TWI695769B - Method for forming vertical crack of brittle material substrate and breaking method of brittle material substrate - Google Patents

Abstract

The present invention provides a method capable of forming vertical cracks with high certainty on a brittle material substrate.

A method of forming a vertical crack on a brittle material substrate includes: a groove line forming step, a groove line forming a linear groove portion on a main surface; and an auxiliary line forming step, which is formed by rolling a scoring wheel by crimping and rolling Auxiliary line where groove lines cross, the scoring wheel is provided with blade tips with a plurality of grooves at equal intervals on the outer periphery; in the groove line forming step, the groove lines are formed in a manner to maintain a crack-free state below; In the auxiliary line forming step, the auxiliary line is formed in a state where the scoring wheel is inclined at a predetermined inclination angle with respect to the forming direction of the auxiliary line in the horizontal plane; starting from the intersection of the two lines, a vertical crack from the groove line is generated Of stretch.

Description

Method for forming vertical crack of brittle material substrate and breaking method of brittle material substrate

The invention relates to a method for breaking a brittle material substrate, in particular to a method for forming a vertical crack when the brittle material substrate is broken.

The manufacturing process of a flat display panel, a solar cell panel, or the like generally includes a step of dividing a substrate (mother substrate) made of a brittle material such as a glass substrate, a ceramic substrate, and a semiconductor substrate. In this breaking, the following technique is widely used, that is, a scribing tool such as a diamond point (diamond sharp knife) or a cutter wheel is used to form a scribing line on the surface of the substrate, so that a crack (vertical crack) moves from the scribing line to the substrate Stretch in the thickness direction. When forming the scribe line, although the vertical crack may fully extend in the thickness direction to break the substrate, the vertical crack may only partially extend in the thickness direction. In the latter case, after the scribe line is formed, stress application called a cracking step is performed. Through the cracking step, the vertical crack is fully extended in the thickness direction, so that the substrate is broken along the scribe line.

As the above-mentioned method of extending a vertical crack by forming a scribe line, there are the following well-known methods, which form a linear processing mark (also referred to as an auxiliary line, which serves as a starting point (trigger) during vertical crack extension (for example, refer to Patent Literature 1).

Patent Literature 1: Japanese Patent Laid-Open No. 2015-74145

For example, the method of using auxiliary lines disclosed in Patent Document 1 has the following advantages over the method of not using this method, that is, when forming a scribe line for breaking, the cutter wheel or diamond can be used The force (impact) applied by the scribing tool such as sharp points to the substrate is set to be small. For example, even if a weak force (load) that makes it difficult to extend a vertical crack acts to form a scribe line, the auxiliary line can be used as a trigger to properly extend the vertical crack from the scribe line.

However, especially in the case of breaking the brittle material substrate in the manufacturing process of the mass product, when a high yield (reliable breaking) is required, the technique disclosed in Patent Document 1 aims at starting from the auxiliary line The extension of the vertical crack may not guarantee its reliability (reliability).

The present invention has been accomplished in view of the above-mentioned problems, and its object is to provide a method capable of forming a vertical crack with high certainty at a predetermined breaking position of a brittle material substrate.

In order to solve the above-mentioned problems, the invention of claim 1 is a method of forming a vertical crack at a breaking position when the brittle material substrate is divided in the thickness direction, and is characterized by comprising: a groove line forming step in which the brittle material A groove line of a linear groove portion is formed on one main surface of the substrate; and an auxiliary line forming step is to form an auxiliary line of a processing mark crossing the groove line by pressing and rolling the scoring wheel on the one main surface, The scoring wheel has a blade tip with a plurality of grooves at equal intervals on the outer peripheral portion; in the groove line forming step, the groove line is formed in a manner to maintain a crack-free state under the groove line; In the line forming step, the auxiliary line is formed in a state where the scoring wheel is inclined at a predetermined inclination angle with respect to the forming direction of the auxiliary line in the horizontal plane; starting from the intersection of the groove line and the auxiliary line, the Vertical cracks extend from the groove line to the thickness direction of the brittle material substrate.

The invention of claim 2 is in the method of forming a vertical crack of a brittle material substrate according to claim 1, in the auxiliary line forming step, the auxiliary line is formed inside the brittle material substrate along with the auxiliary line during the formation of the auxiliary line An internal crack region where a plurality of auxiliary cracks are generated on the side; a predetermined extension direction side of a vertical crack formed on the groove line with the internal crack region To determine the formation position of the trench line and the auxiliary line.

The invention of claim 3 is the method of forming the vertical crack of the brittle material substrate described in claim 2, in which the auxiliary line is formed to intersect the groove line near the side opposite to the predetermined extension direction of the vertical crack on the groove line .

The invention of claim 4 is in the method of forming a vertical crack of a brittle material substrate described in claim 2 or claim 3, in the auxiliary line forming step, the front side of the direction of travel of the scoring wheel is in the horizontal plane from the The direction of formation of the auxiliary line is inclined toward the side opposite to the predetermined extension direction of the vertical crack on the groove line.

