JP3036906B2 - Glass processing method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass processing method and apparatus which can be used when, for example, high-quality thin glass for an LCD substrate is cut quickly and accurately along a desired shape.

[0002]

2. Description of the Related Art To cut a glass body such as a sheet glass,
In general, a method of making a cut in glass (scribing) with a diamond tool or a cemented carbide tool, and applying mechanical stress along the cut to split (cut) the glass.

In this case, instead of applying mechanical stress, there has been proposed a method of irradiating a CO ₂ laser beam along a scribe line (scribe line) to apply thermal strain to the portion and to cut the portion (see FIG. 1). See Japanese Utility Model Application Laid-Open No. Sho 62-175042).

[0004]

In the case where a high-quality thin glass sheet for an LCD substrate, which has been frequently used in recent years, is to be accurately cut along a desired complicated shape, the above-mentioned conventional technique is required. The method has the following problems.

That is, when mechanical scribing is performed with a diamond tool, a carbide tool, or the like, and when the scribe line has a curved shape, a crack (crack) in a direction away from the scribe line is likely to occur. For,
There is a problem that it is difficult to cut a complicated shape including a curve and the yield is poor.

Further, when mechanical scribing is performed and when cutting is performed by applying mechanical stress, dust such as shavings and fine chips is easily generated, and this dust is one of the factors that lower the yield of the final product. There was also a problem that it would be.

SUMMARY OF THE INVENTION The present invention has been made in view of the above background, and provides a glass processing method and apparatus capable of easily and quickly breaking a glass body to be processed into a complicated shape while suppressing generation of dust and the like. It is intended to provide.

[0008]

In order to solve the above-mentioned problems, the present invention provides (1) scribing a surface portion of a glass body to be processed, and applying a scribing to the glass body along the scribing portion. In the glass processing method of applying a strain and cutting the glass body to be processed from the portion, a laser beam in an ultraviolet region having a high absorptivity to the glass body to be processed is focused on a surface portion of the glass body to be processed. By scanning the converging point along the shape to be processed, a step of scribing the surface portion of the glass body to be processed, and a step of applying a scribing to the glass body to be processed along the scribed portion A step of irradiating a laser beam in an infrared region having an absorptance to apply thermal strain to the site by fracturing the laser beam. In one glass processing methods, the laser beam of the ultraviolet region, excimer laser light, or pulsed Nd: using a third harmonic light or fourth harmonic light of a YAG laser, a CO ₂ laser beam as the laser beam of the infrared region (3) A glass processing apparatus that performs the glass processing method of Configuration 1 or 2, wherein the glass processing apparatus performs the method of Configuration 1 or 2. A first laser device that generates a laser beam in an ultraviolet region having a high absorptivity for a body, a second laser device that generates a laser beam in an infrared region having a high absorptivity for the glass body to be processed, A first focusing means for focusing the laser light in the ultraviolet region emitted from the first laser device; and a laser beam in the infrared region emitted from the second laser device. A second condensing means for condensing the light, and scribing by scanning the laser beam in the ultraviolet region condensed by the first condensing means on the glass body to be processed along a shape to be processed; A structure comprising: a first scanning unit; and a second scanning unit that scans the laser light in the infrared region focused by the second focusing unit along the scribing site. It is.

[0009]

In the above configuration 1, laser light in the ultraviolet region having a high absorptivity to the glass body to be processed is focused on the surface of the glass body to be processed, and the focal point is adjusted along the shape to be processed. By performing the scanning, a good scribing can be performed on the surface of the glass body to be processed. This point has been found by the present inventors, and it has conventionally been extremely difficult to apply laser scribing to a glass body. On the other hand, the present inventors have found that good scribing can be performed by using laser light in the ultraviolet region.

[0010] That is, since the laser light in the ultraviolet region has a remarkably high absorptivity with respect to a normal glass material, when it is irradiated on the glass body, it is absorbed only on the very surface of the glass body.
Therefore, by condensing and irradiating the surface of the glass body with the laser light in the ultraviolet region having a predetermined intensity or more, the energy of the laser light falls within the extreme surface portion of the glass body, that is, within a depth range of several μm or outside. Can be concentrated and absorbed. By appropriately setting the focused spot diameter, the laser beam in the ultraviolet region, which can be obtained practically, can be used to evaporate the energy density of the laser beam concentrated on the surface of the glass body. It has been found that it can be increased to the extent of scattering. Hereinafter, this operation will be described.

