KR20130002254A - Scribe method for glass substrate - Google Patents

Abstract

PURPOSE: A scribing method for glass substrates is provided to stably form scribe grooves in a cross scribing process. CONSTITUTION: A scribing method of glass substrates comprises the following steps: forming penetration holes at an intersection point of the scribe target lines; and advancing a crack along the scribing target lines. The penetration holes have four edge portions(11a-11d) which are extended along the scribe target line. The penetration holes are in star form or rectangular form. In the first process, the penetration holes are formed by green laser. The second process comprises the following step: cooling the heated area after irradiating laser light along the scribe target line of the substrate. [Reference numerals] (A) Mother substrate; (B) Perforation; (C) Scribing; (D) Polishing; (E) Completion

Description

[0001] SCRIBE METHOD FOR GLASS SUBSTRATE [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scribe method, and more particularly, to a scribe method of a brittle material substrate which scribes along a predetermined scribe line crossing each other of the brittle material substrate.

As a technique for segmenting brittle material substrates such as glass substrates, a segmentation method using crack propagation has been proposed. In this method, first, an initial crack is formed on the surface of a glass substrate by a cutter wheel or the like. Then, a laser beam is irradiated from this initial crack, a board | substrate is heated, and the heated area | region is cooled. As a result, the crack progresses by using the initial crack as a trigger, and a scribe groove is formed along the scribe scheduled line.

This kind of scribe method is shown by patent document 1. As shown in FIG. In the method of patent document 1, an initial stage crack is formed at the time of processing a board | substrate, and an elliptical heating spot is scanned along a scribe plan line after that. As a result, cracks continuously progress along the scribe line.

Japanese Laid-Open Patent Publication No. 2003-137578

In Patent Document 1, in the formation of an initial crack, it is described that a laser beam of high power is collected on a substrate surface to process a hole, and a crack is created from the hole (paragraph 0054). However, there is no detailed description of the hole as the initial crack.

By the way, the cover glass for touch panels divides and forms one mother board | substrate. More specifically, a plurality of scribe plan lines intersecting in the X and Y directions are set on the mother substrate, and scribe grooves are formed along the plurality of scribe plan lines. That is, a plurality of cover glasses are obtained by cross scribing a mother substrate and dividing along a formed scribe groove. Each cover glass divided | segmented is formed in four curves by curve processing by grinding | polishing.

However, the polishing process which curves each part of the glass after the division takes time.

An object of the present invention is to provide a scribing method in which a scribe groove can be stably formed when cross scribing along a scribing predetermined line intersecting with each other, and furthermore, polishing of each part in a later step is easy. .

The method for scribing a brittle material substrate according to the first invention is a method for scribing along a scribing predetermined line crossing each other of the brittle material substrate, and includes a first step and a second step. The first process forms a through hole having four edge portions penetrating the substrate and extending along the intersecting scribe lines, at the intersections of the intersecting scribe lines. The 2nd process advances a crack along a scribe planned line using a through hole as a starting point.

In this method, a through hole as an initial crack is formed at the intersection of the scribe scheduled line. This through hole has four edge portions extending along an intersecting scribe scheduled line. Thereafter, a crack progresses along the scribe scheduled line starting from each edge portion of the through hole.

Here, since the through hole has an edge portion extending along the scribing scheduled line, in the second step, the crack is likely to move along the scribing scheduled line, and the desired scribe groove can be stably formed. In addition, since the through holes are formed at the points where the scribing scheduled lines intersect, that is, the portions corresponding to the four corner portions in the substrate after the division, the polishing table of the four corner portions can be reduced after the division. Can be.

In the method for scribing a brittle material substrate according to the second invention, in the method of the first invention, the through hole formed in the first step is formed between two adjacent edge portions and curved to bulge toward the inside of the hole. It is a star shape which has four edge parts of a circular arc shape.

Here, the through hole is a molding consisting of four edge portions and four edge portions connecting them, and furthermore, the four edge portions are arcuate shapes that are curved to bulge toward the inside of the hole. Therefore, the four corner parts in the board | substrate after a division | segmentation are circular arc shape at the time of division | segmentation. For this reason, in grinding | polishing process of four corner parts in the process after a division | segmentation, the grinding | polishing stand of each corner part can be reduced.

In the method for scribing the brittle material substrate according to the third invention, in the method of the first invention, the through-holes formed in the first step are four straight lines formed between two adjacent edge portions. It is a rectangular shape having an edge portion.

Here, the through hole is rectangular. For this reason, although it is not the same as 2nd invention, in the process after a division | segmentation, when grinding | polishing four corner parts to curve shape, the grinding | polishing stand of each corner part can be reduced.

In the method for scribing the brittle material substrate according to the fourth invention, in any one of the first to third inventions, a through hole is formed by a green laser in the first step.

In the method for scribing the brittle material substrate according to the fifth invention, in any one of the first to third inventions, in the second step, the laser beam is irradiated and heated along the scribe scheduled line of the substrate, Cooling the heated area develops cracks along the scribe line.

