TWI694913B - Method for forming vertical cracks in brittle material substrate and cutting method for brittle material substrate - Google Patents

Abstract

The invention provides a method for forming vertical cracks on a brittle material substrate without glass chips.

A method for forming a vertical crack on a brittle material substrate includes: a groove line forming step, which forms a linear groove portion, ie, a groove line, on a main surface; and an indentation forming step, which uses a specific pressing body Partially press the vicinity of the trench line to form an indentation; in the trench line forming step, the trench line is formed in a manner to maintain a crack-free state directly under the trench line, and according to the indentation in the indentation forming step As a result, vertical cracks extend from the trench line along the thickness direction of the brittle material substrate.

Description

Method for forming vertical cracks in brittle material substrate and cutting method for brittle material substrate

The present invention relates to a method for cutting a brittle material substrate, and particularly to a method for forming a vertical crack when the brittle material substrate is cut.

The manufacturing process of a flat panel display panel, a solar cell panel, etc. generally includes a step of cutting a substrate (mother substrate) containing a brittle material such as a glass substrate, a ceramic substrate, a semiconductor substrate, etc. In this cutting, a technique is widely used in which a scribing tool such as a diamond tip or a cutter wheel is used to form a scribing line on the surface of the substrate, and a crack (vertical crack) extends from the scribing line in the thickness direction of the substrate. In the case of forming a scribe line, there are cases where the vertical cracks are fully extended in the thickness direction to cut the substrate, and there are cases where the vertical cracks are only partially extended in the thickness direction. In the latter case, after the scribing line is formed, stress application called a breaking step is performed. By the breaking step, the vertical cracks are completely advanced in the thickness direction, thereby cutting the substrate along the scribe line.

As such a method of extending a vertical crack by the formation of a scribe line, a method of forming a linear processing mark, which is also called an auxiliary line and becomes a starting point (trigger) when the vertical crack extends, is known (for example, refer to a patent Literature 1).

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2015-74145

When a scribing tool is used to form a scribing line, there are cases where fine chips or powders of the substrate material, that is, glass chips, are attached to the surface of the substrate.

For example, as disclosed in Patent Document 1, in the case of using an auxiliary line, when the scribe line for cutting is formed, the force given by the scribing tool to the substrate is small, so it is not easy to generate glass chips, but when forming the auxiliary line There is a possibility of glass chips.

The present invention has been completed in view of the above-mentioned problems, and its object is to provide a method for forming vertical cracks while suppressing the generation of glass chips more than before.

In order to solve the above-mentioned problems, the invention of claim 1 is characterized in that it is a method of forming a vertical crack at the cutting position when the brittle material substrate is cut in the thickness direction, and is provided with: a groove line forming step, which is based on the brittleness A groove line, that is, a groove line, is formed on one main surface of the material substrate; and an indentation forming step is to form a pressure by locally pressing the vicinity of the groove line of the brittle material substrate with a specific pressing body In the trench line forming step, the trench line is formed in a manner to maintain a crack-free state directly under the trench line, and accompanying the formation of the indentation in the indentation forming step, so that The micro-cracks extending from the indentation reach below the groove line, thereby extending the vertical crack from the groove line in the thickness direction.

The invention of technical solution 2 is a method of forming a vertical crack in a brittle material substrate of technical solution 1, wherein the front end of the specific pressing body is tapered, and in the step of forming the indentation, by using the tapered shape The front end portion presses the brittle material substrate to form the indentation.

The invention of technical solution 3 is a method of forming a vertical crack in a brittle material substrate of technical solution 2, wherein the front end portion of the specific pressing body has a conical shape.

The invention of technical solution 4 is a method of forming vertical cracks in a brittle material substrate according to any one of technical solutions 1 to 3, wherein the indentation is formed on the vertical crack of the trench line Near the opposite side of the predetermined stretch direction of the mark.

The invention of the technical solution 5 is characterized in that it is a method of cutting the brittle material substrate in the thickness direction, and is provided with: a vertical crack formation step, which is formed by the vertical cracks according to any one of the technical solutions 1 to 4 Method to form vertical cracks on the brittle material substrate; and a fracture step, which is to break the brittle material substrate along the vertical cracks.

