JP3751122B2 - Cleaving method - Google Patents

Description

の条件で割断加工を行い、次いで材料に照射する熱源を１本のレーザビームとする以外は上記と同じ条件（通常の加工条件）で割断加工を行った。
【００２４】
そして、以上の二つの条件で加工を行った各試料について、それぞれの加工面の傾き（断面傾き）を測定したところ、通常条件による加工の場合、断面傾きが０．５ｍｍであったのに対し、補助熱源を付加した加工の場合、その値が０．１ｍｍ以下までに軽減されることが確認できた。
【００２５】
このような結果から、本発明の割断加工方法が、加工精度の上で優れた加工法であること、特に、加工材料の縁部を加工する際に有効な加工法であることが分かる。
【００２６】
【発明の効果】
以上説明したように、本発明の割断加工方法によれば、割断加工実行中において、割断予定線に沿って移動させる主熱源の斜め前方（または側方）に補助熱源を追従させて移動するので、割断予定線を挟んだ両側の材料幅が非対称な加工材料を加工する場合であっても、割断加工線の両側に作用する熱分布及び熱応力分布のバランスを均等にすることができる。その結果、加工面の断面傾きが従来に比して軽減された加工精度の高い割断加工を実現できる。
【図面の簡単な説明】
【図１】通常の割断加工方法の問題点を示す図で、割断加工予定線を中心とする熱分布曲線と応力分布曲線を併記して示す図
【図２】本発明の割断加工方法の説明図
【図３】本発明の割断加工方法の作用説明図で、割断加工予定線を中心とする熱分布曲線と応力分布曲線を併記して示す図
【図４】本発明の割断加工方法の実施に使用する装置の概略構成を示す図
【符号の説明】
１ 加工テーブル
２，３ レーザ発振器
４ 光学系
Ａ レーザビーム（主熱源）
Ｂ レーザビーム（補助熱源）
Ｗ 加工材料
Ｌ 割断予定線
ＣR 亀裂
ａ 加工始点
ｂ 加工終点[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cleaving apparatus for cleaving a material using a thermal stress generated by applying a heat source such as a laser beam to a brittle material such as glass, ceramics or a semiconductor wafer.
[0002]
[Prior art]
Examples of techniques for separating and processing materials include a scriber or laser fusing. However, in these processes, there is a problem that cullet (debris), melted scars, microcracks, and the like are generated during cutting.
[0003]
In order to solve such problems, recently, a cleaving method for cleaving brittle materials using thermal stress generated by application of a heat source such as a laser beam has been proposed.
[0004]
This processing method is a technique in which a crack is created in a brittle material in advance, a heat source is locally applied to the crack tip to generate thermal stress, and the crack is grown by the movement of the heat source to separate the material. This method is characterized in that the problem of the conventional processing method described above can be solved because no cracks or particles are generated due to the property of growing cracks.
[0005]
[Problems to be solved by the invention]
By the way, as described above, the method for cleaving the brittle material applies a heat source such as a laser beam in front of the crack tip generated in advance in the work material, and generates a temperature gradient between the center of the heat source and the periphery. In this processing method, if the width of the work material on both sides across the planned cutting line is asymmetric, the heat distribution is asymmetric due to heat accumulation. Thus, the balance of the thermal stress distribution in the material surface and the thickness direction is lost (see FIG. 1). As a result, a strong shear stress is generated, and as a result of the difference between the front and back undulations (cross-sectional inclination of the processed surface), there is a problem that the overall processing accuracy is remarkably 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 across the planned cutting line is asymmetric, it is possible to cleave the material with high processing accuracy. The purpose is to provide a cleaving method.
[0007]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention develops a material by moving a heat source along a planned cutting line while growing a crack formed at a processing start point of the material by a thermal stress generated by application of the heat source. In the cleaving method to be separated, as shown in FIG. 2, a main heat source (for example, a laser beam) A is applied in front of the tip of the crack CR formed in the work material W having asymmetric width on both sides across the planned cutting line L. The main heat source A is moved along the planned cutting line L, and the auxiliary heat source (for example, a laser beam) B is moved to follow the main heat source A diagonally forward (or laterally). Characterized by performing crack CR growth.
[0008]
By adding the auxiliary heat source B in this way, even when the processing material width is asymmetric with respect to the planned cutting line L, the cutting process can be performed with high processing accuracy.
That is, when the auxiliary heat source B is moved following the main cutting heat source A to be moved along the planned cutting line L during the cleaving process, the heat distribution acting around the planned cutting line L is moved. As shown in FIG. 3, the balance of the thermal stress distribution is even on both sides of the cleaving line L, and as a result, the difference between the surface waviness and the back surface waviness, that is, the cross-sectional inclination is reduced, so that overall machining accuracy is improved. To do.
[0009]
Here, in the cleaving method of the present invention, the application area of the auxiliary heat source B is determined by the processing speed and output, and is 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.
[0010]
Regarding the distance between the main heat source A and the auxiliary heat source B, 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, the distance P1 in the direction orthogonal to the planned processing line It is appropriate that the distance P2 in the range of 2 mm to 10 mm and the planned processing line direction P2 is in the range of 2 mm to 10 mm. When the auxiliary heat source B is placed on the side (straight side) of the main heat source A, the distance between the centers of the two is A range of 2 mm to 10 mm is appropriate.
