TWI715718B - Breaking method of brittle substrate - Google Patents

Abstract

The subject of the present invention is to form a crack line along the groove line more reliably and easily after forming a groove line without a crack under it.

The blade front edge 51 is prepared. The blade front edge 51 has a ridge PS and a vertex PP by having the first to third surfaces SD1 to SD3. By sliding the leading edge 51 on one surface SF1 of the brittle substrate 4 in the direction from the ridge line PS toward the first surface SD1, the groove line TL having a groove shape is formed in a crack-free state. The edge ED of the brittle substrate 4 is cut by the ridge line PS of the front edge 51, so that the crack of the brittle substrate 4 in the thickness direction DT extends from the edge ED along the groove line TL, thereby forming a crack line CL. With the crack line CL, under the trench line TL, the continuous connection of the brittle substrate 4 in the direction crossing the trench line TL is interrupted.

Description

Breaking method of brittle substrate

The invention relates to a method for breaking a brittle substrate.

In the manufacture of flat-panel display panels or solar cell panels and other electrical equipment, it is often necessary to break the brittle substrate. In a typical breaking method, first, crack lines are formed on the brittle substrate. The term "crack line" in this specification refers to a crack that locally advances in the thickness direction of the brittle substrate and extends linearly on the surface of the brittle substrate. Secondly, the so-called breaking step is carried out. Specifically, by applying stress to the brittle substrate, the crack of the crack line completely advances in the thickness direction. Thereby, the brittle substrate is broken along the crack line.

According to Patent Document 1, the depression on the upper surface of the glass plate is generated during cutting. In this patent document 1, this depression is called "scribing". In addition, simultaneously with the engraving of the scribe line, a crack extending from the scribe line in the direct downward direction is generated. As shown in the technique of Patent Document 1, in the conventional typical technique, the crack line is formed simultaneously with the formation of the scribe line.

According to Patent Document 2, a breaking technique that is significantly different from the above-mentioned typical breaking technique is proposed. According to this technique, first, a groove shape called "scribing" in Patent Document 2 is formed by plastically deforming by the sliding of the leading edge of the blade on the brittle substrate. In this specification, this groove shape is hereinafter referred to as "groove line". At the point in time when the groove line is formed, not below it Fang formed a crack. Then, the crack line is formed by extending the crack along the groove line. That is, unlike the typical technology, once the groove line without a crack is formed, a crack line is formed along the groove line thereafter. Then, the usual breaking step is performed along the crack line.

The groove line without cracks used in the technique of the above-mentioned Patent Document 2 can be formed by sliding of the cutting edge with a lower load than the typical scribing line formed simultaneously with cracks. Due to the smaller load, the damage applied to the leading edge of the blade becomes smaller. Therefore, according to this breaking technology, the life of the cutting edge can be extended.

[Prior Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 9-188534

[Patent Document 2] International Publication No. 2015/151755

In the conventional typical technique, no cracks formed during scribing means that the scribing failed. However, in the cutting technique of Patent Document 2 described above, groove lines without cracks are intentionally formed by scribing. And, then, a crack line along the groove line is generated. In order to start the formation of crack lines, it is necessary to give the brittle substrate an opportunity to release the internal stress generated in the brittle substrate by the formation of the groove line. Regarding the method of giving this opportunity, various methods are proposed in the aforementioned Patent Document 2. According to the research of the inventors, these methods are also useful, but there is a problem that the probability of forming a crack line is slightly lower, or the work burden is slightly greater due to the need for an additional breaking step.

The present invention was completed in order to solve the above-mentioned problems, and its purpose is to provide a brittle substrate that can more reliably and easily form a crack line along the groove line after forming a groove line without a crack underneath it. Breaking method.

The method for breaking a brittle substrate according to one aspect of the present invention has the following steps a) to e).

a) Prepare a brittle substrate with a surface provided with edges and a thickness direction perpendicular to the surface.

b) Prepare the blade front edge, the blade front edge has: a first surface; a second surface, which is adjacent to the first surface; and a third surface, which forms a ridge line by being adjacent to the second surface and by It is adjacent to each of the first surface and the second surface to form a vertex.

c) A groove line with a groove shape is formed on one surface of the brittle substrate by plastic deformation by sliding the leading edge of the blade in the direction from the ridge line to the first surface on one surface of the brittle substrate. The groove line is formed in a crack-free state, that is, under the groove line, the brittle substrate is continuously connected in the direction intersecting the groove line.

d) By using the ridge line of the sliding blade front edge in step c) to cut the edge of one surface of the brittle substrate, the cracks of the brittle substrate in the thickness direction are extended from the edge along the groove line, thereby forming a crack line. With the crack line, under the groove line, the continuous connection of the brittle substrate in the direction crossing the groove line is interrupted.

e) Break the brittle substrate along the crack line.

