JP2018001474A - Parting method of brittle substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control precisely the angle of a parted surface with respect to the surface of a brittle substrate.SOLUTION: A brittle substrate 4 having a first surface SF1 and a second surface SF2 is prepared. Plastic deformation is generated on the second surface SF2 by moving the cutting edge on the second surface SF2 of the brittle substrate 4, so that a dummy line DL having a groove shape is formed. The process forming the dummy line DL is performed so as to obtain a crackless state in which the brittle substrate 4 is continuously connected in the direction crossing the dummy line DL immediately below the dummy line DL. The crack line CL is formed on the first surface SF1 of the brittle substrate 4. The process forming the crack line CL is performed so that continuous connection is broken in the direction in which the brittle substrate 4 crosses the crack line CL immediately below the crack line CL. By extending the crack line CL, a parted surface is formed in the brittle substrate 4.SELECTED DRAWING: Figure 7

Description

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

  In the manufacture of electrical equipment such as flat display panels or solar cell panels, it is often necessary to break a brittle substrate. In a typical cutting method, first, a crack line is formed on a brittle substrate. In this specification, “crack line” means that a crack partially progressing in the thickness direction of the brittle substrate extends in a line shape on the surface of the brittle substrate. Next, a so-called break process is performed. Specifically, by applying a stress to the brittle substrate, the cracks in the crack line are completely advanced in the thickness direction. Thereby, a brittle board | substrate is parted along a crack line.

  According to Patent Document 1, a depression on the upper surface of the glass plate is generated during scribing. In this Patent Document 1, this indentation is referred to as a “scribe line”. Further, simultaneously with the engraving of the scribe line, a crack extending in the downward direction from the scribe line is generated. As can be seen from the technique of Patent Document 1, in the conventional typical technique, the crack line is formed simultaneously with the formation of the scribe line.

  According to Patent Document 2, a cutting technique significantly different from the above-described typical cutting technique is proposed. According to this technique, first, by generating plastic deformation by sliding the blade edge on the brittle substrate, a groove shape called “scribe line” in Patent Document 2 is formed. Hereinafter, this groove shape is referred to as a “trench line”. At the time when the trench line is formed, no crack is formed below the trench line. Then, the crack line is formed by extending the crack along the trench line. That is, unlike a typical technique, a trench line without a crack is once formed, and then a crack line is formed along the trench line. Thereafter, a normal breaking process is performed along the crack line.

  The trench line without cracks used in the technique of Patent Document 2 can be formed by sliding the blade edge with a lower load than a typical scribe line with simultaneous crack formation. When the load is small, the damage applied to the cutting edge is reduced. Therefore, according to this cutting technique, the life of the cutting edge can be extended.

  In many cases, in the division of a brittle substrate using a crack line, it is desired that the crack line extends in the brittle substrate perpendicular to the surface thereof. Thereby, a sectional surface perpendicular to the substrate surface is obtained. On the other hand, depending on the use or shape of the brittle substrate to be divided, it may be desirable to form a diagonally divided section with respect to the substrate surface. For example, when a brittle substrate is divided along a closed curve, if a sectional surface perpendicular to the substrate surface is formed by the breaking process, it is difficult to extract the inner part of the closed curve from the outer part after the breaking process. In order to facilitate this, it is necessary to make the dividing surface oblique to the substrate surface, in other words, to provide a draft angle.

  According to Patent Document 3, in order to provide a draft angle, the cut line inclined with respect to the thickness direction of the glass plate is drawn on one side of the glass plate by a diamond disc saw as a cutter to draw a closed curve. Formed. Two methods are exemplified as the method of making the cut line oblique. As a first method, a diamond disc saw is used in an inclined state. As the second method, a diamond disc saw having an asymmetric shape is used.

JP-A-9-188534 International Publication No. 2015/151755 JP-A-7-223828

  According to the method of Patent Document 3, when a crack line is formed on one surface of a brittle substrate, the crack line can be extended in a desired oblique direction in the vicinity of the surface. However, in order to divide the substrate, it is necessary to extend the crack line to the opposite surface of the substrate, and in the process, the extending direction may change due to some uncontrollable factor. Therefore, a cross section inclined in a desired direction may not be obtained. The unintentional change in the extension direction of the crack line is not desirable in the case of forming a vertical dividing section.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a method for cutting a brittle substrate that can accurately control the angle of the section with respect to the surface of the brittle substrate. It is.

