What Is Oxygen Free Electronic (OFE) Copper?
Oxygen free electronic (OFE) copper is a copper that is generally free of oxides and has a purity of 99.96% or higher.
Oxygen-free copper is widely used in the electrical, telecommunications, building materials, and processing materials fields. Copper has high electrical and thermal conductivity, as well as excellent corrosion resistance and workability. However, oxygen free electronic (OFE copper) copper is used when high purity copper is required because oxygen reduces these properties.
JIS (Japanese Industrial Standards) H3100 specifies oxygen free electronic (OFE) copper with a copper content of 99.96 %, or more, as alloy number C1020.
Uses of Oxygen Free Electronic (OFE) Copper
1. Electronic and Electrical Equipment
Wires, wiring, terminals, boards, connectors, etc. are examples.
2. Bus Bars
Power conditioners, transformers, inverters, UPS, etc.
A busbar is a type of conductor used to transmit power between electrical devices. A power conditioner is a power conversion device that takes AC power, converts it to the required form, and supplies stable power. An inverter is a device that converts DC power into AC power. The UPS is an uninterruptible power supply device that protects power from power outages, voltage fluctuations, noise, surges, and other problems and supplies stable power.
3. Heat Exchanger
Coolers, heat exchangers, heat sinks, and cooling fins are examples. A heat sink is a type of cooling device used to dissipate heat generated by electronic components and semiconductors. It is typically a metal fin-shaped component that is attached to electronic components.
4. Music Equipment
Examples include audio cables, amplifiers, and speakers.
5. Automobile
Electric vehicles, hybrid vehicles, fuel cell vehicles, and brakes are examples.
Properties of Oxygen Free Electronic (OFE) Copper
1. Electrical Conductivity
Oxygen free electronic (OFE) copper is an extremely conductive material. Copper is a good conductor of electricity, and the higher the purity, the better the conductivity. Oxygen, on the other hand, is an inhibitor of electricity, so the presence of oxygen in copper reduces its electrical conductivity.
Oxygen free electronic (OFE) copper is a high purity, oxygen-free material with a uniform copper crystal structure and very high electrical conductivity. In addition, the heat treatment of oxygen free electronic (OFE) copper further improves its electrical conductivity by reducing the size of the crystal grains.
2. Thermal Conductivity
Oxygen free electronic (OFE) copper is a material with very high thermal conductivity. The reason for the excellent thermal conductivity of oxygen free electronic (OFE) copper is largely related to the uniformity of its crystalline structure. Because oxygen free electronic (OFE) copper is highly pure and contains no oxygen, the crystal structure of copper is uniform and the bonding between atoms is strong.
Heat transferred through a material exists in the form of vibrational energy produced by the motion of atoms and molecules, so when heat is transferred through oxygen free electronic (OFE) copper, the strong bonding between the atoms allows the heat to be transferred more efficiently.
Oxygen free electronic (OFE) copper also has very good heat treatment performance, allowing the crystalline structure to be controlled by heating or cooling. Heat treatment makes the crystal grains in oxygen free electronic (OFE) copper finer and promotes the diffusion of atoms, thus improving the thermal conductivity.
3. Workability
Oxygen free electronic (OFE) copper is manufactured to a very high purity and has a very flexible metallurgical structure due to its uniform crystalline structure, making it a less brittle material. Heat treatment also makes the crystal grains finer and the metallurgical structure more uniform, resulting in good workability. Because of its high melting point and resistance to oxidation and corrosion, the copper surface is rarely damaged during heat treatment and processing, and the surface condition is maintained, resulting in good workability.
4. Corrosion Resistance
Oxygen free electronic (OFE) copper is a corrosion resistant material. The main reason for this is the formation of an oxide film that protects the metal surface. The oxide film is formed by the reaction of copper and oxygen and is very thin and highly adhesive, covering the copper surface and protecting it from oxidation and corrosion. Oxygen free electronic (OFE) copper is manufactured with high purity and contains no oxygen, so the oxide film produced is more uniform and adheres better.
In addition, the oxide film regenerates quickly and is self-healing, meaning that even if the copper surface is damaged, it will regenerate. This allows the metal surface to be maintained over a long period and is highly resistant to corrosion.
5. Weldability
Oxygen free electronic (OFE) copper has excellent weldability and solderability due to the extremely high purity of copper, its low impurity content, and uniform crystalline particles. In addition, its high thermal conductivity and uniform temperature throughout the joint facilitates processing without distorting the joint.
6. Magnetism
The reason oxygen free electronic (OFE) copper is less magnetic and magnetically inert is its crystal structure. It is pure copper and contains no oxygen, making it an extremely pure material. The crystal structure of oxygen free electronic (OFE) copper has a face-centered cubic lattice structure. The face-centered cubic lattice structure has a dense concentration of atoms, which restricts the movement of free electrons, making oxygen free electronic (OFE) copper magnetically inert.
7. Plasticity
Oxygen free electronic (OFE) copper is a material with good plasticity and retains its strength against bending and folding. The reason lies in its fine crystal structure and grain boundary characteristics.
Oxygen free electronic (OFE) copper has uniform crystal particles and very finely formed grain boundaries, which allow crystal particles to move smoothly between each other during deformation, reducing stress at the deformation point and maintaining strength against bending and folding. In addition, oxygen free electronic (OFE) copper is very pure and free from defects, thus maintaining high strength.
8. Hardness and Strength
Heat treatment of oxygen free electronic (OFE) copper changes the size and arrangement of crystal particles, eliminates defects, and promotes the diffusion of impurities, thereby improving the mechanical properties of the material. In addition, the directionality of crystal particles can be controlled by hot forging or hot rolling, which changes the hardness and strength of the material.
Other Information on Oxygen Free Electronic (OFE) Copper
Oxygen free electronic (OFE) copper has very low magnetic resistance due to the high purity of copper and very low concentration of impurities and oxygen. Magnetoresistance is the resistance created when electromagnetic waves pass through. The greater the magnetoresistance of a material, the more likely it is to impair the passage of electromagnetic waves.
In high-frequency circuits, electromagnetic interference, which affects communication and radio wave transmission, is a problem. Since electromagnetic waves interfere more strongly with materials with greater magnetic resistance at higher frequencies, it is necessary to use materials with lower magnetic resistance in high-frequency circuits.