WO2022174506A1

WO2022174506A1 - Carbon-silicon carbide target material and preparation method therefor and use thereof

Info

Publication number: WO2022174506A1
Application number: PCT/CN2021/086055
Authority: WO
Inventors: 姚力军; 边逸军; 潘杰; 王学泽; 杨慧珍
Original assignee: 宁波江丰电子材料股份有限公司
Priority date: 2021-02-22
Filing date: 2021-04-09
Publication date: 2022-08-25
Also published as: CN113004040A; KR20220120447A; CN113004040B; KR102641901B1

Abstract

A carbon-silicon carbide target material, a preparation method therefor and use thereof. In the preparation method for the carbon-silicon carbide target material, mixing a carbon powder and a silicon carbide powder and then ball-milling twice, drying between two ball-milling steps, and subsequently performing die-filling, sintering and cooling so as to obtain the carbon-silicon carbide target material.

Description

A kind of silicon carbide target and its preparation method and use

technical field

The present application belongs to the technical field of target materials, and relates to the technical field of silicon carbide targets, for example, to a silicon carbide target and a preparation method and uses thereof.

Background technique

The thermal print head includes a base plate made of insulating material, a base layer is made on the base plate, a wire electrode is formed on the base layer, and a heating resistor strip along the main printing direction is formed above the wire electrode and the base layer, and the wire electrode and the heating resistor strip are formed. There is a protective layer on top. The protective layer usually adopts a layer of insulating layer or a layer of insulating layer and a layer of wear-resistant layer. Usually, both the insulating layer and the wear-resistant layer are materials with low thermal conductivity. During the heating process of the heating resistor, the heat generated by the heating resistor is transferred to the printing medium through the protective layer, and the printing medium changes correspondingly according to the amount of the transferred heat. After the heating resistor heats up, the amount of heat transferred to the printing medium is directly related to the thickness and thermal conductivity of the protective layer.

In the process of cooling the thermal print head, the working voltage stops being applied, and the heating resistor stops heating. The ideal state is that the temperature of the surface of the protective layer drops rapidly to the required low temperature state at the moment when the working voltage stops applying. The intermediate cooling is only achieved by heat conduction, so the protective layer needs to have high thermal conductivity characteristics at this time to ensure that the residual heat in the protective layer is conducted away in an instant, but the actual protective layer does not have the characteristics of high thermal conductivity. At the moment when the voltage stops being applied, a large amount of heat remaining in the protective layer is partly conducted through the thermal print head itself, and the other is conducted through the printing medium, and the heat conducted through the printing medium can easily lead to " Smearing" phenomenon, which affects the print quality. If the thickness of the protective layer is reduced, although the heat transfer efficiency will be improved, the abrasion resistance of the thermal print head will be greatly reduced, which will seriously affect the performance of the thermal print head.

At the same time, due to the material properties of the insulating layer and the wear-resistant layer itself, the wear-resistant layer and the wire electrode cannot be in direct contact, so the insulating layer must exist, but when the insulating layer and the wear-resistant layer are in direct contact, the wear-resistant layer often occurs. The wear resistance of the wear-resistant layer cannot be fully utilized, which greatly reduces the wear resistance of the print head.

CN203651201U discloses a thermal printing head, comprising a base plate made of insulating material, a base layer is arranged on the base plate, and it is characterized in that a wire electrode is formed on the base layer, a heating resistor body strip along the main printing direction is formed on the wire electrode, and the wire electrode is formed. The protective layer is divided into three layers, the bottom layer is an insulating layer with low wear resistance, the middle layer is a high thermal conductivity layer with thermal conductivity at least twice that of the insulating layer, and the top layer is a high thermal conductivity layer. For the wear-resistant layer, the thermal response rate of the upper surface of the thermal print head is improved, so that the heat transferred upwards increases when the temperature rises. The intermediate layer acts as a transition layer and increases the adhesion between the insulating layer and the wear-resistant layer, which can fully The high hardness of the wear-resistant layer is used to ensure the wear resistance of the thermal print head.

CN112010675A and CN108409330A also respectively disclose printed ceramic materials to support the development of thermal printing and 3D printing. However, with the expansion of thermal printing and 3D printing markets, the demand for silicon carbide targets that can improve printing equipment and work efficiency is increasing in the industry. The wear resistance of the film layer requires the target to have a high density and a uniform microstructure without pores.

However, due to the special material properties of SiC targets, the production technology is difficult and the post-processing is difficult, so it is difficult to produce SiC targets with high density and stable performance. Require.

Therefore, it is necessary to develop a method for preparing a silicon carbide target with high density, uniform microstructure and no pores.

SUMMARY OF THE INVENTION

The purpose of the present application is to provide a silicon carbide target and a preparation method and use thereof, and the preparation method of the silicon carbide target can obtain a silicon carbide target with high density and purity; the obtained silicon carbide The microstructure of the target is uniform and the sputtering performance of the target is excellent. When used in the field of printing, it can effectively improve the working efficiency and service life of printing equipment, and has broad application prospects.

For this purpose, the application adopts the following technical solutions:

In a first aspect, the present application provides a method for preparing a silicon carbide target, the preparation method comprising the following steps:

(1) mixing carbon powder and silicon carbide powder, and performing first ball milling in a solvent environment to obtain a first mixture;

(2) After the first mixture described in step (1) is dried, it is mixed with a solvent and a polyol, and the second mixture is obtained through the second ball milling;

(3) Step (2) The second mixture is subjected to mold loading, sintering and cooling in sequence to obtain the silicon carbide target.

