Method and device for dressing grinding wheel

Abstract

A dresser for a grinding wheel is provided with: a dresser moving table (25) to which a dresser (10) is fixed; a shape measurement unit (35) that measures the shapes of the dresser (10) and the grinding wheel (16); a displacement evaluation unit (31) that measures the displacement of the dresser (10) and the grinding wheel (16); a vibration measurement unit (32) that measures the vibrations of the dresser (10) and the grinding wheel (16); a working heat evaluation unit (33) that measures temperature and heat flow; a control unit (30) that controls the cut-in amount, the rotational speed, and the position of the dresser (10) on the basis of the measurement results of the displacement evaluation unit (31), the vibration measurement unit (32), and the processing heat evaluation unit (33); a machining condition database (37-1) that stores the measurement results of the displacement evaluation unit (31), the vibration measurement unit (32), and the machining heat evaluation unit (33) in association with the shapes of the dresser (10) and the grinding wheel (16) measured after dressing; and a machining learning model (37-2) for shaping the grinding wheel having a groove shape with high precision and high quality according to the grinding wheel dressing device, and suppressing variations in shape (quality).

Description

TECHNICAL FIELD

[0001] The present application relates to a dressing method and dressing device for a grinding wheel having a groove shape of a chamfering device for a semiconductor wafer. BACKGROUND

[0002] In recent years, multi-variety small-lot production of semiconductor wafers and the like is being promoted. With the goal of multi-variety small-lot production, quality improvement of wafers, yield improvement, and the like, the requirement for high precision, quality improvement of a grinding wheel having a groove shape used in chamfering processing of wafers is increasing.

[0003] In addition, with SiC (silicon carbide) as a compound of carbon (C) and silicon (Si) as the first, materials that have a large band gap (UWBG), strong bonding between atoms that constitute the crystal, and are not easily damaged, such as GaN (gallium nitride), gallium oxide, AlGaN, diamond, are expected as power elements, high-frequency elements, and semiconductor materials that are small, low-power consumption, and high-efficiency compared to silicon semiconductors, and excellent in radiation resistance, and practicalization is being promoted. However, UWBG materials such as 4H-SiC are difficult to process, and therefore high precision, quality improvement of the groove shape of the grinding wheel is strongly required.

[0004] Chamfering processing in a semiconductor wafer manufacturing process requires a process of repeatedly dressing the grinding wheel with a dresser and measuring the edge shape of the wafer after grinding until the wafer becomes the desired shape.

[0005] In addition, it is known that finish machining of the outer peripheral chamfer of the semiconductor wafer is performed by so-called spiral grinding in which the grinding wheel is inclined with respect to the wafer and the chamfer portion is ground in order to prevent the occurrence of grinding marks in the circumferential direction. However, in spiral grinding, fine adjustment is essential for shape formation based on dressing of the grinding wheel, and it takes time and requires a skilled specialist.

[0006] In Patent Literature 1, it is described that in dressing for spiral grinding using a dresser for groove formation, in order to improve the transfer rate, processability, and the precision of the groove formed by the dresser, the upper or lower portion of the groove formed in the grinding wheel is processed with the dresser. It is also described that the dresser is then repeatedly lowered or raised in the thickness direction with respect to the grinding wheel.

[0007] In addition, a process of dressing with a laser is known. In Patent Literature 2, it is described that dressing with a laser is performed using an ultrashort pulse laser such as a femtosecond laser in order to reduce the thermal influence on the shaped tool and obtain high processing precision, and dressing is performed within a prescribed range before and after the traveling direction centered on the focal point of the laser. PRIOR ART DOCUMENTS PATENT LITERATURE

[0008] Patent Literature 1: Japanese Patent Application Publication No. 2022-325 Patent Literature 2: Japanese Patent Application Publication No. 2015-98041 SUMMARY PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] In the above-described prior art, the technology described in Patent Literature 1 requires adjustment of the movement of the dresser by a skilled full-time staff member when dressing the grinding wheel for chamfering. In addition, with a difficult-to-machine material such as SiC, machining is time-consuming, and it is difficult to form the desired shape, and the shape (creation) deviation caused by dressing of the grinding wheel is large.

