JP6357746B2 - Scribing wheel, holder unit, scribing device, scribing wheel manufacturing method and scribing method - Google Patents

Description

  The present invention includes a scribing wheel suitable for forming a scribe line on the surface of a brittle material substrate that is harder than a general amorphous glass substrate, such as a ceramic substrate, a sapphire substrate, or a silicon substrate, and the scribing wheel. The present invention relates to a holder unit, a scribing device, a scribing wheel manufacturing method, and a scribing method.

  When dividing an amorphous glass substrate used for a liquid crystal panel or the like, generally, a scribing wheel made of a cemented carbide as described in Patent Document 1 or a polycrystal that is harder than the cemented carbide. A scribing wheel made of a diamond sintered body is used. This polycrystalline diamond sintered body is obtained by sintering a mixture of diamond particles (content 75 to 90 vol%) and a binder (such as cobalt) under high temperature and high pressure.

  However, when cutting a ceramic substrate such as alumina that is harder than a glass substrate, for example, a scribing wheel made of a cemented carbide disclosed in Patent Document 1 or a scribing wheel made of a polycrystalline diamond sintered body immediately cuts the cutting edge. Will be chipped or worn, and cracks will not be formed after several tens of meters. Therefore, it is not realistic to cut a ceramic substrate that is harder than a glass substrate by using a scribing wheel made of cemented carbide or a scribing wheel made of a polycrystalline diamond sintered body.

  Therefore, when cutting a hard substrate such as a ceramic substrate, it has been studied to use a scribing wheel made of polycrystalline diamond or single crystal diamond which is harder than cemented carbide or sintered polycrystalline diamond. .

Japanese Utility Model Publication No. 55-106635

  When a ceramic substrate is cut using a scribing wheel made of only diamond, such as polycrystalline diamond or single crystal diamond, it is much longer than a scribing wheel made of cemented carbide or sintered polycrystalline diamond. It was possible to form the cracks necessary for splitting.

  However, even with a scribing wheel made of only diamond, the ceramic substrate is very hard, and thus it is impossible to completely prevent chipping and abrasion of the blade edge. Therefore, it is desired to prevent the cutting edge and wear of the blade as much as possible and to use the scribing wheel for as long as possible.

  The present invention provides a scribing wheel, a holder unit, a scribing device, and a scribing wheel that have a longer life when a ceramic substrate that is harder than a glass substrate is cut using a scribing wheel whose blade is made only of diamond. It is an object to provide a method and a scribing method.

In order to achieve the above object, the scribing wheel of the present invention is a scribing wheel whose blade is made of only diamond , used for cutting at least one brittle material substrate selected from the group consisting of ceramic, sapphire and silicon , cutting edge of the blade, the radius 0.8 to 3 [mu] m of which is R chamfered, the diamond Ri Ah single crystal diamond tip R the radius of the cutting edge relative to a surface roughness Ra of the brittle material substrate It characterized that you have been large.

According to the scribing wheel of the present invention, since the cutting edge is rounded by the R chamfering process, even if it is used for cutting a ceramic substrate having a large surface roughness , the single crystal is compared with the scribing wheel not subjected to the R chamfering process. While reducing the influence on the strength due to the crystal orientation of diamond, chipping of the cutting edge can be greatly reduced, and the life of the scribing wheel can be extended.

  In addition, the scribing wheel of the present invention is characterized in that it is used for dividing at least one brittle material substrate selected from the group consisting of ceramic, sapphire, and silicon.

  According to the scribing wheel of the present invention, a long distance can be satisfactorily cut with respect to a brittle material substrate harder than a general amorphous glass substrate used for a liquid crystal panel or the like.

  Moreover, the holder unit of the present invention includes any one of the scribing wheels described above and a holder that rotatably holds the scribing wheel.

  According to the holder unit of the present invention, chipping of the cutting edge of the scribing wheel can be greatly reduced, the scribing wheel has a long life, and the holder unit is suitable for cutting a ceramic substrate or the like.

  Moreover, the scribing apparatus of the present invention includes the holder unit described above.

  According to the scribing apparatus of the present invention, chipping of the cutting edge of the scribing wheel can be significantly reduced, and the scribing apparatus has a long scribing wheel life and is suitable for cutting a ceramic substrate or the like.