  The method for dividing a brittle substrate of the present invention includes the following steps. A brittle substrate having a first surface and a second surface opposite to the first surface and having a thickness direction perpendicular to the first surface is prepared. A dummy line having a groove shape is formed by causing plastic deformation on the second surface by moving the cutting edge on the second surface of the brittle substrate. The step of forming the dummy line is performed so as to obtain a crackless state in which the brittle substrate is continuously connected immediately below the dummy line in the direction intersecting the dummy line. A crack line is formed on the first surface of the brittle substrate. By extending the crack line, a cross section is formed on the brittle substrate.

  According to the present invention, the dummy line is formed on the second surface opposite to the first surface on which the crack line is formed. Thereby, the direction in which the crack line extends with respect to the first surface of the brittle substrate can be finely adjusted. Therefore, the angle of the divided surface with respect to the first surface of the brittle substrate can be accurately controlled.

It is a flowchart which shows schematically the structure of the brittle board | substrate parting method in Embodiment 1 of this invention. It is a top view which shows roughly the 1st process of the cutting method of a brittle board | substrate in Embodiment 1 of this invention. It is a schematic sectional drawing in alignment with line III-III of FIG. It is a top view which shows roughly the 2nd process of the cutting method of a brittle board | substrate in Embodiment 1 of this invention. It is a schematic sectional drawing in alignment with line VV of FIG. It is a top view which shows roughly the 3rd process of the cutting method of a brittle board | substrate in Embodiment 1 of this invention. It is a schematic sectional drawing in alignment with line VII-VII of FIG. It is a flowchart which shows schematically the structure of the cutting method of a brittle board | substrate in Embodiment 2 of this invention. It is a top view which shows roughly the 1st process of the cutting method of the brittle board | substrate in Embodiment 2 of this invention. It is a schematic sectional drawing in alignment with line XX of FIG. It is a top view which shows roughly the 2nd process of the cutting method of a brittle board | substrate in Embodiment 2 of this invention. It is a schematic sectional drawing in alignment with line XII-XII of FIG. It is a flowchart which shows schematically the structure of the division | segmentation method of a brittle board | substrate in the modification of Embodiment 2 of this invention. It is a top view which shows roughly the 1st process of the cutting method of the brittle board | substrate in the modification of Embodiment 2 of this invention. It is a schematic sectional drawing in alignment with line | wire XV-XV of FIG. It is a top view which shows roughly the 2nd process of the cutting method of a brittle board | substrate in the modification of Embodiment 2 of this invention. It is a schematic sectional drawing which follows the line XVII-XVII of FIG. It is a top view which shows schematically the 3rd process of the cutting method of a brittle board | substrate in the modification of Embodiment 2 of this invention. It is a top view which shows roughly the 4th process of the cutting method of a brittle board | substrate in the modification of Embodiment 2 of this invention. It is a top view which shows roughly the 1st process of the cutting method of the brittle board | substrate in Embodiment 3 of this invention. It is a schematic sectional drawing in alignment with line | wire XXI-XXI of FIG. It is a top view which shows roughly the 2nd process of the cutting method of a brittle board | substrate in Embodiment 3 of this invention. FIG. 23 is a schematic sectional view taken along line XXIII-XXIII in FIG. 22. It is a top view which shows roughly the 1st process of the cutting method of the brittle board | substrate in the 1st modification of Embodiment 3 of this invention. FIG. 25 is a schematic sectional view taken along line XXV-XXV in FIG. 24. It is a top view which shows roughly the 2nd process of the cutting method of a brittle board | substrate in the 1st modification of Embodiment 3 of this invention. FIG. 27 is a schematic sectional view taken along line XXVII-XXVII in FIG. 26. It is a top view which shows roughly the 1st process of the cutting method of the brittle board | substrate in the 2nd modification of Embodiment 3 of this invention. It is a top view which shows roughly the 2nd process of the cutting method of a brittle board | substrate in the 2nd modification of Embodiment 3 of this invention. It is a top view which shows roughly the 1st process of the cutting method of the brittle board | substrate in Embodiment 4 of this invention. FIG. 31 is a schematic cross-sectional view taken along line XXXI-XXXI in FIG. 30. FIG. 31 is a schematic sectional view taken along line XXXII-XXXII in FIG. 30. It is a top view which shows roughly the 2nd process of the cutting method of a brittle board | substrate in Embodiment 4 of this invention. FIG. 34 is a schematic sectional view taken along line XXXIV-XXXIV in FIG. 33. FIG. 34 is a schematic sectional view taken along line XXXV-XXXV in FIG. 33. It is a top view which shows roughly the 1st process of the cutting method of a brittle board | substrate in Embodiment 5 of this invention. FIG. 37 is a schematic sectional view taken along line XXXVII-XXXVII in FIG. 36. It is a top view which shows roughly the 2nd process of the cutting method of a brittle board | substrate in Embodiment 5 of this invention. FIG. 39 is a schematic sectional view taken along line XXXIX-XXXIX in FIG. 38. It is sectional drawing which shows roughly the 3rd process of the cutting method of a brittle board | substrate in Embodiment 5 of this invention. It is sectional drawing which shows the process corresponding to FIG. 40 in a comparative example. It is sectional drawing explaining the effect in Embodiment 5 of this invention. It is sectional drawing which shows the 1st process of the cutting method of the brittle board | substrate in a comparative example. It is sectional drawing which shows schematically the 1st example of the 2nd process of the cutting method of the brittle board | substrate in a comparative example. It is sectional drawing which shows schematically the 2nd example of the 2nd process of the cutting method of the brittle board | substrate in a comparative example. It is sectional drawing which shows roughly the 1st process of the cutting method of a brittle board | substrate in Embodiment 6 of this invention. It is sectional drawing which shows schematically the 2nd process of the cutting method of a brittle board | substrate in Embodiment 6 of this invention. It is sectional drawing which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 7 of this invention. It is sectional drawing which shows schematically the 1st process of the cutting method of a brittle board | substrate in Embodiment 8 of this invention. It is sectional drawing which shows schematically the 2nd process of the cutting method of a brittle board | substrate in Embodiment 8 of this invention. It is sectional drawing which shows schematically the 3rd process of the cutting method of a brittle board | substrate in Embodiment 8 of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

