Forming method of wineglass-shaped micro-hemispherical harmonic oscillator

Abstract

The invention discloses a forming method of a wineglass-shaped micro-hemispherical harmonic oscillator. The forming method comprises the following steps: forming a middle column; forming a substrate; a forming mold is prepared, the forming mold is provided with a forming face and a forming cavity, the forming cavity comprises a first cavity formed in the forming face and a second cavity formed by downwards sinking the center of the bottom of the first cavity, the first cavity is matched with the outer wall face of a spherical shell of the micro-hemispherical harmonic oscillator, and the second cavity is matched with the side wall face of the middle column; a middle column is arranged in the second cavity, the bottom of the cavity wall of the first cavity is formed by the top face of the middle column, and the substrate is arranged on the forming face of the forming mold; and the forming cavity is made to be in a negative pressure environment, the substrate is melted and heated, the substrate is softened and attached to the cavity wall of the first forming cavity under the negative pressure effect, and after the softened substrate is solidified, the wineglass-shaped micro-hemispherical harmonic oscillator is obtained. The overall structural strength of the wineglass-shaped formed micro-hemisphere can be improved, and the energy loss of the wineglass-shaped formed micro-hemisphere is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of preparing a hemispherical resonant gyroscope, and in particular to a method for forming a wine glass-shaped micro-hemispherical resonator. Background Art

[0002] The hemispherical resonator gyroscope is a new type of solid-state navigation gyroscope that measures the precession angle, and its core component is a hemispherical resonator made of fused quartz. Due to its good mechanical and optical properties and the ability to realize three-dimensional shell structure processing through mold forming, fused quartz is a good micromachining material with low thermal conductivity (K FS =1.38W / (m·K)), low thermal expansion coefficient (α FS =0.52×10 -6 / K), stable physical and chemical properties and other excellent properties. It can be transformed into molten glass under high temperature conditions, and its softening temperature is about 1585℃. Therefore, it can be formed by rapid heating and re-cooling. Its good resistance to heat and cold shocks ensures that there will be no fragmentation during the forming process, and the surface of the processed material has good surface roughness.

[0003] In general, the hemisphere used for the preparation of MEMS resonant gyroscopes is basically processed by high-temperature blowtorch blowing, which is relatively simple and can achieve high processing accuracy. Traditional processing uses a graphite mold with a positioning column in the center to hot-form the fused quartz sheet, which is generally divided into the following steps: 1) Use graphite material to make the upper and lower molds of the fused quartz micro-hemispherical shell structure, and install them on a rotating platform to ensure that the mold is aligned with the center of the rotating platform; 2) Place the quartz sheet in the preset mold positioning hole, use the vacuum system to set the vacuum degree to generate negative pressure inside the mold, firmly adsorb the quartz sheet, and turn on the rotating platform to rotate it at high speed; 3) Use a vacuum pump to evacuate the inside of the mold, and use a blowtorch to heat it directly above the fused quartz sheet. Under the action of pressure difference and heating, the softened fused quartz flows into the mold to form a three-dimensional micro-shell structure. After processing, the cross-section of the micro-hemispherical is W-shaped, with a hollow anchor column in the center. This is a classic micro-hemispherical structure, also known as a "birdbath" type micro-hemispherical (foreign "birdbath").

[0004] For the above thermal forming methods, the following problems exist in the actual testing process of the micro-hemisphere:

[0005] 1) In the traditional quartz bird basin micro hemisphere, during the hot forming and softening process, the hemisphere lip edge area has the lowest degree of stretching, while the transition area between the anchor column and the lip edge has the highest degree of stretching, resulting in the characteristics of thick edges and thin tops. The top circumference area is very easy to break during testing and use;

[0006] 2) Reduce the loss of micro-hemispherical anchor pillars: According to the principle of energy loss, the traditional hollow anchor pillars are isolated from the waves on both sides of the shell before reaching the substrate, and cannot produce a canceling effect, which increases the anchor loss. Secondly, shorter anchor pillars make it easier for waves to escape from the shell to the substrate, increasing the loss.

[0007] 3) Due to the inevitable temperature non-uniformity, in the process of softening the sheet to contact with the mold (anchor column position), the center point of the two may slightly shift due to the uneven deformation caused by the temperature difference after the sheet softens, even if there is a limited structure, which will reduce the symmetry of the micro-hemisphericity.

[0008] 4) The anchor column of the quartz bird basin micro-hemisphere is formed by stretching the top of the hemisphere from the inside to the lip. The special hollow deep cavity structure will cause subsequent process problems such as uneven coating and incomplete cleaning. Summary of the invention

[0009] In view of the problems in the background technology, the present invention proposes a method for forming a wine glass-shaped micro-hemispherical resonator, which can improve the overall structural strength of the formed micro-hemispherical resonator and reduce anchor loss.

