CN106477866A - In brittle substrate, the forming method of Incline Crack and substrate disconnect method - Google Patents

Abstract

The invention provides a method for forming an oblique crack in a brittle material substrate and a method for breaking the substrate. The method for forming oblique cracks in a brittle material substrate includes: a groove line forming process, in which a scribing tool having a tip including a ridge line slides or rolls on one main surface of a brittle material substrate to form a groove line, wherein the groove line It is a linear groove portion; and a crack forming process, in which a crack is generated directly below the groove line, and in the groove line forming process, the diamond cutter is inclined at a predetermined inclination angle from the groove line forming advancing direction in the horizontal plane In this state, the groove line is formed so as to maintain a crack-free state directly below the groove line, and in the crack forming step, an oblique crack that is a crack inclined with respect to the main surface of the brittle material substrate is propagated from the groove line.

Description

Formation method of inclined crack in brittle material substrate and substrate breaking method

technical field

The present invention relates to a method for breaking a substrate of brittle material, and more particularly to a method of forming an oblique crack when breaking a substrate of brittle material.

Background technique

The manufacturing process of a flat panel display panel or a solar cell panel generally includes a process of breaking a substrate (mother substrate) made of a brittle material such as a glass substrate, a ceramic substrate, or a semiconductor substrate. For such breakage, a method of forming a scribe line on the surface of the substrate using a scribing tool such as a diamond burr or a cutter wheel, and extending cracks (vertical cracks) from the scribe line toward the thickness of the substrate is widely used. When scribe lines are formed, the vertical cracks often fully propagate in the thickness direction to disconnect the substrate, however, the vertical cracks sometimes propagate only locally in the thickness direction. In the latter case, after the scribe line is formed, a stress application called a breaking process is performed. The vertical cracks are fully extended in the thickness direction by the breaking process, and the substrate is broken along the scribe lines.

As a method for extending a vertical crack by forming a scribe line as described above, there is known a method of forming a linear processing mark (such as Refer to Patent Document 1).

Prior art literature

patent documents

Patent Document 1: Japanese Unexamined Patent Publication No. 2015-74145

Contents of the invention

The technical problem to be solved by the invention

In most cases, the above-mentioned various brittle material substrates are fractured in the thickness direction perpendicular to the main surface of the substrate, but sometimes it is intentionally intended to be broken in such a manner that the fractured surface is inclined relative to the main surface of the substrate. Such breakage is achieved by spreading the crack obliquely with respect to the main surface of the substrate. However, in Patent Document 1, there is no method for forming the above-mentioned crack (oblique crack) by forming an auxiliary line. Nor has any disclosure given any revelations.

The present invention has been made in view of the above technical problems, and an object of the present invention is to provide a new method of forming oblique cracks in a brittle material substrate.

Solutions for technical problems

In order to solve the above-mentioned technical problems, a first aspect of the present invention relates to a method for forming oblique cracks in a brittle material substrate, characterized in that it includes: a groove line forming process, by making a scribing tool having a blade tip containing a ridge line sliding or rolling along a predetermined breaking position of one main surface of the brittle material substrate, thereby forming a groove line, the groove line being a linear groove portion; Cracks are generated, and in the groove line forming step, the ridge line of the scribing tool is inclined at a predetermined inclination angle from a predetermined direction in a horizontal plane, and a crack-free state is maintained directly below the groove line. The groove line is formed in such a manner that in the crack forming step, an oblique crack is propagated from the groove line, and the oblique crack is a crack inclined with respect to the main surface of the brittle material substrate.

A second aspect of the present invention is based on the method for forming oblique cracks in a brittle material substrate described in the first aspect, wherein the absolute value of the inclination angle is 1.0° to 3.0°.

A third aspect of the present invention is based on the method for forming oblique cracks in a brittle material substrate according to the first aspect or the second aspect, wherein the predetermined direction is a direction in which the groove lines are formed.

A fourth aspect of the present invention is based on the method for forming an oblique crack in a brittle material substrate according to the first aspect or the second aspect, wherein the breaking position is set in a curved shape, and the predetermined direction is the tangential direction of the break position.

A fifth aspect of the present invention relates to a method for breaking a brittle material substrate, which is characterized in that it includes: an oblique crack forming step, through the method for forming an oblique crack described in any one of the first to fourth aspects above , forming an oblique crack in the brittle material substrate; and a breaking step, breaking the brittle material substrate along the oblique crack.

