Elliptical ultrasonic vibration auxiliary machining device and method for scanning probe

Abstract

The invention relates to an elliptical ultrasonic vibration auxiliary machining device and method for a scanning probe, and belongs to the technical field of micro-nano machining. The vibration table comprises a vibration table head and two sets of variable-amplitude flexible hinges, the vibration table head is used for fixing a sample, and the two sets of variable-amplitude flexible hinges are distributed on the two sides of the vibration table head at 90 degrees and used for amplifying resonance deformation; the two groups of vibration generation modules are respectively contacted with the two groups of variable-amplitude flexible hinges and are used for applying excitation signals with the same frequency, the same amplitude and different phases and exciting X-direction resonance and Y-direction resonance of a vibration table in an ultrasonic frequency band, so that a sample generates ultrasonic elliptical resonance in an XY plane, and a larger amplitude can be obtained under a relatively small working frequency; furthermore, elliptical vibration of an ultrasonic frequency band is generated at a sample end, the chip discharging behavior and the machining quality are improved, the normal force during machining is reduced, probe abrasion is reduced, and the service life of the probe during hard material machining is prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of micro-nano processing, and particularly relates to an elliptical ultrasonic vibration-assisted processing device and method for a scanning probe. Background Art

[0002] With the rapid development of technologies such as integrated circuits, micro-electromechanical systems, and optoelectronic devices, higher and higher requirements are put forward for the processing accuracy and surface quality of micro-nano scale structures. The scanning probe processing method is widely used in fields such as nano-indentation, nano-scratching, local oxidation, and micro-structure processing due to its extremely high resolution and controllability. However, traditional scanning probe processing mainly relies on a uniaxial (usually vertical) loading method, and there are still certain limitations in terms of material removal efficiency, surface topography control, and probe life. Especially when facing the processing task of high-hardness materials, its processing ability urgently needs to be improved.

[0003] In recent years, ultrasonic vibration-assisted processing technology has shown significant advantages in the micro-processing of hard and brittle materials. By superimposing tiny vibrations at ultrasonic frequencies on the tool or workpiece, the cutting force can be effectively reduced, the processing stress concentration can be decreased, the chip evacuation can be improved, and the tool life can be extended. Especially the two-dimensional ultrasonic elliptical vibration method, by introducing high-frequency vibrations with a phase difference regulation in two orthogonal directions, makes the relative trajectory between the tool and the workpiece elliptical, and can achieve periodic cutting-separation behavior at the sub-micron or even nano scale, which is helpful for the fine control of material fracture and removal behavior.

[0004] However, at present, elliptical ultrasonic vibration processing systems are mostly applied to the macro scale or traditional machine tool structures. The working frequency of the existing elliptical vibration devices for scanning probe processing systems is only several hundred Hz, which limits the improvement of processing efficiency and cutting performance. There is still a lack of a compact two-dimensional ultrasonic elliptical vibration platform suitable for the scanning probe scale. How to effectively integrate ultrasonic vibration-assisted processing with the high-resolution displacement control ability of scanning probes and achieve adjustable and stable elliptical vibration trajectories at the nano scale is the current technical bottleneck in this field. Summary of the Invention

[0005] The purpose of the present invention is to provide an elliptical ultrasonic vibration-assisted processing device and method for a scanning probe to solve problems such as the lack of a suitable ultrasonic elliptical vibration platform in the existing scanning probe processing system.

[0006] To achieve the above purpose, the technical solution of the present invention is as follows: The present invention relates to an elliptical ultrasonic vibration-assisted machining device for a scanning probe, which comprises a vibration table and two sets of vibration generating modules; the vibration table includes a vibration table head and two sets of amplitude-changing flexible hinges, the vibration table head is used for fixing a sample, and the two sets of amplitude-changing flexible hinges are distributed on both sides of the vibration table head at an angle of 90° for amplifying resonance deformation; the two sets of vibration generating modules are respectively in contact with the two sets of amplitude-changing flexible hinges, and are used for applying excitation signals with the same frequency, the same amplitude and different phases, and exciting the vibration table to resonate in the X and Y directions in the ultrasonic frequency band, so that the sample generates ultrasonic elliptical resonance in the XY plane.

