A preparation method of single crystal glass ceramics and single crystal glass ceramics

Abstract

The present invention provides a method for preparing a single-crystal glass-ceramic and a single-crystal glass-ceramic. The method comprises the steps of preparing raw materials and processing the raw materials to obtain a glass powder; and processing the glass powder through a high-temperature pulse method, followed by cooling to obtain the single-crystal glass-ceramic. The high-temperature pulse method is achieved through multiple stages of heating, cooling, and / or heat preservation, with the temperature during the high-temperature pulse method maintained between 780°C and 880°C.

Description

Technical Field

[0001] The present invention belongs to the technical field of low-temperature co-fired ceramics, and in particular relates to a preparation method of single-crystal glass ceramics and single-crystal glass ceramics. Background Art

[0002] Low-temperature co-fired ceramic (LTCC) technology is widely used in various electronic components due to its advantages such as miniaturization, integration, and low cost. With the rapid development of high-frequency communication technology, the requirements for the comprehensive performance of LTCC materials are constantly increasing, and the contradictions between the various properties of LTCC are becoming increasingly prominent.

[0003] The dielectric constant (K value) of existing low-dielectric-constant LTCC substrates is usually in the range of 5 to 8. Due to the low relative dielectric constant of air (approximately equal to 1), some existing LTCC substrates also use inorganic porous materials to reduce the dielectric properties of the LTCC substrate material. However, the large number of voids in the inorganic porous material will inevitably lead to a decrease in the mechanical strength of the formed LTCC substrate and a rapid increase in dielectric loss. In the context of miniaturization and integration of high-frequency communication technology, the LTCC substrate needs to have certain bending and compressive properties to face high-load packaging environments. In addition, since the melting point of silver (Ag) is 961°C, the densification temperature of the LTCC substrate is usually less than 900°C.

[0004] In the microcrystalline glass system, a combination of multiple glasses can usually be used to coordinate the comprehensive performance of LTCC materials. However, how to adjust the sintering process parameters to meet the appropriate sintering temperature, low dielectric constant, low dielectric loss and high bending strength required by the LTCC substrate remains an urgent problem to be solved in this field.

[0005] In order to overcome the above-mentioned defects of the prior art, the art urgently needs a preparation method of single crystal glass ceramics and a single crystal glass ceramic that can balance and improve the dielectric constant, dielectric loss and flexural strength of LTCC substrate materials. Summary of the Invention

[0006] The following is a brief summary of one or more aspects to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceivable aspects and is neither intended to identify key or critical elements of all aspects nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that will be provided later.

[0007] In order to overcome the above-mentioned defects in the prior art, the present invention provides a method for preparing a single crystal glass ceramic and a single crystal glass ceramic, which can balance and improve the dielectric constant, dielectric loss and flexural strength of the LTCC substrate material.

[0008] Specifically, the preparation method of the above-mentioned single crystal glass ceramics provided in the first aspect of the present invention includes the steps of: preparing raw materials and processing the raw materials to obtain glass powder; and processing the glass powder by a high-temperature pulse method, and obtaining single crystal glass ceramics after cooling, wherein the high-temperature pulse method is achieved through multiple stages of heating, cooling and / or heat preservation, and the temperature of the high-temperature pulse method is maintained between 780 and 880°C.

[0009] Preferably, in one embodiment of the present invention, the multiple stages of the high temperature pulse method include a first stage, a second stage, a third stage and / or a fourth stage, and the second stage and the third stage are repeated cycles of heating, cooling and / or keeping warm.

[0010] Preferably, in one embodiment of the present invention, the first stage includes a staged cooling process, which includes the steps of: heating to 780-820°C at a heating rate of 3-5°C / min, and keeping warm for 30-120 minutes; heating to 850-880°C at a heating rate of 1-2°C / min, and then cooling to 820-840°C at a cooling rate of 1-2°C / min; and changing the cooling rate, cooling to 780-800°C at a cooling rate of 0.5-2°C / min, and keeping warm for 60 minutes.

[0011] Preferably, in one embodiment of the present invention, after the first stage is completed, the high-temperature pulse method performs the second stage of repeated cycles, the number of repeated cycles of the second stage is 2 to 8 times, and the second stage includes a staged cooling process, the second stage including the steps of: heating to 850 to 880°C at a heating rate of 1 to 2°C / min, and keeping warm for 30 to 120 minutes; cooling to 820 to 840°C at a cooling rate of 1 to 2°C / min; and changing the cooling rate, cooling to 780 to 800°C at a cooling rate of 0.5 to 2°C / min, and keeping warm for 30 to 120 minutes.

