Silicon nitride ceramic copper-clad substrate and preparation method thereof

Abstract

The invention provides a silicon nitride ceramic copper-clad substrate and a preparation method thereof, the silicon nitride ceramic copper-clad substrate comprises a silicon nitride ceramic substrate, and a Zr-based gradient transition layer and a copper layer are sequentially laminated on the silicon nitride ceramic substrate; the Zr-based gradient transition layer is a Zr-N layer or a Zr-Ru layer; the content of Zr in the Zr-N layer is gradually increased from one side of the silicon nitride ceramic substrate to one side of the copper layer, or the content of N is gradually increased from one side of the silicon nitride ceramic substrate to one side of the copper layer; and the content of Ru in the Zr-Ru layer is gradually increased from one side of the silicon nitride ceramic substrate to one side of the copper layer. The preparation method of the silicon nitride ceramic copper-clad substrate is low in equipment and process control requirements and low in cost, the bonding force and the thermal shock resistance of the copper layer and the silicon nitride ceramic substrate can be improved by utilizing the nanoscale gradient transition layer with the structural gradient, and the comprehensive performance of the silicon nitride ceramic substrate is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of advanced electronic packaging technology and functional thin film preparation technology, and specifically relates to a silicon nitride ceramic copper-clad substrate and a preparation method thereof. Background Art

[0002] Ceramic substrates are the core part of power device modules. On the one hand, they play a key role in mechanical support, and on the other hand, they serve as important heat dissipation materials. High thermal conductivity ceramic substrates (such as silicon nitride and aluminum nitride) have become the most promising packaging substrate materials in the field of high-power devices such as IGBT modules due to their excellent comprehensive performance. Surface metallization is one of the important links for ceramic substrates to achieve chip and electronic component interconnection. It requires that the metal conductive layer has low resistance and strong adhesion to the ceramic substrate, and still has high thermal conductivity after metallization. However, as ceramic materials are strong covalent bond compounds, their electronic coordination is very stable, not easy to react with other materials, and difficult to wet with common metals. The performance of ceramic substrates after surface metallization is closely related to the stability of power devices during operation, which restricts the widespread application of ceramic substrates. Therefore, how to achieve high-reliability ceramic substrate surface metallization is of great significance.

[0003] At present, the commonly used metallization methods are mainly direct copper coating (DBC) and active metal brazing (AMB). The preparation temperature of direct copper coating is high, which leads to large interface stress between metal and ceramic. The preparation process has high requirements for equipment and process control, which increases production costs. The active metal brazing method has high costs, there are few suitable active solders, and the solder composition and process have a great influence on the welding quality. The thickness of the interlayer determines the welding quality, but it is not easy to control. Summary of the invention

[0004] In order to solve the problems of the above-mentioned prior art, the present invention provides a silicon nitride ceramic copper-clad substrate and a preparation method thereof. The preparation method of the silicon nitride ceramic copper-clad substrate has low requirements on equipment and process control, low cost, and can utilize a nanoscale gradient transition layer with a structural gradient to improve the bonding strength and thermal shock resistance between the copper layer and the silicon nitride ceramic substrate, thereby improving the comprehensive performance of the silicon nitride ceramic substrate.

[0005] The present invention is achieved through the following technical solutions: In a first aspect, the present invention provides a silicon nitride ceramic copper-clad substrate, comprising: a silicon nitride ceramic substrate, on which a Zr-based gradient transition layer and a copper layer are sequentially stacked; the Zr-based gradient transition layer is a Zr-N layer or a Zr-Ru layer; the Zr content in the Zr-N layer gradually increases from one side of the silicon nitride ceramic substrate to the copper layer side, or the N content gradually increases from one side of the silicon nitride ceramic substrate to the copper layer side; the Ru content in the Zr-Ru layer gradually increases from one side of the silicon nitride ceramic substrate to the copper layer side.

[0006] Preferably, the thickness of the Zr-based gradient transition layer is 100-800 nm.

[0007] Furthermore, the thickness of the Zr-based gradient transition layer is 100-300 nm.

[0008] Preferably, the copper layer has a thickness of 0.5-2 μm.

