Amathuluzi endabuko okulungisa iphutha PCB zihlanganisa: i-oscilloscope yesizinda sesikhathi, i-TDR (i-time domain reflectometry) i-oscilloscope, i-logic analyzer, ne-frequency domain spectrum analyzer nezinye izinto zokusebenza, kodwa lezi zindlela azikwazi ukunikeza ukubonakaliswa kolwazi oluphelele lwebhodi le-PCB. idatha. Ibhodi le-PCB libizwa nangokuthi ibhodi lesifunda eliphrintiwe, ibhodi lesifunda eliphrintiwe, ibhodi lesifunda eliphrintiwe elifushane, i-PCB (ibhodi lesifunda eliphrintiwe) noma i-PWB (ibhodi lezintambo eziphrintiwe) ngamafuphi, lisebenzisa ibhodi elivikelayo njengesisekelo, lisikwe usayizi othile, futhi okungenani enamathiselwe Iphethini yokuqhuba enezimbobo (njengezimbobo zezingxenye, izimbobo zokubopha, izimbobo ezenziwe ngensimbi, njll.) isetshenziselwa ukufaka esikhundleni se-chassis yezingxenye ze-elekthronikhi zocingo lwangaphambilini futhi ibone ukuxhumana phakathi kwezingxenye ze-elekthronikhi. Ngenxa yokuthi leli bhodi lenziwe ngokusebenzisa ukuphrinta kwe-electronic, libizwa ngokuthi ibhodi lesifunda “eliphrintiwe”. Akulungile ukubiza “ibhodi lesifunda eliphrintiwe” ngokuthi “isifunda esiphrintiwe” ngoba azikho “izingxenye eziphrintiwe” kodwa izintambo kuphela ebhodini lesifunda eliphrintiwe.

Ungaluthola kanjani futhi usebenzise ulwazi lwe-PCB kagesi

Isistimu yokuskena ehambisanayo kagesi ye-Emscan isebenzisa ubuchwepheshe be-antenna enelungelo lobunikazi kanye nobuchwepheshe bokushintshwa kwe-elekthronikhi, obungakwazi ukukala okwamanje kwe-PCB ngesivinini esikhulu. Isihluthulelo se-Emscan ukusetshenziswa kwe-antenna yohlu olunelungelo lobunikazi ukukala imisebe eseduze nenkundla ye-PCB esebenzayo ebekwe kusikena. Lolu hlu lwe-antenna luqukethe ama-40 x 32 (1280) ama-H-field probe amancane, ashumekwe ebhodini lesifunda elinezingqimba eziyisi-8, futhi ungqimba oluvikelayo lwengezwe ebhodini lesifunda ukuze kubekwe i-PCB ngaphansi kokuhlolwa. Imiphumela yokuskena kwe-spectrum ingasinika ukuqonda okujulile kwe-spectrum ekhiqizwe yi-EUT: zingaki izingxenye zefrikhwensi ezikhona, kanye nobukhulu obulinganiselwe bengxenye yefrikhwensi ngayinye.

Ukuskena kwebhendi okugcwele

Idizayini yebhodi le-PCB isuselwe kumdwebo wohlelo lwesekethe ukubona imisebenzi edingwa umklami wesekethe. Idizayini yebhodi yesekethe ephrintiwe ibhekisa kakhulu ekwakhiweni kwesakhiwo, okudingeka kubhekwe izinto ezahlukahlukene ezifana nokwakheka koxhumano lwangaphandle, ukwakheka okuhle kwezingxenye ze-elekthronikhi zangaphakathi, ukwakheka okuhle kokuxhunywa kwensimbi nangezimbobo, ukuvikelwa kozibuthe kagesi, kanye ukuchithwa kokushisa. Idizayini yesakhiwo esihle kakhulu ingasindisa izindleko zokukhiqiza futhi ifinyelele ukusebenza okuhle kwesifunda kanye nokusebenza kokukhipha ukushisa. Umklamo olula wesakhiwo ungenziwa ngesandla, kuyilapho umklamo wesakhiwo oyinkimbinkimbi udinga ukuqashelwa ngosizo lomklamo osizwa yikhompyutha.

