaninzi, umzekelo, khankanya onke amanqaku e-harmonic ye-83M ukujonga i-spectrogram iyonke.

Kwi-spectrogram kwi-Figure 4, inxalenye yegrey yi-spectrogram epheleleyo, kwaye inxalenye eluhlaza okwesibhakabhaka yi-spectrogram kwindawo echaziweyo. Ngokucacisa indawo ebonakalayo kwi-PCB kunye ×, ngokuthelekisa i-spectrogram (eluhlaza okwesibhakabhaka) kunye ne-spectrogram epheleleyo (grey) eyenziwa kweso sikhundla, indawo yomthombo wokuphazamiseka ifunyenwe. Inokubonwa kwi-Figure 4 ukuba le ndlela inokufumana ngokukhawuleza indawo yomthombo wokuphazamiseka kokubili ukuphazamiseka kwe-broadband kunye nokuphazamiseka kwe-narrowband.

Khangela ngokukhawuleza umthombo wokuphazamiseka kwe-electromagnetic

Ulufumana njani kwaye ulusebenzise njani ulwazi lombane wePCB

A spectrum analyzer is an instrument for studying the spectrum structure of electrical signals. It is used to measure signal distortion, modulation, spectral purity, frequency stability, and intermodulation distortion. It can be used to measure certain circuit systems such as amplifiers and filters. Parameter is a multi-purpose electronic measuring instrument. It can also be called frequency domain oscilloscope, tracking oscilloscope, analysis oscilloscope, harmonic analyzer, frequency characteristic analyzer or Fourier analyzer. Modern spectrum analyzers can display analysis results in analog or digital ways, and can analyze electrical signals in all radio frequency bands from very low frequency to sub-millimeter wave bands below 1 Hz.

Ukusebenzisa i-analyzer ye-spectrum kunye ne-probe enye ekufutshane nentsimi inokukhangela “imithombo yokuphazamiseka”. Apha sisebenzisa indlela “yokucima umlilo” njengesikweko. Uvavanyo olukude (uvavanyo oluqhelekileyo lwe-EMC) lunokufaniswa “nokufumanisa umlilo”. Ukuba indawo yokuphindaphinda ingaphezulu kwexabiso elimiselweyo, ithathwa ngokuba “umlilo ufunyenwe.” Isisombululo semveli “somhlalutyi we-spectrum + single probe” sisetyenziswa ngokubanzi ziinjineli ze-EMI ukubona “kweyiphi indawo ye-chassis ilangatye liphuma”. Emva kokuba ilangatye libhaqwe, indlela yokucinezela ye-EMI ngokubanzi kukusebenzisa ukukhusela kunye nokucoca. “Idangatye” ligqunywe ngaphakathi kwimveliso. U-Emscan usivumela ukuba sibone umthombo womthombo wokuphazamiseka-“umlilo”, kodwa kwakhona ukubona “umlilo”, oko kukuthi, indlela umthombo wokuphazamiseka usasazeka.

Inokubonwa ngokucacileyo ukuba kusetyenziswa “ulwazi olupheleleyo lwe-electromagnetic”, kulula kakhulu ukufumana imithombo yokuphazamiseka kombane, ayinokusombulula kuphela ingxaki yokuphazamiseka kwe-narrowband electromagnetic, kodwa iyasebenza nakwi-broadband electromagnetic interference.

Indlela ngokubanzi imi ngolu hlobo lulandelayo:

Ulufumana njani kwaye ulusebenzise njani ulwazi lombane wePCB

(1) Jonga usasazo lwesithuba samaza asisiseko, kwaye ufumane indawo ebonakalayo eneyona amplitude inkulu kwimephu yonikezelo lwesithuba yamaza asisiseko. Ngophazamiseko lwebroadband, cacisa i-frequency embindini wokuphazamiseka kwe-broadband (umzekelo, uphazamiseko lwe-broadband ye-60MHz-80MHz, sinokucacisa i-70MHz), khangela ukuhanjiswa kwendawo yendawo yokuphindaphinda, kwaye ufumane indawo ebonakalayo ene-amplitude enkulu.

(2) Specify the location and look at the spectrogram of the location. Check whether the amplitude of each harmonic point at this position coincides with the total spectrogram. If they overlap, it means that the designated location is the strongest place that produces these interferences. For broadband interference, check whether the location is the maximum location of the entire broadband interference.

(3) Kwiimeko ezininzi, ayizizo zonke ii-harmonics eziveliswa kwindawo enye. Ngamanye amaxesha i-harmonics kunye nee-harmonics ezingaqhelekanga ziveliswa kwiindawo ezahlukeneyo, okanye icandelo ngalinye le-harmonic linokuveliswa kwiindawo ezahlukeneyo. Kule meko, unokufumana indawo enemitha eyomeleleyo ngokujonga ukusasazwa kwendawo yamanqaku amaza owakhathalelayo.

