JP3370310B2 - Scribe method using laser - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a vertical crack by thermal strain by irradiating a brittle material such as a glass plate with a CO ₂ laser.

[0002]

2. Description of the Related Art In a process of cutting a glass plate having a small predetermined square size from a glass substrate having a large size using a glass cutter wheel, the glass plate is scribed in the X direction as a first direction and then orthogonally crossed. It divides | segments by performing the scribing of the Y direction used as a 2nd direction, and giving a bending stress in the subsequent break process.
At the time of scribing in the second direction, the scribing pressure is increased and the scribing speed is made slower than that at the time of scribing in the first direction in order to prevent intersection jump.

[0003]

A scribing method using a laser instead of a conventional scribing method has been put into practical use. This scribing method is a special table 8-50
No. 9947, and the vertical cracks obtained by this method are blind. As shown in FIG. 1, a laser beam from a laser 2 is applied to a laser spot 3 on a glass plate 1 moving in an arrow direction A, and a region heated by the irradiation of the laser beam is Next, by cooling with the refrigerant jet 4, an internal strain stress change occurs in the glass plate 1 and a blind vertical crack is generated. This makes blind scribe lines (blind vertical crack lines)
5 is generated. In the description of the present invention, blind scribe lines and blind vertical cracks are referred to as scribe (scribe lines) and vertical cracks without distinguishing between scribe (scribe lines) and vertical cracks by a glass cutter wheel.

In this laser scribing, the glass plate is scribed in the first direction and then in the Y direction, which is the second direction. By the way, in the cross scribing method using the glass cutter wheel, when scribing in the second direction as described above,
Compared with the case of scribing in the direction, the scribe pressure was increased and the scribe speed was decreased in order to surely insert the vertical crack deeply, thereby increasing the depth of the vertical crack. Therefore, following this method also in laser scribe, when scribe in the second direction, the irradiation energy per unit area per unit time is increased compared to when scribe in the first direction. When the moving speed is slowed or the moving speed is the same, the laser output is increased during scanning in the second direction. However, when scribing in the first direction and the second direction and then separating them, large cracks (cracks that cause the product to become defective) occurred at a location where the scribe lines intersect at a high probability.

The present invention has been made in order to eliminate the occurrence of cracks which are defective at the orthogonal points, and an object of the present invention is to provide a new scribing method which can eliminate cracks which cause defective products.

[0006]

[ MEANS FOR SOLVING THE PROBLEMS] On a surface of a substrate of a brittle material.
Irradiate laser to generate vertical cracks on the substrate due to thermal strain
To form a scribe line, scribe line
The scribing method to break the substrate along
In the first direction, the first scrub due to the vertical crack in the first direction.
Forming an ibrine and then a first direction
A second skirt caused by a vertical crack in a second direction perpendicular to
The second direction consists of forming the live line
In the step of forming a second scribe line
2nd than the vertical crack depth of the 1st scribe line
Shrink the vertical crack depth of the scribe line to make the substrate
At the break, the first cross portion of the second scribe line
Prevents abnormal cracks from occurring.

In the above scribing method, it is preferable that when the vertical crack is formed in the second direction, the irradiation energy irradiated per unit area per unit time as compared with the case where the vertical crack is formed in the first direction. Reduce. In the scribing method, for example, when the relative moving speed of the laser with respect to the substrate is the same in the first direction and the second direction, the laser output in the second direction is reduced with respect to the first direction. Preferably, the laser output in the second direction is reduced by 10 to 40% with respect to the first direction. In the scribing method, for example, when the laser output is the same in the first direction and the second direction, the relative movement speed of the laser in the second direction is increased with respect to the first direction. Preferably, the relative movement speed of the laser in the second direction is 110 to 140% with respect to the first direction.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A scribing method according to an embodiment of the present invention will be described below with reference to the accompanying drawings. FIG.
As shown in FIG. 2, the laser beam from the laser 2 is irradiated to the glass plate 1 moving in the arrow direction A as a laser spot, and the region heated by the irradiation of the laser beam is the refrigerant jet next. As a result of cooling at 4, an internal strain stress change occurs in the glass plate 1 and vertical cracks are generated due to thermal strain. Thereby, a scribe line (vertical crack line) 5 is generated.

As shown in FIG. 2, the glass plate 1 is scribed in the X direction as the first direction (first-in), and then the first
Scribing was performed in the Y direction as a second direction (post-insertion) perpendicular to the direction. Here, by performing scribing under various conditions as will be described later, in the scribe line obtained when no abnormality occurs, the vertical direction formed in the second direction rather than the vertical crack depth in the first direction. It was found that the crack depth was shallow. Specifically, when scribing in the second direction, it was found that the occurrence of abnormality can be suppressed by reducing the irradiation energy per unit area per unit time compared to when scribing in the first direction. .

