JP2000000760A - Method for truing cylinder grinding wheel, and method for grinding semiconductor wafer by means of cylinder grinding wheel formed in the truing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for truing a cylinder grinding wheel to perform high-precise truing even when machine precision (a motion error) of a drive system for the truing material is lower than demand precision of the truing. SOLUTION: This method for truing a cylinder grinding wheel 10 to move a truing material, making contact with the peripheral surface of the rotating cylinder grinding wheel 10, in the direction of the width of the grinding wheel to effect truing of the outer peripheral surface of the cylinder grinding wheel 10 in an arbitrary shape, the forward and backward movement direction (a push direction) of the truing material to and from the cylinder grinding wheel 10 is extended in an inclination angle direction inclined at an angle of 10 deg. or less to the normal LH side based on a tangential line LS on the contact position of the truing material, and the truing track of the truing material is a curved track containing a straight line or a circular arc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of truing a cylindrical grindstone used in a surface grinding device used for processing a hard disk, a glass, and a semiconductor substrate. The present invention relates to a truing method of a cylindrical grindstone that performs truing while moving a truing material in contact with a peripheral surface of a cylindrical grindstone in the grindstone width direction, and a method of grinding a semiconductor wafer using a cylindrical grindstone formed by the truing method.

[0002]

2. Description of the Related Art As one of processing methods used in the production of hard disks, glass and semiconductors, there is a step called surface grinding. Surface grinding is a surface grinding method in which a rotating grindstone is pressed against the surface of a workpiece supported by a workpiece support table to grind the surface of the workpiece. However, this is an operation for cutting the surface of the workpiece little by little using the abrasive grains as a cutting edge to finish precisely, and has an advantage that the cutting speed is extremely high.

On the other hand, a silicon wafer used as a substrate of a semiconductor device is obtained by cutting a silicon single crystal ingot into a wafer shape, and passing through processes such as lapping, etching and polishing to obtain a thickness, size, shape, surface texture, and the like. It is manufactured by adjusting the mirror surface etc., but these machining processes are slow in processing speed due to the processing mechanism,
Since the shape accuracy is also unstable, the ability to process silicon wafers quickly and with high accuracy is becoming insufficient. For this reason, in order to achieve quick and high-precision machining, grinding by a surface grinder is performed instead of partial lapping.

[0004] The grindstone used in the surface grinder is composed of abrasive grains and a binder, and there are various types depending on the type of abrasive grains, the grain size, the degree of concentration, and the type of binder, and these are used properly depending on the processing object. . Alumina Al ₂ O ₃ , silicon carbide SiC, CBN, and diamond are used as abrasive grains. Vitrified bond (magnetic, vitreous), resin bond (thermosetting resin), and metal bond (metal powder) are used as the binder.

[0005] Surface grinding of a silicon wafer is performed by rough grinding or finish grinding to improve the flatness and smoothness after processing. In the rough grinding, a grindstone formed of diamond abrasive grains of # 100 to # 1000 and a vitrified bond is used. In the finish grinding, a diamond grindstone of # 1000 to # 3000 formed by a resin bond or the like is used. In the case of a cylindrical grindstone, these grindstones and binder are formed on the outer peripheral surface of the cylindrical core to a thickness of 1 to 10 mm.

[0006] Using such a grindstone, in order to achieve a precise finish by grinding, the management of the grindstone is an important point, and dressing and dressing (truing) are performed. Here, truing, which is the object of the present invention, refers to shape modification of the grinding wheel grinding surface for modifying the shape of the grinding surface of the grinding wheel. The tools used for the truing and dressing operations are called dressers, and there are various tools for a wide range of grinding operations. Above all, a diamond dresser and a crush roll dresser are held by a dresser holder and can perform a precise operation by table movement.

[0007] For example, as shown in FIG. 5A, a diamond dresser for truing the cylindrical grindstone 10 includes a single-stone dresser 101, a multi-stone dresser 102, an imbricated dresser 103 (hereinafter referred to as truing material 1) and the like. All of them move the truing material 1 in parallel along the peripheral surface of the cylindrical grindstone 10 (see FIG. 5B).

