2026-03-06 18:07:47
An Extrusion Heat Sink is one of the most widely used thermal management solutions in power electronics, LED systems, industrial automation, medical equipment, and computer hardware. Thanks to its cost efficiency, structural strength, and scalable production capability, heat sink extrusion technology remains the backbone of modern cooling system design.
An extrusion heat sink refers to a thermal dissipation component formed by forcing heated metal—typically aluminum—through a precision die to create a continuous cross-sectional profile.
The resulting structure contains fins, base plates, mounting features, and airflow channels integrated into a single profile. After extrusion, the profile is cut, machined, treated, and assembled into finished heat sink extrusions.
Compared with casting or machining, heat sink aluminum extrusion offers:
l Continuous grain structure
l Excellent mechanical strength
l Superior dimensional repeatability
l High-volume production capability
l Lower tooling cost per unit
Because of these advantages, aluminum extrusion heat sink solutions dominate the mid-to-high power cooling market.
The most common material used in aluminum heat sink extrusion is the 6000 series aluminum alloy, especially:
l 6063
l 6061
These alloys offer thermal conductivity ranging from 166–201 W/m·K, along with good corrosion resistance and mechanical durability.
Advantages of aluminum extrusion heat sinks include:
l Lightweight structure
l Excellent machinability
l Strong corrosion resistance
l Cost efficiency in mass production
l Compatibility with anodizing
For most industrial and electronic cooling applications, heat sink aluminium extrusion is the optimal balance between performance and cost.
Although less common, copper heat sink extrusion is used in applications requiring higher thermal conductivity.
Copper offers:
l Thermal conductivity up to 400 W/m·K
l Excellent ductility
l Strong heat spreading capability
However, copper is:
l Heavier
l More expensive
l Harder to extrude
l Less economical for large-volume profiles
Therefore, copper heat sink extrusion is typically reserved for high-density power modules and specialized cooling systems.
A professional heat sink extrusion process involves multiple critical stages to ensure dimensional stability and thermal performance.
Material selection includes:
l 6063-T5 / T6 aluminum billets
l Chemical composition verification
l Hardness testing (≥75HB for T5 condition)
l Tensile strength sampling (≥170MPa typical)
l RoHS / REACH compliance
Billets are cut to required lengths and batch-tracked for full traceability.
For reliable aluminium extrusion heat sink production, die engineering is crucial.
Key parameters include:
l Fin aspect ratio: typically 4:1 to 8:1
l Draft angle: 0.5°–1°
l Extrusion ratio: 15:1–60:1
l Bearing length optimization (3–8mm in critical zones)
Dies are made from H13 tool steel (HRC48–52) and polished to Ra ≤0.4μm in bearing areas.
Billets are heated to 480–520°C before entering an extrusion press (800–2500 tons typical capacity).
Process control parameters:
l Exit temperature: 500–540°C
l Extrusion speed: 1–15 m/min
l Online quenching: air or mist cooling
l Straightness control: ≤1mm/m
The output is a continuous heat sink aluminum extrusion profile that matches the die cross-section.
To remove internal stress:
l Stretch correction: 0.5–1% elongation
l T5 aging: 180°C for 3–4 hours
l T6 treatment (if required):
1. Solution heat treatment at 530°C
2. Rapid quench
3. Artificial aging at 175°C for 8 hours
This step improves strength and dimensional stability.
After extrusion, extrusion heat sinks undergo secondary machining:
l Mounting surface milling (flatness ≤0.1mm)
l Hole drilling and reaming (H7 tolerance)
l Thread tapping (6H/6g tolerance)
l Chamfering (C0.2–C0.5)
Advanced manufacturers use 3-axis to 5-axis CNC centers with ±0.01mm precision.
Common surface finishing options for aluminum heat sink extrusions include:
Anodizing
l Sulfuric acid bath (180–200g/L)
l 18–22°C
l Film thickness 10–20μm
l Sealing process to improve corrosion resistance
Powder Coating
l Electrostatic dry powder
l Decorative and protective
Electroless Nickel Plating
l 8–10% phosphorus content
l Improved solderability
Chromate Conversion Coating
l Conductive surface treatment
Anodizing remains the most popular solution for heat sink aluminium extrusion due to corrosion resistance and aesthetic appearance.
l No moving parts
l Relies on natural convection
l Higher reliability
l Ideal for low-to-medium airflow systems
l Integrated fans or blowers
l Forced convection
l Higher heat transfer rate
l Increased system cost
For high airflow environments, aluminum extrusion heat sinks perform exceptionally well under forced convection conditions.
When selecting or designing a custom heat sink extrusion, consider:
l Thickness (minimum ~0.8mm standard)
l Height-to-thickness ratio (up to 12:1 typical)
l Flared or straight fins
l Pin-fin or plate-fin cross-section
Even heat distribution across the base affects thermal efficiency. Poor spreading causes high temperature gradient from source to fin tips.
Use CFD simulation to evaluate:
l Airflow velocity
l Pressure drop
l Junction-to-ambient thermal resistance
l Heat dissipation curves
Professional extrusion heat sink manufacturers provide thermal modeling support.
Aluminum extrusion heat sink products are widely used in:
l LED lighting modules
l Power inverters
l EV motor controllers
l Medical imaging systems
l Computer CPUs and GPUs
l Industrial automation equipment
l Telecom base stations
Their versatility makes heat sink extrusions essential in electronics and electrical engineering.
Professional extrusion heat sink manufacturers implement strict CTQ control:
Control Item | Standard |
Flatness | ≤0.1mm |
Fin spacing tolerance | ±0.1mm |
Position tolerance | ±0.05mm |
Anodizing thickness | ±10% |
Thermal resistance | Meet design value (e.g., ≤0.5°C/W) |
Salt spray resistance | ≥48 hours no corrosion |
Thermal resistance testing is typically performed under controlled contact pressure using standardized heat load conditions.
Typical industry benchmarks:
l Extrusion output: 300–800kg per shift
l CNC Machining: 50–200 pcs/day
l Surface treatment: 1000–3000 pcs/day
l Standard lead time: 14–25 working days
l New die development: 24–40 days
High-quality custom heat sink extrusion projects often include full traceability documentation and first article inspection (FAI).
Compared to casting or machining:
l Lower per-unit cost in volume
l Excellent structural integrity
l High dimensional consistency
l Flexible cross-section customization
l Good compatibility with secondary processing
l Strong forced convection performance
Because of these benefits, aluminum extrusion heat sinks remain the preferred cooling solution for medium-to-high airflow systems.
An extrusion heat sink is a highly efficient, scalable, and cost-effective thermal solution manufactured through a controlled heat sink extrusion process.
Whether you require:
l Standard heat sink extrusions
l High-density aluminum heat sink extrusions
l Specialized copper heat sink extrusion
l Or a fully engineered custom heat sink extrusion
Modern extrusion heat sink manufacturers can deliver reliable, precision-engineered products that meet demanding industrial and electronic cooling requirements.
With optimized alloy selection, precise die design, strict extrusion control, advanced CNC machining, and professional surface finishing, aluminium extrusion heat sink solutions continue to power the next generation of thermal management systems.
Kingka Tech Industrial Limited
We specialize in precision CNC machining and our products are widely used in telecommunication industry, aerospace, automotive, industrial control, power electronics, medical instruments, security electronics, LED lighting and multimedia consumption.
Address:
Da Long New Village, Xie Gang Town, Dongguan City, Guangdong Province, China 523598
Email:
Tel:
+86 137 1244 4018
