Hot-pressing sintering device for producing silicon carbide ceramic base

Abstract

The utility model discloses a kind of hot-pressing sintering devices for silicon carbide ceramic pedestal production, including furnace shell, ring mould is installed in furnace shell inner cavity middle part, graphite heating sheet and furnace lining are sequentially arranged in the periphery of ring mould, graphite heating sheet and furnace lining are annular structure;The upper die of upper lift is equipped on the ring mould, the lower die of lower lift is equipped below ring mould;Multiple core rods are installed on the lower die, core rod is arranged along vertical direction, and the bottom of core rod is fixedly connected in the lower die, and the bottom of upper die is equipped with the hole for the top end of core rod to enter. The utility model provides a kind of hot-pressing sintering devices for silicon carbide ceramic pedestal production, can make silicon carbide ceramic pedestal be sintered into shape by bidirectional pressure at high temperature, shorten process step, and improve the thermal conductivity, wear resistance and mechanical properties of pedestal.

Description

Technical Field

[0001] This utility model relates to a hot pressing sintering device for the production of silicon carbide ceramic bases, belonging to the field of vacuum chuck production technology. Background Technology

[0002] In the semiconductor manufacturing industry, wafer processing and handling require highly precise and stable support tools, which led to the development of wafer vacuum chucks.

[0003] The structure of a vacuum chuck mainly consists of two parts: a porous base in the middle and a sealing ring at the edge. During operation, the air between the wafer and the base surface is extracted through small holes in the porous base, creating a low pressure between the wafer and the base surface. Due to the air pressure, the wafer is adsorbed onto the chuck surface, thus fixing the wafer in place.

[0004] Currently, the base of the vacuum chuck is formed by pressureless sintering of silicon carbide ceramic material. After the base is formed, it still needs to go through complicated and tedious processes such as processing pores. At the same time, the base also has certain disadvantages, such as low thermal conductivity, poor wear resistance and poor mechanical properties.

[0005] In conclusion, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Utility Model Content

[0006] To address the shortcomings of the prior art, this utility model provides a hot pressing sintering device for the production of silicon carbide ceramic substrates. This device enables silicon carbide ceramic substrates to be sintered and formed under bidirectional pressure at high temperatures, shortening the process steps and improving the thermal conductivity, wear resistance, and mechanical properties of the substrates.

[0007] To solve the above technical problems, the present invention adopts the following technical solution:

[0008] A hot pressing sintering apparatus for producing silicon carbide ceramic substrates includes a furnace shell, an annular mold installed in the center of the furnace shell cavity, and graphite heating plates and a furnace lining arranged sequentially around the annular mold, both of which are annular structures; an upper mold that can be raised and lowered is provided above the annular mold, and a lower mold that can be raised and lowered is provided below the annular mold; multiple mandrels are installed on the lower mold, the mandrels are arranged vertically, and the bottom of the mandrels are fixed inside the lower mold; the bottom of the upper mold is provided with a clearance hole for the top of the mandrels to enter.

[0009] Furthermore, the furnace shell is fixed above the frame, and a pressure cap is installed on the top of the furnace shell. The pressure cap is connected to the frame by multiple telescopic cylinders arranged in the vertical direction, and the telescopic cylinders are distributed around the furnace shell.

[0010] Furthermore, both the upper and lower molds are cylindrical structures, and the upper and lower molds are slidably connected to the inner wall of the ring mold.

[0011] Furthermore, the ring mold, upper mold, and lower mold are all made of graphite.

[0012] Furthermore, a vacuum connector connected to the inner cavity of the furnace shell is installed on the furnace shell.

[0013] Furthermore, the furnace shell is composed of two shells, an inner and an outer shell, with a closed cavity formed between the two shells, and a cooling water connector is installed on the outer wall of the cavity.

[0014] Furthermore, the upper mold is fixed to the bottom of the pressure plate, the pressure plate is connected to the head of the upper hydraulic cylinder, and the cylinder body of the upper hydraulic cylinder is fixed to the pressure cover.

[0015] Furthermore, the lower mold is fixedly connected to the support plate, the support plate is connected to the head of the lower hydraulic cylinder, and the cylinder body of the lower hydraulic cylinder is fixedly connected to the machine frame.

[0016] Furthermore, guide rods are provided on both sides of the upper and lower hydraulic cylinders.

