Tool for detecting coating uniformity of harmonic oscillator
By designing a fixture that combines a jig and a test piece, the coating process was simulated and the film thickness was measured. This solved the problems of accuracy and efficiency in detecting the uniformity of hemispherical resonator coating, and improved the coating quality and resonator performance.
Patent Information
- Application Number
- CN202423266568.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-12-02
- Estimated Expiration
- 2034-12-27
AI Technical Summary
In the existing technology, it is difficult to detect the uniformity of the coating of hemispherical harmonic oscillators. Traditional methods have problems such as low experimental accuracy, low efficiency and high operation difficulty, which affect the vibration characteristics and measurement accuracy of the harmonic oscillator.
Design a tooling comprising a quarter-hemisphere fixture and a test piece. Fix the test piece by pre-setting grooves on the fixture to simulate the coating process. After coating, measure the film thickness and evaluate the coating uniformity using instruments such as an interferometer or an atomic force microscope.
It improves the accuracy and efficiency of coating uniformity detection, reduces operational difficulty, ensures coating quality, and enhances the measurement accuracy and service life of hemispherical resonators.
Smart Images
Figure CN223623578U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of precision manufacturing technology of hemispherical resonant gyroscopes, and in particular relates to a tooling for detecting the uniformity of the coating of the resonator. Background Technology
[0002] The principle of a hemispherical resonant gyroscope is to utilize the Coriolis effect generated by the rotation of a harmonic oscillator in radial standing wave vibration, which causes the mode shape to shift, thereby achieving angle or rotational speed measurement. Hemispherical resonant gyroscopes possess advantages such as good stability, long lifespan, high reliability, resistance to nuclear radiation, resistance to shock vibration, and short start-up time. They have great application prospects in aviation, aerospace, navigation, and civilian fields, and are hailed as a revolutionary and disruptive technology in the field of inertial navigation, possessing significant strategic importance.
[0003] The hemispherical resonator is the core component of a hemispherical resonator gyroscope, and its material is typically high-quality fused silica. When the hemispherical resonator gyroscope is working, the inner and outer spherical surfaces of the hemispherical resonator need to be metallized to make them conductive. Electrostatic excitation then causes the metallized hemispherical resonator to vibrate. By monitoring the capacitance change between the hemispherical resonator and the readout electrode, the vibration and displacement changes of the hemispherical resonator are measured, and the rotation angle of the gyroscope can be calculated.
[0004] In actual production, controlling the thickness and uniformity of the metallization film layer on a hemispherical resonator is technically challenging, requiring various precision machining processes to make it as close as possible to an ideal axisymmetric shape. The thickness, adhesion, and uniformity of the metallization film layer on the insulating surface of the hemispherical resonator directly affect its vibration characteristics. If the film is non-uniform, the adhesion is too high or too low, or the film has internal stress, the frequency difference of the resonator will increase. Non-uniform metallization on the resonator surface directly leads to differences in surface quality, causing increased frequency fragmentation, and consequently reducing the measurement accuracy and lifespan of the hemispherical resonator gyroscope. Therefore, accurate and effective evaluation of the uniformity of the ultrathin film layer on the resonator surface is crucial.
[0005] Coating is performed on a spherical surface, making the measurement of thin film properties very difficult. A common method is the patch method, which uses patches attached to the entire fixture to evaluate the uniformity of a hemispherical harmonic oscillator, treating the spherical surface as multiple planes, thus simplifying the measurement of curved thin films into the measurement and analysis process of planar thin films. Before coating, several partially obscured patches are attached to the surface of the harmonic oscillator. After coating, the obscured parts are removed, creating a step at the junction of the areas with and without the film on the patch surface. The height of the step is the film thickness. Because the patches have a certain thickness and the attachment position cannot be precisely controlled, the edges of the film are easily damaged when the patches are removed, resulting in low experimental accuracy. Huazhong University of Science and Technology designed a coating fixture with grooves on the surface of the fixture to hold the patches in place. However, this design has high requirements for processing technology and is quite difficult. Moreover, it still requires pre-treatment with tape during sample preparation, affecting the coating quality and causing differences from the actual coating, resulting in low experimental efficiency. The Huazhong Institute of Optoelectronic Technology designed a uniformity testing fixture with multiple loading holes distributed on the outer spherical surface of the fixture. A circular test piece is fixed by steps inside the holes. However, this fixing method requires a high level of operational skill, and the test piece does not have a film thickness step on its surface, which places high demands on the testing. Utility Model Content
[0006] The technical problem solved by this utility model is to address the problems existing in the prior art by proposing a tooling for detecting the uniformity of the coating of a resonator. Before the formal coating process, the tooling is used to pre-evaluate the thickness and uniformity of the coating layer, thereby making corrections to the coating process.
