Abstract: The object of the present invention is to provide a polishing apparatus having a grinding member in a compact design that can provide high efficiency for both polishing and dressing operations, and prevents tilting of the grinding member even if the rotation axis thereof is moved away from the outer periphery of the object. A polishing apparatus for an object, comprises: an object holder for holding an object to be polished, such that a surface of the object to be polished faces upward; a dresser disk holder for holding a dresser disk for dressing, such that a dressing surface thereof faces upward; and a grinding member for polishing the object, and for being dressed by the dresser disk, by pressing and sliding the grinding member relative to the object and the dresser disk.

Abstract: A polishing mechanism for treating a vehicle bumper incorporating with a multi-shaft robot is disclosed. A polishing wheel is rotationally attached to an end of the robot. A rotational positioning device is provided for positioning the bumper in a position within a working range of the robot. The positioning device includes a pair of racks, a main shaft rotationally arranged between the racks and capable of being positioned to a desired angle, a carrying rack arranged on the main shaft, and a plurality of holding devices arranged on the carrying rack for fixedly holding the bumper in position. A detecting device is provided for checking the worn-out of the polishing wheel for adjusting an optimum distance between the polishing wheel and the bumper. The assembly further includes a piloting gauge attached to the robot for determining an appropriate distance between the polishing wheel and the bumper.

Abstract: A chemical-mechanical polishing apparatus includes a polishing pad, a polishing table, a wafer holder, a dresser for setting the polishing pad each time after a specified number of wafers are chemically and mechanically polished; and a conditioning controller for controlling the conditions of setting the polishing pad based on a polishing rate and a required length of polishing time. The chemical-mechanical polishing apparatus can suitably correct, after every polishing of the specified number of wafers, the setting conditions of the polishing pad and can properly conduct the subsequent polishing.

Abstract: A polishing cloth mounted on a turntable is dressed by bringing a dresser in contact with the polishing cloth for restoring the polishing capability of the polishing cloth. The dressing is performed by measuring heights of a surface of the polishing cloth at radial positions of the polishing cloth in a radial direction thereof, determining a rotational speed of the dresser with respect to a rotational speed of the turntable on the basis of the measured heights, and dressing the polishing cloth by pressing the dresser against the polishing cloth while the turntable and the dresser are rotating. The dresser has an annular diamond grain layer or an annular SiC layer.

Abstract: The invention relates to a device for rotational cutting of band-shaped material, comprising a rotational cutting cylinder which is fitted with at least one cutting edge and a counter-tool, wherein the band-shaped material is passed between the counter-tool and the rotational cutting roller. The rotational cutting roller is fitted with at least one, and specially two thrust collars placed in the circumference of the counter-tool, which determine the feed motion of the cutting edge towards the counter-tool. According to the invention, at least one sharpening device having at least one sharpening element is provided, which can be placed on the thrust collar or collars or on the counter-tool, said sharpening element removing material from the thrust collars or the counter-tool.

Abstract: A non-destructive method for measuring the thickness loss of a polishing pad due to pad conditioning includes the use of rigid planar members placed on the surfaces of both the conditioned and non-conditioned sections of the polishing pad. Measurements are made using measurement instruments which overhang the depressed conditioned section and measure the height difference between the upper surfaces of the planar members. The measurement instruments may be repositioned and measurements repeated to obtain an average thickness loss.

Abstract: An object of the present invention is to provide a polishing apparatus which is capable of configuring a surface of a polishing tool without damaging the polishing tool. In order to solve the above-mentioned problem, the present invention provide a rotary machining apparatus comprising a polishing tool for polishing a sample; a rotary disk for holding the polishing tool; a tool for configuring a surface of the polishing tool; and a position adjusting mechanism for adjusting a gap between the tool and the polishing tool, which comprises a rotating mechanism for rotating the tool; and a sensor for sensing a change in the rotation of the rotating mechanism, a height at starting to configure the polishing tool using the tool being determined based on the change in the rotation obtained by the sensor.