[0010] The present invention adopts the following technical solutions:

[0011] A method for forming a wine glass-shaped micro-hemispherical resonator comprises the following steps:

[0012] S1, forming the middle column;

[0013] S2, forming substrate;

[0014] S3, prepare a molding mold, the molding mold has a molding surface and a molding cavity, the molding cavity includes a first cavity opened on the molding surface, and a second cavity formed by a downward depression in the bottom center of the first cavity, the first cavity cooperates with the outer wall surface of the spherical shell of the wine glass-shaped micro-hemispherical resonator, the second cavity cooperates with the side wall surface of the middle column, the middle column is placed in the second cavity, the top surface of the middle column forms the bottom of the cavity wall of the first cavity, and the substrate is placed on the molding surface of the molding mold;

[0015] S4, placing the molding cavity in a negative pressure environment, and melting and heating the substrate to soften the substrate and adhere it to the cavity wall of the first cavity under the action of negative pressure, and after the softened substrate is solidified, the wine glass-shaped micro-hemispherical resonator is obtained.

[0016] Preferably, the molded intermediate column includes a column, the top surface of which has a connecting portion integrally formed with the column and coaxially arranged, the side surface of the connecting portion extends outward relative to the side surface of the column to form a first curved surface, and the top surface of the connecting portion is recessed downward to form a second curved surface.

[0017] Preferably, the molded substrate comprises a substrate body, the top surface of the substrate body protrudes upward to form a first truncated cone which is narrow at the top and wide at the bottom, or the center of the top surface of the substrate protrudes upward to form a second truncated cone which is narrow at the top and wide at the bottom.

[0018] Preferably, the curvature radius R1 of the first curved surface is 0.5-1 mm, the curvature radius R2 of the second curved surface is 6-8 mm, the diameter d1 of the cylinder is 1.6-2.4 mm, and the diameter d2 of the outer circle of the top surface of the connecting portion is 2-2.8 mm.

[0019] Preferably, the diameter L of the substrate is 9 mm to 15 mm, the thickness d of the edge of the substrate is 0.2 mm to 1 mm, and the distance D from the bottom surface of the substrate to the top surface of the first truncated cone or the second truncated cone is 0.5 mm to 2.5 mm.

[0020] Preferably, the diameter l of the top circle of the first truncated cone is 3mm-10mm, and the diameter of the bottom circle of the first truncated cone is the diameter L of the substrate; the diameter l1 of the top circle of the second truncated cone is 2mm-6mm, and the diameter l2 of the bottom circle of the second truncated cone is 4mm-8mm.

[0021] Preferably, before step S4, the method further includes: preheating the substrate so that the temperature of the substrate reaches 1000-1100°C.

[0022] Preferably, the specific process of preheating includes:

[0023] The forming mold is rotated around the central axis of the forming cavity, and a hydrogen-oxygen flame nozzle with a diameter of 2mm to 3mm is used to preheat the substrate in a back-and-forth sweeping manner along the radial direction of the substrate. The preheating time is 5 to 10 seconds.

[0024] Preferably, the specific process of the melting heating includes:

[0025] The molding mold is rotated around the central axis of the molding cavity, and a hydrogen-oxygen flame nozzle with a diameter of 1mm to 2mm is aimed at the center of the first truncated cone or the second truncated cone for heating for 5 to 10s. After the temperature of the substrate reaches 1700°C to 1800°C, the molding cavity is placed in a negative pressure environment, and a hydrogen-oxygen flame nozzle with a diameter of 1mm to 2mm is aimed at the radial direction of the substrate at a position 1mm to 2mm away from the center of the substrate to heat the substrate, so that the substrate is softened and adheres to the cavity wall of the first cavity under the action of negative pressure.

[0026] Preferably, the center of the bottom surface of the intermediate column is recessed upward to form a conical positioning groove, and the center of the bottom of the second cavity of the molding mold protrudes upward to form a positioning pin that cooperates with the positioning groove. When the intermediate column is placed in the second cavity, the positioning pin is clamped in the positioning groove.

[0027] Preferably, a limiting groove matching the outer circle of the bottom surface of the substrate is provided at the center of the molding surface of the molding mold, and the center of the bottom surface of the limiting groove is recessed downward to form the first cavity.

[0028] Preferably, the molding mold is a graphite mold, and a negative pressure cavity for connecting to a vacuum device is opened at the center of the bottom surface of the molding mold. The edge of the negative pressure cavity extends upward to form a shell with a wine glass-shaped structure between the first cavity and the negative pressure cavity; the side wall of the negative pressure cavity is a conical surface that is narrow at the top and wide at the bottom.

