Case Study and Results (I) A chip manufacturing plant in China

• A chip manufacturing plant in China

• To be put into operation in August 2022

Fluoride-containing wastewater is generated during wafer production, and its main sources are:

1. 1. Etching process: Fluoride chemical reagents (such as hydrofluoric acid, silicon tetrafluoride) are commonly used for chemical etching of the silicon wafer surface;
   2. Cleaning process: During wafer cleaning, a fluoride solution is used to remove surface impurities.
   3. Chemical Mechanical Polishing (CMP): The polishing slurry may contain fluoride additives.

In the process of treating fluoride-containing wastewater, calcium salts (such as lime and calcium chloride) are often added to neutralize fluoride and convert dissolved fluoride into calcium fluoride precipitate.

Calcium fluoride deposits in the factory’s wastewater treatment system pipes caused a 30% reduction in flow, and the cost of cleaning exceeded 500,000 yuan within one year.

• Install an electronic descaling device to reduce the adhesion rate of calcium fluoride crystals;

• The anti-scaling effect is analyzed by collecting flow and pressure change data before and after the transformation.

• The average annual flow rate increases by 30%, which correspondingly saves 30% of the water pump energy consumption;
• The number of pipeline blockages per year is reduced by 80%, and energy saving and maintenance costs are reduced by approximately RMB 500,000 per year;
• Extend equipment service life.