CN109305750B

CN109305750B - Scribing wheel

Info

Publication number: CN109305750B
Application number: CN201810780430.8A
Authority: CN
Inventors: 岩坪佑磨; 富本博之; 木山直哉; 泉本聪也; 小森正雄; 饭泽一马
Original assignee: Mitsuboshi Diamond Industrial Co Ltd
Current assignee: Mitsuboshi Diamond Industrial Co Ltd
Priority date: 2017-07-26
Filing date: 2018-07-16
Publication date: 2022-12-23
Anticipated expiration: 2038-07-16
Also published as: JP6910643B2; CN109305750A; KR102551257B1; JP2019025671A; CN208649130U; TW201910283A; KR20190012107A; TWI782044B

Abstract

The invention aims to provide a scribing wheel which can form vertical cracks on a substrate more deeply and better. A scribing wheel (100) is provided with: a plurality of blades (101) formed along the outer periphery of the scoring wheel; and a plurality of grooves (102) that are provided between circumferentially adjacent blades (101) and that are recessed toward the central axis (L0). In the groove part (102), when viewed along the direction parallel to the central axis (L0), the parts located on both sides of the deepest part in the circumferential direction are formed into a shape protruding in the direction away from the central axis (L0).

Description

Scribing wheel

Technical Field

The present invention relates to a scribing wheel for forming a scribing line on a brittle material substrate such as a glass substrate.

Background

The cutting of a brittle material substrate such as a glass substrate is performed by a scribing step of forming a scribe line on the surface of the substrate and a breaking step of cutting the substrate along the formed scribe line. In the scribing step, the scribing wheel is moved along a predetermined line while being pressed against the surface of the substrate. Thereby, the scribing wheel is rolled on the surface of the substrate, thereby forming the scribing line.

Patent document 1 below describes a scribing wheel in which a plurality of grooves are formed at predetermined intervals on the outer peripheral edge line. By using the scribing wheel having this structure, a vertical crack can be reliably formed on the substrate immediately after the start of scribing, and a deep vertical crack can be formed.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. H09-188534

Disclosure of Invention

Problems to be solved by the invention

In the case of using the scribing wheel having the above-described structure, the scribe line is formed by intermittently forming the dents at a predetermined pitch on the surface of the substrate and connecting the vertical cracks formed right under the dents. In this case, the narrower the interval between the dents, the easier the vertical crack formed at the dent position is to be connected, and in addition, when the vertical crack extends deeper, a better scribe line can be formed.

In view of the above problem, an object of the present invention is to provide a scribing wheel capable of forming a vertical crack deeper and more favorably on a substrate.

Means for solving the problems

The primary aspect of the present invention relates to a score wheel for forming a score line on a substrate. The scribing wheel of this mode includes: a plurality of blades formed along an outer periphery of the scoring wheel; and a plurality of groove portions provided between the blade portions adjacent in the circumferential direction and recessed toward the central axis side. Here, the groove portion is formed in a shape in which portions located on both sides in the circumferential direction with respect to a deepest portion are convex in a direction away from the central axis when viewed in a direction parallel to the central axis.

According to the scribing wheel of the present embodiment, when the scribing wheel rolls on the surface of the substrate, the portion near the blade portion bites into the substrate to form the dent on the surface of the substrate. In this case, since the groove portion has the above-described shape, the range of the portion which bites into the substrate near the blade portion is increased in the circumferential direction. Therefore, the interval between the dents formed on the substrate is narrowed, and the vertical cracks formed at the dents are easily connected. Further, since the volume of the portion of the substrate which bites into the vicinity of the blade portion is increased, the vertical crack can be further extended at the dent position. Therefore, according to the scribing wheel of the present embodiment, the vertical crack can be formed deeper and better on the substrate.

In the scribing wheel of the present aspect, the groove portion may have a curved shape in which portions located on both sides of the deepest portion in the circumferential direction are formed when viewed in a direction parallel to the central axis. Then, the groove portion smoothly bites into the substrate along with the rolling of the scribing wheel. Therefore, the vertical crack can be smoothly formed on the substrate.