The method for breaking a brittle substrate according to another aspect of the present invention has the following steps a) to e).

a) Prepare a brittle substrate with one surface and a thickness direction perpendicular to one surface. An auxiliary line is provided on one surface, and the auxiliary line has: an auxiliary groove line having a groove shape; and an auxiliary crack line, which is formed by the crack of the brittle substrate in the thickness direction extending along the auxiliary groove line.

b) Prepare the blade front edge, the blade front edge has: a first surface; a second surface, which is adjacent to the first surface; and a third surface, which forms a ridge line by being adjacent to the second surface and by It is adjacent to each of the first surface and the second surface to form a vertex.

c) A groove line with a groove shape is formed on one surface of the brittle substrate by plastic deformation by sliding the leading edge of the blade in the direction from the ridge line to the first surface due to one surface of the brittle substrate. The groove line is formed in a crack-free state, that is, under the groove line, the brittle substrate is continuously connected in the direction intersecting the groove line.

d) By using the ridge line of the sliding blade front edge in step c) to cross the auxiliary line provided on one surface of the brittle substrate, the cracks of the brittle substrate in the thickness direction extend along the groove line from the auxiliary line, thereby Form a crack line. With the crack line, under the groove line, the continuous connection of the brittle substrate in the direction crossing the groove line is interrupted.

e) Break the brittle substrate along the crack line.

According to the method for cutting a brittle substrate according to one aspect of the present invention, first, the cutting edge can be easily prepared. The reason is that the apex of the leading edge of the blade is provided as a location where three of the first surface, the second surface, and the third surface intersect. Suppose that when the apex of the leading edge of the blade is set by the part where more than 3 faces intersect, the position of the remaining faces must be consistent by passing through the intersecting point of the 3 faces. Therefore, higher machining accuracy is required. On the other hand, in the case where the apex of the leading edge of the blade is set by the part where the three faces intersect, it does not require such high machining precision. degree. Second, the crack line along the groove line can be formed more reliably. The reason is that the ridge line of the leading edge of the blade that slides to form the groove line cuts the edge of one surface of the brittle substrate. With this cutting, the opportunity to start the formation of the crack line is obtained with higher certainty.

According to the method for separating a brittle substrate according to another aspect of the present invention, first, the cutting edge can be easily prepared. The reason is that the apex of the leading edge of the blade is provided as a location where three of the first surface, the second surface, and the third surface intersect. Suppose that when the apex of the leading edge of the blade is set by the part where more than 3 faces intersect, the position of the remaining faces must be consistent by passing through the intersecting point of the 3 faces. Therefore, higher machining accuracy is required. On the other hand, when the apex of the leading edge of the blade is set by the part where the three faces intersect, such high machining accuracy is not required. Second, the crack line along the groove line can be formed more reliably. The reason is that the ridge line of the sliding blade front edge to form the groove line locally applies stress to the intersection of the auxiliary line provided on one surface of the brittle substrate and the groove line formed by the apex of the sliding blade front edge . With the application of the stress, the opportunity for the formation of the crack line is obtained with higher certainty.

ED‧‧‧Edge

AL‧‧‧Auxiliary Line

CL‧‧‧Crack Line

SD1‧‧‧Top surface (1st side)

SD2‧‧‧Side (Second side)

SD3‧‧‧Side (Side 3)

SF, SF1‧‧‧Upper surface (one surface)

PP‧‧‧Vertex

TL‧‧‧Trench line

PS‧‧‧Ridge

CLa‧‧‧Auxiliary Rift Line

TLa‧‧‧Auxiliary groove line

4‧‧‧Glass substrate (brittle substrate)

51‧‧‧Blade front edge

51a‧‧‧Auxiliary blade leading edge

Fig. 1 is a side view schematically showing the structure of a cutting tool used in the method of breaking a brittle substrate according to the first embodiment of the present invention.

Fig. 2 is a schematic plan view from the point of arrow II in Fig. 1.

Fig. 3 is a flowchart schematically showing the structure of the method of breaking a brittle substrate according to the embodiments 1 to 5 of the present invention.

Fig. 4 schematically shows the first method of breaking the brittle substrate in the first embodiment of the present invention Top view of steps.

Fig. 5 is a schematic end view taken along the line V-V of Fig. 4.

Fig. 6 is a plan view schematically showing the second step of the method of breaking a brittle substrate according to the first embodiment of the present invention.

Fig. 7 is a schematic end view taken along the line VII-VII of Fig. 6.

Fig. 8 is a plan view schematically showing the configuration of the cutting tool used in the method of breaking the brittle substrate of the comparative example.

FIG. 9 is a flowchart schematically showing the structure of a method of forming a groove line in a method of breaking a brittle substrate according to the second embodiment of the present invention.

Fig. 10 is a plan view schematically showing the first step of the method of breaking a brittle substrate according to the third embodiment of the present invention.

