Process Description

Prior to manufacturing semiconductors, silicon needs to be converted into wafers through various processes: silicon crystal growth, cutting & quality inspection, downsizing and surface finishing processes through grinding, cutting and etching to clean, polish, test and remove defects before packaging. These grinding processes use a large volume of ultrapure water to wash residual dust or metallic ion contaminants on the chips, producing wastewater after CMP cleaning and polishing.

Problem Description

• • Improper or direct discharge of wastewater will result in environmental pollution.
• • Treated water cannot be recycled, resulting in wastage.
• • Limitations in traditional approach (large floor area, high quantity of dosing chemicals used, high volume of sludge, inconsistent water quality).
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Applications

Supernatant exits the supernatant tank through a pump with the use of pressurized water for progressive filtration of 10 micron bag filtration, 1 micron cartridge filtration, an activated carbon adsorption unit and 0.2 microns final precision filtration before entering the collection tank. Water from the collection tank will be passed through a reverse osmosis plant with the use of ceramic membrane filter for microfiltration of remaining supernatants to produce ultrapure water.