According to the inventions of claims 1 to 5, the vertical cracks can be extended at the predetermined cutting position of the brittle material substrate without causing glass chips.

100‧‧‧Pressing body

101‧‧‧Front end

150‧‧‧Scribe tool

151‧‧‧Diamond tip

152‧‧‧handle

AR1‧‧‧arrow

AR2‧‧‧arrow

AR3‧‧‧arrow

AR4‧‧‧arrow

AR5‧‧‧arrow

AX2‧‧‧Axis direction

d‧‧‧Distance

DA‧‧‧Moving direction

DT‧‧‧thickness direction

g‧‧‧Interval

ID‧‧‧Indentation

MC‧‧‧Micro crack

PP‧‧‧Vertex

PS‧‧‧Edge

PF2‧‧‧Blade tip

r‧‧‧radius

R‧‧‧radius

RE‧‧‧Micro crack generation area

RE1‧‧‧ (micro-crack-producing area and groove line) overlap area

SD1‧‧‧Top

SD2‧‧‧Side

SD3‧‧‧Side

SF1‧‧‧One main face

SF2‧‧‧The other main face

T1‧‧‧Starting point

T2‧‧‧End

TL‧‧‧Trench line

VC‧‧‧Vertical crack

W‧‧‧brittle material substrate

FIG. 1 is a plan view illustrating the brittle material substrate W after the trench line TL is formed.

2(a) and (b) are diagrams schematically showing the configuration of the scribe tool 150 for forming the trench line TL.

FIG. 3 is a cross-sectional view of the zx part including a vertical cross-section of the trench line TL.

FIG. 4 is a zx partial cross-sectional view schematically showing the state when the pressing body 100 is lowered.

FIG. 5 is a zx partial cross-sectional view schematically showing a state in which the indentation ID is formed by the pressing body 100.

FIG. 6 is an optical microscope image of the vicinity of the indentation ID when the pressing body 100 having a conical shape with the tip portion 101 is formed on the glass substrate.

FIG. 7 is a diagram schematically showing a state where an indentation ID is formed near the trench line TL.

FIG. 8 is an optical microscope image of the vicinity of the indentation ID when the indentation ID is formed on the glass substrate with the groove line TL formed in advance.

FIG. 9 is a plan view of the brittle material substrate W in a state where the vertical crack VC is extended by the formation of the indentation ID.

FIG. 10 is a plan view of the brittle material substrate W in a state where the vertical crack VC is extended by the formation of the indentation ID.

Fig. 11 is a graph showing the relationship between the load and the diameter of the formed indentation ID.

Fig. 12 is a graph showing the relationship between the load and the maximum crack length formed.

FIG. 13 is an optical microscope image showing a state in which a pressing body 100 having a quadrangular pyramid shape at the front end portion 101 is used to form an indentation, and a vertical crack is extended directly under the groove line TL.

The method of the embodiment of the present invention shown below is for forming a vertical crack for cutting at a specific position (cutting position) of the brittle material substrate W. Roughly speaking, the method is to form a vertical groove from the groove line toward the substrate thickness by forming a processing groove called a groove line at the cutting position, and then forming a local indentation near the groove line Direction stretcher. In addition, in this embodiment, the groove line refers to a fine linear groove portion (recessed portion) that becomes a formation position of a vertical crack directly below it.

Hereinafter, a case where a plurality of cutting positions (cutting lines) parallel to a set of opposite sides is preset for the rectangular brittle material substrate W will be described as an example. In addition, the right-handed xyz coordinate system is appropriately marked in the drawing for explanation. The right-handed xyz coordinate system sets the arrangement direction of the cutting position as the positive x-axis direction, and sets the formation progress direction of the trench line TL It is the positive direction of the y-axis, and the vertical upward direction is the positive direction of the z-axis.

