Artificial crystal manufacturing apparatus

Abstract

To solve the problem that a control member provided in the vicinity of each seed crystal takes labor to assembly a growth frame.SOLUTION: An artificial crystal manufacturing apparatus capable of causing heat convection in a solution in a cylindrical autoclave extending along the vertical axis to melt a crystal raw material and recrystallize the melted crystal raw material using a seed crystal as a core includes: a first support part arranged in the autoclave and attaching one end of the seed crystal; a second support part arranged along the axis vertical to the first support part in the autoclave and attaching the other end of the seed crystal; and a control plate attached to at least one of the first and second support parts and having a plurality of holes.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an apparatus for manufacturing artificial quartz crystal. [Background technology]

[0002] A manufacturing device for producing artificial quartz crystal is known. The manufacturing device described in Patent Document 1 includes a metal container, a growth frame, and a control member. The metal container contains the quartz crystal as raw material, the growth frame, and an alkaline solution. The growth frame supports the seed quartz crystal. The control member is provided near at least one of the ends of the seed quartz crystal. The control member is fitted into the growth frame. The control member controls the convection of the alkaline solution. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-19584 Summary of the Invention [Problem to be solved by the invention]

[0004] The control members are provided in the vicinity of each seed crystal, which poses the problem of time and effort required to assemble the growth frame. [Means for solving the problem]

[0005] The artificial quartz crystal manufacturing apparatus disclosed herein is an artificial quartz crystal manufacturing apparatus that generates thermal convection in a melt within a cylindrical autoclave that extends along a vertical axis, melts the quartz crystal raw material, and recrystallizes the melted quartz crystal raw material using a seed quartz crystal as a nucleus. The apparatus comprises: a first support part that is placed within the autoclave and to which one end of the seed quartz crystal is attached; a second support part that is placed within the autoclave along the vertical axis relative to the first support part and to which the other end of the seed quartz crystal is attached; and a restraint plate that is attached to at least one of the first support part or the second support part and has a plurality of holes. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a diagram showing the schematic configuration of a crystal manufacturing apparatus. [Figure 2] FIG. 2 is a diagram showing a schematic configuration of a support frame body. [Figure 3] FIG. 3 is a diagram showing a schematic configuration of a support portion. [Figure 4] FIG. 10 is a diagram showing the evaluation results of a crystal manufacturing device equipped with a suppression plate. [Figure 5] FIG. 1 is a diagram showing the schematic configuration of a crystal manufacturing apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0007] FIG. 1 shows the schematic configuration of a quartz crystal manufacturing apparatus 100. The quartz crystal manufacturing apparatus 100 produces artificial quartz crystal using hydrothermal synthesis. FIG. 1 shows the cross-sectional configuration of the quartz crystal manufacturing apparatus 100. FIG. 1 shows a first quartz crystal manufacturing apparatus 100a, which is one example of the quartz crystal manufacturing apparatus 100. The first quartz crystal manufacturing apparatus 100a shown in FIG. 1 shows the quartz crystal raw material CM, seed quartz crystal CS, and solution AS used in producing artificial quartz crystal. The quartz crystal manufacturing apparatus 100 corresponds to one example of an artificial quartz crystal manufacturing apparatus.

[0008] The quartz crystal manufacturing apparatus 100 produces artificial quartz crystal using quartz crystal raw material CM, seed quartz crystal CS, and solution AS. The quartz crystal manufacturing apparatus 100 produces artificial quartz crystal by growing the quartz crystal on the seed quartz crystal CS in the presence of high-temperature, high-pressure solution AS. As an example, the quartz crystal manufacturing apparatus 100 produces artificial quartz crystal at a temperature of approximately 360°C and a pressure of 1100 to 1700 atmospheres. The quartz crystal manufacturing apparatus 100 produces artificial quartz crystal by growing the crystal for a period of two to six months.

