Pv ribbons are mainly divided into interconnection tapes and sink tapes in PV module applications. Interconnection tapes mainly include conventional flat tapes, MBB tapes, low temperature tapes, low resistance tapes, shaped tapes, etc.; sink tapes mainly include conventional sink tapes, perforated tapes, black tapes, bending tapes, etc. At present, the mainstream PV ribbon products on the market are MBB PV ribbon for multi-gate modules, with a diameter of 0.28~0.35mm, which is thinner than the previous 5BB conventional flat PV ribbon, which is conducive to reducing cell shading and using sunlight more effectively, while increasing the number of main grids, which is conducive to shortening the transverse current collection path of cells, reducing series resistance and reducing cell power loss.
Pv ribbon consists of substrate and surface coating:
(1) The substrate is copper of different specifications, requiring precise specifications, good electrical conductivity and a certain strength;
(2) The surface coating can use special processes such as electroplating method, vacuum deposition method, spraying method or hot dip plating method to wrap the coating materials such as tin alloy in a certain composition ratio and thickness, evenly on the surface of the copper substrate. Since the copper substrate itself does not have good welding performance, the main role of the tin alloy layer is to make the photovoltaic tape meet the solderability and firmly weld the photovoltaic tape to the main grid of the cell, so as to play a good role in current conduction.
The tinned copper tape for photovoltaic is generally composed of copper as the main base material and tin alloy coating.
Lead content of tinned copper strip
Copper base: imported refined strong oxygen-free copper / T2 purple copper, copper content ≥ 99.99%, conductivity ≥ 98%.
Copper base resistivity: oxygen-free copper ≤ 0.0165Ωmm2/m T2 purple copper ≤ 0.0172Ωmm2/m
Coating composition: 63%Sn37%Pb, 60%Sn40%Pb (optional)
Coating thickness: single-sided coating 0.01-0.05mm, uniform coating, bright and smooth surface
Coating melting point: 183℃, 190℃
Tensile strength: soft state ≥ 25kgf / ㎡ semi-soft state ≥ 30kgf / ㎡
Elongation of welded tape: soft state ≥ 35% 3/4 soft state ≥ 25% 1/2 soft state ≥ 15% ◆Width error: ±0.1mm
Thickness error: ±0.01mm for interconnected strip, ±0.015mm for sinker strip
Leaded silver-tin copper strip plating (higher cost)
Copper base: imported refined strong oxygen-free copper / T2 copper, copper content ≥ 99.99%, conductivity ≥ 98%.
Copper base resistivity: oxygen-free copper ≤ 0.0165Ωmm2 / m T2 copper ≤ 0.0172Ωmm2 / m
Coating composition: 63%Sn35%Pb2%Ag (optional)
Coating thickness: 0.01~0.05mm for single-sided coating, uniform coating, bright and smooth surface.
Coating melting point: 179℃.
Tensile strength: soft state ≥25kgf/㎡ semi-soft state ≥30kgf/㎡.
Elongation of welded tape: soft state ≥ 35% 3/4 soft state ≥ 25% 1/2 soft state ≥ 15
Width error: ±0.1mm
Thickness error: ±0.01mm for interconnecting tape, ±0.015mm for converging tape
Advantages of silver-containing solder tapes:
Increase the metallurgical bond between the solder and the soldered metal. Mechanical strength and electrical conductivity will be better after welding;
the melting point of the ternary alloy is slightly lower than that of the binary alloy after the addition of silver, and its solderability and fluidity are improved;
The electrical resistivity will be reduced and the high temperature resistance will be improved.
Lead-free and environmentally friendly tinned copper strip
Copper base: imported refined strong oxygen-free copper/T2 copper, copper content ≥ 99.99%, conductivity ≥ 98%.
Copper base resistivity: oxygen-free copper ≤ 0.0165Ωmm2 / m T2 copper ≤ 0.0172Ωmm2 / m
Coating composition: 96.5%Sn3.0Ag0.5%Cu, 96.5%Sn3.5Ag (optional)
Coating thickness: single-sided coating 0.01-0.05mm, uniform coating, bright and smooth surface
Coating melting point: 217℃, 221℃.
Tensile strength: soft state ≥ 25kgf/㎡ semi-soft state ≥ 30kgf/㎡
Elongation of welded tape: soft state ≥ 35% 3/4 soft state ≥ 25% 1/2 soft state ≥ 15
Width error： ±0.1mm
Thickness error: ±0.01mm interconnection belt, convergence belt ±0.015mm
Translated with www.DeepL.com/Translator (free version)
