CN114102882A

CN114102882A - Scribing wheel for brittle material substrate and manufacturing method thereof

Info

Publication number: CN114102882A
Application number: CN202110988569.3A
Authority: CN
Inventors: 中川考一; 茂木刚; 盐泽勇雄
Original assignee: Finetech Co ltd
Current assignee: Finetech Co ltd
Priority date: 2020-08-26
Filing date: 2021-08-26
Publication date: 2022-03-01
Also published as: KR20220027036A; TW202208138A; JP2022038435A

Abstract

The invention provides a scribing wheel for a brittle material substrate, which can reduce or inhibit the generation of microcracks in the horizontal direction and can improve the cutting performance of the brittle material substrate with the thickness of less than 0.1mm, and a manufacturing method thereof. The present invention relates to a disk-shaped scribing wheel for providing a scribe line to a brittle material substrate. The scribing wheel (1) is provided with a first cutter (10) and a second cutter (20) alternately in the circumferential direction on the outer periphery (3). The outer peripheral portion includes: a pair of inclined surfaces (3a) intersecting in a V-shape to form a first blade (10); and a recess (22) that is recessed from one or both of the pair of inclined surfaces (3a) to form a second blade (20). In the present invention, the difference S in the radial direction between the position of the cutting edge (11) of the first knife (10) and the position of the cutting edge (21) of the second knife (20) is less than 0.5 [ mu ] m.

Description

Scribing wheel for brittle material substrate and manufacturing method thereof

Technical Field

The present invention relates to a scribing wheel for a brittle material substrate and a method for manufacturing the same, and more particularly, to a scribing wheel as a disk-shaped tool for providing a cutting line to a plate such as a glass substrate, a quartz substrate, or a ceramic substrate, and a method for manufacturing such a scribing wheel.

Background

Scribing and cutting methods are widely used as one of the methods for dividing a brittle material substrate such as a mother glass substrate for a Flat Panel Display (FPD) into unit substrates having a predetermined size. The method is a method of pressing a scribing wheel on a brittle material substrate to rotate so as to endow a cutting line, namely a cutting line, and then applying an external force to the brittle material substrate so as to cut the brittle material substrate along the cutting line, namely, to cut the brittle material substrate. Further, as an example of a scribing wheel, there is known a scribing wheel in which grooves are formed at a predetermined pitch in the cutting edge of the outer peripheral ridge portion and the cutting edge is processed into irregularities, and disclosed in, for example, japanese patent No. 5022602 (patent document 1).

When the scribing wheel having the concave-convex tip is pressed against a brittle substrate and rotated, a cutting line SL as shown in fig. 11 is formed on the surface of the substrate. The cutting line SL is alternately formed continuously with a thick line portion L1 'produced by the convex blade 1 and a thin line portion L2' produced by the concave blade 2. At this time, the knife 1 and the knife 2 also apply a force (hereinafter, referred to as "horizontal pulling force" in the present specification) to the substrate to horizontally cut the substrate from the cutting line SL. As shown particularly by the arrows in fig. 11, this horizontal opening force of knife 1 is greater than that of knife 2. By continuously applying the horizontal pulling forces having different strengths generated by the

blades

1 and 2 to the substrate in this manner, vertical cracks penetrate in the thickness direction of the substrate. Such a vertical crack generated in the substrate reduces the load when the substrate is cut.

The inventors have found that microcracks mc (only a part of the illustration) may occur in the horizontal direction (the developing direction of the substrate) from an angle C which becomes narrower toward the line portion L2 'from a portion of the line portion L1' where the thickness is substantially constant. Such microcracks mc may reduce the bending strength of the substrate after division or may peel off the surface layer of the substrate. In particular, in recent years, thinning of a brittle material substrate has been demanded in accordance with weight reduction, and a glass substrate having a thickness of, for example, 0.2mm or less has been used, but such a thin substrate has low strength inherently, and therefore the generation of the microcracks mc directly causes a reduction in quality.

Further, there is an increasing demand for brittle material substrates having a thickness of 0.1mm (100 μm) or less, and when a conventional scribing wheel is used for such thin substrates, there is a problem that it is difficult to stably divide the substrate because vertical cracks penetrate more than necessary in the thickness direction of the substrate.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 5022602

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made in view of the above problems, and an object thereof is to provide a scribing wheel for a brittle material substrate, which can reduce or suppress the occurrence of horizontal microcracks and can improve the cutting performance of a brittle material substrate having a thickness of, in particular, 0.1mm or less, and a method for manufacturing the scribing wheel.

Means for solving the problems

In order to solve the above problems, according to one aspect of the present invention, there is provided a scribing wheel for a brittle material substrate, the scribing wheel having a disk shape for providing a scribe line to the brittle material substrate, the scribing wheel including a first blade and a second blade alternately provided in a circumferential direction on an outer circumferential portion of the scribing wheel, the outer circumferential portion including: a pair of inclined planes intersecting in a V-shape to form the first blade; and a concave portion recessed from one or both of the pair of inclined surfaces to form the second blade, wherein a difference in a radial direction between a position of the cutting edge of the first blade and a position of the cutting edge of the second blade is less than 0.5 [ mu ] m.

