A method for connecting ceramic / glass and metal using laser surface modification technology

Abstract

The present invention provides a method for connecting ceramic / glass and metal using laser surface modification technology, which solves the technical problems of insufficient wetting and residual stress, physical property mismatch and metallurgical incompatibility existing in the interface between ceramic / glass and metal. The method comprises the following steps: S1. cleaning, grinding and polishing a ceramic / glass sheet; S2. applying a precursor solution on the surface of the ceramic / glass sheet and drying to form a precursor layer; the precursor solution comprises a solute of an easily decomposable metal nitrate or noble metal salt and a reducing agent, and a solvent of water; S3. after laser irradiation of the precursor layer, cleaning and drying the ceramic / glass sheet to obtain a surface-modified ceramic / glass sheet; S4. assembling the surface-modified ceramic / glass sheet and the polished metal sheet in the order of ceramic / glass sheet-metal sheet or ceramic / glass sheet-brazing filler metal sheet under vacuum, overlapping and pressing to form an assembly, and cooling to room temperature. The method can be widely used in the field of ceramic / glass and metal connection technology.

Description

Technical Field

[0001] The present application relates to the technical field of ceramic / glass and metal connection, and in particular to a method for connecting ceramic / glass and metal using laser surface modification technology. Background Art

[0002] Ceramic materials offer advantages such as high hardness, wear resistance, corrosion resistance, and excellent high-temperature performance, while metals, with their high strength, excellent ductility, and excellent electrical and thermal conductivity, form a distinctly complementary performance relationship with ceramics, particularly in high-tech fields such as semiconductor packaging, aerospace, and power electronics. With technological advancements and industrial development, ceramic-to-metal connectors are increasingly being used in new energy vehicles, electronics, semiconductor packaging, IGBT modules, and other fields. For example, the large-scale industrialization of products such as ceramic relays, ceramic sealed connectors, and ceramic substrates has placed higher demands on ceramic-to-metal joining technology. Significant differences in the physical and chemical properties of ceramics and metals, such as thermal expansion coefficient, wettability, and chemical stability, make joining ceramics to metals a challenging task. Ceramic-to-metal joining technology faces numerous challenges, primarily in two areas: ceramics, primarily composed of ionic and covalent bonds, differ significantly from metals, which primarily consist of metallic bonds, resulting in near-impossible wetting between the two materials; and the generally significant difference in thermal expansion coefficient between ceramics and metals. Temperature fluctuations can easily generate residual stress at the interface, leading to failure.

[0003] Glass, with its exceptional heat and corrosion resistance, unparalleled transparency, and light transmittance, perfectly combines with metal materials, bringing unprecedented innovation opportunities to the high-tech sector. Glass-to-metal bonding demonstrates widespread application value in cutting-edge fields such as microelectronics, optics, and aerospace. This combination not only extends device lifespan but also effectively prevents equipment failure and loss of connectivity in harsh environments, providing a solid safety guarantee for scientific and technological advancement and engineering applications. Glass-to-metal bonding faces two fundamental challenges: physical property mismatch and metallurgical incompatibility. Physical property mismatch primarily manifests itself in differences in physical properties such as thermal expansion coefficient and elastic modulus. This can lead to stress concentration at the bonding interface during temperature fluctuations or under load, compromising connection reliability. Metallurgical incompatibility is the primary issue in achieving metallurgical bonding between glass and metal. This is because glass and metal differ significantly in their atomic structure and chemical bonding, making it difficult to achieve a strong bond using traditional metallurgical methods.

[0004] It can be seen that the main technical problems at the ceramic-metal interface are insufficient wetting and residual stress, while the main technical problems at the glass-metal interface are physical property mismatch and metallurgical incompatibility. These technical problems need to be solved urgently. Summary of the Invention

[0005] The purpose of the present invention is to address the deficiencies of the above-mentioned technologies and to provide a method for connecting ceramic / glass and metal using laser surface modification technology, thereby improving the connection effect between the ceramic / glass and metal connection interfaces.