Fig. 11 is a schematic end view taken along the line XI-XI of Fig. 10.

Fig. 12 is a plan view schematically showing the second step of the method of breaking a brittle substrate according to the third embodiment of the present invention.

Fig. 13 is a plan view schematically showing the third step of the method of breaking a brittle substrate according to the third embodiment of the present invention.

Fig. 14 is a plan view schematically showing the first step of the method of breaking a brittle substrate according to the fourth embodiment of the present invention.

Fig. 15 is a plan view schematically showing the second step of the method of breaking a brittle substrate according to the fourth embodiment of the present invention.

Fig. 16 is a cross-sectional view schematically showing the structure of the cutting edge used in the method of breaking a brittle substrate according to the fifth embodiment of the present invention.

Fig. 17 is a cross-sectional view schematically showing the structure of the leading edge of the auxiliary blade used in the method of breaking a brittle substrate according to the fifth embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described based on the drawings. Furthermore, the same or equivalent parts are marked with the same reference numbers in the following drawings, and the description is not repeated.

<Embodiment 1>

(The composition of cutting equipment)

1 and 2, first, the structure of the cutting tool 50 used in the formation step of the groove line of the method of dividing the glass substrate 4 (brittle substrate) of the present embodiment will be described. The cutting tool 50 has a leading edge 51 and a handle 52. The cutting edge 51 is held by being fixed to the handle 52 as its holder.

A top surface SD1 (first surface) and a plurality of surfaces surrounding the top surface SD1 are provided on the blade front edge 51. These multiple surfaces include side surface SD2 (second surface) and side surface SD3 (third surface). The top surface SD1, the side surfaces SD2, and SD3 (first to third surfaces) face in different directions and are adjacent to each other. The cutting edge 51 has a vertex where the top surface SD1, the side surfaces SD2, and SD3 intersect. The apex PP constitutes the protrusion of the blade edge 51. In addition, the side surfaces SD2 and SD3 form a ridge line PS constituting the side of the blade edge 51. The ridge line PS extends linearly from the vertex PP, and has a convex shape extending linearly. According to the above configuration, the blade front edge 51 has: a top surface SD1; a side surface SD2, which is adjacent to the top surface SD1; and a side surface SD3, which forms a ridge PS by being adjacent to the side surface SD2 and is connected to the top surface SD1 Each of and the side surface SD2 are adjacent to each other to form an apex PP.

Preferably, the leading edge 51 is a diamond point. That is, it can reduce the hardness and rough surface In terms of roughness, it is preferable that the leading edge 51 is made of diamond. More preferably, the cutting edge 51 is made of single crystal diamond. More preferably, in terms of crystallography, the top surface SD1 is a {001} plane, and each of the side surfaces SD2 and SD3 is a {111} plane. In this case, the side faces SD2 and SD3 have different directions, but they are crystallographically equivalent crystal faces.

Furthermore, diamonds other than single crystals can also be used. For example, polycrystalline diamonds synthesized by the CVD (Chemical Vapor Deposition) method can also be used. Alternatively, it is also possible to use a sintered diamond in which polycrystalline diamond particles sintered from fine particles of graphite or non-graphite carbon without a binder such as iron group elements are bonded by a binder such as iron group elements.

The shank 52 extends along the axial direction AX. Preferably, the leading edge 51 is mounted on the shank 52 in such a way that the normal direction of the top surface SD1 is substantially along the axial direction AX.

(How to break the glass substrate)

Next, the method of dividing the glass substrate 4 will be described below with reference to the flowchart shown in FIG. 3.

In step S10 (FIG. 3), the glass substrate 4 to be split is prepared (FIG. 1). The glass substrate 4 has an upper surface SF1 (one surface) and an opposite lower surface SF2 (the other surface). An edge ED is provided on the upper surface SF1. In the example shown in FIG. 4, the edge ED has a rectangular shape. The glass substrate 4 has a thickness direction DT perpendicular to the upper surface SF1. Moreover, in step S20 (FIG. 3), the cutting tool 50 (FIG. 1 and FIG. 2) which has the said blade front edge 51 is prepared.

Referring to FIG. 4, a trench line TL is formed in step S30 (FIG. 3). Specifically, perform the following steps.

First, the apex PP of the cutting edge 51 (FIG. 1) is pressed against the upper surface SF1 at the position N1. Thereby, the cutting edge 51 contacts the glass substrate 4. Preferably, the position N1 is as shown in the figure, It is separated from the edge ED of the upper surface SF1 of the glass substrate 4. In other words, at the time when the sliding of the blade front edge 51 starts, the blade front edge 51 is prevented from colliding with the edge ED of the upper surface SF1 of the glass substrate 4.

