Miniature piezoelectric ceramic laser precision machining method

Abstract

The application discloses a micro piezoelectric ceramic laser precision machining method, and aims to provide a micro piezoelectric ceramic laser precision machining method which is high in machining precision, simple and efficient, non-contact, and good in compatibility. The application uses a three-dimensional appearance scanning device, a laser height measuring device and a laser machining system, and comprises the following steps: a, three-dimensional scanning of initial product appearance; b, laser machining height confirmation; c, laser machining position determination; d, laser machining; and e, machining size confirmation. The application is applied to the technical field of machining micro piezoelectric ceramics.

Description

Technical Field

[0001] The present invention relates to a piezoelectric ceramic processing method, and in particular to a micro piezoelectric ceramic laser precision processing method. Background Art

[0002] Piezoelectric ceramics are commonly used in industrial, medical, military, and aerospace applications. They utilize the piezoelectric effect to transmit and receive ultrasonic waves. Advances in science and technology, particularly the continued miniaturization of products in industrial and medical equipment, have placed new demands on the size of piezoelectric ceramics. These demands not only minimize their size but also increase the precision required for machining, posing challenges to traditional machining methods.

[0003] While piezoelectric ceramics offer unmatched performance compared to other materials, they also suffer from a significant drawback: brittleness. To realize their exceptional performance, piezoelectric ceramics must be processed into components with precise shape and dimensional accuracy. However, due to their hardness and brittleness, traditional machining is challenging, especially for high-precision machining. Traditional machining presents significant challenges in terms of efficiency, accuracy, and yield.

[0004] Taking actual engineering requirements as an example, a piezoelectric ceramic product is required to be processed into a rectangular parallelepiped with an outer dimension of 3.5mm x 1.2mm x 0.9mm, with a processing accuracy of ±0.005mm, or 5μm. Before processing, the product size is slightly larger by 0.2-0.5mm. Due to the shrinkage of ceramic sintering, the size of each product is different, and the surface flatness is poor, with unevenness, such as Figure 1 As shown. Traditional machining has the following problems:

[0005] ① Product clamping and positioning issues. Machining requires secure clamping and positioning of the product. However, due to the inherent brittleness and dimensional inconsistency of the product, and the fact that all six sides of the product need to be machined, multiple clamping steps are required. This can lead to edge collapse and cracking during the clamping, positioning, and machining process, resulting in defective or scrapped products.

[0006] ②Processing quality issues: Due to the high processing precision requirements of the product, dimensional accuracy deviations are prone to occur during machining, resulting in product functional performance failing to achieve the expected results;

[0007] ③Processing efficiency issues. Since machining requires multiple clamping and positioning, and the dimensions and processing status need to be repeatedly measured during the machining process, the production efficiency is low. At the same time, precision machining requires a high level of technical skills from the operators, which affects efficiency and yield.

[0008] ④ Cost of consumables. Grinding materials will be continuously consumed during product machining and need to be replaced regularly. Since ceramic materials themselves have a high hardness, the consumption of grinding materials is higher than that of general materials, resulting in increased consumables costs. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a micro piezoelectric ceramic laser precision processing method with high processing accuracy, simplicity, high efficiency, non-contact processing and good compatibility.

[0010] The technical solution adopted by the present invention is: the present invention uses a three-dimensional topography scanning device, a laser height measuring device and a laser processing system, and the micro piezoelectric ceramic laser precision processing method includes the following steps:

[0011] a. Initial product morphology 3D scanning: Before laser processing, a 3D morphology scanning device is used to perform a 3D scan of the surface to be processed, and the laser processing file is formed by layering according to the preset single laser processing volume;

[0012] b. Confirmation of laser processing height: Use a laser height measuring device to measure the initial processing height of the product. The laser processing system adjusts according to the height value fed back to ensure that the laser processing focus is on the product surface. Use the laser height measuring device to measure the product dimensions during and after processing to ensure that the dimensions and accuracy requirements are met after processing.

[0013] c. Laser processing position determination: The coaxial positioning camera of the laser processing system locates the product and transmits the positioning information to the laser processing system. The laser processing system determines the processing position based on the positioning information.

