TWI666182B - Breaking method and processing device for brittle material substrate - Google Patents

Abstract

In the present invention, when the glass substrate is broken, when a plurality of scribe lines are formed with a narrow pitch or cross, the reduction in processing quality is suppressed.

This method includes a first step and a second step. The first step is to move the scoring wheel against the surface of the glass substrate with a specific load, and form a breaking groove along a predetermined breaking line. The second step is to break the glass substrate by applying a breaking force to the breaking groove formed in the first step. In addition, the pressing load of the scoring wheel on the glass substrate in the first step is a load that does not generate ribs when the groove is formed in the first step, and forms a vertical crack directly below the groove.

Description

Breaking method and processing device for brittle material substrate

The invention relates to a method for breaking a substrate of a brittle material, and more particularly to a method for breaking a substrate of a brittle material along a predetermined breaking line. The present invention also relates to a processing device for a brittle material substrate.

In the manufacturing process of the liquid crystal display panel, after the mother substrate forms a crossed scribe line, a breaking force is applied to the mother substrate, and the unit substrate is divided into a plurality of unit substrates along the scribe line.

When forming a scribe line on a mother substrate, for example, a method as shown in Patent Literature 1 and Patent Literature 2 is used. In the methods described in these documents, first, a scribing wheel is used to form a scribe line on the surface of a glass substrate. Thereafter, a breaking force is applied to the glass substrate, thereby breaking along the scribe line.

In particular, in Patent Document 2, the processing is performed so that ribbed lines are present in the scribe lines (breaking grooves). Generally speaking, ribs are formed directly below the groove, and vertical cracks extend from the front end of the ribs in the thickness direction of the substrate. By forming ribs on the scribe lines, the mother substrate can be broken with a relatively small force.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2012-6780

[Patent Document 2] Japanese Patent Laid-Open No. 2008-308380

As shown in Patent Document 2, when the glass substrate is divided, when the slitting groove is formed, the scribe wheel is pressed against the glass with a relatively large pressing load so as to form a rib pattern. Substrate. Thereby, deep cracks are formed along the thickness direction of the glass substrate, and when broken, the glass substrate can be cut well without causing cracks in the horizontal direction.

However, in recent years, a very small unit substrate is required to be separated from a mother substrate. In this case, it is necessary to form a plurality of scribe lines with a narrow pitch, or to cross-scribe with a narrow pitch. In this case, the stress generated by the scribe line formed first may adversely affect the scribe line formed later. Specifically, there is a problem that the quality of the surface (horizontal cracks, chips, peeling, burrs, etc.) is deteriorated on the surface where the scribe line crosses, or the cut end surface becomes non-vertical.

The object of the present invention is to suppress a reduction in processing quality when a brittle material substrate such as a glass substrate is divided, particularly when a plurality of scribe lines are formed with a narrow pitch or a cross scribe is formed.

A method for cutting a brittle material substrate according to one aspect of the present invention is a method of breaking a brittle material substrate along a predetermined breaking line, and includes a first step and a second step. The first step is to move the cutting blade while pressing it against the surface of the brittle material substrate, and form a cutting groove along a predetermined cutting line. In the second step, a breaking force is applied to the breaking groove formed in the first step, and the brittle material substrate is cut. Moreover, in the first step, the pressing load of the cutting blade on the brittle material substrate is a load that does not generate ribs when the groove is formed in the first step, and forms a vertical crack directly below the groove.

Here, the pressing load of the dicing blade on the brittle material substrate is set to be relatively small, and the dicing blade is moved to form a dicing groove along a predetermined dicing line on the surface of the fragile material substrate. By forming the breaking groove in this way, it is not easy to accumulate stress along the inside of the brittle material substrate of the groove. Therefore, when other grooves are formed in the vicinity of the breaking groove formed earlier, or cross grooves are formed, it is difficult to generate debris. And for the same reason The perpendicularity of the end face of the brittle material substrate becomes good.

