Device and method for electrochemical machining with electrostatic induction and acoustic surface wave mask

Abstract

The application relates to a device and method for electrostatic induction and sound surface wave mask electrolytic machining, belonging to the electrolytic machining field. The pump, the liquid storage tank and the electrolytic tank are connected to realize electrolyte circulation. The various components in the electrolytic tank are riveted. The anode and cathode assemblies and the shielding induction electrode assembly are inserted into the electrolytic tank. The positive and negative poles of the power supply are connected with the anode and cathode plates in the anode and cathode assemblies respectively, and the workpiece arranged in the induction electrode assembly is arranged in the electric field between the anode and cathode plates. The piezoelectric ceramic is attached to the base plate of the induction electrode assembly, and the signal generator and the power amplifier are connected with the piezoelectric ceramic. Based on the device, the piezoelectric ceramic is connected with a megasonic driving voltage to generate a surface wave on the surface of the workpiece; the anode and cathode plates are connected with direct current, and the workpiece is arranged in the electric field formed by the anode and cathode plates, so that the surface to be machined of the workpiece is subjected to oxidation reaction, and the non-machining surface is subjected to reduction reaction, thereby realizing wireless induction machining of the workpiece. The application has the advantages of simple operation, re-distribution of the electric field, enhancement of mass transfer, improvement of mask electrolytic machining precision, arrangement of multiple workpieces in the electric field formed by the anode and cathode plates, and substantial improvement of mask electrolytic machining efficiency.

Description

TECHNICAL FIELD

[0001] The application relates to a mask electrochemical machining method, in particular to a device and method for electrostatic induction and surface acoustic wave mask electrochemical machining, and belongs to the field of electrochemical machining. TECHNICAL BACKGROUND

[0002] With the precision and miniaturization of industrial products, the market demand for metal microstructures (devices) has increased dramatically. The methods for manufacturing metal microstructures mainly include LIGA technology or UV-LIGA technology, mechanical micro-machining technology, electric spark machining, laser machining, chemical etching and mask electrochemical machining. Among them, mask electrochemical machining has the advantages of no burr, no deformation, large batch, low cost and the like after machining, and is the mainstream technology for manufacturing metal microstructures, especially difficult-to-machine metal microstructures.

[0003] The traditional mask electrochemical machining process is as follows: an insulating mask pattern is placed on the surface of an anode workpiece to be machined, the electrolyte is filled between the anode workpiece and a flat plate cathode, and electrolytic machining is carried out after the power supply is connected between the anode and the cathode. After removing the insulating mask, a microstructure is obtained on the surface of the workpiece. The current mask electrochemical machining has the problems of poor localization and uniformity, and the machining precision of mask electrochemical machining is lower than that of other metal microstructure machining methods. This is due to two factors, i.e. electric field and mass transfer. Electric field: due to the complex and diverse mask pattern, the area of the cathode plate exposed to the electrolyte and the conductive area of the anode workpiece to be machined are not one-to-one corresponding, the electric field is unevenly distributed, and finally the size precision of the metal microstructure is poor. Mass transfer: during the mask electrochemical machining process, it is difficult to discharge the electrolysis products, and bubbles and solid impurities are irregularly attached to the machining surface, causing uneven dissolution of the anode workpiece, thereby directly affecting the machining precision and surface quality of the metal microstructure.

[0004] To solve the problem of poor machining precision caused by uneven electric field distribution, the invention patent CN 113046803 A proposes an arc-shaped jet cathode moving device and method for improving mask electrolytic machining precision, which improves the edge effect of the electric field by increasing the resistance of the anode edge, and improves the machining uniformity of the microstructure. The invention patent CN 104607734 A proposes a system and method for auxiliary anode mask micro-electrolytic machining array, which uses auxiliary anode to absorb the edge current, making the micro-pit array size uniform. The above-mentioned method improves the mask electrolytic precision by reducing the edge effect of the electric field from a macroscopic point of view, but from a small area, the electric field still exists uneven phenomenon, the essential problem of uneven electric field distribution has not been solved. To solve the mass transfer problem, the invention patent CN 107116274 A proposes a cavitation jet assisted mask electrolytic machining method, which uses the micro water jet formed by the collapse of cavitation jet electrolyte to discharge electrolysis products and improve the machining surface quality. Because the energy generated by the collapse of cavitation jet electrolyte is large, the cavitation jet assisted mask electrolytic machining method causes great damage to the mask. The invention patent CN 106312206 A proposes a movable mask electrolytic machining device and method. The method tightly attaches a metal porous medium to the anode workpiece, and then pumps electrolyte above the porous medium, and the electrolyte flows out from the four sides of the porous medium, making the mass transfer between the electrodes smooth, the flow field distribution uniform, and improving the machining precision. Because the electrolyte is pumped from the outside, the kinetic energy of the electrolyte is continuously consumed during the flow process, and when the aspect ratio of the to-be-processed structure reaches a certain degree, the flow ability of the electrolyte is limited, so the movable mask electrolytic machining method has limited ability in processing large aspect ratio structures.

[0005] In summary, the existing methods for improving mask electrolytic machining precision have certain limitations, so it is necessary to invent a new device and method for improving mask electrolytic machining precision to improve the mask electrolytic machining precision of metal microstructures. SUMMARY

[0006] To overcome the problems of poor localization and uniformity of traditional mask electrolytic machining, the present application provides a device and method for electrostatic induction assisted surface acoustic wave mask electrolytic machining, which homogenizes the inter-electrode electric field distribution by electrostatic induction and improves the mass transfer in the confined space by surface acoustic wave, breaks through the limitations of poor localization and uniformity of traditional mask electrolytic machining, and realizes high-precision and parallel machining of complex metal microstructures.

