emva kokuba PCB uyilo lugqityiwe, yonke into iya kulunga? Enyanisweni, oku akunjalo. Kwinkqubo yePCB processing, iingxaki ezahlukeneyo zihlala zidibana, njengetoti eqhubekayo emva kokuthengiswa kwamaza. Ewe, ayizizo zonke iingxaki “zembiza” yoyilo lwePCB, kodwa njengabaqulunqi, kufuneka siqale siqinisekise ukuba uyilo lwethu lusimahla.

uluhlu lwamagama

I-soldering yamaza

I-Wave soldering kukwenza umphezulu we-soldering webhodi yeplagi-in uqhagamshelane ngokuthe ngqo netoti yolwelo oluphezulu lobushushu ukufezekisa injongo ye-soldering. I-tin yobushushu obuphezulu bobushushu igcina ithambeka, kwaye isixhobo esikhethekileyo senza i-tin engamanzi ibe yinto efana ne-wave-like phenomenon, ke ibizwa ngokuba “yi-wave soldering”. Izinto eziphambili ziyimivalo ye-solder.

Kutheni le nto ibhodi yePCB ibonakala inetoti emva kokujikwa kwamaza? Indlela yokuphepha ngayo?

Inkqubo ye-wave soldering

Amalungu amabini okanye ngaphezulu e-solder axhunyiwe nge-solder, okubangelwa ukubonakala kakubi kunye nomsebenzi, ochazwe njengenqanaba lesiphene nge-IPC-A-610D.

Kutheni le nto ibhodi yePCB ibonakala inetoti emva kokujikwa kwamaza?

Okokuqala, kufuneka siyenze icace into yokuba ubukho betoti kwibhodi yePCB ayiyongxaki yoyilo olubi lwePCB. Isenokuba ngenxa yokungafezeki komsebenzi wokuguquguquka, ukumanzisa okwaneleyo, ukusetyenziswa kokungalingani, ukufudumala kwangaphambili kunye nobushushu be-solder ngexesha le-soldering wave. Kuhle ukulinda isizathu.

Ukuba yingxaki yoyilo lwePCB, sinokuyiqwalasela le miba ilandelayo:

1. Ingaba umgama phakathi kwamalungu e-solder yesixhobo sokuthengisa amaza wanele;

2. Ngaba indlela yothumelo lweplagi ifanelekile?

3. Kwimeko apho ibala lebala lingafikeleli kwiimfuno zenkqubo, ngaba kukho nayiphi na iphedi yokubiwa kwetoti kunye ne-inki yesikrini sesilika esongeziweyo?

4. Ingaba ubude bezikhonkwane zeplagi zide kakhulu, njl.

Ungayiphepha njani itoti kuyilo lwePCB?

1. Khetha amacandelo afanelekileyo. Ukuba ibhodi idinga i-wave soldering, isithuba esicetyiswayo sesixhobo (isithuba esiphakathi phakathi kwee-PIN) sikhulu kuno-2.54mm, kwaye kuyacetyiswa ukuba sibe sikhulu kuno-2.0mm, kungenjalo umngcipheko woqhagamshelo lwetoti uphezulu kakhulu. Apha ungaguqula ngokufanelekileyo iphedi elungiselelweyo ukuhlangabezana neteknoloji yokusetyenzwa ngelixa unqanda uqhagamshelwano lwetoti.

2. Musa ukungena kwi-soldering foot ngaphaya kwe-2mm, ngaphandle koko kulula kakhulu ukudibanisa i-tin. Ixabiso elinobungqina, xa ubude bokukhokela ngaphandle kwebhodi ≤1mm, ithuba lokudibanisa i-tin ye-dense-pin socket iya kuncitshiswa kakhulu.

3. Umgama phakathi kwamakhonkco obhedu akufanele ube ngaphantsi kwe-0.5mm, kwaye ioli emhlophe kufuneka ifakwe phakathi kwamakhonkco obhedu. Yiyo loo nto sihlala sibeka umaleko weoli emhlophe yesilika kwindawo yokuwelda yeplagi xa uyilwa. Ngethuba lenkqubo yoyilo, xa i-pad ivuliwe kwindawo ye-mask ye-solder, qaphela ukuba ugweme ioli emhlophe kwisikrini sesilika.

4. Ibhuloho yeoli eluhlaza kufuneka ingabi ngaphantsi kwe-2mil (ngaphandle kwe-top mount pin-intensive chips ezifana neephakheji ze-QFP), ngaphandle koko kulula ukubangela uxhulumaniso lwe-tin phakathi kweepads ngexesha lokucubungula.

5. Ulwalathiso olude lwamacandelo luhambelana nokuhanjiswa kwebhodi kwi-track, ngoko ke inani lezikhonkwane zokuphatha uxhulumaniso lwe-tin luya kuncitshiswa kakhulu. Kwinkqubo yoyilo lwePCB yobuchwephesha, uyilo lumisela imveliso, ngoko indlela yokuhambisa kunye nokubekwa kwezixhobo zokuthengisela amaza ngokwenene zilungile.

6. Yongeza iipads ezibiweyo ze-tin, yongeza iipads ezibiweyo ekupheleni kwendlela yokuhambisa ngokweemfuno ze-layout zeplagi-in ebhodini. Ubungakanani be-tin eyeba i-pad inokulungiswa ngokufanelekileyo ngokobuninzi bebhodi.

7. Ukuba kufuneka usebenzise iplagi ye-denser pitch plug-in, sinokufakela isiqwenga sokutsalwa kwe-solder kwindawo ephezulu yetoti ye-fixture ukuthintela i-solder paste ekwenzeni kwaye ibangele ukuba iinyawo zecandelo zidibanise kwi-tin.