new 10.125" wide heatsink

[tinitus]

One reason why there will never be any perfectly smooth heatsink could be due to the finning on one side
Another reason could be the pace in production, to keep cost down
But I dont know

Ironically the bigger case trannies will have the worst issues
Or when using mounting angles

Wonder if theres any measuremnts/specs as to how much a heatsink gets out of shape when very hot, due to the finning on one side
Or is it a complete non issue

[Renron]

Originally posted by tinitus
One reason why there will never be any perfectly smooth heatsink could be due to the finning on one side
Another reason could be the pace in production, to keep cost down
But I dont know

Ironically the bigger case trannies will have the worst issues
Or when using mounting angles

Wonder if theres any measuremnts/specs as to how much a heatsink gets out of shape when very hot, due to the finning on one side
Or is it a complete non issue

Tinitus,

You pose a very sound question. Speaking from complete unauthority, it would seem that warping / cupping would be an inherent problem due to the fins. By design, the fins cool down first and the thickest part cools slowest. I would tend to think that the HS would warp on it's own.
Milling would be required for a flat surface. Although we only need a flat surface the size of the Mosfet(s).

Ron

[barrredboss]

Hello diy guys
the reason the flatness is off a little is they are trying to get the feed into the die at the correct speed and also getting the cooling at the correct speed,and type.
its a 98% feed issue at this point most of the hot aluminum flows out of the base first because of less restriction so they block that part off to get the fins to fill at the same rate as the base.when the die runs correctly it will be flat.within industry standard tolerances.
the wider the part the more lax the tolerances are
Hope this helps
Russ

[AndrewT]

Hi,
imagine a circle approximated by short straight chords around the perimeter/circumference.
The shorter each chord length relative to the diameter, the closer the approximation to the true circle.

Look at the curvature on the baseplate of a heatsink. How large is the diameter that such a curvature will define?

How short are the chords of that flat(straight) surface of a transistor relative to that extremely large diameter? 1:100, or 1:1000, or 1:10000?

Whether the curve of the heatsink mounting surface is caused during manufacture or as a result of differential temperature across the thickness of the backplate, the out of straightness of the heat conducting interface is inconsequential, if the isolator/conductor has just a little compliance.

Much more important is the smoothness of the interfaces and exclusion of air from the interface.

[barrredboss]

well put andrew

[flg]

Do you still have sample material left I'm game for a piece about 24-30' long???

[Renron]

Originally posted by flg
Do you still have sample material left I'm game for a piece about 24-30' long???

Do you mean feet? (') or inches (") ?

Ron

[flg]

Holy Heat Sink Batman Inches (ie;a 2-3Ft long piece, I will be cutting it lengthwise for (2) 4.5" peices)

[tinitus]

Any news on the improved heatsinks

[dcbingaman]

Hi, Russ - any updates on the big boys ??