The invention of claim 5 is the method of forming a vertical crack of the brittle material substrate according to any one of claim 1 to claim 4, wherein the inclination angle is 1.0° or more and 2.5° or less.

The invention of claim 6 is the method of forming the vertical crack of the brittle material substrate according to any one of claim 1 to claim 5, after forming the trench line, the auxiliary line is formed.

The invention of claim 7 is a method of dividing a brittle material substrate in the thickness direction, characterized by comprising: a vertical crack formation step, which is the formation of a vertical crack described in any one of claim 1 to claim 6 Method, forming a vertical crack in the brittle material substrate; and a cracking step, which is to break the brittle material substrate along the vertical crack.

According to the inventions of claim 1 to claim 7, since the vertical crack can be extended with high certainty at the predetermined breaking position of the brittle material substrate, the brittle material substrate can be reliably broken at the breaking position.

1‧‧‧platform

2‧‧‧Scribe head

50、150‧‧‧Scribe tool

51‧‧‧Scribe wheel

52‧‧‧pin

53‧‧‧Retainer

100‧‧‧scoring device

151‧‧‧Diamond point

152‧‧‧handle

A1‧‧‧(Auxiliary line AL) start point

A2‧‧‧(Auxiliary line AL) end point

AL‧‧‧Auxiliary line

AX‧‧‧Axis center

C‧‧‧ (the intersection of groove line TL and auxiliary line AL)

CR‧‧‧ Internal crack area

DP‧‧‧Scribe direction

PF‧‧‧ (scoring wheel 51 of) blade tip

SF1‧‧‧ (brittle material substrate W) one main surface (top)

SF2‧‧‧ (brittle material substrate W) the other main surface (below)

T1‧‧‧(Trench line TL) start point

T2‧‧‧ (the end of the trench line TL)

TL‧‧‧Trench line

VC‧‧‧Vertical crack

W‧‧‧brittle material substrate

FIG. 1 is a diagram schematically showing the configuration of the scribing device 100.

FIG. 2 is an enlarged view of the scoring wheel 51 in part A. FIG.

FIG. 3 is a diagram showing the posture of the scoring wheel 51 in the scoring device 100.

FIG. 4 is a plan view illustrating the brittle material substrate W after the trench line TL is formed.

FIG. 5 is a diagram schematically showing the structure of the diamond point 150 used in the formation of the trench line TL.

FIG. 6 is a partial cross-sectional view of zx including a vertical cross-section of the trench line TL.

FIG. 7 is a plan view illustrating the brittle material substrate W in the state when the auxiliary line AL is formed.

FIG. 8 is a plan view illustrating the brittle material substrate W in the extended state of the vertical crack VC accompanying the formation of the auxiliary line AL.

FIG. 9 is a plan view illustrating the brittle material substrate W in the extended state of the vertical crack VC accompanying the formation of the auxiliary line AL.

FIG. 10 is a partial cross-sectional view of zx including a vertical section of the trench line TL and the vertical crack VC.

FIG. 11 is a schematic diagram showing the state near the auxiliary line AL when a vertical crack VC is formed.

FIG. 12 is a photographic example of a brittle material substrate W with an inclination angle θ of 1.4° to form an auxiliary line AL.

FIG. 13 is a photographic example of a brittle material substrate W with an inclination angle θ of 2.5° to form an auxiliary line AL.

FIG. 14 is a graph plotting the VC establishment rate against the load applied when the auxiliary line AL is formed for each inclination angle θ different from the embodiment.

15 is a plan view of the brittle material substrate W in the reference example.

Figure 16, for the reference example, the VC establishment rate is relatively negative when the auxiliary line AL is formed Contains the picture depicted.

<scoring device>

FIG. 1 is a diagram schematically showing the structure of a scribing device 100 used in an embodiment of the present invention. The scribing apparatus 100 is generally used when the brittle material substrate W such as a glass substrate, a ceramic substrate, a semiconductor substrate, etc. is divided at a predetermined breaking position in the thickness direction DT to reduce the size, but this embodiment In the form, the scoring device 100 is mainly used to form an auxiliary line AL (see FIG. 7 etc.) for extending a vertical crack at a breaking position on one of the main surfaces SF1 side of the brittle material substrate W. In this embodiment, the auxiliary line AL is formed at a position crossing the trench line TL (see FIG. 4 and the like) formed at the breaking position on the main surface SF1 side, below the trench line TL The processing mark as the starting point (trigger) when the vertical crack is extended. In addition, the so-called groove line TL is a fine linear groove portion (concave portion) below which becomes a vertical crack formation position. The details of the auxiliary line AL and the trench line TL will be described below.

The scoring device 100 mainly includes a platform 1 on which a brittle material substrate W is placed, and a scoring head 2 for holding a scoring tool 50.

