Shaping and finishing device and method for grinding wheel

Abstract

The present invention provides a method for shaping a grinding wheel (16), which is used in a wafer (W) chamfering device for rough machining, performs shaping at a high speed by using a rough grinding dresser (10-1) so that the grinding wheel (16) becomes a rough-grinding target shape, leaving a machining allowance for shaping, and when the grinding wheel (16) reaches a permissible range of the rough-grinding target shape, performs shaping at a high speed by using the rough grinding dresser (10-1). The present invention relates to a method for shaping and dressing a grinding wheel having a complex groove shape, in which the grinding wheel is shaped and dressed into a target shape for fine grinding using a fine grinding dresser (10-2) having a larger grinding wheel particle size number than a coarse grinding dresser (10-1) as a fine grinding, whereby not only the molding of the grinding wheel having a complex groove shape can be performed with high precision and high quality, but also the time required for shaping and dressing a difficult-to-machine material can be shortened.

Description

Technical Field

[0001] The present disclosure relates to a device and method for shaping and dressing a grinding wheel with a groove shape used in a semiconductor wafer end surface chamfering device. Background Art

[0002] In recent years, semiconductor wafers and other products have been produced in high-mix, low-volume batches. Grooved grinding wheels used for wafer chamfering are facing increasing demands for not only high precision and shape changeability, but also high speed, in order to achieve high-mix, low-volume production, improve wafer quality, and increase yield.

[0003] Furthermore, semiconductors made from ultra-wide band gap (UWBG) materials, such as silicon carbide (SiC), a compound of carbon (C) and silicon (Si), which have large, strong bonds between atoms in the crystal, and high-hardness materials such as gallium nitride (GaN), gallium oxide, aluminum gallium nitride (AlGaN), and diamond, are poised for practical application as semiconductor materials that are smaller, consume less power, and offer higher efficiency than silicon semiconductors, including power devices and high-frequency devices, as well as excellent radiation resistance. However, UWBG materials such as 4H-SiC are difficult to machine, placing higher demands on the precision and quality of the groove shape in grinding wheels.

[0004] The chamfering process in the semiconductor wafer manufacturing process requires repeated shaping (grinding) of the grinding wheel with a dresser (fine grinding), fine grinding of the wafer, and measurement of the edge shape of the ground wafer until the desired shape is achieved. Therefore, high-speed and high-precision shaping of the grinding wheel is crucial.

[0005] Furthermore, to prevent the formation of grinding marks in the circumferential direction, the finishing of the chamfered edges of semiconductor wafers is known to require so-called spiral grinding, in which the grinding wheel is tilted relative to the wafer to grind the chamfered portion. However, spiral grinding requires fine-tuning to achieve the desired shape of the grinding wheel through shaping (the finished surface of the grinding wheel after shaping becomes three-dimensionally asymmetrical with respect to the wheel's rotation axis), which is time-consuming and requires skilled personnel.

[0006] Patent Document 1 describes that in the process of shaping and dressing for spiral grinding using a dresser to form grooves, in order to improve the transfer rate and workability and to utilize the accuracy of the grooves formed by the dresser, the dresser is used to process the upper or lower portion of the grooves formed in the grinding wheel, and then the dresser is repeatedly lowered and raised relative to the grinding wheel in the thickness direction.

[0007] Another known method is shaping and trimming using lasers. Patent Document 2 describes shaping and trimming using lasers, noting that ultrashort pulse lasers, such as femtosecond lasers, are used because they have minimal thermal impact on the tool being formed and provide high processing accuracy. Shaping and trimming are performed within a specified range, both before and after the laser's focal point and in the direction of travel. Prior art literature Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2022-325 Patent Document 2: Japanese Patent Application Laid-Open No. 2015-98041 Summary of the Invention Problems to be solved by the invention

[0009] In the prior art described in Patent Document 1, the dressing of the grinding wheel for chamfering requires specialized personnel, skilled in the movement of the dresser, to adjust the dresser, and repeated processing is time-consuming. Furthermore, for difficult-to-machine materials such as SiC, machining is time-consuming, resulting in difficulty in achieving the desired shape, and the grinding wheel consumption is high, making it difficult to fully reduce grinding costs.

