TW201350246A - Method for cutting workpiece by layer and apparatus by same - Google Patents

Abstract

A method for cutting a workpiece by laser and an apparatus by same is provided. The method includes following steps of providing at least two laser beams including a first laser beam and a second laser beam; focusing the first laser beam on an inner of the workpiece, so as to generate an internal stress layer in the inner of the workpiece; focusing the second laser beam at a surface layer of the workpiece, so as to generate a stress layer of the surface layer; and piling up at least part of stresses released by the internal stress layer and the stress layer of the surface layer, so as to make the workpiece partly break and thus split.

Description

Method and apparatus for cutting an object by laser light

The present invention relates to a method of cutting an object by laser light. More specifically, the present invention relates to the use of at least two beams of laser light, respectively forming at least two stress layers in the interior and the surface of the object to be processed, and using the superimposed stress released by the stress layer to cause the object to be fractured and further divided. Laser light processing method. The invention also relates to an apparatus for implementing the above method.

Cutting the object with laser light has been a common process in the field of laser light processing. The traditional laser light cutting method is to concentrate the laser light on the surface of the object. When the material damage threshold is lower than the laser light power density, the object will undergo physical or chemical changes such as melting, gasification, ionization and repetition. When the power of the laser light used is sufficiently large, the object to be processed can be broken at a position where the above change occurs, thereby achieving the object of cutting the object to be processed. There are many types of lasers used in this way, such as laser pulsed light and continuous laser light. CO ₂ lasers with a maximum laser power of kW or even 10,000 watts are used when cutting thick steel plates.

However, when the fineness of the object to be processed is high, a small power laser illuminator such as a nanosecond laser or an ultrashort laser illuminator is often used. More special is the laser light cutting process applied in the field of glass cutting, which uses a higher power CO ₂ continuous laser and achieves good cutting accuracy. In the cutting process, the laser light only heats the glass device as the object to be processed, and does not cause damage to the glass. In fact, it utilizes the rapid cooling after heating the glass device to generate stress on the glass device, and then the mechanical external force to release the stress, thereby achieving the purpose of splitting the glass device. However, for this type of cutting, this cutting is caused by the limitation of the focusing property of the CO ₂ laser light itself (the minimum focal spot diameter needs to be larger than its wavelength), the heat diffusion caused by high power, and the pollution generated during cooling. The method can only be applied to the cutting of ordinary large-format glass, but not to the fine cutting of the glass with the functional area on the surface, such as a glass-based wafer.

Accordingly, it is an object of the present invention to provide a method for cutting an object by laser light, which method has the advantages of high cutting precision, no pollution, no thermal damage, high processing efficiency, wide application range, and the like, thereby overcoming the use for cutting. Technical defects in conventional laser light cutting methods for glass devices.

The laser light cutting method according to the present invention utilizes at least two different types of laser light to act on the inside and the surface of the object to be processed, and combined with the cooling of the surface layer to form two layers including a surface stress layer and an internal stress layer. Or multiple stress layers. By appropriately controlling the range and spacing of the surface stress layer and the internal stress layer, the stress in the stress layer is released to form a stress profile, and may additionally be supplemented with a certain mechanical external force, thereby causing the object to be processed along a predetermined cutting path. The complete breakage, in order to achieve the purpose of dividing the workpiece.

Another object of the present invention is to provide an apparatus for implementing the above-described laser light cutting method.

The present invention provides a method of cutting an object by laser light, comprising: providing at least two laser beams, wherein the at least two laser beams comprise a first laser beam and a second laser beam; and the first laser beam Focusing on the inside of the object to be processed, the inside of the object is internally generated by the action of the first laser beam on the object to be processed a stress layer; focusing the second laser beam on the surface layer of the object to be processed, and generating a surface stress layer at the surface layer by the action of the second laser beam on the object to be processed; at least partially utilizing the internal stress layer and the surface stress layer The superposition of the released complex stress causes the object to be at least partially broken and thus can be split.

In the aspect of the invention, the surface layer of the object to be processed may include the surface of the object to be processed.

According to a specific embodiment, the internal stress layer is generated by photo damage of the object to be processed by the first laser beam, and the surface stress layer is used to heat the surface layer of the object by utilizing the thermal effect of the second laser beam on the object to be processed. It is produced by cooling.

According to a specific embodiment, the power density of the first laser beam at the focus is greater than the minimum damage threshold of the object under the action of the first laser beam.

According to a specific embodiment, the first laser beam causes photodamage to the object to be processed and forms a stress point near the focus, and the photodamage is selected from the group consisting of melting, gasification, plasmaization, refractive index change, or a combination thereof.