The scoring device 100 includes one or both of a platform moving mechanism and a scoring head moving mechanism (not shown). By providing such mechanisms, the scoring head 2 can hold the scoring tool 50 in the scoring device 100 In this state, it moves relative to the platform 1 in the horizontal plane. In the following, to simplify the description, when performing the scoring operation, the scoring head 2 is moved relative to the stage 1 in the scoring direction DP shown in FIG. 1.

The scoring tool 50 is a tool for scoring the brittle material substrate W. The scoring tool 50 has a scoring wheel (cutter wheel) 51, a pin 52, and a holder 53.

The scoring wheel 51 has a disc shape (abacus bead shape), and has a blade tip PF along its outer periphery. FIG. 2 is an enlarged view of the scoring wheel 51 in part A shown in FIG. The outer circumference of the scoring wheel 51 is macroscopically observed as a uniform circle as shown in FIG. 1, but in fact, as shown in FIG. 2, a plurality of fine grooves G are provided at equal intervals. That is, the scoring wheel 51 is a so-called grooved wheel. In addition, the blade tip PF is attached to a region other than the groove G, and is formed into a substantially triangular shape in cross-sectional view formed by a pair of inclined surfaces sandwiching the ridge line and the ridge line.

The scoring wheel 51 typically has a groove G having a diameter of about several millimeters and a depth of about hundreds of hundreds of degrees. The pin 52 is inserted vertically at the position of the axis center AX of the scoring wheel 51. The holder 53 is held by the scoring head 2 and supports the pin 52 inserted through the scoring wheel 51 so that the scoring wheel 51 can rotate about the axis center AX. That is, the holder 53 supports the scoring wheel 51 integrated with the pin 52 so as to be rotatable about the axis center AX. In more detail, the holder 53 supports the pin 52 horizontally so that the surface 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 hard material such as cemented carbide, sintered diamond, polycrystalline diamond or single crystal diamond. From the viewpoint of making the surface roughness of the ridgeline and the inclined surface small, the entire scribing wheel 51 may be made of single crystal diamond.

In the scoring device 100 having the above-described structure, the scoring wheel 51 is pressure-contacted to one of the main surfaces of the brittle material substrate W fixed on the platform 1 with the other main surface SF2 as the mounting surface (hereinafter , Also referred to as above) In the state of SF1, the scoring head 2 holding the scoring tool 50 is moved in the scoring direction DP. According to this, the scoring wheel 51 in the state of being pressed against the brittle material substrate W is rolled around the axis center AX in the direction indicated by the arrow RT with the blade tip PF slightly intruding into the brittle material substrate W. With this, on the upper surface SF1 of the brittle material substrate W, with the scoring wheel 51 The crimping rolling produces plastic deformation along the moving direction of the scoring wheel 51. In the present embodiment, the pressure rolling operation of the scoring wheel 51 caused by the plastic deformation is referred to as the scoring operation of the scoring wheel 51. When the scoring wheel 51 is pressed against the upper surface SF1, the load applied to the brittle material substrate by the scoring wheel 51 can be adjusted by a load adjustment mechanism (not shown) provided in the scoring head 2.

FIG. 3 is a diagram showing the posture (inclination) of the scoring wheel 51 in the scoring device 100. In the present embodiment, with the scoring direction DP as a reference direction, the scoring wheel 51 is held in the scoring head 2 with respect to the scoring direction DP, and the angle θ when the angle θ is inclined clockwise in the horizontal plane with respect to the scoring direction DP, It is defined as the inclination angle of the scoring wheel 51. The inclination angle θ is also the angle between the extending direction D1 of the perpendicular axis formed by the blade tip PF (edge line) of the scoring wheel 51 and the horizontal axis and the scoring direction DP.

In this embodiment, as described above, when a brittle material substrate W is cut, although the auxiliary line AL is formed, the inclination angle θ when the auxiliary line AL is formed is deliberately set to a value greater than 0°. In addition, by determining the tilt angle θ in this manner, the auxiliary line AL is formed to have inherent properties and states, the details of which are described below.

Specifically, in forming the auxiliary line AL, the scoring device 100 whose inclination angle θ is set in the range of 1.0° to 2.5° is used.

In addition, the inclination of the scoring wheel 51 may be realized by tilting the scoring head 2 or may be realized by changing the installation angle of the scoring tool 50 relative to the scoring head 2 , Or may be implemented in other forms.

<The formation sequence of vertical cracks>

Next, the procedure for forming a vertical crack at the breaking position using the auxiliary line AL performed in this embodiment will be described. 4 to 10 are diagrams showing the formation of the vertical crack in stages. To In the following, a case where a plurality of breaking positions (breaking lines) parallel to a set of opposite sides is preset for a rectangular brittle material substrate W will be described as an example. In addition, in each figure, the right-handed xyz coordinates with the formation travel direction of the auxiliary line AL as the positive x-axis direction, the formation travel direction of the groove line TL as the negative y-axis direction, and the vertical upward direction as the positive direction of the z-axis are marked. .