[0010] Furthermore, the method described in Patent Document 2 has difficulty in expanding the irradiation range, and the portion that can be shaped and dressed at one time is small, making it unsuitable for the entire grinding wheel. Furthermore, it does not consider the possibility of achieving high precision in the overall shape of a grinding wheel having a groove shape.

[0011] The object of the present invention is to provide an efficient grinding wheel shaping and dressing method and device, which can solve the problems of the above-mentioned prior art, not only can complete the shaping of grinding wheels with complex groove shapes with high precision and high quality, but also can shorten the time required for shaping and dressing difficult-to-process materials. Solutions for solving problems

[0012] In order to achieve the above-mentioned object, the structure of the present invention is as follows. [1] A shaping and dressing device for a grinding wheel, which is used for a chamfering device for a wafer, comprises: a dresser including a coarse grinding dresser and a fine grinding dresser arranged coaxially with the rotation axis of the coarse grinding dresser and having finer particles than the coarse grinding dresser; a first sensor for detecting a first position corresponding to at least one of the coarse grinding dresser and the fine grinding dresser in the Z direction along the rotation axis; a second sensor for detecting a second position of the grinding wheel in the Z direction; and a control unit for adjusting the positions of the dresser and the grinding wheel in the Z direction according to the first position and the second position. [2] The grinding wheel dressing device according to [1] is characterized in that, regarding the dresser, the rough grinding dresser and the fine grinding dresser are connected in the Z direction. [3] The grinding wheel dressing device according to [2] is characterized in that it includes a chuck table for fixing the dresser, and the first sensor detects the first position of the chuck table. [4] Based on the grinding wheel shaping and dressing device described in [3], it is characterized in that the above-mentioned chuck worktable has a first conductor or a first magnetic body, the above-mentioned grinding wheel has a second conductor or a second magnetic body, and the above-mentioned first sensor and the above-mentioned second sensor are eddy current sensors. [5] Based on the shaping and dressing device for the grinding wheel described in [4], it is characterized in that the center portion of the dresser in the Z direction is aligned with the center position of the grinding wheel by moving the dresser in such a manner that the difference between the first position and the second position becomes a specific value. [6] Based on the grinding wheel shaping and dressing device described in [5], it is characterized in that the first face angle of the end face of the above-mentioned rough grinding dresser is smaller than the second face angle of the end face of the above-mentioned fine grinding dresser. [7] Based on the grinding wheel shaping and dressing device described in [2], it is characterized by comprising: a shape measuring unit that measures the two-dimensional cross-sectional shape of the above-mentioned rough grinding dresser and the above-mentioned fine grinding dresser and the above-mentioned grinding wheel; a displacement evaluation unit that measures the deformation of the above-mentioned rough grinding dresser or the above-mentioned fine grinding dresser and the above-mentioned grinding wheel; a vibration measuring unit that measures the vibration of the above-mentioned rough grinding dresser or the above-mentioned fine grinding dresser and the above-mentioned grinding wheel; and a processing heat evaluation unit that measures temperature and heat flow, and the above-mentioned control unit controls the cutting amount, rotation speed and position relative to the above-mentioned rough grinding dresser and the above-mentioned fine grinding dresser as processing conditions based on the evaluation of the above-mentioned displacement evaluation unit, the above-mentioned vibration measuring unit and the above-mentioned processing heat evaluation unit. [8] Based on the grinding wheel shaping and dressing device described in [7], it is characterized by comprising: a processing condition database, which is associated with the above-mentioned processing conditions and the measurement results of the above-mentioned shape measuring part after processing; and a processing learning model, which is constructed based on the above-mentioned processing condition database. [9] A method for shaping and dressing a grinding wheel, used in a chamfering device for a wafer, characterized in that, as rough processing, a rough grinding dresser is used to shape and dress the grinding wheel into a rough grinding target shape, and when the grinding wheel reaches an allowable range of the rough grinding target shape, as fine processing, a fine grinding dresser having a grinding wheel grit number larger than that of the rough grinding dresser is used to shape and dress the grinding wheel into a fine grinding target shape.

