JP2001001243A - Method and device for chamfering outer circumferential portion of thin disklike work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact and inexpensive device for chamfering an outer circumferential portion of a thin disklike work to carry out a method for chamfering the outer circumferential portion of the thin disk-like work with short chamfering time. SOLUTION: In this device for chamfering an outer circumferential portion of a thin disklike work, a thin disk-like work W is rotated about its axis, an outer circumferential surface of a grinding wheel 1 is pressed against the outer circumferential surface of the work while the columnar grinding wheel 1 is rotated about its axis to chamfer the outer circumferential part of the work W. A groove 2 is formed over the whole length of the outer circumferential surface of the grinding wheel 1. The groove 2 is smaller toward a bottom, and a bottom surface of the groove 2 is of a recessed curved surface. The work W and the grinding wheel 1 are arranged so that the axis Sw of the work W is located on one of two parallel planes, and the axis S1 of the grinding wheel 1 is located on the other, and both axes are not parallel to each other. A driving device to adjust the distance between the axis Sw of the work W and the axis S1 of the grinding wheel 1 is provided.

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 chamfering an outer peripheral portion of a thin disk-shaped work, and more particularly, to an outer peripheral portion of a thin disk-shaped workpiece for performing chamfering grinding called beveling on an outer peripheral portion such as a semiconductor wafer. Method and apparatus.

[0002] In the present specification, the term "cylindrical" includes not only ordinary cylindrical shapes and short cylindrical shapes but also disk shapes.

[0003]

2. Description of the Related Art An apparatus for chamfering an outer peripheral portion of a thin disk-shaped work is disclosed in Japanese Patent Application Laid-Open No. 5-152259. This chamfering device rotates a thin disk-shaped work and rotates a columnar grindstone, and presses the grindstone outer circumferential surface against the work outer circumferential portion to chamfer the outer circumferential portion of the work. A part chamfering device, wherein a rotation axis of a grindstone is provided to be inclined with respect to a tangential direction of a work. On the outer peripheral surface of the grindstone, the side surfaces are inclined with respect to the upper and lower end surfaces of the grindstone so as to become thinner toward the bottom over the entire length of
A groove whose bottom is parallel to the axis is formed.

In this chamfering apparatus, for example, the upper end surface of a grindstone is pressed against the upper end surface of the outer peripheral portion of the work, and the upper end surface of the outer peripheral portion of the work is chamfered into a predetermined shape. The bottom surface of the groove of the grindstone is pressed against the workpiece, and the lower end surface of the outer peripheral portion of the work is chamfered into a predetermined shape.

[0005]

In the case of the above chamfering device,
There is a problem that only one of the upper and lower end surfaces of the outer peripheral portion of the workpiece can be machined, and the machining time becomes longer.
In addition, after machining of one surface, at least one of the work and the grindstone must be moved in the axial direction and then the other surface needs to be machined. There is a problem that an axial driving device for moving in the direction is required, and the device becomes large and expensive.

An object of the present invention is to provide a method for chamfering the outer peripheral portion of a thin disk-shaped work, which solves the above-mentioned problems and has a short processing time. It is still another object of the present invention to provide a small-sized and inexpensive thin disk-shaped workpiece outer peripheral chamfering apparatus for carrying out this method.

[0007]

Means for Solving the Problems and Effects of the Invention In order to solve the above-mentioned problems, a method for chamfering the outer peripheral portion of a thin disk-shaped work according to the present invention is to rotate the thin disk-shaped work around its axis, and In the method of chamfering the outer peripheral portion of the work by pressing the outer peripheral surface of the grindstone against the outer peripheral portion of the work in a state where the short cylindrical grindstone is rotated around the axis thereof, the outer peripheral portion of the grindstone is chamfered. On the entire surface, a groove is formed which is curved toward the bottom and has a concave bottom surface.The groove is formed such that the axis of the grinding wheel is located on one of two planes parallel to the axis of the workpiece and the other is on the other side. In a state where the workpiece and the grindstone are arranged so that the axes are not parallel to each other, using a thin disk-shaped workpiece outer peripheral chamfering device having a shape for chamfering the outer peripheral portion of the workpiece into a desired shape, the axis of the workpiece and the grindstone are used. Gradually increase the distance from the axis And performs chamfering of the work outer periphery close.

