A heating disc and a control method of heating disc temperature

Abstract

The application provides a heating disc and a control method of temperature of the heating disc. The heating disc comprises a heating disc body, a heat dissipation control plate and a plurality of lifting mechanisms. The heating disc body generates heat according to a preset heat generation power distribution. The heat dissipation control plate is arranged below the heating disc body and has a heat dissipation temperature lower than that of the heating disc body. An upper surface of the heat dissipation control plate is provided with a plurality of convex points in contact with a lower surface of the heating disc body. The plurality of lifting mechanisms are connected to a plurality of positions in the circumferential direction of the heat dissipation control plate and are used for adjusting the height of the plurality of positions according to the measured temperature distribution of the heating disc body, so as to adjust the contact thermal resistance between the convex points and the heating disc body.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor manufacturing, and in particular, to a heating plate and a method for controlling temperature of the heating plate. BACKGROUND

[0002] In the process of semiconductor manufacturing, a heating plate is used to heat a wafer to achieve a specific process temperature. The temperature uniformity of the heating plate directly affects the quality and yield of wafer processing. In practical applications, due to the limitations of materials, structural design and manufacturing process, the temperature uniformity of the heating plate itself is often difficult to reach the ideal level, thereby affecting the process effect of each point on the wafer.

[0003] In order to overcome the above-mentioned defects of the prior art, there is an urgent need in the field for a heating plate technology for adjusting the heat dissipation environment of the heating plate, thereby optimizing the uniformity of the wafer surface temperature. SUMMARY

[0004] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

[0005] In order to overcome the above-mentioned defects of the prior art, the present application provides a heating plate and a method for controlling temperature of the heating plate, for adjusting the heat dissipation environment of the heating plate, thereby optimizing the uniformity of the wafer surface temperature.

[0006] Specifically, according to the first aspect of the present application, the heating plate comprises: a heating plate body, which generates heat according to a preset heat generation power distribution; a heat dissipation control plate, which is arranged below the heating plate body and has a heat dissipation temperature lower than that of the heating plate body, wherein an upper surface of the heat dissipation control plate is provided with a plurality of convex points in contact with a lower surface of the heating plate body; and a plurality of lifting mechanisms, which are connected to a plurality of positions circumferentially of the heat dissipation control plate, for adjusting the height of the plurality of positions according to the measured temperature distribution of the heating plate body, so as to adjust the contact thermal resistance between each of the convex points and the heating plate body.

[0007] Further, in some embodiments of the present application, the lifting mechanism is located below the heat dissipation control plate, for upwardly lifting the lower surface of the heat dissipation control plate to reduce the contact thermal resistance between the corresponding at least one convex point and the heating plate body, or downwardly falling back to increase the contact thermal resistance between the corresponding at least one convex point and the heating plate body.

[0008] Further, in some embodiments of the present application, the heating disc further comprises a support plate arranged below the heat dissipation control plate and having a plurality of sliding grooves, wherein the plurality of sliding grooves are distributed at a plurality of positions around the support plate and each has a first slope extending along a radial direction of the support plate, and the lifting mechanism is radially displaced in the sliding groove to lift or drop the lower surface of the heat dissipation control plate under the guidance of the first slope.

[0009] Further, in some embodiments of the present application, the lifting mechanism comprises a sliding block arranged inside the sliding groove and having a first counter slope on a side facing the first slope, so as to support the lower surface of the heat dissipation control plate via a top surface of the sliding block under the support of the first slope; and a top block arranged inside the sliding groove and contacting a side of the sliding block opposite to the first slope, for pushing the sliding block along a radial direction so as to lift or drop the lower surface of the heat dissipation control plate under the guidance of the first slope.

[0010] Further, in some embodiments of the present application, the top block has a second slope on a side facing the sliding block, and the slope of the second slope is equal to that of the first slope, and the sliding block has a second counter slope on a side opposite to the first slope, so as to stably support the lower surface of the heat dissipation control plate in cooperation with the first slope under the support of the second slope.

