Ultrafast laser polishing equipment for hard and brittle materials

Abstract

The utility model discloses ultrafast laser polishing equipment for hard and brittle materials, which comprises a base, a supporting platform mounted at the top of the base, an XY-axis motion platform mounted at the top of the supporting platform, a processing platform arranged at the driving end of the XY-axis motion platform, two stand columns mounted at the top of the supporting platform, and a mounting plate mounted between the two stand columns in a crossing manner, an infrared femtosecond laser, a laser path system and a laser emitting system are mounted on the mounting plate, and laser beams emitted by the infrared femtosecond laser enter the laser path system and then are focused by the laser emitting system to a hard and brittle material workpiece placed on the machining platform. The laser cold polishing technology is adopted, thermal stress is small, when micro polishing, superhard material polishing, fragile material polishing and high polymer material polishing are conducted, micro cracks are hardly generated on the surfaces of materials, the performance of the materials is hardly influenced, the polishing thickness is easy to control, nanoscale polishing precision can be achieved, the polishing machining efficiency is high, and the equipment cost is low.

Description

Technical Field

[0001] The utility model relates to the technical field of polishing processing of brittle materials, and particularly relates to an ultrafast laser polishing device for brittle materials. Background Technique

[0002] Traditional brittle materials include optical glass, silicon crystals, ceramics, sapphire, etc. Due to their characteristics such as wear resistance, high hardness, and high temperature resistance, they are often used to make key components of instrument systems. Laser crystals and semiconductor materials are typical representatives among them. With the rapid development of the microelectronics field and the optical field, especially the rise of the photovoltaic industry in recent years, higher requirements have been put forward for the surface roughness of materials. Taking the optical system as an example, it has extremely strict requirements for the surface roughness of optical components such as lenses and laser crystals, because this will directly affect key technical indicators such as the energy efficiency and imaging quality of the entire system.

[0003] At present, the traditional processing method commonly used in the industrial production of brittle materials is mechanical polishing, but this processing method is prone to cause surface, subsurface damage or edge cracking of brittle materials. Therefore, researchers have proposed various new polishing technologies, including chemical mechanical polishing, thermochemical polishing, hydration polishing, plasma polishing, laser polishing and other processing technologies with their own characteristics. Among them, laser polishing technology is a technology that irradiates the surface of a workpiece with a laser of a certain wavelength and energy density, so that the material melts, vaporizes and peels off in a very thin range, thereby obtaining a smooth surface. It stands out from many processing technologies with the characteristics of non-contact processing, no mechanical stress generation, comprehensive controllability of multiple parameters, high polishing accuracy, and small single-action area, and has received extensive attention. Since the 1960s of the 20th century, countries such as China, the United States, Russia, Germany, and Japan have successively carried out research on laser polishing technology. After decades of efforts, many research results have been obtained on the laser processing technology and polishing mechanism of common materials such as diamond, semiconductor, metal, and glass. Even in the development process of laser polishing research, the photoionization and photochemical phenomena of material surface and even material overall modification caused by short pulse width and short wavelength lasers have also received certain attention.

[0004] However, compared with other polishing technologies, the existing laser polishing technology has problems such as a relatively small single-action area of laser polishing, being not suitable for large-area polishing, relatively low polishing efficiency for large-area workpieces, generation of microcracks on the material surface, and affecting the material properties. Content of the Utility Model

[0005] To solve the problems existing in the above-mentioned background technology, the present utility model provides an ultrafast laser polishing device for brittle materials. It adopts laser cold polishing technology with very small thermal stress. When polishing micro-polishing, super-hard materials, brittle materials, and polymer materials, almost no micro-cracks are generated on the material surface, and almost no influence is exerted on the performance of the material itself. The polishing thickness is easy to control, and nano-level polishing accuracy can be achieved. The polishing processing efficiency is high. Compared with CMP polishing (chemical mechanical polishing), this device has great cost advantages.

