JP2017052281A - Scribing wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scribing wheel which can improve end surface strength of a fragile material substrate when the substrate is scribed and split.SOLUTION: The circumference of a scribing wheel is polished to V-shaped, to form a diamond film on a polishing surface. Then, a band-like part including the ridge line at the V-shaped tip is coarsely-polished so as to be an apex angle α2, to form a first polishing surface 15. Furthermore, the band-like part including the ridge line in the first polishing surface 15 is finish-polished, to form a second polishing surface 16 of an apex angle α3. At this time, the arithmetic average roughness of the ridge line which is an intersection of the second polishing surface 16 is made to be 0.015 μm or less. Doing so reduces the roughness of the ridge line and the inclined surface of the blade tip, and improves the end surface strength of a fragile material substrate when being scribed.SELECTED DRAWING: Figure 4C

Description

  The present invention relates to a scribing wheel for scribing a brittle material substrate such as a ceramic substrate or a glass substrate.

  In the conventional scribing wheel, the circumferential portion is cut obliquely from both sides with respect to a disc made of cemented carbide or sintered diamond, and a V-shaped cutting edge is formed on the circumferential surface. The scribing wheel has a through hole at the center, and is used by being rotatably attached to a scribing head or the like of a scribing device.

  In order to form a V-shaped cutting edge on the circumferential surface of a conventional scribing wheel, first, a through hole 102 is formed at the center of the disc 101. FIG. 1A shows a side view of the disc 101. Next, as shown in a side view in FIG. 1 (b) and a front view in FIG. 1 (c), the circumferential portion is polished into a V shape from both sides to form a blade edge portion 103. In some cases, the scribing wheel 100 is configured by finishing and polishing the cutting edge portion 103 with a finer-grained abrasive.

Patent Document 1 discloses a glass cutting blade in which a V-shaped blade edge surface is coated with diamond in order to increase the life of the glass cutting blade for cutting a glass substrate. This blade for cutting a glass is shaped by coating a diamond film on the surface of a cutting edge formed of a ceramic that is compatible with diamond and then polishing the diamond film. It has been shown that by using such a glass cutting blade, it is possible to cut hard altitude glass so that the blade has a long life and the cut surface is smooth.

  Patent Document 2 discloses a diamond-coated cutting blade in which a base material such as cemented carbide is coated with a diamond layer in order to prevent slippage or deterioration of cutting quality when cutting an optical fiber, a glass substrate, or the like. ing. This document is characterized in that the surface of the diamond layer is not smoothed after coating.

  Patent Document 3 discloses a tool for polishing a diamond coating by irradiating an ion beam in a diamond-coated tool having a blade portion in which the surface of a tool base material is coated with a diamond coating. In this document, the tip portion of the blade portion is ground to have a blade edge angle larger than the original blade edge angle and a range of the blade edge width of 10 to 100 nm is used as the tip polishing portion, thereby ensuring a predetermined blade edge strength and excellent. It is disclosed that sharpness can be obtained.

Japanese Patent Laid-Open No. 04-224128 JP 2011-126754 A JP2012-11475A

  The blade for glass cutting shown in Patent Document 1 has a structure in which a base material is ceramic, a cross-sectional shape is V-shaped, a diamond film is coated, and further polished. However, this is only one stage of polishing, and the surface roughness after polishing cannot be made sufficiently small. Even in the diamond-coated cutting blade described in Patent Document 2, since the surface is not smoothed, when the brittle material substrate is scribed, the end face accuracy of the substrate is deteriorated as compared with the case where the polishing is not performed. However, the end face strength is inferior.

  When cutting a brittle material substrate such as a glass substrate, it is cut along the scribe line after scribing using a scribing wheel, but the end face when pressure is applied because scratches remain on the cut brittle material substrate end face. Often destroyed from. If there are irregularities on the V-shaped cutting edge formed on the circumferential surface of the scribing wheel, scratches remain on the end face of the brittle material substrate when it is divided, so that the mechanical strength of the brittle material substrate decreases. In addition, when scribing a brittle material substrate having a high hardness such as ceramics, if the cutting edge is uneven, the cutting edge may be chipped during scribing or the diamond film may be peeled off from the uneven portion. Therefore, it is preferable that the ridge line of the V-shaped cutting edge of the scribing wheel has as little as possible unevenness.