[0008]

[SUMMARY OF THE INVENTION Therefore the truing member 1, in order to perform truing against the cylindrical grinding wheel 10 normal direction L _H As shown in FIG. 5 (C), bite into the truing member 1 to grindstone The push-in amount P (the amount of advance and retreat) and the removal allowance D of the grindstone (the amount of cutting in the radial direction of the grindstone) match. In other words, the removal allowance D of the grindstone and its variation depend on the mechanical accuracy of the drive system that moves the truing material 1. 1: 1
It depends on the ratio of For this reason, in order to increase the accuracy of the truing material 1, the mechanical accuracy of the drive system must be increased in proportion thereto.

The final purpose of performing surface grinding using the cylindrical grindstone 10 or the like is to grind a workpiece such as a semiconductor wafer to a high flatness. However, it has been found that when the semiconductor wafer is ground using the cylindrical grindstone 10 whose outer peripheral surface is a straight line, the shape of the workpiece tends to be a convex shape. The cause is that the actual processing time is long because the center of the grinding wheel outer peripheral surface is processed in the diameter direction of the workpiece, and the clogging and wear of the grinding stone become faster than the peripheral part, as a result,
This is probably because the grinding ability at the center of the workpiece was reduced.
Thus, the abrasive layer is crushed by the grinding resistance, and the flat body is originally dented, and the workpiece is affected by this shape, and is likely to be processed into a convex shape.

Therefore, when a workpiece such as a silicon wafer is machined flat using the cylindrical grindstone 10, the cylindrical grindstone 1
It has been found that it is desirable to form the outer peripheral surface of the drum 0 in a drum shape (convex shape) instead of flat in advance. (This finding is the first finding of the present inventor, and therefore the invention of claim 5 is found from this point.) The results are shown in FIG.

A in FIG. 4 (C) is grinding data obtained by processing a 4-inch wafer using a cylindrical grindstone 10 having a straight outer peripheral surface of a "prior art (comparative example)" described in the section of Examples described later. (See FIG. 4 (A)), B shows the grinding of a 4-inch wafer processed by using a cylindrical grindstone 10 having a convex arc on the outer peripheral surface of "the present invention (Example 1)" described in the section of Examples to be described later. The data (see FIG. 4 (B)) are shown respectively. As is clear from this drawing, the linear cylindrical grindstone 10 can obtain only a flatness of 5 to 6 μm, but the outer peripheral surface of the first embodiment has a convex arc shape. It was confirmed that the flatness of the cylindrical grindstone 10 was suppressed to approximately 1 μm or less.

That is, the maximum convexity (curvature height) is 2 to 10 μm.
m, preferably about 3 to 7 μm. More specifically, by flattening a semiconductor wafer using a convex arcuate cylindrical grindstone 10 having a maximum convexity of about 4 μm, a flatness of about 1 μm or less can be maintained as shown in FIG.

That is, the flatness required for a semiconductor wafer is 1 μm or less. To obtain such a high flatness wafer, the shape of the cylindrical grindstone 10 is made drum-shaped, and the management of the shape is controlled in units of several μm. I found it necessary. In order to process a workpiece with high precision,
The shape of the grindstone is important.

However, as described above, as shown in FIG. 5B, the truing method of the cylindrical grindstone 10 is such that the machining allowance D of the grindstone and the mechanical accuracy of the driving system for moving the truing material 1 are in a ratio of 1: 1. Therefore, controlling the convex shape of the grinding wheel in units of several μm requires correspondingly high mechanical precision of the drive system. However, in the conventional truing drive device, it is possible to suppress a run-out error due to vibration or the like in a unit of several μm, in other words, it is possible to process the work in a linear shape. However, as shown in FIG. The moving locus of the truing material 1 that performs truing while moving the peripheral surface in the width direction of the grindstone is several μm.
It is extremely difficult to orbit in an arc while controlling in units.

That is, a drum-shaped (convex circular arc) cylindrical grindstone 10 controlled in units of several μm, which is necessary for grinding a semiconductor wafer capable of maintaining a flatness of about 1 μm or less, can be obtained by the conventional truing method. Did not. It should be noted that, depending on the type of the surface to be ground, more specifically, in the case of a workpiece that is slightly curved in a convex arc shape on the surface plate during grinding, several μm is required.
In some cases, it is preferable to perform grinding using a concave-arc cylindrical grindstone 10 controlled in m units.