Uma wenza umsebenzi wokuskena we-spectrum/spatial, beka i-PCB esebenzayo kusikena. I-PCB ihlukaniswe ngamagridi angu-7.6mm×7.6mm ngegridi yesithwebuli (igridi ngayinye iqukethe i-H-field probe), futhi isebenzise Ngemva kokuskena ibhendi yefrikhwensi egcwele yophenyo ngalunye (ububanzi befrikhwensi bungaba ukusuka ku-10kHz-3GHz) , i-Emscan ekugcineni inikeze izithombe ezimbili, okuyi-spectrogram ehlanganisiwe (Umfanekiso 1) kanye nemephu yesikhala ehlanganisiwe (Umfanekiso 2).

Ungaluthola kanjani futhi usebenzise ulwazi lwe-PCB kagesi

Ukuskena kwe-Spectrum/spatial kuthola yonke idatha ye-spectrum ye-probe ngayinye kuyo yonke indawo yokuskena. Ngemva kokwenza ukuskena kwe-spectrum/spatial, ungathola ulwazi lwemisebe kagesi yawo wonke amaza kuzo zonke izindawo. Ungacabanga nge-spectrum/idatha yokuskena yendawo ku-Figure 1 kanye noFigure 2 njengenqwaba yedatha yokuskena yendawo noma iqoqo le-spectrum Skena idatha. ungakwazi:

1. Buka imephu yokusabalalisa yendawo yephoyinti lemvamisa elicacisiwe (ifrikhwensi eyodwa noma ngaphezulu) njengokubuka umphumela wokuskena wendawo, njengoba kukhonjisiwe kuMfanekiso 3.

2. Buka i-spectrogram yephoyinti lendawo ebonakalayo (igridi eyodwa noma ngaphezulu) njengokubuka umphumela wokuskena kwe-spectrum.

Imidwebo ehlukahlukene yokusabalalisa indawo ku-Fig. 3 iyimidwebo yendawo yesisu yamaphoyinti amafrikhwensi abukwa ngamaphoyinti amafrikhwensi aqokiwe. Itholakala ngokucacisa iphuzu lokuvama ngo-× ku-spectrogram ephezulu kakhulu emfanekisweni. Ungacacisa iphoyinti lefrikhwensi ukuze ubuke ukusatshalaliswa kwendawo kwephuzu lemvamisa ngayinye, noma ungacacisa amaphoyinti amafrikhwensi amaningi, isibonelo, ucacise wonke amaphuzu e-harmonic we-83M ukuze ubuke ingqikithi ye-spectrogram.

Ku-spectrogram kuMfanekiso 4, ingxenye empunga iyingqikithi ye-spectrogram, kanti ingxenye eluhlaza okwesibhakabhaka i-spectrogram endaweni eshiwo. Ngokucacisa indawo ebonakalayo ku-PCB no-×, ukuqhathanisa i-spectrogram (eluhlaza okwesibhakabhaka) kanye nesamba se-spectrogram (empunga) ekhiqizwa kuleso simo, indawo yomthombo wokuphazamiseka iyatholakala. Kungabonakala kuMfanekiso 4 ukuthi le ndlela ingathola ngokushesha indawo yomthombo wokuphazamiseka kokubili ukuphazamiseka kwe-broadband kanye nokuphazamiseka kwe-narrowband.

Thola ngokushesha umthombo wokuphazamiseka kwe-electromagnetic

Ungaluthola kanjani futhi usebenzise ulwazi lwe-PCB kagesi

I-spectrum analyzer iyithuluzi lokufunda ukwakheka kwe-spectrum yamasignali kagesi. Isetshenziselwa ukukala ukuhlanekezela kwesignali, ukuguquguquka, ukuhlanzeka kwe-spectral, ukuzinza kwemvamisa, nokuhlanekezela kwe-intermodulation. Ingasetshenziselwa ukukala izinhlelo ezithile zesekethe njengama-amplifiers nezihlungi. Ipharamitha iyithuluzi lokulinganisa le-elekthronikhi elinezinjongo eziningi. Ingase futhi ibizwe ngokuthi i-frequency domain oscilloscope, i-oscilloscope yokulandelela, i-oscilloscope yokuhlaziya, i-harmonic analyzer, i-frequency characteristic analyzer noma i-Fourier analyzer. Abahlaziyi be-spectrum besimanje bangabonisa imiphumela yokuhlaziya ngezindlela ze-analog noma zedijithali, futhi bangahlaziya amasignali kagesi kuwo wonke amabhendi efrikhwensi yomsakazo kusukela kumabhande amaza amaza aphansi kakhulu ukuya kumamilimitha angaphansi kuka-1 Hz.