The scribing method of the present invention is a scribing method in which a scribing line is formed on at least one brittle material substrate selected from the group consisting of ceramic, sapphire, and silicon by a scribing wheel whose blade is made of only single crystal diamond. Using the scribing wheel , the cutting edge of which is R-chamfered with a radius of 0.8 to 3 μm, scribes the brittle material substrate whose surface roughness Ra is small with respect to the radius R of the tip of the cutting edge. vinegar Rukoto and features.

According to the scribing method of the present invention, a scribing wheel whose blade is made of only single-crystal diamond has a surface roughness larger than that of a general amorphous glass substrate used for a liquid crystal panel or the like, and a hard brittle material substrate. On the other hand, a longer distance scribe line can be formed.

It is a schematic diagram of a scribing device in an embodiment. It is a front view of the holder joint in an embodiment. It is a perspective view of the holder unit in an embodiment. FIG. 4A is a side view of the scribing wheel in the embodiment, and FIG. 4B is a front view of the scribing wheel. FIG. 5A is a front view before R-chamfering of the cutting edge in the embodiment, and FIG. 5B is a front view after R-chamfering of the cutting edge. FIG. 6A is a conceptual diagram showing one method of R chamfering, and FIG. 6B is a conceptual diagram showing another method of R chamfering. FIG. 7A is an explanatory view showing the photographing points of the scribing wheel in the embodiment, and FIG. 7B is a photograph of the cutting edge of the scribing wheel in the embodiment. It is a photograph of the edge of a scribing wheel for comparison. FIG. 9A is a graph relating to the scribing wheel of the embodiment, and FIG. 9B is a graph relating to the scribing wheel for comparison.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment shown below shows an example for embodying the technical idea of the present invention, and is not intended to specify the present invention to this embodiment. The present invention is also applicable to other embodiments within the scope of the claims.

  FIG. 1 is a schematic diagram of a scribing apparatus 10 according to an embodiment of the present invention. The scribing apparatus 10 includes a moving table 11. The moving table 11 is screwed with the ball screw 13 and is moved in the y-axis direction along the pair of guide rails 12a and 12b when the ball screw 13 is rotated by driving of the motor 14.

  A motor 15 is installed on the upper surface of the movable table 11. The motor 15 rotates the table 16 positioned at the upper part on the xy plane and positions it at a predetermined angle. The brittle material substrate 17 as an object to be divided (scribe) is placed on the table 16 and held by a vacuum suction means or the like (not shown).

  The brittle material substrate 17 is a ceramic substrate made of low-temperature fired ceramics or high-temperature fired ceramics, a silicon substrate, a sapphire substrate, or the like, and is at least one brittle material substrate selected from the group consisting of ceramic, sapphire, and silicon. It is a brittle material substrate that is harder than an amorphous glass substrate generally used for a substrate or the like.

  The scribing apparatus 10 includes two CCD cameras 18 that image alignment marks formed on the surface of the brittle material substrate 17 above the brittle material substrate 17 placed on the table 16. A bridge 19 is installed on the columns 20a and 20b so as to extend along the x-axis direction so as to straddle the movable table 11 and the table 16 on the upper side thereof.

  A guide 22 is attached to the bridge 19, and the scribe head 21 is installed so as to move in the x-axis direction while being guided by the guide 22. A holder unit 30 is attached to the scribe head 21 via a holder joint 23.

  FIG. 2 is a front view of the holder joint 23 to which the holder unit 30 is attached. FIG. 3 is a perspective view of the holder unit 30.

  The holder joint 23 has a substantially cylindrical shape, and includes a rotating shaft portion 23a and a joint portion 23b. In a state where the holder joint 23 is attached to the scribe head 21, the rotary shaft portion 23a is attached to the two bearings 24a and 24b via the cylindrical spacer 24c, and the holder joint 23 is held rotatably. .

  The cylindrical joint portion 23b is provided with an internal space 26 having a circular opening 25 on the lower end side. A magnet 27 is embedded in the upper portion of the internal space 26. A holder unit 30 that is detachable by a magnet 27 is inserted into the internal space 26 and attached.

  The holder unit 30 is a unit in which a holder 31, a scribing wheel 40, and a pin (not shown) are integrated. As shown in FIG. 3, the holder 31 has a substantially cylindrical shape and is made of a magnetic metal. On the upper portion of the holder 31, a mounting portion 32 for positioning is provided. The attachment portion 32 is formed by cutting out the upper portion of the holder 31 and includes an inclined portion 32a and a flat portion 32b.