Abstract: Methods for predicting polishing characteristics of polishing pads in mechanical or chemical-mechanical planarization of microelectronic substrate assemblies, and methods and machines for planarizing microelectronic substrate assemblies. One embodiment of a method in accordance with the invention includes ascertaining a surface parameter of a bearing surface of at least one raised feature projecting from a base portion of a raised feature polishing pad. The raised feature, for example, can be a pyramidal structure having a first cross-sectional area at the base portion of the pad and a second cross-sectional area at the bearing surface. The first cross-sectional area is generally greater than the second cross-sectional area. To ascertain the surface parameter of the bearing surface, one particular embodiment of the invention involves determining an indication of the surface area of the bearing surface.

Abstract: A system and method are presented for selectively conditioning a surface of a polishing pad of a CMP apparatus in order to achieve a desired surface profile of a semiconductor wafer. The semiconductor wafer may be subjected to a CMP operation using the CMP apparatus following the conditioning. The present CMP apparatus includes a polishing pad having an underside surface mechanically coupled to a substantially planar surface of a platen, an abrasive surface, and a measurement system. The platen and abrasive surface may be rotatable about respective rotational axes. The present conditioning method includes selecting a region of an upper “polishing” surface of the polishing pad (e.g., a CMP region) encircling a rotational axis of the platen and bounded by first and second radial distances from the rotational axis of the platen.

Abstract: An automatic grinding device for sharpening the knives of a forage harvester chopper drum includes a controller including a counter for counting the number of times the grindstone is adjusted toward the chopper drum during sharpening operation. The controller includes a microprocessor having a non-volatile memory in which may be stored a threshold value, determined by the type of grindstone, to which the count of the counter may be compared for generating a signal indicating the degree of wear of the grindstone so that it may be replaced when worn out.

Abstract: Sensors detect a stock removal of a wafer during polishing, and a CPU calculates the stock removal in accordance with information from the sensors. The CPU compares the actual stock removal detected by the sensors and a model stock removal stored in RAM, and determines timings for dressing and replacing said polishing pad in accordance with a difference between the actual stock removal and the model stock removal. The determination results are shown on a display.

Abstract: In a first step for the purpose of precentering, the dressing too; (27), without axial movement, is brought into contact with the circumference of the rotating grinding worm (11), and those rotary-angle positions of the grinding worm (11) at which the overrunning of the thread gap (36) starts of ends are determined by means of an acoustic-sensor signal and the shaft-angle encoder (18) of the grinding spindle (16). In a second step for the purpose of precision centering, the dressing tool (27) fed into the thread gap (36) is brought into contact with the left-hand and right-hand tooth flanks (38, 39) by axial displacement. In this case, the axial infeed is stopped by means of the acoustic-sensor signal, and the exact grinding-worm thread center is calculated from the contact positions of the dressing tool (27) achieved.

Abstract: An apparatus for use with a chemical mechanical planarization (CMP) system includes an ultrasonic source that is disposed proximate a workpiece carrier. The ultrasonic source generates an ultrasonic signal toward an area of a polishing pad or a workpiece during the polishing of the workpiece held by the carrier. An ultrasonic detector is configured to receive a reflected ultrasonic signal for processing in order to determine the presence of extraneous material at the area of the polishing pad.

Abstract: A method and apparatus for conditioning and monitoring a planarizing medium used for planarizing a microelectronic substrate. In one embodiment, the apparatus can include a conditioning body having a conditioning surface that engages a planarizing surface of the planarizing medium and is movable relative to the planarizing medium. A force sensor is coupled to the conditioning body to detect a frictional force imparted to the conditioning body by the planarizing medium when the conditioning body and the planarizing medium are moved relative to each other. The apparatus can further include a feedback device that controls the motion, position, or force between the conditioning body and the planarizing medium to control the conditioning of the planarizing medium.

Abstract: A method and apparatus for conditioning and monitoring a planarizing medium used for planarizing a microelectronic substrate. In one embodiment, the apparatus can include a conditioning body having a conditioning surface that engages a planarizing surface of the planarizing medium and is movable relative to the planarizing medium. A force sensor is coupled to the conditioning body to detect a frictional force imparted to the conditioning body by the planarizing medium when the conditioning body and the planarizing medium are moved relative to each other. The apparatus can further include a feedback device that controls the motion, position, or force between the conditioning body and the planarizing medium to control the conditioning of the planarizing medium.

