Design and preparation method of ultra-thin conductive layer of micro-hemispherical resonant gyroscope

Abstract

The present invention discloses a design and preparation method of an ultra-thin conductive layer of a micro-hemispherical resonant gyroscope, comprising: obtaining film thickness distribution data of the inner surface of a micro-hemispherical resonator; calculating the deformation energy of each region of the micro-hemispherical resonator, assuming that the region on the micro-hemispherical resonator where the deformation energy accounts for less than a first threshold as region A, and the rest as region B; obtaining the film thickness r corresponding to the inflection point of the resistivity based on a relationship curve between resistivity and film thickness; assuming that the film thickness of region A and region B is r A =a·r、r B =b·r, a and b are the maximum values ​​of the ratio of the film thickness of the plane area to that of area A and area B; based on r A 、r B After coating the inner surface of the micro-hemispherical resonator, the performance is tested and the r B The present invention is applied to the field of micro-electromechanical technology, and can reduce the film thickness of the area where the deformation energy of the micro-hemispherical resonator accounts for a larger proportion, while ensuring the conductivity of the metal film, thereby achieving the purpose of improving performance.

Description

Technical Field

[0001] The invention relates to the field of micro-electromechanical technology, in particular to a design and preparation method of an ultra-thin conductive layer of a micro-hemispherical resonant gyroscope. Background Art

[0002] Gyroscopes, as key sensors for accurately measuring angle changes and angular velocity, constitute the core cornerstone of high-tech fields such as attitude perception and inertial navigation systems. They play an indispensable role in the leap of aerospace technology and precision control in the field of high-end equipment manufacturing. As one of the representatives of the new generation of gyroscopes, the resonant gyroscope cleverly utilizes the inherent physical properties of the resonant structure, the Coriolis effect, to achieve high sensitivity and high precision detection of angular velocity changes. The micro-hemispherical resonant gyroscope is one of the current research hotspots of resonant gyroscopes. Its notable features are the integration of simple processing procedures, compact geometric dimensions and lightweight design, which has become an important breakthrough in research in this field. Its core advantage is that it not only fully inherits the high performance potential of traditional hemispherical resonant gyroscopes in angular velocity measurement and attitude perception, but also effectively avoids the complex and time-consuming resonator preparation process in the traditional processing process through the innovative micro-blowing glass method.

[0003] In the precision manufacturing process of micro-hemispherical resonant gyroscopes, uniformly depositing a metal film on the surface of a micro-hemispherical resonator is an important step. Given the complex micro-shell structure formed by the micro-blowing glass process, the main feature of which is the concave anchor point, it is difficult for traditional magnetron sputtering thin film technology to achieve thickness consistency of the film in various areas on the micro-hemispherical surface. To ensure that the micro-hemispherical resonant gyroscope meets the conductivity standard required for its efficient operation, the deposited metal film must meet a minimum thickness requirement. However, the non-uniformity of the film thickness often causes the film thickness in certain areas of the resonator surface to far exceed this minimum standard, which is not only a waste of material, but more importantly, it will directly weaken the quality factor of the gyroscope. Therefore, exploring and optimizing the micro-hemispherical film structure and its deposition method has become a key research direction for improving the performance of micro-hemispherical resonant gyroscopes.

[0004] In the current prior art, a Chinese invention patent application with publication number CN112281133A discloses a method for correcting the thickness distribution and uniformity of a resonator film layer, which describes a method for achieving film uniformity by adjusting process parameters after monitoring the film thickness, and mainly adjusts the magnetic field distribution, target-substrate distance, sputtering power, sputtering angle, etc. in sputtering coating. However, this method has the disadvantages of being complex to implement and being implemented on a traditional hemispherical resonant structure that is larger than a micro-hemispherical resonant structure, and having poor adjustment effects on film inhomogeneity of complex microstructures such as micro-hemispherical resonators. Summary of the invention

[0005] The metal film is deposited on the micro-hemispherical resonator to enable conductivity, thereby realizing the excitation, detection and control of the gyroscope. At the same time, the damping brought by the film reduces the quality factor of the gyroscope. In order to reduce the decline in the quality factor of the micro-hemispherical resonator by depositing high-quality metal film, reduce its drift and improve its output accuracy, the present invention provides a design and preparation method of an ultra-thin conductive layer of a micro-hemispherical resonator. Under the premise of ensuring the conductivity of the metal film, the film thickness of the area where the deformation energy of the micro-hemispherical resonator accounts for a larger proportion is reduced, thereby achieving the purpose of improving performance.

