KR20160038821A

KR20160038821A - Breaking method and breaking apparatus

Info

Publication number: KR20160038821A
Application number: KR1020150136683A
Authority: KR
Inventors: 세이지 시미즈; 타카시 가와바타; 사토시 고쿠세이; 코우지 야마모토; 유항 미야자키; 요이치 이마이즈미
Original assignee: 미쓰보시 다이야몬도 고교 가부시키가이샤
Priority date: 2014-09-30
Filing date: 2015-09-25
Publication date: 2016-04-07
Also published as: TW201620845A; CN105461203A; JP2016069223A

Abstract

Provided are a breaking method which can divide a glass substrate with a clean cross section by suppressing thermal influence onto the substrate caused by laser emission, and a breaking apparatus. More particularly, the present invention relates to a breaking method and apparatus for breaking a glass substrate (1) along a predetermined scribe line. The breaking method comprises: a mechanical scribe process which forms a crack (S) having a limited depth by relatively moving a cutter wheel (16) by pushing the cutter wheel (16) on the surface of a glass substrate (1); and a laser break process which additionally penetrates the crack (S) processed from the mechanical scribe process by distribution of thermal stress generated by emitting a laser beam along the crack (S), fully cutting the glass substrate (1). In the mechanical scribe process, a crack having a depth of 30 to 80% of the width is formed on the glass substrate (1). In the laser break process, a laser with an oscillation wavelength having a range of 5 μm is used.

Description

BREAKING METHOD AND BREAKING APPARATUS [0001]

The present invention relates to a braking method for braking a glass substrate made of alkali-free glass or the like, and a brake device. More particularly, the present invention relates to a brake method and a brake apparatus for breaking a thin glass substrate suitable for use in a flat panel display (FPD) such as a liquid crystal display or a plasma display.

Conventionally, a crack (crack) for dividing along a line scheduled to be broken along a line to be braked has been processed (processed) on a glass substrate by using a laser scribe method in which scribing is performed by generating a thermal stress distribution on a substrate by scanning while irradiating a laser beam (See, for example, Patent Document 1), or a technique in which a glass substrate having a thin plate thickness is completely divided (full cut processing) (see, for example, Patent Document 2) is known.

In the laser scribing method so far, the vicinity of the substrate surface is scanned and heated by using a CO ₂ laser or the like mainly having a large absorption coefficient by the glass substrate, and the coolant is sprayed from the nozzle of the cooling mechanism to the heating region have. Thereby, cracks for division are generated on the surface of the glass substrate by the stress distribution caused by the compressive stress generated by the preceding heating and the tensile stress caused by the following quenching, or cracks And is cut into a full cut.

In the laser scribe processing for a relatively thick substrate (for example, a thickness of 1 mm or more), tensile stress is applied to the surface side of the substrate, the inside (deep portion) of the substrate is deformed by the temperature difference in the vertical direction due to the effect of the relaxation time, (Compressive stress) is mainly affected by the stress distribution in the vertical direction, and cracks (cracks) are processed by the stress distribution in the vertical direction. On the other hand, in the case of a thin substrate (for example, a thickness of about 0.2 to 0.4 mm), since the temperature difference in the depth direction hardly occurs, the influence of the stress distribution in the vertical direction hardly occurs, The stress distribution in the longitudinal direction along the longitudinal direction is influenced, and when a strong stress distribution is formed by the stress distribution in the longitudinal direction, full cutting can be performed.

International Publication No. WO 03/008352 Japanese Patent Application Laid-Open No. 2001-170786

Conventional full-cut processing (laser braking) using the above-described CO ₂ laser is excellent in that even a thin glass substrate can be divided while maintaining the strength of the cross section, and furthermore, It is preferable that the process can be simplified in that it can be immediately broken (break).

However, in the above-described full-cut processing, it is necessary to generate a large stress difference in the forward and backward directions in that the substrate is divided using only the front-rear direction stress distribution along the scanning path of the laser beam, Calories are needed. In order to do so, it is necessary to increase the output power of the laser to be irradiated or slow down the scanning speed. However, in any case, in laser irradiation with a CO ₂ laser or the like having a large absorption coefficient at the substrate surface, ) Is small and a fine scratch is generated on the surface.

