A ceramic-based composite material heat dissipation substrate and its preparation method and application

Abstract

The present invention discloses a ceramic-based composite material heat dissipation substrate and its preparation method and application, which relates to the technical field of ceramic heat dissipation substrate preparation. The heat dissipation substrate comprises: C f / SiC layer, CVD-SiC layer, silicon nanolayer and copper silicide layer; CVD-SiC layer is coated on C f / SiC layer, the silicon nanolayer covers the upper surface of the CVD-SiC layer, and the copper silicide layer covers the upper surface of the silicon nanolayer; C f The SiC layer is a silicon carbide ceramic-based composite material reinforced with carbon fiber cloth. The resulting ceramic-based composite heat sink substrate boasts a thermal conductivity exceeding 296 W / (m·K), high fracture toughness, and high flexural strength, making it suitable for use in high-power modules. This invention addresses the low thermal conductivity issue of existing ceramic heat sink substrates.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic heat dissipation substrate preparation, and in particular to a ceramic-based composite material heat dissipation substrate and a preparation method and application thereof. Background Art

[0002] With the rise of industries such as rail transit, electric vehicles, hybrid vehicles, high-voltage inverters, DC power transmission, high-power LEDs and 5G communications, high-voltage and high-current power semiconductor devices are widely used. At this time, ceramic heat dissipation substrates with high thermal conductivity, high insulation and high thermal conductivity play an increasingly important role in the field of electronic technology.

[0003] The most basic structure of a ceramic heat sink substrate consists of a ceramic layer and a copper layer. Ceramic layers are categorized by material and primarily include beryllium oxide (BeO), aluminum oxide (Al2O3), aluminum nitride (AlN), and silicon nitride (Si3N4). BeO ceramics have high thermal conductivity but are also toxic. Al2O3 ceramic substrates are widely used due to their low price and excellent thermal shock resistance, but suffer from low thermal conductivity and a mismatch in thermal expansion coefficient with silicon. AlN and Si3N4 ceramic heat sink substrates have a thermal expansion coefficient that closely matches silicon and offer high thermal conductivity. However, to accommodate higher power and withstand higher breakdown voltages, ceramic heat sink substrates require higher thermal conductivity, insulation, and thermal conductivity, and a thermal expansion coefficient that matches that of silicon. These ceramic heat sink substrate materials are no longer fully capable of meeting the trend of power devices toward higher power and higher breakdown voltages. Ceramic heat sink substrates are typically prepared by first forming and sintering ceramic powders to create a ceramic layer. A copper layer is then applied to one or both sides of the ceramic layer using direct copper coating (DBC) or active metal brazing (AMB). The purity, particle size, phase, oxygen content, and molding process of the powder used to form the ceramic layer are key factors influencing the physical and mechanical properties of the ceramic substrate, requiring high levels of material control and process integration. The direct copper coating method offers low cost, but suffers from poor wettability between the ceramic and copper layers, easily creating micropores between them and affecting thermal conductivity. The developed active metal brazing method, based on this method, wets and reacts AgCu solder containing the active elements Ti and Zr at the interface between the ceramic and copper layers, achieving heterogeneous bonding between the ceramic and metal layers. However, its thermal conductivity remains unsatisfactory. Therefore, there is an urgent need for a new ceramic-based composite heat sink substrate. Summary of the Invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a ceramic-based composite material heat dissipation substrate and a preparation method and application thereof, so as to solve the problem of low thermal conductivity of ceramic heat dissipation substrates in the prior art.

[0005] The technical solution of the present invention to solve the above technical problems is as follows: Provide a ceramic matrix composite material heat dissipation substrate, the heat dissipation substrate comprising: C f / SiC layer, CVD-SiC layer, silicon nano layer and copper silicide layer; the CVD-SiC layer is coated on C f / SiC layer, the silicon nano layer covers the upper surface of the CVD-SiC layer, the copper silicide layer covers the upper surface of the silicon nano layer; the C f The / SiC layer is a silicon carbide ceramic matrix composite material reinforced with carbon fiber cloth.

