Ceramic substrate blank powder coating and sintering process

Abstract

The invention relates to the technical field of ceramic substrates, in particular to a ceramic substrate blank powder coating and sintering process. Comprising the following steps: step 1, uniformly stirring boron nitride powder, terpilenol, ethyl cellulose, butyl benzyl phthalate and phosphate, and grinding to obtain coating powder; step 2, printing powder on the surface of the green body by using a silk-screen printing technology to form a powder pattern; a powder coating green body is obtained; step 3, stacking N powder-coated green bodies to obtain laminated green bodies; 4, the laminated green body is subjected to glue discharging sintering and sand blasting in sequence; and obtaining the ceramic substrate.

Description

Technical Field

[0001] The invention relates to the technical field of ceramic substrates, in particular to a ceramic substrate blank powder coating and sintering process. Background Art

[0002] Ultra-large and ultra-thin body powder coating is a special powder application technology, which is mainly used on the surface of ceramic substrates or other large ultra-thin bodies to achieve uniform coating. This technology has important applications in many fields such as ultra-high thermal conductivity, functional ceramic substrates, and electronic components.

[0003] Ceramic substrate is an electronic substrate made of ceramic material, which is an inorganic material. It usually has aluminum oxide (Al2O3), aluminum nitride (AlN) and silicon nitride (Si3N4) as the main components. Ceramic substrate has good thermal conductivity, high frequency and high temperature stability. It is widely used in electronic equipment under harsh environments such as high power, high frequency and high temperature.

[0004] As a strong covalent bond compound, silicon nitride has a very low diffusion coefficient. Therefore, pure silicon nitride cannot be sintered to a dense state. During sintering, a sintering aid must be added to form a liquid phase to help it densify. During the sintering process, the sintering aid is very easy to volatilize, causing the ceramic tile to easily stick and crack. The thinner and larger the green body is, the more serious this problem is.

[0005] In summary, it is of great significance to develop a ceramic substrate green body powder coating sintering process to solve the sintering sticking or cracking problems. Summary of the invention

[0006] The object of the present invention is to provide a ceramic substrate green body powder coating and sintering process to solve the problems raised in the prior art.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A ceramic substrate green body powder coating and sintering process comprises the following steps:

[0009] Step 1: Mix and evenly grind boron nitride powder, pinene alcohol, ethyl cellulose, butyl benzyl phthalate and phosphate to obtain a powder;

[0010] Step 2: Printing the powder coating on the surface of the green body by screen printing technology to form a powder coating pattern; obtaining a powder coating green body;

[0011] Step 3: Take N pieces of powder-coated green compacts and stack them to obtain a stacked green compact;

[0012] Step 4: Debinding, sintering and sandblasting the laminated green body in sequence to obtain a ceramic substrate.

[0013] More optimally, in step 1, the raw materials for the powder coating include, by mass: 25 to 40 parts of boron nitride powder, 25 to 50 parts of pine alcohol, 2 to 8 parts of ethyl cellulose, 0.2 to 5 parts of butyl benzyl phthalate, and 0.2 to 5 parts of phosphate.

[0014] More optimally, in step 2, the powder coating pattern includes one of dot matrix and full board; the thickness of the powder coating printing is 3 to 30um. The pattern size can be designed; the dot matrix pattern includes circle and diamond, the dot matrix pattern diameter is 30 to 300um, the spacing is 30 to 500um, and the powder coating thickness is 3 to 30um.

[0015] More optimally, in step 3, N≥8; the stacking method includes one of sandwich stacking and non-sandwich stacking. The non-sandwich stacking is a direct stacking of powder-coated green sheets (thickness of 0.10-0.14 mm); the sandwich stacking is a stacking of thick green sheets (thickness of 0.44-0.46 mm) with powder on both sides and thin sheets (thickness of 0.10-0.14 mm) without powder coating, i.e., thick sheet-thin sheet-thick sheet method.

