Okunye okucatshangelwayo okubaluleke kakhulu ekwakhiweni kwe-PCB ukunquma ukuthi zingaki izendlalelo zomzila, izindiza eziphansi, nezindiza zamandla ezidingekayo ukuze kuhlangatshezwane nezidingo zokusebenza zesekethe. Idizayini yesitaki ye-PCB ivamise ukuba ukuyekethisa, kucatshangelwa izici ezihlukahlukene. Ngezansi kunezimiso ezibalulekile zokuklama isitaki se-PCB.
Ukuhlela isitaki
Izendlalelo Zangaphandle ezine-GND ne-PWR: Lezi zendlalelo zisetshenziselwa ngokuyinhloko ukwenza umzila kanye nokunciphisa ukulandelelwa. Kuzinhlelo zokusebenza ze-HDI (High-Density Interconnect), isendlalelo sesibili sivamise ukuba ungqimba lwesignali olusetshenziselwa ukulandelela umzila phakathi kwezingxenye ze-BGA ezinephimbo elihle. Kulolu hlelo lokusebenza lwe-HDI, abakhiqizi bavamise ukusebenzisa i-laser drilling ukubhola okujulile okulawulwayo ukuze bafinyelele isendlalelo sesibili.
Izendlalelo zokulinganisa: Zonke izitaki kufanele zibe nesitaki sesendlalelo esilinganiselayo esivela emugqeni omaphakathi we-PCB ukuze kuncishiswe noma kuqedwe ukulwa. Uhlobo nogqinsi lwe-prepreg (impahla ekhulelwe) kufanele inqunywe ngaphambi kokuqala ukwakheka kwe-CAD.
Ukucatshangelwa Kwezokukhiqiza: Kuyadingeka ukwenza ukuhlaziya kwe-stack-up nomkhiqizi ukuze kunqunywe isisindo sethusi, impahla yangaphambi kokulungiswa, kanye nogqinsi oluyinhloko ngaphambi kwesakhiwo se-CAD, ukuqinisekisa ukuthikamezeka okulawulwayo.
Ukomelela Kwezindwangu:
- 1.6mm FR4 impahla isetshenziselwa izitaki ezinezendlalelo ezingu-2–16.
- I-1.8mm FR4 isetshenziselwa izitaki ezinezendlalelo ezingu-10–20.
- I-2.3mm FR4 isetshenziselwa izitaki ezinezendlalelo ezingu-10–32.
Ubukhulu be-PCB obujwayelekile:
- A. 0.8mm (0.031″)
- B. 1.0mm (0.040″)
- C. 1.6mm (0.062″)
- D. 1.8mm (0.070″)
- E. 2.3mm (0.090″)
- F. 3.2mm (0.125″)
stack-up Design Izimiso
Ukuhlukaniswa Kwesendlalelo
Kuma-PCB anezendlalelo eziningi, izendlalelo ngokuvamile zihlanganisa izendlalelo zesignali (S), izendlalelo zamandla (P), nezingqimba zomhlabathi (GND). Izendlalelo zamandla nomhlabathi zivame ukuhlangana futhi zinikeza indlela yokubuya ene-impedance ephansi yamanje egeleza ngemikhondo yesignali eseduze. Izendlalelo zesignali zibekwe kakhulu phakathi kwalawa mandla noma izendlalelo zendiza eyisithenjwa. Izendlalelo ezingaphezulu neziphansi ze-PCB enezingqimba eziningi ngokuvamile zisetshenziselwa ukubeka izingxenye kanye nenani elincane lomzila.
Ukunquma Indiza Yereferensi Yamandla Eyodwa
Ama-Decoupling capacitor kufanele abekwe kuphela phezu kwezingqimba ezingaphezulu neziphansi ze-PCB. Umzila, amaphedi, nama-vias axhumeka kulawa ma-capacitor angaphazamisa kakhulu ukusebenza kwawo. Ngakho-ke, kubalulekile ukuqinisekisa ukuthi imikhondo exhuma kuma-decoupling capacitor mifushane futhi ibanzi ngangokunokwenzeka, nge-vias exhunywe kule mikhondo ibe mfushane ngangokunokwenzeka.
Ukunquma Izindiza Eziningi Eziyisethenjwa Zamandla
Izindiza eziningi zereferensi yamandla zihlukaniswe izifunda ezihlukene, ngasinye sinikeza amazinga kagesi ahlukene. Uma izendlalelo zesignali zincikene nalezi zindiza zamandla amaningi, amasiginali akulezi zendlalelo angase ahlangabezane nezindlela ezingezinhle zokubuya, ezingaba nomthelela omubi kubuqotho besignali. Ngakho-ke, umzila wesignali wedijithali onesivinini esikhulu kufanele ugcinwe kude nezindiza eziningi zereferensi yamandla.
Ukunquma Izindiza Eziningi Eziyisethenjwa ZaseGround (Izindiza Zaphansi)
Izindiza eziningi ezibhekisela emhlabathini zinikeza indlela yokubuya enezithiyo eziphansi zamagagasi, okusiza ekunciphiseni i-EMI yemodi evamile (I-Electromagnetic Interference). Izindiza eziphansi nezinamandla kufanele zihlanganiswe ngokuqinile, futhi izingqimba zesignali kufanele zihlanganiswe ngokuqinile nezindiza eziyisithenjwa eziseduze.
Ukuklama Izinhlanganisela Zomzila
Inhlanganisela yezendlalelo isignali yokulandela umkhondo ewela kuyo ibizwa ngokuthi “inhlanganisela yomzila.” Idizayini engcono kakhulu yenhlanganisela yomzila igwema amaza abuyayo ukuthi angagelezi phakathi kwezindiza eziyizethenjwa ezihlukene. Ngokufanelekile, i-current return kufanele igeleze isuka endaweni eyodwa endizeni eyireferensi iye kwelinye iphuzu endizeni efanayo.
