Multi-layer quartz glass plate and preparation method and system thereof

Abstract

The invention provides a multilayer quartz glass plate and a preparation method and system thereof. The preparation system of the multi-layer quartz glass plate comprises an outer shell and a plurality of quartz glass plates, wherein the inner part of the outer shell is hollow and is provided with a smoke outlet for discharging smoke; the smoke supply device is arranged at the top of the outer shell in a penetrating manner and is used for providing silicon dioxide soot to be deposited on the opaque quartz glass target material positioned below; the bottom heating device is located in the hollow cavity of the outer shell, located below the smoke supply device and used for heating the bottom of the opaque quartz glass target placed above the bottom heating device; and the movable base is supported below the bottom heating device and can drive the bottom heating device to move. According to the preparation method of the multi-layer quartz glass plate, the transparent quartz glass layer is arranged on the surface of the opaque quartz glass in a chemical vapor deposition mode, the production cost can be saved, the manufacturing period can be shortened, meanwhile, the manufactured transparent glass layer does not make contact with other objects before being manufactured, impurities are not prone to being introduced, and the production efficiency is improved. The obtained glass is high in purity.

Description

Technical Field

[0001] This invention relates to the field of quartz glass plate production technology, and in particular to a multilayer quartz glass plate and its preparation method and system. Background Technology

[0002] Quartz glass, with its high purity and high heat resistance, has wide applications in the semiconductor field. Opaque quartz glass, due to its uniformly distributed porous structure, exhibits good heat radiation reflection and is frequently used as a thermal insulation material in semiconductors. However, its unique porous structure means that during etching and cleaning with hydrofluoric acid, tiny surface pores may open, leading to surface roughening and the formation of silica particles, which can negatively impact the material's subsequent use.

[0003] To address the above issues, a multilayer composite quartz glass material was developed, which consists of a layer of transparent quartz glass laminated onto the upper and lower surfaces of opaque quartz glass. This retains the good thermal insulation properties of opaque quartz glass while solving the problem of debris caused by surface pores.

[0004] In existing technologies, there are two methods for manufacturing this type of composite quartz glass material: high-temperature welding and slurry sintering. High-temperature welding involves pressing transparent and opaque quartz glass layers together and then heating them using a burner flame or electricity to fuse the opaque and transparent layers. The raw materials used are typically thin quartz glass sheets, which are processed to obtain the final product. However, when producing large-sized composite quartz glass materials, the processing cycle for the raw materials is long, resulting in high production costs.

[0005] The slurry sintering method involves uniformly coating a prepared slurry onto the surface of opaque quartz glass, followed by heating the surface to obtain a transparent quartz glass layer. This process effectively avoids the lengthy raw material processing time. However, it requires high precision in the composition and ratio of the slurry, a long grinding time, and the introduction of impurities during the slurry grinding process, which can affect the use of subsequent materials. Summary of the Invention

[0006] The main objective of this invention is to provide a multilayer quartz glass plate and its preparation method and system, which aims to reduce the processing cycle and production cost of the multilayer quartz glass plate on the one hand, and to prevent the easy introduction of impurities on the other.

[0007] To achieve the above objectives, the present invention provides a system for preparing multilayer quartz glass plates, comprising: The outer shell is hollow inside and has a smoke vent to exhaust the smoke. A fume supply device, which is installed at the top of the housing and is used to supply silica fume for deposition on the opaque quartz glass target located below; The bottom heating device is located inside the hollow cavity of the outer shell and below the smoke supply device, and is used to heat the bottom of the opaque quartz glass target material placed above it; The movable base supports the bottom heating device and can move the bottom heating device.

[0008] Preferably, the smoke supply device includes a flame hydrolysis burner, which is connected to a raw material supply device for providing silicon-containing precursor compounds and a fuel supply device.

[0009] Preferably, the silicon-containing precursor compound is SiCl4 or octamethylcyclotetrasiloxane, and the fuel is H2, O2, or CH4.