[0016] More optimally, in step 4, the process parameters of the debinding sintering are: debinding temperature is 500-700°C, and the insulation time is 2-8h; sintering temperature is 1750-1900°C, and the insulation time is 2-8h; nitrogen pressure is 0.5Mpa-2Mpa;

[0017] The process parameters of the sandblasting are: the transmission speed is 200-1500 mm / min, the sandblasting pressure is 1.0-3.0 kgf / cm 2 .

[0018] More optimally, the raw materials for the powder coating also include modified chopped basalt fibers, which account for 6% to 8% of the boron nitride powder.

[0019] More optimally, the preparation method of the modified chopped basalt fiber is:

[0020] S1-1: Add chopped basalt fibers to a solvent, add a dispersant and perform ultrasonic dispersion for 20 to 40 minutes to obtain a chopped basalt fiber suspension; slowly add tetrabutyl titanate to anhydrous ethanol and stir to obtain a 0.1 to 0.5 mol / L tetrabutyl titanate solution; dissolve aluminum nitrate in deionized water and stir to obtain a 0.1 to 0.3 mol / L aluminum nitrate solution;

[0021] S1-2: Under stirring conditions, the short-cut basalt fiber suspension is heated to 45-55° C., and at the same time, 0.1-0.5 mol / L tetrabutyl titanate solution, 0.1-0.3 mol / L aluminum nitrate solution, and 25wt%-28wt% ammonia water are added at a rate of 1-3 ml / min, and the pH is adjusted to 8.8-9.2. The mixture is reacted for 3-5 hours, and the mixture is centrifuged, precipitated, and dried to obtain modified short-cut basalt fibers.

[0022] More optimally, in the raw materials of the modified chopped basalt fiber, the mass ratio of chopped basalt fiber suspension, 0.1-0.5 mol / L tetrabutyl titanate solution, 0.1-0.3 mol / L aluminum nitrate solution, and 25wt%-28wt% ammonia water is 10:1-3:0.5-2:1-2;

[0023] In the raw materials of the chopped basalt fiber suspension, the chopped basalt fibers account for 5wt% to 15wt% of the chopped basalt fiber suspension.

[0024] More optimally, the dispersant includes one of polyethylene glycol, polyacrylic acid, and sodium hexametaphosphate; and the solvent includes one of deionized water and anhydrous ethanol.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The present invention can control the size of the powder particles through the dot matrix powder application method, thereby avoiding the problem of density reduction caused by uneven shrinkage;

[0027] (2) The present invention applies powder to thick slices, but does not apply any powder to thin slices, thereby reducing the effect of intercalation powder on the shrinkage of thin green pieces;

[0028] (3) The present invention adopts a debinding sintering process of sandwiching thick slices coated with powder and thin slices without powder, which can reduce the problem of edge deformation during sintering of thin slices;

[0029] (4) The thickness of the powder coating of the present invention can be freely controlled. For green bodies of different sizes, the appropriate thickness of the powder coating can be controlled, and the sintered ceramic pieces shrink evenly without cracking and other problems;

[0030] (5) The present invention introduces modified chopped basalt fibers, specifically nano-titanium dioxide and nano-alumina loaded chopped basalt fibers. In terms of improving the purity of the ceramic substrate, the photocatalytic activity of nano-titanium dioxide can decompose organic impurities on the surface of the green body before sintering, effectively reducing the problem of incomplete debinding, and thus improving the purity of the ceramic substrate. In terms of enhancing wear resistance and extending service life, nano-alumina significantly enhances the hardness and wear resistance of the load layer, making the sintered ceramic substrate more wear-resistant during use, greatly improving its service life.

[0031] On the one hand, the addition of short-cut basalt fiber can adjust the rheological properties of the powder coating, making it easier to control during the powder coating process, effectively improving the uniformity and accuracy of the powder coating; on the other hand, with BS16-6-76 short-cut basalt fiber as the raw material, the fiber forms crystalline phase inclusions during the cooling process after sintering, thereby filling the gaps, improving density, buffering stress, and promoting performance improvement.

