A crystal blank annealing device and annealing process

Abstract

The present application relates to the technical field of heat treatment, and provides a device for annealing a crystal blank and an annealing process. Among them, the device for annealing a crystal blank includes an annealing furnace, a clamping system, a gas pipeline system and a temperature measuring element. The clamping system includes a first driving source, an upper clamp and a lower clamp, and the upper clamp and the lower clamp are relatively arranged in the annealing furnace; the gas pipeline system includes an air intake pipe group, a flow regulating valve group and an automatic adjustment module, and the air intake pipe group includes a plurality of first air intake pipes and a plurality of second air intake pipes, one end of each first air intake pipe is inserted into the upper clamp, and one end of each second air intake pipe is inserted into the lower clamp; the flow regulating valve group is used to adjust the gas flow in each first air intake pipe and each second air intake pipe. The temperature measuring elements are distributed around the upper clamp and the lower clamp, and are used to detect the temperature of different characteristic positions of the crystal blank. The present application can improve the annealing efficiency and annealing quality of large-sized crystal blanks.

Description

Technical Field

[0001] The present application relates to the technical field of heat treatment, and in particular to a device and an annealing process for annealing a crystal blank. Background Art

[0002] When current annealing equipment is annealing large-sized crystal blanks with low thermal conductivity, due to the larger physical size of the processed crystal blanks, the heat is less likely to be transferred out closer to the center, resulting in the annealing effects around the periphery and near the center being out of sync, making it difficult to achieve the best annealing effect.

[0003] In addition, when annealing in the prior art, the crystal blank needs to be placed stably in a crucible or on a support for annealing, and the materials used in the crucible or support are usually different from the crystal blank, and the two must have a part in contact, which is likely to cause additional thermal stress to the crystal blank due to contact with heterogeneous materials. The existing solution is also very simple, which is to process the original crystal blank into multiple crystal blanks with sufficiently small physical sizes, and put a certain amount of crystal blanks in at a time for annealing. In order to achieve a better annealing effect, the crystal blank can be placed in finely divided homogeneous particles for annealing.

[0004] Although this treatment method can ensure the annealing effect, it has the following defects: 1. The one-time annealing process takes a long time, and batch annealing undoubtedly increases the total annealing time and reduces production efficiency; 2. When the customer's required component size is large, it cannot be cut into smaller pieces for annealing, and this method is completely ineffective; 3. The crystal blank may shift in the homogeneous particles due to operational errors in loading the furnace or mechanical vibrations, causing it to deviate from the optimal annealing position, resulting in poor annealing effect. Summary of the invention

[0005] In order to improve the annealing efficiency and annealing quality of large-sized crystal blanks, on the one hand, the present application provides a device for annealing crystal blanks, which adopts the following technical solutions:

[0006] The device for annealing the crystal blank comprises:

[0007] Annealing furnace;

[0008] A clamping system, comprising a first driving source, an upper clamp and a lower clamp, wherein the upper clamp and the lower clamp are relatively arranged in the annealing furnace, and homogeneous washers are arranged on the opposite end surfaces of the upper clamp and the lower clamp, and the first driving source is used to drive the upper clamp and the lower clamp to move relative to each other;

[0009] A gas pipeline system, comprising an air intake pipe group, a flow regulating valve group and an automatic regulating module, wherein the air intake pipe group comprises a plurality of first air intake pipes and a plurality of second air intake pipes, one end of each of the first air intake pipes is passed through the upper fixture, and a plurality of groups of first air outlet hole groups are arranged at intervals on the upper fixture, each group of the first air outlet hole groups comprises a plurality of first air outlet holes, and the first air outlet hole groups are arranged one-to-one with the first air intake pipes and are connected;

[0010] One end of each of the second air inlet pipelines is inserted into the lower fixture, and a plurality of second air outlet hole groups are arranged at intervals on the lower fixture, each of the second air outlet hole groups includes a plurality of second air outlet holes, and the second air outlet hole groups are arranged one-to-one with the second air inlet pipelines and are connected;

[0011] The flow regulating valve group is used to regulate the gas flow in each of the first air intake pipelines and each of the second air intake pipelines, and the automatic regulating module is electrically connected to the flow regulating valve group;

[0012] A temperature measuring element, wherein a plurality of the temperature measuring elements are provided and are distributed around the upper fixture and the lower fixture, and are used to detect the temperature of different characteristic positions of the crystal blank, and the temperature measuring element is electrically connected to the automatic adjustment module.

[0013] By adopting the above technical solution, the annealing furnace is used to provide a thermal environment for annealing, and the crystal blank is clamped by a clamping system to ensure the stability of the crystal blank in the annealing furnace, so that the crystal blank is provided with homogeneous gaskets on the contact surfaces of the upper clamp and the lower clamp in the annealing furnace and the crystal blank, and the homogeneous gaskets are used to eliminate the thermal stress with the crystal blank and thus ensure uniform heating of the crystal blank; when the crystal blank needs to be cooled, the low-temperature process gas is discharged through the gas pipeline along the first gas outlet of the upper clamp and the second gas outlet of the lower clamp to cool the crystal blank; the temperature measuring elements are distributed around the clamps The side corresponds to the characteristic position of the large-size crystal blank, is used to measure the temperature of different characteristic positions of the crystal blank, and feed back the temperature signal to the automatic adjustment module in real time. The automatic adjustment module calculates the cooling rate of different characteristic positions of the crystal blank, and controls the action of the flow regulating valve group according to the cooling rate to control the gas flow in each first air inlet pipeline and the second air inlet pipeline; and then controls the air outlet volume of each first air outlet group in the upper clamp and each second air outlet group in the lower clamp, and controls the cooling rate of different parts of the crystal blank, so that different parts of the crystal blank are annealed synchronously to achieve a good annealing effect.

