Method for adjusting temperature uniformity of AlN ceramic heater

Abstract

The invention discloses a method for adjusting the temperature uniformity of an AlN ceramic heater, and belongs to the technical field of ceramic heaters, and the method comprises the steps: S1, detecting the heater; s2, adding a plurality of emboss on the first low-temperature area, or / and reducing emboss on the first high-temperature area; or increasing the size of the embss on the first low-temperature area, or / and reducing the size of the embss on the first high-temperature area, or increasing the size of the embss on the first low-temperature area, or / and reducing the size of the embss on the first high-temperature area; s3, the AlN ceramic base material of the second high-temperature area of the heat dissipation B surface mark is machined into a groove subjected to cambered surface treatment, and then the surface of the AlN ceramic base material of the second low-temperature area is coated with a material low in heat conductivity; and S4, testing the AlN ceramic heater.

Description

Technical Field

[0001] The invention relates to the technical field of ceramic heaters, and in particular to a method for adjusting the temperature uniformity of an AlN ceramic heater. Background Art

[0002] In the AlN ceramic heater, it is made of high thermal conductivity aluminum nitride ceramic material, which has excellent thermal conductivity, high temperature stability and good insulation, and can work stably for a long time in a high temperature environment. Therefore, it is widely used in industrial heating, automotive electronics, aerospace and semiconductor manufacturing. Especially in the semiconductor field, aluminum nitride ceramic heaters play an important role in the production process, such as in chemical vapor deposition (CVD) and physical vapor deposition (PVD) processes. The AlN heater can provide a stable heating environment and precise temperature control to ensure uniform deposition of materials, uniform film thickness and film quality. With the increase of process temperature and the narrowing of film thickness range, the temperature uniformity of AlN-heater is required to be higher. For example, the CVD-heater used at 650℃ requires that the temperature uniformity should not exceed 13℃, and it should be within 10℃ when used at 600℃. The improvement of the temperature uniformity of AlN-heater has put forward higher requirements on the thermal conductivity of materials, the arrangement of heating electrodes, the design of product structure and the stability of manufacturing. However, in actual production, there are certain fluctuations in material properties, electrode pattern preparation, and cost preparation. The higher the temperature requirements, the higher the proportion of finished products that are scrapped due to unqualified temperature uniformity. Because the finished product has been sintered and finalized, it cannot be adjusted by heating the electrode pattern and optimizing the material. If the structure is the same, it can be downgraded for use, but the heater in the semiconductor is a customized product, and downgrading is rare. Generally, it can only be scrapped. The manufacturing cost of the heater is very high, and scrapping causes a great waste of resources.

[0003] In order to solve the above problems, the present invention provides a low-cost and flexible AlN ceramic heater finished product temperature uniformity adjustment method, which can adjust the heater with excessive temperature uniformity to within the qualified range, reduce the scrap rate of the heater finished product, and reduce resource waste for the industry. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for adjusting the temperature uniformity of an AlN ceramic heater to solve the problem raised in the background technology.

[0005] In order to solve the above technical problems, the technical solution of the present invention is:

[0006] A method for adjusting the temperature uniformity of an AlN ceramic heater, the ceramic heater comprising an AlN ceramic disk, a heating electrode being arranged inside the AlN ceramic disk, the AlN ceramic disk comprising a heat dissipation surface A for adsorbing a wafer and a heat dissipation surface B, the heat dissipation surface A being located above the heat dissipation surface B, a plurality of embosses being evenly distributed on the heat dissipation surface A, the embosses being in contact with the adsorbed wafer to transfer heat to the wafer.

