Ceramic slurry, perforated ceramic substrate and preparation method of perforated ceramic substrate

Abstract

The invention provides a ceramic slurry, a porous ceramic substrate and a preparation method thereof, the ceramic slurry comprises the following components by mass percentage: 35%-40% of ceramic powder, 35%-40% of a sintering aid, 8%-22% of a solvent, 2%-4% of a binder, 1%-4% of a dispersant, 4%-5% of a leveling agent and 1%-3% of a humectant; the mass ratio of the ceramic powder to the sintering aid is (0.9-1.1): 1. The ceramic slurry is prepared from the ceramic powder, the sintering aid, the solvent, the binder, the dispersing agent, the flatting agent and the humectant according to a specific ratio, has a relatively high solid phase content and also has a relatively good self-leveling characteristic, and can be suitable for a 3D printing process; in the 3D printing process, the through hole structure can be kept, the ceramic substrate has good flatness, and the porous ceramic substrate with high precision and small hole error can be prepared.

Description

Technical Field

[0001] The present application relates to the technical field of ceramic materials, and in particular to a ceramic slurry, a porous ceramic substrate and a preparation method thereof. Background Art

[0002] In recent years, the integration of functional ceramic devices has become increasingly higher. Most functional ceramic devices, such as multilayer ceramic capacitors, multilayer ceramic substrates, filters, chip antennas, power dividers, etc., can be prepared by traditional tape casting processes.

[0003] Tape casting is a method of forming ceramic films of a certain thickness by mixing ceramic powder, solvent and various ceramic additives to obtain a stable slurry. LTCC (Low Temperature Co-fired Ceramic) technology is a process of stacking cast ceramic materials as required, printing interconnecting conductors, components and circuits inside, and finally sintering them into an integrated ceramic multilayer material. The process includes steps such as casting, punching, filling holes, lamination, slicing, and co-firing.

[0004] The drilling step is a critical process technology in the manufacture of multi-layer ceramic substrates. The size, position, and accuracy of the holes will directly affect the continuity, wiring density, substrate quality, and yield rate of the internal wiring of the substrate. At present, there are two main methods for drilling holes in raw ceramic tape: mechanical drilling and laser drilling.

[0005] Mechanical punching can achieve high-speed and high-precision movement of raw ceramic sheets through the movement of the platform in the X and Y directions, improving production efficiency and reliability. The current production efficiency can reach more than 1,800 holes / min, and the position accuracy of the punching can reach ±5μm. It is currently the most widely used punching method in the industry. However, its hole diameter is restricted by the hole diameter of the punch needle, which is limited in punching non-standard sizes and special-shaped holes.

[0006] Laser drilling uses a laser to emit a focused laser beam, and emits continuously distributed light pulses along the edge of the through hole onto the raw ceramic tape. The laser energy vaporizes the organic matter and ceramic materials to form a through hole. The ceramic circuit board prepared by the laser drilling process has the characteristics of high bonding between ceramic and metal, no shedding, blistering, etc., achieving the effect of growing together. The holes formed by laser drilling have high surface flatness, with a roughness rate of 0.1μm~0.3μm, and a laser drilling aperture of 0.15mm~0.5mm, with a partial accuracy of 0.06mm, but it also has the disadvantages of high post-processing cost and time-consuming.

[0007] In summary, the conventional ceramic sheet preparation process cannot quickly, efficiently and custom-make high-quality ceramic sheets with through holes. Therefore, the conventional technology still needs to be further improved. Summary of the invention

[0008] Based on this, the present application provides a ceramic slurry for efficiently and high-quality preparation of a porous ceramic substrate, and correspondingly provides a porous ceramic substrate and a preparation method thereof.

[0009] The technical solution proposed in this application is as follows:

[0010] According to the first aspect of the present application, a ceramic slurry is provided, characterized in that, calculated by mass percentage, it comprises 35%~40% ceramic powder, 35%~40% sintering aid, 8%~22% solvent, 2%~4% binder, 1%~4% dispersant, 4%~5% leveling agent, and 1%~3% moisturizing agent; the mass ratio of the ceramic powder to the sintering aid is (0.9~1.1):1.