[0014] Optionally, a plurality of annular air inlet pipelines are disposed in both the upper fixture and the lower fixture, and the annular air inlet pipelines are sequentially spaced from outside to inside, and the inner diameter of the annular air inlet pipelines decreases sequentially from outside to inside;

[0015] Each annular air inlet pipeline in the upper fixture is connected to one of the first air inlet pipelines, each of the annular air inlet pipelines corresponds to a group of first air outlet holes, a plurality of first air outlet holes in the first air outlet hole group are distributed at intervals along the circumference of the annular air inlet pipeline, and each of the first air outlet holes is connected to the corresponding annular air inlet pipeline;

[0016] Each annular air inlet pipeline in the lower clamp is connected to a second air inlet pipeline, and each annular air inlet pipeline corresponds to a group of second air outlet holes. Several second air outlet holes in the second air outlet hole group are distributed at intervals along the circumference of the annular air inlet pipeline, and each second air outlet hole is connected to the corresponding annular air inlet pipeline.

[0017] By adopting the above technical solution, in the upper fixture, the corresponding first air inlet pipeline and the first air inlet hole group are connected through the annular air inlet pipeline, so that the process gas input along the first air inlet pipeline flows through the annular air inlet pipeline and then flows along the corresponding first air inlet hole group to the crystal blank;

[0018] In the lower fixture, the corresponding second air inlet pipeline and the second air inlet hole group are connected through the annular air inlet pipeline, so that the process gas input along the second air inlet pipeline flows through the annular air inlet pipeline and then flows to the crystal blank along the corresponding second air inlet hole group.

[0019] Optionally, a plurality of homogeneous washers are provided on the upper fixture, and the annular air inlet pipeline and the homogeneous washers on the upper fixture are sequentially spaced from outside to inside;

[0020] A plurality of homogeneous washers are arranged on the lower fixture, and the annular air inlet pipeline and the homogeneous washers on the lower fixture are arranged in sequence from outside to inside.

[0021] By adopting the above technical solution, the homogeneous washers on the upper clamp and the lower clamp are arranged at intervals from the outside to the inside to adapt to crystal blanks of different sizes and ensure uniform clamping and cooling.

[0022] Optionally, a gasket groove is formed at one end of the homogeneous gasket away from the crystal blank, and a plurality of the gasket grooves are arranged at intervals along the circumference of the homogeneous gasket.

[0023] By adopting the above technical solution, a gasket groove is opened at the end of the homogeneous gasket away from the crystal blank, thereby improving the gas flowability between the homogeneous gasket and the crystal blank, achieving more uniform cooling of the crystal blank, and further enhancing the annealing effect.

[0024] Optionally, it further includes a circulating cooling system, the circulating cooling system includes a recovery air pipe, a second driving source and a cooling mechanism, and the cooling mechanism is provided with a cooling inlet and a cooling outlet;

[0025] One end of the recovery gas pipe is connected to the annealing furnace, and the other end is connected to the cooling inlet. The second driving source is used to drive the gas in the recovery gas pipeline to flow into the cooling mechanism. The cooling outlet is connected to the intake pipe group.

[0026] By adopting the above technical scheme, low-temperature process gas is blown to the surface of the crystal blank, and after the crystal blank is cooled, it is heated to become high-temperature process gas. The high-temperature process gas flows along the recovery gas pipe to the cooling mechanism driven by the second driving source. The cooling mechanism cools the high-temperature process gas. The low-temperature process gas obtained by cooling by the cooling mechanism is discharged along the cooling outlet to the air inlet pipe group, and then flows from the air inlet pipe group to the annealing furnace. The cooling of the crystal blank realizes the recycling of gas at the same time, thereby improving energy utilization.

[0027] Optionally, the cooling mechanism includes a heat exchanger and a cold machine, the heat exchanger includes a heat exchange shell and a coolant pipe arranged in the heat exchange shell, the cooling inlet and the cooling outlet are both opened on the heat exchange shell, and both ends of the coolant pipe are connected to the cold machine.

[0028] By adopting the above technical solution, a coolant pipe is provided inside the heat exchanger to realize rapid cooling of the process gas flowing into the heat exchanger; the coolant after absorbing heat flows along the coolant pipe to the refrigerator, and the refrigerator cools the coolant after absorbing heat; after the coolant is cooled, it continues to flow into the heat exchanger along the coolant pipe to realize the cooling cycle.

[0029] Optionally, a thermometer is installed on one side of the heat exchanger where a cooling outlet is provided, and the thermometer is used to detect the gas temperature at the cooling outlet, and the second driving source and the cold machine are both electrically connected to the automatic adjustment module.

[0030] By adopting the above technical solution, a thermometer is installed on the side of the heat exchanger with the cooling outlet to detect the gas temperature at the cooling outlet, and the thermometer feeds back the temperature signal to the automatic adjustment module to reasonably control the power of the second driving source and the cold machine to achieve a reasonable cooling effect.

