1. Existing technologies in the industry
① The current mainstream technology SMBB in the industry, as well as the recently popular 0BB technology, both use the same technical principle of screen printing the conductive silver grid lines (main grid lines/sub-grid lines, which are perpendicular to each other) on the surface of the photovoltaic cell, and then welding the metal welding strip to the main grid lines, so that the cells are connected in series.
② Current collection path: cell surface → sub-grid lines → main grid lines → metal welding strips.
2. Stacked grid technology
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① Stacked grid technology is a pan-semiconductor metallization technology and battery string technology.
② Stacked grid core structure:
Prepare a conductive seed layer on the surface of the cell to collect the current on the surface of the cell. Above the seed layer, place an extremely fine triangular conductive wire with ultra-high surface reflectivity. The conductive seed layer and the conductive wire are connected through the conductive connecting material.
③ Stacked grid technology current collection path
Cell surface → conductive seed layer → conductive wire.
④ Advantages of stacked grid technology
The biggest advantage of the stacked grid structure is that it completely avoids the conduction of current in the secondary grid line parallel to the battery surface, and only conducts the current from the conductive seed layer to the conductive wire perpendicular to the battery surface. Therefore, the resistance requirement for the seed layer parallel to the battery surface is greatly reduced, thereby greatly reducing the silver consumption, and even completely eliminating the need for silver!
In addition, the stacked grid technology uses extremely fine triangular conductive wires with ultra-high surface reflectivity, which can reduce the equivalent shading area of the battery surface to less than 1%.
⑤ Impact of components
Combined with high-efficiency battery technology (double polo passivation technology, etc.) that matches the stacked grid technology, taking the 2382*1134 component format as an example, compared with the conventional N-type TOPCon SMBB technology, the power of a single component using the stacked grid technology can be increased by more than 25-30W!
The component products made using this technology not only have high front power, but also have many advantages such as high comprehensive power on both sides, beautiful appearance, strong resistance to hidden cracks, and low risk of hot spots.