JPH1110375A - Cutting method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a cleaving method capable of cleaving a material with high processing accuracy even if the width of a processing material on both sides of an intended cutting line is asymmetric. . SOLUTION: In a cutting method in which a crack formed at a processing starting point of a material is grown by thermal stress generated by application of a heat source and the material is separated by moving the heat source along a predetermined cutting line. The main heat source A is applied to the front of the tip of the crack CR formed in the material W, and the main heat source A is moved along the planned cutting line L, and the auxiliary heat source A is obliquely forward (or laterally) of the main heat source L. By moving while following B, even if the work material width is asymmetric with respect to the planned cutting line L, a uniform heat distribution and a uniform thermal stress distribution can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaving apparatus for cutting a brittle material such as glass, ceramics or a semiconductor wafer by using a thermal stress generated by applying a heat source such as a laser beam to the material. .

[0002]

2. Description of the Related Art Techniques for separating and processing materials include scriber and laser fusing. However, such processing has a problem that cullets (dust), melting marks, microcracks, and the like are generated during cutting. .

[0003] In order to solve such a problem, a cutting method for cutting a brittle material using thermal stress generated by application of a heat source such as a laser beam has recently been proposed.

In this working method, a crack is formed in advance in a brittle material, a heat source is locally applied to the crack tip to generate a thermal stress, and the material is separated by growing the crack by moving the heat source. According to this method, there is a feature that the above-mentioned problems of the conventional processing method can be solved because no cutting margin or particles are generated due to the property of growing a crack.

[0005]

By the way, as described above, a method of cutting a brittle material is to apply a heat source such as a laser beam in front of a crack tip generated in advance in the work material, and to apply a heat source center to the heat source. Because it is a processing method that grows cracks by concentrated stress generated by the temperature gradient generated between the surroundings, in this processing method, if the width of the processing material on both sides of the planned cutting line is asymmetric, Due to the accumulation of heat, the heat distribution becomes asymmetric, and the balance of the thermal stress distribution in the material surface and the thickness direction is broken (see FIG. 1). As a result, a strong shear stress is generated, and a difference (cross-sectional inclination of the processed surface) appears between the front and rear surface undulations. As a result, there is a problem that the overall processing accuracy is significantly deteriorated.

[0006] The present invention has been made in view of such circumstances, and even if the width of the processing material on both sides of the expected cutting line is asymmetric, the material is cut with high processing accuracy. The purpose of the present invention is to provide a cleaving method capable of cutting.

[0007]

In order to achieve the above object, the present invention provides a method for forming a crack at the starting point of processing a material by a thermal stress generated by applying a heat source, and cutting the heat source along a cutting line. In the cleaving method in which the material is separated by moving along, as illustrated in FIG.
A main heat source (for example, a laser beam) A is applied in front of the tip of a crack CR formed in the processing material W, and the main heat source A is moved along the planned cutting line L. In this case, an auxiliary heat source (for example, a laser beam) B is moved to follow the crack CR.
It is characterized by performing growth.

By adding the auxiliary heat source B in this way,
Even when the width of the processing material is asymmetric with respect to the planned cutting line L, the cutting can be performed with high processing accuracy. That is, during the cutting operation, the planned cutting line L
Obliquely forward (or sideways) of the main heat source A to be moved along
When the auxiliary heat source B is moved to follow, the balance between the heat distribution and the thermal stress distribution acting around the planned cutting line L becomes uniform on both sides of the planned cutting line L as illustrated in FIG.
As a result, the difference between the front surface undulation and the back surface undulation, that is, the cross-sectional inclination, is reduced, and the overall processing accuracy is improved.

Here, in the cutting method of the present invention,
The application area of the auxiliary heat source B is determined by the processing speed and the output, and is set to an application area that does not damage the work material such as residual stress. For example, when the processing speed is 10 mm / s and the output is 10 W, the diameter of the auxiliary heat source B is suitably 2 mm to 4 mm.

