Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B37/00—Lapping machines or devices; Accessories
  • B24B37/005—Control means for lapping machines or devices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B37/00—Lapping machines or devices; Accessories
  • B24B37/04—Lapping machines or devices; Accessories designed for working plane surfaces
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B49/00—Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation
  • B24B49/10—Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation involving electrical means
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B49/00—Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation
  • B24B49/14—Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation taking regard of the temperature during grinding
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B49/00—Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation
  • B24B49/16—Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation taking regard of the load
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B57/00—Devices for feeding, applying, grading or recovering grinding, polishing or lapping agents
  • B24B57/02—Devices for feeding, applying, grading or recovering grinding, polishing or lapping agents for feeding of fluid, sprayed, pulverised, or liquefied grinding, polishing or lapping agents

Definitions

• the present invention relates to a device and a method for polishing a specimen according to the preambles of the appended independent claims.
• An exemplary polishing device comprises a rotatable polishing platen and a polish ing pad that is attached to the surface of the polishing platen.
• the polishing device also comprises a specimen holder for holding one or more specimens against the polishing pad. As the polishing platen is rotated, the polishing pad polishes the specimen(s).
• a polishing suspension is typically used in the polishing device to enhance the pol ishing action and to prevent overheating during the polishing process.
• the polish ing suspension contains water and/or other suitable liquids, such as ethanol or glycol for moistening, cooling and lubricating the polishing pad and abrasive parti cles, such as diamond, aluminium oxide or colloidal silica for polishing of the sur- face of the specimen.
• the polishing device may comprise a dispenser for dispens ing the polishing suspension at a predefined rate on the polishing pad.
• the dis can, for example, be configured to dispense a certain amount of the polish ing suspension at regular time intervals on the polishing pad.
• a problem associated with the known polishing devices is that, during the polish- ing, the moisture in the polishing pad can vary considerably as a function of time and as a function of the position on the polishing pad. This has a negative effect on the polishing result. If the polishing pad is too wet, the friction between the specimen and the polishing pad is small, which makes the polishing ineffective and increases the polishing time. If, on the other hand, the polishing pad is too dry, there is a risk that the polishing of the specimen fails due to the large friction be tween the specimen and the polishing pad.
• the device according to the invention i.e. the polishing device
• a specimen i.e. an object
• a solid material such as a piece of a natural (e.g. rock, mineral, ore or meteorite) or artificial (e.g. metal, concrete, ceramic, composite or semiconductor) material.
• polishing means pol ishing, fine-grinding and grinding processes with a polishing pad and a polishing suspension.
• the specimen to be polished is held against the surface of the polishing pad with the specimen holder.
• the specimen holder can be configured to hold one or more specimens against the polishing pad.
• the number of specimens that can be held with the specimen holder against the polishing pad can be, for example, 1, 2-5, 6- 10, or more than 10.
• the specimen holder can comprise, for example, one or more inserts in which the specimens can move freely or are secured by clamping.
• the specimen holder can be attached to a polishing head that presses the specimen(s) with an adjustable pressing force against the polishing pad. The pressing force can be adjusted, for example, based on the values of the measured physical quan tity.
• the polishing pad can be made of different materials, such as a fibrous cloth (e.g. real silk, polyester or acetate) or synthetic non-fibrous (e.g. neoprene, polyure thane or composite) material.
• the polishing pad is preferably disc-shaped, i.e. it has a flat circular shape.
• the polishing pad is preferably porous, enabling it to ab sorb the polishing suspension.
• the diameter of the polishing pad can be, for ex ample, less than 500 mm, preferably 200-400 mm.
• the thickness of the polishing pad can be, for example, less than 3 mm, preferably less than 2 mm, and more preferably less than 1 mm.
• the polishing pad is attached, preferably releasably, to the surface of the rotatable polishing platen. As the polishing platen is rotated, the polishing pad polishes the specimen.
• the polishing platen can be made of a heat conductive and corrosion resistant material, such as aluminium, bronze or stainless steel, or of a plastic, polymer or composite material.
