KR102167941B1 - Method of dividing brittle substrate - Google Patents

Abstract

A blade tip 51 in which a tip portion 51N having axial symmetry in the axial direction AX is formed is prepared. By making the axial direction (AX) of the blade tip 51 perpendicular to one surface (SF1) of the brittle substrate 4, by sliding the tip portion 51N of the blade tip 51 on one surface (SF1) , A crackless trench line is formed. A crack line is formed by extending the crack of the brittle substrate 4 in the thickness direction DT along the trench line TL. The brittle substrate 4 is divided along the crack line.

Description

Method of dividing brittle substrate

The present invention relates to a method for dividing a brittle substrate.

In the manufacture of electric equipment such as a flat display panel or a solar panel, it is often necessary to divide a brittle substrate. In a typical dividing method, first, crack lines are formed on a brittle substrate. In this specification, the "crack line" means that a crack partially advanced in the thickness direction of the brittle substrate extends in a line shape on the surface of the brittle substrate. Next, a so-called brake process is performed. Specifically, by applying stress to the brittle substrate, cracks in the crack line completely advance in the thickness direction. Accordingly, the brittle substrate is divided along the crack line.

According to Patent Document 1, a concave portion in the upper surface of the glass plate is generated during scribing. In this patent document 1, this concave portion is referred to as a "scribe line". In addition, at the same time as the angle of the scribe line, a crack extending in the direct downward direction from the scribe line occurs. As shown in the technique of this patent document 1, in a conventional typical technique, a crack line is formed simultaneously with the formation of a scribe line.

According to Patent Document 2, a segmentation technique remarkably different from the above-described typical segmentation technology is proposed. According to this technique, first, plastic deformation is caused by sliding of the edge of the blade on the brittle substrate, thereby forming a groove shape referred to as a "scribe line" in this patent document 2. In the present specification, hereinafter, this groove-shaped thing is referred to as a "trench line". When the trench line is formed, no crack is formed below the trench line. After that, the crack line is formed by extending the crack along the trench line. That is, unlike typical techniques, a trench line that does not involve cracks is once formed, and then a crack line is formed along the trench line. After that, a normal braking process is performed along the crack line.

The trench line without cracks used in the technique of Patent Document 2 can be formed by sliding the edge of the blade with a lower load than a typical scribe line accompanying the simultaneous formation of cracks. The small load reduces the damage to the blade tip. Therefore, according to this segmentation technique, the life of the blade tip can be increased.

In Patent Document 2, a cutting mechanism having a blade tip and a shank serving as its holder is used. The cutting mechanism has an axial direction, and the shank extends along the axial direction. The trench line is formed by sliding the edge of the blade on the brittle substrate. The blade tip is held by a holder extending along the axial direction. The axial direction is inclined with respect to the upper surface of the brittle substrate. The direction in which the axial direction was projected onto the brittle substrate corresponds to the sliding direction of the blade tip.

Japanese Laid-Open Patent Publication No. Hei 9-188534 International Publication No. 2015/151755

According to the said patent document 2, the direction in which the axial direction was projected onto a glass substrate corresponds to the sliding direction of a blade tip. In other words, anisotropy exists in the action of the edge of the substrate on the brittle substrate. For this reason, it is necessary to adjust the axial direction corresponding to the sliding direction of the blade tip. Therefore, it is necessary to provide a mechanism for adjusting the posture of the blade tip so that the axial direction corresponds to the sliding direction in the dividing apparatus for the brittle substrate. In particular, when the sliding direction of the blade tip is not constant, it is necessary to provide a mechanism for controlling the posture of the blade tip. The necessity of adjusting and controlling the posture of the blade tip can lead to demerits such as an increase in the cost of the segmentation device, an increase in time required for the process, and a decrease in the accuracy of the scribe position.

The present invention has been made in order to solve the above problems, and an object thereof is to provide a method for dividing a brittle substrate in which it is not necessary to adjust the posture of the blade tip according to the sliding direction of the blade tip.

A method for dividing a brittle substrate according to an aspect of the present invention includes the following steps a) to e).

a) A brittle substrate having one side and a thickness direction perpendicular to one side is prepared.

b) A blade tip with a tip end having axial symmetry in the axial direction is prepared.

c) By sliding the tip of the blade tip on one surface while keeping the axial direction of the blade tip perpendicular to one surface of the brittle substrate, the trench line having a groove shape is plastically deformed on one surface of the brittle substrate. Is formed in The trench line is formed so as to obtain a crackless state in which the brittle substrate is continuously connected in a direction below the trench line in a direction crossing the trench line.

d) A crack line is formed by extending the crack of the brittle substrate in the thickness direction along the trench line. The brittle substrate at the bottom of the trench line is broken by the crack line in a direction crossing the trench line.

e) A brittle substrate is divided along the crack line.

In addition, the alphabet characters "a)" to "e)" are attached to distinguish the steps, and do not include meanings with respect to the order of implementation of the steps.

According to the present invention, when a blade tip having a tip end portion having an axisymmetric property is slid over one surface of the brittle substrate, the axial direction of the blade tip is perpendicular to one surface. Accordingly, the relationship between the axial direction and the sliding direction becomes constant without depending on the sliding direction. Therefore, it is not necessary to adjust the posture of the blade tip according to the sliding direction of the blade tip.