[10] Based on the shaping and dressing method of the grinding wheel described in [9], it is characterized in that the target shape of the grinding wheel is determined, and the shaping and dressing is performed according to a shaping and dressing program that reflects the two-dimensional cross-sectional shape and displacement conditions of the rough grinding dresser or the fine grinding dresser and the grinding wheel measured before processing. During the shaping and dressing process, monitoring is performed using a displacement evaluation unit that measures the deformation of the rough grinding dresser or the fine grinding dresser and the grinding wheel, a vibration measurement unit that measures the vibration of the rough grinding dresser or the fine grinding dresser and the grinding wheel, and a processing heat evaluation unit that measures the temperature and heat flow. The processing conditions are associated with the measurement results of the two-dimensional cross-sectional shape of the rough grinding dresser or the fine grinding dresser and the grinding wheel after processing measured by the shape measurement unit, and the database is converted into a processing condition database, and a processing learning model is constructed from the processing condition database. Effects of the Invention

[0013] According to the present invention, as rough processing, a coarse grinding dresser is used to leave a processing allowance and perform shaping and dressing at high speed; when the grinding wheel reaches the allowable range of the rough grinding target shape, as precision processing, a fine grinding dresser with a grinding wheel grit number larger than that of the coarse grinding dresser is used to perform shaping and dressing. Therefore, not only can the grinding wheel with a complex groove shape be formed with high precision and high quality, but the time required for shaping and dressing of difficult-to-process materials can also be shortened. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a partial cross-sectional view showing a dresser according to one embodiment of the present invention. Figure 2 It is a diagram showing the steps of chamfering a wafer. Figure 3 This diagram explains the factors affecting machining accuracy during shaping and trimming. Figure 4 This is an explanatory diagram of the alignment between the dresser and the grinding wheel according to one embodiment. Figure 5 This is a structural diagram of a positioning unit according to one embodiment. Figure 6 This is a block diagram showing the overall system configuration of a shaving and trimming device according to one embodiment. Figure 7 This is a flowchart of a shaping and trimming method according to one embodiment. DETAILED DESCRIPTION

[0015] Figure 1 is a partial cross-sectional view showing a dresser 10 according to one embodiment of the present invention; Figure 2The diagram shows the steps of chamfering the wafer end face using the chamfering device. The chamfering is performed by transferring or processing the shape of the grinding wheel 16 using the dresser 10 (shape dressing), and then grinding the shape of the wafer W using the grinding wheel 16. Figure 2 In the figure, the grinding wheel 16 is mounted on the grinding wheel spindle 17 via a quill 18 and rotates. Because spiral grinding is used, the shape of the dresser 10 is transferred at an upper surface angle θ1 and a lower surface angle θ2 at the end surface, and the shape of the wafer W is transferred at an upper surface angle θ1' and a lower surface angle θ2' at the end surface. For example, the upper surface angle θ1 of the dresser 10 corresponds to the angle of the upper bevel of the end of the dresser 10; the lower surface angle θ2 of the dresser 10 corresponds to the angle of the lower bevel of the end of the dresser 10. For example, the upper surface angle θ1' of the wafer W corresponds to the angle of the upper bevel of the end of the wafer W; the lower surface angle θ2' of the wafer W corresponds to the angle of the lower bevel of the end of the wafer W. The upper surface angle and / or lower surface angle are sometimes simply referred to as the face angle.

[0016] The dresser 10 includes a rough grinding dresser 10-1 for rough machining and a fine grinding dresser 10-2 for fine machining. The dresser 10 may also be configured to be able to replace the rough grinding dresser 10-1 and the fine grinding dresser 10-2. Figure 1 As shown in (a), the cross-sectional shape of the roughing dresser 10-1 and the cross-sectional shape of the fine grinding dresser 10-2 are substantially the same. It should be noted that the cross-sectional shape of the roughing dresser 10-1 and the cross-sectional shape of the fine grinding dresser 10-2 may be the same or different. The coarse grinding dresser 10 - 1 can be configured to be coaxial with the fine grinding dresser 10 - 2 . It should be noted that the axes of the fine grinding dresser 10 - 1 and the fine grinding dresser 10 - 2 can also be slightly offset. For example, Figure 1 As shown in (a) of FIG. 1 , the dresser 10 is formed of a coarse dresser 10-1 and a fine dresser 10-2 in two layers. The coarse dresser 10-1 and the fine dresser 10-2 may be directly bonded or connected via a member such as metal or resin. Figure 1 In the example shown in (a), the fine dresser 10-2 is provided (or bonded) above the rough dresser 10-1. It should be noted that the fine dresser 10-2 may also be provided (or bonded) below the rough dresser 10-1. Furthermore, the roughing dresser 10-1 performs the roughing process by removing the rough grinding target shape at high speed, leaving a machining allowance of 10% to 20% relative to the final target shape (finishing target shape) of the grinding wheel 16. In other words, the rough grinding target shape is 80% to 90% of the fine grinding target shape. Furthermore, the roughing dresser 10-1 performs the roughing process at a higher speed than the fine grinding dresser 10-2, leaving a machining allowance for the final shape produced by the fine grinding dresser 10-2. This improves grinding efficiency.