In addition, the "rib pattern" in the present invention refers to a crack that is continuously below the plastic deformation region formed by pressing the cutting blade against the surface of the substrate and moving it, and continues along the breaking direction. A plurality of curved (ribbed) stripes extending along the thickness direction of the substrate were observed on the end surface (partial surface) of the substrate and formed in the thickness direction of the substrate. A vertical crack was not observed from the front end of the rib pattern (the end portion on the inner side of the substrate) in the thickness direction of the substrate.

In the method for cutting a brittle material substrate according to another aspect of the present invention, in a first step, the cutting blade is pressed against the brittle material substrate with a load of 10N or less and 1N or more.

By processing the cutting blade against the brittle material substrate with such a small pressing load, it is possible to form grooves and vertical cracks required for breaking without generating ribbed lines inside the brittle material substrate.

In the method for cutting a brittle material substrate according to another aspect of the present invention, in the first step, the cutting blade is pressed against the brittle material substrate with a load of 6N or less and 1N or more.

Here, the grooves and vertical cracks required for the topography can be more surely formed without generating rib-like patterns inside the brittle material substrate.

In the method for cutting a brittle material substrate according to another aspect of the present invention, in the first step, a glass substrate having a thickness of 0.1 mm or more and 1 mm or less is formed to include a depth from the surface of 3% or more of the thickness of the substrate and Slots in plastic deformation area below 15%.

Here, compared with the previous processing method, the depth of the plastic deformation region formed in the first step is shallow. Therefore, it is possible to reduce the stress accumulated in the interior of the brittle material substrate when processing is performed in the first step, and it is possible to suppress a reduction in processing quality.

In the method for cutting a brittle material substrate according to another aspect of the present invention, in the second step, the breaking groove formed in the first step is directed downward to support both sides of the groove on the surface of the brittle material substrate. Or use an elastomer (for example, an elastic sheet such as a rubber sheet laid on a platform containing a hard material such as metal or ceramic) to support the surface of a brittle material substrate Body, and presses the back surface of the brittle material substrate at the portion where the groove is formed from above to divide.

By this cutting method, the perpendicularity of the cutting end surface of the brittle material substrate obtained after the cutting can be made good.

In the method for cutting a brittle material substrate according to another aspect of the present invention, the brittle material substrate is glass.

The processing device for a brittle material substrate according to one aspect of the present invention is a device for forming a breaking groove and a vertical crack on the surface of the brittle material substrate along a predetermined breaking line. The device includes a platform on which a brittle material substrate is placed, a cutting blade for cutting the brittle material substrate, a cutting blade pressing mechanism, and a moving mechanism. The cutting blade is freely arranged above the platform. The cutting blade pressing mechanism presses the cutting blade against the surface of the brittle material substrate. The moving mechanism relatively moves the cutting blade and the platform along a predetermined breaking line, and forms a breaking groove on the brittle material substrate. In addition, the cutting blade pressing mechanism presses the cutting blade against the brittle material substrate with a load of a size that does not generate ribs in the cutting groove and forms a vertical crack directly below the groove (the inner side of the substrate).

In the processing device for a brittle material substrate in another aspect of the present invention, the cutting blade is a scoring wheel having an outer peripheral edge portion, and the outer peripheral edge portion is formed by the intersection of the bottoms of the two conical tables having a common rotation axis to form a circumferential ridge line. The scribing wheel has a plurality of notches and protrusions formed alternately in a circumferential direction along a circumferential ridge line.

In the apparatus for processing a brittle material substrate according to another aspect of the present invention, the notch of the scoring wheel is formed at a distance of 10 μm or more and 50 μm (preferably 10 μm or more and 40 μm or less) along the entire circumference of the circumferential ridge line. The depth of the notches is 0.5 μm or more and 5.0 μm or less (preferably 1.0 μm or more and 3.0 μm or less).

