Melt molding equipment

Abstract

To provide a melting formation mold of an oscillator.SOLUTION: A melting formation apparatus includes a melting formation mold, a plate and a ring part. The melting formation mold includes a lower surface, an upper surface parallel to the lower surface, a hole part formed in a part of the upper surface, and a through hole passing through the hole part from a bottom surface to a lower surface. On a surface of the plate, an exhaust port is formed. The ring part is arranged between the lower surface of the melting formation mold and the surface of the plate to connect the melting formation mold and the plate. The ring part surrounds a periphery of the through hole exposed on the lower surface of the melting formation mold and a periphery of the exhaust port exposed on the surface of the plate. In an area where no ring part is arranged, a space is formed between the lower surface of the melting formation mold and the surface of the plate.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present specification relates to a melt-molding apparatus for a transducer. [Background technology]

[0002] Patent Document 1 discloses a Bird-bath Resonator Gyroscope (BRG) that uses fused silica as a vibrator, as a gyro capable of achieving high accuracy. Specifically, a fusion molding die is placed on a plate equipped with exhaust and heat dissipation functions. A quartz plate is placed so as to cover a hole formed in the surface of the fusion molding die. While the pressure inside the hole is reduced using the plate's exhaust function, the top surface of the quartz plate is heated with a burner. A hemispherical vibrator can be produced by melting and deforming the quartz plate so that it fits into the hole. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2018 / 079129 Summary of the Invention [Problem to be solved by the invention]

[0004] The heat from the heated quartz plate is released to the plate via the contact surface between the quartz plate and the surface of the melting mold, and via the melting mold. This creates a temperature gradient in the quartz plate, where the temperature decreases from the center of the hole to the periphery. This temperature gradient can affect the processed shape of the vibrator. [Means for solving the problem]

[0005] One embodiment of a melt-forming mold disclosed in this specification is a melt-forming device including a melt-forming mold, a plate, and a ring portion. The melt-forming mold includes a lower surface, an upper surface parallel to the lower surface, a hole formed in a portion of the upper surface, and a through-hole extending from the bottom of the hole to the lower surface. An exhaust port is formed on the surface of the plate. The ring portion is disposed between the lower surface of the melt-forming mold and the surface of the plate, and connects the melt-forming mold and the plate. The ring portion surrounds the periphery of the through-hole exposed on the lower surface of the melt-forming mold and the periphery of the exhaust port exposed on the surface of the plate. In the area where the ring portion is not disposed, a space is formed between the lower surface of the melt-forming mold and the surface of the plate.

[0006] The ring portion forms a space between the underside of the melt-forming mold and the surface of the plate. Compared to when the entire underside of the melt-forming mold is in contact with the surface of the plate, the contact area between the melt-forming mold and the plate can be reduced, making it possible to reduce the amount of heat released from the melt-forming mold to the plate. In other words, it becomes possible to store heat in the melt-forming mold. This makes it possible to suppress the temperature gradient that occurs in the quartz plate, thereby improving the machining accuracy of the vibrator.

[0007] The ring portion may be integrally formed with the plate and protrude from the surface of the plate. Details of the effects will be described in the examples.

[0008] The ring portion may be integrally formed with the melt-molding mold and protrude from the lower surface of the melt-molding mold. Details of the effects will be described in the examples.

[0009] The ring portion may be formed separately from the plate and the melt-molding mold. Details of the effects will be explained in the examples.

[0010] A recess corresponding to the shape of the ring portion may be formed on the surface of the plate. The ring portion may be disposed inside the recess. When the ring portion is disposed inside the recess, the upper end of the ring portion may protrude from the surface of the plate. Details of the effects will be described in the examples.

[0011] The melting point of the ring portion may be 800°C or higher.

[0012] The distance from the central axis that passes through the center of the hole and is perpendicular to the lower surface of the melt-forming mold to the outer periphery of the ring portion may be shorter than the distance from the central axis to the outer periphery of the melt-forming mold. Details of the effects will be described in the examples.