[0017] After the rough grinding dresser 10-1 is used for shaping and trimming, the fine grinding dresser 10-2 is used for shaping and trimming. The fine grinding dresser 10-2 is used for shaping and trimming as a precision machining, and the portion left after the rough grinding is machined with high precision. Therefore, the face angle of the rough grinding dresser 10-1 is as follows: Figure 1 The face angle θ shown in (b) is smaller than the design value of the wafer W by 1 to 3 degrees.

[0018] Furthermore, the face angle of the roughing dresser 10-1 is preferably smaller than that of the fine dresser 10-2. However, the shapes of the roughing dresser 10-1 and the fine dresser 10-2 can be identical and adjusted according to processing conditions. The grinding wheel of the fine dresser 10-2 has a larger grit size (grinding wheel size) than that of the roughing dresser 10-1, and the abrasive grain size is smaller. In other words, the grains of the fine dresser 10-2 are finer than those of the roughing dresser 10-1.

[0019] like Figure 1 As shown, the shaping and trimming is performed using the rough grinding dresser 10-1 and the fine grinding dresser 10-2. The time required for shaping and trimming can be shortened by using a machining program such as a machining condition database obtained by rough machining that is substantially close to the target shape and accumulating machining history. It should be noted that the rough grinding dresser 10-1 and the fine grinding dresser 10-2 can be as shown. Figure 1 Although the two layers are shown as a single unit, they can also be separated and replaced separately. Even when they are separated and replaced according to the application, the alignment of this embodiment described later can be applied, thereby enabling the coarse dresser 10-1 and the fine dresser 10-2 to be replaced faster than alignment by visual alignment or the like.

[0020] Figure 3 This diagram illustrates the factors related to machining accuracy during trimming. Trimming is ideally automated to improve precision and quality. Conventional trimming relies on visual alignment and the intuitive judgment of professionals to determine machining conditions. Furthermore, trimming operations, particularly for spiral grinding, are time-consuming, sometimes taking more than half a day to set the various conditions.

[0021] Factors affecting machining accuracy include the bending, torsion, vibration, and oscillation of the grinding wheel 16, the surface shape of the dresser 10, the state of the abrasive grains, the force f1 applied during shape transfer and deformation of the dresser 10, processing heat and the coefficient of thermal expansion (CTE), and the alignment of the dresser 10 and the grinding wheel 16. Therefore, to improve machining accuracy, it is necessary to analyze the impact of deformation caused by forces and heat on machining accuracy, construct a machining control model, identify factors that strongly influence performance, and implement machine learning for automation. In particular, sensing the position of the dresser 10 and the grinding wheel 16 in the grinding environment and aligning them based on the measurement results is crucial.

[0022] Figure 4 This figure illustrates the alignment of the dresser 10 and the grinding wheel 16. A laser displacement meter 20 measures the two-dimensional cross-sectional shapes of the dresser 10 and the grinding wheel 16. The position where the center portion T of the dresser 10's end surface aligns with the center position M of the groove bottom of the grinding wheel 16 is set as the reference position by the laser displacement meter 20. Alignment is then performed by moving the center portion T of the dresser 10's end surface to the center position M of the groove bottom of the grinding wheel 16.

[0023] Alignment is achieved by embedding a first conductive body (or magnetic body) 23-1 in the grinding wheel 16 and a second conductive body (or magnetic body) 23-2 in the chuck table 24 that secures the dresser 10. Position detection is performed using eddy current sensors 21-1 and 21-2. It should be noted that the eddy current sensor 21 also measures the displacement of the grinding wheel caused by machining forces during machining, allowing the relationship between the grinding force and deformation of the dresser 10 and grinding wheel 16 to be determined in advance.

