Ukubhola Ubunzulu Obulawulwayo kwiMveliso yePCB: Ukubhola Umva Kuthetha ukuthini ukubhola umva kwiPCB?
Ukubhola emva kwiibhodi zocingo eziprintiweyo ezineeleya ezininzi yinkqubo yokususa i-stub ukuze kuveliswe ii-vias, okuvumela imiqondiso ukuba isuke kwelinye ileya lebhodi iye kwelinye. (Ii-stubs ziya kudala ukubonakalisa, ukusasazeka, ukulibaziseka, kunye neminye imiba ngexesha lokudluliselwa kwesignali, okuya kubangela ukuba isignali igqwetheke.) Ukubhola kubunzulu obulawulwayo kufuna ubuchule obuntsonkothileyo. Ukwenza iibhodi zesekethe ezineeleya ezininzi, ezifana neebhodi ezineeleya ezili-12, kufuna ukudibanisa ileya yokuqala kunye neleya yesithoba. Ngokwesiqhelo, sibhoboza imingxunya kube kanye ngaphambi kokuba sifake ii-vias. Umgangatho wokuqala kunye nomgangatho we-12 ngoko ke ziqhagamshelwe ngoko nangoko. Enyanisweni, umgangatho wokuqala kufuneka uqhagamshelwe kumgangatho wesithoba. Ekubeni kungekho zintambo ezidibanisa amanqanaba e-10 ukuya kwele-12, zifana neepilari. Le kholamu inempembelelo kwindlela yesignali kwaye inokubeka emngciphekweni ukuthembeka kwesignali yonxibelelwano. Ke ngoko, umngxuma wesibini wagqojozwa kwelinye icala lekholamu eyongezelelweyo (ebizwa ngokuba yi-STUB kushishino).
Ngenxa yoko, yaziwa ngokuba yi-back drilling, nangona kunjalo ayicocekanga kangako njengokubhola kuba inyathelo elilandelayo liya kusebenzisa i-electrolyze ethile yobhedu kwaye nencam yokubhola nayo ibukhali. Ke ngoko siza kushiya inqaku elincinci kakhulu; ubude bale STUB iseleyo bubizwa ngokuba yi-B value, kwaye idla ngokuba phakathi kwama-50 ukuya kwi-150 UM.
Itekhnoloji ye-PCB yokugrumba umva
Ngenxa yesidingo sokunciphisa ukulahleka kwesignali kwizicelo ze-frequency ephezulu, umngxuma odibanisa iileya uyafuneka ukuze isignali idlule njengoko isuka kwenye iye kwenye. Kucetyiswa ukuba kususwe ubhedu olungaphezulu kulo mngxuma kwesi sicelo kuba lusebenza njenge-antenna kwaye luchaphazela uthumelo ukuba isignali iza kuhamba ukusuka kumgca wokuqala ukuya kumgca wesibini kwibhodi yeleya ezingama-20, umzekelo.
Ukuze sifumane uzinzo olukhulu lwesignali, sikhupha ubhedu “olugqithisileyo” emngxunyeni sisebenzisa i-back-drilling (ubunzulu obulawulwayo kwi-z-axis). Isiphumo esifanelekileyo kukuba i-stub (okanye ubhedu “olugqithisileyo”) ibe mfutshane kangangoko. Ngokwesiqhelo, ubungakanani be-back-drill kufuneka bube yi-0.2mm enkulu kune-via ehambelanayo.
IInkqubo yokubuyisela umva isusa iziqwengakwiingxobo ezigqunywe ngepleyiti (ii-vias). Iziqwenga azibalulekanga /iinxalenye ezingasetyenziswanga zee-vias, ezidlula ngaphaya komaleko wangaphakathi wokugqibela odibeneyo.
Iziqwenga zingakhokelela ekubeniukubonakalisa, njengoukuphazamiseka komthamo, ukungasebenzi kunye nokuphazamisekaEzi mpazamo zokungaqhubeki ziba zibalulekileyo njengoko isantya sokusasazeka sisanda.