According to a specific embodiment, the relative movement between the first laser beam and the object to be processed causes a plurality of stress points to be formed along a predetermined path to constitute an internal stress layer.

According to a specific embodiment, the internal stress layer includes a plurality of internal stress layers arranged substantially in a direction in which the first laser beam is incident on the object to be processed.

According to a specific embodiment, the plurality of internal stress layers are formed in order in a direction gradually approaching the surface layer of the object to be processed.

According to a specific embodiment, the first laser beam belongs to laser pulse light, has a pulse width of less than 1 nanosecond (ns), and has a pulse repetition frequency ranging from 10 kHz to 1 MHz, wherein the pulse repetition frequency range of the first laser beam More preferred It is 1MHz~80MHz.

According to a specific embodiment, the first laser beam is transmissive to the object to be processed, and its transmittance is greater than zero.

According to a specific embodiment, the object to be processed is a transparent material selected from the group consisting of glass, enamel, quartz or sapphire.

According to a specific embodiment, the second laser beam is continuous laser light or laser pulsed light.

According to a specific embodiment, the wavelength of the second laser beam is within a range in which the object to be processed is linearly absorbed, so that the energy is absorbed by the object to be processed by heat transfer, and the surface temperature of the object to be processed near the focus rises. However, the object to be processed does not cause substantial damage.

According to a specific embodiment, the power density of the second laser beam at the focus is less than the minimum damage threshold of the object under the action of the second laser beam.

According to a specific embodiment, the manner of cooling the surface layer of the heated object to be processed includes using a gaseous cooling medium or a liquid cooling medium.

According to a specific embodiment, the cooling medium used is at a standard atmospheric pressure and the temperature is between -210 ° C and 20 ° C.

According to a specific embodiment, the heating process and the cooling process of the surface layer of the object to be processed are simultaneously performed with the generation of the internal stress layer.

According to a specific embodiment, the heating process and the cooling process of the surface layer of the object to be processed are performed only while forming the inner stress layer of the surface layer closest to the object to be processed.

According to a specific embodiment, the heating process and the cooling process of the surface layer of the object to be processed may be performed after the internal stress layer is generated.

According to a specific embodiment, wherein the superposition of the stress released by the internal stress layer and the surface stress layer is at least partially utilized, the object to be processed is completely broken. Being split.

According to a specific embodiment, in addition to the superposition of the stress released by the internal stress layer and the surface stress layer, the object to be processed is completely broken by further applying a mechanical external force.

The present invention also relates to an apparatus for cutting an object by laser light, comprising: a first laser light portion comprising a first laser light source that generates a first laser beam, the first laser beam being capable of being focused by a focusing mirror or an objective lens Inside the object to be processed, an internal stress layer is internally generated by the action of the first laser beam on the object to be processed; the second laser beam portion includes a second laser source that generates the second laser beam, and the second Ray The beam of light can be focused by a focusing mirror or an objective lens on the surface layer of the object to be processed (including the surface of the object to be processed), and a surface stress layer is generated at the surface layer by the action of the second laser beam on the object to be processed; the image forming portion The imaging optical path and the camera are included to image the object to be processed, the reference point of the moving focusing mirror or the objective lens is determined; the motion system, the component suitable for moving the focusing mirror or the objective lens, and the moving object of the processing object, the moving focusing mirror or the objective lens The component can move the focusing mirror or the objective lens to a predetermined position, thereby focusing the first laser beam and the second laser beam respectively on the inside of the processing object At the surface layer, the moving object of the object can move the object along a predetermined path relative to the focusing mirror or the objective lens, thereby generating an internal stress layer and a surface stress layer at the inside and the surface of the object, respectively, at least partially utilizing The superposition of the complex stresses of the release of the internal stress layer and the surface stress layer enables the object to be at least partially broken and thus split.

According to a specific embodiment, the aperture value of the focusing mirror or the objective lens is not less than 0.4.

The apparatus for cutting an object to be processed by laser light of the present invention further includes a cooling device adapted to discharge the cooling medium, wherein the internal stress layer is generated by the first laser beam to cause damage to the object to be processed, and the surface stress layer is utilized by the second The thermal effect of the laser beam on the object to be processed is cooled by a cooling medium discharged from the surface of the object to be processed by the cooling device.

Preferably, the cooling medium is at a standard atmospheric pressure and the temperature is between -210 ° C and 20 ° C.

According to a specific embodiment, the direction in which the cooling device discharges the cooling medium is substantially along the axis of the focusing mirror or the objective lens, wherein the cooling medium is in a gaseous state.

According to a specific embodiment, the direction in which the cooling device discharges the cooling medium intersects the axis of the focusing mirror or the objective lens, wherein the cooling medium is in a gaseous or liquid state.