<Formation of trench lines>

FIG. 1 is a plan view (xy plan view) of the brittle material substrate W illustrating the state after the trench line TL is formed. FIG. 2 is a diagram schematically showing the configuration of the scribe tool 150 for forming the trench line TL. FIG. 3 is a cross-sectional view of the zx part including a vertical cross-section of the trench line TL. The formation position of the groove line TL shown in FIG. 1 corresponds to the cutting position when the brittle material substrate W is viewed from the main surface (upper surface) SF1 side of the brittle material substrate W.

In the present embodiment, a scoring tool 150 having a diamond tip 151 is used to form the trench line TL. The diamond tip 151 has a truncated pyramid shape as shown in FIG. 2, for example, and is provided with a top surface SD1 (first surface) and a plurality of surfaces surrounding the top surface SD1. In more detail, as shown in Figure 2(b) It is shown that the plurality of surfaces includes a side surface SD2 (second surface) and a side surface SD3 (third surface). The top surface SD1, the side surfaces SD2, and SD3 are oriented in different directions and are adjacent to each other. At the diamond tip 151, the tip PS is formed by the ridge PS including the side surfaces SD2 and SD3, and the apex PP formed by the three surfaces of the top surface SD1, the side surfaces SD2 and SD3. As shown in FIG. 2( a ), the diamond tip 151 is held on one end side of the rod-shaped (columnar) shank 152 with the top surface SD1 becoming the lowermost end.

When the scribing tool 150 is used, as shown in FIG. 2(a), in the state where the axis direction AX2 of the handle 152 is inclined from the vertical direction toward the front of the moving direction DA (positive direction of the y-axis) by a certain angle, That is, the diamond tip 151 is brought into contact with the upper surface SF1 of the brittle material substrate W in such a posture that the top surface SD1 faces the back of the moving direction DA (negative direction of the y-axis). Then, while keeping the contact state, the scoring tool 150 is moved forward in the moving direction DA, thereby sliding the blade tip PF2 of the diamond tip 151. Thereby, plastic deformation along the moving direction DA of the diamond tip 151 occurs. In the present embodiment, the sliding action of the diamond tip 151 that produces the plastic deformation is also referred to as the diamond tip 151 scoring action.

As shown in FIGS. 1 and 3, the trench line TL is formed on the upper surface SF1 of the brittle material substrate W as a fine linear groove extending in the y-axis direction. The groove line TL is formed as a result of plastic deformation generated on the upper surface SF1 of the brittle material substrate W by sliding the diamond tip 151 in a state where the posture of the scoring tool 150 is symmetrical with respect to the moving direction DA . In this case, as schematically shown in FIG. 3, the trench line TL is formed substantially as a groove portion whose cross-section perpendicular to the extending direction is a line-symmetrical shape.

As shown in FIG. 1, the groove line TL is formed at a cutting position defined on the upper surface SF1 of the brittle material substrate W in the positive y-axis direction indicated by the arrow AR1 from the starting point T1 to the ending point T2. Hereinafter, the range on the trench line TL that is relatively close to the starting point T1 is also referred to as the upstream side, and the range that is relatively close to the end point T2 is also referred to as the downstream side.

In addition, in FIG. 1, the starting point T1 and the ending point T2 of the trench line TL are set to be slightly spaced from the end of the brittle material substrate W, but this is not necessary, and can also be based on As the type of the brittle material substrate W to be cut, the use of the cut piece, etc., either or both of them are appropriately set as the end positions of the brittle material substrate W. However, setting the starting point T1 as the end of the brittle material substrate W is applied to the scoring tool 150 as compared with the case where the position slightly spaced from the end is set as the starting point T1 as illustrated in FIG. 1. The impact on the blade tip PF2 becomes larger, so you must pay attention to the life of the blade tip PF2 and the aspect that accidentally causes vertical cracks.

In addition, the formation of the groove line TL on each of the plurality of cutting positions may be a form in which the scoring tool 150 is sequentially formed in a processing device (not shown) provided with a scoring tool 150, Alternatively, a plurality of processing devices for forming trench lines TL may be simultaneously formed in parallel.

When the trench line TL is formed, the load applied by the scribing tool 150 (corresponding to the force of pressing the scribing tool 150 from vertically upward toward the upper surface SF1 of the brittle material substrate W) is set to be sure The trench line TL is formed, but no vertical crack extension from the trench line TL is generated in the thickness direction DT of the brittle material substrate W (FIG. 3).

