KR101556282B1

KR101556282B1 - Processing method of glass substrate

Info

Publication number: KR101556282B1
Application number: KR1020130062309A
Authority: KR
Inventors: 노리후미 아리마; 켄지 후쿠하라
Original assignee: 미쓰보시 다이야몬도 고교 가부시키가이샤
Priority date: 2012-06-19
Filing date: 2013-05-31
Publication date: 2015-09-30
Also published as: TWI498297B; TW201400425A; KR20130142917A; JP5991860B2; CN103508666B; JP2014001102A; CN103508666A

Abstract

(PROBLEMS TO BE SOLVED BY THE INVENTION) A high-strength glass is suppressed from cracking which develops around the periphery, suppressing a decrease in strength, and is subjected to deodorization.
(Solution) This processing method includes a first preliminary irradiation step and a second preliminary irradiating step as a method for deodorizing high-tempered glass along a closed line to be divided. In the first preliminary irradiating step, a laser is condensed at a predetermined depth position inside the substrate, and a laser is scanned along a line along which the substrate is to be divided, thereby forming a first processing trace inside the substrate. In the second preliminary irradiation step, a laser is condensed at a predetermined depth position inside the substrate, and a laser is scanned to surround the line to be divided, on the outer peripheral side of the line to be divided, and a second processing mark is formed on the outer peripheral side of the first processing trace . In the present irradiation step, after the second step, the laser is condensed at a predetermined depth position inside the substrate, and a laser is scanned along the line to be divided so as to advance the crack from the first processing trace toward the front surface or back surface of the substrate.

Description

TECHNICAL FIELD [0001] The present invention relates to a glass substrate processing method,

The present invention relates to a method of processing a glass substrate, and more particularly, to a method of processing a glass substrate for deflecting a tempered glass having a compressive stress on the surface thereof and a tensile stress therein along a closed dividing line will be.

As a technique of dividing a glass substrate by a laser, there is a method of irradiating a CO ₂ laser to a glass substrate to generate thermal stress and to divide the glass substrate. Even in the case of dividing tempered glass whose surface has been strengthened, it is possible to separate by using this conventional technique.

However, if the degree of hardening of the surface of the glass substrate is increased, it can not be divided by the conventional techniques as described above. Thus, as a method of dividing high-strength glass, there is provided a dividing method as shown in Patent Document 1. [

In the method disclosed in Patent Document 1, first, a first damage line as a modified layer is formed in an inner region of the glass substrate where the reinforcement layer is not formed. Likewise, in the inner region where the reinforcing layer is not formed, the second damage line is formed in a region shallower than the first damage line. By forming these damage lines, cracks are developed along the line to be divided, and the glass substrate is divided. Further, at the time of this division, a mechanical scribing which forms a groove by a cutter, or a manual or mechanical operation is used to press both sides of the damaged line to apply a bending force.

WO 2010/096359 A1 (paragraphs 0024, 0026, 0027, 0031, 0032, etc.)

The breaking method disclosed in Patent Document 1 is based on the premise that the glass substrate is divided mainly along a line to be divided of a straight line. Therefore, when such a dividing method is applied to a process in which a single piece of a closed shape such as a rectangular or circular is divided and taken out from a glass substrate as a base material (hereinafter, such processing is referred to as " The machining quality is degraded. Concretely, there is a problem that cracks develop from the laser-scanned portion to the outside, and the surroundings are destroyed. Particularly, in the corner portion where the scanning direction is changed, a large number of cracks are diverged from the line to be divided, and the other portions of the circumference can not be used as products.

In such a situation, there is a problem that not only the yield is bad but also the strength of the glass substrate obtained after the division is lowered.

It is an object of the present invention to suppress cracks generated around the periphery of a high-strength glass during the deodorization process to suppress a decrease in strength.

A method of processing a glass substrate according to a first aspect of the present invention includes the following steps as a method for scraping tempered glass having a compressive stress on a surface thereof and a tensile stress therein along a closed line to be divided .

First preliminary irradiating step: The laser is condensed at a predetermined depth position inside the substrate, and a laser is scanned along the line to be divided, thereby forming a first processing trace inside the substrate.

