Laser direct writing printing method and device for three-dimensional array printing system based on rotating mirror

Abstract

The present invention discloses a laser direct writing printing method for a three-dimensional array printing system based on a rotating mirror, comprising: selecting a line segment with uniform thickness and continuity from a straight line written based on a maximum writing length as the effective writing length of the rotating mirror; calculating a single movement distance of the printing platform according to preset printing parameters and the effective writing length; generating one or more two-dimensional writing data files that are continuously and vertically distributed on the scanning plane of the rotating mirror according to the preset printing parameters, the effective writing length and the single movement distance; inputting the two-dimensional writing data file into the three-dimensional array printing system according to the preset writing power, and cyclically outputting the writing material on the printing platform through the writing laser to obtain an array printout corresponding to the three-dimensional structure. The present invention also provides a laser direct writing printing method. The method provided by the present invention can effectively solve the problem of excessive time consumption in the actual three-dimensional writing process.

Description

Technical Field

[0001] The present invention relates to the technical field of direct writing lithography, and in particular to a laser direct writing printing method and device of a three-dimensional array printing system based on a rotating mirror. Background Art

[0002] 3D laser printing technology is a general term for a type of "additive manufacturing" technology that prints three-dimensional objects by adding materials layer by layer. Its core principle is: "layered manufacturing, layer by layer stacking."

[0003] The process of 3D printing is usually: first modeling through computer-aided design (CAD) or computer animation modeling software, designing the structure to be printed, then slicing the built 3D model into layer-by-layer sections according to the designed algorithm, and then extracting the data of a single plane and importing the data into the 3D printing device. According to the data coordinates and other information of the 3D slices, each moving device works together to print layer by layer. Compared with the previous "subtractive manufacturing", 3D laser printing technology integrates mechanical, material, optical, communication and control technologies, and has the advantages of reducing system R&D cycle, reducing R&D costs and printing any complex shape structure in one piece. At present, 3D printing technology is increasingly used in all aspects of society and life, and has been widely used in aerospace technology, international space, electronics industry, automobile industry, housing construction and pharmaceutical preparation.

[0004] Patent document CN115639729A discloses a fiber parallel laser direct writing method and system based on holographic phase beam splitting. This method injects a horizontally polarized laser into the liquid crystal element of the spatial light modulator, modulates the incident laser according to the loaded holographic phase diagram to generate a first beam array arranged in space according to the design requirements, couples the first beam array into the fiber array, and obtains parallel lasers after focusing the light emitted by the fiber array. The parallel lasers are used to perform laser direct writing on the object to be processed. Although this method can effectively improve the direct writing speed and resolution, it is limited by the scanning distance of the galvanometer, so that the volume of the direct writing print cannot be too large.

[0005] Patent document CN114415481A discloses a writing method and device of a laser direct writing system based on a rotating mirror, the method comprising: constructing a fitting relationship between optical power and the input voltage of an acousto-optic modulator; obtaining the optical power distribution in the effective area scanned by the rotating mirror; determining the single writing field of view range according to the predetermined writing optical power and the optical power distribution; dividing the file to be written according to the single writing field of view range to obtain at least one sub-file; performing grayscale compensation correction on the sub-file to obtain a writing data file; performing coordinate transformation on the initial position coordinates of the row of each writing data file according to the deflection angle of the writing direction; and performing writing using a laser direct writing system based on a rotating mirror according to the transformed initial position coordinates of the row and the fitting relationship. The method discloses a writing system based on a rotating mirror and the principle of writing, but how to solve the problem of three-dimensional array printing is not mentioned in the article. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a laser direct writing printing method of a three-dimensional array printing system based on a rotating mirror, which can effectively solve the problem of excessive time consumption in the actual three-dimensional engraving process.