Ukusebenzisa i-spectrum analyzer kanye ne-near-field probe eyodwa nakho kungathola “imithombo yokuphazamiseka”. Lapha sisebenzisa indlela “yokucisha umlilo” njengesingathekiso. Ukuhlolwa kwe-far-field (ukuhlolwa okujwayelekile kwe-EMC) kungafaniswa “nokubona umlilo”. Uma iphoyinti lokuvama lidlula inani elilinganiselwe, libhekwa njengokuthi “umlilo utholakele.” Isixazululo sendabuko esithi “spectrum analyzer + single probe” ngokuvamile sisetshenziswa onjiniyela be-EMI ukuthola “kuyiphi ingxenye ye-chassis ilangabi liphuma kuyo”. Ngemva kokuba ilangabi selitholakele, indlela evamile yokucindezela i-EMI ukusebenzisa ukuvikela nokuhlunga. “I-Flame” imbozwe ngaphakathi komkhiqizo. I-Emscan isivumela ukuthi sithole umthombo womthombo wokuphazanyiswa-“umlilo”, kodwa futhi sibone “umlilo”, okungukuthi, indlela umthombo wokuphazamiseka osakazeka ngayo.

Kungabonakala ngokucacile ukuthi ngokusebenzisa “ulwazi oluphelele lwe-electromagnetic”, kulula kakhulu ukuthola imithombo yokuphazanyiswa kuka-electromagnetic, hhayi nje kuphela okungaxazulula inkinga yokuphazamiseka kwe-electromagnetic ye-narrowband, kodwa futhi kusebenza kahle ekuphazamiseni kwe-broadband electromagnetic.

Indlela ejwayelekile imi kanjena:

Ungaluthola kanjani futhi usebenzise ulwazi lwe-PCB kagesi

(1) Hlola ukusatshalaliswa kwendawo kwegagasi eliyisisekelo, futhi uthole indawo ebonakalayo enobude obukhulu kakhulu kumephu yokusabalalisa yendawo yegagasi eliyisisekelo. Ngokuphazamiseka kwe-broadband, cacisa imvamisa phakathi kokuphazanyiswa kwe-broadband (isibonelo, ukuphazamiseka kwe-broadband engu-60MHz-80MHz, singacacisa u-70MHz), hlola ukusatshalaliswa kwendawo kwephoyinti lemvamisa, futhi uthole indawo ebonakalayo enobukhulu obukhulu kakhulu.

(2) Cacisa indawo bese ubheka i-spectrogram yendawo. Hlola ukuthi i-amplitude yephoyinti ngalinye le-harmonic kulesi sikhundla iyahambisana yini nengqikithi ye-spectrogram. Uma zigqagqana, kusho ukuthi indawo ebekiwe iyindawo eqine kakhulu ekhiqiza lezi ziphazamiso. Ngokuphazamiseka kwe-broadband, hlola ukuthi ingabe indawo iyindawo ephezulu yakho konke ukuphazamiseka kwe-broadband.

(3) Ezimweni eziningi, akuwona wonke ama-harmonics akhiqizwa endaweni eyodwa. Ngezinye izikhathi ngisho nama-harmonics nama-harmonics angajwayelekile akhiqizwa ezindaweni ezahlukene, noma ingxenye ngayinye ye-harmonic ingase yenziwe ezindaweni ezahlukene. Kulesi simo, ungathola indawo enemisebe enamandla kakhulu ngokubheka ukusatshalaliswa kwendawo kwamaphoyinti emvamisa owakhathalelayo.

(4) Ukuthatha izinyathelo ezindaweni ezinemisebe enamandla kakhulu ngokungangabazeki kuyisixazululo esisebenza kahle kakhulu sezinkinga ze-EMI/EMC.

Lolu hlobo lwendlela yophenyo ye-EMI engalandelela ngempela “umthombo” nendlela yokusakaza ivumela onjiniyela ukuthi baqede izinkinga ze-EMI ngezindleko eziphansi kanye nesivinini esisheshayo. Esimeni sokulinganisa sangempela sedivayisi yokuxhumana, ukuphazamiseka kwemisebe okuphuma kukhebula yolayini wocingo. Ngemva kokusebenzisa i-EMSCAN ukwenza ukulandelela okushiwo ngenhla kanye nokuskena, ama-capacitor ambalwa okuhlunga agcine efakwe ebhodini lokuphrosesa, elixazulule inkinga ye-EMI unjiniyela ayengakwazi ukuyixazulula.