[0011] Further, in some embodiments of the present application, the lifting mechanism further comprises a pushing bolt having a threaded screw near an end of a screw cap, for rotating in a first threaded portion arranged on the support plate to be radially displaced along the support plate, and pushing the top block to be close to and lift the sliding block via an end of the threaded screw away from the screw cap; and a pulling bolt having a threaded screw at an end of a screw cap away from the threaded screw, for rotating in a second threaded portion arranged on the top block to drive the top block to be radially displaced along the support plate away from the sliding block.

[0012] Further, in some embodiments of the present application, the top surface of the sliding block is provided with at least one protruding portion for supporting the lower surface of the heat dissipation control plate via the at least one protruding portion.

[0013] Further, in some embodiments of the present application, the heating disc further comprises a temperature sensor for collecting actual temperatures of a plurality of positions on an upper surface of the heating disc body to represent an actual temperature distribution of the heating disc body; and a controller for driving at least one corresponding lifting mechanism to adjust a height of the heat dissipation control plate at a corresponding position according to the actual temperature distribution of the heating disc body, so as to adjust a contact thermal resistance between each of the protrusions and the heating disc body.

[0014] Further, in some embodiments of the present application, the controller is configured to: in response to the temperature of any of the positions on the upper surface of the heating disc body being higher than the corresponding target temperature, drive the corresponding at least one lifting mechanism to increase the height of the heat dissipation control plate at the corresponding position, so as to reduce the contact thermal resistance between the corresponding at least one protrusion and the heating disc body; and in response to the temperature of any of the positions on the upper surface of the heating disc body being lower than the corresponding target temperature, drive the corresponding at least one lifting mechanism to reduce the height of the heat dissipation control plate at the corresponding position, so as to increase the contact thermal resistance between the corresponding at least one protrusion and the heating disc body.

[0015] Further, the method for controlling the temperature of a heating disc according to the first aspect of the present application comprises the following steps: obtaining the measured temperatures of a plurality of positions on the upper surface of the heating disc body of the heating disc according to any one of the first aspect of the present application, so as to determine the measured temperature distribution of the heating disc body; and according to the measured temperature distribution of the heating disc body, driving the corresponding at least one lifting mechanism of the heating disc to adjust the height of the heat dissipation control plate at the corresponding position, so as to adjust the contact thermal resistance between the protrusions thereof and the heating disc body. BRIEF DESCRIPTION OF DRAWINGS

[0016] The above features and advantages of the present application can be better understood by reading the detailed description of embodiments of the present application in conjunction with the following drawings, in which: components are not necessarily drawn to scale, and components of similar or identical function or features can have the same or similar reference label.

[0017] Figure 1 A structural schematic diagram of a heating disc according to some embodiments of the present application is shown.

[0018] Figure 2 A structural schematic diagram of a support plate according to some embodiments of the present application is shown.

[0019] Figure 3 A structural schematic diagram of a lifting mechanism according to some embodiments of the present application is shown.

[0020] Figure 4 A structural schematic diagram of a protrusion according to some embodiments of the present application is shown.

[0021] Figure 5A A temperature distribution map before adjustment of a lifting mechanism according to some embodiments of the present application is shown.

[0022] Figure 5B A temperature distribution map after adjustment of a lifting mechanism B side height increase of 0.2 mm according to some embodiments of the present application is shown.

[0023] Figure 6A A temperature distribution map after adjustment of the lifting mechanism is shown.

[0024] Figure 6B A temperature distribution map after adjustment of the lifting mechanism A side height adjustment 0.3mm is shown.

[0025] Reference signs:

[0026] 10 heating disc body

[0027] 20 heat dissipation control plate

[0028] 30 support plate

[0029] 31 lifting mechanism

[0030] 32 sliding groove

[0031] 33 sliding block

[0032] 331 convex part

[0033] 34 top block

[0034] 35 first slope

[0035] 36 second slope

[0036] 40 advancing bolt

[0037] 50 pulling bolt DETAILED DESCRIPTION

[0038] The present application will now be described by way of specific embodiments, from which its advantages and benefits will be readily apparent to those of ordinary skill in the art. While the present application will be described in conjunction with preferred embodiments, it will be understood that they are intended to cover alternatives, modifications and equivalents included within the spirit and scope of the application as defined by the appended claims. To provide for an in-depth understanding of the present application, numerous specific details are described in the following description. The present application can be practiced without these specific details. In some instances, detailed descriptions of well-known methods and devices are omitted so as not to obscure the description of the present application with unnecessary detail. Moreover, specific terminology is used throughout the description for the purpose of providing a thorough understanding of the present application. However, the present application will not be limited to the specific terminology so as long as the spirit of the present application is encompassed.