Next, the front edge 51 pressed against as described above is slid on the upper surface SF1 of the glass substrate 4 (refer to the arrow in FIG. 4). The cutting edge 51 (FIG. 1) slides on the upper surface SF1 in a direction from the ridge line PS toward the upper surface SD1. Strictly speaking, the cutting edge 51 slides in the direction DB formed by projecting the direction from the ridge line PS to the top surface SD1 through the vertex PP onto the upper surface SF1. The direction DB is substantially along the direction formed by projecting the extension direction of the ridge PS near the vertex PP onto the upper surface SF1. In FIG. 1, the direction DB corresponds to the direction opposite to the direction formed by projecting the axial direction AX extending from the cutting edge 51 onto the upper surface SF1. Therefore, the cutting edge 51 is pressed into the upper surface SF1 by the shank 52.

Each of the ridge PS and the top surface SD1 of the front edge 51 (FIG. 1) sliding on the upper surface SF1 of the glass substrate 4 and the upper surface SF1 of the glass substrate 4 form an angle AG1 and an angle AG2. Preferably, the angle AG2 is smaller than the angle AG1.

Plastic deformation is generated on the upper surface SF1 by the above sliding. Thereby, a groove line TL having a groove shape is formed on the upper surface SF1 (FIG. 5 ). Preferably, the groove line TL is only generated by the plastic deformation of the glass substrate 4. In this case, no cutting will occur on the upper surface SF1 of the glass substrate 4. In order to avoid cutting, it is sufficient not to make the load of the leading edge 51 excessively high. Since there is no cutting, it can avoid the generation of poor fine chips on the upper surface SF1. However, usually a small amount of cutting is allowed.

The groove line TL is formed by sliding the leading edge 51 from the position N1 to the position N3e through the position N2 due to the position N1 and the position N3e. The position N2 is away from the edge ED of the upper surface SF1 of the glass substrate 4. Location N3e is located on the upper surface of the glass substrate 4 SF1 The edge ED.

The trench line TL is formed in a crack-free state, that is, under the trench line TL, the glass substrate 4 is in a direction DC (Figure 4) intersecting the extending direction of the trench line TL (the horizontal direction in FIG. 4). 5) The state of continuous connection. In the crack-free state, although the groove line TL formed by plastic deformation is formed, no crack is formed along it. In order to obtain a proper crack-free state, the load applied to the leading edge 51 of the blade is adjusted so that it is as small as the time when the groove line TL is formed and does not produce cracks, and so large that it can be produced in a subsequent step The degree of plastic deformation of the internal stress state of the crack.

To form the groove line TL, the sliding blade leading edge 51 finally reaches the position N3e as described above. The crack-free state is maintained at the point in time when the blade front edge 51 is located at the position N2, and further, it is maintained until the moment the blade front edge 51 reaches the position N3e. When the blade front edge 51 reaches the position N3e, the ridge line PS (FIG. 1) of the blade front edge 51 cuts off the edge ED of the upper surface SF1 of the glass substrate 4.

Referring to FIGS. 6 and 7, by the above-mentioned cutting, a slight damage occurs at the position N3e. Taking this failure as a starting point, a crack is generated in a manner to release the internal stress near the trench line TL. Specifically, the crack of the glass substrate 4 in the thickness direction DT extends along the groove line TL from the position N3e of the edge ED of the upper surface SF1 of the glass substrate 4 (refer to the arrow in FIG. 6). In other words, the formation of the crack line CL begins. Thereby, as step S50 (FIG. 3), the crack line CL is formed from the position N3e to the position N1.

Furthermore, in order to make the formation of the crack line CL more reliable, the sliding speed of the cutting edge 51 from the position N2 to the position N3e may be lower than the speed from the position N1 to the position N2. Similarly, the load applied to the leading edge 51 from the position N2 to the position N3e may be greater than the load from the position N1 to the position N2 in the range where the crack-free state is maintained.

With the crack line CL, the continuous connection of the glass substrate 4 in the direction DC (FIG. 7) crossing the extending direction of the trench line TL (the horizontal direction in FIG. 6) is interrupted below the trench line TL. The so-called "connection of continuity" here, in other words, refers to a connection that is not covered by a crack. Furthermore, in the state where the continuous connection is interrupted as described above, the parts of the glass substrate 4 can also be brought into contact with each other through the crack of the crack line CL. In addition, a little continuous connection may be left directly under the trench line TL.

The direction in which the crack line CL (FIG. 6) extends along the groove line TL (FIG. 4) (arrow in FIG. 6) is opposite to the direction in which the groove line TL is formed (arrow in FIG. 4). In order to generate the crack line CL using this directional relationship, when sliding the leading edge 51 in the direction DB (FIG. 1) to form the groove line TL, it is preferable that the angle AG2 is smaller than the angle AG1. If this angle relationship is not satisfied, the crack line CL is unlikely to occur. In addition, if the angle AG1 and the angle AG2 are approximately the same, whether the crack line CL is generated or not will easily become unstable.

