A tool for filing or abrading surfaces or for sharpening instruments such as knives, chisels and the like includes two spaced thin ferromagnetic rails having co-planar upper edges. A magnet is located between the rails with a ferromagnetic plate magnetically held to the rail. The plate has an exposed abrasive coated surface. A first magnetic pole of the magnet concentrates and conducts magnetic flux to the plate through the rails with sufficient force to hold the plate in position against the upper edges of the rails without the need for a retaining cavity to further restrain the plate from moving during use.

An attachment means for attaching a sheet-formed abrasive and/or polishing means to a magnetized support, said attachment means comprising a ferromagnetic base layer and an external adhesive layer to which the abrasive and/or polishing means attached, and where said ferromagnetic base layer comprises a ferromagnetic metal foil and that said attachment means comprises a liner sheet having a first side adhered to a first side of the base layer by means of an internal adhesive layer, the liner sheet having the external adhesive layer disposed on the second side of the liner, the external adhesive layer being capable of releasably fixating the abrasive and/or polishing means and said external adhesive layer being capable of substantially retaining its adhesive capacity after removal of the abrasive and/or polishing means. The base layer is optionally and preferably provided with a friction increasing layer on the second side.

A technique for mounting polishing pads to a platen in chemi-mechanical semiconductor wafer polishing apparatus is disclosed. A lower pad is mounted to the platen, and is trimmed to the size of the platen. An upper pad is mounted to the lower pad, and is sized so that an extreme outer edge portion of the upper pad extends beyond the trimmed outer edge of the lower pad. The outer edge portion of the upper pad is deformed downwardly, towards the lower pad. In this manner, polishing slurry is diverted from the pad-to-pad interface. Additionally, an integral annular lip can be formed on the front face of the upper pad, creating a reservoir for slurry to be retained on the face of the upper pad for enhancing residence time of the polishing slurry prior to the slurry washing over the face of the upper pad.

A technique for mounting polishing pads to a platen in chemi-mechanical semiconductor wafer polishing apparatus is disclosed. A lower pad is mounted to the platen, and is trimmed to the size of the platen. An upper pad is mounted to the lower pad, and is sized so that an extreme outer edge portion of the upper pad extends beyond the trimmed outer edge of the lower pad. The outer edge portion of the upper pad is deformed downwardly, towards the lower pad. In this manner, polishing slurry is diverted from the pad-to-pad interface. Additionally, an integral annular lip can be formed on the front face of the upper pad, creating a reservoir for slurry to be retained on the face of the upper pad for enhancing residence time of the polishing slurry prior to the slurry washing over the face of the upper pad.

A technique for mounting polishing pads to a platen in chemi-mechanical polishing apparatus is disclosed. With two polishing pads, prior to assembly, a seal of material impervious to the chemical action of a polishing slurry is disposed about the perimeter of the interface between the pads. Preferably, the seal is a bead of silicon-based "gasket" material, such as General Electric silicon caulk (RTV) or Dow Corning silicon adhesive, and is disposed in a ring at a radius r' about one inch inward from the perimeter (circumference) of the pads. When the pads are assembled together, the bead squashes and (1) forms a seal, and (2) causes the periphery of the upper pad to curve upward--thereby creating a bowl-like reservoir for increasing the residence time of slurry on the face of the pad prior to overflowing the pad.