Processing method of special-shaped light guide microstructure

Abstract

The invention belongs to the field of laser processing, and relates to a microstructure processing method which comprises the following steps: 1) acquiring a target groove type of a special-shaped light guide microstructure, and determining a light spot form required by the target groove type; 2) modulating a light spot form determined in the step 1) based on an ultrafast laser processing system; (3) according to the light spot form obtained through modulation in the step (2), laser parameters and galvanometer scanning parameters of an ultrafast laser machining system are set, and machining of an approximate target groove profile is completed; and 4) a 3D contourgraph is adopted to detect the approximate target groove profile machining effect obtained in the step 3), a detection result is obtained, the step 2) and the step 3) are repeatedly executed according to the difference between the detection result and the actual target groove profile, and finally machining of the special-shaped light guide microstructure is completed. According to the processing method of the special-shaped light guide microstructure, special-shaped light guide points can be conveniently processed, and the processing efficiency can be improved.

Description

Technical Field

[0001] The invention belongs to the field of laser processing and relates to a microstructure processing method, in particular to a special-shaped light-guiding microstructure processing method. Background Art

[0002] The light guide plate is a structure that uses optical grade acrylic (PMMA) plates, with microstructures made on its surface through laser or other processes, and ultimately diffuses point light sources into surface light sources. It has the advantages of high light conductivity, energy saving, environmental protection, and light weight. It is widely used in LCD displays, various lighting equipment, advertising light boxes, optical instruments, artistic atmosphere lights, home lighting, and many other fields.

[0003] With the development of information technology, flat panel displays have put forward requirements for thinner, lower energy consumption and higher light efficiency light guide plates, so it is necessary to develop high-gain light guide plates. The nanosecond laser dot processing technology in the existing technology is relatively mature, but the processing primitives are relatively single, and it can only process conical blind grooves. It is difficult to process special-shaped light guide points and cannot meet the needs of high-gain light guide plates; while the V-vutting process can process special-shaped light guide points by customizing special cutter heads, but in the actual production process, the single-chip mold requires millions of dots, which has wear problems, resulting in extremely low final product yields, which seriously affects the mass production of high-gain light guide plates. Summary of the invention

[0004] In order to solve the above-mentioned technical problems existing in the background technology, the present invention provides a processing method of a special-shaped light-guiding microstructure which can facilitate the processing of special-shaped light-guiding points and improve the processing efficiency.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A method for processing a special-shaped light-guiding microstructure, characterized in that the method for processing the special-shaped light-guiding microstructure comprises the following steps:

[0007] 1) Obtain the target groove shape of the special-shaped light-guiding microstructure and determine the light spot shape required by the target groove shape;

[0008] 2) modulating a light spot shape that meets the shape determined in step 1) based on an ultrafast laser processing system;

[0009] 3) According to the light spot shape modulated in step 2), the laser parameters and the galvanometer scanning parameters of the ultrafast laser processing system are set to complete the processing of the approximate target groove shape;

[0010] 4) Use a 3D profilometer to detect the approximate target groove processing effect obtained in step 3) to obtain the detection result, and repeatedly perform steps 2) and 3) according to the difference between the detection result and the actual target groove, until the actual processing effect reaches the target groove, and the processing of the special-shaped light-guiding microstructure is completed.

[0011] In the above step 1), the target groove is a crescent groove or a rectangular groove.

[0012] When the target groove is a crescent groove, the specific implementation method of determining the light spot shape required for the target groove type is: using a Gaussian spot, improving the roundness of the light spot and optimizing the energy distribution state of the light beam to obtain the required light spot shape; when the target groove is a rectangular groove, the specific implementation method of determining the light spot shape required for the target groove type is: shaping the light spot into an asymmetric distribution of the light spot energy curve to obtain the required light spot shape.

