Scoring wheel and scoring method

Abstract

The present application provides a scribing wheel and a scribing method capable of improving the strength of the end face of a cut-off substrate. The scribing wheel comprises a plurality of blade portions (110) formed along the outer periphery, and a plurality of groove portions (120) provided between the blade portions adjacent in the circumferential direction and recessed toward the central axis (L0). The groove portions have, on both sides of the deepest portion (120a), a ridge line (121, 122) continuous with the ridge line (111) of the blade portion and extending to the deepest portion. Each ridge line of the groove portion has a change point (Q) at which a second angle (θ2) formed by the ridge line (121b, 122b) on the deepest portion side with respect to the change point and the ridge line of the blade portion is greater than a first angle (θ1) formed by the ridge line (121a, 122a) on the blade portion side with respect to the change point. The change point is provided at a position that sinks into the inside of the substrate when a scribing operation is performed by a load within a range in which a rib-shaped line is formed in the substrate without breaking the substrate.

Description

TECHNICAL FIELD

[0001] The present application relates to a scribing wheel and a scribing method for forming a scribe line on a brittle material substrate such as a glass substrate. BACKGROUND

[0002] The cutting of a brittle material substrate such as a glass substrate is performed by a scribing process of forming a scribe line on a substrate surface, and a breaking process of cutting the substrate along the formed scribe line. In the scribing process, a scribing wheel is moved along a prescribed line while being pressed against the substrate surface. Thereby, the scribing wheel is rolled on the substrate surface, and a scribe line is formed.

[0003] In the following Patent Document 1, a scribing wheel in which a groove portion is formed at a constant interval in the circumferential direction on a ridge line is disclosed. In this scribing wheel, the groove portion is formed in a V-shape when viewed in the circumferential direction, and thereby a ridge line is also formed in the groove portion. In this structure, when the scribing wheel is rolled on the substrate surface while being given a pressing force, a tooth shape (indentation) having a hexagonal shape with six corners is formed on the scribe line. By the two corners provided on the scribe line, the pressing force is not concentrated on the four corners provided outside the scribe line, and thereby the generation of a crack deviating from the scribe line is suppressed, and the cutting quality in the breaking process is improved.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT DOCUMENTS

[0006] Patent Document 1: Japanese Patent Application Publication No. 2010-132542 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] The corners provided outside the scribe line remain on the end surface of the cut substrate. When an external force is applied to the substrate, in the end surface of the substrate, stress is easily concentrated on the corners, and a crack is easily generated at the corners. Since the generation of the crack causes the destruction of the end surface of the substrate, if the generation of the crack at the corners can be suppressed, the strength of the end surface of the substrate can be improved.

[0009] In view of such a problem, an object of the present application is to provide a scribing wheel and a scribing method capable of improving the strength of the end surface of a cut substrate.

[0010] MEANS FOR SOLVING THE PROBLEMS

[0011] A first aspect of the present application relates to a scribing wheel for forming a scribe line on a substrate. The scribing wheel of this aspect includes a plurality of blade portions formed along an outer periphery, and a plurality of groove portions provided between the blade portions adjacent in the circumferential direction and recessed toward a center axis. Here, the groove portions have, on both sides of a deepest portion, a ridge line that is continuous from a ridge line of the blade portion and extends to the deepest portion. Each ridge line of the groove portions has at least one change point at which a second angle formed by a ridge line on the deepest portion side and the ridge line of the blade portion is larger than a first angle formed by a ridge line on the blade portion side and the ridge line of the blade portion. The change point is provided at a position that sinks into the inside of the substrate when a scribing operation is performed by a load within a range in which a rib-shaped line is formed on the substrate and the substrate is not broken.

[0012] According to the scribing wheel of this aspect, it is possible to form a dent with a larger number of corners (a shape with a larger number of sides) on the scribe line of the substrate, and thus it is possible to increase the number of corners formed on the end surface of the substrate after being cut. Thus, stress is easily dispersed and stress concentrated on one corner is reduced, and thus it is possible to suppress the generation of cracks at the corner. Therefore, it is possible to improve the strength of the end surface of the substrate after being cut.

[0013] In the scribing wheel of this aspect, it can be that the change point is provided in a direction away from the center axis than the center in the depth direction of the groove portion.

[0014] According to this structure, when a scribing operation is performed, the change point easily sinks into the inside of the substrate, and thus it is possible to easily improve the strength of the end surface of the substrate.

[0015] In the scribing wheel of this aspect, it can be that the first angle is 10° or less.

[0016] According to this structure, it is possible to more significantly improve the strength of the end surface of the substrate.