[0006] On the basis of the above technical solution, the present invention can also be improved as follows:

[0007] Furthermore, the carbon fiber cloth has a single layer.

[0008] The beneficial effect of adopting the above-mentioned further technical solution is: in order to improve the strength and toughness of the heat dissipation substrate and the heat dissipation uniformity on the entire base surface, the carbon fiber cloth is preferably single-layered to avoid the introduction of multiple layers of carbon fiber cloth into a large number of pores that cannot be densified later and affect the thermal conductivity.

[0009] Further, C f The thickness of the SiC layer is 0.1-0.2 mm.

[0010] Furthermore, the CVD-SiC layer is f The thickness of a single side of the SiC layer is 0.2-1 mm.

[0011] The beneficial effect of adopting the above further technical solution is: to further improve the high power resistance and bending strength of the heat dissipation substrate.

[0012] Furthermore, the thickness of the silicon nanolayer is 15-100 nm.

[0013] The beneficial effect of adopting the above further technical solution is: in order to enhance the bonding strength between the CVD-SiC layer and the copper silicide and achieve better heat dissipation effect, a silicon nano-transition layer is designed between the two, and the thickness of the silicon nano-transition layer is controlled at 15-100nm.

[0014] Furthermore, the thickness of the copper silicide layer is 0.2-0.4 mm.

[0015] The present invention also provides a method for preparing the above-mentioned ceramic-based composite material heat dissipation substrate, which comprises the following steps in sequence:

[0016] S1: Chemical vapor infiltration was used to deposit silicon carbide ceramic matrix on the surface of a single layer of carbon fiber cloth to prepare C f / SiC layer;

[0017] S2: C prepared in step S1 by chemical vapor deposition f The outer surface of the SiC layer is coated with a deposited silicon carbide ceramic substrate to obtain a CVD-SiC layer;

[0018] S3: Using nano-silicon powder as a raw material, vacuum evaporation is used to deposit nano-silicon on the upper surface of the CVD-SiC layer prepared in step S2 to prepare a silicon nano-layer;

[0019] S4: using copper silicide powder as raw material, a copper silicide layer is prepared on the upper surface of the silicon nanolayer prepared in step S3 by a vacuum metal melting method to prepare a ceramic-based composite heat dissipation substrate.

[0020] Furthermore, in steps S1 and S2, C f / SiC layer and CVD-SiC layer.

[0021] Furthermore, in step S1, the chemical vapor infiltration gas flow parameters are bubbling hydrogen: diluted hydrogen: diluted argon = (0.2-0.4) L / min: (0.1-0.3) L / min: (0.2-0.4) L / min, the furnace pressure is 100-200 Pa, and the deposition temperature is 900-1000°C.

[0022] Furthermore, in step S1, the chemical vapor infiltration gas flow parameters are bubbling hydrogen: diluted hydrogen: diluted argon = 0.3 L / min: 0.2 L / min: 0.3 L / min, the furnace pressure is 150 Pa, and the deposition temperature is 950°C.

[0023] Furthermore, in step S2, the chemical vapor deposition gas flow parameters are bubbling hydrogen: diluted hydrogen: diluted argon = (1-2) L / min: (1-1.5) L / min: (1-2) L / min, furnace pressure 450-550 Pa, and deposition temperature 1350-1450°C.

[0024] Furthermore, in step S2, the chemical vapor deposition gas flow parameters are bubbling hydrogen: diluted hydrogen: diluted argon = 1.5 L / min: 1.2 L / min: 1.5 L / min, the furnace pressure is 500 Pa, and the deposition temperature is 1400°C.

[0025] Furthermore, in step S3, the particle size of the nano silicon powder is 5-25 nm.

[0026] Furthermore, in step S3, the vacuum evaporation method is carried out at a temperature of 1500-2000° C. and a furnace pressure of 100-150 Pa.