In the scribing wheel of the present aspect, a ridge of the blade portion extending in the circumferential direction may be present between the circumferentially adjacent groove portions. Accordingly, since the blade portion has a predetermined width in the circumferential direction, the volume of the portion near the blade portion which bites into the substrate becomes larger. Thus, the vertical crack can be formed more deeply on the substrate.

In the scribing wheel of the present aspect, the groove portion may be formed of a curved surface that is convex in a direction away from the central axis when viewed in the circumferential direction, and a radius of curvature of the curved surface may gradually increase from a boundary of the groove portion in the circumferential direction toward the deepest portion of the groove portion. According to this configuration, since the groove portion is formed by the curved surface projecting in the direction away from the center axis of the scribing wheel, when the scribing wheel rolls and the groove portion faces the substrate, the sharp ridge line in the groove portion does not deeply bite into the substrate. Therefore, the occurrence of chipping due to the groove portion coming into contact with the substrate can be suppressed.

Effects of the invention

As described above, according to the present invention, it is possible to provide a scribing wheel capable of forming a vertical crack deeper and well on a substrate with a simple structure.

The effects and significance of the present invention will be further clarified by the following description of the embodiments. However, the embodiment described below is merely an example for carrying out the present invention, and the present invention is not limited to the embodiment described below.

Drawings

Fig. 1 (a) and (b) are a side view and a front view schematically showing a scribing wheel according to an embodiment. Fig. 1 (c) is an enlarged view of a portion of the vicinity of the outer periphery of the scribing wheel according to the embodiment.

Fig. 2 (a) is a cross-sectional view obtained by cutting the scribing wheel of the embodiment in a radial direction through a plane parallel to the central axis at the blade position. Fig. 2 (b) and (c) are cross-sectional views obtained by cutting the scribing wheel of the embodiment in a radial direction through a plane parallel to the central axis at the groove portion position, respectively.

Fig. 3 (a) is a view for explaining a shape of the groove portion of the scribing wheel according to the embodiment when viewed in a direction parallel to the central axis. Fig. 3 (b) is a view schematically showing the shape of the groove portion of the scribing wheel according to the embodiment when viewed in a direction parallel to the central axis. Fig. 3 (c) is a view schematically showing the shape of the groove part of the actually manufactured scribing wheel according to the embodiment when viewed in the direction parallel to the central axis.

Fig. 4 (a) is a view schematically showing a state of formation of a vertical crack when the blade portion of the scribing wheel of the embodiment faces the substrate. Fig. 4 (b) and (c) are views schematically showing the formation state of the vertical crack when the groove of the scribing wheel of the embodiment faces the substrate.

Fig. 5 (a) is a diagram schematically showing a state before the scribing wheel of the embodiment is brought into pressure contact with the substrate. FIG. 5 (b) is a view schematically showing a state before the scribing wheel of the comparative example is brought into pressure contact with the substrate.

Fig. 6 (a) is a view schematically showing a state after the scribing wheel of the embodiment is brought into pressure contact with the substrate. FIG. 6 (b) is a view schematically showing a state after the scribing wheel of the comparative example is brought into pressure contact with the substrate.

Description of the reference numerals:

100 \ 8230and a scribing wheel;

101, 8230and a blade part;

102, 8230a slot part;

102a 8230, the deepest part;

200 \ 8230and a substrate;

201 \8230andvertical cracking.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. For convenience, X, Y, and Z axes orthogonal to each other are shown in the drawings. The Z axis is parallel to the central axis of the scoring wheel.

Fig. 1 (a) and (b) are a side view and a front view schematically showing the structure of the scribing wheel 100. Fig. 1 (c) is an enlarged view of a part of the vicinity of the outer periphery of the scribing wheel 100.