[0031] On the other hand, the present application provides an annealing process, which adopts the following technical solution:

[0032] An annealing process, using the above-mentioned crystal blank annealing device for annealing, comprises the following steps:

[0033] Step 1: Load the furnace, place the crystal blank on the center of the lower fixture surface, make the geometric centers of the two coincide, place the crystal blank stably, and use the clamping system to clamp the crystal blank;

[0034] Step 2: Vacuum, inflate and heat up, and draw high vacuum to 8×10 -4Pa, start heating the annealing furnace until the temperature reaches a preset value, maintain constant temperature, and fill the annealing furnace with process gas. After the process gas is filled, continue heating until the temperature in the annealing furnace reaches the annealing temperature;

[0035] Step 3: Constant temperature treatment: after the center temperature of the crystal blank reaches the annealing temperature, keep the temperature constant for 24-48 hours;

[0036] Step 4: Cooling down, starting the cooling down at a process cooling rate of 2.5-3.5°C / h, and at the same time starting the automatic adjustment module, which calculates the cooling rate of different characteristic positions of the crystal blank according to the temperature signal fed back by the temperature measuring element, and controls the action of the flow regulating valve group according to the cooling rate to adjust the gas flow in the first air inlet pipeline and the second air inlet pipeline;

[0037] Step 5: dismantle the furnace. After the center temperature of the crystal blank drops to room temperature, turn off the second driving source and the cooling machine, open the annealing furnace, start the first driving source to loosen the crystal blank, and take out the crystal blank.

[0038] By adopting the above technical scheme, the cooling rate of different characteristic parts of the crystal blank is carefully controlled through the temperature measuring element and the gas pipeline system, and the heat dissipation of different parts of the crystal blank is adjusted to achieve the effect of synchronous annealing of different parts, thereby improving the annealing quality; in addition, through the setting of homogeneous gaskets, the contact between heterogeneous materials and the crystal blank during the annealing process is avoided, thereby greatly reducing the generation of thermal stress; the crystal blank is clamped by the clamping system to ensure the stability of the crystal blank in the annealing furnace.

[0039] Optionally, in step 2, during the process of heating to a preset value, the heating rate is 10° C. / h.

[0040] By adopting the above technical solution, the heating rate is controlled to 10°C / h, so as to slowly increase the temperature to reduce the thermal stress inside the crystal blank and promote uniform phase change.

[0041] Optionally, in step 2, the total filling rate of the process gas is in the range of 5-7 L / min.

[0042] By adopting the above technical solution, a filling rate of 5-7L / min can usually provide sufficient gas flow to achieve a uniform cooling effect while maintaining a stable process gas layer; a filling rate of 5-7L / min can ensure a stable pressure in the annealing furnace and avoid potential safety hazards.

[0043] In summary, the present application includes at least one of the following beneficial effects:

[0044] 1. The crystal blank annealing device of the present application realizes precise control and real-time monitoring of the temperature during the annealing process by setting up a gas pipeline system, a temperature measuring element and a clamping system, thereby ensuring that the crystal blank is heated uniformly and stably during the annealing process, improving the quality of the crystal blank and the yield rate.

[0045] 2. The present application realizes the recycling of process gases in the annealing furnace by setting up a circulating cooling system, and at the same time, accurately controls the gas flow in each first air inlet pipeline and the second air inlet pipeline, the operating status of the second driving source and the cold machine through the automatic adjustment module, thereby further improving the energy utilization rate and effectively ensuring the consistency and stability of the environment in the annealing furnace.

[0046] 3. The present application ensures stable clamping of the crystal blank and uniform heat transfer by providing a gasket and a gasket groove inside the gasket, thereby preventing the crystal blank from being damaged due to uneven heating during the annealing process, and preventing excessive thermal stress from being generated in the crystal, thereby improving the quality of the crystal after annealing. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram of the overall structure of the device for annealing a crystal blank according to an embodiment of the present application;

[0048] Figure 2 It is a structural schematic diagram of the annealing furnace of an embodiment of the present application;

[0049] Figure 3 Schematic diagram of the distribution structure of the air intake pipe group in the upper fixture and the lower fixture of the embodiment of the present application;

[0050] Figure 4 It is a schematic diagram of the arrangement structure of the annular air intake pipeline and the homogeneous gasket on the upper fixture of the embodiment of the present application;

[0051] Figure 5 yes Figure 1 A schematic diagram of the local enlarged structure at point A in the middle;

[0052] Explanation of the reference numerals: 1. Annealing furnace; 11. Furnace body; 12. Base; 13. Sealing ring; 14. Insulation layer; 141. Flow gap; 15. Return air chamber; 16. Exhaust pipe; 2. Clamping system; 21. First driving source; 22. Upper clamp; 221. First air outlet; 23. Lower clamp; 231. Second air outlet; 24. Water-cooled sleeve; 25. Pressure sensor; 26. Pressure control module; 3. Gas pipeline system; 31. First air inlet pipeline; 311. First air inlet branch pipe; 32. Second air inlet pipeline; 321. Second Inlet branch pipe; 33. Automatic flow control valve; 34. Automatic adjustment module; 35. Annular air inlet pipeline; 4. Temperature measuring element; 5. Homogeneous gasket; 51. Gasket slot; 6. Circulating cooling system; 61. Recovery gas pipe; 62. Second driving source; 63. Heat exchanger; 631. Heat exchange shell; 6311. Cooling inlet; 6312. Cooling outlet; 632. Coolant pipe; 64. Cold machine; 65. Thermometer; 66. Gas supply pipe; 7. Vacuum gauge; 8. Heater; 9. Process gas station; 91. Gas transmission pipe; 10. Crystal blank. DETAILED DESCRIPTION

[0053] The following is combined with Figure 1-5 This application is described in further detail.