Invention effect

According to the above-mentioned first to fifth aspects of the present invention, the brittle material substrate can be broken so that the fracture surface is inclined with respect to the main surface of the substrate by using a method of maintaining a crack-free state directly below the groove line.

Description of drawings

FIG. 1 is a top view of a brittle material substrate W illustrating a state after groove lines TL are formed.

(a) and (b) of FIG. 2 are diagrams schematically showing the configuration of the scribing tool 150 used for forming the groove line TL.

FIG. 3 is a zx partial sectional view including a vertical section of the groove line TL.

FIG. 4 is a plan view of a brittle material substrate W illustrating a state when auxiliary lines AL are formed.

FIG. 5 is a diagram schematically showing the configuration of a scribing device 100 used for forming auxiliary lines AL.

FIG. 6 is a plan view of a brittle material substrate W illustrating a state where an oblique crack IC propagates along with the formation of an auxiliary line AL.

FIG. 7 is a plan view of a brittle material substrate W illustrating a state where an oblique crack IC propagates along with the formation of an auxiliary line AL.

Fig. 8 is a zx partial sectional view of a vertical section including groove line TL and oblique crack IC.

FIG. 9 is a graph showing the relationship between the load applied to the diamond knife 151 when forming the groove line TL and the inclination angle δ of the formed cracks for each case where the value of the inclination angle θ is the same.

FIG. 10 is a graph showing the average value, maximum value and minimum value of the inclination angle δ of six kinds of cracks with different loads applied to the diamond burr 151 for the three horizontal inclination angles θ given to the diamond burr 151. picture.

FIG. 11 is a monolithic glass substrate obtained by applying a load of 1.6N to a diamond burr 151 with an inclination angle θ of -2.1° to form a groove line TL, and performing a breaking process after forming an oblique crack IC. Optical microscope image.

FIG. 12 is a schematic diagram of the formation positions of the groove line TL and the auxiliary line AL when the breaking position is set as a circle.

(a) and (b) of FIG. 13 are diagrams schematically showing the state of the brittle material substrate W after the groove lines TL and the auxiliary lines AL are formed in the manner shown in FIG. 12 .

FIG. 14 is a schematic diagram of the formation positions of groove lines TL and auxiliary lines AL in a mode different from that shown in FIG. 12 when the brittle material substrate W is formed into a truncated cone shape.

FIG. 15 is a schematic diagram of the formation positions of groove lines TL and auxiliary lines AL in a mode different from that shown in FIG. 12 when the brittle material substrate W is formed into a truncated cone shape.

detailed description

The method according to the embodiment of the present invention described below forms a crack (hereinafter referred to as an inclined crack) with respect to the main surface of the substrate for breaking the brittle material substrate W at a predetermined position (break position) of the brittle material substrate W. crack). Roughly speaking, in this method, an oblique crack is propagated from the groove line to the thickness direction of the substrate by forming a processed groove called a groove line at the breaking position, and then forming an auxiliary line to intersect the groove line. It should be noted that, in the present embodiment, the term "groove line" refers to a fine linear groove portion (recess) that becomes the starting position of formation of an oblique crack in the thickness direction of the substrate. The auxiliary line refers to a processing mark formed on the main surface of the brittle material substrate W so as to intersect the groove line, and serves as a starting point (trigger) when an oblique crack propagates directly below the groove line.

Hereinafter, a case where a plurality of linear breaking positions (breaking lines) parallel to a pair of opposite sides are preset for a rectangular brittle material substrate W will be described as an example. In addition, in the figures for explanation, it is appropriately marked that the formation and advancing direction of the auxiliary line AL is the positive direction of the x-axis, the forming and advancing direction of the groove line TL is the positive direction of the y-axis, and the vertical upward direction is the positive direction of the z-axis. The xyz coordinates in the right-handed system of .

＜Formation of groove lines＞

FIG. 1 is a top view (xy plan view) of a brittle material substrate W illustrating a state after groove lines TL are formed. FIG. 2 is a diagram schematically showing the configuration of a scribing tool 150 used for forming the groove line TL. FIG. 3 is a zx partial sectional view including a vertical section of the groove line TL. The formation positions of the groove lines TL shown in FIG. 1 correspond to break positions when the brittle material substrate W is viewed from the side of one main surface (upper surface) SF1 of the brittle material substrate W in a plan view.