The scribing wheel 100 has a disk shape obtained by obliquely cutting off the edges on both sides of the outer peripheral portion. Two inclined surfaces 100a inclined in different directions from each other in a side view are formed on the outer peripheral portion of the scribing wheel 100. The two inclined surfaces 100a intersect to form a plurality of blades 101, and a groove 102 recessed toward the central axis L0 is formed between circumferentially adjacent blades 101. The lengths of the blades 101 in the circumferential direction are equal to each other. Further, the circumferential lengths of the grooves 102 are also equal to each other. Therefore, the pitch in the circumferential direction of the blade portions 101 is constant, and the pitch in the circumferential direction of the groove portions 102 is also constant.

The scribing wheel 100 is formed of cemented carbide, sintered diamond, single crystal diamond, polycrystalline diamond, or the like. A circular hole 100b into which a shaft serving as a rotation shaft is inserted is formed in the center of the scribing wheel 100. The scribing wheel 100 has a diameter of about 1mm to 5mm and a thickness of about 0.4 to 1 mm. The angle of the blade 101, i.e., the angle formed by the two inclined surfaces 100a, is about 100 to 160 °, and the diameter of the hole 100b is about 0.4 to 1.5 mm.

The pitch p1 of the groove portion 102 (the sum of the length (L1) of one groove portion 102 in the circumferential direction and the length (L2) of one blade portion 101 in the circumferential direction) is, for example, about 10 to 100 μm. The groove depth d1 (the difference in the radial distance between the ridge line of the blade 101 and the scoring wheel 100 at the deepest portion of the groove 102) is, for example, about 1 to 10 μm. The length of the region recessed from the ridge of the blade 101 on the outer periphery of the scribing wheel 100, i.e., the length (L1) of the groove 102 in the circumferential direction is, for example, about 3 to 40 μm. The ratio (L1/L2) of the length (L1) of the groove portion 102 in the circumferential direction to the length (L2) of the ridge line of the blade portion 101 (the region sandwiched between the adjacent groove portions 102) is, for example, 0.5 to 5.0.

The groove portion 102 is formed by a curved surface that is convex in a direction away from the center axis L0 when viewed in the circumferential direction. Further, the radius of curvature of the cross section of the scribing wheel 100 in the radial direction gradually increases from the boundary between the groove portion 102 and the blade portion 101 toward the deepest portion of the circumferential center of the groove portion 102.

Fig. 2 (a) is a cross-sectional view obtained by cutting the scribing wheel 100 in the radial direction through a plane (Y-Z plane) parallel to the central axis L0 at the position of the blade 101. Fig. 2 (b) and (c) are cross-sectional views obtained by cutting the scribing wheel 100 in the radial direction through a plane (Y-Z plane) parallel to the central axis L0 at the position of the groove 102. FIGS. 2 (base:Sub>A) to (C) are sectional views at the A-A ', B-B ' and C-C ' positions of FIG. 1 (C), respectively.

As shown in fig. 2 (a), the cross-sectional shape of the blade 101 when viewed along the circumferential direction is a V-shape having a predetermined angle. Even if the cross-sectional shape of the blade section 101 is an arc-shaped curved surface shape obtained by rounding off the corners of the V-shape, the curvature radius R is 2 μm or less.

When the position in the circumferential direction is shifted from the blade portion 101 to the groove portion 102, as shown in fig. 2 (b), the sectional shape of the groove portion 102 as viewed along the circumferential direction is an arc-shaped curved surface shape in which the corners of the V-shape are rounded. Fig. 2 (b) is a radial cross-sectional view of the scoring wheel when the position in the circumferential direction is located at the ridge line position on the shoulder of the groove portion 102. The height of the ridge line on the shoulder at this time is lower than the height of the ridge line of the blade 101 by D1.

When the position in the circumferential direction shifts from the position of the ridge line on the shoulder of the blade 101 to the position of the deepest portion in the center of the blade 101, the cross-sectional shape of the groove 102 as viewed in the circumferential direction is an arc shape having the largest radius of curvature over the entire range of the groove 102, as shown in fig. 2 (c). The height of the deepest portion is lower than the height of the ridge of the blade portion 101 by D2. D2 corresponds to the depth D1 shown in fig. 1 (c).

