JP7629812B2 - Molding device and molding method - Google Patents

Description

This specification relates to a vibrator molding device and molding method.

Patent Document 1 discloses a Bird-bath Resonator Gyroscope (BRG) that uses fused silica as an oscillator, as a gyro capable of achieving high accuracy. Specifically, a quartz plate is placed on a mold such as graphite, and while reducing the pressure on the bottom surface of the quartz plate, the top surface of the quartz plate is heated with a burner to melt and deform the plate, creating a hemispherical oscillator.

US Patent Application Publication No. 2018/079129

To manage this process, it is necessary to obtain temperature information from the quartz plate without contact. However, because the quartz plate deforms quickly and is thin (e.g., 100 μm), it is difficult to obtain temperature information from the quartz plate without contact.

One embodiment of the molding device disclosed herein includes a mold having a flat upper surface and a hole formed in a portion of the upper surface. The molding device includes a ring member disposed on the upper surface and surrounding the outer periphery of the hole. The molding device includes a heating means disposed above the hole. The molding device includes a thermometer disposed above the ring member and capable of measuring the temperature of the ring member without contact.

The ring member does not deform during molding. In addition, the ring member can be made thicker than the material being processed. This allows the temperature of the ring member to be measured without contact using a thermometer. Temperature information corresponding to the material being processed can be accurately detected, making process management possible.

The ring member may be placed on the upper surface via a plate-shaped workpiece material that is placed on the upper surface. Details of the effect will be explained in the examples.

The ring member may have a first portion extending outward from the outer periphery of the ring member. The lower surface of the first portion may be located lower than the lower surface of the ring member and parallel to the lower surface of the ring member. The lower surface of the ring member may be configured to be able to contact the surface of the workpiece material. The lower surface of the first portion may be configured to be able to contact the upper surface. Details of the effects will be explained in the examples.

The first part may have a fixing part that can fix the first part to the upper surface. The details of the effect will be explained in the examples.

The ring member may be arranged so as to contact the upper surface. Details of the effect will be explained in the examples.

The surface of the ring member may be parallel to the upper surface and located above the upper surface. Details of the effect will be explained in the examples.

The back surface of the ring member may have a smaller surface roughness than the front surface of the ring member. The details of the effect will be explained in the examples.

The melting point of the ring member may be 1000°C or higher.

The width of the ring member may be greater than or equal to the measurement spot diameter of the thermometer.

One embodiment of the molding method disclosed in this specification includes a placement step of placing a plate-shaped workpiece material on the upper surface of a mold having an upper surface in which a hole is formed, so as to cover the hole. The molding method includes a heating step of heating the upper surface of the workpiece material with a heating means to melt and deform it while reducing the pressure inside the hole. The molding method includes a measurement step of measuring a predetermined temperature corresponding to the temperature of the workpiece material using a non-contact thermometer. The molding method includes a step of controlling the heating means based on the predetermined temperature. Details of the effects will be explained in the examples.

The molding method may further include a step of placing a ring member surrounding the outer periphery of the hole on the surface of the workpiece material placed on the upper surface by the placing step. In the measuring step, the temperature of the surface of the ring member may be measured. Details of the effect will be explained in the examples.

A ring member that surrounds the outer circumference of the hole may be placed on the upper surface. In the placement process, the workpiece may be placed on the ring member. In the measurement process, the temperature of the surface of the ring member may be measured by measuring the wavelength transmitted through the workpiece. Details of the effects will be explained in the examples.

A roughened area having a large surface roughness may be formed on a portion of the surface of the workpiece. In the measurement process, the temperature of the roughened area may be measured. The details of the effect will be explained in the examples.

In the measurement process, the temperature of the top surface may be measured by measuring the wavelength transmitted through the processed material.

FIG. 2 is a top view of the molding device 1 of the first embodiment. FIG. 2 is a cross-sectional view of the molding device 1 of the first embodiment. FIG. 3 is a cross-sectional view after melt deformation. FIG. 11 is a top view of a molding apparatus 201 according to a second embodiment. FIG. 11 is a cross-sectional view of a molding apparatus 201 according to a second embodiment. FIG. 11 is a cross-sectional view of a molding apparatus 301 according to a third embodiment. FIG. 11 is a cross-sectional view of a molding apparatus 401 according to a fourth embodiment.