[0007] Preferably, the adjustment method comprises:

[0008] S1: Perform temperature uniformity detection on the produced AlN ceramic heater to determine whether the temperature exceeds the tolerance. If it is determined that the temperature exceeds the tolerance, determine and mark the high temperature zone and the low temperature zone, mark the first high temperature zone and the first low temperature zone on the heat dissipation surface A, and mark the second high temperature zone and the second low temperature zone on the heat dissipation surface B;

[0009] S2: adding a plurality of embosses on the first low temperature zone to increase the temperature transferred on the first low temperature zone, or / and reducing the number of embosses on the first high temperature zone to reduce the temperature transferred on the first high temperature zone;

[0010] or increasing the size of the emboss on the first low temperature zone to increase the heat transfer area of ​​the first low temperature zone, or / and decreasing the size of the emboss on the first high temperature zone to decrease the heat transfer area of ​​the emboss on the first high temperature zone;

[0011] S3: processing the AlN ceramic substrate of the second high temperature zone marked on the heat dissipation surface B into a cambered groove to increase the heat dissipation area of ​​the second high temperature zone and improve the heat dissipation efficiency, and then applying a material with low thermal conductivity on the surface of the AlN ceramic substrate of the second low temperature zone to reduce the heat dissipation of the second low temperature zone and balance the temperature of the second low temperature zone and the second high temperature zone;

[0012] S4: After the above steps S2 and / or S3, the AlN ceramic heater is subjected to a temperature uniformity test. If it meets the requirements, it can be used. If it does not meet the requirements, it is further adjusted according to the specific situation.

[0013] Preferably, the emboss is cylindrical, and in the step S2, increasing the size of the emboss on the first low temperature zone is to increase the diameter of the emboss, and reducing the size of the emboss on the first high temperature zone is to reduce the diameter of the emboss on the first high temperature zone.

[0014] Preferably, in step S3, a material with low thermal conductivity such as glass or Al is applied on the surface of the AlN ceramic substrate in the second low temperature zone.2 O 3 or Y 2 O 3 .

[0015] Preferably, in step S4, if the requirements are not met, the number of emboss in the first low temperature zone is further increased according to the specific situation, or / and the number of emboss in the first high temperature zone is further reduced;

[0016] or continue to increase the size of the emboss on the first low temperature zone, or / and continue to reduce the size of the emboss on the first high temperature zone;

[0017] Alternatively, the surface area of ​​the groove may be further increased, or / and the volume of the material with low thermal conductivity coated on the surface of the AlN ceramic substrate in the second low temperature zone may be increased.

[0018] The above technical solution has the following beneficial effects:

[0019] The present invention provides a low-cost and flexible method for adjusting the temperature uniformity of a finished AlN ceramic heater, which can adjust a heater with excessive temperature uniformity to within the qualified product range, reduce the scrap rate of the finished heater, and improve the qualified rate of the finished product, thereby reducing resource waste for the industry and creating significant economic benefits for the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic structural diagram of an AlN ceramic heater of the present invention. DETAILED DESCRIPTION

[0021] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0022] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0023] Example 1

[0024] refer to Figure 1 , a method for adjusting the temperature uniformity of an AlN ceramic heater, comprising:

[0025] S1: Perform temperature uniformity detection on the produced AlN ceramic heater to determine whether the temperature exceeds the tolerance. If it is determined that the temperature exceeds the tolerance, the high temperature area and the low temperature area are determined and marked to facilitate improvement and adjustment in the subsequent steps. The first high temperature area 6 and the first low temperature area 5 are marked on the heat dissipation surface A 2, and the second high temperature area 8 and the second low temperature area 7 are marked on the heat dissipation surface B 3;

[0026] The AlN ceramic heater includes an AlN ceramic disk 1, and a heating electrode is arranged inside the AlN ceramic disk 1. When powered on, the AlN ceramic disk 1 can generate heat to control and adjust the temperature of the AlN ceramic disk 1 when working. The AlN ceramic disk 1 includes a heat dissipation A surface 2 and a heat dissipation B surface 3 for adsorbing wafers. The heat dissipation A surface 2 is located above the heat dissipation B surface 3, that is, the heat dissipation B surface 3 is located on the reverse side of the heat dissipation A surface 2. A plurality of embosses 4 are evenly distributed on the heat dissipation A surface 2. The embosses 4 are in contact with the adsorbed wafer to transfer heat to the wafer. The AlN ceramic heater is an electrostatic chuck. The embosses are located between the wafer and the electrostatic chuck, and their main function is to support and provide a cooling channel. They are small bumps on the heat dissipation A surface of the electrostatic chuck.

