Patent ID: 6436281
Filing Date: 2002-08-20
Classification: B01D,C02F

Abstract:
An apparatus for treating wastewater from a chemical-mechanical polishing process used in chip fabrication, the wastewater containing particles having an abrasive effect and chemically active substances, comprising:an ultra-filtration facility receiving the wastewater and filtering out the particles having the abrasive effect without a substantial dissolution of the particles by the chemically active substances and resulting in ultrafiltrated wastewater; a device for flushing out the particles filtered out in said ultra-filtration facility at sufficiently short intervals so that the particles retained in the ultra-filtration facility are not substantially dissolved by the chemically active substances present in the wastewater, at least one sensor for measuring at least one parameter value of the wastewater after it has passed through said ultrafiltration facility; and a control system operable for selectively passing on the wastewater which has passed through the ultrafiltration facility to either one, both or neither of a reverse-osmosis facility and a micro-filtration facility.