1 is a perspective view schematically showing a configuration of a cutting mechanism used in a method for dividing a brittle substrate in Embodiment 1 of the present invention.
Fig. 2 is a side view schematically showing a configuration of a cutting mechanism used in a method for dividing a brittle substrate according to the first embodiment of the present invention.
3 is a partial cross-sectional view of the vicinity of the tip of the blade tip of FIGS. 1 and 2.
4 is a flow diagram schematically showing the configuration of a method for dividing a brittle substrate in Embodiment 1 of the present invention.
Fig. 5 is a top view schematically showing a first step in the method for dividing a brittle substrate in Embodiment 1 of the present invention.
6 is a schematic cross-sectional view taken along the line VI-VI in FIG. 5;
Fig. 7 is a top view schematically showing a second step of the method for dividing a brittle substrate according to the first embodiment of the present invention.
8 is a schematic cross-sectional view taken along the line VIII-VIII of FIG. 7;
9 is a top view schematically showing a first step in the method for dividing a brittle substrate in Embodiment 2 of the present invention.
FIG. 10 is a diagram illustrating a sliding direction of a blade tip on a brittle substrate in the step of FIG. 9.
Fig. 11 is a top view schematically showing a second step in the method for dividing a brittle substrate in Embodiment 2 of the present invention.
Fig. 12 is a top view schematically showing one step of the method for dividing a brittle substrate in Embodiment 3 of the present invention.
FIG. 13 is a diagram illustrating a sliding direction of a blade tip on a brittle substrate in the step of FIG. 12.
14 is a top view schematically showing a first step in a method for dividing a brittle substrate in Embodiment 4 of the present invention.
FIG. 15 is a diagram illustrating a sliding direction of a blade tip on a brittle substrate in the step of FIG. 14.
Fig. 16 is a top view schematically showing a second step in the method for dividing a brittle substrate according to the fourth embodiment of the present invention.
Fig. 17 is a top view schematically showing one step of the method for dividing a brittle substrate in Embodiment 5 of the present invention.
FIG. 18 is a diagram illustrating a sliding direction of a blade tip on a brittle substrate in the step of FIG. 17.
Fig. 19 is a side view schematically showing one step of the method for dividing a brittle substrate in Embodiment 6 of the present invention.
Fig. 20 is a flow chart schematically showing a partial configuration of a method for dividing a brittle substrate according to the seventh embodiment of the present invention.
Fig. 21 is a top view schematically showing a first step in a method for dividing a brittle substrate according to the eighth embodiment of the present invention.
22 is a schematic cross-sectional view taken along the line XXII-XXII in FIG. 21;
23 is a top view schematically showing a second step of the method for dividing a brittle substrate according to the eighth embodiment of the present invention.
Fig. 24 is a top view schematically showing a third step of the method for dividing a brittle substrate according to the eighth embodiment of the present invention.
Fig. 25 is a flow diagram schematically showing a partial configuration of a method for dividing a brittle substrate according to Embodiment 9 of the present invention.
Fig. 26 is a top view schematically showing one step of the method for dividing a brittle substrate in Embodiment 9 of the present invention.
Fig. 27 is a schematic cross-sectional view taken along the line XXVII-XXVII in Fig. 26;
Fig. 28 is a schematic cross-sectional view taken along the line XXVIII-XXVIII in Fig. 26;
Fig. 29 is a schematic cross-sectional view taken along the line XXIX-XXIX in Fig. 26;
30 is a top view schematically showing one step of a method for dividing a brittle substrate in Embodiment 9 of the present invention.
31 is a schematic cross-sectional view taken along the line XXXI-XXXI in FIG. 30;
Fig. 32 is a schematic cross-sectional view taken along the line XXXII-XXXII in Fig. 30;
Fig. 33 is a top view schematically showing one step of the method for dividing a brittle substrate in Embodiment 9 of the present invention.
Fig. 34 is a schematic cross-sectional view taken along line XXXIV-XXXIV in Fig. 33;
35 is a schematic cross-sectional view taken along the line XXXV-XXXV in FIG. 33;
Fig. 36 is a top view schematically showing one step of the method for dividing a brittle substrate in Embodiment 9 of the present invention.
Fig. 37 is a perspective view schematically showing a configuration of a cutting mechanism used in a method for dividing a brittle substrate according to the tenth embodiment of the present invention.
Fig. 38 is a schematic cross-sectional view taken along line XXXVIII-XXXVIII in Fig. 37;
39 is an example of the surface shape of the tip portion of the blade tip along the line AA in FIG. 38.
Fig. 40 is an example of the surface shape of the tip of the blade tip along the line AA in Fig. 38;

(Form for carrying out the invention)

Hereinafter, an embodiment of the present invention will be described based on the drawings. In the following drawings, the same reference numerals are assigned to the same or corresponding parts, and the description is not repeated.

<Embodiment 1>

Each of FIG. 1 and FIG. 2 is a perspective view schematically showing a configuration of a cutting mechanism 50 used in a method for dividing a glass substrate 4 (a brittle substrate) in the present embodiment. 3 is a partial cross-sectional view of the vicinity of the tip 51N of the blade tip 51 of FIGS. 1 and 2.

The cutting mechanism 50 has a blade tip 51 and a support part 52. The blade tip 51 and the support 52 may be integral members made of the same material.

