Abstract: Provided is a polishing pad material melting device including: a melting unit configured to melt a solid material; a flow path through which the material melted in the melting unit is circulated; and a filter unit fluidically connected to the flow path and including a filter unit body configured to filter the material melted in the melting unit, wherein the flow path includes a circulation path through which the material melted by the melting unit is circulated, and the filter unit is fluidically connected to the circulation path.

Abstract: A polishing pad material purification system includes a melting device configured to melt a solid material put therein, and a homogenizer configured to homogenize the material melted in the melting device. The homogenizer is configured to have a processable amount of material to be homogenized larger than a processable amount of material to be melted by the melting device and configured to stir the material melted in the melting device so as to homogenize it.

Abstract: Provided is a filtration device including: a filter unit having a filter medium; and a holder configured to hold the filter unit and form a flow path in which a fluid passes through the filter medium of the filter unit, wherein a pore size of the filter medium at the downstream end position of the filter unit is smaller than a pore size of the filter medium at the upstream end position of the filter unit.

Abstract: The present invention provides a polishing pad which can improve qualities of an object to be polished by improving the flatness of the object. A polishing surface 1a of a polishing pad 1 is subjected to a mechanical process, such as buffing, so that the flatness of the surface is improved, and corrugations on the polishing surface have a cycle of 5 mm-200 mm and a largest amplitude of 40 ?m or less. As a result, the flatness of the object polished by the polishing pad 1, such as a silicon wafer, is improved.

Abstract: The present invention provides a polishing pad which can improve qualities of an object to be polished by improving the flatness of the object. A polishing surface 1a of a polishing pad 1 is subjected to a mechanical process, such as buffing, so that the flatness of the surface is improved, and corrugations on the polishing surface have a cycle of 5 mm-200 mm and a largest amplitude of 40 ?m or less. As a result, the flatness of the object polished by the polishing pad 1, such as a silicon wafer, is improved.

Abstract: A polishing cloth according to the present invention includes: a polishing cloth substrate; a pressure-sensitive adhesive layer laminated on one face of the polishing cloth substrate; and a release sheet attached to the pressure-sensitive adhesive layer in a releasable manner. The pressure-sensitive adhesive layer includes an adhesive composition containing a polymer, the polymer having a first-order melt transition in a temperature range narrower than 15° C. Thus, the present invention provides a polishing cloth and a method for attaching/detaching the polishing cloth to/from a base plate of a polishing machine such that the polishing cloth can be peeled off the base by simply cooling the base plate and the adhesive layer of the polishing cloth.

Abstract: A retaining device retains a workpiece to allow the workpiece to slide against a polishing pad located on a polishing board opposed to the retaining device. The retaining device includes a plate including a permeable portion and a seal portion having a lower permeability and provided around an outer periphery of the permeable portion. By absorbing air toward a first surface of the permeable portion, the workpiece is attached and attracted to a second surface of the permeable portion opposite to the first surface. The retaining device further includes a retainer ring provided on an outer peripheral portion of the plate for preventing an outer edge of the workpiece from being overhung by polishing; and a backup ring located between the plate and the retainer ring for putting the retainer ring into pressure contact with the polishing pad. Since the workpiece can be attached and attracted to or released from the plate by a simple operation, the time required for retaining the plate is shortened.