IMigaqo eliThoba eSiseko yoYilo lwe-SMB (II)

5. ukhetho lwamacandelo

Ukhetho lwamacandelo kufuneka luthathele ingqalelo ngokupheleleyo indawo eyiyo yePCB, kangangoko kunokwenzeka, ukusetyenziswa kwamacandelo aqhelekileyo.Musa ukulandela ngokumfamekileyo amacandelo amancinci ukuphepha ukunyuka kweendleko, izixhobo ze-IC kufuneka zihlawule ingqalelo kwi-pin shape kunye ne-foot space, i-QFP engaphantsi kwe-0.5mm yesithuba sonyawo kufuneka ithathelwe ingqalelo, kunokuba ukhethe ngokuthe ngqo izixhobo zephakheji ze-BGA.Ukongezelela, ifom yokupakisha yamacandelo, ubungakanani bokuphela kwe-electrode, i-solderability, ukuthembeka kwesixhobo, ukunyamezela kweqondo lokushisa njengokuba liyakwazi ukulungelelanisa neemfuno ze-solder-free soldering) kufuneka kuthathelwe ingqalelo.
Emva kokukhetha amacandelo, kufuneka umisele isiseko sedatha esilungileyo samacandelo, kubandakanywa ubungakanani bofakelo, ubungakanani bephini kunye nomenzi wolwazi olufanelekileyo.

6. ukhetho lwe-PCB substrates

I-substrate kufuneka ikhethwe ngokwemiqathango yokusetyenziswa kwe-PCB kunye neemfuno zokusebenza koomatshini kunye nombane;ngokwesakhiwo sebhodi eprintiweyo ukugqiba inani le-copper-clad surface ye-substrate (i-single-side, i-double-side okanye i-multi-layer board);ngokobukhulu bebhodi eprintiweyo, umgangatho wendawo yeyunithi ephethe amacandelo ukumisela ubukhulu bebhodi ye-substrate.Iindleko zeentlobo ezahlukeneyo zemathiriyeli zahluka kakhulu ekukhetheni i-PCB substrates kufuneka ziqwalasele ezi zinto zilandelayo:
Iimfuno zokusebenza kombane.
Izinto ezifana ne-Tg, i-CTE, i-flatness kunye nekhono le-metallization yomngxuma.
Izinto zexabiso.

7. ibhodi yesekethe eprintiweyo i-anti-electromagnetic interference interference design

Ukuphazamiseka kwe-electromagnetic yangaphandle, kunokusonjululwa ngamanyathelo okukhusela omatshini kunye nokuphucula uyilo oluchasene nokuphazamiseka kwesekethe.Ukuphazamiseka kombane kwindibano yePCB ngokwayo, kuyilo lwePCB, uyilo locingo, oku kulandelayo kufuneka kuqwalaselwe:
Amacandelo anokuthi achaphazele okanye aphazamise omnye nomnye, ukwakheka kufuneka kube kude kangangoko kunokwenzeka okanye kuthathe amanyathelo okukhusela.
Imigca yesignali yee-frequencies ezahlukeneyo, musa ukuhambelana i-wiring ngokusondeleyo omnye komnye kwimigca yesignali ye-high-frequency, kufuneka ibekwe kwicala layo okanye kumacala omabini ocingo oluphantsi lokukhusela.
I-high-frequency, i-high-speed circuits, kufuneka yenziwe ngokusemandleni ukuba ibhodi yesekethe eprintiweyo kabini kunye ne-multi-layer.Ibhodi enamacala amabini kwelinye icala lokucwangcisa imigca yomqondiso, elinye icala linokuthi liyilwe phantsi;ibhodi ye-multi-layer inokuthi ithinteke ekuphazamisekeni kwi-layout yemigca yesignali phakathi komgangatho womhlaba okanye umbane wokunikezelwa kwamandla;kwiisekethe ze-microwave ezinemigca yeribhoni, imigca yesignali yothumelo kufuneka ibekwe phakathi kwemigangatho emibini yokumisa, kunye nobukhulu bomaleko wemidiya phakathi kwabo njengoko kuyimfuneko ekubaleni.
Imigca eprintiweyo yesiseko seTransistor kunye nemigca yesignali ephezulu-frequency kufuneka iyilwe mfutshane kangangoko ukunciphisa ukuphazamiseka kwe-electromagnetic okanye imitha ngexesha lokuhanjiswa komqondiso.
Amalungu ee-frequencies ahlukeneyo awabelani ngomgca womhlaba ofanayo, kwaye iintambo zomhlaba kunye nombane we-frequencies ezahlukeneyo kufuneka zibekwe ngokwahlukeneyo.
Iisekethe zeDijithali kunye neesekethe ze-analog azihlanganisi umgca womhlaba ofanayo ngokumalunga nomhlaba wangaphandle webhodi yesekethe eprintiweyo unokuba noqhagamshelwano oluqhelekileyo.
Sebenza ngomlinganiselo omkhulu onokubakho phakathi kwamacandelo okanye imigca eprintiweyo, kufuneka yandise umgama phakathi komnye nomnye.

8. uyilo lwe-thermal yePCB

Ngokunyuka koxinzelelo lwamacandelo adityaniswe kwibhodi eprintiweyo, ukuba awukwazi ukutshabalalisa ubushushu ngexesha elifanelekileyo, kuya kuchaphazela iiparamitha zokusebenza zesekethe, kwaye nobushushu obuninzi buya kwenza ukuba amacandelo angaphumeleli, ngoko ke iingxaki ze-thermal. kwibhodi eprintiweyo, uyilo kufuneka luqwalaselwe ngononophelo, ngokubanzi luthathe la manyathelo alandelayo:
Ukwandisa indawo yefoyile yobhedu kwibhodi eprintiweyo kunye namacandelo anamandla aphezulu emhlabeni.
izinto ezivelisa ubushushu azifakwanga ebhodini, okanye isinki sobushushu esongezelelweyo.
kwiibhodi ze-multilayer umhlaba wangaphakathi kufuneka uyilwe njengomnatha kwaye usondele kumda webhodi.
Khetha uhlobo lwebhodi ekwaziyo ukumelana nobushushu okanye ekwaziyo ukumelana nobushushu.

9. I-PCB kufuneka yenziwe iikona ezingqukuva

Ii-PCB ze-engile ekunene ziqhelene nokuxinana ngexesha lothumelo, ngoko kuyilo lwePCB, isakhelo sebhodi kufuneka senziwe iikona ezingqukuva, ngokobungakanani bePCB ukumisela iradiyasi yeekona ezingqukuva.Ibhodi yeqhekeza kwaye ungeze icandelo elincedisayo le-PCB kumphetho oncedisayo ukwenza iikona ezingqukuva.