# CNC Machined Heat Sinks & Cold Plates

> CNC machining is appropriate for custom thermal parts when chip location, mounting pattern, flatness, internal channels or prototype quantity prevents use of an extrusion or standard cooler. Aluminum 6061 balances machining, mass and finishing; copper C110 improves conductivity but increases machining and weight considerations.

- HTML page: https://fabvector.com/custom-cnc-parts/cnc-machined-heat-sinks-cold-plates (Portuguese: https://fabvector.com/pt/custom-cnc-parts/cnc-machined-heat-sinks-cold-plates)
- Quote: https://fabvector.com/quote

## Typical applications

- AI accelerator and server cold plates
- Power-electronics heat sinks
- Laser and optics thermal bases
- Battery and inverter cooling plates

## Recommended manufacturing route

1. Define the thermal interface, flow circuit, cover or joining route and test boundary.
2. Machine base datums, channels or fins while controlling thin-feature deflection.
3. Join or seal the cover using the approved process, then clean the flow path.
4. Inspect flatness and perform the specified leak or pressure test before packing.

## Drawing and RFQ controls

| Control | Guidance |
|---|---|
| Thermal interface | State flatness and surface finish over the actual chip or module contact zone. |
| Channel geometry | Avoid unreachable corners and provide wall margin around ports, screws and seals. |
| Joining method | Define brazed, friction-stir-welded, bonded or gasketed construction before quoting. |
| Leak acceptance | Specify medium, pressure, time, temperature and allowable leak rate. |

## Recommended materials

- [aluminum-6061](https://fabvector.com/md/materials/aluminum-6061): Common balance of thermal performance, mass, machining and corrosion protection.
- [copper-c110](https://fabvector.com/md/materials/copper-c110): Higher conductivity for dense heat flux and electrical bus structures.
- [aluminum-6063](https://fabvector.com/md/materials/aluminum-6063): Useful when an extrusion-derived heat-sink form is part of the route.

## Manufacturing processes

- [cnc-milling](https://fabvector.com/md/services/cnc-milling)
- [5-axis-machining](https://fabvector.com/md/services/5-axis-machining)
- [production-machining](https://fabvector.com/md/services/production-machining)

## Compatible finishes

- [anodizing-type-ii](https://fabvector.com/md/finishes/anodizing-type-ii)
- [electroless-nickel-plating](https://fabvector.com/md/finishes/electroless-nickel-plating)
- [chromate-conversion](https://fabvector.com/md/finishes/chromate-conversion)

## Inspection scope to define before production

- Flatness and roughness report for the thermal interface
- Pressure or leak test using RFQ-defined acceptance criteria
- Cleanliness and channel-flow verification when specified

## Buyer questions, answered

### Can FabVector machine both air-cooled heat sinks and liquid cold plates?

Yes. Air-cooled parts focus on fin geometry and base flatness; liquid parts add channels, ports, joining, cleaning and a defined leak-test scope.

### Is copper always better than aluminum for a cold plate?

No. Copper conducts heat better, but aluminum is lighter, easier to machine and often easier to protect from corrosion. Thermal load, coolant, galvanic pairing, mass and cost must be evaluated together.

### What leak-test information is required for a quote?

State test medium, pressure, dwell time, temperature, allowable leakage, port plugs and whether a certificate or raw data is required.

### Can the thermal interface be machined after joining?

Often yes, and post-join finishing can recover flatness affected by brazing or welding. The sequence depends on joint process, access, distortion risk and final coating.

## Related engineering guides

- [Liquid cold-plate design guide](https://fabvector.com/blog/liquid-cooling-cold-plate-cnc-machining)
- [Copper thermal-part machining guide](https://fabvector.com/blog/copper-cnc-machining-thermal-parts)