In addition, the type with a notch in the circumferential direction of the scoring wheel has a shorter length than the protrusion in the circumferential direction, and the type with a longer length in the circumferential direction of the protrusion is longer in the circumferential direction of the notch than the protrusion In the type of scoring wheel with a relatively short length, there is a tendency that the vertical cracks are formed relatively deep. In the scoring wheel of a type having a length longer than that of the protrusion in the circumferential direction, there is a tendency that the end face strength of the substrate after breaking is relatively high.

In the present invention as described above, when breaking a brittle material substrate, especially when a plurality of breaking grooves (scribe lines) are formed with a narrow pitch, or when crossed grooves (scribe lines) are formed (Cross scribe), it is possible to suppress a reduction in processing quality.

1‧‧‧ scoring device

2‧‧‧ platform

3‧‧‧ Scribing Wheel

3a‧‧‧Circular Ridge

3b‧‧‧outer periphery

3c‧‧‧ gap

3d‧‧‧ protrusion

3e‧‧‧through hole

4‧‧‧Pressing mechanism

5‧‧‧ mobile agency

10‧‧‧ Scribble head

15‧‧‧rail

16‧‧‧ball screw

17‧‧‧Guide

18‧‧‧ Motor

19‧‧‧CCD camera

22‧‧‧ Disconnecting platform

a‧‧‧length

b‧‧‧ length

h‧‧‧ depth

C‧‧‧cone

F‧‧‧ breaking force

G‧‧‧ glass substrate

L‧‧‧ Breaking slot

P‧‧‧Pitch

R‧‧‧rotation shaft

X‧‧‧X direction

Y‧‧‧Y direction

Z‧‧‧Z direction

FIG. 1 is a schematic configuration diagram of a processing apparatus according to an embodiment of the present invention.

Fig. 2 is a side view of a scribing wheel according to an embodiment of the present invention.

Figure 3 is a front view of the scoring wheel.

FIG. 4 is a partially enlarged view of FIG. 3.

Fig. 5 is a schematic diagram showing a breaking step.

FIG. 6 is a microscope photograph showing a comparison between a cutting method according to an embodiment of the present invention and a previous cutting method.

[Scribe device]

FIG. 1 shows a device for forming a breaking groove in a glass substrate (an example of a brittle material substrate). The scoring device 1 includes a platform 2, a scoring wheel 3, a pressing mechanism 4, and a moving mechanism 5.

The stage 2 is used to place a glass substrate G, and the glass substrate G placed thereon is fixed by a vacuum suction member. The platform 2 can be rotated horizontally.

The scoring wheel 3 is attached to the scoring head 10. The scoring wheel 3 rolls in a state pressed against the glass substrate G, and a breaking groove and a vertical crack are formed on the glass substrate G. As shown in FIG. 2 and FIG. 3, the scoring wheel 3 has an outer peripheral edge portion 3b which intersects the bottom of two cones C having a common rotation axis R to form a circumferential ridge line 3a; , Which are formed along the circumferential ridge line 3a in the circumferential direction. A through hole is formed in the center of the scoring wheel 3 3e.

As shown in the enlarged view of FIG. 4, the notch 3 c of the scoring wheel 3 is formed along the entire circumference of the circumferential ridge line 3 a at a distance P of 10 μm or more and 50 μm (preferably 10 μm or more and 40 μm or less). The depth h of the notch 3c is preferably 0.5 μm or more and 5.0 μm or less (particularly, 1.0 μm or more and 3.0 μm or less). In the scoring wheel shown in FIG. 4, the circumferential length a of the notch 3c is formed to be shorter than the circumferential length b of the protrusion 3d.

The pressing mechanism 4 includes, for example, an air cylinder or a hydraulic cylinder, and is provided on the scoring head 10. The pressing mechanism 4 can adjust the pressing load of the scoring wheel 3 against the glass substrate G. As the pressing mechanism 4, a servo motor can also be used.

The moving mechanism 5 is a mechanism for relatively moving the platform 2 and the scoring head 10 in the X direction and the Y direction. The X direction is the left-right direction in FIG. 1, and the Y direction is a direction orthogonal to the X direction and perpendicular to the paper surface in FIG. 1.

