KR100497568B1 - A Laser Apparatus for Cutting through a Flat Workpiece of Brittle Material, especially Glass - Google Patents

Abstract

The present invention generates the laser beam intensity and the laser radiation intensity profile of the beam cross section in real time in an optimal state for machining, and performs high-speed cutting with high precision without distortion of cutting lines even when cutting asymmetric materials and curves. It relates to a laser device for cutting brittle material.

In the present invention, the laser generator 30 for emitting a laser beam; A beam splitting part 32 which partially reflects the emitted laser beam and passes the split part into two beams; A reflector 38a for reflecting the part of the laser beam passing through the beam splitting part 32 in a direction parallel to the direction of the other part of the laser beam reflected from the beam splitting part 32; Installed in the laser beam path reflected from the beam splitter 32 and the laser beam path reflected from the reflector 38a, respectively, to match the output intensity of the laser beams with the same or different intensities, respectively. A beam output adjusting unit 34 (34-1) for adjusting; The beam output adjusting units 34 and 34-1 respectively form elliptical shapes of the laser beams having the same or different intensities, and adjust the lengths of the long and short axes of the laser beams of the elliptical shape. Beam deformation optical units 36a and 36b and 36a-1 and 36b-1 for deforming an elliptical beam having the same or different shapes to each other according to cutting conditions of the brittle material; Cutting lines on the surface of the brittle material 14 to be cut by reflecting two laser beams modified in the same or different elliptical beam shape in the beam deformation optical units 36a and 36b and 36a-1 and 36b-1. While irradiating 50 to the first and second elliptical thermal radiation areas 44a and 44b, the first and second elliptical thermal radiation areas 44a and 44b are opened upstream with respect to the conveying direction and partially overlapped with the downstream side. Two first and second elliptical thermal radiation areas 44a irradiated to form a cicada wing-shaped synthetic heat radiating part that forms the highest temperature region by the overlapping portions thereof. Two opposing reflecting portions 38b, 38c and 38b-1, 38c-1, each of which changes the irradiation angle of (44b) to the same or different angles in accordance with the cutting conditions of the brittle material and at the same time changes the amount of overlap. ); Coolant injection for injecting coolant to the cutting line of the brittle material 140 on the downstream side of the cicada wing-shaped synthetic heat radiator formed by a partial overlap of the two first and second elliptical thermal radiation areas 44a and 44b. Device 40; And the laser generator 30, beam power adjusting units 34 and 34-1, beam deformation optical units 36a and 36b, 36a-1 and 36b-1, and reflector sections 38b and 38c and 38b-1. And 38c-1) and a control unit 46 for controlling the coolant injector 40 in accordance with a given cutting condition, wherein the first and second elliptical thermal radiators are irradiated to form the cicada-shaped synthetic thermal radiator. There is provided a laser device for cutting brittle materials, characterized in that the intensity, size, irradiation angle, and overlapping amount of the output of the areas 44a and 44b are adjusted in real time according to the cutting conditions of the brittle material.

Description

Laser device for cutting brittle materials {A Laser Apparatus for Cutting through a Flat Workpiece of Brittle Material, especially Glass}

The present invention relates to a laser device for cutting brittle materials, and more particularly, to generate a laser beam intensity and a laser radiation intensity profile of a beam cross section in real time in an optimal state for processing to cut asymmetric materials and curves. The present invention relates to a laser device for cutting brittle materials, which performs high-speed cutting with high precision without distortion of cutting lines.

In general, in cutting brittle materials such as glass, wafers, and ceramics using a laser, laser thermal cutting is a method of performing high quality clean processing while minimizing residual thermal stress caused by dust or thermal shock generated during laser processing. Laser thermo-cleaving is widely used.

The basic principle of the laser thermal cutting method is to cut the brittle material without loss of material by maximizing the expansion / compression force inside the brittle material by heating and cooling the laser below the softening point using the brittle material. In special cases, cutting can be carried out by laser heating alone without cooling.

The laser thermal cutting method is largely divided into a laser full cutting method and a laser scribing and laser breaking method. In FIG. 1, the surface of the brittle material 14 using the laser full cutting method is used. A process of cutting the brittle material 14 by irradiating the laser beam 10 and subsequently spraying the coolant 11 is shown.