[0027] Furthermore, in step S3, the vacuum evaporation method is performed at a temperature of 1700° C. and a furnace pressure of 120 Pa.

[0028] Furthermore, in step S4, the mesh size of the copper silicide powder is 750-850 mesh.

[0029] Furthermore, in step S4, vacuum metal melting is performed at 830-850°C.

[0030] Furthermore, in step S4, copper silicide powder is buried on the silicon nanolayer to a thickness of 1-2 mm, and then placed in a graphite box with a cover for vacuum metal melting.

[0031] The beneficial effects of adopting the above further technical solution are: in order to reduce the surface roughness of the heat dissipation substrate and accurately control the thickness of the copper silicide layer, the mesh size of the copper silicide powder is 750-850 mesh, the thickness of the buried copper silicide powder is 1-2 mm, and vacuum metal melting is performed at 830-850°C.

[0032] The present invention also provides application of the ceramic-based composite material heat dissipation substrate in the preparation of semiconductor devices.

[0033] The present invention has the following beneficial effects:

[0034] 1. The ceramic layer of the heat dissipation substrate of the ceramic matrix composite material of the present invention is composed of C f / SiC layer and CVD-SiC layer, C f The SiC matrix and CVD-SiC material in the / SiC layer are β-SiC, and their thermal conductivity is higher than that of ceramics such as silicon nitride, aluminum nitride, and aluminum oxide. In addition, C f The / SiC layer contains a single layer of continuous carbon fiber cloth, which not only conducts heat evenly, further improving the heat dissipation efficiency, but also absorbs the thermal stress caused by heat storage in the substrate, and the material has high fracture toughness.

[0035] 2. The copper layer of the ceramic-based composite heat dissipation substrate of the present invention is a copper silicide (Cu5Si) layer, whose thermal conductivity is not much different from that of copper, and the silicon nanolayer is used as a transition layer to make the interface between the copper silicide (Cu5Si) layer and the ceramic layer wet, thereby ensuring its bonding strength.

[0036] 3. The overall thickness of the ceramic matrix composite heat dissipation substrate of the present invention is relatively thin, about 1-2 mm, with small heat storage and fast heat dissipation. In addition, although the thickness is relatively thin, the 0.1-0.2 mm C f / SiC layer and single-sided 0.2mm-1mm CVD-SiC material can ensure its flexural strength.

[0037] 4. The copper silicide (Cu5Si) layer adopts vacuum metal melting process to ensure that there are no defects such as pores at the interface between the ceramic layer and the copper layer, and the thermal conductivity is excellent.

[0038] 5. The ceramic-based composite heat dissipation substrate prepared by the present invention has a thermal conductivity of >296W / (m·K), high fracture toughness and high flexural strength, and is suitable for use in high-power modules. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Schematic diagram of the preparation process of the present invention;

[0040] Figure 2 The bonding strength of the heat dissipation substrates prepared in Examples 1-5 and Comparative Example 1;

[0041] Figure 3 is the bending strength of the heat dissipation substrates prepared in Examples 1-5 and Comparative Example 1;

[0042] Figure 4 is the fracture toughness of the heat dissipation substrates prepared in Examples 1-5 and Comparative Example 1;

[0043] Figure 5 The thermal conductivity of the heat dissipation substrates prepared in Examples 1-5 and Comparative Example 1.

[0044] in, Figure 1 In, 1. Carbon fiber cloth; 2. C f / SiC layer; 3. CVD-SiC layer; 4. Silicon nanolayer; 5. Copper silicide layer. DETAILED DESCRIPTION

[0045] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples are only used to explain the present invention and are not intended to limit the scope of the invention. In the embodiments, if specific conditions are not specified, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0046] Example 1:

[0047] A ceramic matrix composite heat dissipation substrate, comprising: a C f / SiC layer 2, CVD-SiC layer 3 with a thickness of 0.2mm on one side, silicon nanolayer 4 with a thickness of 15nm and copper silicide layer 5 with a thickness of 0.2mm; CVD-SiC layer 3 is coated on C f / the outer surface of the SiC layer 2, the silicon nanolayer 4 covers the upper surface of the CVD-SiC layer 3, and the copper silicide layer 5 covers the upper surface of the silicon nanolayer 4; C f The / SiC layer 2 is a silicon carbide ceramic matrix composite material reinforced with carbon fiber cloth 1.

