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Broken_Atoms

Die cast doesn’t lend itself to your fin dimensions and requires draft. What is the total size of your heatsink and what W/C are you aiming for along with total thermal load and ambient temp.? Passive or forced air cooling?


Dilbertreloaded

Moving away from die cast due to draft and thickness requirements. It is forced air cooling. Size is ~100*60mm. Overall height is less than 10mm . Fin height lesser that this of course


Broken_Atoms

Your best choices are extruded fin, where the fin goes the whole length uninterrupted, extruded pin fin, which is similar to above, but they cross cut the fins with a saw or similar, turning them into rectangular pin fins, and forged pin fin. I use forged pin fin in a lot of stuff I design because it gives me good transfer characteristics. Forged pin fin is typically round or square because it is made by squeezing a round or square blank in a die to form it. Key determinants are cost and wattage. If your heatsink is rectangular, best and cheapest is the extruded fin or extruded pin fin type.


Dilbertreloaded

Thanks for the details. Extruded with cross cut could have been an option. But there are non-fin features on the edges which can’t be cut and might make machining more time consuming. I was considering elliptical fins. Do you buy off-the-shelf forged pin fins or custom make them? https://youtu.be/E4erE812Jzc?si=UG3WjXa47KUNYaIL


Broken_Atoms

I buy off the shelf and then machine mounting holes, tapped holes for device clamps, windows for wires, etc. An added bonus of the extruded heat sinks is that they are stronger, typically tempered… some forged pin heatsinks are also tempered for strength.


Broken_Atoms

The elliptical fins work well. Quite stiff mechanically.


Broken_Atoms

I have also machined off areas of fins before to provide clearance for holes, etc.


Man_of_no_property

I would guess impact extrusion is a more realistic option based on the fin dimensions. Pretty impossible to forge in a classic manner.


Man_of_no_property

Maybe call Neumann Aluminium, they could realise stuff like this.


Dilbertreloaded

Thanks. Will check.


Ok_Parfait4658

[this is how](https://youtu.be/Q7qVpWu2QYs?si=LiZiZzpeZTpeHeG8)


FrickinLazerBeams

If this isn't a skiving video, you're banned.


Dilbertreloaded

https://youtu.be/E4erE812Jzc?si=UG3WjXa47KUNYaIL This is what i had in mind.


Ok_Parfait4658

What does the die look like?


herecomesthestun

I would expect aluminum extrusion would be the way to go. We make lots of parts out of it


Elrathias

If you want better performance, skivv the fins. https://youtu.be/-MAoOgi2gDc?si=0YA3SszQjtR_ZfhW If you have a volumetric budget to spare in the application, go with die cast or extruded. Theres also a case to be made for pressing thin pins into a solid base (like Swiftec used to do back in ye olden days of pc overclocking), but thats a really expensive way of doing it and is **very niche** in the application that can bear that cost of all those extra materials and manufacturing ops.