[0007] The technical solution of this utility model:
[0008] A fixture for detecting the uniformity of a resonator coating, the fixture comprising:
[0009] Two fixtures A1, two fixtures B2, and multiple test pieces 3;
[0010] Each clamp A1 and each clamp B2 is a quarter hemisphere. When two clamps A1 and two clamps B2 are assembled at intervals, they form a whole hemispherical clamp.
[0011] Each of the two clamps A1 and the two clamps B2 has a preset number of grooves 4 on the same side. The other side of the two clamps A1 and the two clamps B2 is a smooth surface. The preset number of grooves 4 are arranged along the direction of the center of the ball. The width and thickness of the grooves 4 match the test piece. One groove 4 is used to place one test piece 3.
[0012] Furthermore,
[0013] The surface of each groove 4 is partially covered. After the test piece 3 is inserted into the groove, it is in a state of being half covered and half exposed. The exposed position of the test piece 3 is the actual coating position of the resonator.
[0014] Furthermore,
[0015] Each clamp A1 has splicing rods 7 on both sides of its bottom, and each clamp B2 has corresponding locking positions 8 on both sides of its bottom. The splicing rods 7 of clamp A1 are inserted into the locking positions 8 of clamp B2 and fixed with screws 5, so that the groove end face of clamp A1 and the smooth surface of clamp B2 are in close contact, thereby fixing the test piece in the groove.
[0016] Furthermore,
[0017] The grooves on the two clamps A1 and the two clamps B2 are exactly the same size, and the distance from the position of the groove on each ring of the hemispherical clamp to the axis of the hemisphere is exactly the same.
[0018] Furthermore,
[0019] When the two clamps A1 and the two clamps B2 are assembled at intervals to form a hemispherical clamp, all the grooves 4 are distributed in a cross shape on the inner wall of the hemispherical clamp.
[0020] Furthermore,
[0021] The tooling also includes: a clamping rod 6;
[0022] The tooling is fixedly connected to the clamping device on the coating machine via the clamping rod 6;
[0023] The coating machine coats the inner wall of a hemispherical fixture. The part of the test piece covered by the groove is not coated, while the part exposed on the test piece is coated. After the test piece is removed, the coating thickness is measured to evaluate the coating uniformity of the coating machine.
[0024] By designing a fixture with the same shape as the hemispherical harmonic oscillator, the actual coating uniformity of the hemispherical harmonic oscillator is simulated. The thickness steps of the film on both sides of the test piece are measured using an interferometer or atomic force microscope. By comparing the differences in film thickness at different locations, uniformity data can be accurately obtained, realizing the evaluation of the metallization coating uniformity of the hemispherical harmonic oscillator. This is beneficial for product improvement and quantitative evaluation and acceptance. Attached Figure Description
[0025] Figure 1 This is an exploded structural diagram of the present invention;
[0026] Figure 2 This is an assembly structure diagram of the present invention;
[0027] Figure 3 This is the front view plan view of this utility model;
[0028] Figure 4 This is a cross-sectional structural diagram of the present invention;
[0029] Figure 5 This is a structural diagram of the tooling;
[0030] Figure 6 for Figure 1 A magnified view of a portion of the image;
[0031] Figure 7 This is a structural diagram of the test piece;
[0032] Figure 8 This is a structural diagram of the clamping rod. Detailed Implementation
[0033] To address the problems existing in the prior art, this utility model proposes a tooling scheme for detecting the uniformity of the coating of a resonator. Before the formal coating process, the device is used to pre-evaluate the film thickness and uniformity, thereby making corrections to the coating process.
[0034] This utility model provides an evaluation device for the uniformity of metallization coating on a hemispherical resonator, including fixtures (including mating parts 1 and 2), a test piece 3, a clamping rod 6, and four screws 5. The four fixtures are quarter-hemispherical in shape and are assembled into a complete hemispherical shape. Each fixture has multiple evenly arranged grooves extending towards the center of the hemispherical shape on one side for placing the test piece. The grooves are semi-closed and semi-exposed; the test piece is shaped to fit the grooves through tolerance design and can be inserted into the grooves. The exposed portion of the test piece corresponds to the actual coated surface of the resonator, while the covered portion is uncoated, forming a thickness step with the coated area. The clamping rod is fixed at the center of the hemispherical shape after the fixtures are assembled.
[0035] Furthermore, the four fixtures are secured with four screws. Two of the fixtures have protruding splicing rods with threaded holes on both sides of their bottom, while the other two fixtures have threaded locking slots on both sides of their bottom that match the splicing rods. The four fixtures are secured by inserting the splicing rods into the locking slots and then securing them with screws. After the four fixtures are assembled, the smooth, groove-free surfaces of the fixtures can firmly hold the test pieces of adjacent fixtures within their grooves, preventing the test pieces from falling off or sliding during the coating process. The fixtures achieve this fixation solely through their tight fit, making clamping and removal very convenient. This allows for rapid assembly and disassembly, improving experimental efficiency.