[0011] In any embodiment, the solid content of the ceramic slurry is 70% to 80%.

[0012] In any embodiment, the ceramic powder includes one or more of alumina powder, aluminum nitride powder, silicon nitride powder and zirconium oxide powder.

[0013] In any embodiment, the solvent includes one or more of deionized water, toluene, ethanol and trichloroethylene.

[0014] In any embodiment, the sintering aid includes one or more of a MnO2-TiO2-MgO multiphase sintering aid, a CaO-MgO-SiO2 multiphase sintering aid, and a CuO-TiO2 multiphase sintering aid.

[0015] In any embodiment, the binder includes one or more of methyl cellulose, acrylic acid, polyvinyl alcohol and polystyrene.

[0016] In any embodiment, the dispersant includes one or more of BYK-154 water-based dispersant, propylene glycol methyl ether acetate, ammonium polyacrylate and polyvinyl pyrrolidone.

[0017] In any embodiment, the leveling agent includes one or more of BYK-UV3510 water-based leveling agent, BYK-3550 water-based leveling agent, BYK-333 water-based leveling agent and BYK-306 water-based leveling agent.

[0018] In any embodiment, the humectant includes one or more of glycerol, butylene glycol, glycereth-26, and methyl gluceth-20.

[0019] According to the second aspect of the present application, a method for preparing the ceramic slurry of the first aspect of the present application is provided, comprising the following steps:

[0020] The ceramic powder and the sintering aid are respectively ball-milled and then mixed to obtain a mixed powder;

[0021] The mixed powder is mixed with the binder, the solvent, the dispersant, the leveling agent and the moisturizing agent, and the mixture is degassed and stirred to obtain the ceramic slurry.

[0022] According to a third aspect of the present application, a method for preparing a ceramic substrate with holes is provided, comprising the following steps:

[0023] Establishing a three-dimensional model of the porous ceramic substrate;

[0024] Establishing a layered slice scanning data path based on the three-dimensional model;

[0025] Putting the ceramic slurry of the first aspect of the present application into the barrel of a 3D printer;

[0026] Printing a ceramic film according to the layered slice scanning data path, and obtaining a green ceramic piece after cooling;

[0027] The green ceramic piece is sintered to obtain a ceramic substrate with holes.

[0028] In any embodiment, during the process of printing the ceramic film, the extrusion pressure of the ceramic slurry is controlled to be 20psi~30psi, the nozzle movement speed is 12mm / s~14mm / s, the distance between the nozzle and the printing platform is 0.4mm~0.6mm, and the line filling rate is 30%~35%.

[0029] In any embodiment, the sintering temperature is 820° C. to 880° C., and the sintering time is 16 h to 20 h.

[0030] According to a fourth aspect of the present application, a ceramic substrate with holes is provided. The ceramic substrate with holes is prepared by the method for preparing the ceramic substrate with holes according to the third aspect of the present application.

[0031] Compared with the traditional technology, this application has at least the following beneficial effects:

[0032] The present application prepares a ceramic slurry by mixing ceramic powder, sintering aid, solvent, binder, dispersant, leveling agent and moisturizer in a specific ratio. The ceramic slurry has a high solid content and good self-leveling properties. The ceramic slurry can be suitable for 3D printing process. In the 3D printing process, the through-hole structure can be maintained and the ceramic substrate can have good flatness. A perforated ceramic substrate with high precision and small hole error can be prepared.

[0033] In addition, the preparation method of the porous ceramic substrate of the present application adopts the ceramic slurry of the present application combined with the 3D printing process to prepare the porous ceramic substrate. The preparation process is simple, the production efficiency is high, the preparation cycle is short, and the preparation cost is low. It can quickly, efficiently and customizedly prepare ceramic substrates with through holes.

