CN114754585A

CN114754585A - Sintering equipment

Info

Publication number: CN114754585A
Application number: CN202210422134.7A
Authority: CN
Inventors: 叶华; 丁培军; 刘红义; 王厚工; 赵佳彬; 史全宇
Original assignee: Beijing Naura Microelectronics Equipment Co Ltd
Current assignee: Beijing Naura Microelectronics Equipment Co Ltd
Priority date: 2022-04-21
Filing date: 2022-04-21
Publication date: 2022-07-15
Anticipated expiration: 2042-04-21
Also published as: CN114754585B; TW202342927A

Abstract

The invention provides a sintering device which comprises an inner shell, an outer shell and a heating device, wherein the outer shell is arranged around the inner shell at intervals; the heating device is arranged between the outer shell and the inner shell and is used for heating the inner shell and the inner part of the inner shell; the inner shell body is enclosed to form a closed space for accommodating the piece to be sintered, the inner shell body is made of a compact material capable of avoiding generation of particles, and gas in the closed space can be isolated from gas outside the inner shell body. The sintering equipment provided by the invention can solve the problems that a large amount of particles and external gas are generated to influence a sintering process in the prior art and the like.

Description

Sintering equipment

Technical Field

The invention relates to the field of semiconductor manufacturing, in particular to sintering equipment.

Background

Electrostatic chucks, which are used to attract a workpiece such as a wafer or a tray in a semiconductor process, are widely used in processes of deposition, etching, ion implantation, and the like. The electrostatic chuck usually has one or more metal electrodes, and a dielectric layer is wrapped outside the metal electrodes, and the material of the dielectric layer can be glass or ceramic, wherein silicate glass has very good pressure resistance and is opposite to Al ₂O₃And AlN and other traditional ceramic materials can be manufactured in a printing and sintering mode, and the manufacturing mode can realize the accurate control of the thickness of the dielectric layer, so that the consistency of the adsorption force and the radio frequency efficiency of the electrostatic chuck can be ensured.

However, in the existing sintering equipment, a process space for accommodating a part to be sintered (such as silicate glass) is generally surrounded by refractory bricks, and since the surfaces of the refractory bricks are loose, a peeling phenomenon is easy to occur, so that a large amount of particles are generated, especially after process gas is introduced into the process space, airflow can carry a large amount of particles to flow in the process space, and part of the particles finally fall on the part to be sintered, so that the process result is often influenced when the part to be sintered is put into use.

In addition, as the process space (formed by the gaps between the refractory bricks) surrounded by the refractory bricks is communicated with the outside atmosphere, the outside gas can penetrate through the refractory bricks to enter the process space when the existing sintering equipment carries out the process, and the moisture or other components in the outside gas can influence the sintering process.

Disclosure of Invention

The invention aims to solve at least one technical problem in the prior art, and provides sintering equipment which can solve the problems that a large number of particles are generated and external gas influences a sintering process in the prior art.

The sintering equipment comprises an inner shell, an outer shell and a heating device, wherein the outer shell is arranged around the inner shell at intervals; the heating device is arranged between the outer shell and the inner shell and is used for heating the inner shell and the interior of the inner shell;

the inner shell is enclosed into a closed space for accommodating a piece to be sintered, and the inner shell is provided with an air inlet and an air outlet which are communicated with the closed space; the material of interior casing is the compactness material that can avoid the granule to produce, and can with gas in the confined space with the gas outside the interior casing is kept apart.

Optionally, the material of the inner casing includes quartz or silicon carbide.

Optionally, the sintering equipment further comprises a pressure control device, wherein the pressure control device is connected with the air inlet and the air outlet, or connected with the air inlet, and is used for controlling the air pressure of the closed space.

Optionally, the pressure control device includes an air inlet pipeline, an air exhaust pipeline, an air pump and a process gas source, wherein,

the two ends of the air inlet pipeline are respectively connected with the air inlet and the process gas source, and a first flow control device is arranged on the air inlet pipeline; the process gas source is used for introducing process gas into the closed space through the gas inlet pipeline;

Two ends of the exhaust pipeline are respectively communicated with the exhaust port and the air suction pump, and a second flow control device is arranged on the exhaust pipeline; the air pump is used for pumping the gas in the closed space through the exhaust pipeline.