[0009] In a second aspect, the present invention provides a method for preparing the silicon nitride ceramic copper-clad substrate, comprising the following steps: S1: double-sided polishing and cleaning of the silicon nitride ceramic substrate; S2: Depositing a Zr-based gradient transition layer on the surface of a silicon nitride ceramic substrate using magnetron sputtering technology; S3: depositing a copper layer on the Zr-based gradient transition layer using magnetron sputtering technology.

[0010] Preferably, in S1, the cleaning process specifically comprises: ultrasonically cleaning the silicon nitride ceramic substrate with acetone and anhydrous ethanol in sequence.

[0011] Preferably, S2 specifically includes: using a Zr target as a target material, and depositing a Zr-N layer on a silicon nitride ceramic substrate by magnetron sputtering under the condition of passing Ar gas and N2 gas; or, using Zr and Ru as target materials, passing Ar gas, and depositing a Zr-Ru layer on a silicon nitride ceramic substrate by magnetron sputtering.

[0012] Furthermore, when depositing the Zr-N layer, the process parameters are: Ar gas flow rate is 10~50 mL / min, N2 gas flow rate is 2~10 mL / min, working gas pressure is 0.30~1.00 Pa, Zr target sputtering power is 50~100 W, and deposition time is 30~100 min; when depositing the Zr-Ru layer, the process parameters are: Ar gas flow rate is 10~50 mL / min, working gas pressure is 0.30~1.00 Pa, Zr target sputtering power is fixed at 60~100 W, Ru target sputtering power is 30~50 W, and deposition time is 60~120 min.

[0013] Preferably, S3 specifically comprises: using a Cu target as a target material, and depositing a copper layer on the Zr-based gradient transition layer by direct current magnetron sputtering under the condition of introducing Ar gas.

[0014] Furthermore, when depositing the copper layer, the process parameters are: DC sputtering power is 80~120 W, Ar gas flow rate is 10~50 mL / min, working gas pressure is 0.5~1 Pa, and deposition time is 1~2 h.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The silicon nitride ceramic copper-clad substrate described in the present invention has a Zr-based gradient transition layer between the silicon nitride ceramic substrate and the copper layer. The Zr-based gradient transition layer is composed of a Zr-N or Zr-Ru layer, and the thermal expansion coefficients of the two are both between ceramic and copper metal. By adjusting the thickness and composition gradient of the gradient transition layer, the interface composition distribution and structural gradient between the silicon nitride ceramic substrate and the copper layer can be optimized, thereby solving the problem of thermal expansion coefficient mismatch between the two, further enhancing interface compatibility, and improving interface bonding strength.

[0016] Furthermore, for the silicon nitride ceramic copper-clad substrate of the present invention, as the thickness of the Zr-based gradient transition layer decreases, the interface bonding strength of the silicon nitride ceramic substrate / copper layer gradually increases. Therefore, the interface bonding strength between the two can be adjusted by adjusting the thickness of the gradient layer, thereby improving the interface bonding performance of the silicon nitride ceramic substrate / copper layer.

[0017] The present invention adopts magnetron sputtering technology to deposit a Zr-N layer, a Zr-Ru layer and a copper layer on a silicon nitride ceramic substrate, and has a simple preparation method, good process repeatability, strong film controllability, low equipment and process control requirements and low cost.

[0018] Furthermore, by adjusting the sputtering process parameters, the composition distribution of the gradient transition layer can be adjusted, its structural gradient can be adjusted, and thus the interface bonding strength can be adjusted. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 This is a process flow chart of metallization of silicon nitride ceramic substrate of the present invention; Figure 2 are cross-sectional morphology diagrams of the Cu / Zr-Ru / silicon nitride substrates in Example 4 (a) and Example 5 (b) of the present invention; Figure 3 These are the test results of the interface bonding strength of the Cu / Zr-Ru / silicon nitride substrate in Examples 4 and 5 of the present invention. DETAILED DESCRIPTION

[0021] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0022] It should be noted that the process equipment or devices not specifically specified in the following embodiments are all conventional equipment or devices in the art.

[0023] It should be noted that the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to define the scope of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the present invention without substantially changing the technical content.

[0024] The silicon nitride ceramic copper-clad substrate of the present invention comprises: a silicon nitride ceramic substrate, on which a Zr-based gradient transition layer and a copper layer are sequentially stacked; the Zr-based gradient transition layer is a Zr-N layer or a Zr-Ru layer; the Zr content in the Zr-N layer gradually increases from the silicon nitride ceramic substrate side to the copper layer side or the N content gradually increases from the silicon nitride ceramic substrate side to the copper layer side; the Ru content in the Zr-Ru layer gradually increases from the silicon nitride ceramic substrate side to the copper layer side.