<Embodiment 1>
A method for dividing a brittle substrate in the present embodiment will be described below with reference to FIG.

  Referring to FIGS. 2 and 3, in step S20 (FIG. 1), upper surface SF1 (first surface) and lower surface SF2 (second surface opposite to the first surface) are provided, and on upper surface SF1. A glass substrate 4 (brittle substrate) having a vertical thickness direction is prepared. The thickness of the glass substrate 4 is preferably 0.7 mm or less, and more preferably 0.5 mm or less.

  Next, in step S40 (FIG. 1), by moving the blade edge on the lower surface SF2 of the glass substrate 4, plastic deformation is generated on the lower surface SF2. Thereby, a dummy line DL having a groove shape is formed. This formation process is performed so that a crackless state, which is a state in which the glass substrate 4 is continuously connected in the direction RD that intersects the dummy line DL immediately below the dummy line DL, is obtained. In the crackless state, the dummy line DL due to plastic deformation is formed, but no crack is formed along the dummy line DL. In order to obtain a crackless state, an excessively large load on the cutting edge only needs to be avoided.

  The dummy line DL is preferably generated only by plastic deformation of the glass substrate 4, and in this case, the scraping on the glass substrate 4 does not occur. In order to avoid scraping, the load on the cutting edge should not be excessively high. By not scraping, it is possible to avoid undesirable fine fragments on the glass substrate 4. However, some shaving is usually acceptable.

  The above-described movement of the blade edge on the glass substrate 4 may be either sliding or rolling. In the case of sliding, a cutting edge (for example, a diamond point) fixed to the holder is used. In the case of rolling, a cutting edge (so-called scribing wheel) that is rotatably held around the axis of the holder is used. In the present embodiment, it is desirable to accurately manage the relative position between the dummy line DL and a crack line CL (FIGS. 4 and 5), which will be described later. The cutting edge is better.

