Electronics Forum | Wed May 08 14:24:22 EDT 2013 | wahahasteven
we are using acrylic conformal coating on the PCB. Under the same program, same parameters (not changing anything on the machine), and we always found one or two boards have some spots which are not coated (shown as picture). The location of the spot
Electronics Forum | Thu May 09 10:12:08 EDT 2013 | wahahasteven
this is one of my project. I have tried to remove coating only on those areas with alcohol and thinner, then program the machine to coat the removed area again. But the result obviously shows that two different tones of coating on the board. I also
Electronics Forum | Fri Sep 09 15:03:46 EDT 2005 | Amol
Hi, I am running a circuit board that needs a part to be put on it after cleaning and before conformal coating. the only problem is that after cleaning and hand assembly of the part, there is a thin whitish residue in the ckt board that one can see w
Electronics Forum | Tue Sep 21 11:34:10 EDT 2004 | davef
Several things to check are: * Ask Multicore if their flux res and your conformal coat are compatible. Conformal coats and NC flux res are notorious for having compatibily issues. * Conformal coat a bare board to determine if there is there is enoug
Electronics Forum | Fri Sep 09 15:53:22 EDT 2005 | patrickbruneel
If the white residue is from a no-clean flux or no- clean solder flux core you can leave it on the board. (Consult with the flux or cored solder manufacturer) Because after being encapsulated with conformal coating the residue is sealed from humidity
Electronics Forum | Thu Sep 27 17:25:33 EDT 2007 | chef
The short answer is immediately after reflow the problem occurs. To be more exact, what you are describing is not "rust". Rust occurs in iron. The oxidation that occurs in Tin-Lead has been sometimes called "white rust". Either way, oxidation occur
Electronics Forum | Fri Apr 26 10:42:28 EDT 2002 | Jim M.
I worked for a telecom company that had sites in the deserts, jungles, mountains and regular built up area's. All boards were built using Aim 291/293 No clean solder paste. (all boards built to Bellcore standard) The boards were coated with Dymax ur
Electronics Forum | Tue Sep 09 15:22:39 EDT 2003 | gdstanton
Anyone have any experience with immersion white tin over copper plating? We are seeing opens develop under BGAs after we bake and conformal coat. And when we lift the parts the pads are 60% of the original size. Need some advice on possible causes
Electronics Forum | Thu Dec 22 10:51:12 EST 2005 | killer1994
Yes, I have been using it for 4 years now. We have the 4 axis, 3 head, 2 lines. Inspection station and ir oven. I have to say you will NOT get better support anywhere in this industry than from PVA. Their crew is top notch, always going above and bey
Electronics Forum | Mon Mar 02 00:38:35 EST 2009 | sachu_70
Hi Jorge, The success of such production purely depends on process control. One needs to first understand the board layout in detail, and evaluate any critical components for their temperature handling capabilities. Remember, you are dealing with com