[0013] The ring portion may have a circular ring shape when viewed from a direction perpendicular to the lower surface of the melt-molding mold. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a top view of a molding apparatus 1 according to a first embodiment. [Figure 2] FIG. 1 is a cross-sectional view of a molding apparatus 1 of a first embodiment. [Figure 3] FIG. 10 is a cross-sectional view after melt deformation. [Figure 4] 1A and 1B are a top view and a cross-sectional view of a BRG 60. [Figure 5] 10 is a cross-sectional view of a case where a vibrator 31 is produced using a plate 1010 of a first comparative example. FIG. [Figure 6] 10 is a cross-sectional view of a case where a vibrator 31 is produced using a molding die 2020 of a second comparative example. FIG. [Figure 7] FIG. 10 is a cross-sectional view of a molding apparatus 201 according to a second embodiment. [Figure 8] FIG. 10 is a cross-sectional view of a molding apparatus 301 according to a third embodiment. [Figure 9] FIG. 10 is a cross-sectional view of a molding apparatus 401 according to a fourth embodiment. [Figure 10] FIG. 5 is a cross-sectional view of a molding device 501 according to a modified example. DETAILED DESCRIPTION OF THE INVENTION [Example]

[0015] 1 and 2 show a molding apparatus 1 of Example 1. FIG. 1 is a top view. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. The molding apparatus 1 includes a plate 10, an exhaust mechanism 11, a molding die 20, a quartz plate 30, a ring unit 40, and a burner 50. In FIG. 1, the ring unit 40 is indicated by a dotted line, and the burner 50 and the exhaust mechanism 11 are not shown.

[0016] Plate 10 is a stainless steel base on which forming die 20 is placed. Exhaust port 10a is formed on surface 10s of plate 10. Exhaust port 10a is connected to exhaust mechanism 11 (e.g., vacuum pump) via exhaust path 10p.

[0017] The forming die 20 is a die for melting and deforming the quartz plate 30 to form a hemispherical vibrator 31. The forming die 20 is made of graphite. In this embodiment, the forming die 20 has a cylindrical shape with a central axis CA. The forming die 20 has a bottom surface 20r, a top surface 20s, a hole 20h, a support 20p, and a through-hole 20e. The bottom surface 20r and the top surface 20s are flat surfaces perpendicular to the central axis CA. The top surface 20s is parallel to the bottom surface 20r. A hole 20h is formed in a portion of the top surface 20s. The hole 20h is a deformation space for the quartz plate 30 to melt and deform. In this embodiment, the hole 20h has a shape formed by hollowing out a cylinder centered on the central axis CA. In other words, the central axis CA is an axis that passes through the center of the hole 20h and is perpendicular to the bottom surface 20r of the forming die 20. The hole 20h has a bottom surface 20b. A support 20p is disposed in the center of the hole 20h, extending vertically upward from the bottom surface 20b. The support 20p is a cylinder with a central axis CA. A plurality of through holes 20e are formed in the bottom surface 20b, penetrating to the lower surface 20r. The through holes 20e are in communication with the exhaust port 10a.

[0018] 1, ring portion 40 has a circular ring shape when viewed from a direction perpendicular to bottom surface 20r of forming die 20 (z direction). Radius R1 from central axis CA to the outer periphery of ring portion 40 is smaller than radius R2 from central axis CA to the outer periphery of forming die 20. Ring portion 40 has a constant width W1 in the circumferential direction.

[0019] As shown in Figure 2, the ring portion 40 is formed integrally with the plate 10 and protrudes upward (in the +z direction) from the surface 10s of the plate 10. The upper surface 40s of the ring portion 40 is in contact with the lower surface 20r of the forming die 20. In other words, the ring portion 40 is disposed between the lower surface 20r of the forming die 20 and the surface 10s of the plate 10, and connects the forming die 20 and the plate 10. In the area where the ring portion 40 is not disposed, a space SP is formed between the lower surface 20r of the forming die 20 and the surface 10s of the plate 10.

[0020] The ring portion 40 surrounds the through-hole 20e exposed on the lower surface 20r and the exhaust port 10a exposed on the front surface 10s. This allows the ring portion 40 to function as a seal that ensures airtightness of the connection path between the through-hole 20e and the exhaust port 10a. The width W1 of the ring portion 40 may be any width that can maintain a predetermined airtightness.

[0021] A quartz plate 30 is placed on the upper surface 20s of the mold 20 so as to cover the hole 20h. The quartz plate 30 is a material to be processed to form the vibrator. The thickness of the quartz plate 30 is, for example, 100 μm or less. In this embodiment, the quartz plate 30 is square, but it may be a point-symmetric polygon such as a hexagon or octagon, or a circle. The burner 50 is a means for heating the quartz plate 30 with a flame. The burner 50 is movable up and down along a central axis CA.

[0022] (Vibrator manufacturing process) The manufacturing process of the vibrator will be described with reference to Figures 2 and 3. In step S1, the mold 20 is placed on the upper surface 40s of the ring portion 40. In step S2, the quartz plate 30 is placed on the upper surface 20s. In step S3, the exhaust mechanism 11 is used to evacuate the exhaust port 10a to the desired vacuum level. The hole portion 20h is also evacuated via the through hole 20e. The quartz plate 30 is adsorbed and fixed to the upper surface 20s. This results in the state shown in Figure 2.

