The resistivity of ultrapure water needs to be consistently ≥18.2 MΩ·cm. Aging of the existing equipment has led to excessive levels of particulate matter and boron ions, resulting in a decrease in product yield.

A dual-stage RO + EDI + polishing mixed bed ultrapure water system was deployed, equipped with a TOC degradation device and a nitrogen-sealed water tank.

Results: The ultrapure water quality exceeded the ASTM E1 standard, increasing chip yield from 88% to 99.6%, and saving approximately 500,000 yuan annually in consumable replacement costs.