[0006] To this end, the present invention provides a method for connecting ceramic / glass and metal using laser surface modification technology, comprising the following steps:

[0007] Step S1: Clean, grind and polish the ceramic / glass sheet.

[0008] Step S2. Coating the precursor solution on the surface of the ceramic sheet / glass sheet obtained in step S1, and then drying to form a precursor layer; in the precursor solution, the solute is an easily decomposable metal nitrate or noble metal salt, a reducing agent, and the solvent is water.

[0009] Step S3. The precursor layer formed on the surface of the ceramic sheet / glass sheet obtained in step S2 is subjected to laser irradiation, and then the ceramic sheet / glass sheet is washed and dried to obtain a surface-modified ceramic sheet / glass sheet.

[0010] On the one hand, laser irradiation provides energy for the generation of metal elements in the precursor layer and the surface remelting of ceramics / glass or the generation of metal elements, wherein the reducing agent in the precursor layer reduces the metal ions in the metal nitrate or precious metal salt to the corresponding metal elements under laser irradiation, forming metal particles on the surface of the ceramics / glass; the surface of the ceramics / glass is remelted or decomposed into metal elements under laser irradiation, wherein the remelted ceramics / glass that are usually not easily decomposed by laser irradiation, such as K9 glass, alumina ceramics, silicon carbide ceramics, etc. The metal element decomposed is a ceramic / glass that is easily decomposed by laser irradiation, such as silicon nitride ceramic decomposition to silicon, aluminum nitride ceramic decomposition to aluminum, etc., which then undergoes a eutectic or metallurgical reaction with the metal element decomposed from the precursor; on the other hand, the surface of the surface-modified ceramic / glass sheet prepared under laser irradiation is covered with a large number of tiny pits that are the same as the laser path, which increases the contact area, thereby improving the bonding force of the contact surface and preparing for step S4; especially when using solder, the welding area is increased and has a certain regulatory effect on the stress distribution of the joint welding. Step S4. Under a vacuum environment, the surface-modified ceramic / glass sheet obtained in step S3 and the polished metal sheet are assembled in the order of ceramic sheet / glass sheet-metal sheet or ceramic sheet / glass sheet-brazing filler-metal sheet, and are superimposed and pressed under a certain heating temperature and pressure to form an assembly. The temperature is cooled to room temperature to achieve the connection between the ceramic sheet / glass sheet and the metal sheet. The modified ceramic / glass sheet and the metal sheet, or both and the brazing material, interact at high temperature to diffuse into each other or form a local liquid phase. As the temperature gradually decreases, these liquid phases solidify, thereby forming a strong metallurgical bond between the ceramic / glass sheet and the metal sheet.

[0011] Preferably, in step S1, the ceramic sheet is one of an oxide ceramic sheet, a nitride ceramic sheet, and a carbide ceramic sheet.

[0012] Preferably, in step S1, the ceramic sheet / glass sheet is placed in an anhydrous alcohol solution and ultrasonically cleaned, and the surface of the ceramic sheet / glass sheet is gradually polished to 2000 mesh using a diamond sand disk and polished.

[0013] Preferably, in step S2, the concentration of the solute in the precursor solution is 300-600 g / L, the metal nitrate is copper nitrate or silver nitrate, the noble metal salt is one or more of palladium nitrate, copper acetate, silver citrate, and chloroauric acid; the reducing agent is one or more of polyvinyl pyrrolidone (PVP), polyethylene glycol (PEG), and polyacrylonitrile (PAN), with a concentration of 90-150 g / L; and the solvent is one of purified water, deionized water, and distilled water. The reducing agent PVP decomposes into methylamine, propionic acid, and carboxylic acid under laser irradiation. The decomposed carboxylic acid, as well as the nitrile groups of the reducing agents polyethylene glycol and polyacrylonitrile themselves, have certain reducing properties, so that the metal ions in the metal nitrates such as copper nitrate and silver nitrate are reduced to the corresponding metal elements such as copper and silver, respectively, and the metal ions in the noble metal salts such as palladium nitrate and copper acetate are reduced to the corresponding metal elements such as palladium and copper, respectively.