[0024] Figure 5 This diagram shows the structure of the alignment unit. The dresser 10 is fixed to the chuck table 24. The second conductor (or magnetic body) 23-2 is embedded in the chuck table 24. The first conductor (or magnetic body) 23-1 is embedded in the center of the groove bottom of the grinding wheel 16. The movable stage 22 has a length measurement function and is equipped with eddy current sensors 21-1 and 21-2.

[0025] The eddy current sensor 21-1 is mounted so that it can move in the Z direction toward a position opposite the first conductive body (or magnetic body) 23-1. The position of the center portion of the groove bottom of the grinding wheel 16 is determined as Z1. The eddy current sensor 21-2 is mounted so that it can move in the Z direction toward a position opposite the second conductive body (or magnetic body) 23-2. The position of the center portion T of the end face of the dresser 10 is determined as Z2. The alignment of the center portion T of the end face of the dresser 10 with the center position M of the groove bottom of the grinding wheel 16 is achieved by moving the dresser 10 so that the difference between Z1 and Z2 reaches a predetermined value, thereby aligning the two ends at the predetermined reference position. It should be noted that, in the embodiment, the sensors for respectively detecting the positions of the dresser 10 (or the chuck table 14) and the grinding wheel 16 are the eddy current sensor 21-1 and the eddy current sensor 21-2, but as long as the positions of the dresser 10 (or the chuck table 14) and the grinding wheel 16 can be detected respectively, sensors other than the eddy current sensors 21-1 and 21-2 may also be used.

[0026] Figure 6 This is a block diagram showing the overall system configuration of a truing device for a grinding wheel 16. The control unit 30 controls (or adjusts) machining conditions such as the amount of cut, rotational speed, and position of the dresser 10 based on evaluations performed by the displacement evaluation unit 31, the vibration measurement unit 32, and the machining heat evaluation unit 33. The displacement evaluation unit 31 evaluates the deformation (displacement) of the dresser 10 and the grinding wheel 16 during machining based on the values ​​measured by the force and displacement measurement unit 36.

[0027] For example, the displacement evaluation unit 31 applies a known force to the dresser 10, measures the displacement of the dresser 10 at that time, and pre-models it. It then measures the deformation of the dresser 10 and grinding wheel 16 during machining (relative to the displacement under no load) and classifies it (quantified based on a benchmark). The vibration measurement unit 32 measures the vibration of the dresser 10 and grinding wheel 16 during machining.

[0028] The vibration measuring unit 32 can be connected to Figure 4 The laser displacement meter 20 and eddy current sensor 21 are shared. The machining heat evaluation unit 33 uses thermocouples and heat flow meters constituting the temperature and heat flow measurement unit 34 to evaluate machining heat of the dresser 10 and the grinding wheel 16 using the measured values ​​of temperature and heat flow.

[0029] The shape measuring unit 35 is composed of a laser displacement meter 20 and other components, 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 to the chuck table 24 mounted on the dresser moving table 25 and can rotate about the rotation axis and can be adjusted to multiple directions along the X, Y, and Z axes. The processing condition database 37-1 monitors the processing conditions and stores them in association with the measurement results after processing by the shape measuring unit 35. The stored results are constructed into a processing learning model 37-2. It should be noted that the control unit 30 also uses the cooling water system to control grinding heat.

[0030] Figure 7 This is a flow chart of the truing method: First, the target shape of the grinding wheel 16 is determined and the target shape is converted into data (step S1). In step S1, the two-dimensional cross-sectional shapes of the dresser 10 and the grinding wheel 16 measured before processing in step S35 and the displacement conditions (relationship between grinding force and deformation) of the dresser 10 and the grinding wheel 16 modeled in step S31 are reflected in the shaping and dressing program (step S2) (step S2).

[0031] Next, a series of processes are performed according to the truing procedure. Rough machining is to truing the grinding wheel 16 by the roughing dresser 10-1 so that the grinding wheel 16 has a rough grinding target shape with a machining allowance for subsequent fine machining (step S3). like Figure 4 As shown, step S3 is performed by setting the position where the end surface center T of the rough grinding dresser 10 - 1 and the groove bottom center position M of the grinding wheel 16 are aligned as the reference position through measurement by the laser displacement meter 20 .