In other words, the formation of the trench line TL is performed directly below the trench line TL, in such a manner that the brittle material substrate W and the trench line TL are continuously connected in a direction (a crack-free state). In addition, in the case where the trench line TL is formed by this correspondence, in the vicinity of the trench line TL of the brittle material substrate W (from the trench line TL, within a range of about 5 μm to 10 μm), as a result of plastic deformation However, internal stresses remain.

The formation of the trench line TL can be achieved, for example, by setting the load applied by the scoring tool 150 to a smaller value than when the same scoring tool 150 is used to form an extended scribing line with vertical cracks.

Even if the trench line TL is formed in the crack-free state, there is no extension of the vertical crack from the trench line TL, so even if the bending moment acts on the brittle material substrate W, it is compared with the case where the vertical crack is formed , It is more difficult to cut off along the trench line TL.

<Formation of indentation and extension of vertical cracks>

When the trench line TL is formed in the above-described manner, indentation is locally formed in the vicinity of the trench line TL. The formation of the indentation is performed by lowering a specific pressing body containing a material having a hardness higher than that of the brittle material substrate W, and pressing the upper surface SF1 of the brittle material substrate W from above.

FIG. 4 is a zx partial cross-sectional view schematically showing the state when the pressing body 100 is lowered, and FIG. 5 is a zx partial cross-sectional view schematically showing the state where the indentation ID is formed by the pressing body 100.

In a state where the brittle material substrate W is arranged horizontally, as shown in FIG. 4, if the lowermost end in the negative direction of the z-axis is pressed by the movement of the unillustrated moving mechanism, the conical front end 101 is pressed When the body 100 descends in the negative z-axis direction, the tip portion 101 immediately abuts on the upper surface SF1 of the brittle material substrate W. After this contact, as shown by arrow AR3 in FIG. 5, if the pressing body 100 is further lowered, the tip portion 101 is pressed into the brittle material substrate W, whereby the brittle material substrate W plastically deforms to form a concave portion, that is Indentation ID. Furthermore, a large number of micro-cracks MC are formed around the indentation ID. On the brittle material substrate W, generally, the micro-crack MC takes any position of the outer edge of the indentation ID as a starting point, with a specific depth (i.e., perpendicular to the upper surface SF1) relative to the upper surface SF1 of the brittle material substrate W Direction) stretch. In FIG. 5, the micro-crack MC is schematically shown as a diagonal line.

In this case, the size of the indentation ID and the length (maximum extension length) of the micro-crack MC correspond to the shape of the pressing body 100 and the load acting on the pressing body 100.

The material of the pressing body 100 can be appropriately selected according to the material of the brittle material substrate W, but from the viewpoint of high hardness and versatility and ease of acquisition, it is preferable to include diamond.

FIG. 6 is an optical microscope image of the vicinity of the indentation ID when the pressing body 100 having a conical shape is formed on the glass substrate, which is a type of brittle material substrate W, and the tip portion 101 is conical. However, the trench line TL has not yet been formed. In FIG. 6, it is confirmed that the indentation ID is substantially circular in plan view, and it is also confirmed that a large number of micro cracks MC extend randomly from the outer edge of the indentation ID toward the outside.

Furthermore, in FIG. 6, at a glance, the micro-crack MC is along the upper surface of the glass substrate It is formed, but in FIG. 6, the micro crack MC appearing on the upper surface SF1 of the glass substrate is observed.

FIG. 7 is a diagram schematically showing a state where an indentation ID is formed near the trench line TL. 8 is an optical microscope image of the vicinity of the indentation ID in the case where the indentation ID is formed on the glass substrate, which is one type of the brittle material substrate W in which the trench line TL is formed in advance.