[0014] Preferably, in step S3, the laser is a continuous laser, the continuous laser power is 1 to 100 W, and the scanning rate is 1 to 5000 mm / min.

[0015] Preferably, in step S3, the laser is a pulsed laser, the pulsed laser power is 1 to 120 W, the laser pulse width is 1 to 400 ms, the laser frequency is 1 to 1000 kHz, and the laser scanning speed is 1 to 5000 mm / min.

[0016] Preferably, in step S3, the processing environment of the ceramic sheet / glass sheet is one of atmospheric atmosphere, vacuum atmosphere, and inert gas atmosphere.

[0017] Preferably, in step S4, the metal sheet is one of titanium sheet, aluminum sheet, copper sheet, aluminum alloy sheet, copper alloy sheet, titanium alloy sheet, and stainless steel sheet; the solder is one of tin-based solder, aluminum-based solder, and silver-based solder.

[0018] Preferably, in step S4, the vacuum degree in the vacuum hot pressing furnace is 1×10 -3 Pa~7×10 -3 Pa.

[0019] Preferably, in step S4, the axial pressure applied during the stacking and pressing to form the assembly is no greater than 6 MPa. The axial force refers to the force perpendicular to the stacking connection surface of the ceramic / glass sheet and the metal sheet. If brazing is used, it refers to the force perpendicular to the brazing surface.

[0020] Preferably, in step S4, the heating rate is 5-20°C / min, the heating temperature is 400-1000°C, the holding time is 1-60 min, and the cooling rate is 5°C / min.

[0021] The present invention provides a method for connecting ceramic / glass and metal using laser surface modification technology, which has the following beneficial effects:

[0022] (1) By using laser to modify the surface of ceramic / glass sheets with precursors, on the one hand, the precursor is decomposed and reduced to a metal element, and the ceramic / glass surface is decomposed after modification, such as silicon nitride is decomposed into silicon element, aluminum nitride is decomposed into aluminum element, etc., thereby forming a metallization layer; a local liquid phase is formed by eutectic reaction to achieve diffusion connection between ceramic and metal at a lower temperature; or the metallization layer is used to achieve wetting of ceramic / glass by inactive solder, thereby achieving medium-temperature or low-temperature brazing of ceramic / glass and metal; thereby solving the technical defects of large thermal stress and affecting joint performance in the existing connection between ceramic / glass sheets and metal; on the other hand, the ceramic / glass surface is modified to form a metallization layer, which effectively promotes the wetting of inactive solder on ceramic / glass, further enriching the connection technology between ceramic / glass and metal.

[0023] (2) The surface of ceramic / glass is modified by laser irradiation, which effectively changes the chemical composition and surface state of the ceramic / glass surface, forms a metallized layer on the surface of the ceramic / glass, and interacts with the precursor layer to achieve high-quality connection between ceramic / glass and metal at a lower temperature, thereby reducing energy consumption. The preparation method is green and environmentally friendly. The obtained ceramic / glass-metal joint has the advantages of low residual stress, uniform mechanical properties and high reliability, which successfully solves the technical difficulties in the connection between ceramic / glass and metal. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application.

[0025] Figure 1 a) Figure 1 c) Macroscopic photographs of the aluminum nitride ceramic sheet before and after surface modification in Example 1 of the present invention; Figure 1 b) Figure 1 d) are scanning electron microscope photographs of the aluminum nitride ceramic sheet before and after surface modification according to Example 1 of the present invention;

[0026] Figure 2 This is a scanning electron microscope photograph of the connection interface between the aluminum nitride ceramic sheet and metallic aluminum in Example 1 of the present invention;

[0027] Figure 3 a) Figure 3 b) are conductivity test photos of K9 glass before and after surface modification in Example 3 of the present invention. DETAILED DESCRIPTION

[0028] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely for the purpose of explaining this application and are not intended to limit this application. The methods used in this invention are conventional methods unless otherwise specified; the raw materials and devices used are conventional commercially available products unless otherwise specified.