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In such a laser full cutting method, the inside of the brittle material 14 is heated to a softening point or less by using the thermal energy of the laser beam 10, and then the coolant 11 is sprayed through a coolant injector to quickly cool the heating part. By maximizing the expansion / compression force throughout the brittle material 14, the brittle material 14 is cut without loss of material and dust generation. However, the above-mentioned laser full cutting method is applicable when the thickness of the brittle material to be cut is thin, and the cutting speed is low, and in particular, when cutting asymmetric materials, there is a limit of precision because cutting distortion occurs in the thermodynamic aspect. .

The laser scribing / breaking method shown in FIG. 2 first irradiates the scribing laser beam 12 to heat the surface portion of the brittle material 14 to a softening point or less, and then to coolant injector. The coolant 13 is sprayed through to cool the heating part quickly, thereby maximizing the expansion / compression force on the surface portion of the brittle material 14 to generate a fine crack.

Then, the breaking laser beam 15 is irradiated along the cutting line where the crack is generated, and thermal shock is further applied to the brittle material 14 to generate the fine cracks by the thickness of the brittle material 14, thereby causing loss and dust. It can be cut smoothly without occurrence.

However, this method also has a problem in that cutting precision occurs due to cutting distortion in cutting thermodynamically asymmetric materials.

On the other hand, when cutting the brittle material by using the above-mentioned laser cutting methods, the laser beam shape irradiated to the brittle material mainly used a conventional elliptical shape and U-shaped / V-shaped curve, which is international patent WO 93/20015 and the United States Patent US5984159 / US6112967 are disclosed, respectively.

Among these, the elliptical shape concentrates thermal energy at the center of the brittle material to be processed, thereby raising the temperature up to the melting point at the center of the material during high speed and high power cutting, thereby causing thermal cracks and cutting defects on the surface of the brittle material. In order to reduce this phenomenon, a special beam mode is used to reduce this phenomenon, but this has been limited because the laser power and beam mode stability are inferior, causing another problem of lowering the reliability of the cutting quality. In addition, since the elliptical shape has a fixed beam power distribution curve, there is a limit in implementing an optimal beam shape suitable for the type of material and the processing site environment.

Accordingly, the U- and V-shaped thermal radiation curves have been used to solve the above problems. In FIG. 3A, the U-shaped thermal radiation curve 20 irradiated onto the brittle material is shown. In FIG. 3B, the laser beam output intensity distribution (I-axis) in the A, B, and C axes is shown. In FIG. 3C, A, B, The temperature distribution (T axis) of the brittle material surface portion on the C axis is shown.

The U-shaped or V-shaped thermal radiation curves are made using masks, oscillating mirrors, mirror wheels, and the like. The thermal radiation curve prevents overheating at the center of the beam and enables the use of a relatively stable beam mode, and the beam shape can be deformed to some extent in accordance with the curve path when the curve is processed. However, this method requires the formation of a U- or V-shaped thermal radiation curve using a single spot (spot or point) laser beam, which makes it difficult to apply the laser full cutting method because it is difficult to heat the entire material. It was mainly used only for the laser scribing method. In addition, since a U-shaped or V-shaped thermal radiation curve should be formed using a single spot laser beam, the laser beam may be formed at a high speed (left or right) along a U- or V-shaped curve centered on a cutting line. 500 ~ 200㎐) alternately to irradiate or block the laser beam at high speed and repeatedly. Therefore, in the case of using the above-described oscillating mirror, the vertical mirror should be oscillated left and right about the vertical axis and the horizontal mirror should be oscillated up and down about the horizontal axis. In order to complete the shape, the vibration angles of the vertical mirror and the horizontal mirror must be shifted along the trajectory of the U-shaped or V-shaped curve while providing a differential at every time, so that the apparatus for doing this becomes very complicated. In addition, in the case of cutting a curve such as a free curve where the cutting line is not a straight line, a U-shaped or V-shaped thermal radiation curve should be formed in a non-symmetrical form (asymmetrically) with respect to the cutting line. Since the shape of the U- or V-shaped curve must be changed at every instant along the curvature of the curve, the left side vibration (deflection) angle and right side vibration (deflection) angle of the vertical mirror, and the upper and lower vibration angle of the horizontal mirror By changing at every moment and moving along the free curve as a whole, the implementation of the device is almost impossible, and even if it is possible, the structure and control process of the device is very complicated. In addition, in the case of using the above-described mirror wheel, the surface of the mirror wheel is a kind of cam-shaped curved surface corresponding to the U-shaped or V-shaped curve. When the laser beam is irradiated to the rotating mirror wheel, the curved surface of the mirror wheel surface This changes the direction of reflection of the beam so that at least one U- or V-shaped thermal radiation curve is drawn during one revolution of the mirror wheel. However, in the case of using the mirror wheel as described above, since one mirror wheel is manufactured in a form capable of generating only one U- or V-shaped curve, a new mirror is changed whenever the characteristics or requirements of the brittle material change. The disadvantage is that the wheel must be redesigned. In addition, such a mirror wheel has a disadvantage that it is impossible to change the shape of the U-shaped or V-shaped curve at any time along the curvature of the free curve, so that the mirror wheel may not be applied except a straight cut line.