• the polishing platen may comprise an electrically insulated electrical contact element (for example a sheet made of austenitic stain less steel and having a thickness of about 0.5 mm) on its surface, to which an electrical contact element (for example a carbon brush) of a measuring instrument can be electrically connected.
• the polishing platen is preferably disc-shaped and heat conductive.
• the diameter of the polishing platen can be, for example, less than 500 mm, preferably 200-400 mm. Preferably, the diameters of the polishing platen and the polishing pad are essentially the same.
• the thickness of the polish ing platen can be, for example, 20-50 mm. The optimal thickness of the polishing platen depends on the diameter and the material of the polishing platen.
• the polishing device may comprise an actuator, such as an electric motor, for ro tating the polishing platen.
• the actuator can be configured to rotate the polishing platen, for example, at a rotational speed of 0-600 rpm.
• the actuator can be con figured to adjust the rotational speed of the polishing platen based on the values of the measured physical quantity. For example, in a case where the friction exceeds a predetermined threshold value or the moisture falls below a predetermined threshold value, the actuator can be configured to reduce the rotational speed of the polishing platen. To reduce possible interferences caused by the actuator, it may be beneficial to add an electrical insulation layer between the polishing platen and the actuator.
• the specimen holder can be rotatable.
• the specimen holder can be rotatable about an axis, which is parallel to the rotation axis of the polishing platen.
• the polishing device may comprise an actuator, such as an electric motor, for rotating the specimen holder.
• the actuator can be config ured to rotate the specimen holder, for example, at a rotational speed of 0-150 rpm.
• the actuator can be configured to adjust the rotational speed of the specimen holder based on the values of the measured physical quantity. For example, in a case where the friction exceeds a predetermined threshold value or the moisture falls below a predetermined threshold value, the actuator can be configured to re Jerusalem the rotational speed of the specimen holder.
• the device according to the invention can measure the physical quantity, which is indicative of the moisture or the friction, in a plurality of positions on the polishing pad and, based on the values of the measured physical quantity, dispense the pol ishing suspension to the plurality of positions on the polishing pad.
• the means for measuring the physical quantity may comprise one or more mova ble sensors, or a plurality of fixed (non-movable) sensors arranged at a predeter mined distance from each other.
• the sensor can be a moisture sensor, which can measure, for example, the (electrical) resistance on the polishing pad or the ca pacitance between the opposite sides of the polishing pad (i.e. the capacitance over the thickness of the polishing pad), which both vary as a function of the mois ture in the polishing pad.
• the sensor can also be a force sensor, which is config ured to measure the friction on the surface of the polishing pad. The measurement of the friction can be based on detecting the lateral force acting on an object that is arranged in contact with the surface of the polishing pad.
• the means for dispensing the polishing suspension may comprise one or more movable spray nozzles, or a plurality of fixed (non-movable) spray nozzles ar ranged at a predetermined distance from each other.
• the means for dispensing the polishing suspension may also comprise a container for the polishing suspen sion.
• the means for dispensing the polishing suspension may com prise a plurality of containers for the polishing suspension or for different polishing suspensions.
• the container(s) can be connected by flexible hoses to the spray nozzles.
• the means for dispensing the polishing suspension may comprise a control unit for controlling the spray nozzles.
• the control unit may comprise a processor and a memory including computer program code, the memory and the computer pro- gram code being configured to, with the processor, cause the spray nozzles to dispense suitable amounts of the polishing suspension to the plurality of positions on the polishing pad.
• the amount of the polishing suspension to be dispensed to each position is determined based on the values of the measured physical quanti ty.
• the values of the measured physical quantity can be compared to a predefined reference value or profile in order to determine the amount of the polishing sus pension to be dispensed.
• the predefined reference value or profile corresponds to the desired moisture content in the polishing pad.
• the amount of the polishing suspension to be dispensed to each position on the polishing pad can be, for ex ample, less than 5 pi / cm 2 , less than 2 pi / cm 2 or 0.5-2 mI / cm 2 .