[0006] To achieve the above object, the present invention provides a design and preparation method of an ultra-thin conductive layer of a micro-hemispherical resonant gyroscope, comprising the following steps:

[0007] Step 1, obtaining the film thickness distribution data of the inner surface of the micro-hemispherical resonator under different process parameters based on numerical simulation;

[0008] Step 2, obtaining a relationship curve between resistivity and film thickness based on the material of the film, and obtaining the film thickness r corresponding to the inflection point of the resistivity in the relationship curve;

[0009] Step 3, calculating the magnitude of deformation energy of each region of the micro-hemispherical resonator, setting the region on the micro-hemispherical resonator where the deformation energy and the overall ratio are less than the first threshold as region A, and setting the other regions as region B;

[0010] Step 4: Let the film thickness of the region A be r A =a·r, let the film thickness of the region B be r B = b·r, wherein a is the maximum value of the ratio of the film thickness of the plane area on the micro-hemispherical resonator to the film thickness of area A in the film thickness distribution data, and b is the maximum value of the ratio of the film thickness of the plane area on the micro-hemispherical resonator to the film thickness of area B in the film thickness distribution data;

[0011] Step 5: Based on the film thickness r of the current region A and region B A 、r B The inner surface of the micro-hemispherical resonator is coated, and the performance of the coated micro-hemispherical resonator is tested. B Iterate until the performance test passes.

[0012] In one embodiment, step 1 is specifically:

[0013] The uniformity of the film thickness distribution on the inner surface of the micro-hemispherical resonator is divided into circumferential uniformity and radial uniformity.

[0014] The circumferential uniformity is achieved by high-speed rotation during the sputtering coating process, specifically:

[0015] ;

[0016] in, x ( t ), y ( t )for t The sputtering coating position at the moment, R is the revolution radius of the planetary gear of the coating equipment, r is the radius of rotation of the sample for the coating equipment, oh 1 is the planetary gear revolution speed, oh 2 is the planetary gear revolution speed, is the phase angle of the sample during its revolution, is the phase angle of the sample during rotation;

[0017] The radial uniformity is characterized by the film deposition rate, specifically:

[0018] ;

[0019] Among them, d m z For radial position z The film deposition rate at i z For radial position z The angle between the local surface normal and the direction of the sputtered atoms during film deposition, or z For radial position z The oblique sputtering angle during film deposition is L z For radial position z The distance from the sputtering source to the deposition surface during film deposition, d s For radial position z The area of ​​the deposition surface during thin film deposition.

[0020] In one embodiment, in step 3, the calculation of the deformation energy of each region of the micro-hemispherical resonator is specifically:

[0021] The force on the micro-hemispherical resonator is not uniform. Each stress and strain is a function of the position parameter. The micro-hemispherical resonator needs to be integrated as follows:

[0022] ;

[0023] in, V For stress s ,strain e and shear stress c , shear strain t The deformation energy calculated by isovariable parameters, s x ,s y 、 s z , e x 、e y 、e z , c yz 、c zx 、c xy , t yz ,t zx ,t xy is the variable quantity;

[0024] Specifically:

[0025] ;

[0026] in, E is the elastic modulus of the material, m is Poisson's ratio, i is the body strain energy;

[0027] Adopt strain e and shear strain c After expressing it, the deformation energy of the micro-hemispherical resonator can be obtained by integration:

[0028] ;

[0029] in, v is the deformation energy;

[0030] The COMSOL Multiphysics simulation software is used to obtain the strain and shear strain of the micro-hemispherical resonator in the working mode, and the percentage distribution of the deformation energy of the micro-hemispherical resonator can be obtained by integrating them.