  The attachment portion 32 side of the holder 31 is inserted into the internal space 26 through the opening 25. At that time, the upper end side of the holder 31 is attracted by the magnet 27, and the inclined portion 32a of the mounting portion 32 comes into contact with the parallel pin 28 passing through the internal space 26, whereby the holder unit 30 is positioned and fixed with respect to the holder joint 23. . Moreover, when removing the holder unit 30 from the holder joint 23, it can be easily removed by pulling the holder 31 downward.

  Since the scribing wheel 40 is a consumable item, it needs to be replaced periodically. In the present embodiment, since the holder unit 30 can be easily attached and detached, the scribing wheel 40 constituting the holder unit 30 is replaced by replacing the holder unit 30 itself. Exchange can be done quickly.

  A holding groove 33 formed by cutting out the holder 31 is provided in the lower portion of the holder 31. Support portions 34 a and 34 b are located below the holder 31 cut out to provide the holding groove 33 with the holding groove 33 interposed therebetween. A scribing wheel 40 is rotatably disposed in the holding groove 33. The support portions 34a and 34b are each formed with a support hole 35 into which a pin for rotatably holding the scribing wheel 40 is inserted.

  Next, the details of the scribing wheel 40 for dividing the brittle material substrate 17 will be described. FIG. 4A is a side view of the scribing wheel 40 attached to the tip of the holder 31, and FIG. 4B is a front view of the scribing wheel 40.

  As shown in FIG. 4, the scribing wheel 40 has a disk shape and includes a wheel main body 41, a blade 42, and a blade edge 43.

  In the vicinity of the center of the wheel main body 41, a through hole 44 that penetrates the wheel main body 41 in the rotation axis direction is formed. By inserting a pin into the through-hole 44, the scribing wheel 40 is rotatably held by the holder 31 via this pin.

  The blade 42 is formed in an annular shape on the outer periphery of the wheel main body 41. The blade 42 is substantially V-shaped when viewed from the front, and the thickness of the blade 42 with respect to the rotation axis direction gradually decreases toward the blade edge 43.

  The cutting edge 43 is different from the cutting edge of a normal scribing wheel, and the tip of the blade 42 is subjected to R chamfering described later, and is rounded along the outermost peripheral portion.

  Next, a method for manufacturing the scribing wheel 40 will be described with reference to the drawings. 5 is an enlarged view of the tip of the blade 42 indicated by a circle A in FIG. 4 (B), FIG. 5 (A) is a front view of the cutting edge 43 before processing, and FIG. 5 (B) is the cutting edge after processing. 43 is a front view of 43. FIG.

  The scribing wheel 40 does not include a binder and is made of only diamond, such as polycrystalline diamond or single crystal diamond. In the present embodiment, the scribing wheel 40 is made of single crystal diamond.

  The scribing wheel 40 made of single crystal diamond first forms a disk-shaped member made of single crystal diamond. Specifically, single-crystal diamond is artificially synthesized and manufactured by a high-temperature high-pressure synthesis method or a chemical vapor deposition method. Then, this single crystal diamond is cut into a disk having a desired radius by a laser or the like.

  Then, the disk-shaped single crystal diamond forms a blade 42 having a sharpened cutting edge 43 as shown in FIG. 5A by cutting both sides of the circumferential portion of the disk. To do. In addition, the ridgeline part of the blade edge | tip 43 at this time is shown with the code | symbol 43a. This state is a general scribing wheel. At this time, the surface roughness of the single crystal diamond can be further reduced as compared with the conventional PCD and cemented carbide, and as a result, the edge of the cutting edge becomes sharper.

  Next, by performing an R chamfering process on the cutting edge 43 of the blade 42 and cutting from the ridge line portion 43a, the tip of the cutting edge 43 is seen in front view along the outermost peripheral portion as shown in FIG. Round it up.

  Here, a specific direction of the R chamfering process for rounding the tip of the blade edge 43 will be described with reference to the drawings. For example, as one method, as shown in FIG. 6A, a support pin 51 is inserted into the through hole 44 of the scribing wheel 40, and the scribing wheel 40 is rotated while rotating around the rotation shaft 52a. The cutting edge 43 is brought into contact with the flat surface 52b of the disc-shaped grindstone 52, and the pins 51 are alternately swung in the directions indicated by the arrows. Thereby, the front-end | tip of the blade edge | tip 43 can be rounded.