[0007] To achieve the above-mentioned purposes, the technical solutions adopted by the present application are as follows:

[0008] The electrostatic induction cooperates with the sound surface wave mask electrolytic processing device, the signal generator 1, the signal line 2, the pump 3, the hose 4, the electrolytic system 5, the power supply 6, the liquid storage tank 7, the power supply line 8, the power amplifier 9 are included.The electrolytic system 5 is powered by connecting the power supply 6 through the power supply line 8.The one end of the electrolytic system 5 is connected to the one end of the pump 3 through the hose 4, the other end of the pump 3 is connected to the one end of the liquid storage tank 7 through another group of hoses 4, the other end of the liquid storage tank 7 is connected to the electrolytic system 5 through the third group of hoses, and the circulation and filtration of the electrolyte 10 in the electrolytic system 5 are driven by the pump 3.The piezoelectric ceramic 531 in the electrolytic system 5 is connected to the output end of the power amplifier 9 through the signal line 2, the input end of the power amplifier 9 is connected to the signal generator 1 through another signal line 2, and the piezoelectric ceramic 531 is controlled to generate different surface waves by adjusting the output of the signal generator 1.

[0009] The electrolytic system 5 includes the electrolytic tank 51, the cathode assembly 52, the shielding induction electrode assembly 53 and the anode assembly 54 arranged inside the electrolytic tank 51, wherein the shielding induction electrode assembly 53 is arranged between the cathode assembly 52 and the anode assembly 54, and the three are arranged in parallel.The electrolytic tank 51 has a plurality of pairs of limiting grooves 519, the cathode assembly 52, the shielding induction electrode assembly 53 and the anode assembly 54 are inserted into the limiting grooves 519 of the electrolytic tank 51, and the fixing function is realized through the limiting grooves 519.According to the different positions of the cathode assembly 52, the shielding induction electrode assembly 53 and the anode assembly 54 inserted into the limiting grooves 519 of the electrolytic tank 51, the reasonable adjustment of the spacing between the three electrodes can be realized.

[0010] The electrolytic tank 51 includes the shell 517, and the framework 511, the sponge 512, the filter screen 513, the vertical plate 514, the positioning plate 515, the lower clamping groove 516 and the upper clamping groove 518 arranged inside the shell 517.The framework 511, the sponge 512, the filter screen 513, the vertical plate 514, the positioning plate 515, the lower clamping groove 516, the shell 517 and the upper clamping groove 518 are riveted, which can be disassembled, facilitating maintenance and replacement of parts.

[0011] The skeleton 511 is a long strip plate structure, horizontally arranged on the top of the shell, and a plurality of embedding grooves 5111 are opened on it. The sponge 512 is a sheet structure, arranged between two filter screens 513. The filter screen 513 is vertically arranged on both sides of the shell 517, and two vertical plates 514 are vertically arranged inside the shell 517 and close to the end filter screen 513. The positioning plate 515 is vertically arranged on the side of the vertical plate 514. The lower clamping groove 516 is horizontally arranged on the lower surface of the shell 517, and the upper clamping groove 518 is horizontally arranged above the shell 517. The filter screen 513 is a square plate structure, and a plurality of square through holes 5131 are arranged on the surface in an array. The periphery is provided with an embedding groove 5132. The vertical plate 514 is a square plate structure, and a plurality of long strip through holes 5141 are arranged on the surface in a horizontal direction. The positioning plate 515 is a long strip plate structure vertically arranged, and an open embedding groove 5151 is arranged on the top, and a closed embedding groove 5152 is arranged below. The lower clamping groove 516 is a square plate structure with an open top, and a plurality of embedding grooves 5161 are arranged at intervals on both sides of the end. The shell 517 is a rectangular structure, and a water outlet 5171 is arranged on one side, and a water inlet 5172 is arranged on the other side opposite to it. The upper clamping groove 518 is a hollow square plate structure, and an upper clamping groove embedding groove 5181 is arranged on it. The embedding groove 5111 of the skeleton 511 is embedded with the embedding groove 5132 in the filter screen 513 and the embedding groove 5142 in the vertical plate 514. The open embedding groove 5151 in the positioning plate 515 is embedded with the embedding groove 5181 in the upper clamping groove 518, and the closed embedding groove 5152 in the positioning plate 515 is embedded with the embedding groove 5161 in the lower clamping groove 516. After the skeleton 511, the sponge 512, the filter screen 513, the vertical plate 514, the positioning plate 515, the lower clamping groove 516 and the upper clamping groove 518 are assembled, they are placed into the shell 517 to form a stable electrolytic cell 51. The filter screen 513 has an array of square through holes 5131, and the vertical plate 514 has an array of long strip through holes 5141, which ensures that the electrolyte 10 can smoothly pass through the electrolytic cell 51. The water inlet 5172 and the water outlet 5171 on the side of the shell 517 are connected with the hose 4. After the electrolyte enters the electrolytic cell 51 from the water inlet 5172, the bubbles are filtered out by the sponge 512, and then pass through the electrolysis area between the two vertical plates 514, and then the other sponge 512 filters out the large solid electrolysis products, and then flows out from the water outlet 5171 to the pump 3.

[0012] The cathode assembly 52 comprises a shielding baffle 521 and a cathode plate 522. The shielding baffle 521 is made of insulating material and has a through hole 5211, and the cathode plate 522 is inlaid in the through hole 5211 of the shielding baffle 521. The cathode plate 522 is connected with the negative pole of the power line 8, the front surface 5221 of the cathode plate 522 is in contact with the electrolyte to cause reduction reaction, and the back surface 5222 of the cathode plate 522 has an insulating layer. The surface of the cathode plate 522 opposite to the anode plate 541 is the front surface 5221 of the cathode plate 522.

