Jorge: We apply water soluble temporary soldermask (TSR)using screen
printing instead of true stencils. The screens are about 1/10 the cost of a
stencil so you don't tie up a lot of dollars in stencil inventory. Unlike
stencils which are permanent the image can be washed out and the screen
re-imaged if there is a rev change or if you just want to use it on a
different P/N.

We use a contract service to mount/stretch and image the screens, most can
work from Gerber or film.

The screens use an aluminum chase with a 60 mesh polyester screen fabric.

The TSR is applied using a 60 durometer urethane squeegee.

Curing can be done at room temp 6-12hrs or accelerated be baking, 130C 5
mins.

The TSR material is supplied by Saati America 800-766-3676. The product name
is Dorn Temporary Solder Mask.
It is actually manufactured by Cerulean Blue Ltd. 206-525-8992. This used to
be an Alpha Metals product called HV-110 which was the screenable version of
there 110 water soluble TSR product family.

The TSR does not contain insoluble fillers such as clay, fumed silica etc,
which can clog wash nozzles build up in tank sumps or wear out pump seals on
aqueous washers.


Regards

Michael Barmuta

Staff Engineer

Fluke Corp.

Everett WA

425-446-6076
-----Original Message-----
From: Jorge Rodriguez [mailto:[log in to unmask]]
Sent: Monday, January 21, 2002 10:46 AM
To: [log in to unmask]
Subject: [TN] WS Solder Mask for Stencil Applications


Fellow Technetters,

        I am looking for a water soluble solder mask that can be compatible
with stencil applications. We do quite a lot of solder mask applications
with a dispensing machine, but I am really looking into using a stencil
since it would speed up the process and help the ability to apply thinner SM
layers. I tried to do it with the one we use on the dispensing machines, but
it's too liquid and starts to cure at ambient temperature after 30 minutes,
so it was not possible.

        Ha anybody accomplished this? Would there be a special WS solder
mask for stencil applications?


        Any comments would be appreciated

Jorge Rodriguez
Process Engineer
Varian Electronics Manufacturing
615 South River Drive
Tempe, AZ 85281
Phone: (480) 968-6790 X 4258
Fax: (480) 829-4000
E-mail: [log in to unmask]

----------------------------------------------------------------------------
-----
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt delivery of Technet send e-mail to [log in to unmask]: SET
Technet NOMAIL
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search previous postings at: www.ipc.org > On-Line Resources & Databases >
E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
----------------------------------------------------------------------------
-----

---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------