[0029] Example 1:

[0030] This embodiment provides a method for joining ceramic and metal using laser surface modification technology, comprising the following steps:

[0031] Step 1: Select an aluminum nitride ceramic sheet and place it in an anhydrous alcohol solution for ultrasonic cleaning for 10 minutes to remove surface impurities and dirt. Then, use diamond sandpaper of different mesh sizes to grind the surface of the aluminum nitride ceramic sheet step by step to 2000 mesh and polish it.

[0032] Step 2: Coat the aluminum nitride ceramic sheet obtained in step 1 with a 1 mm thick precursor solution, the precursor composition of which is 500 g / L Cu(NO3)2, 100 g / L PVP, and the solvent is deionized water; then place the coated material in a drying oven and dry it at 50°C for 1 hour.

[0033] Step 3: Place the aluminum nitride ceramic sheet in step 2 on a laser processing platform, and irradiate the surface of the aluminum nitride ceramic sheet with laser in an atmospheric atmosphere, wherein the laser is a continuous laser, the laser power is 25W, and the laser scanning speed is 100mm / min, so as to achieve surface modification of the ceramic sheet, and a metallized layer is generated on its surface, which is mainly composed of Cu and Al, and comes from the decomposition of aluminum nitride ceramic into N2 and Al under the action of laser and the Cu reduced from the precursor; the processed aluminum nitride ceramic sheet is placed in anhydrous alcohol solution for ultrasonic cleaning for 20 minutes to remove the processing residue on the surface of the ceramic sheet, and then dried in a drying oven at 50°C for 1 hour.

[0034] Step 4: Assemble the surface-modified aluminum nitride ceramic sheet obtained in step 3 and the polished aluminum sheet in the order of ceramic sheet-aluminum sheet and place them in a vacuum hot pressing furnace. Apply an axial pressure of 3 MPa to the assembly of the aluminum nitride ceramic sheet and the aluminum sheet until the vacuum degree reaches 2×10 -3Pa, firstly heated to 500℃ at a heating rate of 20℃ / min and kept warm for 10min, then heated to 600℃ at a heating rate of 10℃ / min and kept warm for 30min, and finally cooled to 300℃ at a cooling rate of 5℃ / min and cooled with the furnace. The Cu-Al metallization layer and the Al sheet undergo eutectic reaction, that is, the connection between the aluminum nitride ceramic sheet and the metal copper sheet is realized, and the obtained ceramic-metal joint has good bonding.

[0035] Example 2:

[0036] This embodiment provides a method for joining ceramic and metal using laser surface modification technology, comprising the following steps:

[0037] Step 1: Select a silicon nitride ceramic wafer and place it in an anhydrous alcohol solution for ultrasonic cleaning for 10 minutes to remove surface impurities and dirt. Then, use diamond sandpaper of different mesh sizes to grind the surface of the silicon nitride ceramic wafer step by step to 2000 mesh and polish it.

[0038] Step 2: Coat the silicon nitride ceramic sheet obtained in step 1 with a 1.5 mm thick precursor solution, the precursor composition of which is 300 g / L AgNO3, 50 g / L PVP and 60 g / L PAN, and the solvent is deionized water; then place the coated material in a drying oven and dry it at 50°C for 1 hour.

[0039] Step 3: Place the silicon nitride ceramic sheet in step 2 on a laser processing platform, and irradiate the surface of the silicon nitride ceramic sheet with laser in an atmospheric atmosphere, wherein the laser is a pulsed laser with a laser power of 70W, a laser pulse width of 75ms, a laser frequency of 100kHz, and a laser scanning speed of 200mm / min, thereby realizing surface modification of the ceramic sheet, and generating a metallized layer on the surface thereof, which is mainly composed of Ag and Si, and is derived from the decomposition of silicon nitride ceramic into N2 and Si under the action of laser and the Ag reduced from the precursor; the processed silicon nitride ceramic sheet is placed in an anhydrous alcohol solution for ultrasonic cleaning for 20min to remove the processing residue on the surface of the ceramic sheet, and then dried in a drying oven at 50°C for 1h.