[0013] The shielding induction electrode assembly 53 comprises the shielding baffle 521, a workpiece 532 and a piezoelectric ceramic 531. The piezoelectric ceramic 531 vibrates at a frequency of more than 1 MHz under the driving voltage in the signal line 2, so as to generate surface waves on the surfaces of the shielding baffle 521 and the workpiece 532. The surface of the workpiece 532 opposite to the cathode plate 522 is the surface to be machined 5323, which causes oxidation reaction. The surface opposite to the anode plate 541 is the non-machining surface 5321, which causes reduction reaction.

[0014] The anode assembly 54 comprises the shielding baffle 521 and the anode plate 541. The anode plate 541 is inlaid in the through hole 5211 of the shielding baffle 521. The anode plate 541 is connected with the positive pole of the power line 8, the front surface 5412 of the anode plate 541 is in contact with the electrolyte to cause oxidation reaction, and the back surface 5411 of the anode plate 541 has an insulating layer. The surface of the anode plate 541 opposite to the cathode plate 522 is the front surface 5412 of the anode plate 541.

[0015] The liquid storage tank 7 comprises a sealing screen 701 and a liquid storage pool 702. The side surface of the liquid storage pool 702 has two water inlets 7021 connected with the pump 3 through the hose 4, and the other side surface of the liquid storage pool 702 has two water outlets 7023 connected with the water inlets 5172 of the electrolytic tank 51 through the hose 4. The top surface of the liquid storage pool 702 has two water injection holes 7022 for adding electrolyte. The liquid storage tank 7 is sealed by the sealing screen 701.

[0016] Further, the signal generator 1 can generate a standard voltage signal with a frequency continuously adjustable in the range of 0-20 MHz, and the voltage peak-peak value of the standard voltage signal is continuously adjustable in the range of 0-20 Vpp.

[0017] Further, the power amplifier 9 has a bandwidth of DC-20 MHz, a voltage gain adjustable in the range of 1-20 times, adjustable input and output impedance, and a maximum output power greater than or equal to 100 W.

[0018] Further, the pump 3 has a filtering function and adjustable flow.

[0019] Further, the power supply 6 has a maximum output power greater than 300W, a current stabilizing and voltage stabilizing function, an adjustable frequency and duty cycle of output voltage, and a maximum output voltage greater than or equal to 80V.

[0020] The method of electrochemical machining by electrostatic induction and surface acoustic wave mask, breaks through the limitation of poor localization and uniformity of traditional mask electrochemical machining, realizes high-precision and parallel machining of complex metal microstructure by homogenizing the electric field distribution between the electrodes through electrostatic induction and improving the flow field mass transfer conditions in the confined space through surface acoustic wave.

[0021] S1. A photoresist mask pattern 5322 is made on the surface 5323 to be machined of the workpiece 532. The photoresist film is patterned by standard processes such as uniform coating, photoresist exposure, and development, exposing the conductive surface 5323 to be machined.

[0022] S2. The patterned workpiece 532 is inlaid in the shielding baffle 521 to form a shielding induction electrode assembly 53 with the piezoelectric ceramic 531. The cathode assembly 52, the shielding induction electrode assembly 53, and the anode assembly 54 are inserted into the limiting groove 519 of the electrolytic cell 51 with appropriate anode-cathode spacing.

[0023] It should be noted that the surface of the workpiece 532 opposite to the cathode plate 522 is the surface 5323 to be machined, which undergoes oxidation reaction. The surface opposite to the anode plate 541 is the non-machining surface 5321 of the workpiece 532, which undergoes reduction reaction.

[0024] S3. The piezoelectric ceramic 531 is supplied with megasonic signals through the signal line 2. The megasonic vibration generated by the piezoelectric ceramic 531 propagates in the form of surface acoustic wave on the surface of the shielding baffle 521 and the workpiece 532. The surface acoustic wave propagating on the workpiece 532 radiates into the electrolyte 10, forming micro-eddy current and macro-flow of the electrolyte 10, promoting the flushing effect of the electrolyte 10 on the surface 5323 to be machined of the workpiece 532, and facilitating the timely discharge of electrolysis products and the timely update of fresh electrolyte, thereby realizing high-precision machining of metal microstructure.

[0025] In particular, the frequency of the piezoelectric ceramic 531 is above 1MHz, i.e. the frequency of the surface acoustic wave is above 1MHz. The low cavitation effect of high-frequency sound wave above 1MHz can reduce the damage of cavitation bubbles to the mask pattern, and at the same time reduce the influence of bubbles on mask electrochemical machining.

[0026] S4. Selecting appropriate duty cycle and voltage, turning on the power supply 6, connecting the cathode plate 522 and the anode plate 541 through the power supply line 8, current passing through the electrolyte 10 and the workpiece 532, oxidation reaction occurring on the surface 5323 of the workpiece 532 to be processed, reduction reaction occurring on the surface 5321 of the workpiece 532 not to be processed, and realizing the electrolytic machining process. At the same time, the surface acoustic wave propagating on the surface 5323 of the workpiece 532 to be processed forms micro-eddy current and macro-flow in the electrolyte 10, which can timely discharge the electrolysis product and supply fresh electrolyte 10.

[0027] Further, the method of the present application can be used for parallel machining of multiple workpieces, in which case multiple shielding electrode assemblies 53 are placed side by side in step S2.

