Electronics Forum | Tue Feb 29 21:53:46 EST 2000 | Kelvin Chow
Dear Robert, On PBGA assembly, BGA sphere shrinkage number depends to the following factors, a. BGA Sphere size (before reflow) b. Solder mask opening diameter As far as I know, no formular has been established yet. Most of my friends just collect
Electronics Forum | Tue Feb 29 21:53:46 EST 2000 | Kelvin Chow
Dear Robert, On PBGA assembly, BGA sphere shrinkage number depends to the following factors, a. BGA Sphere size (before reflow) b. Solder mask opening diameter As far as I know, no formular has been established yet. Most of my friends just collect
Electronics Forum | Thu Feb 11 14:36:42 EST 1999 | Evelyn York
Hey, has anybody experienced problems with solder balls falling off BGA's? I have not been able to identify a contaminant nor any physical problems that would cause this. On packages with 'good' adhesion I have not observed any intermetallic form
Electronics Forum | Fri Aug 22 03:19:08 EDT 2008 | andrzej
Hi, what do you mean by collapsed ? Can you describe or send a photo ?
Electronics Forum | Mon Aug 25 08:44:10 EDT 2008 | rameshr
Dear Andrezj, i had attached the photos for ur reference Kindly advice.
Electronics Forum | Mon Aug 25 10:36:05 EDT 2008 | davef
Yes, it's peculiar that the layout of this board is so disorganized * Pads are not round, uniform, or the same size * Exposed traces have different thickness
Electronics Forum | Wed Aug 27 00:20:38 EDT 2008 | rameshr
Dear davef, Will u pls advice what are all the possible defects caused while soldering ( assembling ) this type of boards.
Electronics Forum | Wed Aug 27 08:25:24 EDT 2008 | davef
We'd expect to see: * Solder starved connections at pads with large trace/pad areas. * Less reliable solder connections at pads that do not match the shape and size of the corresponding pads on the component.
Electronics Forum | Thu Jul 15 12:09:10 EDT 2010 | wrongway
if the BGA has leaded balls use leaded paste if the BGA has lead free balls use lead free paste and set your oven profile to match the paste
Electronics Forum | Fri Aug 22 00:20:29 EDT 2008 | rameshr
Hai, In our process we are using the micro bga of size 13X13mm of pitch 0.45mm,after soldering process the bga found collapsed, we absorbed that the PCB land pattern of the BGA was not in array, uneven distribution of pads (area) & most of the pads
