JP6544149B2 - Method of forming inclined cracks in brittle material substrate and method of dividing brittle material substrate - Google Patents

Description

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

  The manufacturing process of a flat display panel or a solar cell panel generally includes the step of dividing a substrate (mother substrate) made of a brittle material such as a glass substrate, a ceramic substrate, or a semiconductor substrate. For such division, a method of forming a scribe line on a substrate surface using a scribe tool such as a diamond point or a cutter wheel and extending a crack (vertical crack) in the thickness direction of the substrate from the scribe line is widely used. There is. When a scribe line is formed, the vertical crack may completely extend in the thickness direction and the substrate may be divided, but the vertical crack may only partially extend in the thickness direction. In the latter case, after the formation of the scribe line, stress is applied which is called a breaking step. The substrate is cut along the scribe line by completely advancing the vertical crack in the thickness direction by the breaking step.

  As a method for extending a vertical crack by forming such a scribe line, a method for forming a linear processing mark serving as a starting point (trigger) for extending a vertical crack, which is also referred to as an assist line, has already been known. (See, for example, Patent Document 1).

JP, 2015-74145, A

  The division in the thickness direction of the various brittle material substrates described above is often made perpendicular to the main surface of the substrate, but we intentionally want division to be performed so that the division plane is oblique to the main surface of the substrate In some cases. Such division is realized by extending a crack in an oblique direction with respect to the main surface of the substrate, but in Patent Document 1, an aspect in which such a crack (inclined crack) is formed by a method of forming an assist line. There is no disclosure or suggestion.

  The present invention has been made in view of the above problems, and an object thereof is to provide a novel method for forming a sloped crack in a brittle material substrate.

  In order to solve the above-mentioned subject, invention of Claim 1 is a method of forming a slope crack in a brittle material substrate, and a blade edge including a ridge along a predetermined dividing position on one main surface of the brittle material substrate. A trench line forming step of forming a trench line which is a line-like groove by sliding or rolling a scribe tool having a groove, and a crack forming step of generating a crack immediately below the trench line, the trench In the line forming step, the crackless state is maintained immediately below the trench line in a state where the ridge line of the scribe tool is inclined at a predetermined inclination angle from the direction of formation of the trench line in a horizontal plane. It is a crack that forms a trench line and is inclined with respect to the main surface of the brittle material substrate Thereby extending the oblique cracks, characterized in that.

  The invention of claim 2 is the method for forming a sloped crack in the brittle material substrate according to claim 1, characterized in that the absolute value of the slope angle is 1.0 ° to 3.0.

  The invention according to claim 3 is the method for forming a sloped crack in the brittle material substrate according to claim 1 or 2, wherein the dividing position is defined in a curved shape, and in the trench line forming step, The trench line is formed such that a crackless state is maintained immediately below the trench line in a state where the scribing tool is inclined at a predetermined inclination angle from the tangential direction of the dividing position in a horizontal plane. I assume.

  The invention according to claim 4 is a method for dividing a brittle material substrate, wherein the inclined crack is formed in the brittle material substrate by the method for forming a gradient crack according to any one of claims 1 to 3. It is characterized by comprising: a process; and a breaking process of breaking the brittle material substrate along the inclined crack.

  According to the first to fourth aspects of the present invention, the division of the brittle material substrate in a mode in which the divided section is oblique to the main surface of the substrate utilizing a method in which the crackless state is maintained immediately below the trench line. Is possible.