  As another method, as shown in FIG. 6B, a support pin 51 is inserted into the through hole 44 of the scribing wheel 40, and the scribing wheel 40 is rotated while rotating around the rotation shaft 53a. The cutting edge 43 is brought into contact with the flat surface 53b of the soft grinding wheel 53 having flexibility. At this time, it sinks into the flat surface 53b of the grindstone 53, and the tip of the cutting edge 43 can be rounded.

  By the above method, the scribing wheel 40 in which the cutting edge 43 of the blade 42 is round can be manufactured. Further, in this embodiment, as shown in FIG. 5A, before rounding the tip of the blade edge 43, both sides of the circumferential portion of the disk are shaved to form an inclined surface with a sharp tip first. doing. Accordingly, the blade 42 can be sharply sharpened until the inclined surface becomes a mirror surface, and the life of the blade 42 can be further extended by minimizing the surface roughness of the blade 42. Further, since the inclined surface of the blade 42 is finished first, and then the R chamfering of the blade edge 43 is performed, it can be processed relatively easily to the target R radius.

  Next, the dimension of the scribing wheel 40 will be described. The outer diameter of the scribing wheel 40 is 1.0 to 10.0 mm, preferably 1.0 to 5.0 mm, more preferably 1.0 to 3.0 mm. When the outer diameter of the scribing wheel 40 is smaller than 1.0 mm, the handleability of the scribing wheel 40 is lowered. On the other hand, when the outer diameter of the scribing wheel 40 is larger than 10.0 mm, the vertical crack at the time of scribing may not be formed sufficiently deep with respect to the brittle material substrate 17.

  The thickness of the scribing wheel 40 is 0.4 to 1.2 mm, preferably 0.4 to 1.1 mm. When the thickness of the scribing wheel 40 is smaller than 0.4 mm, workability and handleability may deteriorate. On the other hand, when the thickness of the scribing wheel 40 is greater than 1.2 mm, the material for the scribing wheel 40 and the cost for manufacturing increase. Moreover, the hole diameter of the through-hole 44 is 0.8 mm, for example.

  The edge angle of the blade 42 is usually an obtuse angle, and is in the range of 80 to 160 °, preferably 90 to 150 °.

  Further, regarding the rounded cutting edge 43, if the R radius of the R chamfering process is smaller than 0.8 μm, the load is concentrated on the tip of the cutting edge, and pressure is locally applied, so that the chipping and wear of the cutting edge are likely to occur. . On the other hand, if the R radius is too large, the load at the time of scribing will increase significantly, and the cross-sectional quality of the substrate after division will deteriorate. Therefore, the R radius is in the range of 0.8 to 5 μm, preferably 3 μm or less. When the R radius is in the range of 0.8 to 5 μm, the contact area is increased, so that the load is appropriately dispersed, and the local pressure can be suppressed to prevent chipping or abrasion of the blade edge.

  In general, the alumina substrate or the like in the brittle material substrate 17 has a rough surface derived from the particle size of the sintered alumina particles. For example, when the surface roughness Ra of the alumina substrate described later is measured, Ra was 0.296 μm. Therefore, it is considered that the R radius of the blade edge 43 is set to a sufficiently large value in consideration of the surface roughness of the brittle material substrate 17 to be divided, so that the effect of preventing chipping due to the unevenness of the substrate is great. .

  Next, a result of dividing the brittle material substrate 17 using the scribing wheel 40 in which the cutting edge 43 is actually rounded by R chamfering and the scribing wheel 140 in which the cutting edge 43 is not subjected to R chamfering. This will be specifically described. The cutting conditions are as follows.

The scribing wheel 40 made of single crystal diamond has an outer diameter of 2 mm and a cutting edge angle of 120 °. Further, due to the R chamfering process, the R radius of the cutting edge 43 is 1.0 μm. On the other hand, the scribing wheel 140 differs from the scribing wheel 40 only in the presence or absence of the R chamfering process, and is a scribing wheel made of single crystal diamond and having an outer diameter of 2 mm and a cutting edge angle of 120 °. In addition, when the radius R of the front end of the scribing wheel 40 that was not chamfered was measured, it was 0.17 μm.
The divided brittle material substrate 17 is an alumina substrate having a thickness of 0.635 mm (manufactured by Kyocera Corporation, material code: A476T).
The cutting speed was 100 mm / sec, and the cutting was performed by adjusting the scribe load or the like with the goal of the crack penetration amount being 120 μm.