First, the groove line TL is formed using the scoring tool 50 whose inclination angle θ is set to 0°. FIG. 4 is a plan view (xy plan view) of the brittle material substrate W after the trench line TL is formed. FIG. 5 is a diagram schematically showing the configuration of the scoring tool 150 used for forming the trench line TL. FIG. 6 is a partial cross-sectional view of zx including a vertical cross-section of the trench line TL. The formation position of the trench line TL shown in FIG. 4 corresponds to the breaking position when the brittle material substrate W is viewed from above on the upper surface SF1 side.

In the present embodiment, a scribe tool 150 with a diamond point 151 is used to form the trench line TL. The diamond point 151, for example, as shown in FIG. 5, is formed in a pyramidal trapezoid shape, 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 FIG. 5(b), the plural surfaces include 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 mutually different directions and are adjacent to each other. At the diamond point 151, the blade tip PF2 is formed by the ridge line PS formed by the side surfaces SD2 and SD3, and the vertex PP where the three surfaces of the top surface SD1, the side surfaces SD2 and SD3 intersect. As shown in FIG. 5( a ), the diamond tip 151 is held on one end side of the rod-shaped (columnar) shank 152 with the top surface SD1 as the lowermost end.

When the scribing tool 150 is used, as shown in FIG. 5(a), the state in which the axis direction AX2 of the handle 152 is tilted by a predetermined angle from the vertical direction toward the front of the moving direction DA (positive direction of the y-axis) is to make The posture of the top surface SD1 toward the rear of the moving direction DA (negative direction of the y-axis) makes the diamond point 151 abut on the upper surface SF1 of the brittle material substrate W. Then, while keeping the abutment While moving the scoring tool 150 forward in the moving direction DA, the blade tip PF2 of the diamond point 151 slides. Thereby, plastic deformation along the moving direction DA of the diamond point 151 occurs. In this embodiment, the sliding action of the diamond point 151 caused by the plastic deformation is also referred to as the diamond point 151 scoring action.

As shown in FIGS. 4 and 6, the trench line TL is a fine linear groove formed on the upper surface SF1 of the brittle material substrate W so as to extend in the y-axis direction. The groove line TL is formed by sliding the diamond point 151 to plastically deform the upper surface SF1 of the brittle material substrate W in a state where the posture of the scoring tool 150 is symmetrical with respect to the moving direction DA. At this time, as shown schematically in FIG. 6, the trench line TL is formed as a groove portion having a cross-sectional shape substantially perpendicular to the extending direction of a line-symmetrical shape.

As shown in FIG. 4, the trench line TL is formed at the breaking position defined by the upper surface SF1 of the brittle material substrate W, and is formed from the starting point T1 in the negative direction of the y-axis shown by the arrow AR1 to the ending point T2. Hereinafter, the range relatively close to the starting point T1 in the trench line TL is also referred to as the upstream side, and the range relatively close to the end point T2 is referred to as the downstream side.

In addition, in FIG. 4, although the starting point T1 and the ending point T2 of the trench line TL are set at positions slightly away from the end of the brittle material substrate W, this is not a necessary aspect, and it can also be regarded as a breaking target As for the type of the brittle material substrate W or the use of the single piece after breaking, either or both of them are appropriately set at the end positions of the brittle material substrate W. However, when the starting point T1 is set at the end of the brittle material substrate W, as compared with the case where the position slightly away from the end is taken as the starting point T1 as illustrated in FIG. 4, since it is applied to the scoring tool 150 The impact of the blade tip PF2 becomes larger, so care must be taken with regard to the life of the blade tip PF2 and the possibility of unexpected vertical cracks.

In addition, the formation of the groove lines TL at each of the plurality of breaking positions may be formed by using the scoring tool 150 in sequence in a processing device (not shown) provided with a scoring tool 150, or a plurality of A processing device for forming two trench lines TL is formed in parallel at the same time.

During the formation of the trench line TL, the scoring tool is set in such a way that the formation of the trench line TL can be surely performed but the vertical cracks extending from the trench line TL are not generated in the thickness direction DT of the brittle material substrate W The load applied by 150 (equivalent to the force that presses the scoring tool 150 into the upper surface SF1 of the brittle material substrate W from above vertically) (FIG. 6).

In other words, the formation of the trench line TL is performed in such a manner that the brittle material substrate W is continuously connected in the direction crossing the trench line TL (the crack-free state) below the trench line TL. In addition, when the trench line TL is formed in the above-described manner, in the vicinity of the trench line TL of the brittle material substrate W (in the range of approximately 5 μm to 10 μm from the trench line TL), internal stress remains as a result of plastic deformation .

The formation of the trench line TL is achieved, for example, by setting the load applied by the scoring tool 150 to a value smaller than when the same scoring tool 150 is used to form a scribe line with vertical crack extension.

