CN210548928U

CN210548928U - Device for separating transparent brittle material by laser composite cutting

Info

Publication number: CN210548928U
Application number: CN201921221041.8U
Authority: CN
Inventors: 段军; 邓磊敏; 杨泽齐; 熊伟
Original assignee: Huazhong University of Science and Technology
Current assignee: Huazhong University of Science and Technology
Priority date: 2019-07-30
Filing date: 2019-07-30
Publication date: 2020-05-19
Anticipated expiration: 2029-07-30

Abstract

The utility model belongs to the technical field of laser processing application, and discloses a device for separating transparent brittle materials by laser composite cutting, which comprises an ultrashort pulse laser output component, a continuous laser output component, a beam combining component, a Bessel laser synthesis component and an xy two-dimensional workbench; the beam combining component is used for combining the ultrashort pulse laser and the continuous laser into composite laser in the same optical axis; the Bessel laser synthesis assembly is used for processing the composite laser to convert the composite laser into Bessel synthesis laser beams to be further transmitted to the xy two-dimensional worktable, so that the transparent brittle material to be processed is cut and separated at one time. The utility model discloses a to each component subassembly of device and their relation of connection etc. improve, can once accomplish the transparent brittle material of cutting separation at a high speed, need not follow-up separating force or the difference in temperature of exerting and separate the process, can simplify process flow, improve the machining efficiency of the transparent brittle material of laser cutting separation.

Description

Device for separating transparent brittle material by laser composite cutting

Technical Field

The utility model belongs to the technical field of laser beam machining uses, more specifically relates to a device of transparent brittle material of laser composite cutting separation.

Background

There are many mechanisms for laser cutting transparent brittle materials, and the main mechanisms can be divided into the following mechanisms: the method comprises a conventional continuous and nanosecond pulse laser melting cutting separation mechanism, a laser invisible cutting (or internal modified cutting) separation mechanism, a laser thermal stress cutting (or thermal cracking cutting and crack control cutting) separation mechanism and an ultrashort pulse (picosecond and femtosecond) laser ablation cutting separation mechanism. The transparent brittle materials mainly comprise glass, optical crystal materials, sapphire materials, silicon crystal materials and the like with various properties. Conventional continuous and nanosecond pulsed laser melting cutting separation mechanisms achieve cutting separation by melting and rejecting material. The method has the advantages that because the input energy is more, the cutting defects of edge breakage, recasting layer, microcrack and the like of the cutting and separating surface of the transparent brittle material are often caused, the cutting and separating precision and quality are poor, and secondary grinding or polishing is required, so that the process flow and the cost are increased, and the cutting and processing efficiency is reduced; the laser invisible cutting mechanism is that a laser focus is focused to the middle of a transparent material for ablation, and the ablation surface of a cutting and separating surface of the transparent brittle material is reduced, so that the cutting and separating precision and quality are improved, but a subsequent mechanical method is needed for mechanically separating the laser invisible cutting line, so that the processing procedures are increased, the cutting and separating efficiency is reduced, the optical path system is complex, and the equipment is expensive; the laser thermal stress cutting and separating mechanism is that transparent material is heated to expand, and after laser beam leaves, the heated and expanded part is cooled and contracted fast via adding cooling agent or self conduction to induce tensile stress greater than the tensile strength of the material to form penetrating crack for cutting and separating the material. The method can obtain a non-defective high-precision and high-quality cutting and separating surface without secondary grinding or polishing because of no laser melting and ablation phenomena, so that the processing procedure is simple, but has the defects of low cutting and separating speed and low efficiency, and cannot realize the cutting and separating of curve graphs with larger curvatures because cracks are difficult to control to expand along curves; the ultrashort pulse (picosecond and femtosecond) laser ablation cutting separation is a method which has higher efficiency for cutting and separating transparent and brittle materials and better cutting and separating precision and quality at present.

Patent CN 104968620 a proposes a high-speed laser processing method of transparent material, which adopts picosecond bessel beam to process the layered transparent material: the tempered glass pre-cutting device comprises at least one tensile stress layer, at least one compression stress layer and at least one interface region between the at least one tensile stress layer and the at least one compression stress layer, and one of specific applications is pre-cutting of tempered glass. After laser pre-cutting, a certain separating force or temperature difference is applied to separate the material along the pre-cutting path. Patent CN201710287652.1 discloses a method for pre-cutting sapphire with picosecond bessel beams, moving a platform to a designated position, and then scanning carbon dioxide laser with a galvanometer to separate the sapphire along the pre-cutting path. After the transparent brittle material is pre-cut by the ultrashort pulse laser, the method and the corresponding device can separate the material only by applying a certain separation force or temperature difference subsequently, which obviously increases the laser cutting and separating process and reduces the cutting and separating efficiency.