In this way, the curvature radius of the curved surface shape of the groove portion 102 gradually increases from the boundary between the groove portion 102 and the blade portion 101 toward the deepest portion. The circumferential ridge of the groove 102 gradually becomes lower with respect to the ridge of the blade 101 from the boundary between the groove 102 and the blade 101 toward the deepest portion, and recedes in a direction (Y-axis negative direction) closer to the center axis L0 of the scribing wheel 100. The groove 102 is formed by, for example, performing cutting processing using a laser on the scribing wheel 100 in which the blade portion 101 is formed over the entire circumference.

Fig. 3 (a) is a view for explaining a shape of the groove portion 102 of the scribing wheel 100 when viewed in a direction parallel to the center axis L0. Fig. 3 (b) schematically shows the shape of the groove 102 of the scribing wheel 100 when viewed in a direction parallel to the central axis L0.

As shown in fig. 3 (a) and (b), a groove portion 102 having a circumferential width W1 is formed between adjacent blade portions 101. In the groove portion 102, portions located on both sides in the circumferential direction with respect to the deepest portion 102a are formed in a shape protruding in a direction away from the central axis L0 when viewed in a direction parallel to the central axis L0 (Z-axis direction). Here, portions located on both sides in the circumferential direction with respect to the deepest portion 102a are formed in a curved shape protruding in a direction away from the central axis L0. The curvature of the curved shape increases from the circumferential end of the groove 102 toward the deepest portion 102 a. That is, angles θ 1 and θ 2 between the ridge line of the groove portion 102 at both sides of the deepest portion 102a and the ridge line near the boundary positions P3 and P4 of the blade 101 increase toward the deepest portion 102 a. When viewed in a direction parallel to the central axis L0, the edge 101 side end of the groove 102 is connected to the edge 101 at the boundary positions P3 and P4 in a curved manner at a predetermined angle.

When the tangents Ln1, ln2 parallel to the X-Y plane are set to the ridge lines near the boundary positions P3, P4 of the portions on both sides of the deepest portion 102a, the position P2 of the intersection of the tangents Ln1, ln2 is located farther from the central axis L0 than the position P1 of the deepest portion 102 a. That is, a radial distance d12 between the ridge line of the blade 101 and the position P2 is smaller than a radial distance d11 between the ridge line of the blade 101 and the position P1.

Fig. 3 (c) schematically shows the shape of the groove portion 102 in the case where the portions on both sides of the deepest portion 102a have a rounded shape which is convex in the direction away from the central axis L0 as compared with fig. 3 (b).

Here, as shown in fig. 3 (c), the outer peripheral shape at the boundary positions P3 and P4 is also formed into a rounded shape, rather than a sharply curved shape as shown in fig. 3 (b). In this case, the distance between the position P2 of the intersection of the tangents Ln1 and Ln2 and the position P1 of the deepest portion 102a, that is, the difference between d11 and d12 becomes larger than that in fig. 3 (a).

Next, the operation of the blade 101 and the groove 102 when the scribing wheel 100 rolls on the surface of the substrate 200 during the scribing operation will be described.

Fig. 4 (a) schematically shows a state of formation of a median crack 201 when the blade portion 101 of the scribing wheel 100 faces the substrate 200. Fig. 4 (b) and (c) are views schematically showing the state of formation of the vertical crack 201 when the groove 102 of the scribing wheel 100 faces the substrate 200.

As shown in fig. 4 (a), when the blade 101 of the scribing wheel 100 faces the substrate 200, the blade 101 bites into the substrate 200 to plastically deform the substrate 200 and form a vertical crack 201 therebelow. The substrate 200 is, for example, a glass substrate having a thickness of 1mm or less. While the blade 101 faces the substrate 200, the plastic deformation of the blade 101 and the extension of the vertical crack 201 of the substrate 200 are continued.