As the scribing conditions, the conditions shown in Table 1 were used. Here, the output of the laser 2 was kept constant, and the moving speed of the laser spot 3 was controlled. As shown in Table 1, the output in the scribe in the first direction is 30
W, moving speed is 90 mm / sec, and in scribing in the second direction, output is 30 W, moving speed is 70 mm / sec,
The moving speed at the time of scribing in the second direction was made slower than that at the time of the first scribing. In this case, as shown in FIG.
A large unnecessary crack 6 was observed on the break surface in the first direction at the intersection 7 of the scribe line 5, and the generation rate was approximately 75% (3 out of 4).

Next, as shown in Table 1 as scribing conditions, the output in the scribing in the first direction is 30.
W, moving speed is 90 mm / sec, and in scribing in the second direction, output is 30 W, moving speed is 90 mm / sec,
The scribing conditions were the same in the first and second directions.
In this case, the incidence of abnormality is approximately 25% (1 out of 4)
Met.

Finally, as shown in Table 1 as the scribing conditions, the output in the scribing in the first direction is 3
0W, moving speed is 70mm / sec, and the scribe in the second direction is output 30W, moving speed is 90mm / sec. In this way, the moving speed when scribing in the second direction is the first scribe. It was faster than that. In this case, no abnormality was observed.

[0013]

[Table 1]

Next, the conditions shown in Table 2 were used as scribe conditions. Here, the moving speed of the laser spot 3 was made constant, and the output of the laser 2 was controlled. As shown in Table 2, the output is 3 for the scribe in the first direction.
0W, moving speed is 90mm / sec, the scribe in the second direction is 40W, moving speed is 90mm / sec, and the laser 2 output when scribing in the second direction is compared to the first scribe And enlarged. In this case, FIG.
As shown in Fig. 1, the first intersection is at the intersection 7 of the scribe line 5.
The generation of large unnecessary cracks 6 was observed on the break surface in the direction of, and the generation rate was approximately 75% (3 out of 4).

Next, Table 2 shows the same scribe conditions as in Table 1. At this time, in the scribing in the first direction, the output is 30 W, the moving speed is 90 mm / sec, the second
Even when scribing in this direction, the output was 30 W, the moving speed was 90 mm / sec, and the scribing conditions were the same in the first and second directions. The incidence of abnormalities was approximately 25% (1 out of 4).

Finally, as shown in Table 2 as the scribing conditions, the output in the scribing in the first direction is 3
The scribe in the second direction is 0W, the moving speed is 90mm / sec, the output is 20W, the moving speed is 90mm / sec, and the laser 2 output when scribing in the second direction is compared with the first scribe. And made it smaller. In this case, no abnormality was observed.

[0017]

[Table 2]

As can be seen from the above example, the output of the laser 2 or the moving speed of the laser spot 3 is controlled,
At the time of scribing in the second direction, if the irradiation energy per unit area was reduced as compared with the case of scribing in the first direction, a good result that no abnormality occurred was obtained. Typically,
When the relative movement speed of the laser with respect to the substrate is the same in the first direction and the second direction, good results can be obtained by reducing the laser output in the second direction by 10 to 40% with respect to the first direction. It was. Further, when the laser output is the same in the first direction and the second direction, good results were obtained when the relative movement speed of the laser in the second direction was 110 to 140% with respect to the first direction. .

[0019]

As described above, according to the present invention, the depth of the vertical crack formed in the second direction is made smaller when scribing in the second direction than when scribing in the first direction. Unnecessary vertical cracks can be eliminated.

[Brief description of the drawings]

[Figure 1] A diagram showing a laser scribing method

FIG. 2 is a diagram showing scribe line formation in two directions by a laser.

[Figure 3] Diagram showing the occurrence of an abnormality

[Explanation of symbols]

1 Glass plate 2 Laser 6 Crack

Claims (6)

(57) [Claims] 1. A surface of a brittle material substrate is irradiated with a laser to cause vertical cracks in the substrate due to thermal strain, thereby causing a scratch.
Form the brine and move the substrate along the scribe line
In the scribing method for breaking , the first scribing line is formed by a vertical crack in the first direction.
Forming a down, then either forming a second scribe line by a vertical crack in a second direction perpendicular to the first direction
Rannahli, first in the second step of forming a scribe line, shallow vertical crack depth of the second scribe line of a vertical crack depth of the first scribe line in a second direction
Te, when the substrate break, the first and second scribe lines
To prevent the occurrence of abnormal cracks at the intersection of
Scribing method using a laser, characterized in that it has. 2. A scribe line in a second direction is formed.
Forming a scribe line in the first direction.
The scribing method using a laser according to claim 1, wherein the irradiation energy per unit area is reduced as compared with the case . Wherein the same relative movement speed of the laser relative to the substrate in <br/> first and second directions with respect to the first direction, claim to reduce the laser output in the second direction 2
The scribing method using the described laser. 4. The scribing method using a laser according to claim 3, wherein the laser output in the second direction is reduced by 10 to 40% with respect to the first direction. 5. the same laser output in a first direction and a second direction, relative to the first direction, use the laser of claim 2, wherein the make increasing the relative moving speed of the laser in the second direction The scribing method. 6. The relative movement speed of the laser in the second direction with respect to the first direction is set to 110 to 140%.
The scribing method using the described laser.