SUMMERY OF THE UTILITY MODEL

The improvement demand that exists in the transparent brittle material course of working of ultrashort pulse (picosecond and femto second) laser ablation cutting separation, the utility model aims to provide a device of the transparent brittle material of laser composite cutting separation, through improving respectively constituting the subassembly and their relation of connection etc. to the device, regard as Bessel laser light source with both ultrashort pulse laser and continuous laser simultaneously, utilize composite laser to be acted on transparent brittle material with the optical axis simultaneously with ultrafast laser ablation modification mechanism and continuous laser thermal stress cutting separation mechanism, can once accomplish the transparent brittle material of cutting separation at a high speed, need not follow-up separating force or the difference in temperature of exerting and separate the process, can simplify the process flow, improve the machining efficiency of laser cutting separation transparent brittle material.

In order to achieve the purpose, according to the utility model, the utility model provides a device for separating transparent brittle materials by laser composite cutting, which is characterized by comprising an ultrashort pulse laser output component, a continuous laser output component, a beam combining component, a Bessel laser synthesis component and an xy two-dimensional worktable (18, 43); wherein the content of the first and second substances,

the xy two-dimensional working table (18, 43) is used for placing the transparent brittle material to be processed and can drive the transparent brittle material to be processed to move in the xy plane;

the ultrashort pulse laser output assembly comprises an ultrashort pulse laser (1, 30) and a first beam expanding collimating lens (3, 32) matched with the ultrashort pulse laser (1, 30) for use, and is used for outputting ultrashort pulse laser; the ultrashort pulse laser is picosecond pulse laser or femtosecond pulse laser;

the continuous laser output assembly comprises a continuous laser (11, 44) and a second beam expanding and collimating lens (13, 46) matched with the continuous laser (11, 44) and used for outputting continuous laser;

the beam combination component is used for carrying out coaxial beam combination on the ultrashort pulse laser and the continuous laser to form composite laser;

the Bessel laser synthesis assembly is used for processing the composite laser to convert the composite laser into a Bessel synthesis laser beam; the bessel composite laser beam can be further transmitted to the xy two-dimensional worktable (18, 43) so as to carry out one-time cutting separation on the transparent brittle material to be processed.

As a further preferred aspect of the present invention, the beam combining component is specifically a polarization beam combining mirror (5); the polarization directions of the ultrashort pulse laser and the continuous laser are different.

As a further preferred aspect of the present invention, the ultrashort pulse laser is an ultrashort pulse laser having a P polarization direction, and the continuous laser is a continuous laser having an S polarization direction; or the ultrashort pulse laser is ultrashort pulse laser with S polarization direction, and the continuous laser is continuous laser with P polarization direction.

As a further preferred aspect of the present invention, the beam combining component is specifically a dual-wavelength beam combining mirror (34); the ultrashort pulse laser and the continuous laser have different wavelengths and can be combined into composite laser by the dual-wavelength beam combining mirror (34) on the same optical axis.

As a further preference of the present invention, the bessel laser synthesis assembly includes an axicon lens (8, 37) and a 4f system composed of two lenses; after the composite laser is processed by the Bessel laser synthesis assembly, the composite laser is converted into a Bessel synthesized laser beam with a central main lobe diameter not more than 3 microns.

As a further preferred aspect of the present invention, the ultrashort pulse laser (1, 30) is configured to output an ultrashort pulse laser having a wavelength of 266 to 2000 nm;

the continuous laser (11, 44) is used for outputting continuous laser light with the wavelength of 266-2000 nm.

As a further preference of the present invention, the xy two-dimensional table (18, 43) can drive the transparent brittle material to be treated to move at a speed of not less than 100 mm/s.

