CN117550910A - Laser-assisted preparation method of ceramic and metal composite substrate and composite substrate - Google Patents

Abstract

The invention discloses a method for preparing a ceramic and metal composite substrate by laser assistance, which comprises the following steps: pretreating ceramic and metal, wherein the ceramic is made of silicon nitride, aluminum nitride or aluminum oxide, and the metal is made of aluminum or copper; placing the pretreated ceramic on a laser processing platform, and carrying out laser irradiation on the ceramic surface under the protection state of vacuum or inert gas so as to realize the modification of the ceramic surface; and stacking the modified ceramic and the pretreated metal to obtain a connecting structure, and placing the connecting structure in a vacuum diffusion connecting device, wherein the ceramic is positioned above the metal, and heating and pressurizing the connecting structure to realize direct diffusion connection of the ceramic and the metal. The method can obviously reduce the connection temperature of the ceramic and the metal and reduce the connection cost. The invention also provides a composite substrate which is prepared by adopting the method.

Description

Laser-assisted preparation method of ceramic and metal composite substrate and composite substrate

Technical field

The invention relates to the field of welding technology, and in particular to a laser-assisted preparation method of ceramic and metal composite substrates and the composite substrate.

Background technique

With the rapid development of new energy vehicles, rail transportation, aerospace and other fields, higher requirements have been put forward for the thermal management of power modules. As one of the key power conversion and control core components in electronic power systems, the edge-gate bipolar transistor (IGBT) module's reliability has become one of the key issues for the stable operation of electronic power systems. However, the continued miniaturization and rapid increase of power levels of I GBT modules make them have significantly high heat flux density. If the accumulated heat cannot be discharged in time, causing the chip to heat up too high, it will cause the degradation and failure of the I GBT module, which will affect the module. poses a serious threat to reliability.

As a key component in the I GBT module, the ceramic heat dissipation substrate plays the role of mechanical support, heat dissipation and insulation. In order to meet the heat dissipation and reliability requirements of today's power modules, currently commonly used ceramic heat dissipation substrate materials are mainly aluminum nitride and alumina ceramics. By connecting them with copper or aluminum, a heat dissipation substrate that meets the heat dissipation needs of high-power modules can be prepared. However, due to the difference in physical properties between ceramics and metals, it is difficult to connect them. At present, the connection between ceramics and metals is mainly achieved through active brazing. However, the use of solder increases the production cost. At the same time, the solder and the base material are separated during the connection process. Metallurgical reactions will inevitably occur between them, producing intermetallic compounds, resulting in high residual stress and interface thermal resistance after welding of the substrate. Therefore, there is a need to develop a simple and efficient method to solve the above problems.

Contents of the invention

To this end, the present invention provides a method for laser-assisted preparation of ceramic and metal composite substrates and a composite substrate. The ceramic surface is directly irradiated with laser for surface modification and metallization pretreatment, and the microstructure, composition and stress distribution state of the ceramic surface are changed. and other characteristics, achieving the direct combination of ceramics and metals, and the obtained ceramic-metal composite substrate has the advantages of high strength, strong impact resistance, strong current carrying capacity, good thermal conductivity and high reliability.

The invention proposes a method for laser-assisted preparation of ceramic and metal composite substrates, which includes: preprocessing ceramics and metals, wherein the material of the ceramic is silicon nitride, aluminum nitride or aluminum oxide, and the material of the metal is Aluminum or copper; place the pretreated ceramic on a laser processing platform, and perform laser irradiation on the ceramic surface under the protection of vacuum or inert gas to achieve modification of the ceramic surface; The ceramic and the metal after pretreatment are laminated to obtain a connection structure, and the connection structure is placed in a vacuum diffusion connection device, where the ceramic is located above the metal, and the connection structure is Heating and pressure are applied to achieve direct diffusion connection between the ceramic and the metal.

In the above method, ceramics and metals are first pretreated, and then the ceramic surface is metallized by laser irradiation under vacuum or inert gas protection to achieve modification of the ceramic surface, and then the ceramics and metal are assembled and juxtaposed in sequence. Pressurize and heat in a vacuum diffusion connection device to achieve direct diffusion connection of ceramics and metals. In this application, after the ceramic surface is irradiated with laser, the ceramic surface layer made of silicon nitride, aluminum nitride or aluminum oxide is thermally decomposed to form a silicon or aluminum layer, and the surface is metallized. During the connection process, the modified ceramic can interact with the metal The eutectic reaction of copper and aluminum or the solid-phase diffusion reaction with metallic aluminum significantly reduces the connection temperature and reduces the connection cost.

At present, silver-copper-titanium solder is commonly used to connect aluminum nitride and alumina ceramics to copper. The melting temperature of silver-copper-titanium is as high as 780°C, and the welding temperature is 800-900°C. The present invention is based on laser surface irradiation of metal. Chemical modification activates the ceramic surface so that ceramics and copper can be connected based on the copper-aluminum eutectic reaction. The copper-aluminum eutectic reaction temperature is 548°C, and the required welding temperature is 560-640°C. Compared with using silver-copper-titanium solder The connection method significantly reduces the temperature required for connection. As we all know, the residual stress in the connection of dissimilar materials originates from the thermal expansion mismatch between materials. The higher the temperature during connection, the greater the residual stress after cooling. Therefore, the present invention significantly reduces the connection temperature and can significantly reduce the connection temperature. For the connection between aluminum nitride and alumina ceramics and aluminum, the connection is mainly achieved by forming a metal transition layer on the surface of the ceramic, and then forming a liquid phase through the reaction of the metal and aluminum. There must be an unfavorable brittle phase at the interface due to the liquid phase reaction. , this invention is based on laser surface direct metallization modification to activate aluminum nitride and alumina ceramic surfaces, so that ceramics and aluminum can be connected through solid phase diffusion. The connection temperature is between 400-660°C, the connection temperature range is wide, and it can effectively The generation of brittle interface phases is avoided; in addition, compared with the metal transition layer method, the present invention does not require the use of a metal transition layer and can reduce material costs.