The inventors studied a scribing wheel in which microcracks mc are not generated in the horizontal direction from an angle C of a thick scribe line portion L1' (see fig. 11) generated by the above-described blade 1, and found that such microcracks can be reduced or suppressed by setting the difference (interval) in the radial direction between the cutting edge position of the first blade and the cutting edge position of the second blade in the scribing wheel to less than 0.5 μm, and completed the present invention. It is considered that the conventional scribing wheel has a radial distance between the blade 1 and the blade 2 of 0.5 μm or more, because there is no need to cut the scribing wheel requiring the distance to be smaller than 0.5 μm, and it is very difficult to process the distance to be smaller than 0.5 μm.

In the present invention, the scribing wheel comprises sintered diamond, single crystal diamond, or super alloy steel, or a combination thereof.

In the present invention, the first knife is defined by a pair of inclined planes intersecting in a V-shape. The second blade is defined by intersecting the recesses provided on both of the pair of inclined surfaces in a V-shape or by intersecting the recess provided on one of the pair of inclined surfaces in a V-shape with the other of the pair of inclined surfaces.

In one embodiment of the invention, the angle of the second knife is smaller than the angle of the first knife. Preferably, the angle of the second knife is in the range of 99.98% to 10%, more preferably 98% to 90% of the angle of the first knife. By making the angle of the second blade smaller than that of the first blade, the variation in the level of the horizontal opening force applied to the brittle material substrate by the first and second blades can be increased, and the vertical crack in the thickness direction can be elongated.

In one embodiment of the present invention, a difference in a radial direction between the cutting edge position of the first blade and the cutting edge position of the second blade is 0. In the present embodiment, the cutting edge of the second blade forms a square ridge (edge) together with the cutting edge of the first blade, and the cutting line is continuous with a line having substantially the same thickness as shown in fig. 17. However, it is conceivable that, since the recesses forming the second blades are arranged alternately with the first blades in the circumferential direction, variations in the level of the horizontal opening force generated by the first and second blades act on the substrate, whereby vertical cracks may extend inward of the substrate.

In one embodiment of the present invention, a difference in a radial direction between the cutting edge position of the first blade and the cutting edge position of the second blade is 0.2 μm or more and less than 0.5 μm, each of the recesses includes a bottom portion at a circumferential middle portion recessed from one or both of the pair of inclined surfaces to a deepest depth, and two bottom portions connected so that the depths become gradually shallower from the bottom portion toward two first blades adjacent in the circumferential direction, and a radius of curvature of a boundary between the bottom portion and the first blade adjacent to each other is larger than a radius of curvature of a boundary between the bottom portion and the bottom portion adjacent to each other. The inventors have found that when the scribing wheel of such a form is used, the scribe line shown in fig. 28 can be formed on the brittle material substrate surface, and the horizontal microcracks can be further reduced or suppressed. This point will be described later in connection with fig. 25 to 28.

According to another aspect of the present invention, there is provided a method of manufacturing a scribing wheel for a brittle material substrate, the method including: a step A of processing a pair of original inclined planes on the outer periphery of an original body of the scribing wheel to be manufactured, and enabling the pair of original inclined planes to be crossed in a V shape to form a first original knife; a step B of machining a pair of concave portions recessed from both of the pair of original inclined surfaces at a predetermined interval in a circumferential direction, the pair of concave portions forming a second blade, the first original blade and the second blade alternating in the circumferential direction, and a difference in a radial direction between a blade edge position of the first original blade and a blade edge position of the second blade being 0.5 μm or more; and a step C of grinding the pair of original inclined surfaces into a pair of inclined surfaces, wherein the pair of inclined surfaces intersect in a V-shape to form a first blade, and a difference in a radial direction between a blade edge position of the first blade and a blade edge position of the second blade is 0 or more and less than 0.5 [ mu ] m.

The method is a method for manufacturing a scribing wheel for a brittle material substrate, wherein the difference in the radial direction between the position of the cutting edge of the first blade and the position of the cutting edge of the second blade is 0 or more and less than 0.5 [ mu ] m. In the method, diamond, ceramic, iron, or the like having a predetermined grain size may be used for polishing the pair of original slopes, and electron beams, laser, or the like may be used for forming the recesses in the pair of original slopes.

In one embodiment of the present invention, the angle of the second blade is made smaller than the angle of the first blade in the step B, and the angle of the first blade is made larger than the angle of the second blade in the step C. Thereby, the angle of the second knife is made smaller than the angle of the first knife.

In one embodiment of the present invention, the method comprises: and a step D of polishing one of the pair of slopes to remove the recess in the one slope after the step C. Thus, a recess remains only in the other of the pair of inclined surfaces, and the recess intersects with the one inclined surface in a V-shape to define a second blade.