The moving mechanism 5 includes a pair of guide rails 15, a ball screw 16, a guide rod 17, and a motor 18. The pair of guide rails 15 extend in the Y direction and are arranged in parallel with each other, and support the platform 2 in a movable manner in the Y direction. The ball screw 16 moves the platform 2 along a pair of guide rails 15. The guide rod 17 is erected above the platform 2 in the X direction. A scoring head 10 is provided on the guide rod 17 so as to be slidable in the X direction. The motor 18 slides the scoring head 10 along the guide bar 17. Furthermore, a pair of CCD (Charge Coupled Device) cameras 19 are arranged above the guide rod 17 to identify the alignment marks of the glass substrate G formed on the platform 2.

[Breaking method of glass substrate]

Here, as an example, a method for forming a plurality of unit substrates by forming a cutting groove crossing in the X and Y directions on the mother substrate and dividing the mother substrate along the cutting groove is described.

First, a glass substrate G serving as a mother substrate is placed on the stage 2. The alignment mark formed on the glass substrate G is observed by the CCD camera 19, and the position of the glass substrate G on the stage 2 is adjusted.

Then, the scoring head 10 is moved to the scoring start position by the moving mechanism 5, and the scoring wheel 3 is pressed against the surface of the glass substrate G with a specific load by the pressing mechanism 4. The pressing load at this time is set to such a degree that ribs are not formed inside the glass substrate G when the breaking groove is formed, and a vertical crack is formed directly below the groove. Furthermore, in this example, the scribe starting position is a position that enters from the edge of the glass substrate G to the inside.

Then, the moving mechanism 5 is driven to move the glass substrate G or the stage 2 along a plurality of predetermined breaking lines in the X direction, for example. If the process of forming the grooves by the plurality of predetermined breaking lines in the X direction is completed, the grooves are similarly formed by the plurality of predetermined breaking lines in the Y direction. In this example, the end position of each scribe is the same as the start position, and it is the position which entered from the edge of the glass substrate G to the inside.

After the breaking grooves are formed along all of the breaking lines as described above, as shown in FIG. 5, the surface of the glass substrate on which the breaking groove L is formed faces downward, and is placed on the breaking platform 22. Then, a specific breaking force F is applied to the upper side, that is, the side opposite to the surface on which the breaking groove L is formed. Thereby, the glass substrate G is cut along the cutting groove L.

[Experimental example]

FIG. 6 shows an experimental example using a method according to an embodiment of the present invention and a conventional method. The "low-permeability scribing" in Fig. 6 indicates a method according to an embodiment of the present invention, and the "normal scribing" indicates a previous method.

<Condition>

The experimental conditions are as follows.

(1) Glass substrate

The low-permeability scribing and usual scribing are as follows.

Material: Alkali-free glass

Thickness: 0.5mm

(2) Scoring wheel presses against load

Low-permeability scribing: 3N

Usually scribed: 16N

(3) the distance between the lines (cross-cut)

Low-permeability scoring and usual scoring are 3mm

Processing according to the above conditions, the results are as follows.

<Result of Forming Step of Breaking Groove>

In the low-permeability scoring, the depth of the plastic deformation region (groove) formed by the scoring wheel 3 is 10 μm, and vertical cracks are formed below the plastic deformation region and directly below, and no ribbing is observed. Vertical cracks extend from the surface of the substrate to a depth of 25 μm.

In the normal scribing, ribbed lines were observed below the groove formed by the scribing wheel 3. In addition, the vertical cracks extend deeper from the ribs to the bottom. If the observation surface and the intersection point are enlarged, in the low-permeability scratch, no depression such as debris, especially in the intersection point, but in the ordinary scratch, debris appears at the intersection point.

<Result of breaking step>

If you observe the "separation perpendicularity" of the cutting end face, it can be seen that in the low-permeability scribe, the rip is roughly vertical, but in the normal scribe, the part near the upper surface is cut diagonally and is not vertical. Grounding.

