PCB i-wiring ibaluleke kakhulu kuyilo lonke lwePCB. Ukufikelela njani kwiingcingo ezikhawulezayo nezisebenzayo kwaye wenze iingcingo zePCB zibukeke zinde kufanelekile ukuba uzifunde. Yahlelwa imiba esi-7 ekufuneka iqwalaselwe kwiingcingo zePCB, uze ujonge izinto ezishiyiweyo kwaye ugcwalise izithuba!

1. Ukuqhubekeka komhlaba okuqhelekileyo kwisekethe yedijithali kunye neesekethe zeanalog

Ii-PCB ezininzi azisekho iisekethe ezisebenza enye (iisekethe zedijithali okanye ze-analog), kodwa zenziwe ngumxube wesekethe zedijithali kunye ne-analog. Ngoko ke, kuyimfuneko ukuqwalasela ukuphazamiseka phakathi kwabo xa udibanisa, ngokukodwa ukuphazamiseka kwengxolo kwi-wire yomhlaba. I-frequency yesekethe yedijithali iphezulu, kwaye uvakalelo lwesekethe ye-analog yomelele. Ngomgca wesignali, umgca wesignali we-high-frequency kufuneka ube kude kangangoko kunokwenzeka kwisixhobo sesekethe ye-analog. Kumgca osezantsi, yonke i-PCB ine-node enye kwihlabathi langaphandle, ngoko ke Ingxaki yedijithali kunye ne-analog yomhlaba oqhelekileyo kufuneka kujongwane nayo ngaphakathi kwe-PCB, kwaye umhlaba wedijithali kunye nomhlaba we-analog ngaphakathi kwebhodi zihlulwe ngokwenene kwaye ziyahlukana. ayidityaniswanga enye kwenye, kodwa kujongano (ezifana neeplagi, njl. njl.) idibanisa iPCB nelizwe langaphandle. Kukho uxhumano olufutshane phakathi komhlaba wedijithali kunye nomhlaba we-analog. Nceda uqaphele ukuba kukho indawo enye kuphela yoqhagamshelwano. Kukwakho nezizathu ezingezizo eziqhelekileyo kwi-PCB, emiselwa yinkqubo yoyilo.

2. Umgca wesiginali ubekwe kumaleko ombane (emhlabeni)

Kwi-multi-layer eprinted wiring board, kuba akukho ingcingo ezininzi ezisele kwi-signal line layer engakhange ibekwe, ukongeza iileyile ezininzi kuya kubangela inkunkuma kunye nokwandisa umsebenzi wokuvelisa, kwaye iindleko ziya kunyuka ngokufanelekileyo. Ukusombulula le ngxabano, unokuqwalasela i-wiring kumbane (umhlaba) umaleko. Uluhlu lwamandla kufuneka luqwalaselwe kuqala, kwaye umgangatho womhlaba wesibini. Ngenxa yokuba kungcono ukugcina ingqibelelo yokwakheka.

3. Unyango lwemilenze yokudibanisa kwiindawo ezinkulu zabaqhubi

Kwindawo enkulu yomhlaba (umbane), imilenze yamacandelo aqhelekileyo axhunyiwe kuyo. Unyango lwemilenze yokudibanisa kufuneka ithathelwe ingqalelo ngokubanzi. Ngokumalunga nokusebenza kombane, kungcono ukudibanisa iipads zemilenze yecandelo kwindawo yobhedu. Kukho iingozi ezingafunekiyo ezifihlakeleyo ekudibaniseni nasekudityanisweni kwezinto, ezinje: ① Ukuwelda kufuna izifudumezi ezinamandla amakhulu. ②Kulula ukwenza i-solder joints. Ke ngoko, zombini ukusebenza kombane kunye neemfuno zenkqubo zenziwe kwiipads ezinqamlezileyo, ezibizwa ngokuba zizikhuselo zobushushu, ezaziwa ngokuba zii-thermal pads (Thermal), ukwenzela ukuba amajoyinti e-solder anokuthi aveliswe ngenxa yobushushu obugqithileyo becandelo ngexesha le-soldering. Ukwabelana ngesondo kuncitshiswe kakhulu. Ukuqhutyelwa komlenze wamandla (umhlaba) webhodi ye-multilayer iyafana.