  Further, the scribing wheel described in Patent Document 3 is designed to polish the cutting edge by irradiation with an ion beam, but the cutting edge slope of the scribing wheel is not sufficiently polished, and the roughness is relatively rough. It has become. For this reason, when the brittle material substrate is scribed and divided using this scribing wheel, there is a problem in that the end face strength of the substrate is inferior. In addition, since the ion beam is irradiated, there are problems that the roughness of the slopes on both sides of the cutting edge differs from the ridge line and that it is difficult to make the ridge line straight in a side view.

  The present invention has been made in view of such problems, and when a brittle material substrate is scribed and divided using a scribing wheel coated with a diamond film, the edge surface accuracy of the divided substrate is high and the edge surface strength is increased. An object of the present invention is to provide a scribing wheel that can be made large, can prevent chipping and peeling of the diamond film, and can extend the life of the scribing wheel, and a method for manufacturing the scribing wheel.

  In order to solve this problem, the scribing wheel of the present invention is a scribing wheel in which a ridge line is formed along a circumferential portion and has a cutting edge composed of the ridge line and inclined surfaces on both sides of the ridge line. A scribing wheel base material in which a cutting edge portion is formed along the circumference, a diamond film formed on the surface of the cutting edge of the scribing wheel base material, and a belt-like shape formed in regions on both sides of a ridge formed by the diamond film And a belt-like second polishing surface having a width narrower than the width of the first polishing surface formed in regions on both sides of the ridge line at the tip of the first polishing surface. The apex angle at which the first polishing surface intersects is larger than the apex angle at which the inclined surface of the diamond film intersects, and the apex angle at which the second polishing surface intersects the first polishing surface. Larger than the apex angle The arithmetic average roughness Ra of the second polishing surface is smaller than the arithmetic average roughness Ra of the first polishing surface, and the arithmetic average roughness Ra of the ridge line portion where the second polishing surface intersects is 0.00. 015 μm or less.

  Here, the apex angle at which the inclined surfaces of the diamond film intersect may be 80 to 150 °.

  According to the present invention having such a feature, the cutting edge of the scribing wheel is polished into a V shape, a diamond film is formed on the polishing surface, only the tip portion is roughly polished, and then finish polishing is performed. Therefore, the unevenness of the ridge line portion necessary as the cutting edge can be reduced. For this reason, when the brittle material substrate is divided using a scribing wheel, an excellent effect is obtained that the end face accuracy is high and the end face strength can be improved. Such a feature is particularly effective when scribing and cutting a thin brittle material substrate. In addition, since the diamond film is used, even when scribing a brittle material substrate with high hardness, the scribing wheel wears little and the unevenness of the ridge line part is small. Since it is difficult to occur, the life of the scribing wheel can be extended. Such a feature is particularly effective when scribing a hard brittle material substrate.

FIG. 1 is a side view and a front view showing a conventional scribing wheel and its manufacturing process. FIG. 2 is a front view and a side view of the scribing wheel according to the embodiment of the present invention. FIG. 3 is a side view showing the manufacturing process of the scribing wheel according to the present embodiment. FIG. 4A is an enlarged cross-sectional view of the tip portion showing a state where a diamond film is formed on the base material of the scribing wheel according to the present embodiment. FIG. 4B is an enlarged cross-sectional view showing a tip portion of a scribing wheel subjected to rough polishing. FIG. 4C is an enlarged cross-sectional view showing a tip portion of a scribing wheel that has been subjected to finish polishing. FIG. 4D is an enlarged cross-sectional view showing a tip portion of a scribing wheel subjected to finish polishing according to another example. FIG. 5A is an enlarged cross-sectional view of a ridge line portion before polishing of a blade edge according to a modification of the present embodiment. FIG. 5B is an enlarged cross-sectional view of a ridge line portion after polishing of the blade edge according to a modification of the present embodiment. FIG. 6A is a diagram showing arithmetic average roughness before and after polishing of the scribing wheel according to Examples 1 and 4 of the present invention. FIG. 6B is a diagram showing arithmetic average roughness before and after polishing of the scribing wheel according to Examples 2 and 5 of the present invention. FIG. 6C is a diagram showing arithmetic average roughness before and after polishing of the scribing wheel according to Examples 3 and 6 of the present invention.

