Micro piezoelectric ceramic laser precision machining method

Abstract

The invention 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, efficient, free of contact machining and good in compatibility. A three-dimensional shape scanning device, a laser height measuring device and a laser processing system are used in the method. The method comprises the following steps: a, performing three-dimensional scanning on the shape of an initial product; b, confirming the laser processing height; c, determining a laser processing position; d, laser processing; and e, confirming the machining size. The method is applied to the technical field of micro piezoelectric ceramic processing.

Description

Technical Field

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

[0002] Piezoelectric ceramics are commonly used devices in the fields of industry, medicine, military and aerospace. They use the piezoelectric effect of piezoelectric ceramics to transmit and receive ultrasonic waves. With the development of science and technology, especially the continuous miniaturization of products in the fields of industry and medical equipment, new requirements have been put forward for the size of piezoelectric ceramics. Not only does the size need to be miniaturized, but the processing accuracy requirements are also getting higher and higher, which has brought challenges to traditional mechanical processing methods.

[0003] Although piezoelectric ceramics have superior properties that other materials cannot match, they also have a significant disadvantage, namely brittleness. In order to achieve the excellent performance that piezoelectric ceramics have, they must be processed into components with certain shape accuracy and dimensional accuracy. However, due to the hardness and brittleness of piezoelectric ceramics, traditional mechanical processing is very difficult, especially to meet high-precision processing. Traditional mechanical processing has great problems in processing efficiency, processing accuracy and yield.

[0004] Taking actual engineering needs 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, and the processing accuracy is ±0.005mm, that is, 5μm. The product size before processing 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, and it is uneven, such as Figure 1 As shown. Traditional machining has the following problems: ① Product clamping and positioning issues. Machining requires the product to be firmly clamped and positioned. However, due to the brittleness and size inconsistency of the product itself, and because all six sides of the product need to be processed, multiple clamping is required, which leads to product edge collapse and fragmentation during the clamping, positioning and processing process, resulting in product defects or scrapping; ② Processing quality issues. Due to the high processing accuracy requirements of the product, mechanical processing is prone to dimensional accuracy problems, resulting in product functional performance failing to achieve the expected results; ③ Processing efficiency issues. Since machining requires multiple clamping and positioning, and the size 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 for operators, which affects efficiency and yield. 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 higher hardness, the consumption of grinding materials is higher than that of general materials, resulting in increased consumables costs. Summary of the invention

[0005] 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 and high efficiency, non-contact processing and good compatibility.

[0006] 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: a. 3D scanning of initial product morphology: Before laser processing, a 3D morphology scanning device is used to perform 3D scanning on the surface to be processed, and the laser processing image is formed by layering according to the preset single laser processing amount; 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 is adjusted according to the feedback height value to ensure that the laser processing focus is on the product surface. Use a laser height measuring device to measure the product size during and after processing to ensure that the size and accuracy requirements are met after processing. c. Determination of laser processing position: 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 image based on the three-dimensional topography and combines the height and position information to process the product once or multiple times; e. Confirmation of processing dimensions: 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 so, the processing is completed, otherwise repeat the above process.

[0007] Furthermore, the three-dimensional shape scanning device is a line scan camera.

[0008] Furthermore, the laser height measuring device is a laser coaxial displacement meter.

[0009] Furthermore, in steps b and e, the measuring range of the laser coaxial displacement meter is one order of magnitude higher than the machining accuracy requirement.

[0010] Furthermore, the processing accuracy of the micro piezoelectric ceramic product reaches ±5μm, the measurement range of the laser coaxial displacement meter is ±1.6mm, and the resolution is 0.25μm.

[0011] Furthermore, the laser processing system includes a laser, an adjustable variable-power 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 emitted by the laser passes through the adjustable variable-power 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.

[0012] Furthermore, the laser is an ultraviolet picosecond laser, and the piezoelectric ceramics are processed by the ultraviolet picosecond laser, and the minimum single processing volume reaches 2μm.

[0013] Furthermore, 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 measuring system and the processing system remain consistent. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the product structure before piezoelectric ceramics processing; Figure 2 It is a schematic diagram of the structure of the laser processing system; Figure 3 It is a processing flow chart of the present invention. DETAILED DESCRIPTION

[0015] like Figure 2 and Figure 3 As shown, in this embodiment, in view of 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: 1. 3D shape scanning device: Before laser processing, a line scan camera is used to perform 3D scanning on the surface to be processed, and the scanning results are used to generate laser processable documents through self-made software; 2. Laser height measurement device: Use a laser coaxial displacement meter to measure the size of the product during and after processing to ensure that the size and accuracy requirements are met after processing; since the product processing accuracy requirement is ±5μm, the displacement meter should be one order of magnitude higher than the processing accuracy 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 size and accuracy processing requirements of the product; 3. Laser processing system: Laser processing system such as Figure 2As shown. The laser processing system comprises a laser 1, an adjustable variable 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 emitted by the laser 1 sequentially passes through the adjustable variable beam expander 2, the beam shaping device 3, the reflector 4, the high-speed high-precision galvanometer 5, and the telecentric lens 6 to process the micro piezoelectric ceramic product 9; a part of the light passing through the reflector 4 enters the coaxial positioning camera 7, and a part enters the high-speed high-precision galvanometer 5.

[0016] 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.

[0017] In this embodiment, the three-dimensional shape 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 measuring system and the processing system remain consistent.

[0018] The effects of the present invention are: 1. Laser processing has high precision, and the single processing volume can reach 2μm; 2. Generate laser processing documents according to 3D topography, automatically locate and process products, simple operation and high efficiency; 3. Laser non-contact processing, no mechanical stress, no product edge collapse or damage; 4. Laser processing is compatible with products of various other shapes and has good compatibility.

[0019] Although the embodiments of the present invention are described with practical solutions, they do not constitute limitations on 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 processing of micro piezoelectric ceramics, which uses a three-dimensional topography scanning device, a laser height measuring device and a laser processing system, and is characterized by: The micro piezoelectric ceramic laser precision processing method comprises the following steps: a. 3D scanning of initial product morphology: Before laser processing, a 3D morphology scanning device is used to perform 3D scanning on the surface to be processed, and the laser processing image is formed by layering according to the preset single laser processing amount; 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 is adjusted according to the feedback height value to ensure that the laser processing focus is on the product surface. Use a laser height measuring device to measure the product size during and after processing to ensure that the size and accuracy requirements are met after processing. c. Determination of laser processing position: 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 image based on the three-dimensional topography and combines the height and position information to process the product once or multiple times; e. Confirmation of processing dimensions: 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 so, 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 scanning 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 measuring 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 variable-power 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) having a processing fixture; a micro piezoelectric ceramic product (9) is placed on the processing fixture on the precision motion platform (8); laser light emitted by the laser (1) passes through the adjustable variable-power 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 to process 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).

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. When the ultraviolet picosecond laser is used to process piezoelectric ceramics, the minimum single processing volume reaches 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 measuring system and the processing system remain consistent.

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