Abstract: A tool for treatment of rock, masonry or concrete by drilling, grinding or cutting off, the tool has a plurality of cutting segments each having a plurality of bonded cutting bodies formed as diamond crystals and subjected to an abrasive wear during an operation, a tool base body which carries the cutting segments, and at least one marking provided on at least one segment and forming a wear indicator, the at least one marking being arranged so that it changes during operation of the tool with wear of the cutting segments.

Abstract: The record of changes in the size of a workpiece, which is measured by a gage head during grinding, is graphed on a color LCD of a control part. It is therefore possible to know if there is an abrupt change or no change in the size of the workpiece during the grinding just by looking at the graph. Thus, the sharpness of a grinding wheel can easily be judged during the grinding.

Abstract: In a method and an apparatus for carrying out said method for grinding surfaces of workpieces with a grinding wheel, an electrode is provided which is disposed spaced apart from the grinding wheel, so that a gap is formed. An electrolytic cooling lubricant is introduced into the gap. By means of a power source, a current is generated which is conducted through the electrode, the electrolytic lubricant and the grinding wheel. An electrochemical conditioning of the grinding wheel thereby takes place, the wheel being thus sharpened. During the grinding operation, the forces exerted by the grinding wheel on the workpiece to be ground are measured, on the basis of which the electrochemical conditioning of the grinding wheel is controlled by changing the intensity of the said current using a computing and control device. The electrochemical conditioning of the grinding wheel can be carried out before, during and/or after the grinding operation, continuously or in intervals.

Abstract: In a chemical-mechanical polishing (CMP) process, semiconductor substrates are rotated against a polishing pad in order to planarize substrate layers. The condition of the polishing pad directly affects the polishing rate of material removal and uniformity of removal from the semiconductor wafer. Conditioning of the polishing pad surface with an abrasive improves polishing uniformity and rates, however, it has the detrimental affect of removing a quantity of pad material. A method and apparatus for monitoring polishing pad wear during processing is developed to extend the pad's useful life, and maintain pad uniformity. This is accomplished in the present invention by measuring and monitoring the diminished pad thickness using a non-intrusive measurement system, and creating a closed-loop system for adjusting the chemical-mechanical polishing tool process parameters.

Abstract: Material removing machining is for wafer shaped workpieces, in particular semiconductor wafers. There is a method for achieving a wear performance which is as linear as possible for a tool which has an essentially planar working surface for the material removing machining of wafer shaped workpieces. The tool has a wear performance which is as linear as possible. There are also a method and a device for measuring a wear profile on an essentially planar working surface for the material removing machining of wafer shaped workpieces. There is also a carrier which is used for the two-sided material removing machining of wafer shaped workpieces.

Abstract: Disclosed herein is a polishing device including a polishing plate having an upper surface on which a polishing pad is attached, a polishing head having a lower surface opposed to an upper surface of the polishing pad on the polishing plate, for holding a substrate to be polished on the lower surface, and a pressure source for applying a polishing pressure to the polishing head, whereby the substrate held by the polishing head is pressed against the upper surface of the polishing pad under the polishing pressure applied from the pressure source to perform polishing of the substrate. The polishing head is provided with a contact pressure adjusting mechanism capable of adjusting an in-plane contact pressure of the substrate against the upper surface of the polishing pad on the polishing plate at every area of the substrate. Accordingly, the uniformity and the planarity in the plane of the substrate surface to be polished can be improved with a high throughput.

Abstract: A pad shaping tool for shaping a polishing pad. The tool includes a disk having a first side and a second side and at least two discontinuous pad shaping surfaces located in spaced apart positions relative to each other on the first side of the disk. The pad shaping surfaces are simultaneously engageable with a polishing surface of the polishing pad for shaping the polishing surface as the pad rotates relative to the tool to change a cross sectional profile of the polishing surface from a curved shape to a flatter shape. A process for reconditioning the polishing pad on a rotatable platform of a wafer polishing machine includes the steps of engaging the pad shaping tool with the polishing surface of the pad such that at least two discontinuous pad shaping surfaces of the tool simultaneously engage the polishing surface, and rotating the polishing pad while preventing translational movement of the tool relative to the pad so that the tool shapes the polishing surface of the pad to be more nearly flat.

