Yintoni ubudlelwane phakathi kocingo lwePCB, ngomngxuma kunye nomthamo okhoyo wokuthwala?

Uqhagamshelo lombane phakathi kwamacandelo kwi-PCBA luphunyezwa ngocingo lwefoyile yobhedu kunye nemingxuma kwimaleko nganye.

Uqhagamshelo lombane phakathi kwamacandelo kwi-PCBA luphunyezwa ngocingo lwefoyile yobhedu kunye nemingxuma kwimaleko nganye. Ngenxa yeemveliso ezahlukeneyo, iimodyuli ezahlukeneyo zobukhulu obuhlukeneyo ngoku, ukuze kuphunyezwe umsebenzi ngamnye, abaqulunqi kufuneka bazi ukuba i-wiring eyiliweyo kunye nomngxuma inokuthwala i-current ehambelanayo, ukuze kufezekiswe umsebenzi wemveliso, ukukhusela imveliso. ukusuka ekutshisweni xa i-overcurrent.

Apha kwazisa ukuyilwa kunye novavanyo lwangoku lokuthwala umthamo we-wiring kunye nemingxuma edlulayo kwi-FR4 ipleyiti yobhedu kunye neziphumo zovavanyo. Iziphumo zovavanyo zinokubonelela ngereferensi ethile kubayili kuyilo lwexesha elizayo, ukwenza uyilo lwePCB lube nengqiqo ngakumbi kwaye luhambelane neemfuno zangoku.

Uqhagamshelo lombane phakathi kwamacandelo kwi-PCBA luphunyezwa ngocingo lwefoyile yobhedu kunye nemingxuma kwimaleko nganye.

Kwinqanaba langoku, eyona nto iphambili yebhodi yesekethe eprintiweyo (PCB) yipleyiti yobhedu edityanisiweyo yeFR4. I-foil yobhedu enobunyulu bobhedu obungekho ngaphantsi kwe-99.8% iqonda uxhulumaniso lombane phakathi kwecandelo ngalinye kwinqwelomoya, kunye nomngxuma wokudlula (VIA) uqaphela uxhulumaniso lombane phakathi kwefoyile yobhedu kunye nomqondiso ofanayo kwisithuba.

Kodwa indlela yokuyila ububanzi befoyile yobhedu, indlela yokuchaza i-aperture ye-VIA, sihlala siyila ngamava.

Ukuze wenze uyilo loyilo lube nengqiqo ngakumbi kwaye luhlangabezane neemfuno, umthamo wangoku wokuthwala wefoyile yobhedu kunye needayamitha zocingo ezahlukeneyo uyavavanywa, kwaye iziphumo zovavanyo zisetyenziswa njengesalathiso soyilo.

Uhlalutyo lwezinto ezichaphazela umthamo wangoku wokuthwala

Ubungakanani bangoku be-PCBA buyohluka kunye nomsebenzi wemodyuli wemveliso, ngoko ke kufuneka siqwalasele ukuba i-wiring esebenza njengebhulorho inokuthwala ukudlula kwangoku. Izinto eziphambili ezimisela umthamo wangoku wokuthwala zezi:

Ubukhulu befoyile yobhedu, ububanzi bocingo, ukunyuka kwamaqondo obushushu, ukucwenga ngokuvula umngxuma. Kuyilo lokwenene, kufuneka siqwalasele imeko yemveliso, iteknoloji yokuvelisa iPCB, umgangatho wepleyiti njalo njalo.

1.Ifoyile yobhedu ubukhulu

Ekuqaleni kophuhliso lwemveliso, ubukhulu befoyile yobhedu yePCB buchazwa ngokwexabiso lemveliso kunye nobume bangoku kwimveliso.

Ngokubanzi, kwiimveliso ezingenazo zangoku eziphezulu, ungakhetha umphezulu (wangaphakathi) umaleko wefoyile yobhedu malunga ne-17.5μm ubukhulu:

Ukuba imveliso inenxalenye yangoku ephezulu, ubungakanani beplate banele, unokukhetha umphezulu (wangaphakathi) umaleko omalunga ne-35μm ubukhulu befoyile yobhedu;

Ukuba uninzi lweempawu kwimveliso ziphezulu ngoku, umaleko wangaphakathi wefoyile yobhedu malunga ne-70μm ubukhulu kufuneka ukhethwe.

