Thermal Management
Custom aluminum heatsinks & cold plates
A heatsink is fundamentally an extruded aluminum profile with fins, so it sits inside our extrusion flow — and we take it further: extruded, skived, bonded, CNC-machined and liquid-cooled designs, then assembled with heat pipes, fans and fittings. Tell us the watts, the airflow and the envelope and we propose the construction and alloy.
What a custom heatsink is
Heat leaves a component by conduction into a base, then by convection from a fin surface into air or liquid. The job of the heatsink is to present as much conducting and radiating surface as the envelope allows, with the lowest thermal resistance between the hot source and that surface. Aluminum is the default material because it conducts well (~150–230 W/m·K for common extrusion alloys), is light, and is cheap to shape by extrusion.
Because fins are just a constant cross-section repeated along a length, extrusion is the natural way to make a heatsink. From there we extend to skived and bonded fins when the aspect ratio outruns what a die can hold, to CNC when the geometry is 3D, and to liquid cold plates when air can no longer carry the heat away. One supplier runs the whole chain, so the fin, the base flatness and the post-machining are controlled together.
The practical question is never "what is a heatsink" but "which construction fits my power density and space" — the rest of this page is that decision.
Why Teyalu for heatsinks
- Extrusion root — fins, base and post-machining in one flow
- Extruded, skived, bonded, CNC and liquid cooling all in-house
- DFM review before tooling reduces rework
- Anodize, powder coat, bonding and assembly under one roof
- English engineering support, 24h response
- One quote and one production schedule
Heatsink types we make
From cost-effective extruded fins to high-density skived and liquid cooling — pick by power density and space.
Extruded Heatsinks
High-fin-density profiles, economical for medium power. Fin ratio to ~40:1 in selected geometries.
See extruded →Skived Fin
Ultra-thin, dense fins cut from solid bar — maximum surface area in tight space, no bond line.
See skived →Bonded Fin
Extruded base + stamped fins bonded or soldered for high aspect ratios and complex base shapes.
See bonded →CNC Machined
Complex shapes, pin fins and tight tolerances for low-volume runs and prototypes.
See CNC →Liquid Cold Plates
Aluminum plates for power electronics and battery cooling; vacuum-brazed or FSW.
See cold plates →Assemblies
Heatsinks with heat pipes, fans, insets and welded fittings — built and tested to spec.
See assemblies →Which type do I need? A decision table
The single most useful rule: match the construction to your power density and the space you have. Use this to narrow to one or two candidates, then we confirm with a thermal estimate.
| If your design… | Start with | Why |
|---|---|---|
| Medium power, high volume, air-cooled | Extruded | Lowest tooling, cheapest per part, fins to ~40:1 |
| High power density, thin tall fins, tight space | Skived | Fin as thin as 0.2–0.5 mm; no bond line, best conduction |
| High aspect ratio but complex base / off-axis | Bonded | Stamped fins + machined base; flexible geometry |
| Low volume, 3D shape, pin fins, prototype | CNC machined | No die; full 3D freedom, ±0.01 mm features |
| Air cannot carry the heat away | Liquid cold plate | Water/glycol loop moves far more heat per volume |
| Hot spot offset from available fins | Assembly + heat pipe | Pipe spreads heat to a larger fin area |
Exact fin ratio and thermal resistance depend on alloy, fin geometry and airflow — we model these against your drawing rather than quote a single number.
Extruded vs skived vs bonded vs CNC — quick guidance
Extruded
- Best for medium power, high volume
- Lowest tooling cost
- Fin ratio limited (~40:1 in selected geometry)
- One piece, no joint
Skived
- Thinnest, tallest fins (0.2–0.5 mm)
- No bond line — best conduction
- Higher piece cost, no die
- Best for very tight spaces
Bonded
- High aspect ratio fins (0.2–0.8 mm)
- Complex, machined base shapes
- Bond line adds a little resistance
- Good middle option
CNC / Liquid
- CNC: complex, low volume, pin fins
- Liquid: highest heat density
- Highest piece cost
- Used when air is not enough
Full write-up, fin-ratio limits and aluminum-vs-copper trade-offs in each type page and our materials guide.
From drawing to finished heatsink — the process
A typical custom heatsink job mirrors our extrusion flow, with the fin stage driving the rest:
1 · Design & die
We model the fin and base from your thermal spec — fin pitch, height and base flatness set here.
2 · Extrude / form
Extrude the finned section; or skive from bar; or stamp fins for bonding; or CNC the shape.
3 · Bond / join
For bonded fins: solder or epoxy the fins to the base. For assemblies: add heat pipes or fittings.
4 · Machine base
Face-mill the base flat, drill and tap mounting holes to ±0.01 mm where needed.
5 · Finish
Anodize (clear or black) to raise emissivity; or powder coat when color/weather matter.
6 · Inspect & pack
Check flatness, fin integrity and finish; pack fins to survive shipping.
Heatsink design guide (DFM)
The same early review that saves cost on extrusion applies to fins. Key rules:
Fin ratio
Extrusion holds fin height-to-thickness around 15:1–20:1 in practice, up to ~40:1 in selected geometry. Beyond that, move to skived or bonded.
Base flatness
The base meets the device, so it is face-milled flat — typically to 0.05–0.1 mm for good thermal contact. State it clearly.