Abstract: A polishing system includes a polishing pad for polishing a surface of a layer provided on a substrate, a surface condition measuring device for detecting a condition of a polishing surface of the polishing pad and a controller for controlling a process to the polishing pad by judging whether the polishing pad can be continuously used for polishing of the surface of the layer provided on the substrate, on the basis of a signal indicative of a measurement from the surface condition measuring device.

Abstract: A polishing method characterized by measuring the thickness of a film of a monitoring piece to be polished which is to be used exclusively for monitoring polishing amount, and obtaining polishing amount on the basis of the results of measurement, and judging, on the basis of the resulting polishing amount, setting/change of polishing condition of a polishing object, whether it is necessary or not to replace a polishing pad, and/or completion of run-in polishing after replacement of the polishing pad, and an apparatus to be used for practicing same.

Abstract: A carding machine includes a main carding cylinder having a circumferential surface carrying a cylinder clothing thereon; and a cooperating with the main carding cylinder. The traveling flats assembly includes a plurality of clothed flat bars arranged in a series and a flat drive for moving the clothed flat bars in an endless path having a working path portion along which the flat bar clothings cooperate with the cylinder clothing and a return path portion; and a grinding assembly for sharpening the cylinder clothing. The grinding assembly includes a grinding flat bar adapted to be positioned in the series of clothed flat bars to be moved by the flat drive in unison with the clothed flat bars; and a grinding element mounted on the grinding flat bar. The grinding element is in a contacting relationship with the cylinder clothing along the working path portion of the traveling flats assembly.

Abstract: The present invention is directed to polishing pads useful in determining an end to the useful wear life thereof. In a simple embodiment of the present invention, a polishing pad that is used with slurries is dyed on one side in a manner that causes the dye to permeate the pad to a limited depth that does not cause total coloring. Another embodiment of the present invention involves a fixed abrasive pad that has fixed abrasives embedded into the pad to a selected depth where at least one color level is within the portion of the pad that contains the fixed abrasives. After dyeing the pad, the pad is attached to the polishing platen. During the polishing operation, a color change signals a time to stop the polishing operation and change the pad. With multiple colors in the pad, limited only by the ability to dye the pad with uniform depth levels, characteristic wear patterns can be observed and adjustments made accordingly to prolong and optimize pad life.

Abstract: Method of surface finishing covalent-ionic ceramics comprising: (a) repeatedly rubbing a finishing medium against an exposed surface of the ceramic, the medium being constituted of an ionic bonded oxide having grains harder than the grains of the covalent-ionic bonded ceramic; (b) interrupting the rubbing at frequent intervals to dress the medium by a single point diamond tool; and (c) continuing the repeated rubbing and dressing interruptions of steps (a) and (b) until a surface roughness of about 0.04 micrometer Ra has been achieved on the ceramic and the exposed surface of the ceramic retains an ionic residue of the finishing medium. Also, a method of effecting reduced friction between lubricated rubbing surfaces, comprising: (a) forming one of the rubbing surfaces of silicon nitride based ceramics having a polished surface roughness about 0.

Abstract: A method and apparatus for monitoring polishing pad wear during processing is developed to extend the pad's useful life, and maintain pad uniformity. This is accomplished in the present invention by measuring and monitoring the diminished pad thickness using a non-intrusive measurement system, and creating a closed-loop system for adjusting the chemical-mechanical polishing tool process parameters. The non-intrusive measurement system consists of an interferometer measurement technique utilizing ultrasound or electromagnetic radiation transmitters and receivers aligned to cover any portion of the radial length of a polishing pad surface. The measurement system is sensitive to relative changes in pad thickness for uniformity, and to abrupt changes such as detecting wafer detachment from the CMP wafer carrier.

