A ceramic heating disc and a preparation method thereof

Abstract

The application provides a ceramic heating disc and a preparation method thereof, and relates to the technical field of ceramic heating discs.The ceramic heating disc comprises an upper disc body, a lower disc body, a heating wire, a tray, ceramic tubes and a piston plate, the tray is arranged in the upper disc body, the heating wire is arranged in the lower disc body, the upper disc body and the lower disc body drive the bottom end of the tray to press the heating wire when they are installed with each other, a plurality of ceramic tubes are arranged in the tray, the upper disc body and the tray are filled with heat-conducting oil, the heat-conducting oil is arranged in a closed space formed by the piston plate and the ceramic tubes, and the heat-conducting oil is automatically sprayed when the piston plate moves to a preset position driven by the expansion of the heat-conducting oil; and the closed space automatically extracts the upper layer of the heat-conducting oil in the storage space after the heat-conducting oil is released.The heating wire can be placed and fixed at any position in the lower disc body without center positioning, the heat-conducting oil in the storage space is heated to make the thin wafer uniformly heated; the plurality of ceramic tubes force the heat-conducting oil in the storage space to flow with each other, which is beneficial to heat convection and accelerates the uniform heating of the heat-conducting oil in the storage space.

Description

Technical Field

[0001] This invention relates to the field of ceramic heating plate technology, and more specifically, to a ceramic heating plate and its preparation method. Background Technology

[0002] In the semiconductor chip manufacturing process, there are processing steps such as wafer material deposition and removal, and wafer bonding. During the process, the wafer needs to be heated or hot-pressed. Ceramic heating plates are widely used in this field because of their advantages of high strength, corrosion resistance and low impurities.

[0003] The heating wires inside the existing ceramic heating plate are fixed by welding. If misalignment occurs during the welding process, it will affect the uniform heating of the wafer, and the heat transfer of the heating wire will be uneven. Summary of the Invention

[0004] To address the above problems, this invention provides a ceramic heating plate and its preparation method.

[0005] This invention provides a ceramic heating plate, comprising an upper plate body, a lower plate body, a heating wire, a tray, a ceramic tube, and a piston plate. The tray is disposed inside the upper plate body, and the heating wire is placed inside the lower plate body. When the upper and lower plate bodies are installed together, the bottom end of the tray is driven to press the heating wire. A plurality of ceramic tubes are evenly disposed inside the tray. The storage space formed between the upper plate body and the tray is filled with heat-conducting oil. The piston plate is disposed inside the ceramic tubes, and the sealed space formed by its bottom end and the side wall of the ceramic tube is filled with heat-conducting oil. When the heat-conducting oil in the sealed space is in an expanded state, the piston plate is driven to move vertically upward. When the piston plate moves upward to a preset position, the expanded heat-conducting oil is autonomously sprayed into the lower layer of the storage space. When the heat-conducting oil in the sealed space is depressurized, the piston plate returns to its original position, and the upper layer of heat-conducting oil in the sealed space is autonomously extracted.

[0006] Optionally, a copper base is coaxially fixedly connected to the bottom end of the ceramic tube. The copper base is fixedly installed in the hole opened at the bottom end of the tray. The size of the copper base matches the size of the hole. The sealed space formed by the bottom end of the piston plate, the side wall of the ceramic tube, and the upper end of the copper base is filled with heat-conducting oil.

[0007] Optionally, the outer side of the piston plate is slidably connected to the inner sidewall of the ceramic tube, a second spring is fixedly connected to the middle of the bottom end of the piston plate, the bottom end of the second spring is fixedly connected to the middle of the end face of the copper base, and a plurality of uniformly distributed and through first microholes are opened in the circumferential direction along the axis of the inner sidewall of the ceramic tube.

[0008] Optionally, an oil inlet pipe is fixedly installed in the middle of the piston plate, the lower end of the oil inlet pipe is located in a sealed space, a one-way valve is fixedly installed on the lower end of the oil inlet pipe, the oil inlet pipe is slidably connected to the middle of the upper end of the ceramic tube, and a limiting ring is coaxially fixed on the inner side wall of the ceramic tube.