[0007] Preferably, each of the vibration generating modules includes a piezoelectric ceramic sheet, an electrode sheet and a fixing hinge; the fixing hinge corresponds to the amplitude-changing flexible hinge and is used for clamping the piezoelectric ceramic sheet and the electrode sheet between the corresponding fixing hinge and amplitude-changing flexible hinge; the electrode sheet is arranged between the positive and negative plates of the piezoelectric ceramic sheet and is used for inputting a signal to the positive electrode of the ceramic sheet, and the piezoelectric ceramic sheet is used for receiving the signal and exciting the vibration mode of the vibration generating module.

[0008] Preferably, each of the vibration generating modules further includes a counterweight block, and the counterweight block is fixed on the corresponding fixing hinge through a connecting stud for adjusting the difference in resonance frequencies in the X and Y directions; the connecting stud penetrates through the fixing hinge and presses the piezoelectric ceramic sheet against the amplitude-changing flexible hinge.

[0009] Preferably, a sample balance block is further arranged on the bottom surface of the vibration table for balancing the mass distribution of the vibration table after installing the sample, so that the mass distribution of the vibration table is symmetric with respect to the XY plane.

[0010] Preferably, it further includes a base and a support plate, the vibration generating module is arranged on the base, the support plate is arranged on the base through an adjusting screw, the vibration table is arranged on the support plate, and the support plate is used for providing auxiliary support for the vibration table and finely adjusting the height and tilt angle of the vibration table.

[0011] Preferably, the cross-sectional shape of the amplitude-changing flexible hinge is an asymmetric trapezoid.

[0012] The present invention also relates to an elliptical ultrasonic vibration-assisted machining method for a scanning probe, which includes the following steps: S1. Fix the sample and the sample balance block on the top surface and the bottom surface of the vibration table head respectively. S2. Apply excitation signals with the same frequency, the same amplitude and different phases to the two sets of vibration generating modules, amplify the vibration through the amplitude-changing flexible hinges, and excite the vibration table to resonate in the X and Y directions in the ultrasonic frequency band, so that the sample generates ultrasonic elliptical resonance in the XY plane. S3. According to the processing requirements, change the amplitudes and phases of the excitation signals input to the two vibration generation modules to achieve ultrasonic elliptical vibration assisted machining with different trajectories.

[0013] Preferably, in S1, quick-drying glue or paraffin is used to symmetrically mount the sample and the sample balance block on the top and bottom surfaces of the head of the vibration table.

[0014] Preferably, the vibration table is arranged on the support plate, and in S3, the height of the support plate and the vibration table is also adjusted through the adjusting screws arranged on the support plate to reduce the out-of-plane vibration of the sample in the Z direction.

[0015] Preferably, the phase difference between the two vibration generation modules in S2 and S3 is 90°.

[0016] Adopting the technical solution provided by the present invention, compared with the prior art, it has the following beneficial effects: 1. The elliptical ultrasonic vibration assisted machining device for a scanning probe involved in the present invention includes a vibration table. The vibration table includes a vibration table head and two sets of amplitude-changing flexible hinges. The vibration table head is used to fix the sample, and the two sets of amplitude-changing flexible hinges are distributed on both sides of the vibration table head at 90° for amplifying the resonance deformation to generate elliptical vibration at the sample end. At the same time, the cross-section of the amplitude-changing flexible hinge is an asymmetric trapezoid, which can reduce the out-of-plane vibration in the Z direction and make it more suitable for the scanning probe machining system. Through the coordinated excitation of the X and Y direction resonance modes of the sample vibration table by two sets of piezoelectric ceramic sheets, an elliptical vibration trajectory is applied to the machined sample, enabling the probe and the machined sample to achieve periodic cutting-separation behavior at the sub-micron or even nano scale, improving the chip removal behavior, and further improving the machining quality. The present invention reduces the contact area between the probe and the machined sample through the elliptical trajectory, thereby reducing the normal force during machining, reducing probe wear, and improving the service life of the probe during the machining of hard materials; it can increase the frequency of the elliptical vibration assisted machining of the scanning probe to the ultrasonic frequency band, increasing the efficiency of the elliptical vibration assisted machining based on the scanning probe.