[0039] In the description of the present application, it should be noted that unless specifically defined otherwise, the terms "mounting", "connected", "connection" should be understood broadly, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0040] In addition, "up", "down", "left", "right", "top", "bottom", "horizontal", "vertical" used in the following description should be understood as the orientation shown in the section and the related drawings. The relative terms are only for the convenience of description, and do not mean that the device described thereby needs to be manufactured or operated in a particular orientation, and therefore should not be understood as a limitation on the present application.

[0041] It can be understood that although the terms "first", "second", "third" and the like can be used herein to describe various components, regions, layers and / or parts, these components, regions, layers and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers and / or parts. Therefore, the first component, region, layer and / or part discussed below can be referred to as the second component, region, layer and / or part without departing from some embodiments of the present application.

[0042] As described above, in the semiconductor manufacturing process, the heating disc plays an important role, which is used to heat the wafer to achieve a specific process temperature. And the temperature uniformity of the heating disc directly affects the quality and yield of wafer processing. In practical application, due to the limitation of material, structure design and manufacturing process, the temperature uniformity of the heating disc itself is often difficult to reach the ideal level. Thus affecting the process effect of each point on the wafer.

[0043] In order to overcome the above-mentioned defects existing in the prior art, the present application provides a heating disc and a control method for the temperature of the heating disc, which is used to adjust the heat dissipation environment of the heating disc, so as to optimize the uniformity of the wafer surface temperature

[0044] In some non-limiting embodiments, the control method for the temperature of the heating disc provided by the second aspect of the present application can be based on the heating disc provided by the first aspect of the present application.

[0045] Please refer to Figure 1 , Figure 1 The structure schematic diagram of the heating disc provided according to some embodiments of the present application is shown.

[0046] As Figure 1As shown, the heating disc provided by the first aspect of the present application comprises a heating disc body 10, a heat dissipation control plate 20 and a plurality of lifting mechanisms 31.

[0047] The heating disc body 10 generates heat according to a preset heat generation power distribution. Here, the heat generation power may cause uneven heat generation power distribution due to machining precision, or may have uniform heat generation power distribution, but due to uneven process gas spraying, uneven pumping, etc., there may be a problem of uneven measured temperature distribution.

[0048] The heat dissipation control plate 20 is arranged below the heating disc body 10 and is used to control the heat dissipation of the heating disc. The heat dissipation control plate 20 has a heat dissipation temperature lower than that of the heating disc body 10, wherein the upper surface of the heat dissipation control plate 20 is provided with a plurality of convex points 21 in contact with the lower surface of the heating disc body 10.

[0049] The plurality of lifting mechanisms 31 are connected to a plurality of positions circumferentially of the heat dissipation control plate 20, and are used to adjust the height of the plurality of positions according to the measured temperature distribution of the heating disc body 10, so as to adjust the contact thermal resistance between each convex point 21 and the heating disc body 10.

[0050] Further, the lifting mechanism 31 is located below the heat dissipation control plate 20 and is used to lift the lower surface of the heat dissipation control plate 20 upward to reduce the contact thermal resistance between the corresponding at least one convex point 21 and the heating disc body 10, or to fall downward to increase the contact thermal resistance between the corresponding at least one convex point 21 and the heating disc body 10.

[0051] Please refer to Figures 2-3 , Figure 2 A structural schematic diagram of a support plate provided by some embodiments of the present application is shown. Figure 3 A structural schematic diagram of a lifting mechanism provided by some embodiments of the present application is shown.

[0052] As Figures 2-3 shown, the heating disc further comprises a support plate 30 arranged below the heat dissipation control plate 20 and having a plurality of sliding grooves 32, wherein the plurality of sliding grooves 32 are distributed at a plurality of positions circumferentially of the support plate 30 and each has a first slope 35 extending along the radial direction of the support plate 30, and the lifting mechanism 31 is radially displaced in the sliding groove 32 to lift the lower surface of the heat dissipation control plate 20 upward or fall downward under the guidance of the first slope 35.