[0009] Optionally, a fixing plate is provided at the upper end of the first micropore, and a lifting plate is provided at the upper end of the fixing plate. The outer side of the fixing plate is fixed to the inner side wall of the ceramic tube, and the outer side of the lifting plate is slidably connected to the inner side wall of the ceramic tube. A plurality of evenly distributed and through second micropores are opened in the inner circumferential direction of the side wall of the ceramic tube. The second micropores are located between the upper end of the fixing plate and the bottom end of the lifting plate. A third spring is fastened between the middle of the upper end of the fixing plate and the middle of the bottom end of the lifting plate.

[0010] Optionally, the lower end of the ceramic tube is formed with a tapered section, and the bottom end of the tapered section of the ceramic tube is fixed to the upper surface of the copper base.

[0011] Optionally, a locking ring is fixedly provided at the lower periphery of the upper disc body, and the locking ring is fastened to the upper end of the lower disc body by a plurality of bolts.

[0012] Optionally, the outer circumference of the tray is formed with an outer ring, and a plurality of evenly distributed first springs are fixedly mounted on the bottom end of the outer ring along the circumferential direction. The inner side of the upper tray is formed with an inner ring, and the bottom end of the first spring is fixedly mounted on the upper end face of the inner ring. The outer ring of the tray is slidably connected to the inner side of the upper tray.

[0013] Optionally, terminals are provided at both ends of the heating wire for electrical connection to an external power source.

[0014] A method for preparing a ceramic heating plate, based on the ceramic heating plate described above, comprises the following steps:

[0015] S1: The upper plate, lower plate, tray, ceramic tube and piston plate are made by sintering. The piston plate has an annular groove on its outer periphery. Then the sealing ring is installed in the annular groove. Next, the piston plate is installed inside the ceramic tube and the lower end is filled with heat transfer oil. Then multiple ceramic tubes are fixed to the bottom of the tray by brazing.

[0016] S2: Next, install the tray inside the upper tray body, and fill the storage space between the upper tray body and the tray with heat-conducting oil;

[0017] S3: Next, place the heating wire on the bottom surface of the lower plate body. The heating wire has terminals at both ends. Then, install the upper plate body and the lower plate body together. When installing, press the bottom of the tray against the top of the heating wire.

[0018] The beneficial effects of the ceramic heating plate of this invention are as follows: the heating wire can be placed and fixed in the lower plate body at any position without the need for central positioning. By heating the heat-conducting oil in the storage space, the thin wafer is heated evenly, avoiding warping or stress cracking caused by local overheating. Furthermore, the heating wire is easy to replace. When the heat-conducting oil expands in the sealed space, it pushes the piston plate vertically upward to a preset position. The expanded heat-conducting oil autonomously sprays into the lower layer of the storage space. The sprayed heat-conducting oil impacts the lower layer of heat-conducting oil in the storage space. By setting multiple ceramic tubes, the sprayed heat-conducting oil effectively impacts the lower layer of heat-conducting oil in all directions, forcing the lower layer of heat-conducting oil to flow between each other, which is beneficial for heat convection and accelerates the uniform heating of the lower layer of heat-conducting oil. When the heat-conducting oil in the sealed space is depressurized, the piston plate returns to its original position, and the upper layer of heat-conducting oil in the sealed space is autonomously extracted. After extraction, the oil is immediately heated, and then sprayed and impacted again through thermal expansion, accelerating the uniform heating of both the upper and lower layers of heat-conducting oil. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall three-dimensional structure of a ceramic heating plate according to an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the overall internal structure of a ceramic heating plate according to an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram showing the position of the heating wire in a ceramic heating plate according to an embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of the upper plate structure in a ceramic heating plate according to an embodiment of the present invention;

[0023] Figure 5 This is a schematic diagram of the tray structure in a ceramic heating plate according to an embodiment of the present invention;

[0024] Figure 6 This is a schematic diagram of the copper base and the external structure of the ceramic tube in a ceramic heating plate according to an embodiment of the present invention;

[0025] Figure 7 This is a schematic diagram of the internal structure of a ceramic tube in a ceramic heating plate according to an embodiment of the present invention;

[0026] Figure 8 This is a schematic diagram of the piston plate movement state in a ceramic heating plate according to an embodiment of the present invention.

