Membrane filter element for chemical-mechanical polishing slurries

摘要

A filter media for physically separating particles of an abrasive media having a given mean average particle size from a chemical-mechanical polishing (CMP) slurry. The abrasive media has a particle size distribution including particles larger than the mean average particle size. The filter media is provided as being formed of at least one sheet of a porous membrane having a first and second surface defining a thickness dimension of the membrane therebetween, and having a plurality of generally cylindrical capillary pores formed through the thickness dimension sized effective to capture the particles larger than the mean average particle size. In service, the slurry is supplied to the first side of the filter media, and is passed through the media to the second side thereof such that at least a portion of the particles of the abrasive media larger than the mean average particle size is retained on the first side of the filter media. Such portion may include particles of the abrasive media which are smaller than the pore size of the membrane.