In addition, due to the above reasons, in the conventional cutting method by generating a U-shaped or V-shaped thermal radiation curve, it is impossible or impossible to remove the cutting line distortion phenomenon due to the thermodynamic phenomenon. Therefore, there is a limit to high precision cutting work.

For example, as shown in FIG. 4, in the case of cutting the brittle material 14 by laser thermal cutting by implementing a conventional elliptical, U-shaped, V-shaped beam shape or the like, the laser beam irradiation path 22a Between (a) 24a and actual cutting lines 24a and 24b, a cutting distortion phenomenon due to thermodynamic phenomenon occurs.

In FIG. 4, first, in the straight cutting line 22a, the area narrower than the heat transfer speed in the wide area (ie, the left area of the cutting line 22a in the drawing) (ie, the right area of the cutting line 22a). Since the heat transfer speed in the c) is higher, the temperature of the left region of the cutting line 22a is higher, so that the actual cutting line 24a, which generates the maximum thermal expansion / contraction stress, is bent toward the narrow region where the temperature is low. This will occur. In view of this, the distortion phenomenon should be corrected by providing a laser beam energy that is relatively larger than the left region of the cutting line 22a, but this correction is impossible in the related art, and thus the cutting quality is deteriorated.

In addition, in FIG. 4, when the cutting line has the shape of the cutting line 22b of the curve shown in the figure, the heat distribution in the inner side is smaller than the heat transfer on the outside of the cutting line 22b, so that the temperature distribution is different. The actual cutting line 24b in which the thermal expansion / contraction stress is generated is a distortion phenomenon that is bent inside the cutting line 22b. In view of this, the energy of the laser beam should be provided relatively larger than the inside of the cutting line 22b to correct the distortion phenomenon. However, such a correction is impossible in the related art, and thus the cutting quality is deteriorated. In addition, all of the conventional cutting methods by the U-shaped or V-shaped thermal radiation curve, the output intensity of the left and right sides can not be adjusted based on the cutting line. Therefore, when cutting asymmetric materials or cutting along a curve, it was difficult to prevent the distortion of the cutting line. In the conventional cutting methods described above, a small spot laser beam is alternately irradiated to the left and right sides along a U-shaped or V-shaped curve (using an oscillating mirror), or of a U-shaped or V-shaped curve. Start from one end of the open side and continuously move to the other end (mirror wheel usage). Therefore, in order to increase the cutting speed, the output intensity of the laser beam should be increased accordingly. In this case, the possibility of overheating becomes large, which makes it difficult to increase the cutting speed. That is, in order to increase the overall cutting speed, the alternating speed of one laser beam spot (speed of irradiating oscillating mirror from side to side) or feed speed (speed of moving the mirror wheel along a U-shaped or V-shaped curve) Increase the speed without increasing the output intensity of the laser beam, resulting in insufficient heating of the cutout. Therefore, in order to properly heat the entire cut portion, it is inevitable to increase the energy of one spot, that is, the output intensity of the laser beam, as the speed is increased, and accordingly, excessive thermal shock such as the spot portion is locally overheated to melt the material. This problem arises.

Accordingly, the present invention has been made in view of the above-mentioned problems in the prior art, and when cutting the brittle material using the laser, the beam shape of the laser and the output intensity distribution of the laser beam cross section are generated in real time in a state that is optimal for processing. It is an object of the present invention to provide a laser device and a method of cutting brittle materials using the same, which can precisely cut along a cutting target line without distortion, even without melting the asymmetric material and curves.

