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From [log in to unmask] Fri Aug 23 09: |
01:44 1996 |
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Hi,
I don't have any hard numbers for heat dissipation for you, but I
hope this helps. I've done this a number of times at different
companys and it seems to work. Provide a solid copper area as big as
possible under the component to be heatsinked on the external layers.
Remove solder mask where ever the component touches the heatsinked
plane. If possible duplicate this plane on all layers. Stitch the
multiple planes together with vias, (I've used .023 dia and .033 dia
with equal success). Put the vias on a .100" staggered grid if
possible. (tip of the hat to Ralph Hersey here).
x x x
x= via hole
- x x x
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.10 x x x
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- x | x x
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-| |-.050"
If possible make via connections to the planes solid ie. no
thermals. If you are using forced air cooling you might use a few
larger holes to allow air circulation.
Best of luck,
Rob
ROBERT BUTTERWORTH
ADC VIDEO SYSTEMS
WALLINGFORD, CT 06492
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