In this embodiment, a scribing tool 150 including a diamond burr 151 is used to form the groove line TL. The diamond knife 151 is formed in, for example, a truncated pyramid shape as shown in FIG. 2 , and has a top surface SD1 (first surface) and a plurality of surfaces surrounding the top surface SD1. In more detail, as shown in (b) of FIG. 2 , these plural surfaces include side SD2 (second surface) and side SD3 (third surface). The top surface SD1 , the side surfaces SD2 and SD3 face different directions and are adjacent to each other. In the diamond knife 151 , a blade point PF2 is formed by a vertex PP formed by a ridge line PS formed by the side faces SD2 and SD3 and three faces of the top face SD1 and the side faces SD2 and SD3 . As shown in FIG. 2( a ), the diamond knife 151 is held such that the top surface SD1 is at the lowermost end on one end side of the rod-shaped (column-shaped) shank 152 .

In addition, in this embodiment, with the moving direction DA of the diamond knife 151 as a reference direction, the top surface SD1 is arranged in the xy plane as shown in (b) of FIG. In the state of the knife 151 , the angle θ when the diamond knife 151 is inclined clockwise by an angle θ with respect to the moving direction DA in the horizontal plane is defined as the inclination angle of the diamond knife 151 . The inclination angle θ is also the angle formed by the vertical plane formed by the ridge line PS of the diamond knife 151 and the direction D1 of the orthogonal axis of the horizontal plane and the moving direction DA of the diamond knife 151 . In addition, the inclination angle θ can take either positive or negative values. It should be noted that the counterclockwise direction is a direction in which the angle θ is positive when viewed from the handle 152 side.

In the case of using the scribing tool 150, as shown in (a) of FIG. The diamond knife 151 is brought into contact with the upper surface SF1 of the brittle material substrate W in a state where a predetermined inclination angle θ other than 0° is obtained. Then, while maintaining such a contact state, the scriber tool 150 is moved forward in the moving direction DA, and the blade edge PF2 of the diamond knife 151 is slid. Thereby, plastic deformation along the moving direction DA of the diamond knife 151 occurs. In this embodiment, the sliding motion of the diamond blade 151 that causes such plastic deformation is also referred to as the scribing motion of the diamond blade 151 .

As the diamond knife 151, a known diamond knife can be used. However, when forming the groove line TL, the absolute value of the inclination angle θ is set within a range of 1.0° to 3.0°. When the absolute value of the inclination angle θ is set to be larger than 3.0°, the groove line TL cannot be properly formed. Also, when the absolute value of the inclination angle θ is less than 1.0°, the propagation direction of the crack from the groove line TL is substantially perpendicular to the upper surface SF1 , and an oblique crack cannot be properly formed.

As shown in FIGS. 1 and 3 , the groove 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 upper surface SF1 of the brittle material substrate W is plastically deformed by sliding the diamond knife 151 in a state where the posture of the scribing tool 150 is symmetrical with respect to the moving direction DA. As a result, the groove lines TL are formed.

As shown in FIG. 1 , at a predetermined breaking position on the upper surface SF1 of the brittle material substrate W, the groove line TL is formed from the starting point T1 to the ending point T2 along the positive direction of the y-axis indicated by the arrow AR1 . In the following description, the range relatively closer to the starting point T1 in the groove line TL is also referred to as the upstream side, and the range relatively closer to the end point T2 is also referred to as the downstream side.

It should be noted that in FIG. 1, the starting point T1 and the ending point T2 of the groove line TL are set at positions separated from the ends of the brittle material substrate W. Depending on the type of the brittle material substrate W, the use of the cut pieces, etc., one or both of them are located at the end positions of the brittle material substrate W as appropriate. However, setting the starting point T1 at the end of the brittle material substrate W will cause the blade applied to the scribing tool 150 to be less than when the starting point T1 is set at a position separated from the end as illustrated in FIG. 1 . The impact of the tip PF2 increases, so care must be taken in consideration of the life of the tool tip PF2 and the occurrence of unexpected vertical cracks and oblique cracks.

In addition, the formation of the groove lines TL at each of the plurality of breaking positions may be sequentially formed using the scribing tool 150 in a processing device (not shown) including a scribing tool 150, or may be formed using a plurality of scribing tools 150. The groove lines TL are formed in parallel by processing devices at the same time.