[0010] In addition, the technology described in Patent Literature 2 is difficult to expand the irradiation range, and the portion that can be dressed at one time is small, and it is not possible to implement the entire grinding wheel, and it does not consider making the shape of the entire grinding wheel with a groove shape highly precise.

[0011] The present application aims to solve the problems of the above-described prior art, and to provide a dressing device and method for a grinding wheel that forms the shape of a grinding wheel with a groove shape with high precision and high quality, and suppresses the deviation of the shape (quality). MEANS FOR SOLVING THE PROBLEMS

[0012] To achieve the above-described object, the present application is a dressing method for a grinding wheel of a chamfering device for a wafer, which determines a target shape of the grinding wheel, and dresses the grinding wheel to become the target shape based on at least the shapes of a dresser and the grinding wheel measured before machining, and a displacement condition that represents the relationship between the applied force and displacement of the dresser and the grinding wheel.

[0013] In addition, in the above-described dressing method for a grinding wheel, it is preferable that, in the dressing, the displacement, vibration, and machining heat of the dresser and the grinding wheel are monitored.

[0014] In addition, in the above-described dressing method for a grinding wheel, it is preferable that the displacement condition of the dresser is axial displacement.

[0015] In addition, in the above-described dressing method for a grinding wheel, it is preferable that the displacement condition of the grinding wheel is displacement caused by bending and twisting.

[0016] In addition, in the above-described dressing method for a grinding wheel, it is preferable that, after dressing, the shapes of the dresser and the grinding wheel are measured, and if the shapes are within an allowable range compared to the target shapes of the dresser and the grinding wheel, respectively, the wafer is ground with the grinding wheel, and a good or bad determination is made.

[0017] In addition, in the above-described method for dressing grinding wheels, preferably, the monitoring results are stored in association with the shapes of the dresser and the grinding wheel measured after dressing as a machining condition database, and a machining learning model is constructed from the machining condition database.

[0018] Furthermore, the present invention includes a dressing device for a grinding wheel used in a wafer chamfering apparatus, comprising: a dressing device moving stage for fixing the dressing device and allowing the rotation axis and X, Y, and Z axes to be variable; a shape measuring unit for measuring the shape of the dressing device and the grinding wheel; a displacement evaluation unit for measuring the displacement of the dressing device and the grinding wheel; a vibration measuring unit for measuring the vibration of the dressing device and the grinding wheel; a processing heat evaluation unit for measuring temperature and heat flow; a control unit for controlling the cutting depth, rotational speed, and position of the dressing device based on the measurement results of the displacement evaluation unit, the vibration measuring unit, and the processing heat evaluation unit; a processing condition database for storing the measurement results and the shapes of the dressing device and the grinding wheel measured after dressing in association; and a processing learning model constructed from the processing condition database.

[0019] Furthermore, in the aforementioned grinding wheel dressing device, the control unit dresses the grinding wheel to achieve the target shape based at least on the shape of the dresser and the grinding wheel measured by the shape measuring unit before processing, the axial displacement of the dresser, and the displacement caused by the bending and torsion of the grinding wheel. The effects of the invention

[0020] According to the present invention, since the target shape of the grinding wheel is determined at least based on the shape of the dresser and the grinding wheel measured before processing, as well as the displacement conditions of the dresser and the grinding wheel, the grinding wheel is dressed to make it into the target shape. Therefore, a grinding wheel dressing apparatus and method can be obtained to produce a grinding wheel with a groove shape with high precision and high quality, and to suppress shape (quality) deviations. Attached Figure Description

[0021] Figure 1 This is a diagram illustrating a force-displacement model of a dresser and a grinding wheel according to an embodiment of the present invention. Figure 2 This is a block diagram illustrating the overall system structure of a trimming device according to one embodiment. Figure 3 This is an explanatory diagram showing the chamfering process on the wafer end face. Figure 4 This is an explanatory diagram of factors related to machining accuracy during finishing. Figure 5 This is an explanatory diagram showing the deformation caused by the machining force during dressing of a grinding wheel and its measurement. Figure 6 is a diagram showing alignment of a dresser and a grinding wheel according to one embodiment Figure 7 is a diagram showing an alignment portion according to one embodiment Figure 8 is a flowchart of a dressing method according to one embodiment DETAILED DESCRIPTION

[0022] Figure 1 is a diagram showing modeling of force-displacement of a dresser 10 and a grinding wheel 16 according to one embodiment of the present application, Figure 2 is a block diagram showing the overall system structure of a dressing device according to one embodiment. Figure 3 is a diagram showing steps of chamfering processing of a wafer W in a chamfering device.

