Electronics Forum | Tue Apr 11 16:42:56 EDT 2000 | Chad Notebaert
I�m thinking �Poor intermatallic� It could be a few things. Lets start at the beginning. -Is your paste a 63/37 mixture? -Have you monitored you screen printing, Verify Solder deposition, Are you getting enough paste? -You say the solder looks like i
Electronics Forum | Mon Apr 17 19:30:27 EDT 2000 | Boca
All of the above is good stuff. To add, I have seen this several times if the assembly is wavesoldered. Heat from the wave can partially reflow the top side SM solder joints and weaken them. To test, check joint strength before wave and then after
Electronics Forum | Wed Jul 01 04:54:28 EDT 2015 | jvercamm
hi, the last post on pad cratering dates from 2012. We have (likely similar) problems with a RoHS 783 solder ball BGA size 29x29mm^2 (organic package BT), pitch is 1mm and solder ball diam is 0.5mm the field failure is after 12 months, almost exclu
Electronics Forum | Wed Nov 10 02:20:07 EST 1999 | Marc
The padsfor large heat sinks are being designed on our boards with large copper ground planes surrounding them by our engineers. I am having great difficulty keeping the reflow temperature below 230 degrees in order for the temperature of the copper
Electronics Forum | Wed Apr 14 19:47:13 EDT 2021 | solderingpro
Sounds like you may have already found the issue: inconsistency from your supplier. Seeing as Gold really doesnt oxidize and you're using an inert environment (N2 I suspect), I would turn my attention to the supplier. You said yourself, the "Shine
Electronics Forum | Fri Mar 24 14:06:07 EST 2006 | mdemos1
Hi. We are designing in a 128 pin LQFP that has a heat sink in the center of the package. The size of this is 7.44 by 7.55 mm. Can anyone recommend what pad size should be on the board for this? How about stencil aperture/pattern? Thanks, Mike.
Electronics Forum | Tue Apr 25 10:42:38 EDT 2006 | TMC
Almost all of the components on the bottom side are passives however, there are a couple of mBGA's and qfp's. I am aware that even if the components on the bottom do get reflowed, surface tension of solder will hold them in place. As far as IC's, w
Electronics Forum | Mon May 24 17:17:21 EDT 1999 | JohnW
| | Can anyone steer me towards a supplier of heatsinks suitable for use on a PQFP 160. Before you shoot me down in flames, I know that I am not going to get much heat away from the die because of the plastic but the application is such that the boar
Electronics Forum | Mon Oct 26 02:00:36 EDT 2020 | chucherry5076
https://www.jrpanel.com/R The heat generated by electronic equipment causes the internal temperature to rise rapidly. If the heat is not dissipated in time, the equipment will continue to heat up and the components will overheat and fail, resulting
Electronics Forum | Mon Jun 21 16:36:54 EDT 1999 | John Thorup
| | | Does anyone have experience with placing heat sinks on BGAs? I have limited experience with PSA (pressure sensitive adhesives)heat sinks, and am interested with the possibility of a clip-on device. I am specifically concerned with ease of ass