Optionally, the pressure control device comprises an air inlet pipeline and a process gas source, wherein,

the two ends of the air inlet pipeline are respectively connected with the air inlet and the process gas source, and a first flow control device is arranged on the air inlet pipeline; the process gas source is used for introducing process gas into the closed space through the gas inlet pipe;

the exhaust port is in communication with an external atmosphere.

Optionally, the number of the gas inlets is two, and the process gas source includes an oxygen source and an inert gas source;

the number of the air inlet pipelines is two, and two ends of one air inlet pipeline are respectively communicated with one air inlet and the oxygen source; two ends of the other air inlet pipeline are respectively communicated with the other air inlet and the inert gas source; and the two air inlet pipelines are provided with the first flow control devices.

Optionally, the air inlet pipeline is further provided with a pressure regulating valve, and the pressure regulating valve is located at the upstream of the first flow control device.

Optionally, a filter is further disposed on the air intake pipeline, and the filter is configured to filter particles in the air intake pipeline.

Optionally, the air pump includes a variable frequency pump, and the air pumping speed can be adjusted by the variable frequency pump.

Optionally, the heating device includes heating members, and the heating members are circumferentially and uniformly arranged along the inner shell.

Optionally, the heating device further includes a temperature detection unit and a control unit, wherein the temperature detection unit is configured to detect a temperature in the enclosed space and send the temperature to the control unit;

the control unit is electrically connected with the heating component and is used for controlling the heating power of the heating component according to the temperature.

Optionally, the heating component includes a plurality of sub-heating components, and the plurality of sub-heating components correspond to a plurality of different areas partitioned in the enclosed space;

each region is correspondingly provided with at least one temperature detection unit, and the temperature detection unit is used for detecting the temperature in the region and sending the temperature to the control unit;

the control unit is electrically connected with the plurality of sub-heating parts and is used for controlling the heating power of the sub-heating parts of the corresponding area according to the temperature detected by the temperature detection unit corresponding to each area.

Optionally, a heat insulation member is disposed between the outer casing and the inner casing, and the heat insulation member surrounds the inner casing and is located outside the heating device.

Optionally, the heat insulating member includes at least one of aluminum silicate and asbestos.

The invention has the following beneficial effects:

the sintering equipment provided by the invention comprises an inner shell and an outer shell, wherein the inner shell is enclosed to form a closed space for accommodating a piece to be sintered, and the material of the inner shell has higher compactness compared with the prior art, so that the material with high compactness is not easy to peel off, thereby avoiding the generation of particles, further avoiding the generation of a large number of particles during a sintering process, and further reducing or avoiding the possibility that the particles fall on the piece to be sintered to influence a process result; meanwhile, the inner shell is made of high-compactness materials, and gas in the closed space can be isolated from gas outside the inner shell, so that the gas outside the inner shell can be prevented from entering the closed space to influence the sintering process.

Drawings

FIG. 1 is a schematic diagram of an electrostatic chuck;

FIG. 2 is a side view of a sintering apparatus of the prior art;

FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2;

FIG. 4A is a side view of a sintering apparatus according to an embodiment of the present invention;

FIG. 4B is a cross-sectional view taken along line B-B of FIG. 4A;

FIG. 5A is another cross-sectional view taken along line B-B of FIG. 4A;

FIG. 5B is a schematic structural diagram of the pressure control device shown in FIG. 5A;

fig. 6 is a sectional view of another sintering apparatus according to an embodiment of the present invention.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the following provides a detailed description of the sintering apparatus provided by the present invention with reference to the accompanying drawings.

An electrostatic chuck is used for adsorbing a processed object such as a wafer or a tray in a semiconductor process, and generally has one or more metal electrodes, and a dielectric layer is wrapped outside the metal electrodes, for example, a bipolar electrostatic chuck shown in fig. 1, which includes two electrodes 11 and a dielectric layer 12 wrapped outside the two electrodes 11, wherein the two electrodes 11 are both connected to a dc power supply, and the dc power supply is used for applying a dc voltage to the two electrodes 11 to adsorb the processed object such as a wafer or a tray onto the dielectric layer 12 through electrostatic attraction. In addition, bumps 121 are disposed on the dielectric layer 12 for reducing a contact area between the wafer 13 and the dielectric layer 12, so as to reduce particle contamination on the wafer 13. The material of the bump 121 may be the same as or different from that of the dielectric layer 12.