On the other hand, Patent Document 2 (column 0055) describes laser scribing using a CO laser, a YAG laser, and an excimer laser instead of a CO ₂ laser having a wavelength of 10.6 μm. However, there is no detailed description of the use of CO lasers in this document.

In general, when a laser having a small absorption coefficient with respect to a glass substrate is used, in principle, absorption in the vicinity of the substrate surface is suppressed, When scribing is performed, another problem as described below occurs.

That is, in the case of using a laser having a small absorption coefficient of 1 mu m, such as an Nd: YAG laser, at least 90% of energy is transmitted without being absorbed by the glass substrate, This may cause heat damage to the substrate. In addition, it is necessary to take care of missing the heat transmitted from the back surface of the substrate, and the apparatus becomes complicated.

Therefore, there is a fear that heat damage to the surface or inside of the substrate becomes a problem in the full-cut processing, that is, the laser braking processing, by heating the glass substrate by injecting CO ₂ or Nd: YAG laser.

On the other hand, as a full cutting process in which no thermal effect occurs at all, a scribe line accompanied by cracking is formed by rolling a cutter wheel (also referred to as a scribing wheel) with a glass substrate while pushing the scribing wheel, There is a mechanical method of pressing and dividing. However, there is a problem in that when the crack is divided into the entire thickness direction and divided, the divided end faces are damaged by contact with each other or the cracks are not developed straightly in the thickness direction, .

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a braking method capable of suppressing thermal influence by heating in a laser beam irradiation on a glass substrate to be divided and breaking the glass substrate into a clean section having a high section strength, The purpose is to provide.

In order to achieve the above object, the present invention takes the following technical means. That is, the breaking method of the present invention is a breaking method for breaking a glass substrate along a line to be braked, wherein the glass substrate is relatively moved while pushing the cutter wheel against the surface of the glass substrate to form a crack having a finite depth along the expected breaking line And a laser breaking step of further penetrating the cracks processed in the mechanical scribing process by the thermal stress distribution generated by scanning the laser beam along the cracks to cut the glass substrate completely, In the mechanical scribing step, a crack of 30 to 80% of the thickness of the glass substrate is formed on the surface of the glass substrate, and in the laser braking step, the laser is used to break by using a laser beam having an oscillation wavelength of 5 m.

Here, the laser of the 5 탆 size corresponds specifically to a CO laser, for example.

The present invention also provides a brake device for breaking a glass substrate along a line to be braked, the brake device comprising: a cutter wheel for performing a mechanical scribe process for forming cracks of finite depth along a line to be braked on a surface of the glass substrate; A processing control unit for controlling the pressing load of the cutter wheel so that the depth of the crack formed by the wheel is 30 to 80% of the thickness of the glass substrate; and a thermal stress distribution generated by scanning the laser beam along the crack, And a laser irradiating section for performing a laser breaking process of penetrating the cracks processed in the mechanical scribing step and pulling the glass substrate into a full cut state, wherein the oscillation wavelength of the laser irradiated from the laser irradiating section is 5 m The brake device is also characterized.

In the above invention, it is preferable that the cutter wheel used in the mechanical scribing process is a cutter wheel having a groove with a groove formed along a ridge line having a diameter of 1 to 3 mm.

The glass substrate may have a thickness of 0.1 to 0.4 mm.

According to the present invention, in the preceding mechanical scribing step, a deep crack of 30 to 80% of the thickness of the glass substrate can be easily processed by using the cutter wheel. It is also preferable that the cutter wheel is scribed using a cutter wheel having a notch on the tip of a blade which is difficult to slip. Further, by using the cutter wheel having grooves, the penetration depth of the crack can be set within the above-mentioned range even if it is lowered. This crack can be infiltrated in the thickness direction of the substrate by a laser break process using a subsequent 5 mu m large laser (CO laser), and thus the breaking process is performed. At this time, since the portion to be broken, that is, the remaining portion of the crack is thin, it is possible to make the full cut state sufficiently even by reducing the stress distribution generated on the substrate by suppressing the amount of heat input by laser irradiation. Therefore, it is possible to process the laser irradiation furnace in which the amount of heat input is suppressed.