Regarding the connection between silicon nitride ceramics and copper, silver-copper-titanium solder is currently used to achieve the connection, which requires consumption of solder and is expensive. The present invention can effectively change the surface inertness of the silicon nitride ceramic by performing laser surface direct metallization treatment on the silicon nitride ceramic, and realize the direct connection between the silicon nitride ceramic and copper through the silicon-copper eutectic reaction without using solder, which is effective Reduce material costs; similarly, for the connection between silicon nitride ceramics and aluminum, through the laser direct metallization method of the present invention, through the silicon-aluminum eutectic reaction, the direct connection between silicon nitride ceramics and aluminum can be achieved, and there is no need to use solder. , effectively reducing material costs.

In some embodiments, the method of pretreating ceramics includes:

Clean the ceramics to remove oil dirt and impurities from the surfaces to be connected of the ceramics;

Different sanding discs are used to gradually grind and polish the surfaces to be connected of the ceramics.

In some embodiments, the method of pretreating metal includes: mechanically processing metal materials to obtain metal samples to be connected; cleaning the metal samples to remove Oil stains and impurities on the surface to be connected; use different sand disks to grind and polish the surfaces to be connected of the metal samples step by step.

In some embodiments, after the modification of the ceramic surface is achieved, the method further includes: immersing the modified ceramic surface in an organic solvent to prevent oxidation of the ceramic surface, wherein the organic solvent includes acetone, alcohol , liquid paraffin.

In some embodiments, the wavelength of the laser is 1000nm-1100nm, the spot diameter of the laser is 15μm-60μm, the pulse width of the laser is 200ns-300ns, and the pulse frequency of the laser is 50KHz-200KHz, so The power of the laser is 30-80W, the scanning speed of the laser is 50mm/min-1000mm/min, and the scanning pitch of the laser is 15-60 μm.

In some embodiments, the inert gas is at least one of helium and argon.

In some embodiments, the vacuum degree within the vacuum diffusion connection device is 1.5×10 ^-3 Pa-6.5× ^{10 -3 Pa} .

In some embodiments, the pressure applied to the connection structure is 2MPa-15MPa.

In some embodiments, the method of heating the connection structure specifically includes: heating the connection structure by thermal radiation in a vacuum or protective gas atmosphere environment, so that the temperature of the connection structure reaches 500°C. ℃ and keep it for 10 minutes, then continue to raise the temperature to 560°C-1000°C and keep it for 30min-120min, and finally cool it down to 300°C at a cooling rate of 5°C/min-10°C/min and then cool it.

The invention proposes a composite substrate, which is prepared by the above method.

The composite substrate of the present invention is prepared by the above method. The composite substrate has the advantages of high strength, strong impact resistance, strong current carrying capacity, good thermal conductivity and high reliability.

Instructions with pictures

FIG. 1 is a schematic diagram of a composite substrate according to an embodiment of the present invention.

FIG. 2 is a flow chart of a method for laser-assisted preparation of ceramic and metal composite substrates according to an embodiment of the present invention.

FIG. 3 is a flow chart of the method for pretreating ceramics in FIG. 2 .

Figure 4 is a flow chart of the method for pretreating metal in Figure 2.

Figure 5 is a scanning electron microscope image of a ceramic surface after laser surface modification according to an embodiment of the present application.

Figure 6 is a scanning electron microscope image of the connection interface between ceramic and metal according to an embodiment of the present application.

Description of main component symbols

Composite substrate 100 ceramics 10 Metal 20 laser 200 Vacuum diffusion connection device 300 Scanning track 400

Detailed ways

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application and cannot be understood as limiting the present application.

The following disclosure provides many different embodiments or examples for implementing the various structures of the present application. To simplify the disclosure of the present application, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the application. Furthermore, this application may repeat reference numbers and/or reference letters in different examples, such repetition being for the purposes of simplicity and clarity and does not by itself indicate a relationship between the various embodiments and/or arrangements discussed. In addition, this application provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.

Referring to FIG. 1 , the present invention also provides a composite substrate 100 . The composite substrate 100 includes a ceramic 10 and a metal 20 disposed on the ceramic 10 . Both the ceramic 10 and the metal 20 have a layered structure and are stacked. The composite substrate 100 has high connection strength and can be suitably used as the radiation shielding metal 20 material.

Referring to Figure 2, the present invention proposes a method for laser 200-assisted preparation of a ceramic 10 and metal 20 composite substrate 100, including:

S10, preprocess the ceramic 10 and the metal 20, where the ceramic 10 is made of silicon nitride, aluminum nitride or aluminum oxide, and the metal 20 is made of aluminum or copper;

Referring to Figure 3, in some embodiments, the method of pretreating ceramic 10 includes:

S11, clean the ceramic 10 to remove oil dirt and impurities on the surface to be connected of the ceramic 10;

S12, use different sanding discs to grind and polish the surfaces to be connected of the ceramic 10 step by step.

Referring to Figure 4, in some embodiments, the method of pretreating metal 20 includes:

S13, perform mechanical processing on the metal 20 material to obtain the metal 20 sample to be connected;

S14, clean the metal 20 sample to remove oil dirt and impurities on the surface to be connected of the metal 20 sample;

S15, use different sanding discs to grind and polish the surfaces to be connected of the metal 20 sample step by step.

