Electronics Forum | Thu Dec 11 15:38:26 EST 2008 | hegemon
Dave is correct. Try http://www.ccrco.com Removal of conformal coatings from specific sites might be a more manual process. Think small abrasive cabinet, and an air wand shooting wheat chaff or a (softer) plastic bead media. For components with A
Electronics Forum | Thu Sep 01 12:07:35 EDT 2016 | pavel_murtishev
Is there any field proven spray cleaning technique able to remove flux residues under OSRAM LEDs? Is it possible in principle? The problem is that OSRAM LEDs are low standoff ones and I absolutely have no idea how cleaning agent could get there. Mo
Electronics Forum | Thu May 05 11:50:03 EDT 2005 | russ
Just went through this with a customer. Removed BGAs and noticed discolered pads at some locations. It was determined that these were open connections that had some type of flux migration between the ball. They also took solder readily. This may
Electronics Forum | Thu May 05 16:18:47 EDT 2005 | jimmiem
The black pads that we see are on the BGA component. We removed the component from its site and on 2-3 pads 100% of the ball stuck to the pad on the PCB and the corresponding BGA pad was black.
Electronics Forum | Thu May 05 11:55:52 EDT 2005 | jimmiem
Was it determined what caused the flux migration?
Electronics Forum | Thu May 05 17:23:54 EDT 2005 | jimmiem
Thanks Russ and Dave for time and patience. Best regards jm
Electronics Forum | Thu May 05 17:15:46 EDT 2005 | russ
You got what I think someone has called a "cold melt". If you were to run your removal profile awhile longer you would not see this. Anyway, you don't have any issues as this is very common (at least in my experience). FYI I was thinking your oxid
Electronics Forum | Wed May 04 13:13:43 EDT 2005 | Jimmie
We have seen the black dot on the BGA pad after the component has been removed from a PCB. When most likely could this corrosion have occurred, while the component was in storage, during manufacturing of the unit? We have a number of these BGA's th
Electronics Forum | Thu May 05 12:00:16 EDT 2005 | russ
Bad cleaning practice is suspect. It is believed that W.S. flux was used to solder adjacent components and then hand cleaned. This is not definite but it is pretty certain.
Electronics Forum | Thu May 05 12:22:01 EDT 2005 | jimmiem
could there have been a solderablity issue with that pad to begin with, allowing the flux in (from improper cleaning of adjacent work) to expadite an error may have happened later down the road?
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