Thermal field device for lithium niobate crystal growth

Abstract

The utility model discloses a thermal field device for lithium niobate crystal growth, which belongs to the technical field of thermal field devices, and comprises an induction coil and a metal crucible positioned on a central axis in the induction coil, the outer surface of the metal crucible is coaxially sleeved with a thermal insulation cylinder, and the thermal insulation cylinder is in the shape of a big-end-down circular truncated cone. A heat insulation cylinder with the upper bottom and the lower bottom sealed coaxially sleeves the heat preservation cylinder, and a gap is formed between the heat insulation cylinder and the heat preservation cylinder. An air cylinder is arranged in the center of the top of the heat insulation cylinder, and an air inlet hole communicating with the interior of the heat insulation cylinder is formed in the inner bottom of the air cylinder; an annular cylinder is arranged at the bottom of the heat insulation cylinder, and exhaust holes communicating with the interior of the annular cylinder are formed in the inner bottom of the heat insulation cylinder. The annular cylinder is communicated with the air cylinder through a pipeline, a cooling box is installed on the pipeline in a communicating mode, and a relay pump is installed on the cooling box; the defects in the crystal growth process are reduced through accurate thermal field control and cooling effects, and the purity and uniformity of the crystals are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of thermal field devices, in particular to a thermal field device for growing lithium niobate crystals. Background Art

[0002] Lithium niobate crystal is an important functional material widely used in the fields of optics and electronics. Its high-quality growth depends on precise thermal field control. In traditional crystal growth equipment, due to the limitations of thermal field design, problems such as uneven temperature gradients are prone to occur.

[0003] During the crystal growth process, as the liquid level in the crucible drops, the temperature gradient of the crystal gradually decreases, which can easily lead to cracks, internal stress and defects in the crystal during growth, thereby affecting its optical properties and structural stability.

[0004] To this end, we propose a thermal field device for growing lithium niobate crystals. Utility Model Content

[0005] In order to overcome the shortcomings of the existing technology, the utility model provides a thermal field device for growing lithium niobate crystals. The insulation cylinder helps to guide the heat distribution and form a temperature gradient in the upper and lower directions of the crucible. The circulation path of the gas cylinder, the annular cylinder and the cooling box realizes the circulation and control of the inert gas, removes excess heat in time, and further improves the temperature control accuracy.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A thermal field device for growing lithium niobate crystals comprises an induction coil and a metal crucible located at the central axis of the induction coil.

[0008] The outer surface of the metal crucible is coaxially covered with a heat-insulating cylinder, the outer shape of the heat-insulating cylinder is a truncated cone with a small upper portion and a large lower portion, and the outer surface of the heat-insulating cylinder is coaxially covered with a heat-insulating cylinder with upper and lower bottom seals, and a gap is formed between the heat-insulating cylinder and the heat-insulating cylinder;

[0009] An air cylinder is provided at the top center of the heat-insulating cylinder, and an air inlet hole communicating with the interior of the heat-insulating cylinder is provided at the inner bottom of the air cylinder;

[0010] An annular cylinder is provided at the bottom of the heat-insulating cylinder, and an exhaust hole communicating with the interior of the annular cylinder is provided at the inner bottom of the heat-insulating cylinder;

[0011] The annular cylinder and the gas cylinder are communicated with each other through a pipeline, and a cooling box is installed on the pipeline, and a relay pump is installed on the cooling box.

[0012] As a preferred solution of a thermal field device for growing lithium niobate crystals described in the present invention, a support seat is provided at the bottom of the insulation cylinder, a motor is provided inside the support seat, the output shaft of the motor penetrates the insulation cylinder and is connected to the center of the bottom surface of the metal crucible, and the output shaft of the motor and the insulation cylinder are sealed and rotated.

[0013] As a preferred solution of the thermal field device for growing lithium niobate crystals described in the present invention, a seed crystal rod is provided on the inner central axis of the metal crucible, the upper end of the seed crystal rod penetrates the insulation cylinder, and the seed crystal rod and the insulation cylinder are slidably connected up and down.

[0014] As a preferred solution of the thermal field device for growing lithium niobate crystals described in the present invention, a sleeve for the seed rod to penetrate is provided at the inner center of the gas cylinder, the upper end of the seed rod penetrates the sleeve and the two are connected to each other in an upward and downward sliding manner.