[0023] In step S4, a heating process is performed. Specifically, the burner 50 is ignited and lowered at a desired speed. This allows the quartz plate 30 to be melted and deformed into a desired shape, as shown in FIG. 3. In step S5, the burner 50 is raised and extinguished in response to detection of the processing end point. In step S6, the unformed region UR of the quartz plate 30 is removed by a CMP method or the like, thereby completing the vibrator 31 shown in FIG. 4.

[0024] In step S7, a Bird-bath Resonator Gyroscope (BRG) is assembled. FIG. 4(A) shows a top view of the assembled BRG 60. FIG. 4(B) shows a cross-sectional view taken along line BB in FIG. 4(A). The BRG 60 includes a transducer 31, a glass substrate 61, and a silicon electrode 62. The transducer 31 includes an anchor 31a and a rim 31r. The anchor 31a is fixed to a fixed portion 61f of the glass substrate 61. The silicon electrode 62 is disposed so as to surround the periphery of the rim 31r.

[0025] (effect) The following describes the problem. To increase the sensitivity of the BRG 60 (i.e., to generate large excitation vibrations with a low drive voltage and obtain a large capacitance change as output), the inclination angle θ (see FIG. 4B) of the rim 31r of the vibrator 31 must approach 90°. By making the rim 31r parallel to the side of the silicon electrode 62 and reducing the distance between them, the change in capacitance due to the effect of the rotation angle is increased. Here, as a first comparative example, a case in which the vibrator 31 is fabricated using the plate 1010 shown in FIG. 5 will be described. The plate 1010 of the first comparative example does not have a ring portion 40. Therefore, the entire lower surface 20r of the mold 20 is in contact with the surface 1010s of the plate 1010. Thick arrows indicate heat conduction, and the greater the number and area of ​​the arrows, the greater the amount of heat transfer. In the mold 20 of the first comparative example, the entire lower surface 20r serves as a heat conduction path to the plate 1010, so the width HW1 of the heat conduction path is very wide. Therefore, as shown by the thick arrow, a large portion of the heat of the quartz plate 30 is released to the plate 1010 via the forming die 20. As a result, the quartz plate 30 has a temperature gradient in which the temperature decreases toward the outer periphery of the hole 20h, and an undeformed region NR (a region that is not heated above the softening temperature of quartz and does not deform the quartz plate 30) is formed. Therefore, the inclination angle θ becomes smaller than 90°.

[0026] Now, a description will be given of the fabrication of a vibrator 31 using the forming die 20 of this embodiment shown in FIG. 3. In the forming die 20 of this embodiment, a space SP is formed between the lower surface 20r of the forming die 20 and the surface 10s of the plate 10 by the ring portion 40. The thermal conductivity of the air in the space SP is significantly lower than that of the graphite of the forming die 20. Therefore, the ring portion 40 alone can serve as the heat conduction path to the plate 10. As a result, the width HW2 of the heat conduction path in this embodiment (FIG. 3) can be narrower than the width HW1 of the heat conduction path in the first comparative example (FIG. 5). As indicated by the thick arrow, the amount of heat transferred from the forming die 20 to the plate 10 can be significantly reduced. In other words, by storing heat in the forming die 20, the temperature distribution in the forming die 20 can be made more uniform. This suppresses the temperature gradient occurring in the quartz plate 30, thereby suppressing the formation of undeformed regions NR and enabling the inclination angle θ to approach 90°.

[0027] Furthermore, in the forming die 20 of this embodiment, the support pillars 20p can be prevented from being locally heated, thereby suppressing large local deformation near the support pillars 20p. This makes it possible to form the head portion 31h (FIG. 4) of the vibrator 31 thicker or to position the head portion 31h closer to the outer periphery. Furthermore, since heat can be stored in the forming die 20, the temperature rise gradient of the quartz plate 30 can be increased. This makes it possible to shorten the processing time. Furthermore, as the processing time is shortened, it becomes possible to reduce gas consumption and increase the number of times the forming die 20 can be reused.