Abstract: A process for conditioning a polishing pad has been developed that incorporates in-situ conditioning where the conditioning is performed while the substrate (27, 40) is on the polishing pad (22) but terminates before the polishing of the substrate (27, 40) is completed. In one embodiment, ex-situ conditioning of the polishing pad (22) is used on the polishing pad between substrates (27, 40). The process has benefits of both in-situ and ex-situ conditioning.

Abstract: A method and apparatus for controlling a polishing characteristic of a polishing pad used in planarization of a substrate. The method preferably includes controlling the temperature of a planarizing surface of the polishing pad so that waste matter accumulations on the planarizing surface soften and/or become more soluble, and/or material comprising the planarizing surface attains approximately its glass transition temperature. The waste matter accumulations and/or a portion of the planarizing surface are in this way softened and more easily removed. The planarizing surface is either heated directly by directing a flow of heated planarizing liquid or heated air to the planarizing surface or indirectly by heating a support surface beneath the polishing pad or by heating the air proximate to the polishing pad.

Abstract: A laser element is mounted above a polishing pad of a workpiece polishing machine to monitor and control flatness of the pad. Actual flatness of the pad is determined by a computer processor which receives thickness measurements from the laser element and compares the thickness at the inner diameter portion of the pad with the thickness at the outer diameter portion of the pad. If the flatness varies substantially from a target flatness, a conditioning device mounted on the machine is moved appropriately relative to the pad to conform its flatness to the target flatness.

Abstract: An electrode (4) is disposed spaced away from and in facing relation with an electrically conductive grinding wheel (2). There is applied a voltage across the grinding wheel and the electrode with making electrically conductive fluid (7) flow between the grinding wheel and the electrode. A position of the grinding wheel is numerically controlled with the grinding wheel being dressed by electrolysis to thereby grind a work with the grinding wheel. The work is ground in accordance with command data Zx.sup.(i), and then a shape of a ground surface is measured by means of a measuring device (12). The measurement data is filtered to thereby record shape error data e.sub.x.sup.(i). There is established new command data Zx.sup.(i+1) by adding compensation, and then the work is ground again with the thus established new command data. The compensation refers to past command data, and determines new command data to be equal to an expected value of the past command data.

Abstract: A polishing apparatus is used for polishing a workpiece such as a semiconductor wafer to a flat mirror finish. The polishing apparatus has an interlock function includes a turntable having a polishing surface thereon, a top ring for holding a workpiece to be polished and pressing the workpiece against the polishing surface on the turntable, a first motor for rotating the turntable, and a second motor for rotating the top ring. The polishing apparatus further comprises a first actuator for lifting and lowering the top ring, a second actuator for moving the top ring in a horizontal direction, and a control unit for controlling the motors and the actuators. The control unit controls the motors and the actuators in such a manner that when an abnormality is detected in at least one of the motors and the actuators, at least one of the motors and the actuators other than that of the abnormality performs a predetermined operation.

Abstract: The device has a work-piece spindle (3) that can be shifted parallel to the spindle axis (C'). On it, in addition to the work-piece toothed wheel, at least one toothed dressing wheel is mounted on which the globoid grinding worm (10) is periodically dressed. On a tool-changer (12), a toothed honing wheel (18) is lodged rotatably on an additional arm (16); with it, the work-piece toothed wheel is honed after grinding. The toothed honing wheel (18) is dressed on the same or a second toothed dressing wheel. The device makes possible an efficient fine machining of toothed wheels.

Abstract: Several quantities related to pad wear during chemical mechanical polishing have been improved by measuring the emissivity of the pad within the annulus of wear. This emissivity value is shown to relate directly to the amount of wear in the pad and is used to control the pressure on a conditioner that is employed to compensate for pad wear. By using multiple conditioners, each of which presses on the pad with a force that is related to the pad emissivity in its annulus of wear, the uniformity of material removal, both in time and space, is improved.

Abstract: A grinding machine for grinding a wafer includes a pressure sensing grinding wheel and a source of wheel dressing. Based on a pressure signal received from the grinding wheel, a contoller provides a control signal to the source of wheel dressing to release the wheel dressing to sharpen the grinding wheel. A method of grinding wafers includes the steps of grinding a wafer, receiving a signal indicative of the amount of grinding and controlling the release of wheel dressing in response to the signal. The controller can also receive signals from a spindle shaft speed sensor and a spindle motor current detector to determine when, and how much, wheel dressing to release.

