Skip to content

Home / Copper Heat Sink and Cold Plate Machining

Copper Heat Sink and Cold Plate Machining

A copper heat sink is mostly machining with a little metal in it. Fin thickness, gap, height and count set the price, and the mounting face is usually the tightest feature on the part. The shops we match are the ones that already run copper fin packs and know what aspect ratio they can hold.

If your part is a plain fin pack at volume, we will also say so when skiving or bonded fins are the cheaper process. That answer is worth more than three quotes for the wrong one.

Get matched with a copper machining shopQuick RFQ

What the part needs

Grade
C11000 ETP. Same thermal conductivity as C101 for less money. Free-machining grades lose conductivity, which is the one thing a heat sink is for.
Fin geometry
Aspect ratio, fin height over gap, up to about 10 to 1 is comfortable. Past that the price rises faster than the geometry.
Base flatness
Called out on the mounting face only, with the finish the thermal interface material needs.
Finish
As machined on fins. Ra 0.8 or better on the interface face if the TIM needs it.
Channels
For cold plates: joining method, pressure test and leak criterion stated up front.
Plating
Nickel where the sink is soldered or must stay bright. Otherwise bare.
Free for buyersShops pay for matched requests.
Up to 3 shopsOnly shops whose work fits.
NDA on requestFiles stay with us until it is signed.
Reply within 24 business hoursWith matched shops or a clear no.

Grades that fit

Published typical values for the alloy, never a promise from a shop. Each grade has its own reference page.

  • C11000
    Electrolytic tough pitch copper    The right answer for nearly every heat sink. Roughly 390 W per metre per kelvin, stocked in plate, machines like C101.
  • C10100
    Oxygen free electronic copper    Vacuum and cryogenic thermal parts, where oxygen content matters more than cost.

What drives the price

If a quote looks high, one of these is usually the reason, and most of them can be changed on the drawing.

  • Fin aspect ratioTall thin fins in a narrow gap mean a small fragile cutter, light passes and many of them.
  • Fin countWhatever one fin costs, you pay it that many times on every part.
  • Base flatnessThe mounting face is often a separate finishing operation after the fins, because cutting the fin pack releases stress.
  • Process choiceMachining wins on prototypes and integrated features. Skiving wins on plain fin packs at volume.

What to put on the drawing

Send these and the quotes you receive will be comparable. The RFQ builder writes the material lines for you.

  • Fin thickness, gap, height and count
  • Flatness and finish on the mounting face only
  • Grade, normally C11000, with temper
  • Channel joining method and leak test if the part is liquid cooled
  • Whether the part is plated, and where
  • Real quantity, and whether machining is the intended production process

Send the drawing

Short version here, or the full RFQ form with tolerance, finish and plating fields. Your files go only to the shops we match. Ask for an NDA and nothing moves until it is signed.

We are a matching service, not a machine shop. How matching works.

STEP, IGES, PDF, DWG or DXF. Cannot upload from your phone? Email the files to after you send this form.
Reply within 24 business hours.

Questions buyers ask

Something else? Email .

Copper or aluminum for my heat sink?

Copper conducts heat about twice as well and weighs about three times as much. It wins where heat is concentrated and space is tight, and loses where the sink is large and convection limited. A copper base with aluminum fins is often the right answer.

What fin thickness can be machined in copper?

Thin fins are possible but the cost climbs with aspect ratio. Give us the thermal target and the shops will tell you the cheapest geometry that meets it.

Can you match a liquid cooled cold plate?

Yes. State the joining method, the pressure test and the leak criterion in the RFQ. Those decide which shops can take it.

Should a production heat sink be machined at all?

Often not. A plain straight fin pack at volume is usually skived or bonded. We say so rather than match you with a shop that will quote the wrong process.

Read before you send