Gary,

From your information I assume that this is a new problem appearing after
some time?

You indicate that the "oily" (I use that term only as a descriptive) is
easily "wiped off". I would suggest that you are not actually wiping it off
as much as moving it about the surface.

Have you checked to see if you have any dewetting issues? Could it be some
form of silicone contamination that has crept into your process?

The high gloss resist could well be only partially cured but you might also
ask your supplier if he is modifying the material in-process? By that I
refer to the occasional use of a wetting agent that the operator might see
fit to add to keep his process in good shape - although that is a no-no
unless it is approved by the resist manufacturer.

Hope this also helps.

Regards,
Graham Naisbitt

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WEB: http://www.concoat.co.uk

CONCOAT Ltd
Alasan House, Albany Park
CAMBERLEY GU15 2PL UK

Tel: +44 (0) 1276 691100  Fax: +44 (0) 1276 691227
----- Original Message -----
From: Gary Camac <[log in to unmask]>
To: <[log in to unmask]>
Sent: 10 January 2000 15:00
Subject: [TN] Residue on assemblies after cleaning


> Good morning everyone,
>
> We are seeing a film on some circuit board assemblies after
> a pass through our in-line cleaner.
>
> We are using an RA flux and a soaponifier in the cleaner.
> The film is only showing up on boards that have a high gloss
> LPI mask.
> Multiple passes through the cleaner will not remove the
> film.
> The film can be easily wiped off with a dry wipe.
> The film can be cleaned off brushing with isopropyl alcohol
> The pattern of the film is an image of the flux residue that
> was on the board prior to cleaning.
>
> Any ideas as to what is going on.
>
> Thanks in Advance,
> Gary Camac
>
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