[0036] Furthermore, multiple grooves on the side of the fixture extend from the lip of the sphere to its center. The width and depth of these grooves are equal to the width and thickness of the test piece, respectively. Through tolerance fitting, the test piece is secured by mutual side-to-side contact, allowing it to be easily inserted into the grooves without adhesive bonding and preventing it from falling off. This avoids the scratches and peeling of the film edges that occur during traditional patch removal methods. The coated test piece can be easily and completely removed without damaging the film, thus improving evaluation accuracy.
[0037] Furthermore, since the grooves on the fixture are all the same size, and the distance from the test piece groove position to the hemispherical axis of each row on the fixture is all the same, the error caused by inaccurate position control in the traditional patching method is avoided, thus improving experimental efficiency and accuracy.
[0038] Furthermore, the fixture was designed with the machining difficulty in mind, and the device is reusable, which reduces experimental costs and subsequent maintenance costs.
[0039] Example 1:
[0040] This example provides a device for evaluating the uniformity of metallization coating on a hemispherical resonator. The device is fixed to the coating machine. After the coating is completed, the operator detects the film thickness at different locations on the device and statistically analyzes the data to determine the uniformity of the resonator coating. The uniformity of the coating can be corrected before the formal coating to ensure the accuracy of the hemispherical resonator.
[0041] See Figures 1-6 Specifically, the uniformity testing device proposed in this scheme includes two clamps A1, two clamps B2, some test pieces 3, four screws 5, and a clamping rod 6.
[0042] Among them, clamps A1 and B2 are in the shape of a quarter hemisphere, and the four clamps are assembled to form a whole hemispherical clamp, such as Figure 2 It can be regarded as a hemispherical shell with a certain thickness.
[0043] Fixtures A1 and B2 have five grooves 4 on one side, arranged along the center of the sphere. It should be noted that the surface of each groove is partially covered. After the test piece is inserted into the groove, it is in a state of partial coverage and partial exposure. The exposed position is the actual coating surface of the resonator.
[0044] In this embodiment, the width and thickness of the groove match the test piece. The groove 4 has a depth of 6.1 mm, a width of 2.1 mm, and a thickness of 0.5 mm. The test piece 3 can be separated from clamps A1 and B2 and can be inserted and removed.
[0045] Grooves 4 are distributed on the inner wall of the fixture, see [reference]. Figure 6 On the orthographic projection plane, the grooves 4 are distributed in a cross shape on the inner walls of clamps A1 and B2. The grooves 4 are evenly distributed along the surface of the hemisphere toward the center of the sphere on the inner walls of clamps A1 and B2.
[0046] like Figure 7 As shown, test piece 3 serves as the carrier of the membrane layer. The specific usage method is as follows: First, test piece 3 is inserted into groove 4. Next, the four clamps are assembled. First, two clamps A1 are placed facing each other, then two clamps B2 are joined together. The splicing rod 7 of clamp A1 is inserted into the slot 8 of clamp B2. (See...) Figure 1Ensure that the smooth surface of each fixture is flush against the groove surface of the adjacent fixture, and tighten the test piece in groove 4. Place screw 5 in the threaded hole of the fixture splicing rod 7 and tighten it to form a hemispherical fixture assembly. Then, turn on the coating equipment to coat a thin film inside the fixture assembly. Half of the test piece 3 is also coated with a thin film, while the other side is not coated due to the presence of groove 4. After coating, remove the test piece 3 from groove 4 and place it on measuring instruments such as a profilometer, interferometer, and atomic force microscope to check the film thickness on the test piece 3. By comparing the film thickness results at different locations, the coating uniformity of the inner wall of the hemispherical fixture can be determined, thereby evaluating the coating uniformity of the hemispherical harmonic oscillator.
[0047] The fixture needs to be secured to the coating machine with the clamping rod 6, such as... Figure 8 As shown, clamping rod 6 is fixed at the center hole of the fixture to support the fixture. Figure 1 The clamping device on the coating machine is used to fix the clamping rod 6, thereby fixing the entire device to the coating equipment.
[0048] By designing a fixture with the same shape as the hemispherical harmonic oscillator, the actual coating uniformity of the hemispherical harmonic oscillator can be simulated. The thickness steps of the film on both sides of the test piece can be measured using an interferometer or atomic microscope, which can accurately obtain the film thickness and uniformity data. This enables the evaluation of the metallization coating uniformity of the hemispherical harmonic oscillator, which is beneficial for product improvement and quantitative evaluation and acceptance.