In the method for scribing the brittle material substrate according to the sixth invention, in the method of the fourth invention, in the second step, the laser is irradiated and heated along the scribe scheduled line of the substrate, and the heated region is cooled. Thereby advancing the crack along the scribe line.

As described above, in the present invention, when cross-scribing the brittle material substrate, the scribe groove can be stably formed, and the polishing of each part in the subsequent step is facilitated.

1 is a schematic structural diagram of a scribing apparatus for performing a scribing method according to an embodiment of the present invention;
2 is a diagram illustrating a conventional processing procedure of the touch panel cover glass.
3 is a view showing a processing procedure according to an embodiment of the present invention of the touch panel cover glass.
4 is a diagram illustrating another example of the through hole.
FIG. 5 is an enlarged photograph showing crack propagation (scribing traces) after scribing by three kinds of through holes and bending of the scribe after dividing; FIG.

[Device configuration]

1 is a diagram showing a schematic configuration of a scribing apparatus for performing a method according to an embodiment of the present invention. In addition, in FIG. 1, the through hole is formed in the state after a 1st process, ie, a glass substrate, and the state which is performing the scribe process which is a 2nd process is shown.

The scribe device 1 is an apparatus for dividing a mother glass substrate into the some glass substrate used for the cover glass of a touch panel, for example. The glass substrate used here is mainly a chemically tempered glass having a reinforcing layer formed on its surface. This chemical tempered glass has a tempered layer having a compressive stress on its surface by ion exchange treatment.

<Scribe device>

The scribing apparatus 1 is equipped with the irradiation part 2 which irradiates a laser beam toward glass substrate G, the cooling part 3, and the moving part which is not shown in figure. The cooling unit 3 injects the coolant supplied from a coolant source (not shown) through the nozzle 4 to form a cooling spot CP. The moving part relatively moves the nozzle 4 of the irradiation part 2 and the cooling part 3 with glass substrate G along the scribe plan line SL set to glass substrate G. As shown in FIG.

The irradiation unit 2 has a laser oscillator (for example, a CO ₂ laser) for irradiating the laser beam LB, and the laser beam LB is placed on the glass substrate G through an optical system. Irradiation is made as the beam spot LS.

<Through hole forming apparatus>

The scribe apparatus 1 is provided with an irradiation part (not shown) for through-hole formation. This irradiation part for through-hole formation forms the through-hole which becomes a starting point of the crack propagation at the time of forming a scribe groove in glass substrate G. As shown in FIG. The irradiation part for through-hole formation is equipped with the laser oscillator which emits a green laser, for example, and an optical system.

[Scribe method]

Here, in order to compare with the method of the present invention, the processing procedure of the conventional cover glass of the touch panel will be briefly described with reference to Fig. First, a mother substrate is prepared (a), and an initial crack (not shown) is formed in the mother substrate G by a cutter wheel or the like at the substrate end. Then, the laser beam is irradiated and scanned along the scribe scheduled line with respect to the mother substrate G, and further cooled to form a scribe groove SG (b). Thereafter, a splitting force is applied to both sides of the scribe groove SG, whereby the mother substrate G is divided into a plurality of glass substrates. Next, each part of the divided glass substrate is polished to have a curved shape (c, d).

Next, the processing sequence by one Example of this invention is demonstrated using FIG.

First, in the first step, a plurality of through holes H penetrating from the surface of the substrate to the back surface of the mother substrate G (a) are formed (b). These through holes H are formed by irradiating a green laser to a board | substrate, for example. Each through-hole H is formed in the intersection of the scribe plan line of the X direction and Y direction (refer FIG. 3) orthogonal to each other. In addition, each through hole H is a shaping | molding shape which has the edge extended along a scribing scheduled line, as is clear from FIG.3 (b). More specifically, each through hole H includes four edge portions 11a to 11d extending along the scribe scheduled line SL, and two adjacent edge portions (as shown in an enlarged view in FIG. 3). It is a shaping | molding shape which has four arcuate edge parts 12a-12d formed between 11a-11b, 11b-11c, 11c-11d, and 11d-11a, and curved so that it may bulge toward the inside of a hole.

Next, in a 2nd process, as shown to FIG. 1 and FIG. 3, the laser beam LB is irradiated from the irradiation part 2. As shown in FIG. This laser beam LB is irradiated onto the mother substrate G as the beam spot LS. The laser beam LB emitted from the irradiator 2 is moved relative to the mother substrate G along the scribe plan line SL. The mother substrate G is heated to a temperature lower than the softening point of the mother substrate G by the beam spot LS. In addition, the cooling spot CP is followed in the moving direction rearward of the beam spot LS.

As described above, the compressive stress is generated in the vicinity of the beam spot LS heated by the irradiation of the laser beam LB. However, since the cooling spot CP is formed by the injection of the refrigerant immediately afterwards, the vertical crack is generated. Tensile stress effective for the formation of cracks occurs. By this tensile stress, the vertical crack along the scribe plan line SL is formed starting from the through-hole H formed in the mother substrate G, and the desired scribe groove c is formed.

Thereafter, a splitting force is applied to both sides of the scribe groove SG, whereby the mother substrate G is divided into a plurality of glass substrates. Next, each part of the divided glass substrate is polished to have a curved shape (d, e).