In the apparatus for cutting an object by laser light of the present invention, the first laser beam may be laser pulsed light having a pulse width of less than 1 nanosecond (ns) and a pulse repetition frequency ranging from 10 kHz to 1 MHz, wherein the pulse repetition The frequency range is more preferably 1 MHz to 80 MHz.

In the apparatus for cutting an object to be processed by laser light according to the present invention, the first laser beam is transmissive to the object to be processed, and its transmittance is greater than zero.

In the apparatus for cutting an object by laser light of the present invention, the power density of the first laser beam at the focus is larger than the minimum damage threshold of the object under the action of the first laser beam.

In the apparatus for cutting an object to be processed by laser light of the present invention, the second laser beam may be continuous laser light or laser pulsed light.

In the apparatus for cutting an object by laser light of the present invention, the power density of the second laser beam at the focus is smaller than the minimum damage threshold of the object under the action of the second laser beam.

The apparatus for cutting an object to be processed by laser light according to the present invention may further include The mechanism for applying a mechanical external force to the object to be processed causes the object to be completely broken and divided by the mechanical external force applied by the mechanism in addition to the superposition of the stress released by the internal stress layer and the surface stress layer.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

A specific embodiment of the laser light cutting method of the present invention will now be further explained with reference to the accompanying drawings. Further, in the drawings of the present specification, an apparatus for implementing the laser light cutting method of the present invention is also schematically shown.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic illustration of the optical path and system of a laser light cutting method embodying the present invention. As an illustrative illustration, as shown in FIG. 1, the optical path system embodying the laser light cutting method of the present invention may be generally constructed of three parts. In the first part, the laser beam L1 is emitted by the first laser light source 1, and the beam diameter is enlarged and collimated by the laser beam expander 3, and then reflected by the laser beam 10 into the laser focusing mirror 11 and focused on the object to be processed. The interior of 12. At this time, physical damage to the object 12 can be caused in a certain region in the vicinity of the focus of the laser light inside the object 12, and a photodamage or a plurality of simultaneous occurrences such as melting, vaporization, plasmaization, and refractive index change occur. Photoinduced damage, and the object 12 is not affected by the irradiation of the laser light outside the certain area described above. In this way, in the object 12 to be processed, a stress change occurs in a certain region near the focus, and an internal stress point 16 is formed.

According to a preferred embodiment of the invention, the laser focusing mirror 11 has a shorter focal length. Alternatively, an objective lens can be used as the laser focusing mirror. Preferably, the focusing mirror or objective lens has a numerical aperture NA > 0.4.

The second part of the optical path system implementing the laser light cutting method of the present invention consists of The second laser light source 2 emits a laser beam L2, is collimated by the laser collimator 4, is reflected by the laser beam mirror 9, passes through the laser beam mirror 10, enters the laser beam focusing mirror 11, and is focused on the object to be processed. At the surface of 12.

The third portion of the optical path system is an imaging optical path for the purpose of imaging the object 12 to determine a reference point for moving the focusing mirror or objective lens 11 to adjust the focus position of the laser beam on the object 12. Preferably, the imaging optical path is the coaxial imaging optical path shown in FIG. The so-called coaxial imaging optical path means that the imaging axis of the imaging optical path is coaxial with the laser focusing mirror 11. Specifically, in the coaxial imaging optical path, the light source 5 emits a light beam, and the light beam is reflected by the mirror 8, and sequentially penetrates the laser light mirror 9 and the laser light mirror 10 to enter the laser light focusing mirror 11 to illuminate the object to be processed. The surface of 12. The reflected light is reversely entered into the laser focusing mirror 11, and sequentially penetrates the laser beam mirror 10, the laser beam mirror 9, and the mirror 8, and is focused and imaged by the imaging lens 7 on the CCD camera 6. It should be understood that other types of imaging systems in the field of laser light processing may also be employed in the present invention.

The apparatus embodying the laser light cutting method of the present invention may further include a motion system, as shown in FIG. 1, which includes a three-dimensional motion device having an X-axis motion platform 13, a Y-axis motion platform 14, and a Z-axis motion platform 15. The laser light focusing mirror 11 is connected to the Z-axis motion platform 15 and can move up and down with the movement of the Z-axis motion platform 15. The object 12 is disposed on a workpiece table (not shown) that can be driven by the X-axis motion platform 13 and the Y-axis motion platform 14, so that the object 12 can be moved along with the X-axis motion platform 13 or the Y-axis motion platform 14. The movement moves relative to the focusing mirror or the objective lens 11.