[0028] As a second comparative example, a case where a vibrator 31 is fabricated using a molding die 2020 shown in FIG. 6 will be described. The molding die 2020 of the second comparative example includes a peripheral groove 20t formed to surround the outer periphery of the hole 20h. The molding die 2020 is placed on a plate 1010 that does not include a ring. The peripheral groove 20t provides thermal insulation, preventing heat transfer from the quartz plate 30 to the outer periphery of the molding die 2020. As a result, the temperature gradient occurring in the quartz plate 30 can be suppressed. However, the second comparative example requires high machining precision for the peripheral groove 20t. For example, if the peripheral groove 20t is misaligned with respect to the hole 20h or if the circumferential width of the peripheral groove 20t varies, non-uniformity (asymmetry) occurs in the heat dissipation, deteriorating the symmetry of the shape of the vibrator 31. Furthermore, the provision of the peripheral groove 20t reduces the strength of the molding die 2020. Furthermore, the presence of thin portions such as the inner wall 20w that are heated by the flame accelerates mold deterioration (e.g., burning away of graphite) that accompanies flame processing. On the other hand, in the forming mold 20 of this embodiment, the ring portion 40 provided on the plate 10 can suppress the temperature gradient that occurs in the quartz plate 30. Therefore, there is no need to process the forming mold 20 with a peripheral groove 20t. This can prevent the symmetry of the vibrator 31 from deteriorating, the strength of the forming mold 20 from decreasing, and accelerated deterioration of the forming mold 20.

[0029] In the molding die 20 of this embodiment, the radius R1 from the central axis CA to the outer periphery of the ring portion 40 is smaller than the radius R2 to the outer periphery of the molding die 20 (FIG. 1). As a result, under the condition that the circumferential width W1 of the ring portion 40 is constant, the area of ​​the upper surface 40s can be made smaller compared to when a ring portion having a radius R2 is formed. This makes it possible to further reduce the amount of heat transferred from the molding die 20 to the plate 10. [Example]

[0030] 7 shows a cross-sectional view of a molding apparatus 201 of Example 2. Example 2 differs from Example 1 in that it includes a ring portion 240. Components common to the molding apparatus 1 of Example 1 are given the same reference numerals, and description thereof will be omitted.

[0031] The ring portion 240 is integrally formed with the forming die 20 and protrudes downward (in the -z direction) from the lower surface 20r of the forming die 20. The lower surface 240r of the ring portion 240 is in contact with the surface 10s of the plate 10. According to the second embodiment as well, a space SP can be formed between the lower surface 20r of the forming die 20 and the surface 10s of the plate 10. Therefore, the same effects as those of the forming apparatus 1 of the first embodiment can be obtained. [Example]

[0032] 8 shows a cross-sectional view of a molding apparatus 301 of Example 3. Example 3 differs from Example 1 in that it includes a ring portion 340. Components common to the molding apparatus 1 of Example 1 are given the same reference numerals, and description thereof will be omitted.

[0033] The ring portion 340 is configured separately from the plate 10 and the molding die 20. A first recess 10c1 corresponding to the shape of the ring portion 340 is formed in the surface 10s of the plate 10. The ring portion 340 is disposed inside the first recess 10c1. The first recess 10c1 enables automatic positioning of the ring portion 340. When the ring portion 340 is disposed inside the first recess 10c1, an upper end 340u of the ring portion 340 protrudes from the surface 10s of the plate 10. This allows a space SP to be formed.

[0034] Additionally, a second recess 10c2 having a depth greater than that of the first recess 10c1 is formed on the inner circumferential side of the first recess 10c1. This allows the volume of the exhaust port 10a to be increased. This makes it possible to suppress pressure fluctuations that occur when a leak occurs while the exhaust port 10a is being evacuated.

[0035] The ring portion 340 is formed from a material with a melting point of 800°C or higher. Specific examples of materials for the ring portion 340 include high-melting-point metals (e.g., gold, platinum, zirconia, etc.), various alloys, oxides, etc. Materials that can be used for the ring portion 340 are listed below. These materials may be used alone, in combination, or as a compound.

[0036] Examples of materials for the ring portion 340 include gold, platinum, zirconia, silver, aluminum nitride, silicon nitride, boron nitride, silicon carbide, alumina, germanium, cobalt, samarium, silicon, scandium, stainless steel, quartz glass, tungsten, tantalum, titanium, iron, copper, niobium, nickel, neodymium, manganese, and molybdenum. [Example]

[0037] 9 shows a cross-sectional view of a molding apparatus 401 of Example 4. Example 4 differs from Example 1 in that it includes tapered ring portions 440 and 441. Components common to the molding apparatus 1 of Example 1 are given the same reference numerals, and description thereof will be omitted.

[0038] The ring portion 440 is formed integrally with the plate 10 and protrudes upward (in the +z direction) from the surface 10s. The ring portion 441 is formed integrally with the forming die 20 and protrudes downward (in the -z direction) from the lower surface 20r. The cross section of the ring portions 440 and 441 taken along a plane passing through the central axis CA is triangular. As a result, a tapered surface 440t is formed on the inner diameter side of the ring portion 440. Furthermore, a tapered surface 441t is formed on the outer diameter side of the ring portion 441. The tapered surfaces 440t and 441t are in contact with each other.