Now, let the absorption coefficient of the glass body be α (c
m ^-1 ), and ^assuming that the depth at which the laser beam attenuates to 1/100 is t (cm), then e- ^αt = 0.01 (1). From this equation (1), t = 4.61 / α (2)

If the beam diameter of the laser beam is d (cm), the volume V (cm ³ ) in which the laser beam is absorbed is as follows: V = (d / 2) ² πt (3) Here, it is assumed that the laser light is uniformly absorbed in the volume V. The absorbed energy at this time is E (J), and the density of the glass body is ρ (g / cm
³ ) If the specific heat is C (J / g · K) and the temperature rise is T (K), then E = CρVT (4). From this equation (4), T = E / CρV (5) By substituting the above equations (2) and (3) into the equation (5), T = (αE) / {4.61πρC (d / 2) ² }
(6) In this equation (6), the following values are inserted as typical values of the absorption coefficient of the laser light in the ultraviolet region with respect to the ordinary glass body, the laser light power in the ultraviolet region that can be generated practically at present, and the like.

Α = 10000 d = 0.003 cm (30 μm) C = 0.2 cal / g · K ρ = 2.3 g / cm ³ E = 0.0001J (100 μJ) As a result, T = 6700K. This temperature is well above the sublimation point of the glass body. Here,
It is assumed that a pulse laser having a sufficiently short pulse width (about 10 ns) is used and there is no dissipation of heat due to heat conduction or the like. This is a reasonable assumption for a laser in the ultraviolet region. When a pulse laser is used,
By irradiating the pulse laser light at each position while shifting the irradiation position along the processing shape, scribing along the processing shape can be performed.

Now, after the step of scribing the surface of the glass body to be processed with a width of several tens of μm and a depth of several μm in this manner, the glass body was laid along the scribed portion in Configuration 2. By irradiating a laser beam in an infrared region such as a CO ₂ laser to apply thermal strain that leads to the cutting, the glass body to be processed can be cut along the scribing shape.

According to this method, since the scribing is performed by the laser beam, the scribing can be performed accurately, easily and quickly even in a complicated shape including a curve without cracks or the like in other parts. Moreover, at the time of the scribing, the glass body is sublimated and evaporated and scattered, so that there is no generation of dust such as shavings, which may be an obstacle in a later manufacturing process.
In addition, the step of applying thermal strain is also performed by irradiating laser light in the infrared region, so that thermal strain can be applied exactly along the scribed part, and harmful stress etc. will be applied to other parts. Will not join. Therefore, there is no possibility of cracking or chipping at the time of cleaving, and the cleaving can be performed with a high yield.

Further, according to Configuration 3, Configuration 1 or 2
An apparatus that can easily carry out the above method can be obtained.

[0017]

FIG. 1 is a perspective view of a glass processing apparatus according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view (cut along a YZ plane) of a condensing optical system, and FIG. FIG. 4 is a cross-sectional view (cut on the XZ plane), FIG. 4 is a horizontal view (cut on the XY plane) of the deflecting optical system, and FIG. 5 is a process explanatory view of a glass processing method according to one embodiment. Hereinafter, with reference to these drawings,
First, a glass processing apparatus according to one embodiment of the present invention will be described, and then a glass processing method according to the present invention will be described.

[0018] In glass processing apparatus Figure 1 of an embodiment, reference numeral 1 is an ultraviolet region (UV) laser device, reference numeral 2 is CO ₂ laser device, reference numeral 3 is a glass processing apparatus.

The UV laser device 1 generates and emits the fourth harmonic (wavelength: 266 nm) pulse light of an Nd: YAG laser, and internally emits a CW-Q switch pulse Nd:
It incorporates a YAG laser device and a harmonic generation element that receives a fundamental laser beam emitted from the Nd: YAG laser device and emits its fourth harmonic light. The energy of the emitted pulse light is 200 μJ, and the pulse repetition frequency is 5 KHz.

The CO ₂ laser device continuously emits a laser beam having a wavelength of 10.6 μm, and has an output power of 25.
W.