[0031] In one embodiment, in step 5, the performance test is a micro-hemispherical resonant gyroscope circuit noise test.

[0032] In one embodiment, the pair r B Iterate until the performance test is passed as follows:

[0033] Step 501, determine the current r B Whether the circuit noise of the micro-hemispherical resonant gyroscope meets the design standard of the gyroscope is:

[0034] If so, let r B =r B - d ·r and then perform step 501 again, wherein, d is the iteration parameter, and 0< d <1;

[0035] Otherwise, proceed to step 502;

[0036] Step 502, let r B =r B + d After r, output the current r A、 r B As a result of design.

[0037] In one embodiment, in step 5, a film is coated on the inner surface of the micro-hemispherical resonator by magnetron sputtering.

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

[0039] 1. The present invention obtains the influence proportion of the quality factor of each position of the micro-hemispherical resonator through numerical simulation, and designs a film structure with regional thickness distribution in combination with the uniform distribution of the film. Under the premise of ensuring the conductivity of the metal film, the film thickness of the area where the deformation energy of the micro-hemispherical resonator accounts for a larger proportion is reduced, thereby achieving the purpose of improving performance;

[0040] 2. The present invention innovatively divides the uniformity of the micro-hemispherical resonator film into circumferential uniformity and longitudinal uniformity. On the premise that the circumferential uniformity can be ensured by high-speed rotation of the planetary gear, a relatively uniform method is used for the longitudinal uniformity. In short, more film is plated in the area that has a large impact on the resistivity but does not reduce the quality factor, and ultra-thin film is plated in the area that has a small impact on the resistivity and has a large proportion of the quality factor. This method can quickly realize the manufacture of micro-hemispherical resonators with high quality factors and low resistivity, which will greatly improve the manufacturing efficiency of micro-hemispherical resonators. It also opens up new ideas and methods for the coating of other high-precision devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0042] Figure 1 Flow chart of the design and preparation method of the ultra-thin conductive layer of the micro-hemispherical resonant gyroscope in an embodiment of the present invention;

[0043] Figure 2Schematic diagram of the thickness distribution of the film on the micro-hemispherical resonator in the embodiment of the present invention;

[0044] Figure 3 A bar graph showing the distribution of film thickness on a micro-hemispherical resonator in an embodiment of the present invention;

[0045] Figure 4 is a curve diagram showing the relationship between film thickness and resistivity in an embodiment of the present invention;

[0046] Figure 5 A schematic diagram of the operation of a micro-hemispherical resonator in an embodiment of the present invention;

[0047] Figure 6 Schematic diagram of the thin film mask coating process in an embodiment of the present invention.

[0048] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0051] This embodiment discloses a design and preparation method for an ultra-thin conductive layer of a micro-hemispherical resonator gyroscope, which reduces the film thickness of the area where the deformation energy of the micro-hemispherical resonator accounts for a larger proportion while ensuring the electrical conductivity of the metal film, thereby achieving the purpose of improving performance.

[0052] refer to Figure 1 The design and preparation method of the ultra-thin conductive layer of the micro-hemispherical resonant gyroscope in this embodiment mainly includes the following steps:

[0053] Step 1, obtaining the film thickness distribution data of the inner surface of the micro-hemispherical resonator under different process parameters based on numerical simulation;

[0054] Step 2, obtaining a relationship curve between resistivity and film thickness based on the material of the film, and obtaining the film thickness r corresponding to the inflection point of the resistivity in the relationship curve;

[0055] Step 3, calculating the magnitude of deformation energy of each region of the micro-hemispherical resonator, setting the region on the micro-hemispherical resonator where the deformation energy and the overall ratio are less than the first threshold as region A, and setting the other regions as region B;

[0056] Step 4: Let the film thickness of region A be r A =a·r, let the film thickness in region B be r B = b·r, where a is the maximum value of the ratio of the film thickness of the plane area on the micro-hemispherical resonator to the film thickness of area A in the film thickness distribution data, and b is the maximum value of the ratio of the film thickness of the plane area on the micro-hemispherical resonator to the film thickness of area B in the film thickness distribution data;

[0057] Step 5: Based on the film thickness r of the current region A and region B A 、r B The inner surface of the micro-hemispherical resonator is coated, and the performance of the coated micro-hemispherical resonator is tested. B Iterations are performed until the performance test is passed, wherein preferably, a film is coated on the inner surface of the micro-hemispherical resonator by magnetron sputtering.

