JP2014198658A - Method of breaking high-strength glass substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of breaking a high-strength glass substrate which allows mirror surface processing without deviation of a breaking line from a scribe line or occurrence of chipping or shark teeth in breaking processing of a high-strength substrate.SOLUTION: A high-strength glass substrate 1 in which a scribe line 10 is formed along a cleavage schedule line 10 of the high-strength glass substrate 1 by laser scribing is supported on a breaking table 2 so that the scribe line 10 is in the back surface, and a resin 42 having flexibility is pressed at the position corresponding to the scribe line 10 on the surface of the high-strength glass substrate 1 opposite to the surface having the scribe line 10 so as to hold the scribe line uniformly, and a pressure is applied to an initial crack 11 of the scribe line 10.

Description

The present invention is applied to a glass for flat panel displays used in smartphones, tablet terminals, notebook computers, touch table screens, television screens, etc., in particular aluminosilicate glass or float glass having a chemically strengthened glass surface, and then subjected to air cooling. The present invention relates to a method for breaking a high-strength glass substrate for processing tempered glass (hereinafter collectively referred to as high-strength glass).

Recently, in the cutting of glass substrates, a thermal stress scribing method (hereinafter abbreviated as laser scribing) using laser beam irradiation has come to be used in place of the diamond tip mechanical method that has been used for the past century. . According to laser scribing, defects inherent in the mechanical method, that is, a decrease in glass strength due to the occurrence of microcracks, contamination due to the occurrence of cullet at the time of cleaving, the presence of a lower limit value of the applied plate thickness, and the like can be eliminated.

In laser scribing, generally, glass is locally heated and irradiated with laser light to the extent that vaporization, melting, and cracks do not occur. At this time, the glass heating portion tries to expand thermally, but cannot sufficiently expand due to the reaction from the surrounding glass, and compressive stress is generated in this heating region. Even in the peripheral non-heated region, the peripheral portion is further distorted by the expansion from the heating portion, and as a result, compressive stress is generated. Such compressive stress is in the radial direction with the heating center point as the origin, and propagates throughout the glass plate almost at the speed of sound after heating occurs. When the object has a compressive stress, a tensile stress proportional to the Poisson's ratio is generated in the orthogonal direction.

If there is a crack at the position where the tensile stress is present, stress expansion occurs at the crack tip, and if the expanded stress exceeds the fracture toughness value of the material, the crack expands. That is, a controlled cleaving occurs in which the crack progresses from the crack tip toward the heating center. Therefore, the crack can be extended by scanning the laser irradiation point in advance.

Laser scribing of glass substrates uses this principle, and when cooling is performed near the maximum point of tensile stress, the tensile stress amplified by the shrinkage of the glass at this time is useful for strengthening the cleaving, and cleaving by combining heating and cooling. Has been proposed (see Patent Document 1).
According to Patent Document 1, CO2 laser light is used as the heating laser light. 99% of the energy in the beam spot of the CO2 laser light is absorbed by the glass surface layer having a depth of 3.7 μm of the glass plate 6 and is not transmitted through the entire thickness of the glass plate. This is due to the extremely large absorption coefficient of glass at the CO2 laser wavelength. As a result, heating occurs only in the surface layer of the glass plate, and compressive stress is generated in this heating region.

When cooling is performed at a cooling point located outside the heating region, tensile stress is generated, and surface scribes starting from the initial crack are generated behind the cooling point. The depth of this scribe is usually about 100 μm for soda glass or the like. However, the glass plate is highly brittle and it is easy to mechanically cleave it by applying a bending stress in accordance with this scribe line. The process of cleaving by applying the bending stress is referred to as “break”. The laser beam is scanned in the scanning direction. This method has many advantages compared with the conventional mechanical method, and has gradually been applied to the production of flat panel display devices.