[0029] Compared with the prior art, the advantages of the present invention are:

[0030] Compared with the conventional method of directly blowing a micro-hemispherical resonator by a high-temperature blowtorch, the method for forming a wine glass-shaped micro-hemispherical resonator of the present invention cancels the design of a center pin of a forming mold, and the mold cavity of the forming mold includes a first mold cavity matched with the outer wall surface of the spherical shell of the wine glass-shaped micro-hemispherical resonator, and a second mold cavity accommodating a pre-prepared intermediate column. By pre-preparing an intermediate column with optimized structure, when the intermediate column is placed in the second mold cavity, its top surface forms the bottom of the cavity wall of the first mold cavity, so that the substrate is only used to form the spherical shell of the wine glass-shaped micro-hemispherical resonator. Specifically, in the second mold cavity, the substrate is formed. After placing the middle column, the substrate on the first cavity is heated and the first cavity is in a negative pressure state, the substrate softens and adheres to the cavity wall of the first molding cavity under the action of negative pressure and contacts the middle column. After the softened substrate is solidified, the substrate forms a spherical shell of a wine glass-shaped micro-hemispherical resonator, and the spherical shell is fixedly connected to the middle column to form a wine glass-shaped micro-hemispherical resonator. Thus, the present invention changes the traditional processing idea of ​​molding the spherical shell and the anchor column from a piece of fused quartz at the same time, avoids the phenomenon that the thickness of the micro-hemispherical shoulder is too thin due to the molding of the anchor column, and the overall structural strength of the micro-hemispherical resonator is greatly improved. In addition, the present invention realizes the molding of the micro-hemispherical resonator by welding, and the prefabricated middle column can be designed as a solid anchor column, which avoids the problem of increased anchor loss caused by the limitation of the traditional one-piece molding mold structure that can only mold hollow anchor columns, and reduces the energy loss of the micro-hemispherical resonator from the perspective of anchor loss.

[0031] Compared with the method of bonding the shell and the anchor column to form a micro-hemispherical resonator, the method for forming the wine glass-shaped micro-hemispherical resonator of the present invention realizes the forming of the wine glass-shaped micro-hemispherical resonator by welding. Since the substrate is fixedly connected to the intermediate column by welding, the two are the same amorphous material and the fixing process does not require heterogeneous materials, so that no interface melting can be achieved between the quartz parts, and the whole is integrated; and although the bonding method can achieve a higher bonding strength, it will form an obvious discontinuous connection interface (bonding layer). After excitation, the shell vibrates at a high frequency, and the bonding interface will be subjected to a large shear force. There will be a risk of interface peeling and device damage during long-term operation. The quartz device after melting by hydrogen-oxygen flame, due to the characteristics of the amorphous structure of the amorphous material, the overall structure and material are continuous, and no stress concentration area will be generated, which can provide a higher overall structural strength than bonding. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to make the present invention more easily understood, the present invention will be described in more detail by referring to the specific embodiments shown in the accompanying drawings. These drawings only depict typical embodiments of the present invention and should not be considered as limiting the scope of protection of the present invention.

[0033] Figure 1 It is an exploded schematic diagram of the application state of the molding method of the wine glass-shaped micro-hemispherical resonator according to an embodiment of the present invention.

[0034] Figure 2 It is a cross-sectional schematic diagram of the application state of the molding method of the wine glass-shaped micro-hemispherical resonator according to an embodiment of the present invention.

[0035] Figure 3 This is a schematic diagram of the front structural view of the intermediate column formed according to an embodiment of the present invention.

[0036] Figure 4 It is a schematic diagram of the cross-sectional structure of the intermediate column formed according to an embodiment of the present invention.

[0037] Figure 5 This is a schematic diagram of CNC forming of the middle column according to an embodiment of the present invention.

[0038] Figure 6 A schematic structural diagram of a substrate formed according to an embodiment of the present invention.

[0039] Figure 7 Another schematic diagram of the structure of a substrate formed according to an embodiment of the present invention.

[0040] Figure 8 It is a schematic diagram of the three-dimensional structure of a forming mold according to an embodiment of the present invention.

[0041] Fig. 9 It is a schematic diagram of the three-dimensional structure of the forming mold from another perspective of an embodiment of the present invention.

[0042] Fig.10 It is a schematic diagram of the cross-sectional structure of a molding die according to an embodiment of the present invention.

[0043] Fig.11 The figure is a schematic diagram of the three-dimensional structure of the micro-hemispherical resonator after molding according to an embodiment of the present invention.

[0044] Fig.12 The figure is a schematic diagram of the cross-sectional structure of the micro-hemispherical resonator after molding according to the embodiment of the present invention.

[0045] Reference numerals:

[0046] 1. Molding mold; 11. Molding surface; 12. First cavity; 13. Column cavity; 14. Connecting cavity; 15. Arc surface; 16. Positioning pin; 17. Limiting groove; 18. Negative pressure cavity; 19. Boss; 2. Middle column; 21. Column; 22. Connecting part; 23. First arc surface; 24. Second arc surface; 25. Positioning groove; 3. Substrate; 31. Substrate body; 32. First truncated cone; 33. Second truncated cone; 4. Spherical shell. DETAILED DESCRIPTION

[0047] The following describes the implementation modes of the present invention with reference to the accompanying drawings so that those skilled in the art can better understand the present invention and implement it. However, the enumerated embodiments are not intended to limit the present invention. In the absence of conflict, the following embodiments and the technical features in the embodiments may be combined with each other, wherein the same components are represented by the same figure marks.