When forming the groove line TL, the load applied by the scribing tool 150 (equivalent to the force of pressing the scribing tool 150 into the upper surface SF1 of the brittle material substrate W from vertically above) is set so that the groove line TL can be reliably formed. However, in the thickness direction DT of the brittle material substrate W, vertical cracks and oblique cracks from the groove line TL do not grow to such an extent ( FIG. 3 ).

In other words, the groove line TL is formed so that the brittle material substrate W is continuously connected in a direction intersecting the groove line TL (crack-free state) immediately below the groove line TL. It should be noted that, when the groove line TL is formed corresponding to this, in the vicinity of the groove line TL of the brittle material substrate W (in the range of about 5 μm to 10 μm from the groove line TL), as a result of plastic deformation, internal stress.

In the case where the inclination angle θ is positive, such residual internal stress has a tendency to segregate (incline) to the right side of the formation advancing direction of the groove line TL (the direction indicated by the arrow AR1 in FIG. 1 ), and at the inclination angle θ When it is negative, such residual internal stress tends to concentrate on the left side of the formation progress direction of the groove line TL (the direction indicated by the arrow AR1 in FIG. 1 ). 3, in the case of the former, there is a tendency that the groove portion formed as the groove line TL is concentrated below the left half (positive side in the x-axis direction) in the figure, and in the case of the latter, there is a tendency that It tends to concentrate below the right half of the figure (the negative side in the x-axis direction) of the groove portion.

For example, the groove line TL is formed by setting the load applied by the scribing tool 150 to a value smaller than when the same scribing tool 150 is used to form a scribe line with vertical cracks or oblique crack propagation.

In a crack-free state, even if a groove line TL is formed, no vertical cracks or oblique cracks will propagate from the groove line TL. Therefore, even if a bending moment acts on the brittle material substrate W, it is not the same as that formed with the groove line TL. Compared with cracks, it is less likely to be disconnected along the groove line TL.

＜Formation of auxiliary lines and propagation of oblique cracks＞

When the groove line TL is formed in the above-described manner, the auxiliary line AL is formed next.

FIG. 4 is a plan view of a brittle material substrate W illustrating a state when auxiliary lines AL are formed. FIG. 5 is a diagram schematically showing the configuration of a scribing device 100 used for forming auxiliary lines AL. 6 and 7 are plan views of a brittle material substrate W illustrating a state in which an oblique crack IC propagates along with the formation of an auxiliary line AL. Fig. 8 is a zx partial sectional view of a vertical section including groove line TL and oblique crack IC.

In this embodiment, as shown in FIG. 4 , the auxiliary line AL draws the upper surface of the brittle material substrate W along the positive direction of the x-axis (orthogonal to the groove line TL) shown by the arrow AR2 near the downstream side of the groove line TL. The surface SF1 is a processing mark formed by plastic deformation in the range from the starting point A1 to the ending point A2.

The auxiliary line AL is formed using the scribing tool 50 included in the scribing device 100 shown in FIG. 5 . The scribing device 100 mainly includes a workbench 1 for placing a brittle material substrate W, and a scribing head 2 for holding a scribing tool 50. The scribing tool 50 has a scribing wheel (knife wheel) 51, a pin 52 and a bracket. 53.

The scribing wheel 51 is disc-shaped (bacus bead-shaped), has a uniform blade point PF along its outer periphery, and is roughly triangular in cross-sectional view (including a ridge line and a pair of edges sandwiching the ridge line). inclined surface). The scribing wheel 51 typically has a diameter of the order of several mm. The pin 52 is vertically inserted into the position of the axis center AX of the scribing wheel 51 . The bracket 53 is held by the scribing head 2 and supports the pin 52 inserted into the scribing wheel 51 so that the scribing wheel 51 can rotate about the axis center AX. That is, the bracket 53 pivotally supports the scribing wheel 51 via the pin 52 so as to be rotatable about the axis center AX. In more detail, the bracket 53 supports the pin 52 horizontally so that the plane formed by the blade tip PF (outer peripheral portion) of the scribing wheel 51 extends in the vertical direction.

The blade tip PF is formed of a hard material such as cemented carbide, sintered diamond, polycrystalline diamond, or single crystal diamond, for example. From the viewpoint of reducing the surface roughness of the above-mentioned ridge lines and inclined surfaces, the entire scribing wheel 51 may be made of single crystal diamond.