[0032] In addition, the nanoparticle loading layer increases the compatibility of the powder with other components of the powder coating, making the powder coating system more stable and reducing agglomeration. Nano-titanium dioxide, nano-aluminum oxide and chopped basalt fibers work together to significantly improve the overall performance of the ceramic substrate.

[0033] The above process can produce a ceramic sheet with a size of 10 inches and a thickness of 0.1 to 0.15 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0035] Figure 1 This is a photo of the ceramic substrate of Example 4 after sintering.

[0036] Figure 2 This is a photo of the ceramic substrate of Comparative Example 1 after sintering.

[0037] Figure 3 This is a graph showing the effect of different powder printing thicknesses on the sintering shrinkage of the green body in Example 4. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] It should be noted that all raw material purchasing manufacturers involved in the present invention are not subject to any special restrictions and exemplarily include: In the following embodiments, the model of the chopped basalt fiber is BS16-6-76.

[0040] Embodiment 1: A ceramic substrate green body powder coating sintering process, comprising the following steps:

[0041] Step 1: Mix 30g of boron nitride powder, 40g of terpineol, 5g of ethyl cellulose, 1g of butyl benzyl phthalate, and 0.5g of phosphate ester, and grind them using three rollers to obtain a powder;

[0042] Step 2: Print the powder coating on the surface of the green body by screen printing technology to form a full-plate powder coating pattern. The thickness of the powder coating printing is 10um to obtain a powder coating green body;

[0043] Step 3: Take 15 powder-coated green sheets and stack them without sandwich (the thickness of each green sheet is 0.12 mm) to obtain a laminated green sheet;

[0044] Step 4: Debind the laminated green body at 650°C and keep it warm for 4 hours, sinter it at 1850°C with a nitrogen pressure of 1.5Mpa for 2 hours to obtain a ceramic sheet; then set the ceramic sheet transmission speed to 500mm / min and the sandblasting pressure to 2.5kgf / cm 2 The surface is sandblasted by a sandblasting machine to remove the boron nitride powder on the surface to obtain a ceramic substrate.

[0045] Embodiment 2: A ceramic substrate green body powder coating sintering process, comprising the following steps:

[0046] Step 1: Mix 30g of boron nitride powder, 40g of terpineol, 5g of ethyl cellulose, 1g of butyl benzyl phthalate, and 0.5g of phosphate ester, and grind them using three rollers to obtain a powder;

[0047] Step 2: Use screen printing technology to print powder on both sides of the green body to form a full-plate powder pattern. The thin sheet is not powdered. The thickness of the powder printing is 10um to obtain a powdered green body;

[0048] Step 3: Take 15 powder-coated green sheets and stack them in layers (thick green sheets (thickness 0.45 mm) with powder on both sides and thin sheets (thickness 0.12 mm) without powder coating are stacked in sequence, i.e., thick sheet-thin sheet-thick sheet), to obtain laminated green sheets;

[0049] Step 4: Debind the laminated green body at 650°C and keep it warm for 4 hours, sinter it at 1850°C with a nitrogen pressure of 1.5Mpa for 2 hours to obtain a ceramic sheet; then set the ceramic sheet transmission speed to 500mm / min and the sandblasting pressure to 2.5kgf / cm 2 The surface is sandblasted by a sandblasting machine to remove the boron nitride powder on the surface to obtain a ceramic substrate.