The distance between the main heat source A and the auxiliary heat source B is, as shown in FIG. 2, when the application position of the auxiliary heat source B is obliquely forward with respect to the main heat source A. It is appropriate that the distance P1 is in the range of 2 mm to 10 mm and the distance P2 in the direction of the planned processing line is in the range of 2 mm to 10 mm. Suitably, the distance is in the range of 2 mm to 10 mm.

In the cutting method according to the present invention, the positional relationship (distance) between the main heat source and the auxiliary heat source is adjusted according to the processing position with respect to the material edge, and as shown in FIG. To obtain a uniform heat distribution and thermal stress distribution.

Further, the shapes of the main heat source and the auxiliary heat source applied to the processing material may be circular or elliptical.
When the crack growth approaches the processing end point of the planned cutting line,
If a processing method such as making the shape of the heat source circular is adopted, the crack can be advanced in a good state, and the tensile force applied in front of the application position of the heat source at the end point of the processing is reduced, and the vicinity of the processing end point is reduced. Processing bending can be prevented.

The heat source applied to the present invention may be, for example, an electron beam, an electric heater or a flame, in addition to the laser beam.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. First, as shown in FIG. 4, an apparatus used for carrying out the cleaving method of the present invention is a processing table (biaxial movement) 1 on which a processing material W such as a glass material is placed.
, Two laser oscillators 2 and 3 and an optical system 4 for guiding each output laser beam to the surface of the processing material W placed on the processing table 1. B can be irradiated onto the work material W at the same time. By moving the processing table 1, one laser beam (main heat source) A can be moved along the planned cutting line L, and the other laser beam (auxiliary heat source) B can be moved by the laser beam as the main heat source. A can be moved following A.

The optical system 4 includes a mirror, a condenser lens, a diaphragm (not shown), and the like. The optical system 4 individually condenses the laser beams from the laser oscillators 2 and 3 to form a laser beam A serving as a main heat source. Is irradiated to the cut line L, and the laser beam B serving as an auxiliary heat source is applied to a position obliquely forward (the material end side) of the laser beam A.

The optical system 4 is also capable of adjusting the positional relationship (relative angle) between the two mirrors, and by adjusting the positional relationship between the two laser beams A and B (the relative position). Center-to-center distance) can be changed.

Next, the processing procedure will be described with reference to FIG. First, an initial crack is generated at the processing start point a of the processing material W. The initial crack can be created by forming a notch at the end of the material using a hard tool, or by focusing a high-power laser beam on the surface of the work material to form a hole and forming a crack from this hole. A well-known method such as a method for creating the image is adopted.

Next, a laser beam A, which is a main heat source, is radiated on the planned cutting line L in front of the tip of the initial crack, and at the same time, a laser beam, which is an auxiliary heat source, is obliquely forward (on the material end side) of the laser beam A. While irradiating the laser beam B, the laser beam A is moved along the planned cutting line L by the movement of the processing table 1, and the laser beam B is moved in the direction along the planned cutting line L by following the laser beam A. , Crack CR
From the processing start point a to the processing end point b. In addition,
At this time, the distance between the laser beams A and B, that is, P1 and P2 shown in FIG. The heat distribution and the thermal stress distribution are set to be equal on both sides of the planned cutting line L.

As described above, when the laser beam B as an auxiliary heat source is moved obliquely forward of the laser beam A, which is the main heat source, during the cutting process, as shown in FIG. The balance between the heat distribution and the thermal stress distribution acting on the periphery of the cutting line L becomes uniform on both sides of the planned cutting line L, thereby reducing the difference between the front surface undulation and the back surface undulation, that is, the cross section inclination. The accuracy is improved.

In the above embodiment, the laser beam B serving as the auxiliary heat source is irradiated obliquely forward of the laser beam A serving as the main heat source. Even if the light is irradiated on the side (right side), the same operation and effect as described above can be obtained. The positional relationship between these two laser beams A and B is appropriately changed during the cutting process so that the crack CR grows in a good condition at all times in accordance with the growth state of the crack CR. Is also good.