S20, place the pretreated ceramic 10 on the laser 200 processing platform, and irradiate the surface of the ceramic 10 with the laser 200 under the protection of vacuum or inert gas to achieve modification of the surface of the ceramic 10;

Among them, after the surface of the ceramic 10 is modified, the surface of the ceramic 10 has the schematic structure in FIG. 5 .

In some embodiments, the wavelength of the laser 200 is 1000nm-1100nm, the spot diameter of the laser 200 is 15μm-60μm, the pulse width of the laser 200 is 200ns-300ns, the pulse frequency of the laser 200 is 50KHz-200KHz, and the power of the laser 200 is 30-80W, the scanning speed of the laser 200 is 50mm/min-1000mm/min, and the scanning distance of the laser 200 is 15-60μm.

In some embodiments, the scanning trajectory 400 of the laser 200 is in a round-trip pattern.

In some embodiments, the inert gas is at least one of helium and argon.

In some embodiments, after modifying the surface of the ceramic 10 , the method further includes:

The surface of the modified ceramic 10 is immersed in an organic solvent to prevent the surface of the ceramic 10 from being oxidized. The organic solvent includes acetone, alcohol, and liquid paraffin.

S30, the modified ceramic 10 and the pretreated metal 20 are stacked to obtain a connection structure, and the connection structure is placed in the vacuum diffusion connection device 300, where the ceramic 10 is located above the metal 20, and the connection structure is heated. Pressure to achieve direct diffusion connection between ceramic 10 and metal 20.

After the ceramic 10 and the metal 20 are connected, the connection point between the ceramic 10 and the metal 20 has the schematic structure in FIG. 6 .

In some embodiments, the vacuum degree within the vacuum diffusion connection device 300 is 1.5×10 ⁻³ Pa to 6.5×10 ⁻³ Pa.

In some embodiments, the pressure applied to the vertical connection structure is 2MPa-15MPa.

In some embodiments, the method of heating the connection structure specifically includes:

In a vacuum or protective gas atmosphere, the heating belt around the connecting structure is heated by current, and then the heating belt heats the connecting structure through thermal radiation, so that the connecting structure is heated to 500°C and kept warm for 10 minutes, and then continues to be heated to 560°C. -1000℃ and kept for 30min-120min, and finally cooled to 300℃ at a cooling rate of 5℃/min-10℃/min and then cooled.

In the above method, the ceramic 10 and the metal 20 are first pre-treated, and then the surface of the ceramic 10 is subjected to laser 200 irradiation metalization treatment under vacuum or inert gas protection to achieve modification of the surface of the ceramic 10, and then the ceramic 10 is It is assembled with the metal 20 in sequence and placed in the vacuum diffusion connection device 300 and heated under pressure to realize direct diffusion connection between the ceramic 10 and the metal 20 . In this application, after the surface of the ceramic 10 is irradiated with the laser 200, the surface layer of the ceramic 10 made of silicon nitride, aluminum nitride or aluminum oxide undergoes thermal decomposition to form a silicon or aluminum layer, and the surface is metallized. During the connection process, the modified Ceramic 10 can undergo a eutectic reaction with metal 20 copper and aluminum, or a solid-phase diffusion reaction with metal 20 aluminum, which significantly reduces the connection temperature and reduces connection costs.

At present, silver-copper-titanium solder is commonly used to connect aluminum nitride and alumina ceramics 10 to copper. The melting temperature of silver-copper-titanium is as high as 780°C, and the welding temperature is 800-900°C. However, the present invention is based on laser 200 surface radiation. The surface of the ceramic 10 is modified and activated according to the metallization, so that the ceramic 10 and copper can be connected based on the copper-aluminum eutectic reaction. The copper-aluminum eutectic reaction temperature is 548°C, and the required welding temperature is 560-640°C. Compared with using The silver-copper-titanium solder connection method significantly reduces the temperature required for connection. As we all know, the residual stress in the connection of dissimilar materials originates from the thermal expansion mismatch between materials. The higher the temperature during connection, the greater the residual stress after cooling. Therefore, the present invention significantly reduces the connection temperature and can significantly reduce the connection temperature. For the connection between aluminum nitride and aluminum oxide ceramics 10 and aluminum, the connection is mainly achieved by forming a transition layer of metal 20 on the surface of ceramic 10, and then forming a liquid phase through the reaction of metal 20 and aluminum. The interface must exist due to the liquid phase reaction. Unfavorable brittle phase, the present invention is based on laser 200 surface direct metallization modification to activate the surface of aluminum nitride and alumina ceramic 10, so that the ceramic 10 and aluminum can be connected through solid phase diffusion, and the connection temperature is between 400-660°C. The connection temperature range is wide and the generation of brittle interface phases can be effectively avoided; in addition, compared with the metal 20 transition layer method, the present invention does not require the use of a metal 20 transition layer and can reduce material costs.

Regarding the connection between the silicon nitride ceramic 10 and copper, the connection is currently achieved by brazing with silver-copper-titanium solder, which requires consumption of solder and is expensive. The present invention can effectively change the surface inertness of the silicon nitride ceramic 10 by performing laser direct metallization treatment on the surface of the silicon nitride ceramic 10, and then realize the direct connection between the silicon nitride ceramic 10 and copper through the silicon-copper eutectic reaction without the need for The use of solder can effectively reduce material costs; similarly, for the connection of silicon nitride ceramics 10 and aluminum, through the direct metallization method of the laser 200 of the present invention, through the silicon-aluminum eutectic reaction, the silicon nitride ceramics 10 and aluminum can be connected. Direct connection without using solder, effectively reducing material costs.

The technical solution of the present invention is not limited to the specific implementations exemplified below, but also includes any combination between specific implementations.