[0013] The above-mentioned ultrafast laser processing system includes a laser, an optical path transmission system, a beam modulation module, a galvanometer scanning system, a spot morphology auxiliary detection module and an industrial computer, wherein the spot morphology auxiliary detection module includes a beam quality analyzer; the laser generates ultrafast laser, and the ultrafast laser enters the beam modulation module, the galvanometer scanning system and the spot morphology auxiliary detection module in sequence through the optical path transmission system; the spot morphology auxiliary detection module implements feedback of the beam modulation state to the industrial computer; the industrial computer outputs a modulation signal to the beam modulation module according to the real-time feedback of the beam modulation state to realize a specific spot state; the industrial computer controls the galvanometer scanning system to complete the processing of the target groove type.

[0014] The specific implementation method of the above step 2) is: use the beam modulation module of the ultrafast laser processing system to perform beam phase shaping, detect the spot shape through the beam quality analyzer of the spot shape auxiliary detection module, perform online closed-loop testing, and finally modulate the spot shape that meets the determination in step 1).

[0015] When the target slot is a rectangular slot, the specific implementation method of step 3) is:

[0016] a.1) Control the groove depth and length by controlling the power of the ultrafast laser;

[0017] a.2) Set the processing trajectory of the rectangular groove, determine the spot energy distribution and spot length through the beam modulation module of the ultrafast laser processing system, adjust the groove width and inner wall angle through the beam modulation module, and optimize the groove roughness through the beam modulation module, and finally process the target groove shape that is approximately a rectangular groove.

[0018] The specific implementation method of optimizing the groove roughness through the beam modulation module is: adjusting the power of the ultrafast laser through the beam modulation module to optimize the smoothness of the energy step.

[0019] When the target groove is a crescent groove, the specific implementation method of step 3) is:

[0020] b.1) machining the microgrooves by setting different focal positions, detecting the angle of the inner wall of the microgrooves, and preliminarily determining the machining focus; the machining focus is the Z-axis coordinate corresponding to the minimum focus spot;

[0021] b.2) adjusting the ultrafast laser fundamental frequency and power based on the processing focus obtained in step b.1);

[0022] b.3) based on the ultrafast laser fundamental frequency and power obtained in step b.2), setting the processing trajectory, processing the microgrooves, measuring the inner wall angle of the actual microgrooves, and adjusting the overlap rate according to the inner wall angle;

[0023] b.4) Based on the result obtained in step b.3), the processing speed is set, the roughness of the micro-groove is measured, and the laser parameters and the galvanometer scanning parameters of the ultrafast laser processing system are continuously optimized, and finally a target groove shape similar to a crescent groove is formed by processing.

[0024] The machining trajectory in the above step b.3) is formed by gradually moving from the outside of the crescent groove to the inside in a spiral manner.

[0025] When the target groove is a rectangular groove, the machining trajectory of the rectangular groove in step b.2) is formed by a single linear reciprocating motion.

[0026] The advantages of the present invention are:

[0027] The present invention provides a processing method for a special-shaped light-guiding microstructure, including: 1) obtaining a target groove type of the special-shaped light-guiding microstructure and determining the spot shape required for the target groove type; 2) modulating a spot shape that meets the shape determined in step 1) based on an ultrafast laser processing system; 3) setting the laser parameters and galvanometer scanning parameters of the ultrafast laser processing system according to the spot shape modulated in step 2) to complete the processing of the approximate target groove type; 4) using a 3D profiler to detect the processing effect of the approximate target groove type obtained in step 3) to obtain the detection result, and repeatedly performing steps 2) and 3) according to the difference between the detection result and the actual target groove type, and finally completing the processing of the special-shaped light-guiding microstructure. The present invention can process a new type of high-gain light-guiding point through an ultrafast laser, and the processing efficiency is high. In addition, a variety of special groove types can be customized, and a special product library can be established, which is friendly to the mass production stage and can achieve rapid changeover. Compared with the traditional collision point process to produce high-gain light guide plates, the production yield of the present invention is much higher than that of traditional means. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of a special-shaped light-guiding microstructure obtained based on the processing method of the special-shaped light-guiding microstructure provided by the present invention;

