Ceramic substrate and method for manufacturing same

Abstract

The ceramic substrate comprises the following components in percentage by weight: 63-90% of spheroidal aluminum nitride powder; tabular aluminum nitride powder, the weight percentage of which is 0.05%-30%; boron nitride powder, the weight percentage of which is 0.05%-2%; and yttrium oxide powder, wherein the weight percentage of the yttrium oxide powder is 0.05%-5%. The invention further provides a manufacturing method of the ceramic substrate. The manufacturing method comprises a knife method and a non-pressure primary sintering process.

Description

Technical Field

[0001] The present application relates to a ceramic substrate and a method for manufacturing the same, and in particular to a ceramic substrate containing aluminum nitride and a method for manufacturing the same. Background Art

[0002] Ceramic substrates need to pass reliability and thermal cycle tests during the production process. The structural toughness and thermal conductivity of existing ceramic substrates made of powdered aluminum nitride are still insufficient to meet existing needs.

[0003] Therefore, how to improve the structural toughness and thermal conductivity of the ceramic substrate by improving the structural design has become a problem to be solved in this technical field. Summary of the invention

[0004] The technical problem to be solved by the present application is to provide a method for manufacturing a ceramic substrate in view of the deficiencies in the prior art, so as to improve the structural toughness and thermal conductivity.

[0005] In order to solve the above-mentioned technical problems, one of the technical solutions adopted in the present application is to provide a method for manufacturing a ceramic substrate, including the following processes: providing raw materials, the raw materials including ceramic raw material powder, an organic solvent and an adhesive, wherein the ceramic raw material powder includes spherical aluminum nitride powder, plate-like aluminum nitride powder, boron nitride powder and yttrium oxide powder; crushing and mixing the raw materials to form a slurry; stirring the slurry to degas the slurry; forming the raw materials into a plurality of thin green sheets by a scraper forming method; cutting the plurality of thin green sheets to form a plurality of ceramic green sheets that meet predetermined sizes; and sintering the plurality of ceramic green sheets to form a ceramic substrate.

[0006] In order to solve the above-mentioned technical problems, another technical solution adopted in the present application is to provide a ceramic substrate, including: spherical aluminum nitride powder, whose weight percentage is 63% to 90%; plate-shaped aluminum nitride powder, whose weight percentage is 0.05% to 30%; boron nitride powder, whose weight percentage is 0.05% to 2%; and yttrium oxide powder, whose weight percentage is 0.05% to 5%.

[0007] One of the beneficial effects of the present application is that the ceramic substrate and the manufacturing method thereof provided by the present application can enhance the structural toughness strength of the ceramic substrate by adding plate-shaped aluminum nitride powder and boron nitride. The present application adds high thermal conductivity boron nitride powder and yttrium oxide to improve thermal conductivity.

[0008] To further understand the features and technical contents of the present application, please refer to the following detailed description and drawings of the present application. However, the drawings provided are only for reference and illustration and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the process of manufacturing the ceramic substrate of the present application.

[0010] Figure 2 This is a schematic diagram of the structure of the ceramic substrate of the present application. DETAILED DESCRIPTION

[0011] The following is an explanation of the embodiments disclosed in the present application through specific embodiments. Those skilled in the art can understand the advantages and effects of the present application from the contents disclosed in this specification. The present application can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways based on different viewpoints and applications without departing from the concept of the present application. In addition, the drawings of the present application are only simple schematic illustrations and are not depicted according to actual sizes. It is stated in advance. The following embodiments will further explain the relevant technical contents of the present application in detail, but the disclosed contents are not intended to limit the scope of protection of the present application.

[0012] See also Figure 1 As shown, the present application provides a method for manufacturing a ceramic substrate, which includes the following process: Step S10, providing raw materials, wherein the raw materials include ceramic raw material powder, organic solvent and adhesive. The ceramic raw material powder, or ceramic substrate material powder, includes spherical aluminum nitride powder, plate-shaped aluminum nitride powder, boron nitride (BN) powder and yttrium oxide (Y2O3) powder.

[0013] The proportions of the ceramic raw material powders are as follows: spherical aluminum nitride powder, whose weight percentage is 63% to 90%; plate-shaped aluminum nitride powder, whose weight percentage is 0.05% to 30%; boron nitride powder, whose weight percentage is 0.05% to 2%; yttrium oxide powder, whose weight percentage is 0.05% to 5%.

[0014] The ceramic substrate of this embodiment can improve the toughness of the ceramic substrate by adding plate-like aluminum nitride powder, that is, non-spherical aluminum nitride powder, and utilizing its elongated structure. The plate-like aluminum nitride powder of this embodiment can be prepared by carbon thermal reduction. Its advantages are high purity of the synthetic powder, stable performance, and fine and uniform powder particle size. The carbon thermal reduction method is to subject a mixed powder of plate-like aluminum oxide powder and carbon powder to a reduction nitridation reaction in flowing nitrogen at high temperature (about 1400°C to 1800°C), and then remove carbon to generate aluminum nitride powder.