[0032] After rough machining, the shape of the dresser 10 and grinding wheel 16 is measured by the laser displacement meter 20 in the shape measurement unit 35. This is compared with the rough grinding target shape to determine whether to proceed to the next step of precision machining. If the shape of the dressed grinding wheel 16 does not fall within the allowable range of the rough grinding target shape, the process returns to the rough machining process in step 3. The shape of the dresser 10 is also measured, and the machining conditions are associated with the two-dimensional cross-sectional shape after machining. This is then stored in a database called a machining condition database 37-1, and a machining learning model 37-2 is constructed, thereby contributing to higher precision.

[0033] When the grinding wheel 16 reaches the permissible range of the rough grinding target shape, the grinding wheel 16 is truing-dressed by the fine grinding dresser 10 - 2 so that the grinding wheel 16 becomes the fine grinding target shape (step S4 ). Step S4 is performed by setting the position where the center portion T of the end surface of the dresser 10-2 is aligned with the center position M of the groove bottom of the grinding wheel 16 as the reference position using the laser displacement meter 20. Furthermore, after precision machining, the shape of the dresser 10-2 and the grinding wheel 16 is measured using the laser displacement meter 20 in the shape measuring unit 35 (step S5), and a quality assessment is performed (step S6).

[0034] If the shaped dresser 10-2 is not within the allowable range of the target grinding shape, the process returns to the precision machining process of step 4. If it is within the allowable range of the target grinding shape, the wafer W is ground with the grinding wheel 16 to which the shape has been transferred, and a quality check is performed with respect to the design value (target value) of the edge.

[0035] The quality determination of the dresser 10 in step 3 and step S4 may also utilize the results previously accumulated in the processing condition database 37-1. In addition, the quality determination of the grinding wheel 16 after rough machining in step 3 preferably utilizes the results accumulated in the processing condition database 37-1.

[0036] During the shaping and trimming process in a series of processes from step 3 to step 6, the displacement evaluation unit 31, the vibration measurement unit 32, the processing heat evaluation unit 33, etc. are used to monitor, thereby establishing a correlation between the processing conditions and the measurement results after processing by the shape measurement unit 35 and compiling them into a database (step S37). The machining learning model 37-2 for high-precision, high-speed machining is constructed from the databased machining condition database 37-1. The shaping and trimming program refers to the machining learning model 37-2.

[0037] Machining learning model 37-2 is a machine learning model that outputs the results of a computer's evaluation and judgment of input data. For example, machining learning model 37-2 can output optimal machining conditions by inputting values ​​monitored by the displacement evaluation unit 31, vibration measurement unit 32, and machining heat evaluation unit 33. The shaping and trimming program queries machining learning model 37-2 as needed to obtain the evaluation and judgment results.

[0038] As described above, in the semiconductor wafer manufacturing process, the above embodiment uses a roughing dresser 10-1 and a fine grinding dresser 10-2 to perform the shaping of the grinding wheel 16 in two steps related to chamfering. This allows for increased processing speed and high-precision groove shapes, even when spiral grinding difficult-to-machine materials. Furthermore, shaping can be shortened by utilizing a roughing process that closely approximates the target shape, a machining condition database 37, and a machining learning model 37-2 to implement an efficient tool path shaping program.

[0039] Figure 2 、3 The description is for explaining the shape transfer of the dresser 10. In order to pursue higher precision, the upper or lower portion of the groove formed on the grinding wheel 16 can be processed using a fine grinding dresser 10-2. Thereafter, the dresser 10 is lowered or raised relative to the grinding wheel 16 in the thickness direction to grind side by side.

[0040] Furthermore, to shape the grinding wheel 16 closer to the target shape, the roughing dresser 10-1 removes the bulk of the material, followed by high-precision shaping with the fine dresser 10-2. This can also be applied to wafers W made of 4H-SiC, a difficult-to-machine material, other polytypes (such as 3C-SiC, 6H-SiC, and 15R-SiC), GaN (gallium nitride), gallium oxide, and AlGaN, all difficult-to-machine materials with a large energy gap. Furthermore, even with difficult-to-machine materials, the machining time of the grinding wheel 16 can be shortened, and quality can be improved. In particular, high-precision shaping and uniform surface conditions (waviness and roughness) can be achieved, which are ideal for subsequent processes. Description of Reference Numerals

[0041] 10: Dresser; 10-1: Rough grinding dresser; 10-2: Fine grinding dresser; 16: Grinding wheel; 17: Grinding wheel spindle; 18: Sleeve shaft; 20: Laser displacement meter; 21: Eddy current sensor; 22: Moving stage; 23-1: First conductor; 23-2: Second conductor; 24: Chuck table; 25: Dresser moving stage; 30: Control unit; 31: Displacement evaluation unit; 32: Vibration measurement unit; 33: Processing heat evaluation unit; 34: Temperature and heat flow measurement unit; 35: Shape measurement unit; 36: Displacement measurement unit; 37-1: Processing condition database; 37-2: Processing learning mode; M: Center position of groove bottom; T: Center of end face; W: Wafer.