In practical applications, increasing the dc voltage U applied to the electrode 11, decreasing the thickness d of the dielectric layer 12 is a key means for increasing the adhesion force, and the ratio U/d of the dc voltage to the thickness represents the dielectric strength of the dielectric layer 12. When the dielectric strength of the dielectric layer 12 cannot meet the requirement, the dielectric layer 12 may break down, which results in abnormal adsorption force, abnormal use of the electrostatic chuck, and even wafer damage, so that the dielectric strength of the dielectric layer 12 is generally selected to be higher as better as possible without affecting other properties in selecting materials of the dielectric layer 12. Based on the above, the silicate glass has high dielectric strength, has very good pressure resistance, and is relatively Al₂O₃And AlN and other traditional ceramic materials can be manufactured in a printing and sintering mode, and the manufacturing mode can realize the accurate control of the thickness of the dielectric layer, so that the consistency of the adsorption force and the radio frequency efficiency of the electrostatic chuck can be ensured.

Fig. 2 is a side view of a sintering apparatus of the related art. Fig. 3 is a sectional view taken along line a-a of fig. 2. Referring to fig. 2 and 3, a conventional sintering apparatus 2 for sintering glass ceramic (e.g., silicate glass) includes a metal casing 21, a cover (not shown) is disposed on the metal casing 21, a process space 23 enclosed by a refractory brick wall 22 is disposed inside the metal casing 21, and the refractory brick wall 22 is used for heat preservation and insulation. Furthermore, a heating pipe 24, which may be a silicon-molybdenum rod, is disposed in the process space 23 for heating the process space 23; a thermocouple 25 is also arranged in the process space 23 and used for detecting the temperature of the process space 23 and sending the temperature to a control unit 26; the control unit 26 is adapted to control the heating power of the heating tube 24 based on the detected temperature. Furthermore, in order to ensure that the process space 23 has sufficient oxygen during the sintering process, compressed air can be supplied into the process space 23 by means of an inlet line 27.

However, since the surface of the firebrick cavity 22 is loose, the spalling phenomenon is easy to occur, which causes a large amount of particles to be generated, especially in the case of supplying compressed air into the process space 23, the airflow carries a large amount of particles to flow in the process space 23, part of the particles finally fall on the piece to be sintered, and the process result is often influenced when the piece to be sintered is put into use. Taking the part to be sintered as silicate glass as an example, if a large number of particles enter the silicate glass, the voltage resistance of the silicate glass is greatly reduced, and the electrostatic chuck is easily broken down at high voltage, so that the electrostatic chuck cannot be used normally.

In addition, since the process space 23 (formed by the refractory brick walls 22) is communicated with the outside atmosphere (the metal shell 21 is communicated with the outside atmosphere), the existing sintering equipment 2 can only be applied to normal pressure sintering, the pressure in the space is not controllable, the applicable sintering process is limited, and the outside air can penetrate through the refractory brick walls 22 to enter the process space 23 during the process, and the moisture or other components in the outside air may affect the sintering process.

In order to solve at least one of the above technical problems, referring to fig. 4A and fig. 4B, an embodiment of the present invention provides a sintering apparatus 3, which can be applied to a component requiring sintering in a semiconductor processing apparatus, such as a dielectric layer in an electrostatic chuck, wherein the dielectric layer is silicate glass.

The sintering apparatus 3 comprises an outer casing 31, an inner casing 33, a heating device 35 and a pressure control device 39, wherein the outer casing 31 may be, for example, a metal casing, and the outer casing 31 may be, for example, a box, and the cross-sectional shape thereof along the line B-B in fig. 4A may be square, rectangular, circular, etc. The outer shell 31 has an opening and a cover (not shown) for opening or closing the opening, and the piece to be sintered can be moved into or out of the outer shell 31 when the cover is opened; the cover body and the outer shell 31 can be sealed through a sealing ring or other sealing structures to seal the opening and ensure that the inside of the outer shell 31 is isolated from the outside. However, the embodiment of the present invention is not limited to this, and in practical applications, the inside of the outer casing 31 may be communicated with the outside according to different requirements, in this case, the cover and the outer casing 31 may not be provided with a sealing structure or the gap between the cover and the outer casing 31 may be filled with a heat insulating material such as asbestos, and in addition, the outside of the outer casing 31 may be coated with a heat insulating material to reduce heat loss, improve heating efficiency, and prevent the outside ambient temperature from affecting the temperature inside the heat insulating member 32.