[0023] As shown in Figure 3 , chamfering processing is performed by shape transfer or processing (dressing) of a grinding wheel 16 by a dresser 10, and then shape of a wafer W is ground by grinding wheel 16. In Figure 3 , grinding wheel 16 is mounted on a wheel spindle 17 via a sleeve 18 and rotated. The upper surface angle θ1, the lower surface angle θ2 of the end surface of dresser 10 are adjusted to be slightly smaller angles (specifically, about 2-3 deg) than the upper surface angle θ1', the lower surface angle θ2' of the wafer W as a target. In addition, in the case of performing spiral grinding, the groove shape (target shape) of grinding wheel 16 is not always symmetrical in the up and down direction, in which case, the upper surface angle θ1, the lower surface angle θ2 of the end surface of dresser 10 are also adjusted accordingly.

[0024] One embodiment is characterized in that, in a dressing procedure 30-1 Figure 8 in which a series of processes of dressing is performed, the shapes of dresser 10 and grinding wheel 16 measured before processing, and the displacement conditions of dresser 10 and grinding wheel 16 modeled are reflected. For example, the dressing conditions include adjustment conditions of the pressing force of dresser 10 against grinding wheel 16. When dresser 10 is pressed against grinding wheel 16, grinding wheel 16 is displaced, and dresser 10 is also displaced due to the reaction force from grinding wheel 16. Since the processing force is determined by the dressing conditions, it is preferable to make the shape of dresser 10 a chamfer angle that takes into account the displacement of dresser 10 and grinding wheel 16 caused by the processing force from the predetermined dressing conditions.

[0025] Figure 1 (a) shows a structure in which the relationship of the displacement conditions of dresser 10 is modeled, Figure 1(b) shows a structure that models the relationship of the displacement condition of the grinding wheel 16. In (a), the measurement of the displacement condition of the dresser 10 is to provide a laser displacement meter 20 on the lower side of the dresser 10, and to load a known load from the upper side with a tension gauge 40 (may be a force sensor, a weight). Then, the measurement of the displacement δ is performed by the laser displacement meter 20. Thus, the displacement condition (force-displacement relationship) of the dresser 10 is obtained as the axial displacement.

[0026] In Figure 1 (b), the measurement of the displacement condition of the grinding wheel 16 is to provide a laser displacement meter 20 on the side of the grinding wheel 16, and to press the dresser 10 against the groove of the grinding wheel 16 with a known force, to measure the bending stiffness of the grinding wheel 16, and to obtain the displacement of the grinding wheel 16 caused by bending and twisting.

[0027] Thus, the displacement condition (force-displacement relationship) of the grinding wheel 16 is obtained as the displacement of the grinding wheel 16 caused by bending and twisting. The deviation of the quality of the dresser 10 and the grinding wheel 16 is reflected as other displacement conditions. Further, the grinding wheel 16 is mounted on the grinding wheel spindle 17 via the sleeve 18 and rotated.

[0028] Figure 4 is an explanatory diagram of factors related to the machining accuracy at the time of dressing. As Figure 4 indicated, the machining accuracy related factors are bending, twisting, vibration, the surface shape of the dresser 10, the state of abrasive grains, the force fl applied at the time of shape transfer, the deformation of the dresser 10, and the machining heat and the coefficient of thermal expansion (CTE), the alignment of the dresser 10 and the grinding wheel 16, and the like as indicated by the arrows of the grinding wheel 16.