Thereafter, when the groove 102 of the scribing wheel 100 faces the substrate 200 as shown in fig. 4 (b) due to the rolling of the scribing wheel 100, the groove 102 is gradually retreated from the vertical crack 201 as the curvature radius of the groove 102 changes. When the radius of curvature of the groove 102 reaches a predetermined value, the groove 102 completely exits the median crack 201 and contacts the upper surface of the substrate 200, and presses only the upper surface of the substrate 200.

While the groove portions 102 press the upper surface of the substrate 200, the substrate 200 is elastically deformed as shown in fig. 4 (c) by the pressing of the groove portions 102. By this pressing, the vertical crack 201 formed immediately before by the blade portion 101 is propagated. Then, the vertical crack 201 is also formed at the contact position of the groove portion 102.

After the groove 102 is withdrawn from the vertical crack 201 in this way, the groove 102 presses the upper surface of the substrate 200 to elastically deform and stretch only the vertical crack 201 formed by the blade 101 immediately before. Therefore, at least during this period, the generation of chips due to plastic deformation becomes less. Further, since the groove portion 102 has a curved surface projecting in a radial direction away from the center axis L0 of the scribing wheel 100 and no sharp ridge is formed in the groove portion 102, when the scribing wheel 100 rolls and the groove portion 102 faces the substrate 200, the sharp ridge in the groove portion 102 does not bite into the substrate 200 and is plastically deformed. Thus, the generation of debris can be effectively suppressed.

Further, since the cross section of the groove portion 102 in the radial direction is formed by a curved surface that is convex in a direction away from the central axis L0, the groove portion 102 is gradually separated from the median crack 201 and retreated from the state of being bitten by the blade portion 101 while the contact position with the substrate 200 is shifted from the blade portion 101 to the groove portion 102, and a large impact is not applied to the median crack 201. Thus, the generation of debris can be suppressed also during this period.

Fig. 5 (a) is a view schematically showing a state before the scribing wheel 100 having the above-described structure is brought into pressure contact with the substrate 200. Fig. 5 (b) schematically shows a state before the scribing wheel 110 of the comparative example is brought into pressure contact with the substrate 200.

In the scribing wheel 110 of the comparative example, when viewed in a direction parallel to the central axis L0, the groove portions 112 are formed so as to be recessed in a direction toward the central axis L0, and the blade portions 111 are formed between the adjacent groove portions 112. At this time, if the tangents Ln1, ln2 parallel to the X-Y plane are set on the ridge lines near the boundary positions P3, P4 with the blade 111 at both sides of the deepest portion 112a, the position P2 of the intersection of the tangents Ln1, ln2 is closer to the central axis L0 than the position P1 of the deepest portion 112 a. That is, the radial distance d12 between the ridge line of the blade section 111 and the position P2 is greater than the radial distance d11 between the ridge line of the blade section 111 and the position P1. The blade 111 has the same shape as the blade 101 of the scribing wheel 100 of the above embodiment. In addition, as in the above-described embodiment, the cross section of the groove portion 112 parallel to the radial direction is formed as a curved surface protruding in a direction away from the central axis L0. Therefore, the curvature radius of the groove portion 112 when viewed in the circumferential direction increases toward the deepest portion of the groove portion 112.

Fig. 6 (a) and (b) are views schematically showing the scribing wheel 100 of the above embodiment and the scribing wheel 110 of the comparative example in a state after pressure bonding with the substrate 200 in the scribing operation.

As shown in fig. 6 (b), in the scribing wheel 110 of the comparative example, since the portions located on both sides in the circumferential direction with respect to the deepest portion 112a of the groove portion 112 are recessed in the direction toward the central axis L0, the portion V1 biting into the substrate 200 is restricted by the blade portion 111 and a part of the groove portion 112 continuous to the front and rear thereof, and the interval G1 of the portion V1 biting into the substrate 200 is increased.