[0034] Furthermore, by adopting the ceramic slurry of the present application and controlling the extrusion pressure of the ceramic slurry, the nozzle movement speed, the distance between the nozzle and the printing platform, and the line filling rate during the 3D printing process within the scope of the present application, it is more conducive to maintaining the hole structure during the 3D printing process and making the ceramic substrate have better flatness, and a perforated ceramic substrate with higher precision and smaller hole error can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to better describe and illustrate the embodiments or examples provided by the present application, reference may be made to one or more drawings. The additional details or examples used to describe the drawings should not be considered as limiting the scope of the disclosed application, the embodiments or examples currently described, and any of the best modes of these applications currently understood. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0036] Figure 1 This is a process flow chart of a method for preparing a ceramic slurry according to one embodiment of the present application;

[0037] Figure 2 This is a process flow chart of a method for preparing a ceramic substrate with holes according to an embodiment of the present application;

[0038] Figure 3 This is a photograph of a ceramic substrate with holes according to one embodiment of the present application. DETAILED DESCRIPTION

[0039] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present application. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. Unless otherwise specifically stated, various raw materials, reagents, instruments and equipment used in the present application, etc. can be purchased from the market or can be prepared by existing methods.

[0041] At present, the traditional preparation process of ceramic sheets is usually prepared by traditional casting process. It is not possible to quickly, efficiently and custom-make ceramic sheets with through holes. In this regard, the present application mainly improves the preparation method of ceramic slurry and ceramic substrate, effectively improves the quality of band-pass ceramic substrate, improves preparation efficiency, shortens preparation cycle and reduces preparation cost.

[0042] In one embodiment of the present application, a ceramic slurry is provided, which comprises, by mass percentage, 35% to 40% ceramic powder, 35% to 40% sintering aid, 8% to 22% solvent, 2% to 4% binder, 1% to 4% dispersant, 4% to 5% leveling agent and 1% to 3% moisturizing agent; wherein the mass ratio of ceramic powder to sintering aid is (0.9 to 1.1):1.

[0043] The above-mentioned ceramic slurry of the present application is prepared by mixing ceramic powder, sintering aid, solvent, binder, dispersant, leveling agent and moisturizer in a specific ratio to form a ceramic slurry, so that the ceramic slurry has a high solid content and good self-leveling properties. The ceramic slurry can be suitable for 3D printing process, and can maintain the through-hole structure and make the ceramic substrate have good flatness in the 3D printing process, and can prepare a perforated ceramic substrate with high precision and small hole error.

[0044] In some embodiments, the solid content of the ceramic slurry is 70% to 80%. Controlling the solid content of the ceramic slurry within the above range can make the ceramic slurry have a suitable viscosity, which is beneficial for obtaining a porous ceramic substrate with high precision and small hole error when the ceramic slurry is used for 3D printing.

[0045] It can be understood that the solid content of the ceramic slurry can be 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80% and any value within the range formed by any two of the above values.

[0046] In some embodiments, the ceramic powder includes one or more of alumina powder, aluminum nitride powder, silicon nitride, silicon nitride, and zirconium oxide.

[0047] In some embodiments, the sintering aid includes one or more of a MnO2-TiO2-MgO multiphase sintering aid, a CaO-MgO-SiO2 multiphase sintering aid, and a CuO-TiO2 multiphase sintering aid. Among them, the MnO2-TiO2-MgO multiphase sintering aid is a mixed sintering aid mainly composed of MnO2, TiO2 and MgO. Among them, MnO2 mainly plays a role in promoting sintering, TiO2 can make the multiphase sintering aid have suitable mechanical properties, and MgO plays a role as a microstructure stabilizer.

[0048] In some embodiments, the solvent includes one or more of deionized water, toluene, ethanol and trichloroethylene.

[0049] In some of the embodiments, the binder includes one or more of methyl cellulose, acrylic acid, polyvinyl alcohol and polystyrene.

[0050] In some embodiments, the dispersant includes one or more of BYK-154 water-based dispersant, propylene glycol methyl ether acetate, ammonium polyacrylate and polyvinyl pyrrolidone. The BYK-154 water-based dispersant is a product of BYKChemie of Germany, and its main component is an ammonium salt solvent of an acrylate copolymer.

[0051] In some embodiments, the leveling agent includes one or more of BYK-UV3510 water-based leveling agent, BYK-3550 water-based leveling agent, BYK-333 water-based leveling agent and BYK-306 water-based leveling agent. Among them, BYK-UV3510 water-based leveling agent is a product of BYK Chemie of Germany, and its main component is polyether modified polydimethylsiloxane.