[0012] Preferably, in one embodiment of the present invention, after the second stage is completed, the high-temperature pulse method performs the third stage of repeated cycles, and the number of repeated cycles of the third stage is 2 to 8 times, including the steps of: heating to 850 to 870°C at a heating rate of 1 to 3°C / min and keeping warm for 30 to 120 minutes; and cooling to 780 to 800°C at a cooling rate of 0.5 to 2°C / min and keeping warm for 30 to 120 minutes.

[0013] Preferably, in one embodiment of the present invention, after the third stage is completed, the high-temperature pulse method performs the fourth stage, and the fourth stage includes the steps of heating to 850-880°C at a heating rate of 1-2°C / min and keeping warm for 60-380 minutes.

[0014] Preferably, in one embodiment of the present invention, the steps of preparing raw materials and processing the raw materials to obtain glass powder include: weighing the raw materials and mixing them thoroughly, melting the mixed raw materials at 1300-1500°C for 1-3 hours to obtain glass liquid; rapidly cooling the glass liquid through a cooling rolling mill to obtain glass sheets; placing the glass sheets into a grinder for preliminary crushing to obtain glass particles; and passing the glass particles through an air flow mill in combination with an air flow classifier to form the glass powder.

[0015] Preferably, in one embodiment of the present invention, the glass particles have a particle size range of 0.5 to 2.0 mm.

[0016] Preferably, in an embodiment of the present invention, the preset particle size range of the glass powder is 3.0-4.0 μm.

[0017] Preferably, in one embodiment of the present invention, the glass powder includes 40.4-47.2 mol% of CaO, 10-17 mol% of B2O3, 36-42 mol% of SiO2 and 0-5.34 mol% of Al2O3.

[0018] In addition, the single crystal glass ceramic provided according to the second aspect of the present invention is produced by the method for producing the single crystal glass ceramic provided according to the first aspect of the present invention.

[0019] Preferably, in one embodiment of the present invention, the main crystal phase of the single crystal glass ceramic is single crystal β-CaSiO3. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above features and advantages of the present invention will be better understood after reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings. In the drawings, the components are not necessarily drawn to scale, and components with similar related properties or characteristics may have the same or similar reference numerals.

[0021] Figure 1 A flow chart showing a method for preparing single crystal glass ceramics according to some embodiments of the present invention is shown;

[0022] Figure 2 shows a microscopic morphology of single crystal glass ceramics provided according to some embodiments of the present invention;

[0023] Figure 3The performance test results of various glass ceramics provided according to multiple embodiments of the present invention and multiple comparative examples are shown;

[0024] Figure 4 The bending strength results of various glass ceramics provided according to various embodiments of the present invention and various comparative examples are shown; and

[0025] Figure 5 A comparison chart of the XRD patterns of the glass ceramics provided in Example 1 of the present invention and Comparative Example 1 is shown.

[0026] Reference numerals:

[0027] 100: Preparation method of single crystal glass ceramics;

[0028] S110-S120: steps; and

[0029] 501, 502: lines. DETAILED DESCRIPTION

[0030] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Note that the various aspects described below with reference to the accompanying drawings and specific embodiments are merely exemplary and should not be construed as limiting the scope of protection of the present invention.

[0031] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0032] Furthermore, the terms "upper," "lower," "left," "right," "top," "bottom," "horizontal," and "vertical" used in the following description should be understood to refer to the orientations depicted in that section and the accompanying drawings. These relative terms are used solely for convenience of description and do not necessarily imply that the devices described herein must be manufactured or operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0033] It will be understood that although the terms "first," "second," "third," etc. may be used herein to describe various components, regions, layers, and / or portions, these components, regions, layers, and / or portions should not be limited by these terms, and these terms are merely used to distinguish different components, regions, layers, and / or portions. Thus, a first component, region, layer, and / or portion discussed below may be referred to as a second component, region, layer, and / or portion without departing from some embodiments of the present invention.

[0034] As mentioned above, with the miniaturization and integration of high-frequency communication technologies, the requirements for the comprehensive performance of LTCC materials are constantly increasing, and the contradictions between the various LTCC properties are becoming increasingly prominent. Currently, the existing LTCC substrate materials are mainly microcrystalline glass systems and glass / ceramic composite systems. In the microcrystalline glass system, a combination of multiple glasses can usually be used to coordinate the comprehensive performance of LTCC materials. However, how to adjust the sintering process parameters to meet the appropriate sintering temperature, low dielectric constant, low dielectric loss and high bending strength required by the LTCC substrate remains an urgent problem to be solved in this field.