In contrast, in the scribing wheel 100 of the embodiment, as shown in fig. 6 (a), since the portions located on both sides in the circumferential direction with respect to the deepest portion 102a of the groove portion 102 are convex in the direction away from the central axis L0, the portion V0 biting into the substrate 200 is large in the range except the vicinity of the deepest portion 102a, and the interval G0 of the portion V0 biting into the substrate 200 is narrow.

Thus, when comparing the scribing wheel 100 with the scribing wheel 110, the volume of the portion V0 of the scribing wheel 100 biting into the substrate 200 is significantly increased and the interval G0 of the portion V0 biting into the substrate 200 is significantly narrowed compared to the scribing wheel 110. The larger the volume of the portion that bites into the substrate 200, the larger the plastic deformation of the substrate 200 occurs, and the deeper vertical crack 201 is formed therebelow. Further, the narrower the interval of the portions which bite into the substrate 200, the easier the vertical cracks 201 generated by the plastic deformation are connected, and the better the scribe line can be formed.

Therefore, according to the scribing wheel 100 of the embodiment, the vertical cracks 201 can be formed deeper just below the dent position, that is, the position where the blade portion 101 bites, than the scribing wheel 110 of the comparative example, and the vertical cracks 201 formed below the respective blade portions 101 can be easily connected to each other. Thus, according to the scribing wheel 100 of the embodiment, a better scribing line can be formed.

In the scribing wheel 100 of the embodiment, since the volume of the portion V0 biting into the substrate 200 is larger than that of the scribing wheel 110 of the comparative example, it is conceivable that: the blade 101 is less likely to bite into the substrate 200 than in the comparative example. Therefore, it is conceivable that: in the scribing wheel 100 of the embodiment, as described above, the median crack 201 can be extended more deeply just below the dent position, but the load for causing the blade portion 101 to bite into the substrate 200 is increased.

Thus, the inventors measured the load required to form the rib on the substrate 200 experimentally for the scribing wheel 100 of the embodiment and the scribing wheel 110 of the comparative example. In the experiment, a glass substrate having a thickness of 0.5mm was used as the substrate 200. The scoring speed was 100 mm/sec. The structure other than the shape of the groove 102 when viewed in the direction along the center axis L0 is the same in the scribing wheel 100 and the scribing wheel 110. Here, the load was changed for each scribing line formation of the scribing wheel 100 of the embodiment and the scribing wheel 110 of the comparative example, and a range of the load in which the rib can be formed on the substrate 200 and the scribing quality is good was confirmed.

As a result of the verification, the load at which the rib was formed and the scribing quality was good was 7.0 to 16.0N in the case of using the scribing wheel 110 of the comparative example, whereas the load at which the rib was formed and the scribing quality was good was 5.0 to 15.0N in the case of using the scribing wheel 100 of the embodiment. In this way, it can be confirmed that: by using the scribing wheel 100 of the embodiment, the vertical crack 201 can be formed on the substrate 200 with a lower load than the comparative example. Thus, it can be confirmed that: by using the scribing wheel 100 of the embodiment, a good scribing line can be formed even at a lower load.

< effects of the embodiment >

According to the present embodiment, the following effects can be exhibited.

As shown in fig. 6 (a), when the scribing wheel 100 rolls on the surface of the substrate 200, a portion near the blade 101 bites into the substrate 200 to form a dent on the surface of the substrate 200. At this time, since the groove portion 102 has the shape of fig. 3 (a) to (c), the range of the portion V0 which bites into the substrate 200 near the blade portion 101 is increased in the circumferential direction. Therefore, the gap G0 between the dents formed on the substrate 200 is narrowed, and the vertical cracks 201 formed at the dents become easily connected. Further, since the volume of the portion V0 that bites into the substrate 200 near the blade 101 is increased, the vertical crack 201 can be further extended at the dent position. Thus, according to the scribing wheel 100 of the embodiment, the vertical crack 201 can be formed deeper and better on the substrate 200.