In view of the drawbacks of the prior art, the present invention provides a truing of the cylindrical grindstone 10 which enables high-precision truing even when the mechanical accuracy (operation error) of the drive system of the truing material 1 is inferior to the required accuracy of truing. The aim is to provide a method. Another object of the present invention is to
It is an object of the present invention to provide a method of truing the cylindrical grindstone 10 that enables the outer peripheral portion of the cylindrical grindstone 10 to be trued arbitrarily and accurately not only in a straight line but also in an uneven curve shape.

Another object of the present invention is to provide a method of truing a cylindrical grindstone 10 capable of accurately truing the outer periphery of a convex or concave circular grindstone in units of several μm. I do.

Another object of the present invention is to provide a method for grinding a semiconductor wafer with high accuracy using the cylindrical grindstone 10 formed by the truing method.

[0019]

According to the first aspect of the present invention,
In the truing method of the cylindrical grindstone 10, in which the truing material 1 contacted with the rotating cylindrical grindstone 10 is moved in the width direction of the grindstone 10 in order to truing the outer peripheral surface of the cylindrical grindstone 10 into an arbitrary shape. moving direction of the cylindrical grinding wheel 10 of the timber 1 (pushing direction) is, at least within 30 ° to the normal line L _H side with respect to a tangent L _S on the contact position of the truing member 1, preferably inclined at an angle within 10 ° The truing trajectory of the truing material 1 is a curved trajectory including a straight line or an arc.

The present invention can be used not only for grinding a semiconductor wafer but also for a workpiece such as a glass substrate or a hard disk which requires a high degree of flatness with high precision.

[0021]

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

The present invention will be specifically described with reference to FIG.
The truing member 1 in the prior art, in order to perform truing against the normal line L _H direction with respect to the cylindrical grinding wheel 10, the cash D takes the reciprocating amount P and the grindstone of the truing member 1 'match, grindstone The allowance D 'depends on the mechanical accuracy of the drive system for moving the truing material 1 at a ratio of 1: 1. Therefore, when the mechanical accuracy of the drive system for moving the truing material 1 varies, the flatness of the grinding wheel surface is immediately affected. In order to truing the outer circumference of the grinding wheel in a convex (concave) arc shape in units of several μm,
The mechanical accuracy of the drive system for moving the truing material 1 is also several μm.
Although control must be performed in units, it is extremely difficult to obtain such accuracy in the drive system.

On the other hand, the truing material 1 is
0 but not spoken bite into the grinding wheel be pressed against the tangential L _S direction of the contact position, bite by pressing the tangent line L _S L _P direction inclined at an inclination angle λ in normal L _H side than at Happens. The maximum bite width Dmax of the whetstone at this time
(Maximum cutting amount that can be cut in the grinding wheel radial direction at this inclination angle)
Is expressed by a grinding wheel radius R and an inclination angle λ as shown in the following equation. Dmax = R (1−cosλ) At this time, the pushing amount P of the truing material 1 is P = R · sinλ.

That is, when the grinding wheel radius R is 100 mm and the inclination angle λ is 1 °, the removal allowance D of the grinding wheel is at most 15
It is cut down to μm. The pushing amount P of the truing material 1 at this time is about 1745 μm, and the movement accuracy (mechanical accuracy) of the truing material 1 for cutting the grinding stone by 15 μm in the radial direction is 1745 μm, which is 100 times or more. Similarly, when the grinding wheel radius is R = 100 mm and the inclination angle is 0.25 °, the machining allowance D of the grinding wheel is 1 μm, and the pushing amount of the truing material 1 is 436 μm in machine accuracy (that is, 400 times or more in machine accuracy). When the inclination angle is within 10 °, the tolerance is 10 times or more. It should be noted that the removal amount D of the grindstone can be controlled by adjusting the pushing amount P of the truing material 1 to an arbitrary position without moving it to the maximum bite amount.

However, when the inclination angle λ is set to 30 ° with respect to an object having a grinding wheel radius R of 100 mm, the pushing amount P of the truing material 1 is about 50 mm at the maximum and the allowance of the grinding stone (bite amount) is about 13. Shaved to 4mm. That is, at such an angle, only about four times the machine precision is allowed, and the effect of the present invention is not substantially achieved. Also, 3
If the angle is set to be smaller than 0 °, the smaller the value is, the wider the allowable range of the machine accuracy. Therefore, the inclination angle λ is set to at least within 30 ° to the normal line L _H side with respect to the tangent L _S of the grinding wheel, to substantially achieve the effect of the present invention 10 ° within, more preferably within 1 ° It is good that the inclination angle is inclined at the angle of. Thus, the present invention enables high-precision truing even when the mechanical accuracy of the drive system of the truing material 1 is inferior to the required accuracy of the truing material.