• the polishing suspension enhances the polishing action and prevents overheating during the polishing process.
• the polishing suspension contains water and/or oth er suitable liquids, such as alcohols (e.g. ethanol, glycol or isopropyl alcohol) for moistening, cooling and lubricating the polishing pad.
• suitable liquids such as alcohols (e.g. ethanol, glycol or isopropyl alcohol) for moistening, cooling and lubricating the polishing pad.
• the polishing suspension may also contain abrasive particles, such as diamonds, aluminium oxide or colloi dal silica for polishing of the surface of the specimen.
• the polishing sus pension i.e. slurry or fluid
• the polishing sus pension is a mixture of liquid(s) and abrasive(s).
• An advantage of the device according to the invention is that it can provide and maintain a substantially constant and uniform moisture content in the polishing pad during the polishing process. Another advantage of the device according to the invention is that it enables to achieve a uniform and high-quality polishing result of the specimen. Still another advantage of the device according to the invention is that it enables to optimize (minimize) the consumption of the polishing suspension in the polishing process.
• the physical quantity is the re sistance on the polishing pad and the means for dispensing a polishing suspen sion is configured to dispense the polishing suspension to a position on the polish ing pad if in said position the value of the resistance is larger than a first threshold value.
• the resistance on the polishing pad varies as a function of the moisture in the polishing pad. The wetter the polishing pad is, the smaller the resistance is.
• the physical quantity is the capaci tance between the opposite sides of the polishing pad and the means for dispens ing a polishing suspension is configured to dispense the polishing suspension to a position on the polishing pad if in said position the value of the capacitance is smaller than a second threshold value.
• the capacitance between the opposite sides of the polishing pad varies as a function of the moisture in the polishing pad. The wetter the polishing pad is, the larger the capacitance is.
• the physical quantity is the friction on the surface of the polishing pad and the means for dispensing a polishing suspen sion is configured to dispense the polishing suspension to a position on the polish ing pad if in said position the value of the friction is larger than a third threshold value.
• the friction on the surface of the polishing pad varies as a function of the moisture in the polishing pad. The wetter the polishing pad is, the smaller the fric tion is.
• the means for measuring a physical quantity comprises a sensor arranged in contact with the surface of the polishing pad and means for moving the sensor between the plurality of positions on the polishing pad.
• the means for moving the sensor is configured to move the sensor along the surface of the polishing pad.
• the sensor can be a moisture sensor, which measures the resistance on the polishing pad and/or the capacitance verti cally between the opposite sides of the polishing pad.
• the sensor can alternatively be a force sensor, which measures the friction on the surface of the polishing pad.
• the means for moving the sensor comprises an arm arranged above the polishing pad and an actuator for moving the sensor along the arm.
• the arm is preferably straight, and its longitudinal axis is arranged parallel to the plane of the polishing pad.
• the arm is preferably arranged above the polishing pad in such a manner that it extends from the centre to the periphery of the polishing pad. This enables the sensor to be moved to all possible positions on the polishing pad as the polishing platen is rotated.
• the actuator can be an electric motor.
• the means for moving the sensor is the specimen holder that is configured to hold the sensor against the polishing pad.
• the specimen holder can comprise, for example, an insert in which the sen sor can move freely or is secured by clamping.
• the sensor may comprise a wire less transmitter or transceiver for communicating with a remote device, such as a measuring instrument and/or a control unit that controls the spray nozzle(s).
• the means for measuring a physical quantity comprises an array of sensors arranged in contact with the surface of the polishing pad.
• the sensors can be attached to an arm that is arranged above the polishing pad.
• the sensors are attached to the arm at a predetermined distance from each other.
• the arm is preferably straight, and its longitudinal axis is arranged parallel to the plane of the polishing pad.
• the arm is preferably arranged above the polishing pad in such a manner that it extends from the centre to the periphery of the polishing pad.
• the number of sensors depends on the diameter of the polishing pad and the needed measurement accuracy, and it can be, for ex ample, less than 100, less than 50, less than 20, or 6-12.