Through the utility model discloses above technical scheme who thinks, compare with prior art, have the characteristics of long focal depth according to Bessel light beam to ultrashort pulse laser and continuous laser are both regarded as Bessel laser light source simultaneously, utilize compound laser to act on transparent brittle material with the optical axis simultaneously with ultrafast laser ablation modification mechanism and continuous laser thermal stress cutting separation mechanism, can realize the separation of the disposable high-speed cutting of transparent brittle material, need not follow-up separating force or the difference in temperature of exerting and separate the process. Specifically, the utility model discloses utilize ultrashort pulse laser to transparent brittle material ablation modification mechanism, for example can adopt repetition frequency to satisfy 1-2000kHz, peak power density fullFoot is higher than 10¹²W/cm²The ultrashort pulse Bessel beam is characterized in that a micro-point columnar modified micro-channel is preprocessed on the transparent brittle material, and the bonding force of the transparent brittle material along the direction of a sweeping cutting separation path is weakened; simultaneously utilizes a laser thermal stress cutting separation mechanism, and particularly can adopt a power density less than 10¹¹W/cm²The continuous Bessel laser heats the modified area of the transparent brittle material, and only causes the transparent brittle material between the columnar modified microchannels to expand by heating on the premise of not generating any melting or ablation phenomenon. After the laser beam leaves the action area, the heated and expanded material is rapidly cooled through interface convection heat dissipation and self conduction heat dissipation, tensile stress larger than the binding force of the brittle material between the columnar modified microchannels is induced, penetrating microcracks are rapidly formed and are broken, so that the transparent brittle material is cut and separated at one time at a high speed, the subsequent separation process of applying separation force or temperature difference is not needed, and the processing efficiency of cutting and separating the transparent brittle material is improved.

After the two beams of laser are amplified and collimated by respective beam expanding collimating lenses, the two beams of laser are combined on the same optical axis through a polarization beam combiner or a dual-wavelength beam combiner to form a combined laser beam; the combined laser beam forms a Bessel beam through a Bessel laser synthesis assembly (the combined laser beam particularly can pass through a cone lens and then is focused by a 4f system consisting of two lenses to form the Bessel beam with the central main lobe diameter smaller than 3 microns), and the laser composite cutting separation is carried out on the transparent brittle material on the two-dimensional worktable. Furthermore, the movement of the two-dimensional workbench can be controlled, and the one-time cutting separation of any curve of the transparent brittle material can be realized.

The utility model is suitable for a transparent brittle materials such as glass of various performances, optical crystal material and sapphire material and silicon crystal material. The utility model discloses preferably all control the wavelength of ultrashort pulse laser and continuous laser 266-2000nm, under this wavelength condition, can have good transmissivity to the transparent brittle material that uses glass as the representative.

Drawings

FIG. 1 is a schematic view of an apparatus for laser compound cutting separation of transparent brittle materials.

FIG. 2 is a schematic view of a second apparatus for laser compound cutting separation of transparent brittle materials.

The meanings of the reference symbols in the figures are as follows: 1 is an ultrashort pulse laser, 2 is a P (or S) polarized laser beam, 3 is a beam expanding collimator lens (i.e., a first beam expanding collimator lens), 4 is a laser beam, 5 is a polarizing beam combiner lens, 6 is a synthesized coaxial laser beam, 7 is a light guide lens, 8 is a cone lens, 9 is a bessel synthesized laser beam, 10 is an industrial personal computer, 11 is a continuous laser, 12 is a laser beam with S (or P) polarization, 13 is a beam expanding collimator lens (i.e., a first beam expanding collimator lens), 14 is a laser beam, 15 is a light guide lens, 16 is a bessel synthesized beam, 17 is a transparent and brittle material, 18 is an xy two-dimensional worktable (i.e., an xy worktable), 19 is a focusing lens, 20 is a focusing lens, 30 is an ultrashort pulse laser, 31 is an ultrashort pulse laser beam, 32 is a beam expanding collimator lens (i.e., a second beam expanding collimator lens), 33 is a laser beam, 34 is a dual-wavelength beam combiner lens, 35 is a coaxial laser beam, 36 is a light guide lens, 37 is a cone lens, 38 is a bessel combined laser beam, 39 is a focusing lens, 40 is a focusing lens, 41 is a bessel combined beam, 43 is an xy two-position worktable, 44 is a continuous laser, 45 is a continuous laser beam, 46 is a beam expanding collimating lens (i.e. a second beam expanding collimating lens), 47 is a laser beam, 48 is a light guide lens, and 49 is an industrial personal computer.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Furthermore, the technical features mentioned in the embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

Fig. 1 shows one of the devices for separating transparent brittle materials by laser composite cutting according to the present invention. The device mainly comprises an ultrashort pulse laser 1, a continuous laser 11, beam expanding collimating lenses 3 and 13, a polarization beam combining lens 5, light guide lenses 7 and 15, a cone lens 8, focusing

lenses

19 and 20 and an xy two-dimensional worktable 18. The device is suitable for ultrashort pulse laser and continuous laser with different polarization directions.