[0040] Step 4: Assemble the surface-modified silicon nitride ceramic sheet obtained in step 3 and the polished copper sheet in the order of ceramic sheet-copper sheet and place them in a vacuum hot pressing furnace. Apply an axial pressure of 6 MPa to the assembly of the silicon nitride ceramic sheet and the copper sheet until the vacuum degree reaches 2×10 -3Pa, firstly heated to 700℃ at a heating rate of 20℃ / min and kept warm for 10min, then heated to 800℃ at a heating rate of 10℃ / min and kept warm for 60min, and finally cooled to 300℃ at a cooling rate of 5℃ / min and cooled with the furnace. The Ag-Si metallization layer and the copper sheet undergo eutectic reaction, that is, the connection between the silicon nitride ceramic sheet and the metal copper sheet is realized, and the obtained ceramic-metal joint has good bonding.

[0041] Example 3:

[0042] This embodiment provides a method for joining glass and metal using laser surface modification technology, comprising the following steps:

[0043] Step 1: Select a K9 glass sheet and place it in an anhydrous alcohol solution for ultrasonic cleaning for 10 minutes to remove surface impurities and dirt. Then use diamond sandpaper of different mesh sizes to grind the surface of the K9 glass sheet step by step to 2000 mesh and polish it.

[0044] Step 2: Coat the K9 glass sheet obtained in step 1 with a 1 mm thick precursor solution, the precursor composition of which is 600 g / L Cu(NO3)2, 120 g / L PVP, and the solvent is deionized water; then place the coated material in a drying oven and dry it at 50°C for 1 hour.

[0045] Step 3: Place the K9 glass sheet prepared in step 2 on a laser processing platform, and irradiate the surface of the K9 glass sheet with laser in an argon atmosphere. The laser is a pulsed laser with a laser power of 50 W, a laser pulse width of 250 ms, a laser frequency of 200 kHz, and a laser scanning speed of 200 mm / min to achieve surface modification of the glass. A copper metallization layer is generated on the surface. The metallization layer is conductive and has a resistance of 3.2 Ω after testing. The processed K9 glass sheet is ultrasonically cleaned in an anhydrous alcohol solution for 20 minutes to remove processing residues on the glass surface, and then dried in a drying oven at 50°C for 1 hour.

[0046] Step 4: Assemble the surface-modified K9 glass sheet obtained in step 3 and the polished aluminum sheet in the order of ceramic sheet-aluminum sheet and place them in a vacuum hot pressing furnace. Apply an axial pressure of 1 MPa to the assembly of the K9 glass sheet and the aluminum sheet until the vacuum degree reaches 5×10 -3 Pa, firstly raised to 300℃ at a heating rate of 20℃ / min and kept at that temperature for 10min, then raised to 400℃ at a heating rate of 10℃ / min and kept at that temperature for 60min, and finally cooled to 300℃ at a cooling rate of 5℃ / min and cooled with the furnace. The Cu metallization layer and the Al sheet diffused and reacted, thus realizing the connection between the K9 glass sheet and the metal copper sheet. The obtained glass-metal joint had good bonding.

[0047] Example 4:

[0048] This embodiment provides a method for joining ceramic and metal using laser surface modification technology, comprising the following steps:

[0049] Step 1: Alumina ceramic sheets are selected as ceramic sheets. The alumina ceramic sheets are placed in anhydrous alcohol solution and ultrasonically cleaned for 10 minutes to remove surface impurities and dirt. Then, diamond sandpaper with different mesh sizes is used to grind the surface of the alumina ceramic sheets step by step to 2000 mesh and polish them.

[0050] Step 2: Coat the alumina ceramic sheet obtained in step 1 with a 1.5 mm thick precursor solution containing 600 g / L Cu(NO3)2, 100 g / L PVP, and 50 g / L PEG, with deionized water as the solvent. Place the coated material in a drying oven and dry at 50°C for 1 hour.