Furthermore, the outer shell 31 surrounds the inner shell 33 at intervals, i.e. there is an annular space 34 between the outer shell 31 and the inner shell 33, and a heating device 35 is arranged in this annular space 34 for heating the inner shell 33 and its interior for the sintering process of the piece to be sintered. In some alternative embodiments, as shown in fig. 4B, a heat insulation member 32 is further disposed in the annular space 34, and the heat insulation member 32 surrounds the inner casing 33 and is located outside the heating device 35 for heat preservation and insulation, so that heat loss can be reduced, heating efficiency can be improved, and the external environment temperature can be prevented from affecting the temperature inside the heat insulation member 32. The heat insulating member 32 includes, for example, at least one of aluminum silicate and asbestos.

The inner shell 33 encloses a closed space 36 for accommodating the piece to be sintered, the cross-sectional shape of the inner shell 33 along the line B-B in fig. 4A may be the same as or different from the cross-sectional shape of the outer shell 31 along the line B-B in fig. 4A, and the volume of the closed space 36 should be larger than the volume of the piece to be sintered, so as to ensure that the piece to be sintered can be accommodated. The inner casing 33 also has an opening for the movement of the to-be-sintered member into and out of, which opening is provided in correspondence with the opening of the outer casing 31 described above, and after the to-be-sintered member is moved into the closed space 36 via the opening, a cover may be additionally provided to open or close the opening, and a sealing structure such as a gasket or the like may be provided on the cover to seal the opening on the inner casing 33, so as to ensure that the closed space 36 is isolated from the outside of the inner casing 33, i.e., that external gas does not enter the closed space 36 from the opening.

Furthermore, the inner housing 33 has gas inlets and gas outlets communicating with the enclosed space 36, in practical applications, the number of gas inlets is the same as the number of types of process gases, for example, and different types of process gases can correspondingly enter the enclosed space 36 from different gas inlets, for example, two gas inlets and one gas outlet are shown in fig. 4B, and the specific positions are shown by arrows in fig. 4B, for example. The material of the inner case 33 is dense enough to avoid the generation of particles, and the gas in the closed space 36 can be isolated from the gas outside the inner case 33. Compared with the prior art (such as a refractory brick wall), the material of the inner shell 33 has higher compactness, and the material with high compactness is not easy to peel off, so that the generation of particles can be avoided, further, the generation of a large number of particles during the sintering process can be avoided, and further, the possibility that the particles fall on the to-be-sintered piece to influence the process result is reduced or avoided; meanwhile, the inner shell 33 is made of a high-density material, and the gas in the closed space 36 can be isolated from the gas outside the inner shell 33, so that the gas outside the inner shell 33 can be prevented from entering the closed space 36 to influence the sintering process.

In alternative embodiments, the material of the inner housing 33 includes quartz or silicon carbide. Both of the two materials have high compactness, which does not generate particles, and can realize gas isolation on the inner side and the outer side of the inner shell 33, that is, external gas cannot penetrate through quartz or silicon carbide to enter the inner part of the inner shell 33, but the embodiment of the invention is not limited to this, and in practical application, other high-compactness materials which can not generate particles and can realize gas isolation on the inner side and the outer side of the inner shell 33 can be adopted.

Specifically, when the inner casing 33 is made of silicon carbide, since the heating device 35 is located outside the inner casing 33, the generated heat can heat the inner casing 33 made of silicon carbide by thermal convection and thermal radiation, and then the inner casing 33 can conduct the heat to the workpiece to be sintered in the closed space 36 by thermal convection and thermal radiation. When the inner casing 33 is made of quartz, the inner casing 33 made of quartz can be heated by the heat generated by the heating device 35 through thermal convection and thermal radiation, and then the inner casing 33 conducts the heat to the to-be-sintered member in the closed space 36 through thermal convection and thermal radiation, and at the same time, the heat generated by the heating device 35 can also be directly radiated to the to-be-sintered member in the closed space 36 through the quartz, so the inner casing 33 made of quartz has higher heating efficiency relative to silicon carbide, but the silicon carbide has better heat resistance than the quartz, therefore, the inner casing 33 made of quartz or silicon carbide can be selected according to sintering processes at different temperatures, for example, when the working temperature is below 1200 ℃, the inner casing 33 can be made of quartz, and when the working temperature is above 1200 ℃, the inner casing 33 can be made of silicon carbide.