For example, the ultrashort pulse laser 1 outputs a wavelength range (266-2000nm) and has a P (or S) polarized laser beam 2, which is expanded and collimated by the beam expanding collimator 3 to become a laser beam 4, and enters a transmission end of the polarization beam combiner 5 for transmitting the P (or S) polarized laser; the continuous laser 11 outputs a wavelength range (266-2000nm) and has an S (or P) polarized laser beam 12, the S (or P) polarized laser beam is expanded and collimated by an expanding collimator 13 to form a laser beam 14, and the laser beam 14 is guided into a reflecting end of a polarization beam combiner 5 for reflecting the S (or P) polarized laser by a light guide mirror 15; after passing through the polarization beam combiner 5, the laser beams 4 and 14 are combined into a laser beam 6 having the same optical axis, and are input to the axicon lens 8 through the light guide mirror 7. The synthesized coaxial laser beam 6 passes through the cone lens 8 to form a Bessel synthesized laser beam 9, and passes through a 4f system consisting of focusing

mirrors

19 and 20 to compress the diameter of the central main lobe of the Bessel synthesized beam to a Bessel synthesized beam 16 of a few micrometers, and the transmission distance without diffraction penetrates through the whole thickness of the transparent brittle material 17. The transparent brittle material 17 is fixed on an xy two-dimensional worktable 18, and an industrial personal computer 10 can be further adopted to control the ultrashort pulse laser 1, the continuous laser 11 and the xy worktable 18 to carry out laser composite cutting separation of any curve on the transparent brittle material 17.

Fig. 2 shows another device for realizing laser composite cutting and separating of the transparent brittle material of the utility model. The device consists of an ultrashort pulse laser 30, a continuous laser 44, beam expanding

collimating mirrors

32 and 46, a dual-wavelength beam combining mirror 34,

light guide mirrors

36 and 48, a cone lens 37, focusing

mirrors

39 and 40 and an xy workbench 43. The device is suitable for ultrashort pulse laser and continuous laser with different wavelengths (no requirement on the polarization directions of the ultrashort pulse laser and the continuous laser).

The ultra-short pulse laser 30 outputs a laser beam 31 with a wavelength range (266-2000nm), the laser beam is expanded and collimated by a beam expanding and collimating lens 32 to form a laser beam 33, and the laser beam 33 enters a surface, with a transmission function, of the laser with the wavelength, of a dual-wavelength beam combining lens 34; a laser beam 45 with the wavelength range (266-2000nm) output by the continuous laser 44 is expanded and collimated by a beam expanding collimator 46 to form a laser beam 47, and the laser beam 47 is guided into one surface of the dual-wavelength beam combiner 34 with the reflection function for the wavelength laser by a light guide mirror 48; the

laser beams

33 and 47 pass through the two-wavelength beam combining mirror 34, then are combined into the laser beam 35 with the same optical axis, and are input into the conical lens 37 through the light guide mirror 36, the combined laser beam 36 with the same optical axis passes through the conical lens 37, then the Bessel combined laser beam 38 is formed, and passes through the 4f system consisting of the focusing

mirrors

39 and 40, the diameter of the central main lobe of the Bessel combined laser beam is compressed to the Bessel combined laser beam 41 with the diameter smaller than 3 microns, and the diffraction-free transmission distance penetrates through the whole thickness of the transparent brittle material 17. The transparent brittle material 17 is fixed on the xy two-dimensional table 43. Moreover, the ultra-short pulse laser 30, the continuous laser 44 and the xy table 43 may be further controlled by an industrial personal computer 49 to perform laser compound cutting separation of an arbitrary curve on the transparent brittle material 17 (the industrial personal computer 49 may be directly a commercially available product in the prior art, and may be controlled by a control method known in the prior art; of course, the industrial personal computer 49 is not necessary and is an optional component). The specific wavelength ranges of both the ultrashort pulse laser and the continuous laser can be determined according to the model of the dual-wavelength beam combiner 34, for example: the wavelength of the ultrashort pulse laser can be 400-700nm, and the wavelength of the continuous laser can be 800-1300 nm.