[0014] d. Laser processing: The laser generates a processing file based on the three-dimensional topography and combines the height and position information to process the product once or multiple times;

[0015] e. Processing size confirmation: The laser height measuring device measures the product height and compares it with the initial value to see whether it meets the preset processing requirements. If it does, the processing is completed, otherwise repeat the above process.

[0016] Furthermore, the three-dimensional topography scanning device is a line scan camera.

[0017] Furthermore, the laser height measuring device is a laser coaxial displacement meter.

[0018] Furthermore, in steps b and e, the measurement range of the laser coaxial displacement meter is one order of magnitude higher than the machining accuracy requirement.

[0019] Furthermore, the processing accuracy of micro piezoelectric ceramic products reaches ±5μm, the measurement range of the laser coaxial displacement meter is ±1.6mm, and the resolution is 0.25μm.

[0020] Furthermore, the laser processing system includes a laser, an adjustable zoom beam expander, a beam shaping device, a reflector, a high-speed and high-precision galvanometer, a telecentric lens, a coaxial positioning camera and a precision motion platform with a processing fixture; the miniature piezoelectric ceramic product is placed on the processing fixture on the precision motion platform; the laser light emitted by the laser passes through the adjustable zoom beam expander, the beam shaping device, the reflector, the high-speed and high-precision galvanometer, and the telecentric lens in sequence to process the miniature piezoelectric ceramic product; part of the light passing through the reflector enters the coaxial positioning camera, and part enters the high-speed and high-precision galvanometer.

[0021] Furthermore, the laser is an ultraviolet picosecond laser, and when the piezoelectric ceramics are processed using the ultraviolet picosecond laser, the minimum single processing volume reaches 2 μm.

[0022] Furthermore, the three-dimensional profile scanning device, the laser height measuring device and the laser galvanometer processing head of the laser processing system are installed on the same fixed component to ensure that the benchmarks of the measurement system and the processing system remain consistent. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the product structure before piezoelectric ceramic processing;

[0024] Figure 2 It is a structural diagram of the laser processing system;

[0025] Figure 3 It is a processing flow chart of the present invention. DETAILED DESCRIPTION

[0026] like Figure 2 and Figure 3 As shown, in this embodiment, in order to solve these problems existing in traditional mechanical processing, a method for laser processing of micro piezoelectric ceramic components using an ultrafast laser is proposed. The overall system consists of the following parts:

[0027] 1. 3D topography scanning device: Before laser processing, a line scan camera is used to perform a 3D scan of the surface to be processed, and the scanning results are used to generate laser-processable documents through self-made software;

[0028] 2. Laser height measurement device: A laser coaxial displacement meter is used to measure the product dimensions during and after processing to ensure that the product meets the dimensional and precision requirements after processing. Since the product processing precision must reach ±5μm, the displacement meter selected must be an order of magnitude higher than the processing precision requirement. The displacement meter selected in this solution has a measurement range of ±1.6mm and a resolution of 0.25μm, which can meet the product's dimensional and precision processing requirements.

[0029] 3. Laser processing system: Laser processing system such as Figure 2 As shown. The laser processing system includes a laser 1, an adjustable variable-magnification beam expander 2, a beam shaping device 3, a reflector 4, a high-speed, high-precision galvanometer 5, a telecentric lens 6, a coaxial positioning camera 7, and a precision motion platform 8 with a processing fixture. A micro piezoelectric ceramic product 9 is placed on the processing fixture on the precision motion platform 8. The laser light emitted by the laser 1 passes through the adjustable variable-magnification beam expander 2, the beam shaping device 3, the reflector 4, the high-speed, high-precision galvanometer 5, and the telecentric lens 6 in sequence, and then processes the micro piezoelectric ceramic product 9. A portion of the light passing through the reflector 4 enters the coaxial positioning camera 7, and a portion enters the high-speed, high-precision galvanometer 5.

[0030] In this embodiment, an ultraviolet picosecond laser is used to process piezoelectric ceramics. By adjusting the process parameters, the minimum single processing volume can reach 2 μm.

[0031] In this embodiment, the three-dimensional profile scanning device, the laser height measuring device and the laser galvanometer processing head are installed on the same fixed component to ensure that the benchmarks of the measurement system and the processing system remain consistent.