[0017] Compared with the prior art, the present invention, by adopting the above technical solution, has the following advantages:

[0018] This invention utilizes graphite heating plates to heat the raw material powder to below its melting point. The upper and lower molds simultaneously apply axial pressure under the action of a hydraulic cylinder to promote powder sintering. During the hot pressing sintering process, due to the interaction of high temperature and high pressure, the contact, diffusion and flow between particles can be increased, accelerating the rearrangement and densification of the material during the sintering process. The thermal conductivity, wear resistance and mechanical properties of the hot pressing base are significantly improved.

[0019] During the hot pressing sintering process, the mandrel is set through the raw material powder. After the silicon carbide ceramic base is formed, through holes can be formed inside to avoid the subsequent processing of pores, which can shorten the process steps.

[0020] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model;

[0022] Figure 2 This is a schematic diagram of the internal structure of this utility model;

[0023] Figure 3 This is a schematic diagram showing the distribution of the ring die, upper die, and lower die.

[0024] In the figure, 1-ring mold, 2-graphite heating plate, 3-furnace lining, 4-furnace shell, 5-frame, 6-pressure cover, 7-telescopic cylinder, 8-vacuum connector, 9-cooling water connector, 10-upper mold, 11-pressure plate, 12-upper hydraulic cylinder, 13-lower mold, 14-support plate, 15-lower hydraulic cylinder, 16-core rod, 17-avoidance hole, 18-raw material powder. Detailed Implementation

[0025] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model are now described with reference to the accompanying drawings.

[0026] like Figures 1-3 As shown in the figure, this utility model provides a hot pressing sintering device for the production of silicon carbide ceramic bases, including a furnace shell 4, which is fixedly connected to the top of the frame 5. A pressure cover 6 is installed on the top of the furnace shell 4. The pressure cover 6 is connected to the frame 5 by a plurality of telescopic cylinders 7 arranged in the vertical direction. The telescopic cylinders 7 are distributed around the furnace shell 4 to provide power for the raising or lowering of the pressure cover 6.

[0027] A ring mold 1 is installed in the middle of the inner cavity of the furnace shell 4. Graphite heating elements 2 and furnace lining 3 are arranged sequentially around the ring mold 1. Both graphite heating elements 2 and furnace lining 3 are annular structures. The furnace lining 3 is used to reduce the heat radiation loss of the graphite heating elements 2, improve thermal efficiency, and protect the furnace shell 4.

[0028] The ring mold 1 is provided with a liftable upper mold 10 above it and a liftable lower mold 13 below it. Both the upper mold 10 and the lower mold 13 are cylindrical structures and are slidably connected to the inner wall of the ring mold 1.

[0029] The ring mold 1, upper mold 10, and lower mold 13 are all made of graphite.

[0030] Multiple mandrels 16 are mounted on the lower mold 13. The mandrels 16 are arranged vertically, and their bottoms are fixed inside the lower mold 13. The bottom of the upper mold 10 is provided with clearance holes 17 for the tops of the mandrels 16 to enter. The mandrels 16 are used to form through holes in the silicon carbide ceramic substrate of the product.

[0031] The furnace shell 4 is equipped with a vacuum connector 8 that communicates with its inner cavity. The vacuum connector 8 is externally connected to a suction device, so that the inner cavity of the furnace shell 4 is kept in a vacuum state during hot pressing and sintering.

[0032] The furnace shell 4 consists of two shells, an inner and an outer shell, forming a closed cavity between the two shells. A cooling water connector 9 is installed on the outer wall of the cavity for circulating cooling water to be introduced to protect the furnace shell 4, reduce thermal expansion stress, and prevent the furnace shell 4 from deforming or cracking due to excessive temperature difference.

[0033] The upper mold 10 is fixed to the bottom of the pressure plate 11, and the pressure plate 11 is connected to the head of the upper hydraulic cylinder 12. The cylinder body of the upper hydraulic cylinder 12 is fixed to the pressure cover 6. The upper hydraulic cylinder 12 provides power for the movement of the upper mold 10.

[0034] The lower mold 13 is fixedly connected to the support plate 14, the support plate 14 is connected to the head of the lower hydraulic cylinder 15, the cylinder body of the lower hydraulic cylinder 15 is fixedly connected to the frame 5, and the lower hydraulic cylinder 15 provides power for the movement of the lower mold 13.