The preparation method of the silicon carbide target described in the present application improves the mixing uniformity of the carbon powder and the silicon carbide powder by mixing the solvent with the carbon powder and the silicon carbide powder for ball milling, and then performing the second ball milling after drying, adding Polyols play a role similar to granulation, thereby improving the fluidity of the second mixture, which is conducive to the tight compaction of the second mixture in subsequent molding and sintering, improves the uniformity of the surface of the final product, and reduces the surface defects, and improve the density of silicon carbide targets.

Optionally, the particle size of the carbon powder in step (1) is less than 20 μm, such as 10 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm or 20 μm, etc., but not limited to the listed values, The same applies to other non-recited values within this range.

Optionally, the particle size of the silicon carbide powder in step (1) is less than 10 μm, for example, it can be 5 μm, 5.6 μm, 6.2 μm, 6.7 μm, 7.3 μm, 7.8 μm, 8.4 μm, 8.9 μm, 9.5 μm or 10 μm, etc., But not limited to the recited values, other non-recited values within the range are equally applicable.

The particle size of the optional carbon powder and silicon carbide powder in the application is in the above range, which is more conducive to the uniform mixing of the first ball mill and the control of the particle size of the second mixture in the second ball mill, which can effectively ensure the density of the silicon carbide target. .

Optionally, the carbon powder in step (1) is ≥99.995% high-purity carbon powder, and the purity can be, for example, 99.995%, 99.999%, 99.9994% or 99.9996%, etc., but not limited to the listed values, other The same applies to non-recited values.

Optionally, the silicon carbide powder in step (1) is ≥99.9% high-purity silicon carbide powder, and the purity can be, for example, 99.9%, 99.92%, 99.95%, 99.96%, 99.98%, 99.99%, 99.992%, 99.995% Or 99.998%, etc., but not limited to the listed values, other unlisted values within this range are also applicable.

Optionally, the mass ratio of carbon powder and silicon carbide powder in step (1) is 40-50:60-50, for example, 40:60, 45:60, 48:60, 50:60, 40:58 , 42:58, 44:59, 45:55, 48:52 or 50:50, etc., but are not limited to the listed values, and other unlisted values within this range are also applicable.

Optionally, the solvent in step (1) is ethanol.

Optionally, the material-to-ball ratio of the first ball mill in step (1) is 1 to 3:1, such as 1:1, 1.2:1, 1.5:1, 1.8:1, 2.0:1, 2.2:1 , 2.5:1 or 3.0:1, etc., but are not limited to the listed values, and other unlisted values within this range are also applicable.

Optionally, the time of the first ball milling in step (1) is ≥ 24h, for example, it can be 24h, 25h, 26h, 28h, 30h, 32h, or 35h, etc., but not limited to the listed values, and others are not listed in this range. The same value applies.

Optionally, the ball milling medium of the first ball milling in step (1) is silicon carbide balls.

Optionally, the first ball milling in step (1) is performed in a sealed condition.

Optionally, the drying in step (2) includes drying.

Optionally, the drying temperature in step (2) is 100-140°C, for example, 100°C, 105°C, 109°C, 114°C, 118°C, 123°C, 127°C, 132°C, 136°C or 140°C °C, etc., but not limited to the listed numerical values, and other unlisted numerical values within this range are also applicable.

Optionally, the drying time of step (2) is 8-16h, for example, it can be 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h or 16h, etc., but not limited to the listed values, the range The same applies to other values not listed here.

Optionally, the added amount of the solvent in step (2) is 0.1 to 1 wt % of the first mixture, such as 0.1 wt %, 0.2 wt %, 0.3 wt %, 0.4 wt %, 0.5 wt %, 0.6 wt % wt %, 0.7 wt %, 0.8 wt %, 0.9 wt % or 1 wt %, etc., but not limited to the recited values, and other non-recited values within the range are also applicable.

Optionally, the solvent in step (2) is ethanol.

Optionally, the amount of the polyol added in step (2) is 0.1 to 5 wt % of the first mixture, such as 0.1 wt %, 0.5 wt %, 1.0 wt %, 1.8 wt %, 2.0 wt %, 2.5 wt % wt %, 3.0 wt %, 4 wt %, 4.5 wt % or 5 wt %, etc., but not limited to the recited values, and other unrecited values within the range are also applicable.

The polyhydric alcohol described in the present application includes glycerol or propylene glycol, etc., and glycerol can be optionally used, which can better control the particle size of the second mixture.

Optionally, the material-to-ball ratio of the second ball mill in step (2) is 1 to 3:1, such as 1:1, 1.2:1, 1.5:1, 1.8:1, 2.0:1, 2.2:1 , 2.5:1 or 3.0:1, etc., but are not limited to the listed values, and other unlisted values within this range are also applicable.

Optionally, the time of the second ball milling in step (2) is ≥ 24h, for example, it can be 24h, 25h, 26h, 28h, 30h, 32h or 35h, etc., but is not limited to the enumerated values, and others are not listed in this range. The same value applies.

Optionally, the ball milling medium of the second ball milling in step (2) is silicon carbide balls.