Example 1

Embodiment 1 of the present invention proposes a method for laser 200-assisted preparation of a ceramic 10 and metal 20 composite substrate 100, which includes the following steps:

Step 1: Put the ceramic 10 into an acetone solution for ultrasonic cleaning for 10min-20min to remove surface oil and impurities. The material of the ceramic 10 is aluminum nitride. Then use 600#, 1200#, and 2000# sand disks to clean the ceramic 10. The surface is ground and polished step by step; the metal 20 material is machined to obtain a metal 20 sample to be connected, in which the metal 20 material is made of copper, and then the metal 20 sample is placed in an acetone solution for ultrasonic cleaning for 10min-20min. Then, the surfaces to be connected of the metal 20 sample were ground and polished step by step using 400#, 800#, 1200#, and 2000# sandpaper;

Step 2: Place the ceramic 10 obtained in step 1 on the laser 200 processing platform, and irradiate the surface of the ceramic 10 with laser 200 under argon gas protection. The laser 200 wavelength is 1064 nm, the spot diameter is 30 μm, and the laser 200 pulse width is is 240ns, the pulse frequency is 200KHz, the power of the laser 200 is 56W, the scanning speed of the laser 200 is 250mm/min, and the scanning spacing of the laser 200 is 30μm to achieve the modification of the surface of the ceramic 10; after the ceramic 10 is cooled for 1 minute, the ceramic 10 is immersed in In liquid paraffin, anti-oxidation treatment is carried out;

Step three: assemble the laser 200 modified ceramic 10 obtained in step two and the metal 20 obtained in step one in the order of ceramic 10 - metal 20 and place them in the vacuum diffusion connection device 300. An axial pressure of 10 MPa is applied to the connection structure. When the vacuum degree in the vacuum diffusion connection device 300 reaches 1.5×10 ^-3 Pa, the heating is performed. First, the heating rate is controlled to 10°C/min and the temperature is raised to 500°C for 10 minutes, and then the heating rate is controlled. The temperature is raised to 620°C at 5°C/min, maintained for 30 minutes, and finally cooled down to 300°C by controlling a cooling rate of 5°C/min and then cooled to achieve direct diffusion connection between the ceramic 10 and the metal 20 .

Among them, the existing aluminum nitride ceramic 10 and metal 20 copper composite substrate 100 are generally prepared by using AgCuTi solder for soldering connection. The cost of the solder is expensive. Generally, the price of one kilogram of AgCuTi solder paste is about 8,000 yuan. However, using this method There is no need to use solder, and the cost is greatly reduced; in addition, when using AgCuTi solder for brazing, the welding temperature range is 800-900°C. The welding temperature is high and the residual stress after welding is large. However, the welding temperature of this method only needs 560-640°C. The welding temperature is greatly reduced and the residual stress after welding is small.

Example 2

A method of laser 200-assisted preparation of a composite substrate 100 of ceramic 10 and metal 20 in this embodiment includes the following steps:

Step 1: Put the ceramic 10 into an acetone solution for ultrasonic cleaning for 10min-20min to remove surface oil and impurities. The material of the ceramic 10 is aluminum nitride. Then use 600#, 1200#, and 2000# sand disks to clean the ceramic 10. The surface is ground and polished step by step; the metal 20 material is machined to obtain a metal 20 sample to be connected, in which the metal 20 material is made of copper, and then the metal 20 sample is placed in an acetone solution for ultrasonic cleaning for 10min-20min. Then, the surfaces to be connected of the metal 20 sample were ground and polished step by step using 400#, 800#, 1200#, and 2000# sandpaper;

Step 2: Place the ceramic 10 obtained in step 1 on the laser 200 processing platform, and irradiate the surface of the ceramic 10 with laser 200 under argon gas protection. The laser 200 wavelength is 1064 nm, the spot diameter is 30 μm, and the laser 200 pulse width is is 240ns, the pulse frequency is 200KHz, the power of the laser 200 is 70W, the scanning speed of the laser 200 is 250mm/min, and the scanning spacing of the laser 200 is 30μm to achieve the modification of the surface of the ceramic 10; after the ceramic 10 is cooled for 3 minutes, the ceramic 10 is immersed in In liquid paraffin, anti-oxidation treatment is carried out;

Step three: assemble the laser 200 modified ceramic 10 obtained in step two and the metal 20 obtained in step one in the order of ceramic 10 - metal 20 materials and place them in the vacuum diffusion connection device 300. Apply an axial pressure of 10MPa to the connection structure, and heat it when the vacuum degree in the vacuum diffusion connection device 300 reaches 1.5×10 ^-3 Pa. First, control the heating rate to 10°C/min and increase the temperature to 500°C for 10 minutes, and then control the temperature increase. The temperature is raised to 620°C at a rate of 5°C/min, maintained for 30 minutes, and finally cooled to 300°C at a controlled cooling rate of 5°C/min and then cooled in the furnace to achieve direct diffusion connection between the ceramic 10 and the metal 20.

