Preparation method of crucible, crucible with crucible and ingot furnace

Abstract

The invention provides a preparation method of a crucible, the crucible with the crucible and an ingot furnace, the crucible is applied to the ingot furnace, the preparation method comprises the steps that a coating is prepared, the coating comprises silicon nitride, silica sol, water and silicon dioxide, and the content of oxygen in solute of the coating is 8%-20%; and the inner surface of the crucible body is coated with the paint, so that a protective coating is formed on the inner surface of the crucible body. According to the preparation method of the crucible, the content of the oxygen element in the solute of the coating is controlled, the stability of the protective coating can be improved, so that the anti-sticking effect can be ensured, meanwhile, the infiltration angle of the protective coating can be increased, and the anti-sticking effect is further improved.

Description

Technical Field

[0001] The invention relates to the technical field of crucibles, and in particular to a method for preparing a crucible and a crucible and an ingot casting furnace having the same. Background Art

[0002] During the silicon powder purification process in the ingot casting furnace, a protective layer is sprayed on the inner surface of the crucible to prevent the single crystal silicon from sticking to the crucible. The pressure in the multi-crystalline ingot casting process is generally maintained at 300mbar-600mbar. With the improvement of the process, the pressure is reduced and is usually less than 100mbar.

[0003] In the related technology, for example, 201810356338.9 discloses a silicon nitride spray-free coating for improving polysilicon ingot crystal flowers and its production method. The coating includes: silicon nitride, fumed silica, an organic binder and deionized water. The coating is manually applied to the surface of the crucible. When the ingot furnace is working in a low-pressure environment, the protective layer of the crucible produced by this method is easily decomposed in the low-pressure environment, resulting in the failure of the anti-sticking effect. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a method for preparing a crucible, which can improve the stability of the protective coating.

[0005] The present invention also provides a crucible having the preparation method of the crucible.

[0006] The present invention also provides an ingot casting furnace having the crucible.

[0007] According to the method for preparing a crucible of an embodiment of the first aspect of the present invention, the crucible is applied to an ingot casting furnace, and the preparation method comprises: preparing a coating, the coating comprising silicon nitride, silica sol, water and silicon dioxide, and the content of oxygen element in the solute of the coating is 8%-20%; applying the coating to the inner surface of the crucible body to form a protective coating on the inner surface of the crucible body.

[0008] According to the method for preparing a crucible of the present invention, the content of oxygen in the solute of the coating is controlled, so that the stability of the protective coating can be improved, thereby ensuring the anti-stick pan effect. At the same time, the wetting angle of the protective coating can be improved, further improving the anti-stick pan effect.

[0009] According to some embodiments of the present invention, in the coating, the ratio of silicon dioxide to silicon nitride is 15%-35%, and the ratio of silica sol to water is 40%-70%.

[0010] According to some embodiments of the present invention, in the coating, the mass ratio of silicon nitride, silicon dioxide, silica sol and water is 1: (0.15-0.35): (0.42-0.75): (0.8-1.25).

[0011] According to some embodiments of the present invention, the silica sol includes a solute and a solvent, the solute of the silica sol is silicon dioxide, the solvent of the silica sol is methanol and water, and the content of silicon dioxide in the silica sol is 20%-35%.

[0012] According to some embodiments of the present invention, the silicon dioxide in the coating is powder and has a particle size of 20nm-50nm.

[0013] According to some embodiments of the present invention, the preparation of the coating comprises: pouring silicon nitride, silica sol, water and silicon dioxide into a stirrer; and stirring until the solute in the coating is evenly dispersed.

[0014] According to some optional embodiments of the present invention, the stirring until the solute in the coating is evenly dispersed includes: stirring for a preset time, and the preset time is greater than or equal to 10 minutes.

[0015] According to some embodiments of the present invention, applying the coating to the inner surface of the crucible body includes: automatically spraying the inner surface of the crucible body by a spraying device.

[0016] According to some embodiments of the present invention, before applying the coating to the inner surface of the crucible body, the preparation method further comprises: heating the crucible body to a preset temperature, wherein the preset temperature is 150° C.-200° C.