[0052] In some embodiments, the humectant includes one or more of glycerol, butylene glycol, glycereth-26, and methyl gluceth-20.

[0053] See also Figure 1 In one embodiment of the present application, a method for preparing the above-mentioned ceramic slurry is provided, and the preparation method comprises the following steps: ball-milling the ceramic powder and the sintering aid respectively and then mixing them to obtain a mixed powder; mixing the mixed powder with a binder, a solvent, a dispersant, a leveling agent and a moisturizing agent, degassing and stirring to obtain a ceramic slurry.

[0054] The above-mentioned method for preparing the ceramic slurry comprises first mixing the ceramic powder and the sintering aid and ball milling to obtain a mixed powder, and then mixing the mixed powder with a solvent, a binder, a dispersant, a leveling agent and a moisturizer, degassing and stirring to prepare the ceramic slurry. The preparation method is simple in process and can obtain a ceramic slurry with a high solid content and good self-leveling properties.

[0055] See also Figure 2 In one embodiment of the present application, a method for preparing a ceramic substrate with holes is provided, and the method comprises the following steps: establishing a three-dimensional model of the ceramic substrate with holes; establishing a layered slicing scanning data path based on the three-dimensional model; placing the ceramic slurry mentioned above in the present application into the barrel of a 3D printer; printing a ceramic film according to the layered slicing scanning data path, and obtaining a green ceramic part after cooling; and sintering the green ceramic part to obtain a ceramic substrate with holes.

[0056] The above-mentioned method for preparing a porous ceramic substrate combines the ceramic slurry of the present application with a 3D printing process to prepare a porous ceramic substrate. The preparation process is simple, the production efficiency is high, the preparation cycle is short, and the preparation cost is low. It can quickly, efficiently and customized prepare ceramic substrates with through holes.

[0057] In some embodiments, during the process of printing the ceramic film, the extrusion pressure of the ceramic slurry is controlled to be 20psi~30psi, the nozzle movement speed is 12mm / s~14mm / s, the distance between the nozzle and the printing platform is 0.4mm~0.6mm, and the line filling rate is 30%~35%. The unit of extrusion pressure psi is the abbreviation of "pounds per square inch", that is, pounds per square inch.

[0058] During the 3D printing process, by controlling the extrusion pressure of the ceramic slurry, the nozzle movement speed, the distance between the nozzle and the printing platform, and the line filling rate within the above range, it is more conducive to maintaining the hole structure during the 3D printing process and making the ceramic substrate have better flatness, so that a porous ceramic substrate with higher precision and smaller hole error can be obtained.

[0059] Among them, the extrusion pressure must match the nozzle movement speed and line filling rate. When the extrusion pressure is high, a faster nozzle movement speed and a larger line filling rate are required, otherwise it is easy to cause the slurry to accumulate and form gullies. Similarly, when the extrusion pressure is low, a slower nozzle movement speed and a smaller line filling rate are required, otherwise it is easy to cause the interruption of the printed silk thread. At the same time, the distance between the nozzle and the printing platform will also affect the accuracy of the printed ceramic substrate. When the distance between the nozzle and the printing platform is small, the needle is easy to scratch the slurry in front, resulting in reduced flatness.

[0060] It should be noted that the line fill rate refers to the proportion of the internal fill part of the model to the total volume. When performing 3D printing, the model usually consists of an external contour and internal fill, and the line fill rate determines the density of the internal fill.

[0061] It can be understood that in the process of printing the ceramic film, the extrusion pressure of the ceramic slurry can be 20psi, 21psi, 22psi, 23psi, 24psi, 25psi, 26psi, 27psi, 28psi, 29psi, 30psi and any value within the range formed by any of the above values; the movement speed of the nozzle can be 12mm / s, 12.2mm / s, 12.5mm / s, 12.8mm / s, 13mm / s, 13.2mm / s, 13.5mm / s s, 13.8mm / s, 14mm / s and any value within the range formed by any of the above values; the distance between the nozzle and the printing platform can be 0.4mm, 0.42mm, 0.45mm, 0.48mm, 0.5mm, 0.52mm, 0.55mm, 0.58mm, 0.6mm and any value within the range formed by any of the above values; the line fill rate can be 30%, 31%, 32%, 33%, 34%, 35% and any value within the range formed by any of the above values.