As a break method, the process of cleaving by applying bending stress is to support the glass substrate on which the scribe line is formed in advance along the planned breaking line on both sides of the scribe line, and to the main surface of the supported glass substrate. A method in which a pressure blade is pressed along a scribe line from the side opposite to the surface to which the scribe line is attached, and is folded along a scribe line previously attached to a glass substrate (see Patent Document 2). In addition, a method has been proposed in which a position where the glass substrate is to be cut is received from a jig and fixed, and a break actuator is applied to the protruding portion of the glass substrate to fold the glass substrate (Patent Document 3 and Patent Document 4).

Japanese Patent No. 3027768 Japanese Patent Laid-Open No. 5-319846 No. 2-4099 JP 2006-319846 A

On the other hand, in recent years, high-strength glass with chemically strengthened glass front and back surfaces has been utilized as glass for flat panel displays such as smartphones, tablet terminals, laptop computers, touch table screens and TV screens to increase the hardness of the glass surface. Has been. As such high-strength glass, for example, gorilla glass from Corning, IOX-FS glass, Dragon Trail glass from Asahi Glass (all are trade names), and the like are known.

The break methods according to Patent Documents 2 to 4 have no problem in break processing of a glass substrate with ordinary soda glass, but in the case of high-strength glass, the break line may be deviated from the scribe line, There is a problem that the quality of the glass substrate after the breakage is deteriorated, for example, chipping and shark teeth are generated and the glass strength is lowered.

The present invention solves such problems, and in break processing of a high-strength glass substrate, the break line does not deviate from the scribe line, and mirror surface processing can be performed without generating chipping or shark teeth on the break surface. An object of the present invention is to provide a break method for a high-strength glass substrate that can be realized.

In order to achieve the above object, the present invention supports a high-strength glass substrate on which a scribe line is formed by laser scribing along a planned cutting line of a high-strength glass substrate on a break table so that the scribe line is on the back surface. Applying pressure to the initial crack of the scribe line while pressing the flexible resin at the position corresponding to the scribe line on the surface opposite to the scribe line of the high-strength glass substrate and pressing the scribe line uniformly By doing so, the crack is advanced along the scribe line to break the high-strength glass.
According to the above configuration, in the break processing of the high-strength glass substrate, the break line does not deviate from the scribe line, and mirror surface processing can be realized without generating chipping, shark teeth, cullet, or the like on the break surface.

Moreover, this invention forms the resin which has a softness | flexibility which presses the position corresponding to the scribe line of the surface on the opposite side to the scribe line of a high intensity | strength glass substrate in the shape of a hollow pipe. According to the above configuration, even when the front and back surfaces of the glass substrate are somewhat uneven, the variation in tightening force when the glass substrate 1 is held between the blade and the break table can be reduced, and the positioning of the scribe line and the blade can be reduced. The accuracy can be relaxed.

  In the present invention, at least the surface of the break table is formed of a flexible resin. According to the said structure, since the force which pulls glass horizontally centering on a scribe line generate | occur | produces, a break line does not deviate from a scribe line.

According to the present invention, in the break processing of a high-strength glass substrate, the break line is not deviated from the scribe line, and mirror surface processing can be realized without generating chipping, shark teeth, cullet, or the like on the break surface. In addition, even if the front and back surfaces of the glass substrate are somewhat uneven, it is possible to reduce the variation in the tightening force when the glass substrate 1 is held between the blade and the break table, and to reduce the positioning accuracy of the scribe line and the blade. Can do.

