Electronics Forum | Fri Dec 04 23:15:45 EST 2015 | mac5
You say that there is no green solder mask around the lands of the BGA only silk screen. If that is the case I would be concerned about the solderabilty of the component if the silk screen gets onto the pads. The application of solder mask is much mo
Electronics Forum | Tue Aug 24 12:20:33 EDT 2004 | davef
The methods Terry mentioned are good, but our operators are too impatient. Here's how they do site prep, after removing the BGA: * Use a soldering iron to melt the solder at the base of the ball. * Flick the ball[s] from the pad[s] with the solderin
Electronics Forum | Mon Nov 30 08:39:05 EST 2015 | spoiltforchoice
http://blog.screamingcircuits.com/2010/09/smd-vs-nsmd.html such as this? Which handily also tells you what you might want to google.
Electronics Forum | Sat May 30 01:31:49 EDT 2009 | mika
make 4 square rounded corner apertures on the ground pad and the total reduction of 20 % (80 % solder paste). Then you still be able to solder the terminals around. Don't worry to much of the void's. Just following my tips and you will be fine. The
Electronics Forum | Tue Jun 14 08:37:18 EDT 2005 | jdumont
Morning all, just took a look at a new board we just got in and the there are different pad areas under the same BGA. What happened is engineering uses wider trace sizes for some pads and those overlap when more than one go to the same pad. This caus
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 | Sat Oct 06 05:33:47 EDT 2001 | spchua
I had recently encounter the "black and grey" pads problems for the BGA pad after the convection re-flow. The pads shows in in "black and grey" color and a litter solder in it, and it happen in ramdom, when applied heat and solder on the "black and g
Electronics Forum | Sat Jun 18 08:03:58 EDT 2005 | davef
kenscj: Responding to your points of interest: * On the smoothness of BGA solder balls causing solder ball misalign, void, solder short after reflow: We expect the solder balls to be smooth and have no sharp irregularities. We can't recall attribut
Electronics Forum | Fri Mar 16 17:15:51 EDT 2007 | davef
Ask the board fabricator to: * Fill the vias with resin. * Then metalize and copper plate the filled via along with the pad. * Then plate with solderability protection. This results in what appears to be a solid pad. For more, look here: http://www
Electronics Forum | Fri Jun 17 07:38:59 EDT 2005 | jdumont
Thanks for taking a look at the pics. I have made my thoughts on this type of design known to all. Im going to let this run through and have them put a note in the file for this board to reduce the trace size for the next time the board gets rev'd up