[0035] In order to overcome the above-mentioned defects in the prior art, the present invention provides a method for preparing a single crystal glass ceramic and a single crystal glass ceramic, which can balance and improve the dielectric constant, dielectric loss and flexural strength of the LTCC substrate material.

[0036] The following will first describe the above-mentioned single-crystal glass-ceramics with reference to some examples of methods for preparing single-crystal glass-ceramics. Those skilled in the art will appreciate that these examples of methods for preparing single-crystal glass-ceramics are merely some non-limiting implementation methods provided by the present invention, intended to clearly illustrate the main concepts of the present invention and to provide some specific solutions that are convenient for the public to implement, and do not constitute any limitation on the execution subject and execution order of the various steps in the methods for preparing single-crystal glass-ceramics.

[0037] Please refer to Figure 1 , Figure 1 A flow chart of a method for preparing single crystal glass ceramics according to some embodiments of the present invention is shown.

[0038] like Figure 1 As shown, the method 100 for preparing single crystal glass ceramics may include step S110: preparing raw materials and processing the raw materials to obtain glass powder.

[0039] The preparation method 100 of single crystal glass ceramics can be applied to all microcrystalline glass formulas. Here, the preparation method 100 of single crystal glass ceramics is described in detail by taking a glass powder with a formula of 40.4-47.2 mol% CaO, 10-17 mol% B2O3, 36-42 mol% SiO2 and 0-5.34 mol% Al2O3 as an example.

[0040] In a preferred embodiment, the raw materials include SiO2, H3BO3, CaCO3, and Al(OH)3 weighed in a stoichiometric ratio. SiO2 can be made of AR (Analytical Reagent) grade silicon oxide, B2O3 can be made of electronic-grade boric acid, CaO can be made of calcium carbonate, and Al2O3 can be made of aluminum hydroxide.

[0041] After weighing the raw materials according to the stoichiometric ratio, the raw materials can be thoroughly mixed using a mixer. To ensure a more uniform mixing of the raw materials, zirconium beads (i.e., grinding media) can be added to the mixing tank at a 1:1 ball-to-material ratio (the ratio of the mass of the material to the grinding media) for 2 hours.

[0042] Afterwards, the mixed raw materials are melted, and the molten glass liquid is poured into a cooling mill for rapid cooling to obtain glass sheets. The mixed raw materials can be melted at 1300-1500°C for 1-3 hours. Specifically, to prevent contamination by other elements, a platinum crucible can be used during the melting process. In addition, to prevent excessive volatilization of the boron element, a cake pressing and batch feeding process can also be used for melting. The molten glass liquid is poured into a cooling mill for rapid cooling, thereby rapidly cooling the glass liquid into glass sheets. Here, the cooling mill can be a double-roll cooling mill.

[0043] The glass flakes are then placed in a grinder for preliminary crushing to obtain glass particles. In one embodiment, the glass flakes can be initially crushed into glass particles with a particle size range of approximately 0.5 to 2.0 mm using a three-drum grinder. Here, the glass particles are calcium borosilicate (CBS) glass particles. The glass particles are then jet milled in conjunction with an airflow classifier to obtain a glass powder within a predetermined particle size distribution range. The predetermined particle size distribution range of the glass powder can be 3.0 to 4.0 μm.

[0044] Thus, a glass powder including 40.4 to 47.2 mol% of CaO, 10 to 17 mol% of B2O3, 36 to 42 mol% of SiO2 and 0 to 5.34 mol% of Al2O3 can be obtained.

[0045] Please continue to refer to Figure 1 The preparation method 100 of single crystal glass ceramics may further include step S120: treating the glass powder by a high temperature pulse method, and obtaining single crystal glass ceramics after cooling, wherein the high temperature pulse method is achieved through multi-stage heating, cooling and / or heat preservation, and the temperature of the high temperature pulse method is maintained between 780 and 880°C.

[0046] Preferably, the multi-stage high temperature pulse method may include a first stage, a second stage, a third stage and / or a fourth stage, wherein the second stage and the third stage are repeated cycles of heating, cooling and / or keeping warm.