[0029] Figure 5 is an explanatory diagram showing the deformation of the dresser caused by the machining force at the time of dressing of the grinding wheel 16 and the measurement thereof. Figure 5 (a) shows the stress (machining force) applied to the dresser 10 at the time of dressing of the upper surface of the grinding wheel 16 and the displacement direction of the grinding wheel 16 accompanied thereby, Figure 5 (b) shows the stress (machining force) applied to the dresser 10 at the time of dressing of the lower surface of the grinding wheel 16 and the displacement direction of the grinding wheel accompanied thereby. At the time of dressing of the upper surface of the groove, the dresser 10 is pressed against the upper surface of the grinding wheel 16, and the stress is applied to the dresser 10 in the direction of the arrow as the reaction force thereof. The dresser 10 deforms (displaces) in the direction of the arrow according to the material or the like thereof (stiffness). On the other hand, as Figure 5(a) shown, the axis of the grinding wheel 16 is tilted from the dotted line toward the direction of the dashed line, or displaced toward the horizontal direction (X). Furthermore, the drawing is schematic and exaggerated for explanation, and the actual displacement is sometimes smaller than that shown in the drawing.

[0030] The same is true when the lower surface of the groove is finished. As shown by the arrow, stress is applied to the dresser 10 to deform (displace) it. On the other hand, the axis of the grinding wheel 16 is tilted from the dotted line toward the direction of the dashed line, or displaced toward the horizontal direction (X) because the dresser 10 is pressed. Figure 5 (b) shown, the axis of the grinding wheel 16 is tilted from the dotted line toward the direction of the dashed line, or displaced toward the horizontal direction (X). The eddy current sensor 21 provided below the grinding wheel 16 measures the displacement of the grinding wheel 16 caused by the machining force in finishing either of the upper surface and the lower surface. Furthermore, as shown in Figure 1 The relationship between the machining force and the deformation (displacement) of the dresser 10 and the grinding wheel 16 is obtained in advance as a displacement condition.

[0031] To improve the machining accuracy, it is necessary to construct a machining control model that analyzes the influence of deformation caused by force, heat, and the like on the machining accuracy, specify factors that strongly affect the performance, and perform machine learning for automation. In particular, the alignment of the dresser 10 and the grinding wheel 16 becomes the basis for these. When the device is operated for finishing and grinding, grinding dust is generated, and coolant and the like are constantly supplied to the grinding site, so a firm measurement structure becomes important.

[0032] Figure 6 is an explanatory view of the alignment of the dresser 10 and the grinding wheel 16, Figure 7 is a structural view of the alignment portion. The laser displacement meter 20 measures the two-dimensional cross-sectional shape of the dresser 10 and the grinding wheel 16. By measuring with the laser displacement meter 20, the end surface central portion T of the dresser 10 and the groove bottom central position M of the grinding wheel 16 are derived from the two-dimensional cross-sectional shape. The relative positional relationship of the dresser 10 and the grinding wheel 16 is set to a reference position so that they coincide. The alignment is performed by moving the positions of the dresser 10 and the grinding wheel 16 in a manner that matches the reference position.

[0033] As shown in Figure 7 The alignment of the dresser 10 and the grinding wheel 16 is performed by embedding the first electrically conductive body 23-1 (or the magnetically permeable body) in the grinding wheel 16 and the second electrically conductive body 23-2 (or the magnetically permeable body) in the chuck table 24 that fixes the dresser 10, and detecting the positions with the eddy current sensors 21-1, 21-2.

[0034] In Figure 7In this configuration, the dresser 10 is fixed to the chuck table 24. A second conductor 23-2 (or a magnetic material) is embedded in the chuck table 24. A first conductor 23-1 (or a magnetic material) is embedded in the center of the groove bottom of the grinding wheel 16. The moving stage 22 has a length measuring function and is equipped with eddy current sensors 21-1 and 21-2.

[0035] Eddy current sensor 21-1 is movably mounted on the moving stage 22 in the Z direction at a position opposite to the first conductor 23-1 (or magnetic body), determining the position of the center of the groove bottom of the grinding wheel 16 as Z1. Eddy current sensor 21-2 is movably mounted on the moving stage 22 in the Z direction at a position opposite to the second conductor 23-2 (or magnetic body), determining the position of the center T of the end face of the dresser 10 as Z2. The alignment of the center T of the end face of the dresser 10 and the center position M of the groove bottom of the grinding wheel 16 is such that the dresser 10 is moved in such a way that the difference between Z1 and Z2 is a predetermined value, thus aligning with the set reference position.