Thus, the Z-axis motion stage 15 can be moved up and down by the coaxial imaging optical path of the optical path system, thereby causing the laser focusing mirror 11 to move up and down, so that the upper surface of the object 12 is clearly imaged on the CCD camera 6. Z-axis at this time The moving platform position is a reference point, and the Z-axis moving platform is moved toward the inside of the object to be processed by a predetermined distance so that the focus of the laser focusing mirror 11 is located at a predetermined position inside the object to be processed. At this time, if the first laser light source 1 is turned on to emit the laser light, the object 12 can be photo-damaged in a certain area in the vicinity of the focus, and the stress point 16 is formed inside the object 12. At this time, the position of the Z-axis moving platform is kept stationary, and the X-axis moving platform 13 or the Y-axis moving platform 14 can move the processing object 12 relative to the laser focusing mirror 11 along a predetermined cutting path. At the same time as the movement, the laser light (i.e., the laser beam L1) is emitted to form an internal stress layer 17 inside the object 12, as shown by the hatched portions in Figs. 2a and 2b. Specifically, in Fig. 2a, when the laser beam L1 uses laser pulsed light, its internal stress points (shown as black dots in the figure) exhibit a discrete distribution, and these discrete stress points combine to form an internal stress layer. 17; In Fig. 2b, when the laser beam L1 uses quasi-continuous laser light, its internal stress points overlap each other and exhibit a continuous distribution state, and the internal stress layer 17 is composed of these continuously overlapping stress points. It should be noted that in Fig. 2b, only the internal stress layer 17 is shown, and internal stress points which are in a continuously distributed state overlapping each other are not specifically drawn.

Referring now to FIG. 3, when the X-axis moving platform 13 or the Y-axis moving platform 14 drives the object 12 to move along the cutting path relative to the laser focusing mirror 11, forming an internal stress layer 17, the Z-axis moving platform 15 is changed. The predetermined distance moved toward the inside of the object 12 allows the laser beam L1 to be concentrated at another predetermined position inside the object 12. At this time, the X-axis moving platform 13 or the Y-axis moving platform 14 is moved again relative to the laser focusing mirror 11 along the same cutting path, so that a new internal stress layer 17 can be formed. By analogy, a plurality of internal stress layers 17 at different positions can be formed inside the object 12 to be processed. Preferably, the plurality of internal stress layers 17 are gradually approaching the processing object The direction of the surface layer of the object 12 (the meaning of the term "surface layer", which will be explained and explained in detail below) is formed in order. Taking the technical solution of forming three internal stress layers in FIG. 3 as an example, it is preferable to form the lowermost internal stress layer in the figure, and then form an internal stress layer at the intermediate position, and finally form the uppermost, that is, the closest to the processing object. The internal stress layer of the surface layer.

A process for forming a surface stress layer at the surface layer of the object 12 to be processed by the laser light cutting method and system or apparatus of the present invention will be described in detail below with reference to Figs. 4a and 4b. 4a is a schematic view showing the laser beam L2 of FIG. 1 illuminating the surface layer of the object to be processed. Fig. 4b shows the focused spot distribution of the laser beam L2 on the surface of the object to be processed. It should be noted that in the description and description of the technical solution of the present invention, the term "surface layer" refers to a substance layer on the object to be processed which is very close to the processing surface as the incident surface of the laser light, but also includes the object to be processed. Machined surface. In other words, the term "surface layer" refers to a machined surface on a workpiece and a portion adjacent to the machined surface.

According to a preferred embodiment of the present invention, the surface of the object 12 can be heat-treated while the stress layer closest to the surface layer is formed inside the object 12 by the laser beam L1. Specifically, the laser beam L2 is adjusted by the laser collimator 4 and then concentrated by the laser focusing mirror 11 on the surface or surface of the object 12. As shown in Fig. 4a, the laser beam L2 is focused on the surface of the object 12 to form a focused spot 18 (shown in Figure 4b). The power of the laser beam L2 is adjusted so that the power density in the range of the focused spot is smaller than the damage threshold of the object 12 under the action of the laser light, so that the laser beam L2 does not melt on the surface and the surface of the object 12. One or more kinds of photodamage such as gasification, plasmaization, and refractive index change. In this way, the laser light energy is transmitted to the surface and the surface layer of the object 12 only in the form of heat generation, and heat distribution is formed within and outside the range of the focused spot, resulting in the vicinity of the focus. The surface temperature of the object to be processed rises, but the object to be processed does not cause substantial damage. When the object 12 is moved relative to the laser focusing mirror 11 along a predetermined cutting path, a strip-shaped heat distribution region along the cutting path can be formed. When the laser beam L2 used is laser pulsed light, the focused spot 18 is discrete, and the running speed of the workpiece stage and the frequency of the laser beam L2 are controlled, so that the heated area of the focused spot 18 is continuously distributed, as attached. Figure 4b shows.