[0010] Preferably, the multilayer quartz glass plate preparation system further includes a top heating device for heating the opaque quartz glass target material deposited with silica dust, the top heating device including multiple heating rods or burners evenly arranged on a plane.

[0011] Preferably, the exhaust port is connected to an external air extraction device via a butterfly valve.

[0012] This invention further proposes a method for preparing a multilayer quartz glass plate, comprising the following steps: An opaque quartz glass target is placed above the bottom heating device, and a smoke supply device is installed above the opaque quartz glass target. After the bottom heating device is turned on to heat the opaque quartz glass target to the first preheating temperature, the smoke supply device is turned on. The smoke supply device generates silica fume to be deposited on the opaque quartz glass target located below. When the silica fume layer on the opaque quartz glass target reaches the preset thickness, the fume supply device is turned off, and a top heating device is installed above the opaque quartz glass target on which silica fume has been deposited. After the top heating device is turned on for a predetermined time, the silica fume above the opaque quartz glass target is heated to a transparent state.

[0013] Preferably, when a smoke supply device is installed above an opaque quartz glass target, the distance between the nozzle of the smoke supply device and the opaque quartz glass target is 100mm to 400mm; the preset thickness is 0.5mm to 3mm; when the smoke supply device generates silica soot to deposit on the opaque quartz glass target below, the density of the silica soot layer on the opaque quartz glass target is controlled to be 0.8g / cm³. 3 ~1.2g / cm 3 .

[0014] Preferably, when the smoke supply device is turned on and generates silica fume to be deposited on the opaque quartz glass target located below, the movable base below the bottom heating device is simultaneously controlled to move so as to cause the opaque quartz glass target to oscillate back and forth along a plane parallel to the deposition plane.

[0015] Preferably, the first preheating temperature is 500℃~1400℃, the second preset temperature is 1200℃~1500℃, and the temperature uniformity deviation of the opaque quartz glass target deposition surface is less than 100℃.

[0016] The present invention also proposes a multilayer quartz glass plate, which is prepared by the above-described method.

[0017] The method for preparing multilayer quartz glass plates proposed in this invention has the following beneficial effects: 1. By using chemical vapor deposition to set a transparent quartz glass layer on the surface of opaque quartz glass, the high-temperature welding method used in the prior art can be avoided in processing the transparent quartz glass layer, which greatly saves production costs and shortens the manufacturing cycle. 2. The transparent glass layer produced does not come into contact with other objects before it is completed, making it less likely to introduce impurities and resulting in high glass purity. At the same time, it is faster to manufacture because it eliminates the grinding time of the existing slurry sintering method. 3. By adjusting the movement of the movable base, it is easy to manufacture multi-layered quartz glass of various shapes and sizes; 4. By adjusting the deposition process, the thickness and density of silica fume can be controlled, making it easy to produce multilayer quartz glass with transparent quartz glass layers of different thicknesses. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the first embodiment of the multilayer quartz glass plate preparation system of the present invention; Figure 2 This is a schematic diagram of the top heating device in the first embodiment of the multilayer quartz glass plate preparation system of the present invention; Figure 3 This is a schematic diagram of the top heating device in the second embodiment of the multilayer quartz glass plate preparation system of the present invention; Figure 4 This is a schematic flowchart of the preparation method of the multilayer quartz glass plate of the present invention; Figure 5 This is a schematic diagram of the structure of the transparent quartz glass layer prepared according to the first embodiment of the preparation method of the multilayer quartz glass plate of the present invention; Figure 6 This is a schematic diagram of the structure of the transparent quartz glass layer prepared according to the second embodiment of the preparation method of the multilayer quartz glass plate of the present invention.

[0019] In the figure, 1-smoke supply device, 2-opaque quartz glass deposition target, 3-bottom heating device, 4-movable base, 5-smoke exhaust port, 6-heating rod, 7-silica soot layer, 8-transparent quartz glass layer, 9-top heating device, 10-burner.