[0058] The physical process of magnetron sputtering depositing thin films on the inner surface of a micro-hemispherical resonator is mainly divided into Ar+ impacting the target surface, target atom emission and transportation, and thin film deposition on the substrate. Therefore, in the specific implementation of step 1, the uniformity of the film thickness distribution on the inner surface of the micro-hemispherical resonator is divided into circumferential uniformity and radial uniformity.

[0059] Circumferential uniformity is mainly achieved through high-speed rotation during sputtering, namely:

[0060] (1)

[0061] in, x ( t ), y ( t )for t The sputtering coating position at the moment, R is the revolution radius of the planetary gear of the coating equipment, r is the radius of rotation of the sample for the coating equipment, oh 1 is the planetary gear revolution speed, oh 2 is the planetary gear revolution speed, is the phase angle of the sample during its revolution, is the phase angle of the sample during rotation;

[0062] It can be seen from formula (1) that high-speed rotation can effectively improve the circumferential uniformity of the micro-hemispherical resonator, that is, the uniformity of the film in the XY plane. Radial uniformity usually requires adjustment of process parameters to achieve, and it is relatively complicated. In the installation of the target material, γ is used as the setting of the target material inclination angle, and the combination of the Ar+ ion incident angle α and the sputtered atom exit angle β is better than vertical incidence for specific structures of the resonator (such as anchor points and concave areas of the skirt). The regulation of the film deposition rate involves multiple key parameters, mainly including the exit angle β of the sputtered atoms, the distance L from the sputtering source to the deposition surface, and the cosθ deposition mode determined by the angle θ between the local surface normal and the sputtered atom direction during the deposition process, specifically:

[0063] ;

[0064] Among them, d m z For radial position z The film deposition rate at i z For radial position z The angle between the local surface normal and the direction of the sputtered atoms during film deposition, or z For radial position z The oblique sputtering angle during film deposition is L z For radial position z The distance from the sputtering source to the deposition surface during film deposition, d s For radial position z The area of ​​the deposition surface during thin film deposition.

[0065] For example, when the oblique sputtering angle is 45°, the sputtering distance is 1500 mm, and the rotation speed during the sputtering coating process is sufficient, the results of the thin film simulation are as follows: Figure 2 , Figure 3 As shown. Figure 2 , Figure 3 It can be seen that the film thickness on the inner surface of the micro-hemispherical resonator is uniformly distributed along the circumference and regionally distributed along the longitudinal direction. Among them, the thickest area of ​​the film is the plane of the anchor rod and the shell teeth, that is, Figure 3 Points 1 and 2 in the figure; the thinnest area of ​​the film is the concave part of the anchor rod, that is, Figure 3 Point 4 in.

[0066] The performance of a micro-hemispherical resonator is deeply affected by the deformation energy distribution and energy dissipation mechanism in each region. Accurately analyzing the proportion of deformation energy in these regions is crucial to quantifying the effect of film damping on the quality factor (Q value) of the entire resonator. The force on the micro-hemispherical resonator is not uniform, and each stress and strain is a function of the position parameter. The resonator needs to be integrated as follows:

[0067] ;

[0068] in, V For stress s ,strain e and shear stress c , shear strain t The deformation energy calculated by isovariable parameters, s x ,s y 、 s z , e x 、e y 、e z , c yz 、c zx 、c xy , t yz ,t zx ,t xy is the variable quantity;

[0069] Specifically:

[0070] ;

[0071] in, E is the elastic modulus of the material, m is Poisson's ratio, i is the body strain energy;

[0072] Adopt strain e and shear strain c After expressing it, the deformation energy of the micro-hemispherical resonator can be obtained by integration:

[0073] ;

[0074] in, v is the deformation energy;

[0075] The COMSOL Multiphysics simulation software is used to obtain the strain and shear strain of the micro-hemispherical resonator in the working mode, and the percentage distribution of the deformation energy of the micro-hemispherical resonator can be obtained by integrating them.

