Enqubweni yokuklama ye-PCB, abanye onjiniyela abafuni ukubeka ithusi phezu kwawo wonke ungqimba olungezansi ukuze bonge isikhathi. Ingabe lokhu kulungile? Ingabe i-PCB kufanele ifakwe i-copper plated?
Okokuqala, sidinga ukucaca: i-copper plating engezansi inenzuzo futhi iyadingeka ku-PCB, kodwa i-copper plating ebhodini lonke kufanele ihlangabezane nemibandela ethile.
Izinzuzo ze-copper plating engezansi
1. Ngokombono we-EMC, yonke indawo yongqimba olungezansi imbozwe ngethusi, ehlinzeka ngokuvikela okungeziwe kokuvikela kanye nokucindezelwa komsindo wesignali yangaphakathi nesignali yangaphakathi. Ngesikhathi esifanayo, iphinde ibe nesivikelo esithile sokuzivikela semishini engaphansi kanye nezimpawu.
2. Ngokombono wokukhipha ukushisa, ngenxa yokwanda kwamanje kokuminyana kwebhodi le-PCB, i-chip eyinhloko ye-BGA nayo idinga ukucabangela izindaba zokukhipha ukushisa kakhulu. Lonke ibhodi lesifunda lisekelwe ngethusi ukuze kuthuthukiswe amandla okukhipha ukushisa kwe-PCB.
3. Ngokombono wenqubo, ibhodi lonke lisekelwe ngethusi ukwenza ibhodi le-PCB lisabalaliswe ngokulinganayo. Ukugoba kwe-PCB nokugoba kufanele kugwenywe phakathi nokucubungula nokucindezela kwe-PCB. Ngesikhathi esifanayo, ukucindezeleka okubangelwa i-PCB reflow soldering ngeke kubangelwa i-foil yethusi engalingani. I-PCB warpage.
Isikhumbuzi: Kumabhodi anezendlalelo ezimbili, i-copper coating iyadingeka
Ngakolunye uhlangothi, ngenxa yokuthi ibhodi elinezingqimba ezimbili alinayo indiza yereferensi ephelele, inhlabathi egandayiwe inganikeza indlela yokubuyisela, futhi ingasetshenziswa njengereferensi ye-coplanar ukufeza injongo yokulawula impedance. Ngokuvamile singabeka indiza yaphansi phezu kongqimba olungezansi, bese sibeka izingxenye eziyinhloko nemigqa yamandla kanye nemigqa yesignali kungqimba olungaphezulu. Kumasekhethi aphezulu angenawo amandla, ama-analog circuits (ama-analog-to-digital conversion circuits, ama-switch-mode power converting circuits), i-copper plating ingumkhuba omuhle.
Izimo ze-copper Plating phansi
Nakuba ungqimba olungezansi lwethusi luyilungele kakhulu i-PCB, lusadinga ukuhlangabezana nemibandela ethile:
1. Beka ngangokunokwenzeka ngesikhathi esifanayo, ungafaki konke ngesikhathi esisodwa, gwema isikhumba sethusi ekuqhekekeni, bese wengeza ngezimbobo endaweni engaphansi kwendawo yethusi.
Isizathu: Isendlalelo sethusi esisoqwembeni olungaphezulu kufanele sephulwe futhi sibhujiswe yizingxenye kanye nemigqa yesignali kungqimba olungaphezulu. Uma i-foil yethusi iphansi kahle (ikakhulukazi i-foil yethusi encane futhi ende iphukile), izoba yi-antenna futhi ibangele izinkinga ze-EMI.
2. Cabangela ibhalansi yokushisa yamaphakheji amancane, ikakhulukazi amaphakheji amancane, njenge-0402 0603, ukugwema imiphumela ephawulekayo.
Isizathu: Uma lonke ibhodi lesifunda lifakwe ngethusi, ithusi lezikhonkwane zengxenye lizoxhunywa ngokuphelele nethusi, okuzokwenza ukuthi ukushisa kuphele ngokushesha, okuzodala ubunzima ekuqothulweni nasekusebenzeni kabusha.
3. Ukubekwa phansi kwalo lonke ibhodi lesekethe ye-PCB kungcono ukuthi kube yisisekelo esiqhubekayo. Ibanga ukusuka phansi ukuya kusignali lidinga ukulawulwa ukuze kugwenywe ukungaqhubeki ekubambeni kolayini wokudlulisela.
Isizathu: Ishidi lethusi lisondele kakhulu phansi lizoshintsha ukuthinta kolayini wokudlulisa we-microstrip, futhi ishidi lethusi elingaqhubeki lizoba nomthelela omubi ekunqanyulweni kokuvinjwa kolayini wokudlulisela.
4. Ezinye izimo ezikhethekile zincike esimweni sohlelo lokusebenza. Idizayini ye-PCB akufanele ibe umklamo ophelele, kodwa kufanele ikalwe futhi ihlanganiswe nemibono eyahlukene.
Isizathu: Ngaphezu kwezimpawu ezibucayi ezidinga ukumiswa, uma kunemigqa yesignali eminingi enesivinini esiphezulu kanye nezingxenye, inani elikhulu lamakhefu ethusi amancane namade lizokhiqizwa, futhi iziteshi zezintambo ziqinile. Kuyadingeka ukugwema izimbobo zethusi eziningi ngangokunokwenzeka ukuze uxhume ungqimba lomhlabathi. Ungqimba olungaphezulu lungakhethwa ngaphandle kwethusi.