[0028] The present application has the following advantages:

[0029] (1) Homogenizing the electric field. The workpiece is in the electric field between the anode plate and the cathode plate. On the one hand, the substrate of the shielding electrode assembly binds the electric field lines at the edge of the electric field, eliminating the influence of the edge effect. On the other hand, the ion current in the electrolyte generated by the potential difference between the anode plate and the cathode plate is changed when passing through the workpiece, which is constrained by the oxidation / reduction reaction of the surface to be processed and the equal amount of positive and negative charges. The combined effect of the above two aspects homogenizes the inter-electrode electric field distribution of the new method.

[0030] (2) Improving mass transfer. When the surface wave propagates, the vibration of the surface to be processed has a parallel component and a vertical component with the solid-liquid interface. On the one hand, the parallel component generates tangential stress on the electrolyte, causing the electrolyte at the solid-liquid interface to form micro-eddy current, promoting the flushing effect of the electrolyte on the processing surface, and thinning the fluid boundary layer. On the other hand, the vertical component generates normal stress on the electrolyte, ejecting the electrolyte near the surface to be processed, promoting the timely discharge of electrolysis products and the timely update of fresh electrolyte.

[0031] (3) High machining precision. Electric field and mass transfer are two major factors affecting the precision of mask electrolytic machining. The present application homogenizes the inter-electrode electric field distribution through electrostatic induction and improves the mass transfer in the confined space through surface acoustic wave, breaking through the limitations of traditional mask electrolytic machining in terms of localization and uniformity, and realizing high-precision machining of complex metal microstructures.

[0032] (4) High machining efficiency. Since the workpiece is non-contact powered and placed in the electric field between the cathode plate and the anode plate, etching can be realized. Therefore, the method of the present application can place multiple workpieces between the cathode plate and the anode plate for parallel machining, greatly improving the machining efficiency.

[0033] (5) The process is strong. The surface acoustic wave is easier to integrate, which is conducive to saving device space. A small piece of piezoelectric ceramic can form a surface acoustic wave on a larger workpiece surface, promoting mass transfer in the mask electrochemical machining process. In the mask electrochemical machining process, the workpiece does not need to be directly powered by the power supply, but is placed in the electric field between the cathode plate and the anode plate. The method of mask electrochemical machining using an induction electrode simplifies the operation process, and only needs to insert the workpiece between the cathode and anode to process, and the process is stronger. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is an overall view of the electrostatic induction and surface acoustic wave mask electrochemical machining device of the application.

[0035] Figure 2 It is an overall view of the electrolysis system.

[0036] Figure 3 It is a plan view of the electrolytic tank.

[0037] Figure 4 It is a skeleton axonometric view.

[0038] Figure 5 It is a filter screen axonometric view.

[0039] Figure 6 It is an upright plate axonometric view.

[0040] Figure 7 It is a positioning plate axonometric view.

[0041] Figure 8 It is a lower clamping groove axonometric view.

[0042] Figure 9 It is a shell axonometric view.

[0043] Figure 10 It is an upper clamping groove axonometric view.

[0044] Figure 11 It is a cathode assembly axonometric view.

[0045] Figure 12 It is a shielding baffle axonometric view.

[0046] Figure 13 It is a cathode plate axonometric view.

[0047] Figure 14 It is a shielding induction electrode assembly axonometric view.

[0048] Figure 15 It is a workpiece axonometric view.

[0049] Figure 16 It is an anode assembly axonometric view.

[0050] Figure 17 It is an anode plate axonometric view.

[0051] Figure 18 is a total view of the liquid storage tank;

[0052] Figure 19 is an axonometric view of the liquid storage tank;

[0053] Figure 20 is a schematic view of the workpiece;

[0054] Figure 21 is a schematic diagram of the principle of electrochemical machining with electrostatic induction and surface acoustic wave mask

[0055] Figure 22 is a schematic diagram of the principle of multi-workpiece parallel machining.

[0056] In the figure: 1 signal generator; 2 signal line; 3 pump; 4 hose; 5 electrolysis system; 6 power supply; 7 liquid storage tank; 8 power supply line; 9 power amplifier; 10 electrolyte;

[0057] 51 electrolytic cell; 511 skeleton; 512 sponge; 513 filter screen; 514 vertical plate; 515 positioning plate; 516 lower clamping groove; 517 shell; 518 upper clamping groove; 519 limiting groove; 5111 embedded groove 5111; 5131 square through hole; 5132 filter screen embedded groove; 5141 long strip-shaped through hole; 5142 vertical plate embedded groove; 5151 open embedded groove; 5152 closed embedded groove; 5161 lower clamping groove embedded groove; 5171 water outlet; 5172 water inlet;

[0058] 52 cathode assembly; 521 shielding baffle; 522 cathode plate; 5211 through hole; 5221 front surface of the cathode plate; 5222 back surface of the cathode plate;

[0059] 53 shielding induction electrode assembly; 531 piezoelectric ceramic; 532 workpiece; 5321 non-machining surface; 5322 mask pattern; 5323 surface to be machined;

[0060] 54 anode assembly; 541 anode plate; 5412 front surface of the anode plate; 5411 back surface of the anode plate;

[0061] 701 sealing screen; 702 liquid storage tank; 7021 water inlet; 7022 water injection hole; 7023 water outlet. DETAILED DESCRIPTION

[0062] The application will be further described below in conjunction with specific embodiments.

[0063] The core idea of the present application is to provide a device and method for electrochemical machining by electrostatic induction and surface acoustic wave mask, to introduce surface acoustic wave into the mask electrochemical process in a specific way, and to realize mask electrochemical machining by using electrostatic induction principle. Through electrostatic induction, the electric field distribution between the electrodes is homogenized, and through surface acoustic wave, the flow field mass transfer condition in the limited space is improved, thus breaking through the limitations of poor localization and uniformity of traditional mask electrochemical machining, and realizing high-precision and parallel machining of complex metal microstructure.