[0053] Further, the lifting mechanism 31 comprises a slider 33 and a top block 34. The slider 33 is arranged inside the sliding groove 32, and a first reverse slope is arranged on the side of the slider 33 facing the first slope 35, so that the slider 33 supports the lower surface of the heat dissipation control plate 20 via the top surface of the slider 33 under the support of the first slope 35. The top block 34 is arranged inside the sliding groove 32 and contacts the side of the slider 33 away from the slope, and is used to push the slider 33 in the radial direction so as to lift the lower surface of the heat dissipation control plate 20 upward or fall back under the guidance of the slope.

[0054] Further, the side of the top block 34 facing the slider 33 is provided with a second slope 36 with the same slope as the first slope 35. The side of the slider 33 away from the first slope 35 is provided with a second reverse slope, so that the slider 33 stably supports the lower surface of the heat dissipation control plate 20 under the support of the second slope 36 in cooperation with the first slope 35.

[0055] Those skilled in the art can understand that the first slope 35 and the second slope 36 can only be configured with one of them to guide the slider 33 to lift the lower surface of the heat dissipation control plate 20 upward or fall back.

[0056] Please refer to Figure 4 , Figure 4 The structure diagram of the protruding part is shown according to some embodiments of the present application.

[0057] As Figure 4 shown, the top surface of the slider 33 can also be provided with at least one protruding part 331 to support the lower surface of the heat dissipation control plate 20 via the at least one protruding part 331. Thus, the height △h of the heat dissipation control plate 20 at the corresponding position is adjusted to adjust the contact thermal resistance between the protrusions 21 and the heating disc body 10.

[0058] Optionally, the lifting mechanism 31 can also be a jack, and those skilled in the art can set the jack at multiple positions below the heat dissipation control plate 20, so that the contact thermal resistance at the corresponding position is adjusted by rotating the jack to adjust the temperature uniformity of the wafer surface.

[0059] In some embodiments, the lifting mechanism 31 can also comprise a pushing bolt 40 and a pulling bolt 50. The screw rod of the pushing bolt 40 is provided with a thread at the end close to the nut, which is used to rotate in the first threaded part arranged on the support plate 30 to displace along the radial direction of the support plate 30, and push the top block 34 close to and lift the slider 33 via the end of the screw rod away from the nut. The screw rod of the pulling bolt 50 is provided with a thread at the end away from the nut, which is used to rotate in the second threaded part arranged on the top block 34 to displace the top block 34 along the radial direction of the support plate 30 away from the slider 33.

[0060] The working principle of the heating plate will be described below in combination with some embodiments of the heating plate temperature control method. Those skilled in the art can understand that the embodiments of the heating plate temperature control method are only some non-limiting embodiments provided by the present application, which are intended to clearly show the main concept of the present application and provide some specific schemes for facilitating the public to implement, but not to limit the overall function or overall working mode of the heating plate. Similarly, the heating plate is also only some non-limiting embodiments of the present application, which does not limit the execution subject or execution order of each step in the heating plate temperature control method.

[0061] Specifically, first, the heating plate can collect the measured temperature of multiple positions on the upper surface of the heating plate body 10 via the temperature sensor to represent the measured temperature distribution of the heating plate body 10.

[0062] Then, the controller drives the corresponding at least one lifting mechanism 31 to adjust the height of the heat dissipation control plate 20 at the corresponding position according to the measured temperature distribution of the heating plate body 10 to adjust the contact thermal resistance between each protrusion 21 and the heating plate body 10.

[0063] Specifically, the controller drives the corresponding at least one lifting mechanism 31 to increase the height of the heat dissipation control plate 20 at the corresponding position to reduce the contact thermal resistance between the corresponding at least one protrusion 21 and the heating plate body 10 in response to the temperature of any position on the upper surface of the heating plate body 10 being higher than the corresponding target temperature. Correspondingly, the controller can drive the corresponding at least one lifting mechanism 31 to reduce the height of the heat dissipation control plate 20 at the corresponding position to increase the contact thermal resistance between the corresponding at least one protrusion 21 and the heating plate body 10 in response to the temperature of any position on the upper surface of the heating plate body 10 being lower than the corresponding target temperature.