The ball milling media of the first ball mill and the second ball mill described in this application can optionally use silicon carbide balls, which can ensure higher powder purity.

Optionally, the second ball milling in step (2) is performed in a sealed condition.

The first ball mill and the second ball mill described in the present application are carried out under the condition of resealing, which is beneficial to prevent the leakage of slurry in the powder mixing process and improve the product purity.

Optionally, after the second ball-milled material in step (2) is screened, the second mixture is obtained.

Optionally, the particle size range of the second mixture in step (2) is ≤ 200 μm, such as 200 μm, 190 μm, 180 μm, 170 μm, 165 μm, 160 μm, 150 μm, 120 μm or 100 μm, etc., but not limited to the listed Numerical values, other non-recited values in the range apply equally.

Optionally, the flatness of the surface of the second mixture after the mold is installed in step (3) is less than or equal to 0.5mm, such as 0.1mm, 0.15mm, 0.19mm, 0.20mm, 0.28mm, 0.30mm, 0.37mm, 0.40mm, 0.46mm or 0.5mm, etc., but not limited to the listed values, and other unlisted values within this range are also applicable.

In the present application, the performance of the sintered silicon carbide target can be improved by ensuring that the flatness after mold installation is less than or equal to 0.5 mm.

Optionally, the mold loading in step (3) includes: loading the second mixture into the mold, wrapping it with a wrapping material, and then compacting it.

Because the silicon carbide powder is light and slippery, the selection of the wrapping material can further effectively prevent the powder from being pulled out of the mold during the sintering process, and improve the sintering performance and yield.

Optionally, the wrapping material in step (3) is carbon fiber cloth.

Optionally, cold pressing is also included between the mold-loading and sintering in step (3).

Optionally, the cold pressing in step (3) includes manually applying pressure to the mold until it cannot be pressed.

Optionally, in step (3), vacuuming and filling with protective gas are included between the mold-loading and the sintering.

Optionally, vacuuming to absolute vacuum degree≤100Pa described in step (3), for example, can be 50Pa, 56Pa, 62Pa, 67Pa, 73Pa, 78Pa, 84Pa, 89Pa, 95Pa or 100Pa, etc., but not limited to the listed values , other non-recited values in this range are also applicable.

Optionally, the described vacuuming time of step (3) ≥ 40min, such as 40min, 42min, 43min, 45min, 48min, 50min, 52min, 55min, 60min, 65min or 70min, etc., but not limited to the enumerated values , other non-recited values in this range are also applicable.

The present application controls the rate of vacuuming by controlling the total time of vacuuming, preventing powder from being drawn out during vacuuming, significantly improving the density of the final SiC target, and reducing the risk of target cracking.

Optionally, the protective gas in step (3) is filled to a gauge pressure of -0.08～-0.1MPa, for example, it can be -0.08MPa, -0.082MPa, -0.085MPa, -0.09MPa, -0.095MPa or -0.1MPa etc., but not limited to the recited values, other unrecited values within the range are equally applicable.

Optionally, the protective gas in step (3) includes argon.

Optionally, the sintering in step (3) includes: under the condition of filling with protective gas, the first temperature is raised to the first temperature; the second temperature is raised to the second temperature, and the second heat preservation is performed; While keeping warm, the second pressure is increased to the second pressure, and the pressure is maintained until the second heat preservation ends; the third temperature is continued to be increased to the third temperature, and the vacuum is carried out during the third heating process to the third temperature increase; After the third temperature and the third pressure increase to the third pressure, the third heat preservation is carried out.

The present application can optionally adopt three-stage heating and two-stage boosting steps to match, which is more conducive to improving the sintering effect and ultimately improving the density of the silicon carbide target.

Optionally, the rate of the third temperature increase in step (3) is smaller than the rate of the second temperature increase than the rate of the first temperature increase.

Optionally, the rate of the first temperature increase in step (3) is 8 to 12°C/min, such as 8°C/min, 8.5°C/min, 8.9°C/min, 9.4°C/min, 9.8°C/min , 10.3°C/min, 10.7°C/min, 11.2°C/min, 11.6°C/min or 12°C/min, etc., but are not limited to the listed values, and other unlisted values within this range are also applicable.

Optionally, the first temperature in step (3) is 1400-1500°C, such as 1400°C, 1412°C, 1423°C, 1434°C, 1445°C, 1456°C, 1467°C, 1478°C, 1489°C or 1500°C °C, etc., but not limited to the listed numerical values, and other unlisted numerical values within this range are also applicable.

Optionally, the second heating rate in step (3) is 4 to 6°C/min, for example, 4°C/min, 4.3°C/min, 4.5°C/min, 4.7°C/min, 4.9°C/min , 5.2°C/min, 5.4°C/min, 5.6°C/min, 5.8°C/min or 6°C/min, etc., but are not limited to the listed values, and other unlisted values within this range are also applicable.

Optionally, the duration of the second insulation in step (3) is 40 to 100 min, such as 40 min, 47 min, 54 min, 60 min, 67 min, 74 min, 80 min, 87 min, 94 min or 100 min, etc., but not limited to the listed Numerical values, other non-recited values in the range apply equally.

Optionally, the second temperature in step (3) is 1750-1850°C, such as 1750°C, 1762°C, 1773°C, 1784°C, 1795°C, 1806°C, 1817°C, 1828°C, 1839°C or 1850°C °C, etc., but not limited to the listed numerical values, and other unlisted numerical values within this range are also applicable.