This laser braking by the laser beam of 5 mu m has a smaller loss in heat transfer due to heat dispersion from the surface as compared with the CO ₂ laser which has been used in the past and the laser braking with a heat input smaller than that of the CO ₂ laser ), It is possible to efficiently heat a necessary portion with a small amount of heat input, and thermal damage on the surface of the glass substrate can be suppressed. In the case of using a laser beam of 1 m such as an Nd: YAG laser, 90% or more of energy is transmitted without being absorbed by the glass substrate, resulting in a large loss of thermal energy. And only 20 to 30% of the energy is absorbed without being absorbed. Therefore, it is possible to increase the thermal efficiency, and it is not necessary to consider that the transmitted heat is missed.

Therefore, by the combination of the preceding mechanical scribing step and the laser scribing step with a laser beam of 5 mu m size, it is possible to avoid the damage caused by the heat of the laser beam on the glass substrate, It is possible to braking with a clean section having a high section strength.

In the conventional CO ₂ laser, the cross-sectional shape of the beam spot of the laser beam is set to be an elliptical beam and the long axis thereof is scanned toward the beam advancing direction in order to secure the heat input. In the present invention, It is possible to make the sectional shape of the beam spot into a small annular shape. As a result, there is an effect that precision can be performed even at the time of separation of a deformed shape to perform scanning along a curved line.

1 is a schematic front view showing one embodiment of a braking device for carrying out the braking method of the present invention.
2 is a view showing a cutter wheel used in the present invention.
3 is a perspective view illustrating a laser braking process according to the breaking method of the present invention.
4 is a perspective view for explaining a breaking state of the glass substrate in the present invention.
5 is a block diagram showing a controller for controlling the brake device of the present invention.

(Mode for carrying out the invention)

Hereinafter, the details of the present invention will be described based on one embodiment shown in Figs. 1 to 5. Fig. In this embodiment, as the glass substrate 1 to be divided, a thin alkali-free glass plate having a thickness of 0.1 to 0.4 mm is used.

Fig. 1 shows a brake device A used in the present invention, and includes a table 4 on which a glass substrate 1 is placed. The table 4 has supporting means for holding the glass substrate 1 at a predetermined position on the table 4. [ In this embodiment, as the supporting means, the substrate 1 is sucked and supported via a plurality of small air suction holes (not shown) opened on the surface of the table 4. The table 4 is movable along the horizontal rail 5 in the Y direction (forward and backward direction in FIG. 1) and is driven by a screw shaft 6 rotated by a motor (not shown) . Further, the table 4 is capable of rotating in a horizontal plane by a rotary drive unit 7 incorporating a motor.

The bridge 10 having the support pillars 8 and 8 on both sides provided with the table 4 therebetween and the beam 9 extending horizontally in the X direction is supported by the table 4, As shown in FIG.

A guide 11 extending horizontally in the X direction is provided in the beam 9. A scribe head 12 for a cutter wheel and a scribe head 13 for a laser irradiating portion are connected to a motor 14 And is attached so as to be movable in the X direction along the guide 11 by a moving mechanism (not shown) serving as a driving source. A cutter wheel 16 is attached to a scribe head 12 for a cutter wheel via a holder 15 which is lifted and lowered by a lifting mechanism 18. A laser beam is projected onto a scribe head 13 And a laser irradiating unit 17 for irradiating the laser beam to converge the laser beam.

In the present embodiment, the laser irradiation unit 17 and the cutter wheel 16 are attached to the respective scribe heads 12 and 13, but they may be attached to the same scribe head.

The cutter wheel 16 is used so as to be capable of machining a high penetration crack S of 30 to 80% of the substrate thickness when it is pressed against the surface of the glass substrate 1 and rolled. In this embodiment, as shown in Fig. 2, grooves (cut-away) 16a are formed along the circumferential ridgelines, and a disc body 16c made of cemented carbide ) Is used as the cutter wheel.

The cutter wheel 16 having grooves for machining with high penetration has a Penett (registered trademark) cutter wheel and APIO (registered trademark) cutter wheel manufactured by Mitsubishi Diamond Corporation. The former can form a deeper crack S and the latter can form a shallow crack S rather than an electron, so that it can be appropriately selected in accordance with the substrate to be processed.