In the crack-free state, even if the trench line TL is formed, there will be no extension of the vertical crack from the trench line TL, so even if the bending moment acts on the brittle material substrate W, compared with the case where the vertical crack is formed , It is also difficult to produce a break along the trench line TL.

After forming the trench line TL, the auxiliary line AL is formed by the scoring device 100 provided with the scoring tool 50 whose inclination angle θ is set in the range of 1.0° to 2.5°. FIG. 7 is a plan view illustrating the brittle material substrate W in the state when the auxiliary line AL is formed. Figures 8 and 9 illustrate the accompanying assistant A top view of the brittle material substrate W in the state where the vertical crack VC formed by the auxiliary line AL extends. FIG. 10 is a partial cross-sectional view of zx including a vertical section of the trench line TL and the vertical crack VC.

In this embodiment, the auxiliary line AL, as shown in FIG. 7, is near the downstream side of the trench line TL, in the positive x-axis direction indicated by the arrow AR2 (in a manner orthogonal to the trench line TL), A machining mark formed by plastic deformation on the upper surface SF1 of the brittle material substrate W within the range from the starting point A1 to the ending point A2.

In more detail, the formation of the auxiliary line AL is performed in such a manner that the formation traveling direction of the auxiliary line AL indicated by the arrow AR2 coincides with the scribing direction DP (positive x-axis direction). Therefore, the formation of the auxiliary line AL is performed in a state where the forward direction of the scoring wheel 51 is inclined to the y-axis negative direction side downstream of the position where the auxiliary line AL is formed.

At this time, in a state where the scoring wheel 51 is pressed against the upper surface SF1 of the brittle material substrate W, the scoring head 2 moves in the scoring direction DP, so that the scoring wheel 51 rolls. As a result, the auxiliary line AL is formed as a machining mark intermittent in the x-axis direction, and the larger the inclination angle θ, the wider the width (see FIGS. 12(a) and 13(a)), and the cross-sectional shape is asymmetric (See Fig. 12(b)). In addition, the formation of the auxiliary line AL is also the same as the case of forming the trench line TL, and the purpose is not to extend the vertical crack immediately below it. Therefore, the load applied by the wheel 51 at the time of forming the auxiliary line AL may also be It is set to a smaller value than when using the same scoring wheel 51 to form a scoring line with vertical crack extension.

When the auxiliary line AL is formed as described above under the condition that the load applied by the scoring wheel 51 is above a predetermined threshold, and the auxiliary line AL crosses the trench line TL, as shown by arrow AR3 in FIG. 8 , From the position of the intersection point C with each trench line TL toward the predetermined extension direction of the vertical crack VC (in the case of FIG. 8, it is the upstream side of the trench line TL) in order As shown in FIG. 10, the vertical crack VC extends from the trench line TL to the thickness direction DT of the brittle material substrate W.

Finally, as shown in FIG. 9, at all the breaking positions, vertical cracks VC extending from the trench line TL are generated. That is, with the formation of the auxiliary line AL (the auxiliary line AL becomes a trigger), at each breaking position of the brittle material substrate W in which the trench line TL has been formed but is in a crack-free state, a secondary groove is formed Vertical crack VC where the slot line TL extends.

This is because in the case where the groove line TL is formed using the scribing tool 150 with the diamond point 151, the vertical crack VC generated immediately below the groove line TL has the property of extending toward the top surface SD1 side. That is, the vertical crack VC generated near the auxiliary line AL has the property of extending in a specific direction. In the present embodiment in which the trench line TL is formed by arranging the top surface SD1 of the diamond point on the upstream side of the trench line TL, after the auxiliary line AL is formed, a vertical crack VC is formed on the upstream side of the trench line TL Although it stretches, it is difficult to stretch in the opposite direction.

In this manner, the brittle material substrate W with the vertical crack VC formed at the breaking position is sent to a predetermined breaking device (not shown). In the fracturing device, a bending moment is applied to the brittle material substrate W by a so-called three-point bending or four-point bending method, thereby performing a cracking step of extending the vertical crack VC to the SF2 below the brittle material substrate W . Through this breaking step, the brittle material substrate W is broken at the breaking position.

As in the case of the above sequence, since the formation of the trench line TL at the breaking position does not accompany the extension of the vertical crack VC, the vertical crack is formed at the same time as the formation of the conventional and scoring line. Compared with the situation, there is an advantage that the load applied by the scoring tool 50 can be reduced. This advantage contributes to the longevity of the scoring tool 50 used in the breaking of the breaking position.

<Details of vertical crack extension>

FIG. 11 is a schematic view showing a state near the auxiliary line AL when the vertical crack VC is formed by forming the auxiliary line AL after the formation of the continuous trench line TL. In addition, FIGS. 12 and 13 are photographic examples of the brittle material substrate W on which the auxiliary line AL is formed. In addition, FIG. 12 is an example of photography when the inclination angle θ is set to 1.4°, and FIG. 13 is an example of photography when the inclination angle θ is set to 2.5°.

