IiMfuno zoyilo zePCBA

I. Imvelaphi

PCBA welding yamkelaukuthambisa umoya oshushu, exhomekeke kwi-convection yomoya kunye nokuqhutyelwa kwe-PCB, i-welding pad kunye ne-lead wire yokufudumeza.Ngenxa yobungakanani bobushushu obuhlukeneyo kunye neemeko zokufudumeza iipads kunye nezikhonkwane, ukushisa okushushu kweepads kunye nezikhonkwane ngexesha elifanayo kwinkqubo yokufudumeza i-welding iphinde ihluke.Ukuba umahluko weqondo lobushushu mkhulu ngokwentelekiso, kunokubangela ukuwelda kakubi, njenge-QFP pin open welding, ukufunxa ngentambo;Ukumiswa kwe-Stele kunye nokususwa kwamacandelo e-chip;Ukuqhekeka kwe-Shrinkage ye-BGA solder joint.Ngokufanayo, sinokucombulula ezinye iingxaki ngokutshintsha amandla obushushu.

II.Iimfuno zoyilo
1. Uyilo lweepads zokutshisa ubushushu.
Kwi-welding ye-heat sink elements, kukho ukunqongophala kwe-tin kwiipads zokutshisa ukushisa.Esi sisicelo esiqhelekileyo esinokuphuculwa ngokuyilwa kobushushu bokushisa.Kule meko ingentla, ingasetyenziselwa ukwandisa umthamo wobushushu woyilo lomngxuma wokupholisa.Qhagamshela umngxuma okhuphayo kuluhlu lwangaphakathi oludibanisa istratum.Ukuba uxhulumaniso lwe-stratum lungaphantsi kwe-6 layers, luyakwazi ukuhlukanisa inxalenye kwi-signal layer njenge-radiating layer, ngelixa unciphisa ubungakanani bokuvula ubuncinci obukhoyo obukhoyo.

2. Uyilo lwejekhi yokumisa yamandla aphezulu.
Kolunye uyilo olukhethekileyo lwemveliso, imingxunya yeekhatriji ngamanye amaxesha kufuneka idityaniswe ngaphezulu komgangatho omnye womgangatho womgangatho.Ngenxa yokuba ixesha loqhagamshelwano phakathi kwepini kunye ne-tin wave xa i-wave soldering imfutshane kakhulu, oko kukuthi, ixesha le-welding lihlala li-2 ~ 3S, ukuba umthamo wobushushu wesokethi mkhulu, ubushushu be-lead bunokungahlangani. iimfuno ze-welding, ukwenza indawo ye-welding ebandayo.Ukuthintela oku kungenzeki, i-design ebizwa ngokuba yi-star-moon hole isoloko isetyenziswa, apho umngxuma we-weld uhlukaniswe nomhlaba / umaleko wombane, kwaye umbane omkhulu ugqithiswa kumngxuma wamandla.

3. Uyilo lweBGA solder joint.
Ngaphantsi kweemeko zenkqubo yokuxuba, kuya kubakho into ekhethekileyo "ye-shrinkage fracture" ebangelwa ukuqiniswa kwe-unidirectional ye-solder joints.Isizathu esisisiseko sokwenziwa kwesi siphene ziimpawu zenkqubo yokuxuba ngokwayo, kodwa inokuphuculwa ngoyilo lokulungiswa kwe-wiring yekona ye-BGA ukucotha ukupholisa.
Ngokutsho amava PCBA processing, ukuncipha jikelele ukwaphuka solder joint ibekwe kwikona BGA.Ngokwandisa umthamo ubushushu BGA kwikona solder joint okanye ukunciphisa isantya conduction ubushushu, iyakwazi ungqamaniso namanye amalungu solder okanye ukupholisa phantsi, ukuze ukuphepha isenzeko yokwaphulwa phantsi BGA warping uxinzelelo olubangelwa ukupholisa kuqala.

4. Uyilo lweepads zecandelo le-chip.
Ngobuncinci kunye nobukhulu obuncinci bezinto zetshiphu, kukho izinto ezininzi ezinje ngokutshintsha, ukusetwa kwestele kunye nokujika.Ukwenzeka kwezi ziganeko kuhambelana nezinto ezininzi, kodwa ukuyila kwe-thermal yeepads kuyinkalo ebaluleke ngakumbi.Ukuba esinye isiphelo sepleyiti welding kunye noqhagamshelo ngocingo olubanzi ngokwentelekiso, kwelinye icala kunye noqhagamshelo ucingo emxinwa, ngoko ubushushu kumacala omabini iimeko ezahlukeneyo, ngokubanzi kunye nephedi yoqhagamshelo ngocingo olubanzi luya kunyibilika (ukuba, ngokwahlukileyo ingcinga jikelele, njalo wacinga kunye pad uqhagamshelo ngocingo olubanzi ngenxa umthamo ubushushu enkulu kunye nokunyibilika, eneneni ucingo olubanzi waba ngumthombo ubushushu, Oku kuxhomekeke kwindlela PCBA ishushu), kunye noxinzelelo lomphezulu eveliswa isiphelo sokuqala anyibilikisiwe unokuphinda shift. okanye ujike isiqalelo.
Ngoko ke, ngokuqhelekileyo kuthenjwa ukuba ububanzi bocingo oludibeneyo kunye nephedi akufanele lube lukhulu ngaphezu kwesiqingatha sobude becala lomgca odibeneyo.

I-oveni ye-NeoDen Reflow