[0025] The Zr-based gradient transition layer of the present invention is composed of a Zr-N or Zr-Ru layer, the thermal expansion coefficients of both are between ceramic and copper metal, and the Zr-based gradient transition layer has a composition gradient, which can cause a structural gradient. By adjusting the thickness and composition gradient of the gradient transition layer, the interface composition distribution and structural gradient between the silicon nitride ceramic substrate and the copper layer can be optimized, thereby solving the problem of thermal expansion coefficient mismatch between the two, further enhancing interface compatibility, and improving interface bonding strength.

[0026] The thickness of the Zr-based gradient transition layer of the present invention is nanometer-scale. Specifically, the thickness of the gradient transition layer is preferably 100-800 nm, more preferably 100-300 nm. The thinner the Zr-based gradient transition layer, the higher the interface bonding strength of the silicon nitride ceramic copper-clad substrate, that is, the gradient transition layer between the silicon nitride ceramic substrate and the copper layer in the present invention has an abnormal size effect.

[0027] In a specific embodiment of the present invention, the thickness of the copper layer is 0.5-2 μm.

[0028] like Figure 1 As shown, the preparation method of the silicon nitride ceramic copper-clad substrate of the present invention comprises: S1, double-sided polishing and cleaning of the silicon nitride ceramic substrate, and then drying and placing in a vacuum chamber for standby use; S2, depositing a Zr-based gradient transition layer on a silicon nitride ceramic substrate by magnetron sputtering; S3, depositing a copper layer on the Zr-based gradient transition layer by direct current magnetron sputtering to obtain a silicon nitride ceramic copper-clad substrate.

[0029] In some specific embodiments of the present invention, S2 specifically refers to: by reactive magnetron sputtering, with a Zr target as the target material and N2 gas as the reaction gas for depositing the Zr-N layer, while introducing Ar gas, adjusting the N2 flow rate, working gas pressure or sputtering power of the Zr target to deposit a Zr-N gradient layer on a silicon nitride ceramic substrate, wherein Ar gas is used as the sputtering gas.

[0030] In some specific embodiments of the present invention, S2 specifically comprises: depositing a Zr-Ru layer on a silicon nitride ceramic substrate by reactive magnetron sputtering with a Zr target and a Ru target as target materials by adjusting the target sputtering power and the working gas pressure.

[0031] In a specific embodiment of the present invention, when depositing the Zr-N layer, the sputtering process parameters are: when depositing the Zr-N layer, the process parameters are: Ar gas flow rate is 10~50 mL / min, N2 gas flow rate is 2~10 mL / min, working gas pressure is 0.30~1.00 Pa, Zr target sputtering power is 50~100 W, and deposition time is 30~100 min.

[0032] In a specific embodiment of the present invention, when depositing the Zr-Ru layer, the process parameters are: Ar gas flow rate is 10~50 mL / min, the working gas pressure is 0.30~1.00 Pa, the Zr target sputtering power is fixed at 60~100 W, the Ru target sputtering power is 30~50 W, and the deposition time is 60~120 min.

[0033] In a specific embodiment of the present invention, S3 specifically comprises: using a DC magnetron sputtering method, taking a Cu target as a target material, and depositing a copper layer on the Zr-based gradient transition layer under the condition of passing Ar gas.

[0034] In a specific embodiment of the present invention, when depositing the copper layer, the process parameters are: Cu target sputtering power is 80~120 W, Ar gas flow rate is 20~50 mL / min, working gas pressure is 0.5~1 Pa, and sputtering deposition time is 1~2 h.

[0035] In addition, it should be noted that in the present invention, the sputtering deposition is carried out at room temperature.

[0036] Example 1 The metallization method of the silicon nitride ceramic substrate of the present invention comprises: Step 1), after double-sided polishing of the silicon nitride ceramic substrate, ultrasonic cleaning was carried out in acetone and anhydrous ethanol for 10 min, and then taken out and dried with a hair dryer and placed in a vacuum chamber for standby use. The Zr target (Φ50 mm×5 mm, purity 99.95%) and the Cu target (Φ50 mm×5 mm, purity 99.95%) were polished with 600-mesh water sandpaper, ultrasonically cleaned in acetone for 10 min, and then installed on the target position of the sputtering chamber.