[0017] A second aspect of the present application relates to a scribing method for forming a scribe line on a substrate. The scribing method of this aspect moves a scribing wheel on a surface of the substrate while imparting a load to the scribing wheel within a range in which a change point sinks into the inside of the substrate, the scribing wheel including a plurality of blade portions formed along an outer periphery, and a plurality of groove portions provided between the blade portions adjacent in the circumferential direction and recessed toward a center axis, the groove portions having, on both sides of a deepest portion, a ridge line that is continuous from a ridge line of the blade portion and extends to the deepest portion, each ridge line of the groove portions having at least one change point at which a second angle formed by a ridge line on the deepest portion side and the ridge line of the blade portion is larger than a first angle formed by a ridge line on the blade portion side and the ridge line of the blade portion.

[0018] According to the scribing method of this aspect, it is possible to achieve the same effects as the first aspect.

[0019] Effects of Invention

[0020] As described above, according to the present application, it is possible to provide a scribing wheel and a scribing method capable of improving the strength of the end surface of a cut substrate.

[0021] The effects and advantages of the present application will be further clarified by the following description of the embodiments shown in the drawings. However, the following embodiments are only examples of implementing the present application, and the present application is not limited by the contents described in the following embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 (a) of FIG. 1 is a side view schematically showing a scribing wheel of the embodiment, Figure 1 (b) of FIG. 1 is a front view schematically showing the scribing wheel of the embodiment. Figure 1 (c) of FIG. 1 is a perspective view showing a portion of the scribing wheel of the embodiment in the vicinity of the outer periphery in an enlarged manner.

[0023] Figure 2 (a) of FIG. 2 is an enlarged cross-sectional view in the vicinity of a groove portion of the embodiment obtained by cutting the scribing wheel in a plane perpendicular to the center axis at the position of the ridge line of the scribing wheel. Figure 2 (b) of FIG. 2 is a view for explaining a change point provided at the first ridge line and the second ridge line of the groove portion of the embodiment.

[0024] Figure 3 is a view schematically showing the structure of a scribing device of the embodiment.

[0025] Figure 4 (a) of FIG. 4 is a view schematically showing a state in which the scribing wheel of the embodiment is sunk into a substrate in a scribing operation. Figure 4 (b) and Figure 4 (c) of FIG. 4 are views for explaining a result of the scribing wheel of the embodiment being sunk into the substrate, i.e., an indentation formed on a scribe line.

[0026] Figure 5 (a) of FIG. 6 is a view schematically showing a state in which the scribing wheel of the comparative example is sunk into a substrate in a scribing operation. Figure 5 (b) and Figure 5 (c) of FIG. 6 are views for explaining a result of the scribing wheel of the comparative example being sunk into the substrate, i.e., an indentation formed on a scribe line.

[0027] Figure 6 (a) of FIG. 8 is a table showing the specifications of each scribing wheel of wheels 1 to 7, Figure 6 (b) and Figure 6 (c) of FIG. 8 are views for explaining the specifications. Figure 6Fig. 1 of the accompanying drawings is a graph showing the relationship between the groove angle and the difference between the depth of the change point and the depth of the indentation when the scribing action was performed on the substrate using wheels 1 to 7 and by a load of 7 N (Newton).

[0028] Figure 7 Fig. 1 of the accompanying drawings is a graph showing the relationship between the groove angle and the difference between the depth of the change point and the depth of the indentation when the scribing action was performed on the substrate using wheels 1 to 7 and by a load of 7 N (Newton). Figure 7 Fig. 1 of the accompanying drawings is a graph showing the relationship between the groove angle and the difference between the depth of the change point and the depth of the indentation when the scribing action was performed on the substrate using wheels 1 to 7 and by a load of 7 N (Newton).

[0029] Figure 8 Fig. 1 of the accompanying drawings is a graph showing the relationship between the groove angle and the difference between the depth of the change point and the depth of the indentation when the scribing action was performed on the substrate using wheels 1 to 7 and by a load of 7 N (Newton). Figure 8 Fig. 1 of the accompanying drawings is a graph showing the relationship between the groove angle and the difference between the depth of the change point and the depth of the indentation when the scribing action was performed on the substrate using wheels 1 to 7 and by a load of 7 N (Newton).

[0030] BRIEF DESCRIPTION OF THE DRAWINGS

[0031] 100 scribing wheel

[0032] 110 blade portion

[0033] 111 land

[0034] 120 groove portion

[0035] 121 first land (land)

[0036] 121a land on the blade portion side

[0037] 121b land on the deepest portion side

[0038] 122 second land (land)

[0039] 122a land on the blade portion side

[0040] 122b land on the deepest portion side

[0041] F substrate

[0042] Q change point

[0043] θ1 first angle

[0044] θ2 second angle

[0045] L0 center axis DETAILED DESCRIPTION

[0046] Hereinafter, an embodiment of the present application will be described with reference to the accompanying drawings. Note that in each drawing, X-axis, Y-axis and Z-axis which are orthogonal to each other are marked for convenience. Y-axis is parallel to the center axis of the scribing wheel.

[0047] Figure 1 (a) is a side view schematically showing the structure of the engraving wheel 100. Figure 1 (b) is a schematic front view showing the structure of the engraving wheel 100. Figure 1 (c) is a perspective view showing a portion of the outer periphery of the engraved wheel 100 magnified.

[0048] The engraving wheel 100 has a circular plate shape obtained by obliquely cutting off the edges on both sides of its outer periphery. In a frontal view, two inclined surfaces 101 inclined in opposite directions are formed on the outer periphery of the engraving wheel 100. Multiple cutting edges 110 are formed by the intersection of the two inclined surfaces 101, and grooves 120 recessed towards the central axis L0 are formed between adjacent cutting edges 110 in the circumferential direction. The lengths of the cutting edges 110 in the circumferential direction are equal. Furthermore, the lengths of the grooves 120 in the circumferential direction are also equal. Therefore, the pitch of the cutting edges 110 in the circumferential direction is constant, and the pitch of the grooves 120 in the circumferential direction is also constant.

[0049] The scribing wheel 100 is formed of cemented carbide, sintered diamond, single-crystal diamond, or polycrystalline diamond. A circular hole 102 is formed in the center of the scribing wheel 100 for inserting a shaft that serves as a rotation axis.

[0050] like Figure 1 As shown in (c), the cutting edge 110 has a V-shaped cross-section when viewed in the circumferential direction.

[0051] like Figure 1 As shown in (c), the groove 120 extends from the edge of the grading wheel 100 toward the end faces on both sides of the grading wheel 100 along the inclined surfaces 101 on both sides, and has a V-shaped cross-section when viewed circumferentially. Thus, the groove 120 has: a first edge 121 that continues from the edge 111 of the adjacent cutting edge 110 and extends toward the deepest part 120a of the groove 120; and a second edge 122 that continues from the edge 111 of the other adjacent cutting edge 110 and extends toward the deepest part 120a. The first edge 121 and the second edge 122 are connected at the deepest part 120a and are symmetrical about the deepest part 120a.

[0052] The groove 120 is formed, for example, by laser cutting of a scribe wheel 100 with a blade 110 formed over the entire circumference.

[0053] Figure 2 (a) is an enlarged sectional view of the area near the groove 120 obtained by cutting along the edge of the scribed wheel 100 with a plane (XZ plane) perpendicular to the central axis L0. Figure 2(b) is a diagram used to explain the variation point Q set on the first ridge 121 and the second ridge 122 in the groove 120.

[0054] like Figure 2 As shown in (a), the first ridge 121 and the second ridge 122 of the groove 120 extend from the boundary position between the groove and the ridge 111 of the cutting edge 110 in a generally straight line (straight line, or nearly straight arc) in a direction inclined relative to the ridge 111 of the cutting edge 110. Then, while drawing an arc, they change direction downward and extend in a generally straight line (straight line, or nearly straight arc) to reach the deepest part 120a. That is, as Figure 2 As shown in (b), the first edge 121 and the second edge 122 have a change point Q. The second angle θ2 formed by the edge 121b and 122b on the side of the deepest part 120a with respect to the change point Q and the edge 111 of the cutting edge 110 is greater than the first angle θ1 formed by the edge 121a and 122a on the side of the cutting edge 110 with respect to the change point Q and the edge 111 of the cutting edge 110.

[0055] The survey is performed along the first edge line 121 and the second edge line 122, and the inclination of the tangent at each survey point is obtained. The range between point P1 on the side of the blade 110 where the change in the inclination of the tangent is greater and point P2 on the side of the deepest part 120a is defined as the range of change, and the midpoint of this range of change (from P1 to P2) is defined as the change point Q.

[0056] An approximate straight line Ln1 is calculated from each survey point up to point P1 on the edge lines 121a and 122a on the side of the cutting edge 110. The angle between the edge line 111 of the cutting edge 110 and the approximate straight line Ln1 is defined as the first angle θ1. Similarly, an approximate straight line Ln2 is calculated from each survey point up to point P2 on the edge lines 121b and 122b on the side of the deepest part 120a. The angle between the edge line 111 of the cutting edge 110 and the approximate straight line Ln2 is defined as the second angle θ2.

[0057] The depth d2 of the change point Q (the radial distance between the edge 111 of the cutting edge 110 and the change point Q) is set to be half the depth d1 of the groove (the radial distance between the edge 111 of the cutting edge 110 and the deepest part 120a of the groove 120). That is, the change point Q is set in a direction away from the central axis L0 from the center in the depth direction of the groove 120.

[0058] like Figure 1As shown in (c), the groove portion 120 has, on both sides of the deepest portion 120a in the circumferential direction, a first groove surface 123 curved in the same shape as the first ridge line 121, and a second groove surface 124 curved in the same shape as the second ridge line 122. Since the first ridge line 121 and the second ridge line 122 have the change point Q, the first groove surface 123 and the second groove surface 124 are divided into a surface 123a, 124a (hereinafter referred to as a first gentle slope surface 123a, a second gentle slope surface 124a) on the blade portion 110 side having a relatively gentle slope, and a surface 123b, 124b (hereinafter referred to as a first steep slope surface 123b, a second steep slope surface 124b) on the deepest portion 120a side having a relatively steep slope, with the position corresponding to the change point Q as a boundary. Figure 1

[0059] Note that the groove portion 120 is very small in size (micrometer order). Therefore, in the case where the groove portion 120 is formed by cutting processing using a laser, it is difficult to form the first ridge line 121 and the second ridge line 122 by a regular straight line or a circular arc. Therefore, in practice, the first ridge line 121 and the second ridge line 122 are formed by a straight line or a circular arc drawn in a slightly deformed line.

[0060] The scribing wheel 100 of the present embodiment is used for a scribing device 1.

[0061] Figure 3 is a view schematically showing the structure of the scribing device 1.

[0062] As shown in (c), the groove portion 120 has, on both sides of the deepest portion 120a in the circumferential direction, a first groove surface 123 curved in the same shape as the first ridge line 121, and a second groove surface 124 curved in the same shape as the second ridge line 122. Since the first ridge line 121 and the second ridge line 122 have the change point Q, the first groove surface 123 and the second groove surface 124 are divided into a surface 123a, 124a (hereinafter referred to as a first gentle slope surface 123a, a second gentle slope surface 124a) on the blade portion 110 side having a relatively gentle slope, and a surface 123b, 124b (hereinafter referred to as a first steep slope surface 123b, a second steep slope surface 124b) on the deepest portion 120a side having a relatively steep slope, with the position corresponding to the change point Q as a boundary. Figure 3

[0063] The moving stage 2 is screwed with the ball screw 3. In addition, the moving stage 2 is supported by a pair of guide rails 4 so as to be movable in the Y-axis direction. When the ball screw 3 is rotated by driving of a motor not shown, the moving stage 2 moves along the pair of guide rails 4 in the Y-axis direction.

[0064] A motor 5 is provided on the upper surface of the moving stage 2. The motor 5 rotates and positions a placement portion 6 disposed above it at a prescribed angle in the XY plane. The placement portion 6 places a substrate F made of a fragile material such as glass. The placement portion 6 has a vacuum suction mechanism not shown, by which the substrate F is held on the placement portion 6.

[0065] In the scribing device 1, a bridge 7 is erected on a pair of supports 8a, 8b provided on both sides of the moving stage 2 and the placement portion 6 above the moving stage 2 in such a manner as to span the moving stage 2 and the placement portion 6 above the moving stage 2. A guide rail 9 is installed on the bridge 7.

[0066] ​​The grading head 10 is connected to the guide rail 9 via the transfer unit 11. The transfer unit 11 slides on the guide rail 9, at which point the grading head 10 moves in the X-axis direction.

[0067] When forming scribe lines on the surface of substrate F using the scribe apparatus 1, the scribe wheel 100 is mounted on the holder unit 12 in a manner that allows it to rotate around the central axis L0. Furthermore, the holder unit 12, which holds the scribe wheel 100, is mounted on the scribe head 10.

[0068] When the scribing operation begins, the scribing apparatus 1 moves the scribing head 10 downwards, applying a predetermined load to the scribing wheel 100 while bringing the scribing wheel 100 into contact with the substrate F. Then, the scribing apparatus 1 moves the scribing head 10 in the X-axis direction. As a result, the scribing wheel 100 rolls on the surface of the substrate F, forming scribing lines on the substrate F. The load applied to the scribing wheel 100 is set to a range that forms rib-like patterns on the substrate F without damaging the substrate F. This load range can vary depending on the thickness of the substrate F, etc. Hereinafter, for ease of explanation, the "range that forms rib-like patterns on the substrate F without damaging the substrate F" will be referred to as the "allowable range".

[0069] As needed, the marking action is repeatedly performed while moving the mounting part 6 in the Y-axis direction. Furthermore, as needed, after rotating the mounting part 6 by a predetermined angle, such as 90°, the marking action is repeatedly performed while moving the mounting part 6 in the Y-axis direction.

[0070] Figure 4 (a) is a schematic diagram showing the state in which the scribing wheel 100 of this embodiment is embedded in the substrate F during the scribing operation. Figure 4 (b) and Figure 4 (c) is a diagram used to illustrate the result of the scribing wheel 100 sinking into the substrate F, i.e., the indentation 130 formed on the scribing line.

[0071] like Figure 4 As shown in (a), in the scribing wheel 100 of this embodiment, the change point Q of the first ridge 121 and the second ridge 122 of the groove 120 is set at the position where it is embedded in the interior of the substrate F when the scribing action is performed with a load within the allowable range.

[0072] In the 100-axis direction of the engraving wheel Figure 4When the scribe wheel 100 rotates in the direction of arrow (a) and rolls in the opposite direction, the outer periphery of the scribe wheel 100 contacts the surface of the substrate F in the sequence of first steep slope 123b → first gentle slope 123a → cutting edge 110 → second gentle slope 124a → second steep slope 124b, and sinks into the interior of the substrate F. This forms an indentation 130 on the surface of the substrate F. As the scribe wheel 100 rolls on the surface of the substrate F, the indentations 130 are arranged in a row along the scribe lines at intervals equal to the pitch of the cutting edge 110.

[0073] like Figure 4 As shown in (c), the substrate F is penetrated by the first steep slope 123b, forming an angle 131 on the scribe line of the substrate F. The substrate F is penetrated by the first gentle slope 123a, forming two angles 132 on both sides of the scribe line. Next, the cutting edge 110 penetrates the substrate F, forming four angles 133 on both sides of the scribe line. Then, the substrate F is penetrated by the second gentle slope 124a, forming two angles 134 on both sides of the scribe line. Finally, the substrate F is penetrated by the second steep slope 124b, forming an angle 135 on the scribe line. Thus, as... Figure 4 (b) and Figure 4 As shown in (c), the indentation 130 becomes approximately decagonal.

[0074] Figure 5 (a) is a diagram schematically showing the state in which the scribe wheel 200 of the comparative example is embedded in the substrate F during the scribe operation. Figure 5 (b) and Figure 5 (c) is a diagram used to illustrate the result of the scribing wheel 200 sinking into the substrate F, namely the indentation 230 formed on the scribing line.

[0075] like Figure 5 As shown in (a), in the comparative example of the scribing wheel 200, the variation point Q of the first ridge 221 and the second ridge 222 of the groove 220 is set at a position that does not sink into the interior of the substrate F when the scribing action is performed with a load within the allowable range.

[0076] 200-degree engraving wheel Figure 5 When the scribe wheel 200 rotates in the direction of arrow (a) and rolls in the opposite direction, the outer periphery of the scribe wheel 200 contacts the surface of the substrate F in the sequence of the first gentle slope 223a of the first groove surface 223 → the cutting edge 210 → the second gentle slope 224a of the second groove surface 224, and sinks into the interior of the substrate F. As a result, an indentation 230 is formed on the surface of the substrate F. In the scribe wheel 200, the first steep slope 223b of the first groove surface 223 and the second steep slope 224b of the second groove surface 224 do not sink into the substrate F.

[0077] like Figure 5As shown in (c), the indentation 230 becomes a substantially hexagonal shape by the first gentle slope 223a sinking into the substrate F, and forming a corner 231 on the scribe line of the substrate F. Next, the four corners 232 are formed on both sides of the scribe line by the blade portion 210 sinking into the substrate F. Next, the indentation 230 becomes a substantially hexagonal shape by the second gentle slope 224a sinking into the substrate F, and forming a corner 233 on the scribe line. Thus, as shown in (d), the indentation 230 becomes a substantially hexagonal shape. Figure 5 As shown in (b), the indentation 230 becomes a substantially hexagonal shape by the first gentle slope 223a sinking into the substrate F, and forming a corner 231 on the scribe line of the substrate F. Next, the four corners 232 are formed on both sides of the scribe line by the blade portion 210 sinking into the substrate F. Next, the indentation 230 becomes a substantially hexagonal shape by the second gentle slope 224a sinking into the substrate F, and forming a corner 233 on the scribe line. Thus, as shown in (d), the indentation 230 becomes a substantially hexagonal shape. Figure 5 As shown in (c), the indentation 230 becomes a substantially hexagonal shape by the first gentle slope 223a sinking into the substrate F, and forming a corner 231 on the scribe line of the substrate F. Next, the four corners 232 are formed on both sides of the scribe line by the blade portion 210 sinking into the substrate F. Next, the indentation 230 becomes a substantially hexagonal shape by the second gentle slope 224a sinking into the substrate F, and forming a corner 233 on the scribe line. Thus, as shown in (d), the indentation 230 becomes a substantially hexagonal shape.

[0078] Note that even in the scribe wheel in which the first ridge line and the second ridge line of the groove portion do not have a change point, that is, the first ridge line and the second ridge line are in a straight line shape or a circular arc shape close to a straight line, the indentation becomes a substantially hexagonal shape as in the scribe wheel 200 of the comparative example.

[0079] After the scribe process of forming the scribe line, a breaking process is performed. In the breaking process, the substrate F is cut at the scribe line. Thus, a substrate F of a prescribed size is produced. The end surface in the substrate F formed by the cutting has corners other than the corners on the scribe line of the indentation. In the substrate F obtained using the scribe wheel 200 of the comparative example, two corners 232, 232 remain on the end surface with respect to one indentation, and in the substrate F obtained using the scribe wheel 100 of the embodiment, four corners 132, 133, 133, 134 remain on the end surface with respect to one indentation.

[0080] When an external force is applied to the cut substrate F, stress easily concentrates on the corners of the end surface of the substrate F, and thus a crack easily occurs at the corners. Furthermore, the occurrence of the crack can lead to the destruction of the end surface of the substrate F.

[0081] In the scribe wheel 100 of the embodiment, compared to the scribe wheel 200 of the comparative example in which the change point Q does not sink into the inside of the substrate F, it is possible to form an indentation with more corners in the substrate F, and thus it is possible to increase the corners formed on the end surface of the cut substrate F. Thus, stress easily disperses and thus the stress concentrated on one corner decreases, and thus it is possible to suppress the occurrence of a crack at the corners. Thus, it is possible to improve the strength of the end surface of the cut substrate F.

[0082] <Experiment>

[0083] The inventors of the present application confirmed the effects in the case of using the scribe wheel 100 having the above-described structure through experiments. In the experiments, the strength of the end surface of the substrate F cut using the scribe wheels was verified for the scribe wheels of wheels 1 to 4 having the structure of the scribe wheel 100 of the embodiment, and the three scribe wheels of wheels 5 to 7 not having the structure of the scribe wheel 10. Hereinafter, the experiments and the experimental results will be described with reference to the drawings.

[0084] Figure 6(a) of FIG. 1 is a table showing the specifications of each of the scribing wheels 1 to 7, Figure 6 (b) of FIG. 1 and Figure 6 (c) of FIG. 1 is a diagram for explaining the specifications.

[0085] To produce the scribing wheels 1 to 7, the groove angle β is defined as follows. That is, as shown in (c) of FIG. 1, a reference line Lr is set at a position that is a prescribed proportion of the depth dl of the groove from the ridge line 111 of the blade portion 110. Approximate straight lines Ln3 and Ln4 of the first ridge line 121 and the second ridge line 122 up to the reference line Lr are found, and the angle formed by the two approximate straight lines Ln3 and Ln4 is set as the groove angle β. Figure 6

[0086] The scribing wheels 1 to 7 are produced so that the groove angle β changes by 5° each time. For each scribing wheel, the width Wl in the circumferential direction of the groove portion 120 and the depth dl of the groove are equal, with the first angle θl, the second angle θ2, and the position of the change point Q being determined so as to achieve the respective groove angles β. The greater the groove angle β, the smaller the first angle θl and the greater the second angle θ2, and the smaller the distance in the radial direction from the ridge line 111 of the blade portion 110 to the change point Q (hereinafter referred to as the "change point depth"). Note that in the scribing wheel 7 in which the change point Q is not present, the angle formed by the approximate straight lines of the first ridge line 121 and the second ridge line 122 and the ridge line 111 of the blade portion 110 is set as the first angle θl.

[0087] In addition, for the scribing wheels 1 to 7, the diameter D, the angle (the angle formed by the two inclined surfaces 101) α of the blade portion 110, the number n of the blade portions 110, and the width W2 in the circumferential direction of the blade portion 110 are equal.

[0088] Figure 6 (d) of FIG. 1 is a diagram showing the relationship between the groove angle β and the difference between the change point depth and the indentation depth when the scribing wheels 1 to 7 are used and the scribing operation is performed on the substrate F by a load of 7 N (Newton). Note that in the scribing wheel 7 in which the change point Q is not present, the difference between the groove depth and the indentation depth is regarded as the difference between the change point depth and the indentation depth.

[0089] In the case where the change point Q sinks inside the substrate F during the scribing operation, the indentation depth is greater than the change point depth, and the above-described difference takes a negative value.

[0090] Figure 6 ​(d) shows the following: in the wheels 1 to 4 in which the groove angle β is 163.0°, 158.0°, 153.0°, 148.0°, respectively, and the first angle θ1 is 7.0°, 11.0°, 12.5°, 15.5°, respectively, the change point Q sinks into the inside of the substrate F, and in the wheels 5 to 7 in which the groove angle β is 143.0°, 138.0°, 133.0°, respectively, and the first angle θ1 is 17.2°, 20.2°, 22.3°, respectively, the change point Q does not sink into the inside of the substrate F.

[0091] Note that although not illustrated, the relationship between the groove angle β and the difference between the change point depth and the indentation depth when the scribing action is performed on the substrate F using the wheels 1 to 7 and by the loads of 9N, 11N, respectively, also shows the same tendency as (d) of FIG. 8. Therefore, it is considered that for the loads of 9N, 11N, in the wheels 1 to 4 in which the groove angle β is 163.0°, 158.0°, 153.0°, 148.0°, respectively, the change point Q sinks into the inside of the substrate F, and in the wheels 5 to 7 in which the groove angle β is 143.0°, 138.0°, 133.0°, respectively, the change point Q does not sink into the inside of the substrate F. Figure 6

[0092] The thickness of the substrate F used was 0.4 mm. The loads 7N, 9N, 11N are loads commonly included in the allowable ranges of the wheels 1 to 7, 7N is a value on the low load side in the allowable range, and 11N is a value on the high load side in the allowable range.

[0093] Figure 7 (a) of FIG. 9 is a graph showing the relationship between the groove angle β and the end face strength of the cut substrate F when the scribing action is performed using the wheels 1 to 7 and by the loads of 7N, 9N, 11N. The end face strength of the substrate F was measured by a four-point bending end face strength test.

[0094] As shown in (a) of FIG. 9, the end face strength of the substrate F is substantially equal between the wheels 5 to 7 in which the change point Q does not sink into the inside of the substrate F, but the end face strength of the substrate F is significantly improved compared with the wheels 5 to 7 in the wheels 1 to 4 in which the change point Q sinks into the inside of the substrate F. In addition, between the wheels 1 to 4, the greater the groove angle β, the greater the end face strength of the substrate F. Figure 7

[0095] (b) of FIG. 9 is a graph showing the relationship between the first angle θ1 and the end face strength of the cut substrate F when the scribing action is performed using the wheels 1 to 7 and by the loads of 7N, 9N, 11N. Figure 7 As shown in (b) of FIG. 9, the end face strength of the substrate F is substantially equal between the wheels 5 to 7 in which the change point Q does not sink into the inside of the substrate F, but the end face strength of the substrate F is significantly improved compared with the wheels 5 to 7 in the wheels 1 to 4 in which the change point Q sinks into the inside of the substrate F. In addition, between the wheels 1 to 4, the greater the first angle θ1, the greater the end face strength of the substrate F.

[0096] Figure 7 ​​As shown in (b), among the wheels 1 to 4 that sink into the inside of the substrate F at the change point Q, the smaller the first angle θ1, the greater the end face strength of the substrate F. In particular, in the cases where the load is 7 N and 9 N, it is shown that the end face strength is greatly improved in the range where the first angle θ1 is between 12.5° and 11.0°, and in the case where the load is 11 N, it is also shown that the end face strength is greatly improved when the first angle is less than 11.0°.

[0097] Therefore, according to Figure 7 the result shown in (b) indicates that the end face strength of the substrate F can be more significantly improved by configuring the scribing wheel 100 such that the first angle θ1 is 10° or less.

[0098] As described above, according to the experimental results, it is known that the structure of the scribing wheel 100 according to the present embodiment can improve the end face strength of the cut substrate F.

[0099] <Effects of the Embodiment>

[0100] According to the present embodiment, the following effects can be achieved.

[0101] As Figure 4 shown in (a), for the scribing wheel 100, the change point Q possessed by the first ridge line 121 and the second ridge line 122 of the groove portion 120 is disposed at a position that sinks into the inside of the substrate F when the scribing operation is performed with a load within the range in which the rib-shaped lines are formed in the substrate F without breaking the substrate F. Thus, as Figure 4 shown in (b) and Figure 4 shown in (c), compared with a structure in which the change point Q does not sink into the inside of the substrate F or a structure in which the change point Q is not present, it is possible to form indentations 130 with more angles (more-sided shapes) on the scribing lines of the substrate F, and thus it is possible to increase the number of angles formed on the end face of the cut substrate F. Thus, stress is easily dispersed and stress concentrated on one angle is reduced, and thus it is possible to suppress the generation of cracks at the angles. Therefore, it is possible to improve the end face strength of the cut substrate F.