As the laser irradiated from the laser irradiation unit 17 of the present invention, a CO laser having an oscillation wavelength of 5 m is used. The output power and scanning speed of the laser are different depending on the thickness and the material of the glass substrate 1 to be processed and the depth of the crack S to be processed, Select a condition that reduces the damage. That is, it is preferable to select a condition in which the output power is reduced as much as possible and the scanning speed is not too slow, within the dividable range.

The brake device A of the present invention includes a controller 20, an input operating portion 21, and a display portion 22 as shown in the block diagram of Fig. The controller 20 is a functional component implemented by computer hardware such as a CPU, a RAM, and a ROM, and is provided with a machining control unit 23. The processing control unit 23 controls the suction and holding of the glass substrate 1 by the suction support means, the movement of the table 4 by the screw shaft 6 and the rotation drive unit 7, the scribing by the motor 14 And the output power of the laser from the laser irradiating unit 17, such as the movement of the glass substrate 1 (12, 13), the lifting and lowering operation of the cutter wheel 16 by the lifting mechanism 18, ) Of the machining operation. The input operation section 21 is an interface for the operator to input various operation instructions and data to the brake device A, and the display section 22 is for displaying the process menu and the operation status.

Next, the break method of the present invention using the above apparatus will be described.

First, as shown in Figs. 1 and 3, a glass substrate 1 is placed on a table 4, and a cutter wheel 16 is pressed against the surface of the glass substrate 1, S) (mechanical scribing step).

In this mechanical scribing step, by using the cutter wheel 16 with grooves, it is possible to easily process a deep crack S as much as 30 to 80% of the thickness of the glass substrate 1 with a low pressing load. Further, since the cutter wheel with grooves is difficult to be slipped on the substrate (easy to catch), the cutter wheel is collided with the glass end to form a notch that will be a trigger, and a scribe The scribe can be started (interrupted) from the inner side a little more than the base judgment without performing the scribing. In this embodiment, the depth L of the crack S is about 70% with respect to the thickness of the glass substrate 1 of 0.2 mm. The depth of the crack S can be controlled by controlling the pressing load of the cutter wheel 16 by the machining control section 23 of the controller 20. [

Subsequently, the laser beam is irradiated with the CO laser beam from the laser irradiator 17 along the crack S, and the laser beam is scanned and heated. By the thermal stress distribution generated at this time, the crack S processed in the preceding mechanical scribing step is further penetrated in the thickness direction, and the glass substrate 1 is cut into a full cut (laser break step).

In Fig. 4, P1 indicates a heating region by a laser beam.

In the laser braking process, a CO laser having an oscillation wavelength of 5 μm is used. Since the CO laser is absorbed only in the vicinity of the surface of the glass substrate, but partially absorbed inside the substrate, the inside of the substrate can be directly heated. Further, since the thickness of the substrate is as small as 0.2 mm, it is instantaneously heated from the surface to the back of the heating region P1 by laser irradiation, and the temperature difference in the depth direction hardly occurs. Therefore, uniform compression stress is generated in the heating region P1 in the depth direction.

On the other hand, the periphery of the heating region P1 is not heated, and a stress distribution is formed around the heating region P1. In other words, a compressive stress is generated in the heating region P1 and a tensile stress is generated around the heating region P1. As a result, a force acting to guide the glass substrate 1 acts as shown by the arrow in Fig. 4, The substrate 1 can be cut (braked).

Particularly, the CO laser used in the present invention is not only absorbed only in the vicinity of the surface of the glass substrate, but absorbs part of the inside of the substrate, So that it is possible to efficiently and rapidly heat the vicinity of the cross-sectional face. Therefore, as compared with the CO ₂ laser widely used in the past, the loss at the time of heat transfer due to heat dispersion from the surface is reduced, and laser break (full cut) at an incident heat smaller than that of the CO ₂ laser becomes possible. It is possible to efficiently heat the required portion with the heat input amount, and thermal damage on the surface of the glass substrate 1 can be suppressed.

In addition, by using a CO laser of 5 mu m size, the energy transmitted through the glass substrate 1 can be sufficiently suppressed. That is, in the case of using a laser beam of 1 m such as an Nd: YAG laser, 90% or more energy is transmitted without being absorbed by the glass substrate to cause a large loss of thermal energy. Absorbed, and only 20 to 30% of the energy is transmitted without being absorbed, so that the thermal efficiency can be increased. Further, by combining with the mechanical scribing process, there is no need to perform full cutting with a laser, so that the output power of the laser can be suppressed to be small and the generation of scratches on the surface of the substrate can be suppressed, It is possible to brake in a cross section.