[0064] The present application will be further described in detail below in combination with the embodiments shown in the drawings. Obviously, the described examples are only a part of the examples of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0065] A device for electrochemical machining by electrostatic induction and surface acoustic wave mask is shown in Figure 1 .

[0066] Figure 1 The device for electrochemical machining by electrostatic induction and surface acoustic wave mask is a general view, mainly comprising a signal generator 1, a signal line 2, a pump 3, a hose 4, an electrolysis system 5, a power supply 6, a liquid storage tank 7, a power supply line 8, and a power amplifier 9. The signal generator 1 transmits a standard voltage signal to the power amplifier 9 through the signal line 2, drives the piezoelectric ceramic 531 to generate a surface wave. Under the action of the pump 3, the electrolyte 10 in the electrolysis system 5 flows back to the electrolysis system 5 through the hose 4 and the liquid storage tank 7, to realize the circulation and filtration of the electrolyte 10. The power supply 6 supplies power to the electrolysis process of the electrolysis system 5 through the power supply line 8.

[0067] The signal generator 1 is characterized by being capable of generating a standard voltage signal with a continuous adjustable frequency of 0-20 MHz, and a continuous adjustable voltage peak-to-peak value of the standard voltage signal of 0-20 Vpp.

[0068] The power amplifier 9 is characterized by a bandwidth of DC-20 MHz, a voltage gain of 1-20 times adjustable, adjustable input and output impedance, and a maximum output power greater than or equal to 100 W.

[0069] The pump 3 is characterized by having a filtration function and adjustable flow.

[0070] The power supply 6 is characterized by a maximum output power greater than 300 W, a steady current and steady voltage function, an adjustable frequency and duty cycle of the output voltage, and a maximum output voltage greater than or equal to 80 V.

[0071] Figure 2For the overall view of electrolysis system 5, mainly including electrolytic tank 51, cathode assembly 52, shielded induction electrode assembly 53, anode assembly 54. The electrolytic tank 51 has a plurality of pairs of limiting grooves 519, the cathode assembly 52, the shielded induction electrode assembly 53, the anode assembly 54 are inserted into the limiting grooves 519 of the electrolytic tank 51, and the fixing function is realized through the limiting grooves 519. According to the different positions of the cathode assembly 52, the shielded induction electrode assembly 53 and the anode assembly 54 inserted into the limiting grooves 519 of the electrolytic tank 51, the reasonable adjustment of the three electrode spacings is realized.

[0072] Figure 3 For the cross-sectional view of the electrolytic tank 51, mainly including: including skeleton 511, sponge 512, filter screen 513, vertical plate 514, positioning plate 515, lower clamping groove 516, shell 517, upper clamping groove 518. The skeleton 511, sponge 512, filter screen 513, vertical plate 514, positioning plate 515, lower clamping groove 516, shell 517, upper clamping groove 518 are riveted between them, which can be disassembled, facilitating maintenance and replacement of parts. Each two adjacent positioning plates 515 form a limiting groove 519, the cathode assembly 52, the shielded induction electrode assembly 53, the anode assembly 54 are inserted into the limiting grooves 519 of the electrolytic tank 51, and the fixing function is realized through the limiting grooves 519.

[0073] Figure 4 For the skeleton 511 axonometric view, Figure 5 For the filter screen 513 axonometric view, Figure 6 For the vertical plate 514 axonometric view, Figure 7 For the positioning plate 515 axonometric view, Figure 8 For the lower clamping groove 516 axonometric view, Figure 9 For the shell 517 axonometric view, Figure 10This is an isometric view of the upper slot 518. The frame 511 has a fitting groove 5111 that fits into the fitting groove 5132 in the filter screen 513 and the fitting groove 5142 in the upright plate 514. The open fitting groove 5151 in the positioning plate 515 fits into the fitting groove 5181 in the upper slot 518, and the closed fitting groove 5152 in the positioning plate 515 fits into the fitting groove 5161 in the lower slot 516. After the frame 511, sponge 512, filter screen 513, upright plate 514, positioning plate 515, lower slot 516, and upper slot 518 are assembled, they are placed in the housing 517 to form a stable electrolytic cell 51. The filter screen 513 has an array of square through holes 5131, and the upright plate 514 has an array of elongated through holes 5141 to ensure that the electrolyte 10 can pass smoothly through the electrolytic cell 51. The housing 517 has four inlets 5172 on one side and four outlets 5171 on the opposite side. The inlets 5172 and outlets 5171 are connected to the hose 4. After the electrolyte enters the electrolytic cell 51 through the inlets 5172, air bubbles are filtered out by the sponge 512. After passing through the electrolysis zone, large solid electrolytic products are filtered out by the sponge 512 and flow to the pump 3 through the outlets 5171.

[0074] Figure 11 The image shows an isometric view of the cathode assembly 52, which mainly includes a shielding baffle 521 and a cathode plate 522. Figure 12 Axonometric drawing of shielding baffle 521. Figure 13 This is an isometric view of the cathode plate 522. The shielding baffle 521 is made of insulating material and has a through hole 5211. The cathode plate 522 is embedded in the through hole 5211 of the shielding baffle 521. The cathode plate 522 is connected to the negative terminal of the power line 8. The front side 5221 of the cathode plate 522 is in contact with the electrolyte and undergoes a reduction reaction. The back side 5222 of the cathode plate 522 has an insulating layer.

[0075] It should be noted that the surface of the cathode plate 522 that faces the anode plate 541 is the front side 5221 of the cathode plate 522.