[0006] To achieve the above object, the present utility model adopts the following technical solutions:

[0007] The present utility model provides an ultrafast laser polishing device for brittle materials, including a base. A support platform is installed on the top of the base. An XY-axis motion platform is installed on the top of the support platform. A processing platform is provided at the driving end of the XY-axis motion platform. The processing platform can move along the X-axis and Y-axis under the drive of the XY-axis motion platform. Two columns are installed on the top of the support platform. An installation plate is installed across between the two columns. An infrared femtosecond laser, a laser optical path system, and a laser beam output system are installed on the installation plate. The laser beam emitted by the infrared femtosecond laser enters the laser optical path system and then is focused by the laser beam output system onto the brittle material workpiece placed on the processing platform.

[0008] During operation, place the brittle material workpiece to be polished on the processing platform. Through the cooperation of moving the XY-axis motion platform, the Z-axis servo motor, and the CCD component, position and focus on the brittle material workpiece to be polished. After setting the laser polishing process parameters, turn on the infrared femtosecond laser. The infrared femtosecond laser generates and emits laser, which is conducted by the laser optical path system to the laser beam output system, and finally focuses on the surface of the brittle material workpiece for polishing operation.

[0009] Further, a dust extraction device is also provided beside the laser beam output system. The dust extraction device includes a dust suction hood and a first dust suction pipe. The dust suction hood is fixedly installed on the installation plate through a mounting bracket. The open end of the dust suction hood is located directly above the processing platform. The dust suction hood is connected to a vacuum system through the first dust suction pipe.

[0010] During the polishing operation of the device, when the laser beam acts on the brittle material workpiece placed on the processing platform, splashes and dust will be generated. The vacuum system works. Through the cooperation of the dust suction pipe and the dust suction hood, the splashes and dust generated during polishing are sucked away from the open end of the dust suction hood.

[0011] Furthermore, the processing platform is a vacuum platform, which includes a bottom plate and an upper plate. The bottom plate is connected to the driving end of the XY-axis moving platform. The upper plate is installed on the top of the bottom plate. The upper plate has a hollow interior and is provided with a plurality of first suction holes on the top. A honeycomb plate is installed on the top of the upper plate. The honeycomb plate is provided with a plurality of second suction holes. The number and positions of the first suction holes and the second suction holes correspond to each other one by one. The upper plate is connected to the vacuum pumping system through a second dust suction pipe.

[0012] During the polishing operation, the spatter and dust that fall onto the processing platform are sucked away through the second suction holes on the honeycomb plate, enter the interior of the upper plate through the first suction holes, and then are sucked away by the second dust suction pipe. In a specific embodiment, the end of the second dust suction pipe can be directly connected to the first dust suction pipe, so that when the vacuum pumping system is turned on, the dust suction hood and the vacuum platform operate simultaneously; or the second dust suction pipe and the first dust suction pipe are respectively connected to the vacuum pumping system, and according to the usage requirements, it is possible to control the dust suction hood and the vacuum platform to be opened and operated separately or simultaneously.

[0013] Furthermore, limit edges are respectively provided around the top of the upper plate. The four limit edges enclose an installation space, and the honeycomb plate is adaptively installed in the installation space.

[0014] Since it is necessary to ensure that the second suction holes on the honeycomb plate and the first suction holes opened on the top of the upper plate correspond to each other one by one during installation, so as to ensure the effect of sucking dust. In order to facilitate the installation of the honeycomb plate, limit edges are respectively provided around the top of the upper plate in advance. The space enclosed between the limit baffles forms a positioning installation space for installing the honeycomb plate, and the positioning and installation process of the honeycomb plate is more accurate, convenient and fast.

[0015] Furthermore, a CCD (Charge Coupled Device) component is provided beside the laser light output system. The CCD component is drivingly connected to the Z-axis driving component located on the mounting plate, and the CCD component can move along the Z-axis under the drive of the Z-axis driving component.

[0016] As the off-axis CCD of the laser light output system, it plays important functions such as positioning and focusing when the equipment needs to start polishing.

