1. A method for preparing a heating element is characterized by comprising the following steps:

placing a heating element green body in a sintering device, placing at least three pre-sintered support pieces around the heating element green body to support a plate positioned above the heating element green body, placing the sintering device in an inert protective atmosphere, and sintering the heating element green body, wherein the heating element green body is an aluminum nitride ceramic green body containing a circuit layer;

the composition of the support piece is the same as that of the heating element green body, the pre-sintering temperature of the support piece is (T-100 ℃) to T, T is the sintering reaction temperature of aluminum nitride and a sintering aid, the thickness of the support piece is 0.2mm to 1mm larger than that of the heating element green body, and the plate is used for pressurizing the heating element green body in the sintering process.

2. A heat-generating body production method as described in claim 1, characterized in that the sintering aid is Y₂O₃、CaO、Er₂O₃、Yb₂O₃、Sm₂O₃、Dy₂O₃、Li₂O、B₂O₃、CaF₂、YF₃And CaC₂At least one of (1).

3. A heat-generating body preparation method as described in claim 2, characterized in that the pre-firing temperature of the support is 1400 ℃ to 1600 ℃ for 1.5h to 10 h.

4. A heat-generating body production method as described in claim 1, characterized in that the plate is a tungsten steel plate, the thickness of which is 5mm to 10mm, and the flatness is 0.01mm to 0.03 mm.

5. A heating element production method as described in claim 1, characterized in that the temperature for sintering said heating element green body is 1700 ℃ to 1900 ℃ for 1.5h to 8 h.

6. A heating body production method as described in claim 1, characterized in that said sintering device is a tungsten crucible or a boron nitride crucible.

7. A heat-generating body production method as described in claim 1, characterized in that the heat-generating body green body has a diameter of 265mm to 385mm and a thickness of 6mm to 24 mm.

8. A heating element production method as described in any one of claims 1 to 7, characterized in that the heating element green body production method comprises the steps of:

s100: preparing aluminum nitride ceramic slurry to form a ceramic green tape;

s200: printing metal slurry on the ceramic green tape to form a circuit;

s300: and (3) laminating and pressing the ceramic green ceramic tape.

9. A heating element produced by the production method as claimed in any one of claims 1 to 8.

10. Use of the heat-generating body according to claim 9 as a wafer heating apparatus.

Background

In semiconductor processing, bonding, debonding, etching, or deposition are generally performed on a wafer surface through various physical or chemical methods. In the above processing steps and processing equipment, a ceramic heating element is generally used to heat a silicon wafer, and the temperature uniformity of the ceramic heating element directly affects the processing quality of the wafer and ultimately affects the performance and yield of chips.

With the development of large-scale integrated circuits, high-power modules and LEDs, in order to further improve packaging efficiency, reduce cost and expand application area, wafers for manufacturing chips tend to use large-sized wafers such as 8 inches and 12 inches. In order to meet the requirements of large-size wafer packaging quality and yield, the industry needs to provide a corresponding large-size and high-quality ceramic heating body to meet the requirements of a heat treatment process in the processing process.

At present, the most commonly used ceramic heating element in the semiconductor packaging equipment industry is an aluminum nitride ceramic heating plate. The aluminum nitride ceramic heating plate is usually prepared by printing high-temperature metal such as W, Mo or Mo-Mn and the like into a circuit by adopting a screen printing thick film technology and a ceramic-metal high-temperature co-firing technology, and packaging the circuit into a multilayer aluminum nitride ceramic by the high-temperature co-firing technology to form a heating circuit. However, the aluminum nitride ceramic heating plate is usually sintered by adopting a liquid phase sintering mode at a temperature of over 1800 ℃, a liquid phase generated by the reaction of a sintering aid and aluminum oxide on the surface of aluminum nitride powder migrates at a high temperature, and factors such as the temperature in a hearth, the uniformity of the carbon content in the blank after binder removal, the gas flow around the blank and the like may cause the uneven distribution of the liquid phase in the blank, so that stress is generated in the blank, and the warping deformation of the aluminum nitride ceramic heating plate after sintering is caused. In addition, the sintering shrinkage of the aluminum nitride ceramic and the printing metal paste is difficult to be completely consistent, and sintering stress is generated between the two phases to cause deformation.