  4 and 5, crack line CL is formed on upper surface SF <b> 1 of glass substrate 4 in step S <b> 60 (FIG. 1). The crack line CL may be formed by a normal scribing method. In that case, typically, the crack line CL is formed to extend vertically from the upper surface SF <b> 1 of the glass substrate 4.

  Referring to FIGS. 6 and 7, in step S <b> 80 (FIG. 1), the split line PS is formed on the glass substrate 4 by extending the crack line CL. That is, a breaking process for dividing the glass substrate 4 along the crack line CL is performed. The breaking process can be performed by applying an external force to the glass substrate 4. For example, by pressing a stress applying member (for example, a member called “break bar”) on the lower surface SF2 toward the crack line CL (FIG. 5) on the upper surface SF1 of the glass substrate 4, cracks in the crack line CL are obtained. Is applied to the glass substrate 4. In addition, when the crack line CL has completely progressed in the thickness direction at the time of formation (time of FIG. 5), formation of the crack line CL and division of the glass substrate 4 occur simultaneously.

  According to the experiment of the present inventor, a phenomenon (see solid arrow in FIG. 7) in which the extension path of the crack line CL (broken arrow in FIG. 7) tries to move away from the dummy line DL was observed. This phenomenon is considered to be caused by an internal stress generated in the glass substrate 4 when the dummy line DL is formed. By utilizing this phenomenon, the direction in which the crack line CL extends (the extending direction in FIG. 7) with respect to the upper surface SF1 can be finely adjusted. Therefore, the angle of the divided section PS with respect to the upper surface SF1 can be accurately controlled.

  In the process of dividing the glass substrate 4, the dummy line DL has a dimension SH larger than zero from a position obtained by projecting the position of the crack line CL on the upper surface SF1 onto the lower surface SF2 of the glass substrate 4 along the thickness direction. (FIG. 5) is shifted. Thereby, in FIG. 5, it is avoided that it becomes uncertain whether the extension of the crack line CL is induced to the left or right of the dummy line DL.

  Note that the dummy line DL may be formed after the formation of the crack line CL, and then the crack line CL may be extended to the lower surface SF2. However, in order to make the dummy line DL act more reliably and sufficiently on the crack line CL, it is preferable to form the dummy line DL before the formation of the crack line CL as described above.

<Embodiment 2>
In the present embodiment, the method of forming crack line CL (FIGS. 4 and 5) is different from that in the first embodiment. Hereinafter, a method for dividing the glass substrate 4 in the present embodiment will be described below.

  First, similarly to the first embodiment, the glass substrate 4 is prepared and the dummy line DL is formed in steps S20 and S40 (FIG. 8).

  Referring to FIGS. 9 and 10, next, in step S50 (FIG. 8), as shown by the arrow (FIG. 9), the blade edge is moved on the upper surface SF1 (FIG. 10) of the glass substrate 4. Then, plastic deformation is generated on the upper surface SF1. Thereby, a trench line TL having a groove shape is formed. This formation process is performed so that a crackless state, which is a state in which the glass substrate 4 is continuously connected in the direction RT (FIG. 10) intersecting the trench line TL immediately below the trench line TL, is obtained. In the crackless state, the trench line TL is formed by plastic deformation, but no crack is formed along the trench line TL. In order to obtain a crackless state, an excessively large load on the cutting edge only needs to be avoided.

  The trench line TL is preferably generated only by plastic deformation of the glass substrate 4, and in this case, the scraping on the glass substrate 4 does not occur. In order to avoid scraping, the load on the cutting edge should not be excessively high. By not scraping, it is possible to avoid undesirable fine fragments on the glass substrate 4. However, some shaving is usually acceptable.

  The above-described movement of the blade edge on the glass substrate 4 may be either sliding or rolling. In the case of sliding, a cutting edge (for example, a diamond point) fixed to the holder is used. In the case of rolling, a cutting edge (so-called scribing wheel) that is rotatably held around the axis of the holder is used. In the present embodiment, it is desired to accurately manage the relative position between the trench line TL and the dummy line DL, and in that respect, the sliding blade edge is superior to the rolling blade edge.

  Referring to FIGS. 11 and 12, next, in step S60 (FIG. 8), a crack line CL is formed. This formation process is performed by extending a crack from the trench line TL. In the present embodiment, the crack line CL is formed as shown by the arrow in FIG. 11, starting from the fine breakage caused by the cutting edge being cut down at the position NP by the edge of the glass substrate 4 as shown in FIG. Start to be.