Iinqwelo-moya zangasemvakunye neeBhodi zeSekethe eziPrintiweyo ezixineneyo ngokukodwa, zinokunyamezelaukuphazamiseka okubalulekileyo kokuthembeka kwesignalingokusebenzisa iziqwenga. Ii-PCB eziQhelekileyo eziphezulu(umz. ngolawulo lwe-Impedance), ukusetyenziswa kwe-backdrilling, kunye nokusetyenziswa kweii-vias ezingaboniyo nezingcwatyiweyo, ingaba yinxalenye yesisombululo.
I-Backdrill ingafakwa kwinaluphi na uhlobo lwebhodi yeseketheapho iziqwenga zibangela ukonakala kobunyani besignali, ngaphandle kokuqwalasela uyilo kunye noyilo oluncinci. Ngokwahlukileyo koko, xa usebenzisa ii-blind vias, kufuneka kukhunjulwe umlinganiselo wophawu.
Iimpawu ze-PCB back drilling
Iingenelo zokubhola umqolo
● Nciphisa ukuphazamiseka kwengxolo kunye ne-deterministic jitter;
● Phucula ukuthembeka kwesiginali;
● Ukunciphisa ubukhulu bendawo;
● Nciphisa ukusetyenziswa kwee-vias ezifihliweyo nezingaboniyo kwaye unciphise ubunzima bokuveliswa kwe-PCB;
● Izinga leempazamo zebhithi eliphantsi (BER);
● Ukuncitshiswa kwesignali okuncinci ngokuthelekiswa okuphuculweyo kwe-impedance;
● Impembelelo encinci yoyilo kunye noyilo;
● Ukwandiswa kwebhendi yetshaneli;
● Amanani edatha anyukileyo;
● ukwehla kokukhutshwa kwe-EMI/EMC ukusuka kwisiphelo se-stub;
● Ukunciphisa ukuvuseleleka kweendlela zokuqaqamba kwesandi;
● Ukuncokola okuncitshisiweyo nge-crosstalk;
● Iindleko eziphantsi kunee-laminations ezilandelelanayo.
Ububi bokubhola umqolo
Imiqondiso ephezulu idla ngokuba neengxaki ezinokunxulunyaniswa nokusetyenziswa kakubi kwee-stubs. Makhe sijonge ezinye zeengxaki ezibangelwa zii-stubs.
I-Jitter Deterministic:
Zombini iiwotshi zilinganisa ixesha, kwaye ubungakanani bempazamo yexesha bubizwa ngokuba yi-jitter. I-jetter yokuthintela yinto eyaziwa ngokuba yi-regular (oko kukuthi, limited) temporal modification.
Ukunciphisa uphawu:
Xa isandi sinciphile, ubukhali baso buyancipha kwaye ukubetha kwentliziyo kuba buthathaka.
Imitha evela kwi-EMI:
I-via stub ingasetyenziswa njenge-antenna, ikhupha i-EMI.
Iimpawu ngokubanzi
● Uninzi ziibhodi eziqinileyo ngasemva;
● Isetyenziswa rhoqo kwiileya ezisi-8 okanye ngaphezulu;
● Ubukhulu bebhodi bungaphezulu kwe-2.5mm;
● Ubungakanani obuncinci bokubambelela yi-0.3mm;
● I-Backdrill inkulu nge-0.2mm kune-vias;
● Ukunyamezela ubunzulu be-backdrill+/-0.05MM.
Loluphi uhlobo lwe-PCB olufuna ukugrunjwa ngasemva?
Ngokwesiqhelo, imingxunya yebhodi yePCB igqojozwa ebhodini (ukusuka phezulu ukuya ezantsi). Ukuba umkhondo odibanisa imingxunya edlulayo ukufutshane nomaleko ophezulu (okanye umaleko osezantsi), kuya kubangela ukuqhekeka kwe-stub kumngxunya odlulayo wekhonkco lonxibelelwano lwePCB, nto leyo eya kuchaphazela umgangatho wesignali kwaye ibangele ukubonakaliswa. Imiqondiso ehamba ngesantya esiphezulu ichaphazeleka ngakumbi yile mpembelelo.