[0017] 2. The elliptical ultrasonic vibration assisted machining device for a scanning probe involved in the present invention is provided with a sample balance block on the bottom surface of the vibration table to balance the mass distribution of the vibration table after installing the sample, making the mass distribution of the vibration table symmetric with respect to the XY plane, and adding an auxiliary support plate to reduce the out-of-plane vibration of the machined sample in the Z direction and reduce the influence of the out-of-plane vibration in the Z direction on the machining process. Description of the Drawings

[0018] Figure 1 is a structural diagram of the elliptical ultrasonic vibration assisted machining device for a scanning probe involved in the present invention; Figure 2 is a schematic diagram of the connection relationship between the fixed hinge and the counterweight block; Figure 3 Schematic structural diagram of the support plate; Figure 4 Top view of the vibration table; Figure 5 Side view of the vibration table; Figure 6 Vibration effect diagram of the amplitude-variable flexible hinge with a rectangular cross-section; Figure 7 Vibration effect diagram of the amplitude-variable flexible hinge with an asymmetric trapezoidal cross-section; Figure 8 Elliptical vibration trajectory generated at the head of the sample vibration table.

[0019] Reference numerals: 1 - vibration table, 2 - sample, 3 - piezoelectric ceramic sheet, 4 - electrode sheet, 5 - fixed hinge, 6 - counterweight, 7 - base, 8 - support plate, 9 - connecting stud, 10 - set screw, 11 - adjusting screw, 12 - head of the vibration table, 13 - amplitude-variable flexible hinge, 14 - sample balance weight. Detailed implementation manners

[0020] To further understand the content of the present invention, the present invention will be described in detail in combination with embodiments. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0021] Referring to the attached Figure 1 As shown, the present invention relates to an elliptical ultrasonic vibration-assisted machining device for a scanning probe, which includes a base 7, a support plate 8, a vibration table 1, and two sets of vibration generating modules. The base 7 is used to connect the elliptical ultrasonic vibration-assisted machining device and the scanning probe system through a fixed hinge 5. The support plate 8 and the vibration generating modules are directly installed on the base 7, and the vibration table 1 is arranged on the support plate 8. The resonance frequencies corresponding to the resonance modes of the overall X and Y directions of the vibration table 1 and the two sets of vibration generating modules are set in the ultrasonic frequency band. By respectively exciting these two vibration modes, elliptical vibration in the ultrasonic frequency band can be combined and generated in the XY plane.

[0022] Referring to the attached Figure 4 As shown, the vibration table 1 includes a head 12 of the vibration table and two sets of amplitude-variable flexible hinges 13. The head 12 of the vibration table is used to fix the sample 2, and the two sets of amplitude-variable flexible hinges 13 are distributed at 90° on both sides of the head 12 of the vibration table. The top view of the amplitude-variable flexible hinge 13 is a flexible hinge with a circular shape. By adjusting the resonance energy density distribution through the change in cross-sectional area, the deformation is concentrated at the small cross-section, thereby amplifying the resonance deformation. Referring to the attached Figure 5 As shown, a sample balance weight 14 is further provided on the bottom surface of the vibration table 1, which is used to balance the mass distribution of the vibration table 1 after installing the sample 2, so that the mass distribution of the vibration table 1 is symmetric with respect to the XY plane, thereby reducing the out-of-plane vibration in the Z direction.

[0023] The two sets of the vibration generating modules are respectively in contact with two sets of amplitude-varying flexible hinges 13, and are used for applying excitation signals with the same frequency, the same amplitude and different phases, and exciting the X and Y-direction resonances of the vibration table 1 in the ultrasonic frequency band, so that the sample 2 generates ultrasonic elliptical resonance in the XY plane. Refer to the attached Figure 1 As shown, each of the vibration generating modules includes a piezoelectric ceramic sheet 3, an electrode sheet 4 and a fixed hinge 5; the fixed hinge 5 corresponds to the amplitude-varying flexible hinge 13 and is used for clamping the piezoelectric ceramic sheet 3 and the electrode sheet 4 between the corresponding fixed hinge 5 and the amplitude-varying flexible hinge 13; the electrode sheet 4 is arranged between the positive and negative plates of the piezoelectric ceramic sheet 3 and is used for inputting a signal to the positive electrode of the ceramic sheet, and the piezoelectric ceramic sheet 3 is used for receiving the signal and exciting the vibration mode of the vibration generating module. Each of the vibration generating modules further includes a counterweight 6, and the counterweight 6 is fixed on the corresponding fixed hinge 5 through a connecting stud 9 and is used for adjusting the resonance frequency difference in the X and Y directions, and the connecting stud penetrates through the fixed hinge 5 and presses the piezoelectric ceramic sheet 3 onto the amplitude-varying flexible hinge 13, as Figure 2 shown.