[0062] In some embodiments, the sintering temperature is 820° C. to 880° C., and the sintering time is 16 hours to 20 hours. Controlling the sintering temperature and sintering time of the green ceramic piece within the above range is conducive to obtaining a porous ceramic substrate with better performance.

[0063] It can be understood that the sintering temperature may be 820°C, 825°C, 830°C, 835°C, 840°C, 845°C, 850°C, 855°C, 860°C, 865°C, 870°C, 875°C, 880°C and any value within the range formed by any of the above values; the sintering time may be 16h, 16.5h, 17h, 17.5h, 18h, 18.5h, 19h, 19.5h, 20h and any value within the range formed by any of the above values.

[0064] See also Figure 3 In one embodiment of the present application, a ceramic substrate with holes is provided, which is prepared by the method for preparing the ceramic substrate with holes described above. The ceramic substrate with holes has good flatness, high precision and small hole error.

[0065] The present application will be further described below in conjunction with specific embodiments and comparative examples, but they should not be construed as limiting the scope of protection of the present application.

[0066] Embodiment 1:

[0067] (1) Take Al2O3 ceramic powder and MnO2-TiO2-MgO composite sintering aid, where the mass ratio of MnO2, TiO2 and MgO in the MnO2-TiO2-MgO composite sintering aid is 1:1:2; place Al2O3 ceramic powder and MnO2-TiO2-MgO composite sintering aid in different ball mills of a planetary ball mill; weigh a certain amount of zirconia balls, where the mass ratio of large and small balls is 1:1, and the ball-to-material ratio is 2:1; add anhydrous ethanol as a solvent to the two ball mills, respectively, and the solvent cannot be higher than 2 / 3 of the height of the jar, the speed is 400r / min, and the ball milling time is 4h. Place the ball-milled MnO2-TiO2-MgO composite sintering aid and Al2O3 ceramic powder in a 60℃ oven, dry and grind to achieve the best effect.

[0068] (2) Weigh the ground Al2O3 ceramic powder and MnO2-TiO2-MgO composite sintering aid and mix them to obtain a mixed powder. Then add solvent deionized water, binder methyl cellulose, dispersant BYK-154 water-based dispersant, leveling agent BYK-UV3510 leveling agent and moisturizing agent propylene glycol, mix well and add them into a beaker to achieve the best effect. Stir and mix the above mixture in a vacuum degassing mixer, vacuum degassing, the vacuum degree is 0.01Mpa, and the stirring time is 180s to obtain a ceramic slurry. Among them, the amount of Al2O3 ceramic powder in the ceramic slurry is 38wt%, the amount of MnO2-TiO2-MgO multiphase sintering aid is 38wt%, the amount of deionized water is 10wt%, the amount of methyl cellulose is 3wt%, the amount of BYK-154 water-based dispersant is 3wt%, the amount of BYK-UV3510 water-based leveling agent is 5wt%, and the amount of propylene glycol is 3wt%.

[0069] (3) Establish a three-dimensional model of the porous ceramic substrate to be prepared through three-dimensional mapping software; establish a layered slice scanning data path based on the three-dimensional model, and input it into the operating system to control the distance between the lower end of the nozzle and the printing platform, the extrusion pressure, the nozzle movement speed and other parameters during the 3D printing process. Install the barrel on the 3D printer, put the above-mentioned ceramic slurry into the barrel of the 3D printer, and print the ceramic film according to the layered slice scanning data path. Among them, the nozzle diameter is 0.4mm, the nozzle movement speed is 13mm / s, the distance between the nozzle and the printing platform is 0.5mm, the extrusion pressure is 25psi, the line filling rate is 35%, and the film thickness is 140μm. After printing, the ceramic film is cooled to obtain a raw ceramic part.

