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 | 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
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 | Mon May 10 16:37:01 EDT 2004 | davef
First some definitions, the two main types for solder masking near BGA pads are: 1 Pad, Non-Solder Mask Defined. In circuit board design, pads with spacing that does not allow solder (usually bumps) on the pads to contact the adjacent solder mask. [
Electronics Forum | Fri May 07 17:02:01 EDT 1999 | Earl Moon
| On 1.27mm (0.050 inches) Standard Ball Grid Array's. | The ball size diameter starts at approximately 0.025 inches. | | If the ball size decreases to 0.012 inches (due to the solder flowing down a via) is the solder connection reliable? | | This
Electronics Forum | Thu May 13 18:36:55 EDT 1999 | Andrew Wulff
| | On 1.27mm (0.050 inches) Standard Ball Grid Array's. | | The ball size diameter starts at approximately 0.025 inches. | | | | If the ball size decreases to 0.012 inches (due to the solder flowing down a via) is the solder connection reliable? |
Electronics Forum | Fri Mar 19 10:06:22 EDT 2010 | karlo
Rework is typically done by heating the BGA to 170-180C to first scrape off the fillet. Then, heat to above reflow, and lift the BGA. Then, collapse the solder with heat and flux. Then, back down at 170-180C, scrape off the underfill from the boar