[0020] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0022] It should be noted that in the description of this invention, the terms "lateral," "longitudinal," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] This invention proposes a system for preparing multilayer quartz glass plates.

[0024] Reference Figure 1 and Figure 2 This invention provides a first embodiment of a system for preparing multilayer quartz glass plates. In this embodiment, the system for preparing multilayer quartz glass plates includes: The outer shell is hollow inside and has a smoke exhaust port 5 to exhaust the smoke. A smoke supply device 1 is installed at the top of the outer casing and is used to supply silica soot to be deposited on the opaque quartz glass target located below. The bottom heating device 3 is located inside the hollow cavity of the outer shell and below the smoke supply device 1, and is used to heat the bottom of the opaque quartz glass target material placed above it. The movable base 4 is supported under the bottom heating device 3 and can move the bottom heating device 3.

[0025] The movable base 4 can move the bottom heating device 3 and the opaque quartz glass target above it in the XY plane parallel to the deposition target surface. Simultaneously, the movable base 4 can also rotate around a central axis perpendicular to the target surface, or it can remain stationary. The movement pattern is adjusted according to the shape and size of the target material. When using a circular target, the movable base 4 needs to rotate around the central axis perpendicular to the target surface; when using a square target, the movable base 4 does not need to rotate around the central axis perpendicular to the target surface. The movement of the movable base 4 ensures that silica dust particles are uniformly deposited on the surface of the opaque quartz glass target.

[0026] In this embodiment, the smoke supply device 1 includes a flame hydrolysis burner, which is connected to a raw material supply device for providing silicon-containing precursor compounds and a fuel supply device. The flame hydrolysis burner can be a burner used for external vapor deposition (OVD), axial vapor deposition (VAD), or chemical vapor deposition (CVD), and can be made of quartz glass, metal, or metal alloy.

[0027] Specifically, the silicon-containing precursor compound is SiCl4 or octamethylcyclotetrasiloxane, and the fuel is H2, O2, or CH4. Silica soot is produced through oxidation and hydrolysis reactions during combustion of the silicon-containing precursor compound and fuel in a flame hydrolysis burner.

[0028] Furthermore, the multilayer quartz glass plate preparation system also includes a top heating device 9 for heating the opaque quartz glass target material deposited with silica fume (the heating method of the top heating device 9 can be flame heating, electric heating, or other heating methods). In this embodiment, the top heating device 9 includes multiple heating rods 6 evenly arranged on a plane. After the silica fume layer on top of the opaque quartz glass target material is deposited, it still needs to be heated to obtain a transparent quartz glass surface that is basically free of bubbles. The heating temperature of the top heating device 9 is 1200℃~1500℃, and more preferably 1300℃~1400℃.

[0029] Furthermore, the flue gas outlet 5 is connected to an external extraction device via a butterfly valve. The butterfly valve controls the opening size of its connection channel and controls the extraction pressure inside the furnace. By controlling the extraction pressure inside the furnace, the amount of high-temperature flue gas discharged and the temperature of the deposition target surface are controlled.

[0030] The working process of this multilayer quartz glass plate preparation system is as follows: An opaque quartz glass target is placed above a bottom heating device 3, and a fume supply device 1 is installed above the opaque quartz glass target; after the bottom heating device 3 is turned on to heat the opaque quartz glass target to the first preheating temperature, the fume supply device 1 is turned on, and the fume supply device 1 generates silica fume to be deposited on the opaque quartz glass target located below; when the silica fume layer on the opaque quartz glass target reaches a preset thickness, the fume supply device 1 is turned off, and a top heating device 9 is set above the opaque quartz glass target with deposited silica fume; after the top heating device 9 is turned on for a predetermined time, the silica fume above the opaque quartz glass target is heated to a transparent state.