In some optional embodiments, on the basis that the material of the inner casing 33 can isolate the gas in the enclosed space 36 from the gas outside the inner casing 33, as shown in fig. 5A and 5B, the sintering apparatus provided in the embodiments of the present invention may further include a pressure control device 39, and the pressure control device 39 is connected to the gas inlet and the gas outlet, or only connected to the gas inlet, and is used for controlling the gas pressure in the enclosed space 36.

On the basis that the high-compactness inner shell 3 is used for isolating the gas in the closed space 36 from the gas outside the inner shell 33, the pressure control device 39 can be connected with the gas inlet and the gas outlet or only connected with the gas inlet to control the gas pressure of the closed space 36 so as to meet the requirements of different sintering processes on the gas pressure.

For example, the pressure control device 39 may be used to control the pressure of the enclosed space 36 to be about one atmosphere, or the enclosed space 36 may be in a vacuum state, so as to meet the requirements of different sintering processes on the pressure.

In some alternative embodiments, the pressure control device 39 is connected to the air inlet and the air outlet of the inner housing 33, so as to control the air pressure of the enclosed space 36 by controlling the air flow at the air inlet and the air outlet, respectively. Specifically, as shown in fig. 5B, the pressure control device 39 includes a gas inlet line 391, a gas outlet line 397, a gas pump 398 and a process gas source, wherein the process gas source includes an oxygen source 392 and an inert gas source 393, correspondingly, two gas inlets of the inner housing 33 are provided, and two gas inlet lines 391 are provided, wherein two ends of one gas inlet line 391 are respectively communicated with one of the gas inlets and the oxygen source 392; two ends of the other air inlet pipeline 391 are respectively communicated with the other air inlet and the inert gas source 393; a first flow control device 394 is disposed on each of the two air inlet lines 391 for controlling the air flow of the air inlet lines 391 to control the air pressure of the enclosed space 36. The first flow control device 394 is, for example, a gas Mass Flow Controller (MFC).

Oxygen source 392 is operable to supply oxygen to enclosed space 36 via inlet line 391. Taking the part to be sintered as silicate glass as an example, oxygen can react with the silicate glass to generate Al during the sintering process ₂O₃The crystals, which contribute greatly to the increase in the pressure resistance of the silicate glass, can be used to increase the Al content by introducing sufficient oxygen into the closed space 36 during the sintering process₂O₃The ratio of the silicate glass to the glass can improve the pressure resistance of the silicate glass.

The inert gas source 393 is used for introducing inert gas into the closed space 36 through the gas inlet pipeline 391, the inert gas and oxygen are introduced into the closed space 36 at a certain proportion simultaneously in the process of sintering process, the inert gas does not participate in reaction, and the proportion of the inert gas and the oxygen is satisfied as follows: under the premise that enough oxygen is introduced into the closed space 36, the air pressure of the closed space 36 reaches a preset air pressure value. The inert gas is, for example, nitrogen.

It should be noted that, in practical applications, the number and the type of the process gas sources may be adaptively designed according to different sintering processes, and the number of the gas inlets and the gas inlet pipes, etc. may be adjusted accordingly, for example, only an oxygen source may be provided to introduce pure oxygen into the enclosed space 36, in this case, the gas inlets and the gas inlet pipes are both one, which is not particularly limited in the embodiment of the present invention.

As shown in fig. 5B, both ends of the exhaust pipe 397 are respectively communicated with the exhaust port and the air pump 398, and a second flow control device 399 is provided on the exhaust pipe 397 to control the gas flow rate of the exhaust pipe 397, which may be combined with the first flow control device 394 to control the gas pressure of the closed space 36. The second flow control device 399 is, for example, a flow regulating valve. A suction pump 398 is used to draw gas from the enclosed space 36 through a discharge line 397.