[0015] As a preferred solution of the thermal field device for growing lithium niobate crystals described in the present invention, a bracket is provided above the top surface of the insulation cylinder, a telescopic cylinder is provided on the top of the bracket, and the telescopic end of the telescopic cylinder is connected to the seed crystal.

[0016] As a preferred solution of the thermal field device for growing lithium niobate crystals described in the present invention, heat conducting plates are provided at intervals on the inner wall of the cooling box.

[0017] As a preferred solution of the thermal field device for growing lithium niobate crystals described in the present invention, an inflation tube is provided in communication with the outer side wall of the gas cylinder.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The combined design of the heat preservation tube and the thermal insulation tube improves the temperature uniformity around the crucible. The shape of the heat preservation tube helps to guide the heat distribution, forming a temperature gradient in the upper and lower directions of the crucible, thereby improving the stability and quality of crystal growth.

[0020] By utilizing the circulation passages of the gas cylinder, annular cylinder and cooling box, the circulation and control of the inert gas can be achieved, excess heat can be removed in time, the temperature control accuracy can be further improved, defects in the crystal growth process can be reduced, and the purity and uniformity of the crystal can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of a thermal field device for growing lithium niobate crystals.

[0022] Figure 2 Schematic diagram of an insulating cylinder for a thermal field device for growing lithium niobate crystals.

[0023] Figure 3 Schematic diagram of an annular cylinder of a thermal field device for growing lithium niobate crystals.

[0024] Figure 4 Schematic diagram of a support base for a thermal field device for growing lithium niobate crystals.

[0025] Among them: 1. Induction coil; 2. Insulation cylinder; 3. Gas cylinder; 4. Inflating tube; 5. Seed crystal rod; 6. Telescopic cylinder; 7. Bracket; 8. Cooling box; 9. Relay pump; 10. Ring cylinder; 11. Support seat; 12. Metal crucible; 13. Insulation cylinder; 14. Air inlet; 15. Heat conducting plate; 16. Motor; 17. Exhaust hole; 18. Sleeve. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below with reference to the accompanying drawings.

[0027] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0028] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0029] Example

[0030] Please refer to Figures 1 to 4 As shown, the present invention provides a thermal field device for growing lithium niobate crystals, comprising an induction coil 1 and a metal crucible 12 located at the center axis of the induction coil 1. The outer surface of the metal crucible 12 is coaxially sleeved with a heat-insulating tube 13. The heat-insulating tube 13 has a frustum shape that is smaller at the top and larger at the bottom. The heat-insulating tube 13 is coaxially sleeved with an insulation tube 2 with upper and lower bottom seals on the outer surface. A gap is formed between the insulation tube 2 and the heat-insulating tube 13.

[0031] The design of the heat preservation tube 13, which is small at the top and large at the bottom, helps to guide the heat distribution, make the heat field more uniform, realize the temperature gradient control in the upper and lower directions of the crucible, and improve the stability and quality of crystal growth. The truncated cone structure can better meet the actual needs of the thermal field, which is conducive to concentrating heat in the key area of ​​the crucible, avoiding unnecessary heat dispersion, ensuring the temperature stability of the crystal growth area, and thus reducing the occurrence of defects.

[0032] An air cylinder 3 is provided at the top center of the heat-insulating cylinder 2. An air inlet 14 communicating with the interior of the heat-insulating cylinder 2 is provided at the inner bottom of the air cylinder 3. An air charging pipe 4 is provided on the outer side wall of the air cylinder 3. An annular cylinder 10 is provided at the bottom of the heat-insulating cylinder 2. An exhaust hole 17 communicating with the interior of the annular cylinder 10 is provided at the inner bottom of the heat-insulating cylinder 2. A pipeline is connected between the annular cylinder 10 and the air cylinder 3. A cooling box 8 is installed on the pipeline. A relay pump 9 is installed on the cooling box 8. Heat-conducting sheets 15 are provided at intervals on the inner wall of the cooling box 8.