[0048] like Figure 1 and Figure 2 As shown, the method for forming a wine glass-shaped micro-hemispherical resonator of this embodiment includes the following steps:

[0049] S1, forming middle column 2;

[0050] S2, forming substrate 3;

[0051] S3, prepare a molding die 1, the molding die 1 has a molding surface 11 and a molding cavity, the molding cavity includes a first cavity 12 opened on the molding surface 11, and a second cavity formed by the bottom center of the first cavity 12 being depressed downward, the first cavity 12 is matched with the outer wall surface of the spherical shell of the wine glass-shaped micro-hemispherical resonator, the second cavity is matched with the side wall surface of the middle column 2, the middle column 2 is placed in the second cavity, the top surface of the middle column 2 forms the bottom of the cavity wall of the first cavity 12, and the substrate 3 is placed on the molding surface 11 of the molding die 1;

[0052] S4, placing the molding cavity in a negative pressure environment, and melting and heating the substrate 3, so that the substrate 3 is softened and adhered to the cavity wall of the first cavity 12 under the action of negative pressure, and after the softened substrate 3 is solidified, a wine glass-shaped micro-hemispherical resonator is obtained.

[0053] Therefore, compared with the conventional method of directly blowing a micro-hemispherical resonator by a high-temperature blowtorch, the method for forming a wine glass-shaped micro-hemispherical resonator of the present invention cancels the design of the center pin of the forming mold, and the mold cavity of the forming mold includes a first mold cavity 12 matched with the outer wall surface of the spherical shell of the wine glass-shaped micro-hemispherical resonator, and a second mold cavity accommodating a pre-prepared intermediate column. By pre-preparing an intermediate column 2 with optimized structure, when the intermediate column 2 is placed in the second mold cavity, its top surface forms the bottom of the cavity wall of the first mold cavity 12, so that the substrate 3 is only used to form the spherical shell 4 of the wine glass-shaped micro-hemispherical resonator. Specifically, in the second mold cavity, After the middle column 2 is placed, the substrate 3 on the first cavity 12 is heated and the first cavity 12 is in a negative pressure state, the substrate 3 softens and adheres to the cavity wall of the first cavity 12 under the action of negative pressure and contacts the middle column 2. After the softened substrate 3 is solidified, the substrate forms a spherical shell 4 of the micro-hemispherical resonator, and the spherical shell 4 is fixedly connected to the middle column 2 to form a wine glass-shaped micro-hemispherical resonator. Thus, the present invention changes the traditional processing idea of ​​forming the spherical shell and the anchor column from a piece of fused quartz at the same time, avoids the phenomenon that the thickness of the micro-hemispherical shoulder is too thin due to the formation of the anchor column, and the overall structural strength of the micro-hemispherical resonator is greatly improved. In addition, the present invention realizes the formation of the micro-hemispherical resonator by welding, and the prefabricated middle column can be designed as a solid anchor column, which avoids the problem of increased anchor loss caused by the limitation of the traditional one-piece molding mold structure that can only form a hollow anchor column, and reduces the energy loss of the micro-hemispherical resonator from the perspective of anchor loss.

[0054] Compared with the method of bonding the shell and the anchor column to form a micro-hemispherical resonator, the method for forming the wine glass-shaped micro-hemispherical resonator of the present invention realizes the forming of the wine glass-shaped micro-hemispherical resonator by welding. Since the substrate is fixedly connected to the intermediate column by welding, the two are the same amorphous material and the fixing process does not require heterogeneous materials, so that no interface melting can be achieved between the quartz parts, and the whole is integrated; and although the bonding method can achieve a higher bonding strength, it will form an obvious discontinuous connection interface (bonding layer). After excitation, the shell vibrates at a high frequency, and the bonding interface will be subjected to a large shear force. There will be a risk of interface peeling and device damage during long-term operation. The quartz device after melting by hydrogen-oxygen flame, due to the characteristics of the amorphous structure of the amorphous material, the overall structure and material are continuous, and no stress concentration area will be generated, which can provide a higher overall structural strength than bonding.

[0055] Specifically, Figure 3 and Figure 4As shown, the intermediate column 2 formed in step S1 includes a column 21, the top surface of the column 21 has a connecting portion 22 integrally formed with the column 21 and coaxially arranged, and the side surface of the connecting portion 22 extends outward relative to the side surface of the column 21 to form a first arc surface 23. Correspondingly, the second cavity includes a column cavity 13, and a connecting cavity 14 connecting the column cavity 13 and the first cavity 12, the cavity wall surface of the connecting cavity 14 extends outward relative to the cavity wall surface of the column cavity 13 to form a circular arc surface 15 connected to the cavity wall of the first cavity 12, and the circular arc surface 15 cooperates with the first arc surface 23.