When the auxiliary line AL is formed in the scribing direction DP, that is, the positive x-axis direction (direction perpendicular to the y-axis), the entire position of the auxiliary line AL is formed in the brittle material substrate W, on the positive side of the auxiliary line AL in the y-axis direction (FIG. In 11, on the side above the auxiliary line AL, an internal crack region CR in which countless auxiliary cracks AC starting from the auxiliary line AL are formed is formed. This can also be confirmed in, for example, FIGS. 12(a) and 13(a) when the brittle material substrate W is viewed from the upper SF1 side.

In more detail, the internal crack region CR is generated starting from any position of the auxiliary line AL as a starting point, and appears in a range from the (+y, -z) direction to the -z direction. This can also be confirmed from FIG. 12(b) and FIG. 13(b). The internal crack region CR is formed in a range of about several tens of μm at maximum in the positive direction of the y-axis of the auxiliary line AL from the auxiliary line AL when the upper surface SF1 is viewed from above. However, although the illustration is omitted in FIG. 11, the formation of auxiliary cracks is a phenomenon that occurs with a probability, so although the ratio is small, auxiliary cracks AC may also occur in other ranges.

Since the internal crack region CR is formed in the entire area of the auxiliary line AL, the internal crack region CR is also generated with a high probability near the intersection of the auxiliary line AL and the trench line TL. As described above, since the internal stress remains in the vicinity of the trench line TL, when the auxiliary line is formed so that the internal crack region CR is formed on the predetermined extension direction side of the vertical crack VC of the trench line TL, the internal crack region CR is formed in the area where residual internal stress exists, and the residual internal stress near the trench line TL is relieved. As a result, as shown by arrow AR4 in Fig. 11(b) As shown, the vertical crack VC extending from the trench line TL is generated toward the predetermined extending direction of the vertical crack VC (the upstream side of the trench line TL in this embodiment). The above is the detail of the extension of the vertical crack VC generated by the method of the present embodiment described above.

In addition, in the method of the present embodiment, the auxiliary line AL is formed by using the scoring wheel 51 whose tilt angle θ is set to 1.0° to 2.5° as described above and deliberately inclined so that the internal crack region CR is biased to the scoring wheel 51 is opposite to the side inclined forward in the direction of travel, and the formation position of the auxiliary line AL and the trench line TL is set so that the breaking position extends on the side where the internal crack region CR is formed. Thereby, the reliability of the extension of the vertical crack VC from the trench line TL at the breaking position is improved. That is, the formation of the auxiliary line AL using the scribing wheel 51 intentionally inclined used in this embodiment has an effect of defining the extension of the vertical crack VC and improving the reliability of its extension. That is, when breaking the brittle material substrate W, the tilt direction of the scoring wheel 51, the formation position of the auxiliary line AL and the formation position of the groove line TL are determined according to the breaking position thereof, whereby the breaking position can be determined The vertical crack VC is surely extended.

In addition, in the case where the inclination angle θ is less than 1.0°, since the skew distribution of the internal crack region CR does not occur, and the reliability of crack extension decreases, it is relatively unfavorable. In addition, the larger the inclination angle θ, the more the rolling of the scoring wheel 51 when forming the auxiliary line AL becomes difficult, and debris tends to be easily generated.

As explained above, according to the present embodiment, when the brittle material substrate is divided at the predetermined breaking position, the groove line under the condition that no vertical cracks are generated below the groove line is formed at the formation position corresponding to the breaking position The formation and the formation of the auxiliary line under the condition that the scoring wheel intentionally inclined in the horizontal plane makes the auxiliary crack perpendicular to the predetermined direction of the vertical crack VC, which is biased on the upstream side of the groove line, thereby enabling This breaking position does make the vertical crack stretch. By surely forming vertical cracks, the brittle material substrate can be reliably broken at the breaking position in the next step, that is, the breaking step. In this case, the load applied by the scribing wheel at the time when the groove line and the auxiliary line are formed can be set to a smaller value than when the scribing operation with vertical crack extension is performed.

<Example>

By changing the formation conditions of the auxiliary line AL to perform the formation of the trench line TL and the auxiliary line AL a plurality of times in the order shown in the above embodiment, the occurrence of the extension of the vertical crack VC was evaluated. As the brittle material substrate W, a 0.3 mm thick glass substrate is used.

Specifically, by changing the tilt angle θ at three levels of 1.4°, 2.5°, and 4.9°, and the load applied to the scoring wheel 51 at 0.75N, 1.1N, 1.5N, 1.9N, 2.25N, The changes in the seven levels of 2.6N and 3.0N form the auxiliary line AL under a total of 21 conditions. The moving speed of the scoring head 2 is set to 100 mm/sec. In addition, as the scoring wheel 51, a wheel diameter of 1.8 mm, a thickness of 0.65 mm, a diameter of the insertion hole of the pin 52 of 0.8 mm, a blade tip angle of 100°, the number of grooves G of 300, and grooves G The depth is 3μm.