Kwi-PCB enamaleko angaphezu kwamabini, ukuba umphezulu kunye ne-foil yobhedu yangaphakathi isebenzisa ubukhulu obufanayo kunye nobubanzi obufanayo bocingo, umthamo wangoku womgangatho ophezulu kunalowo we-inner layer.

Thatha ukusetyenziswa kwe-35μm yefoyile yobhedu kuzo zombini iileya zangaphakathi nangaphandle ze-PCB njengomzekelo: isekethe yangaphakathi ilayitiwe emva kokufakwa, ngoko ubukhulu befoyile yobhedu yangaphakathi yi-35μm.

Emva kwe-etching yesekethe yangaphandle, kuyimfuneko ukubhoba imingxuma. Ngenxa yokuba imingxuma emva kokugrumba ayinayo ukusebenza koqhagamshelo lombane, kuyimfuneko kwi-electroless copper plating, eyiyo yonke inkqubo yobhedu yobhedu, ngoko ke ifoyile yobhedu yomphezulu iya kugqunywa ngobunzima obuthile bobhedu, ngokubanzi phakathi kwe-25μm kunye ne-35μm, ngoko ubukhulu bokwenene befoyile yobhedu yangaphandle bumalunga ne-52.5μm ukuya kwi-70μm.

Ukufana kwe-foil yobhedu kuyahluka kunye nomthamo wabanikezeli beplate yobhedu, kodwa umahluko awubalulekanga, ngoko ke impembelelo kumthwalo wangoku inokungahoywa.

2.Intambo yocingo

Emva kokuba ubukhulu be-foil yobhedu bukhethiweyo, ububanzi bomgca buba yi-factory eqinisekileyo yomthamo wokuthwala ngoku.

Kukho ukutenxa okuthile phakathi kwexabiso eliyiliweyo lobubanzi bomgca kunye nelona xabiso lokwenyani emva kokubhala. Ngokuqhelekileyo, ukutenxa okuvumelekileyo ngu +10μm/-60μm. Ngenxa yokuba i-wiring ifakwe, kuya kubakho intsalela yolwelo kwikona yocingo, ngoko ke ikona yocingo iya kuba yeyona ndawo ibuthathaka.

Ngale ndlela, xa ubala ixabiso lomthwalo wangoku womgca kunye nekona, ixabiso langoku lomthwalo elilinganiswe kumgca ochanekileyo kufuneka liphindwe (W-0.06) / W (W ububanzi bomgca, iyunithi mm).

3.Ukunyuka kobushushu

Xa iqondo lobushushu linyuka ukuya okanye liphezulu kunobushushu be-TG ye-substrate, kunokubangela ukuguqulwa kwe-substrate, njengokulwa kunye ne-bubbling, ukwenzela ukuba kuchaphazele amandla okubopha phakathi kwe-foil yobhedu kunye ne-substrate. Ukuguqulwa kwe-warping ye-substrate kunokukhokelela ekuqhekekeni.

Emva kokuba i-PCB i-wiring idlula i-current enkulu yangoku, indawo ebuthathaka kakhulu yocingo lwe-foil yobhedu ayikwazi ukufudumala kwindalo ixesha elifutshane, ngokumalunga nenkqubo ye-adiabatic, iqondo lokushisa likhuphuka ngokukhawuleza, lifikelela kwindawo yokunyibilika kobhedu, kwaye ucingo lobhedu lutshiswe. .

4.Ukucwenga ngomngxuma wokuvula

I-Electroplating ngokusebenzisa imingxuma inokuqonda uxhulumaniso lombane phakathi kweeleyile ezahlukeneyo ngobhedu lwe-electroplating eludongeni lomngxuma. Ekubeni ilubhedu lweplate yepleyiti yonke, ubukhulu bobhedu bodonga lomngxuma bufana nokucandwa kwimingxuma yokuvula nganye. Umthamo wangoku wokuthwala wokucandwa kwimingxuma enobungakanani bepore obahlukeneyo uxhomekeke kwiperimeter yodonga lobhedu.