[0029] Figure 2 It is a flow chart of the processing method of the special-shaped light-guiding microstructure provided by the present invention;

[0030] Figure 3 It is a schematic diagram of determining the required modulated light spot state according to the crescent groove;

[0031] Figure 4 It is a schematic diagram of determining the required modulated light spot state according to the rectangular slot;

[0032] Figure 5 This is a schematic diagram of the processing trajectory of the crescent groove. DETAILED DESCRIPTION

[0033] In order to fundamentally solve the many problems in the product production process, ultrafast laser processing technology is introduced. First, laser is a non-contact processing, there is no loss, and it will not cause secondary scratches on the surface of the sample; secondly, in the process of product change, it is very convenient, just call the parameter library; finally, when processing different models of products, the traditional process requires customized tool heads, while the laser only needs to modify the parameters. Therefore, the introduction of laser technology has many obvious advantages.

[0034] The present invention provides a method for processing a special-shaped light-guiding microstructure, comprising the following steps:

[0035] 1) Obtain the target groove type of the special-shaped light-guiding microstructure and determine the light spot shape required by the target groove type; wherein, refer to Figure 1 The target groove is a crescent groove or a rectangular groove. Of course, it can also be constructed based on the method provided by the present invention, such as a peanut shape, a W-shaped micro groove and other groove types. For example, a variety of special groove types can be customized to establish a special product library, which is friendly to the mass production stage and can achieve rapid changeover. Figure 3 When the target slot is a crescent slot, the specific implementation method for determining the spot shape required for the target slot type is: using a Gaussian spot, improving the spot roundness and optimizing the beam energy distribution state to obtain the required spot shape; see Figure 4 When the target slot is a rectangular slot, the specific implementation method of determining the light spot shape required for the target slot type is: shaping the light spot into an asymmetric distribution of the light spot energy curve to obtain the required light spot shape.

[0036] 2) Based on the ultrafast laser processing system, modulate the light spot shape that meets the determination in step 1); specifically, use the beam modulation module of the ultrafast laser processing system to perform beam phase shaping, detect the light spot shape through the beam quality analyzer, perform online closed-loop testing, and finally modulate the light spot shape that meets the determination in step 1). Figure 2The ultrafast laser processing system used in the present invention includes a laser, an optical transmission system, a beam modulation module, a galvanometer scanning system, a spot morphology auxiliary detection module and an industrial computer; the spot morphology auxiliary detection module includes a beam quality analyzer; the laser generates ultrafast laser, and the ultrafast laser enters the beam modulation module, the galvanometer scanning system and the spot morphology auxiliary detection module in sequence through the optical transmission system; the spot morphology auxiliary detection module implements feedback of the beam modulation state to the industrial computer; the industrial computer outputs a modulation signal to the beam modulation module according to the real-time feedback of the beam modulation state to achieve a specific spot state; the industrial computer controls the galvanometer scanning system to complete the processing of the target slot type. The ultrafast laser processing system used in the present invention has a beam modulation function in hardware, and can match the corresponding spot morphology according to the actual slot type requirements. In terms of software, CAM software function development is carried out. For large-format light guide plate mold processing, the variable overlap rate processing between different formats of the galvanometer is realized through software control algorithm optimization, and finally it can be ensured that the product is processed without splicing lines and the expected goal is achieved. During the large-format processing, the high-precision coordination of the various components of the equipment ensures the processing accuracy. In the later stage, the corresponding parameters can be set separately for the development of different models of products, and the process library can be gradually improved. At present, in the process of process development, the raw materials to be processed are first obtained, and the corresponding beam modulation state is preliminarily matched according to the actual groove requirements, and the corresponding process parameters are set to start processing. After testing and comparing the actual effect and the theoretical difference, the relevant parameters are adjusted again, and the entire debugging process forms a closed loop.