In practical applications, the corresponding kind of the suction pump 398 may be selected according to different requirements for the vacuum degree of the enclosed space 36, and the suction pump 398 may be, for example, a molecular pump, a vacuum pump, or the like. In some alternative embodiments, the air pump 398 may be a variable frequency pump, which can adjust the air pumping speed, and besides adjusting the air flow of the air inlet line 391 by using the first flow control device 394 and adjusting the air flow of the air outlet line 397 by using the second flow control device 399, the air pressure of the enclosed space 36 can be controlled by adjusting the air pumping speed of the variable frequency pump, and in practical applications, these three adjusting manners can be freely combined according to specific needs, for example, by simultaneously controlling the air flow of the air inlet line 391 and the air pumping speed of the variable frequency pump (and/or the air flow of the air outlet line 397), the air flow flowing into the enclosed space 36 can be made to be consistent with the air flow flowing out from the enclosed space 36, and the air pressure of the enclosed space 36 is dynamically balanced, on the basis of this, if the air pressure of the enclosed space 36 is desired to be increased, the method can be realized by increasing the gas flow of the gas inlet pipeline 391 or reducing the pumping speed of the variable frequency pump (and/or the gas flow of the gas outlet pipeline 397); conversely, if it is desired to reduce the pressure in the enclosed space 36, this can be accomplished by reducing the flow rate of the air in the inlet line 391 or by increasing the pumping speed of the inverter pump (and/or the flow rate of the air in the outlet line 397). Thus, the pressure of the enclosed space 36 can be controlled to an operating pressure of from several mTorr to several hundred Torr, thereby meeting the pressure requirements of different sintering processes.

In some optional embodiments, in order to ensure the stability of the pressure at the front end of the first flow control device 394, a pressure regulating valve 395 is further disposed on the air inlet pipeline 391, and the pressure regulating valve 395 is located upstream of the first flow control device 394 and is used for regulating the pressure at the front end of the first flow control device 394 in the air inlet pipeline 391, so that the control accuracy of the first flow control device 394 can be improved.

In some alternative embodiments, in order to prevent particles from being mixed into the process gas, the inlet line 391 is further provided with a filter 396, and the filter 396 is used for filtering particles in the inlet line 391, so that the introduction of particles from the inlet line into the closed space 36 can be avoided.

In other alternative embodiments, as shown in fig. 6, the embodiment of the present invention further provides a sintering apparatus 3' which is different from the sintering apparatus 3 shown in fig. 5B only in that: the pressure control device 39' is connected to the inlet of the inner housing 33 and not to the outlet, which is connected to the external atmosphere. In this case, the pressure control device 39' controls the pressure of the enclosed space 36 by controlling the flow rate of the gas at the gas inlet. In order to communicate the exhaust port with the external atmosphere, an exhaust structure such as an exhaust line may be provided.

Specifically, the pressure control device 39' includes an air inlet pipeline and a process gas source, which have the same structure and function as the air inlet pipeline and the process gas source in the pressure control device 39, and are used for introducing process gas (such as pure oxygen or a certain proportion of oxygen and inert gas) into the enclosed space 36, which are not described in detail herein.

This pressure control device 39' eliminates the need for an exhaust line and an air pump, as compared to the pressure control device 39 described above and shown in fig. 5B. In this case, the first flow control device 394 can be used to control the flow of the gas in the gas inlet line 391 to control the pressure of the enclosed space 36 within a range greater than the atmospheric pressure, so that the enclosed space 36 forms a micro-positive pressure environment, which can effectively prevent the gas outside the inner housing 33 from entering the enclosed space 36 through the gas outlet, and thus ensure that the gas in the enclosed space 36 is relatively pure even if the enclosed space 36 is communicated with the atmospheric environment.

In some alternative embodiments, in order to improve the uniformity of the heating temperature, the heating device 35 includes heating elements which are circumferentially arranged and uniformly arranged along the inner shell 33, so as to ensure that the inner shell 33 and the inside thereof are uniformly heated in the circumferential direction of the inner shell 33. The heating member is, for example, a heating tube or a heating wire, etc.

In some optional embodiments, in order to improve the automation and accuracy of the temperature control, the heating device 35 further comprises a temperature detection unit 37 and a control unit 38, wherein the temperature detection unit 37 is configured to detect the temperature in the enclosed space 36 and send the temperature to the control unit 38; the temperature detection unit 37 is, for example, a thermocouple. The control unit 38 is electrically connected to the heating member for controlling the heating power of the heating member to increase or decrease the temperature in the enclosed space 36 based on the sensed temperature. The control unit 38 is, for example, a controller.