[0027] S2: adding a number of embosses 4 to the first low temperature zone 5 to increase the temperature transmitted to the first low temperature zone 5, and then performing a temperature uniformity test on the AlN ceramic heater at this time, and continuously adjusting until the temperature uniformity meets the requirements;

[0028] Or reduce the emboss 4 located on the first high temperature zone 6 to reduce the temperature transferred on the first high temperature zone 6. After reducing a certain number of emboss 4 on the first high temperature zone 6, perform a temperature uniformity test and continuously adjust until the temperature uniformity meets the requirements.

[0029] The emboss 4 is cylindrical, and in step S2, increasing the size of the emboss 4 on the first low temperature zone 5 is to increase the diameter of the emboss 4, and decreasing the size of the emboss 4 on the first high temperature zone 6 is to decrease the diameter of the emboss 4 on the first high temperature zone 6;

[0030] S3: Processing the AlN ceramic substrate of the second high temperature zone 8 marked on the heat dissipation surface B 3 into a cambered groove 10 to increase the heat dissipation area of ​​the second high temperature zone 8 and improve the heat dissipation efficiency, and then applying a material block 9 with low thermal conductivity on the surface of the AlN ceramic substrate of the second low temperature zone 7 to reduce the heat dissipation of the second low temperature zone 7, and cooperating with step S2 to balance the temperature of the second low temperature zone 7 and the second high temperature zone 8, and adjusting the AlN ceramic heater to meet the requirements;

[0031] The surface of the AlN ceramic substrate in the second low temperature zone 7 is coated with a material block 9 with low thermal conductivity, such as glass or Al2 O 3 or Y 2 O 3 ;

[0032] S4: After the above step S2 and / or step S3, the AlN ceramic heater is subjected to a temperature uniformity test. If it meets the requirements, it can be used. If it does not meet the requirements, it is adjusted according to the specific situation, and the number of emboss 4 on the first low temperature zone 5 is increased, or / and the number of emboss 4 on the first high temperature zone 6 is reduced according to the specific situation.

[0033] or continue to increase the size of the emboss 4 on the first low temperature zone 5, or / and continue to reduce the size of the emboss 4 on the first high temperature zone 6;

[0034] Or continue to increase the surface area of ​​the groove 10, or / and increase the volume of the material block 9 with low thermal conductivity coated on the surface of the AlN ceramic substrate in the second low temperature zone 7;

[0035] The present invention provides a low-cost and flexible method for adjusting the temperature uniformity of finished AlN ceramic heaters, which can adjust heaters with poor temperature uniformity to within the qualified product range, reduce the scrap rate of finished heaters, and improve the qualified rate of finished products, thereby reducing resource waste for the industry and creating significant economic benefits for enterprises.

[0036] Example 2

[0037] A method for adjusting the temperature uniformity of an AlN ceramic heater, comprising:

[0038] S1: Perform temperature uniformity detection on the produced AlN ceramic heater to determine whether the temperature exceeds the tolerance. If it is determined that the temperature exceeds the tolerance, the high temperature area and the low temperature area are determined and marked to facilitate improvement and adjustment in the subsequent steps. The first high temperature area 6 and the first low temperature area 5 are marked on the heat dissipation surface A 2, and the second high temperature area 8 and the second low temperature area 7 are marked on the heat dissipation surface B 3;

[0039] The AlN ceramic heater includes an AlN ceramic disk 1, and a heating electrode is arranged inside the AlN ceramic disk 1. When powered on, the AlN ceramic disk 1 can generate heat to control and adjust the temperature of the AlN ceramic disk 1 when working. The AlN ceramic disk 1 includes a heat dissipation A surface 2 and a heat dissipation B surface 3 for adsorbing wafers. The heat dissipation A surface 2 is located above the heat dissipation B surface 3, that is, the heat dissipation B surface 3 is located on the reverse side of the heat dissipation A surface 2. A plurality of embosses 4 are evenly distributed on the heat dissipation A surface 2, and the embosses 4 are in contact with the adsorbed wafer to transfer heat to the wafer.