[0049] The specific method for using this uniformity detection device is described below:
[0050] Step 1: Install the test piece 3 in the groove 4 of clamps A1 and B2. The test piece 3 should fit in contact with the inner wall of the groove 4. The edge of the groove 4 can be partially chamfered to facilitate installation and clamping.
[0051] Step 2: Assemble the four fixtures. First, place two fixtures A1 facing each other, then join the two fixtures B2 together. Insert the splicing rod 7 of fixture A1 into the slot 8 of fixture B2. Make sure that the smooth surface of each fixture is in close contact with the groove surface of the adjacent fixture, and tighten the test piece in the groove 4. Place the screw 5 in the threaded hole on the splicing rod 7 of the fixture and tighten it to form a hemispherical fixture as a whole.
[0052] Step 3: Fix the assembled fixture in the coating equipment by using clamping rod 6 to fix the fixture;
[0053] Step 4: Turn on the coating equipment and coat the inside of the fixture.
[0054] Step 5: After the coating is completed, remove test piece 3 and measure the thickness of the film on each different test piece 3 using a step meter. This can be equivalent to the film thickness at different positions of the hemispherical fixture, and the uniformity of the coating on the hemispherical device can be calculated.
[0055] The selection of measuring equipment includes, but is not limited to, the use of a profilometer, and may also include, depending on the accuracy requirements, the use of other measuring instruments such as a profilometer, interferometer, and atomic force microscope.
[0056] The calculation method for the coating uniformity of hemispherical devices is: Non-uniformity = (Tmax - Tmin) / (Tmax + Tmin) × 100%.
[0057] Example 2:
[0058] The shape and position of the grooves 4 in fixtures A1 and B2 are not limited. Their positions can be changed to be unevenly distributed according to actual usage requirements. Test pieces 3 of different sizes and matching grooves 4 can be designed accordingly to achieve a more refined uniformity evaluation.
[0059] The beneficial effects achieved by adopting this technical solution are as follows: by designing a fixture with the same shape as the hemispherical harmonic oscillator, the actual coating uniformity of the hemispherical harmonic oscillator is simulated. The thickness steps of the film on both sides of the test piece are measured by using an interferometer or atomic force microscope. By comparing the differences in film thickness at different locations, uniformity data can be accurately obtained, realizing the evaluation of the metallization coating uniformity of the hemispherical harmonic oscillator, which is conducive to product improvement and quantitative evaluation and acceptance.
Claims
1. A tooling for detecting the uniformity of a resonator coating, characterized in that, The tooling includes: Two fixtures A (1), two fixtures B (2), and multiple test pieces (3); Each clamp A(1) and each clamp B(2) is a quarter hemisphere. When two clamps A(1) and two clamps B(2) are assembled at intervals, they form a hemispherical clamp as a whole. Two clamps A (1) and two clamps B (2) each have a preset number of grooves (4) on the same side. The other side of the two clamps A (1) and two clamps B (2) is a smooth surface. The preset number of grooves (4) are arranged along the center of the sphere. The width and thickness of the grooves (4) match the test piece. One groove (4) is used to place one test piece (3).
2. The tooling for detecting the uniformity of a resonator coating according to claim 1, characterized in that, The surface of each groove (4) is partially covered. After the test piece (3) is inserted into the groove, it is in a state of being half covered and half exposed. The exposed position of the test piece (3) is the actual coating position of the resonator.
3. The tooling for detecting the uniformity of a resonator coating according to claim 1, characterized in that, Each clamp A (1) has splicing rods (7) on both sides of its bottom, and each clamp B (2) has corresponding slots (8) on both sides of its bottom. The splicing rods (7) of clamp A (1) are inserted into the slots (8) of clamp B (2) and fixed with screws (5) so that the groove end face of clamp A (1) and the smooth surface of clamp B (2) are in close contact, thereby fixing the test piece in the groove.
4. The tooling for detecting the uniformity of a resonator coating according to claim 1, characterized in that, The grooves on the two clamps A(1) and the two clamps B(2) are exactly the same size, and the distance from the groove position of each ring on the hemispherical clamp to the axis of the hemisphere is exactly the same.
5. The tooling for detecting the uniformity of a resonator coating according to claim 1, characterized in that, When two clamps A (1) and two clamps B (2) are assembled at intervals to form a hemispherical clamp, all the grooves (4) are distributed in a cross shape on the inner wall of the hemispherical clamp.
6. The tooling for detecting the uniformity of a resonator coating according to claim 2, characterized in that, The tooling also includes: a clamping rod (6); The tooling is fixedly connected to the clamping device on the coating machine via a clamping rod (6); The coating machine coats the inner wall of a hemispherical fixture. The part of the test piece covered by the groove is not coated, while the part exposed on the test piece is coated. After the test piece is removed, the coating thickness is measured to evaluate the coating uniformity of the coating machine.