Figures 1 and 2 show the molding device 1 of Example 1. Figure 1 is a top view. Figure 2 is a cross-sectional view taken along line II-II in Figure 1. The molding device 1 includes a plate 10, a molding die 20, a quartz plate 30, a ring 40, a burner 50, and a thermometer 60. Note that the plate 10, the burner 50, and the thermometer 60 are omitted from Figure 1.

The plate 10 is a stainless steel platform on which the molding die 20 is placed. The plate 10 has an opening 10a. The opening 10a can be evacuated by a vacuum pump (not shown).

The molding die 20 is a die for forming a hemispherical vibrator using fused silica. The vibrator is a component of a Bird-bath Resonator Gyroscope (BRG). The molding die 20 is made of graphite. In this embodiment, the molding die 20 is a disk shape with a central axis CA. The molding die 20 has an upper surface 20s, a hole 20h, a support 20p, and an exhaust port 20e. The upper surface 20s is a flat surface perpendicular to the central axis CA. A hole 20h is formed in a part of the upper surface 20s. The hole 20h is a deformation space for the quartz plate 30 to melt and deform. In this embodiment, the hole 20h is formed in a cylindrical shape centered on the central axis CA. A support 20p extending vertically upward from the bottom surface 20b is arranged in the center of the hole 20h. The support 20p is a cylinder with the central axis CA as its central axis. The bottom surface 20b has multiple exhaust ports 20e that penetrate to the back surface 20r. The exhaust ports 20e are connected to the opening 10a.

A quartz plate 30 is disposed on the upper surface 20s 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. In this embodiment, the quartz plate 30 is square, but it may be rectangular or circular.

A ring 40 is disposed on the surface of the quartz plate 30 so as to surround the outer periphery of the hole 20h. In other words, the ring 40 is disposed on the upper surface 20s via the quartz plate 30. The ring 40 is circular, and its center coincides with the central axis CA. The inner diameter D1 of the ring 40 is larger than the diameter D2 of the hole 20h. The width W1 of the ring 40 is equal to or larger than the measurement spot diameter of the thermometer 60. The thickness T1 of the ring 40 is equal to or larger than the thickness T2 of the quartz plate 30.

The rear surface 40r of the ring 40 has a smaller surface roughness than the front surface 40s. By increasing the smoothness of the rear surface 40r, the thermal resistance of the contact interface with the quartz plate 30 can be reduced. Since the heat transfer from the quartz plate 30 to the ring 40 can be increased, it is possible to bring the temperature of the ring 40 closer to the temperature of the quartz plate 30. Furthermore, by worsening the surface roughness of the front surface 40s, the emissivity of far-infrared rays can be increased. It is possible to improve the measurement accuracy of the thermometer 60.

It is preferable that the width W1 and thickness T1 of the ring 40 are as small as possible within the range that can be measured by the thermometer 60. This makes it possible to suppress the heat discharge and storage by the ring 40, thereby improving the accuracy of temperature measurement.

The burner 50 is a means for heating the quartz plate 30 with a flame. The burner 50 can move up and down along the central axis CA. The thermometer 60 is a non-contact thermometer that uses far-infrared rays. The measurement spot of the thermometer 60 is located on the surface of the ring 40.

(Material for Ring 40)
The ring 40 is made of a material with a melting point of 1000°C or more. The reason is explained below. The quartz plate 30 arranged in the hole 20h has a heat conduction path only in the surface direction of the quartz plate. Therefore, in the heating process described later, it is heated to 1600°C or more by the burner 50. On the other hand, the quartz plate 30 arranged on the upper surface 20s has a heat conduction path to the molding die 20. Therefore, since heat is exhausted during the heating process, the maximum temperature can be suppressed to a temperature lower than 1000°C (e.g., about 700°C). Since the ring 40 is located on the surface of the quartz plate 30 arranged on the upper surface 20s, the maximum temperature of the ring 40 is also suppressed to a temperature lower than 1000°C. Therefore, by setting the melting point of the ring 40 to 1000°C or more, it is possible to prevent the ring 40 from melting.

The material of the ring 40 is preferably a material that is resistant to oxidation (e.g., gold). This can prevent cracks caused by oxidation due to flames. The material of the ring 40 is also preferably a material with high density. This can increase the mass of the ring 40, preventing the ring 40 from moving due to the flame pressure of the burner 50. The material of the ring 40 is also preferably resistant to thermal shock caused by burner heating and can be processed into a ring shape.

