Laser processing light path

Abstract

The utility model discloses a laser processing light path, including laser, beam shaper, focusing objective lens and drive unit, the laser is used for emitting laser, the beam shaper and focusing objective lens are arranged on the propagation path of the laser in order, the beam shaper is in transmission connection with the drive unit. In the laser machining process, the driving unit can drive the beam shaper to move, so that the beam shaper moves out of a laser propagation path, a laser machining light path generates laser in Gaussian distribution, and a hole is formed in a product through machining. And then the beam shaper is moved into the propagation path of the laser, the laser in Gaussian distribution is converted into laser in flat top distribution through the beam shaper, the hole formed in the product is continuously machined, the side wall of the hole is rectangular, and the purpose of reducing the taper of the hole formed in the product is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of laser processing, in particular to a laser processing optical path. Background Art

[0002] Non-contact laser processing is a green processing method with the advantages of small spot size, good directionality, high brightness, and no tool wear. It has become the preferred processing method for surface microstructure processing of brittle materials represented by ceramics.

[0003] However, the energy distribution of the non-contact laser beam on the cross section perpendicular to the optical axis is Gaussian distribution, and its energy distribution is relatively uneven, with too high energy in the middle and low energy around. This makes the microholes processed by non-contact laser have a certain taper, which cannot meet the processing requirements of microholes for zero taper or small taper, and requires secondary rework, resulting in low processing efficiency and high cost. Utility Model Content

[0004] In view of the above-mentioned deficiencies in the prior art, the present application provides a laser processing optical path, which can obtain a hole with zero taper or small taper through laser processing.

[0005] This embodiment adopts the following technical solutions:

[0006] A laser processing optical path comprises a laser, a beam shaper, a focusing lens and a driving unit, wherein the laser is used to emit laser light, the beam shaper and the focusing lens are sequentially arranged on a propagation path of the laser light, and the beam shaper is drivingly connected to the driving unit;

[0007] When the driving unit drives the beam shaper to move out of the propagation path of the laser, the laser emits laser light to the focusing lens, which is focused by the focusing lens and then irradiated to the product to form a hole;

[0008] When the driving unit drives the beam shaper to move into the propagation path of the laser, the laser emits laser light to the beam shaper, so that the laser light changes from Gaussian distribution to flat-top distribution, and then enters the focusing objective lens, is focused by the focusing objective lens, and then irradiates the hole to reduce the taper of the hole.

[0009] Furthermore, the laser processing optical path further includes a collimation unit, which is arranged on the propagation path of the laser and located between the laser and the beam shaper.

[0010] Furthermore, in the laser processing optical path, the collimating unit is an off-axis parabolic reflector.

[0011] Furthermore, the laser processing optical path also includes a quarter wave plate, which is arranged on the propagation path of the laser and located between the collimating unit and the laser.

[0012] Furthermore, the laser processing optical path also includes a first beam splitter prism and a detection camera. The first beam splitter prism is arranged on the propagation path of the laser and is located between the beam shaper and the focusing objective lens. The laser can pass through the first beam splitter prism and enter the focusing objective lens. The ambient light reflected by the hole can be reflected by the first beam splitter prism and enter the detection camera.

[0013] Furthermore, the laser processing optical path also includes a second beam splitter prism and a light source. The second beam splitter prism is arranged on the propagation path of the laser and is located between the first beam splitter prism and the focusing objective lens. The laser can pass through the first beam splitter prism, the second beam splitter prism and enter the focusing objective lens in sequence. The light source emits white light, which is reflected by the second beam splitter prism and then illuminates the hole through the focusing objective lens. The white light reflected by the hole passes through the second beam splitter prism and is then reflected by the first beam splitter prism to enter the detection camera.

[0014] Furthermore, the laser processing optical path also includes a first polarizer and a second polarizer, the first polarizer and the second polarizer are arranged on the propagation paths of the white light and the ambient light, the first polarizer is located between the light source and the second beam splitter prism, and the second polarizer is located between the first beam splitter prism and the detection camera.

[0015] Furthermore, the laser processing optical path also includes a tube lens, which is arranged on the propagation path of the white light and the ambient light and is located between the first beam splitter prism and the detection camera.

[0016] Furthermore, the laser processing optical path also includes an infrared filter, which is arranged on the propagation path of the white light and the ambient light and is located between the first beam splitter prism and the detection camera.