[0032] The present invention has the following effects:

[0033] 1. Laser processing has high precision, and the single processing volume can reach 2μm;

[0034] 2. Generate laser processing documents according to 3D topography and automatically locate the processed products, with simple operation and high efficiency;

[0035] 3. Laser non-contact processing, no mechanical stress, no product edge collapse or damage;

[0036] 4. Laser processing is compatible with products of various other shapes and has good compatibility.

[0037] Although the embodiments of the present invention are described with practical solutions, they do not limit the meaning of the present invention. For those skilled in the art, it is obvious to modify the implementation scheme and combine it with other solutions based on this description.

Claims

1. A method for laser precision machining of micro piezoelectric ceramics, which utilizes a three-dimensional topography scanning device, a laser height measurement device, and a laser machining system, and is characterized by: The micro piezoelectric ceramic laser precision processing method comprises the following steps: a. Initial product morphology 3D scanning: Before laser processing, a 3D morphology scanning device is used to perform a 3D scan of the surface to be processed, and the laser processing image file is formed by layering according to the preset single laser processing volume; b. Confirmation of laser processing height: Use a laser height measuring device to measure the initial processing height of the product. The laser processing system adjusts according to the height value fed back to ensure that the laser processing focus is on the product surface. Use the laser height measuring device to measure the product dimensions during and after processing to ensure that the dimensions and accuracy requirements are met after processing. c. Laser processing position determination: The coaxial positioning camera of the laser processing system locates the product and transmits the positioning information to the laser processing system. The laser processing system determines the processing position based on the positioning information. d. Laser processing: The laser generates a processing file based on the three-dimensional topography and combines the height and position information to process the product once or multiple times; e. Processing size confirmation: The laser height measuring device measures the product height and compares it with the initial value to see whether it meets the preset processing requirements. If it does, the processing is completed, otherwise repeat the above process.

2. The method for laser precision machining of micro piezoelectric ceramics according to claim 1, characterized in that: The three-dimensional shape scanning device is a line scan camera.

3. The method for laser precision machining of micro piezoelectric ceramics according to claim 1, characterized in that: The laser height measuring device is a laser coaxial displacement meter.

4. The method for laser precision machining of micro piezoelectric ceramics according to claim 3, characterized in that: In steps b and e, the measurement range of the laser coaxial displacement meter is one order of magnitude higher than the machining accuracy requirement.

5. The method for laser precision machining of micro piezoelectric ceramics according to claim 4, characterized in that: The processing accuracy of micro piezoelectric ceramic products reaches ±5μm, the measurement range of the laser coaxial displacement meter is ±1.6mm, and the resolution is 0.25μm.

6. The method for laser precision machining of micro piezoelectric ceramics according to claim 1, characterized in that: The laser processing system comprises a laser (1), an adjustable zoom beam expander (2), a beam shaping device (3), a reflector (4), a high-speed and high-precision galvanometer (5), a telecentric lens (6), a coaxial positioning camera (7) and a precision motion platform (8) with a processing fixture; a micro piezoelectric ceramic product (9) is placed on the processing fixture on the precision motion platform (8); the laser light emitted by the laser (1) passes through the adjustable zoom beam expander (2), the beam shaping device (3), the reflector (4), the high-speed and high-precision galvanometer (5) and the telecentric lens (6) in sequence to process the micro piezoelectric ceramic product (9); part of the light passing through the reflector (4) enters the coaxial positioning camera (7), and part enters the high-speed and high-precision galvanometer (5).

7. The method for laser precision machining of micro piezoelectric ceramics according to claim 6, characterized in that: The laser (1) is an ultraviolet picosecond laser, and the ultraviolet picosecond laser is used to process piezoelectric ceramics, with the minimum single processing volume reaching 2 μm.

8. The method for laser precision machining of micro piezoelectric ceramics according to claim 1, characterized in that: The three-dimensional shape scanning device, the laser height measuring device and the laser galvanometer processing head of the laser processing system are installed on the same fixed component to ensure that the benchmarks of the measurement system and the processing system are consistent.

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