In order to achieve the above object, a laser generator for emitting a laser beam; A beam splitter which partially reflects the emitted laser beam and passes the split laser beam into two beams; A reflector reflecting the partial laser beam passing through the beam splitter in a direction parallel to the direction of the other laser beam reflected by the beam splitter; A beam output adjusting unit installed in each of the laser beam path reflected by the beam splitter and the laser beam path reflected by the reflector, and respectively adjusting the output intensity of the laser beams to the same or different intensities according to cutting conditions; Each beam power adjusting unit forms elliptical shapes of the laser beams having the same or different intensities, and adjusts the lengths of the long and short axes of the laser beams of the elliptical shape to match the cutting conditions of the brittle material. Beam deformation optics for transforming elliptical beams of the same or different shape; The beam deformation optical unit irradiates the first and second elliptical thermal radiation regions to the cutting lines on the surface of the brittle material to be cut by reflecting two laser beams modified in the same or different elliptical beam shapes. 1,2 elliptical heat radiating area is irradiated to form a cicada wing-shaped synthetic heat radiating part which forms the highest temperature area by the overlapping part of the upstream side and the downstream side with respect to the conveying direction. Two opposite reflections each of which change the irradiation angles of two first and second elliptical thermal radiation regions irradiated to form a synthetic thermal radiation unit at the same or different angles according to the cutting conditions of the brittle material and at the same time varying the overlapping amount. cervix; A coolant injector for injecting a coolant to a cutting line of the brittle material at a downstream side of a cicada wing shaped synthetic heat radiator formed by a partial overlap of the two first and second elliptical heat radiating regions; And a control unit for controlling the laser generator, the beam output adjusting unit, the beam deformation optical unit, the reflecting mirror unit, and the coolant spraying device according to a given cutting condition, wherein the first two irradiated to form the cicada wing-shaped synthetic heat radiating unit. There is provided a laser device for cutting brittle materials, characterized in that the intensity, size, irradiation angle, and overlapping amount of output of the elliptical thermal radiation region are adjusted in real time according to the cutting conditions of the brittle materials.

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Hereinafter, with reference to the accompanying drawings will be described the configuration and operation of the present invention by looking at the embodiment of the laser device for cutting brittle material and the cutting process of the brittle material using the same.

As shown in Figures 5 and 6, the laser device for cutting brittle material according to the present invention, the laser generating unit 30 for emitting a laser beam, and a part of the laser beam emitted and partially reflected and passed through And splitting the beam splitting part 32 divided into two beams and the laser beam passing through the beam splitting part 32 in a direction parallel to the direction of the other laser beam reflected by the beam splitting part 32. It is provided in the reflector 38a, the laser beam path reflected by the beam splitter 32, and the laser beam path reflected by the reflector 38a, respectively, to match the output intensity of the laser beams to the cutting conditions. The ellipsoidal beams are adjusted to the same or different intensities 34 and 34-1 and the respective laser beams are adjusted to the same or different intensities in the respective beam output adjusters 34 and 34-1. Sang Forming and modifying the length of the long axis and short axis of the laser beam of each elliptical shape, the beam deformation optical unit (36a, 36b) (36a) to transform the elliptical beam of the same or different shape according to the cutting conditions of the brittle material -1, 36b-1 and the beam deformation optical unit 36a, 36b (36a-1, 36b-1) to reflect and cut two laser beams modified in the same or different elliptical beam shape to each other The first and second elliptical thermal radiation areas 44a and 44b are irradiated to the cutting lines 50 on the surface of the brittle material 14, and the first and second elliptical thermal radiation areas 44a and 44b The first and second sides irradiated so as to form a cicada wing-shaped synthetic heat radiating part that forms a maximum temperature region by overlapping portions of the upstream side and a downstream part thereof. , 2 elliptical thermal radiation zone (44a) Two opposite reflecting portions 38b, 38c (38b-1, 38c-), each of which changes the irradiation angle of (44b) to the same or different angles in accordance with the cutting conditions of the brittle material and at the same time changes the amount of overlap. 1) and a coolant at a cutting line of the brittle material 140 at a downstream side of the cicada-shaped synthetic heat radiating portion formed by a partial overlap of the two first and second elliptical thermal radiating areas 44a and 44b. A coolant injector 40 for injecting, the laser generator 30, beam power adjusting units 34, 34-1, beam deformation optical units 36a, 36b, 36a-1, 36b-1, and reflector sections And control section 46 for controlling the 38b, 38c, 38b-1, 38c-1, and coolant injector 40 in accordance with a given cutting condition.