[0024] The support plate 8 is arranged on the base 7 through adjusting screws 11. Specifically, two threaded holes and two through holes are respectively arranged at two diagonals of the support plate 8. Two set screws 10 pass through the two through holes and are connected to two threaded holes on the base 7, and two adjusting screws 11 are threadedly connected to the two threaded holes of the support plate 8. The screws thread through the threaded holes and contact the upper surface of the base 7. The vibration table 1 is arranged on the support plate 8, as Figure 3 shown. In this way, the support plate 8 is not only used for providing auxiliary support for the vibration table 1, but also can be used for adjusting the height and tilt angle of the vibration table 1.

[0025] Refer to the attached Figures 6 - 7 As shown, the cross section of the amplitude-varying flexible hinge 13 can adopt a uniform rectangular cross section or an asymmetric trapezoidal cross section. As Figure 6 shown in (a)-(c), the process of exciting the vibration of the vibration table will cause compression and tensile deformation of the amplitude-varying flexible hinge 13. When the amplitude-varying flexible hinge is a rectangular cross section, it has a compressive or tensile relative force on the head 12 of the vibration table during the compression or tension process, thereby causing the head of the vibration table to be deformed and tilted on the surface of the sample 2, which is manifested as out-of-plane vibration in the Z direction of the processed surface during the processing process. Figure 7 shown in (a)-(c), compared with the amplitude-varying flexible hinge 13 with a uniform cross section, the amplitude-varying flexible hinge 13 with an asymmetric trapezoidal cross section generates parasitic movement in the Z direction during deformation to compensate for the plane tilt of the sample 2 caused by the vibration displacement of the conventional rectangular cross section hinge, making the vibration of the processed surface more stable and reducing the influence of the out-of-plane vibration in the Z direction caused by the tilt on the processing process. Therefore, in this embodiment, the amplitude-varying flexible hinge 13 with an asymmetric trapezoidal cross section is preferably used.

[0026] Based on the above elliptical ultrasonic vibration assisted machining device for a scanning probe, the present invention also relates to a method for elliptical ultrasonic vibration assisted machining of a scanning probe, which comprises the following steps: S1. Fix the sample 2 and the sample balance block 14 on the top surface and the bottom surface of the head 12 of the vibration table respectively using quick-drying glue or paraffin; S2. Apply excitation signals with the same frequency, the same amplitude, and different phases to the two groups of vibration generating modules, with a phase difference of 90°. Amplify the vibration through the amplitude-changing flexible hinge 13, and excite the X and Y-direction resonances of the vibration table 1 in the ultrasonic frequency band, so that the sample 2 generates ultrasonic elliptical resonance in the XY plane, forming an elliptical vibration trajectory as shown in Figure 8 the figure; S3. According to the processing requirements, adjust the height of the support plate 8 and the vibration table 1 by the adjusting screw 11 provided on the support plate 8, reduce the out-of-plane vibration of the sample 2 in the Z direction, and change the amplitude and phase of the excitation signals input to the two groups of vibration generating modules to achieve ultrasonic elliptical vibration assisted machining with different trajectories.

[0027] The elliptical ultrasonic vibration assisted machining device and method for a scanning probe according to the present invention are used to assist the scanning probe machining of micro-nano scale structures such as integrated circuits, micro-electromechanical systems, and optoelectronic devices, so as to improve the machining accuracy and surface quality.