[0009] Several figures, including FIG. 1, show an XYZ coordinate system. The Y axis is an axis parallel to the vertical direction. The Y axis corresponds to an example of a vertical axis. The +Y direction is the direction from below to above the crystal manufacturing apparatus 100. The -Y direction is the direction from above to below the crystal manufacturing apparatus 100. The X axis is perpendicular to the Y axis. The +X direction is the direction from the front to the back of the crystal manufacturing apparatus 100 shown in FIG. 1. The -X direction is the direction from the back to the front of the crystal manufacturing apparatus 100 shown in FIG. 1. The Z axis is perpendicular to the X axis and Y axis. The +Z direction is the direction from left to right of the crystal manufacturing apparatus 100 shown in FIG. 1. The -Z direction is the direction from right to left of the crystal manufacturing apparatus 100 shown in FIG. 1.

[0010] Quartz raw material CM is the source of silicon oxide used to manufacture artificial quartz. It is dissolved in high-temperature, high-pressure solution AS. One example of quartz raw material CM is Lasca, a natural quartz flake.

[0011] Seed crystal CS is a piece of quartz crystal formed into a specific shape from synthetic quartz crystal. The seed crystal CS is used as a nucleus for recrystallization of the raw quartz crystal CM dissolved in the solution AS and for crystal growth. The seed crystal CS can be shaped like a rod or a plate. For example, the seed crystal CS is synthetic quartz crystal sliced ​​to a thickness of about 1 mm.

[0012] The dissolving solution AS dissolves the quartz raw material CM under high temperature and pressure. An alkaline solution is used as the dissolving solution AS. Examples of alkaline solutions include aqueous sodium hydroxide (NaOH) solutions and aqueous sodium carbonate (Na2CO3) solutions. The dissolving solution AS may contain additives such as lithium nitrate, sodium nitrite, and lithium hydroxide.

[0013] The first crystal manufacturing apparatus 100a is equipped with a chamber 2, a convection control plate 3, a first heater 5a, a second heater 5b, a pressure gauge 6, and a safety valve 7. The first crystal manufacturing apparatus 100a houses a support frame 20. The first crystal manufacturing apparatus 100a is also equipped with a temperature sensor (not shown) and other devices.

[0014] The chamber 2 is a cylindrical container extending along the Y-axis. The chamber 2 is configured to be able to contain the solution AS and the like under high temperature and high pressure conditions. The chamber 2 is heated by a first heater 5a and a second heater 5b. The solution AS contained inside the chamber 2 is heated to a predetermined temperature by the first heater 5a and the second heater 5b. The interior of the chamber 2 is pressurized by a pressurizing means (not shown). The solution AS contained inside the chamber 2 is pressurized to a predetermined pressure by the pressurizing means. The chamber 2 corresponds to an example of an autoclave. The chamber 2 has a main body portion 2a and a lid portion 2b.

[0015] The main body 2a is a cylindrical body having a bottom. The side of the main body 2a parallel to the Y axis is configured to be cylindrical or approximately cylindrical. The cylindrical shape of the side of the main body 2a improves the pressure resistance of the chamber 2. The dimensions of the main body 2a are an inner diameter of 300 to 1000 mm and a height along the Y axis of 5 to 20 mm.

[0016] The main body 2a contains the crystal raw material CM, the seed crystal CS, the solution AS, and the support frame 20. The crystal raw material CM is positioned in the -Y direction within the main body 2a. The seed crystal CS and the support frame 20 are positioned in the +Y direction from the crystal raw material CM. The solution AS immerses the crystal raw material CM and the seed crystal CS within the main body 2a.

[0017] The lid 2b opens and closes the opening of the main body 2a. The opening of the main body 2a is located in the +Y direction of the main body 2a. By opening the lid 2b, the user can remove the support frame 20 and other components housed in the main body 2a.

[0018] The main body 2a and the lid 2b are made of iron-based metals such as carbon steel and alloy steel, titanium-based metals, aluminum-based metals, etc. The main body 2a and the lid 2b are preferably made of high-tensile steel. By making the main body 2a and the lid 2b out of high-tensile steel, the pressure resistance of the chamber 2 can be improved.