[0037] 3) According to the spot shape modulated in step 2), the laser parameters and galvanometer scanning parameters of the ultrafast laser processing system are set to complete the processing of the approximate target groove type; considering that when the laser parameters of the ultrafast laser are debugged, the laser processing focus position affects the microgroove inner wall angle; the processing track overlap rate affects the microgroove inner wall angle and the microgroove depth; the laser frequency and single pulse energy affect the microgroove depth and the microgroove bottom morphology; the laser scanning speed also affects the microgroove depth and roughness. Therefore, the present invention performs corresponding debugging according to different target grooves and completes the processing of the approximate target groove type. Specifically:

[0038] When the target slot is a rectangular slot, the specific implementation method of step 3) is:

[0039] a.1) Control the groove depth and length by controlling the power of the ultrafast laser;

[0040] a.2) Setting the processing trajectory of the rectangular groove, determining the spot energy distribution and the spot length through the beam modulation module of the ultrafast laser processing system, adjusting the groove width and the inner wall angle through the beam modulation module, and optimizing the micro-groove roughness through the beam modulation module, and finally processing to form a target groove shape that is approximately a rectangular groove, wherein the processing trajectory of the rectangular groove is formed by a single linear reciprocating motion. Exemplarily, the specific implementation method of optimizing the groove roughness through the beam modulation module is: adjusting the power of the ultrafast laser through the beam modulation module to optimize the smoothness of the energy step.

[0041] When the target slot is a crescent slot, the specific implementation method of step 3) is:

[0042] b.1) Process the microgrooves by setting different focal positions, detect the angle of the inner wall of the microgrooves, and preliminarily determine the processing focus; the processing focus is the Z-axis coordinate corresponding to the minimum focus spot; after determining the focus, the Z-axis is always in this position during the processing and does not move, otherwise the processing of the target groove cannot be achieved. Exemplarily, when looking for the focus, the initial system Z-axis coordinate is set to a, and a product is processed every 0.1mm within the range of a±1mm, and finally the size and inner wall angle of the actual processed product are detected by a 3D profiler to determine the desired focus.

[0043] b.2) adjusting the ultrafast laser fundamental frequency and power based on the processing focus obtained in step b.1);

[0044] b.3) Based on the ultrafast laser fundamental frequency and power obtained in step b.2), set the processing trajectory, process the microgrooves, measure the inner wall angle of the actual microgrooves, and adjust the overlap rate according to the inner wall angle; wherein, see Figure 5 The processing trajectory is formed by gradually moving from the outside of the crescent groove to the inside in a spiral manner.

[0045] b.4) Based on the result obtained in step b.3), the processing speed is set, the roughness of the micro-groove is measured, and the laser parameters and the galvanometer scanning parameters of the ultrafast laser processing system are continuously optimized, and finally a target groove shape similar to a crescent groove is formed by processing.

[0046] 4) Use a 3D profilometer to detect the processing effect of the approximate target groove obtained in step 3) to obtain the detection result, and repeatedly perform steps 2) and 3) according to the difference between the detection result and the actual target groove, and finally complete the processing of the special-shaped light-guiding microstructure.

Claims

1. A method for processing a special-shaped light-guiding microstructure, characterized in that: The processing method of the special-shaped light-guiding microstructure comprises the following steps: 1) Obtain the target groove shape of the special-shaped light-guiding microstructure and determine the light spot shape required by the target groove shape; 2) modulating a light spot shape that meets the shape determined in step 1) based on an ultrafast laser processing system; 3) According to the light spot shape modulated in step 2), the laser parameters and the galvanometer scanning parameters of the ultrafast laser processing system are set to complete the processing of the approximate target groove shape; 4) Use a 3D profilometer to detect the approximate target groove processing effect obtained in step 3) to obtain the detection result, and repeatedly perform steps 2) and 3) according to the difference between the detection result and the actual target groove, until the actual processing effect reaches the target groove, and the processing of the special-shaped light-guiding microstructure is completed.