In addition, the groove lines TL are fixed to the load applied to the scribing tool 150, and 100 lines are formed for each forming condition of the auxiliary line AL.

Fig. 14 shows the rate of occurrence of vertical crack VC extension from the total of 100 trench lines TL for the three tilt angles θ and the load applied during the formation of the auxiliary line AL (hereinafter, referred to as the VC establishment rate) ).

As shown in FIG. 14, when the inclination angle θ is 1.4°, the VC establishment rate of 90% or more can be obtained when the load applied by the scoring wheel 51 is 1.1 N or more, and when the inclination angle θ is 2.5°, When the load applied by the scoring wheel 51 is set to 1.5 N or more, a VC establishment rate of 95% or more can be obtained. On the other hand, when the inclination angle θ is 4.9°, the highest VC establishment rate is only about 90%.

These results show that when the inclination angle θ is 1.4°, a load of at least 1.1 N is applied to the scoring wheel 51. In addition, when the inclination angle θ is 2.4°, at least a load is applied to the scoring wheel 51 With a load of 1.5N, the vertical crack VC can be extended from the trench line TL with a higher probability. In addition, it is shown that the vertical crack VC can be extended even if the inclination angle θ is further increased, but its reliability is low.

In addition, if the scoring wheel 51 with the same conditions is used to perform the scoring operation and the vertical cracks are to be stretched together with the formation of the scoring line, a load of at least about 3 to 4 N must be applied. Therefore, the results of this embodiment also show The formation of the auxiliary line AL can be performed by applying a smaller load than the load applied by the scribing wheel 51 at the time of the scoring operation accompanying the vertical crack extension. If further explained, the formation of the trench line TL can be carried out with the same degree of load or less as the formation of the auxiliary line AL. Therefore, the method of the above embodiment and the vertical cracks are directly extended by the scoring operation. Compared with the method, it can be said that the method can extend the vertical crack with a low load.

<Modifications and Reference Examples>

In the above embodiment, although the auxiliary line AL is formed after the trench line TL is formed, the order of forming the trench line TL and the auxiliary line AL may be reversed.

In addition, in the above-mentioned embodiment, although the trench line TL and the auxiliary line AL are orthogonal to the upper surface SF1 of the brittle material substrate W, this is not a necessary aspect as long as the slave trench accompanying the formation of the auxiliary line AL can be appropriately realized The extension of the vertical crack from the groove line TL may be a state where the groove line TL and the auxiliary line AL obliquely cross.

Furthermore, in the above embodiment, the groove line TL performed by the scoring tool 150 Formation is performed by sliding the diamond point 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, but Instead of this, the groove can be formed by sliding the diamond point 151 in a state where the axial direction AX2 of the handle 152 is inclined toward the rear of the moving direction DA, that is, with the top surface SD1 facing the front of the moving direction DA线TL.

Alternatively, in the above-mentioned embodiment, although the diamond tip 151 is used for the formation of the trench line TL, it may be replaced by the state in which the trench line TL is formed by rolling the scoring wheel by crimping. At this time, as the scoring wheel, a scoring wheel that is not provided with a groove at the tip of the blade is preferably used. This can be achieved, for example, by separately preparing a scoring device 100 for forming a groove line TL having a grooveless scoring wheel and a scoring wheel 51 having a fixed inclination angle θ in the range of 1.0° to 2.5° The scoring device 100 for forming the auxiliary line AL is realized by using these scoring devices to form the trench line TL and the auxiliary line AL, respectively.

However, in the case of the latter two, unlike the above-mentioned embodiment, the predetermined extending direction of the vertical crack is the downstream side of the trench line TL. Therefore, in these aspects, the auxiliary line AL is formed near the upstream side of the trench line TL in a state where the scoring wheel 51 is inclined so that the inclination angle θ is negative. More specifically, the auxiliary line AL may be formed in a state where the forward direction of the scoring wheel 51 is inclined toward the downstream side of the formation position of the auxiliary line AL, that is, the side in the negative y-axis direction.

At this time, the auxiliary line AL is formed in such a manner that the auxiliary crack AC is biased in the predetermined extending direction of the vertical crack VC, that is, the downstream side of the trench line TL, as in the above-described embodiment. The extension direction appropriately generates the extension of the vertical crack from the groove line TL. As a result, it is possible to make the vertical line with high reliability at the breaking position where the trench line TL is formed Straight cracks extend.