[0037] Step 2), when the background vacuum of the sputtering chamber is 5.0×10 -4 Pa, Ar gas (purity 99.99%) was introduced, the Ar gas flow rate was set to 20 mL / min, the working gas pressure was 0.5 Pa, the DC power supply was turned on, the Zr target sputtering power was adjusted to 60 W to start depositing the Zr-N layer, the N2 gas flow rate was gradually increased from 0 to 10 mL / min, the sputtering time was 45 min, and a Zr-N / silicon nitride substrate was obtained.

[0038] Step 3), based on step 2), a copper layer is prepared. Specifically, the operation is as follows: The sputtering process parameters are: the background vacuum of the sputtering chamber is 5.0×10 -4 Pa, a DC sputtering Cu target was used, the sputtering power was 100 W, the Ar gas flow rate was 20 mL / min, the working gas pressure was 0.5 Pa, and the Cu layer was sputtered for 60 min to obtain a Cu / Zr-N / silicon nitride substrate.

[0039] Example 2 The metallization method of the silicon nitride ceramic substrate of the present invention comprises: Step 1), after double-sided polishing of the silicon nitride ceramic substrate, ultrasonic cleaning was carried out in acetone and anhydrous ethanol for 10 min, and then taken out and dried with a hair dryer and placed in a vacuum chamber for standby use. The Zr target (Φ50 mm×5 mm, purity 99.95%) and the Cu target (Φ50 mm×5 mm, purity 99.95%) were polished with 600-mesh water sandpaper, ultrasonically cleaned in acetone for 10 min, and then installed on the target position of the sputtering chamber.

[0040] Step 2), when the background vacuum of the sputtering chamber is 5.0×10 -4Pa, Ar gas (purity 99.99%) was introduced, the Ar gas flow rate was set to 20 mL / min, the working gas pressure was 0.5 Pa, the DC power supply was turned on, the Zr target sputtering power was adjusted from 55 W to 75 W, the Zr-N layer was deposited, the N2 gas flow rate was 6 mL / min, and the sputtering time was 45 min to obtain a Zr-N / silicon nitride substrate.

[0041] Step 3), based on step 2), a copper layer is prepared. Specifically, the operation is as follows: The sputtering process parameters are: the background vacuum of the sputtering chamber is 5.0×10 -4 Pa, a DC sputtering Cu target was used, the sputtering power was 100 W, the Ar gas flow rate was 20 mL / min, the working gas pressure was 0.5 Pa, and the Cu layer was sputtered for 60 min to obtain a Cu / Zr-N / silicon nitride substrate.

[0042] Example 3 The metallization method of the silicon nitride ceramic substrate of the present invention comprises: Step 1), after double-sided polishing of the silicon nitride ceramic substrate, ultrasonic cleaning was carried out in acetone and anhydrous ethanol for 10 min, and then taken out and dried with a hair dryer and placed in a vacuum chamber for standby use. The Zr target (Φ50 mm×5 mm, purity 99.95%) and the Cu target (Φ50 mm×5 mm, purity 99.95%) were polished with 600-mesh water sandpaper, ultrasonically cleaned in acetone for 10 min, and then installed on the target position of the sputtering chamber.

[0043] Step 2), when the background vacuum of the sputtering chamber is 5.0×10 -4 Pa, Ar gas (purity 99.99%) was introduced, the Ar gas flow rate was set to 20 mL / min, the working gas pressure increased from 0.5 Pa to 1.0 Pa, the DC power supply was turned on, the Zr target sputtering power was adjusted to 60 W to start depositing the Zr-N layer, the N2 gas flow rate was 6 mL / min, and the sputtering time was 45 min to obtain a Zr-N / silicon nitride substrate.

[0044] Step 3), based on step 2), a copper layer is prepared. Specifically, the operation is as follows: The sputtering process parameters are: the background vacuum of the sputtering chamber is 5.0×10 -4 Pa, a DC sputtering Cu target was used, the sputtering power was 100 W, the Ar gas flow rate was 20 mL / min, the working gas pressure was 0.5 Pa, and the Cu layer was sputtered for 60 min to obtain a Cu / Zr-N / silicon nitride substrate.