Fin pitch
Too close and air cannot flow; too open and you lose area. We size pitch to your airflow (natural vs forced).
Mounting
Give clearance for holes, threads and standoffs; tell us the device footprint so fins align with the hot zone.
Finish
Anodizing improves radiation and looks; for max conduction keep it thin (Type II ~10 µm) and avoid paint on the contact face.
Tolerances
Let extrusion carry the general shape; machine only the base, holes and seats. See our tolerances guide.
Alloy choice for heatsinks
Thermal conductivity drives the choice more than strength. 6063 conducts well and anodizes cleanly, so it is the usual fin alloy. 6061 is the choice when the base also carries load or needs machining; 6101 and 6060 appear in some thermal bus and thin-wall work. Copper conducts ~1.8× better but is heavy and costly — used only as inserts or vapor chambers where the gain pays for itself.
| Alloy | Thermal conductivity (typical) | Use in heatsinks |
|---|---|---|
| 6063 | ~200 W/m·K | Finned profiles, general thermal |
| 6061 | ~150–170 W/m·K | Base + machined, structural thermal |
| 6060 | ~190–200 W/m·K | Thin-wall fins |
| 6101 | ~200+ W/m·K | Thermal bus / conductive sections |
Values are typical ranges for the alloy family; final conductivity depends on temper and impurity control. Full comparison in our materials guide.
Heatsink capability & typical limits
| Parameter | Typical capability |
|---|---|
| Extruded fin ratio | ~15:1–20:1 practical, up to ~40:1 selected geometry |
| Skived fin thickness | 0.2–0.5 mm, height to ~100 mm |
| Bonded fin thickness | 0.2–0.8 mm, height to ~150 mm |
| Base flatness (machined) | 0.05–0.1 mm typical |
| CNC positioning | ±0.01 mm |
| Liquid cold plate pressure | working 3–10 bar; brazed / FSW seal |
| Finish | Anodize II/III, powder coat, brush, blast |
Need a thermal estimate before you commit?
- Tell us power (W), hot-spot location, airflow (m/s or LFM) or liquid flow, ambient and target junction temp.
- We return a proposed construction, alloy and a rough resistance range — no obligation.
Where our heatsinks go
Power electronics
IGBT and inverter heatsinks, busbar carriers. See power electronics.
Data center & telecom
Server enclosures and liquid-cooling plates for high-density heat. See telecom & data center.
EV charging
Cooling plates and enclosures for charge points and power modules.
LED & lighting
Extruded heat-sink channels and housings for luminaires.
Industrial automation
Drives, controllers and machine thermal parts.
Medical
Anodized, clean thermal components for instruments.
Frequently asked questions
What is the best heatsink type for high power density?
When air cooling can still work, skived or bonded fins win because they hold thinner, taller fins than extrusion (fin as thin as 0.2–0.5 mm vs ~1 mm for extrusion). When the power density outruns air entirely, move to a liquid cold plate — a water/glycol loop removes far more heat per unit volume. The cut-over depends on your watts, envelope and airflow; send those and we propose the construction.
Extruded vs machined heatsink — which should I pick?
Extruded is cheaper per part and scales to volume; it suits constant cross-sections with fins to ~40:1 in selected geometry. CNC machined suits low volume, prototypes and 3D or pin-fin shapes that a die cannot make, at higher piece cost. Many production heatsinks are extruded fins with a CNC-machined, drilled base — the extrusion carries the shape, machining carries the precise features.
What fin ratio can aluminum extrusion hold?
In practice a fin height-to-thickness around 15:1–20:1 runs cleanly; ~40:1 is achievable only in selected geometries with careful die design. Beyond that, fins tend to bend, fill poorly or limit quench, so we recommend skived or bonded construction instead. We confirm the real limit during die design rather than promise a single number.
Should I anodize a heatsink?
Usually yes for the fin area: anodizing (clear or black, Type II ~10 µm) raises emissivity and protects the surface, and a thin layer barely hurts conduction. Keep the contact face clean or machine it after anodizing so the device sits flat. Where color and weather resistance matter more than radiation, powder coat instead — but not on the contact face.
How do I specify a heatsink for quoting?
Send the drawing plus power to dissipate (W), hot-spot location, airflow (natural/forced, m/s or LFM) or liquid flow rate, ambient and target junction temperature, the space envelope and mounting method. With those we return a construction, alloy and a rough thermal-resistance range, then a firm quote after DFM review.
Can you assemble the heatsink with a fan or heat pipe?
Yes — see our heatsink assemblies page. We add copper heat pipes (typically 6/8 mm) to move heat from an offset hot spot to the fin area, and we build active (fan-assisted) modules for industrial use. We define the assembly and test it to your spec.
What is the typical lead time for a custom heatsink?
Tooling and first-article lead time runs in weeks, set by fin complexity, die design and finishing; repeat orders are much faster. For bonded or skived builds there is no extrusion die, so lead time is shorter. Share the drawing and we return a dated plan before you commit.
Do you make standard stock heatsinks?
No — we build to your drawing, not a catalog. Every fin profile is project-specific. If you need a quick off-the-shelf part we can often supply extruded bar for your own machining while the custom tooling is built.
Tell us your thermal budget
Send power, airflow and envelope — we'll propose a construction, alloy and a free DFM review.