[0070] (4) The green ceramic parts are placed in a tube furnace for debinding and sintering. The debinding temperature is 400℃, the debinding time is 12h, the sintering temperature is 850℃, and the sintering time is 18h. After sintering, a ceramic substrate with holes is obtained. The through-hole error rate of the ceramic substrate with holes is 5%, and the gully height is 0.0012mm. Among them, the gully height refers to the distance between the highest point and the lowest point of the ceramic substrate after the printed ceramic substrate is self-leveled and dried, which can characterize the flatness of the ceramic substrate to a certain extent.

[0071] Embodiment 2:

[0072] This embodiment is basically the same as embodiment 1, except that in step (2), the amount of Al2O3 ceramic powder is 36wt%, the amount of MnO2-TiO2-MgO multiphase sintering aid is 40wt%, the amount of deionized water is 12wt%, the amount of methyl cellulose is 4wt%, the amount of BYK-154 water-based dispersant is 1.5wt%, the amount of BYK-UV3510 water-based leveling agent is 5wt%, and the amount of propylene glycol is 1.5wt%.

[0073] Embodiment 3:

[0074] This embodiment is basically the same as embodiment 1, except that in step (2), the amount of Al2O3 ceramic powder is 40wt%, the amount of MnO2-TiO2-MgO multiphase sintering aid is 37wt%, the amount of deionized water is 12wt%, the amount of methyl cellulose is 2wt%, the amount of BYK-154 water-based dispersant is 2wt%, the amount of BYK-UV3510 water-based leveling agent is 5wt%, and the amount of propylene glycol is 2wt%.

[0075] Embodiment 4:

[0076] This embodiment is basically the same as Embodiment 1, except that in step (3), the moving speed of the nozzle is 14 mm / s, the distance between the nozzle and the printing platform is 0.6 mm, the extrusion pressure is 30 psi, and the line filling rate is 30%.

[0077] Embodiment 5:

[0078] This embodiment is basically the same as Embodiment 1, except that in step (3), the moving speed of the nozzle is 12 mm / s, the distance between the nozzle and the printing platform is 0.4 mm, the extrusion pressure is 20 psi, and the line filling rate is 30%.

[0079] Embodiment 6:

[0080] This embodiment is basically the same as Embodiment 1, except that in step (3), the moving speed of the nozzle is 18 mm / s, the distance between the nozzle and the printing platform is 1 mm, the extrusion pressure is 10 psi, and the line filling rate is 40%.

[0081] Comparative Example 1:

[0082] This comparative example is basically the same as Example 1, except that in step (2), the amount of Al2O3 ceramic powder is 50wt%, the amount of MnO2-TiO2-MgO multiphase sintering aid is 20%, the amount of deionized water is 14wt%, the amount of methyl cellulose is 4wt%, the amount of BYK-154 water-based dispersant is 4wt%, the amount of BYK-UV3510 water-based leveling agent is 5wt%, and the amount of propylene glycol is 3wt%.

[0083] Test method:

[0084] (1) Through-hole error rate test

[0085] Use a vernier caliper to measure the dimensions of the through hole of the ceramic substrate before and after sintering. The diameter of the through hole before sintering is recorded as L0, and the diameter of the through hole after sintering is recorded as L1. The formula for calculating the linear shrinkage rate is:

[0086]

[0087] (2) Gully height test

[0088] Due to insufficient self-leveling between the lines of direct writing printing, there will be uneven ups and downs between adjacent printed lines, which are called "gullies". The distance D between the highest point and the lowest point on the surface of the ceramic substrate is measured using an optical microscope, which is the gully height.

[0089] (3) Surface roughness test

[0090] The roughness of the substrate surface will directly affect the flatness of the substrate. If the surface roughness is too large, it will directly lead to a large signal delay. In severe cases, it will cause the electrode and microstrip transmission line to short-circuit, causing the circuit / device to not work properly. The surface roughness can be characterized by the arithmetic mean deviation of the profile, and is generally tested using a roughness measuring instrument. Specifically, a diamond stylus with a tip curvature radius of about 2μm is used to slowly slide along the measured surface of the ceramic substrate. The up and down displacement of the diamond stylus is converted into an electrical signal by an electrical length sensor, and the surface roughness value is indicated by the display instrument after amplification, filtering, and calculation.