Effects of the invention

In the scribing wheel of the present invention, by setting the difference in the radial direction between the position of the edge of the first blade and the position of the edge of the second blade to less than 0.5 μm, it is possible to reduce or suppress microcracks in the horizontal direction from the cutting line portion formed by the first blade.

Drawings

Fig. 1 is a perspective view of a scribing wheel according to a first embodiment of the present invention.

Fig. 2 is a side view of the scoring wheel of fig. 1.

Fig. 3 is a front view of the scoring wheel of fig. 1.

Fig. 4 is an enlarged view of a part of fig. 2.

Fig. 5 is an explanatory diagram roughly showing a manufacturing process of the scribing wheel in fig. 1 and the like.

Fig. 6 is an explanatory diagram roughly showing a manufacturing process a of the scribing wheel in fig. 1 and the like.

Fig. 7 is an explanatory diagram roughly showing a manufacturing process B of the scribing wheel in fig. 1 and the like.

Fig. 8 is an explanatory diagram roughly showing a manufacturing process C of the scribing wheel in fig. 1 and the like.

Fig. 9 is an explanatory diagram corresponding to the manufacturing process of fig. 6 to 8.

Fig. 10 is a schematic view of a scribe line provided on a glass substrate by the scribe wheel of fig. 1 or the like.

Fig. 11 is a schematic view of a scribe line provided on a glass substrate by a conventional scribing wheel.

Fig. 12 is a perspective view of a scribing wheel according to a second embodiment of the present invention.

Fig. 13 is a side view of the scoring wheel of fig. 12.

Fig. 14 is a front view of the scoring wheel of fig. 12.

Fig. 15 is a sectional view taken along line a-a of fig. 13.

Fig. 16 is an enlarged view of a portion circled B of fig. 15.

Fig. 17 is a schematic view of a scribe line provided on a glass substrate by the scribe wheel of fig. 12 or the like.

Fig. 18 shows a modification of the scribing wheel of the second embodiment.

Fig. 19 is a modification of the scribing wheel of the first embodiment.

Fig. 20 is an explanatory diagram roughly showing a manufacturing process D of the scribing wheel of fig. 19.

Fig. 21 is a partial side view of a scribing wheel according to a third embodiment of the present invention.

Fig. 22 is a partial perspective view of the scribing wheel of fig. 21.

Fig. 23 is a partially enlarged view of fig. 21.

Fig. 24 is a schematic view of a scribe line provided to the surface of the glass substrate by the scribe wheel of fig. 21 and the like.

Fig. 25 is a partial side view of a scribing wheel according to a fourth embodiment of the present invention.

Fig. 26 is a partial perspective view of the scribing wheel of fig. 25.

Fig. 27 is a partially enlarged view of fig. 25.

Fig. 28 is a schematic view of a scribe line provided to the surface of the glass substrate by the scribe wheel of fig. 25 and the like.

Fig. 29 is a graph showing permeability comparison under the same rotational pressure.

Description of the reference numerals

1. 1A, 61A, 10, 201: a scribing wheel; 2: a main body portion; 3: a peripheral portion; 3 a: a pair of inclined planes; 3A: the slope of the recess is eliminated; 4: a ridge portion; 10. 70, 110, 210: a first knife; 11. 71, 111, 211: a tip of the first knife; 20. 80, 120, 220: a second knife; 21. 81, 121, 221: a tip of the second knife; 22. 82, 122, 222: a recess; 122a, 222 a: a bottom; 122b, 222 b: a bottom side portion; SL1, SL2, SL3, SL 4: cutting a line; c1': an angle; r1, R1 ', R2, R2': a radius of curvature.

Detailed Description

Hereinafter, several embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to such embodiments, and modifications and the like can be made within the scope of the claims and equivalent scope. Fig. 1, 2, and 3 are perspective, side, and front views of a scribing wheel (hereinafter also simply referred to as "wheel") 1 according to a first embodiment of the present invention. Fig. 4 is a drawing in which a part of fig. 2 is enlarged. Hereinafter, the left and right of the wheel 1 (and the

wheels

61, 101, 201 described later) are based on fig. 3, 14, and the like unless otherwise specified. The wheels 1(61, 101, 201) are substantially bilaterally symmetrical. Therefore, the description of one of the left and right sides of the wheel 1(61, 101, 201) is also applicable to the other of the left and right sides. The wheel 1 includes a disk-shaped main body 2 and an outer peripheral portion 3 having a triangular cross section and projecting radially outward from the main body 2. The wheel 1 includes first blades 10 and second blades 20 alternately in the circumferential direction at a ridge portion 4 which is the radially outer end portion of the outer peripheral portion 3. The main body 2 has left and right annular side surfaces 2a perpendicular to the axis of the wheel 1. The main body 2 further includes a shaft hole 5 penetrating between the left and right side surfaces 2 a. The wheel 1 is used by being attached to a scribing device by passing a shaft portion of the scribing device, not shown, through a shaft hole 5 of the main body portion 2.