[0040] S2: increasing the size of the emboss 4 on the first low temperature zone 5 to increase the heat transfer area of ​​the first low temperature zone 5, or reducing the size of the emboss 4 on the first high temperature zone 6 to reduce the heat transfer area of ​​the emboss 4 on the first high temperature zone 6;

[0041] S3: processing the AlN ceramic substrate of the second high temperature zone 8 marked on the heat dissipation surface B 3 into a cambered groove 10 to increase the heat dissipation area of ​​the second high temperature zone 8 and improve the heat dissipation efficiency, and then applying a material block 9 with low thermal conductivity on the surface of the AlN ceramic substrate of the second low temperature zone 7 to reduce the heat dissipation of the second low temperature zone 7 and balance the temperature of the second low temperature zone 7 and the second high temperature zone 8;

[0042] S4: After the above steps S2 and / or S3, the AlN ceramic heater is subjected to a temperature uniformity test. If it meets the requirements, it can be used. If it does not meet the requirements, it is further adjusted according to the specific situation.

[0043] Example 3

[0044] A method for adjusting the temperature uniformity of an AlN ceramic heater, comprising:

[0045] Conduct temperature uniformity test on the produced AlN ceramic heater to determine whether the temperature exceeds the tolerance. If it is determined that the temperature exceeds the tolerance, determine and mark the high temperature area and the low temperature area to facilitate improvement and adjustment in the following steps. Mark the first high temperature area 6 and the first low temperature area 5 on the heat dissipation surface A 2, and mark the second high temperature area 8 and the second low temperature area 7 on the heat dissipation surface B 3;

[0046] The AlN ceramic heater includes an AlN ceramic disk 1, and a heating electrode is arranged inside the AlN ceramic disk 1. When powered on, the AlN ceramic disk 1 can generate heat to control and adjust the temperature of the AlN ceramic disk 1 when working. The AlN ceramic disk 1 includes a heat dissipation A surface 2 and a heat dissipation B surface 3 for adsorbing wafers. The heat dissipation A surface 2 is located above the heat dissipation B surface 3, that is, the heat dissipation B surface 3 is located on the reverse side of the heat dissipation A surface 2. A plurality of embosses 4 are evenly distributed on the heat dissipation A surface 2, and the embosses 4 are in contact with the adsorbed wafer to transfer heat to the wafer.

[0047] Several emboss 4 are added to the first low temperature zone 5 to increase the temperature transferred to the first low temperature zone 5, and emboss 4 located on the first high temperature zone 6 are reduced to reduce the temperature transferred to the first high temperature zone 6. By adjusting the first low temperature zone 5 and the first high temperature zone 6, the adjustment is faster and more convenient under the cooperation of the two, that is, the first low temperature zone 5 does not need to add too many emboss 4, and the first high temperature zone 6 does not need to reduce too many emboss 4, so as to ensure that the AlN ceramic heater can better support the adsorption wafer during operation;

[0048] Finally, the AlN ceramic heater is tested for temperature uniformity. If it meets the requirements, it can be used. If it does not meet the requirements, it will be adjusted according to the specific situation.

[0049] Example 4

[0050] A method for adjusting the temperature uniformity of an AlN ceramic heater, comprising:

[0051] Conduct temperature uniformity test on the produced AlN ceramic heater to determine whether the temperature exceeds the tolerance. If it is determined that the temperature exceeds the tolerance, determine and mark the high temperature area and the low temperature area to facilitate improvement and adjustment in the following steps. Mark the first high temperature area 6 and the first low temperature area 5 on the heat dissipation surface A 2, and mark the second high temperature area 8 and the second low temperature area 7 on the heat dissipation surface B 3;

[0052] The AlN ceramic heater includes an AlN ceramic disk 1, and a heating electrode is arranged inside the AlN ceramic disk 1. When powered on, the AlN ceramic disk 1 can generate heat to control and adjust the temperature of the AlN ceramic disk 1 when working. The AlN ceramic disk 1 includes a heat dissipation A surface 2 and a heat dissipation B surface 3 for adsorbing wafers. The heat dissipation A surface 2 is located above the heat dissipation B surface 3, that is, the heat dissipation B surface 3 is located on the reverse side of the heat dissipation A surface 2. A plurality of embosses 4 are evenly distributed on the heat dissipation A surface 2, and the embosses 4 are in contact with the adsorbed wafer to transfer heat to the wafer.

