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| Reply To: | TechNet E-Mail Forum. |
| Date: | Wed, 23 Jun 1999 14:20:58 +0100 |
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Joyce et al,
Very interesting. One other observation is that we have measured many
standard UV epoxy coatings and found that the uncured material in the
shadowed areas was 10000 times more conductive than the exposed/cured
material.
Regards,
Graham Naisbitt
[log in to unmask]
Concoat Ltd
Alasan House, Albany Park
CAMBERLEY GU15 2PL UK
Tel: +44 (0) 1276 691100 Fax: +44 (0) 1276 691227
----- Original Message -----
From: joyce <[log in to unmask]>
To: TechNet E-Mail Forum. <[log in to unmask]>; Graham Naisbitt
<[log in to unmask]>
Sent: Tuesday, June 22, 1999 1:45 AM
Subject: Re: [TN] Epoxy
> I saw a demo few weeks ago. The trick is to use a hand held UV point
source
> positioned at (almost) glazing angle to the PWB (maximum exposure to the
> adhesive) to get under the components. The unit may have reflective
mirrors
> to reflect the light in different angles... It took 10 - 15 sec to cure
the
> adhesive. I have little concern about the un-exposed photo-activators.
> These un-exposed photo-activators will cause instability of the material
if
> it is not passivated by either thermal cure or other method. (based on my
> out dated knowledge, the excess photo-activators were normally used to
> ensure the material reach the full cure easily. If anyone have updated
> infor. please let me know).
> My 2 cents.
> jk
> At 01:08 PM 6/21/99 +0100, you wrote:
> >Iain and other TechNetters
> >
> >Forgive my ignorance but is there such a material?
> >
> >I would have thought that a UV adhesive couldn't be used in such an
> >application unless you can bend light to get under the component and
react
> >the photo-initiator.
> >
> >I thought bending light was tricky so if there are such things, I have
some
> >applications in mind so would love to hear from the experts.
> >
> >Regards,
> >Graham Naisbitt
> >
> >[log in to unmask]
> >
> >Concoat Ltd
> >Alasan House, Albany Park
> >CAMBERLEY GU15 2PL UK
> >
> >Tel: +44 (0) 1276 691100 Fax: +44 (0) 1276 691227
> ><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
> ><HTML><HEAD>
> ><META content="text/html; charset=iso-8859-1" http-equiv=Content-Type>
> ><META content="MSHTML 5.00.2314.1000" name=GENERATOR>
> ><STYLE></STYLE>
> ></HEAD>
> ><BODY bgColor=#ffffff>
> ><DIV><FONT size=2>Iain and other TechNetters<BR><BR>Forgive my ignorance
> but is
> >there such a material?<BR><BR>I would have thought that a UV adhesive
couldn't
> >be used in such an<BR>application unless you can bend light to get under
the
> >component and react<BR>the photo-initiator.<BR><BR>I thought bending
light was
> >tricky so if there are such things, I have some<BR>applications in mind
so
> would
> >love to hear from the experts.<BR></FONT></DIV>
> ><DIV><FONT size=2>Regards,<BR>Graham Naisbitt</FONT></DIV>
> ><DIV> </DIV>
> ><DIV><FONT size=2><A
>
>href="mailto:[log in to unmask]">[log in to unmask]</
> A></FONT></DIV>
> ><DIV> </DIV>
> ><DIV><FONT size=2>Concoat Ltd<BR>Alasan House, Albany Park<BR>CAMBERLEY
> GU15 2PL
> >UK</FONT></DIV>
> ><DIV> </DIV>
> ><DIV><FONT size=2>Tel: +44 (0) 1276 691100 Fax: +44 (0) 1276
> >691227</FONT></DIV></BODY></HTML>
> >
>
>
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