interesting stuff

Oops, meant D5506:

Are we looking at the same stuff? It says 1.46 W/m/K right at the top. Shin Etsu makes paste that's better than 2.5 W/m/K.

Cheers

Phil Hobbs

Ah, okay, better. Its claimed Young's modulus is 30 million PSI, though, which is pretty hard--it's 3 times higher than 6061 aluminum, if you believe the numbers.

Cheers

Phil Hobbs

See my correction. Wrong link.

This is impressive, for a rigid plastic; most plastics are more like 0.2 w/m-k. I'm thinking of putting this between a PCB and a heat sink, where some of the dpak transistors might be kilovolts off ground. I'd use the recently-discussed idea of thermal vias to bottomside copper pour patches.

AlN is a lot better, but it's very stiff and I don't know if it can be trusted for HV. In theory, it absorbs moisture and hydrolizes or something like that.

Sil-pad type things run 1-5 w/m-k but would need to be thicker than this stuff to stand off the voltage.

Kapton is fabulous for voltage but terrible thermally.

Got a sample coming. There's nothing like actually handling stuff.

That stuff is extremely stiff, though--you'll need something else to take up the mechanical slack.

Alumina might has a better tradeoff of dielectric strength, cost, and stiffness.

Cheers

Phil Hobbs

Hmm, heat capacity times density is 1.8 J/cc-K which is nice. Plastics tend to have a lower heat capacity, I don't really understand why, bigger pieces of stuff stuck together, and moving around?

(do people measure the Debye temperature of plastics?)

George H.

Almost as good as the cheese on a hot pizza.