[0076] The deformation energy of an object will cause energy dissipation due to damping, which will in turn affect the quality factor of the micro-hemispherical gyroscope. Figure 2 , Figure 3The results of numerical simulation of the micro-hemispherical resonator in the example show that the deformation energy of the anchor rod of the micro-hemispherical resonator only accounts for 0.9% of the whole, so depositing a thin film on the anchor rod will not affect the overall quality factor of the gyroscope. The deformation energy on the shell accounts for 99.1% of the whole, so the metal film on the shell is the main area that affects the overall quality factor of the gyroscope. Therefore, in step 2, when the first threshold is set to 1%, the anchor rod area on the micro-hemispherical resonator is area A, and the other areas are area B.

[0077] The thickness of the metal film has a great relationship with the resistivity. The thicker the film, the stronger the conductivity. There is also an obvious inflection point r (nm) of the resistivity, such as Figure 4 As shown. If the micro-hemispherical resonator film is radially uniform, then only the film thickness at the inflection point needs to be deposited. The micro-hemispherical resonator has a non-uniform film thickness caused by the morphology structure. Figure 2 , Figure 3 In the example, the thinnest part is the concave part of the anchor rod, and its thickness is only 30% of the film thickness at the plane position. Because the conductivity of the film is determined by the thinnest area in the longitudinal direction, in theory, a metal film with a thickness of 3.3r (nm) should be designed and deposited to obtain a micro-hemispherical resonator with better conductivity. However, the design value of 3.3r (nm) will greatly reduce the quality factor of the micro-hemispherical gyroscope because the film thickness is too thick. If the second thinnest position of the resonator is selected as a design consideration, the thickness of this position is 50% of the plane position, so only a film with a thickness of 2r (nm) needs to be designed and deposited to meet the requirements. The film deposited on the anchor rod of the micro-hemispherical resonator will not affect the quality factor of the resonator. You can choose to design a thicker 3.3r (nm) film on the anchor rod to solve the problem of excessive resistivity caused by insufficient film thickness. Resistivity mainly refers to the resistivity from the shell teeth to the anchor point, such as Figure 5 As shown, Figure 5 Middle: C j and C i Represents the plate capacitor composed of different shell teeth, R j , R i Represents the resistance between the shell teeth and the anchor point, V D represents the applied excitation voltage, V sw Represents the demodulated carrier signal, V H Indicates the high voltage at the detection end.

[0078] According to the above analysis, only a 2r (nm) thick film is needed for the other shell parts. The designed film of the micro-hemispherical resonator is a layered structure with a thick film at the anchor rod and a thin film at the shell, which reduces the thickness by 40% compared with the direct design of 3.3r (nm). This will greatly reduce the film damping and effectively improve the quality factor of the micro-hemispherical resonator. That is, in the film thickness distribution data in step 4, the maximum value a=3.3 of the ratio of the film thickness of the plane area on the micro-hemispherical resonator to that of area A, and the maximum value b=2 of the ratio of the film thickness of the plane area on the micro-hemispherical resonator to that of area B in the film thickness distribution data.

[0079] In the specific implementation of step 5, magnetron sputtering is used to coat the inner surface of the micro-hemispherical resonator. The thin film material prepared by magnetron sputtering is usually high-quality, dense, and uniform, and the sputtered film has good mechanical strength and adhesion to the substrate, which improves the firmness and durability of the coating. These advantages are most needed for the micro-hemispherical resonant gyroscope, so the use of magnetron sputtering coating plus masking can deposit ultra-thin film structures.

[0080] In this embodiment, the preparation of the mask includes three parts, namely: finite element simulation to solve the shape of the micro-hemispherical resonator formed by the glass micro-blowing method, three-dimensional modeling mask and 3D printing mask.