[0064] Those skilled in the art can understand that the target temperature can be a preset control temperature in a zoned temperature control scheme, or an average temperature determined according to the temperature of at least one adjacent position in a temperature uniformity optimization scheme.

[0065] Please refer to Figures 5A-5B and Figures 6A-6B , Figure 5A shows the temperature distribution map before the adjustment of the lifting mechanism according to some embodiments of the present application. Figure 5B shows the temperature distribution map after the adjustment of the lifting mechanism B side to increase 0.2mm according to some embodiments of the present application. Figure 6A shows the temperature distribution map before the adjustment of the lifting mechanism according to some embodiments of the present application. Figure 6B shows the temperature distribution map after the adjustment of the lifting mechanism A side to increase 0.3mm according to some embodiments of the present application.

[0066] As shown in FIG. 6, the highest temperature area is represented by red color and the lowest temperature area is represented by purple color, and the temperature from red to blue area changes continuously from high to low. The difference between the highest temperature and the lowest temperature is 25.2℃ before the adjustment of the lifting mechanism 31, and the difference between the highest temperature and the lowest temperature is reduced to 18.8℃ after the lifting mechanism 31B side is adjusted to be 0.2mm higher. Figures 5A-5B As shown in FIG. 6, the highest temperature area is represented by red color and the lowest temperature area is represented by purple color, and the temperature from red to blue area changes continuously from high to low. The difference between the highest temperature and the lowest temperature is 25.2℃ before the adjustment of the lifting mechanism 31, and the difference between the highest temperature and the lowest temperature is reduced to 18.8℃ after the lifting mechanism 31B side is adjusted to be 0.2mm higher.

[0067] As shown in FIG. 6, the highest temperature area is represented by red color and the lowest temperature area is represented by purple color, and the temperature from red to blue area changes continuously from high to low. The difference between the highest temperature and the lowest temperature is 25.2℃ before the adjustment of the lifting mechanism 31, and the difference between the highest temperature and the lowest temperature is reduced to 18.8℃ after the lifting mechanism 31B side is adjusted to be 0.2mm higher. Figures 6A-6B As shown in FIG. 6, the highest temperature area is represented by red color and the lowest temperature area is represented by purple color, and the temperature from red to blue area changes continuously from high to low. The difference between the highest temperature and the lowest temperature is 25.2℃ before the adjustment of the lifting mechanism 31, and the difference between the highest temperature and the lowest temperature is reduced to 18.8℃ after the lifting mechanism 31B side is adjusted to be 0.2mm higher.

[0068] Therefore, the test verification shows that changing the distance between the heat dissipation control plate 20 and the back surface of the heating plate, changing the contact thermal resistance between the heating plate and the heat dissipation control plate 20, and changing the thermal radiation environment can improve the uniformity of the temperature on the front surface of the heating plate and the wafer surface.

[0069] In summary, the heating plate and the control method of the temperature of the heating plate provided by the present application can change the contact thermal resistance between the upper surface of the heat dissipation control plate 20 and the lower surface of the heating plate through the lifting mechanism 31, thereby adjusting the heat dissipation environment of the heating plate, and optimizing the uniformity of the wafer surface temperature.

[0070] Although the above-described methods are illustrated and described as a series of acts for the sake of simplicity, it should be understood and appreciated that the methods are not limited by the order of acts, as some acts may, in accordance with one or more embodiments, occur in different orders and / or concurrently with other acts from that shown and described herein. And, not all illustrated acts can be required to implement the methods in accordance with one or more embodiments.

[0071] The foregoing description of the present disclosure has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the present disclosure to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the present disclosure be limited not with this detailed description, but rather by the claims appended hereto.