Second preliminary irradiating step: The laser is condensed at a predetermined depth position inside the substrate, and a laser is scanned on the outer peripheral side of the line to be divided to surround the line to be divided so as to form a second processing mark on the outer peripheral side of the first processing mark do.

Main irradiation step: After the second preliminary irradiation step, the laser is condensed at a predetermined depth position inside the substrate, and a laser is injected along the line to be divided, thereby advancing the crack from the first processing trace toward the front surface or back surface of the substrate.

In this method, first, a first processing trace is formed along the line along which the material is to be divided in the substrate. Next, on the outer peripheral side of the first processing trace, another second processing trace is formed so as to surround the first processing trace. After the processing marks are formed along the line to be divided and the outer peripheral side of the line to be divided, the laser is scanned along the line to be divided again. By this laser irradiation and scanning, cracks develop on the front surface or the back surface of the substrate from the first processing trace, and cracks further propagate along the line to be divided. At this time, since the process trace is formed in the second preliminary irradiation process on the outer circumference side of the line to be divided, it is possible to suppress the crack from branching from the line to be divided and propagating outwardly of the line to be divided.

Here, since cracks deviating from the line scheduled to be divided are suppressed, damage to the surrounding glass substrate can be suppressed and the yield can be improved when a piece is cut out from the glass substrate of the base material. Further, for the same reason, it is possible to suppress deterioration of the strength of the glass substrate taken out.

In the method of processing a glass substrate according to the second invention, in the method of the first invention, laser scanning in the first preliminary irradiation step and laser scanning in the second preliminary irradiation step are continuously performed.

Here, the preliminary irradiation step can be easily carried out in a short time.

In the method of processing a glass substrate according to the third invention, the condensing positions of the laser in the first preliminary irradiation step and the second preliminary irradiation step are at the same depth position.

Here, as in the second invention, the preliminary irradiation step can be easily carried out in a short time.

The method for processing a glass substrate according to a fourth invention is characterized in that in the method according to any one of the first to third inventions, laser light is condensed at a predetermined depth position inside the substrate, and further out of the scanning lines in the second preliminary irradiation step Irradiating the laser beam with a laser to form a third process trace on the outer circumferential side of the second process trace.

In this case, since a machining mark is further formed on the outer circumferential side of the machining mark of the line to be machined to be divided, the machining can be more easily performed.

The method for processing a glass substrate according to the fifth invention is characterized in that, in the method of the fourth invention, laser scanning in the first preliminary irradiation step to the third preliminary irradiation step is performed continuously.

In the method of processing a glass substrate according to the sixth invention, in the method according to the fifth invention, the condensing positions of the laser in the first preliminary irradiation step to the third preliminary irradiation step are at the same depth position.

In the method of processing a glass substrate according to a seventh aspect of the present invention, in the first to sixth aspects of the present invention, the converging position of the laser in the present irradiating step is shifted from the converging position of the laser in the first preliminary irradiating step, Or a position close to the back surface.

Here, in the present irradiation step, since the laser beam is condensed and scanned at a position closer to the substrate than the first processing trace, cracks are likely to easily reach the substrate surface. Therefore, the dividing step after the main irradiation step becomes easy.

INDUSTRIAL APPLICABILITY As described above, according to the present invention, it is possible to suppress cracks generated around the periphery of a tempered glass having a reinforcing layer having a compressive stress on its surface, thereby suppressing a decrease in strength.

1 is a schematic sectional view of a tempered glass to which a breaking method according to an embodiment of the present invention is applied.
2 is a diagram showing a laser scanning line of a processing method according to an embodiment of the present invention.
Fig. 3 is a photograph showing the result (before separation) of Experiment 1 of the processing method according to one embodiment of the present invention. Fig.
4A is a photograph showing the glass substrate after the irradiation.
Fig. 4B is a photograph of a glass substrate taken out of the substrate around the line to be divided L0.
Fig. 5 is a photograph showing the result (overall) of the comparative experiment divided by the conventional machining method.