It is a top view of the brittle material substrate W which illustrates the mode after trench line TL formation. It is a figure which shows roughly the structure of the scribe tool 150 used for formation of the trench line TL. FIG. 35 is a zx partial cross sectional view including a vertical cross section of a trench line TL. It is a top view of the brittle material substrate W which illustrates the mode at the time of assist line AL formation. It is a figure which shows roughly the structure of the scribing apparatus 100 used for formation of assist line AL. It is a top view of brittle material substrate W which illustrates a mode of extension of inclination crack IC accompanying formation of assist line AL. It is a top view of brittle material substrate W which illustrates a mode of extension of inclination crack IC accompanying formation of assist line AL. FIG. 17 is a zx partial cross-sectional view including vertical lines of a trench line TL and a sloped crack IC. It is the graph which plotted the relationship between the load applied to the diamond point 151 when forming the trench 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. It is the graph which plotted the average value about the inclination angle (delta) of six kinds of cracks with which the load applied to the diamond point 151 is different about the three levels of inclination angles (theta) given to the diamond point 151, and minimum value, respectively. . Individual obtained by performing a breaking process after forming an inclined crack IC on a glass substrate having a trench line TL formed by applying a load of 1.6 N to a diamond point 151 having an inclination angle θ of −2.1 ° It is an optical microscope image of a piece. It is a figure which shows the formation position of the trench line TL in case a division | segmentation position is determined by circular shape, and the assist line AL. FIG. 13 is a view schematically showing a state of the brittle material substrate W after the trench line TL and the assist line AL are formed in the mode shown in FIG. 12. FIG. 13 is a view showing the formation positions of the trench line TL and the assist line AL in a mode different from the mode shown in FIG. 12 when the brittle material substrate W is hollowed out in a truncated cone shape. FIG. 13 is a view showing the formation positions of the trench line TL and the assist line AL in a mode different from the mode shown in FIG. 12 when the brittle material substrate W is hollowed out in a truncated cone shape.

  The method according to the embodiment of the present invention described below is a crack for dividing the brittle material substrate W at a predetermined position (division position) of the brittle material substrate W, and is inclined with respect to the main surface of the substrate Cracks (hereinafter referred to as inclined cracks) are formed. Generally speaking, the method comprises: from the trench line to the substrate, by forming the processed groove, which is called a trench line, for the dividing position, and then forming the assist line in a manner to cross the trench line. The inclined crack is extended in the thickness direction. In the present embodiment, the trench line is a fine line-shaped groove portion (concave portion) which is a formation starting position in the substrate thickness direction of the inclined crack. Further, the assist line is a processing mark which is formed on the main surface of the brittle material substrate W in a mode of crossing the trench line and which becomes a starting point (trigger) when extending the inclined crack immediately below the trench line.

  In the following, a case will be described as an example in which a plurality of linear dividing positions (division lines) parallel to a pair of opposite sides are set in advance with respect to the rectangular brittle material substrate W. In the drawings used for the description, the right-handed system is used where the direction of formation of the assist line AL is the x-axis positive direction, the direction of formation of the trench line TL is the y-axis positive direction, and the vertical upper direction is the z-axis positive direction. xyz coordinates are attached.

<Formation of trench line>
FIG. 1 is a top view (xy plan view) of a brittle material substrate W illustrating a state after formation of a trench line TL. FIG. 2 schematically shows a configuration of scribe tool 150 used to form trench line TL. FIG. 3 is a zx partial cross-sectional view including the vertical cross-section of the trench line TL. The formation position of the trench line TL shown in FIG. 1 corresponds to a division position when the brittle material substrate W is viewed in plan from the one main surface (upper surface) SF1 side.

  In the present embodiment, a scribe tool 150 provided with a diamond point 151 is used to form the trench line TL. The diamond point 151 has, for example, a truncated pyramidal shape as shown in FIG. 2 and is provided with a top surface SD1 (first surface) and a plurality of surfaces surrounding the top surface SD1. More specifically, as shown in FIG. 2 (b), the plurality of surfaces include a side surface SD2 (second surface) and a side surface SD3 (third surface). Top surface SD1, side surfaces SD2 and SD3 face in mutually different directions, and are adjacent to each other. At the diamond point 151, a blade edge PF2 is formed by a ridge line PS composed of the side surfaces SD2 and SD3 and a vertex PP formed by three surfaces of the top surface SD1 and the side surfaces SD2 and SD3. As shown in FIG. 2A, the diamond point 151 is held in a mode in which the top surface SD1 is the lowermost end on one end side of a rod-like (columnar) shank 152.