That is, when the outer peripheral portion of the cylindrical grindstone 10 is trued in a straight line, even if there is a vibration on the drive system side, the machining allowance D of the grindstone affected by the vibration is within an inclination angle of 1 ° or less. For example, it affects only about 1/100 and enables truing with high accuracy. In addition, even when truing the outer peripheral portion of a grinding wheel having a convex or concave arc shape in a unit of several μm arbitrarily in a concave-convex curve shape, if the inclination angle is 1 °, the machine of the drive system of the truing material 1 is required. Since the accuracy is 100 times or more, even when the accuracy of the driving system of the truing material 1 is significantly inferior to the required accuracy of the truing, it is possible to accurately and accurately perform the truing.

More specifically, the truing material 1 contacting the peripheral surface of the rotating cylindrical grindstone 10 according to claim 2.
Is moved in the width direction of the grinding wheel while the cylindrical grinding wheel 10 having a convex arc shape is moved.
Is formed, as shown in FIG.
Center point Cb of the circular orbit of the truing material 1 forming the
Is set to be shifted from the initial center point Ca, which is separated from the coordinate reference line Z-Z passing through the rotation axis of the cylindrical grindstone 10 by the radius A of the circular orbit of the truing material 1 to the coordinate reference line Z-Z, By performing truing such that the movement trajectory m of the truing material 1 takes an arc trajectory m outside the coordinate reference line Z-Z, the outer peripheral surface of the cylindrical grindstone 10 is formed in a slightly convex arc shape. Features.

When the truing material 1 in contact with the rotating cylindrical grindstone 10 is moved in the width direction of the grindstone to form the cylindrical grindstone 10 having a concave arc shape, as shown in FIG. As shown in the figure, the center point Cb of the arc trajectory of the truing material 1 forming the arc trajectory m is defined by a radius A of the arc trajectory m of the truing material 1 from a coordinate reference line Z-Z passing through the rotation axis of the cylindrical grindstone 10. Separated initial center point C
a or from the initial center point Ca (coordinate reference line Z−
Z), the tracing is performed such that the moving trajectory m of the truing material 1 takes an arc trajectory m inside the coordinate reference line Z-Z. The surface is formed in a slightly concave arc shape.

In the truing method in which the truing trajectory of the truing material 1 is an arc trajectory m, for example, as set forth in claim 4, the distance between the both ends of the cylindrical grinding wheel 10 (total width of the grinding wheel) 2H, Whetstone 10
Radius R, the curvature height of the grinding wheel outer peripheral surface to be obtained k, and the inclination angle λ with respect to the tangent L _S of moving direction of the truing member 1, the radius of the circular arc track m truing material 1 obtained from these basic data It is preferable that the arc trajectory m is set from A and the center point Cb of the arc trajectory m of the truing material 1, and the truing of the outer peripheral surface of the grindstone is performed while moving the truing material 1 along the set arc trajectory m.

Next, the operation procedure of the invention according to the second to fourth aspects will be described step by step with reference to FIG. (Procedure 1) As basic data, the distance between both ends of the cylindrical grindstone 10 (total width of the grindstone) 2H, the radius R of the cylindrical grindstone 10, the curvature height k of the outer peripheral surface of the grindstone to be obtained, and the tangent L of the truing material 1 in the reciprocating direction. Set the inclination angle λ with respect to _S. (Procedure 2) The radius A of the circular orbit m of the truing material 1 and the center point Cb of the circular orbit m of the truing material 1 are obtained from the basic data. The way of finding is as follows.