4. Indima yesixokelelwano sothungelwano kwikhebula

Kwiinkqubo ezininzi zeCAD, i-wiring izimisele ngokusekelwe kwinkqubo yenethiwekhi. Igridi ixinene kakhulu kwaye indlela iye yanda, kodwa inyathelo lincinci, kwaye inani ledatha kwintsimi likhulu kakhulu. Oku kuya kuba neemfuneko eziphezulu zendawo yokugcina isixhobo, kunye nesantya sekhompyutheni yeemveliso zombane ezisekelwe kwikhompyutha. Impembelelo enkulu. Ezinye iindlela azivumelekanga, njengalezo zihlalwa ngamaphedi emilenze yecandelo okanye ngokufaka imingxuma kunye nemingxuma emileyo. Iigridi ezinqabileyo kakhulu kunye neendlela ezimbalwa kakhulu zinempembelelo enkulu kwizinga lokusabalalisa. Ngoko ke kufuneka kubekho inkqubo yegridi efanelekileyo ukuxhasa iingcingo. Umgama phakathi kwemilenze yamacandelo asemgangathweni yi-intshi ye-0.1 (2.54 mm), ngoko ke isiseko senkqubo yegridi ngokuqhelekileyo imiselwe kwi-intshi ze-0.1 (2.54 mm) okanye i-multiple edibeneyo engaphantsi kwe-0.1 intshi, njenge: 0.05 intshi, 0.025 intshi, 0.02 intshi njl.

5. Unyango lokunikezelwa kwamandla kunye nocingo lomhlaba

Nokuba i-wiring kwibhodi yonke ye-PCB igqitywe kakuhle kakhulu, ukuphazamiseka okubangelwa ukuqwalaselwa okungafanelekanga konikezelo lwamandla kunye nocingo lomhlaba luya kunciphisa ukusebenza kwemveliso, kwaye ngamanye amaxesha kuchaphazela izinga lokuphumelela kwemveliso. Ngoko ke, i-wiring yokunikezelwa kwamandla kunye nocingo lomhlaba kufuneka kuthathwe ngokungathí sina, kwaye ukuphazamiseka kwengxolo eyenziwa ngumbane kunye nocingo lomhlaba kufuneka kuncitshiswe ukuqinisekisa umgangatho wemveliso. Yonke injineli ebandakanyeka kuyilo lweemveliso ze-elektroniki iyayiqonda imbangela yengxolo phakathi kocingo lomhlaba kunye nocingo lwamandla, kwaye ngoku kuphela ukucutha kwengxolo encitshisiweyo kubonakaliswe: kuyaziwa ukuba yongeza ingxolo phakathi kombane kunye nomhlaba. ucingo. Lotus capacitor. Yandisa ububanzi bamandla kunye neengcingo zomhlaba kangangoko kunokwenzeka, ngokufanelekileyo ucingo oluphantsi lubanzi kunocingo lwamandla, ubudlelwane babo bu: ucingo lomhlaba “locingo lwamandla” ucingo lwesignali, ngokuqhelekileyo ububanzi bocingo lwesignali bu: 0.2 ~ 0.3mm, obona bubanzi bugqibeleleyo bunokufikelela ku-0.05 ～0.07mm, intambo yamandla yi-1.2～2.5mm. Kwi-PCB yesekethe yedijithali, ucingo olubanzi lomhlaba lungasetyenziselwa ukwenza i-loop, oko kukuthi, umnatha ophantsi ungasetyenziswa (umhlaba wesiphaluka se-analog awukwazi ukusetyenziswa ngale ndlela). Indawo enkulu yobhedu yobhedu isetyenziswa njengocingo lomhlaba, olungasetyenziswanga kwibhodi eprintiweyo. Idityaniswe phantsi njengocingo lomhlaba kuzo zonke iindawo. Okanye inokwenziwa kwibhodi ye-multilayer, kwaye ukunikezelwa kwamandla kunye neengcingo zomhlaba zithatha umaleko omnye.

