Copper-clad aluminum wire
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Copper-clad aluminum wire, commonly abbreviated as CCAW is a conductor composed of an inner aluminum core and outer copper cladding. The primary application of this conductor is high-quality coils where weight is an issue, such as the voice coils in headphones, portable loudspeakers or mobile coils in other applications.
The properties of copper-clad aluminum wire include:
- Lighter than pure copper
- Higher conductivity than pure aluminum
- Higher strength than aluminum
- Better solderability than aluminum
- More expensive than a pure aluminum wire; cost relative to pure copper may be hard to establish due to the volatility of copper prices.
The skin effect causes alternating current to concentrate on the outer surface of the conductor. For this reason (as well as for solderability), the outer layer is composed of copper which has higher conductivity. Resistance of the wire approaches that of a pure copper wire at sufficiently high frequency.
