Mike,
Question 1: Whatever cure mechanism you use, be sure not to leave any
uncured material around, as it is likely to cause trouble in the future,
whether it me just messy, or something else. For example, the electrical
characteristics of the uncured coating are likely to be very different than
the cured one.
One point about moisture cure is, of course, that it is moisture dependent,
and as Jon More stated, not in your control - can vary in cure time from
very short to, sometimes, not at all!
Question 2: A good idea if your pcb geometry needs it. Years ago, I saw a
curing machine where the lamp was swung back and forth in an arc over the
conveyor whilst the assembly moved through, to help in this area. Lamps can
also be added on the sides of conveyors, giving extra light perpendicular to
the overhead lamp.
If you can choose a coating which cures with UV *and* visible light, you
might find a better result. The visible light travels farther, reflects and
bounces around into the nooks and crannies much better.
Regards,
Peter
--
--------------------------------------------------------
Peter Swanson [log in to unmask]
INTERTRONICS http://www.intertronics.co.uk
INTERTRONICS is dedicated to providing quality
material, consumable and equipment solutions to the
electronics manufacturing and other technology based
industries, with the highest levels of technical
support and customer service.
-----Original Message-----
From: Mike Manwell [mailto:[log in to unmask]]
Sent: 06 December 2001 14:41
To: [log in to unmask]
Subject: [TN] 2 Conformal Coating ?'s
Hello,
Thanks in advance if you have taken the time to read this!
#1- Im trying different materials in a spray application. Both are cured
using UV. One material does a "secondary cure" w/ moisture. This is cool
because after 100 hours after UV cure, all material is fully cured.
The other material Im trying uses HEAT for a secondary cure, or, if
shodowed during UV cure, the material wont cure and never will. Obviously I
dont want the stuff dripping or running anywhere, but being new to this
wonderful process, just dont feel good about leaving uncured material on a
product for it's entire life. Iv been told that you can "test" the product
to see if the uncured material is causing a problem but Im not sure what
type of test that would consist of. Any insight?
#2- Has anyone out there ever installed refelctive metal plates in their UV
oven to limit shadowing?
Thanks so much,
Mike Manwell
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