Copper-clad aluminum wire

Copper-clad aluminum wire, commonly abbreviated as CCAW or CCA, is a conductor composed of an inner aluminum core and outer copper cladding.

Uses

The primary applications involve of this conductor revolve around weight reduction requirements. These applications include high-quality coils, such as the voice coils in headphones, portable loudspeakers or mobile coils; high frequency coaxial applications; such as RF antennas; CATV distribution cables; and power cables.

CCA was also used in mains cable for domestic and commercial premises. The copper/aluminium construction was adopted to avoid some of the problems with aluminium wire, yet retain some of the cost advantage. But, solid copper is most commonly used in internal residential 120v or 240v wiring in the US.

CCA became extremely popular on emerging markets as a cheap replacement for copper category 5e twisted pair cables.

Properties

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, due to the lack of the oxide layer which prevents solder adhesion when soldering bare aluminum.
• Less expensive than a pure copper wire
• Typically produced as a 10% or 15% by copper volume product

Skin effect

The skin effect causes alternating current to concentrate on the more-conductive copper cladding of the conductor, causing the resistance of the wire to approach that of a pure copper wire at high frequencies, which makes the copper-clad aluminum wire a good fit for such applications. The skin effect is also utilized in copper-clad steel wire such as RG-6 coax, which is also commonly used in high frequency applications with high strength requirements.