• the sensors can be moisture sensors, which measure the resistance on the polishing pad and/or the capacitance between the opposite sides of the polishing pad.
• the sensors can alternatively be force sensors, which measure the friction on the surface of the polishing pad.
• the senor comprises at least two electrical contact elements arranged in contact with the surface of the polishing pad, and the means for measuring a physical quantity comprises means for meas uring the resistance between two of the at least two electrical contact elements.
• the electrical contact elements i.e. the electrodes, provide an electrical path through which electrical properties of the polishing pad can be measured.
• the electrical contact elements can have different shapes and sizes.
• the electrical contact elements are made of an electrically conductive material, which is prefera bly also wear and corrosion resistant. Preferable materials for the electrical contact elements are, for example, stainless steel and tool steel.
• the electrical contact elements are electrically isolated from each other to prevent short circuits.
• the means for measuring the resistance between two of the at least two electrical con tact elements may comprise a measuring instrument that is electrically connected with electrical connections, such as wires, cables or carbon brushes, to two elec trical contact elements of the sensor.
• the measuring instrument is configured to measure the resistance between these two electrical contact elements.
• the means for measuring a physical quantity comprises means for measuring the capacitance between one of the at least two electrical contact elements and the polishing platen.
• the means for measuring the capacitance between one of the at least two electrical contact ele ments and the polishing platen may comprise a measuring instrument that is elec trically connected with electrical connections, such as wires, cables or carbon brushes, to the electrical contact element and the polishing platen.
• the measuring instrument is configured to measure the capacitance between the electrical con- tact element and the polishing platen.
• a resistor can be used between the measur ing instrument and the polishing platen to reduce interference.
• the means for measuring a physical quantity comprises a compression element for pressing the sensor against the surface of the polishing pad.
• the compression element enables to keep the sensor in contact with the surface of the polishing pad with a suitable pressing force.
• the pressing force of the compression element can be adjustable.
• the compression element can be, for example, a spring.
• the compression element can utilize air pressure, gravity, or magnetic or electromagnetic force in producing the suitable pressing force.
• the means for measuring a physical quantity comprises means for measuring the lateral force acting on the sensor.
• the means for measuring the lateral force may comprise a force sensor that is attached to the sensor.
• the means for measuring a physical quantity comprises a contactless moisture sensor arranged above the polishing pad and means for moving the contactless moisture sensor between the plurality of positions on the polishing pad.
• the contactless moisture sensor can measure the moisture in the polishing pad.
• the contactless moisture sensor can be, for ex ample, an optical sensor.
• the means for moving the contactless moisture sensor may comprise an arm arranged above the polishing pad and an actuator for mov ing the contactless moisture sensor along the arm.
• the means for measuring a physical quantity comprises an array of contactless moisture sensors arranged above the polishing pad.
• the contactless moisture sensors can measure the moisture in the polishing pad.
• the contactless moisture sensors can be, for example, optical sen sors.
• the contactless moisture sensors can be attached to an arm that is arranged above the polishing pad. Preferably, the contactless moisture sensors are at tached to the arm at a predetermined distance from each other.
• the contactless moisture sensor is a spectrometer that is configured to measure the intensity of light reflected from the surface of the polishing pad as a function of the wavelength.
• the intensity of the reflected light depends on the moisture in the polishing pad.
• the intensity of the reflected light at a certain wavelength can act quite differently as the moisture in the polishing pad changes. For example, when the moisture in the polishing pad decreases, the intensity of the reflected light can increase at one wavelength and decrease at the other wavelength.
• the spectrometer may comprise a plurality of optical detectors, each of them being adapted to detect light at a different wave length.
• the wavelength range of the spectrometer can be, for example, 400-700 nm, 300-1000 nm or 750-2500 nm.
• the distance between the spec trometer and the surface of the polishing pad is kept constant during the meas urement.
• the surface of the polishing pad can be illuminated with one or more light sources, such as a light-emitting diode (LED).