[0033] The circulation path of the gas cylinder 3, the annular cylinder 10 and the cooling box 8 realizes the circulation and control of the inert gas, removes the excess heat in time, further improves the temperature control accuracy, improves the temperature uniformity around the crucible, and contributes to the stability of crystal growth. The precise thermal field control and cooling effect reduce the defects in the crystal growth process and improve the purity and uniformity of the crystal.

[0034] A seed crystal rod 5 is provided on the inner central axis of the metal crucible 12. The upper end of the seed crystal rod 5 penetrates the heat-insulating cylinder 2, and the seed crystal rod 5 and the heat-insulating cylinder 2 are connected to each other in an up-and-down sliding manner. A sleeve 18 for the seed crystal rod 5 to penetrate is provided in the inner center of the gas cylinder 3. The upper end of the seed crystal rod 5 penetrates the sleeve 18 and is connected to each other in an up-and-down sliding manner. A bracket 7 is provided above the top surface of the heat-insulating cylinder 2. A telescopic cylinder 6 is provided on the top of the bracket 7. The telescopic end of the telescopic cylinder 6 is connected to the seed crystal supply;

[0035] A support base 11 is provided at the bottom of the insulation cylinder 2. A motor 16 is provided inside the support base 11. The output shaft of the motor 16 penetrates the insulation cylinder 2 and is connected to the center of the bottom surface of the metal crucible 12. The output shaft of the motor 16 is in sealed rotation connection with the insulation cylinder 2.

[0036] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, it is understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A thermal field device for growing lithium niobate crystals, comprising an induction coil (1) and a metal crucible (12) located at the center axis of the induction coil (1), characterized in that: The outer surface of the metal crucible (12) is coaxially sleeved with a heat-insulating cylinder (13), the outer shape of the heat-insulating cylinder (13) is a truncated cone with a small upper portion and a large lower portion, and the outer surface of the heat-insulating cylinder (13) is coaxially sleeved with a heat-insulating cylinder (2) with upper and lower bottom seals, and a gap is provided between the heat-insulating cylinder (2) and the heat-insulating cylinder (13); An air cylinder (3) is provided at the top center of the heat-insulating cylinder (2), and an air inlet (14) communicating with the interior of the heat-insulating cylinder (2) is provided at the inner bottom of the air cylinder (3); An annular cylinder (10) is provided at the bottom of the heat-insulating cylinder (2), and an exhaust hole (17) communicating with the interior of the annular cylinder (10) is provided at the inner bottom of the heat-insulating cylinder (2); The annular cylinder (10) and the gas cylinder (3) are connected via a pipeline, and a cooling box (8) is installed on the pipeline, and a relay pump (9) is installed on the cooling box (8).

2. The thermal field device for growing lithium niobate crystals according to claim 1, characterized in that: A support seat (11) is provided at the bottom of the insulation tube (2), and a motor (16) is provided inside the support seat (11). The output shaft of the motor (16) penetrates the insulation tube (2) and is connected to the center of the bottom surface of the metal crucible (12). The output shaft of the motor (16) and the insulation tube (2) are in sealed rotation connection.

3. The thermal field device for growing lithium niobate crystals according to claim 1, characterized in that: A seed crystal rod (5) is provided on the inner central axis of the metal crucible (12), the upper end of the seed crystal rod (5) penetrates the heat insulation cylinder (2), and the seed crystal rod (5) and the heat insulation cylinder (2) are connected in an up-and-down sliding manner.

4. The thermal field device for growing lithium niobate crystals according to claim 3, characterized in that: A sleeve (18) for the seed crystal rod (5) to penetrate is provided at the inner center of the gas cylinder (3); the upper end of the seed crystal rod (5) penetrates the sleeve (18) and the two are connected to each other in an upward and downward sliding manner.

5. The thermal field device for growing lithium niobate crystals according to claim 3, characterized in that: A bracket (7) is provided above the top surface of the heat-insulating cylinder (2), a telescopic cylinder (6) is provided on the top of the bracket (7), and a telescopic end of the telescopic cylinder (6) is connected to the seed crystal supply.

6. The thermal field device for growing lithium niobate crystals according to claim 1, characterized in that: Heat conducting sheets (15) are arranged at intervals on the inner wall of the cooling box (8).

7. The thermal field device for growing lithium niobate crystals according to claim 1, characterized in that: An inflation tube (4) is provided in communication with the outer side wall of the air cylinder (3).

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