The outer peripheral portion 3 has a pair of left and right inclined surfaces 3a inclined with respect to left and right side surfaces 2a of the main body portion 2. The left and right inclined surfaces 3a gradually approach each other radially outward, and intersect in a V-shape at the ridge portion 4 to define a first blade 10. The point 11 of the first knife 10 is along the outer periphery of the wheel 1 furthest radially outward. A pair of left and right recesses 22 are provided in the left and right slopes 3a at predetermined intervals in the circumferential direction. The left and right concave portions 22 are recessed from the inclined surfaces 3a, and intersect in a V-shape at the ridge portion 4 to define the second blade 20. The angle a2 (refer to fig. 9) of the second knife 20 is set to be smaller than the angle (a1) of the first knife 10. In the present embodiment, a1 is 95 to 110 °, and a2 is 90 to 98% of a 1. The point 21 of the second knife 20 forms the outer periphery of the wheel 1 together with the point 11 of the first knife 10. The outer peripheries formed by the cutting edges 11, 21 of the first and

second blades

10, 20 are also the ridge lines of the ridge portion 4.

In the present embodiment, the length of one second blade 20 in the circumferential direction is about 3 to 4 times the length of one first blade 10 in the circumferential direction. Referring to fig. 4, the cutting edge 21 of each second blade 20 is slightly recessed radially inward from both circumferential ends (the contact points with the cutting edges 11 of the first blades 10 adjacent to each other on the left and right in fig. 4) toward the circumferential midpoint, and the recess radially inward is largest at the circumferential midpoint. The recess of the second blade 20 (and the recess 22) is curved so as to be convex inward in the radial direction. In the present embodiment, the difference S in the radial direction between the position of the cutting edge 11 of the first blade 10 and the circumferential direction midpoint of the cutting edge 21 of the second blade 20 is 0.2 μm, but may be set to 0.1 μm or more and less than 0.5 μm. The pitch of the first blade 10 is 0.014 μm or more and 0.019 μm or less. The diameter of the wheel 1 is 2.6mm, and the thickness of the wheel 1, i.e., the interval between the left and right side surfaces 2a, is 0.65 mm.

Table 1 shows preferred specification ranges and the like of the scribing wheel 1.

[ Table 1]

Table 1: scribing wheel 1

Wheel diameter	Thickness of wheel	Angle of first knife A1	Angle of second knife A2	Distance of first knife	Blade tip spacing (difference) S
						2.6mm	0.65mm	95°～110°	90%. E of A198％	0.014μm～0.019μm	0.1μm～0.5μm

Next, a method of manufacturing the scribing wheel 1 will be described. Fig. 5 to 8 are explanatory views roughly showing the manufacturing process of the wheel 1. Fig. 9 is an explanatory diagram corresponding to the manufacturing process of fig. 6 to 8. First, a starting material 1' to be finally formed into a wheel 1 is prepared (see fig. 5). The body 1 'is in the form of a disk that is expanded radially outward from the main body 2 of the wheel 1, and has left and right side surfaces 2a (common to the left and right side surfaces 2a of the wheel 1, and therefore the same reference numerals are used) and a peripheral side surface 3' that connects the radially outer ends of the left and right side surfaces 2 a. In fig. 5 to 8, the original body 1' and the wheel 1 are shown in cross-sections as viewed from the line C-C of fig. 4. Next, as shown in fig. 6, a pair of original slopes 3a 'are roughly formed on the outer peripheral portion of the original material 1' (step a). The pair of original inclined surfaces 3a 'are crossed in a V-shape to form a first original blade 10'. The first original knife 10 'has a tip 11'. The angle of the first blade 10' is set to be substantially the same as the angle of the first blade 10 that is finally formed. The pair of primary inclined surfaces 3a 'and the first primary blade 10' are slightly radially outward of the pair of final inclined surfaces 3a and the first blade 10 (see fig. 8, etc.).

Next, as shown in fig. 7, the recesses 22 are laser-machined in the pair of original slopes 3 a' at predetermined intervals in the circumferential direction (step B). The pair of left and right concave portions 22 intersect in a V-shape to define the second blade 20. The second blade 20 has a tip 21. Referring to fig. 9, the angle a2 of the second blade 20 is set to 90% to 98% of the angle (substantially a1) of the first primary blade 10'. Therefore, the vertical depth d (see fig. 9) of the pair of recesses 22 with respect to the original inclined surface 3 a' gradually becomes slightly deeper from the cutting edge 21 located on the ridge line toward the radial inner end 22b of the recess 22. By forming the second knives 20, the first primary knives 10' alternate with the second knives 20 in the circumferential direction. At this time, the difference S ' (see fig. 9) in the radial direction between the position of the cutting edge 11 ' of the first master knife 10 ' and the position of the cutting edge 21 of the second knife 20 is set to slightly exceed 0.5 μm.

