JP2000042886A - Wafer chamfering grinding wheel inspecting method and device, and wafer chamfering method using this inspecting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wafer chamfering grinding wheel inspecting method and a device shortening inspection time and improving accuracy by automatically measuring surface run-out, center run-out, a groove position, groove shape and the unbalance quantity by the same measuring apparatus. SOLUTION: This wafer chamfering grinding wheel inspecting device is provided with a first noncontact displacement sensor 15 moving in a parallel direction to a spindle axis while facing, in a contactless state, the peripheral surface of a grinding wheel 1 fixed to a spindle by a positioning means; a second noncontact displacement sensor disposed to face the grinding wheel surface positioned within a place orthogonal to the spindle 11; a vibration sensor 18 for detecting the vibration of the spindle 11; a computing means for computing inspection data of the position of a groove 2, groove shape, center run-out, and the like on the basis of detection signals from the first noncontact displacement sensor, inspection data of surface run-out and the like on the basis of the second noncontact displacement sensor, and the unblance quantity on the basis of detection signals from the vibration sensor 18; and a recording medium writing means for writing computed data computed by the computing means, in a recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for inspecting a wafer chamfering grindstone for grinding a chamfered portion of a wafer, and a method for chamfering a wafer using the inspection method. The present invention relates to a wafer chamfering grindstone inspection method and apparatus for measuring a grindstone groove shape and a groove position corresponding to a chamfer shape and a grindstone mounting accuracy when chamfering by grinding, and a wafer chamfering method using the inspection method.

[0002]

2. Description of the Related Art A semiconductor wafer is processed by a slicing process in which a cylindrical semiconductor ingot is cut (sliced) into a thin plate by a wire saw or a circular inner peripheral blade into a thin plate, and a wafer obtained by slicing. A chamfering step of removing corners of the peripheral part to prevent chipping of the peripheral part, a lapping step of polishing both sides to adjust the thickness and flatness of the chamfered wafer, and a lapping wafer From the etching step of immersing the wafer in an etchant to remove the processing distortion and etching the entire surface, and the polishing step of mirror polishing to improve the surface roughness and flatness of the etched wafer Become.

[0003] Chamfering is performed not only after the slicing step but also during other steps. For example, if the chamfered shape is broken even after the lapping step, chamfering for correction may be performed, and chamfering is one of the important steps.

Conventionally, as a technique for chamfering an end face of a semiconductor silicon wafer, a technique for chamfering an end face through a plurality of steps of grinding a chamfered portion and mirror-finishing a chamfered portion is generally used. In the chamfering grinding step, since the outer diameter of the wafer 3 is not always a perfect circle as shown in FIG. 7, the wheel type grinding wheel 1 rotating at a high speed while rotating the wafer 3 held at the grinding stage 4 (vacuum chuck) at a low speed. The wafer 3 is ground in accordance with the shape of the grindstone groove 2 by bringing the wafer 3 into contact with the grindstone 1 based on (NC) numerical control using data obtained by digitizing the finished shape, The so-called grinding technique for chamfering the wafer 3 and stabilizing the outer diameter of the wafer 3 is generally used.

[0005] The wheel-type grindstone 1 comprises a disk-shaped base metal,
An abrasive layer around the base metal is provided, and the abrasive layer is
Diamond abrasive grains or CBN (cubic boron nitride)
Abrasive grains are combined with a metal binder, and one or more grindstone grooves 2 corresponding to the wafer chamfering shape are provided on the peripheral surface.
Since the wafer end face shape is formed following the shape of the grinding wheel groove 2, the inspection of the groove shape is extremely important.

In this grinding process, since the grinding is performed by bringing the grinding wheel groove 2 into contact with the wafer end face, the wobble of the grinding wheel 1 (axial wobbling of the grinding wheel shaft) and the wobbling of the grinding wheel (whole wheel) (grinding wheel) are performed. The axial thrust direction deflection) directly affects the shape of the wafer end surface and the condition of the ground surface. Further, since the grinding wheel 1 rotates at a high speed, if the weight balance of the grinding wheel 1 is not stabilized, resonance or run-out occurs in the grinding wheel 1, which directly affects the shape of the wafer end face and the shape of the ground surface.

