Electronics Forum | Tue Jul 07 08:42:49 EDT 2009 | ewchong
kpm, you are probably right. under magnification those two pads show some exposed copper which means that they were contaminated or had insufficient solder paste before reflow.
Electronics Forum | Thu Jan 10 11:22:48 EST 2013 | pbarton
Looks to me like under etching of the underlying copper and the gold is just plated to all of the exposed copper surface. Is this characteristic the same on all solderable pads? You will not be able to remove this gold.
Electronics Forum | Mon Apr 07 15:22:17 EDT 2014 | garym4569
Found the issue. The footprint is incorrect. The inductor completely shields the paste from heat. Slid the inductor on the pad to expose the pad and paste, and perfect solder joint. This part was a last minute design change with a larger body.
Electronics Forum | Fri Jun 10 17:55:16 EDT 2022 | jdengler
Generally we overprint on the exposed part of these pads. When there isn't enough clearance at the end of the pad we place solder preforms with the placement machine. Jerry
Electronics Forum | Mon Jul 07 11:46:29 EDT 2008 | aj
Hi All, Can anyone advise the spec for land size of a lead 0.2mm in width? I am placing a TQFP128 0.4mm pitch, the leads seem to be wider than the actual pads they are been placed on? I am also experiencing poor wetting on this part , it has NiPdAU
Electronics Forum | Tue Dec 05 15:10:55 EST 2000 | Francois Monette
Victor, here are a few more elements of information to answer your question. Both the temperature and relative humidity on the manufacturing floor have a significant impact relative to the rate of diffusion of moisture inside a plastic package and t
Electronics Forum | Tue Dec 14 12:00:34 EST 1999 | Kris Wiederhold
We recently reduced our standard aperture reduction to aid in the reduction of solder on gold defects. Since this reduction in aperture size, we have been experiencing exposed copper at the end of the component pads. The heel and toe joints are per
Electronics Forum | Thu Jul 09 21:04:50 EDT 1998 | Dave F
| Hi there, | I am looking for some informations concerning the shear or pull strength of a typical TQFP 20 mils leads in relationship with the Copper/Tin intermetalic layer thickness. Could anyone help? | | Thank in advandce. | rgs, | chiakl Chiakl
Electronics Forum | Mon Oct 23 06:51:36 EDT 2000 | fastech6
I have a problem with solder getting into exposed gold pads. What is the best rework procedure for removing the solder and restoring the gold condition of the pad? At the moment, we are also covering the gold pad with kapton tape prior to solder
Electronics Forum | Thu Sep 16 17:56:48 EDT 2010 | asksmt
Ok Thanks, i have reduced thermal pad size by 4.5 mils on top and bottom part of this footprint where the problem was occuring, so now the clearance between thermal pad and lead pads are 12 mils instead of 7.5 mils on two sides. (i kept the signal pa