According to a preferred embodiment of the present invention, at the same time as or after the surface or surface layer of the object 12 is heated in the above manner, it can be cooled by using a low-temperature gas or a liquid as a cooling medium. Thus, the surface stress layer 21 (shown in FIGS. 7 to 9) can be formed at the surface layer of the object 12 to be processed. Further, when only one stress layer is formed inside the object 12, heating and cooling of the surface layer thereof may be performed while forming the internal stress layer; when a plurality of stress layers are formed inside, it is preferable to form the layer closest to the surface layer. At the same time as the stress layer, the surface layer is heated and cooled. In addition, it should be noted that for some objects to be processed, only the cooling process may be omitted, and the stress layer may be formed on the surface layer or surface thereof.

As an exemplary illustration, FIG. 5 is a schematic view showing cooling of the surface layer of the heated object 12 by the coaxial cooling device 19. The term "coaxial cooling device" means that the center of the cooling medium discharge hole of the cooling device is substantially on the same axis as the laser beam focusing mirror 11. In other words, the direction in which the cooling device discharges the cooling medium is substantially along the axis of the focusing mirror or objective lens 11. It should be noted that the coaxial cooling device 19 is not suitable for using a liquid as the cooling medium because the liquid cooling medium is introduced because the cooling medium discharge hole of the coaxial cooling device 19 and the laser focusing mirror 11 are substantially in the same axis. When the space between the laser beam focusing mirror 11 and the surface of the object 12 is processed, the lens of the focusing mirror 11 is easily contaminated, thereby causing damage to the lens. Therefore, for the coaxial cooling device 19, a low temperature gas is preferably used as the cooling medium. Specifically, the low-temperature gas can be introduced into the space between the laser beam focusing mirror 11 and the surface of the object 12 from the outside, and blown onto the surface of the object 12 to be processed. At the same time, the object 12 is moved along a predetermined cutting path, so that the strip-shaped heat distribution area on the surface of the object 12 is rapidly cooled, and the heat is discharged to the outside. Preferably, the cooling gas to be used is, for example, CO ₂ gas, low-temperature nitrogen gas or the like, and its temperature ranges from -210 ° C to 20 ° C.

Fig. 6 is a schematic view showing the cooling of the surface layer of the object to be processed by the cooling medium in a paraxial manner. Unlike the coaxial cooling device 19, for the paraxial cooling device 20, the direction in which the cooling device discharges the cooling medium intersects the axis of the focusing mirror or objective lens 11, rather than being coaxial or parallel. As shown in FIG. 6, when cooling is performed using the paraxial cooling device 20, the cooling medium is introduced from the side of the laser focusing mirror 11, and the cooling medium does not easily contact the lens of the focusing mirror 11, and thus the paraxial cooling device 20 In other words, it is feasible to use a gas or a liquid as a cooling medium. Thus, the cooling gas or the liquid is guided to the surface of the object 12, and the object 12 is moved along a predetermined cutting path, so that the surface of the object 12 is rapidly cooled, and the heat is discharged to the laser focusing mirror 11 The other side. Preferably, the cooling gas to be used is, for example, CO ₂ gas, low-temperature nitrogen gas or the like, and its temperature ranges from -210 ° C to 20 ° C.

7 to 9 show schematic diagrams of stress release of the surface stress layer 21 on the object to be processed and one or more internal stress layers 17 on the inside, causing partial breakage of the object to be processed. In Fig. 7, there is only one internal stress layer 17; in Fig. 8, there are two internal stress layers 17; in Fig. 9, there are three internal stress layers 17. As is clear from these drawings, after the internal stress layer 17 composed of internal stress points and the surface stress layer 21 are formed on the object 12 by the above-described laser light processing process, the internal stress is applied. When the superimposed stress of the layer 17 and the surface stress layer 21 is released, a stress cross section is formed on the object 12 to be processed, causing at least partial breakage of the object 12 to be processed. The range and spacing of the surface stress layer 21 and the internal stress layer 17 and the spacing and arrangement between the internal stress layers 17 can be appropriately controlled according to the specific conditions of the object to be processed and the specific cutting requirements, as well as other processing conditions. A combination of appropriate size and orientation is obtained in the object to be processed, and when the stress is released, the desired stress profile is formed. The state of the stress profile produced under the above three different conditions is shown in Figs. 7 to 9.

Fig. 10 shows a case where a plurality of generated stress sections are observed from the side of the object to be processed. When the stress on the surface layer and the inside of the object to be processed is sufficiently large, the superposition of the stress on the surface layer and the inside can cause the object to be completely broken. This usually occurs when the longitudinal stress depth caused by the surface stress layer and the internal stress layer is greater than or equal to one-third of the thickness of the object to be processed.