For this reason, the chamfering whetstone 1 comprises a wafer 3
Before performing the groove processing, a grindstone groove 2 inspection and the like are performed.
As the inspection items, the corresponding inspection items were measured in the three inspection processes of the above-described three processes of the surface runout / center runout measurement of the grinding wheel 1 (entire wheel), the groove position / shape measurement of the grinding wheel groove 2, and the overall unbalance amount measurement. Thereafter, an inspection table is created, and based on the inspection table, the amount of processing is corrected on the side of the processing apparatus on which the chamfering grindstone 1 is mounted, and chamfering grinding is performed.

[0008] The conventional inspection process will be briefly described with reference to FIG. 6. The grindstone 1 on which the groove processing has been completed is attached to a processing jig 51, and the grindstone 1 is rotated at a low speed using a dial gauge or the like. The runout and center runout are measured. (First inspection process)

Next, in order to measure the position and the shape of the grindstone groove 2, the flat carbon 52 is pressed against the grindstone groove 2 while rotating the grindstone 1 as shown in FIG. make.

The carbon replica produced by the above-described method is enlarged by a projector, and an operator plots each point based on a projected cross section as shown in FIG. 5 to obtain each dimension (groove position, grindstone outer diameter, grindstone groove). Bottom diameter, groove bottom R portion, etc.) are calculated, and the groove position and groove shape of the grinding groove are measured. (Second Inspection Step) Note that FIG. 5 shows a displacement profile diagram of the laser displacement meter according to the embodiment of the present invention.

Next, the amount of imbalance due to the rotation of the grindstone is measured. (Third inspection process)

[0012]

Therefore, in the conventional inspection process of the chamfering grindstone, the surface runout / center runout measurement (first inspection process), the groove position / shape measurement (second inspection process), and the unbalance amount measurement ( It is divided into three inspection steps (third inspection step), and the inspection requires time.

Also, since the center runout is measured not at the bottom of the groove to be ground but at the outside diameter, there is deviation from the center runout of the actual grinding process. Furthermore, in the second inspection step, since each part is measured by projecting a replica, the surface roughness of the grinding groove portion related to the quality after grinding cannot be measured, and therefore, There is a problem that the resulting chamfered part quality is not known until the wafer 3 is actually ground.

Then, as shown in FIG. 4B, after the grindstone maker has performed the groove processing, the grindstone inspection is performed, and an inspection table based on the inspection result is attached to each of the grindstones and sent to the wafer processing maker. Can be In the wafer processing maker, after performing the same inspection again in the acceptance inspection and confirming the inspection table, the whetstone is attached to a chamfering device at an actual chamfering site, the processing amount is corrected based on the inspection table, and a predetermined amount is corrected. Processing is performed.

Therefore, in the prior art, the input of the groove position / shape data to the chamfering grinding device must be performed by an operator from an inspection table, which complicates on-site work.

In view of the drawbacks of the prior art, the present invention automatically measures surface runout / center runout measurement, groove position / shape measurement, and unbalance amount measurement by the same measuring machine, thereby shortening the inspection time and improving the accuracy. It is also possible to measure the center runout and surface roughness of the groove bottom, and to provide a wafer chamfering grindstone inspection method and apparatus for stabilizing the wafer quality after grinding, and a wafer chamfering method using the inspection method. Aim.

[0017]

According to the first aspect of the present invention,
In order to solve the above-mentioned problem, a grindstone whose grooving corresponding to the wafer chamfering shape has been completed is mounted on a spindle shaft having the same shape as the chamfering grinding device and rotated to contact or non-contact with the grindstone rotation position or the spindle shaft. One or a plurality of sensors arranged face-to-face in a state detects a wheel peripheral surface displacement in an in-plane direction parallel to the spindle axis, a wheel runout positioned in a plane orthogonal to the spindle axis, and spindle axis vibration, and detects the detection data. Calculating the calculated values corresponding to the groove position / groove shape, center runout, surface runout, and unbalance amount by predetermined calculation means, and then taking the calculated data into a storage medium. Suggest.

According to a second aspect of the present invention, the grinding wheel after the inspection is mounted on a spindle shaft of the chamfering grinding apparatus by using the storage medium into which the operation data according to the first aspect is taken, and the chamfering grinding is performed. The present invention proposes a wafer chamfering method characterized in that arithmetic data is read from the recording medium by the storage medium reading device provided on the device side, the amount of processing is corrected, and chamfering is performed.