  The state of the cutting edge due to the formation of scribe lines on the surface of the brittle material substrate 17 under the above-described cutting conditions will be described with reference to photographs taken and the like. 7A and 7B show the results of segmentation with respect to the scribing wheel 40, FIG. 7A is an explanatory diagram showing photographed points, and FIG. 7B shows a photograph of the cutting edge 43 and the amount of crack penetration. FIG. 8 is a photograph of the cutting edge of the scribing wheel 140 and the amount of crack penetration. FIG. 9 is a graph showing the amount of chipping of the cutting edge at the travel distance, FIG. 9A is a graph regarding the scribing wheel 40, and FIG. 9B is a graph regarding the scribing wheel 140.

  As shown in FIG. 7 (A), for photographing the blade edge 43, an arbitrary point P1 of the scribing wheel 40 is determined, and P2, P3, P4, and P5 are determined in increments of about 45 ° with respect to the point P1. It decided from the front of the scribing hole 40 at each point of P1-P5. Note that the cutting edge of the scribing wheel 140 of FIG. 8 was also photographed at the same point as the scribing wheel 40.

  Further, in FIG. 9, the size (width) of the chip formed on the blade edge is shown by a bar graph of the number a for 10 to 50 μm, the number b for 50 to 100 μm, and the number c for 100 μm to 100 μm. . Further, the penetration amount (μm) of the cracks shown in FIGS. 7B and 8 is shown by a line graph of d.

  As can be seen from FIG. 9, the scribing wheel 40 with a rounded cutting edge 43 has a crack penetration comparable to that of the scribing wheel 140 with no rounded cutting edge. Therefore, even when the cutting edge 43 was subjected to R chamfering, the permeation amount did not decrease.

  On the other hand, with respect to chipping of the cutting edge, in the scribing wheel 140, the chipping of the cutting edge increased rapidly since the traveling distance of the cutting edge exceeded 500 m, and particularly large chipping of 100 μm or more occurred. However, in the scribing wheel 40, there was almost no change in the cutting edge 43 until the traveling distance of the cutting edge was about 1000, and no large chip of 100 μm or more was generated even when the cutting distance was 1500 m.

  In this way, by performing R chamfering on the cutting edge 43 like the scribing wheel 40 and rounding the cutting edge 43, chipping of the cutting edge 43 can be greatly reduced, and the life of the scribing wheel 40 can be extended. it can. In particular, in the case of single crystal diamond, since the tip of the blade edge 43 has a very sharp shape in the state of FIG. 5A, the blade edge 43 is very likely to be chipped when used for cutting an alumina substrate. However, by rounding the cutting edge 43, the chipping of the cutting edge 43 can be greatly reduced even with the scribing wheel 40 made of single crystal diamond.

  By the way, in the photograph of the cutting edge of the scribing wheel 140 in which the chamfering process is not performed on the cutting edge shown in FIG. 8, a large chipping is generated at the shooting points P4 and P5, but not so much at P1 and P2. It can be seen that does not occur.

  This is because the scribing wheel 140 is made of single crystal diamond, and the single crystal diamond has a crystal orientation and hardness varies greatly depending on the crystal orientation. Therefore, in the case of a scribing wheel made of polycrystalline diamond, there is not much difference in the occurrence of chipping depending on the position of the cutting edge, and chipping occurs similarly in the entire cutting edge. On the other hand, in the case of a scribing wheel made of single crystal diamond, as shown in FIG. 8, the occurrence of chipping varies depending on the position of the cutting edge depending on the crystal orientation of the single crystal diamond.

  However, like the scribing wheel 40 made of single crystal diamond of the present embodiment, the cutting edge 43 is rounded and the cutting edge 43 is rounded, as shown in FIG. Since occurrence of large chipping can be suppressed at any point, the influence on the strength due to the crystal orientation of the single crystal diamond can be reduced. Further, depending on the crystal orientation of the single crystal diamond, it is very difficult to uniformly process the shape of the cutting edge 43 having a sharp tip as shown in FIG. 5A on the entire circumference of the scribing wheel 40. However, since the R chamfering of the cutting edge 43 as shown in FIG. 5B is performed, the machining like the cutting edge 43 of FIG. 5A is not required uniformly over the entire circumference.