According to this method, one surface of the outer peripheral end of the work can be simultaneously processed by one side surface of the groove, the other surface of the outer peripheral end of the work can be processed by the other side surface, and the outer peripheral end portion can be simultaneously processed by the bottom surface of the groove. Therefore, the processing time of the work is shortened, and it is not necessary to move the grindstone and the work in the axial direction.

In order to carry out the above method, the outer peripheral chamfering apparatus for a thin disk-shaped work according to the present invention rotates the thin disk-shaped work around its axis and rotates the columnar grindstone around its axis. In this state, a groove is formed over the entire length of the grindstone outer peripheral surface chamfering device in a thin disc-shaped work outer peripheral chamfering device that chamfers the outer peripheral portion of the work by pressing the outer peripheral surface of the grindstone against the outer peripheral portion of the work. The work and the grindstone have a curved surface that becomes thinner and has a concave groove bottom, with the axis of the grindstone positioned on one of the two planes parallel to the axis of the work, and the axes not parallel to each other. And a drive device for adjusting the distance between the axis of the workpiece and the axis of the grindstone.

In the above chamfering apparatus, it is natural that the curvature of the bottom surface of the groove is larger than the curvature of the curved surface to be formed at the outer peripheral end of the work. In addition, the fact that the groove becomes thinner toward the bottom means that at least one side surface is inclined with respect to the end surface of the grindstone, but the inclination of this side surface is continuous with the outer peripheral end portion of the work by this side surface. It is natural that the inclination is larger than the inclination of the inclined portion formed as described above.

According to this apparatus, the above method can be easily carried out, and there is no need to move the grindstone and the work in the axial direction, so that the apparatus is small and inexpensive.

Further, the contact area between the grindstone and the work is larger than when the axis of the grindstone and the axis of the work are parallel, so that the number of abrasive grains in contact with the work increases and the grindstone and the work come in contact with each other. The contact pressure of the workpiece decreases, and the processing accuracy of the workpiece increases.

In addition, since the gap between the grindstone and the wafer does not disappear even if the shape of the outer peripheral portion of the work approaches the shape of the beveling to be formed here, the grinding fluid is applied to the contact portion between the grindstone and the work. Processing accuracy is further improved.

In the above chamfering apparatus, it is preferable that the angle formed by the axis of the grindstone with respect to the axis of the work can be changed when viewed from a direction perpendicular to the parallel plane where the axes of the work and the grindstone are located. .

This is because, if the angle is changed for each work, the outer peripheral portion of each work can be chamfered into a different shape. Further, when chamfering a semiconductor wafer or the like, it is preferable to change the angle between processing the portion where the orientation flat is formed and processing the other portion.
For example, if the angle θ2 at which the beveling is formed on the orientation flat of the work is made smaller than the angle θ1 at which the beveling is formed other than the orientation flat, beveling having a shape different from that of the other parts can be formed on the orientation flat. it can.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

FIGS. 1 and 2 show a grinding wheel of an outer peripheral chamfering device.
(1) and the thin disk-shaped semiconductor wafer chamfered by it
(W) is shown. An orientation flat (O) is formed on the wafer (W) in advance.

The grindstone (1) is rotated about its axis (S1) by a known rotary drive (not shown). The wafer (W) is held in a horizontal state by a known holding or suction mechanism (not shown), and is rotated about its axis (Sw) by a rotation driving device (not shown).

In this chamfering apparatus, the axis (Sw) of the wafer (W) is aligned with a plane (Pw) which is one of vertical planes parallel to each other.
The wafer (W) and the grindstone (1) are arranged so that the axis (S1) of the grindstone (1) is positioned on the other plane (P1). Further, a wafer (W) and a grindstone (1) are arranged so that the two axes (Sw) and (S1) are not parallel to each other.
As shown in the figure, the axis (S1) starts from the direction perpendicular to the plane (P1) (Pw).
The axis (S1) of the grindstone (1) is inclined at an angle θ1 with respect to the axis (Sw) of the wafer (W) which is perpendicular.