Here, since the through-hole H is formed by shaping | molding which has the arcuate edge part curved so that it may bulge toward the inside of a hole, the four corner | angular parts of each board | substrate after dividing are curved shape chamfered. Therefore, the amount to be polished (polishing table) in the polishing step is very small, and the polishing work can be easily performed in a short time.

[Another example of through hole]

The shape of the through hole is not limited to the molding as shown in FIG. 3. For example, as shown in FIG. 4, a rectangle may be sufficient. Specifically, the through hole H 'shown in FIG. 4 includes four edge portions 21a to 21d extending along the scribe scheduled line SL, and two adjacent edge portions 21a to 21b and 21b. It is a rectangular shape which has four linear edge parts 22a-22d formed between -21c, 21c-21d, and 21d-21a.

Even with such a through-hole H ', although the grinding | polishing stand of each board | substrate of a board | substrate increases compared with the through-hole H of shaping | molding, compared with the conventional processing method, polishing amount can be reduced.

[Experimental Example]

Table 1 shows the evaluation of the scribe grooves in the case where three types of through holes are formed in the mother substrate by the green laser, and the laser output is changed after that. In addition, the glass substrate here is soda-lime glass.

laser
Print ○ (comparative example) ◇ ： Rectangle Castle Gabu Bend Gabu Bend Gabu Bend 120 ○ 141 ○ 40 ○ 64 140 ○ 326 ○ 21 ○ 26 200 ○ 131 ○ 80 ○ 38

○ ： A scribe is possible

Bent: The maximum deviation amount from the scribe scheduled line is shown, and the unit is [μm].

In the above experimental example, each condition of a 1st process (formation of a through hole) and a 2nd process (scribe) is as follows.

[First process]

In the first step, the laser spot was processed while moving in the height direction (Z-axis direction) while rotating the light converging point. In other words, the through hole was formed while moving the laser spot in a spiral shape.

Wavelength: 532nm

Laser power: 5W

Repetition frequency: 20 kHz

Condensing Point Rotation Radius: 500rps

Z axis travel distance: 40μm

Scanning speed: 30mm / s

[The second process]

Wavelength: 10.6μm

Laser power: 120 ~ 200W

Repetition frequency: 10 kHz

Scanning Speed: 250mm / s

In addition, the enlarged photograph in the vicinity of the through-hole before division in the case of the laser output 140W of Table 1, and the enlarged photograph which shows the bending after division are shown in FIG. In Fig. 5, (a) forms a circular through hole having a diameter of 4 mm, and after scribing and dividing thereafter, (b) shows a rectangular through hole having a side of 4 mm, and then Example in the case of scribing and dividing, (c) is an example in the case where one side forms the through-hole of 4 mm shaping | molding, and then scribes and dividing. In each figure, the upper end shows the state of the crack propagation (scribe mark) before the division (break), and the lower end shows the bending of the scribe after the division.

From the above experimental results, although scribing is possible irrespective of the shape of a through-hole, it turns out that when the shape of a through-hole is circular, the bending is large and in the case of rectangle and shaping | molding, the bending is small. That is, it was found that the bend of the scribe decreases as the edge (acute angle) of the portion along the scribe planned line of the through hole serving as the starting point of the scribe becomes an edge (acute angle).

[Other Example]

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

In the above embodiment, the case where the scribe groove is formed in the second step (laser irradiation and cooling treatment) has been described. However, the present invention can be similarly applied to the case where the glass is divided by the second step. have.

1: scribe device
11a ~ 11d, 21a ~ 21d: edge part of through hole
12a-12d, 22a, 22d: edge of through hole
G: Mother Board
LB: Laser Beam
LS: Beam Spot
SL: Scheduled Line
CP: Cooling Spot
H, H ': through hole

Claims (6)

It is a scribing method of a brittle material board | substrate which scribes along a predetermined scribe line which cross | intersects a brittle material board | substrate, and,
A first step of forming a through hole having four edge portions extending through the substrate and along the intersecting scribing lines at the intersections of the intersecting scribe lines,
2nd process of advancing a crack along a scribe plan line using the said through hole as a starting point.
Scribe method of a brittle material substrate comprising a. The method of claim 1,
The through hole formed in the first step is formed between two adjacent edge portions and has four edge portions of an arc shape which are curved to bulge toward the inside of the hole. A method of scribing a brittle material substrate having a shape of a shape. The method of claim 1,
The through-hole formed in the said 1st process is a rectangular shape which has four linear edges formed between two adjacent said edge parts, The scribing method of the brittle material board | substrate. 4. The method according to any one of claims 1 to 3,
In the first step, a through hole is formed by a green laser. 4. The method according to any one of claims 1 to 3,
In the second step, the method for scribing a brittle material substrate in which a crack is advanced along a scribe line by cooling the heated region while heating the laser beam along the scribe line of the substrate. . 5. The method of claim 4,
The said 2nd process WHEREIN: The scribing method of the brittle material board | substrate which advances a crack along a scribing predetermined line by cooling a heated area | region by irradiating and heating a laser beam along a scribing predetermined line of a board | substrate.

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