The conceptual side view explaining the mode at the time of glass substrate installation position adjustment in the break device of the high strength glass which concerns on the Example of this invention Front view of the break blade and the blade cylinder when viewed from the camera direction in FIG. The top view which shows the glass substrate imaging | photography position at the time of the high strength glass installation position adjustment in the break method of the high strength glass which concerns on the Example of this invention. The conceptual side view explaining the mode at the time of the break position adjustment of the glass substrate in the break method of the high strength glass which concerns on the Example of this invention 4A and 4B are views of the break blade and the blade cylinder when viewed from the camera direction in FIG. 4, where FIG. 5A is a front view, and FIG. Plan view of FIG. It is a conceptual side view explaining the mode at the time of the break of the glass substrate in the break method of the high strength glass which concerns on the Example of this invention, (a) is a front view, (b) is BB of FIG. 5 (a). 'Line cross section The photograph which shows the break surface of the glass substrate broken by the break method of the high strength glass which concerns on the Example of this invention

The present invention supports a high-strength glass substrate in which a scribe line is formed by laser scribing along a planned cutting line of the high-strength glass substrate on a break table so that the scribe line is on the back surface, and the scribe line of the high-strength glass substrate In a state where the flexible resin is pressed at a position corresponding to the scribe line on the surface opposite to the scribe line and the scribe line is uniformly pressed, pressure is applied to the initial crack of the scribe line along the scribe line. The crack is advanced to break the high strength glass.
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

FIG. 1 is a conceptual side view for explaining a state at the time of adjusting a high-strength glass installation position in a breaker for high-strength glass according to an embodiment of the present invention. A glass substrate 1 made of high-strength glass is placed on a break table 2 for holding the substrate. It is preferable that at least the surface of the break table 2 is made of a resin such as acrylic having some flexibility, and a material having rigidity such as a metal is not preferable. The glass substrate 1 is preliminarily formed with a scribe line 10 by laser scribing or the like on one main surface, and the surface on which the scribe line 10 is formed becomes the back side of the glass substrate 1, that is, the scribe line 10 breaks. It is placed in contact with the upper surface of the table 2. A camera 3 for photographing the glass substrate 1 placed on the break table 2 is disposed above the break table 2. At least two cameras 3 are arranged in the direction perpendicular to the paper surface of FIG. 1, that is, in the length direction of the scribe line 10 of the glass substrate 1.

A break blade 4 that is movable in the X-X ′ direction in conjunction with the camera 3 is provided at a position of a predetermined distance Z behind the camera 3. The break blade 4 is configured by installing a flexible resin blade 42 at the tip of a blade holding portion 41. The blade 42 is formed by forming a flexible resin, for example, urethane rubber in the shape of a hollow pipe. The blade 42 is subjected to a surface treatment so that the glass substrate 1 is less sticky when it is brought into close contact with the glass substrate 1 or glass. It is configured to be covered with a thin sheet having low adhesion to the substrate 1, for example, a Teflon (registered trademark) sheet having a thickness of about 0.1 mm. The break blade 4 is configured to be pressed downward by a blade cylinder 5 provided at an upper portion thereof.

FIG. 2 is a front view of the break blade 4 and the blade cylinder 5 as viewed from the direction of the camera 3 in FIG. The break blade 4 extends in a direction perpendicular to the paper surface of FIG. 1 and is long in the extending direction of the scribe line 10 of the glass substrate 1 as shown in FIG. The blade 42 is held by the blade holding portion 41 by inserting pins (not shown) provided at both ends in the length direction of the blade holding portion 41 into the hollow portion.

The length direction of the blade 42 that coincides with the length direction of the blade holding portion 41 is parallel to the arrangement direction of the cameras 3, which is the direction of a straight line connecting the plurality of cameras 3, and the break blade 4 and the camera 3 are 1 move in the direction of the arrow XX ′ in FIG. 1, that is, in the direction orthogonal to the length direction of the blade 42 and the arrangement direction of the cameras 3. The blade cylinder 5 acts so as to press the break blade 4 uniformly in its length direction, and like the camera 3, the length direction of the break blade 4, that is, the length direction of the scribe line 10 of the glass substrate 1. At least two of them are installed, and the direction of the straight line connecting them coincides with the length direction of the blade 42 above the blade 42.