Specific examples of materials for the ring 40 include high melting point metals (e.g., gold, platinum, zirconia, etc.), various alloys, oxides, etc. Materials that can be used for the ring 40 are listed below. These materials may be used alone, in combination, or as a compound.

Examples of materials for ring 40: 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, molybdenum.

The thermal conductivity of the ring 40 is preferably higher than that of the mold 20. This allows the ring 40 to be heated more uniformly than the mold 20. The ring 40 is in contact with the quartz plate 30 on the outer periphery of the hole 20h. Therefore, the ring 40 can function as a heat transfer material to uniformize the temperature of the quartz plate 30 on the outer periphery of the hole 20h. It is possible to suppress variation in the processed shape of the 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 plate 10. In step S2, the quartz plate 30 is placed on the upper surface 20s. In step S3, the opening 10a is evacuated to a desired vacuum level. The hole 20h is also evacuated via the exhaust port 20e. The quartz plate 30 is adsorbed and fixed to the upper surface 20s. In step S4, the ring 40 is placed on the surface of the quartz plate 30. This results in the state shown in Figure 2.

In step S5, a heating process is performed. Specifically, the burner 50 is ignited and lowered at a desired speed. In step S6, a measurement process is performed. The temperature of the ring 40 is measured using the thermometer 60.

In step S7, the processing parameters are controlled based on the temperature measurement value of the ring 40. Specifically, various processing parameters such as the gas flow rate of the burner 50, the distance between the burner 50 and the quartz plate 30, the reduced pressure, and the heating time are feedback-controlled based on the temperature measurement value. This allows the quartz plate 30 to be melted and deformed into the desired shape, as shown in FIG. 3.

In step S8, the burner 50 is raised and extinguished in response to detecting the end point of processing based on the temperature measurement value. After the quartz plate 30 has cooled to the desired temperature, the hole 20h is opened to the atmosphere. The melt-processed quartz plate 30 is removed from the molding die 20. In step S9, the unformed portion is removed by a CMP method or the like to complete the vibrator.

(effect)
The problem is explained below. In the conventional technology that does not use the ring 40, it is difficult to obtain the temperature information of the quartz plate in a non-contact manner. This is due to the fact that the quartz plate deforms at high speed and has a small thickness (e.g., 100 μm). Therefore, in the past, process control was performed by controlling processing parameters (e.g., the gas flow rate of the burner, the distance between the burner and the quartz plate, the heating time, etc.) without using temperature information. Because the accuracy of the process control was low, the variation in the processed shape of the vibrator increased, leading to a decrease in yield.

In the technology of this embodiment, the ring 40 is placed on the quartz plate 30. The ring 40 does not deform during molding. The thickness T1 of the ring 40 can be made thicker than the thickness T2 of the quartz plate 30. Therefore, the temperature of the ring 40 can be measured non-contact with the thermometer 60. Since the temperature of the ring 40 follows the temperature change of the quartz plate 30 with high accuracy, it is possible to obtain temperature information corresponding to the temperature of the quartz plate 30 by measuring the temperature of the ring 40. Since the process can be controlled based on the temperature information of the quartz plate 30, it is possible to improve the accuracy of the process control. Since the variation in the processed shape of the vibrator can be suppressed, the yield is improved and the manufacturing cost can be reduced. In addition, the use of the temperature information makes it possible to improve the accuracy of the thermal design of the molding die 20.

The ring 40 has a high thermal conductivity, so the temperature can be made uniform in the circumferential direction. Therefore, by measuring the temperature at one point on the ring 40 with the thermometer 60, the average temperature of the entire ring 40 can be obtained. Since accurate temperature information can be obtained, it is possible to improve the accuracy of process management. The temperature of multiple points on the ring 40 may also be measured.

Figures 4 and 5 show a top view and a cross-sectional view of the molding device 201 of Example 2. Example 2 differs from Example 1 in that the ring 240 has a flange 240f. Parts that are common to the molding device 1 of Example 1 are given the same reference numerals and will not be described.

The ring 240 has a flange 240f extending outward from the outer periphery of the ring 240. The lower surface 240fr of the flange 240f is located lower than the lower surface 240r of the ring 240. The lower surface 240fr of the flange 240f is parallel to the lower surface 240r of the ring 240. The lower surface 240r of the ring 240 is configured to be able to contact the surface of the quartz plate 30. The lower surface 240fr of the flange 240f is configured to be able to contact the upper surface 20s of the molding die 20.