[0007] A laser direct writing printing method of a three-dimensional array printing system based on a rotating mirror, the three-dimensional array printing system comprising a light source component for providing laser, a rotating mirror, a scanning component consisting of a scanning lens, a scene and a dichroic mirror, an objective lens and a printing platform for fixing a writing material and an analog digital output card for controlling the laser intensity;

[0008] The laser emitted by the light source assembly is reflected by the rotating mirror to be a writing laser scanning in the x-axis direction, and then projected to the scanning assembly to converge the writing laser to the dichroic mirror through the scanning lens and the field lens. The dichroic mirror refracts the converged writing laser into the objective lens, and the writing laser is projected onto the writing material on the printing platform through the objective lens;

[0009] The laser direct writing printing method comprises the following steps:

[0010] The maximum writing length of a single-line scan of the rotating mirror is obtained, and a continuous line segment with uniform thickness is selected from the straight line written based on the maximum writing length as the effective writing length of the rotating mirror.

[0011] The single movement distance of the printing platform is calculated based on the preset printing parameters and the effective writing length obtained in step 1. The preset printing parameters include the size of the preset array, the size of a single writing structure in the array, and the spacing between adjacent writing structures in the array.

[0012] Based on the preset printing parameters, effective engraving length and single moving distance, the three-dimensional structure to be printed is cut into layers to generate one or more two-dimensional engraving data files that are continuously distributed vertically on the scanning plane of the rotating mirror.

[0013] According to the preset engraving power, one or more two-dimensional engraving data files are input into the three-dimensional array printing system, and the engraving material on the printing platform is cyclically output by the engraving laser to obtain the array print corresponding to the three-dimensional structure.

[0014] The method provided by the present invention generates corresponding two-dimensional engraving data by presetting printing parameters, effective engraving length and single movement distance of the printing platform, and repeatedly outputs the engraving data according to the corresponding engraving position, so that only a single three-dimensional structure needs to be analyzed, which greatly saves the time-consuming analysis of the entire structure compared to the traditional engraving process.

[0015] Preferably, the three-dimensional array printing system further comprises a writing observation component, including: a camera, an illumination light source, an aperture, a focusing lens, an equal-proportional beam splitter and an imaging lens;

[0016] The illumination light emitted by the illumination light source is projected onto the focusing lens through the aperture and converted into parallel light. The parallel light is then reflected by the proportional beam splitter and focused into the entrance pupil of the objective lens. The image of the writing material within the field of view of the objective lens is obtained through the camera, so as to effectively monitor the changes of the printed part during the printing process, thereby avoiding reducing the printing waste rate.

[0017] Preferably, during printing, the structure printing in the z-axis direction is completed by adjusting the offset of the objective lens focal length, thereby simplifying the position calibration work of the structure writing process perpendicular to the scanning direction of the rotating mirror.

[0018] Specifically, the printing platform includes an air bearing displacement stage that can move along the y-axis direction and a piezoelectric displacement stage installed on the air bearing displacement stage and can be adjusted in the z-axis direction. The writing material is placed on the piezoelectric displacement stage, and the height of the piezoelectric displacement stage is adjusted to meet the printing requirements of different sizes.

[0019] Specifically, the calculation process of the single moving distance according to the effective writing length and the preset printing parameters is as follows:

[0020] When the effective writing length is greater than the plane length of a single writing structure and less than the sum of the plane length of a single writing structure and the spacing between adjacent writing structures, the single moving distance is the sum of the effective writing length and the spacing between adjacent writing structures;

[0021] When the effective writing length is divisible by the sum of the plane length of a single writing structure and the spacing between adjacent writing structures, the single displacement distance is the effective writing length;

[0022] When the effective writing length cannot be divided by the sum of the plane length of a single writing structure and the spacing between adjacent writing structures, the single displacement distance is the maximum multiple of the sum of the plane length of a single writing structure and the spacing between adjacent writing structures within the allowable range of the effective writing length.

[0023] Specifically, the specific process in step 3 is as follows:

[0024] Within the effective writing length range, the three-dimensional structure is segmented along a direction perpendicular to the scanning plane of the rotating mirror to obtain corresponding continuous two-dimensional plane images;

[0025] The two-dimensional plane image is converted into a pixel value data matrix, and all pixel data matrices are filled according to preset printing parameters and a single moving distance to obtain a two-dimensional writing data file with a uniform matrix size.

[0026] Specifically, the filling is performed by supplementing zero matrix data into the pixel data matrix so that the length of the pixel data matrix along the scanning direction of the rotating mirror is consistent with the effective writing length.