(Mode for carrying out the invention)

[Glass Substrate]

Fig. 1 shows an example of a sectional configuration of a glass substrate to be cut. This glass substrate is a tempered glass having compressive stress on the surface and tensile stress in the inside. Concretely, it has a large compressive stress (CS) in the vicinity of the front surface and the back surface as it approaches the front surface and the back surface. On the inside of the substrate reaching a predetermined depth from the front surface and the back surface, the film has a reverse tensile stress CT. In Fig. 1, " DOL " represents the depth of the reinforcing layer having compressive stress on the surface of the substrate.

[Method of separation]

In the case where the tempered glass as described above (hereinafter sometimes simply referred to as " substrate ") is divided along a closed line to be divided, the following steps are performed. Here, a description will be given taking as an example a case where a rectangular piece of glass substrate having four R-shaped corners is cut out from a glass substrate which is one base material.

The laser is focused on a region having a tensile stress inside the substrate and a laser is scanned along the line to be divided L0 as shown in Fig. 2, and a line to be divided L0) is surrounded by two layers. Hereinafter, the line on the outer peripheral side of the line along which the component is to be divided L0 is referred to as the first outer peripheral line L1 and the line on the outer peripheral side of the first outer peripheral line L1 is referred to as the second outer peripheral line L2. By the laser scanning as described above, the first, second, and third processing marks are formed in the substrate along the line to be divided L0 and the first and second outer peripheral lines L1 and L2 on the outer periphery thereof. Here, the processing marks are regions in which the substrate is once softened or melted by the laser and solidified again.

2, laser irradiation along the line along which the material is to be divided L0 and laser irradiation along the first and second outer peripheral lines L1 and L2 on the outer peripheral side are performed in a continuous process, that is, . Therefore, while the laser irradiation along the first outer peripheral line L1 is scanned so as to surround the entirety of the line to be divided L0, the laser irradiation along the second outer peripheral line L2 is performed so that only three sides of four sides are surrounded Is injected.

&Lt; Main Investigation Step &

After completion of the preliminary irradiation process as described above, the laser is condensed at the position on the surface side of the laser condensing position in the preliminary irradiation process, and the laser is scanned along the line along which the substance is to be divided L0. The laser irradiation in this case may be a one-turn scan along the line along which the material is to be divided L0, but it is preferable to perform two-turn scanning in order to surely divide the object.

By performing the above-described process, the outer side of the first and second outer peripheral lines L1 and L2 and the outer side of the dividing line L0 are divided and the area inside the divided line to be divided L0 is taken out can do.

(Experimental Example)

Hereinafter, experimental results to which the present invention is applied are shown. In addition, the shape of the extracted shape is a rectangle having one side of 30 mm and a shape formed by connecting four corners with a curved line having a radius of 5 mm. The interval between the lines is 1 mm.

[Experiment 1]

In Experiment 1, the following method was applied to a high-tempered glass having a thickness of 1.1 mm (see Fig. 1 for the sectional configuration). The repetition frequency of the laser is 3 MHz in the following experiments.

Laser was continuously scanned along each of the scanning lines L0, L1 and L2 shown in Fig. The number of times of scanning is one. The irradiation conditions of the laser are the same in each line and are as follows.

Laser output: 6W

Scanning speed: 300 mm / s

Processing depth: 368㎛

Fig. 3 shows the shape of the glass substrate in the case where the above preliminary irradiation is carried out. Further, in order to prevent the substrate from being damaged during handling of the substrate for photographing, a transparent tape is adhered to the substrate.

The laser was injected twice (two turns) along the line along which the material is to be divided L0 shown in Fig. The irradiation conditions of the laser are as follows.

Laser output: 6W

Scanning speed: 300 mm / s

Processing depth: 145㎛

As a result of this investigation, no cracks as branched from the line scheduled to be divided to the outer periphery side occurred. Fig. 4A shows the glass substrate after the irradiation, and Fig. 4B shows the glass substrate taken out of the substrate around the line to be divided L0.

[Experiment 2]

In Experiment 2, the following method was carried out for a high tempered glass having a thickness of 0.7 mm (see Fig. 1 for the sectional configuration). The repetition frequency of the laser is 3 MHz in the same manner in the above experiment.