[0017] Furthermore, the laser optical path system includes a laser mirror assembly, a laser beam expander assembly, a light regulating mirror assembly and a beam shaping assembly. The laser beam emitted by the infrared femtosecond laser is conducted to the laser light output system through the laser mirror assembly, the laser beam expander assembly and the beam shaping assembly in sequence.

[0018] Among them, the laser mirror assembly is used to change the propagation direction and spatial distribution of the laser beam; the laser beam expander assembly is used to adjust the size and divergence angle of the laser beam, expand the diameter of the laser beam to reduce the energy density of the laser, avoid excessive damage to the material during focusing, and improve the uniformity of the light spot at the same time; the dimming mirror assembly is used to adjust the intensity or energy of the laser beam; the beam shaping assembly is used to change the shape and quality of the laser beam, such as converting an irregular beam into a regular circular or square light spot, or improving the mode of the beam.

[0019] Further, the laser light output system includes a mirror assembly and a laser galvanometer assembly. The mirror assembly reflects the laser to the laser galvanometer assembly, and the laser galvanometer assembly focuses the laser beam onto the hard and brittle material product placed on the processing platform.

[0020] Among them, the mirror assembly is used to change the propagation direction and spatial distribution of the laser beam; the laser galvanometer assembly realizes the precise deflection and scanning of the laser beam in the XY plane.

[0021] Further, the infrared femtosecond laser, the laser optical path system and the laser light output system are all covered by a light shield.

[0022] Further, the base is a hollow structure inside. A load-bearing support frame is provided at the top of the base. The support platform is installed on the load-bearing support frame. An electrical control system is arranged inside the base, and a plurality of support feet are installed at the bottom of the base.

[0023] The base is the main load-bearing component of the equipment, and the height and level of the equipment can be adjusted through the support feet under the base; the load-bearing support frame, the base and the support feet form the main load-bearing part to carry the whole equipment, and the electrical control system is arranged inside the base.

[0024] Compared with the prior art, the utility model has the following beneficial effects:

[0025] In the utility model, the infrared femtosecond laser is used as a polishing "tool", and the laser cold polishing technology is adopted. The thermal stress is very small. When polishing micro-polishing, super-hard materials, brittle materials and polymer materials, almost no micro-cracks are generated on the material surface, and almost no influence is exerted on the performance of the material itself. The polishing thickness is easy to control, nano-level polishing accuracy can be achieved, the polishing processing efficiency is high. Compared with CMP polishing (chemical mechanical polishing), this equipment has great cost advantages; moreover, this equipment is easy to operate and can be operated through simple training, and is suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The following further elaborates the utility model in detail in conjunction with the drawings and specific embodiments.

[0027] Figure 1 This is a schematic diagram of the overall structure of the ultrafast laser polishing equipment for brittle materials in the present utility model;

[0028] Figure 2 This is a partial structure schematic diagram of the processing platform and the dust extraction device in the present utility model;

[0029] Figure 3 This is a top view schematic diagram of the laser optical path system after removing part of the light shield in the present utility model;

[0030] Among them, the specific reference numerals are as follows:

[0031] Base 1, support feet 2, load-bearing support frame 3, support platform 4, XY-axis moving platform 5, processing platform 6, bottom plate 7, upper plate 8, limit edge 9, honeycomb plate 10, column 11, mounting plate 12, light shield 13, infrared femtosecond laser 14, laser mirror assembly 15, laser beam expander assembly 16, light regulating mirror assembly 17, beam shaping assembly 18, mirror assembly 19, laser galvanometer assembly 20, CCD assembly 21, Z-axis drive assembly 22, dust extraction device 23, dust suction hood 24, first dust suction pipe 25, second dust suction pipe 26. Specific embodiments

[0032] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the protection scope of the present utility model.