Optionally, the duration of the second boost in step (3) is 12-25min, for example, it can be 12min, 14min, 15min, 17min, 18min, 20min, 21min, 23min, 24min or 25min, etc., but not limited to the listed value, other non-recited values in this range also apply.

Optionally, the second pressure in step (3) is 7-9 MPa, such as 7 MPa, 7.3 MPa, 7.5 MPa, 7.7 MPa, 7.9 MPa, 8.2 MPa, 8.4 MPa, 8.6 MPa, 8.8 MPa or 9 MPa, etc., But not limited to the recited values, other non-recited values within the range are equally applicable.

Optionally, the rate of the third temperature increase in step (3) is 1 to 3.5°C/min, such as 1°C/min, 1.3°C/min, 1.6°C/min, 1.9°C/min, 2.2°C/min , 2.5°C/min, 2.7°C/min, 3°C/min, 3.3°C/min or 3.5°C/min, etc., but are not limited to the listed values, and other unlisted values within this range are also applicable.

Optionally, the third temperature in step (3) is 1950-2050°C, such as 1950°C, 1962°C, 1973°C, 1984°C, 1995°C, 2006°C, 2017°C, 2028°C, 2039°C or 2050°C °C, etc., but not limited to the listed numerical values, and other unlisted numerical values within this range are also applicable.

Optionally, in the third heating process described in step (3), vacuumize to absolute vacuum degree≤100Pa, such as 100Pa, 95Pa, 90Pa, 85Pa, 80Pa, 75Pa or 70Pa, etc., but not limited to the enumerated values, The same applies to other non-recited values within this range.

Optionally, the duration of the third boost in step (3) is 40-80min, such as 40min, 45min, 50min, 54min, 58min, 60min, 67min, 70min, 76min or 80min, etc., but not limited to the listed value, other non-recited values in this range also apply.

Optionally, the third pressure in step (3) is 30-40 MPa, for example, it can be 30 MPa, 32 MPa, 33 MPa, 34 MPa, 35 MPa, 36 MPa, 37 MPa, 38 MPa, 39 MPa or 40 MPa, etc., but not limited to the listed values, The same applies to other non-recited values within this range.

Optionally, the duration of the third insulation in step (3) is 150-220min, such as 150min, 160min, 166min, 170min, 180min, 189min, 197min, 205min, 213min or 220min, etc., but not limited to the listed Numerical values, other non-recited values in the range apply equally.

Optionally, the cooling in step (3) includes: after the sintering is completed, the heating is stopped, the temperature is lowered to the second temperature, the pressure is released, the protective gas is introduced, and the furnace is cooled to the fourth temperature to complete the cooling.

Optionally, the cooling in step (3) is natural cooling with the furnace.

Optionally, the protective gas in step (3) includes argon.

Optionally, the fourth temperature in step (3) is less than or equal to 200°C, such as 20°C, 40°C, 60°C, 80°C, 100°C, 120°C, 140°C, 160°C, 180°C, or 200°C, etc. , but not limited to the recited values, and other non-recited values within this range are equally applicable.

Optionally, after the cooling in step (3), the method further includes: machining the silicon carbide target material.

As an optional technical solution of the present application, the preparation method comprises the following steps:

(1) Mix carbon powder with a particle size of less than 20 μm and silicon carbide powder with a particle size of less than 10 μm in a mass ratio of 40 to 50:60 to 50, and conduct first ball milling with silicon carbide balls in an ethanol environment under sealed conditions. The time ≥ 24h, the material-to-ball ratio is 1 to 3:1, and the first mixture is obtained;

(2) After drying the first mixture in step (1), it is mixed with ethanol and polyol. The amount of ethanol added is 0.1 to 1% by weight of the first mixture, and the amount of polyol added is the first mixture. 0.1-5wt% of the powder, the second ball milling is carried out through silicon carbide balls in a sealed condition, the time of the second ball milling is ≥ 24h, and the ball-milled material is sieved to obtain the second mixture;

(3) The second mixture in step (2) is loaded into a mold, and the flatness of the surface of the second mixture after the mold is ≤0.5mm, and then cold-pressed, and then evacuated to an absolute vacuum of ≤100Pa, filled with The protective gas to the gauge pressure is -0.08 ~ -0.1MPa, and the first temperature rises to 1400 ~ 1500 °C at 8 ~ 12 °C/min under the condition of protective gas filling;

Then the second temperature is raised to 1750-1850°C at 4-6°C/min, and the second heat preservation is carried out for 40-100min; while the second heat preservation is performed, the second pressure is increased to 7-9MPa within 12-25min, and the pressure is maintained to The second heat preservation is over;

Continue to heat up to 1950-2050°C for the third time at 1～3.5°C/min, vacuumize to the end of the third heat-up during the third heat-up process, and evacuate to absolute vacuum degree≤100Pa; After the third pressure increase to 30-40MPa within 40-80min, carry out the third heat preservation for 150-220min; after the third heat preservation is over, stop heating, cool down to 1750-1850℃, release the pressure, pass in protective gas and cool down with the furnace to ≤200°C to obtain the silicon carbide target.

The preparation method provided by the present application improves the uniformity of the microstructure on the surface of the product by improving the mixing method of carbon powder and silicon carbide powder, and reduces the defects on the surface. Significantly increases the density of the product.

