Ingqiqo esithoba ye PCB ukuhlolwa

1. Akuvumelekanga ngokungqongqo ukusebenzisa izixhobo zovavanyo ezisekelwe phantsi ukuze uchukumise iTV ephilayo, i-audio, ividiyo kunye nezinye izixhobo zeplate engezantsi ukuvavanya ibhodi ye-PCB ngaphandle kwe-transformer yodwa.

Akuvumelekanga ngokungqongqo ukuvavanya ngokuthe ngqo i-TV, i-audio, ividiyo kunye nezinye izixhobo ngaphandle kwe-transformer yokuhlukanisa amandla kunye nezixhobo kunye nezixhobo ezinezivalo ezisekelwe phantsi.

Nangona irekhoda yekhasethi yerediyo ngokubanzi inesiguquli samandla, xa udibana neTV ekhethekileyo okanye izixhobo ezivakalayo, ngakumbi amandla aphumayo okanye ubume bombane osetyenziswayo, kufuneka uqale ufumanise ukuba i-chassis yomatshini ihlawuliswa. , Ngaphandle koko kuya kuba lula kakhulu I-TV, i-audio kunye nezinye izixhobo ezihlawuliswa nge-backplane zibangela isiphaluka esifutshane sonikezelo lwamandla, oluchaphazela umjikelezo odibeneyo, obangela ukwanda okuqhubekayo kwesiphoso.

2. Nika ingqalelo ekusebenzeni kwe-insulation yentsimbi ye-soldering yombane xa uvavanya ibhodi ye-PCB

Akuvumelekanga ukusebenzisa intsimbi yokuxubha ukudibanisa ngamandla. Qinisekisa ukuba i-iron soldering ayihlawuliswa. Kungcono ukuguba iqokobhe lentsimbi yokuthambisa. Qaphela ngakumbi ngesekethe ye-MOS. Kukhuselekile ukusebenzisa intsimbi ephantsi ye-solder ye-voltage ye-6 ~ 8V.

3. Ngaphambi kokuvavanya ibhodi yePCB, qonda umgaqo wokusebenza weesekethe ezidibeneyo kunye neesekethe ezinxulumene nazo

Ngaphambi kokuba uhlole kwaye ulungise isekethe edibeneyo, kufuneka uqale uqhelane nomsebenzi wesekethe edibeneyo esetyenziswayo, isekethe yangaphakathi, iiparamitha eziphambili zombane, indima yephini nganye, kunye nombane oqhelekileyo wephini, i-waveform kunye nokusebenza. umgaqo wesekethe eyenziwe ngamacandelo eperipheral.

Ukuba le miqathango ingentla idibene, ukuhlalutya kunye nokuhlolwa kuya kuba lula kakhulu.

4. Musa ukwenza isekethe emfutshane phakathi kwezikhonkwane xa uvavanya ibhodi yePCB

Xa ulinganisa i-voltage okanye uvavanya i-waveform nge-oscilloscope probe, musa ukubangela isekethe emfutshane phakathi kwezikhonkwane zesekethe edibeneyo ngenxa yokutyibilika kovavanyo okanye iiprobes. Kungcono ukulinganisa kwi-peripheral eprintiweyo yesekethe eqhagamshelwe ngokuthe ngqo kwizikhonkwane.

Naliphi na isiphaluka esifutshane somzuzwana singonakalisa ngokulula isiphaluka esidibeneyo. Kuya kufuneka ulumke ngakumbi xa uvavanya iisekethe ezidibeneyo zeCMOS.

5. Ukuchasana kwangaphakathi kwesixhobo sokuvavanya ibhodi yePCB kufuneka kube kukhulu

When measuring the DC voltage of the IC pins, a multimeter with the internal resistance of the meter head greater than 20KΩ/V should be used, otherwise there will be a large measurement error for the voltage of some pins.

6. Nika ingqalelo ukutshatyalaliswa kobushushu bombane odibeneyo wesiphaluka xa ufumanisa ibhodi yePCB

Umbane odibeneyo wesiphaluka kufuneka ube nokutshatyalaliswa kobushushu obuhle, kwaye akuvumelekanga ukusebenza kwindawo ephezulu yamandla ngaphandle kokushisa ubushushu.

7. Ucingo olukhokelayo lwebhodi yePCB kufuneka luvavanywe ngokufanelekileyo

Ukuba ufuna ukongeza amacandelo angaphandle ukutshintsha iindawo ezonakalisiweyo zesekethe edibeneyo, kufuneka kukhethwe amacandelo amancinci, kwaye i-wiring kufuneka ibe nengqiqo ukuphepha ukudibanisa okungafunekiyo kwe-parasitic, ngakumbi ukusekwa phakathi kwesiphaluka esidibeneyo somsindo we-amplifier kunye ne-preamplifier circuit circuit. .