Thola ngokushesha indawo yephutha lesifunda

Ungaluthola kanjani futhi usebenzise ulwazi lwe-PCB kagesi

Ngokukhula kobunzima be-PCB, ubunzima nomsebenzi wokulungisa iphutha nawo uyakhula. Nge-oscilloscope noma i-logic analyzer, inombolo eyodwa kuphela noma inombolo elinganiselwe yemigqa yesignali ingabonwa ngesikhathi esifanayo. Nokho, kungase kube nezinkulungwane zemigqa yesignali ku-PCB. Onjiniyela bangathola inkinga kuphela ngolwazi noma inhlanhla. Inkinga.

Uma “sinolwazi oluphelele lukazibuthe kagesi” lwebhodi elivamile kanye nebhodi elinephutha, singaqhathanisa idatha yakho kokubili ukuze sithole i-spectrum yefrikhwensi engavamile, bese sisebenzisa “ubuchwepheshe bendawo yomthombo wokuphazamiseka” ukuze sithole indawo i-spectrum yefrikhwensi engavamile. Thola indawo kanye nembangela yokwehluleka.

Umfanekiso wesi-5 ubonisa i-spectrum ye-frequency yebhodi evamile kanye nebhodi elingalungile. Ngokuqhathanisa, kulula ukuthola ukuthi kukhona ukuphazamiseka okungavamile kwe-broadband ebhodini elinephutha.

Bese uthola indawo lapho lokhu “i-spectrum engavamile” kukhiqizwa khona kumephu yokusabalalisa yendawo yebhodi enephutha, njengoba kuboniswe kuMfanekiso 6. Ngale ndlela, indawo enephutha itholakala kugridi (7.6mm×7.6mm), futhi inkinga ingaba nkulu kakhulu. Ukuxilongwa kuzokwenziwa maduze.

Ungaluthola kanjani futhi usebenzise ulwazi lwe-PCB kagesi

Izimo zokufaka izicelo zokuhlola ikhwalithi yedizayini ye-PCB

I-PCB enhle idinga ukuklanywa ngokucophelela ngunjiniyela. Izinkinga okufanele zicatshangelwe zihlanganisa:

(1) Idizayini ye-cascading enengqondo

Ikakhulukazi ukuhlelwa kwendiza yaphansi kanye nendiza yamandla, nokuklanywa kongqimba lapho imigqa yesignali ebucayi nemigqa yesignali ekhiqiza imisebe eminingi ikhona. Kukhona futhi ukuhlukaniswa kwendiza yaphansi kanye nendiza yamandla, kanye nomzila wemigqa yesignali kuyo yonke indawo ehlukene.

(2) Gcina i-impedance yomugqa wesignali ngokuqhubekayo ngangokunokwenzeka

Njengoba ambalwa ngangokunokwenzeka; amathrekhi ambalwa we-engeli yesokudla ngangokunokwenzeka; futhi incane ngangokunokwenzeka indawo yokubuya yamanje, ingakhiqiza ama-harmonics amancane kanye nomfutho wemisebe ophansi.

(3) Isihlungi samandla esihle

Uhlobo lwe-capacitor yesihlungi olunengqondo, inani le-capacitance, ubuningi, nendawo yokubeka, kanye nokuhlelwa okunengqimba okunengqondo kwendiza yaphansi kanye nendiza yamandla, kungaqinisekisa ukuthi ukuphazamiseka kukazibuthe kulawulwa endaweni encane kakhulu ngangokunokwenzeka.

(4) Zama ukuqinisekisa ubuqotho bendiza yaphansi

Ungaluthola kanjani futhi usebenzise ulwazi lwe-PCB kagesi

Njengoba ambalwa ngangokunokwenzeka; okunengqondo ngokusebenzisa isikhala sokuphepha; isakhiwo sedivayisi esinengqondo; okunengqondo ngohlelo lokuqinisekisa ubuqotho bendiza yaphansi ngezinga elikhulu kakhulu. Ngokuphambene, ama-vias aminyene futhi amakhulu kakhulu ngokusebenzisa isikhala sokuphepha, noma ukwakheka kwedivayisi okungenangqondo, kuzophazamisa ubuqotho bendiza yaphansi kanye nendiza yamandla, okuholela esilinganisweni esikhulu se-inductive crosstalk, imisebe yemodi evamile, futhi kuzobangela isekethe izwela ukuphazamiseka kwangaphandle.