(4) Ukuthatha amanyathelo kwiindawo ezinemitha enamandla kakhulu ngokungathandabuzekiyo sesona sisombululo sisebenzayo kwiingxaki ze-EMI / EMC.

Olu hlobo lwendlela yophando ye-EMI enokulandelela ngokwenene “umthombo” kunye nendlela yokusasaza ivumela iinjineli ukuba ziphelise iingxaki ze-EMI ngexabiso eliphantsi kunye nesantya esikhawulezayo. Kwimeko yokulinganisa yokwenyani yesixhobo sonxibelelwano, uphazamiseko olusasazwayo olusasazwa kwintambo yefowuni. Emva kokusebenzisa i-EMSCAN ukuphumeza ukulandelela okukhankanywe ngasentla kunye nokuskena, ii-capacitors ezimbalwa zokucoca zaye zafakwa ekugqibeleni kwibhodi yeprosesa, eyasombulula ingxaki ye-EMI ukuba injineli ayinakuyicombulula.

Quickly locate the circuit fault location

Ulufumana njani kwaye ulusebenzise njani ulwazi lombane wePCB

Ngokunyuka kobunzima bePCB, ubunzima kunye nomthwalo wokulungisa umonakalo nawo uyanda. Nge-oscilloscope okanye i-logic analyzer, enye kuphela okanye inani elincinci lemigca yesignali inokubonwa ngexesha elifanayo. Nangona kunjalo, kusenokubakho amawaka emigca yemiqondiso kwiPCB. Iinjineli zinokufumana ingxaki kuphela ngamava okanye ithamsanqa. Ingxaki.

Ukuba “sinolwazi olupheleleyo lwe-electromagnetic” yebhodi eqhelekileyo kunye nebhodi ephosakeleyo, sinokuthelekisa idatha yezi zimbini ukufumana i-spectrum engaqhelekanga, kwaye emva koko sisebenzise “iteknoloji yendawo yokuphazamiseka” ukufumana indawo i-spectrum yefrikhwensi engaqhelekanga. Fumana indawo kunye nonobangela wokusilela.

Umzobo we-5 ubonisa i-frequency spectrum yebhodi eqhelekileyo kunye nebhodi ephosakeleyo. Ngokuthelekisa, kulula ukufumanisa ukuba kukho uphazamiseko olungaqhelekanga lwebroadband kwibhodi enempazamo.

Emva koko fumana indawo apho le “frequency spectrum engaqhelekanga” yenziwe kwimephu yokusabalalisa indawo yebhodi ephosakeleyo, njengoko kuboniswe kuMzobo 6. Ngale ndlela, indawo ephosakeleyo ifumaneka kwigridi (7.6mm × 7.6mm), kwaye ingxaki inokuba nzulu kakhulu. Ukuxilongwa kuya kwenziwa ngokukhawuleza.

Ulufumana njani kwaye ulusebenzise njani ulwazi lombane wePCB

Iimeko zesicelo zokuvavanya umgangatho woyilo wePCB

A good PCB needs to be carefully designed by an engineer. The issues that need to be considered include:

(1) Uyilo olufanelekileyo lwe-cascade

Ngokukodwa ilungiselelo lenqwelomoya yomhlaba kunye nenqwelomoya yamandla, kunye noyilo lomaleko apho imigca yesignali enovakalelo kunye nemigca yesignali evelisa i-radiation eninzi ikhona. Kukwakho nokwahlulwa kwenqwelo-moya ephantsi komhlaba kunye nenqwelomoya yamandla, kunye nokuhanjiswa kwemigca yemiqondiso kwindawo eyohluliweyo.

(2) Gcina i-impedance yomgca wesignali ngokuqhubekayo ngokusemandleni

Ngeendlela ezimbalwa kangangoko kunokwenzeka; iingoma ezimbalwa ze-engile ekunene kangangoko kunokwenzeka; kwaye incinci kangangoko indawo yokubuyisela yangoku, inokuvelisa i-harmonics encinci kunye ne-radiation intensity ephantsi.

(3) Isihluzi samandla esilungileyo

Uhlobo lwe-capacitor yesihluzi esifanelekileyo, ixabiso le-capacitance, ubuninzi, kunye nendawo yokubeka, kunye nolungelelwaniso olufanelekileyo lwenqwelomoya ephantsi komhlaba kunye nenqwelomoya yamandla, inokuqinisekisa ukuba ukuphazamiseka kombane kulawulwa kweyona ndawo incinci inokwenzeka.