When the brittle material substrate W is partially pressed by the pressing body 100, as illustrated in FIG. 6, a large number of micro-cracks MC are randomly formed around the indentation ID. As shown in FIG. 7, this phenomenon refers to not only the formation of an indentation ID at a portion pressed by the pressing body 100, but also a specific range around the indentation ID that becomes a micro-cracking area RE, which is an area where micro-cracking MC may occur. Here, the micro-crack generation region RE can be regarded as a connection between the center position of the indentation ID and the position reached by the largest length in plan view among the large number of micro-cracks MC generated by the formation of the indentation ID The line is the area other than the indentation ID in the circular area of the radius.

In the present embodiment, the indentation ID is formed in such a manner that the micro-crack MC is generated by extending to below the trench line TL and overlapping the trench line TL in a plan view. According to other insights, this situation can also be said to form the indentation ID in such a way that a part of the micro-crack generation region RE overlaps with the trench line TL after the trench line TL is formed in the above-described manner. In FIG. 7, the overlapping region RE1 of the micro-crack generation region RE and the trench line TL is surrounded by a thick broken line.

Furthermore, the indentation ID is a circle with a radius r when viewed from above, and when the microcrack generation region RE is assumed to be an annular region formed with a fixed width on its outside, the radius r of the indentation ID, microcracks Between the radius R of the outermost side of the generation area RE and the distance d between the center of the indentation ID and the trench line TL, r<d<R

When the relationship is established, it can be said that a part of the micro-crack generation region RE overlaps the trench line TL. Furthermore, regarding the former, it can also be said that between the interval g, the radius r, the distance d, and the radius R of the indentation ID and the trench line TL g=d-r<R-r

Relationship established.

When the indentation ID is formed under the condition that the micro-crack generation region RE overlaps the trench line TL, the micro-crack MC extending to the overlap region RE1 is generated with an appropriate probability. If such a micro-crack MC reaches the area where the residual internal stress exists directly under the trench line TL, this situation becomes the beginning, resulting in the release of the residual internal stress near the trench line TL, thereby generating a vertical from the trench line TL Crack VC stretch. This situation is the detail of the extension of the vertical crack VC generated by the technique of this embodiment. In FIG. 8, a micro-crack MC reaches the formation site of the trench line TL (shown by a dotted line in the figure), and the state where the vertical crack VC travels from the arrival site is observed.

In this way, the indentation ID is formed in such a manner that the micro-crack generation region RE overlaps the trench line TL, thereby extending the vertical crack VC from the trench line TL.

In addition, FIG. 8 illustrates the case where the indentation ID is formed on the left side of the trench line TL, but the formation position of the indentation ID may be the right side of the trench line TL.

In fact, when the vertical crack VC is about to be stretched by the formation of the indentation ID, it is sufficient to form the indentation ID in such a manner that the micro-crack MC overlapping the trench line TL is surely generated. Specifically, according to the material or thickness of the brittle material substrate W, the formation position (distance from the trench line TL) or the formation of the indentation ID of the indentation ID that can cause such micro-cracks MC is experimentally set in advance Conditions such as the load applied to the pressing body 100 may be sufficient.

Furthermore, it is not preferable to form the indentation ID in such a way that the indentation ID overlaps with the trench line TL. The reason for this is that even if the indentation ID is formed overlapping the compressed region by the formation of the trench line TL, the micro-crack MC does not preferably occur.

9 and 10 are plan views of the brittle material substrate W in which the trench line TL shown in FIG. 1 is formed, and the vertical crack VC is stretched by the formation of the indentation ID.

As shown by arrow AR4 in FIG. 9, if each trench line TL arranged in the x-axis direction The indentation ID is continuously formed in the vicinity of the downstream side, and the vertical cracks VC on each trench line TL sequentially extend toward the upstream side of the trench line TL, which is a predetermined extension direction, as indicated by the arrow AR5. Finally, as shown in FIG. 10, at all cutting positions, vertical cracks VC extending from the trench line TL are generated. That is, the formation of the indentation ID becomes the beginning (the micro-crack MC extending from the indentation ID becomes a trigger), and the self-groove is formed at each cutting position of the brittle material substrate W without the crack state although the trench line TL was formed before The vertical crack VC where the slot line TL extends.