(5) Thola ukuvumelana phakathi kobuqotho besignali nokuhambisana kwe-electromagnetic

Ngokwesisekelo sokuqinisekisa umsebenzi ojwayelekile wemishini, khulisa isikhathi sonqenqema esikhuphukayo nesiwayo sesiginali ngangokunokwenzeka ukuze unciphise i-amplitude kanye nenani lama-harmonic emisebe kagesi ekhiqizwa isignali. Isibonelo, udinga ukukhetha i-resistor yokudambisa efanelekile, indlela yokuhlunga efanelekile, njalonjalo.

Esikhathini esedlule, ukusetshenziswa kolwazi oluphelele lwenkundla kagesi olukhiqizwa yi-PCB lungahlola ngokwesayensi ikhwalithi yomklamo we-PCB. Ngokusebenzisa ulwazi oluphelele lukazibuthe we-electromagnetic lwe-PCB, ikhwalithi yokuklama ye-PCB ingahlolwa kusukela kulezi zici ezine ezilandelayo: 1. Inani lamaphoyinti emvamisa: inani lama-harmonics. 2. Ukuphazamiseka kwesikhashana: ukuphazamiseka kwe-electromagnetic okungazinzile. 3. Ukuqina kwemisebe: ubukhulu bokuphazamiseka kazibuthe endaweni ngayinye yefrikhwensi. 4. Indawo yokusabalalisa: usayizi wendawo yokusabalalisa yokuphazanyiswa kukagesi endaweni ngayinye yefrikhwensi ku-PCB.

Esibonelweni esilandelayo, ibhodi A liwukuthuthukiswa kwebhodi B. Imidwebo yohlelo lwamabhodi amabili kanye nokuhlelwa kwezingxenye eziyinhloko kufana ncamashi. Imiphumela ye-spectrum/spatial scanning yamabhodi amabili ikhonjisiwe kuMfanekiso 7:

Kusukela ku-spectrogram ku-Figure 7, kungabonakala ukuthi ikhwalithi yebhodi A ingcono ngokusobala kunebhodi B, ngoba:

1. Inani lamaphoyinti e-frequency ebhodi A ngokusobala lingaphansi kwalelo lebhodi B;

2. I-amplitude yamaphoyinti amaningi e-frequency yebhodi A mancane kunaleyo yebhodi B;

3. Ukugxambukela kwesikhashana (amaphoyinti amafrikhwensi angamakiwe) ebhodi A kungaphansi kwalokho kwebhodi B.

Ungaluthola kanjani futhi usebenzise ulwazi lwe-PCB kagesi

Kungabonakala kumdwebo wesikhala ukuthi indawo yokusabalalisa yokuphazamiseka kuka-electromagnetic ye-A plate incane kakhulu kunaleyo ye-B plate. Ake sibheke ukusatshalaliswa kokuphazamiseka kwe-electromagnetic endaweni ethile. Uma sibheka ukusatshalaliswa kokuphazamiseka kazibuthe kagesi endaweni yemvamisa engu-462MHz eboniswe kuMfanekiso 8, i-amplitude ye-A plate incane futhi indawo incane. Ibhodi B inobubanzi obukhulu kanye nendawo yokusabalalisa ebanzi ikakhulukazi.

Isifinyezo salesi sihloko

Ulwazi oluphelele lukazibuthe kagesi lwe-PCB lusivumela ukuthi sibe nokuqonda okunembile kwe-PCB iyonke, okungasizi onjiniyela kuphela ukuxazulula izinkinga ze-EMI/EMC, kodwa futhi kusiza onjiniyela balungise iphutha le-PCB futhi baqhubeke bethuthukisa ikhwalithi yokuklama ye-PCB. Ngokufanayo, kunezinhlelo zokusebenza eziningi ze-EMSCAN, njengokusiza onjiniyela ukuxazulula izinkinga zokuthintwa yi-electromagnetic susceptibility nokunye.