As shown in fig. 3 (a) to (c), in the groove portion 102, portions located on both sides in the circumferential direction with respect to the deepest portion 102a are formed in a curved shape when viewed in a direction parallel to the central axis L0. Accordingly, the groove 102 smoothly bites into the substrate 200 with the rolling of the scribing wheel 100. Therefore, the vertical crack 201 can be smoothly formed on the substrate 200.

As shown in fig. 3 (a) to (c), the scribing wheel 100 is configured such that a ridge of the blade 101 extending in the circumferential direction is present between circumferentially adjacent grooves 102. Accordingly, since the blade 101 has a predetermined width in the circumferential direction, the volume of the portion V0 that bites into the substrate 200 near the blade 101 becomes larger. Thus, the vertical crack 201 can be formed more deeply on the substrate 200.

As shown in fig. 2 (b) and (c), the groove portion 102 is formed by a curved surface that is convex in a direction away from the central axis L0 when viewed in the circumferential direction, and the curvature radius of the curved surface is configured to gradually increase from the boundary between the groove portion 102 and the blade portion 101 toward the deepest portion 102a of the groove portion 102. Since the groove 102 is formed by the curved surface projecting in the direction away from the center axis L0 of the scribing wheel 100, when the scribing wheel rolls and the groove 102 faces the substrate 200, the sharp ridge line in the groove 102 does not deeply bite into the substrate. Therefore, the groove 102 can be prevented from contacting the substrate 200 and generating a chip.

< modification example >

The embodiments of the present invention can be variously modified in addition to the above.

For example, in the above-described embodiment, as shown in fig. 3 (a) to (c), the shape of the portions on both sides of the deepest portion 102a is a curved shape in which the curvature changes toward the deepest portion 102a when viewed in the direction parallel to the central axis L0, but the shape of the portions is not limited thereto, and may be appropriately changed as long as the portions are convex in the direction away from the central axis L0. For example, when viewed in a direction parallel to the central axis L0, both sides of the deepest portion 102a may be curved with a constant curvature, or may include straight portions.

In the above embodiment, as shown in fig. 3 (a) to (c), there are ridge lines of the blade 101 along the circumferential direction, but the length of the ridge line of the blade 101 in the circumferential direction may be significantly shortened, or the ridge line of the blade 101 extending along the circumferential direction may be substantially eliminated in the processing step of the groove portion 102. The length of the ridge line of the blade 101 in the circumferential direction can be appropriately adjusted according to the number of the grooves 102 formed in the outer periphery of the scribing wheel 100. Similarly, the width W1 of the groove 102 in the circumferential direction can be appropriately adjusted according to the number of grooves 102 formed in the outer periphery of the scribing wheel 100.

In the above embodiment, as shown in fig. 2 (b) and (c), the groove portion 102 as viewed in the circumferential direction has a curved surface shape protruding in a direction away from the central axis, but the groove portion 102 as viewed in the circumferential direction may have another shape such as a shape in which a sharp ridge similar to the blade portion 101 is formed in the groove portion 102 or a plane perpendicular to the radial direction.

The embodiments of the present invention can be modified in various ways as appropriate within the scope of the technical idea described in the claims.

Claims

1. A scribing wheel for forming a scribing line on a substrate,

the scribing wheel comprises:

a plurality of blades formed along an outer periphery of the scoring wheel; and

a plurality of grooves which are provided between the blades adjacent in the circumferential direction and are recessed toward the central axis,

in the groove portion, portions located on both sides in the circumferential direction with respect to a deepest portion are formed in a shape protruding in a direction away from the central axis when viewed in a direction parallel to the central axis,

in the groove portion, portions located on both sides in the circumferential direction with respect to the deepest portion are formed in a curved shape when viewed in a direction parallel to the central axis,

the curvature of the curved shape increases from the circumferential end of the groove portion toward the deepest portion.

2. The score wheel of claim 1,

a ridge of the blade portion extending in the circumferential direction is present between the circumferentially adjacent groove portions.