As shown in Fig. 3, the blade tip 51 is formed with a tip portion 51N having axial symmetry in the axial direction AX. That is, the surface of the tip portion 51N is a surface obtained by rotating a curve around the axial direction AX. The front surface of the tip portion 51N is a curved surface having a convex shape toward the outside. The surface of the tip 51N may be a part of a spherical surface. It is preferable that the radius of curvature of the tip portion 51N is 3 µm or more and 40 µm or less. The surface of the tip 51N may be a conical surface, and the apex of this conical surface may be rounded. The dimension along the axial direction AX of the tip 51N is typically 0.5 µm or more, and usually 1.0 µm or more is sufficient, and preferably 2.0 µm or more. As a result, the portion of the blade tip 51 that comes into direct contact with the glass substrate 4 is usually included substantially in the tip portion 51N. In addition, although the above-described "axis symmetry" is preferably an ideal geometric axisymmetric property, a substantial axisymmetric property may be used in consideration of the action on the glass substrate 4. The latter is referred to as "pseudo-axisymmetric" in this specification, and details thereof will be described in Embodiment 10 described later.

Preferably, the whole of the blade tip 51 including the tip portion 51N has axial symmetry in the axial direction AX. In Fig. 3, the blade tip 51 includes a straight conical shape having axial symmetry in the axial direction AX, and a tip portion 51N is formed at the apex of the counterweight shape. In the cross section including the axial direction AX (FIG. 3), if the shape of the tip portion 51N is ignored, the angle of the vertex of this counterweight is preferably 120° or more, and more preferably 130° or more. Further, this angle is preferably 160° or less, and more preferably 150° or less.

It is preferable that the support part 52 extends along the axial direction AX. The entire cutting mechanism 50 may have axial symmetry in the axial direction AX.

Next, a method for dividing the glass substrate 4 will be described below with reference to the flow diagram shown in FIG. 4.

In step S10 (FIG. 4), the glass substrate 4 (FIG. 2) to be divided is prepared. The glass substrate 4 has an upper surface SF1 (one surface) and an opposite lower surface SF2 (the other surface). An edge ED is formed on the upper surface SF1. The upper surface SF1 is typically flat. In the example shown in FIG. 5, the edge ED has a rectangular shape. The glass substrate 4 has a thickness direction DT perpendicular to the upper surface SF1. Further, in step S20 (FIG. 4), the above-described cutting mechanism 50 (FIG. 1 to FIG. 3) having the blade tip 51 is prepared.

Referring to Fig. 5, in step S30 (Fig. 4), a trench line TL having a linear shape is formed. Specifically, the following steps are performed.

First, the tip 51N of the blade tip 51 (FIGS. 1 to 3) is pressed against the upper surface SF1 at the position N1. Thereby, the tip 51N contacts the glass substrate 4. It is preferable that the position N1 is separated from the edge ED of the upper surface SF1 of the glass substrate 4, as shown. In that case, when the sliding start of the blade tip 51, the blade tip 51 can be avoided from colliding with the edge ED of the upper surface SF1 of the glass substrate 4.

Next, while making the axial direction AX of the blade tip 51 perpendicular to the upper surface SF1 of the glass substrate 4, the tip 51N of the blade tip 51 slides on the upper surface SF1 ( 5). During sliding, a load is applied to the blade tip 51 from the outside. This load direction is perpendicular to the upper surface SF1. Plastic deformation occurs on the upper surface SF1 by sliding.

By this plastic deformation, a trench line TL having a groove shape (see FIG. 6) is formed on the upper surface SF1 of the glass substrate 4. The trench line TL is a direction DC (FIG. 6) where the glass substrate 4 intersects the extending direction of the trench line TL (transverse direction in FIG. 5) below the trench line TL. It is formed so that a crackless state which is a state which is continuously connected in may be obtained. In the crackless state, although the trench line TL is formed due to plastic deformation, the resulting crack is not formed. In order to obtain a crackless state, the load applied to the blade tip 51 is so small that no cracking occurs at the time of formation of the trench line TL, and also creates a state of internal stress that can cause cracks in a later process. It is adjusted so that it is large enough to cause plastic deformation as it is produced.

It is preferable that the trench line TL is generated only by plastic deformation of the glass substrate 4, and in that case, no cutting occurs on the upper surface SF1 of the glass substrate 4. In order to avoid being cut, it is sufficient not to make the load of the blade tip 51 excessively high. By not being cut, it is possible to avoid occurrence of undesirable fine fragments on the upper surface SF1. However, slight shaving is usually acceptable.

The formation of the trench line TL slides the tip 51N of the blade tip 51 between the position N1 and the position N3e, from the position N1 to the position N3e via the position N2. It is done by doing. The position N2 is separated from the edge ED of the upper surface SF1 of the glass substrate 4. The position N3e is located at the edge ED of the upper surface SF1 of the glass substrate 4. Accordingly, the blade tip 51 that has been slid to form the trench line TL finally reaches the position N3e. The crackless state is maintained at the time when the blade tip 51 is positioned at the position N2, and is maintained until the moment when the blade tip 51 reaches the position N3e. When the blade tip 51 reaches the position N3e, the blade tip 51 cuts off the edge ED of the upper surface SF1 of the glass substrate 4.

With reference to Figs. 7 and 8, fine breakage occurs at the position N3e by the above cutting. Using this fracture as a starting point, cracks are generated so as to relieve internal stress in the vicinity of the trench line TL. Specifically, cracks of the glass substrate 4 in the thickness direction DT along the trench line TL from the position N3e located at the edge ED of the upper surface SF1 of the glass substrate 4 Is extended (refer to the arrow in Fig. 7). In other words, the formation of the crack line CL starts. Accordingly, as step S50 (Fig. 4), the crack line CL is formed from the position N3e to the position N1. The direction in which the crack line CL extends along the trench line TL (arrow in FIG. 7) is opposite to the direction in which the trench line TL is formed (arrow in FIG. 5 ).