Claims

1. A heating tray, characterized by The application relates to a heating disc body, a heat dissipation control plate and a plurality of lifting mechanisms. The heat dissipation control plate is arranged below the heating disc body and has a heat dissipation temperature lower than that of the heating disc body. The upper surface of the heat dissipation control plate is provided with a plurality of convex points in contact with the lower surface of the heating disc body. The lifting mechanisms are connected to a plurality of positions around the heat dissipation control plate and are used for adjusting the height of the plurality of positions according to the measured temperature distribution of the heating disc body so as to adjust the contact thermal resistance between the convex points and the heating disc body. The lifting mechanisms are arranged below the heat dissipation control plate and are used for upwardly lifting the lower surface of the heat dissipation control plate so as to reduce the contact thermal resistance between at least one corresponding convex point and the heating disc body or are used for downwardly falling back so as to increase the contact thermal resistance between at least one corresponding convex point and the heating disc body.

2. The heating tray of claim 1, wherein, The application further relates to a support plate arranged below the heat dissipation control plate and having a plurality of sliding grooves.

3. The heating tray of claim 2, wherein, The plurality of sliding grooves are distributed at a plurality of positions around the support plate and respectively have first slopes extending along the radial direction of the support plate. The lifting mechanisms are radially displaced in the sliding grooves and are guided by the first slopes to upwardly lift the lower surface of the heat dissipation control plate or to fall back.

4. The heating tray of claim 3, wherein, The lifting mechanisms comprise sliding blocks arranged in the sliding grooves and having first reverse slopes on the sides facing the first slopes. The first reverse slopes are used for supporting the lower surface of the heat dissipation control plate via the top surfaces of the sliding blocks under the support of the first slopes. The lifting mechanisms further comprise top blocks arranged in the sliding grooves and in contact with the sides of the sliding blocks away from the first slopes.

5. The heating tray of claim 4, wherein, The top blocks have second slopes on the sides facing the sliding blocks. The second slopes have the same slope as the first slopes.

6. The heating tray of claim 5, wherein, The sides of the sliding blocks away from the first slopes are provided with second reverse slopes matched with the first slopes. The lifting mechanisms further comprise push bolts and pull-out bolts. The push bolts have threads on the ends of the screw rods close to the screw nuts.

7. The heating tray of claim 4, wherein, The threads are used for rotating in the first threaded portions arranged on the support plates so as to be radially displaced along the support plates and push the top blocks close to and upwardly lift the sliding blocks via the ends of the screw rods away from the screw nuts.

8. The heating tray of claim 1, wherein, The pull-out bolts have threads on the ends of the screw rods away from the screw nuts. The threads are used for rotating in the second threaded portions arranged on the top blocks so as to be radially displaced along the support plates and away from the sliding blocks. The top surfaces of the sliding blocks are provided with at least one convex part. The application further relates to temperature sensors used for collecting the measured temperatures of a plurality of positions on the upper surface of the heating disc body so as to represent the measured temperature distribution of the heating disc body. The application further relates to a control device connected to the temperature sensors and the lifting mechanisms. The control device is used for collecting the measured temperature distribution of the heating disc body and adjusting the height of the plurality of positions around the heat dissipation control plate according to the measured temperature distribution so as to adjust the contact thermal resistance between the convex points and the heating disc body. a controller configured to drive at least one of the lifting mechanisms to adjust the height of the heat spreading control plate at the corresponding position to adjust the contact thermal resistance between the corresponding at least one of the protrusions and the heating tray body according to the measured temperature distribution of the heating tray body.

9. The heating tray of claim 8, wherein, The controller is configured to: drive at least one of the lifting mechanisms to increase the height of the heat spreading control plate at the corresponding position to decrease the contact thermal resistance between the corresponding at least one of the protrusions and the heating tray body in response to the temperature at any of the positions on the upper surface of the heating tray body being higher than the corresponding target temperature; and drive at least one of the lifting mechanisms to decrease the height of the heat spreading control plate at the corresponding position to increase the contact thermal resistance between the corresponding at least one of the protrusions and the heating tray body in response to the temperature at any of the positions on the upper surface of the heating tray body being lower than the corresponding target temperature.

10. A method of controlling the temperature of a heating plate, characterized by, comprising the steps of: obtaining the measured temperatures at a plurality of positions on the upper surface of the heating tray body of the heating tray to determine a measured temperature distribution of the heating tray body; and drive at least one of the lifting mechanisms of the heating tray to adjust the height of the heat spreading control plate at the corresponding position to adjust the contact thermal resistance between the corresponding at least one of the protrusions and the heating tray body according to the measured temperature distribution of the heating tray body.

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