[0048] A ceramic matrix composite heat dissipation substrate, the preparation method of which comprises the following steps in sequence (the preparation process diagram is shown in FIG. Figure 1 ):

[0049] S1: First, a single-layer carbon fiber cloth 1 is placed perpendicular to the residual airflow direction in a chemical vapor vacuum furnace, and a silicon carbide ceramic matrix is ​​deposited on the surface of the single-layer carbon fiber cloth 1 using chemical vapor infiltration (CVI) (airflow parameters are bubbling hydrogen: diluted hydrogen: diluted argon = 0.3 L / min: 0.2 L / min: 0.3 L / min, furnace pressure 150 Pa, deposition temperature 950°C) to obtain C f / SiC layer 2 (thickness 0.17 mm);

[0050] S2: Continue in the same chemical vapor vacuum furnace, change the gas flow parameters and temperature parameters, that is, the gas flow parameters are bubbling hydrogen: diluted hydrogen: diluted argon = 1.5L / min: 1.2L / min: 1.5L / min, the furnace pressure is 500Pa, the deposition temperature is 1400℃, and the C prepared in step S1 is deposited by chemical vapor deposition. f The outer surface of the SiC layer 2 is coated with a deposited silicon carbide ceramic substrate to obtain a CVD-SiC layer 3 (single-side thickness of 0.2 mm);

[0051] S3: After the ceramic layer is prepared, nano-silicon powder with a particle size of 15 nm is used as the raw material, and the deposition side is placed in a vacuum evaporation furnace. Nano-silicon is evaporated on the upper surface of the CVD-SiC layer 3 prepared in step S2 by vacuum evaporation (temperature 1700°C, furnace pressure 120 Pa) to prepare a silicon nano-layer 4 (thickness 15 nm);

[0052] S4: Using 800-mesh copper silicide powder as raw material, the silicon nanolayer 4 is covered with copper silicide powder to a thickness of 1 mm, and then placed in a graphite box with a lid. In a vacuum metal melting furnace, at 840°C, a copper silicide layer 5 (thickness 0.2 mm) is prepared on the upper surface of the silicon nanolayer 4 prepared in step S3 using a vacuum metal melting method. After being taken out of the furnace, the surface is polished to obtain a ceramic-based composite heat dissipation substrate.

[0053] Example 2:

[0054] A ceramic matrix composite heat dissipation substrate, comprising: a C-based composite material with a thickness of 0.17 mm f / SiC layer 2, CVD-SiC layer 3 with a thickness of 1mm on one side, silicon nanolayer 4 with a thickness of 100nm and copper silicide layer 5 with a thickness of 0.4mm; CVD-SiC layer 3 is coated on C f / the outer surface of the SiC layer 2, the silicon nanolayer 4 covers the upper surface of the CVD-SiC layer 3, and the copper silicide layer 5 covers the upper surface of the silicon nanolayer 4; C f The / SiC layer 2 is a silicon carbide ceramic matrix composite material reinforced with carbon fiber cloth 1.