[0031] Finally, the other side of the sintered opaque quartz glass target with one transparent glass layer is used as the deposition surface, and the above steps are repeated to obtain a multilayer composite material that provides a transparent quartz glass layer on the surface of the opaque quartz glass layer.

[0032] The multilayer quartz glass plate preparation system proposed in this invention has the following beneficial effects: 1. Multi-layer quartz glass plates can be manufactured through a simple structure. A chemical deposition process, which is different from the existing high-temperature welding method and slurry sintering method, can be used. On the one hand, the processing of the transparent quartz glass layer 8 is avoided, which greatly saves production costs and shortens the manufacturing cycle. On the other hand, the transparent glass layer does not come into contact with other objects before it is completed, resulting in high glass purity. 2. The preparation system for this multilayer quartz glass plate has the advantages of simple structure and stable and reliable operation.

[0033] The present invention also provides a second embodiment of a system for preparing multilayer quartz glass plates. (Refer to...) Figure 3 This embodiment differs from the first embodiment described above in that the top heating device 9 includes multiple burners 10 evenly arranged on a plane. The burners 10 of the top heating device 9 can synchronously oscillate back and forth relative to the opaque quartz glass target material on which the silica soot layer 7 is deposited.

[0034] The present invention also proposes a method for preparing multilayer quartz glass plates.

[0035] Reference Figure 4 This invention proposes a method for preparing multilayer quartz glass plates, comprising the following steps: Step S10: Place the opaque quartz glass target material above the bottom heating device 3, and install the smoke supply device 1 above the opaque quartz glass target material; Step S20: After turning on the bottom heating device 3 to heat the opaque quartz glass target to the first preheating temperature, turn on the smoke supply device 1. The smoke supply device 1 generates silica fume to be deposited on the opaque quartz glass target located below. Step S30: When the silica fume layer on the opaque quartz glass target reaches a preset thickness, the fume supply device 1 is turned off, and a top heating device 9 is installed above the opaque quartz glass target on which silica fume has been deposited. Step S40: After turning on the top heating device 9 for a predetermined time, heat the silica fume above the opaque quartz glass target until it becomes transparent.

[0036] Specifically, when the fume supply device 1 is installed above the opaque quartz glass target, the distance between the nozzle of the fume supply device 1 and the opaque quartz glass target is 100mm to 400mm, more preferably 150mm to 250mm. In step S30, the preset thickness is 0.5mm to 3mm, preferably 1mm to 2mm, and the thickness deviation of the silica fume layer is less than 0.1mm. When the fume supply device 1 generates silica fume to deposit on the opaque quartz glass target below, the density of the silica fume layer 7 on the opaque quartz glass target is controlled to be 0.8g / cm³. 3 ~1.2g / cm 3 The density uniformity of the silica fume layer directly affects the quality of the sintered transparent glass layer. Significant differences in the thickness and density of the fume layer can lead to cracking during sintering. Therefore, its parameters need to be strictly controlled.

[0037] The first preheating temperature is 500℃~1400℃, preferably 700℃~1200℃, and more preferably 800℃~1000℃. The second preset temperature is 1200℃~1500℃, preferably 700℃~1200℃, and more preferably 800℃~1000℃. The temperature uniformity deviation of the opaque quartz glass target deposition surface is less than 100℃, preferably less than 50℃, and more preferably less than 20℃.

[0038] Opaque quartz glass targets can be round, oval, square, etc. Opaque quartz glass targets are typically 1.5mm to 4mm thick or other thicknesses, with a diameter greater than 400mm × 400mm for square targets, or greater than φ500mm for round targets, or other sizes.

[0039] Furthermore, when the fume supply device 1 is activated, generating silica fume to deposit on the opaque quartz glass target located below, the movable base 4 below the bottom heating device 3 is simultaneously moved to cause the opaque quartz glass target to oscillate back and forth along a path parallel to the deposition plane. By moving the opaque quartz glass target during the deposition process using the movable base 4, it is ensured that the silica fume particles are uniformly deposited on the surface of the opaque quartz glass target.