Adjacent to the end of the break blade 4, an initial crack pressing cylinder 6 is provided on a straight line in the length direction of the break blade 4. In FIG. 2, the break blade 4 and the initial crack pressing cylinder 6 are illustrated separately from each other, but the end of the break blade 4 is located immediately above the initial crack 11 of the scribe line 10 formed on the glass substrate 1. The break blade 4 and the initial crack pressing cylinder 6 are preferably arranged without a gap.

When the camera 3 and the blade cylinder 5 move in a direction perpendicular to the paper surface of FIG. 2, the initial crack pressing cylinder 6 moves in a direction perpendicular to the paper surface of FIG. 2 in conjunction with the camera 3 and the blade cylinder 5. Therefore, the plurality of cameras 3, the break blade 4, the blade cylinder 5, and the initial crack pressing cylinder 6 are all arranged in an integrated manner and move together in the direction of the arrow X-X 'in FIG. When these groups move in the direction of arrow XX ′, the length direction of the blade 42 and the arrangement direction of the cameras 3, which is the direction of the straight line connecting the plurality of cameras 3, move in a parallel relationship. To do.

Next, the operation will be described.
First, as shown in FIG. 1, the camera 3 is moved to the photographing position of the glass substrate 1 placed on the break table 2 to photograph the position of the scribe line 10 formed on the glass substrate 1. The shooting position at this time is shown in FIG. A straight line corresponding to the arrangement direction of the cameras 3, which is a linear direction connecting a plurality of cameras 3, is shown as the reference line 8 at the photographing position. The glass substrate 1 is placed on the break table 2 and the scribe line of the glass substrate 1 is placed. The position of the glass substrate 1 is adjusted so that 10 matches the straight line 8 as the reference line. As described above, the break blade 4 and the camera 3 move in parallel with each other when moved in the direction of arrow XX ′ in FIG. 1, that is, in the direction orthogonal to the length direction of the blade 42 and the arrangement direction of the cameras 3. Therefore, by adjusting the position of the glass substrate 1 so that the scribe line 10 of the glass substrate 1 coincides with the straight line 8 as the reference line, the scribe line 10 of the glass substrate 1 is That is, the blade 42 is adjusted to a position parallel to the length direction.

Next, in FIG. 1, the break blade 4 is moved in the direction of the arrow X ′ so that the break blade 4 is positioned immediately above the scribe line 10 of the glass substrate 1 on the break table 2 as shown in FIG. 4. In this case, since the camera 3 and the break blade 4 are separated by a predetermined distance Z, the position of the break blade 4 is scribed on the glass substrate 1 by moving the break blade 4 by the distance Z in the arrow X ′ direction. It is moved to a position corresponding to the position directly above the line 10.

5A is a front view of the break blade 4, the blade cylinder 5, and the initial crack pressing cylinder 6 when viewed from the direction of the camera 3 in FIG. 4, and FIG. 5B is AA ′ in FIG. It is a line sectional side view. At this time, as shown in FIG. 4, the blade 42 is at a position directly above the glass substrate 1 and facing the scribe line 10, but does not extend to a position corresponding to the initial crack 11 of the scribe line 10.

FIG. 6 is a plan view of FIG. The arrangement direction of the blade cylinders 5, which is a linear direction connecting the plurality of blade cylinders 5, coincides with the scribe lines 10 of the glass substrate 1. On the other hand, the blade 42 corresponds to the position over the entire length of the scribe line 10 of the glass substrate 1. The initial crack pressing cylinder 6 is located immediately above the initial crack 11 of the scribe line 10.

In this state, when the break blade 4 is pushed downward by the blade cylinder 5 and the blade 42 of the break blade 4 is pressed against the glass substrate 1, the blade 42 is moved to the surface of the glass substrate 1 as shown in FIGS. A force pressing the glass substrate 1 downward on the (upper surface) side works. Thereby, the scribe line 10 of the glass substrate 1 is pressed on the opposite surface side of the glass substrate 1. Accordingly, a preliminary force is applied to the scribe line 10 of the glass substrate 1 in the opening direction. As described above, the blade 42 is formed in the shape of a flexible resin hollow pipe, and the break table 2 is made of a flexible resin. Therefore, even if the front and back surfaces of the glass substrate 1 are somewhat uneven, the blade 42 breaks. The variation in the tightening force when the glass substrate 1 is held between the tables 2 can be reduced, and the positioning accuracy of the scribe line 10 and the blade 42 can be relaxed. In this way, the scribe line 10 of the glass substrate 1 is uniformly pressed and held between the blade 42 and the break table 10 in the length direction and the width direction.