[0027] Explanation of reference numerals in the attached drawings: 100, upper plate; 101, locking ring; 102, bolt; 200, lower plate; 300, heating wire; 400, tray; 401, first spring; 500, copper base; 501, ceramic tube; 502, limiting ring; 503, piston plate; 504, second spring; 505, first micro-orifice; 600, oil inlet pipe; 601, one-way valve; 700, fixing plate; 701, lifting plate; 702, third spring; 703, second micro-orifice. Detailed Implementation

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] In the description of this specification, the references to terms such as "embodiment," "one embodiment," "some implementations," "exemplary," and "one implementation," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or implementation is included in at least one embodiment or implementation of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or implementation. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or implementations.

[0031] The terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature.

[0032] like Figure 1-8As shown, this embodiment of the invention provides a ceramic heating plate, including an upper plate 100, a lower plate 200, a heating wire 300, a tray 400, ceramic tubes 501, and a piston plate 503. The tray 400 is disposed inside the upper plate 100, and the heating wire 300 is placed inside the lower plate 200. When the upper plate 100 and the lower plate 200 are installed together, the bottom end of the tray 400 is driven to press the heating wire 300. A plurality of ceramic tubes 501 are evenly disposed inside the tray 400. The space between the upper plate 100 and the tray 400 forms a... The storage space is filled with heat-conducting oil. The piston plate 503 is located inside the ceramic tube 501. The sealed space formed by the bottom end of the piston plate 503 and the side wall of the ceramic tube 501 is filled with heat-conducting oil. When the heat-conducting oil in the sealed space is in an expanded state, it drives the piston plate 503 to move vertically upward. When the piston plate 503 moves upward to the preset position, the expanded heat-conducting oil is automatically sprayed into the lower layer of the storage space. When the heat-conducting oil in the sealed space is depressurized, the piston plate 503 resets and automatically extracts the upper layer of heat-conducting oil from the sealed space.

[0033] In this embodiment, the heating wire 300 is placed inside the lower plate 200, and then the upper plate 100 and the lower plate 200 are installed together. During the installation process, the bottom end of the tray 400 located inside the upper plate 100 presses the heating wire 300 firmly. At this time, the position of the heating wire 300 is fixed, and there will be no shaking or poor contact with the bottom end of the tray 400. After the installation is completed, the heating wire 300 is energized. The heating wire 300 generates heat after being energized. Since the bottom end of the tray 400 presses the heating wire 300 firmly, the generated heat is transferred to the tray 400. At the bottom, the storage space formed between the upper plate 100 and the tray 400 is filled with heat-conducting oil. Therefore, the generated heat is dissipated through the bottom of the tray 400 into the heat-conducting oil within the storage space. Once the heat-conducting oil in the storage space is uniformly heated, the heat is evenly transferred to the upper plate 100, thus uniformly heating the thin wafer at the top of the upper plate 100 and preventing warping or stress cracking of the thin wafer due to localized overheating. When the bottom of the tray 400 is heated by the heating wire 300, the lower layer of heat-conducting oil within the storage space is heated first. Then, heat is transferred to the upper layer of heat transfer oil. Simultaneously, multiple ceramic tubes 501 located inside the tray 400 are also heated. The heat is transferred to the heat transfer oil within the sealed space formed by the bottom end of the piston plate 503 and the sidewalls of the ceramic tubes 501. When the heat transfer oil in the sealed space is heated to an expanded state, the oil pressure increases, pushing the piston plate 503 vertically upwards. When the piston plate 503 moves upwards to a preset position, the expanded heat transfer oil autonomously sprays into the lower layer of the storage space. The sprayed heat transfer oil impacts the lower layer of heat transfer oil in the storage space. This process, achieved by setting multiple ceramic tubes 501... The ceramic tube 501 effectively impacts the sprayed heat transfer oil in all directions on the lower layer of heat transfer oil in the storage space, forcing the lower layer of heat transfer oil to flow with each other, which is conducive to heat convection and accelerates the uniform heating of the lower layer of heat transfer oil in the storage space. When the heat transfer oil in the sealed space is depressurized, the piston plate 503 resets and automatically extracts the upper layer of heat transfer oil in the sealed space. After the heat transfer oil is extracted from the sealed space, it is heated and then sprayed and impacted again through thermal expansion. This process is repeated until the upper and lower layers of heat transfer oil in the sealed space are uniformly heated, so that the thin wafer can be uniformly heated.