[0033] The embodiment of the present utility model provides an ultrafast laser polishing equipment for brittle materials, as Figure 1 shown, including a base 1. The base 1 has a hollow internal structure, and a load-bearing support frame 3 is provided at its top. A support platform 4 is installed on the load-bearing support frame 3. An electrical control system is provided inside the base 1. A plurality of support feet 2 are installed at the bottom of the base 1. The base 1 is the main load-bearing component of the equipment, and the height and level of the equipment can be adjusted through the support feet 2 below the base 1. The load-bearing support frame 3, the base 1, and the support feet 2 form the main load-bearing part, bearing the entire equipment;

[0034] The support platform 4 is a marble platform. The support platform 4 is flatly laid on the load-bearing support frame 3 and fixed by bolts. An XY-axis moving platform 5 is installed at the top of the support platform 4. The XY-axis moving platform 5 can adopt a driving component that can move along the X-axis and Y-axis in the prior art. The driving end of the XY-axis moving platform 5 is provided with a processing platform 6. The processing platform 6 can move along the X-axis and Y-axis under the drive of the XY-axis moving platform 5;

[0035] At the top of the support platform 4, two columns 11 are fixedly connected by bolts. An installation plate 12 made of marble is installed across between the two columns 11. The columns 11 and the installation plate 12 are fixedly connected by bolts. An optical vertical plate is installed on the installation plate 12, and an infrared femtosecond laser 14 and a laser optical path system are installed on the optical vertical plate. The laser light output system is fixedly installed on the optical vertical plate through an L-shaped fixing member. The laser beam emitted by the infrared femtosecond laser 14 enters the laser optical path system and then is focused by the laser light output system onto the hard and brittle material workpiece placed on the processing platform 6.

[0036] During operation, the hard and brittle material workpiece to be polished is placed on the processing platform 6. Through the cooperation of the XY-axis moving platform 5, the Z-axis servo motor, and the CCD component 21, the hard and brittle material workpiece to be polished is positioned and focused. After setting the laser polishing process parameters, the infrared femtosecond laser 14 is turned on. The infrared femtosecond laser 14 generates and emits laser, and the laser is conducted by the laser optical path system to the laser light output system, and finally is focused on the surface of the hard and brittle material workpiece for polishing operation.

[0037] As Figure 2 shown, a dust extraction device 23 is also provided beside the laser light output system. The dust extraction device 23 includes a dust suction hood 24 and a first dust suction pipe 25. The dust suction hood 24 is fixedly installed on the installation plate 12 through a mounting frame. The open end of the dust suction hood 24 is located directly above the processing platform 6. The dust suction hood 24 is connected to the vacuum system through the first dust suction pipe 25. During the polishing operation of the equipment, the laser beam acts on the hard and brittle material workpiece placed on the processing platform 6, generating splashes and dust. The vacuum system works, and the splashes and dust generated during polishing are sucked away by the cooperation of the dust suction pipe and the dust suction hood 24 from the open end of the dust suction hood 24.

[0038] The processing platform 6 is a vacuum platform. The vacuum platform includes a bottom plate 7 and an upper plate 8. The bottom plate 7 is connected to the driving end of the XY-axis moving platform 5. The upper plate 8 is installed on the top of the bottom plate 7. The upper plate 8 has a structure with a hollow interior and multiple first suction holes opened at the top. A honeycomb plate 10 is installed on the top of the upper plate 8. Multiple second suction holes are opened on the honeycomb plate 10. The number and positions of the first suction holes and the second suction holes correspond to each other one by one. The upper plate 8 is connected to the vacuum system through a second dust suction pipe 26. The splashes and dust that fall onto the processing platform 6 during the polishing operation are sucked away through the second suction holes on the honeycomb plate 10, enter the interior of the upper plate 8 through the first suction holes, and then are sucked away by the second dust suction pipe 26. In a specific embodiment, the end of the second dust suction pipe 26 can be directly connected to the first dust suction pipe 25, so that when the vacuum system is turned on, the dust suction hood 24 and the vacuum platform operate simultaneously; or the second dust suction pipe 26 and the first dust suction pipe 25 are respectively connected to the vacuum system, and according to the usage requirements, it can be controlled to open the dust suction hood 24 and the vacuum platform to operate separately or simultaneously.