Example 3

A method of laser 200-assisted preparation of a composite substrate 100 of ceramic 10 and metal 20 in this embodiment includes the following steps:

Step 1: Put the aluminum nitride ceramic 10 into an acetone solution for ultrasonic cleaning for 10min-20min to remove surface oil and impurities. The material of the ceramic 10 is aluminum nitride, and then use 600#, 1200#, and 2000# sand disks respectively. The surface of the ceramic 10 is ground and polished step by step; the metal 20 material is mechanically processed to obtain a metal 20 sample to be connected, in which the metal 20 material is made of copper. The metal 20 sample is then placed in an acetone solution for ultrasonic cleaning for 10 minutes. -20min, and then use 400#, 800#, 1200#, 2000# sandpaper to grind and polish the surfaces to be connected step by step;

Step 2: Place the ceramic 10 obtained in step 1 on the laser 200 processing platform, and irradiate the surface of the ceramic 10 with laser 200 under argon gas protection. The laser 200 wavelength is 1064 nm, the spot diameter is 30 μm, and the laser 200 pulse width is is 240ns, the pulse frequency is 200KHz, the laser 200 power is 42W, the laser 200 scanning speed is 250mm/min, and the laser 200 scanning spacing is 15μm to achieve the modification of the surface of the ceramic 10; after the ceramic 10 is cooled for 3 minutes, the ceramic 10 is immersed in In liquid paraffin, anti-oxidation treatment is carried out;

Step three: assemble the laser 200 modified ceramic 10 obtained in step two and the metal 20 obtained in step one in the order of ceramic 10 - metal 20 materials and place them in the vacuum diffusion connection device 300. The connecting structure applies an axial pressure of 15MPa, and the heating is performed when the vacuum degree in the vacuum diffusion connection device 300 reaches 1.5×10 ^-3 Pa. First, the heating rate is controlled to 10°C/min and the temperature is raised to 500°C for 10 minutes, and then the temperature is controlled. The temperature is raised to 620°C at a rate of 5°C/min, maintained for 30 minutes, and finally cooled to 300°C at a controlled cooling rate of 5°C/min and then cooled in the furnace to achieve direct diffusion connection between the ceramic 10 and the metal 20.

Example 4:

A method of laser 200-assisted preparation of a composite substrate 100 of ceramic 10 and metal 20 in this embodiment includes the following steps:

Step 1: Put the ceramic 10 into an acetone solution for ultrasonic cleaning for 10min-20min to remove surface oil and impurities. The material of the ceramic 10 is aluminum nitride. Then use 600#, 1200#, and 2000# sand disks to clean the ceramic 10. The surface is ground and polished step by step; the metal 20 material is machined to obtain a metal 20 sample to be connected, in which the metal 20 material is made of aluminum. The metal 20 sample is then placed in an acetone solution for ultrasonic cleaning for 10min-20min. Then, the surfaces to be connected of the metal 20 sample were ground and polished step by step using 400#, 800#, 1200#, and 2000# sandpaper;

Step 2: Place the ceramic 10 obtained in step 1 on the laser 200 processing platform, and irradiate the surface of the ceramic 10 with laser 200 under argon gas protection. The laser 200 wavelength is 1064 nm, the spot diameter is 30 μm, and the laser 200 pulse width is is 240ns, the pulse frequency is 200KHz, the laser 200 power is 70W, the laser 200 scanning speed is 200mm/min, and the laser 200 scanning spacing is 15μm to achieve the modification of the surface of the ceramic 10; after the ceramic 10 is cooled for 3 minutes, the ceramic 10 is immersed in In liquid paraffin, anti-oxidation treatment is carried out;

Step three: assemble the laser 200 modified ceramic 10 obtained in step two and the metal 20 obtained in step one in the order of ceramic 10 - metal 20 materials and place them in the vacuum diffusion connection device 300. Apply an axial pressure of 10 MPa to the connection structure, and heat it when the vacuum degree in the vacuum diffusion connection device 300 reaches 1.5×10 ^-3 Pa. First, control the heating rate to 10°C/min, increase the temperature to 400°C and keep it for 10 minutes, and then control the temperature rise. The temperature is raised to 550°C at a rate of 5°C/min, maintained for 30 minutes, and finally cooled down to 300°C at a cooling rate of 5°C/min and then cooled to achieve direct diffusion connection between the ceramic 10 and the metal 20 .

Example 5:

A method of laser 200-assisted preparation of a composite substrate 100 of ceramic 10 and metal 20 in this embodiment includes the following steps:

Step 1: Put the ceramic 10 into an acetone solution for ultrasonic cleaning for 10min-20min to remove surface oil and impurities. The material of the ceramic 10 is aluminum nitride. Then use 600#, 1200#, and 2000# sand disks to clean the ceramic 10. The surface is ground and polished step by step; the metal 20 material is machined to obtain a metal 20 sample to be connected, in which the metal 20 material is made of aluminum. The metal 20 sample is then placed in an acetone solution for ultrasonic cleaning for 10min-20min. Then, the surfaces to be connected of the metal 20 sample were ground and polished step by step using 400#, 800#, 1200#, and 2000# sandpaper;

Step 2: Place the ceramic 10 obtained in step 1 on the laser 200 processing platform, and irradiate the surface of the ceramic 10 with laser 200 under argon gas protection. The laser 200 wavelength is 1064 nm, the spot diameter is 30 μm, and the laser 200 pulse width is is 240ns, the pulse frequency is 200KHz, the power of the laser 200 is 56W, the scanning speed of the laser 200 is 250mm/min, and the scanning spacing of the laser 200 is 30μm to achieve the modification of the surface of the ceramic 10; after the ceramic 10 is cooled for 3 minutes, the ceramic 10 is immersed in In liquid paraffin, anti-oxidation treatment is carried out;

Step three: assemble the laser 200 modified ceramic 10 obtained in step two and the metal 20 obtained in step one in the order of ceramic 10 - metal 20 materials and place them in the vacuum diffusion connection device 300. Apply an axial pressure of 10 MPa to the connection structure, and heat it when the vacuum degree in the vacuum diffusion connection device 300 reaches 1.5×10 ^-3 Pa. First, control the heating rate to 10°C/min, increase the temperature to 400°C and keep it for 10 minutes, and then control the temperature rise. The temperature is raised to 500°C at a rate of 5°C/min, maintained for 30 minutes, and finally cooled to 300°C at a controlled cooling rate of 5°C/min and then cooled in the furnace to achieve direct diffusion connection between the ceramic 10 and the metal 20.