In the laser device of the present invention, as described above, two first and second elliptical thermal radiation areas 44a that form a cicada wing-shaped synthetic heat radiator having the upstream side of the cutting line 50 and the downstream side partially overlapping each other. Beam 44, 34b, beam deformation optical units 36a, 36b, 36a-1, 36b-1, and reflector sections 38b, 38c, 38b-1. , 38c-1) enables 'laser full cutting' while changing the intensity, size, irradiation angle and overlap of the output in real time according to the cutting conditions of the brittle material.

That is, the laser beam divided into two paths can be separately adjusted by the beam power adjusting units 34 and 34-1 to the intensity suitable for the cutting conditions, and the respective beam deformation optical units 36a and 36b and 36a. -1, 36b-1) can be adjusted separately in the form of an ellipse having a long axis and a short axis suitable for the cutting conditions, and through the respective reflector portions 38b, 38c (38b-1, 38c-1) The irradiation angles and overlapping amounts of the first and second thermal radiation areas 44a and 44b can be adjusted, so that a synthetic thermal radiation part having a shape suitable for cutting conditions can be formed.

In addition, the two first and second elliptical thermal radiation areas 44a and 44b irradiated to partially overlap the cutting line 50 of the brittle material alternately irradiate beam spots having a fine point shape to both sides along the cutting curve. Unlike the conventional U- or V-shaped heat radiating portion formed by applying, since one laser beam is deformed into an elliptical shape that constitutes a 'large and complete' heat radiating region, simply irradiating the surface of the brittle material Intact heat radiating part is fully realized. Therefore, as in the prior art, a complicated process such as irradiating to both sides along the cutting curve is not necessary. In particular, the synthetic thermal radiation unit according to the present invention overlaps one side of the first and second thermal radiation regions 44a and 44b in the shape of a cicada wing, so that the highest temperature region is formed at the overlapped portion. Accordingly, by matching the overlapped portions with the cutting lines 50, a heat radiating portion that is optimal for cutting brittle materials is realized. Also, reflector portions 38b, 38c (38b-1, 38c-1) for adjusting the irradiation angle and the overlapping amount of the first and second elliptical thermal radiation regions 44a, 44b constituting the cicada wing-shaped synthetic thermal radiation portion. Is arranged in the final output line following the beam deformation optical units 36a and 36b and 36a-1 and 36b-1. Therefore, in order to adjust the irradiation type (irradiation angle, overlapping amount) of the cicada wing-shaped synthetic heat radiating part, the positions and angles of the beam deformation optical parts 36a, 36b, 36a-1, 36b-1 are separately determined. Only the reflector portions 38b and 38c and 38b-1 and 38c-1 may be independently controlled without the inconvenience and complicated structure and process of adjusting them. For example, when the cutting line is formed of a free curve, the reflecting mirror portions 38b, 38c (38b-1, 38c-1) and the beam deformation optical portions 36a, 36b (36a-1, 36b-1) It is sufficient to change the reflection angles of the reflecting mirror portions 38b and 38c and 38b-1 and 38c-1 while conveying them integrally (as one unit) along the cutting line. In this case, the conveyance of the reflector portions 38b, 38c (38b-1, 38c-1) and the beam deformation optics 36a, 36b (36a-1, 36b-1) is combined with the transfer of the brittle material in a free curve. Only the reflective mirror portions 38b, 38c (38b-1, 38c-1) and the beam deformation optical portions 36a, 36b (36a-1, 36b-1) are transported along the cutting line, or without transferring brittle material. Transfer it integrally. In FIG. 5, the two reflector portions 38b and 38c and 38b-1 and 38c-1 are adjusted in the direction of arrow display. That is, the reflecting mirrors 38b and 38b-1 are rotated left and right on the drawing about the longitudinal axis, and the other reflecting mirrors 38c and 38c-1 are rotated before and after the horizontal axis. The beam deformation optical parts 36a and 36b and 36a-1 and 36b-1 are not related to the irradiation angle or the overlapping amount of the reflecting mirror parts 38b and 38c and 38b-1 and 38c-1. Only the characteristics (output intensity, ellipse shape) of the beam input to the reflector portions 38b and 38b-1 are adjusted.