[0027] Specifically, in step 4, the writing power is calculated by power cycling according to the preset initial power, the single replenishment power and the number of power steps. The specific process of the power cycling is as follows:

[0028] Step 1: Set the initial power, single step power and number of power steps;

[0029] Step 2, importing the two-dimensional writing data file to be printed into the three-dimensional array printing system, and printing a single three-dimensional structure using the initial writing power set in step 1;

[0030] Step 3: After completing a writing operation, the power consumption and time consumption of the entire writing process are recorded, and according to the single step power and the number of power steps, the current power of the three-dimensional array printing system is adjusted to obtain an updated power;

[0031] Step 4, using the updated power obtained in step 3 to write through the three-dimensional array printing system, and recording the power consumption and time consumption of the whole writing process;

[0032] Step 5, repeat step 3 to step 4 until the power step times are completed and the writing power set is obtained;

[0033] Step 6: Filter the first one third of the writing power set with the shortest time consumption, and select the writing power with the lowest power consumption during the entire writing process from the screening results as the final writing power of the three-dimensional array printing system.

[0034] Specifically, in step 3, the adjustment expression formula of the current power is as follows: ; In the formula, Indicates the current power. Indicates the single replenishment power. Indicates the number of power steps, Indicates the update power.

[0035] Specifically, the writing material includes photoresist, glass and silicon substrate.

[0036] The present invention also provides a laser direct writing printing device, including a memory, one or more processors and a three-dimensional array printing system, for implementing the above-mentioned laser direct writing printing method of the three-dimensional array printing system based on a rotating mirror, and the specific steps are as follows:

[0037] A three-dimensional structure to be printed is obtained, and after the three-dimensional array printing system and the three-dimensional structure to be printed are processed by the laser direct writing printing method, the three-dimensional structure to be printed is printed by the three-dimensional array printing system to obtain an array printout corresponding to the three-dimensional structure to be printed.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The present invention processes the three-dimensional structure to be printed to generate a two-dimensional engraving data file, calculates the engraving position of each engraving structure according to the array size and the single field of view scanning range, only needs to parse the data once, and repeatedly outputs the data at different positions, thereby realizing array printing of the three-dimensional structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A flow chart of the laser direct writing printing method provided by the present invention;

[0041] Figure 2 A schematic diagram of a system device provided in this embodiment;

[0042] Figure 3 A schematic diagram of the scanning direction of the rotating mirror and the moving direction of the printing platform provided in this embodiment;

[0043] Figure 4 A schematic diagram of the rotating mirror waveform provided in this embodiment;

[0044] Figure 5 A schematic diagram of a result of a three-dimensional array printing system provided in this embodiment;

[0045] In the figure, 1, 780nm femtosecond laser; 2, 780nm half-wave plate; 3, first reflector; 4, second reflector; 5-6, diffraction grating; 7, roof reflector; 8, reflector; 9, first 4f beam expander lens; 10, second 4f beam expander lens; 11, third reflector; 12, fourth reflector; 13, 780nm spatial light modulator; 14, reflector; 15, lens; 16, 780nm multi-channel acousto-optic modulator; 17. Lens; 18. Dichroic mirror; 19. Image rotator; 20. Reflector; 21. Rotating mirror; 22. Scanning lens; 23. Field lens; 24. Dichroic mirror; 25. High NA objective lens; 26. Photoresist sample; 27. Piezoelectric translation stage; 28. Air bearing translation stage; 29. ​​Imaging lens; 30. Proportional beam splitter; 31. Condenser lens; 32. Aperture; 33. Illumination source; 34. Camera; 35. Analog digital output card. DETAILED DESCRIPTION

[0046] In order to better explain the purpose of the present invention and specific implementation methods, the present invention will be further described in detail below in conjunction with implementation examples and accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Those skilled in the art can make modifications or equivalent substitutions based on the understanding of the technical solution of the present invention, and the principles of the technical solution of the present invention should be included in the protection scope of the present invention.