[0035] Guide rods are provided on both sides of the upper hydraulic cylinder 12 and the lower hydraulic cylinder 15 to provide precise linear guidance and stable support.

[0036] The specific working principle of this utility model is as follows:

[0037] The raw material powder 18 is placed in the ring mold 1, and the raw material powder 18 is heated below its melting point using graphite heating elements 2. The upper mold 10 and lower mold 13 simultaneously apply axial pressure under the action of a hydraulic cylinder to promote powder sintering. During hot pressing sintering, the interaction of high temperature and high pressure increases the contact, diffusion, and flow between particles, accelerating the rearrangement and densification of the material during sintering. During sintering, a mandrel is inserted through the raw material powder 18, and after the silicon carbide ceramic substrate is formed, through-holes can be formed inside to avoid subsequent processing of porosity.

[0038] The above description provides examples of the preferred embodiments of this utility model. Any aspects not detailed herein are common knowledge to those skilled in the art. The scope of protection of this utility model is determined by the claims. Any equivalent modifications based on the technical teachings of this utility model are also within the scope of protection of this utility model.

Claims

1. A hot pressing sintering apparatus for producing silicon carbide ceramic substrates, characterized in that: The furnace includes a furnace shell (4), a ring mold (1) is installed in the middle of the inner cavity of the furnace shell (4), and graphite heating plates (2) and furnace lining (3) are arranged in sequence around the ring mold (1). Both graphite heating plates (2) and furnace lining (3) are annular structures. A liftable upper mold (10) is provided above the ring mold (1), and a liftable lower mold (13) is provided below the ring mold (1). Multiple mandrels (16) are installed on the lower mold (13). The mandrels (16) are arranged in a vertical direction. The bottom of the mandrels (16) is fixed in the lower mold (13). The bottom of the upper mold (10) is provided with a clearance hole (17) for the top of the mandrels (16) to enter.

2. The hot pressing sintering apparatus for producing silicon carbide ceramic substrates as described in claim 1, characterized in that: The furnace shell (4) is fixed above the frame (5). A pressure cover (6) is installed on the top of the furnace shell (4). The pressure cover (6) and the frame (5) are connected by multiple telescopic cylinders (7) arranged in the vertical direction. The telescopic cylinders (7) are distributed around the furnace shell (4).

3. The hot pressing sintering apparatus for producing silicon carbide ceramic substrates as described in claim 1, characterized in that: Both the upper mold (10) and the lower mold (13) are cylindrical structures, and the upper mold (10) and the lower mold (13) are slidably connected to the inner wall of the ring mold (1).

4. The hot pressing sintering apparatus for producing silicon carbide ceramic substrates as described in claim 1, characterized in that: The ring mold (1), upper mold (10) and lower mold (13) are all made of graphite.

5. The hot pressing sintering apparatus for producing silicon carbide ceramic substrates as described in claim 1, characterized in that: The furnace shell (4) is equipped with a vacuum connector (8) that communicates with its inner cavity.

6. The hot pressing sintering apparatus for producing silicon carbide ceramic substrates as described in claim 1, characterized in that: The furnace shell (4) is composed of two shells, an inner and an outer shell, with a closed cavity formed between the two shells. A cooling water connector (9) is installed on the outer wall of the cavity.

7. The hot pressing sintering apparatus for producing silicon carbide ceramic substrates as described in claim 1, characterized in that: The upper mold (10) is fixed to the bottom of the pressure plate (11), the pressure plate (11) is connected to the head of the upper hydraulic cylinder (12), and the cylinder body of the upper hydraulic cylinder (12) is fixed to the pressure cover (6).

8. The hot pressing sintering apparatus for producing silicon carbide ceramic substrates as described in claim 7, characterized in that: The lower mold (13) is fixed to the support plate (14), the support plate (14) is connected to the head of the lower hydraulic cylinder (15), and the cylinder body of the lower hydraulic cylinder (15) is fixed inside the frame (5).

9. The hot pressing sintering apparatus for producing silicon carbide ceramic substrates as described in claim 8, characterized in that: Guide rods are provided on both sides of the upper hydraulic cylinder (12) and the lower hydraulic cylinder (15).

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