Copper electroplating plays a crucial role in cost reduction and efficiency enhancement during the metallization process of photovoltaic cells. Metallization primarily involves creating electrode grids for photovoltaic cells, and the mainstream method for mass production is silver paste screen printing. However, with the rapid increase in the supply of N-type cells, the consumption of silver paste has risen significantly compared to PERC cells. The high cost of silver paste is a major impediment to the industrialization of N-type cells. In this regard, copper plating technology offers significant advantages through its innovative silver-free approach. Photovoltaic copper plating involves depositing copper metal on the substrate surface using an electrolysis method to create copper grids for cells. Therefore, when compared to the traditional silver paste screen printing method, this revolutionary technology can reduce silver paste costs, improve conductivity, enhance plasticity, and adjust size. It is expected to replace the screen printing technology that consumes more silver, thereby aiding HJT, XBC, and other cell production processes in cost reduction, efficiency enhancement, and mass production.
The photovoltaic copper plating process primarily focuses on the graphic and plating stages, but its technological pathway has not been finalized yet. The copper plating process encompasses four key steps: seed layer deposition, patterning, plating, and post-treatment. Currently, various combinations of processes are employed for each of these stages. Patterning involves film masking, exposure, development, and other steps, with main technologies including LDI, conventional mask lithography, laser slotting, and inkjet printing. LDI, in particular, holds great application potential as it doesn’t require masking during laser lithography. Laser slotting has already been adopted in the production of BC-type cells for mass production. The electroplating process includes vertical plating, horizontal plating, insertion plating, flexible contact plating, and other technologies. Specifically, companies like Dongwei Technology, JBAO, Robo Tech, and Sunwell have been advancing the client verification process for their respective technology solutions. With overall performance improvements and cost process optimizations, the technology of PV copper plating is expected to become more defined, and the combination of technical routes and processes is anticipated to be finalized by 2024.
The pilot testing of copper plating technology is anticipated to gain momentum, leading to its gradual integration into mass production, thus opening up more opportunities in the market. Currently, there’s a notable acceleration in cost reduction and efficiency improvement for HJT cells, along with progress in downstream bidding. More companies are also in the process of stockpiling XBC cells and strategizing for their large-scale production. Additionally, the adoption of silver-free copper plating technology is expected to see an uptick. Compared to the silver-coated copper +0BB/NBB process, copper plating's mass production progress has been somewhat slower. However, its advantage lies in its ability to enhance cell efficiency by 0.3% to 0.5%, consequently boosting the power output of high-end modules. In the short term, it is expected that silver-coated copper +0BB/NBB will remain the primary method for mass-producing HJT cells in order to achieve cost reductions. Nevertheless, the pilot testing of copper plating is set to be expedited in 2023 and 2024, gradually transitioning into mass production by 2024. As the economics of this process continue to improve, the benefits of copper plating are likely to become more pronounced. Therefore, by 2025 and 2026, the photovoltaic copper plating equipment market is expected to reach a valuation of 3.4-7.2 billion yuan.
