Electronics Forum | Sat Aug 27 09:22:14 EDT 2011 | davef
It's tough to say from the picture, but it looks like the connection has not gotten hot enough to cause the solder to flow properly. What was the time above liquidous plus 20*C?
Electronics Forum | Fri Aug 19 06:49:27 EDT 2011 | leadthree
I got this MQFP-144 and the soldering looks always very flimsy. I think I use a suitable leaded paste (water-soluble) and the stencil thickness is also OK. The IC on the image looks a bit shifted, that's not the problem. The problem is rather that
Electronics Forum | Mon Aug 22 13:28:47 EDT 2011 | scottp
No, don't put weight on it. If the part is really "floating" on the solder and not wetting properly and the solderability looks good on all your other parts then I'd suspect a part problem. Get with the QFP supplier and make sure the Sn isn't too t
Electronics Forum | Fri Aug 19 07:40:24 EDT 2011 | scottp
What do the heel fillets look like and what level of IPC-610 (class 1,2, or 3) are you working to? Do the joints on all 4 sides look bad or just the one side? Do other parts on the board look OK?
Electronics Forum | Sat Aug 20 05:56:44 EDT 2011 | leadthree
I will try to get a pix for heels. Normal IPC standard Yes, all for sides are the same (ignore the little misalignment, usually that is fine). I wonder if the IC is maybe too lite and 'swims' on the liquid tin and if it would help to put some weig
Electronics Forum | Mon Aug 22 06:30:59 EDT 2011 | janz
very often toes on the QFP packages are exposed to base material and during time they oxidize. That is why you can have problem with solder fillet. Most important is heel fillet. Regarding your misalignment of IC if this is repeatable check your pl
Electronics Forum | Fri Jul 27 15:51:29 EDT 2007 | hussman
Well I agree with jdumont in the fact that you should reduce the center pad at least 50%. Generally the sides of the leaded ends are not plated and solder will not wick up. This means only the bottoms of the leads wil solder. Look in this area whe
Electronics Forum | Tue Jul 24 07:57:55 EDT 2007 | davef
It sounds like the QFN component is not solderable. * Use ANSI/J-STD-002, Solderability Tests for Component Leads, Terminations, Lugs, Terminals, and Wires * Contact your QFN component supplier for help * Consider a more active flux, since you might
Electronics Forum | Tue Feb 17 18:17:28 EST 1998 | John Wilson
I am looking for any information or testing data done on the amount of weight that can be held by a bga package based on size of the solder sphere and number of spheres. I am reflowing components with a bga package on the opposite side and looking f
Electronics Forum | Fri Jul 27 08:49:35 EDT 2007 | cman
We are currently have failures on one of our QFN > components. We are running this product with > lead free paste, lead free boards and lead free > parts. They have done a pull test on this > component and it showed that the solder joint > mai