Example 6:

A method of laser 200-assisted preparation of a composite substrate 100 of ceramic 10 and metal 20 in this embodiment includes the following steps:

Step 1: Put the ceramic 10 into an acetone solution for ultrasonic cleaning for 10min-20min to remove surface oil and impurities. The material of the ceramic 10 is alumina. Then use 600#, 1200#, and 2000# sand disks to clean the surface of the ceramic 10. Grind and polish step by step; mechanically process the metal 20 material to obtain a metal 20 sample to be connected, in which the metal 20 material is made of aluminum. Then put the metal 20 sample into an acetone solution for ultrasonic cleaning for 10min-20min, and then The surfaces to be connected of the metal 20 sample were ground and polished step by step using 400#, 800#, 1200#, and 2000# sandpaper;

Step 2: Place the ceramic 10 obtained in step 1 on the laser 200 processing platform, and irradiate the surface of the ceramic 10 with laser 200 under argon gas protection. The laser 200 wavelength is 1064 nm, the spot diameter is 30 μm, and the laser 200 pulse width is is 240ns, the pulse frequency is 100KHz, the power of the laser 200 is 70W, the scanning speed of the laser 200 is 500mm/min, and the scanning spacing of the laser 200 is 30μm, that is, the modification of the surface of the ceramic 10 is realized; after the ceramic 10 is cooled for 3 minutes, the ceramic 10 is immersed in In liquid paraffin, anti-oxidation treatment is carried out;

Step three: assemble the laser 200 modified ceramic 10 obtained in step two and the metal 20 obtained in step one in the order of ceramic 10 - metal 20 materials and place them in the vacuum diffusion connection device 300. The connection structure applies an axial pressure of 5MPa, and the heating is performed when the vacuum degree in the vacuum diffusion connection device 300 reaches 1.5×10 ^-3 Pa. First, the heating rate is controlled to 10°C/min and the temperature is raised to 400°C for 10 minutes, and then the temperature is controlled. The temperature is raised to 550°C at a rate of 5°C/min, maintained for 30 minutes, and finally cooled to 300°C at a controlled cooling rate of 5°C/min and then cooled in the furnace to achieve direct diffusion connection between the ceramic 10 and the metal 20.

Example 7:

A method of laser 200-assisted preparation of a composite substrate 100 of ceramic 10 and metal 20 in this embodiment includes the following steps:

Step 1: Put the ceramic 10 into an acetone solution for ultrasonic cleaning for 10min-20min to remove surface oil and impurities. The material of the ceramic 10 is alumina. Then use 600#, 1200#, and 2000# sand disks to clean the surface of the ceramic 10. Grind and polish step by step; mechanically process the metal 20 material to obtain a metal 20 sample to be connected, in which the metal 20 material is made of aluminum. Then put the metal 20 sample into an acetone solution for ultrasonic cleaning for 10min-20min, and then The surfaces to be connected of the metal 20 sample were ground and polished step by step using 400#, 800#, 1200#, and 2000# sandpaper;

Step 2: Place the ceramic 10 obtained in step 1 on the laser 200 processing platform, and irradiate the surface of the ceramic 10 with laser 200 under argon gas protection. The laser 200 wavelength is 1064 nm, the spot diameter is 30 μm, and the laser 200 pulse width is is 240ns, the pulse frequency is 150KHz, the power of the laser 200 is 70W, the scanning speed of the laser 200 is 500mm/min, and the scanning spacing of the laser 200 is 30μm to achieve the modification of the surface of the ceramic 10; after the ceramic 10 is cooled for 3 minutes, the ceramic 10 is immersed in In liquid paraffin, anti-oxidation treatment is carried out;

Step three: assemble the laser 200 modified ceramic 10 obtained in step two and the metal 20 obtained in step one in the order of ceramic 10 - metal 20 materials and place them in the vacuum diffusion connection device 300. The connecting structure applies an axial pressure of 8MPa. When the vacuum degree in the vacuum diffusion connection device 300 reaches 1.5×10 ^-3 Pa, heating is performed. First, the heating rate is controlled to 10°C/min and the temperature is raised to 400°C for 10 minutes, and then the temperature is controlled. The temperature is raised to 500°C at a rate of 5°C/min, maintained for 30 minutes, and finally cooled down to 300°C at a cooling rate of 5°C/min and then cooled to achieve direct diffusion connection between the ceramic 10 and the metal 20 .

Example 8:

A method of laser 200-assisted preparation of a composite substrate 100 of ceramic 10 and metal 20 in this embodiment includes the following steps:

Step 1: Put the ceramic 10 into an acetone solution for ultrasonic cleaning for 10min-20min to remove surface oil and impurities. The material of the ceramic 10 is alumina. Then use 600#, 1200#, and 2000# sand disks to clean the surface of the ceramic 10. Grind and polish step by step; mechanically process the metal 20 material to obtain a metal 20 sample to be connected, in which the metal 20 material is made of copper. Then put the metal 20 sample into an acetone solution for ultrasonic cleaning for 10min-20min, and then The surfaces to be connected of the metal 20 sample were ground and polished step by step using 400#, 800#, 1200#, and 2000# sandpaper;