Furthermore, the reason why the predetermined extending direction of the vertical crack VC becomes the upstream direction as described above is that: when the scribe tool 150 having the diamond tip 151 is used to form the trench line TL, the trench line TL The vertical crack VC generated directly below has the property of extending toward the side where the top surface SD1 exists. That is, the vertical crack VC has the property of extending in a specific direction. In the present embodiment in which the trench line TL is formed with the top surface SD1 of the diamond tip on the upstream side of the trench line TL, when the indentation ID is formed, the vertical crack VC is upstream of the trench line TL It stretches laterally, but the vertical crack VC is not easy to stretch in the opposite direction.

Therefore, in the case shown in FIG. 9, the indentation ID is formed in the vicinity of the side opposite to the predetermined extending direction of the vertical crack VC on the trench line TL, that is, in the vicinity of the downstream side of the trench line TL.

In the case of attempting to stretch the vertical crack VC by the method of the present embodiment, any of the processing for forming the trench line TL and the processing for forming the indentation ID produces plastic deformation only on the brittle material substrate W Therefore, it is less likely that glass chips will be generated during each process. That is, according to the technique of this embodiment, the vertical crack VC can be extended without glass chips.

The brittle material substrate W in which the vertical crack VC is formed at the cutting position as described above is given to a specific breaking device (not shown). In the breaking device, the bending moment acts on the brittle material substrate W by the so-called 3-point bending or 4-point bending method, thereby extending the vertical crack VC to the other main surface of the brittle material substrate W (below The breaking step up to SF2 (see Figure 2). By going through this breaking step, the brittle material substrate W is cut at the cutting position.

As described above, according to the present embodiment, after the groove line is formed at the cutting position of the brittle material substrate, an indentation is partially formed near the groove line, and at this time, a micro crack extending from the indentation is made Reaching below the formation position of the groove line, by this, the vertical crack VC can be stretched surely without cutting glass at the cutting position of the brittle material substrate.

<Example>

(Example 1)

In this embodiment, the influence of the load applied to the pressing body 100 on the size of the indentation ID and the maximum length of the micro-crack MC (hereinafter, referred to as the maximum crack length) has been confirmed.

Specifically, a glass substrate with a thickness of 0.2 mm is prepared as a brittle material substrate W, and a diamond tip that exhibits a conical shape with a tip portion 101 and an opening angle of 122° and a radius of curvature of 10 μm is used as the pressing body 100, which is applied to The load of the pressing body 100 is divided into 4 levels of 1.3N, 2.5N, 3.8N, and 5.0N to form an indentation ID.

FIG. 11 is a graph showing the relationship between the load and the diameter of the indentation ID formed, and FIG. 12 is a graph showing the relationship between the load and the maximum crack length formed.

It is confirmed from FIGS. 11 and 12 that the larger the load, the larger the size of the indentation ID and the maximum crack length.

(Example 2)

In this embodiment, the influence of the load applied to the pressing body 100 and the distance between the indentation ID (more specifically, the center position) and the groove line on the extension of the vertical crack VC is analyzed. The conditions of the pressing body 100 and the brittle material substrate W are the same as in Example 1.

Specifically, the load applied to the pressing body 100 is divided into 4 levels of 1.3N, 2.5N, 3.8N, and 5.0N, and the distance between the center position of the indentation and the groove line is divided into 0 μm, ±10 μm, and ±20 μm. , 9 grades of ±30μm and ±40μm, thereby determining all 36 sets of conditions where the combination of the load applied to the pressing body 100 and the distance between the center position of the indentation and the groove line is completely different. Furthermore, the case where the distance between the center position of the indentation and the trench line becomes negative means that the indentation is formed on the opposite side to the trench line TL when the distance becomes positive. Furthermore, the formation of the indentation ID under various conditions was performed on the brittle material substrate W in which the trench line TL having a width of about 10 μm was formed in advance by the scoring tool 150.

Table 1 shows the presence or absence of vertical cracks VC extending from the trench line TL for all 36 groups.

In Table 1, the column for the condition where the vertical crack VC is stretched is marked with "○", and the column for the condition where it is not stretched is marked with "×".