When the initial crack 11 of the glass substrate 1 is pressed by the initial crack pressing cylinder 6 in a state in which a preliminary force is applied in the direction in which the scribe line 10 of the glass substrate 1 is pressed by the blade 42 and the scribe line 10 opens, the glass The crack progresses along the scribe line 10 from the initial crack 11 in the substrate 1. This crack progresses along the scribe line 10 and also advances in the thickness direction of the glass substrate 1 because the glass substrate 1 is pressed by the blade 42 and a preliminary force is applied in the direction in which the scribe line 10 opens. To do. Therefore, the cleaving of the glass substrate 1 proceeds due to wear in the direction along the scribe line 10 of the crack and in the direction along the thickness of the glass substrate 1, and eventually the cleaving reaches the end opposite to the initial crack 11. Break. As shown in FIG. 8, there is almost no chipping or shark teeth on the break surface of the glass substrate 1 thus broken. In addition, no residue such as cullet is generated.

When a flexible resin such as urethane rubber is used as the material of the blade 4, if the glass substrate 1 is pressed strongly, it may be difficult to separate from the glass substrate 1 after the break due to its adhesiveness. Peeling from the glass substrate 1 is facilitated by subjecting the rubber to a surface treatment or a treatment such as covering a thin sheet with low adhesion, for example, a Teflon (registered trademark) sheet having a thickness of about 0.1 mm.

When the break surface of the glass substrate 1 re-breaked according to the present embodiment is observed in detail, the perpendicularity of the break surface is within 50 μm of deviation with respect to the scribe line 10, chipping is 10 μm or less, and the shark teeth are Not observed. Therefore, it can be said that so-called mirror finishing was performed.

For comparison, when the glass substrate 1 was placed on the break table 2 without using the blade 4 and the initial crack 11 was pressed by the initial crack pressing cylinder 6 and a break was attempted, the break occurred to some extent. The break stopped after the progress and the break line was detached from the scribe line 10 and the break could not be completed. Therefore, it was confirmed that the use of the blade 4 is indispensable for performing a stable break.

As described above, according to the present invention, in the break processing of a high-strength glass substrate, the break line does not deviate from the scribe line, and mirror surface processing can be realized without causing chipping or shark teeth on the break surface. A break method for a high-strength glass substrate can be provided.

The high-strength glass break method according to the present invention is a high-strength glass in which a reinforced layer is formed on a glass surface used in recent years for flat panel displays such as liquid crystal displays and plasma displays, and display devices such as mobile phones and portable terminals. It is suitable for application to the mirror cleaving.

DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Break table 3 Camera 4 Break blade 5 Blade cylinder 6 Initial crack press cylinder 8 Reference line 10 Scribe line 11 Initial crack 41 Blade holding part 42 Blade

Claims (3)

  A high-strength glass substrate that supports a high-strength glass substrate in which a scribe line is formed on a main surface of the high-strength glass substrate along a planned cutting line on a break table so that the surface on which the scribe line is formed is a back surface. A method for breaking high-strength glass, comprising pressing a resin having flexibility at a position corresponding to the scribe line on the surface opposite to the scribe line to apply pressure to the initial crack of the scribe line. .   The method for breaking high-strength glass according to claim 1, wherein the resin having flexibility is in the form of a hollow pipe. The method for breaking high-strength glass according to claim 1, wherein at least a surface of the break table is formed of a resin having flexibility.