A groove (2) is formed over the entire circumference of the grindstone (1) so that the entire surface is a polished surface. The upper and lower side surfaces (2b) of the groove (2) are inclined with respect to the upper and lower end surfaces of the grindstone (1) so as to become thinner toward the bottom. The bottom surface (2a) of the groove (2) has a concave curved surface, and the side surface (2b) of the groove (2) connected to the bottom surface (2a) has a flat surface. This whetstone (1)
When the axis (Sw) of (W) and the axis (S1) of the grindstone (1) intersect at an angle θ1, as shown in FIG. 2A, the outer peripheral end has a curved surface (R1) having a curvature of R1. Wa), a plane portion (Wb) continuous with the curved surface portion (Wa) is for forming beveling having an inclination of α1 with respect to a horizontal plane, and the curvature R of the bottom surface (2a) is
2 is larger than R1, and the inclination α2 of the side surface (2b) with respect to the horizontal plane is larger than α1.

The chamfering device is provided with a distance between the two axes (S1) and (Sw), that is, a plane on which the respective axes (S1) and (Sw) are located.
A suitable driving device (not shown) for adjusting the distance between (Pw) and (P1) is also provided. In addition, a rotary drive device and a drive device (not shown) are known devices used in a normal chamfering device,
Detailed description is omitted.

In the chamfering device configured as described above, the processing of the wafer (W) is performed as follows. For example, the contact portion of the wafer (W) with the grindstone (1) rotates in the direction of arrow B shown in FIG. 1, that is, in the horizontal direction, and the contact portion of the grindstone (1) with the wafer (W) changes to the arrow A. In the direction shown, that is, in the direction inclined by θ1 from the horizontal direction, the distance between the two axes (S1) and (Sw) is reduced by the driving device, and the wafer (W)
The groove (2) of the whetstone (1) is pressed against the groove.

The upper and lower ends of the outer peripheral surface of the wafer (W) are pressed against the side surface (2b) of the groove (2), and the distance between the two axes (S1) and (Sw) gradually increases while chamfering is performed. , And eventually
The outer surface of the wafer (W) is aligned with the bottom (2a) of the groove (2).
The outer peripheral portions of the upper and lower end surfaces of (W) are pressed against the side surfaces (2b) of the groove (2), and a curved surface portion (Wa) and a flat surface portion (Wb) are simultaneously formed on the wafer (W).

In the outer peripheral chamfering device of the present invention, the force acting in the direction of arrow A acts on the outer peripheral surface of the wafer (W) as a component force in the directions of arrow B and arrow C. No large force is applied in one direction. Also, the contact area between the grindstone (1) and the wafer (W) is larger than when the axis of the grindstone (1) is parallel to the axis of the wafer (W). As the number of abrasive grains increases, the contact pressure between the whetstone (1) and the wafer (W) decreases.

Further, the curvature R of the curved surface portion (Wa) of beveling
Since the beveled curved surface (Wa) is formed on the bottom surface (2a) of the groove (2) having the curvature R2 larger than 1, the grinding resistance is reduced.

In addition, even if the outer peripheral shape of the wafer (W) approaches the beveling shape to be formed here,
Since the gap between (1) and the wafer (W) does not disappear, the grinding fluid spreads to the contact portion between the grinding wheel (1) and the wafer (W).

When forming the beveling on the orientation flat (O), the angle θ2 of the axis of the grindstone (1) with respect to the axis (Sw) of the wafer (W) is made smaller than the angle θ1 of forming the beveling on the other part. Good. that way,
Since the same effect as increasing the curvatures R2 and α2 of the bottom surface (2a) of the groove (2) can be obtained, the curvature of the tip of the beveling formed on the orientation flat (O) becomes smaller than the orientation flat (O). The inclination angle of the plane portion of the beveling formed in the orientation flat (O) is larger than the curvature R1 of the beveling in the portion where the orientation flat (O) is not formed, and the inclination angle of the plane portion of the beveling in the portion where the orientation flat (O) is not formed. Be larger. Because of this, the orientation flat
The radial length of the beveling of (O) can be made shorter than the radial length of the beveling in the portion where the orientation flat (O) is not formed.

The shape of the groove (2) of the grindstone (1) is not limited to that of the above-described embodiment. For example, the cross section of the groove may be parabolic.

In the above embodiment, the grinding stone (1)
The contact portion of the wafer (W) moves in the direction of arrow A, and the contact portion of the wafer (W) contacts the grinding wheel (1) moves in the direction of arrow B.
(1) and the wafer (W) are rotated. For example, the contact portion between the grindstone (1) and the wafer (W) may rotate in the direction opposite to the arrow A to perform the processing.