[0028] The above has described the present invention in detail in combination with the embodiments, but the content described is only the preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. An elliptical ultrasonic vibration assisted machining device for a scanning probe, characterized in that: It includes a vibration table and two sets of vibration generation modules; the vibration table includes a vibration table head and two sets of amplitude-changing flexible hinges. The vibration table head is used to fix the sample, and the two sets of amplitude-changing flexible hinges are distributed at both sides of the vibration table head at 90°, for amplifying the resonance deformation; the two sets of vibration generation modules are respectively in contact with the two sets of amplitude-changing flexible hinges, for applying excitation signals with the same frequency, the same amplitude and different phases, and exciting the vibration table to resonate in the X and Y directions in the ultrasonic frequency band, so that the sample generates ultrasonic elliptical resonance in the XY plane.

2. The elliptical ultrasonic vibration assisted machining device for a scanning probe according to claim 1, wherein: Each of the vibration generation modules includes a piezoelectric ceramic sheet, an electrode sheet and a fixed hinge; the fixed hinge corresponds to the amplitude-changing flexible hinge, for clamping the piezoelectric ceramic sheet and the electrode sheet between the corresponding fixed hinge and amplitude-changing flexible hinge; the electrode sheet is arranged between the positive and negative plates of the piezoelectric ceramic sheet, for inputting signals to the positive electrode of the ceramic sheet, and the piezoelectric ceramic sheet is used to receive signals and excite the vibration mode of the vibration generation module.

3. The elliptical ultrasonic vibration assisted machining device for a scanning probe according to claim 2, characterized in that: Each of the vibration generation modules further includes a counterweight block, and the counterweight block is fixed on the corresponding fixed hinge through a connecting stud, for adjusting the resonance frequency difference in the X and Y directions; the connecting stud penetrates through the fixed hinge and presses the piezoelectric ceramic sheet on the amplitude-changing flexible hinge.

4. The elliptical ultrasonic vibration assisted machining device for a scanning probe according to claim 1, characterized in that: A sample balance block is further arranged on the bottom surface of the vibration table, for balancing the mass distribution of the vibration table after installing the sample, so that the mass distribution of the vibration table is symmetrical with respect to the XY plane.

5. The elliptical ultrasonic vibration assisted machining device for a scanning probe according to claim 1, characterized in that: It further includes a base and a support plate. The vibration generation module is arranged on the base, the support plate is arranged on the base through adjusting screws, the vibration table is arranged on the support plate, and the support plate is used to provide auxiliary support for the vibration table and finely adjust the height and tilt angle of the vibration table.

6. The elliptical ultrasonic vibration assisted machining device for a scanning probe according to claim 1, characterized in that: The cross-sectional shape of the amplitude-changing flexible hinge is an asymmetric trapezoid.

7. An elliptical ultrasonic vibration assisted machining method for a scanning probe, characterized in that, It includes the following steps: S1. Fix the sample and the sample balance block on the top surface and the bottom surface of the vibration table head respectively. S2. Apply excitation signals with the same frequency, the same amplitude and different phases to the two sets of vibration generation modules, amplify the vibration through the amplitude-changing flexible hinges, and excite the vibration table to resonate in the X and Y directions in the ultrasonic frequency band, so that the sample generates ultrasonic elliptical resonance in the XY plane. S3. According to the processing requirements, change the amplitude and phase of the excitation signals input to the two sets of vibration generation modules to realize ultrasonic elliptical vibration-assisted processing with different trajectories.

8. The elliptical ultrasonic vibration assisted machining method for a scanning probe according to claim 7, characterized in that: In S1, use quick-drying glue or paraffin to symmetrically install the sample and the sample balance block on the top surface and the bottom surface of the vibration table head.

9. The elliptical ultrasonic vibration assisted machining method for a scanning probe according to claim 7, characterized in that: The vibration table is arranged on the support plate, and in S3, the height of the support plate and the vibration table is further adjusted through the adjusting screws arranged on the support plate to reduce the out-of-plane vibration of the sample in the Z direction.

10. The elliptical ultrasonic vibration assisted machining method for a scanning probe according to claim 7, wherein: The phase difference between the two sets of vibration generation modules in S2 and S3 is 90°.

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