Kevin,
For our applications, if the board is coated, the edges of the board are
coated as well, except in certain situations, such as where connectors are
at the edge of the board. Why? Well, the time honored "we have always
done it this way".
Part of the rationale is that at the board edge, you have the glass
bundles of the laminate exposed and water can potentially wick into those
glass bundles, creating problems over the long haul. In most cases, I
think that if the boards are routed from the panel, the routing process
tends to seal the edges and conformal coat is not needed. However, if you
are shearing or punching the board out, then those fibers are not sealed
(in my opinion) and should be coated to seal the edges.
In order for me to change that stance, I would have to have to prove to
our ever skeptical design engineers that not coating a board edge will
never create a problem in any environment for any of the 20-30 years
design life we use on any product we have ever made. Then change an
entire corporate culture.
I am already burned in effigy 2-3 times per week.
Doug Pauls
Rockwell Collins
Kevin Glidden <[log in to unmask]>
Sent by: TechNet <[log in to unmask]>
06/05/2009 10:30 AM
Please respond to
TechNet E-Mail Forum <[log in to unmask]>; Please respond to
Kevin Glidden <[log in to unmask]>
To
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Subject
Re: [TN] Conformal coating of PCB edges
No takers on this one, so maybe I will reword it...
How many are requiring conformal coat application to PCB edges, and why?
Thanks!
-----Original Message-----
From: Kevin Glidden [mailto:[log in to unmask]]
Sent: Wednesday, June 03, 2009 1:47 PM
To: [log in to unmask]
Subject: [TN] Conformal coating of PCB edges
Can anyone point me to an industry document where this is mentioned /
required / recommended, or is this left entirely up to choice?
I believe most consider this a good and desirable thing?
How do automated selective spray systems accomplish this?
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