  Further, in the present embodiment, with the moving direction DA of the diamond point 151 as a reference direction, the top surface SD1 is disposed in the xy plane as shown in FIG. 2B, and the diamond point 151 is on the side of the top surface SD1. The angle θ when the diamond point 151 is inclined clockwise by an angle θ in the horizontal plane with respect to the movement direction DA in the state of view is defined as the inclination angle of the diamond point 151. The inclination angle θ is also an angle between the extending direction D1 of the orthogonal axis of the vertical plane formed by the ridge line PS of the diamond point 151 and the horizontal plane and the moving direction DA of the diamond point 151. Moreover, inclination angle (theta) can take any positive / negative value. When viewed from the side of the shank 152, the counterclockwise direction is a positive direction of the angle θ.

  When using the scribing tool 150, as shown in FIG. 2A, the axial direction AX2 of the shank 152 is inclined from the vertical direction toward the moving direction DA forward (y-axis positive direction) by a predetermined angle, Also, the diamond point 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 which is not 0 ° is given. Then, the blade tip PF2 of the diamond point 151 is made to slide by moving the scribing tool 150 forward in the moving direction DA while keeping such a contact state. As a result, plastic deformation occurs along the moving direction DA of the diamond point 151. In the present embodiment, the sliding operation of the diamond point 151 which causes such plastic deformation is also referred to as a scribing operation by the diamond point 151.

  As the diamond point 151, a known one can be applied. However, when forming the trench line TL, the inclination angle θ is set in the range of 1.0 ° to 3.0 ° in absolute value. When the absolute value of the inclination angle θ is set to be larger than 3.0 °, the trench line TL is not preferably formed. When the absolute value of the inclination angle θ is smaller than 1.0 °, the extension direction of the crack from the trench line TL is almost perpendicular to the upper surface SF1, and the inclination crack is not preferably formed.

  As shown in FIGS. 1 and 3, the trench line TL is formed on the upper surface SF1 of the brittle material substrate W as a fine line-shaped groove extending in the y-axis direction. The trench line TL is formed as a result of plastic deformation that occurs on the upper surface SF1 of the brittle material substrate W by sliding the diamond point 151 in a state where the posture of the scribing tool 150 is symmetrical with respect to the moving direction DA. .

  The trench line TL is formed from the start point T1 to the end point T2 in the y-axis positive direction indicated by the arrow AR1 at the dividing position defined on the upper surface SF1 of the brittle material substrate W, as shown in FIG. Hereinafter, the range relatively close to the start 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 also referred to as the downstream side.

  In FIG. 1, although the start point T1 and the end point T2 of the trench line TL are positioned slightly apart from the end of the brittle material substrate W, this is not an essential aspect, and the brittleness to be divided is Depending on the type of the material substrate W, the use of the individual pieces after division, etc., either one or both may be set as the end position of the brittle material substrate W. However, in the aspect in which the start point T1 is the end of the brittle material substrate W, the cutting edge PF2 of the scribing tool 150 is different from the case where the position slightly separated from the end is the start point T1 as illustrated in FIG. Since the impact to be applied is large, it is necessary to be careful in terms of the life of the cutting edge PF2 and the occurrence of an unexpected vertical crack.

  In addition, the formation of the trench line TL at each of the plurality of dividing positions may be in a mode of sequentially forming using the scribing tool 150 in a processing device (not shown) including one scribing tool 150, or a plurality of trenches It may be an aspect of forming in parallel by using a processing device for forming the line TL.

  In forming the trench line TL, formation of the trench line TL is reliably performed, which corresponds to a load applied by the scribing tool 150 (corresponding to a force for pushing the scribing tool 150 against the upper surface SF1 of the brittle material substrate W from above vertically). However, in the thickness direction DT of the brittle material substrate W, it is set so that extension of the vertical crack from the trench line TL does not occur (FIG. 3).

  In other words, the formation of the trench line TL is performed so as to maintain the state (crackless state) in which the brittle material substrate W is continuously connected in the direction crossing the trench line TL immediately below the trench line TL. Incidentally, when the trench line TL is formed by the corresponding method, internal stress remains as a result of plastic deformation in the vicinity of the trench line TL of the brittle material substrate W (within about 5 μm to about 10 μm from the trench line TL). Do.