• LED light-emitting diode
• the contactless moisture sensor is a polymer membrane.
• the resistance of the polymer membrane depends on the moisture.
• the moisture in the polishing pad can be measured by arranging the polymer membrane close to the surface of the polishing pad.
• the polymer membrane can be provided with two electrical contact elements.
• the polymer membrane is preferably attached to a substrate, such as a glass piece.
• the device comprises means for measuring the temperature of the sensor and/or the polishing pad, and means for adjusting the rotational speed of the polishing platen and/or the specimen holder based on a value of the measured temperature.
• the means for measuring the temperature may comprise contact and/or contactless temperature sensors.
• the device comprises means for measuring the vibration of the sensor and means for adjusting the rotational speed of the polishing platen and/or the specimen holder based on a value of the meas ured vibration.
• the means for measuring the vibration may comprise a vibration sensor that is attached to the sensor.
• the device comprises means for cooling the polishing platen.
• the polishing platen can be cooled by spraying water onto the bottom side of the polishing platen.
• the device may comprise a splash guard to prevent the mist of cooling water escaping onto the polishing pad.
• the splash guard can be made of, for example, plastic.
• the means for dispensing a polishing suspension comprises a spray nozzle arranged above the polishing pad and means for moving the spray nozzle between the plurality of positions on the polish ing pad.
• the means for dispensing a polishing suspension may comprise one or more containers for the polishing suspension or for different polishing suspen sions.
• the container can be connected, for example, by a flexible hose to the spray nozzle.
• the means for moving the spray noz zle comprises an arm arranged above the polishing pad and an actuator for mov ing the spray nozzle along the arm.
• the arm is preferably straight, and its longitu dinal axis is arranged parallel to the plane of the polishing pad.
• the arm is prefer ably arranged above the polishing pad in such a manner that it extends from the centre to the periphery of the polishing pad. This enables the spray nozzle to be moved to all possible positions on the polishing pad as the polishing platen is ro tated.
• the actuator can be an electric motor.
• the means for moving the spray noz zle is the specimen holder to which the spray nozzle is attached.
• the means for dispensing a polishing suspension comprises an array of spray nozzles arranged above the polishing pad.
• the spray nozzles can be attached to an arm.
• the spray nozzles are attached to the arm at a predetermined distance from each other.
• the arm is preferably straight, and its longitudinal axis is arranged parallel to the plane of the polishing pad.
• the arm is preferably arranged above the polishing pad in such a manner that it extends from the centre to the periphery of the polishing pad.
• the number of spray nozzles depends on the diameter of the polishing pad, and it can be, for example, less than 100, less than 50, less than 20, or 6-12.
• the means for dispensing a polishing suspension may comprise one or more containers for the polishing suspension or for different polishing suspensions.
• the container(s) can be connected, for example, by flexible hoses to the spray nozzles.
• the device comprises means for evaporating the polishing suspension from the polishing pad.
• the polishing sus pension can be evaporated with a stream of compressed air to a desired position on the polishing pad.
• the present invention also relates to a method for polishing a specimen.
• the method according to the invention comprises holding the specimen with a speci men holder against a polishing pad that is attached to a polishing platen, rotating the polishing platen about an axis, measuring a physical quantity indicative of the moisture or the friction in a plurality of positions on the polishing pad, and dispens ing a polishing suspension, based on values of the measured physical quantity, to the plurality of positions on the polishing pad.
• An advantage of the method according to the invention is that it can provide and maintain a substantially constant and uniform moisture content in the polishing pad during the polishing process. Another advantage of the method according to the invention is that it enables to achieve a uniform and high-quality polishing result of the specimen. Still another advantage of the method according to the invention is that it enables to consume less polishing suspension during the polishing process.
• Fig. 1 illustrates a polishing device according to a first embodiment of the invention
• fig. 2 illustrates a polishing device according to a second embodiment of the invention.
• Fig. 1 illustrates a polishing device according to a first embodiment of the inven tion.
• the polishing device comprises a polishing platen 101 that can be rotated about an axis with an actuator 102.