The screw 241 passes through a screw hole formed in the flange 240f and is screwed into the top surface 20s. The screw 241 makes it possible to fix the flange 240f to the top surface 20s.

(effect)
The ring 240 can be fixed to the upper surface 20s by the screw 241. It is possible to prevent the ring 240 from moving due to the flame pressure. In addition, since the pressing pressure of the ring 240 can be increased, it is possible to improve the airtightness between the quartz plate 30 and the upper surface 20s. When the hole 20h is decompressed, it is possible to suppress pressure fluctuations, so it is possible to suppress variations in the processed shape of the vibrator.

(Modification of the second embodiment)
The flange 240f does not have to include the screw 241. This also makes it possible for the flange 240f to restrict the movement of the quartz plate 30 in the planar direction.

Figure 6 shows a cross-sectional view of the molding device 301 of Example 3. Example 3 differs from Example 1 in that the ring 40 is disposed between the upper surface 20s and the quartz plate 30. Parts common to the molding device 1 of Example 1 are given the same reference numerals and will not be described.

The ring 40 is arranged so as to contact the upper surface 20s of the mold 20. The surface 40s of the ring 40 is parallel to the upper surface 20s and is located above the upper surface 20s. The quartz plate 30 is arranged on the surface 40s of the ring 40.

The thermometer 60 measures the wavelength transmitted through the quartz plate 30. Specifically, quartz glass is transparent at wavelengths of approximately 3 μm or less. Therefore, for example, near-infrared light (wavelengths of approximately 0.78 μm to 1.5 μm) is measured. This makes it possible to measure the temperature of the ring 40.

(effect)
The problem will be explained. In order to increase the sensitivity of the gyro sensor, it is necessary to make the inclination angle θ (see FIG. 3) of the rim of the vibrator closer to 90°. However, since the rim portion is difficult to deform, the inclination angle θ becomes smaller than 90°. This is because the heat of the quartz plate 30 heated by the burner 50 is discharged to the mold 20 through the contact surface between the quartz plate 30 and the upper surface 20s of the mold 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, so that the rim portion is difficult to deform. In this embodiment, the ring 40 allows the quartz plate 30 to have a structure in which it floats above the upper surface 20s. Since the contact area between the quartz plate 30 and the upper surface 20s can be reduced, the amount of heat discharged from the quartz plate 30 to the mold 20 can be reduced. Since the temperature drop at the outer periphery of the hole 20h can be suppressed, it is possible to make the inclination angle θ of the rim closer to 90°.

(Modification of the third embodiment)
A configuration may be adopted in which the quartz plate 30 is in contact with the upper surface 20s without providing the ring 40. A wavelength (e.g., near-infrared rays) transmitted through the quartz plate 30 may be measured by the thermometer 60. This makes it possible to obtain temperature information corresponding to the temperature of the quartz plate 30 by measuring the temperature of the upper surface 20s located below the quartz plate 30.

Figure 7 shows a cross-sectional view of the molding device 401 of Example 4. Example 4 differs from Example 1 in that it does not include a ring 40. Parts that are common to the molding device 1 of Example 1 are given the same reference numerals and will not be described.

The quartz plate 30 has a processing region R1 that is machined into an oscillator, and a peripheral region R2 that is not machined into an oscillator. The surface of the processing region R1 is a smooth surface on the nanometer order. A rough surface region is formed on at least a portion of the surface of the peripheral region R2. The rough surface region is an area in which the surface roughness is greater than that of the processing region R1. The measurement spot of the thermometer 60 is located in the rough surface region.

(effect)
The quartz plate 30, which has a flatness on the order of nanometers, reflects far-infrared rays, so the temperature of the quartz plate 30 itself cannot be measured by the thermometer 60. In this embodiment, a rough surface area is formed in the peripheral area R2, and the temperature of the rough surface area is measured by the thermometer 60. Since the surface reflection of far-infrared rays does not occur in the rough surface area, it becomes possible to measure the temperature using the thermometer 60. It becomes possible to perform non-contact temperature measurement of the quartz plate 30 without using the ring 40. Furthermore, since the peripheral area R2 is an area that is removed after processing (see step S9), there is no problem even if a rough surface area is formed.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples given above.

(Modification)
The material of the vibrator is not limited to the quartz plate 30. Any dielectric material that melts and deforms may be used. The material of the mold 20 is not limited to graphite.

The diameter D2 and depth of the hole 20h may vary. Also, the height and diameter of the support 20p may vary.