  Next, in step S80 (FIG. 8), a dividing surface is formed as in the first embodiment. That is, the glass substrate 4 is divided.

  Also in the present embodiment, the same effect as in the first embodiment can be obtained. Further, in the present embodiment, after the trench line TL is formed in a crackless state as shown in FIG. 10, the crack line CL is formed immediately below the trench line TL as shown in FIG. According to the study of the present inventor, this method can make the sectional surface along the crack line CL smoother than that of the first embodiment.

  The formation of the crack line CL in the present embodiment is considered to occur so as to release the internal stress generated when the trench line TL is formed. The trigger for stress release is not limited to the cut-off of the edge of the glass substrate 4 as described above (FIG. 9). Hereinafter, a modified example (FIG. 13) from this viewpoint will be described.

  Referring to FIGS. 14 and 15, trench line TL is formed in step S30 (FIG. 13). Unlike the above-described embodiment, in this modification, the cutting edge does not cut down the edge of the glass substrate 4. Referring to FIGS. 16 and 17, dummy line DL is formed in step S40 (FIG. 13). The order of forming the trench line TL and the dummy line DL is arbitrary.

  Referring to FIG. 18, in step S60 (FIG. 13), an assist line AL that intersects trench line TL is formed on upper surface SF1 of glass substrate 4. With this as a trigger, crack lines CL begin to be formed as shown by arrows in the figure.

  Referring to FIG. 19, in step S <b> 80 (FIG. 13), a divided section PS is formed as in the first embodiment. That is, the glass substrate 4 is divided.

<Embodiment 3>
Referring to FIGS. 20 and 21, in the present embodiment, the process of forming crack line CL is performed such that crack line CL has a curved portion on upper surface SF <b> 1 of glass substrate 4. More specifically, the process of forming the crack line CL is performed so that the crack line CL forms a closed curve on the upper surface SF <b> 1 of the glass substrate 4.

  In the present embodiment, dummy line DL is formed inside the closed curve of crack line CL in plan view (FIG. 20). The dummy line DL may have a shape obtained by reducing the closed curve of the crack line CL. As described in the first embodiment, the order of forming the dummy line DL and the crack line CL is arbitrary.

  With reference to FIG. 22 and FIG. 23, the divided section PS is formed on the glass substrate 4 by extending the crack line CL. That is, a breaking process for dividing the glass substrate 4 along the crack line CL is performed. As shown in FIG. 23, the formed partial cross-section PS has a taper shape from the lower surface SF2 toward the upper surface SF1 due to the action of the dummy line DL.

  Since the configuration other than the above is substantially the same as the configuration of the first or second embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and description thereof will not be repeated.

  According to the present embodiment, when the above-described tapered shape acts as a draft, the inner portion 4i can be easily taken out from the outer portion 4o of the crack line CL in the glass substrate 4.

  Further, the maximum dimension in the width direction (maximum dimension in the horizontal direction in FIG. 23) of the outer portion of the divided section PS is equal to or less than the width dimension LO of the outer portion of the crack line CL on the upper surface SF1. Thereby, when the outer part of the divided section PS is used as a product, the maximum dimension in the width direction can be managed to be equal to or less than the width dimension LO of the outer part of the crack line CL on the upper surface SF1.

  Next, a first modification will be described below.

  Referring to FIGS. 24 and 25, in this modification, dummy line DL is formed outside the closed curve of crack line CL in plan view (FIG. 24). The dummy line DL may have a shape obtained by enlarging the closed curve of the crack line CL.

  With reference to FIG. 26 and FIG. 27, the dividing surface PS is formed on the glass substrate 4 by extending the crack line CL. As shown in FIG. 27, the formed sectional surface PS has a tapered shape from the upper surface SF1 toward the lower surface SF2 by the action of the dummy line DL.

  According to this modified example, the taper shape described above acts as a draft, whereby the inner portion 4i can be easily taken out from the outer portion 4o of the crack line CL in the glass substrate 4.