[0011]
Further, in the cleaving method of 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. A thermal distribution and a thermal stress distribution are obtained.
[0012]
Furthermore, the shape of the main heat source and the auxiliary heat source applied to the work material may be circular or elliptical. In this case, the crushing process is performed with the heat source shape being an ellipse, and the growth of cracks is processed in the planned fracture line. By adopting a processing method that makes the shape of the heat source circular when approaching the end point, it is possible to advance the crack in a good state and reduce the tensile force applied in front of the application position of the heat source at the end of processing. Accordingly, it is possible to prevent the bending of the machining near the machining end point.
[0013]
In addition to the laser beam, the heat source applied to the present invention includes, for example, an electron beam, an electric heater, or a flame.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, as shown in FIG. 4, an apparatus used for carrying out the cleaving method of the present invention includes a processing table (biaxial movement) 1 on which a processing material W such as a glass material is placed, and two laser oscillators 2. , 3 and an optical system 4 that guides each output laser beam to the surface of the processing material W placed on the processing table 1, and simultaneously irradiates the processing material W with two laser beams A and B. can do. Then, by moving the machining 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 is moved to the laser beam that is the main heat source. It can be moved following A.
[0015]
The optical system 4 includes a mirror, a condensing lens, a diaphragm (not shown), etc., and condenses the laser beams from the laser oscillators 2 and 3 individually, and plans to cleave the laser beam A as a main heat source. It is configured to irradiate the line L and irradiate a laser beam B serving as an auxiliary heat source obliquely forward (on the material end side) of the laser beam A.
[0016]
The optical system 4 can also adjust the positional relationship (relative angle) of the two mirrors, and the positional relationship (distance between the centers) of the irradiation positions of the two laser beams A and B can be adjusted. ) Can be changed.
[0017]
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. To create the initial crack, a hard tool is used to form a notch at the end of the material, or a laser beam is focused on the surface of the work material at a high output to process the hole, and the crack is formed from this hole. A known method such as a creation method is employed.
[0018]
Next, the laser beam A as the main heat source is irradiated on the planned cutting line L in front of the tip of the initial crack, and at the same time, the laser beam B as the auxiliary heat source is irradiated obliquely forward (on the material end side) of the laser beam A. However, by moving the machining table 1, the laser beam A is moved along the planned cutting line L, the laser beam B is moved in the direction along the planned cutting line L by following the laser beam A, and crack CR Is guided from the machining start point a to the machining end point b. At this time, the distance between the laser beam A and the laser beam B, that is, P1 and P2 shown in FIG. 1, take into consideration the processing position with respect to the material edge of the processing material W and the amount of heat applied by the laser beams A and B. Then, the heat distribution and the thermal stress distribution are set to be uniform on both sides of the planned cutting line L.
[0019]
As described above, when the laser beam B is moved as an auxiliary heat source in an obliquely forward direction of the laser beam A that is the main heat source during the cleaving process, as shown in FIG. The balance of thermal distribution and thermal stress distribution acting around L is even on both sides of the cleaving line L, thereby reducing the difference between the surface waviness and the back surface waviness, that is, the cross-sectional inclination, thereby improving machining accuracy. To do.
[0020]
In the above embodiment, the laser beam B serving as the auxiliary heat source is irradiated obliquely in front of the laser beam A serving as the main heat source. ), The same effects as the above can be obtained. In addition, the positional relationship between these two laser beams A and B is appropriately changed during the cleaving process so that the crack CR always grows in good condition according to the growth condition of the crack CR. Also good.
[0021]
Here, in the above embodiment, an example in which two laser oscillators for the main heat source and the auxiliary heat source are used is shown. However, as one laser oscillator, the output beam is divided by a beam splitter or the like. Thus, it is possible to adopt a method of obtaining a laser beam for an auxiliary heat source.
[0022]
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. For example, the present invention can be implemented using an electron beam, an electric heater, or a flame. is there.
[0023]
【Example】
The example which implemented the cleaving method of this invention is described below.