[0051] Step 3. Place the alumina ceramic sheet prepared in step 2 on a laser processing platform, and irradiate the surface of the alumina ceramic sheet with laser in an atmospheric atmosphere, wherein the laser is a continuous laser, the laser power is 40W, and the laser scanning speed is 500mm / min, thereby realizing surface modification of the ceramic sheet, and generating a copper metallization layer on the surface thereof. The metallization layer is conductive and its resistance is 3.5Ω after testing; the processed alumina ceramic sheet is placed in an anhydrous alcohol solution for ultrasonic cleaning for 20 minutes to remove the processing residue on the surface of the ceramic sheet, and then dried in a drying oven at 50°C for 1 hour.

[0052] Step 4: Assemble the surface-modified alumina ceramic sheet obtained in step 3 with the polished aluminum sheet and Al88Si12 brazing filler metal in the order of ceramic sheet-brazing filler metal-aluminum sheet and place them in a vacuum hot pressing furnace without applying axial pressure. Wait until the vacuum degree reaches 2×10 -3 Pa, firstly raised to 500℃ at a heating rate of 20℃ / min and kept warm for 10min, then raised to 600℃ at a heating rate of 10℃ / min and kept warm for 20min, and finally cooled to 300℃ at a cooling rate of 5℃ / min and cooled with the furnace. With the promotion of the copper metallization layer, the wetting of the brazing material on the alumina ceramic sheet was achieved, that is, the connection between the alumina ceramic sheet and the metal aluminum sheet was achieved at 600℃, and the obtained ceramic-metal joint was well bonded.

[0053] Example 5:

[0054] This embodiment provides a method for joining ceramic and metal using laser surface modification technology, comprising the following steps:

[0055] Step 1: Select a silicon carbide ceramic sheet as the ceramic sheet, place the silicon carbide ceramic sheet in an anhydrous alcohol solution and ultrasonically clean it for 10 minutes to remove surface impurities and dirt, then use diamond sandpaper of different mesh sizes to grind the surface of the silicon carbide ceramic sheet step by step to 2000 mesh, and polish it.

[0056] Step 2: Coat the silicon carbide ceramic sheet obtained in step 1 with a 2 mm thick precursor solution containing 400 g / L AgNO3, 20 g / L PEG, and 70 g / L PAN, with deionized water as the solvent. Place the coated material in a drying oven and dry at 50°C for 1 hour.

[0057] Step 3. Place the silicon carbide ceramic sheet in step 2 on a laser processing platform, and irradiate the surface of the silicon carbide ceramic sheet with laser in a vacuum atmosphere, wherein the laser is a pulsed laser with a laser power of 80 W, a laser pulse width of 100 ms, a laser frequency of 20 kHz, and a laser scanning speed of 150 mm / min, thereby achieving surface modification of the ceramic sheet, and generating a continuous silver metallization layer on the surface thereof. The metallization layer is conductive and tested to have a resistance of 2.3 Ω; the processed silicon carbide ceramic sheet is ultrasonically cleaned in an anhydrous alcohol solution for 20 minutes to remove processing residues on the surface of the ceramic sheet, and then dried in a drying oven at 50°C for 1 hour.

[0058] Step 4: Assemble the surface-modified silicon carbide ceramic sheet obtained in step 3 with the polished titanium sheet and AgCuIn20-31 solder in the order of ceramic sheet-solder-titanium sheet and place them in a vacuum hot pressing furnace without applying axial pressure. Wait until the vacuum degree reaches 1.5×10 -3 Pa, firstly raised to 500℃ at a heating rate of 20℃ / min and kept warm for 10min, then raised to 700℃ at a heating rate of 10℃ / min and kept warm for 30min, and finally cooled to 300℃ at a cooling rate of 5℃ / min and cooled with the furnace. With the promotion of the silver metallization layer, the wetting of the brazing material on the silicon carbide ceramic sheet was achieved, that is, the connection between the silicon carbide ceramic sheet and the metal titanium sheet was achieved at 700℃, and the obtained ceramic-metal joint had good bonding.

[0059] Experimental test:

[0060] Figure 1 a) Figure 1 c) are macroscopic photos of the aluminum nitride ceramic sheet before and after surface modification in Example 1 of the present invention. Figure 1 As shown in a), the original aluminum nitride ceramic is white; Figure 1 As shown in Figure c), black and silver-white substances appear on the surface of the aluminum nitride ceramic sheet after surface modification, indicating that the laser surface modification effect is obvious and new substances are generated.