[0019] The convection control plate 3 is positioned inside the chamber 2 in the +Y direction of the crystal raw material CM. The convection control plate 3 is positioned inside the chamber 2 in the -Y direction of the seed crystal CS. The convection control plate 3 is positioned along the Y axis between the crystal raw material CM and the seed crystal CS. The convection control plate 3 has convection holes along the Y axis. As an example, the convection control plate 3 is made of a mesh-like body with multiple convection holes formed in it. The convection holes allow the dissolving solution AS to flow from below to above the convection control plate 3, or from above to below. The internal space of the chamber 2 is divided by the convection control plate 3 into a first compartment 11 and a second compartment 12.

[0020] The first compartment 11 is part of the internal space of the chamber 2. The crystal raw material CM is placed in the first compartment 11. In the first compartment 11, the crystal raw material CM is dissolved in the dissolving liquid AS. The first compartment 11 is located in the -Y direction of the convection control plate 3.

[0021] The second compartment 12 is part of the internal space of the chamber 2. A seed crystal CS is placed in the second compartment 12. The seed crystal CS is attached to a support frame 20. In the second compartment 12, the melted crystal raw material CM recrystallizes using the seed crystal CS as a nucleus. The second compartment 12 is located in the +Y direction of the first compartment 11 and the convection control plate 3.

[0022] The first heater 5a is disposed on the outer peripheral surface of the chamber 2. The first heater 5a is disposed in a region of the outer peripheral surface of the chamber 2 that corresponds to the outer periphery of the first section 11. The first heater 5a heats the first section 11 within the chamber 2. The first heater 5a heats the crystal raw material CM and the solution AS within the first section 11. The first heater 5a heats the crystal raw material CM and the solution AS, thereby dissolving the crystal raw material CM in the solution AS. The solution AS dissolves silicon oxide, a component of the crystal raw material CM. For example, the first heater 5a heats the solution AS within the first section 11 to a temperature within the range of 360°C to 410°C.

[0023] The second heater 5b is positioned on the outer periphery of the chamber 2. The second heater 5b is positioned in the region of the outer periphery of the chamber 2 that corresponds to the outer periphery of the second section 12. The second heater 5b is positioned in the +Y direction of the first heater 5a. The second heater 5b heats the second section 12 in the chamber 2. The second heater 5b heats the seed crystal CS and the solution AS in the second section 12 to a predetermined temperature. By heating the seed crystal CS and the solution AS to a predetermined temperature, the second heater 5b recrystallizes the crystal raw material CM dissolved in the solution AS using the seed crystal CS as a nucleus. Silicon oxide is recrystallized on the seed crystal CS.

[0024] The solution AS in the second section 12 is heated by the second heater 5b to a temperature lower than the solution AS in the first section 11. As an example, the solution AS in the second section 12 is preferably heated to a temperature 10°C to 60°C lower than the solution AS in the first section 11. When the temperature of the solution AS in the second section 12 is lower than the temperature of the solution AS in the first section 11, thermal convection of the solution AS occurs between the first section 11 and the second section 12. The solution AS that has dissolved the crystal raw material CM in the first section 11 moves to the second section 12 by thermal convection. The solution AS that has dissolved the crystal raw material CM recrystallizes the crystal raw material CM in the second section 12 using the seed crystal CS as a nucleus.

[0025] The first heater 5a and the second heater 5b are set to their respective temperatures by a control device (not shown). The first heater 5a and the second heater 5b are configured by sheath heaters or the like.

[0026] The pressure gauge 6 monitors the pressure inside the chamber 2. The pressure gauge 6 is provided on the lid 2b of the chamber 2. A user of the crystal manufacturing apparatus 100 monitors the pressure inside the chamber 2 with the pressure gauge 6, and thereby adjusts the pressure inside the chamber 2 to a predetermined pressure.

