If the rework is extensive, don't you just strip off the coating and put on new coating after the rework is done? 
Inge

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Gumpert, Ben
Sent: den 14 november 2007 13:01
To: [log in to unmask]
Subject: [TN] Conformal Coating Breakdown


Anyone have some information on what happens to conformal coatings as you heat them up, what temperature do they start to deteriorate? (Specifically acrylics and urethanes)

What I'm really getting at is that I have some boards that need hot air rework, but they have been coated. There are moisture sensitive components on the board, so I would like to bake the boards prior to rework. I would prefer to make the bake as short as possible, but that puts the temperature (125°C) at the top of the temperature range for these coating materials. (In fact, some boards that I have baked have gotten a brown tint to the coating).

Will I do any damage to the conformal coating by baking at this temperature? If not, what temperature would cause damage?

Thanks,
Ben Gumpert

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