[0055] A ceramic-based composite material heat dissipation substrate, the preparation method of which comprises the following steps in sequence:

[0056] S1: First, a single-layer carbon fiber cloth 1 is placed perpendicular to the residual airflow direction in a chemical vapor vacuum furnace, and a silicon carbide ceramic matrix is ​​deposited on the surface of the single-layer carbon fiber cloth 1 using chemical vapor infiltration (CVI) (airflow parameters are bubbling hydrogen: diluted hydrogen: diluted argon = 0.4 L / min: 0.3 L / min: 0.4 L / min, furnace pressure 200 Pa, deposition temperature 1000 ° C) to obtain C f / SiC layer 2 (thickness 0.17 mm);

[0057] S2: Continue in the same chemical vapor vacuum furnace, change the gas flow parameters and temperature parameters, that is, the gas flow parameters are bubbling hydrogen: diluted hydrogen: diluted argon = 2L / min: 1.5L / min: 2L / min, the furnace pressure is 550Pa, the deposition temperature is 1450℃, and the C prepared in step S1 is deposited by chemical vapor deposition. f The outer surface of the SiC layer 2 is coated with a deposited silicon carbide ceramic substrate to obtain a CVD-SiC layer 3 (single-side thickness of 1 mm);

[0058] S3: After the ceramic layer is prepared, nano-silicon powder with a particle size of 5 nm is used as the raw material, and the deposition side is placed in a vacuum evaporation furnace. Nano-silicon is evaporated on the upper surface of the CVD-SiC layer 3 prepared in step S2 by vacuum evaporation (temperature 2000°C, furnace pressure 150 Pa) to prepare a silicon nano-layer 4 (thickness 100 nm);

[0059] S4: Using 750-mesh copper silicide powder as raw material, the silicon nanolayer 4 is covered with copper silicide powder to a thickness of 2 mm, and then placed in a graphite box with a lid. In a vacuum metal melting furnace, at 830°C, a copper silicide layer 5 (thickness 0.4 mm) is prepared on the upper surface of the silicon nanolayer 4 prepared in step S3 using a vacuum metal melting method. After being taken out of the furnace, the surface is polished to obtain a ceramic-based composite heat dissipation substrate.

[0060] Example 3:

[0061] A ceramic matrix composite heat dissipation substrate, comprising: a C f / SiC layer 2, CVD-SiC layer 3 with a thickness of 0.3mm on one side, silicon nanolayer 4 with a thickness of 50nm and copper silicide layer 5 with a thickness of 0.3mm; CVD-SiC layer 3 is coated on C f / the outer surface of the SiC layer 2, the silicon nanolayer 4 covers the upper surface of the CVD-SiC layer 3, and the copper silicide layer 5 covers the upper surface of the silicon nanolayer 4; C f The / SiC layer 2 is a silicon carbide ceramic matrix composite material reinforced with carbon fiber cloth 1.

[0062] A ceramic-based composite material heat dissipation substrate, the preparation method of which comprises the following steps in sequence:

[0063] S1: First, a single-layer carbon fiber cloth 1 is placed perpendicular to the residual airflow direction in a chemical vapor vacuum furnace, and a silicon carbide ceramic matrix is ​​deposited on the surface of the single-layer carbon fiber cloth 1 using chemical vapor infiltration (CVI) (airflow parameters are bubbling hydrogen: diluted hydrogen: diluted argon = 0.2 L / min: 0.1 L / min: 0.2 L / min, furnace pressure 100 Pa, deposition temperature 900 ° C) to obtain C f / SiC layer 2 (thickness 0.1 mm);

[0064] S2: Continue in the same chemical vapor vacuum furnace, change the gas flow parameters and temperature parameters, that is, the gas flow parameters are bubbling hydrogen: diluted hydrogen: diluted argon = 1L / min: 1L / min: 1L / min, the furnace pressure is 450Pa, the deposition temperature is 1350℃, and the C prepared in step S1 is deposited by chemical vapor deposition. f The outer surface of the SiC layer 2 is coated with a deposited silicon carbide ceramic substrate to obtain a CVD-SiC layer 3 (single-side thickness of 0.3 mm);

[0065] S3: After the ceramic layer is prepared, nano-silicon powder with a particle size of 25 nm is used as the raw material, and the deposition surface is placed in a vacuum evaporation furnace. Nano-silicon is evaporated on the upper surface of the CVD-SiC layer 3 prepared in step S2 by vacuum evaporation (temperature 1500°C, furnace pressure 100 Pa) to prepare a silicon nano-layer 4 (thickness 50 nm);

[0066] S4: Using 850-mesh copper silicide powder as raw material, the silicon nanolayer 4 is covered with copper silicide powder to a thickness of 1.5 mm, and then placed in a graphite box with a lid. In a vacuum metal melting furnace, at 850°C, a copper silicide layer 5 (with a thickness of 0.3 mm) is prepared on the upper surface of the silicon nanolayer 4 prepared in step S3 using a vacuum metal melting method. After being taken out of the furnace, the surface is polished to obtain a ceramic-based composite heat dissipation substrate.