[0050] Embodiment 3: A ceramic substrate green body powder coating sintering process, comprising the following steps:

[0051] Step 1: Mix 30g of boron nitride powder, 40g of terpineol, 5g of ethyl cellulose, 1g of butyl benzyl phthalate, and 0.5g of phosphate ester, and grind them using three rollers to obtain a powder;

[0052] Step 2: Print the powder on the surface of the green body by screen printing technology to form a dot-matrix powder pattern with a diameter of 150um, a spacing of 265um, and a thickness of 10um to obtain a powder-coated green body;

[0053] Step 3: Take 15 powder-coated green sheets and stack them without sandwich (the thickness of each green sheet is 0.12 mm) to obtain a laminated green sheet;

[0054] Step 4: Debind the laminated green body at 650°C and keep it warm for 4 hours, sinter it at 1850°C with a nitrogen pressure of 1.5Mpa for 2 hours to obtain a ceramic sheet; then set the ceramic sheet transmission speed to 500mm / min and the sandblasting pressure to 2.5kgf / cm 2 The surface is sandblasted by a sandblasting machine to remove the boron nitride powder on the surface to obtain a ceramic substrate.

[0055] Embodiment 4: A ceramic substrate green body powder coating sintering process, comprising the following steps:

[0056] Step 1: Mix 30g of boron nitride powder, 40g of terpineol, 5g of ethyl cellulose, 1g of butyl benzyl phthalate, and 0.5g of phosphate ester, and grind them using three rollers to obtain a powder;

[0057] Step 2: Use screen printing technology to print powder on both sides of the green body to form a dot-matrix powder pattern. The thin sheet is not powdered. The diameter is 150um, the spacing is 265um, and the powder thickness is 10um, so as to obtain a powdered green body;

[0058] Step 3: Take 15 powder-coated green sheets and stack them in layers (thick green sheets (thickness 0.45 mm) with powder on both sides and thin sheets (thickness 0.12 mm) without powder coating are stacked in sequence, i.e., thick sheet-thin sheet-thick sheet), to obtain laminated green sheets;

[0059] Step 4: Debind the laminated green body at 650°C and keep it warm for 4 hours, sinter it at 1850°C with a nitrogen pressure of 1.5Mpa for 2 hours to obtain a ceramic sheet; then set the ceramic sheet transmission speed to 500mm / min and the sandblasting pressure to 2.5kgf / cm 2 The surface is sandblasted by a sandblasting machine to remove the boron nitride powder on the surface to obtain a ceramic substrate; Figure 1 shown.

[0060] Embodiment 5: A ceramic substrate green body powder coating sintering process, comprising the following steps:

[0061] Step 1: S1: Add short basalt fibers to deionized water, add polyethylene glycol to the short basalt fiber suspension at a rate of 10 wt% of the short basalt fiber, and ultrasonically disperse for 30 minutes to obtain a short basalt fiber suspension; slowly add tetrabutyl titanate to anhydrous ethanol, stir to obtain a 0.3 mol / L tetrabutyl titanate solution; dissolve aluminum nitrate in deionized water, stir to obtain a 0.2 mol / L aluminum nitrate solution; S2: Under stirring conditions, heat the short basalt fiber suspension to 50° C. according to a mass ratio of 10:1.8:1.1:1.4, and simultaneously add 0.3 mol / L tetrabutyl titanate solution, 0.2 mol / L aluminum nitrate solution, and 26 wt% ammonia water at a rate of 2 ml / min, adjust the pH to 9.0, react for 4 hours, centrifuge, precipitate, and dry to obtain modified short basalt fibers;

[0062] Step 2: 30 g of boron nitride powder, 40 g of terpineol, 5 g of ethyl cellulose, 1 g of butyl benzyl phthalate, 0.5 g of phosphate ester, and 2.1 g of modified chopped basalt fiber were mixed evenly and ground with three rollers to obtain a powder coating;

[0063] Step 3: Print the powder on both sides of the green body by screen printing technology to form a dot-matrix powder pattern. The thin sheet is not powdered. The diameter is 150um, the spacing is 265um, and the powder thickness is 10um, so as to obtain a powdered green body;

[0064] Step 4: Take 15 powder-coated green sheets and stack them in layers (thick green sheets (thickness 0.45 mm) with powder on both sides and thin sheets (thickness 0.12 mm) without powder coating are stacked in sequence, i.e., thick sheet-thin sheet-thick sheet), to obtain laminated green sheets;

[0065] Step 5: Debind the laminated green body at 650°C and keep it warm for 4 hours, sinter it at 1850°C with a nitrogen pressure of 1.5Mpa for 2 hours to obtain a ceramic sheet; then set the ceramic sheet transmission speed to 500mm / min and the sandblasting pressure to 2.5kgf / cm 2 The surface is sandblasted by a sandblasting machine to remove the boron nitride powder on the surface to obtain a ceramic substrate.

[0066] Comparative Example 1: Based on Example 1, the green body was not subjected to powder coating treatment, and the other processes remained unchanged, specifically:

[0067] Step 1: Take 15 green sheets and stack them in a non-sandwich manner (the thickness of each green sheet is 0.12 mm) to obtain a laminated green sheet;

[0068] Step 2: Debind the laminated green body at 650°C and keep it warm for 4 hours, then sinter it at 1850°C with a nitrogen pressure of 1.5Mpa for 2 hours to obtain a ceramic sheet; then set the ceramic sheet transmission speed to 500mm / min and the sandblasting pressure to 2.5kgf / cm 2 The surface is sandblasted by a sandblasting machine to remove the boron nitride powder on the surface to obtain a ceramic substrate; Figure 2 shown.

[0069] Comparative Example 2: Based on Example 1, no phosphate was added, and the other processes remained unchanged, specifically:

[0070] Step 1: Mix 30g of boron nitride powder, 40g of terpineol, 5g of ethyl cellulose and 1g of butyl benzyl phthalate and grind them using three rollers to obtain a powder;

[0071] Step 2: Print the powder coating on the surface of the green body by screen printing technology to form a full-plate powder coating pattern. The thickness of the powder coating printing is 10um to obtain a powder coating green body;

[0072] Step 3: Take 15 powder-coated green sheets and stack them without sandwich (the thickness of each green sheet is 0.12 mm) to obtain a laminated green sheet;

[0073] Step 4: Debind the laminated green body at 650°C and keep it warm for 4 hours, sinter it at 1850°C with a nitrogen pressure of 1.5Mpa for 2 hours to obtain a ceramic sheet; then set the ceramic sheet transmission speed to 500mm / min and the sandblasting pressure to 2.5kgf / cm 2 The surface is sandblasted by a sandblasting machine to remove the boron nitride powder on the surface to obtain a ceramic substrate.

[0074] Comparative Example 3: Based on Example 5, only unloaded chopped basalt fibers were added, and the rest of the process remained unchanged, specifically:

[0075] Step 1: 30 g of boron nitride powder, 40 g of terpineol, 5 g of ethyl cellulose, 1 g of butyl benzyl phthalate, 0.5 g of phosphate ester, and 2.1 g of chopped basalt fiber were mixed evenly and ground with three rollers to obtain a powder coating;

[0076] Step 2: Use screen printing technology to print powder on both sides of the green body to form a dot-matrix powder pattern. The thin sheet is not powdered. The diameter is 150um, the spacing is 265um, and the powder thickness is 10um, so as to obtain a powdered green body;

[0077] Step 3: Take 15 powder-coated green sheets and stack them in layers (thick green sheets (thickness 0.45 mm) with powder on both sides and thin sheets (thickness 0.12 mm) without powder coating are stacked in sequence, i.e., thick sheet-thin sheet-thick sheet), to obtain laminated green sheets;

[0078] Step 4: Debind the laminated green body at 650°C and keep it warm for 4 hours, sinter it at 1850°C with a nitrogen pressure of 1.5Mpa for 2 hours to obtain a ceramic sheet; then set the ceramic sheet transmission speed to 500mm / min and the sandblasting pressure to 2.5kgf / cm 2 The surface is sandblasted by a sandblasting machine to remove the boron nitride powder on the surface to obtain a ceramic substrate.