  The residual internal stress tends to be unevenly distributed to the right in the direction of formation of the trench line TL (the direction indicated by the arrow AR1 in FIG. 1) when the inclination angle θ is positive, and when the inclination angle θ is negative. Are tending to be unevenly distributed on the left side in the direction of formation of the trench line TL (the direction indicated by the arrow AR1 in FIG. 1). If it is based on FIG. 3, in the case of the former, there is a tendency to be unevenly distributed below the left half (the positive side in the x-axis direction) of the groove formed as the trench line TL in the drawing, and in the case of the latter, the drawing of the groove It tends to be unevenly distributed below the right half (negative side in the x-axis direction).

  The formation of such a trench line TL sets, for example, the load applied by the scribing tool 150 to a smaller value as compared to the case of forming the scribing line with the extension of the vertical crack using the same scribing tool 150. Is realized.

  In the crackless state, even if the trench line TL is formed, there is no extension of vertical cracks or inclined cracks from the trench line TL, so even if a bending moment acts on the brittle material substrate W, In comparison to the case where such a crack is formed, the division along the trench line TL is less likely to occur.

<Formation of Assist Line and Extension of Inclined Crack>
When the trench line TL is formed in the above-described manner, the assist line AL is subsequently formed.

  FIG. 4 is a top view of the brittle material substrate W illustrating how the assist line AL is formed. FIG. 5 schematically shows a configuration of scribing apparatus 100 used for forming assist line AL. 6 and 7 are top views of the brittle material substrate W illustrating the state of extension of the inclined crack IC with the formation of the assist line AL. FIG. 8 is a zx partial cross-sectional view including the vertical cross section of the trench line TL and the inclined crack IC.

  In the present embodiment, as shown in FIG. 4, in the vicinity of the downstream side of trench line TL, assist line AL is in the positive direction of the x-axis indicated by arrow AR2 (as orthogonal to trench line TL) as starting point A1. To the end point A2 is a processing mark formed by causing plastic deformation on the upper surface SF1 of the brittle material substrate W.

  The assist line AL is performed using the scribing tool 50 provided in the scribing apparatus 100 shown in FIG. The scribing apparatus 100 mainly includes a table 1 on which the brittle material substrate W is placed, and a scribing head 2 for holding a scribing tool 50. The scribing tool 50 includes a scribing wheel (cutter wheel) 51 and a pin 52. And a holder 53.

  The scribing wheel 51 has a disk-like (collar bead-like) shape, and is uniformly provided with a blade edge PF (consisting of a ridge line and a pair of inclined surfaces sandwiching the ridge) substantially in a triangular shape in cross section . The scribing wheel 51 typically has a diameter of about several millimeters. The pin 52 is vertically inserted at the position of the axial center AX of the scribing wheel 51. The holder 53 is held by the scribing head 2 and supports a pin 52 inserted through the scribing wheel 51 in such a manner that the scribing wheel 51 can rotate around the axial center AX. That is, the holder 53 rotatably supports the scribing wheel 51 around the axis AX by the pin 52. More specifically, the holder 53 horizontally supports the pin 52 such that the surface formed by the cutting edge PF (outer peripheral portion) of the scribing wheel 51 extends in the vertical direction.

  The cutting edge PF is formed of, for example, a hard material such as cemented carbide, sintered diamond, polycrystalline diamond or single crystal diamond. From the viewpoint of reducing the surface roughness of the ridge line and the inclined surface described above, the whole scribing wheel 51 may be made of single crystal diamond.

  When forming the assist line AL, the scribing wheel 51 is fixed to the upper surface SF1 of the brittle material substrate W mounted horizontally on the table 1 of the scribing apparatus 100 with the other main surface SF2 as the mounting surface. In the pressure-contacted state, the scribing head 2 holding the scribing tool 50 is moved by the moving mechanism (not shown) in the scribing direction DP which is also the forming advancing direction of the assist line AL indicated by the arrow AR2. Then, the scribing wheel 51 in a state of being in pressure contact with the brittle material substrate W rolls around the axial center AX in the direction indicated by the arrow RT in a state where the cutting edge PF slightly intrudes into the brittle material substrate W. As a result, on the upper surface SF1 of the brittle material substrate W, plastic deformation occurs along the moving direction of the scribing wheel 51 along with the press-contacting rolling of the scribing wheel 51.