In addition, the control values of the controller 46 are determined through thermodynamic analysis or experiment, and these control values are previously input to the controller 46 through the controller input unit 48 connected to the controller 46, or in particular cases. Will be entered. As shown by a dotted line in FIG. 6, the laser generating unit 30, the beam power adjusting unit 34, 34-1, the beam deformation optical units 36a, 36b, 36a-1, 36b-1, Reflector portions 38b and 38c and 38b-1 and 38c-1 are controlled by the controller 46 through separate control lines 49.

In addition, the brittle material 14 to be cut is transported in the direction of the arrow 60 of FIG. 6 while the laser beam is being irradiated by the laser device 100 according to the present invention to allow relative cutting movement.

By performing the cutting operation using the laser device 100 for cutting brittle materials configured as described above, cutting can be performed with high precision and high speed without a cutting path error according to the state and processing environment of the brittle material to be processed.

That is, the laser beam 31 emitted from the laser generator 30 is divided, and the output intensity, direction, and position of each divided laser beam are independently adjusted through the controller 46, and then the laser is overlapped again. Since the shape and processing conditions of the beam can be automatically optimized in real time, it is possible to perform distortion-free cutting even when cutting asymmetric materials and curves, and to perform high-precision, high-speed optimal cutting.

The cutting method thereof will be described in detail with reference to FIG. 6.

In cutting the brittle material 14 using the laser device 100 for cutting brittle material according to the present invention, first, necessary control values are input to the controller 46 through the controller input unit 48.

At this time, the control value input to the control unit 46 is of course derived in advance through thermodynamic analysis or experiment.

In addition, the output intensity of each laser beam emitted through the laser generator 30 and split through the beam splitter 32 is adjusted through the beam output adjusters 34 and 34-1. The intensity of the laser beam output from the beam output adjuster 34 and the beam output adjuster 34-1 may be adjusted to the same intensity or different to each other depending on the cutting conditions.

Herein, the beam output adjusting unit 34, 34-1 preferably adjusts the intensity of the laser beam within the range of 0% to 50%.

Subsequently, the laser beams of the two paths adjusted through the beam power adjusting units 34 and 34-1 are cut conditions of the brittle material in the beam deformation optical units 36a and 36b and 36a-1 and 36b-1, respectively. To elliptical beams of the same or different shape. In this case, the shape (size, shape) of the elliptical beam can be adjusted by adjusting the length of the long axis and short axis of the laser beam.

Subsequently, the laser is transformed into an elliptical beam shape with an output intensity suitable for cutting through the beam power adjusting units 34 and 34-1 and the beam deformation optical units 36a and 36b and 36a-1 and 36b-1. The beams are formed on the cutting line 50 of the brittle material 14 as two first and second elliptical thermal radiation regions 44a and 44b by reflecting mirror portions 38b and 38c and 38b-1 and 38c-1. It is irradiated to form a cicada wing-shaped synthetic heat radiator. The cicada-shaped composite thermal radiation beam is formed by the reflector portions 38b and 38c and 38b-1 and 38c-1 so that the upstream side of the cutting direction is opened and the downstream side is partially overlapped. Here, the two first and second elliptical thermal radiation areas 44a and 44b constituting the cicada wing-shaped synthetic heat radiating part are adjusted at the same or different angles according to the cutting conditions of the brittle material and at the same time their overlapping amount Adjusted.

By doing so, the intensity, shape (size), irradiation angle, and overlapping amount of the laser beam output to the brittle material 14 to be cut are automatically controlled in real time to perform distortion-free cutting even when cutting asymmetric materials and curves. It is possible to perform the cutting work of high precision and high speed.

7A to 7C show an example of a synthetic thermal radiation region that appears when cutting brittle materials through the laser device of the present invention. Fig. 7A shows the output intensity distribution (I axis) of the elliptical beam with respect to the composite thermal radiator on the A, B and C axes of FIG. 7A, and FIG. The temperature distribution (T axis) is shown.

7A to 7C, the first and second elliptical thermal radiation areas 44a and 44b on both sides forming the cicada wing-shaped synthetic heat radiator have the same size, the same output intensity, the same irradiation angle, and the symmetric overlap state, that is, An example is shown when irradiated in a state of perfect symmetry. As shown in FIG. 7A, in cutting brittle materials using the laser device according to the present invention, two first and second elliptical thermal radiation areas 44a and 44b are symmetrical to both sides of the cutting line 50. The upstream side (downward in Fig. 7a) in the conveying direction is opened while the downstream side is partially overlapped. This shows a symmetrical output distribution on both sides, as shown in the beam intensity intensity profile (I axis) along the A, B, and C axes of FIG. 7B, and on the conventional U-shaped beam shape of FIG. 3B. It can be seen that it shows a good shape compared to the beam output intensity distribution accordingly.