[0017] Furthermore, the laser processing optical path also includes a cutoff filter, which is arranged on the propagation path of the white light and the ambient light and is located between the first beam splitter prism and the detection camera.

[0018] Compared with the prior art, the present application provides a laser processing optical path, in which a driving unit can drive a beam shaper to move, so that the beam shaper moves out of the propagation path of the laser, so that the laser processing optical path generates a laser with a Gaussian distribution, and forms a hole on the product; then the beam shaper is moved into the propagation path of the laser, so that the laser with the Gaussian distribution is converted into a laser with a flat-top distribution through the beam shaper, and the hole formed on the product is further processed, so that the side wall morphology of the hole is rectangular, thereby achieving the purpose of reducing the taper of the hole formed on the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of a specific embodiment of the laser processing optical path provided in this application.

[0020] Figure 2 for Figure 1 Schematic diagram of the laser processing optical path shown.

[0021] Among them, 1. laser; 2. 1 / 4 wave plate; 3-1. first reflector; 3-2. second reflector; 3-3. third reflector; 3-4. fourth reflector; 3-5. fifth reflector; 3-6. sixth reflector; 4. collimation unit; 5. beam shaper; 6. focusing objective lens; 7. drive unit; 8-1. first beam splitter prism; 8-2. second beam splitter prism; 9. detection camera; 10. light source; 11-1. first polarizer; 11-2. second polarizer; 12. aperture; 13. cut-off filter; 14. tube lens; 15. infrared filter;

[0022] 100. Product; X1. Laser with Gaussian distribution; X2. Laser with flat-top distribution. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and effect of the present application clearer and more specific, the present application is further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application. Without further description, the elements, structures and features in one embodiment can also be beneficially combined with other embodiments.

[0024] It should be noted that when a metastructure is referred to as being "fixed to" or "set on" another metastructure, it may be directly on the other metastructure or indirectly on the other metastructure. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0025] The orientation or positional relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element structure referred to must have a specific orientation, be constructed and operate in a specific orientation.

[0026] See also Figure 1 , is a schematic diagram of the structure of the laser processing optical path provided in the present application, and the laser processing optical path includes a laser 1, a beam shaper 5, a focusing lens 6 and a driving unit 7. The laser generated by the laser processing optical path can form the required holes on the product 100.

[0027] Laser 1 is used to emit laser light. In the actual processing process, appropriate laser process parameters can be set according to the processing requirements and material-related properties. For example, when product 100 is a brittle material such as ceramics, and micropores need to be processed on the ceramics, laser 1 with appropriate power and wavelength can be selected so that the micropores formed by the processing meet the requirements.

[0028] The beam shaper 5, also known as DOE, is used to shape the beam. Its working principle is to change the intensity distribution of the output beam by changing the size of the input beam. After the laser 1 emits the laser, the laser beam intensity presents a Gaussian distribution in space, which has the characteristics of high energy intensity in the middle and gradually decreasing energy intensity along the Gaussian profile. After the laser passes through the beam shaper 5, the Gaussian distribution can be converted into a flat-top distribution, so that the laser is shaped into a flat-top beam with uniform energy distribution.

[0029] After the laser 1 emits laser light, the laser light will propagate along a preset path. The beam shaper 5 and the focusing lens 6 are sequentially arranged on the propagation path of the laser light, so that the laser light first passes through the beam shaper 5 , then passes through the focusing lens 6 , and finally irradiates the product 100 .

[0030] The driving unit 7 is connected to the beam shaper 5 in a transmission manner, so that the driving unit 7 can drive the beam shaper 5 to move, thereby moving the beam shaper 5 out of the propagation path of the laser, or moving the beam shaper 5 back into the propagation path of the laser. Specifically, the driving unit 7 can be a motor, a cylinder, etc., which can drive the beam shaper 5 to move according to a control signal sent by an external main control system.

[0031] During actual processing, the driving unit 7 first drives the beam shaper 5 to move out of the propagation path of the laser, and the laser 1 emits laser light to the focusing lens 6. After being focused by the focusing lens 6, the laser light is irradiated onto the product 100 to form a hole.

[0032] like Figure 2As shown in the left figure, at this time, the spot energy distribution of the laser on the surface of the product 100 is Gaussian distribution, and the side wall morphology of the hole processed by the Gaussian distribution laser X1 on the product 100 will also be Gaussian distribution, and the hole has a certain taper.