[0036] exist Figure 2 In the system structure, as processing conditions, the control unit 30 controls the cutting depth, rotational speed, and position of the dresser 10 based on the evaluations of the displacement evaluation unit 31, the vibration measurement unit 32, and the processing heat evaluation unit 33. The displacement evaluation unit 31 evaluates the deformation (displacement) of the dresser 10 and the grinding wheel 16 during processing based on the measurements in the force-displacement measurement unit 36.

[0037] Displacement evaluation unit 31 according to Figure 1 (b) Models the displacement conditions of the dresser 10 and grinding wheel 16 caused by the known load, measure the deformation (displacement from no load) of the dresser 10 and grinding wheel 16 during machining, and perform calibration (numericalization based on a reference). The vibration measurement unit 32 measures the vibration of the dresser 10 and grinding wheel 16 during machining.

[0038] Vibration measuring unit 32 can also be connected with Figure 6 The laser displacement gauge 20 and eddy current sensor 21 shown are shared. That is, vibration can also be estimated based on these measurements. The machining heat evaluation unit 33 evaluates the machining heat of the dresser 10 and the grinding wheel 16 by using the measured values ​​of temperature and heat flow from the thermocouples or heat flow meters constituting the temperature and heat flow meter measurement unit 34.

[0039] The shape measuring unit 35 is composed of a laser displacement meter 20, etc., and measures at least the two-dimensional cross-sectional shape of the dresser 10 and the grinding wheel 16. The grinding wheel 16 is mounted on the grinding wheel spindle 17. The dresser 10 is fixed on the chuck table 24 mounted on the dresser moving table 25, and the rotary axis, X, Y and Z axes are variable.

[0040] The processing condition database 37-1 stores the results of monitoring the displacement, vibration, and processing heat of the dresser 10 and the grinding wheel 16 in association with the measurement results of the shape measuring section 35 after dressing. The stored results are constructed as a processing learning model 37-2. Further, the control section 30 controls the grinding heat of the cooling water system.

[0041] Figure 8 is a flowchart of the dressing method. The flow also includes an optimization step of the shape of the dresser 10. First, as step S35, the shapes of the dresser and the grinding wheel before processing are measured. As shown in Figure 1 (a), the target shape of the dresser 10 is set to Figure 3 the chamfer angle of the upper surface angle θ1 and the lower surface angle θ2 of the end surface, and the like.

[0042] Next, the target shape of the grinding wheel 16 is decided and data is created. (Step S1) In the dressing program 30-1, the two-dimensional cross-sectional shapes of the dresser 10 and the grinding wheel 16 measured before processing in step S35, the displacement conditions (bending, twisting, and the like of the grinding wheel 16) of the dresser 10 and the grinding wheel 16 modeled as step S31, and the above target shape are reflected. (Step S2)

[0043] Next, dressing is performed as step S3. The dressing is performed in accordance with the dressing program 30-1. In the dressing, the grinding wheel 16 is processed into the target shape by the dresser 10. Further, as shown in Figure 6 step S3 is performed by measuring with the laser displacement meter 20, and a position where the end surface central portion T of the dresser 10 and the groove bottom central position M of the grinding wheel 16 coincide is set as a reference position.

[0044] In the dressing, monitoring of the processing conditions is performed by the displacement evaluation section 31, the vibration measurement section 32, the processing heat evaluation section 33, the temperature and heat flow measurement section 34, and the like. (Step S4) In addition, after the dressing, the shapes of the dresser 10 and the grinding wheel 16 are measured with the laser displacement meter 20 of the shape measuring section 35 (step S5), and a good or bad determination is made. In the case where they are within the allowable range compared to the target shapes of the dresser 10 and the grinding wheel 16, respectively, the wafer W is ground with the grinding wheel 16, and a good or bad determination of the edge design value (target value) is made. (Step S6)

[0045] In a case where the dressing dresser 10 and the grinding wheel 16 are not within the allowable range of the target shape and the wafer W ground by the grinding wheel 16 after the shape transfer is not within the allowable range of the design value (target value) of the edge, the process returns to the step S35, the step S1. The processing conditions and the two-dimensional cross-sectional shape after processing are associated as the processing condition database 37-1 and are database-ized, and the processing learning model 37-2 is constructed. (Step S37)

[0046] In addition, the processing condition database 37-1 is database-ized in association with the results of the monitoring by the displacement evaluation section 31, the vibration measurement section 32, the processing heat evaluation section 33, the temperature, the heat flow measurement section 34, and the like as the processing conditions in the dressing. The processing learning model 37-2 is constructed from the database-ized processing condition database 37-1. In the step S3, the dressing program 30-1 refers to the processing learning model 37-2.

