Electronics Forum | Fri Dec 27 10:04:56 EST 2002 | haran
Big pad located at the middle of the package. On the PCB,we need to have solder paste printed on the thermal pad which is at the middle and the other pads of the perimeter BGA.
Electronics Forum | Tue Feb 18 22:15:04 EST 2003 | davef
Arturo, So, you're not shorting to a thermal pad. Given that you're shorting to outer balls, tell us about: * Location of the shorting among the outer balls. * Board construction. * BGA constuction. * Paste deposition. * Temperature measurements ta
Electronics Forum | Sat Dec 28 02:58:12 EST 2002 | emeto
If the problem is in the big thermal pad.The surface strains in that pad are different then the others and through the reflow period there is an affinity between them(only if they are too close). I recommend you to reduce the theramal pad. Make smal
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 | Wed Jun 03 13:56:09 EDT 2009 | mika
less total area of voids, which mean a much more strength in the joint and much easier to solder such a cooling pad grounded via vias, with this approach! The same goes for big cooling pads of let say Power transistors without any via etc. Always re
Electronics Forum | Mon Dec 16 10:31:21 EST 2002 | davef
Grant, On those 'dry pads', where does the solder paste end-up after soldering? On: * Pads * Component leads * Someplace else [Where?]
Electronics Forum | Fri May 15 10:04:59 EDT 2009 | aj
Hi all, Is there any standard for percentage voiding on the center thermal pad on a QFN? We use the dot matrix array for paste to allow for outgassing etc, but we have had a couple of xray inspection "fails" for voiding on this pad , in or around 3
Electronics Forum | Mon Dec 07 14:55:41 EST 2015 | clydestrum
So I have an issue coming up that I'm not too sure how to handle. A board was designed with the wrong footprint for a 3-lead transistor in which the single-lead side has a much larger (think thermal pad for qfn) copper land than what is meant for the
Electronics Forum | Fri Feb 27 11:33:32 EST 2004 | Bryan
Very strange question,but interesting.Is there anyone who have conducted any experiments to figure out the results?I made a profile board,one thermal couple on pad and other one drilled into the ball of BGA.the 2 points are perpendicular to conveyor
Electronics Forum | Thu Aug 13 14:10:01 EDT 2015 | markhoch
Hi Sam, I have a feeling that what you're trying to communicate is that your DPAK's are skewing off the pad during reflow. This is caused by a thermal "mismatch" where the solder paste on one side of the DPAK becomes molten before the other, then th
winsouce.jpg)