[0047] Before generating a stable phase, microcrystalline glass will preferentially generate a metastable phase with an intermediate state to ensure the energy transition. Here, the high-temperature pulse method provided by the preparation method 100 of single crystal glass ceramics can transform the metastable phase into a stable phase single crystal by adjusting the sintering process and utilizing the abnormal grain growth (AGG, Abnormal Grain Growth) mechanism, thereby realizing the single crystalization of glass ceramics. Specifically, through high and low temperature pulse cycles, the preparation method 100 of single crystal glass ceramics can accelerate the speed at which large grains of β-CaSiO3 devour small grains of α-CaSiO3, and convert them into single crystal β-CaSiO3 at a lower temperature, thereby forming a glass ceramic in which only a single target crystal phase β-CaSiO3 exists, thereby improving the mechanical strength of the single crystal glass ceramics.

[0048] In a preferred embodiment, the high-temperature pulse method may include a first stage, which includes a staged cooling process. In the first stage, the high-temperature pulse method processes the glass powder at a heating rate of 3-5°C / min, raising the temperature to 780-820°C and then holding the temperature for 30-120 minutes. The temperature is then raised to 850-880°C at a heating rate of 1-2°C / min. The temperature is then lowered to 820-840°C at a cooling rate of 1-2°C / min. The cooling rate is then changed to 780-800°C at a cooling rate of 0.5-2°C / min, and the temperature is held for 60 minutes.

[0049] The high-temperature pulse method also includes a second stage after the first stage. The second stage includes cooling in stages. The second stage can be repeated in a cycle. Preferably, the number of repeated cycles of the second stage can be 2 to 8 times. Specifically, the second stage includes the steps of heating to 850 to 880°C at a heating rate of 1 to 2°C / min and keeping warm for 30 to 120 minutes. Thereafter, cooling to 820 to 840°C at a cooling rate of 1 to 2°C / min, and then changing the cooling rate to cool to 780 to 800°C at a cooling rate of 0.5 to 2°C / min and keeping warm for 30 to 120 minutes.

[0050] After the second stage, the high-temperature pulse method can be repeated in a third stage. Preferably, the third stage can be repeated 2 to 8 times. The third stage includes: heating to 850-870°C at a heating rate of 1-3°C / min and holding at that temperature for 30-120 minutes. Then, cooling to 780-800°C at a cooling rate of 0.5-2°C / min and holding at that temperature for 30-120 minutes.

[0051] Please refer to Figure 2 , Figure 2 Shown are microscopic morphologies of single crystal glass ceramics provided according to some embodiments of the present invention.

[0052] Finally, the high temperature pulse method may further include a fourth stage, wherein the temperature is raised to 850-880°C at a heating rate of 1-2°C / min and kept at this temperature for 60-380 minutes. After the fourth stage, the processed glass powder is cooled to form the single crystal glass ceramic provided by the second aspect of the present invention, such as Figure 2 As shown in FIG, the single crystal glass ceramics are dense and non-porous. In addition, the main crystal phase of the formed single crystal glass ceramics is single crystal β-CaSiO3.

[0053] The following are several preferred embodiments, based on which the preparation method of the single crystal glass ceramics and the single crystal glass ceramics proposed in the present invention are described in detail.

[0054] In the preparation process of the single crystal glass ceramics provided in Example 1, the raw materials can first be prepared according to the stoichiometric ratio requirements. The SiO2 included in the glass powder can use Chinese medicine AR grade silicon oxide as a raw material, the raw material of B2O3 can be electronic grade boric acid, the CaO can use calcium carbonate as a raw material, and the Al2O3 can use aluminum hydroxide as a raw material. Afterwards, a mixer is used to fully mix the raw materials, and zirconium beads can be loaded into the mixing tank at a ball-to-material ratio of 1:1, and the mixing time is 2 hours. A platinum crucible is then used to melt the raw materials, and a press cake batch feeding process is adopted to prevent excessive volatilization of the boron element. The melting temperature is 1300-1500°C, and the melting time is 1 to 3 hours. Afterwards, the molten glass liquid is poured into a double-roll cooling mill for rapid cooling, thereby rapidly cooling the glass liquid into glass sheets. The glass sheets are then initially crushed into glass particles of about 0.5 to 2.0 mm by a three-cylinder grinder, and the glass particles are then passed through an air flow mill in conjunction with an air flow classifier to obtain a glass powder of 3 to 4 μm. The composition of the glass powder is 41.68 mol% of CaO, 15.01 mol% of B2O3, 40.97 mol% of SiO2 and 2.34 mol% of Al2O3.