[0047] A laser direct writing printing method of a three-dimensional array printing system based on a rotating mirror comprises the following steps:

[0048] According to the maximum writing length of a single line scan of the rotating mirror, the voltage is controlled so that the rotating mirror can write lines on the photoresist, the thickness of the lines is measured, and a relatively continuous length with uniform thickness is selected as the effective scanning length of the rotating mirror.

[0049] In order to easily calculate the engraving data and the moving position of the translation stage during the actual engraving process, values ​​such as 100um and 150um can usually be selected as the effective scanning length of the rotating mirror.

[0050] According to the preset printing parameters and the effective writing length obtained in step 1, the single movement distance of the printing platform is calculated, wherein the specific calculation process of the single displacement distance is as follows:

[0051] When the effective writing length is greater than the plane length of a single writing structure and less than the sum of the plane length of a single writing structure and the spacing between adjacent writing structures, the single moving distance is the sum of the effective writing length and the spacing between adjacent writing structures;

[0052] When the effective writing length is divisible by the sum of the plane length of a single writing structure and the spacing between adjacent writing structures, the single displacement distance is the effective writing length;

[0053] When the effective writing length cannot be divided by the sum of the plane length of a single writing structure and the spacing between adjacent writing structures, the single displacement distance is the maximum multiple of the sum of the plane length of a single writing structure and the spacing between adjacent writing structures within the allowable range of the effective writing length.

[0054] In this embodiment, the planar processing size of the three-dimensional array structure can be 10cm*10cm, and the planar size of a single three-dimensional structure is about 150um*150um.

[0055] Based on the preset printing parameters, effective engraving length and single moving distance, the three-dimensional structure to be printed is cut into layers to generate one or more two-dimensional engraving data files that are continuously distributed vertically on the scanning plane of the rotating mirror.

[0056] According to the preset writing power, the writing data file is input into the three-dimensional array printing system, and the writing material on the printing platform is cyclically output by the writing laser to obtain the corresponding three-dimensional array printout, wherein the writing power is selected as follows:

[0057] Step 1: Set the initial power, single step power and number of power steps;

[0058] Step 2: import the single three-dimensional structure data to be printed into the three-dimensional array printing system, and perform writing using the initial writing power set in step 1;

[0059] Step 3: After completing a writing operation, the power consumption and time consumption of the entire writing process are recorded, and according to the single step power and the number of power steps, the current power of the three-dimensional array printing system is adjusted to obtain an updated power;

[0060] Step 4, using the updated power obtained in step 3 to write through the three-dimensional array printing system, and recording the power consumption and time consumption of the whole writing process;

[0061] Step 5, repeat step 3 to step 4 until the power step times are completed and the writing power set is obtained;

[0062] Step 6: Filter the first one third of the writing power set with the shortest time consumption, and select the writing power with the lowest power consumption during the entire writing process from the screening results as the final writing power of the three-dimensional array printing system.

[0063] like Figure 2 The three-dimensional array printing system provided in this embodiment has the following specific working process:

[0064] The 780nm femtosecond laser 1 (writing light laser) generates a beam of 780nm femtosecond laser, which is adjusted in polarization direction through the 780nm half-wave plate 2. After the laser direction is adjusted by the first reflector 3 and the second reflector 4, it passes through the diffraction grating 5-6, and then the beam is raised in height by the roof reflector 7, and then returns to the diffraction grating 6-5 along the original path. The reflector 3 is selected as a D-type reflector. The light beam returned from the diffraction grating 5 is reflected by the reflector 4, propagates from the top of the reflector 3 (i.e., passes over the reflector 3), and is reflected by the reflector 8 into the beam expansion lens group 9-10 to complete the beam expansion. The light beam direction is then adjusted by the third reflector 11 and the fourth reflector 12, and then incident on the 780nm spatial light modulator 13. The single light beam is modulated into multiple light beams by loading a hologram on the spatial light modulator 13. After being reflected by the reflector 14, the hologram is Fourier transformed by the lens 15, and multiple focal points are generated at the focal plane of the lens 15.

[0065] The 780nm multi-channel acousto-optic modulator 16 is placed at the focal plane of the lens 15, and each channel passes through a focus to achieve independent modulation of each beam of light. The divergent light is then re-collimated by the lens 17, passes through the dichroic mirror 18, and enters the image rotator 19.

