Looking for online CNC service that does thin wall (<1mm) copper

I am working on a small electronics prototype where I added some fins to the heatsink for better heat dissipation. The fins were 0.5mm thick and the first service I contacted said their process cant do walls that narrow and that I should bring them up to 1mm and resubmit my design. A lot of the online services I have found said they can go down to 0.5mm in thickness but want the average wall thickness to be 1mm. The problem with that is my project is so small the walls are currently set at 1mm. So I am hoping to find a service that is either okay with the 0.5mm fin design as is or would be willing to meet me somewhere in the middle and not force me to bring it all the way up to the full 1mm fins. If anyone has any ideas for some online services to look into that would be great of just some general advice.

Thanks in advanced, Jonathan

Have you considered folding the fins from 0.5mm sheet then soldering them to the heatsink base ?

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Originally Posted by Tubbstcg

I am working on a small electronics prototype where I added some fins to the heatsink for better heat dissipation. The fins were 0.5mm thick and the first service I contacted said their process cant do walls that narrow and that I should bring them up to 1mm and resubmit my design. A lot of the online services I have found said they can go down to 0.5mm in thickness but want the average wall thickness to be 1mm. The problem with that is my project is so small the walls are currently set at 1mm. So I am hoping to find a service that is either okay with the 0.5mm fin design as is or would be willing to meet me somewhere in the middle and not force me to bring it all the way up to the full 1mm fins. If anyone has any ideas for some online services to look into that would be great of just some general advice.

Thanks in advanced, Jonathan

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Do you have a drawing if the fins are not to tall that is not difficult to machine, and if it was you could rough machine then use an EDM to do the finished size

You may also be able to wire EDM where it can't be machined

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Originally Posted by Zorbit

Have you considered folding the fins from 0.5mm sheet then soldering them to the heatsink base ?

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That would be a very poor heatsink, the joint weld would have to be done with a laser to have any chance of a reasonable heat transfer

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Originally Posted by mactec54

That would be a very poor heatsink, the joint weld would have to be done with a laser to have any chance of a reasonable heat transfer

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Not welded, silver soldered. Silver has better thermal conductivity than copper.

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Originally Posted by Zorbit

Not welded, silver soldered. Silver has better thermal conductivity than copper.

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In your post you said to solder them to the heatsink!!

It would be welded if it was done with a laser is what I posted

The problem with your answer is silver solder solder is not 100% silver so the thermal conductivity of the joint would not be better than copper

AG=Silver 429 only silver
CU=Copper 401

Pure silver wins, but no body is going to use pure silver for a joint like this

The average silver solder rod starts at only 5% silver so to get a 95% silver content rod the cost per rod would put this to rest very quickly and it still would not have the same thermal as copper

Silver solder is commonly used here in the UK, EasyFlo is a popular brand. Typically 55% silver, 15% copper, rest cadmium and zinc. People have been making heat exchangers and radiators with it for 100 years. I'm sure it would be cheaper than EDM.

I thought this was for a prototype anyway, if not then perhaps the best way it to find someone who can skive copper.

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Originally Posted by Zorbit

Silver solder is commonly used here in the UK, EasyFlo is a popular brand. Typically 55% silver, 15% copper, rest cadmium and zinc. People have been making heat exchangers and radiators with it for 100 years. I'm sure it would be cheaper than EDM.

I thought this was for a prototype anyway, if not then perhaps the best way it to find someone who can skive copper.

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It would be easy to machine if the fins are not to deep, these copper parts in the attach photo I machined and are less then .5mm thick they where machined from solid

It is used around the world and there are lots of different application's where it can be used, Easy-Flo is a better name for it as it is not a solder 55% silver that would be expensive

Silver Soldering Vs. Soldering

Soldering, or soft soldering, is any joining of metals using a filler metal that melts below 840°F. Note that the melting points for silver soldering are considerably higher. “Silver solder” is a misnomer and is a form of brazing. It is sometimes referred to as “silver braze.” The American Welding Society discourages the term “silver solder.”

UK terms are a bit different. Brazing is usually referring to a joint where brass is the filler and is applied like a welding rod, Silver Soldering is usually done with pre-shaped shims or rings of solder plus flux placed into or onto a joint and then the job heated with a torch or in an oven. It's pretty cheap, the gaps between parts are extremely small.

It makes sense to standardise names, we already use AWS designations for welding rods, so we'll probably stop calling it silver soldering soon too. We're keeping Aluminium though ;-)

Here's a few examples of soldered / brazed heatsink;

Tran-Tec Corporation - Bonded Fin Heat Sinks

Bonded Fin & Brazed Fin Heat Sink Assemblies (boydcorp.com)

Thermo Cool | Bonded Fins (thermocoolcorp.com)

Best High Power Led Heatsink, Welcome To Wholesale Now (lorithermal.com)

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Originally Posted by Zorbit

Here's a few examples of soldered / brazed heatsink;

Tran-Tec Corporation - Bonded Fin Heat Sinks

Bonded Fin & Brazed Fin Heat Sink Assemblies (boydcorp.com)

Thermo Cool | Bonded Fins (thermocoolcorp.com)

Best High Power Led Heatsink, Welcome To Wholesale Now (lorithermal.com)

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A brazed joint is anything that a torch is used for, that requires over 840 Degree melt temperature

I think it will always be called silver solder even though it is not a solder, I'm an experienced user and always have it on hand along with Sil-Fos for copper to copper joints

There is some good ideas in those links, slots could be milled and then shrink fit the fins in place would most likely work for a proto types, he has not posted a drawing so we have no idea of what is really needed

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Originally Posted by Tubbstcg

I am working on a small electronics prototype where I added some fins to the heatsink for better heat dissipation.

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I'm willing the bet that you'd be able to find an extrusion that will fit the bill , unless you've got some funky shapes to the heatsink , I've machined many heatsinks from solid , or finish machined extrusions . If you can find an extrusion that fit your needs , then there will be a big cost savings in having the rest finish machined on the pockets , drill/tapped holes etc

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Originally Posted by metalmayhem

I'm willing the bet that you'd be able to find an extrusion that will fit the bill , unless you've got some funky shapes to the heatsink , I've machined many heatsinks from solid , or finish machined extrusions . If you can find an extrusion that fit your needs , then there will be a big cost savings in having the rest finish machined on the pockets , drill/tapped holes etc

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Aluminum extruded heat sinks are everywhere, Copper as an extruded heat sink, not so many choices

copper ya not so much , I missed seeing copper .

To me this is a classic case of a design meeting the real world. Some things designed on a computer cannot be built. Listen to the vendors and revise your design. But surely an appropriate heat sink can be purchased without the need for machining.

.5 mm heatsink fins? Is that even enough mass to move the heat? I seriously doubt youll find any reliable way to supply this as a machined feature and if so, it will be very expensive.