Abstract: An improved tool includes a milling tool rotatable about an axis, and a coaxially mounted grinding wheel positioned slightly axially towards a workpiece from the milling tool. The milling tool provides rough finish on a workpiece, and the grinding tool follows, providing finish grinding. The present invention recognizes that the grinding tool will be deflected away from the workpiece at high speed due to centrifugal forces. The present invention positions the milling tool relative to the grinding wheel at a location that compensates for the expected deflection of the grinding wheel, and achieves the desired amount of grinding. In further features of this invention, the phenomena of deflection of the grinding wheel due to increased speed is utilized to compensate for wear on the milling tool.

Abstract: Grinding and regulating wheels are carried on opposed feed slides on a machine base. A workrest is fixed to the base between the opposed wheels. Wheel dressers are mounted to cross-slides on the base, behind the wheels, independent of the feed slides. CNC dressing occurs through combined transverse motions of feed slide (with wheel) and cross slide (with dresser).

Abstract: An apparatus and method for detecting the roughness of a CMP pad surface, in situ, during pad conditioning by measuring and making use of surface friction effects. The effect is advantageously exploited to determine an endpoint for the pad conditioning process i.e. when the surface roughness of the pad is within a desired range, to facilitate the qualification of conditioning process parameter changes by determining their effect on the conditioning process, and to optimize these parameters. Also, the effect is employed to measure non-uniformities in the pad's surface roughness, and to guide corrective measures. Generally, these objectives are accomplished using an apparatus which includes a floating head having its bottom surface in contact with the top surface of a rotating CMP pad undergoing a CMP pad conditioning process. A bracket is employed to restrain the floating head so as to prevent the head from moving along with the rotating CMP pad.

Abstract: It is provided a drive and control device for a grinding machine of the type comprising a rotatable abrasive wheel (2), translating members (3) of the wheel (3) with respect to a rotating piece (4) to be ground, and restoring means (5) to reset the wheel (2) comprising a diamond-resetting member (6) and a balancing member (7), the device comprising sensor members (10) adapted to detect the piece roundness and electronic means (19) adapted to generate actuating signals (23) of the restoring means (5), in the presence of a roundness of the piece (4) different from a predetermined roundness. The process consists in grinding the piece and simultaneously measuring the piece diameter until achievement of a predetermined diameter, detecting the piece roundness, and operating said restoring means in interlocked relationship with the detected roundness.

Abstract: The present invention relates to a system for measuring a grinding force between a workpiece and a grinding wheel during the operation of a computer controlled grinding machine. A force transducer is mounted on a drive screw assembly between a moveable slide and a motor used to control movement of the slide. The force transducer generates a control signal that is conditioned and received by a digital signal processor, which instructs a machine controller to perform grinding operations in response to the measured force.

Abstract: A semiconductor wafer dicing saw is controlled by monitoring blade exposure from a flange holding the blade during the wafer dicing process. As the wafer is cut and separated into discrete electronic chips, the dicing blade wears. As the blade is brought closer and closer toward the wafer during cutting, the blade exposure is continuously being reduced. The small dimensions, coolant flow, and close tolerances typical in the wafer dicing process, do not permit visual inspection. Excess blade wear and thus reduced exposure or flange clearance between the blade cutting edge and flange edge will cause damage to the wafer and blade by restricting coolant flow or by contact of the flange with the wafer.

Abstract: A system for polishing a semiconductor wafer, the system comprising a wafer polishing assembly for polishing a face of a semiconductor wafer at a polishing rate and a polishing uniformity, the wafer polishing assembly including a platen subassembly defining a polishing area, and a polishing head selectively supporting a semiconductor wafer and holding a face of the semiconductor wafer in contact with the platen subassembly to polish the wafer face; and a controller selectively adjusting one of a plurality of adjustable polishing parameters during polishing of the wafer.