6. Ukukhangela umthetho woyilo (i-DRC)

Emva kokugqitywa koyilo lwe-wiring, kuyimfuneko ukujonga ngokucophelela ukuba i-design ye-wiring ihambelana nemithetho eyenziwe ngumyili, kwaye kwangaxeshanye, kuyimfuneko ukuqinisekisa ukuba imigaqo emiselweyo ihlangabezana neemfuno zenkqubo yokuvelisa ibhodi eprintiweyo. . Ukuhlolwa ngokubanzi kunemiba ilandelayo: umgca kunye nomgca, umgca Ingaba umgama phakathi kwepadi yecandelo, umgca kunye nomngxuma, i-pad yecandelo kunye nomngxuma, kunye nomngxuma kunye nomngxuma kunengqiqo kwaye ingaba ihlangabezana neemfuno zokuvelisa. Ngaba ububanzi bomgca wamandla kunye nomgca osezantsi bufanelekile, kwaye ngaba kukho ukudibanisa okuqinileyo phakathi komgca wamandla kunye nomgca ophantsi (i-impedance ephantsi yamaza)? Ngaba kukho nayiphi na indawo kwi-PCB apho ucingo oluphantsi lunokwandiswa? Ingaba amanyathelo angcono athathiweyo kwimigca yeempawu eziphambili, njengobude obufutshane, umgca wokukhusela wongezwa, kwaye umgca wokungena kunye nomgca wokuphuma uhlukaniswe ngokucacileyo. Ingaba kukho iingcingo zomhlaba ezihlukeneyo zesekethe ye-analog kunye nesekethe yedijithali. Nokuba imizobo (efana nee-iyikhoni kunye nezichasiselo) ezongeziweyo kwi-PCB ziya kubangela umqondiso wesekethe emfutshane. Guqula iimilo zemigca ezingafunekiyo. Ngaba kukho umgca wenkqubo kwi-PCB? Ingaba i-mask ye-solder iyahlangabezana neemfuno zenkqubo yokuvelisa, nokuba isayizi ye-mask ye-solder ifanelekile, kunye nokuba ilogo yomlinganiswa icinezelwe kwiphedi yesixhobo, ukuze ingachaphazeli umgangatho wesixhobo sombane. Ingaba umphetho wesakhelo sangaphandle somgangatho womhlaba wamandla kwibhodi ye-multi-layer iyancitshiswa, ukuba i-foil yobhedu yomgangatho womhlaba wamandla ibonakaliswe ngaphandle kwebhodi, kulula ukubangela isiphaluka esifutshane.

7. Ngoyilo

I-Via lelinye lamacandelo abalulekileyo e-PCB ene-multi-layer, kwaye iindleko zokomba zihlala zithatha i-30% ukuya kwi-40% yeendleko zokwenziwa kwe-PCB. Ukubeka nje, wonke umngxuma kwi-PCB unokubizwa ngokuba yi-via. Ukusuka kwindawo yokujonga umsebenzi, i-vias inokwahlulwa ibe ngamacandelo amabini: enye isetyenziselwa ukudityaniswa kombane phakathi kwemigangatho; enye isetyenziselwa ukulungisa okanye ukubeka izixhobo. Ngokwemigaqo yenkqubo, ii-vias zidla ngokuhlulwa zibe ziindidi ezintathu, ezizezi, nge-dias eyimfama, ngokungcwatywa nge-vias kunye nange-vias.

Imingxuma eyimfama ibekwe kwindawo ephezulu nangaphantsi yebhodi yesekethe eprintiweyo kwaye inobunzulu obuthile. Zisetyenziselwa ukudibanisa umgca womphezulu kunye nomgca wangaphakathi ongaphantsi. Ubunzulu bomngxuma ngokuqhelekileyo abudluli umlinganiselo othile (i-aperture). Umngxuma ongcwatywayo ubhekiselele kumngxuma wokudibanisa obekwe kwinqanaba elingaphakathi lebhodi yesekethe eprintiweyo, engadlulisi kumphezulu webhodi yesekethe. Ezi ntlobo zimbini zemingxuma zikhankanywe ngasentla zibekwe kuluhlu lwangaphakathi lwebhodi yesekethe, kwaye zigqitywe ngenkqubo yokuqulunqa umngxuma ngaphambi kokuba i-lamination, kunye nemigangatho emininzi yangaphakathi inokugqithwa ngexesha lokusekwa kwe-via. Uhlobo lwesithathu lubizwa ngokuba ngumngxuma, ongena kuyo yonke ibhodi yesekethe kwaye ingasetyenziselwa uqhagamshelo lwangaphakathi okanye njengenxalenye yokubeka umngxuma wokumisa. Kuba umngxuma wokutyhutyha kulula ukuyiqonda kwinkqubo kwaye iindleko zisezantsi, isetyenziswa kwiibhodi ezininzi eziprintiweyo zesekethe endaweni yezinye iindidi ezimbini zokutyhubela imingxunya. Oku kulandelayo ngemingxunya, ngaphandle kokuba kucaciswe ngolunye uhlobo, kuthathwa njengemingxuma.