Step 2: Place the ceramic 10 obtained in step 1 on the laser 200 processing platform, and irradiate the surface of the ceramic 10 with laser 200 under argon gas protection. The laser 200 wavelength is 1064 nm, the spot diameter is 30 μm, and the laser 200 pulse width is is 240ns, the pulse frequency is 150KHz, the power of the laser 200 is 70W, the scanning speed of the laser 200 is 500mm/min, and the scanning spacing of the laser 200 is 30μm to achieve the modification of the surface of the ceramic 10; after the ceramic 10 is cooled for 3 minutes, the ceramic 10 is immersed in In liquid paraffin, anti-oxidation treatment is carried out;

Step three: assemble the laser 200 modified ceramic 10 obtained in step two and the metal 20 obtained in step one in the order of ceramic 10 - metal 20 materials and place them in the vacuum diffusion connection device 300. The connecting structure applies an axial pressure of 15MPa, and the heating is performed when the vacuum degree in the vacuum diffusion connection device 300 reaches 1.5×10 ^-3 Pa. First, the heating rate is controlled to 10°C/min and the temperature is raised to 500°C for 10 minutes, and then the temperature is controlled. The temperature is raised to 620°C at a rate of 5°C/min, maintained for 30 minutes, and finally cooled to 300°C at a controlled cooling rate of 5°C/min and then cooled in the furnace to achieve direct diffusion connection between the ceramic 10 and the metal 20.

Example 9:

A method of laser 200-assisted preparation of a composite substrate 100 of ceramic 10 and metal 20 in this embodiment includes the following steps:

Step 1: Put the ceramic 10 into an acetone solution for ultrasonic cleaning for 10min-20min to remove surface oil and impurities. The material of the ceramic 10 is alumina. Then use 600#, 1200#, and 2000# sand disks to clean the surface of the ceramic 10. Grind and polish step by step; mechanically process the metal 20 material to obtain a metal 20 sample to be connected, in which the metal 20 material is made of copper. Then put the metal 20 sample into an acetone solution for ultrasonic cleaning for 10min-20min, and then The surfaces to be connected of the metal 20 sample were ground and polished step by step using 400#, 800#, 1200#, and 2000# sandpaper;

Step 2: Place the ceramic 10 obtained in step 1 on the laser 200 processing platform, and irradiate the surface of the ceramic 10 with laser 200 under argon gas protection. The laser 200 wavelength is 1064 nm, the spot diameter is 30 μm, and the laser 200 pulse width is is 240ns, the pulse frequency is 150KHz, the power of the laser 200 is 56W, the scanning speed of the laser 200 is 300mm/min, and the scanning spacing of the laser 200 is 30μm to achieve the modification of the surface of the ceramic 10; after the ceramic 10 is cooled for 3 minutes, the ceramic 10 is immersed in In liquid paraffin, anti-oxidation treatment is carried out;

Step three: assemble the laser 200 modified ceramic 10 obtained in step two and the metal 20 obtained in step one in the order of ceramic 10 - metal 20 materials and place them in the vacuum diffusion connection device 300. The connecting structure applies an axial pressure of 15MPa, and the heating is performed when the vacuum degree in the vacuum diffusion connection device 300 reaches 1.5×10 ^-3 Pa. First, the heating rate is controlled to 10°C/min and the temperature is raised to 500°C for 10 minutes, and then the temperature is controlled. The temperature is raised to 600°C at a rate of 5°C/min, maintained for 30 minutes, and finally cooled down to 300°C at a cooling rate of 5°C/min and then cooled to achieve direct diffusion connection between the ceramic 10 and the metal 20 .

Example 10:

A method of laser 200-assisted preparation of a composite substrate 100 of ceramic 10 and metal 20 in this embodiment includes the following steps:

Step 1: Put the ceramic 10 into the acetone solution for ultrasonic cleaning for 10min-20min to remove surface oil and impurities. The material of the ceramic 10 is silicon nitride. Then use 600#, 1200#, and 2000# sand disks to clean the ceramic 10. The surface is ground and polished step by step; the metal 20 material is machined to obtain a metal 20 sample to be connected, in which the metal 20 material is made of copper, and then the metal 20 sample is placed in an acetone solution for ultrasonic cleaning for 10min-20min. Then, the surfaces to be connected of the metal 20 sample were ground and polished step by step using 400#, 800#, 1200#, and 2000# sandpaper;

Step 2: Place the ceramic 10 obtained in step 1 on the laser 200 processing platform, and irradiate the surface of the ceramic 10 with laser 200 under argon gas protection. The laser 200 wavelength is 1064 nm, the spot diameter is 30 μm, and the laser 200 pulse width is is 240ns, the pulse frequency is 150KHz, the power of the laser 200 is 56W, the scanning speed of the laser 200 is 300mm/min, and the scanning spacing of the laser 200 is 30μm to achieve the modification of the surface of the ceramic 10; after the ceramic 10 is cooled for 3 minutes, the ceramic 10 is immersed in In liquid paraffin, anti-oxidation treatment is carried out;

Step three: assemble the laser 200 modified ceramic 10 obtained in step two and the metal 20 obtained in step one in the order of ceramic 10 - metal 20 materials and place them in the vacuum diffusion connection device 300. An axial pressure of 5MPa is applied to the connection structure, and heating is performed when the vacuum degree in the vacuum diffusion connection device 300 reaches 1.5×10 ^-3 Pa. First, the heating rate is controlled to 10°C/min and the temperature is raised to 750°C for 10 minutes, and then the temperature is controlled. The temperature is raised to 850°C at a rate of 5°C/min, maintained for 30 minutes, and finally cooled to 300°C at a controlled cooling rate of 5°C/min and then cooled in the furnace to achieve direct diffusion connection between the ceramic 10 and the metal 20.