[0039] Specifically, limiting stop edges 9 are respectively provided around the top of the upper plate 8, and the four limiting stop edges 9 enclose an installation space, and the honeycomb plate 10 is adaptively installed in the installation space. Since it is necessary to ensure that the second suction holes on the honeycomb plate 10 correspond one by one to the first suction holes opened at the top of the upper plate 8 during installation, this can ensure the effect of sucking dust. In order to facilitate the installation of the honeycomb plate 10, limiting stop edges 9 are respectively provided around the top of the upper plate 8 in advance, and a positioning installation space for installing the honeycomb plate 10 is enclosed between the limiting baffles, and the positioning and installation process of the honeycomb plate 10 is more accurate, convenient and fast.

[0040] A CCD component 21 (charge-coupled device component) is provided beside the laser light output system, and the CCD component 21 is drivingly connected to a Z-axis driving component 22 located on the mounting plate 12, and the CCD component 21 can move along the Z-axis under the drive of the Z-axis driving component 22. As a paraxial CCD of the laser light output system, it plays important functions such as positioning and focusing when the device needs to start polishing.

[0041] As Figure 3 shown, the laser light path system includes a laser mirror component 15, a laser beam expander component 16, a dimming mirror component 17 and a beam shaping component 18. The laser beam emitted by the infrared femtosecond laser 14 is sequentially conducted to the laser light output system through the laser mirror component 15, the laser beam expander component 16 and the beam shaping component 18. Among them, the laser mirror component 15 is used to change the propagation direction and spatial distribution of the laser beam; the laser beam expander component 16 is used to adjust the size and divergence angle of the laser beam, expand the diameter of the laser beam to reduce the energy density of the laser and avoid excessive damage to the material during focusing, and at the same time can improve the uniformity of the light spot; the dimming mirror component 17 adjusts the intensity or energy of the laser beam by changing the position or angle of some optical elements in the light path; the beam shaping component 18 is used to change the shape and quality of the laser beam, such as converting an irregular beam into a regular circular or square light spot, or improving the mode of the beam.

[0042] The laser light output system includes a mirror component 19 and a laser galvanometer component 20. The laser is reflected by the mirror component 19 into the laser galvanometer component 20, and the laser galvanometer component 20 focuses the laser beam on the hard and brittle material product placed on the processing platform 6. Among them, the mirror component 19 is used to change the propagation direction and spatial distribution of the laser beam; the laser galvanometer component 20 realizes the precise deflection and scanning of the laser beam in the XY plane.

[0043] Specifically, the infrared femtosecond laser 14, the laser light path system and the laser light output system are all covered by a light shielding cover 13.

[0044] The specific working principle of this device is as follows:

[0045] (1) Place the workpiece of the hard and brittle material to be polished on the processing platform 6. Control the movement of the hard and brittle material workpiece on the processing platform 6 in the X-axis and Y-axis directions through the XY-axis movement platform 5, and drive the CCD component 21 to move in the Z-axis direction through the Z-axis drive component 22, so as to realize the positioning and focusing of the hard and brittle material workpiece to be polished;

[0046] (2) After setting the laser polishing process parameters, turn on the infrared femtosecond laser 14. The infrared femtosecond laser 14 generates and emits laser light. The laser light is transmitted through the laser mirror assembly 15, the laser beam expander assembly 16, and the beam shaping assembly 18 to the laser light output system, and the laser light is reflected to the laser galvanometer assembly 20 by the mirror assembly 19. The laser beam is regulated by the laser galvanometer assembly 20 to polish the surface of the hard and brittle material workpiece;

[0047] (3) The splashes and dust generated during the polishing operation will be sucked away by the suction pipe connected to the processing table (vacuum platform) and the dust suction hood 24. After the polishing is completed, take away the hard and brittle material workpiece to complete the polishing.

