What kind of Sil-Pad do you use?

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What kind of Sil-Pad do you use?

Postby W1AC » Thu May 08, 2014 9:09 am

I'm rebuilding a Class E RF deck, and I've been going cross-eyed selecting components on the Digi-Key site. The last item on my shopping list is Sil-pad: it's the insulation material used to mount the 11N90's and 614 chips on the heat sink on the old layout.

If you've used Sil-pad, please give me a clue as to what I'll need.

I figure that -

  • A 450 watt Class E RF deck that puts out 385 watts has about 70 watts of heat to dissipate, counting the drivers and incidentals.
  • In a push-pull configuration, that's ~33 watts per bank of 11N90's.
  • The Sil-pad specs list thermal performances of several degrees centigrade per watt, which scare me.
  • I need to know which Sil-pad material is 'best' for this application.
  • I also need to know if anyone has some spare mica standoffs and some heat grease :roll:

Thanks in advance.


Bill, W1AC
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The trick is to avoid the hot spots!
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Re: What kind of Sil-Pad do you use?

Postby kf1z » Thu May 08, 2014 10:24 am

You could be over-thinking it a bit... :-)

Use digikey BER178-ND

The IXDD-614 do NOT need one... just a little dab of grease. the tab on those is ground.
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Re: What kind of Sil-Pad do you use?

Postby n1ps » Thu May 08, 2014 6:53 pm

I like to use a little compound on the 11n90 too, even with the silpad.

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