[0054] The embodiments of the present application provide a device for annealing a crystal blank.

[0055] like Figure 1 and Figure 2 As shown, the annealing furnace 1 includes an annealing furnace 1, a clamping system 2, a gas pipeline system 3 and a temperature measuring element 4. The annealing furnace 1 includes a furnace body 11 and a base 12. An opening is provided at one end of the furnace body 11, and the opening of the furnace body 11 is arranged toward the base 12. The furnace body 11 slides in the vertical direction, so that the base 12 can open or close the opening of the furnace body 11 to take and place the crystal blank 10. A sealing ring 13 is embedded and fixed at one end of the base 12 close to the furnace body 11 to ensure the sealing of the furnace body 11 when it is closed. A plurality of heaters 8 are also fixed in the furnace body 11. Insulating layers 14 are fixed in the furnace body 11 and on the end surface of the base 12 close to the furnace body 11. The insulating layers 14 surround the heaters 8. A return air cavity 15 is formed between the insulating layers 14 and the inner wall of the furnace body 11. A flow gap 141 is provided on the insulating layers 14 in the furnace body 11, so that the gas inside the insulating layers 14 can enter the return air cavity 15 through the flow gap 141. In this embodiment, the heater 8 is specifically configured as an electric heating heater, and two groups of heaters 8 are provided, and the two groups of heaters 8 are arranged at intervals. A vacuum gauge 7 is also fixed to the furnace body 11, and the detection end of the vacuum gauge 7 passes through the side wall of the furnace body 11 and is located inside the furnace body 11. The furnace body 11 is also connected to an exhaust pipe 16.

[0056] like Figure 1 and Figure 3As shown, the clamping system 2 includes a first driving source 21, an upper clamp 22 and a lower clamp 23. The upper clamp 22 and the lower clamp are located between the two groups of heaters 8, and the upper clamp 22 and the lower clamp 23 are arranged opposite to each other in the vertical direction. Washer groups are fixedly installed on the opposite end surfaces of the upper clamp 22 and the lower clamp 23, and the washers can be fixed by inlaying, bonding or other methods. In this embodiment, the upper clamp 22 and the lower clamp 23 are both set in the shape of a circular plate. As shown in FIG. Figure 3 and Figure 4 As shown, the gasket group includes multiple circles of homogeneous gaskets 5 arranged from outside to inside, and the homogeneous gaskets 5 are arranged in a circular ring shape; and the inner diameter of the homogeneous gaskets 5 in the gasket group decreases from outside to inside to accommodate crystal blanks 10 of different sizes. In other embodiments, the upper clamp 22 and the lower clamp 23 can also be arranged in a rectangular shape, and accordingly, the homogeneous gaskets 5 are also arranged in a rectangular circle.

[0057] like Figure 2 As shown, the end of the upper fixture 22 away from the lower fixture 23 is coaxially connected to a water-cooled sleeve 24, and one end of the water-cooled sleeve 24 passes through the furnace body 11, and the end of the lower fixture 23 away from the upper fixture 22 is also coaxially connected to the water-cooled sleeve 24. When the heater 8 is running, cooling water can be input into the water-cooled sleeve 24 to cool the upper fixture 22 and the lower fixture 23 to prevent high temperature from damaging the upper fixture 22 and the lower fixture 23. In this embodiment, the upper fixture 22 and the lower fixture 23 are both connected to the water-cooled sleeve 24 by threaded connection. The water-cooled sleeve 24 on the upper fixture 22 is connected to the annealing furnace 1 by a sealing ring 13 to achieve a sealed sliding connection, and the water-cooled sleeve 24 on the lower fixture 23 is connected to the annealing furnace 1 by a sealing ring 13 to achieve a sealed fixed connection.

[0058] like Figure 1 and Figure 2 As shown, the clamping system 2 also includes an electrically connected pressure sensor 25 and a pressure control module 26, and the pressure sensor 25 is connected to a water-cooled sleeve 24 connected to the upper clamp 22. The first driving source 21 is used to drive the upper clamp 22 and the lower clamp 23 to move relative to each other, so as to clamp and release the crystal blank 10. In this embodiment, the first driving source 21 is specifically configured as a motor, and a transmission component is connected between the first driving source 21 and the water-cooled sleeve 24 connected to the upper clamp 22, and the first driving source 21 is electrically connected to the pressure control module 26. The transmission component can be a gear rack transmission component, a screw nut transmission component, etc.

[0059] After the first driving source 21 is started, the upper clamp 22 can move in the vertical direction under the transmission action of the transmission component to perform a clamping or loosening action. The pressure sensor 25 is electrically connected to the pressure control module 26. The pressure sensor 25 transmits the pressure signal applied by the upper clamp 22 to the crystal blank 10 to the pressure control module 26. The pressure control module 26 controls the operation of the first driving source 21 according to the pressure signal to automatically achieve a clamping or loosening action. In other embodiments, the first driving source 21 and the lower clamp 23 can also be connected by a transmission component to drive the lower clamp 23 to move in the vertical direction to achieve a clamping or loosening action. In this embodiment, the accuracy of the pressure sensor 25 is 0.1% FS.