[0056] The top surface of the connecting portion 22 is concave downward to form a second curved surface 24. That is, after the middle column 2 is located in the second cavity, the top surface of the connecting portion 22, the second curved surface 24, forms the bottom of the cavity wall of the first cavity 12, and closes the bottom of the cavity wall of the first cavity 12, so that the cavity wall of the first cavity 12 forms a hemispherical surface that matches the outer surface of the spherical shell of the wine glass-shaped micro-hemispherical resonator.

[0057] like Figure 5 As shown, the quartz rod can be processed with a ball cutter through CNC technology to form an intermediate column 2 with a first curved surface 23 and a second curved surface 24, that is, a rod with an inverted fishtail cross-section is formed to meet the local sealing after welding with the quartz sheet, so that there is no gap between the mold and the spherical shell after welding.

[0058] In this embodiment, the formed middle column 2 is a solid anchor column, which reduces anchor loss and reduces the energy loss of the hemisphere from the perspective of anchor loss.

[0059] In addition, in order to avoid the problem of local stress concentration caused by geometric discontinuity (right angle) of the structure, which may cause structural damage to the micro-hemispherical body during vibration, the cavity wall surface of the connecting cavity 14 extends outward relative to the cavity wall surface of the columnar cavity 13 to form an arc surface 15 that matches the first arc surface 23. Specifically, during the molding process, the central part of the quartz substrate is softened by the heat reflux and extends downward to be naturally fused with the top surface of the middle column. After molding, this area forms a corresponding micro-hemispherical rounded corner structure; at the same time, the internal stress distribution of quartz is highly related to the cooling process, and the gentle rounded corner transition can ensure the uniform heat transfer speed between the anchor column-spherical shell and the graphite mold, and minimize the local thermal stress caused by the difference in cooling speed, so that the end face stress and plane stress of the micro-hemispherical shell and the anchor column connection area are consistent with the whole, that is, the thermoelastic loss of the micro-hemispherical body is reduced and the Q value is improved; in addition, the rounded corner design can make the degree of cold shrinkage around the connection area uniformly distributed during the cooling process, thereby improving symmetry.

[0060] The size of the middle column needs to match the formed micro-hemispherical shell. In this embodiment, Figure 3As shown, the curvature radius R1 of the first arc surface 23 is 0.5-1 mm, the curvature radius R2 of the second arc surface 24 is 6-8 mm, the diameter d1 of the column 21 is 1.6-2.4 mm, the diameter d2 of the outer circle of the top surface of the connecting portion 22 is 2-2.8 mm, and the overall height h of the middle column is 6-8 mm.

[0061] The intermediate column 2 uses the same fused quartz material as the substrate 3, and needs to be subjected to pre-welding treatment before welding, including welding surface cleaning (ultrasonic cleaning with organic cleaning agents, etc.), welding surface polishing (cerium oxide polishing liquid & wool wheel treatment, surface roughness Ra should be less than 10nm), geometric shape inspection (eliminating damage, surface wear, irregular shape, etc.), and annealing homogenization.

[0062] Specifically, the substrate 3 formed in step S2 includes a substrate body 31, such as Figure 6 As shown, the top surface of the substrate body 31 is convex upward to form a first truncated cone 32 which is narrow at the top and wide at the bottom, or as shown in FIG. Figure 7 As shown, the center of the top surface of the substrate 3 bulges upward to form a second truncated cone 33 which is narrow at the top and wide at the bottom.

[0063] The CMP (chemical mechanical polishing) process can be used to thin the edge area of ​​the columnar quartz sheet to form the above-mentioned substrate with a truncated cone, so that the truncated cone area is heated and softened and then melted with the connecting part of the middle column to fill the gap in the connecting area, so that the formed shell and the middle column form a smooth connection without collapse, so that the thickness distribution of the formed hemispherical micro shell is more uniform, avoiding local stress concentration, and making the overall strength of the shell higher.

[0064] Special treatment of substrate 2. This embodiment uses chemical mechanical polishing equipment, and is equipped with quartz grinding fluid and chemical polishing fluid to form a structure in which the edge area is slightly thinner than the center. The quartz grinding fluid needs to be matched with a grinding disc of a certain mesh size (resin, wool, diamond) and process parameters (rotation speed, feed rate, etc.) to process the quartz sheet; the chemical polishing fluid is used to remove the sub-damage layer on the surface of the quartz sheet and reduce the surface roughness. The surface roughness Ra should be less than 10nm.

[0065] After grinding, the substrate is generally called a trapezoidal plate, and the cross-sectional view is as follows: Figure 6 and Figure 7 shown. Figure 6 and Figure 7 There are two different types of trapezoidal plates, the difference is: Figure 6 Along the edge of the quartz plate, a ring with a right-angled triangle cross section is removed by grinding and polishing; Figure 7 Along the edge of the quartz sheet, a ring with a right-angled trapezoidal cross section is removed by grinding and polishing, and a circular platform extends inward along the edge, forming a combined structure of a rectangular and isosceles trapezoidal boss.