[0055] The glass powder was then treated using a high-temperature pulse method. In the first stage, the temperature was raised to 800°C at a rate of 5°C / min and held for 30 minutes. Next, the temperature was raised to 880°C at a rate of 1°C / min and then lowered to 820°C at a rate of 1°C / min. The cooling rate was then changed to 0.5°C / min to 800°C, where it was held for 60 minutes.

[0056] The second stage was then repeated four times. In the second stage, the temperature was first increased to 880°C at a rate of 1°C / min and held for 60 minutes. The temperature was then decreased to 820°C at a rate of 1°C / min. The rate was then changed to 800°C at a rate of 0.5°C / min and held for 60 minutes.

[0057] After the second stage was repeated four times, the third stage was performed. Here, the third stage was repeated four times. In the third stage, the temperature was first increased to 870°C at a rate of 1°C / min and held at that temperature for 60 minutes. The temperature was then decreased to 800°C at a rate of 0.5°C / min and held at that temperature for 60 minutes.

[0058] Finally, after the third stage, the fourth stage is carried out. The temperature is raised to 880°C at a rate of 1°C / min and held at that temperature for 360 minutes. After cooling, a large-area single-crystal β-CaSiO3 glass-ceramic is obtained.

[0059] Please refer to Figure 3 and Figure 4 , Figure 3 The performance test results of various glass ceramics provided by multiple embodiments and multiple comparative examples according to the present invention are shown. Figure 4 The figures show the bending strength results of various glass ceramics provided according to various embodiments of the present invention and various comparative examples.

[0060] like Figure 3 As shown in FIG, at 10 MHz, the dielectric constant of the single crystal glass ceramic obtained in Example 1 is 4.08, and the dielectric loss is 0.00327; at 15 GHz, the dielectric constant of the single crystal glass ceramic is 4.10, and the dielectric loss is 0.00325; Figure 4 As shown in FIG1 , the flexural strength of the single crystal glass ceramic obtained in Example 1 is 278 MPa. Therefore, it can be seen that the single crystal glass ceramic provided by the present invention has a small dielectric constant (4.10@15GHz) and dielectric loss (0.00325) and a high mechanical strength (278 MPa).

[0061] In the preparation process of the single crystal glass ceramics provided in Example 2, the raw materials can first be prepared according to the stoichiometric ratio requirements. The SiO2 included in the glass powder can use Chinese medicine AR grade silicon oxide as a raw material, the raw material of B2O3 can be electronic grade boric acid, the CaO can use calcium carbonate as a raw material, and the Al2O3 can use aluminum hydroxide as a raw material. Afterwards, a mixer is used to fully mix the raw materials, and zirconium beads can be loaded into the mixing tank at a ball-to-material ratio of 1:1, and the mixing time is 2 hours. A platinum crucible is then used to melt the raw materials, and a press cake batch feeding process is adopted to prevent excessive volatilization of the boron element. The melting temperature is 1300-1500°C, and the melting time is 1 to 3 hours. Afterwards, the molten glass liquid is poured into a double-roll cooling mill for rapid cooling, thereby rapidly cooling the glass liquid into glass sheets. The glass sheets are then initially crushed into glass particles of about 0.5 to 2.0 mm by a three-cylinder grinder, and the glass particles are then passed through an air flow mill in conjunction with an air flow classifier to obtain a glass powder of 3 to 4 μm. The composition of the glass powder is 41.68 mol% of CaO, 15.01 mol% of B2O3, 40.97 mol% of SiO2 and 2.34 mol% of Al2O3.

[0062] The glass powder was then treated using a high-temperature pulse method. In the first stage, the temperature was raised to 800°C at a rate of 5°C / min and held for 30 minutes. Next, the temperature was raised to 880°C at a rate of 1°C / min and then lowered to 820°C at a rate of 1°C / min. The cooling rate was then changed to 0.5°C / min to 800°C, where it was held for 60 minutes.

[0063] Then, the second stage was performed, and the second stage cycle was repeated twice. In the second stage, the temperature was first increased to 880°C at a heating rate of 1°C / min and held at this temperature for 60 minutes. Then, the temperature was cooled at a cooling rate of 1°C / min to 820°C. The cooling rate was then changed to 0.5°C / min to 800°C and held at this temperature for 60 minutes.

[0064] After the second stage was repeated twice, the third stage was performed. Here, the third stage was repeated six times. In the third stage, the temperature was first increased to 870°C at a rate of 1°C / min and held at that temperature for 60 minutes. The temperature was then decreased to 800°C at a rate of 0.5°C / min and held at that temperature for 60 minutes.