[0034] The heating wire 300 can be placed and fixed in any position within the lower plate 200 without the need for center positioning. By heating the heat transfer oil in the storage space, the thin wafer is heated evenly, preventing warping or stress cracking caused by localized overheating. Furthermore, the heating wire 300 is easy to replace. When the heat transfer oil expands within the sealed space, it pushes the piston plate 503 vertically upward to a preset position. The expanded heat transfer oil autonomously sprays into the lower layer of the storage space. The sprayed heat transfer oil impacts the lower layer of heat transfer oil in the storage space, thus... Multiple ceramic tubes 501 are installed so that the sprayed heat transfer oil can effectively impact the lower layer of heat transfer oil in the storage space from all directions, forcing the lower layer of heat transfer oil in the storage space to flow with each other, which is conducive to heat convection and accelerates the uniform heating of the lower layer of heat transfer oil in the storage space. When the heat transfer oil in the sealed space is depressurized, the piston plate 503 resets and automatically extracts the upper layer of heat transfer oil in the sealed space. After the heat transfer oil is extracted from the sealed space, it is heated immediately, and then sprayed and impacted through thermal expansion to accelerate the uniform heating of the upper and lower layers of heat transfer oil.

[0035] like Figure 2 , Figure 5 and Figure 7 As shown, optionally, a copper base 500 is coaxially fixedly connected to the bottom end of the ceramic tube 501. The copper base 500 is fixedly installed in the hole opened at the bottom end of the tray 400. The size of the copper base 500 matches the size of the hole. The sealed space formed by the bottom end of the piston plate 503, the side wall of the ceramic tube 501 and the upper end of the copper base 500 is filled with heat-conducting oil.

[0036] In this embodiment, multiple copper bases 500 are evenly distributed and installed in the holes opened at the bottom of the tray 400. Since the bottom of the tray 400 presses the heating wire 300, the heat generated when the heating wire 300 is energized will not only be transferred to the bottom of the tray 400, but also to the multiple copper bases 500. Since the thermal conductivity of copper is much greater than that of the ceramic material tray 400, the copper bases 500 will be heated in a short time and transfer the heat to the heat-conducting oil filled in the sealed space. The heat-conducting oil absorbs a large amount of heat in a short time and expands, pushing the piston plate 503 to move vertically upward.

[0037] like Figure 2 , Figure 7 and Figure 8 As shown, optionally, the outer side of the piston plate 503 is slidably connected to the inner side wall of the ceramic tube 501, and a second spring 504 is fixedly connected to the middle of the bottom end of the piston plate 503. The bottom end of the second spring 504 is fixedly connected to the middle of the end face of the copper base 500. Multiple uniformly distributed and through first microholes 505 are opened in the circumferential direction along the axis of the inner side wall of the ceramic tube 501.