In order to avoid the above problems, there is a method of ensuring flatness of a large-sized ceramic substrate by performing a secondary sintering correction or a primary sintering-followed polishing process to meet the use requirements. However, for the aluminum nitride ceramic heating element, the secondary sintering correction method, i.e. the secondary sintering, will result in the growth of aluminum nitride ceramic grains, thereby reducing the bending strength and thermal conductivity of the product, and also resulting in the decrease of the equipment utilization rate and the increase of the labor and energy costs. The process cost of the aluminum nitride ceramic heating element with higher cost is higher, and the large-scale production and the market popularization of the product are not facilitated.

The grinding method after one-time sintering is to eliminate the surface unevenness by flat grinding or grinding after the aluminum nitride ceramic substrate is sintered, which needs to reserve a certain grinding allowance for the product, thereby increasing the production and material cost of the product. More importantly, for the aluminum nitride co-fired ceramic heating element, although the surface flatness of the product can meet the requirement by simply utilizing the post-grinding processing, the distances between the positions of all points of the printed circuit layer and the surface are often inconsistent, and the temperature uniformity of all points is difficult to meet the use requirement finally.

Disclosure of Invention

Based on the above, the invention provides a preparation method of the heating element, and the heating element prepared by the method has high flatness and thermal conductivity.

A method for preparing a heating element comprises the following steps:

placing a heating element green body in a sintering device, placing at least three pre-sintered support pieces around the heating element green body to support a plate positioned above the heating element green body, placing the sintering device in an inert protective atmosphere, and sintering the heating element green body, wherein the heating element green body is an aluminum nitride ceramic green body containing a circuit layer;

the composition of the support piece is the same as that of the heating element green body, the pre-sintering temperature of the support piece is (T-100 ℃) to T, T is the sintering reaction temperature of aluminum nitride and a sintering aid, the thickness of the support piece is 0.2mm to 1mm larger than that of the heating element green body, and the plate is used for pressurizing the heating element green body in the sintering process.

Optionally, in the above method for preparing a heating element, the sintering aid is Y₂O₃、CaO、Er₂O₃、Yb₂O₃、Sm₂O₃、Dy₂O₃、Li₂O、B₂O₃、CaF₂、YF₃And CaC₂At least one of (1).

Optionally, in the preparation method of the heating element, the pre-sintering temperature of the support is 1400-1600 ℃ and the time is 1.5-10 h.

Optionally, in the above method for manufacturing a heating element, the plate is a tungsten steel plate, the thickness of the tungsten steel plate is 5mm to 10mm, and the flatness of the tungsten steel plate is 0.01mm to 0.03 mm.

Optionally, in the preparation method of the heating element, the sintering temperature of the heating element green body is 1700-1900 ℃, and the time is 1.5-8 h.

Optionally, in the above method for preparing a heating element, the sintering device is a tungsten crucible or a boron nitride crucible.

Optionally, in the preparation method of the heating element, the diameter of the heating element green body is 265-385 mm, and the thickness is 6-24 mm.

Optionally, in the method for preparing a heating element, the method for preparing the heating element green body includes the following steps:

s100: preparing aluminum nitride ceramic slurry to form a ceramic green tape;

s200: printing metal slurry on the ceramic green tape to form a circuit;

s300: and (3) laminating and pressing the ceramic green ceramic tape.

In another aspect of the present invention, there is further provided a heating element produced by the above production method.

In another aspect of the invention, the heating element is used as a wafer heating device.

According to research, the heating element green body is not enough in initial strength and is easy to deform and even crack when being pressurized at a low sintering temperature in the pressurizing and sintering process. When the sintering temperature is higher, deformation and warpage also occur, and the green body strength is improved, so that the green body is difficult to flatten in the subsequent heating and sintering process. In addition, the high temperature for a long time can cause the growth of ceramic crystal grains and the reduction of thermal conductivity. And the pressureless sintering state of the heating element green body before (T-100 ℃) to T can be ensured by controlling the material quality, the pre-sintering temperature and the height of the support piece. Along with the rise of the sintering temperature, when the temperature is within (T-100 ℃) to T, the aluminum nitride in the supporting piece and the heating element green compact reacts with the sintering aid and starts to densify, and because the plate is arranged above the supporting piece, the supporting piece has a faster sintering shrinkage rate in the thickness direction compared with the heating element green compact under the action of the self-weight pressure of the plate, so that the plate can be pressed on the heating element green compact, and the purpose of one-time pressure sintering is achieved.