[0076] Figure 14 The isometric view of the shielded induction electrode assembly 53 mainly includes a shielding baffle 521, a workpiece 532, and a piezoelectric ceramic 531. Figure 15 This is an isometric view of workpiece 532. The piezoelectric ceramic 531 vibrates under the driving voltage in signal line 2, thereby generating surface waves on the shielding baffle 521 and the surface of workpiece 532. The surface 5323 of workpiece 532 to be processed has a mask pattern 5322.

[0077] It should be noted that the surface of workpiece 532 opposite to cathode plate 522 is the surface to be processed 5323, which undergoes an oxidation reaction. The surface opposite to anode plate 541 is the surface not to be processed 5321, which undergoes a reduction reaction.

[0078] Figure 16 Figure 8 is an axonometric view of the anode assembly 54, mainly comprising the shield baffle 521 and the anode plate 541. Figure 17 Figure 9 is an axonometric view of the anode plate 541. The anode plate 541 is inlaid in the through hole 5211 of the shield baffle 521. The anode plate 541 is connected to the positive pole of the power supply line 8, the front surface 5412 of the anode plate 541 is in contact with the electrolyte and oxidation reaction occurs, and the back surface 5411 of the anode plate 541 has an insulating layer.

[0079] It should be noted that the surface of the anode plate 541 opposite to the cathode plate 522 is the front surface 5412 of the anode plate 541.

[0080] Figure 18 Figure 10 is a general view of the liquid storage tank 7, mainly comprising the sealing screen 701 and the liquid storage pool 702. Figure 19 Figure 11 is an axonometric view of the liquid storage pool 702. The side surface of the liquid storage pool 702 has two water inlets 7021 connected to the pump 3 through the hose 4; the other side surface of the liquid storage pool 702 has two water outlets 7023 connected to the water inlets 5172 of the electrolytic cell 51 through the hose 4. The top surface of the liquid storage pool 702 has two water injection holes 7023 for adding electrolyte. The liquid storage tank 7 is sealed by the sealing screen 701.

[0081] A method for electrochemical machining by electrostatic induction and surface acoustic wave mask is shown in Figure 21 . Figure 21 Figure 13 is a schematic diagram of the principle of electrochemical machining by electrostatic induction and surface acoustic wave mask. The following steps are implemented:

[0082] S1. Figure 20 Figure 14 is a schematic diagram of the workpiece 532. A photoresist mask pattern 5322 is made on the surface to be machined 5323 of the workpiece 532. Through standard processes such as uniform coating, photoresist exposure, and development, the photoresist film is patterned to expose the conductive surface to be machined 5323.

[0083] S2. The patterned workpiece 532 is inlaid in the shield baffle 521 to form a shielded sensing electrode assembly 53 with the piezoelectric ceramic 531. The appropriate anode-cathode distance is selected, and the cathode assembly 52, the shielded sensing electrode assembly 53, and the anode assembly 54 are inserted into the limiting groove 519 of the electrolytic cell 51.

[0084] It should be noted that the surface of the workpiece 532 opposite to the cathode plate 522 is the surface to be machined 5323, where oxidation reaction occurs. The surface opposite to the anode plate 541 is the non-machining surface 5321 of the workpiece 532, where reduction reaction occurs.

[0085] S3. The piezoelectric ceramic 531 is supplied with a megasonic signal through the signal line 2, and the megasonic vibration generated by the piezoelectric ceramic 531 propagates in the form of a surface acoustic wave on the surface of the shielding baffle 521 and the workpiece 532. The surface acoustic wave propagating on the workpiece 532 radiates into the electrolyte 10, forming micro-eddy current and macro-flow of the electrolyte 10, promoting the flushing effect of the electrolyte 10 on the surface 5323 of the workpiece 532 to be processed, facilitating the timely discharge of electrolysis products and the timely update of fresh electrolyte, and further realizing high-precision processing of metal microstructure.

[0086] In particular, the frequency of the piezoelectric ceramic 531 is above 1 MHz, i.e. the frequency of the surface acoustic wave is above 1 MHz. The low cavitation effect of high-frequency sound wave above 1 MHz can reduce the damage of cavitation bubbles to the mask pattern, and at the same time reduce the influence of bubbles on mask electrochemical machining.

[0087] S4. Selecting appropriate duty cycle and voltage, turning on the power supply 6, connecting the cathode plate 522 and the anode plate 541 through the power supply line 8, and the current passes through the electrolyte 10 and the workpiece 532, the oxidation reaction occurs on the surface 5323 of the workpiece 532 to be processed, and the reduction reaction occurs on the non-processing surface 5321 of the workpiece 532, realizing the process of electrolytic machining. At the same time, the surface acoustic wave propagating on the surface 5323 of the workpiece 532 to be processed forms micro-eddy current and macro-flow in the electrolyte 10, which can timely discharge electrolysis products and supply fresh electrolyte 10.

[0088] It should be noted that:

[0089] (1) In the process of mask electrochemical machining, the workpiece does not need to be directly supplied with electricity through the power supply, but only needs to be placed in the electric field between the cathode plate and the anode plate. The inductive electrode mask electrochemical method is convenient to operate and has better processability.

[0090] (2) The role of the inductive electrode in improving the electric field: the workpiece is in the electric field between the anode plate and the cathode plate, on the one hand, the base plate of the inductive electrode assembly binds the electric field lines at the edge of the electric field, eliminating the influence of the edge effect of the electric field; on the other hand, the ion current in the electrolyte generated by the potential difference between the anode plate and the cathode plate is changed when passing through the workpiece, which is constrained by the oxidation / reduction reaction of the surface to be processed and the non-processing surface of the workpiece and the equal amount of positive and negative charges. The path of the current is changed, and the common action of the above two aspects makes the inter-electrode electric field distribution of the new method uniform.