8. To inspect the PCB board to ensure the welding quality

Xa ukuthengiswa, i-solder iqinile, kwaye ukuqokelela kwe-solder kunye neepores kunokubangela ukuba i-solder yobuxoki. Ixesha le-soldering ngokuqhelekileyo alikho ngaphezu kwemizuzwana ye-3, kwaye amandla entsimbi ye-solder kufuneka ibe malunga ne-25W ngokufudumeza kwangaphakathi.

Isekethe edibeneyo ethe yathengiswa kufuneka ihlolwe ngokucophelela. Kungcono ukusebenzisa i-ohmmeter ukulinganisa ukuba kukho isiphaluka esifutshane phakathi kwezikhonkwane, qinisekisa ukuba akukho ukunamathela kwi-solder, uze uvule amandla.

9. Musa ukumisela lula umonakalo wesekethe edibeneyo xa uvavanya ibhodi yePCB

Musa ukugweba ukuba isiphaluka esidibeneyo sonakaliswe lula. Ngenxa yokuba uninzi lweesekethe ezidibeneyo zidityaniswe ngokuthe ngqo, xa isekethe ingaqhelekanga, inokubangela utshintsho olomeleleyo lwamandla ombane, kwaye olu tshintsho alubangelwanga ngumonakalo wesekethe edibeneyo.

Ukongezelela, kwezinye iimeko, xa i-voltage elinganisiweyo yepini nganye ihambelana okanye isondele kwixabiso eliqhelekileyo, ayinakuhlala ibonisa ukuba isiphaluka esidibeneyo silungile. Ngenxa yokuba iforum ye-elektroniki ye-EDA365 ifumene ukuba ezinye iimpazamo ezithambileyo aziyi kubangela utshintsho kumbane we-DC.

Indlela yokulungisa ibhodi yePCB

Kwibhodi entsha ye-PCB esanda kuthathwa emva, i-EDA365 Electronics Forum icebisa ukuba uqale uqaphele ukuba kukho iingxaki ebhodini, njengokuba kukho iintanda ezicacileyo, iisekethe ezimfutshane, iisekethe ezivulekileyo, njl. Ukuba kuyimfuneko, khangela ukuba ukumelana phakathi konikezelo lwamandla kunye nocingo lomhlaba mkhulu ngokwaneleyo.

Kwibhodi yesekethe esandula ukuyilwa, ukulungisa ingxaki kaninzi kudibana nobunzima, ngakumbi xa ibhodi inkulu kwaye kukho izinto ezininzi, ngokuqhelekileyo akunakwenzeka ukuqala. Kodwa ukuba uyazi kakuhle iseti yeendlela zokulungisa iimpazamo, ukulungisa ingxaki kuya kufumana isiphumo esiphindwe kabini ngesiqingatha somzamo.

Amanyathelo okulungisa ibhodi yePCB:

1. Kwibhodi entsha yePCB esandula ukubuyiselwa umva, kufuneka siqale sijonge ukuba ngaba kukho naziphi na iingxaki ebhodini, ezinje ngokuba kukho iintanda ezicacileyo, iisekethe ezimfutshane, iisekethe ezivulekileyo, njl. ukumelana phakathi konikezelo lwamandla kunye nocingo lomhlaba mkhulu ngokwaneleyo.

2. Emva koko amacandelo afakwe. Iimodyuli ezizimeleyo, ukuba awuqinisekanga ukuba zisebenza ngokufanelekileyo, kukulungele ukungazifaki zonke, kodwa ukufaka inxalenye ngenxalenye (kwiisekethe ezincinci, unokuzifaka zonke ngaxeshanye), ukuze kube lula. ukumisela uluhlu lweempazamo. Kuphephe ukuba nengxaki ekuqaliseni xa udibana neengxaki.

Ngokubanzi, unokufakela unikezelo lwamandla kuqala, kwaye emva koko ukhanyise ukuze ujonge ukuba umbane ophumayo wobonelelo lwamandla uqhelekile. Ukuba awunakuzithemba kakhulu xa unika amandla (nokuba uqinisekile, kuyacetyiswa ukuba wongeze i-fuse, nje ukuba kunokwenzeka), cinga ukusebenzisa unikezelo lwamandla oluhlengahlengisiweyo kunye nomsebenzi wangoku wokunciphisa.

Cwangcisa kwangaphambili ukhuseleko lwangoku lwangoku kuqala, emva koko unyuse kancinci ixabiso lombane wonikezelo lwamandla alawulwayo, kwaye ubeke iliso kwigalelo langoku, igalelo lombane, kunye nombane ophumayo. Ukuba akukho ukhuseleko olugqithisiweyo kunye nezinye iingxaki ngexesha lokulungiswa okuphezulu, kwaye i-voltage ephumayo ifikelele kwisiqhelo, ukunikezelwa kwamandla kulungile. Ngaphandle koko, qhawula unikezelo lwamandla, fumana indawo yempazamo, kwaye uphinde la manyathelo angasentla de unikezelo lwamandla luqhelekile.