[0065] Finally, after the third stage, the fourth stage is carried out. The temperature is raised to 880°C at a rate of 1°C / min and held at that temperature for 360 minutes. After cooling, a large-area single-crystal β-CaSiO3 glass-ceramic is obtained.

[0066] like Figure 3As shown in FIG, at 10 MHz, the dielectric constant of the single crystal glass ceramic obtained in Example 2 is 4.15, and the dielectric loss is 0.00330; at 15 GHz, the dielectric constant of the single crystal glass ceramic is 4.20, and the dielectric loss is 0.00328; Figure 4 As shown, the flexural strength of the single crystal glass ceramics obtained in Example 2 is 270 MPa.

[0067] In the preparation process of the single crystal glass ceramics provided in Example 3, the raw materials can first be prepared according to the stoichiometric ratio requirements. The SiO2 included in the glass powder can use Chinese medicine AR grade silicon oxide as a raw material, the raw material of B2O3 can be electronic grade boric acid, the CaO can use calcium carbonate as a raw material, and the Al2O3 can use aluminum hydroxide as a raw material. Afterwards, a mixer is used to fully mix the raw materials, and zirconium beads can be loaded into the mixing tank at a ball-to-material ratio of 1:1, and the mixing time is 2 hours. A platinum crucible is then used to melt the raw materials, and a press cake batch feeding process is adopted to prevent excessive volatilization of the boron element. The melting temperature is 1300-1500°C, and the melting time is 1 to 3 hours. Afterwards, the molten glass liquid is poured into a double-roll cooling mill for rapid cooling, thereby rapidly cooling the glass liquid into glass sheets. The glass sheets are then initially crushed into glass particles of about 0.5 to 2.0 mm by a three-cylinder grinder, and the glass particles are then passed through an air flow mill in conjunction with an air flow classifier to obtain a glass powder of 3 to 4 μm. The composition of the glass powder is 41.68 mol% of CaO, 15.01 mol% of B2O3, 40.97 mol% of SiO2 and 2.34 mol% of Al2O3.

[0068] The glass powder was then treated using a high-temperature pulse method. In the first stage, the temperature was raised to 780°C at a rate of 3°C / min and held at that temperature for 60 minutes. Next, the temperature was raised to 850°C at a rate of 2°C / min and then lowered to 830°C at a rate of 2°C / min. The cooling rate was then changed to 1°C / min to 780°C, where it was held for 60 minutes.

[0069] The second stage was then repeated eight times. In the second stage, the temperature was first increased to 880°C at a rate of 2°C / min and held at that temperature for 80 minutes. The temperature was then decreased to 820°C at a rate of 2°C / min. The temperature was then reduced to 780°C at a rate of 1°C / min and held at that temperature for 80 minutes.

[0070] After the second stage was repeated eight times, the third stage was performed. Here, the third stage was repeated five times. In the third stage, the temperature was first increased to 870°C at a rate of 2°C / min and held at that temperature for 80 minutes. The temperature was then decreased to 780°C at a rate of 1°C / min and held at that temperature for 80 minutes.

[0071] Finally, after the third stage, the fourth stage is carried out. The temperature is raised to 880°C at a rate of 1°C / min and held at that temperature for 380 minutes. After cooling, a large-area single-crystal β-CaSiO3 glass-ceramic is obtained.

[0072] like Figure 3 As shown in FIG, at 10 MHz, the dielectric constant of the single crystal glass ceramic obtained in Example 3 is 4.21, and the dielectric loss is 0.00329; at 15 GHz, the dielectric constant of the single crystal glass ceramic is 4.26, and the dielectric loss is 0.00327; Figure 4 As shown, the flexural strength of the single crystal glass ceramics obtained in Example 3 is 267 MPa.

[0073] The following are several comparative examples compared with the above-mentioned Example 1, based on which the preparation method of the single crystal glass ceramics proposed in the present invention and the performance effects of the prepared single crystal glass ceramics are further explained.

[0074] In Comparative Example 1, the glass powder obtained in Example 1 was treated by a heat treatment method. Specifically, the temperature was raised to 880°C at a heating rate of 5°C / min and kept at that temperature for 20 minutes. After cooling, a glass ceramic was obtained.

[0075] like Figure 3 As shown, at 10 MHz, the dielectric constant of the glass ceramic obtained in Comparative Example 1 is 5.17, and the dielectric loss is 0.00376; at 15 GHz, the dielectric constant of the glass ceramic is 4.25, and the dielectric loss is 0.00386; Figure 4 As shown, the flexural strength of the glass ceramic obtained in Comparative Example 1 is 196 MPa. This shows that the dielectric properties and mechanical strength of the glass ceramic obtained by a simple heat treatment method are far lower than those of the single crystal glass ceramic provided by the present invention.