[0038] In this embodiment, when the heating wire 300 is energized, the copper base 500 is heated in a short time. The heat is transferred to the heat-conducting oil in the sealed space. The heat-conducting oil absorbs a large amount of heat in a short time and expands, pushing the piston plate 503 to move vertically upward. At the same time, it stretches the second spring 504. When the piston plate 503 moves upward to the preset position, that is, when the piston plate 503 moves upward to the position above the first micro-hole 505, the sealed space at the lower end of the piston plate 503 is connected to the multiple first micro-holes 505. The storage space is connected to the outside, so the heat transfer oil in the sealed space, under high pressure, is autonomously sprayed into the lower layer of heat transfer oil in the storage space through multiple first micro-holes 505. This effectively impacts the lower layer of heat transfer oil in all directions, forcing it to flow between layers, which is beneficial for heat convection and accelerates the uniform heating of the lower layer of heat transfer oil. When the heat transfer oil in the sealed space is depressurized, the piston plate 503 moves vertically downward and resets under the restoring deformation pull of the second spring 504. Here, the piston plate 503 is made of high-temperature resistant ceramic material, the sealing ring sleeved on the outside of the piston plate 503 is made of silicone boron rubber, and the second spring 504 is made of nickel-based alloy material, all of which have high-temperature resistance properties.

[0039] like Figure 7 and Figure 8 As shown, optionally, an oil inlet pipe 600 is fixedly installed in the middle of the piston plate 503, the lower end of the oil inlet pipe 600 is located in a closed space, a one-way valve 601 is fixedly installed on the lower end of the oil inlet pipe 600, the oil inlet pipe 600 is slidably connected to the middle of the upper end of the ceramic tube 501, and a limit ring 502 is coaxially fixed on the inner side wall of the ceramic tube 501.

[0040] In this embodiment, the piston plate 503 is initially located at the upper end of the limiting ring 502. When the heat transfer oil in the sealed space is heated and expands, it pushes the piston plate 503 upward and reaches the preset position. Then, the heat transfer oil is sprayed to release pressure. After the heat transfer oil in the sealed space is released, the piston plate 503 moves vertically downward under the pull of the second spring 504 to recover its deformation. When the piston plate 503 moves downward to the upper end of the limiting ring 502, it is limited. At this time, the piston plate 503 cannot continue to move downward. Since the amount of heat transfer oil in the sealed space is very small at this time, a negative pressure will be generated in the sealed space. This will drive the upper end of the oil inlet pipe 600 to automatically extract the upper layer of heat transfer oil in the storage space, so that the heat transfer oil can automatically fill the sealed space, so as to facilitate thermal expansion and spraying again, and accelerate the uniform heating of the upper and lower layers of heat transfer oil in the storage space. Here, the one-way valve 601 ensures that the oil inlet pipe 600 can deliver oil into the sealed space but cannot discharge oil.

[0041] like Figure 7 and Figure 8As shown, optionally, a fixing plate 700 is provided at the upper end of the first microhole 505, and a lifting plate 701 is provided at the upper end of the fixing plate 700. The outer side of the fixing plate 700 is fixed to the inner side wall of the ceramic tube 501, and the outer side of the lifting plate 701 is slidably connected to the inner side wall of the ceramic tube 501. Multiple evenly distributed and through second microholes 703 are opened in the inner circumferential direction of the side wall of the ceramic tube 501. The second microholes 703 are located between the upper end of the fixing plate 700 and the bottom end of the lifting plate 701. A third spring 702 is fastened between the middle of the upper end of the fixing plate 700 and the middle of the bottom end of the lifting plate 701.

[0042] In this embodiment, after the heat transfer oil in the storage space is uniformly heated, the oil expands due to heat, causing the pressure to rise. The expanded oil then enters the space between the upper middle part of the fixed plate 700 and the bottom end of the lifting plate 701 through the second micro-hole 703. As the oil pressure increases, it pushes the lifting plate 701 to move vertically upwards, increasing the volume of the storage space to store the expanded heat transfer oil. Multiple ceramic tubes 501 store the expanded oil in the storage space, dispersing the pressure within the space. By reserving expansion space, the oil overflows after heating.

[0043] like Figure 7 and Figure 8 As shown, optionally, the lower end of the ceramic tube 501 is formed with a tapered section, and the bottom end of the tapered section of the ceramic tube 501 is fixed to the upper surface of the copper base 500.