(4) Zama ukuqinisekisa ingqibelelo yenqwelomoya ephantsi

Ulufumana njani kwaye ulusebenzise njani ulwazi lombane wePCB

Ngeendlela ezimbalwa kangangoko kunokwenzeka; ngokufanelekileyo ngokusebenzisa izithuba zokhuseleko; uyilo lwesixhobo esifanelekileyo; ngokufanelekileyo ngelungiselelo lokuqinisekisa imfezeko yenqwelomoya ephantsi ngowona mlinganiselo mkhulu. Ngokuchasene noko, i-vias exineneyo kwaye inkulu kakhulu ngesithuba sokhuseleko, okanye uyilo lwesixhobo esingekho ngqiqweni, luya kuchaphazela kakhulu imfezeko yenqwelomoya esemhlabeni kunye nenqwelomoya yamandla, okukhokelela kwisixa esikhulu se-inductive crosstalk, imo yokusasazeka kwemitha, kwaye iya kubangela isekethe ngakumbi. uvakalelo kuphazamiseko lwangaphandle.

(5) Fumana ulungelelwaniso phakathi kwemfezeko yomqondiso kunye nokuhambelana kwe-electromagnetic

Kwisiseko sokuqinisekisa umsebenzi oqhelekileyo wesixhobo, yongeza ixesha lokunyuka kunye nokuwa komda wesignali kangangoko kunokwenzeka ukunciphisa i-amplitude kunye nenani le-harmonics yemitha ye-electromagnetic eveliswa ngumqondiso. Ngokomzekelo, kufuneka ukhethe i-resistor efanelekileyo yokudambisa, indlela yokucoca efanelekileyo, njalo njalo.

Kwixesha elidlulileyo, ukusetyenziswa kolwazi olupheleleyo lwe-electromagnetic field oluveliswe yi-PCB lunokuphonononga ngokwesayensi umgangatho woyilo lwePCB. Ngokusebenzisa ulwazi olupheleleyo lwe-electromagnetic ye-PCB, umgangatho woyilo we-PCB unokuvavanywa kule miba ilandelayo ine: 1. Inani lamanqaku aphindaphindwayo: inani leeharmonics. 2. Ukuphazamiseka okwethutyana: ukuphazamiseka kwe-electromagnetic okungazinzanga. 3. Ubunzulu bemitha: ubukhulu bokuphazamiseka kwe-electromagnetic kwindawo nganye yamaza. 4. Indawo yosasazo: ubungakanani bendawo yokuhanjiswa kokuphazamiseka kombane kwindawo nganye yamaza kwiPCB.

Kulo mzekelo ulandelayo, ibhodi A luphuculo lwebhodi B. Imizobo ecwangcisiweyo yeebhodi ezimbini kunye nokwakheka kwamacandelo aphambili ayafana ncam. Iziphumo zespectrum / zokuskena kwendawo yeebhodi ezimbini ziboniswe kuMfanekiso 7:

Ukusuka kwi-spectrogram kuMfanekiso 7, kunokubonwa ukuba umgangatho webhodi A ngokucacileyo ungcono kunalowo webhodi ye-B, kuba:

1. Inani lee-frequency points zebhodi A ngokucacileyo lingaphantsi kwelo lebhodi B;

2. I-amplitude yamanqaku amaninzi e-frequency yebhodi A incinci kunebhodi ye-B;

3. Ukuphazamiseka okwethutyana (amanqaku e-frequency angaphawulwanga) yebhodi A ingaphantsi kwaleyo yebhodi B.

Ulufumana njani kwaye ulusebenzise njani ulwazi lombane wePCB

Inokubonwa kwidayagram yendawo ukuba indawo yokusasazwa kokuphazamiseka kwe-electromagnetic ye-A plate incinci kakhulu kunaleyo ye-B plate. Makhe sijonge kwi-electromagnetic interference distribution kwindawo ethile. Xa sijonga kwi-electromagnetic interference distribution kwi-462MHz frequency point eboniswe kuMfanekiso 8, i-amplitude ye-A plate incinci kwaye indawo incinci. Ibhodi B inoluhlu olukhulu kunye nendawo yokusabalalisa ngokukodwa.

Isishwankathelo seli nqaku

Ulwazi olupheleleyo lwe-electromagnetic ye-PCB lusivumela ukuba sibe nokuqonda okucacileyo kwe-PCB iyonke, engancedi kuphela iinjineli ekusombululeni iingxaki ze-EMI/EMC, kodwa ikwanceda iinjineli ukuba zilungise i-PCB kwaye ziqhubeke ziphucula umgangatho woyilo we-PCB. Ngokufanayo, zininzi izicelo ze-EMSCAN, ezinjengokunceda iinjineli ekusombululeni imiba ye-electromagnetic susceptibility, njalo njalo.