[0040] The preparation method is illustrated in detail below through two examples.

[0041] Example 1 An opaque quartz glass plate with a diameter of 600 mm and a height of 2 mm is placed on the bottom heating device 3 as a deposition target. The bottom heating device 3 is turned on to heat the opaque quartz glass target to 1200℃. The moving base 4 is activated, which, while maintaining a central rotation, oscillates back and forth along the XY plane parallel to the deposition plane, causing the opaque quartz glass target to move relative to the fume supply device 1. The fume supply device 1 is then activated, and the generated silica fume is deposited on the opaque quartz glass target below under the guidance of the airflow. Undeposited silica fume is discharged from the device through the exhaust port 5. When the silica fume layer deposited on the opaque quartz glass target reaches a thickness of 1.5 mm, the fume supply device 1 is stopped. At this point, the density of the silica fume layer 7 is measured to be 1.2 g / cm³. 3 An opaque quartz glass target with a deposited silica soot layer 7 is transferred to a top heating device 9. The top heating device 9 is then turned on, and the temperature is raised to 1400℃. After maintaining this temperature for 30 minutes, the silica soot layer 7 on the surface of the opaque quartz glass target becomes transparent. At this point, the thickness of the transparent glass layer is 0.75 mm. The above operation is repeated to deposit a silica soot layer 7 on the other side of the opaque quartz glass and heat the soot layer to obtain a transparent quartz glass layer 8. Figure 5 As shown.

[0042] The obtained multilayer quartz glass composite material was observed under a strong light. There were no bubbles at the interface. After soaking in a 4 vol% hydrofluoric acid solution for 30 minutes, the interface remained intact without delamination.

[0043] Example 2 An opaque quartz glass plate measuring 500×500×2mm is placed on the bottom heating device 3 as a deposition target. The bottom heating device 3 is turned on to heat the opaque quartz glass target to 1200℃. The moving base 4 is activated; it does not rotate but oscillates back and forth along the XY plane parallel to the deposition plane, causing relative movement between the opaque quartz glass target and the fume supply device 1. The fume supply device 1 is then activated, and the generated silica fume is deposited on the opaque quartz glass target below under the guidance of the airflow. Undeposited silica fume is discharged from the device through the exhaust port 5. When the silica fume layer deposited on the opaque quartz glass target reaches a thickness of 2.5mm, the fume supply device 1 is stopped. At this point, the density of the silica fume layer 7 is measured to be 1.2g / cm³. 3 An opaque quartz glass target with a deposited silica soot layer 7 is transferred below a top heating device 9. The top heating device 9 is then turned on, and its burner flame raises the temperature to 1400°C. After maintaining this temperature for 60 minutes, the silica soot layer 7 on the surface of the opaque quartz glass target becomes transparent, resulting in a transparent glass layer with a thickness of 1.5 mm. The above operation is repeated to deposit a silica soot layer 7 on the other side of the opaque quartz glass and heat the soot layer to obtain a transparent quartz glass layer 8. Figure 6 As shown.

[0044] The obtained multilayer quartz glass composite material was observed under a strong light. There were no bubbles at the interface. After soaking in a 4 vol% hydrofluoric acid solution for 30 minutes, the interface remained intact without delamination.

[0045] The method for preparing multilayer quartz glass plates proposed in this invention has the following beneficial effects: 1. By using chemical vapor deposition to deposit a transparent quartz glass layer 8 on the surface of opaque quartz glass, the high-temperature welding method used in the prior art can be avoided in processing the transparent quartz glass layer 8, which greatly saves production costs and shortens the manufacturing cycle. 2. The transparent glass layer produced does not come into contact with other objects before it is completed, making it less likely to introduce impurities and resulting in high glass purity. At the same time, it is faster to manufacture because it eliminates the grinding time of the existing slurry sintering method. 3. By adjusting the movement mode of the movable base 4, it is easy to manufacture multi-layer quartz glass of various shapes and sizes; 4. By adjusting the deposition process, the thickness and density of silica fume can be controlled, making it easy to produce multilayer quartz glass with transparent quartz glass layers of different thicknesses.