Next, the pair of master bevels 3a is ground with diamond of a predetermined grain size to form a first master blade 10' as shown in fig. 8 (step C). At this time, the pair of original inclined surfaces 3 a' are polished so as to be substantially parallel to the pair of final inclined surfaces 3 a. Thus, the angle A1 of the first blade 10 is substantially the same as the angle of the first primary blade 10' and is greater than the angle A2 of the second blade 20. In the present embodiment, the angle A2 of the second blade 20 is set to 90% to 98% of the angle A1 of the first blade 10. In the step C, the difference S in the radial direction between the position of the cutting edge 11 of the first blade 10 and the position of the cutting edge 21 of the second blade 20 is set to 0.2 μm. Then, the recess 22 is made slightly shallow by the step C. That is, the depth of the recess 22 from the inclined surface 3a becomes slightly smaller than the depth from the original inclined surface 3 a'. The scribing wheel 1 is obtained in the above manner. The above-described steps a to C are also substantially applied to the manufacture of the

wheels

61, 101, 201 (see fig. 12, 21, 25, and the like) of the second to fourth embodiments described later, and in the wheel 61, the original inclined surface (3 a') is ground into the inclined surface 3a in the step C so that the difference S in the radial direction between the position of the cutting edge 71 of the first blade 70 and the position of the cutting edge 81 of the second blade 80 becomes zero.

Fig. 10 is a schematic view of a cutting line SL1 imparted on the glass substrate by the wheel 1. The cutting line SL1 is alternately formed in succession with a thicker line portion L1 produced by the first knife 10 and a thinner line portion L2 produced by the second knife 20. Fig. 11 is a schematic view of a conventional scribing wheel (hereinafter, also referred to as a "comparative example wheel") having a convex blade 1 and a concave blade 2 for applying a scribe line SL on a glass substrate. In the comparative example wheel, the distance in the radial direction between the position of the cutting edge of the blade 1 and the position of the cutting edge of the blade 2 was 1.5 μm, the angle of the blade 1 was substantially the same as the angle of the blade 2, and the wheel diameter, the wheel thickness, and the pitch of the blade 1 were substantially the same as the wheel 1. The thickness, rotational pressure, rotational speed, and the like of the glass substrate to be provided with the cutting lines SL1 and SL are also set to be the same for the wheel 1 as for the comparative example wheel. In the cutting line SL1 generated by the wheel 1, the radial direction interval S between the cutting edge 11 of the first blade 10 and the cutting edge 21 of the second blade 20 is set to 0.2 μm, and therefore the difference between the thicknesses of the line portion L1 and the line portion L2 is smaller than the cutting line SL of fig. 11. That is, line portion L1 ratio of cutting line SL1The line portion L1 'of the cutting line SL is thin, and the line portion L2 and the line portion L2' are substantially the same thickness. Thus, it can be considered that the variation between line portion L1 and line portion L2 in cutting line SL1 is reduced, thereby reducing or suppressing microcracks m_c。

Table 2 shows the results of the experiment using the scribing wheel 1 and the comparative example wheel. The experiment was performed as follows. First, a scribe wheel 1 and a comparative wheel were used to apply cutting lines to glass substrates having thicknesses of 100 μm (0.1mm) and 150 μm (0.15mm) at the same rotational pressure and rotational speed, and the length (μm) in the thickness direction of a vertical crack generated in each glass substrate was measured. The operation was repeated eight times or more for glass substrates of various thicknesses.

[ Table 2]

Table 2: comparison of vertical crack penetration at same rotational pressure

The first vertical crack length of the glass substrate having a thickness of 100 μm produced by the comparative example wheel was 90.9 μm. This indicates that the vertical cracks penetrated 90.9% with respect to the thickness of 100 μm. Thus, the first "permeability" was 90.9%. Comparative example A glass substrate having a thickness of 100 μm had a second median crack length of 89.2 μm (permeability of 89.2%), and the third to eighth median cracks (permeability) are shown in Table 2.

The first vertical crack length generated by the wheel 1 on a glass substrate having a thickness of 100 μm was 83.4 μm (permeability 83.4%). The second to eighth vertical cracks (permeability) are shown in table 2.

The first generation of a vertical crack of 127.3 μm in length on a 150 μm thick glass substrate by the comparative example wheel. Therefore, the permeability was 84.9% to 127.3 μm/150 μm. The second to eighth vertical cracks and the permeability after that are shown in table 2.

The first vertical crack length generated by wheel 1 on a glass substrate having a thickness of 150 μm was 109.8 μm (permeability 73.2%). The second to eighth vertical cracks (permeability) are shown in table 2.

FIG. 29 shows the average permeability of Table 2 and the estimated permeability of a glass substrate having a thickness of 150 μm to 50 μm estimated from the measured values of many permeabilities similar to those in the above experiment for a glass substrate having a thickness of 200 μm to 100 μm.

It is generally known that when a glass substrate is divided by applying a cutting line, if the permeability of a vertical crack is in a range of 75% to 90%, the dividing operation of the substrate is stable. From table 2 and fig. 29, it is understood that the wheel 1 of the present invention has a permeability of 75% to 90% to a glass substrate having a thickness of 150 μm or less, particularly 100 μm or less, and the substrate dividing operation is stable. On the other hand, in the comparative example wheel, the permeability to a glass substrate having a thickness of 100 μm or less was more than 90%, and the substrate dividing operation was considered to be unstable.