The schematic structure of the glass processing apparatus main body 3 includes a base 4, a Y-direction scanning frame 5 attached to the base 4 so as to be movable with respect to the base 4 in the Y-axis direction in FIG.
An X-direction scanning stage 6 attached to the Y-direction scanning frame 5 so as to be movable in the X-axis direction in the drawing with respect to the Y-direction scanning frame 5, and a condensing optic fixed to the X-direction scanning stage 6 System 7 And the UV
The UV laser beam L ₁ and the infrared laser beam L ₂ emitted from the laser device 1 and the CO ₂ laser device 2 are respectively transmitted through the optical path changing reflecting mirrors 81 and 82 and 91 and 92, and further the Y-direction scanning frame. The light is guided to a condensing optical system 7 through a deflecting optical system 10 fixed to 5, is condensed by the condensing optical system 7, and then irradiates a glass plate 11 to be processed fixed on a base 4. It is.

The Y-direction frame 5 has a substantially "gate" shape, and a slider 5 is provided below the legs 5a and 5b, respectively.
c, 5d (sliders 5d are not shown), and these sliders 5c, 5d are slidable on rails 4a, 4b (rails 4b are not shown) formed respectively on the left and right ends of the base 4 in the figure. It is fitted to. A guide screw 4c is threadedly engaged with the slider 4a, and the guide screw 4c is rotationally driven by a pulse motor 4d to control the movement of the Y-direction scanning frame 5 in the Y-axis direction. The pulse motor 4d is controlled by a control device (not shown).

As shown in FIG. 2, the X-direction scanning stage 6 is slidably fitted on a rail 5f attached to a longitudinally lower portion of the beam 5e of the Y-direction scanning frame 5, and is shown in FIG. It is movable in the X-axis direction. An arm 5g is attached to the X-direction scanning stage 6. A guide screw 5h is screwed through the arm 5g, and the guide screw 5h is driven to rotate by a pulse motor 5i. ing. The pulse motor 5i is fixed to the Y-direction scanning frame 5, and is controlled by a control device (not shown). Therefore, by controlling the rotation of the pulse motor 5i according to a control command from a control device (not shown), the movement of the X-direction scanning stage 6 in the X-axis direction can be controlled. A focusing optical system 7 is fixed to the X-direction scanning stage 6.

The condensing optical system 7 includes an X-direction scanning stage 6
, Two deflecting mirrors 72 a and 72 b fixed above the base 71,
1, two condenser lenses 73a, 73 attached below
3b.

The deflecting mirrors 72a and 72b are both tilted by 45 ° with respect to the XY plane, are arranged at a predetermined distance from each other in the Y-axis direction, and are each provided with a mirror holder 74a having a tilt adjustment mechanism. (FIG. 3
) And 74b (not shown).
Deflecting mirrors 72a, 72b, respectively, on a substrate of glass or the like UV laser beam L ₁ and the CO ₂ laser beam L ₂ approximately 1
A dielectric multilayer film that reflects 00% is coated. The mirror holders 74a and 74b are fixed to the base 71 via columns 75a (see FIG. 3) and 75b (not shown), respectively. The deflection mirror 7
2a and 72b are housed in a cover case 71a, and the cover case 71a is provided with laser beam incident windows 71b (see FIG. 3) and 71c (not shown). The laser light entrance windows 71b and 71c are respectively provided with deflection mirrors 72.
It is formed on a straight line that passes through the centers of a and 72b and is parallel to the X-axis direction.

The condenser lenses 73a and 73b are held by lens holders 76a and 76b, respectively. The lens holders 76a and 76b are attached to the base 71 via focus adjustment mechanisms 77a (see FIG. 3) and 77b, respectively. Have been. The focus adjustment mechanisms 77a and 77b are constituted by a well-known rack-and-pinion mechanism or the like, and the focal point of the laser beam can be adjusted up and down by moving the lens holders 76a and 76b up and down. . Further, below the deflection mirrors 72a and 72b,
Laser light emission windows 78a and 78b are formed through the base 71. Then, these laser light emission windows 78
A bellows-like cover tube 79a, 79b is provided between the lens holders a, 78b and the lens holders 76a, 76b.

Therefore, the laser beam entrance windows 71b, 71
c, the laser light incident along the X-axis direction is changed by 90 degrees by deflection mirrors 74a and 74b, respectively, and guided to condensing lenses 73a and 73b through laser light exit windows 78a and 78b. ,
The light is condensed on the glass plate 11 to be processed by 73b. These converging points can be scanned along a target processing shape by appropriately moving the Y-direction scanning frame 5 and the X-direction scanning stage 6 described above. The UV laser light L ₁
Is about 30 μm, and the focused spot diameter of CO ₂ laser light is about 100 μm. The glass plate 11 to be processed is a thin plate of low alkali glass (300 × 30).
0 × 1 mm).