When forming the auxiliary line AL, the scribing wheel 51 is in a state where the scribing wheel 51 is pressed against the upper surface SF1 of the brittle material substrate W that is horizontally placed on the other main surface SF2 and fixed on the table 1 of the scribing device 100 , the scribing head 2 holding the scribing tool 50 is moved in the scribing direction DP by a moving mechanism not shown, wherein the scribing direction DP is also the advancing direction for forming the auxiliary line AL indicated by the arrow AR2. Then, the scribing wheel 51 in pressure contact with the brittle material substrate W rolls around the axis center AX in the direction indicated by the arrow RT with the blade edge PF entering the brittle material substrate W at a point. Accordingly, as the scribing wheel 51 presses and rolls, plastic deformation occurs on the upper surface SF1 of the brittle material substrate W along the moving direction of the scribing wheel 51 .

In this embodiment, the pressure-contact rolling operation of the scribing wheel 51 that causes such plastic deformation is referred to as the scribing operation of the scribing wheel 51 . It should be noted that the load applied by the scribing wheel 51 to the brittle material substrate when the scribing wheel 51 is pressed against the upper surface SF1 can be adjusted by a load adjustment mechanism (not shown) included in the scribing head 2 .

If the auxiliary line AL in the above manner is formed under the condition that the load applied by the scribing wheel 51 is equal to or greater than a predetermined threshold value, each time the auxiliary line AL crosses the groove line TL, as shown by arrow AR3 in FIG. 6 , From the position of the intersection point C with each groove line TL as a starting point, the cracks from the groove line TL to the thickness direction DT of the brittle material substrate W are sequentially generated toward the intended propagation direction of the oblique crack IC (the upstream side of the groove line TL in FIG. 6 ). Propagation of oblique cracked ICs.

At this time, the propagation direction of the inclined crack IC in the thickness direction of the brittle material substrate W, that is, the slope of the inclined crack IC depends on the inclination angle θ of the diamond knife 151 when the groove line TL is formed. Specifically, as shown in FIG. 8, taking the propagation direction of the vertical crack VC that propagates when the groove line TL is formed at θ=0°, that is, the vertical downward (positive direction of the z-axis) as the reference direction, from the time of scribing When the ridge line PS is viewed toward the extending direction of the top surface (the downstream side of the groove line TL in this embodiment), the inclination angle δ of the inclined crack IC is defined by taking the clockwise direction as positive. At this time, if the inclination angle θ is positive, then δ is also positive. That is, the oblique crack IC inclines and expands toward the positive side in the x-axis direction from the groove line TL. On the other hand, if the inclination angle θ is negative, δ is also negative. That is, the oblique crack IC extends from the groove line TL to the negative side in the x-axis direction. It should be noted that the inclination direction of such an oblique crack IC corresponds to the above-mentioned side where the residual internal stress tends to concentrate when the groove line TL is formed. The reason for this is that the fine cracks, that is, the microcracks formed on the surface of the brittle material substrate W together with the formation of the auxiliary lines AL are guided directly below the groove lines, the residual internal stress is released, and the propagation of the inclined crack IC occurs.

As described above, the absolute value of the inclination angle θ of the diamond burr 151 is set in the range of 1.0° to 3.0°, and the absolute value of the inclination angle δ of the oblique crack IC is also set in the range of 1.0° to 3.0°. It should be noted that there is approximately a linear (linear) relationship between the inclination angle θ of the diamond burr 151 and the inclination angle δ of the oblique crack IC.

After the auxiliary line AL is formed, finally, as shown in FIG. 7 , the propagation of the oblique crack IC from the groove line TL is generated at all the breaking positions. That is, taking the formation of the auxiliary line AL as an opportunity (using the auxiliary line AL as a trigger), a secondary groove line TL is formed at each break position of the brittle material substrate W in which the groove line TL has been formed but has no cracks until now. Extended oblique crack IC.

It should be noted that the reason why the intended propagation direction of the oblique crack IC is the direction toward the upstream side of the groove line TL as described above is that when the groove line TL is formed using the scribe tool 150 including the diamond knife 151, the The oblique crack IC generated directly below the groove line TL has a property of spreading toward the side where the top surface SD1 exists. That is, the oblique crack IC has a property of spreading in a specific direction. In this embodiment in which the groove line TL is formed such that the top surface SD1 of the diamond cutter is arranged on the upstream side of the groove line TL, when the auxiliary line AL is formed, the oblique crack IC propagates on the upstream side of the groove line TL, but it is difficult to Expand in the opposite direction.