[0053] Alternatively, the size of the emboss 4 on the first low temperature zone 5 is increased to increase the heat transfer area of ​​the first low temperature zone 5, and the size of the emboss 4 on the first high temperature zone 6 is reduced to reduce the area of ​​heat transfer of the emboss 4 on the first high temperature zone 6. By coordinating the two for adjustment, the adjustment is faster and more convenient, that is, there is no need to set too many emboss 4 of larger size on the first low temperature zone 5, and the overall consistency of the surface of the AlN ceramic heater is maintained;

[0054] The AlN ceramic heater is tested for temperature uniformity. If it meets the requirements, it can be used. If it does not meet the requirements, it will be adjusted according to the specific situation.

[0055] Example 5

[0056] A method for adjusting the temperature uniformity of an AlN ceramic heater, comprising:

[0057] Conduct temperature uniformity test on the produced AlN ceramic heater to determine whether the temperature exceeds the tolerance. If it is determined that the temperature exceeds the tolerance, determine and mark the high temperature area and the low temperature area to facilitate improvement and adjustment in the following steps. Mark the first high temperature area 6 and the first low temperature area 5 on the heat dissipation surface A 2, and mark the second high temperature area 8 and the second low temperature area 7 on the heat dissipation surface B 3;

[0058] The AlN ceramic heater includes an AlN ceramic disk 1, and a heating electrode is arranged inside the AlN ceramic disk 1. When powered on, the AlN ceramic disk 1 can generate heat to control and adjust the temperature of the AlN ceramic disk 1 when working. The AlN ceramic disk 1 includes a heat dissipation A surface 2 and a heat dissipation B surface 3 for adsorbing wafers. The heat dissipation A surface 2 is located above the heat dissipation B surface 3, that is, the heat dissipation B surface 3 is located on the reverse side of the heat dissipation A surface 2. A plurality of embosses 4 are evenly distributed on the heat dissipation A surface 2, and the embosses 4 are in contact with the adsorbed wafer to transfer heat to the wafer.

[0059] The AlN ceramic substrate of the second high temperature zone 8 marked on the heat dissipation surface B 3 is processed into a cambered groove 10 to increase the heat dissipation area of ​​the second high temperature zone 8 and improve the heat dissipation efficiency. Then, a material block 9 with low thermal conductivity is applied to the surface of the AlN ceramic substrate of the second low temperature zone 7 to reduce the heat dissipation of the second low temperature zone 7, balance the temperature of the second low temperature zone 7 and the second high temperature zone 8, and adjust the AlN ceramic heater to meet the requirements;

[0060] The surface of the AlN ceramic substrate in the second low temperature zone 7 is coated with a material block 9 with low thermal conductivity, such as glass or Al 2 O 3 or Y 2 O 3 ;

[0061] The AlN ceramic heater is tested for temperature uniformity. If it meets the requirements, it can be used. If it does not meet the requirements, it is adjusted according to the specific situation. According to the specific situation, the number of emboss 4 in the first low temperature zone 5 is increased, or / and the number of emboss 4 in the first high temperature zone 6 is reduced.

[0062] Example 6

[0063] Conduct temperature uniformity test on the produced AlN ceramic heaters and proceed to the next step after judging whether the temperature exceeds the tolerance;

[0064] In the first low temperature zone 5 of the heat dissipation surface A 2, the overall area of ​​the emboss 4 is increased by 6%, and the overall area of ​​the emboss 4 in the first high temperature zone 6 is reduced by 6%. The adjusted test data and the data without adjustment are shown in Table 1;

[0065] Table 1:

[0066] 100℃ 200℃ 300℃ 400℃ 500℃ 600℃ 650℃ Before adjustment 1 1.6 2.3 5.1 8.3 12.8 16.2 After adjustment 0.8 1.3 1.7 3.9 6.6 9.7 14

[0067] As shown in Table 1, the AlN ceramic heater had a temperature deviation before adjustment. After emboss 4 was added in the first low temperature zone 5 and emboss 4 was reduced in the first high temperature zone 6, its temperature uniformity was reduced, that is, it met the requirements after adjustment. There was no temperature deviation after adjustment. For example, when used at 600°C, the temperature uniformity of the unqualified product before adjustment was 12.8 degrees Celsius, which did not meet the requirement within 10°C. After adjustment, it was less than 10°C, which met the requirements.