In addition, in order to ensure the formation of the crack line CL, the speed at which the blade tip 51 slides from the position N2 to the position N3e is lower than the speed from the position N1 to the position N2. You can do it. Similarly, the load applied to the blade tip 51 from the position N2 to the position N3e may be larger than the load from the position N1 to the position N2 in the range where the crackless state is maintained.

The glass substrate 4 below the trench line TL by the crack line CL crosses the extending direction of the trench line TL (transverse direction in Fig. 7) (DC) (Fig. 8) The continuous connection is broken. Here, "continuous connection" means, in other words, a connection that is not blocked by cracks. In addition, as described above, in the state in which the continuous connection is cut off, portions of the glass substrate 4 may be in contact with each other through the crack of the crack line CL. Further, a slightly continuous connection may remain directly under the trench line TL.

Next, in step S60 (FIG. 4), the glass substrate 4 is divided along the crack line CL. That is, a so-called brake process is performed. The brake process can be performed by application of an external force to the glass substrate 4. For example, a stress applying member (for example, a member referred to as ``break bar'') on the lower surface SF2 toward the crack line CL (Fig. 8) on the upper surface SF1 of the glass substrate 4 By pressing, stress is applied to the glass substrate 4 to spread the cracks of the crack line CL. In addition, when the crack line CL completely advances in the thickness direction DT at the time of its formation, the formation of the crack line CL and the division of the glass substrate 4 occur simultaneously.

The glass substrate 4 is divided by the above. In addition, the above-described crack line CL formation process is essentially different from the so-called brake process. The braking process completely separates the substrate by further extending the cracks already formed in the thickness direction. On the other hand, the forming process of the crack line CL brings about a change from the crackless state obtained by the formation of the trench line TL to a state having cracks. It is considered that this change occurs due to the release of the internal stress of the crackless state.

According to this embodiment, when the blade tip 51 on which the tip portion 51N having axisymmetric property is formed slides on the upper surface SF1 of the glass substrate 4, the axis of the blade tip 51 with respect to the upper surface SF1 The direction AX becomes vertical (Fig. 2). Accordingly, the relationship between the axial direction AX and the sliding direction DA becomes constant without depending on the direction DA in which the tip 51N of the blade tip 51 slides. Therefore, it is not necessary to adjust the posture of the blade tip 51 along the sliding direction DA of the blade tip 51.

In addition, in another embodiment to be described later, when the blade tip 51 slides on the upper surface SF1 of the glass substrate 4 for the formation of the trench line TL, the blade tip 51 with respect to the upper surface SF1 ), the axial direction (AX) becomes vertical. Accordingly, also in other embodiments, the same effects as those of the present embodiment are obtained.

<Embodiment 2>

In Embodiment 1, the trench line TL has a linear shape. On the other hand, in the present embodiment, the trench line TL includes a curved shape. Hereinafter, a process of forming the trench line TL will be described in detail.

Referring to FIG. 9, in the present embodiment, the trench line TL has a curved shape. Correspondingly, the step of forming the trench line TL includes a step of sliding the tip 51N of the blade tip 51 toward the direction DA1 (first direction), and then, the tip 51N. It includes a step of sliding toward (DA2) (second direction).

Referring to FIG. 10, the direction DA2 is different from the direction DA1. Further, the sliding direction DA of the tip portion 51N of the blade tip 51 continuously changes between the direction DA1 and the direction DA2, as indicated by a broken line in the drawing.

Subsequently, a crack line is formed along the trench line TL. Referring to FIG. 11, the glass substrate 4 is divided along this crack line.

In addition, since the configurations other than the above are substantially the same as those of the first embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and the description thereof is not repeated.

In this embodiment, the sliding direction DA changes between the direction DA1 and the direction DA2. At the point where the tip 51N of the blade tip 51 has axial symmetry and the axial direction AX of the blade tip 51 is perpendicular to the upper surface SF1 (Fig. 2), the above-described sliding direction DA ) Does not affect the relationship between the axial direction AX and the sliding direction DA. Therefore, it is not necessary to adjust the posture of the blade tip 51 according to the sliding direction DA of the blade tip 51. In other words, even when the trench line TL including the curved portion is formed, it is not necessary to adjust the posture of the blade tip 51 according to the sliding direction DA of the blade tip 51.

<Embodiment 3>

With reference to FIG. 12, in the present embodiment, the trench line TL substantially includes a closed curve. Correspondingly, as shown in FIG. 13, the sliding direction DA changes over all directions, as indicated by a broken line in the figure. In other words, the tip portion 51N of the blade tip 51 slides toward the front direction. In addition, since the configurations other than the above are substantially the same as those of the second embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and the description thereof is not repeated.

<Embodiment 4>

14 and 15, in the present embodiment, when the trench line TL is formed, while bringing the tip 51N of the blade tip 51 into contact with the upper surface SF1 of the glass substrate 4, , The direction DA to which the tip portion 51N faces is discontinuously changed from the direction DA1 to the direction DA2.

Subsequently, a crack line is formed along the trench line TL. Referring to FIG. 16, the glass substrate 4 is divided along this crack line.

In addition, since the configurations other than the above are substantially the same as those of the second embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and the description thereof is not repeated.