The brittle material substrate W formed with the oblique crack IC at the breaking position in the above-described manner is supplied to a predetermined breaking device not shown. In the breaking device, a bending moment is applied to the brittle material substrate W by so-called three-point bending or four-point bending to perform a breaking step of propagating the oblique crack IC to the lower surface SF2 of the brittle material substrate W. Through such a breaking process, the brittle material substrate W is broken at the breaking position.

As described above, according to the present embodiment, when the brittle material substrate is to be broken at a predetermined breaking position, the diamond cutter is tilted at the forming position corresponding to the breaking position, and the The formation of the groove line under the condition that vertical cracks and oblique cracks do not occur below, and then the auxiliary line is formed on the upstream side of the groove line, thereby allowing the oblique crack to propagate at the breaking position.

<Example>

The groove line TL was formed using a diamond burr 151 having a different inclination angle θ, and the auxiliary line AL was formed thereafter, and the inclination angle δ of the propagated crack was evaluated. Specifically, as the diamond burr 151, a diamond burr with a curvature radius of 9.5 μm of the ridge line PS of the blade tip PF2 was prepared, and the inclination angle θ was changed to three different types: -2.1°, 0.0°, and 1.9°. inclination angle, and change the load applied to the diamond cutter 151 to 6 different levels of 1.0N, 1.1N, 1.3N, 1.4N, 1.5N and 1.6N when forming the groove line TL, so that all 18 types In this case, the inclination angle δ is obtained.

As the brittle material substrate W, a glass substrate with a thickness of 0.2 mm was prepared. The moving speed of the scribing head 2 when forming the auxiliary line AL was set at 100 mm/sec. As the scribing wheel 51, a wheel diameter of 2.0 mm, a thickness of 0.65 mm, and a pin 52 insertion hole with a diameter of 0.8 mm were used. , The scribing wheel with a tip angle of 100°.

FIG. 9 is a graph showing the relationship between the load applied to the diamond knife 151 when forming the groove line TL and the inclination angle δ of the formed crack for each case where the value of the inclination angle θ is the same. In addition, FIG. 10 shows the average of the inclination angles δ of six types of cracks with different loads applied to the diamond burr 151 for the three horizontal inclination angles θ given to the diamond burr 151 based on the results shown in FIG. 9 . Graph of value (Ave.), maximum value (Max) and minimum value (Min).

9 and 10, it can be confirmed that the difference between the inclination angle θ given to the diamond knife 151 when the groove line TL is formed and the inclination angle δ of the crack extending from the groove line TL by forming the auxiliary line AL after forming the groove line TL is confirmed. There is roughly a positive correlation between them.

In addition, FIG. 11 is a single glass substrate obtained by applying a load of 1.6N to a diamond burr 151 with an inclination angle θ of -2.1° to form a groove line TL, and performing a breaking process after forming an oblique crack IC. Optical microscope image of the slice. More specifically, FIG. 11 shows a single piece obtained by breaking a glass substrate on which the groove line TL is formed so that the inclination angle θ is -2.1° and the front side when viewed in the drawing is the downstream side. . It can be confirmed from FIG. 11 that the disconnection plane is inclined in the direction shown as the case of θ<0 in FIG. 8 . This means that an oblique crack IC is formed in this direction.

＜Modifications＞

In the above-described embodiment, the auxiliary lines AL are formed after the groove lines TL are formed, but the formation order of the groove lines TL and the auxiliary lines AL may be reversed.

In addition, in the above-mentioned embodiment, the groove line TL and the auxiliary line AL are perpendicular to each other on the upper surface SF1 of the brittle material substrate W, but this is not a necessary method, as long as the inclination along with the formation of the auxiliary line AL can be realized ideally. If the crack propagates from the groove line TL, the groove line TL and the auxiliary line AL may also adopt a diagonal crossing manner.

Furthermore, in the above-mentioned embodiment, the intersection of the groove line TL and the auxiliary line AL is used as the starting point of the oblique crack propagation, but an oblique crack may be propagated by forming microcracks near the groove line TL. For example, on the upper surface SF1 of the brittle material substrate W, microcracks are formed by locally pressing the vicinity of the groove line TL with a predetermined pressing body to form an indentation. Accompanying the formation of the indentation, the microcracks extending from the indentation reach below the groove line TL, whereby the oblique cracks propagate directly below the above groove line.