According to the invention, the large-size ceramic heating element is prepared by adjusting the supporting piece and the sintering temperature thereof and combining the plate through one-time pressure sintering, and the heating element prepared by the process is relatively flat, has high thermal conductivity and can meet the requirements of the large-size wafer packaging process.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic front perspective view of a sintering apparatus used in one embodiment of the present invention in positional relationship to a support and a plate;

in the figure: 1-a sintering device; 2-a support; 3-plate material.

Detailed Description

Reference will now be made in detail to embodiments of the invention, one or more examples of which are described below. Each example is provided by way of explanation, not limitation, of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used on another embodiment to yield a still further embodiment.

It is therefore intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. Other objects, features and aspects of the present invention are disclosed in or are apparent from the following detailed description. It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Other than as shown in the operating examples, or where otherwise indicated, all numbers expressing quantities of ingredients, physical and chemical properties, and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about". For example, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can be suitably varied by those skilled in the art in seeking to obtain the desired properties utilizing the teachings disclosed herein. The use of numerical ranges by endpoints includes all numbers within that range and any range within that range, for example, 1 to 5 includes 1, 1.1, 1.3, 1.5, 2, 2.75, 3, 3.80, 4, and 5, and the like.

A method for preparing a heating element comprises the following steps:

placing the heating element green compact in a sintering device, placing at least three pre-sintered support pieces around the heating element green compact to support a plate above the heating element green compact, placing the sintering device in an inert protective atmosphere, and sintering the heating element green compact, wherein the heating element green compact is an aluminum nitride ceramic green compact containing a circuit layer;

the composition of the support piece is the same as that of the heating element green body, the pre-sintering temperature of the support piece is (T-100 ℃) to T, T is the sintering reaction temperature of the aluminum nitride and the sintering aid, the thickness of the support piece is 0.2mm to 1mm larger than that of the heating element green body, and the plate is used for pressurizing the heating element green body in the sintering process.

The support piece and the heating body green body are controlled to be consistent in composition, so that the support piece and the heating body green body can be ensured to have the same shrinkage rate in the same state, and after a plate is placed on the support piece, the plate can be ensured to have a faster shrinkage rate under the self-gravity action of the plate, so that the plate can apply pressure to the heating body green body.

In some embodiments, the sintering aid may be any one of the sintering aids commonly used in the art, and may be, for example, a rare earth oxide, an alkali metal oxide, a non-metal oxide, a carbide, or a fluoride. Wherein the rare earth oxide can be Y₂O₃、Er₂O₃、Yb₂O₃、Sm₂O₃、Dy₂O₃And the like. The alkali metal oxide may be Li₂And O. The non-metal oxide can be B₂O₃. The carbide may be CaC₂. The fluoride may be CaF₂、YF₃And the like.

In some embodiments, the pre-sintering temperature of the support is 1400-1600 ℃ and the time is 1.5-10 h, and the pre-sintering temperature can be 1450 ℃, 1500 ℃, 1550 ℃ and the like.

In some embodiments, the thickness of the support member is larger than the thickness of the heat-generating body green body by 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9 mm.

In some embodiments, the shape of the support is not limited to being able to support a plate, including but not limited to a cylinder, a regular prism, or an irregular prism. Preferably, the support is a regular prism. More preferably, the support member is a rectangular parallelepiped. Still more preferably, the length and width of the support member are independently selected from 15mm to 45 mm.

In some embodiments, the number of supports can be 3, 4, 5, 6, etc.

In some embodiments, the plate may be any material resistant to high temperatures of 2000 ℃, and in view of cost, the plate used in the present invention is preferably a tungsten steel plate, wherein the tungsten steel plate has a thickness of 5mm to 10mm and a flatness of 0.01mm to 0.03 mm. In such a thickness range, the tungsten steel plate material can be applied with a pressure required for the heating element green body. The flatness of the heating body green body can be further ensured by controlling the flatness of the plate.

