Metal ceramic substrate and preparation method thereof

Abstract

The invention relates to a metal ceramic substrate and a preparation method thereof, and belongs to the technical field of ceramic substrates. The preparation method comprises the following steps: S1, carrying out patterning treatment on the surface of a ceramic substrate to form a pattern with preset depth and width on the surface of the ceramic substrate; depositing a bonding layer on the patterned surface through a physical vapor deposition technology to obtain a composite ceramic substrate; s2, depositing a bonding layer on the surface of the metal layer through a physical vapor deposition technology to obtain a composite metal layer; and S3, the bonding layer of the composite metal layer is attached to the bonding layer of the composite ceramic substrate, and the metal ceramic substrate is obtained through hot pressing. The interface between the metal layer and the ceramic substrate is free of pores, and oxide is not formed; and the bonding strength of the metal layer and the ceramic substrate is increased, so that the metal ceramic substrate has better thermal stability.

Description

Technical Field

[0001] The present invention belongs to the technical field of ceramic substrates, and particularly relates to a metal-ceramic substrate and a preparation method thereof. Background Art

[0002] Copper-clad ceramic substrates are widely used in the field of electronic packaging and have achieved remarkable development, especially showing wide applications and prospects in the heat dissipation packaging of high-power electronic devices. At present, copper-clad ceramic substrates have been widely used in fields such as high-power LEDs, power semiconductor devices, motor drivers, IGBT power modules, and electric vehicle controllers. These applications benefit from the excellent heat dissipation performance and mechanical stability of copper-clad ceramic substrates, which can effectively reduce the operating temperature of devices, improve the reliability and service life of devices.

[0003] The DBC (Direct Bond Copper) technology is a ceramic surface metallization technology mainly developed based on alumina ceramic substrates. It first appeared in the 1970s and was proposed by J.F. Burgess, Y.S. Sun and others; in the mid-1980s, the DBC research and development team of the US GE (General Electric) Company put this technology into practical use.

[0004] The DBC technology is a technology that coats one or both sides of a highly insulating ceramic substrate (such as alumina or aluminum nitride) with metallic copper, and then forms a composite material by bonding the metallic copper to the ceramic substrate through high-temperature heating. The DBC technology generates a layer of copper oxide layer by thermal oxidation or chemical oxidation on the surface of the copper foil, and then at a high temperature of 1060°C - 1080°C, uses the Cu-Cu2O (copper - cuprous oxide) eutectic liquid phase to wet the contact surface between the ceramic and the copper, and generates a CuAlO2 (copper-aluminum oxide) compound, thereby realizing the bonding between copper and ceramic. Because there is no electroplating process and no waste water is discharged, it is a pollution-free and environmentally friendly green product and can be applied to many fields such as semiconductor coolers, electronic heaters, high-power power semiconductor modules, and power control circuits.

[0005] The DBC (Direct Bonded Copper) technology still faces the problem of controlling the interfacial oxygen content in practical applications, which is mainly reflected in the following two aspects: First, the copper foil used in the process has a relatively large thickness (in the conventional range of 100μm - 600μm), and it is difficult to achieve an ideal metallurgical bond between the copper foil and the ceramic substrate during the high-temperature bonding process; Second, the formation kinetics of the interfacial oxide is difficult to precisely control, which will lead to micron-sized pore defects at the copper-ceramic interface. The existence of these interfacial defects will significantly reduce the heat dissipation performance of the device and become a weak link in the failure during the power cycle, ultimately affecting the long-term reliability of the electronic device. Also, because the temperature used in the manufacturing process is relatively high, the current technology still needs to use a high temperature of 1060°C for bonding, which not only consumes a lot of energy but also easily damages the materials, and the materials that can use this technology are limited.

[0006] Therefore, there is an urgent need for a new method to improve the bonding strength between the metal layer and the ceramic substrate to improve its thermal stability and electrical properties. Summary of the Invention

[0007] To solve the above technical problems, the present invention provides a metal-ceramic substrate and a preparation method thereof, which make the interface between the metal layer and the ceramic substrate pore-free and do not form oxides; increase the bonding strength between the metal layer and the ceramic substrate, and make it have better thermal stability.

[0008] The first object of the present invention is to provide a preparation method of a metal-ceramic substrate, which includes the following steps:

[0009] S1. Pattern the surface of the ceramic substrate to form a pattern with a preset depth and width on the surface of the ceramic substrate; then deposit a bonding layer on the patterned surface through physical vapor deposition technology to obtain a composite ceramic substrate;

[0010] S2. Deposit a bonding layer on the surface of the metal layer through physical vapor deposition technology (PVD, Physical Vapor Deposition) to obtain a composite metal layer;

[0011] S3. Bond the bonding layer of the composite metal layer to the bonding layer of the composite ceramic substrate and obtain the metal-ceramic substrate through hot pressing.

[0012] In an embodiment of the present invention, in S1, the material of the ceramic substrate is selected from nitrides, oxides, carbides or semiconductors.

[0013] In an embodiment of the present invention, the nitride is selected from aluminum nitride or silicon nitride;

[0014] And / or, the oxide is selected from aluminum oxide, silicon oxide or antimony oxide;

[0015] And / or, the carbide is silicon carbide;

[0016] And / or, the semiconductor is selected from silicon, indium phosphide, gallium arsenide or diamond.

[0017] In one embodiment of the present invention, in S1, the patterning process is selected from inductively coupled plasma (ICP) etching and / or chemical etching.

[0018] In one embodiment of the present invention, the process parameters of the inductively coupled plasma etching are: radio frequency power is 100W - 1000W, chamber pressure is 1mTorr - 50mTorr, and bias voltage is 100V - 300V;

[0019] And / or, the reagent used in the chemical etching is obtained by mixing phosphoric acid and hydrogen peroxide in a mass ratio of (50 - 85):(15 - 50); the temperature of the chemical etching is 25°C - 50°C.

[0020] In one embodiment of the present invention, in S1, the depth of the pattern is 1nm - 10nm, for example, it can be 1nm, 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm, 10nm, etc.; the width is 1nm - 20nm, for example, it can be 1nm, 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm, 10nm, 11nm, 12nm, 13nm, 14nm, 15nm, 16nm, 17nm, 18nm, 19nm, 20nm, etc.; the pitch is 1nm - 20nm, for example, it can be 1nm, 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm, 10nm, 11nm, 12nm, 13nm, 14nm, 15nm, 16nm, 17nm, 18nm, 19nm, 20nm, etc.;

[0021] And / or, the shape of the pattern is selected from cube, cylinder or cone.

[0022] In one embodiment of the present invention, in S1 and S2, the process parameters of the deposition are independently: electron beam power is 5kW - 20kW, for example, it can be 5kW, 6kW, 7kW, 8kW, 9kW, 10kW, 11kW, 12kW, 13kW, 14kW, 15kW, 16kW, 17kW, 18kW, 19kW, 20kW, etc.; the chamber vacuum degree is 1×10 -7 Torr - 1×10 -5Torr; the temperature is from 20°C to 200°C, and for example, it can be 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, etc.

[0023] In one embodiment of the present invention, in S1 and S2, the material of the bonding layer is independently selected from one or more of titanium, platinum, gold, silver, copper, aluminum, indium, gold-tin alloy, and gold-indium alloy;

[0024] and / or, the thickness of the bonding layer is independently 0.1μm - 1μm, and for example, it can be 0.1μm, 0.2μm, 0.3μm, 0.4μm, 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1μm, etc.

[0025] In one embodiment of the present invention, in S1 and S2, the thickness of the metal layer is 10μm - 100μm, and for example, it can be 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, 100μm, etc.

[0026] In one embodiment of the present invention, in S1 and S2, the material of the metal layer is copper.

[0027] In one embodiment of the present invention, in S3, the temperature of the hot pressing is 100°C - 300°C, and for example, it can be 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, etc.; the pressure is 500N / m 2 - 2000N / m 2 and for example, it can be 500N / m 2 、550N / m 2 、600N / m 2 、650N / m 2 、700N / m 2 、750N / m 2 、800N / m 2 、850N / m 2 、900N / m 2 、950N / m 2 、1000N / m 2 、1050N / m 2, 1100 N / m 2 , 1150 N / m 2 , 1200 N / m 2 , 1250 N / m 2 , 1300 N / m 2 , 1350 N / m 2 , 1400 N / m 2 , 1450 N / m 2 , 1500 N / m 2 , 1550 N / m 2 , 1600 N / m 2 , 1650 N / m 2 , 1700 N / m 2 , 1750 N / m 2 , 1800 N / m 2 , 1850 N / m 2 , 1900 N / m 2 , 1950 N / m 2 , 2000 N / m 2 etc.

[0028] The second object of the present invention is to provide a cermet substrate prepared by the preparation method described above.

[0029] The technical solution of the present invention has the following advantages compared with the prior art:

[0030] (1) The bonding layer in the cermet substrate of the present invention is made of a metal material. Compared with metal oxides such as copper-aluminum oxides, preparing the bonding layer with a metal material can make the cermet substrate have a smaller thermal resistance and good thermal conductivity.

[0031] (2) The preparation method of the present invention uses a lower hot pressing temperature, so that the deformation amount generated by the metal layer and the ceramic substrate is smaller. After the finished product is made, the deformation amount when returning to room temperature is also smaller. Therefore, the residual stress is smaller, and the warpage degree caused by the residual stress after the finished product is combined is reduced.

[0032] (3) The preparation method of the present invention uses a metal material to prepare the bonding layer. Under hot pressing conditions, the bonding layer and the ceramic substrate are bonded by co-gold bonding, which increases the bonding strength between the metal layer and the ceramic substrate and makes it have better thermal stability. In addition, no oxide layer needs to be formed for this bonding. Therefore, there are no pores at the interface between the metal layer and the ceramic substrate, and no oxides are formed. And it lays a good material foundation for the subsequent high-precision (below 2 μm) wire process requirements. At the same time, a low-temperature process is adopted, with a wide selection of materials and a wide range of application fields. Brief Description of the Drawings

[0033] The present invention will be further described below in conjunction with specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. It should be understood that the specific embodiments are only used to explain the present invention, but the exemplified embodiments do not limit the present invention.

[0034] In the present invention, unless otherwise specified, the technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the technical field to which the present invention belongs.

[0035] In the present invention, unless otherwise specified, the term "and / or" used in the present invention includes any and all combinations of one or more of the related listed items.

[0036] In the present invention, unless otherwise specified, the experimental methods used in the embodiments of the present invention are all conventional methods without special instructions, and the materials, reagents, etc. used can be obtained from commercial channels without special instructions.

[0037] Figure 1 It is a schematic diagram of the patterned ceramic substrate in Embodiment 1 of the present invention;

[0038] Figure 2 It is a schematic diagram of the cermet substrate in Embodiment 1 of the present invention;

[0039] Figure 3 It is a schematic diagram of the patterned ceramic substrate in Embodiment 2 of the present invention;

[0040] Figure 4 It is the ultrasonic void detection result of the cermet substrate prepared in Embodiment 1 of the present invention;

[0041] Figure 5 It is the ultrasonic void detection result of the cermet substrate prepared in Comparative Example 1 of the present invention;

[0042] Figure 6 It is a schematic diagram of the scratch test in Test Example 2 of the present invention. Detailed implementation manners

[0043] The present invention will be further described below in conjunction with specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. It should be understood that the specific embodiments are only used to explain the present invention, but the exemplified embodiments do not limit the present invention.

[0044] In the present invention, unless otherwise specified, the technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the technical field to which the present invention belongs.

[0045] In the present invention, unless otherwise specified, the term "and / or" includes any and all combinations of one or more of the related listed items.

[0046] In the present invention, unless otherwise specified, the experimental methods used in the embodiments of the present invention are all conventional methods without special instructions, and the materials, reagents, etc. used can be obtained from commercial channels without special instructions.

[0047] Example 1

[0048] The cermet substrate of the present invention and its preparation method specifically include the following steps:

[0049] S1. Pattern the surface of a ceramic substrate with a thickness of 330 μm by inductively coupled plasma etching or chemical etching techniques to form cubic patterns with a depth of 5 nm, a width of 10 nm, and a pitch of 10 nm on the surface of the ceramic substrate ( Figure 1 ), and then deposit a bonding layer on the patterned surface by physical vapor deposition techniques to obtain a composite ceramic substrate; wherein, the material of the ceramic substrate is silicon carbide; the process parameters of inductively coupled plasma etching are: radio frequency power is 130 W, chamber pressure is 5 mTorr, and bias voltage is 150 V;

[0050] S2. By physical vapor deposition techniques, select an electron beam evaporation device to deposit a bonding layer on the surface of a metal layer with a thickness of 80 μm to obtain a composite metal layer;

[0051] In S1 and S2, the deposition process parameters are: electron beam power is 10 kW, chamber vacuum is 2×10 -6 Torr, temperature is 60 °C; the material of the metal layer is copper; the bonding layer includes a first bonding layer, a second bonding layer, and a third bonding layer; the materials of the first bonding layer, the second bonding layer, and the third bonding layer are titanium, platinum, and gold respectively, and the thicknesses are 0.1 μm, 0.2 μm, and 0.5 μm respectively;

[0052] S3. Bond the bonding layer of the composite metal layer to the bonding layer of the composite ceramic substrate, and hot press under the conditions of a temperature of 280 °C and a pressure of 500 N / m 2 to obtain a cermet substrate ( Figure 2 ).

[0053] Example 2

[0054] The cermet substrate of the present invention and its preparation method specifically include the following steps:

[0055] S1. Pattern the surface of a ceramic substrate with a thickness of 330 μm by inductively coupled plasma etching or chemical etching techniques to form cylindrical patterns on the surface of the ceramic substrate with a depth of 5 nm, a diameter of 10 nm, and a pitch of 10 nm ( Figure 3 ), and then deposit a bonding layer on the patterned surface by physical vapor deposition techniques to obtain a composite ceramic substrate; wherein, the material of the ceramic substrate is aluminum nitride; the reagent used for chemical etching is obtained by mixing phosphoric acid and hydrogen peroxide in a mass ratio of 85:15; the temperature of chemical etching is 25 °C;

[0056] S2. By physical vapor deposition techniques, select an electron beam evaporation equipment to deposit a bonding layer on the surface of a metal layer with a thickness of 80 μm to obtain a composite metal layer;

[0057] In S1 and S2, the deposition process parameters are: the electron beam power is 10 kW, the chamber vacuum degree is 2×10 -6 Torr, and the temperature is 60 °C; the material of the metal layer is copper; the bonding layer includes a first bonding layer, a second bonding layer, and a third bonding layer; the materials of the first bonding layer, the second bonding layer, and the third bonding layer are titanium, platinum, and gold respectively, and the thicknesses are 0.1 μm, 0.2 μm, and 0.5 μm respectively;

[0058] S3. Bond the bonding layer of the composite metal layer to the bonding layer of the composite ceramic substrate and hot press under the conditions of a temperature of 280 °C and a pressure of 500 N / m 2 to obtain a metal-ceramic substrate.

[0059] Example 3

[0060] The metal-ceramic substrate and its preparation method of the present invention specifically include the following steps (basically the same as Example 1, the difference lies in the bonding layer materials and the hot pressing process):

[0061] S1. Pattern the surface of a ceramic substrate with a thickness of 330 μm by inductively coupled plasma etching or chemical etching techniques to form cubic patterns on the surface of the ceramic substrate with a depth of 5 nm, a width of 10 nm, and a pitch of 10 nm; then deposit a bonding layer on the patterned surface by physical vapor deposition techniques to obtain a composite ceramic substrate; wherein, the material of the ceramic substrate is silicon carbide; the process parameters of inductively coupled plasma etching are: the radio frequency power is 130 W, the chamber pressure is 5 mTorr, and the bias voltage is 150 V;

[0062] S2. By physical vapor deposition techniques, select an electron beam evaporation equipment to deposit a bonding layer on the surface of a metal layer with a thickness of 80 μm to obtain a composite metal layer;

[0063] In S1 and S2, the deposition process parameters are as follows: the electron beam power is 10 kW, the chamber vacuum degree is 2×10 -6 Torr, the temperature is 60 °C; the material of the metal layer is copper; the materials of the bonding layers are respectively gold-tin alloy, and the thickness is 0.8 μm;

[0064] S3. Bond the bonding layer of the composite metal layer to the bonding layer of the composite ceramic substrate, and hot press at a temperature of 160 °C and a pressure of 500 N / m 2 to obtain a metal-ceramic substrate.

[0065] Comparative Example 1

[0066] The metal-ceramic substrate and its preparation method of the present invention specifically include the following steps (basically the same as Example 1, the difference lies in the depth of the pattern):

[0067] S1. Pattern the surface of the ceramic substrate by inductively coupled plasma etching technology or chemical etching technology to form cubic patterns with a depth of 1000 nm, a width of 10 nm, and a pitch of 10 nm on the surface of the ceramic substrate; then deposit a bonding layer on the patterned surface by physical vapor deposition technology to obtain a composite ceramic substrate; wherein, the material of the ceramic substrate is silicon carbide; the process parameters of inductively coupled plasma etching are: the radio frequency power is 130 W, the chamber pressure is 5 mTorr, and the bias voltage is 150 V;

[0068] S2. By physical vapor deposition technology, select an electron beam evaporation device to deposit a bonding layer on the surface of a metal layer with a thickness of 80 μm to obtain a composite metal layer;

[0069] In S1 and S2, the deposition process parameters are as follows: the electron beam power is 10 kW, the chamber vacuum degree is 2×10 -6 Torr, the temperature is 60 °C; the material of the metal layer is copper; the bonding layer includes a first bonding layer, a second bonding layer, and a third bonding layer; the materials of the first bonding layer, the second bonding layer, and the third bonding layer are respectively titanium, platinum, and gold, and the thicknesses are respectively 0.1 μm, 0.2 μm, and 0.5 μm;

[0070] S3. Bond the bonding layer of the composite metal layer to the bonding layer of the composite ceramic substrate, and hot press at a temperature of 280 °C and a pressure of 500 N / m 2 to obtain a metal-ceramic substrate.

[0071] Comparative Example 2

[0072] Basically the same as Example 1, the difference is that: the material of the bonding layer is silicon dioxide, and the thickness is 0.8 μm.

[0073] Comparative Example 3

[0074] Basically the same as Example 1, except that: the material of the bonding layer is alumina and the thickness is 0.8 μm.

[0075] Test Example 1

[0076] The cermet substrates prepared in Example 1 and Comparative Example 1 were subjected to ultrasonic void detection, and the results are as Figure 4 - Figure 5 shown (the white areas are the void parts). From Figure 4 - Figure 5 it can be seen that the cermet substrate prepared in Example 1 basically has no pores generated, while the cermet substrate prepared in Comparative Example 1 generates a large number of pores. This is because the surface of the ceramic substrate in Comparative Example 1 has a large etching depth, and it is easy to form more voids during hot pressing bonding. And more voids will form a large interfacial thermal resistance, thereby causing a decrease in thermal conductivity. It shows that the method of the example can effectively bond the metal layer and the ceramic substrate and reduce the generation of voids.

[0077] Test Example 2

[0078] Referring to Figure 6 shown, according to ASTM standard C1624, the cermet substrates prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to a scratch test. The critical scratch load refers to the bonding strength and mechanical failure mode between the ceramic substrate and the metal layer determined by the scratch test. In the test, a diamond stylus with a specified geometry (such as a Rockwell C indenter) was used to scratch the coating surface at a constant speed or with an increasing normal force. The larger the critical scratch load value, the greater the force required to break the bond between the metal and the ceramic substrate. The specific test results are shown in Table 1:

[0079] Table 1

[0080] Specimen Critical scratch load [N] Example 1 144 Example 2 158 Example 3 124 Comparative Example 1 26 Comparative Example 2 78 Comparative Example 3 80

[0081] As can be seen from Table 1, the cermet substrate of Example 1 has a large critical scratch load, while the cermet substrate of the comparative example generates more voids during hot pressing bonding, resulting in a poor bonding ability between the ceramic substrate and the metal layer. Therefore, when performing the scratch test, the measured critical scratch load is small. It shows that the method of the example can effectively improve the bonding ability between the metal layer and the ceramic substrate.

[0082] Test Example 3

[0083] The cermet substrates prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to a thermal conductivity test. Thermal conductivity refers to the ability of a material to conduct heat. The higher the thermal conductivity, the faster the heat transfer of the material; the lower the thermal conductivity, the slower the heat transfer. The thermal conductivity of a multi-layer structure can be derived from the series thermal resistance of each layer, including the thermal resistance of the material itself and the thermal resistance of the contact surface. For example, the total thermal resistance is the sum of the thermal resistances of each layer of material plus the contact thermal resistance of each contact surface.

[0084] Taking Example 1 as an example, the steps for measuring the thermal conductivity are as follows:

[0085] (1) Calculate the thermal resistance of each material layer: The material of the metal layer is copper with a thickness of 80 μm. The materials of the bonding layers are titanium, platinum, and gold with thicknesses of 0.1 μm, 0.2 μm, and 0.5 μm respectively. The material of the ceramic substrate is silicon carbide with a thickness of 330 μm.

[0086]

[0087]

[0088] (2) Calculate the interfacial thermal resistance at the contact surface between the ceramic substrate and the bonding layer: The roughness RMS of the contact surface is 10 nm;

[0089]

[0090] (3) Add up all the thermal resistances to obtain the total thermal resistance.

[0091] R 总 =R 金属层 +R 陶瓷基板 +R 结合层 +R 界面热阻 =1.08×10 -6 m 2 K / W

[0092] (4) Divide the total thickness by the total thermal resistance to obtain the equivalent thermal conductivity

[0093] d 总 =d 金属层 +d 陶瓷基板 +d 结合层 =80+330+1.6=4.116×10 -4 m

[0094]

[0095] Taking Comparative Example 1 as an example, the steps for measuring the thermal conductivity are as follows:

[0096] (1) Calculate the thermal resistance of each material layer: The material of the metal layer is copper with a thickness of 80 μm. The materials of the bonding layers are titanium, platinum, and gold with thicknesses of 0.1 μm, 0.2 μm, and 0.5 μm respectively. The material of the ceramic substrate is silicon carbide with a thickness of 330 μm.

[0097]

[0098] (2) Calculate the interfacial thermal resistance at the contact surface between the ceramic substrate and the bonding layer: The roughness RMS of the contact surface is 1000 nm;

[0099]

[0100] (3) Add up all the thermal resistances to obtain the total thermal resistance.

[0101] R 总 = R 金属层 + R 陶瓷基板 + R 结合层 + R 界面热阻 = 2.07×10 -6 m 2 K / W

[0102] (4) Divide the total thickness by the total thermal resistance to obtain the equivalent thermal conductivity

[0103] d 总 = d 金属层 + d 陶瓷基板 + d 结合层 = 80 + 330 + 0.8 = 4.116×10 -4 m

[0104]

[0105] The specific test results of the thermal conductivity are shown in Table 2:

[0106] Table 2

[0107] Specimen Thermal conductivity (W / mK) Example 1 382 Example 2 391 Example 3 379 Comparative Example 1 199 Comparative Example 2 187 Comparative Example 3 280

[0108] As can be seen from Table 2, the cermet substrate of the example has a high thermal conductivity, indicating that the method of the example can effectively improve the heat conduction efficiency of the cermet substrate, thereby improving the ability of the material to conduct heat.

[0109] Comparing Example 1 with Comparative Example 1, it can be seen that adjusting the etching depth on the surface of the ceramic substrate will cause a significant decrease in the thermal conductivity. This is because the surface of the ceramic substrate in Comparative Example 1 has a large etching depth, and large voids will be formed during hot pressing bonding, resulting in a large interfacial thermal resistance, thus causing a significant increase in the overall thermal resistance and a consequent decrease in the thermal conductivity.

[0110] Comparing Example 1 with Comparative Example 2, it can be seen that replacing the material of the bonding layer with silicon dioxide will cause a significant decrease in the thermal conductivity. This is because silicon dioxide has a low thermal conductivity and is commonly used as a heat-resistant and heat-insulating material, resulting in a significant increase in the overall thermal resistance and a consequent decrease in the thermal conductivity.

[0111] Comparing Example 1 with Comparative Example 3, it can be seen that replacing the material of the bonding layer with alumina will cause a significant decrease in the thermal conductivity. This is because the thermal conductivity of alumina is relatively low. Although it can be used as a general simple heat-conducting substance, the thermal conductivity of alumina is still lower than that of general metals. Therefore, it causes an increase in the overall thermal resistance and a consequent decrease in the thermal conductivity.

[0112] Obviously, the above embodiments are merely examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. And the obvious changes or modifications derived therefrom still fall within the protection scope of the present invention.

Claims

1. A method for preparing a cermet substrate, characterized in that Including the following steps: S1. Pattern the surface of the ceramic substrate to form a pattern with a preset depth and width on the surface of the ceramic substrate; then deposit a bonding layer on the patterned surface by physical vapor deposition technology to obtain a composite ceramic substrate; S2. Deposit a bonding layer on the surface of the metal layer by physical vapor deposition technology to obtain a composite metal layer; S3. Bond the bonding layer of the composite metal layer to the bonding layer of the composite ceramic substrate, and obtain the metal-ceramic substrate through hot pressing.

2. The method for preparing a metal-ceramic substrate according to claim 1, in S1, the material of the ceramic substrate is selected from nitrides, oxides, carbides or semiconductors.

3. The method for preparing a metal-ceramic substrate according to claim 2, the nitride is selected from aluminum nitride or silicon nitride; and / or, the oxide is selected from aluminum oxide, silicon oxide or antimony oxide; and / or, the carbide is silicon carbide; and / or, the semiconductor is selected from silicon, indium phosphide, gallium arsenide or diamond.

4. The preparation method of the cermet substrate according to claim 1, characterized in that, In S1, the patterning method is selected from inductively coupled plasma etching and / or chemical etching.

5. The preparation method of the cermet substrate according to claim 4, wherein The process parameters of the inductively coupled plasma etching are: radio frequency power is 100W - 1000W, chamber pressure is 1mTorr - 50mTorr, and bias voltage is 100V - 300V.

6. The method for preparing a cermet substrate according to claim 1, wherein, In S1, the depth of the pattern is 1nm - 10nm, the width is 1nm - 20nm, and the pitch is 1nm - 20nm; and / or, the shape of the pattern is selected from cube, cylinder or cone.

7. The preparation method of the cermet substrate according to claim 1, characterized in that, In S1 and S2, the process parameters of the deposition are independently: the electron beam power is 5 kW - 20 kW, the chamber vacuum degree is 1×10 -7 Torr - 1×10 -5 Torr, and the temperature is 20°C - 200°C.

8. The preparation method of the cermet substrate according to claim 1, wherein, In S1 and S2, the material of the bonding layer is independently selected from one or more of titanium, platinum, gold, silver, copper, aluminum, indium, gold-tin alloy and gold-indium alloy; and / or, the thickness of the bonding layer is independently 0.1μm - 1μm.

9. The method for preparing a cermet substrate according to claim 1, characterized in that, In S3, the temperature of the hot pressing is 100°C - 300°C, and the pressure is 500 N / m 2 - 2000 N / m 2 .

10. A metal-ceramic substrate prepared by the preparation method according to any one of claims 1 - 9.

Images