Next, in step S60 (FIG. 3), the glass substrate 4 is divided along the crack line CL. That is, the so-called breaking step is performed. The breaking step can be performed by applying an external force to the glass substrate 4. For example, by facing the crack line CL (FIG. 7) on the upper surface SF1 of the glass substrate 4, a stress applying member (for example, a member called a "breaking rod") is pressed against the lower surface SF2, and the crack is opened. The stress of the crack of the line CL is applied to the glass substrate 4. Furthermore, when the crack line CL is completely advanced in the thickness direction DT when it is formed, the formation of the crack line CL occurs simultaneously with the breaking of the glass substrate 4.

According to the above, the glass substrate 4 is divided. Furthermore, the step of forming the crack line CL described above is essentially different from the so-called breaking step. The breaking step is to completely separate the substrate by extending the formed crack in the thickness direction. On the other hand, the crack line CL The formation step comes from the change from the crack-free state to the cracked state obtained by the formation of the trench line TL. It is believed that the change is caused by the release of internal stress in the crack-free state.

(Comparative example 1)

Referring to FIG. 8, the vertex PP of the cutting edge 59 of this comparative example is set at the intersection of the four surfaces SE1 to SE4. Four ridge lines PS1 to PS4 are provided from the vertex PP. In this case, in the step of FIG. 4, the edge ED of the upper surface SF1 of the glass substrate 4 can be cut off by any one of the ridge lines PS1 to PS4. Therefore, similar to the present embodiment, there is an advantage that the crack line CL can be easily and reliably formed. On the other hand, the formation of the leading edge 59 requires high machining accuracy, and therefore has the disadvantage that its formation is not easy. The reason is that when the apex PP of the cutting edge is set at the intersection of the surfaces SE1~SE4 as in this comparative example, it is necessary to pass through the point where the three surfaces intersect to make the remaining one The positions of the faces are the same.

(Comparative example 2)

In this comparative example, the sliding direction of the cutting edge 51 is set to be the opposite of the direction DB (FIG. 1 ). In this case, in the step of FIG. 4, the edge ED of the upper surface SF1 of the glass substrate 4 is cut from the top surface SD1 instead of the ridge line PS. That is, at the time of cutting, the sharp ridge line PS in the above-mentioned present embodiment functions. In contrast, in this comparative example, the flat top surface SD1 functions. Therefore, in this comparative example, it becomes less likely to produce the minute damage which is an opportunity to start the formation of the crack line CL. Therefore, it is surely difficult to form the crack line CL.

(effect)

According to this embodiment, first, the blade front edge 51 can be easily prepared. The reason is that, unlike the above-mentioned comparative example 1, the apexes of the cutting edge 51 are the top surface SD1, the side surface SD2, and the side surface SD3. Where the 3 faces intersect. Suppose that when the apex of the leading edge of the blade is set by the part where more than 3 faces intersect, the position of the remaining faces must be consistent by passing through the intersecting point of the 3 faces. Therefore, higher machining accuracy is required. On the other hand, when the apex of the leading edge of the blade is set by the part where the three faces intersect, such high machining accuracy is not required. Second, the crack line CL along the trench line TL can be formed more reliably. The reason is that, unlike the above-mentioned comparative example 2, the ridge line PS of the blade front edge 51 that slides to form the groove line TL cuts the edge ED of the upper surface SF1 of the glass substrate 4. With this cutting, the opportunity to start the formation of the crack line CL is obtained with higher certainty.

<Embodiment 2>

Again, referring to FIG. 4, in this embodiment, the lubricant is supplied to the position where the leading edge 51 of the upper surface SF1 of the glass substrate 4 can slide. In other words, the step of forming the groove line TL (FIG. 4) (FIG. 3: Step S30) is shown in FIG. 9, and includes the step S31 of supplying lubricant and the step of sliding the blade leading edge 51 at the position where the lubricant is supplied. S32. In order to implement step S31, for example, a lubricant supply part (not shown) may be provided in the handle 52 (FIG. 1). In addition, since the structure other than these is substantially the same as the structure of the said Embodiment 1, the description is not repeated. In addition, step S31 can also be applied to the following embodiments 3 to 5.

In this embodiment, as in the first embodiment, the direction DB (FIG. 1) is selected as the advancing direction of the cutting edge 51. Under the condition that the load on the leading edge 51 of the blade is the same, sliding in the direction DB is more likely to damage the leading edge 51 than sliding in the opposite direction. According to this embodiment, this damage can be effectively suppressed. In this way, the life of the leading edge of the blade can be extended.

<Embodiment 3>

10, in step S10 (FIG. 3), prepare the same glass as in the first embodiment above Substrate 4. However, in this embodiment, the auxiliary line AL is provided on the upper surface SF1 of the glass substrate 4. 11, the auxiliary line AL has an auxiliary trench line TLa and an auxiliary crack line CLa. The auxiliary trench line TLa has a groove shape. The auxiliary crack line CLa is formed by the crack of the glass substrate 4 in the thickness direction DT extending along the auxiliary groove line TLa.