Ukuze kufunyanwe umgangatho ophezulu wokudluliselwa kwesignali, ngokuqhelekileyo kuyaqondakala ukuba umkhondo wesekethe kwibhodi ye-PCB eneSignals zayo ngesantya esimalunga ne-1Gbps kufuneka uqwalaselwe ukuba uquka uyilo lwe-back-drill. Kakade ke, ukuyila imigca yoqhagamshelwano olukhawulezayo kufuna ubunjineli benkqubo kwaye akulula njengoko kunokubonakala. Ukuba amakhonkco onxibelelwano lwenkqubo awamade kakhulu okanye amandla okuqhuba etshiphusi aqine ngokwaneleyo, umgangatho wesignali unokuba msulwa ngaphandle kokubhola umva. Ke ngoko, ukulinganisa ikhonkco lonxibelelwano lwenkqubo yeyona ndlela ichanekileyo yokumisela ukuba i-back-drill iyafuneka okanye ayifuneki.
Usenokuba uyazi ukuba, ukongeza ekusebenziseni iteknoloji yokubhola umva, iindlela ezahlukeneyo zokwakha zingasetyenziswa ukunciphisa okanye ukwenza ngcono ubude be-stub. Ezi ziquka amalungiselelo ahlukeneyo okuqokelela izinto, apho imikhondo yesekethe itshintshelwa kwiileya ezikufutshane nesiphelo se-stub, imingxunya ye-via eyombiweyo nge-laser (microvias), okanye ii-via ezingaboniyo nezingcwatywe. Ukongeza, njengoko ezinye iindlela zisetyenziswa ukunciphisa ukubonakaliswa kwesignali kwiibhodi ezisebenzisa i-frequency ephezulu (engaphezulu kwe-3GHz), akufuneki ukubhola umva.
Nangona kunjalo, ezi ndlela azisoloko zisebenza kwisakhiwo sokuvelisa kwaye zixabisa iindleko zokunciphisa ukulahleka kwesiginali kwii-PCB ezininzi ezinoxinano oluphezulu okanye ii-backplanes/mid-planes. Ngoko ke, ukhetho olusebenzayo kuphela kukugrumba i-via stub. Xa imingxunya ye-vias engaboniyo ingeyona ndlela ifanelekileyo, ukugrumba i-back drill kuba yimfuneko kwiibhodi ezisebenzisa i-frequency ephezulu (ngaphezulu kwe-1GHz ngaphakathi kwe-3GHz).
Kwaye ekubeni i-PCB ineeleyara ezininzi kangaka, eminye imingxunya ayinakuyilwa njengemingxunya engaboniyo (umzekelo, kwi-PCB eneeleyara ezili-16, eminye ngemingxunya kufuneka idibane neeleyara ukusuka ku-1 ukuya ku-10 kwaye enye ngemingxunya kufuneka idibane neeleyara ukusuka ku-7 ukuya ku-16; olu yilo alufanelekanga kwimingxunya engaboniyo kodwa lufanelekile ekubholeni ngasemva).
Ungayenza njani i-PCB back drilling?
Inkqubo yokuDribha umva
1. Ukuze ufumane umngxuma wokuqala wokugrumba, sebenzisa umngxuma wokubeka kwindawo kwi-PCB enikiweyo.
2. Ngaphambi kokuba uplate, sebenzisa i-membrane eyomileyo ukuvala umngxuma wendawo.
3. Xuba umngxuma ngobhedu ukuze wenze isekethe yesikhokelo.
4.Yenza umzobo wangaphandle kwi-PCB.
5. Emva kokudala ipateni yomaleko wangaphandle, ibhodi yemizobo iya kwenziwa kwi-PCB. Ngaphambi kwale nkqubo, kubalulekile ukuvala umngxuma wokubeka nge-membrane eyomileyo ngaphambi kokuba uqale le nkqubo.
6.Sebenzisa imingxunya yokubeka ukubhola kokuqala ukuze ulungelelanise ukubhola okungasemva, uze usebenzise i-drill bit ukubhola imingxunya efakwe ngombane efuna le nkqubo.
7. Emva kokugrumba kokugqibela, ibhodi kufuneka icoceke ukuze kususwe naziphi na iidrili eziseleyo.
8. Emva kokuba ibhodi iqinisekisiwe kwaye ukuthembeka kwesiginali kuphuculwe, qwalasela ukuba umsebenzi wokugrumba wenziwa ngokufanelekileyo na.