[0039] When forming die 20 is placed on plate 10, tapered surface 441t slides on tapered surface 440t due to the weight of forming die 20. This makes it possible to automatically position forming die 20. Furthermore, tapered surfaces 440t and 441t engage with each other so as to eliminate any gaps, thereby improving airtightness.

[0040] Although specific examples of the present invention have been described above in detail, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and alterations of the specific examples exemplified above.

[0041] (Variation) In Example 1, the shape of the ring portion 40 formed integrally with the plate 10 is not limited to the shape shown in FIG. 2 and may be various. For example, as shown in a modified molding apparatus 501 in FIG. 10, a ring portion 540 may be formed on the outermost periphery of the plate 10. This allows a heat transfer path to be formed from the quartz plate 30 to the plate 10 via the outermost periphery of the forming mold 20, as indicated by the thick arrow, thereby increasing the distance of the heat transfer path. This makes it possible to suppress the temperature gradient occurring in the quartz plate 30. Note that in Example 2, the shape of the ring portion 240 formed integrally with the forming mold 20 is not limited to the shape shown in FIG. 7. For example, a ring portion may be formed on the outermost periphery of the forming mold 20.

[0042] In the third embodiment (FIG. 8), there may be various modes for disposing the separately formed ring portion 340. For example, the ring portion 340 may be disposed on a flat surface 10s on which the first recess 10c1 is not formed.

[0043] In the fourth embodiment (FIG. 9), the shape of the tapered surfaces and the manner of contact may be various. For example, the tapered surface on the outer diameter side of ring portion 440 and the tapered surface on the inner diameter side of ring portion 441 may be in contact with each other. Also, for example, ring portion 440 may have a groove with a V-shaped cross section, and ring portion 441 may have a protrusion with a triangular cross section, and the two may engage with each other.

[0044] The material of the mold 20 is not limited to graphite. Various materials can be used as long as they have a predetermined thermal shock resistance and thermal conductivity, and may be, for example, boron nitride.

[0045] The material of the vibrator is not limited to the quartz plate 30. Any dielectric material that melts and deforms can be used.

[0046] Furthermore, the technical elements described in this specification or drawings may exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated in this specification or drawings may achieve multiple objectives simultaneously, and achieving one of those objectives alone is technically useful. [Explanation of symbols]

[0047] 1, 201, 301, 401, 501: molding device 10: plate 10a: exhaust port 20: molding die 20s: upper surface 20h: hole portion 20r: lower surface 20e: through hole 40, 240, 340, 440, 540: ring portion SP: space

Claims

1. A melt-molding device comprising a melt-molding mold, a plate, and a ring portion, The melt-molding mold is The underside and an upper surface parallel to the lower surface; a hole formed in a part of the upper surface; a through hole penetrating from a bottom surface of the hole portion to the lower surface; It is equipped with An exhaust port is formed on the surface of the plate, the ring portion is disposed between a lower surface of the melt-forming mold and a surface of the plate, and connects the melt-forming mold and the plate; the ring portion surrounds the periphery of the through hole exposed on the lower surface of the melt-forming mold and the periphery of the exhaust port exposed on the surface of the plate, In a region where the ring portion is not disposed, a space is formed between a lower surface of the melt-forming mold and a surface of the plate, The ring portion is a first ring portion integrally formed with the plate and protruding from a surface of the plate; a second ring portion that is integrally formed with the melt-forming mold and protrudes from a lower surface of the melt-forming mold; It contains A first tapered surface is formed on the inner diameter side of the first ring portion, A second tapered surface is formed on the outer diameter side of the second ring portion, The first tapered surface and the second tapered surface are in contact with each other. Melt molding equipment.

2. A melt molding device as described in claim 1, wherein the first ring portion and the second ring portion have a triangular cross section in a plane passing through the center of the hole portion and a central axis perpendicular to the underside of the melt molding mold.

3. 3. The melt molding device according to claim 1, wherein a distance from a central axis passing through the center of the hole and perpendicular to the underside of the melt molding mold to an outer periphery of the first ring portion and an outer periphery of the second ring portion is shorter than a distance from the central axis to an outer periphery of the melt molding mold.

4. 4. The melt-molding device according to claim 1, wherein the ring portion has a circular ring shape when viewed from a direction perpendicular to the lower surface of the melt-molding mold.

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