A computer implemented method of monitoring a polishing process includes, for each sweep of a plurality of sweeps of an optical sensor across a substrate undergoing polishing, obtaining a plurality of current spectra, each current spectrum of the plurality of current spectra being a spectrum resulting from reflection of white light from the substrate, for each sweep of the plurality of sweeps, determining a difference between each current spectrum and each reference spectrum of a plurality of reference spectra to generate a plurality of differences, for each sweep of the plurality of sweeps, determining a smallest difference of the plurality of differences, thus generating a sequence of smallest difference, and determining a polishing endpoint based on the sequence of smallest differences.

A computer implemented method of monitoring a polishing process includes, for each sweep of a plurality of sweeps of an optical sensor across a substrate undergoing polishing, obtaining a plurality of current spectra, each current spectrum of the plurality of current spectra being a spectrum resulting from reflection of white light from the substrate, for each sweep of the plurality of sweeps, determining a difference between each current spectrum and each reference spectrum of a plurality of reference spectra to generate a plurality of differences, for each sweep of the plurality of sweeps, determining a smallest difference of the plurality of differences, thus generating a sequence of smallest difference, and determining a polishing endpoint based on the sequence of smallest differences.

A blade sharpening system for log saw machines is provided. An example multiphase grinding wheel has a grinding face with one or more abrasive concentric rings for sharpening the cutting blade of the log saw machine, and one or more padded concentric rings consisting of fiber padding. Sharpening with the multiphase grinding wheel improves cut quality, increases blade life, removes glues and varnishes from the cutting blade, reduces blade deformation, and hones the edge of the cutting blade. A pneumatic tensioning system uses air bladders to apply a dynamically cushioned pressure between the grinding wheels and the cutting blade. The fiber-padded grinding wheels and the air bladder tensioner provide improved sharpness of the cutting blade and longer life for the mechanical components. The padded grinding wheels decrease fire risk, and the tensioner can be operated remotely, decreasing human injuries common with conventional setup actions near the sharp cutting blade.

A blade sharpening system for log saw machines is provided. An example multiphase grinding wheel has a grinding face with one or more abrasive concentric rings for sharpening the cutting blade of the log saw machine, and one or more padded concentric rings consisting of fiber padding. Sharpening with the multiphase grinding wheel improves cut quality, increases blade life, removes glues and varnishes from the cutting blade, reduces blade deformation, and hones the edge of the cutting blade. A pneumatic tensioning system uses air bladders to apply a dynamically cushioned pressure between the grinding wheels and the cutting blade. The fiber-padded grinding wheels and the air bladder tensioner provide improved sharpness of the cutting blade and longer life for the mechanical components. The padded grinding wheels decrease fire risk, and the tensioner can be operated remotely, decreasing human injuries common with conventional setup actions near the sharp cutting blade.

A grinding and/or cutting tool which has at least one surface region for a lateral grinding process and a surface region for a circumferential grinding process and/or a cutting process. The surface regions have different removal properties. The material properties of the surface regions differ in that the surface regions have different abrasive materials, grinding particle shapes, particle scattering patterns, particle sizes, degrees of hardness, structures, and/or binders. In one embodiment, the grinding and/or cutting tool has two of the surface regions for a lateral grinding process, and the two surface regions for a lateral grinding process are arranged at a distance from one another. The surface region for a circumferential grinding process or for a cutting process is arranged preferably between the two surface regions for a lateral grinding process.

A grinding and/or cutting tool which has at least one surface region for a lateral grinding process and a surface region for a circumferential grinding process and/or a cutting process. The surface regions have different removal properties. The material properties of the surface regions differ in that the surface regions have different abrasive materials, grinding particle shapes, particle scattering patterns, particle sizes, degrees of hardness, structures, and/or binders. In one embodiment, the grinding and/or cutting tool has two of the surface regions for a lateral grinding process, and the two surface regions for a lateral grinding process are arranged at a distance from one another. The surface region for a circumferential grinding process or for a cutting process is arranged preferably between the two surface regions for a lateral grinding process.

A polishing or grinding pad with a multilayer reinforcement is provided. In one aspect, a floor polishing or grinding pad assembly employs a flexible pad, at least two reinforcement layers or rings with different characteristics, and multiple floor-contacting tools such as abrasive disks. In another aspect, a workpiece polishing or grinding pad assembly includes a flexible and rotatable pad, a polymeric reinforcement layer coupled to the pad and a metallic reinforcement layer to which are coupled abrasive tools. In yet another aspect, a floor-facing reinforcement is more flexible than a pad-facing reinforcement which is more rigid.

A polishing or grinding pad with a multilayer reinforcement is provided. In one aspect, a floor polishing or grinding pad assembly employs a flexible pad, at least two reinforcement layers or rings with different characteristics, and multiple floor-contacting tools such as abrasive disks. In another aspect, a workpiece polishing or grinding pad assembly includes a flexible and rotatable pad, a polymeric reinforcement layer coupled to the pad and a metallic reinforcement layer to which are coupled abrasive tools. In yet another aspect, a floor-facing reinforcement is more flexible than a pad-facing reinforcement which is more rigid.

A pad conditioning disk configured to condition a polishing pad of a chemical mechanical polishing tool including a plurality of zones comprising cutting elements that selectively engage the polishing pad based on a positioning of the plurality of zones, is provided. An associated chemical mechanical polishing (CMP) tool and method for conditioning a polishing pad during a chemical mechanical polishing process is also provided.

Various embodiments disclosed relate to an abrasive article. The abrasive article includes a first major surface and an opposed second major surface. Each major surface contacts a peripheral side surface. A central axis extends through the first and second major surfaces. A first layer of abrasive particles is dispersed within the abrasive article according to a first predetermined pattern. Further a second layer of abrasive particles spaced apart from the first layer of abrasive particles and is dispersed within the abrasive article along a according to a second predetermined pattern. A binder material retains the first and second layers of abrasive particles in the abrasive article. A portion of the binder material is located between the first and second layers of abrasive particles. That portion of the binder material is substantially continuous.