In some embodiments, the shape of the plate may be a cylinder, a regular prism, or an irregular prism. The regular prism may be a regular prism, for example, a rectangular parallelepiped, a cube, a regular pentagonal prism, a regular hexagonal prism, a regular octagonal prism, or a regular dodecagonal prism. Preferably, the plate is cylindrical in shape.

In some embodiments, the size of the plate material is not limited to the one capable of pressing the heat-generating body green body, and for example, the plate material may have a diameter of 305mm to 475mm and a thickness of 5mm to 10 mm.

In some embodiments, the temperature for sintering the green heating element is 1700 ℃ to 1900 ℃ for 1.5h to 8 h.

In some embodiments, the sintering apparatus is a tungsten crucible or a boron nitride crucible.

In some embodiments, the heat-generating body green compact has a diameter of 265mm to 385mm and a thickness of 6mm to 24 mm.

In some embodiments, the method for producing the heat-generating body green body may be any one commonly used in the art, and preferably, the method for producing the heat-generating body green body includes the steps of:

s100: preparing aluminum nitride ceramic slurry to form a ceramic green tape;

s200: printing metal slurry on the ceramic green tape to form a circuit;

s300: and (3) laminating and pressing the ceramic green ceramic tape.

In some embodiments, the printing method in step S200 may be screen printing, and the metal paste has a composition of W, Mo and at least one of Mo — Mn.

In some embodiments, the number of circuit layers is not limited, and may be one or more, for example, 1 layer, 2 layers, 4 layers, 6 layers, 7 layers, 9 layers, 10 layers, and the like. Preferably, the thickness of each layer of printed circuit is between 15 μm and 30 μm.

In some embodiments, the method of press forming in step S300 is at least one of hot-press lamination and warm isostatic-press lamination. Preferably, the molding method is hot-press lamination and warm isostatic-press lamination.

In some embodiments, the hot-pressed stack has a pressure of 10MPa to 30MPa, a temperature of 40 ℃ to 80 ℃ and a time of 5min to 60 min.

In some embodiments, the warm isostatic pressing stack has a pressure of 40MPa to 80MPa, a temperature of 60 ℃ to 80 ℃, and a time of 5min to 60 min.

In some embodiments, the inert protective atmosphere comprises a helium atmosphere, a nitrogen atmosphere, an argon atmosphere, and the like.

In another aspect of the present invention, there is further provided a heating element produced by the above production method.

In another aspect of the invention, the heating element is used as a wafer heating device.

The heat-generating body of the present invention, the production method and the use thereof are explained in further detail below with reference to specific examples and comparative examples.

Example 1

FIG. 1 is a schematic front perspective view showing the positional relationship between a sintering apparatus used for producing an aluminum nitride ceramic heating element, a support and a plate in this example. In this embodiment, the sintering apparatus 1 is a boron nitride crucible, the support 2 is pre-sintered at 1500 ℃ for 2h, and the plate 3 is a tungsten steel plate.

1) Preparation of aluminum nitride ceramic heating element green body

Taking aluminum nitride ceramic slurry to prepare a ceramic green tape by tape casting, wherein 3.5 wt% of Y is added into the aluminum nitride slurry₂O₃Is a sintering aid. By passingThe silk-screen printing technology prints tungsten metal slurry on a ceramic green ceramic tape and dries the ceramic green ceramic tape to form a circuit, and the printed green ceramic tape is superposed in an up-and-down contraposition mode, wherein the interior of the green ceramic tape comprises 6 layers of printed circuits. And then, carrying out hot pressing on the laminated multilayer ceramic green tape at the temperature of 65 ℃ for 45min under the pressure of 20MPa, then carrying out isostatic pressing at the temperature of 60 ℃ and 60 ℃ for 35min for forming, and processing to prepare an aluminum nitride ceramic heating body green body with the diameter of 265mm and the thickness of 15 mm.

2) Preparation of aluminium nitride ceramic heating body

And 3 leftover materials left in the cutting process are taken out and placed in a sintering furnace at 1500 ℃ for pre-sintering for 2 hours after glue discharging, 3 supporting pieces 2 with the length and width of 20mm and the thickness of 15.2mm are formed, then the supporting pieces 2 are placed in a boron nitride crucible, and tungsten steel plates with the diameter of 320mm, the thickness of 10mm and the flatness of 0.015mm are placed on the supporting pieces 2. Then placing the aluminum nitride ceramic heating element green body in the step 1) under a tungsten steel plate, covering a crucible cover, placing a boron nitride crucible in a vacuum atmosphere sintering furnace, carrying out nitrogen sintering at 1800 ℃ for 2h, and starting pressurizing the heating element green body at 1500-1600 ℃ in the sintering process to prepare the aluminum nitride ceramic heating element. The obtained aluminum nitride ceramic heating element was subjected to warpage amount and thermal conductivity test, and the test results are shown in table 1.

Example 2

The support 2 in this example was prefired at 1550 c for 2 h.

1) Preparation of aluminum nitride ceramic heating element green body

Taking aluminum nitride ceramic slurry to prepare a ceramic green tape by tape casting, wherein 5 wt% of Y is added into the aluminum nitride slurry₂O₃Is a sintering aid. The tungsten metal slurry is printed on a ceramic green ceramic tape by a screen printing process and dried to form a circuit, and the printed green ceramic tape is superposed in an up-and-down contraposition mode, wherein the interior of the green ceramic tape comprises 4 layers of printed circuits. And then, carrying out hot pressing on the laminated multilayer ceramic green tape at the temperature of 70 ℃ and the pressure of 15MPa for 60min, then carrying out isostatic pressing at the temperature of 70 ℃ and the pressure of 80MPa for 25min for molding, and processing to prepare an aluminum nitride ceramic heating body green body with the diameter of 300mm and the thickness of 10 mm.

2) Preparation of aluminium nitride ceramic heating body

And 4 leftover materials left in the cutting process are taken out and placed in a sintering furnace at 1550 ℃ for presintering for 2 hours to form 4 supporting pieces 2 with the length and the width of 30mm and the thickness of 10.5 mm. It was then placed in a boron nitride crucible and a tungsten steel plate having a diameter of 380mm, a thickness of 6mm and a flatness of 0.02mm was placed on the support 2. And then placing the aluminum nitride ceramic heating element green body in the step 1) below a tungsten steel plate, covering a crucible cover, placing a boron nitride crucible in a vacuum atmosphere sintering furnace, carrying out nitrogen sintering at 1750 ℃ for 4h, and starting pressurizing the heating element green body at the tungsten steel plate of 1500-1600 ℃ in the sintering process to prepare the aluminum nitride ceramic heating element. The obtained aluminum nitride ceramic heating element was subjected to warpage amount and thermal conductivity test, and the test results are shown in table 1.

Example 3

In the embodiment, the support member 2 is preburnt at 1600 ℃ for 2 h.

1) Preparation of aluminum nitride ceramic heating element green body

Taking aluminum nitride ceramic slurry to prepare a ceramic green tape by tape casting, wherein 4 wt% of Y is added into the aluminum nitride slurry₂O₃Is a sintering aid. The tungsten metal slurry is printed on a ceramic green ceramic tape by a screen printing process and dried to form a circuit, and the printed green ceramic tape is superposed in an up-and-down contraposition mode, wherein the interior of the green ceramic tape contains 2 layers of printed circuits. And then, carrying out hot pressing on the laminated multilayer ceramic green tape at 75 ℃ for 60min under 12MPa, then carrying out isostatic pressing at 80 ℃ and 80 ℃ for 20min for forming, and processing to prepare an aluminum nitride ceramic heating body green body with the diameter of 360mm and the thickness of 6 mm.