[0033] Afterwards, the driving unit 7 drives the beam shaper 5 to move into the propagation path of the laser, and the laser 1 emits laser light to the beam shaper 5, so that the laser light changes from Gaussian distribution to flat-top distribution, and then enters the focusing lens 6, is focused by the focusing lens 6, and irradiates the aforementioned hole.

[0034] like Figure 2 As shown in the middle and right figures, a multi-pulse processing technology can be used to repair the side wall morphology of the aforementioned hole using a flat-top distributed laser X2 to reduce the taper of the aforementioned hole and meet the processing requirements of zero-taper or small-taper holes.

[0035] Therefore, the present application drives the beam shaper 5 to move through the driving unit 7, firstly moves the beam shaper 5 out of the propagation path of the laser, makes the laser generated by the laser processing optical path to be Gaussian distribution, and uses the laser X1 with Gaussian distribution to process and form a hole on the product 100; then moves the beam shaper 5 into the propagation path of the laser, makes the laser generated by the laser processing optical path to be converted into a flat-top distribution through the beam shaper 5, and uses the laser X2 with flat-top distribution to continue processing the hole on the product 100 to reduce the taper of the hole.

[0036] In some embodiments, the laser processing optical path further includes a quarter wave plate 2 , which is disposed on the propagation path of the laser and located between the collimating unit 4 and the laser 1 .

[0037] The laser light generated by the laser 1 has good directivity and belongs to linear polarized light. However, the spot shape of the linear polarized laser light is elliptical, which makes it difficult to obtain uniform and consistent processing effects during hole processing, especially when processing microholes. The 1 / 4 wave plate 2 can convert linear polarized light into circular polarized light, so that the spot shape of the laser light is converted into a circle, so as to obtain uniform and consistent processing effects.

[0038] In some embodiments, the laser processing optical path further includes a collimating unit 4 , which is disposed on the propagation path of the laser and located between the laser 1 and the beam shaper 5 .

[0039] The laser light emitted by the laser 1 is usually a cone-shaped beam with a certain divergence angle. When the laser light enters the collimating unit 4, the divergence angle of the laser light can be reduced to achieve collimated output of the laser light, so as to facilitate laser transmission.

[0040] The collimating unit 4 can use a lens group, a reflector group, a prism group, etc. to change the diameter and divergence angle of the laser beam to achieve collimated output of the laser.

[0041] Preferably, the collimation unit 4 uses an off-axis parabolic reflector, which can reflect and focus the laser beam at an angle of 90 degrees (or any other convenient angle) to achieve collimated laser output, and has the advantages of no center obstruction, no chromatic aberration, and no introduction of spherical aberration.

[0042] The laser processing optical path may also include one or more reflectors, the function of which is to change the propagation direction of the laser so as to set a reasonable laser propagation path.

[0043] In a specific embodiment, Figure 1 As shown, a first reflector 3-1, a second reflector 3-2, a third reflector 3-3 and a fourth reflector 3-4 are provided in the laser processing optical path, and a laser 1, a 1 / 4 wave plate 2, a first reflector 3-1, a collimation unit 4, a second reflector 3-2, a third reflector 3-3, a fourth reflector 3-4, a beam shaper 5 and a focusing objective lens 6 are arranged in sequence.

[0044] The distance between the third reflector 3-3 and the fourth reflector 3-4 is adjustable, so that a flying light path is formed between the third reflector 3-3 and the fourth reflector 3-4. The laser light passing through the third reflector 3-3 and the fourth reflector 3-4 has been collimated by the collimation unit 4, so it will not affect the normal propagation of the laser light in the flying light path.

[0045] In some embodiments, the laser processing optical path further includes a first beam splitter prism 8 - 1 and a detection camera 9 . The first beam splitter prism 8 - 1 is disposed on the propagation path of the laser and is located between the beam shaper 5 and the focusing objective lens 6 .

[0046] During the processing, the laser can pass through the first beam splitter prism 8-1 and enter the focusing objective lens 6, and after focusing, it is emitted to the product 100 and processed to form a hole; the ambient light reflected by the aforementioned hole can be reflected by the first beam splitter prism 8-1 into the detection camera 9 and imaged; through the main control system, the hole depth and aperture of the aforementioned hole can be measured to adjust the processing parameters and processing operations until the aforementioned hole meets the processing requirements.