In the present embodiment, the auxiliary line AL is provided on the upper surface SF1 of the glass substrate 4 by simultaneously forming the auxiliary trench line TLa and the auxiliary crack line CLa. Such auxiliary line AL can be formed by a usual typical cutting method. For example, such auxiliary line AL, as shown by the arrow in FIG. 10, can be performed by placing the cutting edge on the edge ED of the upper surface SF1 of the glass substrate 4 and then moving it on the upper surface SF1. The minute cracks are generated by the impact at the time of leaving, so that when the auxiliary groove line TLa is formed, the auxiliary crack line CLa can be easily formed at the same time. In order to prevent damage to the leading edge of the blade and the glass substrate 4 when placed, the leading edge of the blade preferably has a shape different from the shape of the leading edge 51 and suitable for placing. Specifically, the blade front edge is preferably a holder capable of rotating (wheel-shaped one). In other words, the leading edge of the blade is preferably the one that rotates on the glass substrate 4 rather than the one that slides. Furthermore, the starting point of the auxiliary line AL is the edge ED in FIG. 10, but it can also be separated from the edge ED.

Next, in step S20 (FIG. 3), the same blade edge 51 as in the first embodiment is prepared. Furthermore, in order to facilitate the preparation of the blade front edge for the auxiliary line AL, the blade front edge 51 may also be used to form the auxiliary line AL described above. Alternatively, a cutting edge having the same shape as that of the cutting edge 51 may be used to form the auxiliary line AL.

Referring to FIG. 12, secondly, a trench line TL is formed in step S30 (FIG. 3). Specifically, perform the following steps.

First, the same operation as in the first embodiment is performed. Specifically, in the position N1 presses the apex PP of the cutting edge 51 (FIG. 1) against the upper surface SF1. Next, the pressed blade front edge 51 is slid in the direction DB (FIG. 1) on the upper surface SF1 of the glass substrate 4 (refer to the arrow in FIG. 12). Thereby, the trench line TL is formed on the upper surface SF1 in a crack-free state.

In this embodiment, the groove line TL is formed by sliding the cutting edge 51 between the position N1 and the position N3a from the position N1 through the position N2 to the position N3a. The position N3a is arranged on the auxiliary line AL. The position N2 is arranged between the position N1 and the position N3a. Preferably, the cutting edge 51 exceeds the position N3a on the auxiliary line AL and then slides to the position N4. Preferably, the position N4 is away from the edge ED.

In order to form the groove line TL, the sliding blade leading edge 51 crosses the auxiliary line AL at the position N3a as described above. Therefore, the ridge line PS (FIG. 1) of the cutting edge 51 also crosses the auxiliary line AL. By this intersection, a slight damage is generated at the position N3a. Taking this failure as a starting point, a crack is generated in a way to release the internal stress near the trench line TL. Specifically, the crack of the glass substrate 4 in the thickness direction DT extends along the groove line TL from the position N3a on the auxiliary line AL (refer to the arrow in FIG. 13). In other words, the formation of the crack line CL begins (Figure 13). Thereby, as step S50 (FIG. 3), the crack line CL is formed from the position N3a to the position N1. After the crack line CL is formed, as in the first embodiment, the crack line CL causes the continuous connection of the glass substrate 4 in the direction crossing the groove line TL under the groove line TL to be interrupted.

After the blade edge 51 reaches the position N3a, it is separated from the glass substrate 4. Preferably, after the blade leading edge 51 slides beyond the position N3a to the position N4, it moves away from the glass substrate 4.

Next, in step S60 (FIG. 3 ), as in the first embodiment, the glass substrate 4 is divided along the crack line CL. Based on the above, the method of cutting the glass substrate 4 of this embodiment is performed.

According to this embodiment, first, for the same reason as in the first embodiment, the cutting edge 51 can be easily prepared. Second, as in the first embodiment, the crack line CL along the trench line TL can be formed more reliably. The reason is that the ridge line PS of the sliding edge 51 to form the groove line TL is directed toward the auxiliary line AL provided on the upper surface SF1 of the glass substrate 4 and the groove formed by the apex of the sliding edge 51 The position N3a (FIG. 12) where the line TL intersects locally applies stress. With the application of the stress, an opportunity to start the formation of the crack line CL is obtained with higher certainty.

<Embodiment 4>

In this embodiment, different from the third embodiment, the auxiliary groove line TLa and the auxiliary crack line CLa of the auxiliary line AL (FIG. 11 and FIG. 12) are similar to those described in the first embodiment. The trench line TL and the crack line CL are formed by the method of forming. Hereinafter, this method will be specifically described.