[0066] In summary, by optimizing the mold structure, the overall stretching degree of the micro-hemispherical shell is made uniform, and by optimizing the intermediate column and substrate structure, the thickness distribution of the micro-hemispherical is optimized, which greatly improves the uniformity of the Q value of the micro-hemispherical.

[0067] In this embodiment, Figure 6 and Figure 7 As shown, the diameter L of the substrate 3 is 9 mm to 15 mm, the thickness d of the edge of the substrate 3 is 0.2 mm to 1 mm, and the distance D from the bottom surface of the substrate 3 to the top surface of the first truncated cone 32 or the second truncated cone 33 is 0.5 mm to 2.5 mm.

[0068] In this embodiment, Figure 6 As shown, the diameter l of the top circle of the first truncated cone 32 is 3 mm to 10 mm, and the diameter of the bottom circle of the first truncated cone 32 is the diameter L of the substrate 3; Figure 7 As shown, the diameter l1 of the top circle of the second truncated cone 33 is 2 mm to 6 mm, and the diameter l2 of the bottom circle of the second truncated cone 33 is 4 mm to 8 mm.

[0069] In this embodiment, before step S4, the process further includes: preheating the substrate 3 so that the temperature of the substrate 3 reaches 1000-1100°C.

[0070] In this embodiment, the specific process of preheating includes:

[0071] The forming mold 1 is rotated around the central axis of the forming cavity, and a hydrogen-oxygen flame nozzle with a diameter of 2 mm to 3 mm is used to preheat the substrate 3 in a back-and-forth sweeping manner along the radial direction of the substrate 3. The preheating time is 5 to 10 seconds.

[0072] In this embodiment, the specific process of melting and heating includes:

[0073] The molding die 1 is rotated around the central axis of the molding cavity, and a hydrogen-oxygen flame nozzle with a diameter of 1 mm to 2 mm is aimed at the center of the first frustum 32 or the second frustum 33 for heating for 5 to 10 seconds. After the temperature of the substrate 3 reaches 1700°C to 1800°C, the molding cavity is placed in a negative pressure environment, and a hydrogen-oxygen flame nozzle with a diameter of 1 mm to 2 mm is aimed at the position of 1 mm to 2 mm away from the center of the substrate 3 in the radial direction of the substrate 3 to heat the substrate 3, so that the substrate 3 is softened and adheres to the cavity wall of the first cavity 12 under the action of negative pressure.

[0074] In general, the temperature generated by the oxyhydrogen flame far exceeds the melting point of fused quartz (about 1750°C), and the heating and melting process can generally be completed in a relatively short time. In order to make the thickness distribution of the micro-hemispherical shell uniform, the present invention uses nozzles of different specifications (two sets of oxyhydrogen flame systems equipped with nozzles are clamped on the x-axis by a screw rail system for replacement), and adopts a two-step method to complete the micro-hemispherical molding: 1) First, use a nozzle with a diameter between 2mm and 3mm, and control the nozzle through a screw rail to perform a sweeping preheating on the entire area of ​​the substrate, and at the same time start the mold turntable to uniformly increase its temperature to about 1000-1100°C in 3-5 seconds. Preheating is to make the temperature of each area uniform during the molding process to prevent the accumulation of thermal stress caused by sudden temperature changes; 2) After the preheating is completed, the quartz plate center is heated by replacing the hydrogen-oxygen flame nozzle with a diameter of 1mm-2mm through the screw rail system, while keeping the mold turntable rotating. The temperature of the heating area reaches the melting temperature (1700℃~1800℃) after 5 to 10 seconds measured by the temperature meter. At this time, the vacuum system is turned on to form it downward (see Figure 2 Schematic diagram); while forming, the nozzle needs to be translated 1mm to 2mm from the center position parallel to the periphery of the substrate to increase the heating range and achieve the synchronization of softening and extension of the entire substrate as much as possible to prevent excessive heating of the center position so that it extends too quickly, resulting in a thin top shell and too thick edges; after the substrate is softened by heat as a whole, the spherical shell 4 of the wine glass-shaped micro-hemisphere is formed according to the mold.

[0075] In this embodiment, Fig.10 As shown, the center of the bottom surface of the column body 21 of the middle column 2 is recessed upward to form a conical positioning groove 25, and the center of the bottom of the second cavity of the molding mold 1 is protruded upward to form a positioning pin 16 that cooperates with the positioning groove 25. When the middle column 2 is placed in the second cavity, the positioning pin 16 is stuck in the positioning groove 25.

[0076] After the middle column 2 is assembled in the second cavity, the positioning pin 16 fits into the positioning groove 25 to anchor the middle column 2 at the center of the second cavity, while preventing the anchor column from shaking slightly during the molding process, which may cause structural errors.