For the groove, a mold having the same shape as the wafer (W) having beveling to be formed is used. The axis of this mold is on one of two parallel planes, the axis of the grindstone forming the groove is on the other, and The mold may be formed by pressing a mold against a grindstone in a state where the two axes are inclined so that the angle between them becomes θ1.

The dresser has the same shape as the above-mentioned mold, and the dresser is inclined in such a manner that the axis of the dresser is inclined to one of two parallel planes, the axis of the grinding wheel is inclined to the other, and the angle between both axes is θ1. It is good to use it in a state.

When beveling is formed on the orientation flat (O), it is natural that the dresser is inclined by θ2.

In the above embodiment, the shape of the beveling formed on the wafer (W) is vertically symmetrical, but beveling that is not vertically symmetrical can be formed by changing the cross-sectional shape of the groove.

The angle at which beveling is formed on the wafer (W) is preferably at least 10 degrees or less, but the thickness and diameter of the wafer (W), the thickness and diameter of the grindstone (1), An appropriate value may be set as appropriate depending on the shape of the beveling and the like.

[Brief description of the drawings]

FIG. 1 is a front view of an essential part of a thin disk-shaped work outer peripheral chamfering device of the present invention.

FIG. 2 is a plan view of the chamfering device.

FIG. 3A is a diagram showing beveling formed by the chamfering device, and FIG. 3B is an enlarged view of a groove of the chamfering device.

FIG. 4 is a front view of a main part when beveling is formed on an orientation flat in the chamfering device.

FIG. 5 is a plan view when beveling is formed on an orientation flat in the chamfering device.

[Explanation of symbols]

 (1) Whetstone (2) Groove (2a) Bottom surface (2b) Side (W) Workpiece (wafer) (P1) (Pw) Parallel face (S1) Grindstone axis (Sw) Workpiece axis

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuki Sakura 2-34, Minamiuematsucho, Yao-shi, Osaka Mitsuyo Machinery Co., Ltd. F-term (reference) 3C049 AA03 AA09 AA13 CA05

Claims (4)

[Claims] In a state where a thin disk-shaped work is rotated around its axis and a short columnar grindstone is rotated around its axis, the grindstone is pressed against the outer periphery of the work and the outer periphery of the work is rotated. In the method of chamfering the outer peripheral portion of a thin disk-shaped work, a groove is formed on the entire outer periphery of the grindstone, the groove being tapered toward the bottom and having a concave bottom surface, and the groove is parallel to the axis of the work. In one of the two planes, with the work and the grindstone arranged such that the axis of the grindstone is located on the other side and the two axes are not parallel to each other,
A thin plate for chamfering the outer periphery of a work by gradually reducing the distance between the axis of the work and the axis of the grindstone using a thin disk-shaped work outer periphery chamfering device having a shape that chamfers the outer periphery of the work to a desired shape Chamfering method for the outer periphery of a disk-shaped work 2. An apparatus for chamfering an outer peripheral portion of a thin disk-shaped work for carrying out the method according to claim 1, wherein the thin disk-shaped work is rotated around an axis thereof and a columnar grindstone is rotated. In a thin disk-shaped workpiece outer peripheral chamfering device that performs chamfering of the outer peripheral portion of the work by pressing the outer peripheral surface of the grindstone against the outer peripheral portion of the work while being rotated around the axis, a groove is formed over the entire length of the outer peripheral surface of the grindstone, The groove becomes narrower toward the bottom and the groove bottom forms a concave surface, so that the axis of the grinding wheel is positioned on one of the two parallel planes of the workpiece and the other is not parallel to each other. A work and a grindstone are disposed on the outer periphery of the work, and a drive device for adjusting a distance between the axis of the work and the axis of the grindstone is provided. 3. The method according to claim 1, wherein the angle formed by the axis of the grindstone with respect to the axis of the work can be changed when viewed from a direction perpendicular to a parallel plane on which the axes of the work and the grindstone are located. 3. The apparatus for chamfering an outer peripheral portion of a thin disk-shaped work according to claim 2. 4. The angle formed by the axis of the grindstone with respect to the axis of the work differs depending on whether beveling is formed on the orientation flat of the work or beveling other than the orientation flat. The chamfering device for an outer peripheral portion of a thin disk-shaped workpiece according to claim 2 or 3, wherein the angle θ2 when forming the beveling is smaller than the angle θ1 when forming beveling other than the orientation flat.