  In the present embodiment, the press-contacting and rolling operation of the scribing wheel 51 causing such plastic deformation is referred to as a scribing operation by the scribing wheel 51. The load applied to the brittle material substrate by the scribing wheel 51 when pressing the scribing wheel 51 against the upper surface SF1 can be adjusted by a load adjusting mechanism (not shown) provided on the scribing head 2.

  If formation of the assist line AL in the above-described manner is performed under the condition that the load applied by the scribing wheel 51 is equal to or higher than a predetermined threshold value, each time the assist line AL crosses the trench line TL, As indicated by an arrow AR3 in FIG. 6, starting from the position of the intersection point C with each trench line TL, in the planned extension direction of the inclined crack IC (upstream of the trench line TL in the case of FIG. 6). Extending the inclined crack IC in the thickness direction DT of the brittle material substrate W from the trench line TL sequentially occurs.

  At this time, the extending direction of the inclined crack IC in the thickness direction of the brittle material substrate W, that is, the inclination of the inclined crack IC corresponds to the inclination angle θ of the diamond point 151 when the trench line TL is formed. Specifically, as shown in FIG. 8, at the time of scribing, the vertically downward direction (z-axis positive direction) which is the extending direction of the vertical crack VC extending when the trench line TL is formed with θ = 0 ° as the reference direction Is defined as positive in clockwise direction as viewed from the extending direction of the ridge line PS with respect to the top surface of the (in the present embodiment, the downstream side of the trench line TL), the inclination angle .theta. In this case, δ is also positive. That is, the inclined crack IC inclines and extends from the trench line TL to the positive side in the x-axis direction. On the other hand, when the inclination angle θ is negative, δ is also negative. That is, the inclined crack IC inclines and extends from the trench line TL to the negative side in the x-axis direction. The inclination direction of the inclined crack IC coincides with the side on which the residual internal stress tends to be unevenly distributed when forming the trench line TL described above. This is because a micro crack which is a fine crack generated on the surface of the brittle material substrate W along with the formation of the assist line AL is led immediately below the trench line, and the residual internal stress is released to cause extension of the inclined crack IC. .

  As described above, while the absolute value of the inclination angle θ of the diamond point 151 is set in the range of 1.0 ° to 3.0 °, the absolute value of the inclination angle δ of the inclined crack IC is also 1.0 °. It becomes -3.0 degrees. There is a substantially linear relationship between the inclination angle θ of the diamond point 151 and the inclination angle δ of the inclination crack IC.

  After the formation of the assist line AL, finally, as shown in FIG. 7, extension of the inclined crack IC from the trench line TL occurs at all the dividing positions. That is, the formation of the assist line AL is triggered (the assist line AL is a trigger), and at each division position of the brittle material substrate W which has been in the crackless state although the trench line TL is formed until then. , And an inclined crack IC extending from the trench line TL.

  The planned extension direction of the inclined crack IC is directed to the upstream side of the trench line TL as described above, when the trench line TL is formed using the scribe tool 150 provided with the diamond point 151, the trench line This is because the inclined crack IC generated immediately below the TL has a property of extending to the side where the top surface SD1 exists. That is, the inclined crack IC has a property of extending in a specific one direction. In the present embodiment in which the trench line TL is formed in a mode in which the top surface SD1 of the diamond point is disposed on the upstream side above the trench line TL, the slope on the upstream side of the trench line TL when forming the assist line AL. The crack IC extends but is difficult to extend in the opposite direction.

  The brittle material substrate W in which the inclined crack IC is formed at the dividing position in the above manner is applied to a predetermined breaking device not shown. In the breaking apparatus, the bending step is applied to the brittle material substrate W by the so-called three-point bending or four-point bending method to perform the breaking step of extending the inclined crack IC to the lower surface SF2 of the brittle material substrate W . By passing through the breaking step, the brittle material substrate W is divided at the dividing position.