As shown in FIG. 4, the deflecting optical system 10 includes a UV light reflected by the reflecting mirrors 91 and 92.
The traveling directions of the laser light L ₁ and the CO ₂ laser light L ₂ are 90 ° by the two deflecting mirrors 101 and 102, respectively.
This is changed so as to be incident on the condensing optical system 7. The deflection mirrors 101 and 102 are both at 45 ° with respect to the YZ plane.
45 degrees with respect to the Y-axis direction on the XY plane.
Are arranged at a predetermined distance from each other in the direction in which they are formed, and are respectively attached to mirror holders 101a and 102a having a tilt adjustment mechanism. Each of the deflecting mirrors 101 and 102 has a substrate made of glass or the like coated with a dielectric multilayer film that reflects almost 100% of UV laser light and CO ₂ laser light. The mirror holders 101a and 102a are respectively fixed to a base 103 via columns (not shown), and the base 103 is fixed to the Y-direction scanning frame 5. The deflecting mirrors 101 and 102 are housed in a cover case 104. The cover case 104 is provided with laser light entrance windows 105a and 105b and laser light exit windows 106a and 106b, respectively.
The V laser light L ₁ and the CO ₂ laser light L ₂ enter and exit through these entrance and exit windows, respectively, and the emitted laser light is introduced into the condensing optical system 7 as described above, and Is collected.

In the apparatus of this embodiment, the first scanning means (UV laser light scanning means) and the second scanning means (CO ₂ laser light scanning means) of the present invention are connected to one XY scan. Because it is also used by the stage,
This has the advantage that the structure is relatively simple.

The glass processing method of an embodiment Next, a procedure for implementing the glass processing method of an embodiment of the present invention will be described with reference to glass processing device described above.

The method of this embodiment uses the UV laser light L ₁
And a step of cleaving by the CO ₂ laser beam L ₂ performed after the scribing step.

In the scribing step, the UV laser light L ₁
Through the condenser lens 73a of the condenser lens system 7 on the very surface of the glass plate 11 to be processed (condensing spot diameter: about 3
0 μm) to evaporate the glass member at the focal point (FIG. 5).
(See (a)). In FIG. 5A, an arrow p indicates a transpiration. At the same time, by moving the Y-direction scanning frame 5 and the X-direction scanning stage 6 as appropriate, the focal point of the UV laser light L _1, is scanned along a machining shape of interest. In this case, the scanning speed is determined in consideration of the repetition cycle (5 KHz) of the pulse oscillation of the UV laser device 1,
The transpiration spots from each pulse are made to slightly overlap. Thus, a groove 12 having a width of several tens of μm and a depth of several μm is formed on the extreme surface of the glass plate 11 to be processed along the shape to be processed (see FIG. 5B), and scribing is performed.

[0033] Then, the CO ₂ laser beam L ₂ by the cleaving step, the CO ₂ laser beam L _2, the grooves 12 in the surface of the work the glass plate 11 is formed through the condenser lens 73b of the focusing lens system 7 The light is condensed on the portion (condensed spot diameter: about 100 μm), and thermal strain s is applied to this portion (see FIG. 5C). As a result, a crack 13 enters in the thickness direction along the groove 12 and is cut from this portion (FIG. 5).
(D)). At the same time, the Y-direction scanning frame 5 and the X-direction scanning stage 6 are appropriately moved to scan the focal point of the CO ₂ laser beam L ₂ along the groove 12. Thereby, the glass plate 11 to be processed can be cut into a shape to be processed.

According to the above-described embodiment, since scribing is performed by UV laser light, scribing is performed accurately, easily, and quickly without causing cracks or the like in other parts even in a complicated shape including a curve. In addition, during the scribing, the glass body is sublimated and evaporated and scattered, so that dusts such as shavings, which may be obstacles in later manufacturing processes, etc., are generated. There is no. In addition, since the step of applying thermal strain is also performed by irradiating laser light in the infrared region, it is possible to apply thermal strain exactly along the scribed part,
No harmful stress is applied to other parts. Therefore,
There is no risk of cracking or chipping at the time of cleaving, and cleaving can be performed with a high yield.