[0066] After being modulated by the image rotator 19, the 780nm femtosecond laser enters the rotating mirror 21 after being reflected by the reflector 20. After being reflected by the rotating mirror 21, the multi-beam passes through the scanning lens 22, the field lens 23, and then is reflected by the dichroic mirror 24, and then enters the high NA objective lens 25 and is focused on the photoresist sample 26. The piezoelectric displacement stage 27 and the air bearing displacement stage 28 drive the photoresist sample 26 to perform scanning motion under program control.

[0067] The illumination light source 33 is an LED lamp. The emitted illumination light is converted into parallel light by the focusing lens 31 after passing through the aperture 32, and then reflected by the proportional beam splitter 30, and then passes through the imaging lens 29 and the dichroic mirror 24 in sequence, and is focused to the entrance pupil of the high NA objective lens 25. In addition, the image of the photoresist sample 26 is sequentially imaged by the high NA objective lens 25, the dichroic mirror 24, the imaging lens 29, and the proportional beam splitter 30 to the camera 34 for writing observation.

[0068] When the data to be written at a single time is of m*n structure size, it is only necessary to perform data segmentation in the direction of the rotating mirror scanning, where m represents the number of structures in the direction perpendicular to the rotating mirror scanning, and n represents the number of structures within the effective scanning length range of the rotating mirror in the rotating mirror scanning direction, such as Figure 3 As shown, in the actual engraving process, the horizontal scanning direction of the rotating mirror is perpendicular to the horizontal movement direction of the printing platform, thereby improving the engraving efficiency during a single displacement process.

[0069] If n is a perfect divisor of the number of columns in the array, the stage only needs to move 4 / n times. If n is not a perfect divisor of the number of columns in the array, the stage only needs to move "(4 / n) + 1" times to complete the writing of the entire array.

[0070] When the data is of 4*4 structure size, the traditional galvanometer needs to move 16 times to complete the 4*4 array writing, while the rotating mirror only needs 5 times to complete the 4*4 array writing, which greatly improves the writing efficiency. Figure 4 As shown, this is the waveform diagram of the system's rotating mirror output.

[0071] like Figure 5 The following is a schematic diagram of the system printout results.

Claims

1. A laser direct writing printing method for a three-dimensional array printing system based on a rotating mirror, It is characterized in that The three-dimensional array printing system includes a rotating mirror, and the laser direct writing printing method includes the following steps: The maximum writing length of a single-line scan of the rotating mirror is obtained, and a continuous line segment with uniform thickness is selected from the straight line written based on the maximum writing length as the effective writing length of the rotating mirror; The single movement distance of the printing platform is calculated according to the preset printing parameters and the effective writing length. The preset printing parameters include the size of the preset array, the size of a single writing structure in the array, and the spacing between adjacent writing structures in the array. The calculation process of the single movement distance according to the effective writing length and the preset printing parameters is as follows: When the effective writing length is greater than the plane length of a single writing structure and less than the sum of the plane length of a single writing structure and the spacing between adjacent writing structures, the single moving distance is the sum of the effective writing length and the spacing between adjacent writing structures; When the effective writing length is divisible by the sum of the plane length of a single writing structure and the spacing between adjacent writing structures, the single displacement distance is the effective writing length; When the effective writing length cannot be divided by the sum of the plane length of a single writing structure and the spacing between adjacent writing structures, the single displacement distance is the maximum multiple of the sum of the plane length of a single writing structure and the spacing between adjacent writing structures within the allowable range of the effective writing length; Based on the preset printing parameters, effective writing length and single moving distance, the three-dimensional structure to be printed is cut into layers to generate one or more two-dimensional writing data files that are continuously and vertically distributed on the scanning plane of the rotating mirror; According to the preset writing power, one or more two-dimensional writing data files are input into the three-dimensional array printing system, and the writing material on the printing platform is cyclically output by the writing laser to obtain the array print corresponding to the three-dimensional structure. The writing power is calculated by power cycling according to the preset initial power, single replenishment power and power step number. The specific process of the power cycling is as follows: Step 1: Set the initial power, single step power and number of power steps; Step 2, importing the two-dimensional writing data file to be printed into the three-dimensional array printing system, and printing a single three-dimensional structure using the initial writing power set in step 1; Step 3: After completing a writing operation, the power consumption and time consumption of the entire writing process are recorded, and according to the single step power and the number of power steps, the current power of the three-dimensional array printing system is adjusted to obtain an updated power; Step 4, using the updated power obtained in step 3 to write through the three-dimensional array printing system, and recording the power consumption and time consumption of the whole writing process; Step 5, repeat step 3 to step 4 until the power step times are completed and the writing power set is obtained; Step 6: Filter the first one third of the writing power set with the shortest time consumption, and select the writing power with the lowest power consumption during the entire writing process from the screening results as the final writing power of the three-dimensional array printing system.