  As described above, according to the present embodiment, when dividing a brittle material substrate at a predetermined dividing position, vertical cracks and inclined cracks occur immediately below at the forming position corresponding to the dividing position. The formation of the trench line under the non-condition is performed while inclining the diamond point, and by forming the assist line on the upstream side of the trench line, the inclined crack can be extended at the dividing position.

<Example>
Trench lines TL were formed at diamond points 151 having different inclination angles θ, and then assist lines AL were formed to evaluate the inclination angle δ of the extended crack. Specifically, a diamond point 151 having a curvature radius of 9.5 μm of the ridge line PS of the blade edge PF2 is prepared as the diamond point 151, and the inclination angle θ is set to -2.1 °, 0.0 °, 1.9 °. In addition to the difference, the load applied to the diamond point 151 at the time of forming the trench line TL is equal to six levels of 1.0N, 1.1N, 1.3N, 1.4N, 1.5N, and 1.6N. The inclination angle δ was determined for the street case.

  As the brittle material substrate W, a glass substrate having a thickness of 0.2 mm was prepared. The moving speed of the scribing head 2 at the time of forming the assist line AL is 100 mm / sec, and as the scribing wheel 51, the wheel diameter is 2.0 mm, the thickness is 0.65 mm, and the diameter of the insertion hole of the pin 52 is 0.8 mm. The blade angle of 100 ° was used.

  FIG. 9 is a graph in which the relationship between the load applied to the diamond point 151 when forming the trench line TL and the inclination angle δ of the formed crack is plotted for each case where the value of the inclination angle θ is the same. Further, FIG. 10 shows, based on the results shown in FIG. 9, the averages for the inclination angles δ of six types of cracks different in load applied to the diamond point 151 with respect to the three levels of inclination angles θ given to the diamond point 151. It is the graph which plotted the value (Ave.), the maximum value (Max), and the minimum value (Min).

  From FIG. 9 and FIG. 10, the inclination angle θ given to the diamond point 151 when forming the trench line TL and the formation of the assist line AL after the formation of the trench line TL and the cracks extending from the trench line TL It is confirmed that there is approximately positive correlation with the inclination angle δ.

  Further, in FIG. 11, a breaking process is performed after formation of the inclined crack IC on a glass substrate in which a trench line TL is formed by applying a load of 1.6 N to the diamond point 151 whose inclination angle θ is −2.1 °. It is an optical microscope image of the piece obtained by More specifically, FIG. 11 shows a piece obtained by breaking the glass substrate in which the trench line TL is formed such that the inclination angle θ is −2.1 ° and the front side in the drawing is on the downstream side. ing. It is confirmed from FIG. 11 that the cross section is inclined in the direction shown as the case of θ <0 in FIG. This means that the inclined crack IC is formed in such a direction.

<Modification>
In the above embodiment, the assist line AL is formed after the trench line TL is formed, but the formation order of the trench line TL and the assist line AL may be reversed.

  In the above embodiment, the trench line TL and the assist line AL are orthogonal to each other on the upper surface SF1 of the brittle material substrate W, but this is not an essential aspect, and a trench line associated with the formation of the assist line AL. The trench line TL and the assist line AL may obliquely intersect as long as the extension of the inclined crack from the TL is preferably realized.

  Furthermore, in the above embodiment, the point at which the trench line TL and the assist line AL intersect is the starting point of the inclined crack extension, but in the aspect of extending the inclined crack by forming a micro crack in the vicinity of the trench line TL. It may be. The formation of the micro crack is performed, for example, by forming an indentation by locally pressing the vicinity of the trench line TL on the upper surface SF1 of the brittle material substrate W with a predetermined pressing body. With the formation of the indentation, the micro crack extending from the indentation reaches below the trench line TL, whereby the inclined crack extends immediately below the trench line.

  In the above embodiment, the trench line TL is formed by the scribing tool 150 in a state where the axial direction AX2 of the shank 152 is inclined forward in the moving direction DA, that is, the moving direction DA of the top surface SD1. It is performed by sliding the diamond point 151 in a posture directed rearward, but instead, in a state in which the axial direction AX2 of the shank 152 is inclined rearward in the moving direction DA, that is, Alternatively, the trench line TL may be formed by sliding the diamond point 151 in a posture in which the top surface SD1 is directed forward in the moving direction DA.