As a preferred embodiment, FIG. 11 is a schematic view showing that the object to be processed is partially broken, and then a mechanical external force is applied to cause the object to be completely broken. As shown in Fig. 11, if the object to be processed is only partially broken, that is, the object to be processed is not completely separated, the corresponding device or component can be applied with a certain amount of mechanical external force along the cutting path to process. The object is completely broken, so that the object to be processed is divided.

Figure 12 is a flow chart showing a simple example of a laser light cutting method in accordance with the present invention. Specifically, when the object to be processed is cut by the laser light cutting method of the present invention, in step S1, a predetermined cutting path is first set on the object to be processed. The above cutting path may be an imaginary path located on the object to be processed. Then, in step S2, the object to be processed is imaged (preferably by imaging its surface) using the imaging optical path, thereby determining a reference point for moving the laser focusing mirror in the laser beam processing apparatus embodying the method of the present invention to adjust the lightning The focus position of the beam on the object to be processed. Specifically, in step S3, when the object to be processed is clearly imaged on the camera of the imaging light path, the position of the Z-axis moving platform that drives the laser focusing mirror at this time is taken as the reference point of the moving laser focusing mirror. Thus, in step S4, the laser beam can be focused on a predetermined position inside the object to be processed according to a specific cutting requirement. Next, in step S5, by moving the X-axis motion platform or the Y-axis motion platform of the workpiece table of the object to be processed, the object to be processed is moved relative to the laser focusing mirror along a predetermined cutting path, thereby processing the object. An internal stress layer is formed in the middle. According to specific needs, a plurality of internal stress layers can be formed by adjusting the focus position of the laser beam inside the object to be processed. While the laser beam is used to form the stress layer closest to the surface layer inside the object to be processed, the surface layer of the object to be processed may be heat-treated by another laser beam, and simultaneously or subsequently supplemented by cooling treatment, thereby processing A surface stress layer is formed at the surface layer of the object (S6). In other words, step S5 and step S6 may be performed simultaneously, or after the step S5 is completed, the process of step S6 may be started. Thereafter, in step S7, the release of the superimposed stress of the inner stress layer and the surface stress layer is utilized at least in part, so that the object to be processed is at least partially broken and thus can be divided.

The method and system or apparatus for cutting an object to be processed by laser light according to the present invention have been described in detail above with reference to the accompanying drawings in conjunction with some specific embodiments. It is to be understood that the specific embodiments described above are merely illustrative of the preferred embodiments of the invention and are not intended to limit the scope of the invention. For example, although in the above embodiment, the internal stress layer and the surface stress layer are formed along the predetermined cutting path in the inside and the surface layer (including the surface) of the object to be processed by holding the focusing beam of the processing laser beam while moving along the X axis Or the Y-axis moves the object to be processed. However, there is also a technique of forming an internal stress layer and a surface stress layer on the object to be processed by moving the processed laser beam while keeping the object to be processed. Program. It will be understood by those skilled in the art that as long as the relative movement between the focusing mirror for processing the laser beam and the object to be processed is performed along a predetermined cutting path, a stress layer required to cause the fracture to be formed can be formed in the object to be processed. Therefore, other modifications that can be made by those skilled in the art after reading this specification and the drawings are within the scope of the invention. The specific scope of the invention should be defined by the claims appended hereto.

1‧‧‧First laser source

2‧‧‧second laser source

3‧‧‧Laser beam expander

4‧‧‧ collimator

5‧‧‧Light source

6‧‧‧CCD camera

7‧‧‧ imaging lens

8‧‧‧Mirror

9‧‧‧Laser light mirror

10‧‧‧Laser light mirror

11‧‧‧Laser light focusing mirror

12‧‧‧Processing objects

13‧‧‧X-axis motion platform

14‧‧‧Y-axis motion platform

15‧‧‧Z-axis motion platform

16‧‧‧ Internal stress points

17‧‧‧Internal stressor

18‧‧‧ Focus spot

19‧‧‧Coaxial cooling device

20‧‧‧Parallel cooling device

21‧‧‧Surface stress layer

L1, L2‧‧‧ laser beam

S1, S2, S3, S4, S5, S6, S7‧‧

1 is a schematic view of an optical path and system for implementing a laser light cutting method of the present invention.

Fig. 2a is a schematic view showing a process of concentrating the laser beam L1 of Fig. 1 through a focusing mirror inside a processing object by laser light to form an internal stress layer.