[0017] The crucible according to the second aspect of the present invention includes the method for preparing the crucible according to the first aspect of the present invention.

[0018] According to the crucible of the present invention, by setting the preparation method of the crucible of the first embodiment above, the content of oxygen in the solute of the coating is controlled, so that the stability of the protective coating can be improved, thereby ensuring the anti-stick pan effect. At the same time, the wetting angle of the protective coating can be improved, further improving the anti-stick pan effect.

[0019] The ingot casting furnace according to an embodiment of the third aspect of the present invention comprises the crucible according to the second aspect of the present invention.

[0020] According to the ingot casting furnace of the present invention, by setting the crucible of the above-mentioned second aspect embodiment, the above-mentioned crucible is prepared by the crucible preparation method of the first aspect, and the content of oxygen element in the solute of the coating is controlled, so that the stability of the protective coating can be improved, thereby ensuring the anti-stick pan effect. At the same time, the wetting angle of the protective coating can be improved, thereby further improving the anti-stick pan effect.

[0021] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. DETAILED DESCRIPTION

[0023] The following describes a method for preparing a crucible according to an embodiment of the present invention.

[0024] According to the method for preparing a crucible of an embodiment of the first aspect of the present invention, the crucible is applied to an ingot casting furnace, and the preparation method comprises: preparing a coating, the coating comprising silicon nitride, silica sol, water and silicon dioxide, and the content of oxygen element in the solute of the coating is 8%-20%; applying the coating to the inner surface of the crucible body to form a protective coating on the inner surface of the crucible body.

[0025] Currently, in the polycrystalline ingot casting process, silicon nitride is generally used to prepare a solution and then sprayed on the crucible to form a protective coating on the inner surface of the crucible to prevent sticking. However, the coating in the existing solution is unstable and easily decomposes under low pressure, causing the anti-sticking effect to fail.

[0026] The method for preparing a crucible of the present invention controls the content of oxygen in the solute of the coating, and the oxygen can improve the decomposition resistance of the protective coating. After being sprayed on the inner surface of the crucible, a more stable and dense protective coating that is not easy to decompose under a low-pressure environment can be formed on the inner surface of the crucible, thereby ensuring the effect of preventing the pot from sticking during the ingot casting process. At the same time, the increase in the content of oxygen can increase the wetting angle of the protective coating. After the wetting angle is increased, the hydrophobicity of the protective coating can be improved, and then the corrosion resistance of the protective coating can be enhanced, thereby further preventing the pot from sticking.

[0027] According to the method for preparing a crucible of an embodiment of the present invention, the content of oxygen in the solute of the coating is controlled, so that the stability of the protective coating can be improved, thereby ensuring the anti-stick pan effect. At the same time, the wetting angle of the protective coating can be improved, further improving the anti-stick pan effect.

[0028] According to some embodiments of the present invention, in the coating, the ratio of silicon dioxide to silicon nitride is 15%-35%, and the ratio of silica sol to water is 40%-70%. Thus, controlling the ratio of silicon dioxide to silicon nitride can ensure the proportion of oxygen in silicon dioxide and silicon nitride, thereby ensuring the stability of the coating, and controlling the ratio of silica sol to water can ensure the normal spraying of silica sol after the silica sol is mixed, and at the same time prevent the silica sol from being too dilute to form a dense protective layer.

[0029] For example, the ratio of silicon dioxide to silicon nitride can be 15%, 18%, 21%, 24%, 27%, 30%, 33% or 35%, and the ratio of silica sol to water can be 40%, 45%, 50%, 55%, 60%, 65% or 70%.

[0030] According to some embodiments of the present invention, in the coating, the mass ratio of silicon nitride, silicon dioxide, silica sol and water is 1: (0.15-0.35): (0.42-0.75): (0.8-1.25). In this way, controlling the content of silicon nitride and silicon dioxide in the coating can ensure the content of oxygen elements. At the same time, controlling the content of silica sol and water can prevent the coating from being too viscous and causing the occurrence of a situation where normal spraying cannot be performed.