  However, in the case of such an aspect, unlike the above-described embodiment, the planned extension direction of the inclined crack is on the downstream side of the trench line TL. Therefore, in the aspect, the assist line AL is formed in the vicinity of the upstream side of the trench line TL. Further, in this aspect, the ridge line to the top surface at the time of scribing is set with the vertically downward direction (z-axis positive direction) which is the extending direction of the vertical crack VC extending when the trench line TL is formed with θ = 0 °. If the inclination angle δ of the inclined crack IC is defined with positive clockwise as viewed from the extension direction of PS (in the embodiment, on the upstream side of the trench line TL), δ is also positive if the inclination angle θ is positive. Be positive. That is, the inclined crack IC inclines and extends from the trench line TL to the positive side in the x-axis direction. On the other hand, when the inclination angle θ is negative, δ is also negative. That is, the inclined crack IC inclines and extends from the trench line TL to the negative side in the x-axis direction. The inclination direction of the inclined crack IC coincides with the side on which the residual internal stress tends to be unevenly distributed when forming the trench line TL described above.

  Also in this case, extension of the inclined crack from the trench line TL preferably occurs in the planned extension direction of the inclined crack IC, as in the above-described embodiment.

  Alternatively, in the above embodiment, the diamond point 151 is used to form the trench line TL, but instead, the trench line TL is formed by pressing and rolling the scribing wheel 51 of the scribing device 100. It may be an aspect. In this case, the angle between the extending direction of the orthogonal axis of the vertical plane including the ridge line PF of the scribing wheel and the horizontal plane and the moving direction of the scribing tool is the inclination angle, and the counterclockwise angle is θ when viewed from the holder side. It is the positive direction of

  However, also in this aspect, unlike the above-described embodiment, the planned extension direction of the inclined crack IC is on the downstream side of the trench line TL. Therefore, in these modes, the assist line AL is formed in the vicinity of the upstream side of the trench line TL in a state where the scribing wheel 51 is inclined so that the inclination angle θ is negative as in the second embodiment described above. Make it Similar to the above embodiment, extension of the inclined crack from the trench line TL preferably occurs in the planned extension direction of the inclined crack IC.

  In addition, in the aspect, when the trench line TL is formed with θ = 0 °, the vertically downward direction (z-axis positive direction) which is the extending direction of the vertical crack VC extending is set as the reference direction from the downstream side of the trench line TL. In the case of defining the inclination angle δ of the inclined crack IC with the clockwise direction being positive, the inclination angle θ is also positive when the inclination angle θ is positive. That is, the inclined crack IC inclines and extends from the trench line TL to the positive side in the x-axis direction. On the other hand, when the inclination angle θ is negative, δ is also negative. That is, the inclined crack IC inclines and extends from the trench line TL to the negative side in the x-axis direction. The inclination direction of the inclined crack IC coincides with the side on which the residual internal stress tends to be unevenly distributed when forming the trench line TL described above.

<Application to curvilinear division>
In the above embodiment, the dividing position for dividing the brittle material substrate W is linear, but in the above embodiment, the formation of the inclined crack is determined when the dividing position is curved. Application is possible. Hereinafter, the case where the dividing position is determined to be circular and the brittle material substrate W is truncated in a truncated cone shape along the dividing position will be described as an example.

  FIG. 12 is a diagram showing the formation positions of the trench line TL and the assist line AL when the dividing position is determined to be circular. In such a case, the trench line TL is formed on the top surface SF1 of the brittle material substrate W from the start point T1 along the predetermined circular dividing position, in which case the tangent direction of the dividing position is the diamond point 151 And the inclination angle θ is given with reference to the tangential direction (direction D1 is determined).

  Then, the trench line TL is formed in a circular shape while maintaining the inclination angle θ. However, the end point T2 is set slightly outside the start point T1. When the assist line AL is formed in a manner to cross the trench line TL in the vicinity of the end point T2, extension of the inclined crack IC along the trench line TL occurs from the intersection toward the start point T1.

