Key takeaways:
Fusion presented approaches to reducing silver consumption in metallization of mainstream and advanced cell architectures
Its roadmap combines ultra-fine-line printing with low-silver and silver-free paste technologies
The company reported ongoing customer validation and qualification of silver-coated copper and silver-nickel pastes
China-based metallization paste supplier Fusion New Material presented its latest metallization solutions to reduce silver consumption in TOPCon cell manufacturing at the TaiyangNews Solar and Storage Procurement Briefing.China (SSPB.C) in Shanghai. Although metallization paste solutions could benefit TOPCon, BC, and HJT cell types equally, the company’s presentation focused specifically on advanced TOPCon using LECO for front contacts and poly-fingers on the rear side. Fusion outlined its development directions essential to reducing silver usage in mass production: ultra-fine-line printing and silver-lean metallization solutions.
For ultra-fine-line printing, Fusion offers paste solutions compatible with stencil printing. The company said it is working to reduce the sintered line width of the finger to <10 µm by the end of this year, using a stencil opening <6 µm compared to the current stencil opening standard of 8 µm.
The company also offers low-silver metallization pastes for two-step printing metallization. This is in line with several other metallization paste suppliers that first print a silver seed layer to establish electrical contact with silicon. This is followed by a second print using either silver-coated copper or a pure copper paste on top of the seed layer. Fusion suggests a dashed- or dotted-line printing scheme for the seed layer, followed by the top layer, to minimize silver consumption.
The company discussed the commercialization progress of low-silver pastes, stating that some customers have completed technical validation of silver-coated copper paste with a silver seed layer. Fusion also highlighted ongoing qualification work for silver-nickel paste formulations with different nickel content, progressing towards industrial adoption.
