Izintambo ze-PCB zizothinta okulandelayo I-PCB Assembly ukucubungula. Kufanele sicabangele ngokugcwele ububanzi bomugqa kanye nesikhala somugqa wezintambo, ukuxhumana phakathi kwentambo nephedi yengxenye ye-chip, intambo kanye ne-SOIC, PLCC, QFP, SOT namanye amadivaysi esigabeni sokuklama se-PCB. Ubudlelwano phakathi kokuxhumeka kwephedi, ububanzi bomugqa kanye nokwamanje, kuphela lapho lezi zinkinga zisingathwa kahle, kungacutshungulwa ibhodi le-PCBA eliphezulu.

1. Ububanzi bezintambo

Izidingo zosayizi wobubanzi bezintambo zinjengoba kukhonjisiwe kuthebula, okuhlanganisa ubukhulu bezendlalelo zangaphakathi nezingaphandle kanye ne-foil yethusi emaphethelweni ebhodi kanye nodonga lwembobo engenansimbi.

2. Ububanzi bomugqa kanye nesikhala somugqa wezintambo

Endabeni yokuvumela ukuminyana kokucubungula komhlangano we-PCBA, ukwakheka kwezintambo okuminyana okuphansi kufanele kusetshenziswe ngangokunokwenzeka ukuze kuthuthukiswe amandla okukhiqiza angenasici futhi anokwethenjelwa. Njengamanje, amandla okucubungula abakhiqizi abajwayelekile yilokhu: ubuncane bobubanzi bomugqa ngu-0.127mm (5mil), kanti isikhala esincane somugqa singu-0.127mm (5mil). Ireferensi yedizayini yokuminyana kwezintambo esetshenziswa ngokuvamile iboniswa etafuleni.

3. Ukuxhumana phakathi kwentambo nephedi yengxenye ye-chip

Lapho uxhuma izintambo kanye nezingxenye ze-chip, ngokuyisisekelo, zingaxhunywa nganoma yisiphi isikhathi. Kodwa-ke, ezingxenyeni ze-chip ezishiselwe nge-reflow welding, kungcono ukuklama ngokuvumelana nezimiso ezilandelayo.

a. Ezingxenyeni ezifakwe ngamaphedi amabili, njengama-resistors nama-capacitors, izintambo eziphrintiwe ezixhunywe kuma-pads azo kufanele zidwetshwe ngokulinganayo kusukela phakathi nendawo ye-pad, futhi izintambo eziphrintiwe ezixhunywe ku-pad kufanele zibe nobubanzi obufanayo. Ezintanjeni eziholayo ezinobubanzi bomugqa obungaphansi kuka-0.3mm (12mil), lesi simiso singanakwa.

b. Ukuze uthole amaphedi axhunywe ocingweni olubanzi oluphrintiwe, kungcono ukudlula uguquko lwentambo ephrintiwe emincane phakathi. Lolu cingo oluphrintiwe oluncane luvame ukubizwa ngokuthi “indlela yokufakwa kwe-insulation”, ngaphandle kwalokho, ku-2125 (isiNgisi yi-0805) ) Futhi ama-SMD alandelayo ohlobo lwe-chip athambekele ekushiyekeni kwe-“standing chip” ngesikhathi sokushisela. Izidingo eziqondile zikhonjiswe emfanekisweni.

4. Izintambo zixhunywe kumaphedi e-SOIC, PLCC, QFP, SOT namanye amadivayisi

Lapho uxhuma isifunda kuphedi ye-SOIC, PLCC, QFP, SOT namanye amadivaysi, ngokuvamile kunconywa ukuthi uhole ucingo kusuka kuzo zombili iziphetho zephedi, njengoba kuboniswe esithombeni.

5. Ubudlelwano phakathi kobubanzi bomugqa kanye nowamanje

Uma isilinganiso samanje sesignali sikhulu ngokuqhathaniswa, ubudlelwano phakathi kobubanzi bomugqa kanye nokwamanje budinga ukucatshangelwa. Ukuze uthole amapharamitha athile, sicela ubheke ithebula elilandelayo. Ekwakhiweni nasekucutshungulweni kwe-PCB, i-oz (i-ounce) ivamise ukusetshenziswa njengeyunithi yokujiya yefoyili yethusi. Ugqinsi lwethusi oluyi-1oz luchazwa njengesisindo socwecwe lwethusi endaweni eyintshi yesikwele eyodwa, ehambisana nokujiya komzimba okungama-35μm. Uma i-foil yethusi isetshenziswa njengocingo futhi kudluliswa umsinga omkhulu, ubudlelwano phakathi kobubanzi be-foil yethusi kanye nomthamo wamanje wokuthwala kufanele wehliswe ngo-50% ngokubhekisela kudatha etafuleni.