1) Radius of the circular orbit m of the truing material 1
How to Obtain A Since the curvature height k corresponds to the allowance D of the grindstone, D = k. Next, the truing material is calculated from the allowance D and the inclination angle λ.
The pushing amount P of 1 is obtained. P = D · sin λ / (1−cos λ) As shown in FIG. 1B, H (1/1 of the entire width of the cylindrical grindstone 10)
From 2 distances) and P, obtain the 曲 curvature angle θ of the arc orbit m
Confuse. Asin θ = H θsin θ = H / A The radius A of the circular arc orbit m is obtained from the 曲 curvature angle θ.
You. P + Acos θ = A Acos θ = AP Ｐ cos θ = (AP) / A sin^Twoθ + cos^TwoSubstituting θ = 1, (H / A)^Two+ {(AP) / A}^Two= 1H^Two+ (AP)^Two= A^Two  H^Two+ P^Two= 2AP ∴A = (H^Two+ P^Two) / 2P

2) How to determine the center point Cb of the center arc trajectory m of the truing material 1 The center point Cb of the arc trajectory m of the truing material 1 is determined based on the case of the convex circular cylindrical grindstone 10 and the case of the concave circular arc cylindrical grindstone 10. The formula to be obtained differs depending on the case.

2-1) When obtaining the center point Cb of the circular orbit m of the truing material 1 when forming the convex circular cylindrical grindstone, it becomes clear from the operation diagram shown in FIG. The value obtained by subtracting the shift amount Q of the truing material 1 from the radius A of the circular arc orbit m is the X coordinate of the center Cb. The shift amount Q is: Q = Rs
Since it is obtained by inλ, the X coordinate of Cb is obtained by the following equation. X coordinate of Cb = AQ = A-Rsinλ

FIGS. 2A and 2B illustrate such a point, and the coordinate 、 axis is set to an axis passing through a grinding wheel rotation axis parallel to the inclination angle λ. The coordinate axis Z is set on the axis displaced by 90 ° in the circumferential direction of the cylindrical grindstone 10 with respect to the Χ axis, and the coordinate Y axis is set on the cylindrical grindstone 10 axis.

(Procedure 3) While rotating the cylindrical grindstone 10, the truing material 1 is reciprocated along the circular orbit m along the outer peripheral surface of the cylindrical grindstone 10, and the center point of the circular orbit m is set to the Z axis. Truing is performed by moving the shift amount Q from the side (moving from Ca to Cb).
The reciprocating motion is performed in the range of -H ≦ m ≦ H as shown in FIG. By reciprocating in such a range, the center portion is hardly cut off, and the peripheral portion is pushed in by P and cut off with the allowance D.

As a result, as shown in FIG. 2B, the center point C of the circular orbit of the truing material 1 forming the circular orbit m
b is a coordinate reference line Z-Z passing through the rotation axis Y of the cylindrical grindstone 10.
From the initial center point Ca separated by the radius A of the arc trajectory m of the truing material 1 from the center position, the shift is set to the coordinate reference line ZZ side, and the movement trajectory m of the truing material 1 is set to the coordinate reference line Z-. By performing truing so as to take an arc trajectory m outside of Z, the cylindrical grinding stone 10
Can be formed in a slightly convex arc shape.

2-2) When determining the center point Cb of the circular orbit m of the truing material 1 when forming a concave circular cylindrical grindstone, it becomes clear from the operation diagram shown in FIG. FIG.
As shown in (B), the value obtained by adding the shift amount Q of the truing material 1 to the radius A of the circular orbit m is the center point C of the circular orbit m.
This is the X coordinate of b. Since the shift amount Q is obtained by Q = Rsinλ, the X coordinate of Cb is as follows. X coordinate of Cb = A + Q = A + Rsinλ

FIGS. 3 (B) and 3 (C) illustrate such a point, and as shown in the above (Procedure 3), the truing material is rotated along the circular orbit m while rotating the cylindrical grindstone 10. Truing is performed by moving the center of the circular arc track m to the position of the shift amount Q (from Ca to Cb) while reciprocating the outer peripheral surface of the cylindrical grindstone 10 in the range of -H≤m≤H. In addition, in any case of the above-mentioned convex and concave arc-shaped grinding wheels, the Y coordinate of the center Cb of the arc trajectory m,
As is clear from FIGS. 2 and 3A and 3B, the Z coordinate is Y coordinate = 0 and Z = Rcosλ.