[0091] (3) The role of surface acoustic wave in improving flow field: the vibration of the surface to be processed has parallel and vertical components with the solid-liquid interface. On the one hand, the parallel component generates tangential stress on the electrolyte, causing the electrolyte at the solid-liquid interface to form a micro-vortex, promoting the flushing effect of the electrolyte on the processed surface, and thinning the fluid boundary layer. On the other hand, the vertical component generates normal stress on the electrolyte, ejecting the electrolyte near the surface to be processed, promoting the timely discharge of electrolytic products and the timely update of fresh electrolyte.

[0092] (4) The device and method for mask electrochemical machining by electrostatic induction and surface acoustic wave provided by the application improve the problems of uneven electric field distribution and delayed electrolyte update from two major sources of electric field and flow field, so as to improve the mask electrochemical machining precision of metal microstructure.

[0093] Figure 22 It is a schematic diagram of the principle of multi-workpiece parallel processing. Since the workpiece 532 is non-contact powered, etching can be achieved as long as current passes through, so the mask electrochemical method of the induction electrode of the application can be used for multi-workpiece parallel processing. The specific steps are as follows:

[0094] S1. A photoresist mask pattern 5322 is made on the surface 5323 to be processed of the workpiece 532. Through standard processes such as uniform coating, photoresist exposure, and development, the photoresist film is patterned to expose the conductive surface to be processed 5323.

[0095] S2. The patterned workpiece 532 is inlaid in the shielding baffle 521 to form a shielding induction electrode assembly 53 with the piezoelectric ceramic 531. The appropriate anode-cathode distance is selected, and the cathode assembly 52, three shielding induction electrode assemblies 53, and the anode assembly 54 are inserted into the limiting groove 519 of the electrolytic cell 51.

[0096] S3. The piezoelectric ceramic 531 is connected to the signal line 2 to input megasonic signals, and the megasonic vibration generated by the piezoelectric ceramic 531 propagates in the form of surface acoustic wave on the surface of the shielding baffle 521 and the workpiece 532.

[0097] S4. Select appropriate duty cycle and voltage, turn on the power supply 6, connect the cathode plate 522 and the anode plate 541 through the power supply line 8, and realize the electrolytic machining process.

[0098] The method can significantly improve the precision of mask electrolytic processing of microstructure, and ensure the use performance of the microstructure device. Under the processing conditions of current density 4 A / cm2, electrolysis time 75 s, and 15% sodium chloride electrolyte, the original microgroove array of 100 μm is processed by the electrostatic induction and sound surface wave mask electrolytic processing method, and the problem of poor uniformity and localization of the mask electrolytic processing technology is solved. After the microgroove processing, the etching factor EF of the new method is 6.41, and the coefficient of variation CV is 3.57%. Compared with the traditional anode etching method (EF=0.95, CV=8.36%), the EF of the new method is increased by 575%, and the CV value is reduced by 57.3%, and the etching uniformity and localization are greatly improved. It can be seen that the method can effectively improve the processing precision of the metal microstructure.

[0099] In summary, the electrostatic induction and sound surface wave mask electrolytic processing device and method provided by the embodiments of the present application can process multiple workpieces in parallel without directly supplying power to the workpieces, and promote the discharge of electrolysis products by using the sound surface wave, thereby improving the processing efficiency and greatly improving the processing precision of the metal microstructure.

[0100] The above embodiments only express the implementation of the present application, but cannot be interpreted as a limitation on the scope of the patent of the present application. It should be pointed out that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which all belong to the protection scope of the present application.

Claims

1. An apparatus for electrochemical machining with electrostatic induction and acoustic surface wave mask, characterized in that, The device comprises a signal generator (1), a pump (3), a hose (4), an electrolysis system (5), a power supply (6), a liquid storage tank (7), and a power amplifier (9); the electrolysis system (5) is connected to the power supply (6) through a power supply line (8) for power supply; one end of the electrolysis system (5) is connected to one end of the pump (3) through the hose (4); the other end of the pump (3) is connected to one end of the liquid storage tank (7) through another hose (4); the other end of the liquid storage tank (7) is connected to the electrolysis system (5) through a third hose; the circulation and filtration of electrolyte (10) in the electrolysis system (5) are driven by the pump (3); the piezoelectric ceramic (531) in the electrolysis system (5) is connected to the output end of the power amplifier (9) through a signal line (2); the input end of the power amplifier (9) is connected to the signal generator (1) through another signal line (2); the piezoelectric ceramic (531) is controlled to generate different surface waves by adjusting the output of the signal generator (1); The electrolysis system (5) comprises an electrolytic tank (51), a cathode assembly (52), a shielded induction electrode assembly (53), and an anode assembly (54) arranged inside the electrolytic tank (51); the shielded induction electrode assembly (53) is arranged between the cathode assembly (52) and the anode assembly (54) and the three assemblies are arranged in parallel; the electrolytic tank (51) has multiple pairs of limiting grooves (519); the cathode assembly (52), the shielded induction electrode assembly (53), and the anode assembly (54) are inserted into the limiting grooves (519) of the electrolytic tank (51) and are fixed through the limiting grooves (519); according to the different positions of the cathode assembly (52), the shielded induction electrode assembly (53), and the anode assembly (54) inserted into the limiting grooves (519) of the electrolytic tank (51), the three electrode spacings can be reasonably adjusted; The cathode assembly (52) comprises a shielded baffle (521) and a cathode plate (522); the shielded baffle (521) is made of insulating material and has a through hole (5211); the cathode plate (522) is inlaid in the through hole (5211) of the shielded baffle (521); the cathode plate (522) is connected to the negative electrode of the power supply line (8); the front surface of the cathode plate (522) is in contact with the electrolyte and undergoes a reduction reaction; the back surface of the cathode plate (522) has an insulating layer; the surface opposite to the anode plate (541) of the cathode plate (522) is the front surface of the cathode plate (522); The shielded induction electrode assembly (53) comprises a shielded baffle (521), a workpiece (532), and a piezoelectric ceramic (531); the piezoelectric ceramic (531) vibrates under the driving voltage in the signal line (2) and generates surface waves on the surfaces of the shielded baffle (521) and the workpiece (532); the surface to be machined (5323) of the workpiece (532) has a mask pattern (5322); the surface opposite to the cathode plate (522) of the workpiece (532) is the surface to be machined (5323) and undergoes an oxidation reaction; the surface opposite to the anode plate (541) is a non-machining surface (5321) and undergoes a reduction reaction; The anode assembly (54) comprises a shielding baffle (521) and an anode plate (541), the anode plate (541) is inlaid in the through hole (5211) of the shielding baffle (521), the anode plate (541) is connected with the positive pole of the power line (8), the front surface of the anode plate (541) is in contact with the electrolyte, oxidation reaction occurs, and the back surface of the anode plate (541) has an insulating layer; the surface opposite to the cathode plate (522) of the anode plate (541) is the front surface of the anode plate (541).