[0046] The present invention also proposes a multilayer quartz glass plate.

[0047] In this preferred embodiment, a multilayer quartz glass plate is prepared using a method for preparing multilayer quartz glass plates. The specific steps and beneficial effects of this preparation method are the same as those described in the above embodiments, and will not be repeated here.

[0048] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A system for producing a multi-layered quartz glass sheet, characterized by, It comprises: an outer shell, which is internally hollow and provided with a smoke outlet for discharging smoke; a smoke supply device, which is arranged on the top of the outer shell and used for providing silicon ash to deposit on the opaque quartz glass target below; a bottom heating device, which is arranged inside the hollow chamber of the outer shell and below the smoke supply device, and used for heating the bottom of the opaque quartz glass target placed thereon; a moving base, which is supported below the bottom heating device and can drive the bottom heating device to move.

2. The system for producing a multi-layer quartz glass sheet according to claim 1, wherein The smoke supply device comprises a flame hydrolysis burner, which is connected with a raw material supply device for providing a silicon-containing precursor compound and a fuel supply device.

3. The system for producing a multi-layer quartz glass sheet according to claim 2, wherein The silicon-containing precursor compound is SiCl4 or octamethylcyclotetrasiloxane, and the fuel is H2, O2 or CH4.

4. The system for producing a multi-layer quartz glass sheet according to claim 1, wherein It further comprises a top heating device for heating the opaque quartz glass target on which the silicon ash is deposited, and the top heating device comprises a plurality of heating rods or burners arranged uniformly on a plane.

5. The system for producing a multi-layer quartz glass sheet according to any one of claims 1 to 4, wherein The smoke outlet is communicated with an external air extraction device through a butterfly valve.

6. A method of making a multilayer quartz glass sheet, characterized by, It comprises the following steps: placing the opaque quartz glass target above the bottom heating device and installing the smoke supply device above the opaque quartz glass target; after the bottom heating device is turned on to heat the temperature of the opaque quartz glass target to a first preheating temperature, the smoke supply device is turned on to generate silicon ash to deposit on the opaque quartz glass target below; when the silicon ash layer on the opaque quartz glass target reaches a preset thickness, the smoke supply device is turned off, and the top heating device is arranged above the opaque quartz glass target on which the silicon ash is deposited; after the top heating device is turned on for a predetermined time, the silicon ash above the opaque quartz glass target is heated to a transparent state.

7. The method of producing a multi-layer quartz glass sheet according to claim 6, wherein When the smoke supply device is installed above the opaque quartz glass target, the distance between the smoke supply device spray port and the opaque quartz glass target is 100mm-400mm; the preset thickness is 0.5mm-3mm; when the smoke supply device generates silica soot to deposit on the opaque quartz glass target below, the density of the silica soot layer on the opaque quartz glass target is controlled to be 0.8g / cm 3 -1.2g / cm 3 .

8. The method of producing a multi-layer quartz glass sheet according to claim 6, wherein When the smoke supply device is turned on to generate silicon ash to deposit on the opaque quartz glass target below, the moving base below the bottom heating device is controlled to move to drive the opaque quartz glass target to oscillate back and forth along a deposition plane.

9. The method of producing a multi-layer quartz glass sheet according to claim 6, wherein The first preheating temperature is 500-1400℃, the second preset temperature is 1200-1500℃, and the uniformity deviation of the deposition target surface temperature of the opaque quartz glass target is less than 100℃.

10. A multi-layered quartz glass sheet, characterized by, It is prepared by the preparation method of claim 6.

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