Laser output: 6W

Scanning speed: 300 mm / s

Processing depth: 399㎛

Laser output: 6W

Scanning speed: 300 mm / s

Processing depth: 163㎛

As a result of the above investigation, as in Experiment 1 (see Fig. 4A), cracks as branched from the line scheduled to be divided to the outer periphery did not occur.

[Comparative Experimental Example]

The same extraction form as in Experiments 1 and 2 was subjected to an extraction process by the following conventional method. The object to be cut is a high tempered glass having a thickness of 1.1 mm. The repetition frequency of the laser is 1 MHz.

In the above conventional processing method, as shown in Fig. 5, a plurality of cracks have progressed from the line scheduled to be divided to the outer periphery side.

[Summary of Experimental Results]

A laser beam is irradiated along at least one outer peripheral line on the outer circumferential side of the line to be divided according to the preliminary irradiation to form a processing trace inside the substrate so that cracks develop from the line to be divided to the outer circumferential side during the main irradiation . The reason why the progress of the crack from the line to be divided from the line to be divided to the outer periphery can be suppressed by forming the process trace on the outer peripheral line is not clear. However, since the substrate is once melted when forming the process trace, It is believed that the tensile stress is relaxed and cracks do not progress as desired to the outer circumferential side.

The outline line may be at least one layer, and two or more outer lines may be formed. In this investigation, it is preferable to perform laser scanning once along the line to be divided, but it is preferable to perform two laser scanning in order to more surely perform the division.

[Other Embodiments]

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

(a) The extraction shape is not limited to the above embodiment. For example, a case where a closed shape such as a circle or a star (star shape) is subjected to machining can be applied in the same manner as the present invention.

(b) The number of times of preliminary investigation and the number of times of this investigation are not limited to the above-described embodiment. Further, in Experiments 1 and 2, the processing depth (laser condensing position) is changed in the preliminary irradiation step and the main irradiation step, but the same processing depth may be used in both steps.

(c) The method of laser scanning in the preliminary irradiation step is not limited to the spiral shape. The planned line to be divided and the outline line may be performed in each step without being continued.

(d) The laser light converging position (processing depth) in the present irradiation step is set to be closer to the substrate surface than the light converging position (processing depth) in the preliminary irradiation in the above embodiment, (Depth of processing) of the substrate in the direction from the first processing trace to the back surface of the substrate.

Claims

A method of processing a glass substrate having a compressive stress on a surface thereof and having a tensile stress in the inside thereof, for scraping along a closed line to be divided,
A first preliminary irradiation step of condensing a laser beam at a predetermined depth position inside the substrate and scanning the laser beam along a line to be divided to form a first processing trace in the substrate;
A laser is condensed at a predetermined depth position inside the substrate, and a laser is scanned to surround the scheduled line to be divided on the outer peripheral side of the line to be divided, and a second process trace is formed on the outer peripheral side of the first process trace A preliminary irradiation step,
A laser is condensed at a predetermined depth position in the substrate after the second preliminary irradiation step and a laser is scanned along the line to be divided to scan the surface of the substrate or the back surface of the substrate from the first processing trace, A method of processing a glass substrate comprising the steps of:

The method according to claim 1,
Wherein laser scanning in the first preliminary irradiation step and laser scanning in the second preliminary irradiation step are continuously performed.

The method according to claim 1,
Wherein the converging positions of the laser in the first preliminary irradiation step and the second preliminary irradiation step are at the same depth position.

The method according to claim 1,
Laser light is condensed at a predetermined depth position inside the substrate and a laser is scanned to the outer peripheral side of the scanning line in the second preliminary irradiation step to form a third processing trace on the outer peripheral side of the second processing trace And further comprising a third preliminary irradiation step.

5. The method of claim 4,
Wherein the laser irradiation in the first preliminary irradiation step to the third preliminary irradiation step is performed continuously.

6. The method of claim 5,
Wherein the converging positions of the laser in the first preliminary irradiation step to the third preliminary irradiation step are at the same depth position.

7. The method according to any one of claims 1 to 6,
Wherein the light converging position of the laser in the main irradiating step is a position closer to the front surface or back surface of the substrate than the light converging position of the laser in the first preliminary irradiating step.