[0044] In this embodiment, the copper base 500 is connected to the straight section of the ceramic tube 501 through the tapered part of the ceramic tube 501. Since the inner diameter of the straight section of the ceramic tube 501 is smaller than the diameter of the copper base 500, the expansion of the heat transfer oil in the sealed space is accelerated by the large-area heat conduction of the copper base 500.

[0045] like Figure 1 and Figure 2 As shown, optionally, a locking ring 101 is fixedly provided at the lower end of the outer periphery of the upper plate 100, and the locking ring 101 is fastened to the upper end of the lower plate 200 by a plurality of bolts 102.

[0046] In this embodiment, multiple bolts 102 facilitate the disassembly or assembly of the upper plate 100 and the lower plate 200.

[0047] like Figure 2 and Figure 3 As shown, optionally, the outer ring is formed on the outer periphery of the tray 400, and a plurality of evenly distributed first springs 401 are fixedly provided on the bottom end of the outer ring along the circumferential direction. The inner ring is formed on the inner side of the upper plate body 100, and the bottom end of the first springs 401 is fixed on the upper end face of the inner ring. The outer ring of the tray 400 is slidably connected to the inner side of the upper plate body 100.

[0048] In this embodiment, when the upper plate 100 and the lower plate 200 are installed together, the bottom end of the tray 400 presses against the upper end of the heating wire 300. At this time, the first spring 401 is in an upward-stretched state, and the heating wire 300 can be placed in any position. Here, the sealing ring sleeved on the outer ring of the tray 400 is made of boron rubber, and the first spring 401 is made of nickel-based alloy material.

[0049] like Figure 3 As shown, optionally, both ends of the heating wire 300 are provided with wiring terminals for electrical connection to an external power source.

[0050] In this embodiment, the heating wire 300 is energized by an external power source and wiring terminals. Since this is existing technology, it will not be described in detail.

[0051] like Figure 1-8 As shown, a method for preparing a ceramic heating plate, based on the above-mentioned ceramic heating plate, includes the following steps:

[0052] S1: The upper plate 100, lower plate 200, tray 400, ceramic tube 501 and piston plate 503 are made by sintering. The piston plate 503 has an annular groove on its outer periphery. Then the sealing ring is installed in the annular groove. Next, the piston plate 503 is installed inside the ceramic tube 501 and the lower end is filled with heat transfer oil. Then multiple ceramic tubes 501 are fixed to the bottom of the tray 400 by brazing.

[0053] S2: Next, the tray 400 is installed inside the upper plate body 100, and the storage space between the upper plate body 100 and the tray 400 is filled with heat-conducting oil.

[0054] S3: Next, place the heating wire 300 on the inner bottom surface of the lower plate 200. The heating wire 300 has wiring terminals at both ends. Then, install the upper plate 100 and the lower plate 200 together. During installation, press the bottom of the tray 400 against the top of the heating wire 300.

[0055] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A ceramic heating plate, characterized in that, The device includes an upper plate (100), a lower plate (200), a heating wire (300), a tray (400), ceramic tubes (501), and a piston plate (503). The tray (400) is located inside the upper plate (100), and the heating wire (300) is located inside the lower plate (200). When the upper plate (100) and the lower plate (200) are installed together, the bottom end of the tray (400) is driven to press the heating wire (300) against the upper plate (100). A plurality of ceramic tubes (501) are evenly arranged inside the tray (400). The storage space formed between them is filled with heat-conducting oil. The piston plate (503) is set inside the ceramic tube (501). The sealed space formed by its bottom end and the side wall of the ceramic tube (501) is filled with heat-conducting oil. When the heat-conducting oil in the sealed space is in an expanded state, it drives the piston plate (503) to move vertically upward. When the piston plate (503) moves upward to a preset position, the heat-conducting oil in the expanded state is automatically sprayed into the lower layer of the storage space. When the heat-conducting oil in the sealed space is depressurized, the piston plate (503) is reset and the upper layer of heat-conducting oil in the sealed space is automatically extracted.