[0077] In this embodiment, Figure 8-Figure 10 As shown, the center of the top surface of the molding mold extends upward to form a boss 19, and the top surface of the boss 19 forms a molding surface 11. The center of the molding surface 11 is provided with a limiting groove 17 that matches the outer circle of the bottom surface of the substrate 3. The center of the bottom surface of the limiting groove 17 is recessed downward to form a first cavity 12.

[0078] The substrate 3 is limited by the limiting groove 17 to ensure that the central axis of the substrate completely coincides with the geometric center of the second cavity during the forming process.

[0079] In this embodiment, the molding mold 1 is a graphite mold, and a negative pressure cavity 18 for connecting to a vacuum pump is opened at the center of the bottom surface of the molding mold 1. The edge of the negative pressure cavity 18 extends upward to form a shell with a wine glass-shaped structure between the first cavity 12 and the negative pressure cavity 18.

[0080] The negative pressure cavity 18 of the molding mold is connected to the molding cavity through countless tiny pores on the shell that are invisible to the naked eye. When molding, the negative pressure cavity 18 generates negative pressure by connecting with the negative pressure device, and acts in the molding cavity through the pores, so that the softened molten substrate is formed downward.

[0081] Specifically, the side wall surface of the negative pressure chamber 18 is a conical surface that is narrow at the top and wide at the bottom, which can avoid energy loss in the vortex zone and improve the negative pressure extraction efficiency.

[0082] The following is a process flow of an example of a specific application of the present invention to form a wine glass-shaped micro-hemispherical resonator:

[0083] 1) After confirming that there are no structural defects or other problems by optical microscope observation, the substrate 3 and the intermediate column 2 are ultrasonically cleaned using organic solvents such as acetone and acid (hydrochloric acid, sulfuric acid, etc.);

[0084] 2) The intermediate column 2 is placed in the second cavity of the molding die 1, and after the intermediate column 2 and the central axis of the molding die 1 are self-aligned by the cooperation of the positioning groove 25 and the positioning pin 16, the intermediate column 2 and the molding die 1 are preheated to a temperature of about 1000° C. using an oxyhydrogen flame to prevent the formation of local thermal stress due to excessive temperature difference between the intermediate column 2 and the substrate 3 during the molding process;

[0085] 3) placing the substrate 3 in the limiting groove 17 of the molding die 1, starting the turntable so that the molding die 1 drives the substrate 3 to start rotating at a certain speed; after setting the ratio of hydrogen to oxygen (temperature control), turning on the hydrogen-oxygen flame to preheat and melt-heat the substrate 3;

[0086] 4) After the temperature reaches the melting temperature of the quartz glass by observing with an infrared thermometer, the vacuum system is turned on to generate negative pressure in the negative pressure chamber 18, and the negative pressure suction force is transmitted to the molding cavity of the molding mold through the capillaries of the mold wall. The softened substrate 3 is extended downward under the action of the negative pressure to form a shape;

[0087] 5) The substrate 3 is molded onto the wall surface of the first cavity 12 to form a wine glass-shaped spherical shell structure; at the same time, the center bottom of the substrate 3 contacts the top surface of the middle column 2 to complete the welding.

[0088] Fig.11 and Fig.12The schematic diagram of the structure of the wine glass-shaped micro-hemispherical resonator after forming is shown in Figure 1. Compared with the traditional quartz bird basin shape, the thickness distribution of the hemispherical cup shell is more uniform due to the lack of large-scale stretching, which helps to make the Q value consistent. The transition area between the spherical shell 4 and the middle column 2 of the formed micro-hemispherical resonator is a smooth contour.

[0089] Compared with the traditional quartz bird basin type micro hemisphere, the present invention has the following advantages:

[0090] 1) By optimizing the mold structure, the overall stretching degree of the micro-hemispherical shell is uniform, the thickness distribution of the micro-hemispherical is optimized, and the Q value uniformity of the micro-hemispherical is greatly improved.

[0091] 2) By optimizing the anchor column structure (length and solid design), the anchor column loss of the micro-hemispherical is minimized, further improving the Q value level of the micro-hemispherical.

[0092] 3) Since there is no extremely thin area caused by excessive stretching, the overall structural strength of the micro-hemisphere is greatly improved, and the material loss is reduced to a minimum.