2) Preparation of aluminium nitride ceramic heating body

And taking 5 leftover materials left in the cutting process, discharging the rubber, and placing the leftover materials in a sintering furnace at 1600 ℃ for presintering for 2h to form 5 supporting pieces 2 with the length of 30mm, the width of 20mm and the thickness of 6.8 mm. It was then placed in a boron nitride crucible and a tungsten steel plate having a diameter of 440mm, a thickness of 10mm and a flatness of 0.025mm was placed on the support 2. And then placing the aluminum nitride ceramic heating element green body in the step 1) below a tungsten steel plate, covering a crucible cover, placing a boron nitride crucible in a vacuum atmosphere sintering furnace, carrying out nitrogen sintering at 1780 ℃ for 2h, and starting pressurizing the heating element green body at 1500-1600 ℃ in the sintering process to prepare the aluminum nitride ceramic heating element. The obtained aluminum nitride ceramic heating element was subjected to warpage amount and thermal conductivity test, and the test results are shown in table 1.

Example 4

In this example, the sintering apparatus 1 is a tungsten crucible, and the supporter 2 is pre-sintered at 1500 ℃ for 4 hours.

1) Preparation of aluminum nitride ceramic heating element green body

Taking aluminum nitride ceramic slurry to prepare a ceramic green tape by tape casting, wherein 5 wt% of Li is added into the aluminum nitride slurry₂And O is a sintering aid. The tungsten metal slurry is printed on a ceramic green ceramic tape through a screen printing process and dried to form a circuit, and the printed green ceramic tape is superposed in an up-and-down contraposition mode, wherein the interior of the green ceramic tape comprises 6 layers of printed circuits. And then, carrying out hot pressing on the laminated multilayer ceramic green tape at the temperature of 50 ℃ for 15min under the pressure of 28MPa, then carrying out isostatic pressing at the temperature of 80 ℃ and the pressure of 80MPa for 20min for forming, and processing to prepare an aluminum nitride ceramic heating body green compact with the diameter of 385mm and the thickness of 24 mm.

2) Preparation of aluminium nitride ceramic heating body

Taking 6 leftover materials left in the cutting process, removing glue, placing the leftover materials in a 1500 ℃ sintering furnace for presintering for 4 hours to form 6 supporting pieces 2 with the length and width of 20mm and the thickness of 25mm, then placing the supporting pieces in a tungsten crucible, placing tungsten steel plates with the diameter of 440mm, the thickness of 10mm and the flatness of 0.015mm on the supporting pieces 2, then placing green bodies of the aluminum nitride ceramic heating bodies in the step 1) below the tungsten steel plates, placing the tungsten crucible in a vacuum atmosphere sintering furnace after covering a crucible cover, performing nitrogen sintering for 6 hours at 1650 ℃, and starting pressurizing the green bodies at 1500-1600 ℃ on the tungsten steel plates in the sintering process to prepare the aluminum nitride ceramic heating bodies. The obtained aluminum nitride ceramic heating element was subjected to warpage amount and thermal conductivity test, and the test results are shown in table 1.

Example 5

In this example, the sintering apparatus 1 is a tungsten crucible, and the supporter 2 is prefired at 1550 ℃ for 6 hours.

1) Preparation of aluminum nitride ceramic heating element green body

Taking aluminum nitride ceramic slurry to prepare a ceramic green tape by tape casting, wherein 3 wt% of YF is added into the aluminum nitride slurry₃Is a sintering aid. The tungsten metal slurry is printed on a ceramic green ceramic tape through a screen printing process and dried to form a circuit, and the printed green ceramic tape is superposed in an up-and-down contraposition mode, wherein the interior of the green ceramic tape comprises 6 layers of printed circuits. And then, carrying out hot pressing on the laminated multilayer ceramic green tape at 24MPa and 60 ℃ for 30min, then carrying out isostatic pressing at 50MPa and 60 ℃ for 50min for forming, and processing to prepare an aluminum nitride ceramic heating body green body with the diameter of 320mm and the thickness of 20 mm.

2) Preparation of aluminium nitride ceramic heating body

And 4 leftover materials left in the cutting process are taken out and placed in a sintering furnace at 1550 ℃ for pre-sintering for 6 hours to form 4 supporting pieces 2 with the length and the width of 20mm and the thickness of 20.4 mm. Then placing the aluminum nitride ceramic heating element into a tungsten crucible, placing a tungsten steel plate with the diameter of 380mm, the thickness of 6mm and the flatness of 0.015mm on a support 2, then placing the aluminum nitride ceramic heating element green body in the step 1) under the tungsten steel plate, covering a crucible cover, placing the tungsten crucible into a vacuum atmosphere sintering furnace, carrying out nitrogen sintering at 1750 ℃ for 4h, and starting pressurizing the heating element green body at 1500-1600 ℃ in the sintering process to prepare the aluminum nitride ceramic heating element. The obtained aluminum nitride ceramic heating element was subjected to warpage amount and thermal conductivity test, and the test results are shown in table 1.

