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From: liz@poppyrecords.invalid.invalid (Liz Tuddenham)
Newsgroups: sci.electronics.design
Subject: Re: silicone grease
Date: Mon, 1 Apr 2024 13:42:15 +0100
Organization: Poppy Records
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Martin Brown <'''newspam'''@nonad.co.uk> wrote:

[..]
> If you are prepared to de-rate accordingly then there isn't really a 
> problem but if you want to run them at full power then they need to be
> in intimate contact with their heat sink and that means wetted by some
> sort of heat transfer medium.

Designing audio amplifiers, it often worked out more economical to use
two output devices run gently, rather than a single one pushed to its
limits.  The two thermal paths between die and heatsink are effectively
in parallel and carrying half the power each, so you can run the die
cooler [preferred] or the heatsink hotter [if you really must]. 

You also keep the device well below its maximum current rating where the
current gain is higher and it needs less drive power.  Economies in the
drive stage and current protection may well compensate for the cost of
an extra lump of silicon and a couple of resistors.


-- 
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk