Have you considered an alteration to the aperture in a non-standard form?

For heat sinks, I customarily do not print the entire pad.  I cover 75 - 90%
of the pad with paste, using small dots.  The result is good adhesion and
easy application.  We have used the "beer can opener" trick to confirm full
wetting.  Coverage is easily adjusted, by changing the diameter of the dots.

To improve visibility, possibly add a small half circle or half of an oval
(minor axis radius = 0.015" ??) to the end of the heatsink, to expose some
of the wetted area. (assuming the end of the heat is visible)  The small
addition of the paste shouldn't affect the location of the device and will
provide the visibility the customer needs.

Rich


Richard Elensky
Sr. Manufacturing Engineer
[log in to unmask] <mailto:[log in to unmask]>

Tel:  559-292-1111  x246
Fax:  559-292-9355

Dantel
2991 North Argyle Ave.
Fresno, CA, 93727
Visit our web site at:
http:// www.dantel.com <http://www.dantel.com>


        ----------
        From:  Andre Leclair [SMTP:[log in to unmask]]
        Sent:  Wednesday, October 24, 2001 9:03 AM
        To:  [log in to unmask]
        Subject:  Re: [TN] SMT part with Backside Ground

        David
        We have been x-raying to verify sufficient bonding of the ground
terminal
        to the pad, however the customer ( who is always right!!) wants
solder
        evident to the outer edges to ensure there is enough thermal mass
for heat
        dissipation.


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