[0076] For further information, please refer to Figure 5 , Figure 5 A comparison chart of the XRD patterns of the glass ceramics provided in Example 1 of the present invention and Comparative Example 1 is shown.

[0077] like Figure 5 As shown, the crystal types of the glass ceramics provided in Example 1 and Comparative Example 1 can be determined based on the intensity of the diffraction peaks through the XRD (X-Ray Diffraction) spectrum. Line 501 is the result of the XRD spectrum of the single crystal glass ceramic provided in Example 1, and line 502 is the result of the XRD spectrum of the glass ceramic provided in Comparative Example 1. Figure 5It can be seen that the diffraction peak intensity of line 501 is much greater than that of line 502, indicating that compared with a simple heat treatment method, the preparation method of the single crystal glass ceramic provided by the present invention is more conducive to forming glass ceramics with only a single target crystal phase β-CaSiO3.

[0078] The difference between Comparative Examples 2 and 3 and Example 1 is that Comparative Examples 2 and 3 only use one heat treatment cycle (i.e., the second stage and / or the third stage in the high-temperature pulse method) to process the glass powder obtained in Example 1.

[0079] Comparative Example 2 omitted the third stage of the high-temperature pulse method. Specifically, in the first stage, the temperature was first raised to 800°C at a heating rate of 5°C / min and held at this temperature for 30 minutes. Next, the temperature was raised to 880°C at a heating rate of 1°C / min and then lowered to 820°C at a cooling rate of 1°C / min. Subsequently, the cooling rate was changed to 0.5°C / min to 800°C and held at this temperature for 60 minutes.

[0080] The second stage was then repeated four times. In the second stage, the temperature was first increased to 880°C at a rate of 1°C / min and held for 60 minutes. The temperature was then decreased to 820°C at a rate of 1°C / min. The rate was then changed to 800°C at a rate of 0.5°C / min and held for 60 minutes.

[0081] Finally, skipping the third stage and proceeding to the fourth stage, the temperature was raised to 880°C at a rate of 1°C / min and held at that temperature for 360 minutes. After cooling, the glass ceramic was obtained.

[0082] like Figure 3 As shown, at 10 MHz, the dielectric constant of the glass ceramic obtained in Comparative Example 2 is 5.10, and the dielectric loss is 0.00312; at 15 GHz, the dielectric constant of the glass ceramic is 5.15, and the dielectric loss is 0.00302; Figure 4 As shown, the flexural strength of the glass ceramic obtained in Comparative Example 2 is 185 MPa. This shows that the high temperature pulse method using only one heat treatment cycle will make the dielectric properties and mechanical strength of the formed glass ceramic far lower than the single crystal glass ceramic provided by the present invention.

[0083] Comparative Example 3 omitted the second stage of the high-temperature pulse method. Specifically, in the first stage, the temperature was first increased to 800°C at a heating rate of 5°C / min and held at this temperature for 30 minutes. Next, the temperature was increased to 880°C at a heating rate of 1°C / min and then decreased to 820°C at a cooling rate of 1°C / min. Subsequently, the cooling rate was changed to 0.5°C / min to 800°C and held at this temperature for 60 minutes.

[0084] Then, the second stage was skipped and the third stage was performed. The third stage was repeated four times. In the third stage, the temperature was first increased to 870°C at a heating rate of 1°C / min and held for 60 minutes. Then, the temperature was cooled to 800°C at a cooling rate of 0.5°C / min and held for 60 minutes. Compared with Comparative Example 2, Comparative Example 3 skipped the staged cooling in the second stage and directly cooled to 800°C at a cooling rate of 0.5°C / min.

[0085] Finally, the fourth stage is carried out. The temperature is raised to 880°C at a rate of 1°C / min and held at that temperature for 360 minutes. After cooling, the glass ceramic is obtained.

[0086] like Figure 3 As shown, at 10 MHz, the dielectric constant of the glass ceramic obtained in Comparative Example 3 is 5.23, and the dielectric loss is 0.00267; at 15 GHz, the dielectric constant of the glass ceramic is 5.00, and the dielectric loss is 0.00254; Figure 4 As shown, the flexural strength of the glass ceramic obtained in Comparative Example 3 is 211 MPa. This shows that the high-temperature pulse method using only one heat treatment cycle will make the dielectric properties and mechanical strength of the formed glass ceramic far lower than the single crystal glass ceramic provided by the present invention.

