new gap-pad...

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[Rich S]

On Tuesday, December 28, 2021 at 10:03:04 PM UTC, John Larkin wrote:

https://www.sager.com/manufacturers/laird-performance-materials/laird-tflex-hp34-series-thermal-gap-filler/

This is a graphite-filled material that seems to conduct heat
vertically. The pyrolytic graphite sheets conduct well, but only
in-plane, basically useless.

This claims 34 w/mK, about 10x better than most stuff. It costs from
about $3 to $15 per square inch, which limits use.



--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

Interesting, John.
According to this
https://www.myengineeringtools.com/Data_Diagrams/Chemical_Compound_Thermal_Conductivity.html
alumina is also high, about same, 36 W per meter-K
mica is low, at 0.43 to 0.71

most \"non exotic\" thermal pads seem to be in the 1 to 7 range.
https://ph.parker.com/us/en/thermally-conductive-pads


= RS

 

[John Larkin]

On Fri, 31 Dec 2021 11:20:07 -0800 (PST), Rich S
<richsulinengineer@gmail.com> wrote:

On Tuesday, December 28, 2021 at 10:03:04 PM UTC, John Larkin wrote:
https://www.sager.com/manufacturers/laird-performance-materials/laird-tflex-hp34-series-thermal-gap-filler/

This is a graphite-filled material that seems to conduct heat
vertically. The pyrolytic graphite sheets conduct well, but only
in-plane, basically useless.

This claims 34 w/mK, about 10x better than most stuff. It costs from
about $3 to $15 per square inch, which limits use.



--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

Interesting, John.
According to this
https://www.myengineeringtools.com/Data_Diagrams/Chemical_Compound_Thermal_Conductivity.html
alumina is also high, about same, 36 W per meter-K
mica is low, at 0.43 to 0.71

most \"non exotic\" thermal pads seem to be in the 1 to 7 range.
https://ph.parker.com/us/en/thermally-conductive-pads


= RS

My favorite insulator is aluminum nitride, which conducts heat almost
as well as most aluminum alloys, around 150 w/mk.

I had a batch of custom AlN things made for my 1200-volt Pockels Cell
driver, for around $1 each.

--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

 

[Rick C]

On Tuesday, December 28, 2021 at 5:03:04 PM UTC-5, John Larkin wrote:

https://www.sager.com/manufacturers/laird-performance-materials/laird-tflex-hp34-series-thermal-gap-filler/

This is a graphite-filled material that seems to conduct heat
vertically. The pyrolytic graphite sheets conduct well, but only
in-plane, basically useless.

Not useless, it\'s an excellent heat spreader. Is the across plane conduction so poor that heat can\'t get into the spreader, I doubt it. Once the heat is in the sheet it spreads over a large area and a low cross plane conduction is mitigated by the large area.

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

[boB]

On Fri, 31 Dec 2021 11:46:58 -0800, John Larkin
<jlarkin@highland_atwork_technology.com> wrote:

On Fri, 31 Dec 2021 11:20:07 -0800 (PST), Rich S
richsulinengineer@gmail.com> wrote:

On Tuesday, December 28, 2021 at 10:03:04 PM UTC, John Larkin wrote:
https://www.sager.com/manufacturers/laird-performance-materials/laird-tflex-hp34-series-thermal-gap-filler/

This is a graphite-filled material that seems to conduct heat
vertically. The pyrolytic graphite sheets conduct well, but only
in-plane, basically useless.

This claims 34 w/mK, about 10x better than most stuff. It costs from
about $3 to $15 per square inch, which limits use.



--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

Interesting, John.
According to this
https://www.myengineeringtools.com/Data_Diagrams/Chemical_Compound_Thermal_Conductivity.html
alumina is also high, about same, 36 W per meter-K
mica is low, at 0.43 to 0.71

most \"non exotic\" thermal pads seem to be in the 1 to 7 range.
https://ph.parker.com/us/en/thermally-conductive-pads


= RS

My favorite insulator is aluminum nitride, which conducts heat almost
as well as most aluminum alloys, around 150 w/mk.

I had a batch of custom AlN things made for my 1200-volt Pockels Cell
driver, for around $1 each.

Looked for voltage information but didn\'t see any spec.

I think we use some Laird materials.

boB