  FIG. 2A is a front view of a scribing wheel according to the embodiment of the present invention, and FIG. 2B is a side view thereof. FIGS. 3A to 3D are side views showing the manufacturing process of the scribing wheel of this embodiment. When the scribing wheel 10 is manufactured, for example, a through hole 12 serving as a shaft hole is first formed in the center of a disk 11 serving as a base material of a cemented carbide or ceramic scribing wheel, as shown in FIG. Form.

  Next, a shaft of a motor or the like is communicated with the through hole 12 and the central axis of the through hole 12 is rotated as the rotation shaft 12a, and the entire circumference of the disk 11 is polished from both sides and shown in FIG. In this way, a vertical section V having an inclined surface and a ridgeline is formed, and the inclined surface is defined as a polished surface 13. The apex angle at this time is preferably 80 ° to 150 °, more preferably 90 ° to 140 °. When the angle is 80 ° or less, the tip of the ridge line is easily damaged during processing, and when the angle is 150 ° or more, the utility as a cutting edge tends to be lost.

  Next, a diamond thin film is formed on the substantially V-shaped polished surface 13. First, as shown in the enlarged sectional view of the ridge line portion of the cutting edge in FIG. 4A, the substantially V-shaped polished surface 13 is roughened in advance so that the diamond film can be easily attached. Next, after forming diamonds having nuclei with a particle size of submicron or less on the slope portion, diamond nuclei are grown by chemical vapor reaction to form a diamond film 14 having a thickness of, for example, 10 to 30 μm. Such a diamond film may be formed once to form a single-layer diamond film, or may be repeated many times to form a multilayer diamond film. Here, since the diamond film is formed substantially uniformly on the inclined surface and the ridgeline of the scribing wheel base material, the apex angle of the diamond film becomes substantially equal to the apex angle of the scribing wheel base material. The apex angle of this diamond film is defined as a first apex angle α1. The apex angle α1 is preferably 80 ° to 150 °, more preferably 90 ° to 140 °. When the angle is 80 ° or less, the tip of the ridge line is easily damaged during processing, and when the angle is 150 ° or more, the utility as a cutting edge tends to be lost.

  Next, rough polishing is performed on the diamond film 14. In rough polishing, for example, an abrasive having a particle size of 8000 or less is used. In the case of an abrasive larger than # 8000, the required degree of processing cannot be obtained for the diamond film 14 because the particle size of the abrasive is too fine. In this step, the polishing is performed so that only the belt-like portion including the ridge line becomes the second apex angle α2 (α2> α1). FIG. 4B is an enlarged view showing the tip portion. The polished surface thus formed is referred to as a first polished surface 15. Here, the polishing is performed so that the apex angle α2 is larger than α1 by θ1. θ1 is set to a value larger than 0, for example, 5 °. The width w1 in FIG. 4B indicates the width of the first polishing surface 15, and the minimum value of the width w1 is, for example, 10 to 20 μm.

  Next, as shown in FIG. 4C, finish polishing is performed only on the band-shaped portion having a narrower width w2 (w2 <w1) including the ridgeline of the polishing surface 15 at the center. In the final polishing, polishing is performed using a fine abrasive material having a finer particle size than that of the rough polishing. Then, the surface including the circle composed of the ridge line after the polishing is polished so as to be perpendicular to the rotation axis 12a, and the apex angle is a desired third apex angle α3 (α3> α2). The finished polished surface thus formed is defined as a second polished surface 16. Here, the grain size of the abrasive is preferably 9000 or more, more preferably 10,000 or more, and even more preferably 15000 or more. In the final polishing, polishing is performed by using a fine abrasive having a finer particle size than that of the rough polishing, so that the arithmetic average roughness of the second polishing surface is smaller than the arithmetic average roughness of the first polishing surface. In the final polishing step, polishing is performed until the arithmetic average roughness Ra of the edge surface and the ridge line after polishing is 0.03 μm or less, preferably 0.015 μm or less. If the abrasive particle size is smaller than No. 9000, it is difficult to make the arithmetic average roughness Ra of the blade edge surface and ridge line after polishing 0.03 μm or less. For this reason, the film is likely to be broken or peeled off during scribing, and scratches tend to remain on the end face of the divided brittle material substrate. Here, polishing is performed so that the apex angle α3 is larger than α2 by θ2. θ2 is set to a value larger than 0, for example, 5 °. By this finish polishing, the surface including the circle formed by the ridgeline of the diamond film is made perpendicular to the central axis of the scribing wheel base material. A material having a large final apex angle α3 is suitable for use at a high scribe load, and a material having a small apex angle α3 is suitable for use at a low scribe load.

