The technical requirements of the CCA BUSBAR rolling process are more complex because it involves the different physical properties of the two metals (copper and aluminum), especially in the drawing, rolling, and annealing processes that require precise control of the process parameters to ensure that the copper layer is well bonded to the aluminum core and that the final product has the desired electrical and mechanical properties. The following are the technical requirements during the rolling process of CCA BUSBAR:
- Selection of suitable raw materials
Aluminum core material: High purity aluminum or aluminum alloy is usually used as the core, whose electrical conductivity and mechanical properties are critical to the quality of the product.
Copper strip material: Copper strip should be high purity oxygen-free copper, usually selected with low oxygen content to avoid oxidation and ensure good electrical conductivity.
- Cladding technical requirements
Quality of cladding layer: The copper layer of CCA PV RIBBON should form a strong metallurgical bond with the aluminum core to avoid gaps or delamination between the copper layer and the aluminum core. The thickness of the copper layer should be uniform and in accordance with the design requirements, generally there are different copper layer volume ratios such as 10%, 15%, 20%, etc..
Metallurgical bonding: The copper and aluminum core must be metallurgically bonded to each other, not simply mechanically bonded. Ensure inter-atomic bonding between the copper layer and the aluminum core, usually need to achieve this through high temperature cladding or cold extrusion technology.
- Rolling process control
Rolling equipment selection: the use of suitable rolling equipment, usually multi-pass cold rolling mill, required to have good temperature control, speed control performance, and can provide sufficient rolling pressure.
Temperature control in the rolling process: control the temperature of the metal in the rolling process, to avoid too high a temperature leading to the copper layer and aluminum core detachment. In general, the rolling temperature of CCA PV RIBBON should be controlled at room temperature to about 300°C.
Rolling speed and pressure: Rolling speed should be controlled within the appropriate range to avoid too fast leading to copper layer pulling cracks or uneven. Rolling pressure should also be moderate to avoid excessive deformation of CCA PV RIBBON.
- Copper layer thickness and uniformity
Copper layer thickness control: the thickness of the copper layer is critical to the conductivity of CCA PV RIBBON, so the rolling process needs to strictly control the thickness and uniformity of the copper layer. Generally, the different volume ratios of copper layers (e.g. 10%, 15%, 20%) will be determined according to the application requirements of the final product.
Uniformity requirement: The thickness of the copper layer should be uniform without fluctuation, otherwise it will lead to unstable electrical properties of the product. During the rolling process, the settings of the rolling equipment need to be precisely adjusted to ensure that the copper layer is uniformly wrapped around the aluminum core.
- Drawing process requirements
Drawing speed and drawing ratio: The drawing process is a key step in making CCA PV RIBBON into flat wire. Drawing speed should be controlled within the appropriate range to avoid cracking or fracture of the copper layer. At the same time, the drawing ratio (i.e., the ratio of the aluminum core to the copper layer) needs to be reasonably designed to ensure that the copper layer does not detach from the aluminum core during the drawing process.
Annealing: In order to eliminate internal stresses during the drawing process, annealing is usually required. The annealing process should be controlled at a suitable temperature (approximately 300°C to 400°C) to ensure the ductility and flexibility of CCA PV RIBBON.
- Annealing process control
Annealing Temperature and Time: Annealing is done to improve the ductility of CCA PV RIBBON, to remove internal stresses, and to ensure a tighter bond between the copper layer and the aluminum core. The annealing temperature is usually between 250°C and 400°C. The annealing time needs to be adjusted according to the wire specifications and requirements.
Cooling after annealing: The rate of cooling after annealing has an influence on the properties of CCA PV RIBBON. Too fast or too slow cooling should be avoided to ensure a stable bonding of the copper layer and the aluminum core.
- Wire surface quality requirements
Surface finish: The surface of CCA PV RIBBON should be smooth without scratches, dents or cracks. Surface defects will affect the electrical performance and service life of the wire.
No Exposed Aluminum: During the cladding process, there must be a tight bond between the copper layer and the aluminum core to ensure that there are no areas of exposed aluminum. Exposed aluminum will result in reduced conductivity and is susceptible to oxidation.
- Electrical performance requirements
Electrical Conductivity: The copper layer of CCA PV RIBBON is responsible for the conduction of electric current, so its electrical conductivity is critical. To ensure compliance, the resistance must be rigorously tested, often using resistivity test methods to verify conductivity.
High Frequency Signal Transmission: For CCA PV RIBBON used for high frequency signal transmission, the skin effect and high frequency transmission properties need to be verified to ensure effective signal transmission.
- Mechanical Requirements
Tensile strength: CCA PV RIBBON needs to have a certain tensile strength to ensure that it is not easy to break during stretching and use. The tensile strength requirement depends on the application of CCA PV RIBBON.
Ductility and fatigue resistance: CCA PV RIBBON should have good ductility to adapt to the needs of the drawing and molding process, and be able to withstand a certain amount of fatigue pressure in practical applications.
- Final Product Inspection and Testing
Dimensional Inspection: Conduct dimensional inspection of the finished CCA PV RIBBON to ensure that the outer diameter, copper layer thickness, flat width and thickness are in accordance with the design standards.
Quality inspection: check the surface quality, electrical and mechanical properties of CCA PV RIBBON to ensure that it meets the national standards or customer requirements.
Summarize:
The technical requirements of CCA BUSBAR rolling cover many aspects from raw material selection, process control, dimensional accuracy to surface quality, electrical and mechanical properties. In order to ensure that the performance of CCA PV RIBBON meets the requirements of specific applications, it is necessary to strictly control the key parameters such as temperature, pressure and copper layer thickness during the rolling process, and at the same time to ensure that the combination of copper and aluminum is strong, and the final product has stable electrical properties and good mechanical properties.