[0047] The good or bad determination in the step S5 and the step S6 can also use the results stored in advance in the processing condition database 37-1. In addition, the good or bad determination of the ground grinding wheel 16 after processing in the step S5 preferably uses the results stored in the processing condition database 37-1.

[0048] The processing learning model 37-2 is a machine learning model that outputs the results of the evaluation and determination of the data stored in the processing condition database 37-1. The dressing program 30-1 inputs a query to the processing learning model 37-2 as needed and obtains the results of the evaluation and determination.

[0049] In the above, in one embodiment, the monitoring is performed by the displacement evaluation section 31, the vibration measurement section 32, the processing heat evaluation section 33, the temperature, the heat flow measurement section 34, and the like in the dressing. Moreover, since the processing condition database 37-1 and the processing learning model 37-2 are used and implemented by the dressing program 30-1, it is possible to highly accurately and highly qualitatively form the groove shape and to suppress the deviation of the shape.

[0050] Figure 3 The description of the dressing dresser 10 is described as the shape transfer, but in order to achieve higher accuracy, the upper portion or the lower portion of the groove formed in the grinding wheel 16 can be processed by the dressing dresser 10, and then, one side is cut in a manner that the dressing dresser 10 is relatively lowered or raised in the thickness direction with respect to the grinding wheel 16.

[0051] In addition, in the dressing, monitoring is performed by the displacement evaluation section 31, the vibration measurement section 32, the processing heat evaluation section 33, the temperature and heat flow measurement section 34, and the like. Furthermore, the processing condition database 37-1 and the processing learning model 37-2 are constructed and utilized in order that the wafer W can be applicable to a wafer W of any material using a difficult-to-machine material 4H-SiC, other polytypes (3C-SiC, 6H-SiC, 15R-SiC, and the like), GaN (gallium nitride), gallium oxide, AlGaN. Moreover, one embodiment is preferred in which high quality can be achieved even if the wafer W is a difficult-to-machine material, particularly for a post-process or the like (high-precision shape formation, uniform surface state (waviness, roughness). Explanation of Reference Signs

[0052] 10: dresser 16: grinding wheel 17: grinding wheel spindle 18: sleeve 20: laser displacement meter 21: eddy current sensor 22: moving table 23-1: first electrically conductive body 23-2: second electrically conductive body 24: chuck table 25: dresser moving table 30: control section 30-1: dressing program 31: displacement evaluation section 32: vibration measurement section 33: processing heat evaluation section 34: temperature and heat flow measurement section 35: shape measurement section 36: displacement measurement section 37-1: processing condition database 37-2: processing learning model 40: tension meter W: wafer CLAIM (MODIFIED IN ACCORDANCE WITH ARTICLE 19 OF THE TREATY) 1. A dressing method of a grinding wheel used in a chamfering device for a wafer, characterized by: deciding a target shape of the grinding wheel, The amount of cutting, the rotational speed, and the position of the dresser with respect to the grinding wheel are controlled and dressed based on at least the shape of the dresser and the grinding wheel measured before processing, and a displacement condition representing a relationship of a force and a displacement of the dresser and the grinding wheel in at least one of an axial direction and a horizontal direction applied to a load measurement to make the grinding wheel into the target shape. 2. The dressing method of the grinding wheel according to claim 1, wherein In the dressing, displacement, vibration, and processing heat of the dresser and the grinding wheel are monitored. 3. The dressing method of the grinding wheel according to claim 1 or 2, wherein the displacement condition of the dresser is an axial displacement. 4. The dressing method of the grinding wheel according to claim 3, wherein The displacement condition of the grinding wheel is a displacement caused by bending and twisting. 5. The dressing method of the grinding wheel according to claim 1 or 2, wherein After the dressing, the shapes of the dresser and the grinding wheel are measured, and in a case where the shapes are within an allowable range compared to the target shapes of the dresser and the grinding wheel, respectively, the wafer is ground with the grinding wheel and a good or bad judgment is made. 6. The dressing method of the grinding wheel according to claim 2, wherein The results of the monitoring and the shapes of the dresser and the grinding wheel measured after the dressing are stored in association with each other as a processing condition database, and a processing learning model is constructed from the processing condition database. 7. A dressing device of a grinding wheel used for a chamfering device of a wafer, comprising: A dresser moving stage that fixes a dresser so that a rotational axis, X, Y, and Z axes are variable; A shape measurement section that measures shapes of the dresser and the grinding wheel; A displacement evaluation section that measures displacements of the dresser and the grinding wheel; A vibration measurement section that measures vibrations of the dresser and the grinding wheel; A processing heat evaluation section that measures temperature and heat flow; A control section that controls an amount of cutting, a rotational speed, and a position of the dresser based on measurement results of the displacement evaluation section, the vibration measurement section, and the processing heat evaluation section; A processing condition database that stores the measurement results and the shapes of the dresser and the grinding wheel measured after the dressing in association with each other; and A processing learning model constructed from the processing condition database. The control section controls the amount of cutting, the rotational speed, and the position of the dresser with respect to the grinding wheel using the processing condition database and the processing learning model to make the grinding wheel into a target shape. 8. The dresser for grinding wheel according to claim 7, characterized in that: The control section trims the grinding wheel into a target shape based on at least the shapes of the dresser and the grinding wheel measured by the shape measuring section before processing, the displacement of the dresser in the axial direction, and the displacement of the grinding wheel caused by bending and twisting.