[0027] The safety valve 7 is provided on the cover 2b of the chamber 2. The safety valve 7 releases the pressure inside the chamber 2. When the pressure inside the chamber 2 exceeds a predetermined pressure, the safety valve 7 releases the pressure inside the chamber 2. By releasing the pressure inside the chamber 2, the safety valve 7 prevents the chamber 2 from breaking.

[0028] The support frame 20 supports the seed crystal CS. The support frame 20 is placed in the second compartment 12 inside the chamber 2. The support frame 20 places the seed crystal CS in the second compartment 12. As an example, the support frame 20 is placed in a position where the center of the XZ plane of the support frame 20 coincides or nearly coincides with the imaginary central axis VL. The imaginary central axis VL is an imaginary line that is parallel to the Y axis and passes through the center of the XZ plane of the chamber 2. The support frame 20 has multiple support portions 21.

[0029] The multiple support parts 21 are arranged along the Y axis. The support parts 21 are arranged parallel or approximately parallel to the XZ plane. One end of the seed crystal CS is attached to each of the multiple support parts 21. By attaching one end of the seed crystal CS, the seed crystal CS is supported by the support parts 21. The support frame 20 shown in FIG. 1 has five support parts 21, but is not limited to this. The support frame 20 has two or more support parts 21.

[0030] Fig. 2 shows a schematic configuration of the support frame 20. Fig. 2 shows a first support frame 20a, which is an example of the support frame 20. Fig. 2 shows a part of the first support frame 20a. Fig. 2 shows the first support frame 20a when placed in the chamber 2.

[0031] 2 shows the configuration of the first support portion 21a and the second support portion 21b included in the first support frame 20a. The first support frame 20a has a plurality of support portions 21 including the first support portion 21a and the second support portion 21b. The first support portion 21a and the second support portion 21b are any two adjacent support portions 21 among the plurality of support portions 21. The first support portion 21a and the second support portion 21b are arranged opposite each other. The second support portion 21b is arranged in the -Y direction of the first support portion 21a.

[0032] 2 shows the support frame 23, beams 25, support columns 27, suppression plates 31, and seed crystals CS. The support frame 23, beams 25, support columns 27, and suppression plates 31 are included in the support frame body 20. The support frame body 20 supports multiple seed crystals CS.

[0033] The first support portion 21a and the second support portion 21b include a support frame 23 and a plurality of beam portions 25. The support frame 23 and the plurality of beam portions 25 of the first support portion 21a have the same configuration as the support frame 23 and the plurality of beam portions 25 of the second support portion 21b. The first support portion 21a and the second support portion 21b of the first support frame body 20a include a suppression plate 31.

[0034] The support frame 23 supports a plurality of beam portions 25. The support frame 23 constitutes the outer edge portion of the support portion 21. As an example, the support frame 23 is formed in a shape that follows the inner circumferential surface of the chamber 2. The shape of the support frame 23 shown in FIG. 2 is circular.

[0035] The beams 25 are fixed to the support frame 23. The beams 25 fixed to the support frame 23 are fixed parallel or approximately parallel to one another. The beams 25 are fixed to the support frame 23 at predetermined intervals. As an example, the beams 25 are fixed to the support frame 23 at regular intervals along the Z axis. The beams 25 support the ends of the seed crystal CS. The ends of the seed crystal CS are attached to the beams 25 of the support 21.

[0036] The first support portion 21a and the second support portion 21b support the seed crystal CS. One end of the seed crystal CS is attached to the beam portion 25 of the first support portion 21a. The other end of the seed crystal CS is attached to the beam portion 25 of the second support portion 21b. One side of the seed crystal CS attached to the first support portion 21a and the second support portion 21b is attached along the beam portion 25. One side of the seed crystal CS is attached along the X-axis.