Claims

1. A grinding wheel shaping and dressing device, which is used in a wafer chamfering device, wherein: have: A dresser comprising a coarse grinding dresser and a fine grinding dresser coaxially arranged with a rotation axis of the coarse grinding dresser and having finer particles than the coarse grinding dresser; a first sensor that detects a first position corresponding to at least one of the rough dresser and the fine dresser in a Z direction along the rotation axis; a second sensor for detecting a second position of the grinding wheel in the Z direction; as well as A control unit adjusts positions of the dresser and the grinding wheel in the Z direction according to the first position and the second position.

2. The grinding wheel dressing device according to claim 1, wherein: Regarding the dressers, the rough dresser and the fine dresser are connected in the Z direction.

3. The grinding wheel dressing device according to claim 2, wherein: Equipped with a chuck table to fix the dresser, The first sensor detects the first position of the chuck table.

4. The grinding wheel dressing device according to claim 3, wherein: The chuck table has a first conductive body or a first magnetic body, The grinding wheel has a second conductor or a second magnetic body, The first sensor and the second sensor are eddy current sensors.

5. The grinding wheel dressing device according to claim 4, wherein: The dresser is moved so that the difference between the first position and the second position becomes a specific value, thereby aligning the center portion of the dresser in the Z direction with the center position of the grinding wheel.

6. The grinding wheel dressing device according to claim 5, wherein: A first face angle of an end surface of the rough grinding dresser is smaller than a second face angle of an end surface of the fine grinding dresser.

7. The grinding wheel dressing device according to claim 2, wherein: have: a shape measuring unit for measuring a two-dimensional cross-sectional shape of the roughing dresser, the fine grinding dresser, and the grinding wheel; a displacement evaluation unit for measuring deformation of the rough grinding dresser or the fine grinding dresser and the grinding wheel; a vibration measuring unit for measuring vibrations of the rough grinding dresser or the fine grinding dresser and the grinding wheel; and Processing heat evaluation unit, which measures temperature, heat flow, The control unit controls the cutting amount, rotation speed, and position of the roughing dresser and the fine dresser as machining conditions based on the evaluations of the displacement evaluation unit, the vibration measurement unit, and the machining heat evaluation unit.

8. The grinding wheel dressing device according to claim 7, wherein: have: a processing condition database in which the processing conditions and the measurement results of the shape measuring unit after processing are associated with each other; and A processing learning model is constructed based on the processing condition database.

9. A method for shaping and dressing a grinding wheel, used in a wafer chamfering device, wherein: As a roughing process, the grinding wheel is shaped and dressed to the target shape using a rough grinding dresser. When the grinding wheel reaches the allowable range of the rough grinding target shape, finishing is performed by using a fine grinding dresser having a grinding wheel grit number larger than that of the rough grinding dresser to achieve the fine grinding target shape.

10. The grinding wheel dressing method according to claim 9, wherein: determining a target shape of the grinding wheel and performing the shaping and dressing according to a shaping and dressing program that reflects the two-dimensional cross-sectional shape and displacement conditions of the rough grinding dresser or the fine grinding dresser and the grinding wheel measured before machining; During the shaping and dressing process, monitoring is performed using a displacement evaluation unit that measures the deformation of the rough grinding dresser or the fine grinding dresser and the grinding wheel, a vibration measurement unit that measures the vibration of the rough grinding dresser or the fine grinding dresser and the grinding wheel, and a processing heat evaluation unit that measures temperature and heat flow. The machining conditions are associated with the measurement results of the rough grinding dresser or the two-dimensional cross-sectional shape of the fine grinding dresser and the grinding wheel after machining by the shape measuring unit, and the database is compiled into a machining condition database. A processing learning model is constructed based on the processing condition database.

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