Claims

1. A dressing method of a grinding wheel for a chamfering device for a wafer, characterized by: determining a target shape of the grinding wheel, and dressing the grinding wheel to the target shape based on at least a shape of a dresser and the grinding wheel measured before processing, and a displacement condition representing a relationship of an applied force and a displacement of the dresser and the grinding wheel.

2. The dressing method of a grinding wheel according to claim 1, characterized by: monitoring a displacement, a vibration, and a processing heat of the dresser and the grinding wheel in the dressing.

3. The dressing method of a grinding wheel according to claim 1 or 2, characterized by: the displacement condition of the dresser is an axial displacement.

4. The dressing method of a grinding wheel according to claim 3, characterized by: the displacement condition of the grinding wheel is a displacement caused by bending and twisting.

5. The dressing method of a grinding wheel according to claim 1 or 2, characterized by: after the dressing, measuring a shape of the dresser and the grinding wheel, and in a case where the measured shape of the dresser and the grinding wheel is within an allowable range compared to the target shape of each of the dresser and the grinding wheel, grinding the wafer with the grinding wheel and determining whether or not the wafer is good or not.

3. The dressing method of a grinding wheel according to claim 1 or 2, characterized in that:

6. The dressing method of a grinding wheel according to claim 2, characterized by: storing a result of the monitoring in association with the measured shape of the dresser and the grinding wheel after the dressing as a processing condition database, and constructing a processing learning model from the processing condition database.

7. A dressing device of a grinding wheel for a chamfering device for a wafer, characterized by: a dresser moving stage that fixes a dresser so that a rotation axis, X, Y, and Z axes are variable; a shape measuring section that measures a shape of the dresser and the grinding wheel; a displacement evaluating section that measures a displacement of the dresser and the grinding wheel; a vibration measuring section that measures a vibration of the dresser and the grinding wheel; a processing heat evaluating section that measures a temperature and a heat flow; a control section that controls an amount of cutting in, a rotation speed, and a position of the dresser based on a measurement result of the displacement evaluating section, the vibration measuring section, and the processing heat evaluating section; a processing condition database that stores the measurement result and the measured shape of the dresser and the grinding wheel after the dressing in association with each other; and a processing learning model that is constructed from the processing condition database.

8. The dressing device of a grinding wheel according to claim 7, characterized by: the control section dresses the grinding wheel to a target shape based on at least a shape of the dresser and the grinding wheel measured by the shape measuring section before processing, an axial displacement of the dresser, and a displacement caused by bending and twisting of the grinding wheel. ​ ​ ​ ​ 7. A dressing device for a grinding wheel used in a chamfering device for a wafer, characterized by ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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