Fig. 2b is a schematic view showing a process of concentrating the laser beam L1 of Fig. 1 through a focusing mirror inside a processing object by using quasi-continuous laser pulse light to form an internal stress layer.

Fig. 3 is a schematic view showing the process of forming a plurality of internal stress layers in the object to be processed by the laser light cutting method of the present invention.

Fig. 4a is a schematic view showing the laser beam L2 of Fig. 1 illuminating the surface layer of the object to be processed.

Fig. 4b shows the focused spot distribution of the laser beam L2 on the surface of the object to be processed.

Fig. 5 is a schematic view showing the surface layer of the object to be processed being coaxially cooled by a cooling medium.

Fig. 6 is a schematic view showing the cooling of the surface layer of the object to be processed by a cooling medium by a cooling medium.

Figure 7 shows the surface stress layer on the object to be processed and one inside. Stress release occurs in the stress layer, causing partial fracture of the object to be processed.

Fig. 8 is a schematic view showing the stress release of the surface stress layer on the object to be processed and the two internal stress layers on the inside, causing partial fracture of the object to be processed.

Fig. 9 is a view showing the stress release of the surface stress layer on the object to be processed and the three internal stress layers on the inside, causing partial fracture of the object to be processed.

Fig. 10 is a view showing the stress release of the surface stress layer and the internal stress layer of the object to be processed, causing the object to be completely broken.

Fig. 11 is a schematic view showing that the object to be processed is completely broken by applying a mechanical external force after partial breakage of the object to be processed.

Figure 12 is a flow chart showing the laser light cutting method according to the present invention.

1‧‧‧First laser source

2‧‧‧second laser source

3‧‧‧Laser beam expander

4‧‧‧ collimator

5‧‧‧Light source

6‧‧‧CCD camera

7‧‧‧ imaging lens

8‧‧‧Mirror

9‧‧‧Laser light mirror

10‧‧‧Laser light mirror

11‧‧‧Laser light focusing mirror

12‧‧‧Processing objects

13‧‧‧X-axis motion platform

14‧‧‧Y-axis motion platform

15‧‧‧Z-axis motion platform

16‧‧‧ Internal stress points

L1, L2‧‧‧ laser beam

Claims (38)

