Electronics Forum | Wed Sep 07 00:28:04 EDT 2011 | woodsmt
I have identified a Board design issue and having trouble convincing others of my findings. I have a BGA (Sn63 balls, +1500 IO, 0.6mm ball, 1mm pitch, with heat spreader plate)that has a high incidence of solder shorting on the corners. The board i
Electronics Forum | Thu Jun 16 18:16:32 EDT 2005 | davef
Josh: You're correct it's tough to describe the layout of the BGA pads and traces. We wouldn't be too excited about seeing this board either. On one hand, for the obvious lack of care taken in doing the layout, this is a junk board and you shouldn
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 | 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 | Fri Jun 30 10:42:24 EDT 2000 | Chrys Shea
That pad had a 16 mil dia, so I arrived at 20 mil squares by adding 2 mils to each side of the pad. Following that logic, a 12 mil pad would use a 16 mil square. But a 12 mil pad is on a finer pitch that isn't mentioned, so you should definitely
Electronics Forum | Thu Jun 02 10:54:12 EDT 2011 | davef
Al: We agree with AVFOM. You have a different problem than solder paste mesh selection. Most often, tombstoning occurs when the wetting forces on the two pads are unequal. Examples of things that can cause this are: * Pads are different * Board pad
Electronics Forum | Wed Nov 14 13:05:40 EST 2007 | rgduval
I had one project with micro-vias in 0805 and larger pads, with no issues. But my most recent project had vias that were larger than the 0402 pads that the via was in. To the point that for a number of the lands, there was no visible pads (a couple
Electronics Forum | Thu Nov 15 08:25:08 EST 2007 | rgduval
I do think that the designer goofed, and used too large vias. I believe he only used on size via on the entire board, regardless of whether it was in a pad, or out on the board. I have seen vias in pad work, though. From a manufacturing standpoint
Electronics Forum | Tue Sep 25 14:08:59 EDT 2001 | davef
Oooo, the solder on the pad and PGA ball is flowing during reflow down the via to the secondary side? Why didn�t you say so?? ;-) Why would you expect that gravity and capillary action wouldn�t force solder to flow down the solder plated via to the
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