Fig. 12, 13 and 14 are a perspective view, a side view and a front view of a scribing wheel 61 according to a second embodiment of the present invention. Fig. 15 is a sectional view taken along line a-a of fig. 13. Fig. 16 is an enlarged view of a portion circled B of fig. 15. In the wheel 61, the same reference numerals as those of the wheel 1 are used for the components substantially common to the wheel 1 described above, for example, the main body 2, the outer peripheral portion 3, and the like, and the description thereof is omitted. The wheel 61 includes first blades 70 and second blades 80 alternately in the circumferential direction at a ridge portion 4 that is the radially outer end portion of the outer peripheral portion 3. A pair of left and right inclined surfaces 3a of the outer peripheral portion 3 intersect in a V-shape at the ridge portion 4 to define a first blade 70. A pair of left and right recesses 82 are provided in the left and right slopes 3a at predetermined intervals in the circumferential direction. The right and left recesses 82 are recessed from the inclined surface 3 a. The left and right concave portions 82 intersect in a V-shape at the ridge portion 4 to define the second blade 80. In the present embodiment, the difference S in the radial direction between the position of the cutting edge 71 of the first blade 70 and the position of the cutting edge 81 of the second blade 80 is zero (S is 0). Therefore, the cutting edge 71 of the first blade 70 and the cutting edge 81 of the second blade 80 are along the outer periphery of the perfect circle closest to the outer side in the radial direction in the wheel 1. Further, referring to fig. 16, the angle a1 of the first knife 70 is set to 95 to 110 °, and the angle a2 of the second knife 80 is set to 90 to 98% of the angle a1 of the first knife 70. A2 may be set to 10% to 99.98%. In the present embodiment, the length in the circumferential direction of one first blade 70 is about 1.5 times the length in the circumferential direction of one second blade 80. The wheel 61 is manufactured through the above-described steps a to C substantially similarly to the wheel 1, but in the wheel 61, the original bevel 3 a' is ground into the bevel 3a so that the difference S in the radial direction between the position of the cutting edge 71 of the first blade 70 and the position of the cutting edge 81 of the second blade 80 in the step C becomes zero. The scribing wheel 61 is the same as the wheel 1 (see table 1) except that S is 0.

Fig. 17 is a schematic view of a cutting line SL2 imparted on the glass substrate by the wheel 61. The cutting line SL2 is continuous with a line having a substantially constant thickness, in which the radial direction distance S between the cutting edge 71 of the first blade 70 and the cutting edge 81 of the second blade 80 in the wheel 61 is zero. However, due to the existence of the recess 82 forming the second blade 80 and the difference in angle between the first and

second blades

70 and 80, horizontal pulling forces having different strengths are continuously applied to the substrate, and thus the vertical crack may extend in the thickness direction of the substrate. Further, it is conceivable that in the cutting line SL2, there is little change between the line portion formed by the first blade 70 and the line portion formed by the second blade 80, and therefore the generation of the microcracks mc in the horizontal direction is reduced or suppressed.

In the

wheels

1, 61 of the first and second embodiments described above, the

concave portions

22, 82 are provided on both of the pair of left and right inclined surfaces 3a of the outer peripheral portion 3 to define the

second blades

20, 80, but the present invention is not limited to such an embodiment. Fig. 18 is a front view of a wheel 61A as a modification of the wheel 61 of the second embodiment. In the wheel 61A, recesses 82 are provided at predetermined intervals in the circumferential direction only in one (left) 3A of the pair of left and right

inclined surfaces

3A, 3A. Thus, each second knife 80 (for convenience the same reference number as the second knife 80 of the wheel 61) is delimited by a recess 82 on the left and a bevel 3A on the right. In the wheel 61A, the cutting edge 71 of the first blade 70 and the cutting edge 81 of the second blade 80 are also located at the same position in the radial direction (S is 0), and therefore the microcracks mc can be reduced or suppressed substantially similarly to the wheel 61. The recessed portion-eliminated flat inclined surface 3A on the right side of the wheel 61A is substantially the same surface as the flat inclined surface 3A on the right side of the wheel 1A, which is a modification of the first embodiment described below, and therefore the same reference numerals are used.