In addition, FIG. 15 is a plan view of the brittle material substrate W when the trench line TL and the auxiliary line AL are formed so that the positional relationship is different from the above-mentioned embodiment as a reference example. Specifically, in the case shown in FIG. 15, after the trench line TL is formed toward the positive direction of the y-axis, the vicinity of the end of the brittle material substrate W on the positive side of the y-axis direction faces x as shown by the arrow AR2 β Auxiliary line AL is formed in the positive direction of the axis. At this time, contrary to the above-mentioned embodiments and examples, the auxiliary line AL is formed in a state in which the forward direction of the scoring wheel 51 is inclined upstream from the formation position of the auxiliary line AL. In other words, the auxiliary line AL is formed so that the forward direction of the scoring wheel 51 is on the same side as the extending direction of the trench line TL. Therefore, at this time, if the extension of the vertical crack VC from the trench line TL is generated by the formation of the auxiliary line AL, it is in the direction shown by the arrow AR3 β, that is, from the trench line TL to the auxiliary line AL The intersection C occurs toward the upstream side of the trench line TL.

Fig. 16, in the same way as the above embodiment, the VC establishment rate for the reference example is evaluated under the change of the three levels of inclination angle θ at 1.4°, 2.5°, and 4.9°, and the obtained VC establishment rate is relative to the auxiliary line A graph drawn by the load applied when AL is formed.

As shown in FIG. 16, in the reference example, in the case where the inclination angle θ is 2.5°, a VC establishment rate of 95% or more can be obtained when the load applied by the scoring wheel 51 is 1.9N or more, and the inclination angle θ is 4.9° In the case of 100%, a VC establishment rate of 100% can be obtained when the load applied by the scoring wheel 51 is set to 1.9 N or more. On the other hand, when the inclination angle θ is 1.4°, the VC establishment rate exceeds 90% only when the load is 3.0N.

That is, the relationship between the inclination angle θ and the VC establishment rate in this reference example is opposite to the relationship in the above embodiment. In addition, in the case where the inclination angle θ is 2.5°, the embodiment and the reference example Both of them confirmed that there is a load range that can extend the vertical crack VC with a higher probability. This means that the formation position of the internal crack region CR (relationship with the formation position of the auxiliary line AL) depends on the value of the inclination angle θ, so it is considered to teach the direction in which the extension of the vertical crack VC can be controlled according to the inclination angle θ possibility. However, as described above, if the value of the inclination angle θ is set to be large, debris easily occurs, so in practice, as shown in the above embodiment, it is preferable to set the inclination angle θ to 1.0° to 2.5° Scope.

51‧‧‧Scribe wheel

A‧‧‧Part 1 shown in Figure 1

G‧‧‧slot

PF‧‧‧ (scoring wheel 51 of) blade tip

Claims (7)

A method for forming a vertical crack of a brittle material substrate is to form a vertical crack at the breaking position when the brittle material substrate is divided in the thickness direction, and is characterized by comprising: a groove line forming step in the brittle material substrate A groove line in which a linear groove portion is formed on a main surface; and an auxiliary line forming step of forming an auxiliary line of a processing mark crossing the groove line by pressing and rolling the scoring wheel on the one main surface The scribing wheel has a blade tip with a plurality of grooves at equal intervals on the outer peripheral portion; in the groove line forming step, the groove line is formed in such a way as to maintain a crack-free state under the groove line; and the auxiliary line is formed In the step, the auxiliary line is formed in a state where the scoring wheel is inclined at a predetermined inclination angle with respect to the forming direction of the auxiliary line in the horizontal plane; the intersection point of the groove line and the auxiliary line is used as the starting point to make the vertical crack It extends from the groove line to the thickness direction of the brittle material substrate. A method for forming a vertical crack of a brittle material substrate as claimed in item 1 of the patent scope, wherein, in the auxiliary line forming step, along with the formation of the auxiliary line, a side of the auxiliary line is generated inside the brittle material substrate There are a plurality of auxiliary cracks in the internal crack area; the formation position of the groove line and the auxiliary line is determined in such a manner that the internal crack area is formed on the groove line in the direction of the predetermined extension direction of the vertical crack. A method for forming a vertical crack of a brittle material substrate as claimed in item 2 of the patent scope, wherein the auxiliary line is formed to intersect the groove line near the side opposite to the predetermined extension direction of the vertical crack on the groove line. The method for forming a vertical crack of a brittle material substrate as claimed in item 2 or 3 of the patent scope, wherein, in the auxiliary line forming step, the front side of the scoring wheel travel direction is in the horizontal plane from the auxiliary line forming travel direction It is inclined toward the opposite side of the predetermined extension direction of the vertical crack on the groove line. The method for forming a vertical crack of a brittle material substrate according to any one of items 1 to 3 of the patent application range, wherein the inclination angle is 1.0° or more and 2.5° or less. The method for forming a vertical crack of a brittle material substrate according to any one of claims 1 to 3, wherein after forming the trench line, the auxiliary line is formed. A method for breaking a brittle material substrate, which divides the brittle material substrate in the thickness direction, and is characterized by having: a vertical crack formation step, which is based on the vertical crack of any one of the patent application items 1 to 6 In the forming method, a vertical crack is formed on the brittle material substrate; and a cracking step is to break the brittle material substrate along the vertical crack.

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