[0087] In summary, the single-crystal glass-ceramics provided by the present invention have a small dielectric constant and dielectric loss as well as high mechanical strength, can balance and improve the dielectric constant, dielectric loss and bending strength of the LTCC substrate, and have good application prospects, and are thus widely used in modern 5G / 6G electronic communications fields such as mobile communications, high-frequency electronics, wireless local area networks, satellite communications, and aerospace electronics.

[0088] Although the above methods are illustrated and described as a series of acts for simplicity of explanation, it is to be understood and appreciated that these methods are not limited by the order of the acts, as some acts may occur in a different order and / or concurrently with other acts from those illustrated and described herein or not illustrated and described herein but understandable to those skilled in the art according to one or more embodiments.

[0089] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing single crystal glass ceramics, characterized in that: Including steps: preparing raw materials and processing the raw materials to obtain a glass powder comprising 40.4 to 47.2 mol% of CaO, 10 to 17 mol% of B2O3, 36 to 42 mol% of SiO2, and 0 to 5.34 mol% of Al2O3; and The glass powder is processed by a high-temperature pulse method and cooled to obtain a single crystal glass ceramic, wherein the high-temperature pulse method is achieved by multi-stage heating, cooling and / or heat preservation, and the temperature of the high-temperature pulse method is maintained between 780 and 880° C. The multi-stage high temperature pulse method includes a first stage, a second stage, a third stage and / or a fourth stage, wherein the second stage and the third stage are repeated cycles of heating, cooling and / or keeping warm, wherein: After the first stage, the high temperature pulse method performs a second stage of repeated cycles, the number of repeated cycles of the second stage is 2 to 8 times, and the second stage includes a staged cooling process, the second stage includes the steps of: Raise the temperature to 850-880°C at a heating rate of 1-2°C / min and keep at this temperature for 30-120 minutes; Cooling to 820-840°C at a cooling rate of 1-2°C / min; and Change the cooling rate to 780-800°C at a cooling rate of 0.5-2°C / min and keep it at that temperature for 30-120 minutes; After the second stage, the high temperature pulse method performs the third stage of repeated cycles, the number of repeated cycles of the third stage is 2 to 8 times, including the steps of: Heating the temperature to 850-870°C at a heating rate of 1-3°C / min and keeping the temperature for 30-120 minutes; and The temperature is lowered to 780-800°C at a cooling rate of 0.5-2°C / min and kept at this temperature for 30-120 minutes.

2. The method for preparing a single crystal glass ceramic according to claim 1, wherein: The first stage includes a staged cooling process, and the first stage includes the steps of: Raise the temperature to 780-820°C at a heating rate of 3-5°C / min and keep at this temperature for 30-120 minutes; Heating the temperature to 850-880°C at a heating rate of 1-2°C / min, and then cooling the temperature to 820-840°C at a cooling rate of 1-2°C / min; and Change the cooling rate, cool down to 780-800°C at a cooling rate of 0.5-2°C / min, and keep it at that temperature for 60 minutes.

3. The method for preparing a single crystal glass ceramic according to claim 1, wherein: After the third stage, the high temperature pulse method performs the fourth stage, which includes the following steps: The temperature is raised to 850-880°C at a heating rate of 1-2°C / min and kept at this temperature for 60-380 minutes.

4. The method for preparing a single crystal glass ceramic according to claim 1, wherein: The steps of preparing raw materials and processing the raw materials to obtain glass powder include: Weighing the raw materials and mixing them thoroughly, melting the mixed raw materials at 1300-1500° C. for 1-3 hours to obtain molten glass; Rapidly cooling the molten glass by a cooling mill to obtain a glass sheet; placing the glass sheets into a grinder for preliminary crushing to obtain glass particles; and The glass particles are subjected to air flow milling and air flow classifier to form the glass powder.

5. The method for preparing a single crystal glass ceramic according to claim 4, wherein: The particle size of the glass particles ranges from 0.5 to 2.0 mm.

6. The method for preparing a single crystal glass ceramic according to claim 4, wherein: The preset particle size range of the glass powder is 3.0 to 4.0 μm.

7. A single crystal glass ceramic, characterized in that: The single crystal glass ceramic is produced by the method for producing the single crystal glass ceramic according to any one of claims 1 to 6.

8. The single crystal glass ceramic according to claim 7, wherein The main crystal phase of the single crystal glass ceramic is single crystal β-CaSiO3.

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