Electronics Forum | Fri Feb 11 08:20:25 EST 2005 | Rob
Depends what the joint is on, and how historically it has performed - ie. is it a part that won't wick on the wave, or near a ground plane that never forms properly. It may be that they know something you don't about the board. However any info s
Electronics Forum | Mon May 23 08:22:31 EDT 2005 | davef
Thermal mass is the ability of a material to absorb heat energy. * A lot of heat energy is required to change the temperature of high density areas, like a ground plane. They are therefore said to have high thermal mass. * Light weight areas, such as
Electronics Forum | Thu Jun 02 17:24:19 EDT 2005 | PWH
Could also be a ground plane under one of the terminations of the cap causing heat sink troubles during reflow. One pad liquifies/solidifies before the other. Don't know a good solution for this outside of reworking them.
Electronics Forum | Mon Mar 27 19:32:28 EST 2006 | PWH
You mention "large ground plane pads in the center". Could it be that these large apertures are allowing the blades to "dig" which somehow pulls paste from adjacent apertures as the blades recover?
Electronics Forum | Mon Mar 12 17:16:45 EDT 2007 | coop
the problem must have been the ground plane like you were saying because I increased the preheater temp, slowed down the conveyor speed and they started looking better. Thanks to all for the input, especially davef. Thanks again
Electronics Forum | Fri Sep 12 09:43:13 EDT 2008 | grics
This question maybe more for myself than SWAG, but, could this be a DELTA problem caused by design? (Ground Plane) One side of the component reflows later causing the component to twist???
Electronics Forum | Tue Jul 30 12:36:43 EDT 2013 | patrickbruneel
Yes it is the massive ground plane stealing all heat. You need to have a thermal relieve design for that specific pad.
Electronics Forum | Thu May 21 08:29:05 EDT 2015 | cyber_wolf
DeanM, How do you verify you have great results with the AutoSet feature if you do not check your profiles ? How does the AutoSet take into account large ground planes on certain areas of the board ? just curious
Electronics Forum | Fri Sep 09 05:32:11 EDT 2016 | jasltd
Are your solder relief pads connected to anything in terms of ground planes that would increase the thermal load or are they floating copper? I take it your talking about wave solder relief pads?
Electronics Forum | Fri Oct 21 12:22:56 EDT 2016 | horchak
Looking at your picture I'm not sure you have a wetting problem. Who determined it's not wetted? Are you having functional failures? Is this an isolated incident? What was your TAL? Is the pad on the suspect ball possibly smaller than the others, or
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