Electronics Forum | Thu Sep 15 21:25:43 EDT 2011 | darby
G'day folks - haven't been around for some time but still soldering on. Question for y'all. One of my design engineers has shown me a Creative PCI audio card with a TQFP48 attached. 0.4mm pitch. Let's say the pin width is 0.2mm and the pad design ha
Electronics Forum | Thu Sep 15 21:36:52 EDT 2011 | darby
I also posted this in the design section... G'day folks - haven't been around for some time but still soldering on. Question for y'all. One of my design engineers has shown me a Creative PCI audio card with a TQFP48 attached. 0.4mm pitch. Let's say
Electronics Forum | Wed Nov 17 10:03:29 EST 2010 | scottp
Instead of a minimum thickness, we require no exposed copper or SnCu intermetallic. We've been having a lot of trouble lately with suppliers of SN100 HASL boards giving us pads with very irregular solder deposits with areas of exposed intermetallic.
Electronics Forum | Thu Apr 09 09:25:04 EDT 1998 | Terry Burnette
| I am in urgent need of a pcb land patten (footprint)for this device. I have the component data sheet with with package dimensions from Motorola, but they do not include the recommended land pattern. I requested a patten over a week ago, but have
Electronics Forum | Mon Sep 28 16:15:57 EDT 2009 | davef
That your solder connections reflow properly when heated with a soldering iron, indicates that that your reflow recipe needs improvement. * Thermocouple the pads that require touch-up and adjust your oven recipe to assure that they reach liquidous+20
Electronics Forum | Thu Jul 20 03:00:53 EDT 2006 | reypal
If you are using SMT machine for component placement you may check your nozzle where in some cases solder paste stuck to it and during placement will easily get into gold pad area. otherwise you have use kapton tape in order not to expose those pads.
Electronics Forum | Fri Feb 02 12:37:11 EST 2007 | kennyg
For pads such as a d-pack... what is the effect on heat dissipation of leaving the unsoldered portion of the pad exposed metal or covering with solder mask? Is there a percentage of heat dissipation that is inhibited by covering with mask?
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.