[0081] When discussing the softening deformation behavior of fused quartz under thermal stress, the complex physical mechanisms behind it are deeply analyzed. These mechanisms are intertwined with the close coupling effects of mechanics and heat, the dynamic behavior of non-Newtonian fluids, the precise setting of contact interface conditions, and the high-precision mesh processing strategy required for large deformation problems. Specifically, the concentrated heat flux generated by the blowtorch efficiently acts on the upper surface of the fused quartz sheet, triggering the efficient absorption and conduction of heat. Part of the heat energy penetrates into the graphite mold below through the heat conduction path, while the remaining heat directly causes the temperature of the quartz sheet to increase significantly. With the increase of temperature, the physical properties of fused quartz change significantly, especially its viscosity characteristics show a significant trend of decreasing temperature dependence, which lays the foundation for the subsequent deformation behavior. Driven by multiple external forces (such as the pressure difference between the upper and lower surfaces, the effect of the earth's gravity field, and the possible centrifugal force effect), the fused quartz sheet begins to undergo a complex deformation process, and its height and contour morphology are gradually adjusted and reshaped over time. In order to accurately capture and predict this complex physical process, this embodiment introduces an advanced finite element analysis method as a research tool. This method effectively simulates the stress distribution evolution of the fused quartz sheet during the softening deformation process and the morphological changes of the final shell structure by virtue of its powerful multi-physics field coupling capability, accurate description of nonlinear material behavior, and dynamic adaptive adjustment of the grid under large deformation conditions. At the same time, the results of the finite element analysis of the external structure of the micro-hemispherical resonator are also the basis for the film thickness distribution in step 1.

[0082] In addition, high-precision 3D printers have significant advantages in design and manufacturing flexibility, manufacturing efficiency and speed, precision and detail performance, material diversity, and cost-effectiveness. Traditional 2D mask production, such as chemical etching and photolithography, is difficult to apply to the complex 3D mask manufacturing required for thin film deposition on the inner surface of micro-hemispherical resonators. Although mechanical processing of high-precision microstructures is feasible, efficiency and difficulty are problems. With the leap of 3D printing technology, new ways have been opened up for the production of high-precision microstructures, providing more flexible and efficient options.

[0083] In the specific implementation process of step 5, the performance test is a micro-hemispherical resonant gyroscope circuit noise test, the main function of which is to find the thinnest shell film thickness and maximize the quality factor of the micro-hemispherical resonant gyroscope. The specific process is:

[0084] Step 501, determine the current r B Whether the circuit noise of the micro-hemispherical resonant gyroscope meets the design standard of the gyroscope is:

[0085] If so, let r B =r B - d ·r and then perform step 501 again, wherein, d is the iteration parameter, and 0< d <1;

[0086] Otherwise, proceed to step 502;

[0087] Step 502, let r B =r B + d After r, output the current r A、 r B As a result of design.

[0088] For example, when the thickness of region A is 3.3r (nm), the thickness of region B is 2r (nm), and δ= When 0.1, a 2r (nm) thin film is first deposited on the entire inner surface of the micro-hemispherical resonator, and then a 1.3r (nm) thin film is deposited on the anchor rod using a mask, for example Figure 6 As shown, the circuit noise caused by the micro-hemispherical resonant gyroscope film is then measured. If the circuit noise meets the design standard of the gyroscope, the film thickness on the inner surface is reduced to 1.9r (nm). After the nth attempt fails to meet the circuit noise requirement, the film thickness of the n-1th attempt is selected as the final design thickness.

[0089] It is worth noting that although this embodiment Figure 1The steps in the process are shown in sequence as indicated by the arrows, but the steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of the steps, and the steps can be executed in other orders. Figure 1 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0090] The above description is only a preferred embodiment of the present invention, and does not limit the protection scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the protection scope of the present invention.