[0047] Furthermore, the laser processing optical path may also include a second beam splitter prism 8 - 2 and a light source 10 . The second beam splitter prism 8 - 2 is arranged on the propagation path of the laser and is located between the first beam splitter prism 8 - 1 and the focusing objective lens 6 .

[0048] The light source 10 is used to illuminate the hole formed by the processing to improve the imaging quality. During the processing, the laser can pass through the first beam splitter prism 8-1, the second beam splitter prism 8-2 and enter the focusing objective lens 6 in sequence, and then be emitted to the product 100 after focusing to form a hole. The light source 10 can emit white light, which is reflected by the second beam splitter prism 8-2 and illuminates the hole through the focusing objective lens 6. The white light reflected by the hole and the ambient light pass through the second beam splitter prism 8-2, and then reflected by the first beam splitter prism 8-1 and enter the detection camera 9.

[0049] In some embodiments, the laser processing optical path also includes a first polarizer 11-1 and a second polarizer 11-2. The first polarizer 11-1 and the second polarizer 11-2 are arranged on the propagation paths of white light and ambient light. The first polarizer 11-1 is located between the light source 10 and the second beam splitter prism 8-2, and the second polarizer 11-2 is located between the first beam splitter prism 8-1 and the detection camera 9.

[0050] The first polarizer 11-1 and the second polarizer 11-2 play a filtering role. During the processing, the first polarizer 11-1 or the second polarizer 11-2 can be put into working state alone, and the focus of the focusing lens 6 and the light intensity of the light source 10 can be adjusted at the same time to make the image of the detection camera normal.

[0051] When the laser processing optical path stops working, the first polarizer 11-1 and the second polarizer 11-2 can be in working state at the same time. At this time, even if the light source 10 is not turned off, the imaging screen of the detection camera will be black, which plays a role in protecting the detection camera to avoid frequent opening and closing of the light source 10.

[0052] An aperture 12 may be further disposed between the first polarizer 11-1 and the light source 10. When the white light emitted by the light source 10 passes through the aperture 12, the aperture 12 may control the amount of the white light passing through, so as to change the illumination intensity of the aforementioned hole.

[0053] In addition, the laser processing optical path also includes a cutoff filter 13, which is arranged on the propagation path of white light and ambient light and is located between the first beam splitter prism 8-1 and the detection camera 9. The cutoff filter 13 is used to filter the white light emitted by the light source 10 to make it at a suitable light intensity.

[0054] In some embodiments, the laser processing optical path further includes a tube lens 14 , which is disposed on the propagation path of the white light and the ambient light and is located between the first beam splitter prism 8 - 1 and the detection camera 9 .

[0055] The tube lens 14 is used to form an infinite optical correction system and correct aberrations, thereby making the optical path structure compact and improving the imaging quality of the detection camera 9 .

[0056] The laser processing optical path also includes an infrared filter 15 , which is arranged on the propagation path of the white light and the ambient light and is located between the first beam splitter prism 8 - 1 and the detection camera 9 .

[0057] The infrared filter 15 is used to filter laser light of a certain wavelength to prevent the laser light from entering the detection camera 9 and damaging the lens of the detection camera 9 .

[0058] In order to better understand the present invention, the following Figure 1 and Figure 2 , and give specific examples to illustrate the processing steps of the laser processing light path:

[0059] Step 1: Set the optimal laser process parameters according to the processing requirements and material properties;

[0060] Step 2: The laser 1 emits linearly polarized laser light, which is converted into circularly polarized laser light by the quarter wave plate 2. The circularly polarized laser light is reflected by the first reflector 3-1, collimated by the off-axis parabolic reflector, and then acts on the product 100 by the second reflector 3-2, the third reflector 3-3, the fourth reflector 3-4, the first beam splitter prism 8-1, the second beam splitter prism 8-2 and the focusing lens 6;

[0061] At this time, the spot energy distribution of the circularly polarized laser focused by the focusing lens 6 on the surface of the product 100 is Gaussian distribution, and the laser X1 with Gaussian distribution is used to form microholes on the product 100. At this time, the morphology of the side wall of the microhole is Gaussian distribution;