In a second aspect, the present application provides a silicon carbide target, which is prepared according to the method for preparing a silicon carbide target described in the first aspect.

The density and purity of the target prepared in the first aspect of the present application are high, the performance is excellent, and the application prospect is good.

In a third aspect, the present application provides the use of the silicon carbide target described in the second aspect in thermal printing or 3D printing.

The density of the silicon carbide target prepared in this application is greater than or equal to 95.9%, and under optimal conditions, the density is greater than or equal to 99%, and the purity is greater than or equal to 99.7%, which meets the requirements of magnetron sputtering on the purity and density of the target, and is used for thermal printing. The head wear-resistant layer can improve the working efficiency and service life of thermal printing equipment.

The % referred to in this application to purity and component content refers to mass content.

Compared with the prior art, the present application at least has the following beneficial effects:

(1) The preparation method of the silicon carbide target provided by the application controls the particle size of the second mixture by adopting a secondary ball milling step, which finally improves the uniformity of the surface of the silicon carbide target and reduces the defects on the surface;

(2) the preparation method of the silicon carbide target material provided by the application further adopts three-stage heating and two-stage boosting operations to carry out sintering, which ensures the density of the product and has excellent performance;

(3) The density of the silicon carbide target provided by this application is ≥95.9%, and under optimal conditions, the density is ≥99% and the purity is ≥99.7%, which meets the requirements of the heat-sensitive industry for targets.

Description of drawings

FIG. 1 is a surface structure diagram of the silicon carbide target provided in Example 1 of the present application.

FIG. 2 is a surface structure diagram of the silicon carbide target provided in Comparative Example 3 of the present application.

Detailed ways

The technical solutions of the present application will be further described below with reference to the accompanying drawings and through specific embodiments.

The present application is described in further detail below. However, the following examples are only simple examples of the present application, and do not represent or limit the protection scope of the present application. The protection scope of the present application is subject to the claims.

1. Example

Example 1

This embodiment provides a method for preparing a silicon carbide target, and the preparation method includes the following steps:

(1) Mix carbon powder with a particle size of less than 20 μm and silicon carbide powder with a particle size of less than 10 μm in a mass ratio of 45:55, and perform the first ball milling with silicon carbide balls in an ethanol environment in a sealed condition, and the first ball milling time is 48h , the material-to-ball ratio is 2:1, and the first mixture is obtained;

(2) After the first mixture of step (1) is dried at 120° C. for 12 hours, it is then mixed with ethanol and glycerin. 1 wt% of the material, the second ball milling was carried out by silicon carbide balls in a sealed condition, and the time of the second ball milling was 48h, and the ball-milled material was sieved to obtain a second mixture, and the particle size range of the second mixture was 120～160μm;

(3) The second mixture described in step (2) is loaded into the graphite mold, and the second mixture is wrapped with dense carbon fiber cloth and then compacted to ensure that the flatness of the surface of the second mixture after the mold is installed is 0.35mm Next, put the mold into the vacuum sintering furnace, ensure the mold level after placing, manually apply pressure to the mold and cold-press until it can no longer be pressed. After cold-pressing, use 60min to vacuumize until the absolute vacuum degree drops below 90Pa, and stop pumping Vacuum, fill the vacuum sintering furnace with argon until the gauge pressure is -0.09MPa, stop filling with argon, and while filling with argon, first heat up to 1450°C at 10°C/min;

Then the second temperature was raised to 1800°C at 5°C/min, and the second insulation was carried out for 60min; while the temperature was raised to 1800°C for the second insulation, the pressure was immediately increased to 8MPa in 20min, and the pressure was maintained until the second insulation was completed;

Continue to heat up to 2000°C for the third time at 3°C/min, vacuumize to the end of the third heat-up during the third heat-up process, and evacuate the vacuum degree to the absolute vacuum degree and drop below 100Pa; After the third pressure was raised to 35MPa, the third heat preservation was carried out for 180 minutes; after the third heat preservation was completed, the heating was stopped, the temperature was lowered to 1800 °C, the pressure was released, argon gas was introduced, and the furnace was cooled to 100 °C, taken out, and subjected to grinding and wire cutting. etc. are processed to the required size to obtain the silicon carbide target.

Example 2

(1) Mix carbon powder with a particle size of less than 20 μm and silicon carbide powder with a particle size of less than 10 μm in a mass ratio of 40:60, and perform the first ball milling with silicon carbide balls in an ethanol environment in a sealed condition, and the first ball milling time is 24h , the material-to-ball ratio is 1:1, and the first mixture is obtained;

(2) After the first mixture of step (1) is dried at 100° C. for 16 hours, it is then mixed with ethanol and glycerin. 5wt% of the material, the second ball milling is carried out by silicon carbide balls in the sealed condition, and the time of the second ball milling is 28h, and the ball-milled material is sieved to obtain a second mixture, and the particle size range of the second mixture is 130～180μm;

(3) The second mixture described in step (2) is loaded into the graphite mold, and the second mixture is wrapped with dense carbon fiber cloth and then compacted to ensure that the flatness of the surface of the second mixture after the mold is installed is 0.5mm Next, put the mold into the vacuum sintering furnace, keep the mold level after placing, and manually apply pressure to the mold to cold-press until it can no longer be pressed. After cold-pressing, use 50min to evacuate until the absolute vacuum degree drops below 100Pa, and stop pumping. Vacuum, fill the vacuum sintering furnace with argon gas until the gauge pressure is -0.08MPa, stop filling with argon gas, and at the same time as filling with argon gas, the first temperature rises to 1400°C at 8°C/min;