Vavanya ii-Back Drills
Nje ukuba ucwangciso lugqityiwe, kufuneka siqinisekise ukuba ii-back drills zicwangcisiwe ngokufanelekileyo. Ukuqinisekisa oku, vula zonke ii-layers. Uza kubona ukuba i-rim ye-vias inemibala emibini kuyo. I-layers yokuqala okanye yokuqala iboniswa ngombala obomvu, ngelixa i-layers yokugqibela iboniswa ngombala oluhlaza okwesibhakabhaka. Kulula ukwahlula ii-back-drilled vias kwezinye ii-vias. Ii-back drilled vias kuphela ezibonakalayo ngemibala emibini.
Cofa kwiDrill Table emva kokukhetha indawo kwimenyu ephambili ukuze ufumane ukuba zingaphi iiVias, iiPTH, kunye nezinye iitroll ezenziweyo.
Ubunzima bobuchwephesha benkqubo yokubhoboza umqolo.
1.Ulawulo lobunzulu bokugrumba umva
Ukuze kusetyenzwe ngokuchanekileyo ii-vias ezingaboniyo, ulawulo lobunzulu bokubhola umva lubalulekile. Ukunyamezelana kobunzulu bokubhola umva kuchaphazeleka kakhulu kukuchaneka kwezixhobo zokubhola umva kunye nokunyamezelana kobukhulu obuphakathi. Nangona kunjalo, ukuchaneka kokubhola umva kungachaphazeleka ziinguqu zangaphandle ezifana nokuxhathisa ukubhola, i-engile yencam yokubhola, isiphumo soqhagamshelwano phakathi kwebhodi yokugquma kunye nesixhobo sokulinganisa, kunye ne-warpage yebhodi. Ukuze ufumane iziphumo ezilungileyo kwaye ulawule ukuchaneka kokubhola umva, kubalulekile ukukhetha izixhobo kunye neendlela ezifanelekileyo zokubhola umva ngexesha lokuvelisa. Abayili banokuqinisekisa ukuhanjiswa kwesignali esemgangathweni ophezulu kwaye baphephe iingxaki zokuthembeka kwesignali ngokulawula ngononophelo ubunzulu bokubhola umva.
2. Ulawulo lokuchaneka kokubhola emva
Ulawulo oluchanekileyo lokugrumba umva lubalulekile kulawulo lomgangatho we-PCB kwiinkqubo ezilandelayo. Ukugrumba umva kubandakanya ukugrumba kwesibini ngokusekelwe kububanzi bomngxuma wokuqala wokugrumba, kwaye ukuchaneka kokugrumba kwesibini kubalulekile. Ukuchaneka kokudibana kokugrumba kwesibini kunokuchaphazeleka zizinto ezininzi eziguquguqukayo, ezinje ngokwandiswa kwebhodi kunye nokucutheka, ukuchaneka komatshini, kunye neendlela zokugrumba. Kubalulekile ukuqinisekisa ukuba inkqubo yokugrumba umva ilawulwa ngokuchanekileyo ukugrumba ukuze kuncitshiswe iimpazamo kwaye kugcinwe ukuhanjiswa kwesignali efanelekileyo kunye nokuthembeka.
Inyathelo elibaluleke kakhulu nelinzima kukugrumba kuba nokuba yimpazamo encinci inokubangela umonakalo omkhulu. Ngaphambi kokuba ufake iodolo, kufuneka ucinge ngezakhono zomenzi wePCB. I-Richfulljoy inikezela ngeebhodi ezigrumbiweyo ngamaxabiso afikelelekayo kwaye igxile ekuhlanganiseni iiprototype zePCB. Iingenelo zethu ziquka amaxesha okuhambisa ngokukhawuleza kunye nokuthembeka okuphezulu. I-Richfulljoy, umenzi wePCB owaziwayo eTshayina, unolwazi kunye nezakhono ezifunekayo ukukunceda. Ukuba uneziphakamiso zokudibanisa iPCB okanye iprototype, nceda unxibelelane nathi: mkt-2@rich-pcb.com