[0067] Example 4:

[0068] A ceramic matrix composite heat dissipation substrate, comprising: a C f / SiC layer 2, CVD-SiC layer 3 with a thickness of 0.5mm on one side, silicon nanolayer 4 with a thickness of 60nm and copper silicide layer 5 with a thickness of 0.35mm; CVD-SiC layer 3 is coated on C f / the outer surface of the SiC layer 2, the silicon nanolayer 4 covers the upper surface of the CVD-SiC layer 3, and the copper silicide layer 5 covers the upper surface of the silicon nanolayer 4; C f The / SiC layer 2 is a silicon carbide ceramic matrix composite material reinforced with carbon fiber cloth 1.

[0069] A ceramic-based composite material heat dissipation substrate, the preparation method of which comprises the following steps in sequence:

[0070] S1: First, a single-layer carbon fiber cloth 1 is placed perpendicular to the residual airflow direction in a chemical vapor vacuum furnace, and a silicon carbide ceramic matrix is ​​deposited on the surface of the single-layer carbon fiber cloth 1 using chemical vapor infiltration (CVI) (airflow parameters are bubbling hydrogen: diluted hydrogen: diluted argon = 0.3 L / min: 0.2 L / min: 0.3 L / min, furnace pressure 150 Pa, deposition temperature 950°C) to obtain C f / SiC layer 2 (thickness 0.18 mm);

[0071] S2: Continue in the same chemical vapor vacuum furnace, change the gas flow parameters and temperature parameters, that is, the gas flow parameters are bubbling hydrogen: diluted hydrogen: diluted argon = 1.5L / min: 1.2L / min: 1.5L / min, the furnace pressure is 500Pa, the deposition temperature is 1400℃, and the C prepared in step S1 is deposited by chemical vapor deposition. f The outer surface of the SiC layer 2 is coated with a deposited silicon carbide ceramic substrate to obtain a CVD-SiC layer 3 (single-side thickness of 0.5 mm);

[0072] S3: After the ceramic layer is prepared, nano-silicon powder with a particle size of 10 nm is used as the raw material, and the deposition side is placed in a vacuum evaporation furnace. Nano-silicon is evaporated on the upper surface of the CVD-SiC layer 3 prepared in step S2 by vacuum evaporation (temperature 1700°C, furnace pressure 120 Pa) to prepare a silicon nano-layer 4 (thickness 60 nm);

[0073] S4: Using 760-mesh copper silicide powder as the raw material, the silicon nanolayer 4 is covered with copper silicide powder to a thickness of 1.8 mm. The silicon nanolayer 4 is then placed in a covered graphite box and melted in a vacuum metal melting furnace at 845°C. A copper silicide layer 5 (0.35 mm thick) is formed on the upper surface of the silicon nanolayer 4 produced in step S3 using a vacuum metal melting method. After removal from the furnace, the surface is polished to produce a ceramic matrix composite heat dissipation substrate.

[0074] Example 5:

[0075] A ceramic matrix composite heat dissipation substrate, comprising: a C f / SiC layer 2, CVD-SiC layer 3 with a thickness of 0.9mm on one side, silicon nanolayer 4 with a thickness of 90nm and copper silicide layer 5 with a thickness of 0.39mm; CVD-SiC layer 3 is coated on C f / the outer surface of the SiC layer 2, the silicon nanolayer 4 covers the upper surface of the CVD-SiC layer 3, and the copper silicide layer 5 covers the upper surface of the silicon nanolayer 4; C f The / SiC layer 2 is a silicon carbide ceramic matrix composite material reinforced with carbon fiber cloth 1.