  FIG. 13 schematically shows the appearance of the brittle material substrate W after the trench line TL and the assist line AL are formed in the mode shown in FIG. The inclined crack IC formed in the mode shown in FIG. 12 is inclined to the outside of the brittle material substrate W with respect to the thickness direction of the brittle material substrate W, as shown in FIG. At this time, the area surrounded by the inclined crack IC is a truncated cone (a trapezoidal shape in cross section).

  In such a case, as shown by arrow AR4, when a force is applied to the region surrounded by the inclined crack IC from above the brittle material substrate W, the inclined crack IC further extends. Finally, when the inclined crack IC reaches the opposite surface (lower surface SF2), as shown by arrow AR5 in FIG. 13 (b), the truncated cone (cross-sectional trapezoidal shape) piece W1 is hollowed out.

  FIGS. 14 and 15 are diagrams showing the positions where the trench lines TL and the assist lines AL are formed in a mode different from the mode shown in FIG. 12 when the brittle material substrate W is hollowed out in a truncated cone shape. In the mode shown in FIG. 14, the end point T2 is set to be shifted inward from the start point T1. Also in this case, when the assist line AL is formed in a mode of crossing the trench line TL near the end point T2, extension of the inclined crack IC along the trench line TL occurs from the intersection toward the start point T1.

  While the embodiment shown in FIG. 12 is generally applied when it is desired to obtain a truncated cone-shaped portion, the embodiment shown in FIG. 14 normally has a portion other than the truncated cone-shaped portion. It is applied when you want to acquire. All the modes are common in that the location where the assist line AL is not formed is to be acquired.

  Further, in the mode shown in FIG. 15, the end point T2 is set such that the trench line TL itself overlaps in the vicinity of the start point T1. In such a case, even if the assist line AL is not formed, the overlapping portion of the trench line TL plays a role as the assist line AL, so that a truncated cone-like piece similar to the case shown in FIG. A drilling is realized.

  In the example described above, the dividing position is determined to be circular, but even when the dividing position is determined in another curved shape, the trench line TL is given in such a manner that the inclination angle θ is given to the tangential direction. By forming the inclined crack, the inclined crack can be extended along the dividing position.

1 table 2 scribing head 50 scribing tool 51 scribing wheel 100 scribing device 150 diamond point AL assist line IC inclined crack PF (for scribing wheel) cutting edge PF2 (for diamond point) cutting edge PP (for diamond point) vertex PS (diamond) Point) ridgeline TL trench line W brittle material substrate

Claims (4)

A method of forming an inclined crack in a brittle material substrate, comprising:
A trench line forming process for forming a trench line which is a line-like groove by sliding or rolling a scribing tool having a cutting edge including a ridge along a predetermined dividing position of one principal surface of the brittle material substrate When,
A crack forming step of generating a crack immediately below the trench line;
In the trench line formation step, a crackless state is maintained immediately below the trench line in a state where the ridge line of the scribe tool is inclined at a predetermined inclination angle from the direction of formation of the trench line in a horizontal plane. Forming the trench line on the
In the crack forming step, an inclined crack which is a crack inclined from the trench line to the main surface of the brittle material substrate is extended.
A method of forming an inclined crack in a brittle material substrate, characterized in that A method for forming a sloped crack in a brittle material substrate according to claim 1, wherein
The absolute value of the tilt angle is 1.0 ° to 3.0,
A method of forming an inclined crack in a brittle material substrate, characterized in that A method of forming a graded crack in a brittle material substrate according to claim 1 or 2,
The dividing position is defined in a curved shape,
In the trench line forming step, the trench is maintained such that a crackless state is maintained immediately below the trench line in a state where the scribe tool is inclined at a predetermined inclination angle from the tangential direction of the dividing position in a horizontal plane. Form a line,
A method of forming an inclined crack in a brittle material substrate, characterized in that A method of dividing a brittle material substrate,
An inclined crack forming step of forming an inclined crack in the brittle material substrate by the method of forming an inclined crack according to any one of claims 1 to 3.
A breaking step of breaking the brittle material substrate along the inclined crack;
A method of dividing a brittle material substrate, comprising: