Low-Chemical-Consumption RCA Additive: A Win-Win for Cost Reduction and Sustainability in TOPCon Solar Cell Manufacturing

In the TOPCon solar cell manufacturing process, RCA cleaning is the final wet process step, directly determining the surface cleanliness of wafers before they enter the coating stage — a critical "final touch." If metal contamination is not effectively controlled, it will directly impact passivation quality and cell conversion efficiency. However, although the conventional RCA process is reliable in performance, it has become an industry pain point due to high chemical consumption and high operating costs. How to achieve cost reduction and efficiency improvement while ensuring cleaning quality has become a key concern for all manufacturers.

Effective Reduction of Metal Contamination Risk with Low Chemical Consumption

TOPCon batteries are extremely sensitive to metal contamination. Heavy metal ions such as Fe and Cu can significantly affect passivation quality and open-circuit voltage. The metal contamination control target is strictly required to be maintained below 5×10⁹ atoms/cm². In the conventional RCA process, the front-side etching bath requires high-concentration alkali for etching. Its etching performance and cleanliness directly determine the process window for subsequent cleaning steps.

The high alkali consumption in the front-side etching bath increases the burden on subsequent cleaning baths for metal ion removal. Our low-chemical-consumption RCA front-side etching additive, developed with high-efficiency chelating components and a synergistic corrosion inhibition system, significantly reduces alkali consumption while ensuring etching uniformity, thereby reducing the cleaning burden on downstream baths and minimizing residual risks.

Mass production data shows that after adding this product:

1.Alkali consumption is reduced by approximately 40%, and additive dosage is reduced by about 80% compared to conventional products.

2.Metal ion residue is reduced by approximately 30%, effectively lowering the risk of metal ion accumulation in the front-side etching bath.

3.The metal ion concentration on the wafer surface is stably controlled below 5×10⁹ atoms/cm², providing a cleaner feed-in foundation for subsequent alkaline and acid cleaning steps.

Concentrated Formulation: A Powerful Tool to Hedge Against Rising Logistics Costs

International shipping prices continue to rise, putting significant pressure on chemical transportation costs. For PV cell manufacturers, the large quantities of bulk chemicals required for RCA cleaning — such as alkali, hydrogen peroxide, and hydrofluoric acid — involve high transportation frequency, and logistics costs now account for a notably larger share of total procurement costs.

Our concentrated RCA additive is precisely the targeted solution to this challenge. Through a high-concentration formulation design, a single drum of the additive can process approximately 3 to 5 times more wafers than conventional products. Taking a standard production line (with a monthly output of approximately 6 million wafers) as an example, the concentrated additive dosage is only about 25% of that of conventional products. This results in reduced packaging quantities and lower transportation frequency, directly offsetting the cost pressure caused by rising shipping prices.

From an overall cost perspective, the chemical procurement savings from reduced alkali consumption, combined with the logistics cost savings from the concentrated formulation, can reduce the unit chemical cost of the RCA cleaning process by approximately 25%–30%. At the same time, packaging waste is reduced by about 50%, truly achieving a win-win in both cost reduction and sustainability.

At a time when the demand for cost reduction and efficiency improvement in TOPCon cell manufacturing is increasingly urgent, the low-chemical-consumption RCA additive is not only a technical means for process optimization, but also a strategic choice to address cost pressures.