[0093] The embodiments described above are only preferred specific implementations of the present invention. This specification uses the phrases "in one embodiment", "in another embodiment", "in yet another embodiment" or "in other embodiments" to refer to one or more of the same or different embodiments according to the present disclosure. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for forming a wine glass-shaped micro-hemispherical resonator, comprising the following steps: S1, forming the middle column (2); S2, forming substrate (3); S3, preparing a molding die (1), the molding die (1) having a molding surface (11) and a molding cavity, the molding cavity comprising a first cavity (12) opened on the molding surface (11), and a second cavity formed by a downward depression at the bottom center of the first cavity (12), the first cavity (12) being matched with the outer wall surface of the spherical shell of the wine glass-shaped micro-hemispherical resonator, the second cavity being matched with the side wall surface of the intermediate column (2), the intermediate column (2) being placed in the second cavity, the top surface of the intermediate column (2) forming the bottom of the cavity wall of the first cavity (12), and the substrate (3) being placed on the molding surface (11) of the molding die (1); S4, placing the molding cavity in a negative pressure environment, and melting and heating the substrate (3), so that the substrate (3) is softened and adhered to the cavity wall of the first cavity (12) under the action of negative pressure, and after the softened substrate (3) is solidified, the wine glass-shaped micro-hemispherical resonator is obtained.

2. The method for forming a wine glass-shaped micro-hemispherical resonator according to claim 1, characterized in that: In the step S1, the formed intermediate column (2) comprises a column (21), the top surface of the column (21) has a connecting portion (22) formed integrally with the column (21) and coaxially arranged, the side surface of the connecting portion (22) extends outward relative to the side surface of the column (21) to form a first curved surface (23), and the top surface of the connecting portion (22) is recessed downward to form a second curved surface (24).

3. The method for forming a wine glass-shaped micro-hemispherical resonator according to claim 2, characterized in that: In step S2, the formed substrate (3) comprises a substrate body (31), the top surface of the substrate body (31) protrudes upward to form a first truncated cone (32) that is narrow at the top and wide at the bottom, or the center of the top surface of the substrate (3) protrudes upward to form a second truncated cone (33) that is narrow at the top and wide at the bottom.

4. The method for forming a wine glass-shaped micro-hemispherical resonator according to claim 3, characterized in that: The curvature radius R1 of the first curved surface (23) is 0.5-1 mm, the curvature radius R2 of the second curved surface (24) is 6-8 mm, the diameter d1 of the column (21) is 1.6-2.4 mm, and the diameter d2 of the outer circle of the top surface of the connecting portion (22) is 2-2.8 mm.

5. The method for forming a wine glass-shaped micro-hemispherical resonator according to claim 4, characterized in that: The diameter L of the substrate (3) is 9 mm to 15 mm, the thickness d of the edge of the substrate (3) is 0.2 mm to 1 mm, and the distance D from the bottom surface of the substrate (3) to the top surface of the first truncated cone (32) or the second truncated cone (33) is 0.5 mm to 2.5 mm.

6. The method for forming a wine glass-shaped micro-hemispherical resonator according to claim 5, characterized in that: The diameter l of the top circle of the first truncated cone (32) is 3 mm to 10 mm, and the diameter of the bottom circle of the first truncated cone (32) is the diameter L of the substrate (3); the diameter l1 of the top circle of the second truncated cone (33) is 2 mm to 6 mm, and the diameter l2 of the bottom circle of the second truncated cone (33) is 4 mm to 8 mm.

7. The method for forming a wine glass-shaped micro-hemispherical resonator according to any one of claims 1 to 6, characterized in that: Prior to step S4, the method further includes: preheating the substrate (3) so that the temperature of the substrate (3) reaches 1000-1100°C.

8. The method for forming a wine glass-shaped micro-hemispherical resonator according to claim 7, characterized in that: The specific process of the preheating includes: The forming mold (1) is rotated around the central axis of the forming cavity, and a hydrogen-oxygen flame nozzle with a diameter of 2 mm to 3 mm is used to perform back-and-forth sweeping preheating on the substrate (3) along the radial direction of the substrate (3), and the preheating time is 5 to 10 seconds.

9. The method for forming a wine glass-shaped micro-hemispherical resonator according to claim 8, characterized in that: In step S4, the specific process of the melting heating includes: The molding die (1) is rotated around the central axis of the molding cavity, and a hydrogen-oxygen flame nozzle with a diameter of 1 mm to 2 mm is directed toward the center of the first truncated cone (32) or the second truncated cone (33) to heat the substrate (3) for 5 to 10 seconds until the temperature of the substrate (3) reaches 1700° C. to 1800° C. The molding cavity is placed in a negative pressure environment, and a hydrogen-oxygen flame nozzle with a diameter of 1 mm to 2 mm is directed toward a position 1 mm to 2 mm away from the center of the substrate (3) in the radial direction of the substrate (3) to heat the substrate (3), so that the substrate (3) is softened and adheres to the cavity wall of the first cavity 12 under the action of negative pressure.

10. The method for forming a wine cup-shaped micro-hemispherical resonator according to any one of claims 1 to 6, characterized in that: The center of the bottom surface of the intermediate column (2) is recessed upward to form a conical positioning groove (25), and the center of the bottom of the second cavity of the molding die (1) is protruding upward to form a positioning pin (16) that cooperates with the positioning groove (25). When the intermediate column (2) is placed in the second cavity, the positioning pin (16) is clamped in the positioning groove (25).

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