The Extrusion Process A heated aluminum billet (usually 6063 or 6061) is forced through a steel die to create a continuous profile with integrated fins. The profile is cut to length and finished (anodizing, machining, etc.).

Key Advantages

• Very low per-unit cost at high volume

• Fast, highly automated production

• Monolithic construction = no fin-to-base thermal interface

• Proven reliability for millions of units Major Limitations

• Fin aspect ratio typically ≤ 10:1

• Low fin density → limited surface area

• Almost exclusively aluminum (copper extrusion is rare and expensive)

2. What is a Skived Fin Heat Sink?

The Skiving Process

A sharp blade precisely “shaves” thin fins from a solid block of aluminum or copper. Each fin is bent upright while remaining attached to the base — creating an ultra-dense, one-piece heat sink.

Key Advantages

• Aspect ratios up to 50:1

• Fin thickness as low as 0.2 mm and gaps < 0.5 mm

• Works perfectly with pure copper (~390 W/m·K)

• Zero thermal resistance between fins and base Drawbacks

• Higher per-unit cost (especially at low volume)

• Delicate fins require careful handling

• Slower production than extrusion

3. Head-to-Head Comparison

Design Flexibility

Skiving is not limited by die geometry — engineers can optimize fin height, spacing, and shape for specific airflow conditions.

Cost Reality

Extruded wins at >10k–100k pieces. Skived becomes competitive at lower volumes and is often cheaper than moving to liquid cooling when extrusion can’t meet thermal targets.

Aluminum vs Copper

Copper skived fins (~390 W/m·K) outperform even the best aluminum extruded sinks (~200 W/m·K) by a wide margin when spreading resistance matters.

4. When to Choose Which Technology

Choose Extruded When:

• Power dissipation < 100 W in ample space

• High production volume (10k+ units)

• Cost is the primary constraint

• Standard profiles are acceptable

Choose Skived Fin When:

• High power density (>150–200 W in small volume)

• Limited height/footprint

• Forced convection with strong airflow

• Copper is desired or required

• Performance is non-negotiable (servers, EVs, high-power LEDs, etc.)

Conclusion

Extruded heat sinks remain unbeatable for cost and volume. Skived fin heat sinks are the clear winner when maximum cooling performance in minimal space is required. Choose based on your thermal budget, physical constraints, and production volume — not on habit.

Frequently Asked Questions

• Can skived fins be made from copper?

• Yes — copper is one of the most popular materials for skived fins thanks to its ~390 W/m·K conductivity.

• What is the maximum aspect ratio for extruded fins?

• Typically 6:1 to 10:1. Anything higher becomes extremely difficult and expensive.

• Is skiving more expensive than extrusion?

• Per unit yes, especially at high volume. But skiving has lower or zero tooling cost and often eliminates the need for liquid cooling.

• Which is better for natural convection?

• Skived copper usually wins due to higher conductivity and larger effective surface area, even without a fan.