At the moment when the direction DA changes discontinuously, the blade tip 51 is relatively substantially stationary with respect to the glass substrate 4. In such a stopped state, if the posture of the blade tip 51 is adjusted, damage is likely to occur in the tip portion 51N of the blade tip 51 or the glass substrate 4. According to this embodiment, since it is not necessary to adjust the posture of the blade tip 51, the above-described damage can be avoided.

<Embodiment 5>

Referring to FIG. 17, the trench line TL formed in this embodiment includes a trench line TL1 and a trench line TL2 parallel to each other. The trench line TL1 and the trench line TL2 are formed alternately. When the trench line TL1 is formed, the direction DA that the tip 51N faces is the direction DA1 while bringing the tip 51N of the blade tip 51 into contact with the upper surface SF1 of the glass substrate 4 Becomes. When the trench line TL2 is formed, the direction DA that the tip 51N faces is the direction DA2 while bringing the tip 51N of the blade tip 51 into contact with the upper surface SF1 of the glass substrate 4 Becomes. The direction DA1 and the direction DA2 are opposite to each other. Therefore, as shown in FIG. 18, the direction DA that the tip part 51N faces is either the direction DA1 and the direction DA2. In formation of the trench line TL, the sliding direction DA changes discontinuously between the directions DA1 and DA2.

In addition, since the configurations other than the above are substantially the same as those of the fourth embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and the description is not repeated.

If both of the trench line TL1 and the trench line TL2 are formed by sliding in the direction DA1, the blade edge 51 is moved from one edge (the left edge in the drawing) to the other edge. After forming the trench line TL1 by moving it to (in the drawing, the right edge), an operation only to return the blade tip 51 toward the one edge is required. On the other hand, according to this embodiment, the trench line TL2 is formed during this operation. Accordingly, the time required for the process is shortened. Therefore, productivity can be improved.

<Embodiment 6>

Referring to FIG. 19, in each of the above-described embodiments, when the trench line TL is formed, the blade tip 51 may be rotated around the axial direction AX (refer to the rotation RT in the drawing. ). Rotation RT may be performed while sliding the distal end 51N of the blade tip 51 on the upper surface SF1 of the glass substrate 4. The rotation RT may be performed at all times during sliding, or may be performed intermittently. Alternatively, the rotation RT may be performed without sliding the tip portion 51N of the blade tip 51 on the upper surface SF1 of the glass substrate 4. In this case, the blade tip 51 is rotated in a state where the blade tip 51 is stopped or the blade tip 51 is separated from the glass substrate 4.

According to this embodiment, local abrasion of the blade tip 51 can be avoided. Therefore, it is possible to increase the life of the blade tip 51.

<Embodiment 7>

In each of the above-described embodiments, when the trench line TL is formed, a lubricant is applied to a position where the tip portion 51N of the blade tip 51 slides on the upper surface SF1 of the glass substrate 4. May be supplied. In other words, the step of forming the trench line TL (Fig. 4: Step S30), as shown in Fig. 20, the step S31 of supplying the lubricant, and the blade tip 51 sliding at the position where the lubricant is supplied. You may include step S32. As the lubricant, for example, a liquid lubricant at room temperature or a solid lubricant at room temperature can be used.

In each of the above-described embodiments, at the time of formation of the trench line TL, the upper surface SF1 of the glass substrate 4 and the edge 51 that slides are liable to be worn. According to this embodiment, such abrasion can be suppressed.

<Embodiment 8>

Referring to FIG. 21, in step S10 (FIG. 4 ), the same glass substrate 4 as in the first embodiment is prepared. However, in this embodiment, the assist line AL is formed in advance on the upper surface SF1 of the glass substrate 4. Referring to FIG. 22, the assist line AL has an assist trench line Tla and an assist crack line CLa. The assist trench line Tla has a groove shape. The assist crack line CLa is configured by extending the crack of the glass substrate 4 in the thickness direction DT along the assist trench line Tla.

In the present embodiment, the assist line AL is formed by a step of simultaneously forming the assist trench line Tla and the assist crack line CLa on the upper surface SF1 of the glass substrate 4. This assist line AL can be formed by a conventional conventional scribing method. For example, in such an assist line AL, as indicated by the arrow in FIG. 21, the edge of the blade sits on the edge ED of the upper surface SF1 of the glass substrate 4, and moves on the upper surface SF1. It can be formed by doing. It is preferable that this blade tip is held so as to be rotatable (wheel-shaped). In other words, it is preferable that the blade tip rotates on the glass substrate 4 rather than sliding.

In addition, although the starting point of the assist line AL is the edge ED in FIG. 21, it may be separated from the edge ED. In addition, the assist line AL may be formed by the same method as the method of forming the crack line CL in any one of the first to seventh embodiments. Further, the assist line AL may be formed using a blade tip that slides on the glass substrate 4. Alternatively, in order to facilitate the preparation of the blade tip for the assist line AL described above, the assist line AL may be formed using this blade tip 51.

Next, in step S20 (Fig. 4), the same blade tip 51 as in the first embodiment is prepared.

Referring to Fig. 23, next, a trench line TL is formed in step S30 (Fig. 4). In the present embodiment, the formation of the trench line TL is between the position N1 and the position N3a, from the position N1 to the position N3a via the position N2. It is done by sliding. The position N3a is disposed on the assist line AL. The position N2 is arranged between the position N1 and the position N3a. Preferably, the blade tip 51 is further slid to the position N4 beyond the position N3a on the assist line AL. It is preferable that the position N4 is away from the edge ED.