According to a third aspect of the present invention, there is provided an apparatus for effectively implementing the first aspect of the present invention, wherein a rotatable spindle shaft having the same shape as the chamfering grinding device is fixed to the spindle shaft. Positioning means for fitting a grindstone in a state in which the grinding wheel is positioned, and a first non-contact moving in a direction parallel to the spindle axis while facing the grinding wheel peripheral surface fixed to the spindle shaft by the positioning means in a non-contact state Displacement sensor, a second non-contact displacement sensor disposed facing the grinding wheel surface located in a plane orthogonal to the spindle axis, and a vibration sensor for detecting vibration of the spindle axis,
Inspection data such as groove position / groove shape and center runout based on a detection signal from the first non-contact displacement sensor, and inspection such as surface runout based on a detection signal from the second non-contact displacement sensor. Data, further comprising calculating means for calculating the unbalance amount based on a detection signal from the vibration sensor, and recording medium writing means for writing the calculated data calculated by the calculating means to a storage medium. Is proposed.

The positioning means is, for example, a whetstone 1
Is a means for holding the shaft so that it does not move in the thrust direction (spindle axis direction) or rattle, and means, for example, a taper shank portion provided on the spindle shaft or a holding and fixing means by a nut.

The first non-contact displacement sensor preferably uses a laser displacement meter in order to accurately measure a minute spot-shaped measurement point, but is not limited to this. As the second non-contact displacement sensor, it is preferable to use an eddy current sensor in order to measure the amount of runout of the grinding wheel 1 in the thrust direction. If the vibration sensor is mounted directly on the spindle shaft peripheral surface, the rotation fluctuation of the spindle shaft will occur.
The spindle shaft is preferably mounted on a spindle shaft holder that supports the spindle shaft via a bearing.

According to this invention, for example, while the grinding wheel 1 is rotated by the spindle shaft, the displacement amount in the grinding wheel thrust direction can be measured by the eddy current type displacement sensor. The rotation shake can be detected by the calculation by the calculation means.

The laser displacement meter moves the displacement meter in the axial direction of the spindle at an accurate time speed while rotating the grindstone 1 by the spindle shaft. Then, by taking the displacement on the horizontal axis and the vertical axis on the moving axis, the groove position and the groove shape can be measured. The center runout is fixed to the laser displacement meter, and while the grinding wheel 1 is rotated by the spindle shaft, the displacement amount in the circumferential direction of the grinding wheel can be measured by the laser displacement meter. The center runout can be detected by the calculation by the calculation means.
Also, the vibration sensor can measure vibration (acceleration, amplitude, frequency) by rotating the spindle shaft at high speed.
The amount of imbalance can be detected by calculating by the calculating means in synchronization with the cycle of each rotation by the tachometer.

As described above, the inspection output and the groove position / shape data of the grindstone 1 to be incorporated into the chamfering grinding device can be prepared by calculating the detection output of the sensor by the predetermined calculation means. By storing it on a floppy disk or the like and attaching it to the grindstone 1 to be transferred to the processing maker, the input to the chamfering grinding device can be made from an external storage medium (a floppy disk or the like) and simplified.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to an embodiment shown in the drawings. However, unless otherwise specified, dimensions, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the invention, but are merely illustrative examples.

FIG. 1 is a schematic view showing a chamfering grindstone inspection apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 11 denotes a drive source 12 such as a stepping motor or a servomotor, which can control the number of rotations. A rotatable spindle shaft having the same shape as the spindle shaft on the chamfering grinding machine side. The spindle shaft 11 has a tip end formed in a tapered shank shape corresponding to the inner diameter of the grinding stone. Is configured to be able to be accurately positioned when fitted. Also, the spindle shaft 1
1 is provided with a tachometer 14.

Numeral 15 denotes a laser displacement gauge which is arranged in a plane perpendicular to the axis of the spindle shaft 11 so as to be able to face the grinding wheel fixed to the tapered shank portion 11a in a non-contact state and in a non-contact state. Attached to the Χ-axis direction moving device 16 which moves in a direction parallel to Reference numeral 17 denotes an eddy current type displacement sensor, which is arranged on a fixed station side (not shown) so as to face the grindstone bottom surface 1a located in a plane orthogonal to the spindle shaft 11. The vibration sensor 18 that detects the vibration of the spindle shaft 11 is attached to a spindle shaft holder 20 that supports the spindle shaft 11 via a bearing 19.

