Copper vs Aluminum

Higher conductivity.
Lower weight + cost.
Pick your trade-off.

Copper conducts heat 2.4× better than aluminum. Aluminum weighs 1/3 as much and costs 1/3. For most heat sinks, aluminum is adequate. For high-performance or compact applications, copper earns its premium.

Get a Quote DFM guide

01 · At a glance

Side-by-side summary.

Option A

Copper (C101 / OFE)

391 W/m·K thermal conductivity. 8.96 g/cc density. Premium for high heat flux, compact heat sinks, thermal spreaders. More difficult to machine, much heavier than aluminum.

Option B

Aluminum 6063 / 6061

201 W/m·K (6063) thermal conductivity. 2.70 g/cc density. Standard for LED luminaires, general electronics, consumer heat sinks. Easy to machine, easy to extrude, cheap.

02 · Detailed comparison

Feature-by-feature breakdown.

Attribute	Copper C101	Aluminum 6063
Thermal conductivity	391 W/m·K	201 W/m·K
Density	8.96 g/cc	2.70 g/cc
Specific thermal conductivity	44 W·m²/kg	74 W·m²/kg
Cost per kg raw	$10-15	$3-5
Cost per finished kg part	~3× aluminum	Reference
Machinability	Moderate (gummy)	Excellent
Extrudability	Difficult (hot extrude only)	Excellent (cold)
Corrosion	Oxidizes (dull brown)	Passive oxide (stable)
Electrical conductivity	100% IACS (highest)	62% IACS
Typical applications	CPU cooling, high-power	LED, general, consumer
Fins minimum thickness	0.5 mm	0.8 mm
Emissivity (bare)	0.03 (polished)	0.1 (bare aluminum)

03 · Decision guide

When to choose each.

Choose Copper (C101 / OFE) when:

CPU cooling, high-end computing
Compact high heat flux (>100 W/cm²)
Heat spreaders on electronics
Laser diode mounts (high thermal demand)
When thermal performance margin critical
Combined with aluminum fins (copper base only)

Choose Aluminum 6063 / 6061 when:

LED luminaires (most common application)
Consumer electronics cooling
Low heat flux applications
Weight-sensitive applications (aerospace)
Cost-sensitive production
Extruded profiles at high volume

FAQ

Common questions.

Depends on thermal need. Thermal conductivity difference: 2.4× (copper better). Price difference: 3× (copper more). For most applications, aluminum is adequate — use bigger aluminum heat sink at same effective thermal performance for lower cost. Copper wins when: (1) Space constrained (can't make heat sink bigger). (2) Heat flux so high that even larger aluminum can't keep up. (3) Thermal margin matters (safety factor). (4) Aesthetic appeal in premium product.

Common compromise. Copper base plate (direct contact with heat source) + aluminum fins (convective cooling). Copper spreads heat efficiently to fins; aluminum fins provide cheap large surface area. Common in CPU coolers. Manufacturing: copper base CNC machined, fins extruded aluminum, soldered or epoxy bonded. Best thermal performance per dollar for many applications.

Aluminum is 1/3 copper weight. For aerospace, handheld devices, portable equipment: aluminum wins on weight. Copper heat sink for 100W CPU weighs 1-2 kg. Equivalent aluminum: 0.4-0.7 kg. For desktop applications, weight not critical — copper fine. For mobile devices, aluminum required and performance compromised accordingly (smaller heat sink, lower sustained power).

Aluminum: extrudes easily cold or warm. Complex fin profiles with thin walls. 80% of aluminum heat sinks are extruded profiles. Copper: extrudes only hot (high temperature, high pressure). Limited to simpler profiles, thicker walls. Much higher cost. Most copper heat sinks are CNC machined from plate, not extruded. This contributes to copper cost premium — no cheap extrusion process.

Both materials work with standard thermal interface materials (TIM). Thermal paste: silicone-based, thermal grease, thermal pads. Both interface well. Copper: slightly better wetting with thermal paste. For liquid-metal TIM (gallium-based): must not contact aluminum (corrodes aluminum). Copper compatible with all standard TIMs.

Copper: oxidizes to dull brown over time. Oxide layer has lower thermal conductivity than bare copper. For long-term performance: nickel plating on copper (3-5 µm) maintains surface integrity. Aluminum: forms passive oxide immediately, stable long-term. For both: anodize aluminum or nickel plate copper for outdoor service. Black anodize adds ~3-5°C cooling via radiation enhancement.