3. Okulandelayo, fakela ezinye iimodyuli ngokuthe ngcembe. Emva kokuba imodyuli nganye ifakiwe, vula kwaye uyivavanye. Xa ulayita amandla, landela la manyathelo angasentla ukuphepha ngaphezulu-yangoku kwaye utshise amacandelo ngenxa yeempazamo zoyilo okanye/kunye neempazamo zofakelo.

Finding the method of PCB board failure

1. Fumana ibhodi yePCB engalunganga ngokulinganisa indlela yamandla ombane

Into yokuqala yokuqinisekisa kukuba ingaba i-voltage yezikhonkwane zonikezelo lwamandla yetshiphu nganye iqhelekile, kwaye emva koko ujonge ukuba ii-voltages ezahlukeneyo zereferensi ziqhelekile. Ukongeza, iforum ye-elektroniki ye-EDA365 ikhumbuza: kwakhona uqinisekise ukuba i-voltage yokusebenza kwinqanaba ngalinye liqhelekileyo, njl.

Umzekelo, xa i-silicon transistor ngokubanzi ivuliwe, i-BE junction voltage imalunga ne-0.7V, ngelixa i-junction voltage ye-CE imalunga ne-0.3V okanye ngaphantsi. Ukuba i-BE junction voltage ye-transistor inkulu kune-0.7V (ngaphandle kwee-transistors ezikhethekileyo, ezifana ne-Darlington, njl.), Kungenzeka ukuba i-BE junction ivuliwe.

2. Indlela yokutofa ngomqondiso wokufumana ibhodi yePCB engalunganga

Yongeza umthombo wesignali kwi-terminal yegalelo, kwaye emva koko ulinganise i-waveform yenqaku ngalinye ngokulandelelana ukuze ubone ukuba iqhelekile na ukufumana indawo yempazamo. Ngamanye amaxesha sisebenzisa iindlela ezilula, ezifana nokubamba i-tweezers ngezandla zethu, kunye nokuchukumisa iitheminali zokufaka zonke izigaba ukuze sibone ukuba iitheminali zokuphuma ziyaphendula. Oku kudla ngokusetyenziswa ekukhuliseni iisekethe ezifana ne-audio kunye nevidiyo (kodwa qaphela ukuba ipleyiti esezantsi eshushu Le ndlela ayinakusetyenziselwa iisekethe ezinombane ophezulu okanye iisekethe eziphezulu zombane, ngaphandle koko kunokubangela ukutshitshiswa kombane).

Ukuba akukho mpendulo kwinqanaba langaphambili, kodwa kukho impendulo kwinqanaba elilandelayo, kuthetha ukuba ingxaki ilele kwinqanaba langaphambili kwaye kufuneka ihlolwe.

3. Ezinye iindlela zokufumana iibhodi zePCB ezingalunganga

Zininzi ezinye iindlela zokufumana amanqaku aneempazamo, njengokubukela, ukumamela, ukusezela, ukubamba, njl.

“Ukubona” ​​kukubona ukuba kukho umonakalo ocacileyo womatshini kwicandelo, njengokuqhekeka, ukutshisa, ukuguqulwa, njl.;

“Ukuphulaphula” kuthetha ukumamela ukuba ingaba isandi esisebenzayo siqhelekile na, umzekelo, into ekungafanelanga ukuba ikhale ukukhala, indawo ebekumele ukuba ikhalisa kuyo ayikhali okanye isandi asiqhelekanga, njl. njl.;

“Ukunuka” kukukhangela ukuba ngaba kukho naliphi na ivumba elikhethekileyo, elifana nevumba lokutsha, ivumba le-capacitor electrolyte, njl.

“Ukuchukumisa” kukuvavanya ukuba ubushushu besixhobo buqhelekile ngesandla, umzekelo, kushushu kakhulu okanye kubanda kakhulu.

Some power devices will heat up when they work. If they are cold to the touch, it can basically be judged that they are not working. But if the place that shouldn’t be hot is hot or the place that should be hot is too hot, that won’t work either.

Kwii-transistors zamandla ngokubanzi, ii-chips ze-voltage regulator, njl., kulungile ngokupheleleyo ukusebenza ngaphantsi kwe-70 degrees. Ithini ingqikelelo yeedigri ezingama-70? Ukuba ucinezela isandla sakho phezulu, unokusibamba ngaphezu kwemizuzwana emithathu, oko kuthetha ukuba iqondo lobushushu lingaphantsi kwama-70 degrees (qaphela ukuba kufuneka uchukumise kuqala, kwaye ungatshisi izandla zakho).