[0015] In the present embodiment, the average thickness of the plate-like aluminum nitride powder may be 0.05 μm to 1.8 μm, and the average particle size of the plate-like aluminum nitride powder may be 2 μm to 20 μm, wherein the average particle size divided by the average thickness is more than 3 times. In other words, the length of the plate-like aluminum nitride powder is more than 3 times the thickness. However, the present application is not limited thereto. For example, the average particle size of the plate-like aluminum oxide may be 2 μm, 5 μm, or 7 μm. When the average particle size is 2 μm, the average thickness is 0.08 μm, and the aspect ratio is 25. When the average particle size is 5 μm, the average thickness is 0.07 μm, and the aspect ratio is 70. When the average particle size is 7 μm, the average thickness is 0.1 μm, and the aspect ratio is 70.

[0016] In addition, the ceramic substrate of this embodiment is also filled with boron nitride and yttrium oxide. Boron nitride is resistant to high temperatures and has high thermal conductivity. Yttrium oxide has a cubic structure and a high melting point. The thermal conductivity of yttrium oxide is high, about 13.6W / (m·K). Therefore, the ceramic substrate of this embodiment can improve the toughness (Fracture Toughness), the toughness is greater than 4MPa·m^0.5, and improve the thermal conductivity (Thermal Conductivity), the thermal conductivity can be greater than 150W / mK.

[0017] Next, step S20, a crushing and mixing process. The raw materials are crushed and mixed to form a slurry. For example, the ceramic powder that has been finely ground and calcined is first added to an organic solvent, and if necessary, an anti-agglomeration agent, a defoaming agent, a sintering accelerator, etc. can be added, and then wet-grinding is performed. Then, a binder is added, and if necessary, a plasticizer, a lubricant, etc. can be added for mixing and grinding to form a stable slurry with good fluidity.

[0018] Step S30, stirring the slurry to degas the slurry. In the stirring and degassing process, the slurry is stirred for about 30 minutes in a space below atmospheric pressure, preferably in a near vacuum environment, such as 4000 Pa (Pascals, equal to N / m2), to separate the gas in the slurry.

[0019] Step S41, forming the raw material into a plurality of thin green sheets by scraper forming method. Specifically, the scraper forming method, also known as the stretch forming method, also known as the tape casting method, includes filtering the slurry to filter out the agglomerated or large-particle material powder and the undissolved adhesive. Then, the slurry is coated on a carrier by a scraper, and then the thinned slurry is dried and solidified to form a thin green sheet. The advantages of the scraper forming method in this embodiment are that the scraper method can reduce costs, increase production speed, increase automation, and achieve uniform organizational structure.

[0020] Step S42, cutting the plurality of green sheets to form a plurality of ceramic green sheets of a predetermined size. In other words, the green sheet strips are punched, laminated, etc. according to the size and shape of the finished product to form a green sheet to be sintered.

[0021] Step 43, further subjecting the ceramic green sheets to a cold isostatic pressing (CIP) process. The cold isostatic pressing process is performed at room temperature, usually using rubber or plastic as a sheathing mold material and liquid as a pressure medium. It is mainly used for powder material molding. The ceramic green sheets are sealed in a molding mold with low deformation resistance, and equal pressure is applied to each surface to increase the density of the product and obtain the desired shape. The general pressure used is 100MPa to 630MPa. The cold isostatic pressing process can make the structure of the ceramic green sheets denser.

[0022] Step S44 is a process of applying a release agent, wherein after forming the plurality of ceramic green sheets, a release agent is further applied to the plurality of ceramic green sheets to facilitate subsequent separation of the ceramic green sheets.

[0023] Step S45, placing the plurality of ceramic green sheets into a mold, wherein the mold enables the plurality of ceramic green sheets to be sintered in batches, wherein the mold may be made of graphite or boron nitride to withstand the subsequent sintering temperature.

[0024] Step S46, a degreasing process is performed to remove organic matter from the plurality of ceramic green sheets. Degreasing is a process of removing organic matter from the inside of the formed ceramic green sheets by heating and other physical methods. In this embodiment, the degreasing method may include a thermal degreasing method. Specifically, a plurality of ceramic green sheets are placed in a degreasing furnace and degreasing is performed at 600° C. for 10 hours. The thermal degreasing process may also produce a small amount of sintering. However, the present application is not limited thereto, and for example, it may also be a microwave degreasing method, an organic solvent degreasing method, etc.

[0025] Step S47, sintering the plurality of ceramic green sheets to form a ceramic substrate. Specifically, the present embodiment can be sintered in nitrogen at a temperature of 1700°C to 1900°C. The sintering time can be adjusted according to the thickness of the ceramic green sheets. The sintering process of the present embodiment does not require pressure sintering under a mold, and the finished product can be completed by sintering once, thereby reducing costs. Compared with the existing hot pressing process, the output of a single furnace is small and the cost is high.