Here, in the above embodiment, an example is shown in which two laser oscillators for the main heat source and the auxiliary heat source are used. However, the number of laser oscillators is one, and the output beam is used as a beam splitter or the like. , And a method of obtaining a laser beam for an auxiliary heat source can be adopted.

Further, in the above embodiment, the laser beam is used as the main heat source and the auxiliary heat source. However, the present invention is not limited to this, and the present invention can be applied even if an electron beam, an electric heater or a flame is used. It is feasible.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the cleaving method of the present invention is implemented will be described below. a. Processing material: glass material (500 mm × 400 mm × thickness 0.7 mm) b. Irradiation condition: main heat source A; laser beam (beam diameter 2 mm, heat quantity 6 W) auxiliary heat source B; laser beam (beam diameter 2 mm, heat quantity 10 W) P1 = 2 mm, P2 = 4 mm c. Processing position: material edge 4 mm d. Processing speed: 10 mm / s Cutting is performed, and the heat source to irradiate the material is a single laser beam. Other than the above, the cleaving was performed under the same conditions as above (normal processing conditions).

For each sample processed under the above two conditions, the inclination (cross-sectional inclination) of each processed surface
In the case of processing under normal conditions, it was confirmed that the cross-sectional inclination was 0.5 mm, whereas in the case of processing with the addition of an auxiliary heat source, the value was reduced to 0.1 mm or less. Was.

From these results, it can be seen that the cleaving method of the present invention is a processing method excellent in processing accuracy.
It turns out that this is an effective processing method when processing the edge of the processing material.

[0026]

As described above, according to the cleaving method of the present invention, during the cleaving operation, the auxiliary heat source follows the main heat source obliquely forward (or laterally) along the planned cutting line. Even when processing a material with asymmetrical material width on both sides of the planned cutting line, the balance of heat distribution and thermal stress distribution acting on both sides of the cutting line is evened. be able to. As a result, it is possible to realize a high-precision cutting process in which the cross-sectional inclination of the processing surface is reduced as compared with the related art.

[Brief description of the drawings]

FIG. 1 is a diagram showing a problem of a normal cutting method, and also shows a heat distribution curve and a stress distribution curve centered on a planned cutting line.

FIG. 2 is an explanatory view of a cleaving method of the present invention.

FIG. 3 is an explanatory diagram of an operation of the cutting method according to the present invention, showing a heat distribution curve and a stress distribution curve centered on a planned cutting line.

FIG. 4 is a diagram showing a schematic configuration of an apparatus used for carrying out the cleaving method of the present invention.

[Explanation of symbols]

 Reference Signs List 1 processing table 2, 3 laser oscillator 4 optical system A laser beam (main heat source) B laser beam (auxiliary heat source) W processing material L scheduled cutting line CR crack a processing start point b processing end point

Continued on the front page (72) Inventor Toshihiro Okiyama 1174-22, Gokunino-cho, Himeji City, Hyogo Prefecture 29-1 Hinodecho (72) Inventor Hidenobu Onita 955-1 Miki-cho, Omura City, Nagasaki Prefecture (72) Tomohiro Suenaga 764 Kyowacho, Omura City, Nagasaki Prefecture Asahi Heights 22 (72) Inventor Koichi Kinoshita Omura, Nagasaki Prefecture 1-189-1 Uematsu, Ichimatsu First coat 205 No. (72) Inventor Shunichi Maekawa 1-15 Kasugaoka, Itami-shi, Hyogo

Claims (2)

[Claims] 1. A cutting method for separating a material by moving a heat source along a predetermined cutting line while growing a crack formed at a processing starting point of the material by a thermal stress generated by applying a heat source, Apply the main heat source in front of the tip of the crack formed in the processing material,
While moving this main heat source along the planned cutting line,
A cracking method comprising growing the crack by moving the auxiliary heat source obliquely forward or to the side of the main heat source. 2. The method according to claim 1, wherein a positional relationship between the main heat source and the auxiliary heat source is adjusted according to a processing position with respect to a material edge.