• the actuator 102 can rotate the polishing plat en 101 at different rotational speeds.
• a polishing pad 103 is attached to the polish ing platen 101.
• the polishing pad 103 is used for polishing a specimen 104 that is held against the polishing pad 103 with a specimen holder 105.
• the specimen holder 105 can be rotated about an axis, which is parallel to the rotation axis of the polishing platen 101, with an actuator 106.
• the actuator 106 can rotate the speci- men holder 105 at different rotational speeds. As the polishing platen 101 and the specimen holder 105 are rotated, the polishing pad 103 polishes the specimen 104.
• the polishing device comprises a moisture sensor 107 for detecting the moisture in the polishing pad 103.
• the moisture sensor 107 comprises electrical contact elements 108 and 109, which are arranged in contact with the surface of the pol ishing pad 103.
• the electrical contact elements 108 and 109 provide an electrical path through which electrical properties of the polishing pad 103 can be measured.
• the electrical contact elements 108 and 109 are electrically connected to a meas uring instrument 110 that can measure the resistance between the electrical con tact elements 108 and 109.
• the resistance between the electrical contact ele ments 108 and 109 is indicative of the moisture in a measurement position on the polishing pad 103.
• the measuring instrument 110 is electrically connected to the polishing platen 101, thus allowing to measure the capacitance between one of the electrical contact elements 108, 109 and the polishing platen 101, i.e. between the opposite sides of the polishing pad 103.
• the capacitance between the electrical contact element 108 or 109 and the polishing platen 101 is indicative of the mois ture in a measurement position on the polishing pad 103.
• the moisture sensor 107 is attached with a rod 111 to an arm 112 that is located above the polishing pad 103.
• the arm 112 extends from the centre to the periph ery of the polishing pad 103.
• the moisture sensor 107 can be moved with an ac tuator 113 along the arm 112, thus enabling to move the moisture sensor 107 be tween different positions on the polishing pad 103.
• the rod 111 is provided with a spring 114 for pressing the moisture sensor 107 against the surface of the polish ing pad 103.
• the spring 114 enables to keep the electrical contact elements 108 and 109 in contact with the surface of the polishing pad 103 with a suitable press ing force.
• the polishing device comprises a force sensor 115 for detecting the lateral force acting on the moisture sensor 107.
• the force sensor 115 is attached to the rod 111 and electrically connected to the measuring instrument 110 that can deter mine the lateral force, i.e. the friction on the surface of the polishing pad 103.
• the friction on the surface of the polishing pad 103 is indicative of the moisture in a measurement position on the polishing pad 103.
• the polishing device comprises a spray nozzle 116 for dispensing a polishing sus pension on the polishing pad 103.
• the spray nozzle 116 is attached to an arm 117 that is located above the polishing pad 103.
• the arm 117 extends from the centre to the periphery of the polishing pad 103.
• the spray nozzle 116 can be moved with an actuator 118 along the arm 117, thus enabling to move the spray nozzle 116 between different positions above the polishing pad 103.
• the polishing suspension is stored in a container 119 from which it is conveyed through a flexible hose 120 to the spray nozzle 116 to be dispensed on the polish ing pad 103.
• the polishing device comprises a control unit 121 for controlling the dispensing of the polishing suspension.
• the control unit 121 controls the spray nozzle 116 to dispense suitable amounts of the polishing suspension to desired positions on the polishing pad 103.
• the amount of the polishing suspension to be dispensed to each position is determined based on the determined moisture or the friction on each position.
• the polishing device comprises a temperature sensor 122 attached to the electri cal contact element 108 for measuring the temperature of the electrical contact element 108, and a temperature sensor 123 attached to the arm 112 for contact- lessly measuring the temperature of the polishing pad 103.
• the polishing device also comprises a vibration sensor 124 attached to the rod 111 for measuring the vibration of the moisture sensor 107.
• the control unit 121 can control the rotational speeds of the polishing platen 101 and the specimen holder 105 based on the measured temperatures and/or vibration.