[0037] The first support portion 21a and the second support portion 21b support a plurality of seed crystals CS. Each of the plurality of seed crystals CS is attached with one side aligned with the beam portion 25. Each of the plurality of seed crystals CS is attached with one side aligned with the X-axis. The plurality of seed crystals CS are attached to the first support frame 20a in the same orientation.

[0038] The support pillars 27 connect the first support portion 21a and the second support portion 21b. The support pillars 27 support the first support portion 21a and the second support portion 21b in parallel or approximately parallel relation. The support frame 20 shown in FIG. 2 includes two support pillars 27, but is not limited to this. The first support frame 20a may include three or more support pillars 27 between the first support portion 21a and the second support portion 21b. The support pillars 27 may support a support portion 21 other than the first support portion 21a and the second support portion 21b.

[0039] The suppression plate 31 reduces the impurity content in the artificial quartz crystal that is recrystallized using the seed quartz crystal CS as a nucleus. The suppression plate 31 captures at least one of acmite, emeleusite, and peclite in the solution AS. Acmite, emeleusite, and peclite are by-product minerals that are generated using foreign matter in the solution AS as nuclei. Acmite contains iron. Emelusite contains lithium. Peclite contains calcium. By capturing the by-product minerals with the suppression plate 31, the impurity content in the artificial quartz crystal that is recrystallized using the seed quartz crystal CS as a nucleus is reduced.

[0040] The suppression plate 31 is made of carbon steel or low-alloy steel. Carbon steel is an alloy of iron and carbon. Low-alloy steel is a steel material with a content of elements other than carbon, silicon, manganese, phosphorus, and sulfur of 5% or less. By making the suppression plate 31 out of carbon steel or low-alloy steel, unexpected impurities are prevented from being contained in the artificial quartz crystal. The suppression plate 31 is preferably made of the same material as the inner surface of the chamber 2. The suppression plate 31 can easily capture impurities originating from the inner surface of the chamber 2.

[0041] The suppression plates 31 are attached to the beams 25 of the support part 21. The suppression plates 31 are attached to two adjacent beams 25. The suppression plates 31 are attached between two beams 25. Multiple seed crystals CS are attached to one beam 25. The suppression plates 31 are attached near the seed crystals CS. One suppression plate 31 is attached near multiple seed crystals CS. Attaching the suppression plates 31 to the beams 25 of the support part 21 makes it easier to assemble the support frame 20.

[0042] The suppression plate 31 has a plurality of through holes 31a. The through holes 31a allow the solution AS to flow. The through holes 31a allow the solution AS to flow in the +Y and -Y directions. By flowing the solution AS through the through holes 31a, the solution AS is supplied to the surface of the seed crystal CS. When the solution AS flows through the through holes 31a, the suppression plate 31 becomes more likely to capture by-product minerals in the solution AS. The through holes 31a correspond to an example of a hole.

[0043] The size, number, and arrangement of the through holes 31a in the suppression plate 31 are set appropriately. The size of the through holes 31a is preferably large enough to allow the by-product minerals to pass through. If the size of the through holes 31a is smaller than the size of the by-product minerals, clogging will occur. The amount of solution AS supplied to the seed quartz crystal CS will decrease, slowing down the growth rate of the artificial quartz crystal. The size of the through holes 31a is, for example, in the range of several mm to several tens of mm.

[0044] The support frame 20 shown in Figure 2 is provided with suppression plates 31 on the first support portion 21a and the second support portion 21b. The suppression plate 31 provided on the first support portion 21a covers the top of the multiple seed crystals CS. The suppression plate 31 provided on the second support portion 21b covers the bottom of the multiple seed crystals CS. By providing the suppression plates 31, the impurity content in the artificial crystal that is recrystallized using the seed crystals CS as nuclei is reduced.

[0045] The suppression plates 31 shown in Figure 2 are attached above and below the seed crystal CS, but are not limited to this. The suppression plates 31 may be attached either above or below the seed crystal CS. By attaching the suppression plates 31 above or below the seed crystal CS, the impurity content in the artificial quartz crystal is reduced.