[0076] A ceramic-based composite material heat dissipation substrate, the preparation method of which comprises the following steps in sequence:

[0077] S1: First, a single-layer carbon fiber cloth 1 is placed perpendicular to the residual airflow direction in a chemical vapor vacuum furnace, and a silicon carbide ceramic matrix is ​​deposited on the surface of the single-layer carbon fiber cloth 1 using chemical vapor infiltration (CVI) (airflow parameters are bubbling hydrogen: diluted hydrogen: diluted argon = 0.35 L / min: 0.25 L / min: 0.35 L / min, furnace pressure 155 Pa, deposition temperature 955°C) to obtain C f / SiC layer 2 (thickness 0.19 mm);

[0078] S2: Continue in the same chemical vapor vacuum furnace, change the gas flow parameters and temperature parameters, that is, the gas flow parameters are bubbling hydrogen: diluted hydrogen: diluted argon = 1.8 L / min: 1.3 L / min: 1.8 L / min, the furnace pressure is 520 Pa, the deposition temperature is 1430 ° C, and the C prepared in step S1 is prepared by chemical vapor deposition. f The outer surface of the SiC layer 2 is coated with a deposited silicon carbide ceramic substrate to obtain a CVD-SiC layer 3 (single-side thickness of 0.9 mm);

[0079] S3: After the ceramic layer is prepared, nano-silicon powder with a particle size of 24 nm is used as the raw material, and the evaporation surface is placed in a vacuum evaporation furnace. Nano-silicon is evaporated on the upper surface of the CVD-SiC layer 3 prepared in step S2 by vacuum evaporation (temperature 1750°C, furnace pressure 125 Pa) to prepare a silicon nano-layer 4 (thickness 90 nm);

[0080] S4: Using 830-mesh copper silicide powder as raw material, the silicon nanolayer 4 is covered with copper silicide powder to a thickness of 1.8 mm, and then placed in a graphite box with a lid. In a vacuum metal melting furnace, at 848°C, a copper silicide layer 5 (with a thickness of 0.39 mm) is prepared on the upper surface of the silicon nanolayer 4 prepared in step S3 using a vacuum metal melting method. After being taken out of the furnace, the surface is polished to obtain a ceramic-based composite heat dissipation substrate.

[0081] Comparative Example 1:

[0082] A ceramic-based composite heat dissipation substrate does not include the silicon nanolayer 4, and the rest is the same as in Example 5.

[0083] Test example

[0084] 1. Bonding strength test

[0085] The ceramic matrix composite heat dissipation substrates prepared in Examples 1-5 and Comparative Example 1 were tested for interlayer bonding strength according to ASTM-C633-01 "Standard Test Method for Adhesion or Cohesion Strength of Thermal Spray Coatings". The results are shown in Table 1. Figure 2 .

[0086] Depend on Figure 2 It can be seen that the average bonding strength of the ceramic-based composite heat dissipation substrate prepared by the present invention reaches 34.2 MPa, while the interlayer bonding strength of the comparative example sample is only 20 MPa.

[0087] 2. Bending Strength

[0088] The ceramic matrix composite heat dissipation substrates prepared in Examples 1-5 and Comparative Example 1 were tested for flexural strength according to ASTM-C1341-13S "standard Test Method for Flexural Properties of Continuous Fiber-Reinforced Advanced Ceramic Composites 1". The results are shown in Table 1. Figure 3 .

[0089] Depend on Figure 3 It can be seen that the average bending strength of the ceramic-based composite heat dissipation substrate prepared in the present invention reaches 355.8 MPa.

[0090] 3. Fracture toughness

[0091] The fracture toughness of the ceramic matrix composite heat dissipation substrates prepared in Examples 1-5 and Comparative Example 1 was tested according to ASTM C1421-18 "Standard Test Methods for Determination of Fracture Toughness of Advanced Ceramics at Ambient Temperature".