• the polishing device comprises a spray nozzle 125 for spraying water onto the bottom side of the polishing platen 101 in order to cool the polishing platen 101.
• a splash guard 126 is used to prevent the mist of water escaping onto the polishing pad 103.
• Fig. 2 illustrates a polishing device according to a second embodiment of the in vention.
• the polishing device comprises a polishing platen 201 that can be rotated about an axis with an actuator 202.
• the actuator 202 can rotate the polishing plat en 201 at different rotational speeds.
• a polishing pad 203 is attached to the polish ing platen 201.
• the polishing pad 203 is used for polishing a specimen 204 that is held against the polishing pad 203 with a specimen holder 205.
• the specimen holder 205 can be rotated about an axis, which is parallel to the rotation axis of the polishing platen 201, with an actuator 206.
• the actuator 206 can rotate the speci men holder 205 at different rotational speeds.
• the polishing device comprises three moisture sensors 207 for detecting the mois ture in the polishing pad 203.
• the moisture sensors 207 are arranged at regular intervals from each other and attached with rods 208 to an arm 209 that is located above the polishing pad 203.
• the arm 209 extends from the centre to the periph ery of the polishing pad 203.
• Each of the moisture sensors 207 comprises electrical contact elements 210 and 211, which are arranged in contact with the surface of the polishing pad 203.
• the electrical contact elements 210 and 211 provide an electrical path through which electrical properties of the polishing pad 203 can be measured.
• the electrical con tact elements 210 and 211 are electrically connected to a measuring instrument 212 that can measure the resistance between the electrical contact elements 210 and 211.
• the resistance between the electrical contact elements 210 and 211 is indicative of the moisture in a measurement position on the polishing pad 203.
• the measuring instrument 212 is electrically connected to the polishing platen 201, thus allowing to measure the capacitance between one of the electrical contact elements 210, 211 and the polishing platen 201, i.e. between the opposite sides of the polishing pad 203.
• the capacitance between the electrical contact element 210 or 211 and the polishing platen 201 is indicative of the moisture in a meas urement position on the polishing pad 203.
• the polishing device comprises three spray nozzles 213 for dispensing a polishing suspension on the polishing pad 203.
• the spray nozzles 213 are attached at regu lar intervals to an arm 214 that is located above the polishing pad 203.
• the arm 214 extends from the centre to the periphery of the polishing pad 203.
• the polishing suspension is stored in a container 215 from which it is conveyed through flexible hoses 216 to the spray nozzles 213 to be dispensed on the polish ing pad 203.
• the polishing device comprises a control unit 217 for controlling the dispensing of the polishing suspension.
• the control unit 217 controls the spray nozzles 213 to dispense suitable amounts of the polishing suspension to desired positions on the polishing pad 203.
• the amount of the polishing suspension to be dispensed to each position is determined based on the determined moisture.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
• Constituent Portions Of Griding Lathes, Driving, Sensing And Control (AREA)
• Grinding-Machine Dressing And Accessory Apparatuses (AREA)
• Mechanical Treatment Of Semiconductor (AREA)

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• 2019
  • 2019-11-18 FI FI20195982A patent/FI130973B1/en active
• 2020
  • 2020-11-16 AU AU2020385654A patent/AU2020385654A1/en active Pending
  • 2020-11-16 US US17/776,794 patent/US20220395955A1/en active Pending
  • 2020-11-16 EP EP20815891.5A patent/EP4061576A1/en active Pending
  • 2020-11-16 CN CN202080079861.7A patent/CN114728397B/zh active Active
  • 2020-11-16 WO PCT/FI2020/050764 patent/WO2021099681A1/en unknown
  • 2020-11-16 JP JP2022529095A patent/JP2023503280A/ja active Pending
  • 2020-11-16 CA CA3161142A patent/CA3161142A1/en active Pending
  • 2020-11-16 KR KR1020227020723A patent/KR20220134521A/ko active Search and Examination
  • 2020-11-18 TW TW109140205A patent/TW202122213A/zh unknown

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