2. The laser direct writing printing method of the three-dimensional array printing system based on the rotating mirror according to claim 1, It is characterized in that The generation process of the two-dimensional writing data file is as follows: Within the effective writing length range, the three-dimensional structure is segmented along a direction perpendicular to the scanning plane of the rotating mirror to obtain corresponding continuous two-dimensional plane images; The two-dimensional plane image is converted into a pixel value data matrix, and all pixel data matrices are filled according to preset printing parameters and a single moving distance to obtain a two-dimensional writing data file with a uniform matrix size.

3. The laser direct writing printing method of the three-dimensional array printing system based on the rotating mirror according to claim 2, It is characterized in that The filling is performed by supplementing zero matrix data in the pixel data matrix so that the length of the pixel data matrix along the scanning direction of the rotating mirror is consistent with the effective writing length.

4. The laser direct writing printing method of the rotating mirror-based three-dimensional array printing system according to claim 1, It is characterized in that The three-dimensional array printing system also includes a light source component for providing laser light, a scanning component composed of a scanning lens, a scene and a dichroic mirror, an objective lens, a printing platform for fixing the writing material, and an analog data output card for controlling the laser intensity; The laser emitted by the light source component is reflected by the rotating mirror to become a writing laser scanning in the x-axis direction, and then projected to the scanning component to converge the writing laser to the dichroic mirror through the scanning lens and the field lens. The dichroic mirror refracts the converged writing laser into the objective lens, and the writing laser is projected onto the writing material on the printing platform through the objective lens.

5. The laser direct writing printing method of the three-dimensional array printing system based on the rotating mirror according to claim 4, It is characterized in that The three-dimensional array printing system is provided with a writing observation component, including: a camera, an illumination light source, an aperture, a focusing lens, an equal-proportional beam splitter and an imaging lens; The illumination light emitted by the illumination light source is projected to the focusing lens through the aperture and then converted into parallel light. The parallel light is then reflected by the proportional beam splitter and focused into the entrance pupil of the objective lens. The image of the writing material within the field of view of the objective lens is obtained through the camera.

6. The laser direct writing printing method of the rotating mirror-based three-dimensional array printing system according to claim 5, It is characterized in that During printing, the structure printing perpendicular to the scanning direction of the rotating mirror is completed by adjusting the offset of the objective lens focal length.

7. The laser direct writing printing method of the rotating mirror-based three-dimensional array printing system according to claim 5, It is characterized in that The printing platform comprises an air bearing displacement stage which can move along the y-axis direction and a piezoelectric displacement stage which is mounted on the air bearing displacement stage and can be adjusted in the z-axis direction, and the writing material is placed on the piezoelectric displacement stage.

8. A laser direct writing printing device, It is characterized in that The invention comprises a memory, one or more processors and a three-dimensional array printing system, wherein the memory stores executable codes, and the one or more processors execute the executable codes to implement the laser direct writing printing method of the three-dimensional array printing system based on the rotating mirror according to any one of claims 1 to 7, wherein the specific steps are as follows: obtaining a three-dimensional structure to be printed, processing the three-dimensional array printing system and the three-dimensional structure to be printed by the laser direct writing printing method, and then printing the three-dimensional structure to be printed by the three-dimensional array printing system to obtain an array printout corresponding to the three-dimensional structure to be printed.

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