[0061] Figure 1b) Figure 1 d) are scanning electron microscope photos of the aluminum nitride ceramic sheet before and after surface modification in Example 1 of the present invention. Figure 1 As shown in b), the aluminum nitride ceramic sheet before surface modification is composed of gray aluminum nitride ceramic particles and a small amount of white yttrium oxide sintering agent; Figure 1 As shown in d), a layer of grayish-white substance is added to the surface of the aluminum nitride ceramic sheet after surface modification, indicating that after laser surface modification, a metal element or intermetallic compound layer is formed on the surface of the aluminum nitride ceramic sheet. In addition, the surface of the aluminum nitride ceramic sheet is covered with a large number of tiny pits.

[0062] Figure 2 This is a scanning electron microscope photo of the connection interface between the aluminum nitride ceramic sheet and the metal aluminum sheet in Example 1 of the present invention. Figure 2 As shown in the figure, the diffusion welded joint has no defects such as cracks and holes, indicating that the surface-modified aluminum nitride ceramic sheet and the metal aluminum sheet are well bonded.

[0063] Figure 3 a) Figure 3 b) are the conductivity test photos of the K9 glass sheet before and after surface modification in Example 3 of the present invention. Figure 3 As shown in a), after multimeter testing, K9 glass has no conductivity; Figure 3 As shown in b), after multimeter testing, the surface resistance of the treated K9 glass is 3.2Ω, indicating that after laser surface modification, there is a continuous copper layer on the surface of the K9 glass, achieving surface metallization.

[0064] It should be noted that:

[0065] (1) The laser used in the present invention is a continuous laser or a pulsed laser. When the laser is a continuous laser, the continuous laser power is 1 to 100 W and the scanning rate is 1 to 5000 mm / min. When the laser is a pulsed laser, the pulsed laser power is 1 to 120 W, the laser pulse width is 1 to 400 ms, the laser frequency is 1 to 1000 kHz, and the laser scanning speed is 1 to 5000 mm / min. The laser can be selected according to actual conditions.

[0066] (2) The cleaning method, time, drying time, temperature, etc. of the present invention are determined according to actual conditions. The room temperature of the present invention is 20°C ± 5°C.

[0067] (3) When assembling the surface-modified ceramic sheet with the polished metal sheet, tin-based solder, aluminum-based solder or silver-based solder can be selected according to the actual situation.

[0068] (4) The ceramic sheet used in step 1 of the above embodiment can be one of an oxide ceramic sheet, a nitride ceramic sheet, and a carbide ceramic sheet. The K9 glass sheet described in embodiment 3 is a type of glass, and other glass sheets can also be substituted.

[0069] (5) Among the precursor components of step 2 of the above embodiment, the silver nitrate and copper nitrate used have poor thermal stability and are easily decomposed by heat to form oxides, which are then reduced to metal elements by a reducing agent. Other easily decomposable metal nitrates or precious metal salts can also replace silver nitrate and copper nitrate, among which easily decomposable metal nitrates include palladium nitrate, etc., and easily decomposable precious metal salts include palladium nitrate, copper acetate, silver citrate, chloroauric acid, etc.

[0070] (6) Deionized water is used in step 2 of the above embodiment, but purified water or distilled water may be used instead.

[0071] (7) The vacuum atmosphere in step 3 of the above embodiment may also be an atmospheric atmosphere or an inert gas atmosphere.

[0072] (8) The aluminum sheet, copper sheet, and titanium sheet in step 4 of the above embodiment can also be replaced by aluminum alloy sheet, copper alloy sheet, titanium alloy sheet, stainless steel sheet, etc. The solder can also be tin-based solder, aluminum-based solder, silver-based solder, etc. The vacuum degree in the vacuum hot pressing furnace is preferably 1×10 -3 Pa~7×10 -3 The heating rate, heating temperature, holding time and cooling rate can be set according to actual conditions. Preferably, the heating rate is 5-20°C / min, the heating temperature is 400-1000°C, the holding time is 1-60min, and the cooling rate is 5°C / min.