2. The apparatus of claim 1, wherein the apparatus further comprises a static induction synergic acoustic surface wave mask electrochemical machining device. The electrolytic cell (51) comprises a shell (517), a framework (511), a sponge (512), a filter screen (513), a vertical plate (514), a positioning plate (515), a lower clamping groove (516) and an upper clamping groove (518) arranged in the shell (517). The framework (511) is a long strip plate structure, is horizontally arranged above the shell, and is provided with a plurality of fitting grooves (5111); the sponge (512) is a sheet structure, is arranged between two filter screens (513); the filter screen (513) is vertically arranged on both sides of the shell (517), and two vertical plates (514) are vertically arranged in the shell (517) and close to the filter screen (513); the positioning plate (515) is vertically arranged and close to the side surface of the vertical plate (514), the lower clamping groove (516) is horizontally arranged on the lower surface of the shell (517), and the upper clamping groove (518) is horizontally arranged above the shell (517); after the framework (511), the sponge (512), the filter screen (513), the vertical plate (514), the positioning plate (515), the lower clamping groove (516) and the upper clamping groove (518) are assembled, they are placed into the shell (517) to form a stable electrolytic cell (51); after the electrolyte enters the electrolytic cell (51), the bubbles are filtered out by the sponge (512), pass through the electrolysis area between the two vertical plates (514), are filtered by another sponge (512) again, and flow to the pump (3).

3. The apparatus of claim 1, wherein the apparatus further comprises a static induction sensor. The liquid storage tank (7) comprises a sealing screen (701) and a liquid storage pool (702), the side surface of the liquid storage pool (702) is provided with two water inlets connected with the pump (3), the other side surface is provided with two water outlets connected with the water inlets of the electrolytic cell (51), the top surface of the liquid storage pool (702) is provided with two water injection holes for adding electrolyte, and the liquid storage tank (7) is sealed by the sealing screen (701).

4. A method of electrochemical machining with electrostatic induction and acoustic surface wave mask, characterized in that, The device is realized based on any one of claims 1-3, and comprises the following steps: S1. A photoresist mask pattern (5322) is made on the surface (5323) to be machined of the workpiece (532), the photoresist exposure and development standard process is used to realize the photoresist patterning, and the conductive surface (5323) to be machined is exposed; S2. The patterned workpiece (532) is inlaid in the shielding baffle (521) to form a shielding sensing electrode assembly (53) with the piezoelectric ceramic (531); a proper anode-cathode distance is selected, and the cathode assembly (52), the shielding sensing electrode assembly (53) and the anode assembly (54) are inserted into the limiting groove (519) of the electrolytic cell (51); the surface of the workpiece (532) opposite to the cathode plate (522) is the surface (5323) to be processed, and oxidation reaction occurs; the surface of the workpiece (532) opposite to the anode plate (541) is the non-processed surface (5321) of the workpiece (532), and reduction reaction occurs; S3. A megasonic signal is input to the piezoelectric ceramic (531) through the signal line (2), and the megasonic vibration generated by the piezoelectric ceramic (531) propagates in the form of surface acoustic wave on the surface of the shielding baffle (521) and the workpiece (532); the surface acoustic wave propagating on the workpiece (532) radiates into the electrolyte (10) to form micro-eddy current and macro-flow of the electrolyte (10), promote the flushing effect of the electrolyte (10) on the surface (5323) to be processed of the workpiece (532), and realize high-precision processing of the metal microstructure; S4. A proper duty ratio and voltage are selected, the power supply (6) is turned on, and the cathode plate (522) and the anode plate (541) are connected to the power supply through the power supply line (8); the current passes through the electrolyte (10) and the workpiece (532), oxidation reaction occurs on the surface (5323) to be processed of the workpiece (532), reduction reaction occurs on the non-processed surface (5321) of the workpiece (532), and the electrolytic processing process is realized; at the same time, the surface acoustic wave propagating on the surface (5323) to be processed of the workpiece (532) forms micro-eddy current and macro-flow in the electrolyte (10), discharges the electrolysis products and supplies fresh electrolyte (10) in time.

5. The method of electrochemical processing by electrostatic induction assisted by surface acoustic waves according to claim 4, characterized in that, The method can process multiple workpieces in parallel, and multiple shielding sensing electrode assemblies (53) are placed side by side in parallel in step S2.

6. The method of electrochemical processing by electrostatic induction assisted by surface acoustic waves according to claim 4, characterized in that, The frequency of the piezoelectric ceramic (531) is above 1 MHz.

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