[0079] Comparative Example 4, based on Example 5, adds short-cut basalt fibers loaded with nano-titanium dioxide only, and the rest of the process remains unchanged, specifically:

[0080] Step 1: S1: Add short basalt fibers to deionized water, add polyethylene glycol to the short basalt fiber suspension at a rate of 10 wt%, and ultrasonically disperse for 30 minutes to obtain a short basalt fiber suspension; slowly add tetrabutyl titanate to anhydrous ethanol, and stir to obtain a 0.3 mol / L tetrabutyl titanate solution; S2: Under stirring conditions, according to a mass ratio of 10:1.8:1.4, heat the short basalt fiber suspension to 50°C, and at the same time add 0.3 mol / L tetrabutyl titanate solution and 26 wt% ammonia water at a rate of 2 ml / min, adjust the pH to 9.0, react for 4 hours, centrifuge, precipitate, and dry to obtain modified short basalt fibers;

[0081] Step 2: 30 g of boron nitride powder, 40 g of terpineol, 5 g of ethyl cellulose, 1 g of butyl benzyl phthalate, 0.5 g of phosphate ester, and 2.1 g of modified chopped basalt fiber were mixed evenly and ground with three rollers to obtain a powder coating;

[0082] Step 3: Print the powder on both sides of the green body by screen printing technology to form a dot-matrix powder pattern. The thin sheet is not powdered. The diameter is 150um, the spacing is 265um, and the powder thickness is 10um, so as to obtain a powdered green body;

[0083] Step 4: Take 15 powder-coated green sheets and stack them in layers (thick green sheets (thickness 0.45 mm) with powder on both sides and thin sheets (thickness 0.12 mm) without powder coating are stacked in sequence, i.e., thick sheet-thin sheet-thick sheet), to obtain laminated green sheets;

[0084] Step 5: Debind the laminated green body at 650°C and keep it warm for 4 hours, sinter it at 1850°C with a nitrogen pressure of 1.5Mpa for 2 hours to obtain a ceramic sheet; then set the ceramic sheet transmission speed to 500mm / min and the sandblasting pressure to 2.5kgf / cm 2 The surface is sandblasted by a sandblasting machine to remove the boron nitride powder on the surface to obtain a ceramic substrate.

[0085] Comparative Example 5, based on Example 5, the amount of modified chopped basalt fiber is increased, and the other processes remain unchanged, specifically:

[0086] Step 1: S1: Add short basalt fibers to deionized water, add polyethylene glycol to the short basalt fiber suspension at a rate of 10 wt% of the short basalt fiber, and ultrasonically disperse for 30 minutes to obtain a short basalt fiber suspension; slowly add tetrabutyl titanate to anhydrous ethanol, stir to obtain a 0.3 mol / L tetrabutyl titanate solution; dissolve aluminum nitrate in deionized water, stir to obtain a 0.2 mol / L aluminum nitrate solution; S2: Under stirring conditions, heat the short basalt fiber suspension to 50° C. according to a mass ratio of 10:1.8:1.1:1.4, and simultaneously add 0.3 mol / L tetrabutyl titanate solution, 0.2 mol / L aluminum nitrate solution, and 26 wt% ammonia water at a rate of 2 ml / min, adjust the pH to 9.0, react for 4 hours, centrifuge, precipitate, and dry to obtain modified short basalt fibers;

[0087] Step 2: 30 g of boron nitride powder, 40 g of terpineol, 5 g of ethyl cellulose, 1 g of butyl benzyl phthalate, 0.5 g of phosphate ester, and 8 g of modified chopped basalt fiber were mixed evenly and ground with three rollers to obtain a powder coating;

[0088] Step 3: Print the powder on both sides of the green body by screen printing technology to form a dot-matrix powder pattern. The thin sheet is not powdered. The diameter is 150um, the spacing is 265um, and the powder thickness is 10um, so as to obtain a powdered green body;

