Extruded heat sinks
Fins and base extruded as one profile, then cut, machined and finished.
For drives, inverters and power supplies
Aluminium heat sinks and extrusions, made to your drawing.
Extruded, bonded-fin and skived heat sinks and custom profiles in 6063, 6061 and 1050 aluminium. Manufactured in India, machined, anodised and inspected against your drawing, and delivered to your Incoterm.
- 6063, 6061 or 1050
- Flatness measured
- Measured records
Extruded heat sink, 120 × 40 mm, black anodisedDWG REV. C
- Material
- EN AW-6063 T5
- Finish
- Black anodised, 15 µm
- Critical dimension
- Flatness 0.05 mm, mounting face
- Inspection
- Flatness and anodising thickness
What we make
Bonded and brazed fin heat sinks
Tall, thin fins bonded or brazed into a base, beyond what a die can extrude.
For high-power modules
Skived fin heat sinks
Fins sliced up from a solid block, dense and with no joint at the base.
For compact, high heat loads
Heat sinks with copper inserts
Copper slugs or plates pressed into the base under the hot spot.
For IGBT and MOSFET modules
Liquid cold plates
Machined aluminium plates with sealed channels or pressed tube for liquid cooling.
For data-centre power and fast chargers
Custom extruded profiles
Profiles for frames, rails, covers and enclosure housings, cut and machined.
For enclosures, rails and LED housings
Choosing a heat sink
The heat load and the space decide the fin type. The mounting face decides how much heat gets in.
Fin type for the heat load
- Extruded
- The lowest cost per part, with a low tooling cost.Watch for: The die limits how tall and close the fins can be.
- Bonded or brazed fin
- Taller, thinner fins for more surface in the same space.Watch for: The fin-to-base joint adds thermal resistance; brazed beats epoxy.
- Skived
- Dense fins cut from one block, with no joint.Watch for: Thin fins bend easily in handling and packing.
Mounting face for the heat path
- Flatness
- Held to the drawing and measured, so the device sits flat.Watch for: A gap filled with thermal paste raises the device temperature.
- Surface finish
- Machined or fly-cut to the roughness on the drawing.Watch for: Machine after extrusion, not before; profiles twist slightly.
- Masking
- Areas left bare of anodising for earthing or electrical contact.Watch for: Anodising is an electrical insulator; mark the bare areas on the drawing.
Finish for the surface
- Clear anodised
- Hard, corrosion-resistant and natural in colour.Watch for: Give the thickness, usually 10–25 µm.
- Black anodised
- Radiates more heat in still air, for natural convection.Watch for: Makes little difference where a fan blows across the fins.
- Conversion coated
- A thin coating that keeps the surface conductive and takes paint.Watch for: Specify trivalent; hexavalent chromium is restricted under RoHS.
Specifications
- Types
- Extruded, bonded and brazed fin, skived fin heat sinks; heat sinks with copper inserts; liquid cold plates; custom extruded profiles
- Materials
- EN AW-6063 T5 and T6; EN AW-6061 T6; EN AW-6082 for structural profiles; EN AW-1050 for fins; copper C11000 inserts
- Profile size
- Up to 300 mm circumscribing circle standard
- Length
- Cut to drawing; profiles up to 6 m
- Processes
- Extrusion, CNC machining, fin bonding and brazing, skiving, friction stir welding for cold plates
- Finishes
- Clear and black anodising; trivalent conversion coating; powder coating
- Checks
- Mounting-face flatness; profile dimensions; anodising thickness; thermal resistance and leak test where specified
- Standards
- EN 755-9 and EN 12020 profile tolerances; anodising to ISO 7599; dimensions to your drawing
- Quantities
- Prototype builds to mass production
Which aluminium
6063 extrudes the finest fins and carries heat well. Copper goes only where the heat is concentrated.
Copper105060636061
Thermal conductivity: typical values at room temperature, from published alloy data.
Thermal conductivity
Copper, about 390 W/m·K
1050, about 230 W/m·K
6063-T5, about 209 W/m·K
6061-T6, about 167 W/m·K
- 6063
- The usual extrusion alloy for heat sinks. Extrudes the thinnest fins and anodises well.
- 6061
- Stronger, for heat sinks that also carry load or are machined heavily.
- 1050
- Nearly pure aluminium, for skived and bonded fins where conductivity matters most.
- Copper
- Nearly twice the conductivity of 6063, used as an insert where the heat is concentrated.
Questions buyers ask
Why does mounting-face flatness matter?+
Heat leaves the device through the mounting face. Any gap is filled with thermal paste, which conducts heat far worse than aluminium, so the device runs hotter. We measure flatness and report it with the batch.
Black or clear anodising?+
Black radiates more heat, which helps a heat sink in still air. Where a fan blows across the fins, the colour makes little difference and clear anodising is fine.
Is anodising an electrical insulator?+
Yes. Where the heat sink must be earthed or carry current, those areas are masked or conversion coated instead. Mark them on the drawing.
Can you add copper inserts under the hot spot?+
Yes. A copper slug or plate pressed into the base spreads the heat from a small, hot device before it reaches the fins.
Do you need a new die for my profile?+
A custom profile needs its own extrusion die. Send the drawing and we confirm the profile can be extruded before we quote.
Can you match an existing heat sink from another supplier?+
Yes. Send the drawing, and a sample if the drawing is incomplete. We tell you what can be held before we quote, then make samples for your approval.
Can you take a small order?+
Yes. Small, engineering-heavy batches are work we take, from prototype quantities upwards.
Send the drawing
Email us your enquiry at contact@qumek.com. We respond within 12 hrs.
Your enquiries are confidential with us and we proceed with manufacturing only after signing a NDA.
Need a DFM review, a prototype or a test plan before production? See the services.