Then the second temperature rises to 1750°C at 4°C/min, and the second heat preservation is performed for 40min; while the second heat preservation is performed at 1750°C, the pressure is immediately increased to 7MPa in 12min, and the pressure is maintained until the second heat preservation ends;

Continue to heat up to 2000°C for the third time at 1°C/min, vacuumize to the end of the third heat-up during the third heat-up process, and evacuate the vacuum degree to the absolute vacuum degree and drop below 90Pa; After the third pressure was raised to 30MPa, the third heat preservation was carried out for 280min; after the third heat preservation was completed, the heating was stopped, the temperature was lowered to 1750°C, the pressure was relieved, argon gas was introduced, and the furnace was cooled to 200°C, taken out, subjected to grinding, wire cutting etc. are processed to the required size to obtain the silicon carbide target.

Example 3

(1) Mix carbon powder with a particle size of less than 18 μm and silicon carbide powder with a particle size of less than 9 μm in a mass ratio of 50:50, and conduct the first ball milling with silicon carbide balls in an ethanol environment in a sealed condition, and the first ball milling time is 36h , the material-to-ball ratio is 3:1, and the first mixture is obtained;

(2) The first mixture of step (1) is dried at 140° C. for 8 hours, and then mixed with ethanol and glycerin. The amount of ethanol added is 1wt% of the first mixture, and the amount of glycerol added is the first mixture. 0.1 wt% of 0.1 wt %, the second ball milling is carried out by silicon carbide balls in the sealing condition, and the time of the second ball milling is 36h, and the material after ball milling is sieved to obtain a second mixture, and the particle size range of the second mixture is 140～200μm;

(3) The second mixture described in step (2) is loaded into the graphite mold, and the second mixture is wrapped with dense carbon fiber cloth and then compacted to ensure that the flatness of the surface of the second mixture after the mold is installed is 0.4mm Next, put the mold into the vacuum sintering furnace, ensure the mold level after placing, manually apply pressure to the mold and cold-press until it cannot be pressed. After cold-pressing, use 55min to evacuate until the absolute vacuum degree drops below 90Pa, and stop pumping Vacuum, fill the vacuum sintering furnace with argon gas until the gauge pressure is -0.1MPa, stop filling with argon gas, and at the same time as filling with argon gas, the first temperature rises to 1500°C at 12°C/min;

Then the second temperature is raised to 1850°C at 6°C/min, and the second insulation is carried out for 100min; while the second insulation is heated to 1850°C, the pressure is immediately increased to 9MPa in 25min, and the pressure is maintained until the second insulation is completed;

Continue to heat up to 2050°C for the third time at 3.5°C/min, vacuumize to the end of the third heat-up during the third heat-up process, and pump the vacuum degree to the absolute vacuum degree and drop below 90Pa; After the third pressure was raised to 40MPa, the third heat preservation was carried out for 150min; after the third heat preservation was completed, the heating was stopped, the temperature was lowered to 2050°C, the pressure was released, argon gas was introduced, and the furnace was cooled to 200°C, taken out, subjected to grinding and wire cutting etc. are processed to the required size to obtain the silicon carbide target.

Example 4

This embodiment provides a preparation method of a silicon carbide target, and the preparation method is the same as that of Embodiment 1 except that the particle size range of the carbon powder in step (1) is 5-30 μm.

Example 5

This embodiment provides a preparation method of a silicon carbide target, and the preparation method is the same as that of Embodiment 1 except that the particle size range of the silicon carbide powder in step (1) is 5-20 μm.

Example 6

This embodiment provides a preparation method of a silicon carbide target, and the preparation method is the same as that of Embodiment 1 except that glycerin is replaced with propylene glycol in step (2).

Example 7

This embodiment provides a preparation method of a silicon carbide target. The preparation method is the same as the embodiment except that the second pressure is increased to 35MPa while the second heat preservation is performed in step (3) and the third pressure increase is not performed. 1 is the same.

Example 8

This embodiment provides a method for preparing a silicon carbide target. In the preparation method, the third temperature increase is not performed in step (3), and the second temperature is directly increased to 2050° C. and the second temperature is maintained for 250 minutes. Except that the second boosting and the third boosting are carried out in sequence, the rest are the same as those in Example 1.

Example 9

The embodiment of this example provides a preparation method of a silicon carbide target. The preparation method is the same as that of Embodiment 1 except that the vacuuming time after cold pressing is 34 minutes.

Compared with Example 9, the vacuuming time of Example 1 is longer, the powder is not easily drawn out, and the density of the final product is significantly higher than that of the silicon carbide target in Example 9.

2. Comparative ratio

Comparative Example 1

This comparative example provides a preparation method of a silicon carbide target. The preparation method is the same as in Example 1 except that step (2) is not performed and the first ball milling is directly ball milled for 96 hours.

Comparative Example 2

This comparative example provides a preparation method of a silicon carbide target, and the preparation method is the same as that of Example 1 except that glycerin is not added in step (2).