Fig. 19 is a front view of a wheel 1A as a modification of the wheel 1 of the first embodiment. In the wheel 1A, the recessed portions 22 are provided at predetermined intervals in the circumferential direction only on one (left) 3A of the pair of left and right

inclined surfaces

3A, 3A. Thus, each second knife 20 (for convenience the same reference numbers are used as for the second knife 20 of the wheel 1) is delimited by a recess 22 on the left and a bevel 3A on the right. In the wheel 1A, the radial distance between the position of the cutting edge 11 of the first blade 10 and the position of the cutting edge 21 of the second blade 20 is also 0.2 μm (S is 0.2 μm). This can reduce or suppress microcracks mc substantially similarly to the wheel 1. The flat inclined surface 3A on the right of the wheel 1A from which the concave portion is removed is formed by grinding the right inclined surface 3A as shown in fig. 20 after step C (see fig. 8) in the above-described method for manufacturing the wheel 1 to remove the concave portion 22 of the right inclined surface 3A (step D). In the step D, the position of the cutting edge 21 of the second blade 20 is maintained. Accordingly, the inclination angle of the left and right

inclined surfaces

3A and 3A with respect to a perpendicular line (not shown) passing through the cutting edges 11 and 21 of the first and

second blades

10 and 20 in fig. 9 is slightly smaller than that of the inclined surface 3A.

Fig. 21 and 22 are a partial side view and a partial perspective view of a scribing wheel 101 according to a third embodiment of the present invention. Fig. 23 is a partially enlarged view of fig. 21. In the following description of the wheel 101 and the wheel 201, the same reference numerals as those of the wheel 1 are used for the structures substantially common to the wheel 1 described, for example, the main body portion 2, the outer peripheral portion 3, and the like, and the description thereof is omitted. The wheel 101 includes first blades 110 and second blades 120 alternately in the circumferential direction at a ridge portion 4, which is the radially outer end portion of the outer peripheral portion 3. A pair of left and right inclined surfaces 3a of the outer peripheral portion 3 intersect in a V-shape at the ridge portion 4 to define a first blade 110. A pair of left and right recesses 122 are provided on the left and right slopes 3a at predetermined intervals in the circumferential direction. The left and right concave portions 122 intersect in a V-shape at the ridge portion 4 to define the second blade 120. In the present embodiment, the difference S in the radial direction between the position of the cutting edge 111 of the first blade 110 and the position of the cutting edge 121 of the second blade 120 is 0.4 μm. Further, the angle A1 of the first blade 110 is 120 and the angle A2 of the second blade 120 is 108.

Referring to fig. 23, each recess 122 includes a circumferential-direction middle bottom portion 122a having the deepest recess depth and two bottom side portions 122b connected to each other and gradually shallower in depth from the bottom portion 122a to the two first blades 110 adjacent in the circumferential direction. In the present embodiment, each bottom side portion 122b is a curved surface that is convex inward in the radial direction. The cutting edge 121 of the second blade 120 defined by the left and right recesses 122 also includes a portion 122a (for convenience, the same reference numeral) corresponding to the bottom portion 122a and portions 122b (for convenience, the same reference numeral) corresponding to the two bottom side portions 122 b. In the wheel 101, the convex curvature radius R1 'of the boundary between the circumferentially adjacent bottom flank 122b and the first blade 110 is smaller than the concave curvature radius R2' (R1 '< R2') of the boundary between the circumferentially adjacent bottom flank 122b and the bottom 122 a. Note that R1 '+ R2' is constant.

Fig. 24 is a schematic view showing a cutting line SL3 given to the surface of the glass substrate by the wheel 101. In the cutting line SL3, the thicker line portions L11 produced by the first knife 110 of the wheel 101 and the thinner line portions L12 produced by the second knife 120 are alternately continuous. A cut line SL3 results in an angle C1 'corresponding to the radius of curvature R1' between the bottom side 122b of the recess 122 of the wheel 101 and the first knife 110. The microcracks mc are likely to occur in the horizontal direction from the angle C1' to the outside of the cutting line SL3 (see fig. 11), but the occurrence of such microcracks mc can be suppressed or reduced by setting the radial direction interval S between the cutting edge 111 of the first blade 110 and the cutting edge 121 of the second blade 120 to less than 5 μm.

Fig. 25 and 26 are a partial side view and a partial perspective view of a scribing wheel 201 according to a fourth embodiment of the present invention. Fig. 27 is a partially enlarged view of fig. 25. The wheel 201 includes first blades 210 and second blades 220 alternately in the circumferential direction at a ridge portion 4 which is the radially outer end portion of the outer peripheral portion 3. A pair of left and right inclined surfaces 3a of the outer peripheral portion 3 intersect in a V-shape at the ridge portion 4 to define a first blade 210. A pair of left and right recesses 222 are provided on the left and right slopes 3a at predetermined intervals in the circumferential direction. The left and right concave portions 222 intersect in a V-shape at the ridge portion 4 to define the second blade 220. In the present embodiment, the difference S in the radial direction between the position of the cutting edge 211 of the first blade 210 and the position of the cutting edge 221 of the second blade 220 is 0.4. mu.m. Further, the angle A1 of the first blade 210 is 120 and the angle A2 of the second blade 220 is 108.