1. Ukusuka kwimbono yoyilo, i-via iqulunqwe ikakhulu ngamacandelo amabini, enye i-drill hole phakathi, kwaye enye yindawo ye-pad ejikeleze umngxuma wokubhobhoza. Ubungakanani bala macandelo mabini bumisela ubungakanani be-via. Ngokucacileyo, kuyilo lwePCB olunesantya esiphezulu, esinoxinano oluphezulu, abaqulunqi bahlala benethemba lokuba incinci indlela yomngxunya, ingcono, ukuze kushiywe indawo yocingo ebhodini. Ukongeza, incinci idlula umngxuma, i-parasitic capacitance yayo. Incinci incinci, ifaneleke ngakumbi kwiisekethe zesantya esiphezulu. Nangona kunjalo, ukucuthwa kobungakanani bomngxuma kuzisa ukwanda kweendleko, kwaye ubungakanani be-vias abunakuncitshiswa ngokungenasiphelo. Ithintelwe ngeteknoloji yenkqubo efana nokugrumba kunye nokucwenga: umngxuma omncinci, ukugrumba ngakumbi Xa umngxuma uthatha ixesha elide, kulula ukuphambuka kwindawo ephakathi; kwaye xa ubunzulu bomngxuma budlula amaxesha ama-6 ububanzi bomngxuma owenziweyo, akunakuqinisekiswa ukuba udonga lomngxuma lunokufakwa ngokufanayo ngobhedu. Umzekelo, ubukhulu (ngokusebenzisa ubunzulu bomngxuma) kwibhodi yePCB ene-6-layer eqhelekileyo imalunga ne-50Mil, ngoko ke ubuncinci bedayamitha yokomba enokunikwa ngabavelisi bePCB inokufikelela kuphela kwi-8Mil.

Okwesibini, i-parasitic capacitance ye- via hole ngokwayo ine-parasitic capacitance emhlabeni. Ukuba kuyaziwa ukuba ububanzi bomngxuma wokwahlula kumqolo osemhlabeni we-via yi-D2, ububanzi be-pad yi-D1, kwaye ubukhulu bebhodi ye-PCB yi-T, I-dielectric constant ye-substrate yebhodi ngu-ε, kunye ne-parasitic capacitance ye-via malunga: C = 1.41εTD1 / (D2-D1) Isiphumo esiphambili se-parasitic capacitance ye-pass kwisekethe kukwandisa ixesha lokunyuka komqondiso kunye nokunciphisa Isantya sesiphaluka.

3. I-Parasitic inductance of vias Ngokufanayo, kukho inductances yeparasitic kunye ne-parasitic capacitances kwi-vias. Kuyilo lweesekethe zedijithali ezinesantya esiphezulu, umonakalo obangelwa yi-parasitic inductances ye-vias idla ngokuba mkhulu kunempembelelo ye-parasitic capacitance. I-series yayo ye-parasitic inductance iya kwenza buthathaka igalelo le-bypass capacitor kwaye yenza buthathaka umphumo wokucoca yonke inkqubo yamandla. Singabala ngokulula i-parasitic inductance ye-a via ngale fomyula ilandelayo: L=5.08h[ln(4h/d)+1] apho uL ebhekisa kwi-inductance yokudlula, h bubude bendlela, kwaye d liziko Ububanzi bomngxuma. Inokubonwa kwifomula yokuba ububanzi be-via bunempembelelo encinci kwi-inductance, kwaye ubude bendlela bunempembelelo enkulu kwi-inductance.

4. Ngoyilo kwi-PCB enesantya esiphezulu. Ngokusebenzisa uhlalutyo olungentla lweempawu ze-parasitic ze-vias, siyabona ukuba kuyilo lwe-PCB olunesantya esiphezulu, i-vias ebonakala ilula idla ngokuzisa izinto ezimbi kuyilo lwesekethe. isiphumo.