[0031] For example, the mass ratio of silicon nitride, silicon dioxide, silica sol and water may be 1:0.15:0.42:0.8, 1:0.25:0.60:1.0 or 1:0.35:0.75:1.25.

[0032] According to some embodiments of the present invention, the silica sol includes a solute and a solvent, the solute of the silica sol is silica, the solvent of the silica sol is methanol and water, and the content of silica in the silica sol is 20%-35%. In this way, the solute is silica, which can increase the proportion of silica in the coating, thereby ensuring the proportion of oxygen in the coating, and further ensuring the stability of the protective coating. At the same time, controlling the content of silica in the silica sol can ensure the normal mixing of silica with methanol and water, and ensure that the coating can be sprayed normally.

[0033] For example, the content of silicon dioxide in the silica sol may be 20%, 23%, 26%, 29%, 32% or 35%.

[0034] According to some embodiments of the present invention, the silicon dioxide in the coating is powder and has a particle size of 20nm-50nm. In this way, it can be prevented that the silicon dioxide particle size is too large to be sprayed normally, and at the same time, it can be prevented that the silicon dioxide particle size is too small to form a dense protective coating.

[0035] For example, the silica in the coating is a powder and the particle size may be 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm or 50 nm.

[0036] Furthermore, the silicon nitride particle size in the coating is 20 μm-50 μm. In this way, it can be prevented that the silicon nitride particle size is too large to be sprayed normally, and at the same time, it can be prevented that the silicon nitride particle size is too small to form a dense protective coating.

[0037] For example, the silicon nitride particle size in the coating may be 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm or 50 μm.

[0038] According to some embodiments of the present invention, preparing the coating comprises: pouring silicon nitride, silica sol, water and silicon dioxide into a stirrer; stirring until the solute in the coating is evenly dispersed. In this way, it can be ensured that the silicon dioxide is evenly dispersed in the solution. Preferably, the silicon dioxide is high-purity silicon dioxide, so that the content of oxygen element can be guaranteed.

[0039] According to some optional embodiments of the present invention, stirring until the solute in the coating is uniformly dispersed includes: stirring for a preset time, the preset time being greater than or equal to 10 minutes. In this way, the solute can be ensured to be uniformly dispersed.

[0040] For example, the preset time may be 10 min, 11 min, 12 min, 13 min, 14 min or 15 min.

[0041] According to some embodiments of the present invention, coating the inner surface of the crucible body with the coating includes: automatically spraying the inner surface of the crucible body with a spraying device, thereby ensuring that the coating is sprayed evenly on the inner surface of the crucible, thereby ensuring that the coating forms a protective coating.

[0042] For example, when the spraying device is a spraying robot, the paint is first poured into the spray can, and then the spray robot automatically sprays. When spraying, the pressure in the can is 0.08MPa, the spray pressure of the spray gun is 0.06Mpa, and the atomization pressure of the spray gun is 0.2MPa, so that the paint can be sprayed normally.

[0043] According to some embodiments of the present invention, before applying the coating to the inner surface of the crucible body, the preparation method may further include: heating the crucible body to a preset temperature, the preset temperature being 150° C.-200° C. In this way, during the spraying process, the protective coating can be dried quickly, thereby shortening the curing time of the protective coating.

[0044] For example, the crucible body is heated to a preset temperature, which may be 150°C, 160°C, 170°C, 180°C, 190°C or 200°C.

[0045] The crucible according to the second aspect of the present invention includes the method for preparing the crucible according to the first aspect of the present invention.

[0046] According to the crucible of the embodiment of the present invention, by setting the preparation method of the crucible of the first aspect embodiment above, the content of oxygen element in the solute of the coating is controlled, so that the stability of the protective coating can be improved, thereby ensuring the anti-stick pan effect. At the same time, the wetting angle of the protective coating can be improved, further improving the anti-stick pan effect.

[0047] The ingot casting furnace according to the embodiment of the third aspect of the present invention includes the method for preparing the crucible according to the second aspect of this embodiment.