A method for cutting a processed object using a laser beam, comprising: providing at least two laser beams, wherein the at least two laser beams comprise a first laser beam and a second laser beam; the first laser beam The light beam is focused on an interior of the object to be processed, and an internal stress layer is generated in the interior by the action of the first laser beam on the object to be processed; and the second laser beam is focused on one of the object to be processed At the surface layer, a surface stress layer is generated at the surface layer by the action of the second laser beam on the object to be processed; and at least partially utilizing the superposition of the complex stress released by the internal stress layer and the surface stress layer The object to be processed is at least partially broken and further divided. The method of claim 1, wherein the surface layer of the object to be processed includes a surface of the object to be processed. The method of claim 1, wherein the internal stress layer generates a photoinduced damage to the object by the first laser beam, the surface stress layer is utilized by the second laser beam A thermal effect of the object to be processed is generated by a cooling of the surface layer of the object to be processed. The method of claim 1, wherein the first laser beam has a power density at a focus greater than a minimum damage threshold of the object under the first laser beam. The method of claim 3, wherein the first laser beam generates the photodamage to the object in the vicinity of a focus and forms a stress point selected from a melting point and a gas. , plasmonization, a change in refractive index, or a combination thereof. The method of claim 5, wherein a relative movement between the first laser beam and the object to be processed causes a plurality of the stress points to be formed along a predetermined path to constitute the internal stress layer. The method of claim 6, wherein the internal stress layer comprises a plurality of the internal stress layers arranged substantially in a direction in which the first laser beam is incident on the object to be processed. The method of claim 7, wherein the plurality of internal stress layers are sequentially formed in a direction gradually approaching the surface layer of the object to be processed. The method of claim 1, wherein the first laser beam is a laser pulsed light having a pulse width of less than 1 nanosecond (ns) and a pulse repetition frequency ranging from 10 kHz to 1 MHz. The method of claim 9, wherein the pulse repetition frequency of the first laser beam ranges from 1 MHz to 80 MHz. The method of claim 1, wherein the first laser beam has a transmissivity to the object to be processed, and the first laser beam is transparent. The rate of incidence is greater than zero. The method of claim 11, wherein the object to be processed is a transparent material selected from the group consisting of glass, enamel, quartz or sapphire. The method of claim 1, wherein the second laser beam is a continuous laser beam or a laser beam. The method of claim 13, wherein a wavelength of the second laser beam is within a range linearly absorbed by the object to be processed, so that the energy is absorbed by the object in a heat transfer manner. This causes a temperature rise of the surface layer of the object to be processed near a focus, but does not cause a substantial damage to the object to be processed. The method of claim 1, wherein a power density of the second laser beam at a focus is less than a minimum damage threshold of the object under the second laser beam. The method of claim 3, wherein the cooling of the surface layer of the heated object to be processed comprises using a gaseous cooling medium or a liquid cooling medium. The method of claim 16, wherein the cooling medium is at a standard atmospheric pressure, and the temperature of one of the cooling medium is between -210 ° C and 20 ° C. The method of claim 3, wherein the heating process of the surface layer of the object to be processed, the cooling process, and the generation of the internal stress layer are simultaneously performed. The method of claim 8, wherein the heating process and the cooling process of the surface layer of the object to be processed are performed only while the inner stress layer of the surface layer closest to the object to be processed is formed. . The method of claim 3, wherein the heating process and the cooling process of the surface layer of the object to be processed are performed after the internal stress layer is produced. The method of claim 1, wherein the superposition of the stresses released by the internal stress layer and the surface stress layer at least partially causes the object to be completely broken and divided. The method of claim 21, wherein a mechanical external force is further applied in addition to the superposition of the internal stress layer and the stress released by the surface stress layer, so that the object to be processed is completely broken and is divided. . An apparatus for cutting a processing object by using a laser beam, comprising: a first laser light portion, comprising: a first laser light source for generating a first laser beam, the first laser beam passing through a focusing mirror or a An objective lens is focused on an interior of the object to be processed, and an internal stress layer is generated in the interior by the action of the first laser beam on the object to be processed; and a second laser beam portion includes a second laser beam a second laser beam a light source, the second laser beam passes through the focusing mirror or the objective lens and is focused on a surface layer of the processing object, and a surface stress is generated at the surface layer by the action of the second laser beam on the processing object a imaging portion comprising an imaging optical path and a camera for imaging the object to be processed and determining a reference point for moving the focusing mirror or the objective lens; and a motion system adapted to move the focusing mirror or the a component of the objective lens and/or a component of the object to be processed, the motion system being adapted to move the focusing mirror or the objective lens and the processing object relative to each other, thereby the first laser beam and the second The laser beam is respectively focused on the inside of the object to be processed and the surface layer, and causes a relative movement between the object to be processed and the focusing mirror or the objective lens along a predetermined path, thereby respectively processing the object The inner stress layer and the surface stress layer are generated at the inner portion and the surface layer, wherein at least part of the superposition of the internal stress layer and the complex stress released by the surface stress layer is utilized. The object to be processed is at least partially broken and further divided. The device of claim 23, wherein the focusing mirror or the objective lens has an aperture value of not less than 0.4. The device of claim 23, further comprising a cooling device adapted to discharge a cooling medium, wherein the internal stress layer is generated by the first laser beam to cause damage to the object to be processed, The surface stress layer is formed by cooling the cooling medium discharged by the cooling device after the surface layer of the object to be processed is heated by the thermal effect of the second laser beam on the object to be processed. The device of claim 25, wherein the cooling device discharges a direction of the cooling medium substantially along an axis of the focusing mirror or the objective lens. The device of claim 25, wherein a direction in which the cooling device discharges the cooling medium intersects an axis of the focusing mirror or the objective lens. The device of claim 26, wherein the cooling medium is in a gaseous state. The device of claim 27, wherein the cooling medium is in a gaseous or liquid state. The device of claim 23, wherein the first laser beam is a laser pulsed light having a pulse width of less than 1 nanosecond (ns) and having a pulse repetition frequency ranging from 10 kHz to 1 MHz. The device of claim 30, wherein the pulse repetition frequency of the first laser beam ranges from 1 MHz to 80 MHz. The method of claim 23, wherein the first laser beam has a transmittance for the object to be processed, and a transmittance of the first laser beam is greater than zero. The device of claim 23, wherein the processing pair The surface layer of the object includes a surface of the object to be processed. The device of claim 23, wherein a power density of the first laser beam at a focus is greater than a minimum damage threshold of the object under the first laser beam. The device of claim 23, wherein the second laser beam is a continuous laser beam or a laser beam. The device of claim 23, wherein a power density of the second laser beam at a focus is less than a minimum damage threshold of the object under the second laser beam. The method of claim 25, wherein the cooling medium is at a standard atmospheric pressure, and the temperature of one of the cooling medium is between -210 ° C and 20 ° C. The method of claim 23, further comprising a mechanism for applying a mechanical external force to the object to be further utilized in addition to the superposition of the stresses released by the internal stress layer and the surface stress layer The mechanical external force applied by the mechanism causes the object to be completely broken and divided.