[to sum up]

From the results of the above experiments, it is understood that the following conditions are preferable in order to suppress the deterioration of the cutting processing quality.

The pressing load of the scoring wheel is preferably 10N or less and 1N or more, and a more preferable range is 6N or less and 1N or more.

(2) For a glass substrate having a thickness of 0.1 mm or more and 1.0 mm or less, it is preferable to form a plastic deformation region having a depth from the surface of the glass substrate of 3% to 15% of the thickness of the substrate to resist the load. In this case, no ribs are generated, and a vertical crack is formed just below the plastic deformation region, so that the cutting can be easily performed in the cutting step.

[Other embodiments]

The present invention is not limited to the embodiments described above, and various changes or modifications can be made without departing from the scope of the present invention.

In the embodiment described above, the scoring wheel is used as the scoring cutter, but other cutters may be used. The specifications of the scribing wheel are not limited to the embodiments described above.

Although the glass substrate is described as an example of the brittle material substrate, the brittle material substrate that is an object of the present invention is not limited to the glass substrate.

Claims (9)

A method for cutting a brittle material substrate, which comprises cutting a brittle material substrate along a predetermined breaking line, and includes: a first step, which presses a cutting blade against a surface of the brittle material substrate while moving it along the cutting line; The predetermined line forms a cross groove for breaking; and a second step, which applies a breaking force to the breaking groove formed in the first step, and breaks the brittle material substrate; and the cutting blade in the first step, The compressive load on the brittle material substrate is a load that does not generate ribs when a groove is formed in the first step, and forms a vertical crack directly below the groove. For example, the breaking method for a brittle material substrate according to claim 1, wherein in the first step described above, the cutting blade is pressed against the brittle material substrate with a load of 10N or less and 1N or more. For example, the method for breaking a brittle material substrate according to claim 2, wherein in the first step described above, the cutting blade is pressed against the brittle material substrate with a load of 6N or less and 1N or more. The cutting method for a brittle material substrate according to any one of claims 1 to 3, wherein in the above first step, for a brittle material substrate having a thickness of 0.1 mm or more and 1.0 mm or less, a substrate including a depth from the surface is formed. Grooves in plastically deformed areas with a thickness of 3% to 15%. The breaking method for a brittle material substrate according to any one of claims 1 to 3, wherein in the second step, the breaking groove formed in the first step is directed downward to support the groove on the surface of the brittle material substrate. Both sides, or the entire surface of the fragile material substrate is supported by an elastomer, and the back of the fragile material substrate where the groove is formed is pressed from above to cut off. The breaking method of a brittle material substrate according to any one of claims 1 to 3, wherein the brittle material substrate is glass. A processing device for a brittle material substrate, which is formed along the breaking line to form a crossing groove and a vertical crack on the surface of the brittle material substrate, and includes: a platform for placing the brittle material substrate; The cutting blade for cutting is freely arranged above the platform; the cutting blade pressing mechanism presses the cutting blade against the surface of the brittle material substrate; and the moving mechanism makes the cutting blade and the platform scheduled to be broken along. The relative movement of the wire causes the breaking groove to be formed on the brittle material substrate; and the cutting blade pressing mechanism is a load that does not generate ribs in the breaking groove and forms a vertical crack directly below the groove. The cutting blade is pressed against the brittle material substrate. For example, the processing device for a brittle material substrate according to claim 7, wherein the cutting blade is a scoring wheel having an outer peripheral edge portion, and the outer peripheral edge portion is formed by the intersection of the bottoms of two conical frustums having a common rotation axis, and a circular ridge line is formed. The scoring wheel has a plurality of notches and protrusions formed alternately in a circumferential direction along the circumferential ridge line. For example, the processing device for a brittle material substrate of claim 8, wherein the notch of the scoring wheel is formed along the entire circumference of the circumferential ridge line with a pitch of 10 μm or more and 50 μm or less, and the depth is 0.5 μm or more and 5.0 μm or less.