[0102] Further, the change point Q is disposed in a direction away from the center axis L0 than the center in the depth direction of the groove portion 120. Thus, when the scribing operation is performed, the change point Q easily sinks into the inside of the substrate F, and thus it is possible to easily improve the end face strength of the substrate F.

[0103] Further, in the case where the scribing wheel 100 adopts a structure in which the first angle θ1 is 10° or less, as Figure 7 shown in (b), it is possible to more significantly improve the end face strength of the substrate F.

[0104] <Alterations>

[0105] The embodiment of the present application can be modified variously in addition to the above.

[0106] For example, in the above embodiment, one change point Q is provided at the position that sinks into the inside of the substrate F when the scribing operation is performed by the load within the allowable range, in the first ridge line 121 and the second ridge line 122 of the groove portion 120. However, as shown in (a) of FIG. 10, two change points Q1, Q2 can be provided at the positions that sink into the inside of the substrate F in the first ridge line 121 and the second ridge line 122. In this case, for the change point Q1 on the blade portion 110 side, the angle (corresponding to the second angle of the present application) formed by the ridge line 121b, 122b (between the change point Q1 and the change point Q2) on the deepest portion 120a side with respect to the change point Q1 and the ridge line 111 of the blade portion 110 is larger than the angle (corresponding to the first angle of the present application) formed by the ridge line 121a, 122a on the blade portion 110 side with respect to the change point Q1. Also, for the change point Q2 on the deepest portion 120a side, the angle (corresponding to the second angle of the present application) formed by the ridge line 121c, 122c on the deepest portion 120a side with respect to the change point Q2 and the ridge line 111 of the blade portion 110 is larger than the angle (corresponding to the first angle of the present application) formed by the ridge line 121b, 122b (between the change point Q1 and the change point Q2) on the blade portion 110 side with respect to the change point Q2. As shown in (b) of FIG. 10, in the substrate F, a substantially fourteen-sided indentation 130 is formed on the scribe line. Figure 8 Figure 8

[0107] Also, in the first ridge line 121 and the second ridge line 122, three or more change points Q can be provided at the positions that sink into the inside of the substrate F when the scribing operation is performed by the load within the allowable range.

[0108] Also, as described above, in the case where a plurality of change points Q are provided in the first ridge line 121 and the second ridge line 122, at least one of the change points Q can be provided at the position that does not sink into the inside of the substrate F when the scribing operation is performed by the load within the allowable range.

[0109] Also, in the above embodiment, the change point Q is provided in the direction away from the center axis L0 from the center in the depth direction of the groove portion 120. However, the change point Q can be provided in the direction close to the center axis L0 from the center in the depth direction of the groove portion 120, as long as it is at the position that sinks into the inside of the substrate F when the scribing operation is performed by the load within the allowable range.

[0110] Further, the embodiment of the present application can be modified variously within the scope of the technical idea shown in the technical solution.​​

Claims

1. A scribing wheel for forming scribing lines on a substrate, characterized in that, The engraving wheel has the following features: Multiple cutting edges, which are formed along the outer periphery; and Multiple grooves are provided between adjacent cutting edges in the circumferential direction and recessed towards the central axis. The groove has ridges on both sides of its deepest part that extend continuously from the ridge line of the cutting edge to the deepest part. Each edge of the groove has at least one point of change. The second angle formed by the edge of the deepest side relative to this point of change and the edge of the cutting edge is greater than the first angle formed by the edge of the cutting edge relative to this point of change and the edge of the cutting edge. The change point is positioned where it sinks into the interior of the substrate when a scratching action is performed under load. The load is the range within which rib-like patterns are formed on the substrate without damaging it. The first angle is less than 10°.

2. The engraving wheel according to claim 1, characterized in that, The distance between the ridge of the cutting edge and the point of change in the radial direction of the engraving wheel is less than half the distance between the ridge of the cutting edge and the deepest part of the groove in the radial direction.

3. A scribing method for forming scribing lines on a substrate, characterized in that, The scribing method applies a load to the scribing wheel within a range that causes the variation point to sink into the interior of the substrate, while moving the scribing wheel on the surface of the substrate. The scribing wheel includes: a plurality of cutting edges formed along its outer periphery; and a plurality of grooves disposed between adjacent cutting edges in the circumferential direction and recessed towards the central axis. Each groove has a continuous ridge extending from the ridge line of the cutting edge to the deepest part on both sides of its deepest portion. Each ridge line of the groove has at least one point of transition. A second angle formed by the ridge line on the deepest side relative to this point of transition and the ridge line of the cutting edge is greater than a first angle formed by the ridge line on the cutting edge side relative to this point of transition and the ridge line of the cutting edge. The first angle is less than 10°.

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