Example 11:

A method of laser 200-assisted preparation of a composite substrate 100 of ceramic 10 and metal 20 in this embodiment includes the following steps:

Step 1: Put the ceramic 10 into the acetone solution for ultrasonic cleaning for 10min-20min to remove surface oil and impurities. The material of the ceramic 10 is silicon nitride. Then use 600#, 1200#, and 2000# sand disks to clean the ceramic 10. The surface is ground and polished step by step; the metal 20 material is machined to obtain a metal 20 sample to be connected, in which the metal 20 material is made of aluminum. The metal 20 sample is then placed in an acetone solution for ultrasonic cleaning for 10min-20min. Then, the surfaces to be connected of the metal 20 sample were ground and polished step by step using 400#, 800#, 1200#, and 2000# sandpaper;

Step 2: Place the ceramic 10 obtained in step 1 on the laser 200 processing platform, and irradiate the surface of the ceramic 10 with laser 200 under argon gas protection. The laser 200 wavelength is 1064 nm, the spot diameter is 30 μm, and the laser 200 pulse width is is 240ns, the pulse frequency is 150KHz, the power of the laser 200 is 56W, the scanning speed of the laser 200 is 300mm/min, and the scanning spacing of the laser 200 is 30μm to achieve the modification of the surface of the ceramic 10; after the ceramic 10 is cooled for 3 minutes, the ceramic 10 is immersed in In liquid paraffin, anti-oxidation treatment is carried out;

Step three: assemble the laser 200 modified ceramic 10 obtained in step two and the metal 20 obtained in step one in the order of ceramic 10 - metal 20 materials and place them in the vacuum diffusion connection device 300. Apply an axial pressure of 10MPa to the connection structure, and heat it when the vacuum degree in the vacuum diffusion connection device 300 reaches 1.5×10 ^-3 Pa. First, control the heating rate to 10°C/min and increase the temperature to 500°C for 10 minutes, and then control the temperature increase. The temperature is raised to 600°C at a rate of 5°C/min, maintained for 30 minutes, and finally cooled to 300°C at a controlled cooling rate of 5°C/min and then cooled in the furnace to achieve direct diffusion connection between the ceramic 10 and the metal 20.

It is obvious to those skilled in the art that the present application is not limited to the details of the above-described exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be regarded as illustrative and non-restrictive from any point of view, and the scope of the application is defined by the appended claims rather than the above description, and it is therefore intended that all claims falling within the claims All changes within the meaning and scope of the equivalent elements are included in this application.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present application can be modified. Modifications or equivalent substitutions may be made without departing from the spirit and scope of the technical solution of the present application.

Claims (10)

1. A method for laser-assisted preparation of ceramic and metal composite substrates, which is characterized by comprising: Pretreatment of ceramics and metals, wherein the ceramic is made of silicon nitride, aluminum nitride or aluminum oxide, and the metal is made of aluminum or copper; The pretreated ceramic is placed on a laser processing platform, and the ceramic surface is irradiated with laser under the protection of vacuum or inert gas to achieve modification of the ceramic surface; The modified ceramic and the pre-treated metal are laminated to obtain a connection structure, and the connection structure is placed in a vacuum diffusion connection device, wherein the ceramic is located above the metal, and the connection structure is The connection structure is heated and pressurized to achieve direct diffusion connection between the ceramic and the metal. 2. The laser-assisted preparation method of ceramic and metal composite substrates according to claim 1, characterized in that the method of pretreating ceramics includes: Clean the ceramics to remove oil dirt and impurities from the surfaces to be connected of the ceramics; Different sanding discs are used to gradually grind and polish the surfaces to be connected of the ceramics. 3. The laser-assisted preparation method of ceramic and metal composite substrates according to claim 1, characterized in that the method of pretreating metal includes: Mechanical processing of metal materials to obtain metal specimens to be connected; Clean the metal sample to remove oil dirt and impurities on the surface to be connected of the metal sample; Different sanding discs were used to gradually grind and polish the surfaces to be connected of the metal specimens. 4. The laser-assisted preparation method of ceramic and metal composite substrates according to claim 1, characterized in that, after the modification of the ceramic surface is achieved, the method further includes: The modified ceramic surface is immersed in an organic solvent to prevent oxidation of the ceramic surface, wherein the organic solvent includes acetone, alcohol, and liquid paraffin. 5. The laser-assisted preparation method of ceramic and metal composite substrates according to claim 1, characterized in that the wavelength of the laser is 1000nm-1100nm, the spot diameter of the laser is 15μm-60μm, and the pulse width of the laser is 200ns-300ns, the pulse frequency of the laser is 50KHz-200KHz, the power of the laser is 30-80W, the scanning speed of the laser is 50mm/min-1000mm/min, and the scanning spacing of the laser is 15- 60μm. 6. The laser-assisted preparation method of ceramic and metal composite substrates according to claim 1, wherein the inert gas is at least one of helium and argon. 7. The laser-assisted preparation method of ceramic and metal composite substrates according to claim 1, characterized in that the vacuum degree in the vacuum diffusion connection device is 1.5×10 ^-3 Pa-6.5×10 ^-3 Pa. 8. The laser-assisted preparation method of ceramic and metal composite substrates according to claim 1, characterized in that the pressure applied to the connection structure is 2MPa-15MPa. 9. The laser-assisted preparation method of ceramic and metal composite substrates according to claim 1, wherein the method of heating the connection structure specifically includes: In a vacuum or protective gas atmosphere, the connection structure is heated by thermal radiation, so that the connection structure is heated to 500°C and kept for 10 minutes, and then continues to be heated to 560°C-1000°C and kept for 30min-120min. Finally, the temperature is lowered to 300°C at a cooling rate of 5°C/min-10°C/min and then cooled. 10. A composite substrate, characterized in that it is prepared by the method described in any one of claims 1-9.