Electronics Forum | Wed Jul 31 09:20:47 EDT 2002 | larryk
Dave, I'm assuming your unsoldered fids are exposed copper. Do you have any issues with machine vision due to the various color changes the copper goes through as it oxidies? Larry
Electronics Forum | Fri Aug 22 00:25:20 EDT 2003 | mantis
Kenny, Out of curisoty why do you need to paste the vias.Is it due to contact reliability at test.Can these vias not be soldered during wave process (if any).Can the Style of probe used in the ICT test fixture not be changed to accomodate these unsol
Electronics Forum | Mon Jan 12 08:59:57 EST 2004 | Paul F
I may have a similar problem at the moment with a QFP-68. Do the unsoldered leads leave a perfectly formed footprint in the reflowed solder? Do you usually find this issue occurring towards the corners of the QFP rather than in the middle of a row?
Electronics Forum | Mon Jan 26 04:13:48 EST 2004 | patthemack
First of all, did you profile this board with a mole, such as a KIC? Is the solder flowing, or just not wetting to the part or pad? I work with RF boards as well, but the main problem is tombstoning due to the ground plane side being larger because o
Electronics Forum | Thu Jan 29 18:01:20 EST 2004 | davef
Rethinking to Ramp / Soak: Yano, staying with ramp might not be all that bad after all, just decrease the ramp / slow-down the conveyor.
Electronics Forum | Mon Nov 14 14:59:32 EST 2005 | davef
Additional questions are: * Does the problem appear with pasted/soldered only boards, in addition to those with components? * What is the size of the unsoldered area? What is the size of the pad? * Where is the solder mask, relative to the pad? * Wha
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 | Thu Nov 15 22:10:16 EST 2007 | davef
Questions are: What is: * Purpose of this PCB ink? * Meaning of 'non-conductive?' * Temperature of your laser? * Reason solder mask is not the product of first choice? * Space of the unsoldered region located between soldered areas? * Maximum cure te
Electronics Forum | Thu Apr 05 08:21:52 EDT 2012 | rway
Yes, but no guarantee of solderability. This just puts more paste on the pads. From my experience, unsoldered QFN parts are not due to lack of solder, but reflow.
Electronics Forum | Wed Jun 13 20:38:23 EDT 2012 | kahrpr
It is possible that there is nickel contamination in the gold. Depending on your plating board vendors put nickel down first. The plating also could be to thin. Dave had a good suggestion in trying to solder the pad with a Iron that will tell a lot.
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