As a result, as shown in FIGS. 3A and 3B, the center point Cb of the arc trajectory of the truing material 1 forming the arc trajectory m is shifted from the coordinate reference line Z-Z. An initial center point Ca separated by the radius A of the arc trajectory m is set so as to be shifted away from the coordinate reference line Z-Z, and the movement trajectory m of the truing material 1 is set inside the coordinate reference line Z-Z. By performing truing at an inclination angle λ so as to take an arc trajectory m, truing of the pushing amount P of the truing material 1 is possible,
Thereby, the outer peripheral surface of the cylindrical grindstone 10 can be formed with a margin D in a slightly concave arc shape.

The truing material 1 used in the present embodiment
Other dresser materials may be used in addition to the diamond dresser made from the above-mentioned monolithic diamond, polylithic diamond, or hybrid diamond.

(Example) FIG. 6A shows proof data of the result of Example 1. Cylindrical whetstone 10 full length (H × 2): 120 mm, radius R: 1
Truing of the 00 mm cylindrical grindstone 10 is performed. As the truing material 1, a diamond dresser made of a monolithic diamond was used, the desired grinding stone shape was a convex arc shape, the curvature height k was set to 4 μm, and the inclination angle λ was set to 0.51 °.

First, the pushing amount P of the truing material 1 is determined from the curvature height k. Assuming that the allowance D = k, P = D · sin λ / (1-cos λ) = 0.004 × sin 0.51 ° / (1-cos 0.51 °) = 0.899 mm Next, the circular orbit m of the truing material 1 Is determined. A = (H ² + P ² ) /2P=2002.674 mm Finally, the XYZ coordinates of the center point Cb of the circular orbit m of the truing material 1 are obtained. X coordinate of Cb = A−Q = 2001.784 mm Y coordinate = 0 Z coordinate = Rcosλ = 99.996 mm Above, based on the obtained radius A of the circular orbit m and the XYZ coordinates of the center point Cb of the circular orbit m, FIG. Truing was performed by turning the truing material 1 around Cb along the arc trajectory m shown in FIGS. 2 (A) and 2 (B).

FIG. 6B shows proof data of the results of Example 2. Cylindrical whetstone 10 full length (H × 2): 120 mm, radius R: 1
Truing of the 00 mm cylindrical grindstone 10 is performed. As a truing material 1, a diamond dresser made of a monolithic diamond was used. The desired shape of the grindstone was a concave arc shape, the curvature height k was set to 4 μm, and the inclination angle λ was set to 0.51 °.

First, the pushing amount P of the truing material 1 is obtained from the curvature height k, and then the radius A of the circular orbit m of the truing material 1 is obtained. These calculation formulas and obtained values are the same as those in the first embodiment, and a description thereof will be omitted. Finally, the XYZ coordinates of the center point Cb of the circular orbit m of the truing material 1 are obtained. X coordinate of Cb = A + Q = 2003.564 mm Y coordinate = 0 Z coordinate = Rcosλ = 99.996 mm Above, based on the obtained radius A of the circular arc trajectory m and the XYZ coordinates of the center point Cb of the circular trajectory m, FIG. A) Truing was performed by turning the truing material 1 around Cb along the arc trajectory m shown in (B). As a result, FIG.
Truing was performed in a concave shape as shown in (B), and the allowance D (maximum concave amount) was about 4 μm, which coincides with the result obtained by calculation.

(Comparative Example) Next, a prior art in which the outer peripheral surface is linear is shown as a comparative example. Conventional truing method is to perform truing against the truing member 1 into a cylindrical grinding wheel 10 normal direction L _H.

According to such a conventional truing method, it is easy to truing on a straight line.
In the case where the shape of the outer peripheral surface is intentionally changed to a convex shape or a concave shape in the same manner as described above, the grinding stone has a removal ratio D of 1: 1.
You have to make subtle changes during truing.
In other words, it is necessary to finely adjust the moving amount of the machine by 1: 1 with the allowance D, and control the grinding wheel shape (the allowance D) in units of 1 μm. In the current equipment, the machine must be controlled at the 1 μm level. Was extremely difficult and could not be trued.

[0047]

As described above, according to the present invention, it is possible to perform truing with high accuracy even when the mechanical accuracy (operation error) of the driving system of the truing material is inferior to the required accuracy of truing. In particular, the present invention arbitrarily and accurately truing the outer peripheral portion of the cylindrical grindstone not only in a straight line but also in an uneven curve shape, more specifically, accurately truing the outer peripheral portion of a convex or concave arc-shaped grindstone in units of several μm. It is possible to do. As a result, it becomes possible to grind a semiconductor wafer with high accuracy using the cylindrical grindstone formed by the truing method.