The blade tip 51 slid as described above to form the trench line TL intersects the assist line AL at the position N3a. A minute break occurs at the position N3a by this intersection. Using this fracture as a starting point, cracks are generated so as to relieve internal stress in the vicinity of the trench line TL. Specifically, the crack of the glass substrate 4 in the thickness direction extends along the trench line TL from the position N3a located on the assist line AL (refer to the arrow in Fig. 24). In other words, the formation of the crack line CL (Fig. 24) is started. Accordingly, as step S50 (FIG. 4), the crack line CL is formed from the position N3a to the position N1.

The blade tip 51 is separated from the glass substrate 4 after reaching the position N3a. Preferably, the blade tip 51 moves away from the glass substrate 4 after sliding to the position N4 beyond the position N3a.

Next, in step S60 (FIG. 4), the glass substrate 4 is divided along the crack line CL similarly to the first embodiment. By the above, the method of dividing the glass substrate 4 of the present embodiment is performed.

In Embodiment 1, the glass substrate 4 is cut out at the position N3e (FIG. 5) of the blade tip 51. On the other hand, according to this embodiment, such cut-out is not necessary. Accordingly, damage to the blade tip 51 or the glass substrate 4, which may occur during cutting down by the blade tip 51, can be avoided.

In addition, there may be a case where an opportunity for the start of formation of the crack line CL cannot be obtained just by having the blade tip 51 cross the assist line AL. In such a case, after the trench line TL crossing the assist line AL is formed, the glass substrate 4 may be divided along the assist line AL. Accordingly, it is possible to obtain an opportunity for the start of formation of the crack line CL.

<Embodiment 9>

Referring to FIG. 26, first, a glass substrate 4 is prepared similarly to other embodiments (FIG. 4: Step S10). Further, the blade tip 51 is prepared (FIG. 4: Step S20).

Next, as in the other embodiments, the tip of the blade tip 51 on the upper surface SF1 while the axial direction AX of the blade tip 51 is perpendicular to the upper surface SF1 of the glass substrate 4 (51N) slides. This sliding is performed from the starting point N1 to the end point N3 via an intermediate point N2. As a result, plastic deformation occurs on the upper surface SF1 of the glass substrate 4. As a result, a trench line TL extending from the start point N1 to the end point N3 via the intermediate point N2 is formed on the upper surface SF1 (FIG. 4: Step S30).

The process of forming each of the trench lines TL includes a process of forming a low-weight section LR as a part of the trench line TL (FIG. 25: Step S30L), and a high load as a part of the trench line TL. It includes a process (FIG. 25: step S30H) of forming section HR. In Fig. 26, the low-load section LR is formed from the start point N1 to the middle point N2, and the high-load section HR is formed from the middle point N2 to the end point N3. The load applied to the blade tip 51 in the step of forming the high load section HR is higher than the load used in the step of forming the low load section LR. In other words, the load applied to the blade tip 51 in the process of forming the low-load section LR is lower than the load used in the process of forming the high-load section HR, for example, the high-load section ( HR) is about 30 to 50% of the load. Therefore, the width of the trench line in the high load section HR is larger than the width of the low load section LR. In addition, as shown in FIG. 27, the depth of the high load section HR is greater than the depth of the low load section LR. The cross-section of the trench line TL has a V-shape with an angle of about 150°, for example.

In addition, since a high load is applied to the blade tip 51 in the high load section HR, in consideration of the life of the blade tip 51, the distance of the high load section HR is preferably small. In addition, when the load is changed during the formation of the trench line (TL), in order to sufficiently increase the load in the high load section (HR) at a smaller distance, it is preferable that the scribing speed decreases in the high load section (HR). . That is, since it is difficult to control the instantaneous increase of the load of the blade tip 51, in practice, the position N2 is used as a starting point, and in a certain section, the load increases until a predetermined load is reached, and scribing is performed. Therefore, by reducing the speed in the high load section HR, it is possible to make a high load in a smaller distance, and the distance of the entire high load section HR can be reduced.

The process of forming the trench line TL is continuously connected in the direction DC (Figs. 28 and 29) where the glass substrate 4 intersects the trench line TL directly under the trench line TL. It is carried out so that a crackless state, which is a present state, is obtained. For this purpose, the load applied to the edge of the blade is large enough to cause plastic deformation of the glass substrate 4, and also small enough to not generate cracks using this plastic deformation portion as a starting point.

Next, the process of forming a crack line (FIG. 4: Step S50) is performed as follows.

Referring to FIGS. 30 to 32, first, on the upper surface SF1 of the glass substrate 4, the assist line AL crossing the high load section HR is formed. The assist line AL carries a crack penetrating in the thickness direction of the glass substrate 4. The assist line AL can be formed by an ordinary scribing method.

Next, the glass substrate 4 is separated along the assist line AL. This separation can be performed by a normal braking process. Taking this separation as an opportunity, the crack of the glass substrate 4 in the thickness direction extends along the trench line TL and only in the high load section HR of the trench line TL.

33 and 34, the crack line CL is formed along a part of the trench line TL by the above. Specifically, a crack line CL is formed in a portion between the side newly generated by separation and the intermediate point N2 in the high load section HR. The direction in which the crack line CL is formed is opposite to the direction DA (FIG. 26) in which the trench line TL is formed.

In addition, it is difficult to form the crack line CL in a portion between the side newly generated by the separation and the end point N3. It is estimated that this reason may be because the distribution of the internal stress generated in the vicinity of the trench line TL has anisotropy depending on the formation direction of the trench line TL.