 In addition, as shown in the temperature distribution (T axis) of the brittle material surface portion on the A, B, and C axes of FIG. It can be seen that the distribution is suitable for cutting, and indicates that the surface temperature of the brittle material is in a stable state that does not exceed the melting point (Tm).

In addition, the size of the beam, the output intensity distribution and the temperature of the surface portion of the brittle material as shown in FIGS. 7A to 7C may be controlled by the beam output adjusting unit 34, 34-1 and the beam deformation optical unit through the control unit 46. By adjusting the 36a, 36b (36a-1, 36b-1), the reflecting mirror portions 38b, 38c (38b-1, 38c-1), etc., the optimum state can be adjusted. 8A to 8C show a three-dimensional output distribution diagram showing various modifications of the laser beam depending on the characteristics of the brittle material, cutting conditions, and the like. First, in the example shown in FIG. 8A, as shown in FIGS. 7A to 7C, laser beams having both elliptical beam spot shapes are generally the same with respect to the cutting line, that is, the same size, the same output intensity, the same irradiation angle and symmetry. Shows what it looks like when it is examined in superposition. As such, the two first and second elliptical thermal radiation areas 44a and 44b constituting the cicada wing-shaped synthetic thermal radiation part are symmetrical with respect to the cutting line 50, and the cutting line is a brittle material. It can be said that it is formed in the middle of both left and right sides of the cutting line is a straight line. The shape shown in Figure 8b is to form the heat radiation region on the right of the intensity of the output of the laser beam forming the heat radiation region on the left of the two first, second elliptical heat radiation region synthesized in the shape of a cicada wing It shows the output distribution when it is adjusted higher than the intensity of the laser beam output. Therefore, the temperature of the elliptical thermal radiation region on the left side is high. This is because in the case of asymmetrical cutting in which the area of the brittle material forming the left side of the cutting line is narrow compared to the area of the brittle material forming the right side of the cutting line, the heat transfer rate is faster in the left region of the cutting line, so that the temperature in the right area of the cutting line is maintained higher. If there is a concern that the actual cutting line causing the greatest thermal expansion / contraction stress is bent to the left of the cutting line, increase the output of the thermal radiation area irradiated to the left of the cutting line to raise the temperature of the part in advance. This is suitable when you want to prevent the distortion caused by the actual cutting line. In this case, when the cutting line has a curved cutting line shape, the output of the laser beam forming an elliptical thermal radiation area corresponding to the outer portion of the curve having a relatively high heat transfer (cooling) speed is increased. It is also suitable for preventing distortion of the cutting line. 8C shows a form in which the irradiation angle of the two elliptical thermal radiation regions synthesized in the shape of a cicada wing is increased by increasing the overlap amount. This is suitable when the synthetic heat radiating portion is to be concentrated and formed on the cutting line by changing the overlapping amount of the two beams according to the material, thickness, etc. of the brittle material to be cut. This can be said to be suitable, for example, when the thickness of the brittle material is thin and the cutting speed is to be increased. On the contrary, when the irradiation angle of the laser beam constituting the two elliptical thermal radiation areas is widened, the overlapping amount is reduced, so that the composite thermal radiation part can be spread widely around the cutting line. In addition to the above method, the shape (size, shape) or irradiation angle of the two elliptical thermal radiation regions may be adjusted differently.

As described above, the present invention is capable of performing an optimal cutting operation for the processing environment by modifying or adjusting the shape, position, direction, and output intensity of the laser beam irradiated to the brittle material in real time.

In particular, it can be suitable for cutting brittle materials requiring high quality and high precision by preventing cutting distortion, which is a fatal problem in the conventional cutting method, and realizing high speed cutting. By modifying the shape of the beam to any shape and changing the beam output intensity distribution, thermodynamically asymmetrical materials such as asymmetric plane cutting and curve cutting can be cut at high speed with high accuracy.

In addition, since the brittle material can be cut without heating above the melting point, the brittle material can be cut cleanly by minimizing dust generation without damaging the brittle material.