[0060] like Figure 2 As shown, a plurality of temperature measuring elements 4 are provided, and the temperature measuring elements 4 are distributed around the upper fixture 22 and the lower fixture 23, and are used to detect the temperature of different characteristic positions of the crystal blank 10. In this embodiment, the temperature measuring element 4 is specifically configured as a thermocouple, some of which are penetrated into the annealing furnace 1 along the base 12, and the other part is penetrated into the annealing furnace 1 along the side wall of the furnace body 11. The thermocouples are fixedly connected to the annealing furnace 1.

[0061] like Figure 1 and Figure 3 As shown, the gas pipeline system 3 includes an air intake pipe group, an annular air intake pipeline 35, a flow regulating valve group and an automatic adjustment module 34. A plurality of annular grooves are processed in the upper fixture 22 and the lower fixture 23, and an annular air intake pipeline 35 is fixed in each annular groove by a sealing installation method. The size of the annular air intake pipeline 35 on the upper fixture 22 decreases from the outside to the inside, and the inner diameter of the annular air intake pipeline 35 on the lower fixture 23 also decreases from the outside to the inside. The inner diameter of the annular air intake pipeline 35 is 1.3-1.5 times the inner diameter of the adjacent annular air intake pipeline 35. And the distance between the annular air intake pipeline 35 and the surface of the upper fixture 22 or the lower fixture 23 is 3-5mm.

[0062] like Figure 4 As shown, in this embodiment, six annular air inlet pipes 35 are provided in the upper fixture 22 and the lower fixture 23, and six homogeneous washers 5 are also provided on the upper fixture 22 and the lower fixture 23. The annular air inlet pipes 35 and the homogeneous washers 5 on the upper fixture 22 are arranged in sequence from outside to inside in the order of the annular air inlet pipes 35 and the homogeneous washers 5. The thickness of the homogeneous washers 5 in the innermost circle of the six homogeneous washers 5 is 2 mm, the thickness of the homogeneous washers 5 in the outermost circle is 5 mm, and the thickness of the remaining positions varies uniformly. The total thickness of the homogeneous washers 5 is 8 mm, and the placement groove formed by the homogeneous washers 5 and the end surface of the upper fixture 22 or the lower fixture 23 has a groove depth of 5 mm.

[0063] like Figure 3 and Figure 4As shown, a plurality of first air outlet holes are provided on the end surface of the upper clamp 22 close to the lower clamp 23, and each first air outlet hole group includes a plurality of first air outlet holes 221; the first air outlet holes groups are arranged one-to-one correspondingly to the annular air inlet pipeline 35 in the upper clamp 22, and the plurality of first air outlet holes 221 in the first air outlet hole groups are evenly spaced along the circumferential direction of the corresponding annular air inlet pipeline 35, and are connected to the corresponding annular air inlet pipeline 35.

[0064] The lower fixture 23 has a plurality of second air outlet groups on its end surface close to the upper fixture 22, each of which includes a plurality of second air outlet holes 231; the first air outlet group corresponds to the annular air inlet pipeline 35 in the upper fixture 22, and the plurality of first air outlet holes 221 in the first air outlet group are evenly spaced along the circumference of the corresponding annular air inlet pipeline 35 and are connected to the corresponding annular air inlet pipeline 35. Figure 1 and Figure 3 As shown, a process gas station 9 is provided on one side of the annealing furnace 1, and the process gas station 9 is connected to a gas delivery pipe 91, and one end of the gas delivery pipe 91 passes through the insulation layer 14 along the base 12 to input process gas into the annealing furnace 1. The air inlet pipe group includes a plurality of first air inlet pipes 31 and a plurality of second air inlet pipes 32. Each first air inlet pipe 31 is passed through the upper fixture 22 along the water-cooled shaft sleeve 24 on the upper fixture 22. In this embodiment, seven first air inlet pipes 31 are provided; six of the first air inlet pipes 31 are respectively connected to the six annular air inlet pipes 35 in the upper fixture 22, and another first air inlet pipe 31 passes through the upper fixture 22 along the center of the upper fixture 22. After entering the upper fixture 22, the first air inlet pipe 31 is connected to a plurality of first air inlet branch pipes 311, and the first air inlet branch pipes 311 are arranged in a one-to-one correspondence with the first air outlet holes 221 in the corresponding first air outlet hole group. In this embodiment, there are specifically 12 first air outlet holes 221 in the first air outlet hole group.

[0065] Each second air inlet pipeline 32 is passed through the lower fixture 23 along the water-cooling sleeve 24 on the lower fixture 23. In this embodiment, seven second air inlet pipelines 32 are provided; six of the second air inlet pipelines 32 are connected to the six annular air inlet pipelines 35 in the lower fixture 23 in a one-to-one correspondence, and another second air inlet pipeline 32 passes through the lower fixture 23 along the center of the lower fixture 23. After entering the lower fixture 23, the second air inlet pipeline 32 is connected to a plurality of second air inlet branches 321, and the second air inlet branches 321 are provided in a one-to-one correspondence with the second air outlet holes 231 in the corresponding second air outlet group. In this embodiment, there are specifically 12 second air outlet holes 231 in the second air outlet group.