Claims

1. A design and preparation method of an ultra-thin conductive layer of a micro-hemispherical resonant gyroscope, characterized in that: The steps include: Step 1, obtaining the film thickness distribution data of the inner surface of the micro-hemispherical resonator under different process parameters based on numerical simulation; Step 2, calculating the magnitude of deformation energy of each region of the micro-hemispherical resonator, setting the region on the micro-hemispherical resonator where the deformation energy and the overall proportion are less than a first threshold as region A, and setting the other regions as region B; Step 3, obtaining a relationship curve between resistivity and film thickness based on the material of the film, and obtaining the film thickness r corresponding to the inflection point of the resistivity in the relationship curve; Step 4: Let the film thickness of the region A be r A =a·r, let the film thickness of the region B be r B = b·r, wherein a is the maximum value of the ratio of the film thickness of the plane area on the micro-hemispherical resonator to the film thickness of area A in the film thickness distribution data, and b is the maximum value of the ratio of the film thickness of the plane area on the micro-hemispherical resonator to the film thickness of area B in the film thickness distribution data; Step 5: Based on the film thickness r of the current region A and region B A 、r B The inner surface of the micro-hemispherical resonator is coated, and the performance of the coated micro-hemispherical resonator is tested. B Iterate until the performance test passes.

2. The design and preparation method of the ultra-thin conductive layer of the micro-hemispherical resonant gyroscope according to claim 1 is characterized in that: Step 1 is as follows: The uniformity of the film thickness distribution on the inner surface of the micro-hemispherical resonator is divided into circumferential uniformity and radial uniformity. The circumferential uniformity is achieved by high-speed rotation during the sputtering coating process, specifically: ； in, x ( t ), y ( t )for t The sputtering coating position at the moment, R is the revolution radius of the planetary gear of the coating equipment, r is the radius of rotation of the sample for the coating equipment, ω 1 is the planetary gear revolution speed, ω 2 is the planetary gear revolution speed, is the phase angle of the sample during its revolution, is the phase angle of the sample during rotation; The radial uniformity is characterized by the film deposition rate, specifically: ； Among them, d m z For radial position z The film deposition rate at θ z For radial position z The angle between the local surface normal and the direction of the sputtered atoms during film deposition, η z For radial position z The oblique sputtering angle during film deposition is L z For radial position z The distance from the sputtering source to the deposition surface during thin film deposition, d s For radial position z The area of ​​the deposition surface during thin film deposition.

3. The design and preparation method of the ultra-thin conductive layer of the micro-hemispherical resonant gyroscope according to claim 1 is characterized in that: In step 3, the calculation of the deformation energy of each region of the micro-hemispherical resonator is specifically as follows: The force on the micro-hemispherical resonator is not uniform. Each stress and strain is a function of the position parameter. The micro-hemispherical resonator needs to be integrated as follows: ； Where V is the stress σ ,strain ε and shear stress γ , shear strain τ The deformation energy calculated by isovariable parameters, σ x , σ y , σ z , ε x 、 ε y , ε z , γ yz , γ zx , γ xy , τ yz , τ zx , τ xy is the variable quantity; Specifically: ； in, E is the elastic modulus of the material, μ is Poisson's ratio, θ is the body strain energy; Adopt strain ε and shear strain γ After expressing it, the deformation energy of the micro-hemispherical resonator can be obtained by integration: ； in, v is the deformation energy; The COMSOL Multiphysics simulation software is used to obtain the strain and shear strain of the micro-hemispherical resonator in the working mode, and the percentage distribution of the deformation energy of the micro-hemispherical resonator can be obtained by integrating them.

4. The method for designing and preparing an ultra-thin conductive layer of a micro-hemispherical resonant gyroscope according to claim 1, 2 or 3, characterized in that: In step 5, the performance test is a circuit noise test of a micro-hemispherical resonant gyroscope.

5. The design and preparation method of the ultra-thin conductive layer of the micro-hemispherical resonant gyroscope according to claim 4 is characterized in that: The pair B Iterate until the performance test is passed as follows: Step 501, determine the current r B Whether the circuit noise of the micro-hemispherical resonant gyroscope meets the design standard of the gyroscope is: If so, let r B =r B - δ ·r and then perform step 501 again, wherein, δ is the iteration parameter, and 0< δ <1; Otherwise, proceed to step 502; Step 502, let r B =r B + δ After r, output the current r A、 r B As a result of design.

6. The method for designing and preparing an ultra-thin conductive layer of a micro-hemispherical resonant gyroscope according to claim 1, 2 or 3, characterized in that: In step 5, a film is coated on the inner surface of the micro-hemispherical resonator by magnetron sputtering.

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