The technical elements described in this specification or drawings may exhibit technical utility either alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. The technologies illustrated in this specification or drawings may achieve multiple objectives simultaneously, and achieving any one of those objectives is itself technically useful.

The burner 50 is an example of a heating means. The quartz plate 30 is an example of a workpiece material. The flange 240f is an example of a first part. The screw 241 is an example of a fixing part.

1, 201, 301, 401: molding device 20: molding die 20e: exhaust port 20h: hole 20p: support 20s: upper surface 30: quartz plate 40: ring 50: burner 60: thermometer

Claims (13)

a mold having a flat upper surface and a hole formed in a portion of the upper surface;
A ring member disposed on the upper surface and surrounding an outer periphery of the hole;
A heating means disposed above the hole;
a thermometer disposed above the ring member and capable of measuring a temperature of the ring member in a non-contact manner;
A molding apparatus comprising: The molding device according to claim 1, wherein the ring member is placed on the upper surface via a plate-shaped workpiece material that is placed on the upper surface. the ring member includes a first portion extending outwardly from an outer periphery of the ring member;
a lower surface of the first portion is located lower than a lower surface of the ring member and is parallel to the lower surface of the ring member;
The lower surface of the ring member is configured to be able to contact the surface of the workpiece,
The molding apparatus according to claim 2 , wherein a lower surface of the first portion is configured to be able to contact the upper surface. The first portion includes a fixing portion capable of fixing the first portion to the upper surface.
The molding apparatus according to claim 3. The molding device according to claim 1, wherein the ring member is arranged to contact the upper surface. The molding device according to claim 5, wherein the surface of the ring member is parallel to the upper surface and is located above the upper surface. The molding device according to any one of claims 1 to 6, wherein the back surface of the ring member has a surface roughness smaller than that of the front surface of the ring member. The molding device according to any one of claims 1 to 7, wherein the melting point of the ring member is 1000°C or higher. The molding device according to any one of claims 1 to 8, wherein the width of the ring member is equal to or greater than the measurement spot diameter of the thermometer. a placement step of placing a plate-shaped workpiece on an upper surface of a mold having an upper surface in which a hole is formed, so as to cover the hole;
a step of placing a ring member surrounding an outer periphery of the hole on a surface of the workpiece placed on the upper surface by the placing step;
a heating step of heating an upper surface of the workpiece with a heating means to melt and deform the upper surface while reducing the pressure inside the hole;
a measuring step of measuring a predetermined temperature corresponding to the temperature of the workpiece using a non-contact thermometer;
controlling the heating means based on the predetermined temperature;
Equipped with
In the measuring step, a temperature of a surface of the ring member is measured.
Molding method. a placement step of placing a plate-shaped workpiece on an upper surface of a mold having an upper surface in which a hole is formed, so as to cover the hole;
a heating step of heating an upper surface of the workpiece with a heating means to melt and deform the upper surface while reducing the pressure inside the hole;
a measuring step of measuring a predetermined temperature corresponding to the temperature of the workpiece using a non-contact thermometer;
controlling the heating means based on the predetermined temperature;
Equipped with
A ring member is disposed on the upper surface so as to surround an outer periphery of the hole,
In the placing step, the workpiece is placed on the ring member;
In the measuring step, a wavelength transmitted through the workpiece is measured to measure a temperature of the surface of the ring member.
Molding method. a placement step of placing a plate-shaped workpiece on an upper surface of a mold having an upper surface in which a hole is formed, so as to cover the hole;
a heating step of heating an upper surface of the workpiece with a heating means to melt and deform the upper surface while reducing the pressure inside the hole;
a measuring step of measuring a predetermined temperature corresponding to the temperature of the workpiece using a non-contact thermometer;
controlling the heating means based on the predetermined temperature;
Equipped with
A rough surface region having a large surface roughness is formed on a part of the surface of the workpiece,
In the measuring step, the temperature of the rough surface region is measured.
Molding method. a placement step of placing a plate-shaped workpiece on an upper surface of a mold having an upper surface in which a hole is formed, so as to cover the hole;
a heating step of heating an upper surface of the workpiece with a heating means to melt and deform the upper surface while reducing the pressure inside the hole;
a measuring step of measuring a predetermined temperature corresponding to the temperature of the workpiece using a non-contact thermometer;
controlling the heating means based on the predetermined temperature;
Equipped with
In the measuring step, a wavelength transmitted through the workpiece is measured to measure a temperature of the upper surface.
Molding method.

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