Comparative Example 3

This comparative example provides a preparation method of a silicon carbide target. The preparation method is the same as in Example 1, except that step (1) is not performed, and the two powders are directly used as the first mixture to perform step (2). same.

3. Tests and Results

Observing the morphology of the surface of the silicon carbide target after molding, the surfaces of the silicon carbide targets prepared in Example 1 and Comparative Example 3 are shown in Figure 1 and Figure 2, respectively. It can be seen from this that in Example 1, the The powder mixing method of secondary ball milling has a smooth surface, uniform microstructure, and defects significantly smaller than that of Comparative Example 3, and the density in Comparative Example 3 is only 98.0%. Example 1 has higher density and excellent sputtering performance.

In Comparative Example 1 and Comparative Example 2, the microstructure uniformity of the surface of the silicon carbide target after forming is worse than that in Example 1, and the density in Comparative Example 1 and Comparative Example 2 is only 98.4% and 97.9%, respectively, and the surface defects are obvious. More than Example 1, the target sputtering performance is poor.

In Examples 2 to 9, the uniformity of the structure of the surface of the silicon carbide target is better than that of the Comparative Examples 1 to 2, and the defects of the surface microstructure are less.

Comparing Example 1 and Examples 4 to 5, carbon powder and silicon carbide powder with smaller particle size are used in Example 1. Compared with Examples 4 to 5, the uniformity of the surface structure is higher, and the defects It is shown that by further controlling the particle size range of carbon powder and silicon carbide powder raw materials, silicon carbide targets with fewer surface defects can be obtained.

The density of the silicon carbide targets prepared in the above examples and comparative examples was tested by the drainage method and the glow discharge mass spectrometry method, and the test results are shown in Table 1.

Table 1

	致密度(％)Density (%)	是否开裂Is it cracked
实施例1Example 1	99.899.8	否no
实施例2Example 2	99.399.3	否no
实施例3Example 3	99.199.1	否no
实施例4Example 4	99.099.0	否no

实施例5Example 5	99.199.1	否no
实施例6Example 6	99.699.6	否no
实施例7Example 7	97.397.3	开裂cracked
实施例8Example 8	95.995.9	否no

The following points can be seen from Table 1:

(1) It can be seen from the comprehensive examples 1 to 6 that the silicon carbide target provided by the present application further integrates the process conditions and the method of secondary ball milling, and can obtain a silicon carbide target without cracking and with a density of ≥99.0%, And its surface microstructure is uniform, less defects, and excellent sputtering performance;

(2) Combining Example 1 and Example 7, it can be seen that the three-step boosting method is adopted in Example 1. Compared with the two-step boosting in Example 7, the density of the target material in Example 1 is It is as high as 99.8% without cracking, while the density in Example 7 is only 97.3%, and there is a risk of cracking, which shows that the application can significantly improve the density and reduce the cracking problem by further optimizing the way of boosting during sintering. ;

(3) Combining Example 1 and Example 8, it can be seen that in Example 1, the method of three-step heating is adopted. Compared with the two-step boosting method in Example 8, the density of the target material in Example 1 is It is as high as 99.8% without cracking, while the density in Example 8 is only 95.9%, which shows that the present application significantly improves the density by further optimizing the heating method during sintering.

In summary, the silicon carbide target provided by the present application can significantly reduce surface defects and improve the uniformity of microstructure through the secondary ball milling method, and the density can reach 95.9%, which is dense under optimal conditions. It can reach more than 99.0%, with excellent sputtering performance and broad application prospects.

The applicant declares that the present application illustrates the detailed process equipment and process flow of the present application through the above-mentioned embodiments, but the present application is not limited to the above-mentioned detailed process equipment and process flow, that is, it does not mean that the present application must rely on the above-mentioned detailed process equipment and process flow. Process flow can be implemented.

Claims

A preparation method of a silicon carbide target, comprising the steps of:

(1) mixing carbon powder and silicon carbide powder, and performing first ball milling in a solvent environment to obtain a first mixture;

(2) After the first mixture described in step (1) is dried, it is mixed with a solvent and a polyol, and the second mixture is obtained through the second ball milling;

(3) Step (2) The second mixture is subjected to mold loading, sintering and cooling in sequence to obtain the silicon carbide target.
The preparation method according to claim 1, wherein the particle size of the carbon powder in step (1) is less than 20 μm.
The preparation method according to claim 1 or 2, wherein the particle size of the silicon carbide powder in step (1) is less than 10 μm.
The preparation method according to any one of claims 1-3, wherein the mass ratio of the carbon powder and the silicon carbide powder in step (1) is 40-50:60-50;

Optionally, the solvent described in step (1) is ethanol;

Optionally, the material-to-ball ratio of the first ball mill in step (1) is 1 to 3:1;

Optionally, the time of the first ball milling in step (1) is greater than or equal to 24h;

Optionally, the ball milling medium of the first ball milling in step (1) is silicon carbide balls;

Optionally, the first ball milling in step (1) is performed in a sealed condition.
The preparation method according to any one of claims 1-4, wherein the addition amount of the solvent in step (2) is 0.1-1 wt% of the first mixture;

Optionally, the solvent described in step (2) is ethanol;

Optionally, the added amount of the polyol in step (2) is 0.1-5 wt % of the first mixture.
The preparation method according to any one of claims 1 to 5, wherein the material-to-ball ratio of the second ball mill in step (2) is 1 to 3:1;