Referring to fig. 27, each recess 222 includes a circumferential-direction middle bottom portion 222a having the deepest depression depth and two bottom side portions 222b connected to each other and gradually shallower in depth from the bottom portion 222a toward the two first blades 210 adjacent in the circumferential direction. In the present embodiment, each bottom portion 222b is a curved surface that is convex outward in the radial direction. The cutting edge 221 of the second blade 220 defined by the left and right recesses 222 also includes a portion 222a (for convenience, the same reference numerals) corresponding to the bottom portion 222a and portions 222b (for convenience, the same reference numerals) corresponding to the two bottom side portions 222 b. In the wheel 201, the convex curvature radius R1 of the boundary between the bottom side 222b and the first blade 210 adjacent in the circumferential direction is larger than the concave curvature radius R2 of the boundary between the bottom side 222b and the bottom 222a adjacent in the circumferential direction (R1 > R2). Note that R1+ R2 is constant.

Fig. 28 is a schematic view showing a cutting line SL4 given to the surface of the glass substrate by the wheel 201. In cutting line SL4, the thicker line portions L21 produced by the first knife 210 of wheel 201 and the thinner line portions L22 produced by the second knife 220 are alternately continuous. In the cutting line SL4, the radius of curvature R1 between the bottom side 222b of the recess 222 and the first blade 210 is large, and therefore an angle such as the angle C1' of the cutting line SL3 (refer to fig. 24) is not generated. Therefore, the generation of the microcracks mc can be further reduced or suppressed. Although horizontal microcracks are likely to occur between the thick line portion L21 and the thin line portion L22 in the cutting line SL4 due to the small radius of curvature R2 between the bottom portion 222b and the bottom portion 222a, the microcracks are not generated outside but inside the cutting line SL4, and thus there is no problem.

Claims

1. A scribing wheel for a brittle material substrate, which is a disk-shaped scribing wheel for providing a cutting line to the brittle material substrate,

the periphery of the scribing wheel is alternately provided with a first cutter and a second cutter along the circumferential direction,

the outer peripheral portion includes: a pair of inclined planes intersecting in a V-shape to form the first blade; and a recess formed by recessing from one or both of the pair of inclined surfaces,

the difference in the radial direction between the position of the knife edge of the first knife and the position of the knife edge of the second knife is less than 0.5 mu m.

2. The scribing wheel for a brittle material substrate according to claim 1, wherein the scribing wheel comprises a first wheel having a first end and a second end,

the angle of the second knife is less than the angle of the first knife.

3. The scribing wheel for a brittle material substrate according to claim 1 or 2, wherein the scribing wheel comprises a first wheel having a first end and a second end,

the difference in the radial direction between the point position of the first knife and the point position of the second knife is 0.

4. The scribing wheel for a brittle material substrate according to any one of claims 1 to 3, wherein the scribing wheel is provided with a plurality of grooves,

the recess is recessed from only one of the pair of inclined surfaces, and forms the second blade together with the other of the pair of inclined surfaces.

5. The scribing wheel for a brittle material substrate according to any one of claims 1 to 4, wherein the scribing wheel is provided with a plurality of grooves,

the difference in the radial direction between the position of the edge of the first blade and the position of the edge of the second blade is 0.2 μm or more and less than 0.5 μm,

each of the recesses includes a bottom portion in the middle of the circumferential direction recessed from one or both of the pair of inclined surfaces to a deepest depth, and two bottom side portions connected to each other with the depth gradually becoming shallower from the bottom portion toward two of the first blades adjacent in the circumferential direction,

the radius of curvature of the boundary of the bottom side portion and the first blade adjacent to each other is larger than the radius of curvature of the boundary of the bottom side portion and the bottom portion adjacent to each other.

6. A method for manufacturing a disk-shaped scribing wheel for providing a scribe line to a brittle material substrate, the method comprising:

a step A of processing a pair of original inclined planes on the outer periphery of an original body of the scribing wheel to be manufactured, and enabling the pair of original inclined planes to be crossed in a V shape to form a first original knife;

a step B of machining a pair of concave portions recessed from both of the pair of original inclined surfaces at a predetermined interval in a circumferential direction, the pair of concave portions forming a second blade, the first original blade and the second blade alternating in the circumferential direction, and a difference in a radial direction between a blade edge position of the first original blade and a blade edge position of the second blade being 0.5 μm or more; and

and a step C of grinding the pair of original inclined surfaces into a pair of inclined surfaces, wherein the pair of inclined surfaces intersect in a V-shape to form a first blade, and the difference in the radial direction between the position of the edge of the first blade and the position of the edge of the second blade is 0 to less than 0.5 [ mu ] m.

7. The method of manufacturing a scribing wheel for a brittle material substrate according to claim 6, wherein the scribing wheel is a wheel having a center axis,

in the step B, the angle of the second blade is made smaller than the angle of the first original blade, and in the step C, the angle of the first blade is made larger than the angle of the second blade.

8. The method of manufacturing a scribing wheel for a brittle material substrate according to claim 6 or 7, wherein the scribing wheel is a wheel having a center axis,

the method comprises the following steps: and a step D of polishing one of the pair of slopes to remove the recess in the one slope after the step C.

9. A brittle material substrate is characterized in that,

the scribing wheel according to any one of claims 1 to 5, wherein the scribing wheel is cut.