From the results shown in Table 1, it can be seen that when the distance between the center of the indentation ID forming the indentation ID and the trench line is 0 μm directly above the trench line TL, the vertical crack VC does not stretch, and the center position of the indentation and the groove The greater the distance of the slot line TL, the greater the value of the load after the vertical crack VC extends.

In view of this result and the result shown in Example 1, the indentation can be formed by appropriately setting the formation position of the indentation and the load applied to the pressing body when forming the indentation, and then forming the trench line TL, thereby , The vertical crack VC can be surely extended from the trench line TL.

<variation example>

In the above embodiment, the case where the front end 101 of the pressing body 100 is conical has been described, but the shape of the front end 101 of the pressing body 100 used for forming the indentation for extending the vertical crack is not Limited to this. FIG. 13 shows an optical microscope image when an indentation is formed using the pressing body 100 having a quadrangular pyramid shape at the front end portion 101, and a vertical crack is extended directly under the groove line TL. The results shown in Figure 13 indicate that The shape of the front end 101 of the pressing body 100 forms an indentation according to the conditions corresponding to the extension of the vertical crack.

Furthermore, if vertical cracks can be formed along with the formation of the indentation, the shape of the tip portion 101 may not be tapered, and may be, for example, columnar.

Furthermore, in the above embodiment, the diamond tip 151 is used by sliding the diamond tip 151 in a state where the axial direction AX2 of the handle 152 is inclined forward in the movement direction DA, that is, in a posture with the top surface SD1 facing backward in the movement direction DA. The scoring tool 150 forms the groove line TL, but it can also be replaced by making the diamond point with the posture of the top surface SD1 facing the front of the moving direction DA when the shaft direction AX2 of the handle 152 is inclined toward the back of the moving direction DA 151 slides to form the trench line TL.

Alternatively, in the above embodiment, the diamond tip 151 is used in the formation of the trench line TL, but it may be replaced by a disk shape (abacus bead shape) and a uniform blade edge along the outer periphery A well-known scoring wheel is pressed and rolled at the cutting position to form a trench line TL.

However, the situation in these aspects is different from the above embodiment, and the predetermined extending direction of the vertical crack becomes the downstream side of the trench line TL. Therefore, in these aspects, the vertical crack VC can be extended by forming an indentation ID near the upstream side of the trench line TL.

100‧‧‧Pressing body

101‧‧‧Front end

AR3‧‧‧arrow

DT‧‧‧thickness direction

ID‧‧‧Indentation

MC‧‧‧Micro crack

SF1‧‧‧One main face

TL‧‧‧Trench line

W‧‧‧brittle material substrate

Claims (5)

A method for forming vertical cracks in a brittle material substrate, characterized in that it is a method for forming vertical cracks at a cutting position when the brittle material substrate is cut in the thickness direction, and is provided with: a groove line forming step, which is A groove line, that is, a groove line, is formed on one main surface of the brittle material substrate; and an indentation forming step by locally pressing the vicinity of the groove line of the brittle material substrate with a specific pressing body Forming an indentation; in the trench line forming step, forming the trench line in a manner to maintain a crack-free state directly under the trench line, and by forming the indentation in the indentation forming step So that the micro-cracks extending from the indentation reach below the groove line, and the vertical cracks extend from the groove line in the thickness direction. A method for forming a vertical crack in a brittle material substrate according to claim 1, wherein the front end of the specific pressing body is tapered, and in the step of forming the indentation, the front end portion of the tapered shape is used to press the The brittle material substrate forms the indentation. A method for forming a vertical crack in a brittle material substrate according to claim 2, wherein the front end portion of the specific pressing body has a conical shape. The method of forming a vertical crack in a brittle material substrate according to any one of claims 1 to 3, wherein the indentation is formed near the opposite side of the predetermined extension direction of the vertical crack of the trench line. A method for cutting a brittle material substrate, characterized in that it is a method for cutting a brittle material substrate in the thickness direction, and has: A vertical crack formation step which forms a vertical crack on the brittle material substrate by the vertical crack formation method according to any one of claims 1 to 4; and a fracture step which makes the brittle material substrate along the vertical crack fracture.

Images