First, prepare the leading edge for the formation of the auxiliary line AL. The blade front edge may also be the same as the blade front edge 51 (FIG. 1 and FIG. 2). That is, the formation of the auxiliary line AL and the formation of the trench line TL formed thereafter can also be performed by the common blade edge 51. Alternatively, as the leading edge for forming the auxiliary line AL, a leading edge different from the leading edge 51 (hereinafter, referred to as "auxiliary leading edge") may be prepared. The auxiliary blade front edge may also have the same shape as that of the blade front edge 51 (FIG. 1 and FIG. 2). Alternatively, the auxiliary blade front edge may have a shape different from the shape of the blade front edge 51. When the auxiliary blade front edge has a shape different from the shape of the blade front edge 51, it is also preferable that the auxiliary blade front edge has a top surface SD1, a side surface SD2, and a side surface SD3 forming the apex PP and the ridge line PS. The difference in shape is caused by the difference in the configuration of these components. The "shape" of the leading edge considered here is the part near the apex PP in the leading edge, that is, the shape of the part that acts on the glass substrate 4, and the shape of the part away from the acting part is usually not important. Below, in order not to To repeat, there are cases where the blade front edge used for the formation of the auxiliary line AL is simply referred to as the "blank front edge" regardless of whether it is the blade front edge 51 or the auxiliary blade front edge.

Referring to FIG. 14, secondly, by a method similar to the formation of the trench line TL (FIG. 4 ), the auxiliary trench line TLa is formed in a crack-free state. Referring to FIG. 15, secondly, the auxiliary trench line TLa along the auxiliary trench line TLa (FIG. 14) is formed by a method similar to the method for forming the crack line CL along the trench line TL (FIG. 6 ). Based on the above, the auxiliary line AL is formed (FIG. 11).

Next, as in the third embodiment, in steps S30 and S50 (FIG. 3), the groove line TL (FIG. 12) and the crack line CL (FIG. 13) are formed, and in step S60 (FIG. 3), along the crack The line CL breaks the glass substrate 4. Based on the above, the method of cutting the glass substrate 4 of this embodiment is performed.

In this embodiment, the load applied to the front edge 51 when the groove line TL (FIG. 12) is formed is larger than the load applied to the front edge when the auxiliary groove line TLa (FIG. 14) is formed . According to the experimental research of the inventor, by setting the difference in the load in this way, the crack line CL can be generated more reliably.

Preferably, the angle AG2 (FIG. 1) when the trench line TL (FIG. 12) is formed is smaller than the angle AG2 (FIG. 1) when the auxiliary trench line TLa is formed. By using this angular relationship, especially, even when the leading edge used to form the auxiliary groove line TLa is the leading edge 51 or the auxiliary leading edge having the same shape as the leading edge 51 , It is also easy to set the above load difference. The reason is that when the shape of the cutting edge is the same, the smaller the angle AG2, the greater the load that can form the groove line TL (or the auxiliary groove line TLa) in a crack-free state. In the formation of the trench line TL, if the angle AG2 is too large, it is difficult to achieve formation without cracks at the same time The trench line TL uses a load larger than the load when the auxiliary trench line TLa is formed. In contrast, when the angle AG2 (FIG. 1) when the trench line TL (FIG. 12) is formed is smaller than the angle AG2 when the auxiliary trench line TLa is formed (FIG. 1), when the trench line TL is formed At this time, it is easy to use a load larger than the load when the auxiliary trench line TLa is formed. Therefore, there is no need to worry about applying a high-load-oriented blade leading edge design to the blade leading edge 51 for the groove line TL, and applying a low-load leading edge design to the blade leading edge for the auxiliary groove line TLa. Therefore, in the formation of the auxiliary groove line TLa, the cutting edge 51 used in the formation of the groove line TL or the auxiliary cutting edge having the same shape as the auxiliary cutting edge can be used.

In the case where the angle AG2 (FIG. 1) is different as described above, the leading edge for forming the auxiliary groove line TLa is preferably different from the leading edge 51 for forming the groove line TL , Prepare the leading edge of the auxiliary blade. Thereby, the posture of the blade front edge 51 can be fixed in a state where the angle AG2 of the blade front edge 51 is suitable for the formation of the groove line TL. In other words, between the step of forming the auxiliary groove line TLa and the step of forming the groove line TL, the posture adjustment of the blade leading edge 51 for optimizing the angle AG2 is not required.

<Embodiment 5>

16 and 17, in this embodiment, the leading edge 51 is used in the formation of the groove line TL, and the auxiliary leading edge 51a is used in the formation of the auxiliary groove line TLa as described in the fourth embodiment. The leading edge of the auxiliary blade. The shape of the leading edge 51 and the shape of the auxiliary leading edge 51a are different from each other. For example, in the vicinity of the apex PP (refer to FIG. 2), each of the blade front edge 51 and the auxiliary blade front edge 51a has the angles AP and APa of the ridge line PS of the cross section perpendicular to the ridge line PS, and the angle AP is greater than the angle APa. In addition, since the structure other than these is substantially the same as the structure of the said Embodiment 4, the description is not repeated.