(Example)

The inventors performed a comparative experiment of the laser braking process using a CO ₂ laser and a CO laser after processing a crack having a depth of 70% of a plate thickness with a cutter wheel 16 on a glass substrate having a thickness of 0.2 mm.

As a result, in the case of the CO laser, the temperature of the laser spot, which is the irradiation position of the laser on the surface of the substrate, could be full cut (break) at 337 캜. Further, in the case of using a CO ₂ laser under the same conditions, the temperature of the laser spot on the substrate surface was 444 ° C. At this point, it was found that the CO laser can break at a surface temperature as low as about 100 ° C.

As described above, according to the present invention, in the preceding mechanical scribing step, a crack S of 30 to 80% of the thickness of the glass substrate is processed by using the cutter wheel 16, and subsequently, The crack S is penetrated into the thickness direction of the substrate by the laser break process so as to cut off (break). Thus, since the thickness of the portion processed by the laser brake, that is, the remaining portion of the crack S is thin, the thermal stress distribution due to the heating with the energy which does not cause damage by the CO laser ensures reliable sealing of the glass substrate 1) can be fully cut (braked).

Further, in the laser break process in the present invention, the energy when the CO laser is irradiated can be supplied to the inside of the substrate with a sufficient amount of heat even when scanning by the circular beam spot is performed.

By making the beam spot circular, it is easy to work in a curve shape instead of a straight line. That is, in a conventional laser scribe using a CO ₂ laser, the shape of the beam spot of the laser beam irradiated onto the glass substrate is made ellipse so as not to damage the surface of the substrate, And the scanning direction of the spot and the direction of the major axis in the elliptic beam spot coincide with each other. In this case, since the shape of the beam spot is elliptical, it is difficult to process the curved shape. However, since the laser beam of the present invention can be made into a circular beam spot instead of an elliptical beam spot, So that it is not necessary to match and the curved shape can be easily processed.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the present invention is not limited to the specific embodiments thereof, but may be modified and changed without departing from the scope of the present invention. Do.

The present invention is mainly applied to a braking of a thin glass substrate having a thickness of 0.1 to 0.4 mm.

A: Brake device
S: Crack
1: glass substrate
4: Table
16: Cutter wheel
16a: Home
16b:
16c:
17: Laser irradiation part
20: Controller
23:

Claims

1. A braking method for breaking a glass substrate along a line to be braked,
A mechanical scribe process for forming a finite depth of crack along the line to be braked by relatively moving the cutter wheel while pushing the cutter wheel against the surface of the glass substrate;
And a laser breaking step of further penetrating the cracks processed in the mechanical scribing process by the thermal stress distribution generated by scanning the laser beam along the cracks to cut the glass substrate completely,
In the mechanical scribing step, a crack of 30 to 80% of the plate thickness is formed on the surface of the glass substrate,
Wherein the laser is braked using a laser having an oscillation wavelength of 5 mu m.

The method according to claim 1,
Wherein the cutter wheel has a diameter of 1 to 3 mm and is a cutter wheel having a groove formed along a ridge line forming a blade edge.

3. The method according to claim 1 or 2,
Wherein the glass substrate has a thickness of 0.1 to 0.4 mm.

1. A braking device for braking a glass substrate along a line to be braked,
A cutter wheel for performing a mechanical scribe process for forming cracks of finite depth along a line to be braked on the surface of the glass substrate,
A machining control section for controlling the pressing load of the cutter wheel so that the depth of the crack formed by the cutter wheel is 30 to 80% of the thickness of the glass substrate;
And a laser irradiation unit for performing a laser break process for further penetrating the cracks processed in the mechanical scribing process by the thermal stress distribution generated by scanning the laser beam along the crack to cut the glass substrate to a full cut ,
And the oscillation wavelength of the laser irradiated from the laser irradiating unit is a laser of 5 mu m band.

5. The method of claim 4,
Wherein the cutter wheel has a diameter of 1 to 3 mm and is a cutter wheel having a groove formed along a ridge line forming a blade edge.