In addition, in the above embodiment, the diamond knife 151 is slid with the axial direction AX2 of the shank 152 tilted forward in the moving direction DA, that is, with the top surface SD1 facing rearward in the moving direction DA, thereby passing the scribe line. The tool 150 forms the groove line TL. However, instead of the above-mentioned method, the diamond cutter may be set with the axial direction AX2 of the shank 152 inclined backward in the moving direction DA, that is, with the top surface SD1 facing forward in the moving direction DA. 151 slides to form the groove line TL.

However, in the case of such an aspect, unlike the above-described embodiment, the intended propagation direction of the oblique crack is on the downstream side of the groove line TL. For this reason, in such an aspect, the auxiliary line AL is formed in the vicinity of the upstream side of the groove line TL. In addition, in such a method, the propagation direction of the vertical crack VC that propagates when the groove line TL is formed at θ=0°, that is, the vertical downward direction (the positive direction of the z-axis) is taken as a reference direction, from the ridge line PS at the time of scribing Looking toward the extending direction of the top surface (the upstream side of the groove line TL in this embodiment), the inclination angle δ of the oblique crack IC is defined by taking the clockwise direction as positive. At this time, if the inclination angle θ is positive, δ is also just. That is, the oblique crack IC inclines and expands toward the positive side in the x-axis direction from the groove line TL. On the other hand, if the inclination angle θ is negative, δ is also negative. That is, the oblique crack IC extends from the groove line TL to the negative side in the x-axis direction. It should be noted that the inclination direction of such an oblique crack IC corresponds to the above-mentioned side where the residual internal stress tends to concentrate when the groove line TL is formed.

Also in this case, as in the above-described embodiment, the propagation of the oblique crack from the groove line TL appropriately occurs in the intended propagation direction of the oblique crack IC.

Optionally, in the above-mentioned embodiment, the diamond knife 151 is used to form the groove line TL, but instead of the above-mentioned method, the method of forming the groove line TL by pressing and rolling the scribing wheel 51 of the scribing device 100 can also be adopted. . In this case, the angle formed by the vertical plane including the ridgeline PF of the scribing wheel and the extending direction of the orthogonal axis of the horizontal plane and the moving direction of the scribing tool is an angle of inclination. Viewed from the support side, the counterclockwise direction is Angle θ is the positive direction.

However, also in this form, unlike the above-described embodiment, the intended propagation direction of the oblique crack IC is on the downstream side of the groove line TL. Therefore, in these forms, the scribing wheel 51 is tilted so that the inclination angle θ is negative as in the above-described second embodiment, and the auxiliary line AL is formed in the vicinity of the upstream side of the groove line TL in this state. Similar to the above-described embodiment, the propagation of the oblique crack from the groove line TL occurs appropriately in the intended propagation direction of the oblique crack IC.

In addition, in the above-mentioned form, the propagation direction of the vertical crack VC that propagates when the groove line TL is formed at θ = 0°, that is, the vertical downward direction (z-axis positive direction) is taken as a reference direction, and from the downstream side of the groove line TL Observe that the inclination angle δ of the oblique crack IC is defined by taking the clockwise direction as positive. At this time, if the inclination angle θ is positive, δ is also positive. That is, the oblique crack IC inclines and expands toward the positive side in the x-axis direction from the groove line TL. On the other hand, if the inclination angle θ is negative, δ is also negative. That is, the oblique crack IC extends from the groove line TL to the negative side in the x-axis direction. It should be noted that the inclination direction of such an oblique crack IC corresponds to the above-mentioned side where the residual internal stress tends to concentrate when the groove line TL is formed.

<Applied to curved breaks>

In the above embodiment, the breaking position for breaking the brittle material substrate W is linear, but in the above embodiment, the formation of oblique cracks can also be applied to the case where the breaking position is made curved. Next, an example will be described in which the breaking position is defined as a circle, and the brittle material substrate W is cut into a truncated cone shape along the breaking position.

FIG. 12 is a diagram showing the formation positions of the slot line TL and the auxiliary line AL when the breaking position is set as a circle. In this case, on the upper surface SF1 of the brittle material substrate W, the groove line TL is formed from the starting point T1 along the predetermined circular breaking position. The moving direction DA of the diamond knife 151 at the angle θ is provided with an inclination angle θ (predetermined direction D1 ) based on the tangential direction.