[0066] The first air inlet pipeline 31 is connected to the first air outlet group, and the second air inlet pipeline 32 is connected to the second air outlet group through the annular air inlet pipeline 35. After the process gas enters the first air inlet pipeline 31 and the second air inlet pipeline 32, it can be blown to the surface of the crystal blank 10 more evenly, thereby improving the uniformity of cooling.

[0067] like Figure 4 As shown, a plurality of gasket slots 51 are provided at intervals along the circumference of the homogeneous gasket 5 at one end away from the crystal blank 10 to enhance the gas flow between the homogeneous gasket 5 and the crystal blank 10 and further improve the cooling uniformity of the crystal blank 10. The gasket slots 51 are specifically 3 mm deep and 5 mm wide.

[0068] like Figure 5 As shown, the flow regulating valve group is installed on the air intake pipe group, and the flow regulating valve group includes a plurality of automatic flow regulating valves 33, and each first air intake pipeline 31 and each second air intake pipeline are equipped with an automatic flow regulating valve 33 to regulate the gas flow in each first air intake pipeline 31 and each second air intake pipeline. The automatic regulating module 34 is electrically connected to the temperature measuring element 4 and the flow regulating valve group, respectively, and is used to control the flow regulating valve group according to the temperature detected by the temperature measuring element 4, so as to automatically regulate the gas flow in each first air intake pipeline 31 and the second air intake pipeline 32.

[0069] like Figure 1 and Figure 5 As shown, a circulating cooling system 6 is also provided on one side of the annealing furnace 1. The circulating cooling system 6 includes a recovery air pipe 61, a second driving source 62, and a cooling mechanism including a heat exchanger 63 and a chiller 64. The heat exchanger 63 is composed of a heat exchange shell 631 and an internal coolant pipe 632. The pipe section of the coolant pipe 632 in the heat exchange shell 631 is wavy. A cooling inlet 6311 and a cooling outlet 6312 are respectively provided at both ends of the heat exchange shell 631. Both ends of the coolant pipe 632 are connected to the chiller 64 to form a closed-loop circulation of the coolant.

[0070] like Figure 1 and Figure 5 As shown, one end of the recovery gas pipe 61 is connected to the interior of the annealing furnace 1 and the return air chamber 15 through a perforation on the wall of the annealing furnace 1, and the other end is connected to the cooling inlet 6311; the second driving source 62 can be a vacuum pump or other types of gas pumps, and the second driving source 62 is installed on the recovery gas pipe 61 to drive the gas flow in the recovery gas pipe 61 to achieve the recovery of the process gas in the furnace.

[0071] When the second driving source 62 drives the process gas in the annealing furnace 1 to enter the heat exchange shell 631 along the recovery gas pipe 61, the coolant in the coolant pipe 632 absorbs the heat in the process gas, thereby achieving cooling of the process gas.

[0072] The cooling outlet 6312 is connected to the air supply pipe 66, and the ends of the second air inlet pipes 32 away from the lower fixture 23 are connected to the air supply pipe 66, the first air inlet pipes 31 correspond to the second air inlet pipes 32 one by one, and the ends of the first air inlet pipes 31 away from the upper fixture 22 are connected to the second air inlet pipes 32. Thus, the cooled process gas is recycled into the annealing furnace 1 again.

[0073] like Figure 1 and Figure 5 As shown, in order to accurately control the temperature of the gas after cooling, a thermometer 65 is also installed on one side of the heat exchanger 63 where the cooling outlet 6312 is set. The thermometer 65 can be a digital thermometer, a patch thermometer or a semiconductor thermometer. The thermometer 65 is installed on the gas supply pipe 66 to monitor the temperature of the process gas discharged from the cooling outlet 6312 in real time. The thermometer 65 is electrically connected to the automatic adjustment module 34 and transmits the temperature data to the automatic adjustment module 34. The automatic adjustment module 34 adjusts the power of the second driving source 62 and the working state of the cold machine 64 according to the temperature data to ensure that the process gas is cooled to a preset temperature range before entering the annealing furnace 1.

[0074] The implementation principle of a crystal blank annealing device in the embodiment of the present application is as follows: when using the crystal blank annealing device, the crystal blank 10 is placed between the upper clamp 22 and the lower clamp 23, and the upper clamp 22 is driven by the first driving source 21 and moves toward the lower clamp 23, and the crystal blank 10 is clamped by the homogeneous gasket 5. During the annealing process, the crystal blank annealing device monitors the temperature of different characteristic positions of the crystal blank 10 in real time through the temperature measuring element 4, and automatically adjusts the gas flow in each first air inlet pipeline 31 and the second air inlet pipeline 32 through the automatic adjustment module 34 and the flow regulating valve group, thereby realizing accurate control of the cooling speed of each part of the crystal blank 10. Not only is the precise control and monitoring of the temperature of the crystal blank 10 during the annealing process achieved, ensuring the uniformity and stability of the heating of the crystal blank 10, but also the use of the circulating cooling system 6 improves the energy utilization rate, reduces the production cost, and helps to improve the quality and yield rate of the crystal blank 10.

[0075] The embodiment of the present application also provides an annealing process, using the above-mentioned crystal blank annealing device to perform annealing treatment. Taking the annealing of a large-diameter calcium fluoride single crystal blank wafer as an example, it specifically includes the following steps:

[0076] Step 1: Loading the furnace. Open the furnace body 11, place the crystal blank 10 on the center of the surface of the lower clamp 23, and make the geometric centers of the crystal blank 10 and the lower clamp 23 coincide with each other; after the crystal blank 10 is placed stably, close the furnace body 11. Then, start the first driving source 21 to drive the upper clamp 22 to descend to contact the upper surface of the crystal blank 10.