Referring to FIG. 35, in a direction directly under the high load section HR of the trench line TL by the crack line CL, the glass substrate 4 crosses the extension direction of the trench line TL (DC ), the continuous connection is broken. Here, "continuous connection" means, in other words, a connection that is not blocked by cracks. In addition, as described above, in the state in which the continuous connection is cut off, portions of the glass substrate 4 may be in contact with each other through the crack of the crack line CL.

Next, a break process of dividing the glass substrate 4 along the trench line TL is performed (Fig. 4: Step S60). At this time, by applying a stress to the glass substrate 4, the crack is extended along the lowering section LR with the crack line CL as a starting point. The direction in which the crack is extended (arrow PR in Fig. 36) is opposite to the direction DA (Fig. 26) in which the trench line TL is formed.

By the above, the glass substrate 4 is divided.

According to this embodiment, in the formation of the trench line TL (FIGS. 26 and 27) for defining the position where the glass substrate 4 is divided, the low-load section LR compared to the high-load section HR ), the load applied to the blade tip 51 (FIG. 1) is reduced. Accordingly, damage to the blade tip 51 can be reduced.

In addition, when the low-load section LR and the high-load section HR are in a crackless state (Figs. 33 and 34), the crack, which is the starting point of the glass substrate 4, is falling. It is not in section LR. Therefore, in the case of performing any treatment on the glass substrate 4 in this state, even if an unexpected stress is applied to the lowering section LR, unintended division of the glass substrate 4 is unlikely to occur. Therefore, the above treatment can be stably performed.

In addition, when both the low-load section LR and the high-load section HR are in a crackless state (Figs. 26 and 27), there is no crack in the trench line TL, which is the starting point of the glass substrate 4 being divided. . Therefore, when arbitrary processing is performed on the glass substrate 4 in this state, even if an unexpected stress is applied to the trench line TL, it is difficult to cause unintentional division of the glass substrate 4. Therefore, the above treatment can be performed more stably.

Also, the trench line TL is formed before the assist line AL is formed. Accordingly, when the trench line TL is formed, it is possible to avoid the assist line AL from having an influence. In particular, it is possible to avoid a formation abnormality immediately after the blade tip 51 passes over the assist line AL to form the trench line TL.

<Embodiment 10>

In this embodiment, a case where the tip end of the blade has the pseudo-axial symmetry mentioned in the first embodiment described above will be described.

37 is a perspective view schematically showing the configuration of the cutting mechanism 150 according to the present embodiment. The cutting mechanism 150 has a blade tip 151 having a tip portion 151N instead of the blade tip 51 (FIG. 2) in which the tip portion 51N is formed. The blade tip 151 has a shape of a polygonal weight having rounded vertices. The polygonal weight has a side (SD) and a ridge (RG). A tip portion 151N is formed at the apex of the polygonal weight.

Fig. 38 is a schematic cross-sectional view taken along line XXXVIII-XXXVIII in Fig. 37, perpendicular to the axial direction AX. Line XXXVIII-XXXVIII (FIG. 37) corresponds to a cross section perpendicular to the axial direction AX in the vicinity of the boundary between the tip portion 151N at the blade tip 151 and the other portion. Hereinafter, the shape of the tip portion 151N as viewed from this cross section will be described.

The shape of the tip portion 151N is an n-sided polygon (n≥3) corresponding to the polygonal weight, preferably a regular polygon. In Fig. 38, a hexagonal shape (n=16) is illustrated. The tip portion 151N has n points PT corresponding to n ridge lines RG (FIG. 37), and each of the points PT is in contact with the circumscribed circle CC. Further, the tip portion 151N has n sides SD corresponding to n side surfaces SD (FIG. 37), and each of the sides SD has a dimension DS. The size of the circumscribed circle CC is made constant, and the larger n becomes, the smaller the dimension DS becomes, and as a result, the cross-sectional shape of the tip portion 151N approaches a circle. Therefore, as n increases, the axial symmetry of the tip portion 151N in the axial direction AX becomes closer to the ideal geometrical symmetry. Therefore, when n is large enough, it can be said that the tip portion 151N has axisymmetric properties in terms of its function. That is, it can be said that the tip portion 151N has the pseudo axisymmetric property described above. According to the studies of the present inventors, it can be said that if the dimension DS is 1 μm or less, the tip portion 151N has pseudo axisymmetric properties. The n that satisfies this condition can be calculated, for example, from the angle of the tip portion 151N and the radius of curvature of the tip portion 151N in the vicinity of the axis AX. An example of this calculation will be described below.

Fig. 39 corresponds to the view from the cross section along the line AA of Fig. 38, as an example of the tip portion 151N, the surface shape of the tip portions 151Na to 151Nc having a radius of curvature R = 3 μm in the vicinity of the axis AX Represents. Each of the tip portions 151Na to 151Nc has tip angles of 120°, 130°, and 140°. Since the radius of curvature R in the vicinity of the axis AX is 3 μm, when the dimension along the axial direction AX of the tip 51N is 1 μm, each of the tip portions 151Na to 151Nc has a diameter of 5.08 μm, It has 5.62 μm and 6.56 μm. In other words, each of the tip portions 151Na to 151Nc has a circumference of 15.96 µm, 17.65 µm, and 20.60 µm. Therefore, n with the dimension DS (FIG. 38) of 1 μm or less is 16 or more in the case of the tip portion 151Na, 18 or more in the case of the tip portion 151Nb, and 21 or more in the case of the tip portion 151Nc. to be.