[0045] Example 4 The metallization method of the silicon nitride ceramic substrate of the present invention comprises: Step 1), after double-sided polishing of the silicon nitride ceramic substrate, ultrasonic cleaning was carried out in acetone and anhydrous ethanol for 10 min, and then taken out and dried with a hair dryer and placed in a vacuum chamber for standby use. The Zr target (Φ50 mm×5 mm, purity 99.95%), Ru target (Φ50 mm×5 mm, purity 99.95%) and Cu target (Φ50 mm×5 mm, purity 99.95%) were polished with 600-mesh water sandpaper, ultrasonically cleaned in acetone for 10 min, and then installed on the target position of the sputtering chamber.

[0046] Step 2), when the background vacuum of the sputtering chamber is 5.0×10 -4 Pa, Ar gas (purity 99.99%) was introduced, the Ar gas flow rate was set to 20 mL / min, DC sputtering of Zr target was used, RF sputtering of Ru target was used, the Zr sputtering power was fixed at 100 W, the first stage: working gas pressure 0.43 Pa, Ru sputtering power 30 W, sputtering time 20 min; second stage: working gas pressure 0.5 Pa, Ru sputtering power 35 W, sputtering time 20 min; third stage: working gas pressure 0.7 Pa, Ru sputtering power 40 W, sputtering time 20 min; fourth stage: working gas pressure 1.0 Pa, Ru sputtering power 45 W, sputtering time 20 min, to obtain a Zr-Ru gradient layer / silicon nitride substrate.

[0047] Step 3), based on step 2), a copper layer is prepared. Specifically, the operation is as follows: The sputtering process parameters are: the background vacuum of the sputtering chamber is 5.0×10 -4 Pa, a DC sputtering Cu target was used, the sputtering power was 100 W, the Ar gas flow rate was 20 mL / min, the working gas pressure was 0.5 Pa, and the Cu layer was sputtered for 60 min to obtain a Cu / Zr-Ru / silicon nitride substrate.

[0048] Example 5 The metallization method of the silicon nitride ceramic substrate of the present invention comprises: Step 1), after double-sided polishing of the silicon nitride ceramic substrate, ultrasonic cleaning was carried out in acetone and anhydrous ethanol for 10 min, and then taken out and dried with a hair dryer and placed in a vacuum chamber for standby use. The Zr target (Φ50 mm×5 mm, purity 99.95%), Ru target (Φ50 mm×5 mm, purity 99.95%) and Cu target (Φ50 mm×5 mm, purity 99.95%) were polished with 600-mesh water sandpaper, ultrasonically cleaned in acetone for 10 min, and then installed on the target position of the sputtering chamber.

[0049] Step 2), when the background vacuum of the sputtering chamber is 5.0×10 -4 Pa, Ar gas (purity 99.99%) was introduced, the Ar gas flow rate was set to 20 mL / min, DC sputtering of Zr target was used, RF sputtering of Ru target was used, the Zr sputtering power was fixed at 100 W, and the working gas pressure was fixed at 0.5 Pa; in the first stage: Ru sputtering power was 30 W, and the sputtering time was 17.5 min; in the second stage: Ru sputtering power was 35 W, and the sputtering time was 17.5 min; in the third stage: Ru sputtering power was 40 W, and the sputtering time was 17.5 min; in the fourth stage: Ru sputtering power was 45 W, and the sputtering time was 17.5 min, to obtain a Zr-Ru gradient layer / silicon nitride substrate.

[0050] Step 3), based on step 2), a copper layer is prepared. Specifically, the operation is as follows: The sputtering process parameters are: the background vacuum of the sputtering chamber is 5.0×10 -4 Pa, a DC sputtering Cu target was used, the sputtering power was 100 W, the Ar gas flow rate was 20 mL / min, the working gas pressure was 0.5 Pa, and the Cu layer was sputtered for 60 min to obtain a Cu / Zr-Ru / silicon nitride substrate.

[0051] Figure 2 : is a cross-sectional morphology of the Cu / Zr-Ru / silicon nitride substrate in Example 4 and Example 5 of the present invention. As shown in the figure, the copper layer of the two groups of samples is flat and uniform in thickness, both of which are 0.72μm. The thickness of the gradient transition layer in Example 4 and Example 5 is 0.66μm ( Figure 2 (a)) and 0.26 μm ( Figure 2 (b)). The interface between the copper layer and the gradient transition layer is clear and well adhered. The gradient transition layer has a clear structural gradient, from fine grains to columnar crystals, which is related to the composition gradient of the gradient transition layer. The formed structural gradient can effectively alleviate the stress release of the ceramic-metal interface, thereby enhancing the interface bonding strength.