[0077] During the contact between the upper clamp 22 and the upper surface of the crystal blank 10, the pressure signal applied by the upper clamp 22 to the crystal blank 10 is transmitted to the pressure control module 26; when the pressure sensor 25 reaches the set value P1, the upper clamp 22 stops clamping. The setting principle of P1 is that the clamping system 2 can effectively clamp the crystal blank 10, and the friction force provided to the crystal blank 10 makes the crystal blank 10 unable to move freely. The pressure control module 26 will monitor the pressure value of the clamp in real time after the upper clamp 22 is activated, and when the pressure value changes, it will automatically clamp or release the crystal blank 10.

[0078] Step 2: Vacuuming, filling and heating. Vacuuming the annealing furnace 1 to a vacuum of 8×10 -4 Pa, the heater 8 is restarted to start heating.

[0079] The temperature is increased at a rate of 10° C. / h until the center temperature of the crystal blank 10 reaches 300° C., and then the temperature in the annealing furnace 1 is maintained constant.

[0080] Open the relevant valves on the process gas station 9 and fill the annealing furnace 1 with process gas; the process gas includes argon and carbon tetrafluoride, and the filling volume ratio of argon and carbon tetrafluoride is about 100:1. Fill at a total filling rate of 5-7L / min until the pressure in the annealing furnace 1 reaches 30-50KPa, and continue to heat up to the annealing temperature at the original heating rate.

[0081] Step 3: Constant temperature: When the center temperature of the crystal blank 10 reaches the annealing temperature, the temperature in the annealing furnace 1 is maintained constant for 24-48 hours. The annealing temperature range is 1200-1300°C.

[0082] Step 4, cooling. Start cooling at a cooling rate of 2.5-3.5℃ / h, and turn on the gas pipeline system 3 and the circulating cooling system 6 at the same time. The initial state in the annealing furnace 1 is that the gas flow rates in the first air inlet pipeline 31 and the second air inlet pipeline 32 are the same. After starting to cool down, the automatic adjustment module 34 can calculate the cooling rate of different characteristic parts of the crystal blank 10 based on the temperature signal fed back by the temperature measuring element 4. The opening state of each automatic flow regulating valve 33 is controlled according to the speed of the cooling rate to automatically adjust the gas flow at different positions to adjust the heat dissipation at different positions taken away by the gas, and finally achieve a consistent cooling rate at each part of the crystal blank 10 and meet the process cooling rate requirements.

[0083] Usually, the gas flow rate and spray volume at the center of the surface of the crystal blank 10 are the largest, and decrease in sequence toward the surroundings. When the low-temperature process gas enters different positions of the upper clamp 22 or the lower clamp 23, it will take away a portion of the heat at the corresponding position, so that the homogeneous gasket 5 corresponding to the position transfers the heat at the corresponding position of the crystal surface to the upper clamp 22 or the lower clamp 23. Then, the process gas is sprayed out from the first gas outlet 221 or the second gas outlet 231 and reaches the surface of the crystal blank 10, taking away a portion of the heat from the surface of the crystal blank 10, and flows out through the gasket slot 51, and flows into the return gas chamber 15 along the flow gap 141, and then re-enters the circulation pipeline.

[0084] Step 5: Dismantle the furnace. After the output power of the heater 8 drops to 0 and the center temperature of the crystal blank 10 drops to room temperature, close the gas pipeline system 3 and the circulating cooling system 6. Open the furnace body 11, loosen the crystal blank 10, and carefully take out the annealed crystal blank 10. This annealing is completed.

[0085] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A device for annealing a crystal blank, characterized in that: include: Annealing furnace (1); The clamping system (2) comprises a first driving source (21), an upper clamp (22) and a lower clamp (23), wherein the upper clamp (22) and the lower clamp (23) are arranged relative to each other in the annealing furnace (1), and homogeneous washers (5) are arranged on the opposite end surfaces of the upper clamp (22) and the lower clamp (23), and the first driving source (21) is used to drive the upper clamp (22) and the lower clamp (23) to move relative to each other; A gas pipeline system (3), comprising an air intake pipe group, a flow regulating valve group and an automatic regulating module (34), wherein the air intake pipe group comprises a plurality of first air intake pipes (31) and a plurality of second air intake pipes (32), one end of each of the first air intake pipes (31) is passed through the upper fixture (22), and a plurality of groups of first air outlet hole groups are arranged at intervals on the upper fixture (22), each group of the first air outlet hole groups comprises a plurality of first air outlet holes (221), and the first air outlet hole groups are arranged in one-to-one correspondence with the first air intake pipes (31) and are in communication with each other; One end of each of the second air inlet pipelines (32) is inserted into the lower fixture (23), and a plurality of groups of second air outlet holes are arranged at intervals on the lower fixture (23), each group of the second air outlet holes includes a plurality of second air outlet holes (231), and the second air outlet holes are arranged in a one-to-one correspondence with the second air inlet pipelines (32) and are in communication with each other; the flow regulating valve group is used to regulate the gas flow in each of the first air inlet pipelines (31) and each of the second air inlet pipelines (32), and the automatic regulating module (34) is electrically connected to the flow regulating valve group; a temperature measuring element (4), wherein a plurality of the temperature measuring elements (4) are provided, the temperature measuring elements (4) are distributed around the upper clamp (22) and the lower clamp (23), and are used to detect the temperature of different characteristic positions of the crystal blank (10), and the temperature measuring elements (4) are electrically connected to the automatic adjustment module (34); A plurality of annular air inlet pipelines (35) are disposed in both the upper clamp (22) and the lower clamp (23), and the annular air inlet pipelines (35) are sequentially spaced from the outside to the inside, and the inner diameter of the annular air inlet pipelines (35) decreases sequentially from the outside to the inside; Each annular air inlet pipeline (35) in the upper fixture (22) is connected to one of the first air inlet pipelines (31), each of the annular air inlet pipelines (35) corresponds to a group of first air outlet holes, a plurality of first air outlet holes (221) in the first air outlet hole group are distributed at intervals along the circumference of the annular air inlet pipeline (35), and each of the first air outlet holes (221) is connected to the corresponding annular air inlet pipeline (35); Each annular air inlet pipeline (35) in the lower clamp (23) is connected to a second air inlet pipeline (32), each annular air inlet pipeline (35) corresponds to a group of second air outlet holes, a plurality of second air outlet holes (231) in the second air outlet hole group are distributed at intervals along the circumference of the annular air inlet pipeline (35), and each second air outlet hole (231) is connected to the corresponding annular air inlet pipeline (35).