A tachometer 14 attached to the spindle shaft 11, a laser displacement meter 15 disposed so as to be able to face the wheel in a non-contact state with the outer peripheral surface of the grindstone, and a Χ axial direction moving device 16
Detector 13 for detecting the moving distance and moving speed of the eddy current type displacement sensor 1 arranged so as to face the grinding wheel bottom surface
7, and a detection signal from the vibration sensor 18 for detecting the vibration of the spindle shaft 11 is sent to an arithmetic unit 21 composed of a CPU, and calculates the groove position / groove shape, center runout, surface runout and unbalance amount, respectively. .

The operation data calculated by the operation unit 21 can be written into the FD 23 via the FD drive 22 and the inspection table 26 can be printed via the printer 24.

Next, the outline of the arithmetic unit 21 will be described with reference to FIG. The surface deflection is represented by the maximum value-minimum value of the eddy current displacement sensor 17 when the grinding wheel makes one rotation. Therefore, while rotating the grinding wheel 1 by the spindle shaft 11, the distance from the reference plane detected by the eddy current displacement sensor 17 and the grinding wheel 1 rotation signal detected by the tachometer 14 are taken into the arithmetic unit 21, By selecting the maximum value-minimum value of the eddy current type displacement sensor 17 with the calculator 21 in synchronization with the cycle of each rotation of the grinding wheel, the surface runout can be detected.

The groove position, groove shape, and center runout of the grindstone 1
Is rotated, and the laser displacement meter is scanned in the X direction by the Χ-axis direction moving device 16, and the displacement signal from the laser displacement meter 15 and the detector 13 for detecting the moving distance and the moving speed of the Χ axis direction moving device 16 The displacement profile data as shown in FIG. 5 is obtained by taking the laser displacement along the horizontal axis and the vertical axis on the basis of the above, and the groove position / groove shape is obtained by calculating from this data.

The calculation method is as follows. First, calibration is performed using a large master grindstone manufactured based on the standard upper limit dimension and a small master grindstone manufactured based on the standard lower limit dimension. More specifically, the outer diameter of the grindstone of the master grindstone (large) is set to the upper reference plane Y = 0 (φ: 202.500 mm), and the master grindstone (small) grindstone is set to the lower reference plane Y = 4 (φ: 198.
500 mm), the laser displacement meter 15 is scanned in the X direction while rotating the grindstone 1 to determine whether or not the actually measured grindstone groove 2 is positioned. Get profile data.

The dimensions and the like are calculated from the obtained data by the method described below. Grinding wheel outer diameter (D ₀ ): A value obtained by subtracting the average displacement (Y ₀ ) of the grinding wheel outer diameter φ 1 from the master grinding wheel (large). D ₀ = φ (φ: 202.500 mm) − (Y ₀ × 2) Grindstone groove bottom diameter (Dg-n): Displacement (Yg-n) from the master grindstone (large) to the grindstone groove bottom at the center of the groove Subtracted value. Dg-n = φ (φ: 202.500 mm) − (Yg-n × 2)

Center runout (Gn): Difference between the maximum and minimum displacement at the center of each groove when the grindstone makes one rotation Gn = (Dg-n) max- (Dg-n) min Grindstone groove Position (X _1-n , X _2-n , X _3-n , R _-n ): T-type with R-section (slope section) on both left and right sides of groove bottom; The value of X at which the extension lines intersect (X _1-n , X _2-n ) and the value at the center (X _3-n ), and the R type with the groove bottom having an R shape has the X at which the extension lines of the two slopes intersect. _Is set as the groove position, and such a groove position is obtained from the grinding wheel groove profile data.

Angles (A _1-n , A _2-n ): Two virtual straight lines are drawn on the right and left inclined straight line portions of the grindstone groove 2, and the X value of the displacement intersecting the straight lines is read to calculate the angle. A _1-n = tan ^-1 (ΔX1 / ΔY), A _2-n = tan
^-1 (ΔΧ2 / ΔY) Grindstone groove surface roughness (S _-n ): Find the average of the amount of displacement when the grindstone is rotated once at the center of each groove, and calculate the absolute value of the difference between the individual displacement and the average value. The average value (Ra: center line average roughness) is calculated as the difference (Rmax) between the maximum value and the minimum value after one rotation.