  The scribing wheel is polished by an abrasive such as a grindstone. One inclined surface of the diamond film formed on the cutting edge of the scribing wheel is subjected to rough polishing or finish polishing with a grindstone. By processing with a grindstone, it becomes easy to grind the inclined surface at the same angle over the entire circumference of the scribing wheel. When the rough polishing or finish polishing of one surface is finished, the other surface is similarly polished. In this way, particularly when polishing using a grindstone, it becomes easy to recognize the apex angles α2 and α3 to desired values and to straighten the ridge line of the scribing wheel in a side view. Furthermore, it is possible to easily polish a region having a desired width (w1 or w2).

  In this way, the cutting edge has a two-step V-shape, so that only the tip of the diamond at the cutting edge necessary for the scribing wheel is finish-polished. By reducing the processing area, the processing time is shortened, and the irregularities on the edge of the cutting edge are reduced. Can be reduced. In this embodiment, w2> w1, and the first polishing surface 15 is left on both sides of the second polishing surface 16 after finish polishing as shown in FIG. 4C, but as shown in FIG. 4D. Final polishing may be performed so that the first polishing surface 15 is completely replaced by the second polishing surface 16. In this case, the width w3 is not less than w1 (preferably W3 = w1).

  By polishing in this way, as compared with a conventional scribing wheel made of sintered diamond, all of the portion in contact with the brittle material substrate becomes diamond, so that the wear resistance of the scribing wheel can be improved. In addition, since all of the portion in contact with the brittle material substrate is a diamond film, the roughness of the cutting edge portion and the ridge line contributing to scribe can be reduced. Furthermore, unlike ion beam polishing, both sides of the ridgeline can be polished under the same conditions, so the polished surfaces on both sides can be made to have the same roughness, and the ridgeline can be linear in side view. Easy to do. Therefore, by scribing and dividing a brittle material substrate such as a glass substrate or a ceramic substrate using this scribing wheel, the end face accuracy of the cut surface of the brittle material substrate is improved, and the end face strength can be improved accordingly. Is obtained. Further, by reducing the roughness of the cutting edge and the ridgeline, the effect that the diamond film becomes difficult to peel even when the substrate having high hardness is scribed can be obtained. Therefore, the scribing wheel of the present invention is suitable for scribing a ceramic substrate.

  Needless to say, the particle size of the abrasive shown here is merely an example, and is not limited to this particle size.

  Next, a modification of the present embodiment will be described. In this modified example, as shown in FIG. 5A, which shows an enlarged view of the tip portion of the cutting edge portion, after the polishing surface 13 is formed, the ridge line is further polished in parallel with the rotating shaft 12a of the scribing wheel, and the rotating shaft 12a of the scribing wheel. A circumferential surface 20 having a flat cross section is provided in the ridge line portion of the substrate so as to be parallel to the substrate. The width of the circumferential surface 20 is, for example, about 2 to 10 μm. Thereafter, as in the present embodiment, the polishing surface 13 having the circumferential surface 20 is coated with the diamond film 14 by the CVD method. Here, the first apex angle α1 is an angle formed by an extension line of the inclined surface of the diamond film 14. After this coating, the circumferential portion is polished as shown in FIG. 5B to form a first polished surface, a second polished surface, and a ridge line. In this way, the thickness of the diamond film at the ridge line portion can be increased as compared with the present embodiment, and the abrasion resistance and peeling resistance of the scribing wheel can be improved.