In the above-described embodiment, an example is described in which the fourth harmonic light of a Nd: YAG laser is used as the UV laser light. However, the third harmonic light of a Nd: YAG laser is used as the UV laser light. (Wavelength: 355 nm), excimer laser (ArF: 193 nm, KrF: 248 nm, Xe)
Cl; 308 nm, XeF; 351 nm), nitrogen laser (331 nm) and the like can also be used.

The glass to be processed is a glass other than quartz glass, for example, non-alkali glass (composition example: SiO ₂ ; 49%, Al ₂ O ₃ ; 10%, B
₂ O ₃ ; 15%, ZnO; 25%), neutral borosilicate glass (composition example: SiO ₂ ; 72%, Al ₂ O ₃ ; 5%,
_{B 2 O 3; 9%,} RO; 7.5%, R 2 O; 6.5%,
Here, R is Na or K. ), Soda-lime glass (composition example: SiO ₂ ; 72.5%, Al ₂ O ₃ ; 2)
%, RO; 12%, R ₂ O; 13.5%, provided that R is Na or K. ).

Furthermore, in the above-described embodiment, an example of scanning by an XY stage has been described as a method of scanning a laser beam. However, for example, a well-known galvanometer scanner or the like can be used.

[0038]

As described above in detail, the glass processing method and apparatus according to the present invention apply a laser beam in the ultraviolet region having a high absorptivity to the glass body to be processed to the surface of the glass body to be processed. After condensing and scanning the condensing point along the shape of the object to be processed, scribing is performed on the surface of the glass body to be processed, and then the glass body to be processed is processed along the scribed portion. The laser beam is irradiated in the infrared region having a high absorptivity to give a thermal strain that leads to the cleavage, thereby cutting the glass body to be processed. This makes it possible to cut easily and quickly into a complicated shape while holding down.

[Brief description of the drawings]

FIG. 1 is a perspective view of a glass processing apparatus according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view (cut along a YZ plane) of a light-converging optical system.

FIG. 3 is a cross-sectional view (cut along the XZ plane) of the light collecting optical system.

FIG. 4 is a horizontal sectional view (cut along an XY plane) of the deflection optical system.

FIG. 5 is a process explanatory view of a glass processing method according to one embodiment.

[Description of References] 1 ... UV laser device, 2 ... CO ₂ laser device, 3 ... Glass processing device main body, 5 ... Y-direction scanning frame, 6 ... X-direction scanning stage, 7 ... Condensing optical system, 10 ... Deflection optics System, 1
1 ... glass plate to be processed.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C03B 33/09

Claims (3)

(57) [Claims] In a glass processing method, scribing is performed on a surface portion of a glass body to be processed, strain is applied to the glass body to be processed along a portion where the scribing is performed, and the glass body to be processed is cut from the portion. Laser light in the ultraviolet region having a high absorptivity to the glass body to be processed is focused on the surface of the glass body to be processed, and the focal point is scanned along the shape to be processed, thereby forming the glass body to be processed. A step of scribing the surface portion of the processed glass body, and irradiating the processed glass body with laser light in an infrared region having a high absorptance along the site where the scribing is performed, which is linked to the site. Applying a thermal strain to the glass. 2. The glass processing method according to claim 1, wherein an excimer laser beam is used as the laser beam in the ultraviolet region.
Alternatively, a glass processing method characterized by using third harmonic light or fourth harmonic light of a pulsed Nd: YAG laser and using CO ₂ laser light as the laser light in the infrared region. 3. A glass processing apparatus for performing the glass processing method according to claim 1 or 2, wherein the first laser generates a laser beam in an ultraviolet region having a high absorptivity to the glass body to be processed. A second laser device for generating a laser beam in an infrared region having a high absorptance for the glass body to be processed; and a first laser device for condensing a laser beam in an ultraviolet region emitted from the first laser device. Focusing means; second focusing means for focusing laser light in the infrared region emitted from the second laser device; and laser light in the ultraviolet range focused by the first focusing means on the workpiece. A first scanning unit for performing scribing by scanning the glass body along a shape to be processed, and applying a laser beam in an infrared region focused by the second focusing unit along a portion where the scribing is performed. And a second scanning means for performing scanning.