[0068] Example 7

[0069] Conduct temperature uniformity test on another AlN ceramic heater produced, and proceed to the next step after judging that the temperature is out of tolerance;

[0070] In the second high temperature zone 8 of the heat dissipation surface B 3, a groove 10 with a diameter of 6 cm and a depth of 1 mm is set to increase the heat dissipation area of ​​the second high temperature zone 8. The results of the unqualified product test before and after the adjustment are shown in Table 2;

[0071] Table 2:

[0072] 100℃ 200℃ 300℃ 400℃ 500℃ 600℃ 650℃ Before adjustment 1.1 1.8 2.4 5.7 9.3 14.2 19.8 After adjustment 0.9 1.4 2.1 4.0 7.8 12 16

[0073] It can be seen from Table 2 that after the groove 10 is provided in the second high temperature zone 8, the temperature uniformity becomes smaller and can be met by adjustment.

[0074] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.

Claims

1. A method for adjusting the temperature uniformity of an AlN ceramic heater, characterized in that: The ceramic heater includes an AlN ceramic disk, a heating electrode is provided inside the AlN ceramic disk, and the AlN ceramic disk includes a heat dissipation surface A and a heat dissipation surface B for adsorbing wafers. The heat dissipation surface A is located above the heat dissipation surface B. Several embosses are evenly distributed on the heat dissipation surface A. The embosses are in contact with the adsorbed wafer to transfer heat to the wafer.

2. A method for adjusting the temperature uniformity of an AlN ceramic heater, characterized in that: The adjustment method comprises: S1: Perform temperature uniformity detection on the produced AlN ceramic heater to determine whether the temperature exceeds the tolerance. If it is determined that the temperature exceeds the tolerance, determine and mark the high temperature zone and the low temperature zone, mark the first high temperature zone and the first low temperature zone on the heat dissipation surface A, and mark the second high temperature zone and the second low temperature zone on the heat dissipation surface B; S2: adding a plurality of embosses on the first low temperature zone to increase the temperature transferred on the first low temperature zone, or / and reducing the number of embosses on the first high temperature zone to reduce the temperature transferred on the first high temperature zone; or increasing the size of the emboss on the first low temperature zone to increase the heat transfer area of ​​the first low temperature zone, or / and decreasing the size of the emboss on the first high temperature zone to decrease the heat transfer area of ​​the emboss on the first high temperature zone; S3: processing the AlN ceramic substrate of the second high temperature zone marked on the heat dissipation surface B into a cambered groove to increase the heat dissipation area of ​​the second high temperature zone and improve the heat dissipation efficiency, and then applying a material with low thermal conductivity on the surface of the AlN ceramic substrate of the second low temperature zone to reduce the heat dissipation of the second low temperature zone and balance the temperature of the second low temperature zone and the second high temperature zone; S4: After the above step S2 and / or step S3, the AlN ceramic heater is subjected to a temperature uniformity test. If it meets the requirements, it can be used. If it does not meet the requirements, it is further adjusted according to the specific situation.

3. The method for adjusting the temperature uniformity of an AlN ceramic heater according to claim 2, characterized in that: The emboss is cylindrical. In the step S2, increasing the size of the emboss on the first low temperature zone is to increase the diameter of the emboss, and decreasing the size of the emboss on the first high temperature zone is to decrease the diameter of the emboss on the first high temperature zone.

4. The method for adjusting the temperature uniformity of an AlN ceramic heater according to claim 2, characterized in that: In the step S3, a material with low thermal conductivity such as glass, Al2O3 or Y2O3 is applied on the surface of the AlN ceramic substrate in the second low temperature zone.

5. The method for adjusting the temperature uniformity of an AlN ceramic heater according to claim 2, characterized in that: In the step S4, if the requirements are not met, the number of emboss in the first low temperature zone is further increased, or / and the number of emboss in the first high temperature zone is further reduced according to the specific situation; or continue to increase the size of the emboss on the first low temperature zone, or / and continue to reduce the size of the emboss on the first high temperature zone; Alternatively, the surface area of ​​the groove may be further increased, or / and the volume of the material with low thermal conductivity coated on the surface of the AlN ceramic substrate in the second low temperature zone may be increased.

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