According to this embodiment, in the formation of the auxiliary trench line TLa and the formation of the trench line TL, the cutting edges having different shapes are used. Thereby, as the shape of the cutting edge, when forming each of the auxiliary groove line TLa and the groove line TL, those suitable for relatively low load and those suitable for high load can be used. Therefore, when the auxiliary trench line TLa and the trench line TL are formed, a crack-free state can be obtained more reliably, and the auxiliary crack line CLa and CLa can be generated more reliably from each of the auxiliary trench line TLa and the trench line TL. Crack line CL.

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

AG1‧‧‧Angle

AG2‧‧‧Angle

AX‧‧‧axial

DB‧‧‧direction

DT‧‧‧Thickness direction

ED‧‧‧Edge

PP‧‧‧Vertex

PS‧‧‧Ridge

SD1‧‧‧Top surface (1st side)

SD3‧‧‧Side (Side 3)

SF1‧‧‧Upper surface (one surface)

SF2‧‧‧Lower surface (the other side)

4‧‧‧Glass substrate (brittle substrate)

50‧‧‧Cutting equipment

51‧‧‧Blade front edge

52‧‧‧Handle

Claims (5)

A method for breaking a brittle substrate, comprising the following steps: a) preparing a brittle substrate having a surface and a thickness direction perpendicular to the above-mentioned surface, and an auxiliary line is arranged on one surface, and the auxiliary line has: auxiliary groove line , Which has a groove shape; and an auxiliary crack line, which is formed by the cracks of the brittle substrate in the thickness direction extending along the auxiliary groove line; and further includes the following steps: b) preparing the cutting edge, the cutting edge The edge has: a first surface; a second surface, which is adjacent to the first surface; and a third surface, which forms a ridgeline by being adjacent to the second surface and is connected to the first surface and the second surface. Each of the faces is adjacent to form an apex; and further includes the following steps: c) by sliding the front edge of the blade in the direction from the ridge line toward the first face due to the one face of the brittle substrate, plastic deformation is used to make A groove line having a groove shape is formed on the one surface of the fragile substrate, and the groove line is formed in a non-cracked state, that is, under the groove line, the fragile substrate is connected to the groove A state in which the direction of line crossing is continuously connected; further comprising the following steps: d) By using the above step c) to slide the ridge line of the cutting edge and the auxiliary line provided on the one surface of the fragile substrate, The cracks of the fragile substrate in the thickness direction are extended from the auxiliary line along the groove line, thereby forming a crack line. By the crack line, under the groove line, the fragile substrate is connected to the groove line. The connection of the continuity in the direction of the groove line crossing is interrupted; It further includes the following steps: e) breaking the brittle substrate along the crack line; the step a) includes the following steps: a1) preparing any one of the leading edge and the leading edge of the auxiliary blade, the leading edge of the auxiliary blade having: The first surface; the second surface, which is adjacent to the first surface; and the third surface, which forms a ridgeline by being adjacent to the second surface and is connected to the first surface and the second surface Each of them is adjacent to form a vertex; further comprising the following steps: a2) by making any one of the leading edge of the blade and the leading edge of the auxiliary blade on the one surface of the fragile substrate from the ridge line to the first surface The auxiliary groove line is formed on the one surface of the brittle substrate by plastic deformation. The auxiliary groove line is formed in a crack-free state, that is, below the auxiliary groove line The state where the brittle substrate is continuously connected in the direction intersecting the auxiliary groove line; further comprising the following steps: a3) by extending the cracks of the brittle substrate in the thickness direction along the auxiliary groove line to form The auxiliary crack line, through the auxiliary crack line, causes the continuous connection of the brittle substrate to be interrupted in the direction intersecting the groove line under the auxiliary groove line, and is applied to the above step in step c) The load on the leading edge is larger than the load applied to any one of the leading edge and the auxiliary leading edge in step a2). For example, in the method for breaking a brittle substrate in the first item of the patent application, in the above step a2), the auxiliary blade leading edge having a shape different from that of the blade leading edge is slid. For example, the method for breaking the brittle substrate in the first item of the scope of patent application, wherein in the above step c) The angle formed by the first surface of the blade leading edge and the one surface of the brittle substrate is smaller than the first surface and the brittle substrate of any one of the blade leading edge and the auxiliary blade leading edge in step a2) The angle formed by the above one face. For example, the method for breaking the brittle substrate of the third item of the patent application, wherein in the above step a2), any one of the blade front edge and the auxiliary blade front edge having the same shape as the blade front edge slide. For example, the method for breaking a brittle substrate according to any one of items 1 to 4 in the scope of the patent application, wherein the step c) includes supplying a lubricant to a position on the one surface of the brittle substrate where the leading edge of the blade can slide step.

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