[0092] Depend on Figure 4 It can be seen that the fracture toughness of the ceramic matrix composite heat dissipation substrate prepared by the present invention is ≥7MPa·m 1 / 2 .

[0093] 4. Thermal conductivity

[0094] The thermal conductivity of the ceramic matrix composite heat dissipation substrates prepared in Examples 1-5 and Comparative Example 1 was tested according to ASTM E1461-13 "Standard Test Method for Thermal Diffusivity by the Flash Method". The results are shown in Table 1. Figure 5 .

[0095] Depend on Figure 5 It can be seen that the average thermal conductivity of the ceramic-based composite heat dissipation substrate prepared in the present invention is 296 W / (m·K), while the interlayer bonding strength of the comparative example sample is only 160 W / (m·K).

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A ceramic matrix composite material heat dissipation substrate, characterized in that: The heat dissipation substrate includes: C f / SiC layer (2), CVD-SiC layer (3), silicon nanolayer (4) and copper silicide layer (5); the CVD-SiC layer (3) is coated on the C f / SiC layer (2), the silicon nano layer (4) covers the upper surface of the CVD-SiC layer (3), the copper silicide layer (5) covers the upper surface of the silicon nano layer (4); the C f / SiC layer (2) is a silicon carbide ceramic matrix composite material reinforced by carbon fiber cloth (1); The copper silicide layer (5) is produced by a vacuum metal melting process.

2. The ceramic matrix composite heat dissipation substrate according to claim 1, characterized in that: The C f The thickness of the SiC layer (2) is 0.1-0.2 mm.

3. The ceramic matrix composite heat dissipation substrate according to claim 1, characterized in that: The CVD-SiC layer (3) is in C f The thickness of the SiC layer (2) on one side is 0.2-1 mm.

4. The ceramic matrix composite heat dissipation substrate according to claim 1, characterized in that: The thickness of the silicon nanolayer (4) is 15-100 nm.

5. The ceramic matrix composite heat dissipation substrate according to claim 1, characterized in that: The thickness of the copper silicide layer (5) is 0.2-0.4 mm.

6. The method for preparing a ceramic matrix composite heat dissipation substrate according to any one of claims 1 to 5, characterized in that: The following steps are included in sequence: S1: A silicon carbide ceramic matrix is ​​deposited on the surface of a single layer of carbon fiber cloth (1) using chemical vapor infiltration to obtain C f / SiC layer (2); S2: C prepared in step S1 by chemical vapor deposition f The outer surface of the SiC layer (2) is coated with a deposited silicon carbide ceramic substrate to obtain a CVD-SiC layer (3); S3: using nano-silicon powder as a raw material, vacuum evaporation is used to deposit nano-silicon on the upper surface of the CVD-SiC layer (3) prepared in step S2 to prepare a silicon nano-layer (4); S4: using copper silicide powder as a raw material, a copper silicide layer (5) is prepared on the upper surface of the silicon nanolayer (4) prepared in step S3 by a vacuum metal melting method to prepare a ceramic-based composite material heat dissipation substrate.

7. The method for preparing a ceramic matrix composite heat dissipation substrate according to claim 6, characterized in that: In steps S1 and S2, C is generated in sequence by changing the reaction parameters in the same chemical vapor vacuum equipment. f / SiC layer (2) and CVD-SiC layer (3).

8. The method for preparing a ceramic matrix composite heat dissipation substrate according to claim 6, characterized in that: In step S3, the particle size of the nano silicon powder is 5-25 nm.

9. The method for preparing a ceramic matrix composite heat dissipation substrate according to claim 6, characterized in that: In step S4, the mesh size of the copper silicide powder is 750-850 mesh.

10. Use of the ceramic matrix composite heat dissipation substrate according to any one of claims 1 to 5 in the preparation of semiconductor devices.

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