[0046] The suppression plate 31 may be placed over the entire area of ​​the support portion 21, or may be placed over only a portion of the support portion 21. The placement position of the suppression plate 31 is set as appropriate. Various devices such as temperature sensors may come into contact with the outer peripheral surface of the chamber 2. When devices come into contact with the outer peripheral surface of the chamber 2, temperature variations occur in the solution AS within the chamber 2. The temperature variations in the solution AS cause fluctuations in the convection of the solution AS. When the convection of the solution AS varies, the area within the chamber 2 where by-product minerals are likely to be generated and flow varies. The suppression plate 31 is placed as appropriate to correspond to the area where by-product minerals are likely to be generated and flow.

[0047] Fig. 3 shows a schematic configuration of the support portion 21. Fig. 3 shows the support portion 21 of the second support frame 20b. Fig. 3 shows the support portion 21 in a plan view from the +Y direction. Fig. 3 shows the support portion 21 of the second support frame 20b when placed in the chamber 2.

[0048] The support portion 21 shown in FIG. 3 has seven beam portions 25. The seven beam portions 25 are fixed to the support frame 23. The seven beam portions 25 are arranged at regular intervals along the Z axis. The central beam portion 25 intersects with the imaginary central axis VL. The central beam portion 25 and the multiple beam portions 25 arranged at positions further in the +Z direction than the central beam portion 25 support the suppression plate 31.

[0049] The suppression plate 31 is a rectangular plate-shaped member. The length of the suppression plate 31 along the X axis is adjusted to correspond to the gap between two adjacent beam portions 25. The lengths of the multiple suppression plates 31 along the X axis are adjusted according to the positions at which they are disposed. Each of the multiple suppression plates 31 is attached to two adjacent beam portions 25.

[0050] 3 is configured as a rectangle, but is not limited to this. The suppression plate 31 may be configured in a shape corresponding to the shape of the gap between two adjacent beam portions 25. The suppression plate 31 may be attached to multiple beam portions 25.

[0051] Figure 4 shows the evaluation results of a quartz crystal manufacturing apparatus 100 equipped with suppression plates 31. Examples 1, 2, and 3 in Figure 4 show the evaluation results when artificial quartz crystal was manufactured using a support frame 20 equipped with suppression plates 31. Comparative Example 1 shows the evaluation results when artificial quartz crystal was manufactured using a support frame 20 without suppression plates 31.

[0052] Example 1 shows the evaluation results when artificial quartz crystal was manufactured using the first support frame 20a shown in Figure 2. All of the support parts 21 included in the first support frame 20a have suppression plates 31 attached in the configuration shown in Figure 2. Examples 2 and 3 show the evaluation results when artificial quartz crystal was manufactured using the second support frame 20b equipped with support parts 21 shown in Figure 3. All of the support parts 21 included in the second support frame 20b have suppression plates 31 attached in the configuration shown in Figure 3.

[0053] The conditions for producing the synthetic quartz crystals of Examples 1, 2, and 3, and Comparative Example 1 are shown below. Chamber 2 dimensions: inner diameter 650 mm, height 14 m Internal pressure of chamber 2: 140 MPa Dissolving solution AS: 4% by mass sodium hydroxide aqueous solution Filling rate of dissolving liquid AS: 85% Set temperature of first heater 5a: 390°C Set temperature of second heater 5b: 330°C Growth period: 3 months

[0054] Figure 4 shows the presence or absence of a suppression plate 31, the material of the suppression plate 31, the IC density, and the yield. The IC density and yield indicate the evaluation results. IC stands for inclusion, and refers to inclusions. Inclusions correspond to impurities. The IC density indicates the number of inclusions per unit volume. The yield indicates the yield of artificial quartz crystals that meet JIS C 6704 grade I or higher.