1 and 2 are perspective views showing a process of cutting a brittle material using a conventional laser device

3A is a plan view showing a U-shaped heat radiation curve in a beam shape for cutting a brittle material in a conventional laser device;

FIG. 3B is a diagram showing the output intensity distribution (I-axis) of the thermal radiation curve in the A, B and C axes of FIG. 3A

3C is a diagram showing the temperature distribution (T axis) of the brittle material surface portion on the A, B and C axes of FIG. 3A.

Figure 4 is a perspective view showing the distortion of the cutting line generated when cutting brittle material through a conventional laser device

5 is a perspective view schematically showing a laser device of the present invention;

6 is a schematic diagram schematically showing a laser device of the present invention;

7A is a plan view showing an example of a synthetic thermal radiator that appears when cutting a brittle material through the laser device of the present invention.

FIG. 7B is a diagram showing the laser beam output intensity distribution (I axis) of the synthetic thermal radiator on the A, B, and C axes of FIG. 7A;

FIG. 7C shows the temperature distribution (T axis) of the brittle material surface portion on the A, B, and C axes of FIG. 7A. FIGS. 8A to 8C are three-dimensional outputs showing various modifications of the synthetic thermal radiator according to the present invention. Distribution chart

Explanation of symbols on main parts of the drawing

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30: laser generating unit 31: laser beam

32: beam splitting section 34, 34-1: beam output adjusting section

36a, 36b, 36a-1, 36b-1: beam deformation optics 38a, 38b, 38c, 38b-1, 38c-1: reflector

40: coolant injection device 42: coolant 44a: first elliptical heat radiation zone 44b: second elliptical heat radiation zone

46: control unit 48: control unit input unit

50: cutting line 60: conveying direction of brittle material

100: laser device

Claims (3)

A laser generator 30 for emitting a laser beam; A beam splitting part 32 which partially reflects the emitted laser beam and passes the split part into two beams; A reflector 38a for reflecting the part of the laser beam passing through the beam splitting part 32 in a direction parallel to the direction of the other part of the laser beam reflected from the beam splitting part 32; Installed in the laser beam path reflected from the beam splitter 32 and the laser beam path reflected from the reflector 38a, respectively, to match the output intensity of the laser beams with the same or different intensities, respectively. A beam output adjusting unit 34 (34-1) for adjusting; The beam output adjusting units 34 and 34-1 respectively form elliptical shapes of the laser beams having the same or different intensities, and adjust the lengths of the long and short axes of the laser beams of the elliptical shape. Beam deformation optical units 36a and 36b and 36a-1 and 36b-1 for deforming an elliptical beam having the same or different shapes to each other according to cutting conditions of the brittle material; Cutting lines on the surface of the brittle material 14 to be cut by reflecting two laser beams modified in the same or different elliptical beam shape in the beam deformation optical units 36a and 36b and 36a-1 and 36b-1. While irradiating 50 to the first and second elliptical thermal radiation areas 44a and 44b, the first and second elliptical thermal radiation areas 44a and 44b are opened upstream with respect to the conveying direction and partially overlapped with the downstream side. Two first and second elliptical thermal radiation areas 44a irradiated to form a cicada wing-shaped synthetic heat radiating part that forms the highest temperature region by the overlapping portions thereof. Two opposing reflecting portions 38b, 38c and 38b-1, 38c-1, each of which changes the irradiation angle of (44b) to the same or different angles in accordance with the cutting conditions of the brittle material and at the same time changes the amount of overlap. ); Coolant injection for injecting coolant to the cutting line of the brittle material 140 on the downstream side of the cicada wing-shaped synthetic heat radiator formed by a partial overlap of the two first and second elliptical thermal radiation areas 44a and 44b. Device 40; And The laser generator 30, the beam power adjusting section 34, 34-1, the beam deformation optical sections 36a, 36b, 36a-1, 36b-1, the reflector sections 38b, 38c, 38b-1, 38c-1) and the control unit 46 for controlling the coolant injector 40 in accordance with the given cutting conditions; The intensity, size, irradiation angle, and overlap amount of the outputs of the two first and second elliptical thermal radiation areas 44a and 44b irradiated to form the cicada wing-shaped synthetic thermal radiation unit are adjusted in real time according to the cutting conditions of the brittle material. Laser device for cutting brittle material, characterized in that. delete delete