With respect to the center run-out, while the laser displacement meter 15 is fixed and the grindstone 1 is rotated by the spindle shaft 11,
Since the maximum value-minimum value when the grinding wheel 1 makes one rotation can be detected by the laser displacement meter 15, 1
By calculating in the calculator 21 in synchronization with the cycle of each rotation, the center runout can be represented.

The unbalance amount is obtained by rotating the spindle shaft 11 at a high speed, and detecting the acceleration, amplitude and frequency of the vibration sensor 18 at the time when the spindle shaft 11 reaches the set number of revolutions from the tachometer 14 by the tachometer 14. The amount of imbalance can be detected by performing calculation by the calculator 21 in synchronization with the cycle of each rotation.

Next, the inspection procedure of this embodiment will be described with reference to the flowchart of FIG. (Step 1) After the grinding of the grindstone groove, the grindstone 1 is removed from the processing jig, fitted to the taper shank portion 11a of the spindle shaft 11 of the grindstone inspecting machine, and then the spindle fixing screw is tightened to fix the position.

(Step 2) The grindstone 1 is rotated at a low speed, and the runout of the reference plane is measured based on the detection signal from the eddy current type displacement sensor 17. In this case, if the runout exceeds the standard value, remove it from the inspection machine and
Clean the mounting part such as a and the inner diameter of the grindstone, and measure the run-out of the mounting surface on the inspection machine again.

(Step 3) If the measured value of the surface run-out is within the standard, the laser displacement meter is scanned in the X direction by the Χ-axis direction moving device 16 while rotating the grindstone 1 again at a low speed. Based on displacement signals from the detector 13 and the laser displacement meter 15 for detecting the moving distance and the moving speed of the direction moving device 16, the displacement is plotted on the horizontal axis and the vertical axis as shown in FIG. And displacement profile data can be obtained.

(Step 4) Based on the displacement profile data, the calculator 21 calculates the grinding wheel outer diameter, the grinding wheel groove bottom diameter, the runout, the groove position, the angle, the R shape, and the groove surface roughness by the calculation method. . In addition, the grindstone outer diameter is measured for each grindstone, the grindstone groove bottom diameter, the runout, the grindstone angle, the R shape and the groove surface roughness are measured for each groove, and the groove position is calculated from the distance from the reference plane.

(Step 5) Next, it is determined whether or not the calculation result of each item is within the standard. If the result is out of the standard, the grindstone groove in that portion is reworked or is determined to be defective.

(Step 6) The grinding wheel 1 that has passed the respective standards obtained from the displacement profile data has two kinds of high-speed rotations (two levels) of a first level and a second level.
Then, the arithmetic unit 21 calculates the acceleration, amplitude, and frequency detection data of the vibration sensor 18 when the spindle shaft 11 reaches the set number of revolutions from the tachometer 14 in synchronization with the cycle of each revolution by the tachometer 14. By doing so, the unbalance amount can be detected.

(Step 7) The balance of the grindstone 1 is adjusted so that the unbalance amount is within the standard. (The imbalance amount and position are displayed)

(Step 8) For the whetstone 1 whose unbalance amount (vibration) falls within the standard and passed, the results of the measurement and calculation are printed out on a whetstone inspection table, and the same data is stored in the floppy disk drive 22. Is written on the floppy disk 23 via the.

Then, as shown in FIG. 4A, after the grindstone maker has performed the grindstone inspection as described above, the inspection table 26 and the floppy disk 23 based on the inspection result pass. It is sent to a wafer processing maker attached to each of the finished whetstones.

At the wafer processing maker, a similar inspection is performed again in the acceptance inspection to confirm the inspection table 26 and the contents of the floppy disk 23, and then the floppy disk 23 is transferred to the floppy disk drive 22 on the side of the chamfering / grinding apparatus at the site. The data of the floppy disk 23 is read by the computing unit 30, the processing amount is automatically corrected by the computing unit 30, and the corrected data is input to the chamfering / grinding apparatus to perform predetermined processing. .

As described above, according to the present embodiment, the inspection table 26 and the groove position / shape data of the grindstone 1 to be incorporated into the chamfering grinding device are created by calculating the detection output of the sensor by the predetermined calculator 21. By saving the data on a floppy disk or the like and attaching it to the acceptable grinding wheel 1, the input to the chamfering grinding device can be made from an external storage medium (a floppy disk or the like), thereby simplifying the operation.