In some alternative embodiments, to further improve the heating temperature uniformity and the flexibility of temperature control, the heating member includes a plurality of sub-heating members, and the plurality of sub-heating members correspond to a plurality of different areas divided in the enclosed space 36; at least one temperature detection unit 37 is provided corresponding to each zone, and the at least one temperature detection unit 37 corresponding to each zone is used for detecting the temperature in the zone and sending the temperature to the control unit 38; the control unit 38 is electrically connected to the plurality of sub heating members, and is configured to independently control the heating power of the sub heating members of the corresponding zones according to the temperature detected by the temperature detection unit 37 corresponding to each zone. The plurality of different regions in the closed space 36 may be sequentially divided, for example, along a first axis which is an axis of the inner housing 33 perpendicular to a section along a line B-B in fig. 4A; and/or divided in sequence in the circumferential direction of the inner housing 33. Of course, in practical applications, the dividing manner of the multiple different areas may also adopt any other manner, and this is not particularly limited in the embodiment of the present invention.

In summary, the sintering apparatus provided by the embodiment of the present invention includes an inner casing and an outer casing, the inner casing encloses a closed space for accommodating a to-be-sintered member, and the material of the inner casing has higher compactness compared with the prior art, and the material with high compactness is not easy to peel off, so that generation of particles can be avoided, generation of a large amount of particles during a sintering process can be avoided, and a possibility that the particles fall on the to-be-sintered member to affect a process result is reduced or avoided; meanwhile, the inner shell is made of high-compactness materials, and gas in the closed space can be isolated from gas outside the inner shell, so that the gas outside the inner shell can be prevented from entering the closed space to influence the sintering process.

It will be understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principles of the present invention, and the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and scope of the invention, and such modifications and improvements are also considered to be within the scope of the invention.

Claims

1. A sintering apparatus comprising an inner casing, an outer casing and heating means, wherein the outer casing is spaced around the inner casing; the heating device is arranged between the outer shell and the inner shell and is used for heating the inner shell and the interior of the inner shell;

The inner shell is enclosed into a closed space for accommodating a piece to be sintered, and the inner shell is provided with an air inlet and an air outlet which are communicated with the closed space; the inner shell is made of a compact material capable of avoiding particle generation, and can isolate gas in the closed space from gas outside the inner shell.

2. Sintering equipment as claimed in claim 1, characterized in that the material of the inner casing comprises quartz or silicon carbide.

3. The sintering apparatus according to claim 1, further comprising a pressure control device connected to the gas inlet and the gas outlet or to the gas inlet for controlling the gas pressure of the enclosed space.

4. Sintering plant according to claim 3, characterized in that the pressure control means comprise an inlet line, an outlet line, a suction pump and a source of process gas, wherein,

5. Sintering equipment as claimed in claim 3 or characterized in that the pressure-controlling means comprise a gas inlet line and a source of process gas, wherein,

the exhaust port is in communication with the external atmosphere.

6. The sintering apparatus according to claim 4 or 5, wherein the number of the gas inlets is two, and the process gas source includes an oxygen gas source and an inert gas source;

7. The sintering apparatus as claimed in claim 4 or 5, characterized in that the air inlet pipeline is further provided with a pressure regulating valve, and the pressure regulating valve is located upstream of the first flow control device.

8. Sintering equipment as claimed in claim 4 or 5, characterized in that a filter is arranged on the air inlet line and is used for filtering particles in the air inlet line.

9. Sintering equipment as claimed in claim 4, characterized in that the suction pump comprises a variable-frequency pump, which is capable of adjusting the suction speed.

10. The sintering apparatus according to claim 1, wherein the heating device includes heating members that are circumferentially and uniformly arranged along the inner housing.

11. The sintering apparatus according to claim 10, wherein the heating device further comprises a temperature detection unit and a control unit, wherein the temperature detection unit is configured to detect a temperature in the enclosed space and send the temperature to the control unit;

12. The sintering apparatus as claimed in claim 11, wherein the heating means includes a plurality of sub-heating means corresponding to a plurality of different areas divided in the enclosed space;

the control unit is electrically connected with the plurality of sub-heating components and is used for controlling the heating power of the sub-heating components of the corresponding areas according to the temperature detected by the temperature detection unit corresponding to each area.

13. The sintering apparatus according to claim 1, wherein a heat insulating member is provided between the outer casing and the inner casing, the heat insulating member surrounding the inner casing and located outside the heating device.

14. The sintering apparatus of claim 13, wherein the thermal insulation member comprises at least one of aluminum silicate and asbestos.