2. The method for processing a special-shaped light-guiding microstructure according to claim 1, characterized in that: In the step 1), the target groove is a crescent groove or a rectangular groove.

3. The method for processing a special-shaped light-guiding microstructure according to claim 2, characterized in that: When the target groove is a crescent groove, the specific implementation method of determining the light spot shape required for the target groove type is: using a Gaussian spot, improving the roundness of the light spot and optimizing the energy distribution state of the light beam to obtain the required light spot shape; when the target groove is a rectangular groove, the specific implementation method of determining the light spot shape required for the target groove type is: shaping the light spot into an asymmetric distribution of the light spot energy curve to obtain the required light spot shape.

4. The method for processing a special-shaped light-guiding microstructure according to claim 3, characterized in that: The ultrafast laser processing system includes a laser, an optical transmission system, a beam modulation module, a galvanometer scanning system, a spot morphology auxiliary detection module and an industrial computer, wherein the spot morphology auxiliary detection module includes a beam quality analyzer; the laser generates ultrafast laser, and the ultrafast laser enters the beam modulation module, the galvanometer scanning system and the spot morphology auxiliary detection module in sequence through the optical transmission system; the spot morphology auxiliary detection module implements feedback of the beam modulation state to the industrial computer; the industrial computer outputs a modulation signal to the beam modulation module according to the real-time feedback of the beam modulation state to realize a specific spot state; the industrial computer controls the galvanometer scanning system to complete the processing of the target groove type.

5. The method for processing a special-shaped light-guiding microstructure according to claim 4, characterized in that: The specific implementation method of step 2) is: use the beam modulation module of the ultrafast laser processing system to perform beam phase shaping, detect the spot shape through the beam quality analyzer of the spot shape auxiliary detection module, perform online closed-loop testing, and finally modulate the spot shape that meets the determination in step 1).

6. The method for processing a special-shaped light-guiding microstructure according to claim 5, characterized in that: When the target slot is a rectangular slot, the specific implementation method of step 3) is: a.1) Control the groove depth and length by controlling the power of the ultrafast laser; a.2) Set the processing trajectory of the rectangular groove, determine the spot energy distribution and spot length through the beam modulation module of the ultrafast laser processing system, adjust the groove width and inner wall angle through the beam modulation module, and optimize the groove roughness through the beam modulation module, and finally process the target groove shape that is approximately a rectangular groove.

7. The method for processing a special-shaped light-guiding microstructure according to claim 6, characterized in that: The specific implementation method of optimizing the groove roughness through the beam modulation module is: adjusting the power of the ultrafast laser through the beam modulation module to optimize the smoothness of the energy step.

8. The method for processing a special-shaped light-guiding microstructure according to claim 7, characterized in that: When the target groove is a crescent groove, the specific implementation method of step 3) is: b.1) machining the microgrooves by setting different focal positions, detecting the angle of the inner wall of the microgrooves, and preliminarily determining the machining focus; the machining focus is the Z-axis coordinate corresponding to the minimum focus spot; b.2) adjusting the ultrafast laser fundamental frequency and power based on the processing focus obtained in step b.1); b.3) based on the ultrafast laser fundamental frequency and power obtained in step b.2), setting the processing trajectory, processing the microgrooves, measuring the inner wall angle of the actual microgrooves, and adjusting the overlap rate according to the inner wall angle; b.4) Based on the result obtained in step b.3), the processing speed is set, the roughness of the micro-groove is measured, and the laser parameters and the galvanometer scanning parameters of the ultrafast laser processing system are continuously optimized, and finally a target groove shape similar to a crescent groove is formed by processing.

9. The method for processing a special-shaped light-guiding microstructure according to claim 8, characterized in that: The machining track in step b.3) is formed by gradually moving from the outside of the crescent groove to the inside in a spiral manner.

10. The method for processing a special-shaped light-guiding microstructure according to claim 9, characterized in that: When the target groove is a rectangular groove, the machining trajectory of the rectangular groove in step b.2) is formed by a single linear reciprocating motion.

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