[0049]

As described above, according to the present invention, the groove position, shape, vibration (unbalance), surface runout and center runout can be measured at one time, and the time required for the measurement is greatly reduced.

Further, according to the present invention, since the profile data of the grindstone groove 2 can be directly measured with high precision instead of the projected cross section of the replica as in the prior art, the surface roughness of the grinding groove portion can be measured. By setting the standard of the surface, the surface roughness of the grinding portion of the wafer can be stabilized.

Further, by calculating from the measurement results, groove position / shape data of the chamfering grinder can be created, stored in an external storage medium and directly inputted to the chamfering grinder.
The work at the time of whetstone exchange can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a chamfering grindstone inspection apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating an outline of a computing unit shown in FIG.

FIG. 3 is a flowchart showing an inspection procedure of the embodiment shown in FIG. 1;

FIGS. 4A and 4B are exchange diagrams of inspection data between a grinding wheel maker and a wafer processing maker who have performed the groove processing. FIG. 4A is an embodiment of the present invention, and FIG.

FIG. 5 shows a displacement profile diagram of a laser displacement meter according to an embodiment of the present invention, but basically the same applies to a projection sectional view of a replica of the prior art.

FIG. 6 is a schematic diagram briefly explaining the conventional inspection process.

FIG. 7 is a schematic view of a wafer chamfering process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Whetstone 2 Whetstone groove 3 Wafer 11 Spindle shaft 11a Shank part 12 Drive source 13 Detector 14 Tachometer 15 Laser displacement meter 16 Χ Axial movement device 17 Eddy current displacement sensor 18 Vibration sensor 21 Computing device 22 FD drive 23 FD

Claims (3)

[Claims] 1. A grindstone whose groove processing corresponding to a wafer chamfering shape has been completed is mounted on a spindle shaft having the same shape as that of the chamfering grinding device and rotated to face the grindstone at a grinding wheel rotation position or in a contact or non-contact state with the spindle shaft. One or a plurality of sensors arranged detect a wheel peripheral surface displacement in an in-plane direction parallel to the spindle axis, a wheel runout positioned in a plane perpendicular to the spindle axis, and spindle axis vibration, and the detected data is used as a groove position. A whetstone inspection method, wherein calculated values corresponding to the groove shape, center runout, surface runout, and unbalance amount are calculated by predetermined calculation means, and the calculated data is loaded into a storage medium. 2. A grindstone whose groove processing corresponding to a wafer chamfering shape has been completed is mounted on a spindle shaft having the same shape as that of the chamfering grinding device and rotated to face the grindstone at the grinding wheel rotation position or in a contact or non-contact state with the spindle shaft. One or a plurality of sensors arranged detect a wheel peripheral surface displacement in an in-plane direction parallel to the spindle axis, a wheel runout positioned in a plane perpendicular to the spindle axis, and spindle axis vibration, and the detected data is used as a groove position. After calculating the calculated values corresponding to the groove shape, center runout, surface runout, and unbalance amount by predetermined calculation means, the calculated data is loaded into a storage medium, and the grindstone after the inspection is finished is chamfered and ground. The data is read from the recording medium by the storage medium reading device provided on the chamfering grinding device side, which is attached to the spindle shaft of the device, and chamfered. A wafer chamfering method characterized by performing processing. 3. A rotatable spindle shaft having the same shape as that of the chamfering grinding device, positioning means for fitting a grindstone in a state fixed to the spindle shaft, and a position fixed to the spindle shaft by the positioning means. A first non-contact displacement sensor that moves in a direction parallel to the spindle axis while facing the grindstone peripheral surface in a non-contact state, and a first non-contact displacement sensor that faces the grindstone surface located in a plane orthogonal to the spindle axis. A non-contact displacement sensor, a vibration sensor for detecting vibration of the spindle shaft, and groove position / groove shape and center run-out inspection data based on a detection signal from the first non-contact displacement sensor; Calculating means for calculating inspection data of surface deflection based on a detection signal from the second non-contact displacement sensor and further calculating an unbalance amount based on a detection signal from the vibration sensor; A whetstone inspection device, comprising: a recording medium writing means for writing the operation data calculated by the calculation means into a storage medium.