The cleaving was performed under the same conditions as described above (normal processing conditions) except that the cleaving was performed under the above conditions, and then the heat source applied to the material was a single laser beam.
[0024]
For each sample processed under the above two conditions, the inclination (cross section inclination) of each processed surface was measured. In the case of processing under normal conditions, the cross section inclination was 0.5 mm. In the case of machining with an auxiliary heat source, it was confirmed that the value was reduced to 0.1 mm or less.
[0025]
From these results, it can be seen that the cleaving method of the present invention is an excellent processing method in terms of processing accuracy, and in particular, is an effective processing method when processing the edge of the processing material.
[0026]
【The invention's effect】
As described above, according to the cleaving method of the present invention, during the cleaving process, the auxiliary heat source moves following the diagonally forward (or lateral) side of the main heat source that is moved along the planned cutting line. Even when processing a material with asymmetric material widths on both sides of the planned cutting line, the balance of the thermal distribution and thermal stress distribution acting on both sides of the cutting line can be made uniform. As a result, it is possible to realize cleaving with high machining accuracy in which the cross-sectional inclination of the machined surface is reduced as compared with the prior art.
[Brief description of the drawings]
FIG. 1 is a diagram showing problems of a normal cleaving method, and shows a heat distribution curve and a stress distribution curve centered on a planned cleaving line. FIG. 2 is an explanation of the cleaving method of the present invention. FIG. 3 is a diagram for explaining the operation of the cleaving method of the present invention, and shows a heat distribution curve and a stress distribution curve centered on the planned cleaving line. FIG. 4 is an implementation of the cleaving method of the present invention. Schematic configuration of the equipment used for the above [Explanation of symbols]
1 Processing table 2, 3 Laser oscillator 4 Optical system A Laser beam (main heat source)
B Laser beam (auxiliary heat source)
W Work material L Planned cutting line CR Crack a Machining start point b Machining end point

Claims (2)

In the cleaving method of separating the material by moving the heat source along the planned cleaving line while growing the crack formed at the processing start point of the material by the thermal stress generated by the application of the heat source,
A main heat source is applied in front of the tip of the crack formed in the work material with asymmetrical width on both sides across the planned cutting line , and this main heat source is moved along the planned cutting line, and diagonally forward or side of the main heat source. A cleaving method characterized in that the crack grows by moving the auxiliary heat source to follow the direction. 2. The cleaving method according to claim 1, wherein the positional relationship between the main heat source and the auxiliary heat source is adjusted according to a processing position with respect to the material edge.

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