The following are specific examples:

example 1: the device for separating the transparent brittle material by adopting the first laser composite cutting uses an ultrashort pulse laser with the pulse width of 10 picoseconds and the wavelength of 1064nm and outputting a laser beam in the P polarization direction and a continuous laser beam fiber laser with the wavelength of 1070nm and the output S polarization direction. The output power and the repetition frequency of the ultrashort pulse laser are respectively 70W and 1500kHz, the output power of the continuous fiber laser is 500W, the soda-lime glass with the thickness of 1mm is fixed on an xy workbench, and the moving speed of the xy workbench is 300 mm/s. The method for separating the transparent brittle material by laser composite cutting realizes the one-time cutting separation of the soda-lime glass with the thickness of 1mm, the edge breakage of the cutting separation surface is less than 1 mu m, and the roughness of the cutting separation surface is less than 0.2 mu m.

Example 2: the first laser composite cutting device for separating transparent brittle material uses ultrashort pulse laser with 10 picoseconds pulse width, 1064nm wavelength and P polarization direction laser beam output and continuous fiber laser with 1070nm wavelength and S polarization direction laser beam output. The output power and the repetition frequency of the ultrashort pulse laser are respectively 12W and 80kHz, the output power of the continuous optical fiber laser is 25W, the aluminum-silicon reinforced glass with the thickness of 0.7mm is fixed on an xy workbench, the moving speed of the xy workbench is 400mm/s, the method for separating the transparent brittle material by laser composite cutting is adopted, the one-time cutting and separation of the aluminum-silicon reinforced glass with the thickness of 0.7mm is realized, no large scraps or cracks exist on the cutting and separating surface, the width of the edge ablation trace on the upper and lower separating surfaces is less than 2 mu m, and the roughness of the cutting and separating surface is less than 0.3 mu m.

Example 3: the device for separating the transparent brittle material by adopting the second laser composite cutting uses an ultrashort pulse laser with the pulse width of 10 picoseconds and the wavelength of 532nm and outputting laser beams in the P polarization direction and a continuous fiber laser with the wavelength of 1070nm and outputting laser beams in any polarization direction. The output power and the repetition frequency of the ultrashort pulse laser are respectively 3W and 30kHz, the output power of the continuous optical fiber laser is 200W, the quartz glass with the thickness of 0.5mm is fixed on an xy workbench, the moving speed of the xy workbench is 100mm/s, the method for separating the transparent brittle material by laser composite cutting is adopted, the one-time cutting and separation of the quartz glass with the thickness of 0.5mm is realized, the cutting and separating surface does not have any large scraps and cracks, the edge ablation trace width of the upper and lower separating surfaces is less than 1 micrometer, and the roughness of the cutting and separating surface is less than 0.1 micrometer.

It will be understood by those skilled in the art that the foregoing is merely a preferred embodiment of the present invention, and is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

Claims

1. A device for separating transparent brittle materials by laser composite cutting is characterized by comprising an ultrashort pulse laser output component, a continuous laser output component, a beam combining component, a Bessel laser synthesis component and an xy two-dimensional worktable (18, 43); wherein the content of the first and second substances,

2. The apparatus for laser composite cutting separation of transparent brittle materials as claimed in claim 1, characterized in that the beam combining component is embodied as a polarizing beam combiner (5); the polarization directions of the ultrashort pulse laser and the continuous laser are different.

3. The apparatus for hybrid laser cutting separation of transparent brittle materials as claimed in claim 2, wherein the ultrashort pulse laser is an ultrashort pulse laser having P polarization direction, and the continuous laser is a continuous laser having S polarization direction; or the ultrashort pulse laser is ultrashort pulse laser with S polarization direction, and the continuous laser is continuous laser with P polarization direction.

4. The apparatus for laser composite cutting separation of transparent brittle materials as claimed in claim 1, characterized in that the beam combining component is embodied as a dual-wavelength beam combining mirror (34); the ultrashort pulse laser and the continuous laser have different wavelengths and can be combined into composite laser by the dual-wavelength beam combining mirror (34) on the same optical axis.

5. The apparatus for laser composite cutting separation of transparent brittle materials as claimed in claim 1, characterized in that the bessel laser synthesis assembly comprises an axicon (8, 37) and a 4f system of two lenses; after the composite laser is processed by the Bessel laser synthesis assembly, the composite laser is converted into a Bessel synthesized laser beam with a central main lobe diameter not more than 3 microns.

6. The apparatus for laser hybrid cutting separation of transparent brittle materials as claimed in claim 1, characterized in that the ultrashort pulse laser (1, 30) is adapted to output an ultrashort pulse laser with a wavelength of 266-2000 nm;

7. A device for the composite cutting separation of transparent brittle materials by laser according to claim 1, characterized in that the xy two-dimensional table (18, 43) is capable of moving the transparent brittle material to be processed at a speed of not less than 100 mm/s.