[0048] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An ultrafast laser polishing device for brittle materials, characterized in that, It includes a base (1), a support platform (4) is installed on the top of the base (1), an XY-axis moving platform (5) is installed on the top of the support platform (4), a processing platform (6) is provided at the driving end of the XY-axis moving platform (5), and the processing platform (6) can move along the X-axis and Y-axis under the drive of the XY-axis moving platform (5). Two columns (11) are installed on the top of the support platform (4), and a mounting plate (12) is installed across between the two columns (11). An infrared femtosecond laser (14), a laser optical path system and a laser beam output system are installed on the mounting plate (12). The laser beam emitted by the infrared femtosecond laser (14) enters the laser optical path system and is focused onto the hard and brittle material workpiece placed on the processing platform (6) through the laser beam output system.

2. The ultrafast laser polishing apparatus for brittle materials according to claim 1, wherein A dust extraction device (23) is also provided beside the laser beam output system. The dust extraction device (23) includes a dust suction hood (24) and a first dust suction pipe (25). The dust suction hood (24) is fixedly installed on the mounting plate (12) through a mounting bracket. The opening end of the dust suction hood (24) is located directly above the processing platform (6), and the dust suction hood (24) is connected to a vacuum system through the first dust suction pipe (25).

3. The ultrafast laser polishing device for brittle materials according to claim 2, characterized in that, The processing platform (6) is a vacuum platform. The vacuum platform includes a bottom plate (7) and an upper plate (8). The bottom plate (7) is connected to the driving end of the XY-axis moving platform (5), and the upper plate (8) is installed on the top of the bottom plate (7). The upper plate (8) has a structure with a hollow interior and multiple first suction holes opened at the top. A honeycomb plate (10) is installed on the top of the upper plate (8). Multiple second suction holes are opened on the honeycomb plate (10). The number and positions of the first suction holes and the second suction holes correspond to each other one by one. The upper plate (8) is connected to the vacuum system through a second dust suction pipe (26).

4. The ultrafast laser polishing device for brittle materials according to claim 3, characterized in that, Limit stop edges (9) are respectively provided around the top of the upper plate (8), and the four limit stop edges (9) enclose to form a mounting space, and the honeycomb plate (10) is adaptively installed in the mounting space.

5. The ultrafast laser polishing device for brittle materials according to claim 1, characterized in that, A CCD assembly (21) is provided beside the laser beam output system. The CCD assembly (21) is drivingly connected to a Z-axis driving assembly (22) located on the mounting plate (12), and the CCD assembly (21) can move along the Z-axis under the drive of the Z-axis driving assembly (22).

6. The ultrafast laser polishing apparatus for brittle materials according to claim 1, characterized in that, The laser optical path system includes a laser mirror assembly (15), a laser beam expander assembly (16), a beam dimming mirror assembly (17) and a beam shaping assembly (18). The laser beam emitted by the infrared femtosecond laser (14) is sequentially conducted to the laser beam output system through the laser mirror assembly (15), the laser beam expander assembly (16) and the beam shaping assembly (18).

7. The ultrafast laser polishing apparatus for brittle materials according to claim 1 or 6, characterized in that, The laser light output system includes a mirror assembly (19) and a laser galvanometer assembly (20). The mirror assembly (19) reflects the laser into the laser galvanometer assembly (20), and the laser galvanometer assembly (20) focuses the laser beam onto the hard and brittle material product placed on the processing platform (6).

8. The ultrafast laser polishing apparatus for brittle materials according to claim 7, characterized in that, The infrared femtosecond laser (14), the laser optical path system, and the laser light output system are all covered by a light shielding cover (13).

9. The ultrafast laser polishing apparatus for brittle materials according to claim 1, wherein The base (1) has a hollow internal structure. A load-bearing support frame (3) is provided at its top, and the support platform (4) is installed on the load-bearing support frame (3). An electrical control system is arranged inside the base (1), and a plurality of support feet (2) are installed at the bottom of the base (1).

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