  As described above, the scribing wheel 40 in which the blade 42 is made of only diamond and the cutting edge 43 is rounded by R chamfering with a radius of 0.8 to 5 μm is a group made of ceramic, sapphire, and silicon. Even when used to sever at least one brittle material substrate 17 selected from the above, the chipping of the cutting edge 43 can be greatly reduced compared to a scribing wheel that is not R-chamfered, and the life of the scribing wheel 40 is extended. be able to.

  In the present embodiment, the entire scribing wheel 40 is made of single crystal diamond. For example, only the blade 42 is made of single crystal diamond, the wheel body 41 is made of cemented carbide, and the wheel The scribing wheel 40 in which the main body portion 41 and the blade 42 are fixed by bonding or the like, and at least the blade 42 portion that contacts the brittle material substrate among the inclined surfaces on the circumference of the scribing wheel 40 is formed of single crystal diamond alone. The present invention can also be applied to a scribing wheel. With such a scribing wheel, it is possible to reduce the use of expensive single crystal diamond and provide an inexpensive scribing wheel.

  In the present embodiment, the single scribing diamond is used as the scribing wheel 40, but the scribing wheel 40 made of polycrystalline diamond may be used as the blade 42. Polycrystalline diamond can be obtained by starting with a graphite-type carbon material having a fine grain structure or an amorphous material, which is directly converted and sintered to diamond under ultra-high pressure and high temperature, and chemical vapor deposition ( There is diamond synthesized by the CVD method. In polycrystalline diamond, there is no difference in hardness depending on the crystal orientation on the circumference of the cutting edge described above, but chipping may occur due to dropping of diamond particles forming the cutting edge. The present invention is also effective in preventing chipping of the scribing wheel 40 using such polycrystalline diamond.

  These single crystal diamonds and polycrystalline diamonds are substantially composed only of diamonds and do not contain iron-based metals as binders, but intentionally contain trace amounts of impurities such as boron and phosphorus in the diamond crystals. Including those added. By adding impurities in this way, it is possible to impart conductivity to diamond or to improve heat resistance.

  The scribing device 10 of the present embodiment is configured to be attached via the holder joint 23 when attaching the holder 31 holding the scribing wheel 40 to the scribe head 21. However, the scribing apparatus 10 may be configured to attach the holder 31 directly to the scribe head 21.

  Further, as the scribing device 10 of the present embodiment, a guide 22 and a bridge 19 for moving the scribe head 21 are provided, and a moving table 11 for rotating the table 16 on which the brittle material substrate 17 is placed is provided. However, the present invention is not limited to such a scribing apparatus 10. For example, in order to allow the user to grasp the scribe head 21 to which the holder 31 is attached, a part of the scribe head 21 has a pattern shape, and the user moves the scribe head 21 with the handle to move the brittle material. Even a so-called manual scribing apparatus that divides the substrate 17 is applicable.

DESCRIPTION OF SYMBOLS 10 ... Scribe device 30 ... Holder unit 31 ... Holder 40, 140 ... Scribing wheel 41 ... Wheel main-body part 42 ... Blade 43 ... Blade edge 43a ... Ridge line part

Claims (4)

A scribing wheel whose blade is made of only diamond , used for cutting at least one brittle material substrate selected from the group consisting of ceramic, sapphire and silicon ,
The cutting edge of the blade is R-chamfered with a radius of 0.8 to 3 μm,
The diamond is Ri Oh a single crystal diamond,
The scribing wheel according to claim Rukoto tip R the radius of the cutting edge relative to a surface roughness Ra of the brittle material substrate is increased. A holder unit comprising the scribing wheel according to claim 1 and a holder for rotatably holding the scribing wheel. A scribing device comprising the holder unit according to claim 2 . A scribing method for forming a scribe line on at least one brittle material substrate selected from the group consisting of ceramic, sapphire, and silicon by a scribing wheel whose blade is made of only single crystal diamond,
Using the scribing wheel in which the cutting edge of the blade has an R chamfering process with a radius of 0.8 to 3 μm, the brittle material substrate having a small surface roughness Ra with respect to the tip R radius of the cutting edge is scribed. A scribing method characterized by that.