[0026] Step S48, further cutting and grinding the sintered ceramic substrate according to a predetermined size and thickness, step S49, trimming the ceramic substrate, and finally, step S50, packaging the finished ceramic substrate.

[0027] like Figure 2 Schematic diagram of the ceramic substrate 100 after molding in this embodiment, wherein the raw material ceramic raw material powder C1 includes: quasi-spherical aluminum nitride powder 11, whose weight percentage is 63% to 90%, and 66% in a feasible embodiment; plate-shaped aluminum nitride powder 12, whose weight percentage is 0.05 to 30%, and 30% in a feasible embodiment; a small amount of boron nitride powder 13, whose weight percentage is 0.05 to 2%, and 0.5% in a feasible embodiment; and a small amount of yttrium oxide powder 14, whose weight percentage is 0.05 to 5%, and 3.5% in a feasible embodiment. This application mainly adds plate-shaped aluminum nitride powder and boron nitride, thereby strengthening the structural toughness strength of the ceramic substrate. This application adds high thermal conductivity boron nitride powder and yttrium oxide to improve thermal conductivity. This application does not require a large amount of boron nitride powder, which can reduce costs and is conducive to commercialization. However, this application is not limited to this, wherein the weight percentage of quasi-spherical aluminum nitride powder can be increased to 90%, reducing the weight percentage of plate-shaped aluminum nitride powder.

[0028] Advantageous Effects of Embodiments

[0029] One of the beneficial effects of the present application is that the ceramic substrate and the manufacturing method thereof provided by the present application can enhance the structural toughness strength of the ceramic substrate by adding plate-shaped aluminum nitride powder and boron nitride. The present application adds high thermal conductivity boron nitride powder and yttrium oxide to improve thermal conductivity.

[0030] The contents disclosed above are only feasible embodiments of the present application and are not intended to limit the scope of the present application. Therefore, all equivalent changes and modifications made using the contents of the present application specification and drawings are included in the protection scope of the present application.

Claims

1. A method for manufacturing a ceramic substrate, characterized in that: The following processes are included: Providing raw materials, the raw materials include ceramic raw material powder, organic solvent and adhesive, wherein the ceramic raw material powder includes spherical aluminum nitride powder, plate-like aluminum nitride powder, boron nitride powder and yttrium oxide powder; crushing and mixing the raw materials to form a slurry; Stirring the slurry to deaerate the slurry; Using a scraper forming method, forming the raw material into a plurality of thin green sheets; Cutting the plurality of thin green sheets to form a plurality of ceramic green sheets meeting predetermined sizes; as well as The plurality of ceramic green sheets are sintered to form a ceramic substrate.

2. The method for manufacturing a ceramic substrate according to claim 1, wherein: The ratio of the ceramic raw material powder is: Quasi-spherical aluminum nitride powder, the weight percentage of which is 63% to 90%; Plate-shaped aluminum nitride powder, the weight percentage of which is 0.05% to 30%; Boron nitride powder, the weight percentage of which is 0.05% to 2%; and The weight percentage of yttrium oxide powder is 0.05% to 5%.

3. The method for manufacturing a ceramic substrate according to claim 1, wherein: The stirring and degassing process includes separating the gas in the slurry in a space below atmospheric pressure.

4. The method for manufacturing a ceramic substrate according to claim 1, wherein: The scraper forming method includes filtering the slurry, applying it on a base belt using a scraper, and then drying and curing the slurry after thinning to form the thin green sheet.

5. The method for manufacturing a ceramic substrate according to claim 1, wherein: After forming the plurality of ceramic green sheets, the method further includes performing a cold isostatic pressing process on the plurality of ceramic green sheets, and then coating a release agent on the plurality of ceramic green sheets; then, placing the plurality of ceramic green sheets in a mold, and performing a degreasing process to remove organic matter in the plurality of ceramic green sheets.

6. The method for manufacturing a ceramic substrate according to claim 5, wherein: The degreasing method includes a thermal degreasing method or a microwave degreasing method.

7. The method for manufacturing a ceramic substrate according to claim 1, wherein: The ceramic substrate is further cut and ground according to a predetermined size and thickness, and the ceramic substrate is trimmed.

8. A ceramic substrate, characterized in that: include: Quasi-spherical aluminum nitride powder, the weight percentage of which is 63% to 90%; Plate-shaped aluminum nitride powder, the weight percentage of which is 0.05% to 30%; Boron nitride powder, the weight percentage of which is 0.05% to 2%; and The weight percentage of yttrium oxide powder is 0.05% to 5%.

9. The ceramic substrate according to claim 8, characterized in that The average thickness of the plate-like aluminum nitride powder is 0.05 μm to 1.8 μm, and the average particle size of the plate-like aluminum nitride powder is 2 μm to 20 μm, wherein the average particle size divided by the average thickness is more than 3 times.

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