Electronics Forum | Wed Jun 22 15:03:12 EDT 2005 | patrickbruneel
The only thing ammonia can do is tarnish copper and make it more difficult to solder. And the higher temp in lead-free will discolor the latex (giving it a sticky surface), but the functionality of the mask will be intact. There should be greater co
Electronics Forum | Mon Jun 27 09:38:30 EDT 2005 | Bob R.
What problems are the quality people seeing? I hope they aren't expecting a toe fillet. QFNs are typically cut from an array after plating. This leaves exposed copper on the sides of the part. We'll often see smearing from the sawing process that
Electronics Forum | Fri Jul 15 13:58:32 EDT 2005 | seaK
Our production is putting QFN40 and QFN56 package on board. With 80% opening on terminal, 40% on thermal pad, we found QFN56 100% forming toe fillet, but it does not work out the same to QFN40. We suspect it's because of the weight of component.....
Electronics Forum | Sat Nov 05 05:09:51 EST 2005 | ajay
we do keep out solder paste ready for next shift or for replenish. We specified a location to keep new paste ( only one container ) near stencil machine. As soon as that is use we put another container from freeze, we make sure that at specified loca
Electronics Forum | Mon Feb 27 09:31:10 EST 2006 | Slaine
on sections ive looked at with 7 microns of silver and 4microns of copper, the silver had been totally absorbed into the solder in most places and a large amount in some places all the copper as well, so i think the answer is that to provide long ter
Electronics Forum | Wed Oct 04 14:48:49 EDT 2006 | cw
My soak at 150C - 180C for approx. 85sec to 100sec. I believe this is sufficient. I can't change my paste because customer wants to use SnPb paste with SAC solder balls. They claimed that they have sucessful result with other CM. I need to know if
Electronics Forum | Fri Jan 19 11:34:13 EST 2007 | realchunks
I thought the same thing but he did mention density. I threw out the color thing immediately - which is normal. But to NOTICE a density proble with set programs seem aby-normal. Unless one our maintenance guys got a hold of your machine for a PM.
Electronics Forum | Wed Oct 10 12:04:54 EDT 2007 | russ
everything else EXACTLY the same? meaning exact same product number from the same manufacturer same fluxes used in the paste? no additional no clean "touchup" or hand soldering operations? No expert by any means but it would seem odd to me that the
Electronics Forum | Mon Sep 08 09:59:56 EDT 2008 | vladig
Here we go with another "solderability problem". How do you know the pads on the bare PCB are oxidized? Just based on its colour? If that is the root cause, then why ohter parts on the same board are fine? If you want to solve the problem, get it's
Electronics Forum | Mon Oct 13 11:27:51 EDT 2008 | dwelch123
For 15 years I have used a similar method, only I used two bread pans. You can fit alot more solder in them. In one pan I drilled holes very similar to the photo in one pan and used a reclaiming agent such as Kleenox to prep it a bit. Then used the o
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