[0052] Figure 3 It is the bonding strength test result of the silicon nitride ceramic copper-clad substrate in Examples 4 and 5 of the present invention. The results show that the critical load of Cu / Zr-Ru (0.26 μm) in Example 5 is 67.7 N, which is higher than the critical load (43.15 N) of Cu / Zr-Ru (0.66 μm) in Example 4, indicating that the thinner the gradient transition layer, the higher the interface bonding strength of the silicon nitride ceramic copper-clad substrate, that is, the gradient transition layer between the silicon nitride ceramic substrate and the copper layer in the present invention has an abnormal size effect.

Claims

1. A silicon nitride ceramic copper-clad substrate, characterized in that: include: A silicon nitride ceramic substrate, on which a Zr-based gradient transition layer and a copper layer are sequentially stacked; the Zr-based gradient transition layer is a Zr-N layer or a Zr-Ru layer; the Zr content in the Zr-N layer gradually increases from the silicon nitride ceramic substrate side to the copper layer side, or the N content gradually increases from the silicon nitride ceramic substrate side to the copper layer side; the Ru content in the Zr-Ru layer gradually increases from the silicon nitride ceramic substrate side to the copper layer side.

2. The silicon nitride ceramic copper-clad substrate according to claim 1, characterized in that: The thickness of the Zr-based gradient transition layer is 100-800 nm.

3. The silicon nitride ceramic copper-clad substrate according to claim 2, characterized in that: The thickness of the Zr-based gradient transition layer is 100-300 nm.

4. The silicon nitride ceramic copper-clad substrate according to claim 1, characterized in that: The thickness of the copper layer is 0.5-2 μm.

5. The method for preparing the silicon nitride ceramic copper-clad substrate according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1: double-sided polishing and cleaning of the silicon nitride ceramic substrate; S2: Depositing a Zr-based gradient transition layer on the surface of a silicon nitride ceramic substrate using magnetron sputtering technology; S3: depositing a copper layer on the Zr-based gradient transition layer using magnetron sputtering technology.

6. The method for preparing the silicon nitride ceramic copper-clad substrate according to claim 5, characterized in that: In S1, the cleaning process specifically includes: ultrasonically cleaning the silicon nitride ceramic substrate with acetone and anhydrous ethanol in sequence.

7. The method for preparing the silicon nitride ceramic copper-clad substrate according to claim 5, characterized in that: S2 specifically includes: using a Zr target as a target material, and depositing a Zr-N layer on a silicon nitride ceramic substrate by magnetron sputtering under the condition of passing Ar gas and N2 gas; or using Zr and Ru as target materials, passing Ar gas, and depositing a Zr-Ru layer on a silicon nitride ceramic substrate by magnetron sputtering.

8. The method for preparing the silicon nitride ceramic copper-clad substrate according to claim 7, characterized in that: When depositing the Zr-N layer, the process parameters are: Ar gas flow rate is 10~50 mL / min, N2 gas flow rate is 2~10 mL / min, working gas pressure is 0.30~1.00 Pa, Zr target sputtering power is 50~100 W, and deposition time is 30~100 min; when depositing the Zr-Ru layer, the process parameters are: Ar gas flow rate is 10~50 mL / min, working gas pressure is 0.30~1.00 Pa, Zr target sputtering power is fixed at 60~100 W, Ru target sputtering power is 30~50 W, and deposition time is 60~120 min.

9. The method for preparing the silicon nitride ceramic copper-clad substrate according to claim 5, characterized in that: S3 specifically comprises: using a Cu target as a target material, and depositing a copper layer on the Zr-based gradient transition layer by direct current magnetron sputtering under the condition of introducing Ar gas.

10. The method for preparing the silicon nitride ceramic copper-clad substrate according to claim 9, characterized in that: When depositing the copper layer, the process parameters are: DC sputtering power is 80~120 W, Ar gas flow rate is 10~50 mL / min, working gas pressure is 0.5~1 Pa, and deposition time is 1~2 h.

Images