[0073] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A method for connecting ceramic / glass and metal using laser surface modification technology, characterized in that: The following steps are involved: Step S1. Clean, grind, and polish the ceramic / glass sheet; Step S2. Coating a precursor solution on the surface of the ceramic sheet / glass sheet obtained in step S1 and drying to form a precursor layer; the precursor solution contains a solute of a readily decomposable metal nitrate or noble metal salt and a reducing agent, and a solvent of water; Step S3. irradiating the precursor layer formed on the surface of the ceramic sheet / glass sheet obtained in step S2 with a laser, and then washing and drying the ceramic sheet / glass sheet to obtain a surface-modified ceramic sheet / glass sheet; Step S4. Under a vacuum environment, assemble the surface-modified ceramic sheet / glass sheet obtained in step S3 and the polished metal sheet in the order of ceramic sheet-metal sheet or ceramic sheet / glass sheet-brazing material-metal sheet, overlap and press them under a certain heating temperature and pressure to form an assembly, and cool them to room temperature to achieve the connection between the ceramic sheet / glass sheet and the metal sheet.

2. The method for connecting ceramic / glass and metal using laser surface modification technology according to claim 1, characterized in that: In the step S1, the ceramic sheet is one of an oxide ceramic sheet, a nitride ceramic sheet, and a carbide ceramic sheet.

3. The method for connecting ceramic / glass and metal using laser surface modification technology according to claim 1, characterized in that: In the step S1, the ceramic sheet / glass sheet is placed in an anhydrous alcohol solution and ultrasonically cleaned, and the surface of the ceramic sheet / glass sheet is ground step by step to 2000 mesh using a diamond sand disk, and then polished.

4. The method for connecting ceramic / glass and metal using laser surface modification technology according to claim 1, characterized in that: In step S2, in the precursor solution, the concentration of the solute is 300-600 g / L, the metal nitrate is copper nitrate or silver nitrate, and the noble metal salt is one or more of palladium nitrate, silver citrate, and chloroauric acid; the reducing agent is one or more of polyvinyl pyrrolidone, polyethylene glycol, and polyacrylonitrile, and its concentration is 90-150 g / L; and the solvent is one of purified water, deionized water, and distilled water.

5. The method for connecting ceramic / glass and metal using laser surface modification technology according to claim 1, characterized in that: In step S3, the laser is a continuous laser, the continuous laser power is 1 to 100 W, and the scanning rate is 1 to 5000 mm / min; Alternatively, the laser is a pulsed laser, the pulsed laser power is 1 to 120 W, the laser pulse width is 1 to 400 ms, the laser frequency is 1 to 1000 kHz, and the laser scanning speed is 1 to 5000 mm / min.

6. The method for connecting ceramic / glass and metal using laser surface modification technology according to claim 1, characterized in that: In step S3, the processing environment of the ceramic sheet / glass sheet is one of an atmospheric atmosphere, a vacuum atmosphere, and an inert gas atmosphere.

7. The method for connecting ceramic / glass and metal using laser surface modification technology according to claim 1, characterized in that: In step S4, the metal sheet is one of titanium sheet, aluminum sheet, copper sheet, aluminum alloy sheet, copper alloy sheet, titanium alloy sheet, and stainless steel sheet; the solder is one of tin-based solder, aluminum-based solder, and silver-based solder.

8. The method for connecting ceramic / glass and metal using laser surface modification technology according to claim 1, characterized in that: In step S4, the vacuum degree in the vacuum hot pressing furnace is 1×10 -3 Pa~7×10 -3 Pa.

9. The method for connecting ceramic / glass and metal using laser surface modification technology according to claim 1, characterized in that: In step S4, the axial pressure applied when stacking and pressing the assembly is not greater than 6 MPa.

10. The method for connecting ceramic / glass and metal using laser surface modification technology according to claim 1, characterized in that: In step S4, the heating rate is 5-20°C / min, the heating temperature is 400-1000°C, the holding time is 1-60 minutes, and the cooling rate is 5°C / min.

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