  In addition, the maximum dimension in the width direction (maximum dimension in the horizontal direction in FIG. 27) of the inner part of the divided section PS is equal to or less than the width dimension LI of the inner part of the crack line CL on the upper surface SF1. Thereby, when the inner part of the dividing surface PS is used as a product, the maximum dimension in the width direction can be managed to be equal to or smaller than the width dimension LI of the inner part of the crack line CL on the upper surface SF1.

  Next, a second modification will be described below.

  Referring to FIG. 28, in the present modification, crack line CL has a plurality of portions each having a linear shape. By connecting these, a portion surrounded by the crack line CL in a plan view is provided. The dummy line DL has a plurality of portions each having a linear shape. By connecting these, a portion surrounded by the dummy line DL in a plan view is provided. The portion surrounded by the dummy line DL is provided so as to include the portion surrounded by the crack line CL.

  Referring to FIG. 29, dividing plane PS is formed on glass substrate 4 by extending crack line CL. The formed partial cross-section PS has a tapered shape from the upper surface SF1 toward the lower surface SF2 due to the action of the dummy line DL, as in the first modification (FIG. 27). Therefore, when the inner part of the divided section PS is used as a product, the maximum dimension in the width direction can be managed to be equal to or smaller than the width dimension of the inner part of the crack line CL on the upper surface SF1.

<Embodiment 4>
In the first embodiment (FIG. 5), dummy line DL is only dimension SH (FIG. 5) larger than zero from the position where crack line CL is projected on lower surface SF2 of glass substrate 4 along the thickness direction. It is shifted and this dimension SH may be constant at all positions on the lower surface SF2. On the other hand, in the present embodiment, the size SH is made different depending on the position. This method will be specifically described below.

  30 to 32, the dummy line DL is shifted by a dimension larger than zero from the position where the crack line CL is projected onto the lower surface SF2 of the glass substrate 4 along the thickness direction. This dimension changes on the lower surface SF2 of the glass substrate 4.

  Specifically, the crack line CL has two different points on one side (right side in the drawing) of the glass substrate 4 as one end and the other end. The crack line CL extends from one end to the other end so that its extending direction changes by 180 °. The vicinity of one end and the vicinity of the other end of the crack line CL are parallel to each other on the upper surface SF1. Therefore, in the vicinity of the right side of the glass substrate 4, the width dimension (the dimension in the vertical direction in FIG. 30) parallel to the right side of the portion sandwiched between the crack lines CL on the upper surface SF1 is constant. In a plan view (FIG. 30), the dummy line DL is formed outside the region surrounded by the right side of the glass substrate 4 and the crack line CL. The dummy line DL has a portion formed on the lower surface SF <b> 2 so as to move away from the crack line CL as it approaches the right side of the glass substrate 4.

  With reference to FIGS. 33 to 35, the dividing line PS is formed on the glass substrate 4 by extending the crack line CL. Here, as described above, the dummy line DL has a portion formed on the lower surface SF <b> 2 so as to move away from the crack line CL as it approaches the right side of the glass substrate 4. Thereby, the influence which the dummy line DL has on the extending direction of the crack line CL becomes weaker as the right side of the glass substrate 4 is approached. In other words, the influence of the dummy line DL on the extending direction of the crack line CL increases as the distance from the right side of the glass substrate 4 increases. As a result, the width dimension parallel to the right side (the vertical dimension in FIG. 33) of the portion sandwiched between the crack lines CL on the lower surface SF <b> 2 becomes smaller as the distance from the right side of the glass substrate 4 increases. Specifically, the width dimension LP along the line XXXIV-XXXIV of the portion sandwiched between the crack lines CL is smaller than the width dimension LQ along the line XXXV-XXXV. Thereby, it is easy to move the portion 4a surrounded by the divided section PS and the right side of the glass substrate 4 from the surrounding portion 4b toward the right in the drawing as shown by the broken line arrow in FIG. It becomes. Therefore, the part 4a and the part 4b can be easily separated from each other. If the width dimension LP is larger than the width dimension LQ, such movement is impossible.

<Embodiment 5>
Referring to FIGS. 36 and 37, dummy line DL is formed on lower surface SF2 of glass substrate 4. In the present embodiment, the step of forming the dummy line DL is performed so that the dummy line DL has the first portion DL1 and the second portion DL2.