[0089] Step 4: Take 15 powder-coated green sheets and stack them in layers (thick green sheets (thickness 0.45 mm) with powder on both sides and thin sheets (thickness 0.12 mm) without powder coating are stacked in sequence, i.e., thick sheet-thin sheet-thick sheet), to obtain laminated green sheets;

[0090] Step 5: Debind the laminated green body at 650°C and keep it warm for 4 hours, sinter it at 1850°C with a nitrogen pressure of 1.5Mpa for 2 hours to obtain a ceramic sheet; then set the ceramic sheet transmission speed to 500mm / min and the sandblasting pressure to 2.5kgf / cm 2 The surface is sandblasted by a sandblasting machine to remove the boron nitride powder on the surface to obtain a ceramic substrate.

[0091] Test experiment 1: The thickness of the powder coating printing of the ceramic substrate prepared by the powder coating sintering process of a ceramic substrate blank in Example 4 was controlled: the powder coating thickness was 5μm, 10μm, 15μm, 20μm, 25μm, and 30μm respectively, and the density of the ceramic piece was tested, such as Figure 3 As shown:

[0092] Conclusion: From Figure 3 It can be seen that the powder coating pattern in Example 4 adopts a dot matrix method, and the stacking method uses a thick and thin sheet sandwich stacking method. The sintered ceramic sheets have no sticking, smooth edges, and large shrinkage and density.

[0093] Test experiment 2: The ceramic substrates prepared in Examples 1 to 5 and Comparative Example 1 were tested for adhesion, flatness, shrinkage, and density, and compared in terms of powder coating, stacking methods, and performance, as shown in Table 1 below;

[0094]

[0095] Table 1

[0096] Result analysis: According to the data analysis in Table 1, it can be seen that the size of the ceramic substrate prepared by the specific process of this scheme is increased from 6 inches to 10 inches, and the green body thickness is reduced from the original 0.45mm to 0.12mm. The powder-coated green body can achieve 8 to 20 pieces of green body stacking and debinding sintering, and at the same time can avoid problems such as sticking and uneven shrinkage during green body sintering, thereby improving the yield and production capacity of the ceramic piece.

[0097] Test experiment 3: The impact resistance of the ceramic substrates prepared in Examples 4 to 5 and Comparative Examples 1 to 5 was tested, and the test results are shown in Table 2;

[0098]

[0099] Table 2

[0100] Result analysis: According to the data analysis of Table 2, it can be seen from the data of Example 5 that the modified fiber can improve the compactness, buffer stress, enhance wear resistance and overall impact resistance; from the data of Example 4, it can be seen that without adding modified chopped basalt fiber, the impact resistance is lower than that of Example 5, and the modified chopped basalt fiber can play a role in strengthening and toughening in the ceramic substrate, and improve the impact resistance of the material; from the data of Comparative Example 1, it can be seen that powder coating can improve the uniformity of the surface performance and internal structure of the substrate, and the interlayer stacking can enhance the overall strength and impact resistance of the substrate; from the data of Comparative Example 2 It can be seen from the data that without adding phosphate ester, the uniformity of the powder coating decreases, the overall performance of the substrate decreases, and the impact resistance is affected; from the data of Comparative Example 3, it can be seen that the modified chopped basalt fibers are better integrated with the ceramic matrix and can more effectively play a reinforcing and toughening role, and the unmodified fiber reinforcement effect is relatively poor; from the data of Comparative Example 4, it can be seen that compared with the fibers loaded with titanium dioxide and alumina in Example 5, the effect is weaker, and the improvement of the impact resistance of the ceramic substrate is limited; from the data of Comparative Example 5, it can be seen that too many fibers will lead to uneven fiber dispersion and agglomeration, which will reduce the performance of the material.