  Next, the state before the grinding | polishing of the scribing wheel by the Example of this invention and the state after grinding | polishing are demonstrated. In this example, a carbide alloy scribing wheel substrate having an outer diameter of 2 mm is used. Examples 1, 2, and 3 are diamond films having a particle size of about 5 μm. Examples 4, 5, and 6 have a particle size of 0. A diamond film having a thickness of about 5 μm is formed. In each of Examples 1 and 4, the apex angle α1 of the blade edge before polishing is 110 °, and in rough polishing, polishing is performed using a No. 8000 abrasive so that the apex angle α2 becomes 115 ° after the completion of rough polishing. In the final polishing, polishing is performed using a No. 15000 abrasive so that the apex angle α3 becomes 120 ° after the completion of the final polishing. The thickness of the thinnest part near the ridgeline of the diamond film 14 after polishing is set to 20 μm, for example. For these two examples, the arithmetic mean roughness Ra on the inclined surface on the ridge line portion and on the line parallel to the ridge line a certain distance from the ridge line portion was as shown in FIG. 6A.

  In each of Examples 2 and 5, the apex angle α1 of the blade edge before polishing is 125 °, and after polishing using a No. 8000 abrasive, the apex angle α2 is 130 ° and finish polishing is performed using an No. 15000 abrasive. The surface is later polished so that the apex angle α3 is 135 °. About these two examples, arithmetic mean roughness Ra in the inclined surface on a ridgeline part and a line parallel to the ridgeline away from it by fixed distance was shown to FIG. 6B.

  In each of Examples 3 and 6, the apex angle α1 of the blade edge before polishing is 140 °, and the apex angle α2 is finished by using a No. 8000 abrasive material and the apex angle α2 is 145 ° after No. 15000 polishing material. Polishing is performed so that the apex angle α3 is 150 ° after polishing. About these two examples, arithmetic mean roughness Ra in the inclined surface on the ridgeline part and the line parallel to the ridgeline away from it by a certain distance was shown in FIG. 6C.

  In each of Examples 1 to 6, polishing was possible without chipping the surface during finish polishing. In any of the examples, the arithmetic average roughness Ra of the polished surface after finish polishing was 0.022 μm or less, and was 0.015 μm or less excluding the value of the inclined surface in Example 1. In Examples 4 to 6, the arithmetic average roughness is smaller than in Examples 1 to 3. This is considered to be because, in Examples 1 to 3, since the particle size is large, the arithmetic average roughness of the film surface before polishing is also increased. However, in this case as well, by performing finish polishing, the arithmetic average roughness Ra after finish polishing can be sufficiently lowered. Therefore, when cutting is performed after scribing using this scribing wheel, the end face accuracy of the brittle material substrate is improved. Can be improved.

  The scribing wheel of the present invention can be used for a scribing apparatus for scribing a brittle material substrate, and is particularly effective for a scribing apparatus for scribing a thin brittle material substrate.

DESCRIPTION OF SYMBOLS 10 Scribing wheel 11 Disc 12 Through-hole 12a Rotating shaft 13 Polishing surface 14 Diamond film 15 1st polishing surface 16 2nd polishing surface

Claims (2)

A scribing wheel having a cutting edge formed with a ridge line along a circumferential portion, the ridge line and an inclined surface on both sides of the ridge line,
A scribing wheel base material in which a cutting edge portion is formed along the circumference of the disc;
A diamond film formed on the cutting edge surface of the scribing wheel substrate;
A band-shaped first polished surface formed in regions on both sides of the ridge line formed of the diamond film;
A band-shaped second polishing surface that is narrower than the width of the first polishing surface formed in regions on both sides of the ridgeline at the tip of the first polishing surface;
An apex angle at which the first polishing surface intersects is larger than an apex angle at which the inclined surface of the diamond film intersects, and an apex angle at which the second polishing surface intersects is an apex angle at which the first polishing surface intersects. Bigger than
The arithmetic average roughness Ra of the second polishing surface is smaller than the arithmetic average roughness Ra of the first polishing surface,
A scribing wheel having an arithmetic mean roughness Ra of 0.015 μm or less at a ridge line portion where the second polishing surfaces intersect.   The scribing wheel according to claim 1, wherein an apex angle at which the inclined surfaces of the diamond film intersect each other is 80 to 150 °.