2. A crystal blank annealing device according to claim 1, characterized in that: A plurality of homogeneous washers (5) are provided on the upper fixture (22), and the annular air intake pipeline (35) and the homogeneous washers (5) on the upper fixture (22) are sequentially spaced from outside to inside; A plurality of homogeneous washers (5) are provided on the lower clamp (23), and the annular air intake pipeline (35) and the homogeneous washers (5) on the lower clamp (23) are sequentially spaced from the outside to the inside.

3. A crystal blank annealing device according to claim 2, characterized in that: The homogeneous gasket (5) is provided with a gasket slot (51) at one end away from the crystal blank (10), and a plurality of the gasket slots (51) are arranged at intervals along the circumference of the homogeneous gasket (5).

4. The crystal blank annealing device according to claim 1, characterized in that: It also includes a circulating cooling system (6), the circulating cooling system (6) including a recovery air pipe (61), a second driving source (62) and a cooling mechanism, the cooling mechanism being provided with a cooling inlet (6311) and a cooling outlet (6312); One end of the recovery air pipe (61) is in communication with the annealing furnace (1), and the other end is in communication with the cooling inlet (6311); the second driving source (62) is used to drive the gas in the recovery air pipe (61) to flow into the cooling mechanism; and the cooling outlet (6312) is in communication with the air inlet pipe group.

5. A crystal blank annealing device according to claim 4, characterized in that: The cooling mechanism comprises a heat exchanger (63) and a cold machine (64); the heat exchanger (63) comprises a heat exchange shell (631) and a cooling liquid pipe (632) arranged in the heat exchange shell (631); the cooling inlet (6311) and the cooling outlet (6312) are both opened on the heat exchange shell (631); and both ends of the cooling liquid pipe (632) are connected to the cold machine (64).

6. A crystal blank annealing device according to claim 5, characterized in that: A temperature measuring instrument (65) is installed on one side of the heat exchanger (63) provided with a cooling outlet (6312), and the temperature measuring instrument (65) is used to detect the temperature of the gas at the cooling outlet (6312). The second driving source (62) and the cooling machine (64) are both electrically connected to the automatic adjustment module (34).

7. An annealing process, characterized in that: Annealing is performed using the crystal blank annealing device as claimed in any one of claims 4 to 6, comprising the following steps: Step 1: Loading the furnace, placing the crystal blank (10) on the center of the surface of the lower clamp (23) so that the geometric centers of the two coincide with each other, placing the crystal blank (10) stably, and clamping the crystal blank (10) using the clamping system (2); Step 2: evacuate, fill with gas and raise the temperature. The annealing furnace (1) is evacuated to a high vacuum of less than 8×104 Pa, and the annealing furnace (1) is heated until the temperature reaches a preset value. The temperature is maintained constant, and process gas is filled into the annealing furnace (1). After the process gas is filled, heating is continued until the temperature in the annealing furnace (1) reaches the annealing temperature. Step 3: Constant temperature treatment: after the center temperature of the crystal blank (10) reaches the annealing temperature, the temperature is kept constant for 24-48 hours; Step 4: Cooling down, starting the cooling down at a process cooling rate of 2.5-3.5°C / h, and simultaneously starting the automatic adjustment module (34), wherein the automatic adjustment module (34) calculates the cooling rate of different characteristic positions of the crystal blank (10) according to the temperature signal fed back by the temperature measuring element (4), and controls the operation of the flow regulating valve group according to the cooling rate, so as to adjust the gas flow in the first air inlet pipeline (31) and the second air inlet pipeline (32); Step 5: dismantle the furnace. After the center temperature of the crystal blank (10) drops to room temperature, turn off the second driving source (62) and the cooling machine (64), open the annealing furnace (1), start the first driving source (21) to loosen the crystal blank (10), and take out the crystal blank (10).

8. The annealing process according to claim 7, characterized in that: In the step 2, during the process of heating to the preset value, the heating rate is 10° C. / h.

9. The annealing process according to claim 7, characterized in that: In the step 2, the total filling rate range of the process gas is 57 L / min.

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