[0101] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A ceramic substrate green body powder coating sintering process, characterized in that: The following steps are involved: Step 1: Mix and evenly grind boron nitride powder, pinene alcohol, ethyl cellulose, butyl benzyl phthalate and phosphate to obtain a powder; Step 2: Printing the powder coating on the surface of the green body by screen printing technology to form a powder coating pattern; obtaining a powder coating green body; Step 3: Take N pieces of powder-coated green compacts and stack them to obtain a stacked green compact; Step 4: Debinding, sintering and sandblasting the laminated green body in sequence to obtain a ceramic substrate.

2. A ceramic substrate green body powder coating sintering process according to claim 1, characterized in that: In step 1, the raw materials for the powder coating include, by mass: 25 to 40 parts of boron nitride powder, 25 to 50 parts of pine alcohol, 2 to 8 parts of ethyl cellulose, 0.2 to 5 parts of butyl benzyl phthalate, and 0.2 to 5 parts of phosphate.

3. The ceramic substrate green body powder coating sintering process according to claim 1, characterized in that: In step 2, the powder coating pattern includes one of a dot matrix and a full board; the thickness of the powder coating printing is 3 to 30 um.

4. The ceramic substrate green body powder coating sintering process according to claim 1, characterized in that: In step 3, N≥8; the stacking method includes one of sandwich stacking and non-sandwich stacking.

5. The ceramic substrate green body powder coating sintering process according to claim 1, characterized in that: In step 4, the process parameters of the debinding sintering are: debinding temperature is 500-700° C., and the temperature is kept for 2-8 hours; sintering temperature is 1750-1900° C., and the temperature is kept for 2-8 hours, and the nitrogen pressure is 0.5Mpa-2Mpa; The process parameters of the sandblasting are: the transmission speed is 200-1500 mm / min, the sandblasting pressure is 1.0-3.0 kgf / cm 2 .

6. The ceramic substrate green body powder coating sintering process according to claim 1, characterized in that: The raw materials for the powder coating also include modified short-cut basalt fibers, which account for 6% to 8% of the boron nitride powder.

7. The ceramic substrate green body powder coating sintering process according to claim 6, characterized in that: The preparation method of the modified chopped basalt fiber is: S1-1: Add chopped basalt fibers to a solvent, add a dispersant and perform ultrasonic dispersion for 20 to 40 minutes to obtain a chopped basalt fiber suspension; slowly add tetrabutyl titanate to anhydrous ethanol and stir to obtain a 0.1 to 0.5 mol / L tetrabutyl titanate solution; dissolve aluminum nitrate in deionized water and stir to obtain a 0.1 to 0.3 mol / L aluminum nitrate solution; S1-2: Under stirring conditions, the short-cut basalt fiber suspension is heated to 45-55° C., and at the same time, 0.1-0.5 mol / L tetrabutyl titanate solution, 0.1-0.3 mol / L aluminum nitrate solution, and 25wt%-28wt% ammonia water are added at a rate of 1-3 ml / min, and the pH is adjusted to 8.8-9.

2. The mixture is reacted for 3-5 hours, and the mixture is centrifuged, precipitated, and dried to obtain modified short-cut basalt fibers.

8. The ceramic substrate green body powder coating sintering process according to claim 7, characterized in that: In the raw materials of the modified chopped basalt fiber, the mass ratio of chopped basalt fiber suspension, 0.1-0.5 mol / L tetrabutyl titanate solution, 0.1-0.3 mol / L aluminum nitrate solution, and 25wt%-28wt% ammonia water is 10:1-3:0.5-2:1-2; In the raw materials of the chopped basalt fiber suspension, the chopped basalt fibers account for 5wt% to 15wt% of the chopped basalt fiber suspension.

9. The ceramic substrate green body powder coating sintering process according to claim 7, characterized in that: The dispersant includes one of polyethylene glycol, polyacrylic acid and sodium hexametaphosphate; the solvent includes one of deionized water and anhydrous ethanol.

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