2. A ceramic heating plate as described in claim 1, characterized in that, The bottom end of the ceramic tube (501) is coaxially fixedly connected to a copper base (500). The copper base (500) is fixedly installed in the hole opened at the bottom end of the tray (400). The size of the copper base (500) matches the size of the hole. The sealed space formed by the bottom end of the piston plate (503), the side wall of the ceramic tube (501) and the upper end of the copper base (500) is filled with heat-conducting oil.

3. A ceramic heating plate as described in claim 1, characterized in that, The piston plate (503) is slidably connected to the inner wall of the ceramic tube (501) on the outside. A second spring (504) is fixedly connected to the middle of the bottom end of the piston plate (503). The bottom end of the second spring (504) is fixedly connected to the middle of the end face of the copper base (500). Multiple uniformly distributed and through first microholes (505) are opened in the circumferential direction along the axis of the inner wall of the ceramic tube (501).

4. A ceramic heating plate as described in claim 1, characterized in that, An oil inlet pipe (600) is fixedly installed in the middle of the piston plate (503). The lower end of the oil inlet pipe (600) is located in a sealed space. A one-way valve (601) is fixedly installed on the lower end of the oil inlet pipe (600). The oil inlet pipe (600) is slidably connected to the middle of the upper end of the ceramic tube (501). A limiting ring (502) is coaxially fixed on the inner wall of the ceramic tube (501).

5. A ceramic heating plate as described in claim 3, characterized in that, A fixing plate (700) is provided at the upper end of the first microhole (505), and a lifting plate (701) is provided at the upper end of the fixing plate (700). The outer side of the fixing plate (700) is fixed to the inner side wall of the ceramic tube (501). The outer side of the lifting plate (701) is slidably connected to the inner side wall of the ceramic tube (501). A plurality of evenly distributed and through second microholes (703) are opened in the inner circumferential direction of the side wall of the ceramic tube (501). The second microholes (703) are located between the upper end of the fixing plate (700) and the bottom end of the lifting plate (701). A third spring (702) is fastened between the middle of the upper end of the fixing plate (700) and the middle of the bottom end of the lifting plate (701).

6. A ceramic heating plate as described in claim 2, characterized in that, The lower end of the ceramic tube (501) is formed with a tapered section, and the bottom end of the tapered section of the ceramic tube (501) is fixed to the upper end face of the copper base (500).

7. A ceramic heating plate as described in claim 1, characterized in that, A locking ring (101) is fixedly provided at the lower end of the outer periphery of the upper plate (100), and the locking ring (101) is fastened to the upper end of the lower plate (200) by a plurality of bolts (102).

8. A ceramic heating plate as described in claim 1, characterized in that, The tray (400) has an outer ring formed on its outer periphery. Multiple evenly distributed first springs (401) are fixed at the bottom of the outer ring along the circumferential direction. The upper plate (100) has an inner ring formed on its inner side. The bottom of the first springs (401) is fixed on the upper end face of the inner ring. The outer ring of the tray (400) is slidably connected to the inner side of the upper plate (100).

9. A ceramic heating plate as described in claim 1, characterized in that, Both ends of the heating wire (300) have terminals for electrical connection to an external power source.

10. A method for preparing a ceramic heating plate, based on a ceramic heating plate as described in any one of claims 1-9, characterized in that, The steps are as follows: S1: The upper plate (100), lower plate (200), tray (400), ceramic tube (501) and piston plate (503) are made by sintering. The piston plate (503) has an annular groove on its outer periphery. Then, the sealing ring is installed in the annular groove. Next, the piston plate (503) is installed inside the ceramic tube (501) and the lower end is filled with heat transfer oil. Then, multiple ceramic tubes (501) are fixed to the bottom of the tray (400) by brazing. S2: Next, install the tray (400) inside the upper plate body (100), and fill the storage space between the upper plate body (100) and the tray (400) with heat transfer oil; S3: Next, place the heating wire (300) on the bottom surface of the lower plate (200). The heating wire (300) has terminals at both ends. Then, install the upper plate (100) and the lower plate (200) together. During installation, press the bottom of the tray (400) against the top of the heating wire (300).

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