[0091] The parameters and properties of the ceramic substrates with holes prepared in the above embodiments and comparative examples are shown in the following table.

[0092] Table 1

[0093]

[0094] It can be seen from Table 1 that the through-hole error rate of the porous ceramic substrate prepared in the present application is relatively small; and the groove height and surface roughness of the ceramic substrate are relatively small, and the flatness is relatively good.

[0095] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0096] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A ceramic slurry, characterized in that: Calculated by mass percentage, it includes 35%~40% ceramic powder, 35%~40% sintering aid, 8%~22% solvent, 2%~4% binder, 1%~4% dispersant, 4%~5% leveling agent, and 1%~3% moisturizing agent; the mass ratio of the ceramic powder to the sintering aid is (0.9~1.1):

1.

2. The ceramic slurry according to claim 1, characterized in that The solid content of the ceramic slurry is 70% to 80%.

3. The ceramic slurry according to any one of claims 1 to 2, characterized in that The ceramic powder includes one or more of alumina powder, aluminum nitride powder, silicon nitride powder and zirconium oxide powder.

4. The ceramic slurry according to any one of claims 1 to 2, characterized in that The solvent includes one or more of deionized water, toluene, ethanol and trichloroethylene.

5. The ceramic slurry according to any one of claims 1 to 2, characterized in that The sintering aid includes one or more of a MnO2-TiO2-MgO multiphase sintering aid, a CaO-MgO-SiO2 multiphase sintering aid and a CuO-TiO2 multiphase sintering aid.

6. The ceramic slurry according to any one of claims 1 to 2, characterized in that The binder includes one or more of methyl cellulose, acrylic acid, polyvinyl alcohol and polystyrene.

7. The ceramic slurry according to any one of claims 1 to 2, characterized in that The dispersant includes one or more of BYK-154 water-based dispersant, propylene glycol methyl ether acetate, ammonium polyacrylate and polyvinyl pyrrolidone.

8. The ceramic slurry according to any one of claims 1 to 2, characterized in that The leveling agent includes one or more of BYK-UV3510 water-based leveling agent, BYK-3550 water-based leveling agent, BYK-333 water-based leveling agent and BYK-306 water-based leveling agent.

9. The ceramic slurry according to any one of claims 1 to 2, characterized in that The moisturizing agent includes one or more of glycerol, butylene glycol, glycereth-26 and methyl gluceth-20.

10. A method for preparing the ceramic slurry according to any one of claims 1 to 9, characterized in that: The following steps are involved: The ceramic powder and the sintering aid are respectively ball-milled and then mixed to obtain a mixed powder; The mixed powder is mixed with the binder, the solvent, the dispersant, the leveling agent and the moisturizing agent, and the mixture is degassed and stirred to obtain the ceramic slurry.

11. A method for preparing a ceramic substrate with holes, characterized in that: The following steps are involved: Establishing a three-dimensional model of the porous ceramic substrate; Establishing a layered slice scanning data path based on the three-dimensional model; Putting the ceramic slurry according to any one of claims 1 to 9 into the barrel of a 3D printer; Printing a ceramic film according to the layered slice scanning data path, and obtaining a green ceramic piece after cooling; The green ceramic piece is sintered to obtain a ceramic substrate with holes.

12. The method for preparing a ceramic substrate with holes according to claim 11, characterized in that: During the process of printing the ceramic film, the extrusion pressure of the ceramic slurry is controlled to be 20psi~30psi, the nozzle movement speed is 12mm / s~14mm / s, the distance between the nozzle and the printing platform is 0.4mm~0.6mm, and the line filling rate is 30%~35%.

13. The method for preparing a ceramic substrate with holes according to claim 11 or 12, characterized in that: The sintering temperature is 820° C. to 880° C., and the sintering time is 16 h to 20 h.

14. A ceramic substrate with holes, characterized in that: The porous ceramic substrate is prepared by the method for preparing a porous ceramic substrate according to any one of claims 11 to 13.

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