Comparative example 1

Comparative example 1 was prepared substantially the same as example 1, except that: the sintering device 1 used has no support 2 and no plate 3 placed therein. The method comprises the following specific steps:

1) preparation of aluminum nitride ceramic heating element green body

Taking aluminum nitride ceramic slurry to prepare a ceramic green tape by tape casting, wherein 3.5 wt% of Y is added into the aluminum nitride slurry₂O₃Is a sintering aid. The tungsten metal slurry is printed on a ceramic green ceramic tape through a screen printing process and dried to form a circuit, and the printed green ceramic tape is superposed in an up-and-down contraposition mode, wherein the interior of the green ceramic tape comprises 6 layers of printed circuits. Then stack theThe laminated multilayer ceramic green ceramic tape is hot pressed for 45min at the temperature of 65 ℃ under the pressure of 20MPa, then is pressed for 35min at the temperature of 60MPa and 60 ℃ by isostatic pressing, and is processed to prepare an aluminum nitride ceramic heating body green body with the diameter of 265mm and the thickness of 15 mm.

2) Preparation of aluminium nitride ceramic heating body

Placing the aluminum nitride ceramic heating element green body obtained in the step 1) in a boron nitride crucible, covering the crucible cover, placing the boron nitride crucible in a vacuum atmosphere sintering furnace, and performing nitrogen sintering at 1800 ℃ for 2 hours to prepare the aluminum nitride ceramic heating element. The obtained aluminum nitride ceramic heating element was subjected to warpage amount and thermal conductivity test, and the test results are shown in table 1.

Comparative example 2

Comparative example 2 was prepared substantially the same as example 1, except that: the thickness of the support 2 is 18 mm. The method comprises the following specific steps:

1) preparation of aluminum nitride ceramic heating element green body

Taking aluminum nitride ceramic slurry to prepare a ceramic green tape by tape casting, wherein 3.5 wt% of Y is added into the aluminum nitride slurry₂O₃Is a sintering aid. The tungsten metal slurry is printed on a ceramic green ceramic tape through a screen printing process and dried to form a circuit, and the printed green ceramic tape is superposed in an up-and-down contraposition mode, wherein the interior of the green ceramic tape comprises 6 layers of printed circuits. And then, carrying out hot pressing on the laminated multilayer ceramic green tape at the temperature of 65 ℃ for 45min under the pressure of 20MPa, then carrying out isostatic pressing at the temperature of 60 ℃ and 60 ℃ for 35min for forming, and processing to prepare an aluminum nitride ceramic heating body green body with the diameter of 265mm and the thickness of 15 mm.

2) Preparation of aluminium nitride ceramic heating body

And taking 3 leftover materials left in the cutting process, discharging the rubber, placing the leftover materials in a sintering furnace at 1500 ℃ for presintering for 2 hours to form 3 supporting pieces 2 with the length and width of 20mm and the thickness of 18 mm. Then placing the heating element blank into a boron nitride crucible, placing a tungsten steel plate with the diameter of 320mm, the thickness of 10mm and the flatness of 0.015mm on a support 2, then placing the aluminum nitride ceramic heating element blank in the step 1) under the tungsten steel plate, covering the crucible cover, placing the boron nitride crucible into a vacuum atmosphere sintering furnace, carrying out nitrogen sintering at 1800 ℃ for 2h, and starting to pressurize the heating element blank by the tungsten steel plate above 1750 ℃ in the sintering process to prepare the aluminum nitride ceramic heating element. The obtained aluminum nitride ceramic heating element was subjected to warpage amount and thermal conductivity test, and the test results are shown in table 1.

TABLE 1 test of performance of aluminum nitride ceramic heater

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.