[0062] Step 3: Control the light source 10 to emit white light, and the white light irradiates the microhole in step 2 through the aperture 12, the first polarizer 11-1, the fifth reflector 3-5, the first beam splitter prism 8-1 and the focusing objective lens 6; the incident white light is reflected at various places on the inner wall of the microhole, and enters the detection camera 9 through the focusing objective lens 6, the second beam splitter prism 8-2, the first beam splitter prism 8-1, the infrared filter 15, the tube lens 14, the sixth reflector 3-6, the cutoff filter 13 and the second polarizer 11-2, and is imaged. The hole depth and aperture of the microhole are measured through the main control system until the processing requirements are met;

[0063] Step 4: Control the motor to make the DOE enter the optical path, so that the spot energy distribution of the circularly polarized laser on the surface of the product 100 is transformed from Gaussian distribution to flat-top distribution;

[0064] Step 5: Using the flat-top distribution laser X2, a multi-pulse processing process is used to repair the sidewall morphology of the microhole in step 2;

[0065] Step 6: Detect the micropore sidewall morphology through the detection camera 9 until the micropore sidewall morphology is rectangular, that is, the micropore taper is zero;

[0066] Step 7: Control the laser 1 to turn off the light;

[0067] Step 8: Move the laser processing and imaging system to any position between the farthest and nearest positions of the flying light path, and at the same time move the stage to perform micro-hole processing at the next position, and adjust the laser beam to the initial processing setting to achieve periodic zero-taper group micro-hole processing.

[0068] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and application concept of the present application, and all these changes or substitutions should fall within the protection scope of the claims attached to the present application.

Claims

1. A laser processing optical path, characterized in that: It comprises a laser, a beam shaper, a focusing lens and a driving unit, wherein the laser is used to emit laser light, the beam shaper and the focusing lens are sequentially arranged on the propagation path of the laser light, and the beam shaper is drivingly connected to the driving unit; When the driving unit drives the beam shaper to move out of the propagation path of the laser, the laser emits laser light to the focusing lens, which is focused by the focusing lens and then irradiated to the product to form a hole; When the driving unit drives the beam shaper to move into the propagation path of the laser, the laser emits laser light to the beam shaper, so that the laser light changes from Gaussian distribution to flat-top distribution, and then enters the focusing objective lens, is focused by the focusing objective lens, and then irradiates the hole to reduce the taper of the hole.

2. The laser processing optical path according to claim 1, characterized in that: The invention also comprises a collimating unit, which is arranged on the propagation path of the laser and located between the laser and the beam shaper.

3. The laser processing optical path according to claim 2, characterized in that: The collimating unit is an off-axis parabolic reflector.

4. The laser processing optical path according to claim 2, characterized in that: It also includes a 1 / 4 wave plate, which is arranged on the propagation path of the laser and located between the collimating unit and the laser.

5. The laser processing optical path according to any one of claims 1 to 4, characterized in that: The invention also includes a first beam splitter prism and a detection camera. The first beam splitter prism is arranged on the propagation path of the laser and is located between the beam shaper and the focusing objective lens. The laser can pass through the first beam splitter prism and enter the focusing objective lens. The ambient light reflected by the hole can be reflected by the first beam splitter prism and enter the detection camera.

6. The laser processing optical path according to claim 5, characterized in that: It also includes a second beam splitter prism and a light source. The second beam splitter prism is arranged on the propagation path of the laser and is located between the first beam splitter prism and the focusing objective lens. The laser can pass through the first beam splitter prism, the second beam splitter prism and enter the focusing objective lens in sequence. The light source emits white light, which is reflected by the second beam splitter prism and then illuminates the hole through the focusing objective lens. The white light reflected by the hole passes through the second beam splitter prism and is then reflected by the first beam splitter prism to enter the detection camera.

7. The laser processing optical path according to claim 6, characterized in that: It also includes a first polarizer and a second polarizer, wherein the first polarizer and the second polarizer are arranged on the propagation paths of the white light and the ambient light, the first polarizer is located between the light source and the second beam splitter prism, and the second polarizer is located between the first beam splitter prism and the detection camera.

8. The laser processing optical path according to claim 6, characterized in that: It also includes a tube lens, which is arranged on the propagation path of the white light and the ambient light and located between the first beam splitter prism and the detection camera.

9. The laser processing optical path according to claim 6, characterized in that: It also includes an infrared filter, which is arranged on the propagation path of the white light and the ambient light and is located between the first beam splitter prism and the detection camera.

10. The laser processing optical path according to claim 6, characterized in that: It also includes a cut-off filter, which is arranged on the propagation path of the white light and the ambient light and is located between the first beam splitter prism and the detection camera.

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