  Referring to FIGS. 38 and 39, crack line CL is formed on upper surface SF1 of glass substrate 4. The position where the crack line CL is projected onto the lower surface SF2 of the glass substrate 4 along the thickness direction is sandwiched between the first portion DL1 and the second portion DL2 of the dummy line DL. As described in the first embodiment, the order of forming the dummy line DL and the crack line CL is arbitrary.

  Referring to FIG. 40, dividing line PS is formed on glass substrate 4 by extending crack line CL as indicated by the broken line arrow in the drawing. The crack line CL is guided by the dummy line DL so as to reach between the first portion DL1 and the second portion DL2 of the dummy line DL on the lower surface SF2.

  Referring to FIG. 41, if the dummy line DL is not provided, the extension direction of the crack line CL indicated by the broken line arrow greatly deviates from the desired one as indicated by the solid line arrow due to some factor. There is a possibility of reaching the lower surface SF2. Referring to FIG. 42, in contrast, according to the present embodiment, when the crack line CL attempts to approach the first portion DL1 rather than the second portion DL2 of the dummy line DL, the first portion DL1 is obtained. An action to correct the extending direction of the crack line CL is added in the direction from the direction toward the second portion DL2. Thereby, it is possible to prevent the crack line CL from reaching the position greatly deviating from the desired position on the lower surface SF2.

<Embodiment 6>
In the first to fifth embodiments described above, the process of forming the crack line CL (FIG. 5) has been described in the case where the crack line CL is performed in the vicinity of the upper surface SF <b> 1 of the glass substrate 4 so as to extend vertically from the upper surface SF <b> 1. . On the other hand, in the present embodiment, the process of forming the crack line CL is performed so that the crack line CL extends obliquely from the upper surface SF1 of the glass substrate 4. In general, when the crack line CL (FIG. 43) formed so as to extend in a direction inclined from a direction perpendicular to the upper surface SF1 of the glass substrate 4 (hereinafter also referred to as a direction XP) further extends, the present inventors consider According to this, not only the case of linear extension (FIG. 44) but also the case where the extension direction changes unintentionally (FIG. 45). According to the present embodiment, such a change is suppressed. Hereinafter, the method for that is demonstrated concretely.

  Referring to FIG. 46, dummy line DL and crack line CL are formed. As described above, the crack line CL is formed so that the crack line CL extends obliquely from the upper surface SF <b> 1 of the glass substrate 4. As described in the first embodiment, the order of forming the dummy line DL and the crack line CL is arbitrary. In FIG. 46, the position where the crack line CL is projected on the lower surface SF2 of the glass substrate 4 along the thickness direction is different from the position of the dummy line DL, but these positions are the same. Also good.

  Referring to FIG. 47, a split section is formed on glass substrate 4 by extending crack line CL as shown by the broken line arrow in the figure. When the extension direction of the crack line CL (broken arrow in the figure) approaches the direction XP for some reason, the dummy line DL has an action (solid arrow in the figure) that returns the extension direction to the initial oblique direction. Thereby, the inclination of the crack line CL on the upper surface SF1 is easily maintained up to the lower surface SF2.

  Since the configuration other than the above is substantially the same as the configuration of any of Embodiments 1 to 5 described above, the same or corresponding elements are denoted by the same reference numerals, and description thereof will not be repeated.

<Embodiment 7>
Referring to FIG. 48, the distribution of internal stress generated in glass substrate 4 by forming dummy line DL is schematically shown by a broken line in the drawing. In the first to sixth embodiments described above, the step of forming the dummy line DL is performed so that the internal stress of the glass substrate 4 around the dummy line DL has the symmetry axis XS perpendicular to the lower surface SF2 of the glass substrate 4. You may be broken. Such a dummy line DL can be easily formed using a normal scribing device.

<Eighth embodiment>
Referring to FIG. 49, unlike the dummy line DL of the seventh embodiment (FIG. 48), in the process of forming the dummy line DLi of the present embodiment, the internal stress of the glass substrate 4 around the dummy line DL is glass. This is performed so as to have an oblique axis of symmetry XSi with respect to the lower surface SF2 of the substrate 4. The dummy line DLi can be formed by a cutting edge having an oblique symmetry axis XSi. Specifically, a normal cutting edge is used while being inclined obliquely along the symmetry axis XSi, or instead of providing such an inclination, a special cutting edge having a symmetry axis XSi is prepared. The dummy line DLi can be applied instead of the dummy line DL of the first to sixth embodiments described above. Hereinafter, in particular, a case where the dummy line DLi is applied to a form similar to that of the first embodiment will be described.