FIG. 40 corresponds to the view from the cross section along the line AA of FIG. 38, as an example of the tip portion 151N, the surface shape of the tip portions 151Ni to 151Nk having a radius of curvature R = 5 µm in the vicinity of the axis AX Represents. Each of the tip portions 151Ni to 151Nk has tip angles of 120°, 130°, and 140°. Since the radius of curvature R in the vicinity of the axis AX is 5 μm, when the dimension along the axial direction AX of the tip 51N is 1 μm, each of the tip portions 151Ni to 151Nk has a diameter of 6.17 μm, It has 6.51 μm and 7.26 μm. In other words, each of the tip portions 151Ni to 151Nk has a circumference of 19.38 µm, 20.45 µm, and 22.80 µm. Therefore, n with the dimension DS (FIG. 38) of 1 μm or less is 20 or more for the tip portion 151Ni, 21 or more for the tip portion 151Nj, and 23 or more for the tip portion 151Nk. to be.

Based on the results of examination in Figs. 39 and 40, for example, if n≥16, pseudo axisymmetric properties can be obtained in some cases. Therefore, n is preferably 16 or more. If n≥25, pseudo axisymmetric properties can be obtained while using an arbitrary tip angle and a radius of curvature within a range generally used. In view of the workability and processing time of the operation for forming the tip, n is preferably not unnecessarily large, and therefore, n is preferably 25 or less.

In order to obtain the blade tip 151, for example, the tip of a piece of material having a polygonal column shape (for example, a diamond piece) may be polished a plurality of times to give a substantially polygonal weight to the tip of the piece of diamond. As a modification, an R chamfer may be applied to the ridge line RG (FIG. 37). Accordingly, the linear portion of the side SD (FIG. 38) is shortened, so that the shape of the tip portion 151N becomes closer to a circular shape. In other words, the axial symmetry of the tip portion 151N becomes closer to an ideal one. In this case, pseudo axisymmetric property is obtained even with a smaller n.

In addition, in each of the above embodiments, a case where the edge of the upper surface SF1 has a rectangular shape is illustrated, but other shapes may be used. Further, the case where the upper surface SF1 is flat has been described, but the upper surface may be curved. Further, the case where the trench line TL has a linear shape has been described, but the trench line TL may have a curved shape. In addition, the case where the glass substrate 4 is used as the brittle substrate has been described, but the brittle substrate may be made of a brittle material other than glass, for example, ceramics, silicon, compound semiconductors, sapphire or quartz. have.

AL: assist line
CL: crack line
AX: axial direction
SF1: Top side (one side)
HR: Heavy duty section
LR: low-load section
TL, TL1, TL2: trench line
4: Glass substrate (brittle substrate)
50, 150: cutting mechanism
51, 151: edge of the blade
51N, 151N, 151Na to 151Nc, 151Ni to 151Nk: tip
52: support

Claims (9)

a) a step of preparing a brittle substrate having one surface and a thickness direction perpendicular to the one surface, and additionally
b) A step of preparing a blade tip having a tip end portion having an axial symmetry in the axial direction is provided, and additionally
c) A trench line having a groove shape is plastically deformed by sliding the tip of the blade tip on the one surface while making the axial direction of the blade tip perpendicular to the one surface of the brittle substrate. And a step of forming on the one surface of the brittle substrate, wherein the trench line is a crackless state in which the brittle substrate is continuously connected in a direction below the trench line in a direction crossing the trench line Formed so that the state is obtained, and additionally
d) a step of forming a crack line by extending the crack of the brittle substrate in the thickness direction along the trench line, wherein the brittle substrate in the lower side of the trench line by the crack line In the direction crossing the line, the continuous connection is broken, and additionally
e) a step of dividing the brittle substrate along the crack line,
The tip portion of the blade tip has a radius of curvature of 3 μm or more and 40 μm or less, and a dimension along the axial direction of 0.5 μm or more. The method of claim 1,
The step c),
c1) a step of sliding the tip end of the blade tip toward a first direction,
c2) After the step c1), the tip of the blade is slid toward a second direction different from the first direction.
Containing, a method of dividing a brittle substrate. The method of claim 2,
The step c) is a step of discontinuously changing a direction toward the tip of the blade from the first direction to the second direction while contacting the tip of the blade on the one surface of the brittle substrate. Containing, the method of dividing a brittle substrate. The method of claim 1,
In the step c), the tip portion of the blade tip is slid toward an entire direction. The method according to any one of claims 1 to 4,
The cutting method of a brittle substrate, wherein the blade tip includes a straight conical shape having axial symmetry in the axial direction, and the tip end of the blade tip is formed at a vertex of the counterweight shape. The method according to any one of claims 1 to 4,
The step c) includes a step of rotating the blade tip around the axial direction. The method of claim 6,
The step of rotating the blade tip around the axial direction includes a step of rotating the blade tip around the axial direction while sliding the tip of the blade tip on the one surface of the brittle substrate. How to divide. The method of claim 6,
The process of rotating the edge of the blade around the axial direction includes a process of rotating the edge of the blade around the axial direction without sliding the tip of the edge on the one surface of the brittle substrate. How to divide the substrate. The method according to any one of claims 1 to 4,
The step c) includes a step of supplying a lubricant to a position on the one surface of the brittle substrate where the tip portion of the blade tip slides.

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