Then, the groove line TL is formed in a circular shape while maintaining the inclination angle θ. However, the end point T2 is set at a position slightly shifted outward from the start point T1. When the auxiliary line AL is formed so as to intersect the groove line TL near the end point T2, the oblique crack IC propagates along the groove line TL from the intersection point toward the starting point T1.

FIG. 13 is a diagram schematically showing a state of a brittle material substrate W after forming groove lines TL and auxiliary lines AL in the manner shown in FIG. 12 . The inclined crack IC formed as shown in FIG. 12 is inclined toward the outside of the substrate with respect to the thickness direction of the brittle material substrate W, as shown in FIG. 13( a ). At this time, the region surrounded by the oblique crack IC has a truncated conical shape (trapezoid in cross-sectional view).

In such a case, when a force is applied from above the brittle material substrate W to the region surrounded by the oblique crack IC as indicated by the arrow AR4, the oblique crack IC further expands. Finally, when the oblique crack IC reaches the reverse surface (lower surface SF2), as shown by arrow AR5 in (b) of FIG.

FIGS. 14 and 15 are diagrams showing the formation positions of groove lines TL and auxiliary lines AL in a manner different from that shown in FIG. 12 when the brittle material substrate W is formed into a truncated cone shape. In the aspect shown in FIG. 14, the end point T2 is provided in the position shifted inward from the start point T1. In this case also, when the auxiliary line AL is formed so as to intersect the groove line TL near the end point T2, the propagation of the oblique crack IC along the groove line TL occurs from the intersection point toward the starting point T1.

The method shown in Figure 12 is generally applicable to the situation where it is desired to obtain a part opened into a truncated conical shape, while the method shown in Figure 14 is generally applicable to the case where it is desired to obtain a part other than the part opened into a truncated conical shape . In any case, similarly, the location where the auxiliary line AL is not formed is made the object of acquisition.

In addition, in the aspect shown in FIG. 15, the end point T2 is set so that the groove line TL itself may overlap in the vicinity of the start point T1. In such a case, even if the auxiliary line AL is not formed, and the overlapping portion of the groove line TL functions as the auxiliary line AL, the truncated conical unitary line similar to the case shown in FIG. The opening and taking of the film.

It should be noted that, in the above example, the breaking position is set as a circle, but in the case of setting the breaking position as another curved shape, it can also be formed by giving an inclination angle θ with respect to the tangential direction. The groove line TL makes the inclined crack propagate along the break position.

Explanation of reference signs

1 workbench

2 scribe heads

50 line tool

51 marking wheel

100 marking device

150 line tool

151 Diamond Carving Knife

AL auxiliary line

IC inclined crack

PF (score wheel) tip

PF2 (diamond carving knife) tip

PP (diamond cutter's) apex

PS (diamond cutter) ridge line

TL slot line

W Brittle Material Substrate

Claims (5)

1. A method for forming an inclined crack in a brittle material substrate, for forming an inclined crack in a brittle material substrate, characterized in that, comprising: A groove line forming step of forming a groove line by sliding or rolling a scribing tool having a blade tip including a ridge line along a predetermined breaking position on one main surface of the brittle material substrate, the groove line being a line shaped groove; and a crack forming process that causes a crack directly below the groove line, In the groove line forming step, in a state where the ridge line of the scribing tool is inclined at a predetermined inclination angle from a predetermined direction in a horizontal plane, a crack-free state is maintained directly below the groove line. way to form the groove lines, In the crack forming step, an oblique crack that is inclined with respect to the main surface of the brittle material substrate is propagated from the groove line. 2. The method for forming an inclined crack in a brittle material substrate according to claim 1, wherein, The absolute value of the inclination angle is 1.0°˜3.0°. 3. The method for forming oblique cracks in the brittle material substrate according to claim 1 or 2, characterized in that, The predetermined direction is a direction in which the formation of the groove line proceeds. 4. The method for forming oblique cracks in the brittle material substrate according to claim 1 or 2, characterized in that, The breaking position is defined as a curved line, The predetermined direction is a tangential direction to the disconnected position. 5. A method for breaking a brittle material substrate, for breaking a brittle material substrate, characterized in that it comprises: an oblique crack forming step, forming an oblique crack in the brittle material substrate by the method for forming an oblique crack in the brittle material substrate according to any one of claims 1 to 4; and A breaking process, breaking the brittle material substrate along the inclined crack.