[0055] Examples 1 and 2 show evaluation results when carbon steel was used for the suppression plates 31. Examples 1 and 2 show evaluation results when artificial quartz crystal was produced under the same conditions except for the placement of the suppression plates 31. The IC density of Examples 1 and 2 is improved compared to the IC density of Comparative Example 1. The yield of Examples 1 and 2 is also increased compared to the yield of Comparative Example 1. By using suppression plates 31 made of carbon steel, the quality of the produced artificial quartz crystal is improved.

[0056] Example 3 shows the evaluation results when low-alloy steel was used for the suppression plate 31. The IC density of Example 3 is improved compared to that of Comparative Example 1. The yield of Example 3 is also increased compared to that of Comparative Example 1. By using suppression plate 31 made of low-alloy steel, the quality of the manufactured artificial quartz crystal is improved.

[0057] The first crystal manufacturing apparatus 100a generates thermal convection in the melt AS within a cylindrical chamber 2 extending along the Y axis, melting the crystal raw material CM and recrystallizing the melted crystal raw material CM using the seed crystal CS as a nucleus. The first crystal manufacturing apparatus 100a is equipped with a first support 21a located within the chamber 2 and to which one end of the seed crystal CS is attached, a second support 21b located within the chamber 2 along the Y axis relative to the first support 21a and to which the other end of the seed crystal CS is attached, and a suppression plate 31 attached to at least one of the first support 21a or the second support 21b and having multiple through-holes 31a. Attaching the suppression plate 31 to the support portion 21 makes it easier to assemble the support frame 20. By manufacturing artificial quartz crystal using a support frame 20 that has the suppression plate 31, the number of inclusions contained in the manufactured artificial quartz crystal is reduced, and the yield of high-quality artificial quartz crystal is improved.

[0058] Restraint plate 31 is preferably made of carbon steel or low alloy steel. The suppression plate 31 makes it easier to capture by-product minerals in the solution AS, and the number of inclusions in the manufactured synthetic quartz crystal is reduced.

[0059] The restraint plate 31 preferably captures at least one of acmite, emeleusite, and pectite. The suppression plate 31 captures at least one of the by-product minerals acmite, emeleusite, and pectrite, thereby reducing the number of inclusions contained in the manufactured synthetic quartz crystal.

[0060] Figure 5 shows the schematic configuration of the quartz crystal manufacturing apparatus 100. Figure 5 also shows a cross-sectional view of the quartz crystal manufacturing apparatus 100. Figure 5 also shows a second quartz crystal manufacturing apparatus 100b, which is an example of a quartz crystal manufacturing apparatus 100. The second quartz crystal manufacturing apparatus 100b shown in Figure 5 shows the quartz crystal raw material CM, seed quartz crystal CS, and solution AS used in manufacturing artificial quartz crystal. The second quartz crystal manufacturing apparatus 100b has the same configuration as the first quartz crystal manufacturing apparatus 100a, except that it is equipped with a filter member 9 and a third heater 5c.

[0061] The filter element 9 is positioned in the +Y direction relative to the seed crystal CS in the chamber 2. The convection control plate 3 is positioned in the -Y direction relative to the filter element 9. The filter element 9 captures miscellaneous crystals MC, which are crystal grains. The miscellaneous crystals MC are by-product minerals generated in the dissolving solution AS. By capturing the miscellaneous crystals MC, the filter element 9 suppresses the flow of the miscellaneous crystals MC toward the seed crystal CS.

[0062] As an example, the filter member 9 is made up of two mesh bodies. The two mesh bodies are stacked perpendicular to each other. The filter member 9 may be made up of three or more mesh bodies. The mesh bodies are formed in a rectangular shape. The mesh bodies have meshes of a predetermined size. The mesh size is set to be smaller than the size of the by-product minerals.

[0063] The interior of the chamber 2 is divided into a second section 12 and a third section 13 by a filter member 9. Similar to the first crystal manufacturing apparatus 100a, the second section 12 is the internal space within the chamber 2 where the seed crystal CS is placed.