Abstract: A method and apparatus for determining the amount of conditioning required to be applied to a polishing pad to achieve a desired removal rate during the polishing of a semiconductor wafer utilizes a rotating conditioning wheel in contact with a rotating polishing pad. Preselected points on just polished wafers are measured for removal rate and such measurements are used to calculate the removal rate as a function of wafer radius. When the removal rate changes by a preselected amount, the polishing pad is conditioned in accordance with the calculations.

Abstract: The metal bond wheel forming apparatus includes rotation speed control means 11 for controlling the rotation speed of a grinding wheel 6; energy control means 9 for controlling discharge energy that is supplied to the gap between a wire electrode 1 and the grinding wheel 6; relative speed control means 17 for controlling a relative movement speed either for the wire electrode 1 or for the grinding wheel 6; and detailed machining control means 23 for controlling the rotation speed control means, the energy control means and the relative speed control means, for setting the rotation speed of the grinding wheel and discharge energy appropriate for detailed machining, and for setting the relative movement speed for the wire electrode or for the grinding wheel to enable high speed shaping during the detailed machining.

Abstract: A chemical mechanical polishing system for processing semiconductor wafers has a polishing arm and carrier assembly that press the topside surface of a semiconductor wafer against a motor driven, rotating polishing pad. Improved uniformity of material removal, as well as improved stability of material removal rate, is achieved through the use of a controller that applies a variable wafer backside pressure to the wafers being polished. More specifically, a control subsystem maintains a wafer count, corresponding to how many wafers have been polished by the polishing pad. The control subsystem regulates the backside pressure applied to each wafer in accordance with a predetermined function such that the backside pressure increases monotonically as the wafer count increases. In the preferred embodiment, the control system regulates the backside pressure in accordance with a linear function of the form: Backside Pressure=A+(B.times.Wafer Count).

Abstract: A method for the precision working of the tooth flanks of gear-shaped workpieces with an abrasive internally toothed tool wherein the tool, after each workpiece or after several workpieces, is dressed in the same mounting with a dressing wheel, the tooth system of which corresponds with the one of the gear-shaped workpiece and the tooth flanks of which are covered with extremely hard grinding granules. To improve the tool geometry the dressing of the internally toothed tool is done with a one-flank or a two-flank contact between the dressing wheel and the internally toothed tool and with an electronic forced guiding of the rolling and relative movements between the dressing wheel and the internally toothed tool, and, the precision working in the free or in the torque guided two-flank engagement between the internally toothed tool and the workpiece.

Abstract: A grinding machine including a bed to receive a workpiece and a plurality of grinding wheels mounted on at least one side of the bed for grinding surfaces of a workpiece received in the bed. The grinding machine includes at least one dressing tool being mounted on a slide arranged for movement towards and away from the grinding surfaces of the grinding wheels, the slide being mounted on a carriage for movement generally parallel to the bed, the slide and the carriage being movable by a prime mover under control of a microprocessor.

Abstract: Method for renewing grinding wheel surfaces in a machine for grinding ophthalmic lenses, comprising one or more diamond wheels (2,3,4,5), gripping members (7,8) capable of receiving an ophthalmic lens, and control. Once wheel wear is detected, the surface is renewed using an abrasive disk (9) fitted to the grinding machine in place of a lens in the gripping members. The invention also concerns a disk (9) for carrying out the method, with at least the peripheral surface consisting of abrasive material. A machine for gripping ophthalmic lenses and carrying out the method is also described.

Abstract: An interactive system for lapping transducers has an abrasive surface that communicates with the transducers in order to provide information for controlling the lapping and testing the transducers. The lapping body is preferably shaped as a disk, drum or tape, and communicates with the transducer with a type of signal that the transducer is designed to read and/or write. Thus for lapping a magnetic head or slider to be employed in a hard disk drive, the lapping body contains a magnetic medium layer that is either prerecorded or written by the head during lapping, while the signal received by the head is monitored and analyzed by a processor in order to determine, in part, when to terminate lapping. A series of transducers can be simultaneously lapped while individually monitored, so that each transducer can be removed from the lapping body individually upon receipt of a signal indicating that transducer has been lapped an optimal amount.