  Referring to FIG. 50, a dummy line DLi and a crack line CL are formed. Here, since the dummy line DLi has an oblique symmetry axis XSi, the dimension SH (FIG. 5) may be zero. In other words, the dummy line DLi may be formed at a position where the crack line CL is projected onto the lower surface SF2 of the glass substrate 4 along the thickness direction.

  Referring to FIG. 51, as in the first embodiment, a split section is formed on glass substrate 4 by extending crack line CL as indicated by a broken line arrow in the figure.

  According to the present embodiment, the direction in which the crack line CL extends can be finely adjusted not only by the position of the dummy line DLi on the lower surface SF2 but also by the angle of the symmetry axis XSi of the dummy line DLi.

  In each of the above embodiments, the case where the glass substrate 4 is used as the brittle substrate has been described. However, the brittle substrate may be made of a brittle material other than glass, for example, ceramics, silicon, compound semiconductor, sapphire Or it can be made from quartz.

AL assist line CL crack line DL dummy line SF1 upper surface (first surface)
SF2 bottom surface (second surface)
TL trench line XS, XSi symmetry axis 4 glass substrate (brittle substrate)

Claims (11)

Providing a brittle substrate having a first surface and a second surface opposite to the first surface and having a thickness direction perpendicular to the first surface;
Forming a dummy line having a groove shape by generating a plastic deformation on the second surface by moving a blade edge on the second surface of the brittle substrate, the dummy line comprising: The forming step is performed so as to obtain a crackless state in which the brittle substrate is continuously connected in a direction intersecting the dummy line immediately below the dummy line, and further, the first step of the brittle substrate is performed. Forming a crack line on the surface of 1;
Forming a split section on the brittle substrate by extending the crack line, and
Method for cutting a brittle substrate. Before the step of forming the crack line, by generating plastic deformation on the first surface by moving a blade edge on the first surface of the brittle substrate, a trench line having a groove shape is formed. A step of forming the trench line so as to obtain a crackless state in which the brittle substrate is continuously connected in the direction intersecting the trench line immediately below the trench line. Done,
The step of forming the crack line is performed by extending a crack from the trench line.
The method for dividing a brittle substrate according to claim 1.   The method for cutting a brittle substrate according to claim 1, wherein the step of forming the crack line is performed such that the crack line has a curved portion on the first surface of the brittle substrate.   The method for cutting a brittle substrate according to any one of claims 1 to 3, wherein the step of forming the crack line is performed such that the crack line forms a closed curve on the first surface of the brittle substrate. .   In the step of dividing the brittle substrate, the dummy line is shifted by a dimension larger than zero from a position where the crack line is projected on the second surface of the brittle substrate along the thickness direction. The method for dividing a brittle substrate according to any one of claims 1 to 4.   The method for dividing a brittle substrate according to claim 5, wherein the dimension changes on the second surface of the brittle substrate. The step of forming the dummy line is performed so that the dummy line has a first portion and a second portion,
The position where the crack line is projected on the second surface of the brittle substrate along the thickness direction is sandwiched between the first portion and the second portion. 5. The method for dividing a brittle substrate according to any one of 4 above.   8. The method for cutting a brittle substrate according to claim 1, wherein the step of forming the crack line is performed such that the crack line extends perpendicularly from the first surface of the brittle substrate. 9.   8. The method for cutting a brittle substrate according to claim 1, wherein the step of forming the crack line is performed such that the crack line extends obliquely from the first surface of the brittle substrate. 9.   The step of forming the dummy line is performed so that an internal stress of the brittle substrate around the dummy line has an axis of symmetry perpendicular to the second surface of the brittle substrate. The method for dividing a brittle substrate according to claim 1.   The step of forming the dummy line is performed so that an internal stress of the brittle substrate around the dummy line has an axis of symmetry oblique to the second surface of the brittle substrate. The method for dividing a brittle substrate according to any one of the above.

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