[0064] The third compartment 13 is a part of the internal space of the chamber 2. The third compartment 13 is a space located inside the chamber 2 in the +Y direction from the filter member 9. In the third compartment 13, miscellaneous crystals MC are captured.

[0065] The third heater 5c is disposed on the outer peripheral surface of the chamber 2. The third heater 5c is disposed in a region of the outer peripheral surface of the chamber 2 corresponding to the outer periphery of the third section 13. The third heater 5c is disposed in a position in the +Y direction of the second heater 5b. The third heater 5c heats the third section 13 in the chamber 2. The third heater 5c heats the solution AS in the third section 13 to a predetermined temperature. The third heater 5c heats the solution AS in the third section 13 at a temperature lower than that of the second heater 5b. The set temperature of the third heater 5c is set, for example, to a temperature 10 to 40°C lower than the set temperature of the second heater 5b.

[0066] If the temperature of the solution AS in the third compartment 13 is lower than the temperature of the solution AS in the second compartment 12, thermal convection occurs, causing the solution AS to rise from the second compartment 12 to the third compartment 13. Due to thermal convection, the solution AS in the second compartment 12 moves to the third compartment 13. The temperature of the solution AS that moves from the second compartment 12 drops in the third compartment 13. By-product minerals are more likely to be produced in the solution AS. When by-product minerals are produced in the third compartment 13, they are captured by the filter member 9. This reduces the possibility of the by-product minerals flowing into the seed quartz crystal CS in the second compartment 12. This prevents the artificial quartz crystal from increasing in inclusions.

[0067] The second crystal manufacturing apparatus 100b preferably includes a filter element 9 positioned above the seed crystal CS on the Y axis to capture miscellaneous crystals MC, and a convection control plate 3 positioned below the filter element 9 on the Y axis. The interior of the chamber 2 is divided into a first compartment 11, a second compartment 12, and a third compartment 13 by a convection control plate 3 and a filter member 9. Miscellaneous crystals MC produced in the third compartment 13 are captured by the filter member 9, thereby suppressing the increase of inclusions in the artificial quartz crystal produced. [Explanation of symbols]

[0068] 2...chamber, 2a...main body, 2b...lid, 3...convection control plate, 5a...first heater, 5b...second heater, 5c...third heater, 6...pressure gauge, 7...safety valve, 9...filter member, 11...first compartment, 12...second compartment, 13...third compartment, 20...support frame, 20a...first support frame, 20b...second support frame, 21...support portion, 21a...first support portion, 21b...second support portion, 23...support frame, 25...beam portion, 27...support, 31...restraint plate, 31a...through hole, 100...quartz crystal manufacturing apparatus, 100a...first quartz crystal manufacturing apparatus, 100b...second quartz crystal manufacturing apparatus, AS...solution, CM...quartz crystal raw material, CS...seed quartz crystal, MC...miscellaneous crystals, VL...virtual center line.

Claims

1. An artificial quartz crystal manufacturing apparatus that generates thermal convection in a melt within a cylindrical autoclave extending along a vertical axis, melts quartz crystal raw material, and recrystallizes the melted quartz crystal raw material using seed quartz crystals as nuclei, a first support portion disposed in the autoclave and to which one end of the seed crystal is attached; a second support part disposed in the autoclave along the vertical axis relative to the first support part, to which the other end of the seed crystal is attached; a restraint plate attached to at least one of the first support portion and the second support portion and having a plurality of holes; An artificial quartz crystal manufacturing device comprising:

2. The suppression plate is made of carbon steel or low alloy steel.

2. The artificial quartz crystal manufacturing apparatus according to claim 1.

3. a filter member disposed above the vertical axis relative to the seed quartz crystal and configured to capture crystal grains; a convection control plate disposed below the vertical axis with respect to the filter member, 2. The artificial quartz crystal manufacturing apparatus according to claim 1.

4. The inhibition plate captures at least one of acmite, emeleusite, and pectite.

2. The artificial quartz crystal manufacturing apparatus according to claim 1.

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