[0048] According to the ingot casting furnace of the embodiment of the present invention, by setting the crucible of the above-mentioned second aspect embodiment, and setting the crucible preparation method of the first aspect embodiment in the above-mentioned crucible, the content of oxygen element in the solute of the coating is controlled, so as to improve the stability of the protective coating, thereby ensuring the anti-stick pan effect, and at the same time, the wetting angle of the protective coating can be improved, thereby further improving the anti-stick pan effect.

[0049] The ingot casting furnace according to an embodiment of the present invention is described below.

[0050] According to the ingot casting furnace of the embodiment of the present invention, a crucible and a heating platform are placed inside the ingot casting furnace, and the crucible is prepared by the following preparation method. Before the ingot casting furnace works, the prepared crucible is installed on the heating platform, and the heating platform heats the crucible to realize the ingot casting of the ingot casting furnace.

[0051] The preparation method includes: first heating the heating table to 190° to keep the heating table at a constant temperature, and then preparing the coating. When preparing the coating, first weigh 1200 grams of silicon nitride powder, 700 grams of silica sol, and 1000 grams of pure water, and pour them into a stirrer. Then weigh 200 grams of high-purity silicon dioxide powder, pour them into the stirrer, and stir for 10 minutes to evenly disperse the solute. Finally, use a spray robot to spray the coating on the inner surface of the crucible. During spraying, the pressure in the tank is 0.08MPa, the spray width pressure of the spray gun is 0.06Mpa, and the atomization pressure of the spray gun is 0.2MPa.

[0052] The ingot casting furnace of the present invention adopts the above-mentioned preparation method to prepare the crucible, so that the content of oxygen element in the solute of the crucible surface coating is 8%-20%. Under low-pressure environment, the protective coating is not easy to decompose, thereby ensuring the anti-stick pan effect. Increasing the oxygen element content can also increase the wetting angle of the protective coating, further improving the anti-stick pan effect.

[0054] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0055] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0057] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for preparing a crucible, wherein the crucible is used in an ingot casting furnace. It is characterized in that The preparation method comprises: Preparing a coating, the coating comprising silicon nitride, silica sol, water and silicon dioxide, and the content of oxygen element in the solute of the coating is 8%-20%; The coating is applied to the inner surface of the crucible body to form a protective coating on the inner surface of the crucible body.

2. The method for preparing a crucible according to claim 1, It is characterized in that In the coating, the ratio of silicon dioxide to silicon nitride is 15%-35%, and the ratio of silica sol to water is 40%-70%.

3. The method for preparing a crucible according to claim 1, It is characterized in that In the coating, the mass ratio of silicon nitride, silicon dioxide, silica sol and water is 1:(0.15-0.35):(0.42-0.75):(0.8-1.25).

4. The method for preparing a crucible according to claim 1, It is characterized in that The silica sol comprises a solute and a solvent, the solute of the silica sol is silicon dioxide, the solvent of the silica sol is methanol and water, and the content of silicon dioxide in the silica sol is 20%-35%.

5. The method for preparing a crucible according to claim 1, It is characterized in that The silicon dioxide in the coating is powder and has a particle size of 20nm-50nm.

6. A method for preparing a crucible according to any one of claims 1 to 5, It is characterized in that The coating preparation comprises: Pour silicon nitride, silica sol, water and silicon dioxide into a blender; Stir until the solute in the coating is evenly dispersed.

7. The method for preparing a crucible according to claim 6, It is characterized in that The stirring until the solute in the coating is uniformly dispersed includes: stirring for a preset time, and the preset time is greater than or equal to 10 minutes.

8. A method for preparing a crucible according to any one of claims 1 to 5, It is characterized in that The step of applying the coating to the inner surface of the crucible body comprises: automatically spraying the inner surface of the crucible body by a spraying device.

9. A method for preparing a crucible according to any one of claims 1 to 5, It is characterized in that Before applying the coating to the inner surface of the crucible body, the preparation method further comprises: heating the crucible body to a preset temperature, wherein the preset temperature is 150° C.-200° C.

10. A crucible, It is characterized in that The crucible is prepared by the method for preparing a crucible according to any one of claims 1 to 9.

11. An ingot casting furnace, It is characterized in that Comprising the crucible according to claim 10.