Optionally, the time of the second ball milling in step (2) is greater than or equal to 24h;

Optionally, the ball milling medium of the second ball milling in step (2) is silicon carbide balls;

Optionally, the second ball milling of step (2) is carried out in a sealed condition;

Optionally, after the second ball-milled material in step (2) is screened, the second mixture is obtained;

Optionally, the particle size range of the second mixture in step (2) is ≤200 μm.
The preparation method according to any one of claims 1 to 6, wherein in step (3), the flatness of the surface of the second mixture after the mold is installed is less than or equal to 0.5 mm;

Optionally, cold pressing is also included between the mold-loading and sintering in step (3).
The preparation method according to any one of claims 1 to 7, wherein, in step (3), between the mold loading and the sintering, vacuuming and protective gas filling are included;

Optionally, the step (3) is evacuated to an absolute vacuum degree≤100Pa;

Optionally, the described vacuuming time of step (3) is ≥ 40min;

Optionally, the protective gas in step (3) is filled to a gauge pressure of -0.08～-0.1MPa;

Optionally, the protective gas in step (3) includes argon.
The preparation method according to any one of claims 1 to 8, wherein the sintering in step (3) comprises: first heating up to a first temperature under the condition of filling with protective gas;

Then the second temperature is raised to the second temperature, and the second heat preservation is performed; while the second heat preservation is performed, the pressure is increased to the second pressure through the second heat preservation, and the pressure is maintained until the second heat preservation ends;

Continue to heat up to the third temperature through the third, and carry out vacuuming to the end of the third temperature increase in the third temperature increase process; keep the third temperature and after the third pressure increase to the third pressure, carry out the third heat preservation;

Optionally, the rate of the third temperature increase in step (3) is less than the rate of the second temperature increase and less than the rate of the first temperature increase;

Optionally, the rate of the first temperature increase in step (3) is 8-12°C/min;

Optionally, the first temperature in step (3) is 1400-1500°C;

Optionally, the second heating rate in step (3) is 4-6 °C/min;

Optionally, the duration of the second insulation in step (3) is 40-100 min;

Optionally, the second temperature in step (3) is 1750-1850°C;

Optionally, the duration of the second boost in step (3) is 12 to 25 minutes;

Optionally, the second pressure in step (3) is 7-9 MPa;

Optionally, the third heating rate in step (3) is 1-3.5°C/min;

Optionally, the third temperature in step (3) is 1950-2050°C;

Optionally, in the third heating process described in step (3), vacuumize to absolute vacuum degree≤100Pa;

Optionally, the duration of the third boost in step (3) is 40-80 minutes;

Optionally, the third pressure in step (3) is 30-40 MPa;

Optionally, the duration of the third heat preservation in step (3) is 150-220 min;

Optionally, the cooling in step (3) includes: after the sintering is completed, the heating is stopped, the temperature is lowered to the second temperature, the pressure is released, the protective gas is introduced, and the furnace is cooled to the fourth temperature to complete the cooling;

Optionally, the cooling described in step (3) is natural cooling with the furnace;

Optionally, the protective gas in step (3) includes argon;

Optionally, the fourth temperature in step (3) is less than or equal to 200°C.
The preparation method according to any one of claims 1 to 9, comprising the steps of:

(1) Mix carbon powder with a particle size of less than 20 μm and silicon carbide powder with a particle size of less than 10 μm in a mass ratio of 40 to 50:60 to 50, and conduct first ball milling with silicon carbide balls in an ethanol environment under sealed conditions. The time ≥ 24h, the material-to-ball ratio is 1 to 3:1, and the first mixture is obtained;

(2) After drying the first mixture in step (1), it is mixed with ethanol and polyol. The amount of ethanol added is 0.1 to 1% by weight of the first mixture, and the amount of polyol added is the first mixture. 0.1-5wt% of the powder, the second ball milling is carried out through silicon carbide balls in a sealed condition, the time of the second ball milling is ≥ 24h, and the ball-milled material is sieved to obtain the second mixture;

(3) The second mixture in step (2) is loaded into a mold, and the flatness of the surface of the second mixture after the mold is ≤0.5mm, and then cold-pressed, and then evacuated to an absolute vacuum of ≤100Pa, filled with The protective gas to the gauge pressure is -0.08 ~ -0.1MPa, and the first temperature rises to 1400 ~ 1500 °C at 8 ~ 12 °C/min under the condition of protective gas filling;

Then the second temperature is raised to 1750-1850°C at 4-6°C/min, and the second heat preservation is carried out for 40-100min; while the second heat preservation is performed, the second pressure is increased to 7-9MPa within 12-25min, and the pressure is maintained to The second heat preservation is over;

Continue to heat up to 1950-2050°C for the third time at 1～3.5°C/min, vacuumize to the end of the third heat-up during the third heat-up process, and evacuate to absolute vacuum degree≤100Pa; After the third pressure increase to 30-40MPa within 40-80min, carry out the third heat preservation for 150-220min; after the third heat preservation is over, stop heating, cool down to 1750-1850℃, release the pressure, pass in protective gas and cool down with the furnace to ≤200°C to obtain the silicon carbide target.
A silicon carbide target is prepared by the method for preparing a silicon carbide target according to any one of claims 1 to 10.
Use of the silicon carbide target according to claim 11 in thermal printing or 3D printing.