[Brief description of the drawings]

FIG. 1 shows an operation diagram in which the basic configuration of the present invention is designed.

FIG. 2 is an operation view showing a model for truing a cylindrical grindstone having a convex arc shape.

FIG. 3 is an operational view showing a model for truing a cylindrical arc wheel having a concave arc shape; Show.

FIG. 4 is a graph showing a flatness state of a semiconductor wafer formed by a conventional grindstone and a cylindrical grindstone of the present invention.

FIG. 5 shows the type (A) of the truing material and the processing method in the prior art.

FIG. 6 is verification data obtained by grinding a convex circular cylindrical grindstone and a concave circular cylindrical grindstone.

[Explanation of symbols]

 1 Truing material 10 Cylindrical whetstone

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Taniyoshi Hirano 5-38-3 Ujinahigashi, Minami-ku, Hiroshima-shi, Hiroshima Prefecture Toyo Atec Co., Ltd. 5-Chome No.3-38 Toyo A-Tech Co., Ltd. F-term (reference) 3C047 AA13 AA16 CC14 3C049 AA03 AA19 BA02 BA07 BC02 CA01 CA06 CB01 CB04

Claims (5)

[Claims] 1. A truing method for a cylindrical grindstone in which truing is performed while moving a truing material in contact with the rotating cylindrical grindstone peripheral surface in the width direction of the grindstone in order to truing the outer peripheral surface of the cylindrical grindstone into an arbitrary shape. The direction in which the truing material advances to and retracts from the cylindrical grindstone is a direction in which the truing material is inclined at an angle of 10 ° or less to the normal to the tangent line on the contact position of the truing material, and the truing orbit of the truing material has a straight line or an arc. A truing method for a cylindrical grindstone, characterized by a curved orbit including: 2. A truing method for forming a convex arc-shaped cylindrical grindstone while moving a truing material in contact with a rotating cylindrical grindstone peripheral surface in the width direction of the grindstone, wherein the trajectory of the truing material forming the circular arc trajectory is formed. A center point is shifted from the coordinate reference line passing through the rotation axis of the cylindrical grindstone to the coordinate reference line side from the initial center point separated by the radius A of the arc trajectory of the truing material, and the movement trajectory of the truing material is A truing method for a cylindrical grindstone, wherein the outer peripheral surface of the cylindrical grindstone is formed in a convex arc shape by performing truing so as to take an arc trajectory outside a coordinate reference line. 3. A truing method for forming a concave circular arc-shaped cylindrical grindstone while moving a truing material in contact with a rotating cylindrical grindstone peripheral surface in the grindstone width direction, wherein the arcuate trajectory of the truing material forming the circular arc trajectory is formed. The center point is shifted from the coordinate reference line passing through the rotation axis of the cylindrical grindstone to the side away from the coordinate reference line from the initial center point separated by the radius A of the circular orbit of the truing material, and set.
A truing method for a cylindrical grindstone, wherein the outer peripheral surface of the cylindrical grindstone is formed in a concave arc shape by performing truing so that a movement trajectory of the truing material takes an arc trajectory inside the coordinate reference line. 4. The truing method according to claim 1, wherein the truing trajectory of the truing material is a circular arc trajectory. 2H between the both ends of the cylindrical grindstone (total width of the grindstone), radius R of the cylindrical grindstone, outer peripheral surface of the grindstone to be obtained. Of the truing material, and the inclination angle λ of the truing material with respect to the tangent of the truing material in the reciprocating direction. The radius A of the tracing material arc orbit determined from these basic data and the center point Cb of the truing material arc trajectory determine the arc. A truing method, wherein a trajectory is set, and truing of the outer peripheral surface of the grindstone is performed while moving the truing material along the set arc trajectory. 5. An outer peripheral surface of a cylindrical grindstone is formed in advance into a drum shape (convex circular arc shape) when flattening a silicon wafer with a flatness of about 1 μm or less by a surface grinding means having a cylindrical grindstone attached thereto. A method of grinding a semiconductor wafer using a cylindrical grindstone, wherein a maximum convexity (curvature height) of the arc portion is set to 2 to 10 μm.