Low-dielectric constant wollastonite-based low-temperature co-fired ceramic material and its manufacturing method

Abstract

The present invention discloses a low dielectric constant wollastonite-based low temperature co-fired ceramic material and its manufacturing method, which relates to the technical field of electronic materials. The composition of this ceramic material is Ca x SiO3+awt%SiO2+bwt%R2O+cwt%Bi2O3+dwt%B2O3+ewt%MO (in the formula, 0.9≦x≦1.1, 0

Description

[Technical field]

[0001] The present invention belongs to the technical field of electronic materials, and specifically relates to a wollastonite-based low-temperature co-fired ceramic material with low dielectric constant and a method for producing the same. [Background technology]

[0002] Low-temperature co-fired ceramics (LTCC) is one of the electronic packaging technologies, which includes low-temperature co-fired ceramic materials, device design and other technologies, and low-temperature co-fired ceramics is the basis and key. In recent years, with the rapid development of 5G communication technology, microwave technology has developed toward higher frequencies, such as millimeter waves and submillimeter waves, which places increasingly higher demands on low-temperature co-fired ceramic materials, including low dielectric constant to reduce the signal delay time in the transmission process, and high Q value (1 / tan), which is low dielectric loss to reduce the insertion loss of the device and ensure good frequency selection characteristics. In addition to being able to realize co-firing with metal conductive materials such as Ag and Cu at 900°C, it is also necessary to have sufficient mechanical strength and environmental reliability, and corrosion resistance from electroplating or electroless plating solutions.

[0003] Currently, the high frequency, low dielectric constant, low temperature co-fired ceramic materials being researched mainly include three main systems: crystallized glass, glass ceramic, and ceramic additive. The crystallized glass system requires strict control of the crystallization of the material in the sintering process, and the requirements for the process are relatively strict, so currently only the A6M material from the US company FEERO is widely used. The glass ceramic system requires a lot of glass to achieve low temperature sintering of ceramics, but the rapid increase in material loss becomes a problem. Unlike the glass ceramic system that can introduce a low dielectric constant, the ceramic additive system material generally has difficulty in achieving a low dielectric constant.

[0004] (Ca,Mg)SiO3-based microwave dielectric ceramics have good dielectric properties and low material costs. In the invention patent CN103193389B, at least two kinds of magnesium oxide, calcium oxide or silicon oxide are mixed at 1500-1800℃ to make it vitreous, and the total amount of magnesium oxide, calcium oxide and silicon oxide is 100 mol%, and then materials such as CaTiO3, MgTiO3, ZrTiO4 and TiO2 are added, melted at 1500-1800℃, and fired at 900℃. This method has a complicated process, a high dielectric constant, and a low Q×f value due to two melting steps to make it vitreous. Patent application CN112759378A describes a low-temperature co-fired ceramic, CaO-MgO-TiO2-SiO2 ceramic material, which is made by mixing calcium carbonate, magnesium oxide, titanium dioxide, silicon dioxide, manganese oxide, lithium oxide and bismuth oxide, directly calcining them, and then sintering them at 860-880℃. Lithium oxide and bismuth oxide are added to the components as sintering aids and combined with TiO2 to form the eutectic material Li2TiO3 (900℃). This method adds all the raw materials to the calcination process, which generates uncontrollable reactions between the components during calcination, making the resulting phases complex and uncertain. In addition, the dielectric constant of the material is 9.5±0.1 and the Q×f value is low. The materials described in the above patent all have dielectric constants above 9, which inhibits their use in low dielectric constant and high frequency scenarios. Invention patent CN200410039848.1 reports a compounding method and manufacturing process for low-temperature sintering microwave dielectric ceramics, which uses (Ca,Mg)SiO3 as the main component, CaTiO3 to adjust the frequency temperature coefficient, and Li2CO3 and V2O5 as sintering aids, and this low-temperature sintering microwave dielectric ceramic material can achieve good co-firing matching with silver electrodes, and its material performance is a dielectric constant of 8-10 and a quality factor Qf>25000GHz, and the material has been mass-produced. However, this material has the following problems: (1) The low-melting oxide V2O5 has excellent sintering effect and can significantly reduce the sintering temperature of (Ca,Mg)SiO3 ceramics, but it is highly toxic and harmful to the human body, and cannot meet the increasingly important demand for environmental protection.(2) V2O5 forms a liquid phase during the sintering process to promote ceramic sintering. At the same time, it easily promotes the short-distance diffusion of silver electrodes, increasing the risk of short circuits between layers due to silver migration, thus causing a serious problem of poor product reliability.

Summary of the Invention

Problems to be Solved by the Invention

[0005] To solve the above technical problems, the first object of the present invention is to provide a low-dielectric-constant wollastonite-based low-temperature co-fired ceramic material with a low dielectric constant, a high Q×f value, a low frequency temperature coefficient, and capable of low-temperature sintering. The second object of the present invention is to provide a low-dielectric-constant wollastonite-based low-temperature co-fired ceramic material and its manufacturing method that adopt a synthesis route of synthesizing the main-phase ceramic first, then manufacturing the oxide sintering aid, and finally performing low-temperature sintering. This manufacturing method has a simple sintering process and good reproducibility.

Means for Solving the Problems

[0006] To achieve the above first object, the present invention adopts the following technical means. A low-dielectric-constant wollastonite-based low-temperature co-fired ceramic material, the compounding formula of this low-temperature co-fired ceramic material is Ca x SiO3 + awt%SiO2 + bwt%R2O + cwt%Bi2O3 + dwt%B2O3 + ewt%MO (where 0.9 ≦ x ≦ 1.1, 0 < a ≦ 30, 1 ≦ b ≦ 5, 0 < c ≦ 3, 0 < d ≦ 6, 0 ≦ e ≦ 10, and a, b, c, d, and e are the mass fractions of SiO2, RO, Bi2O3, B2O3, and MO phases with respect to Ca x SiO3, R2O is at least one of Li2O and K2O, MO is one or more of ZnO, MgO, BaO, CoO, CuO, La2O3, and MnO2, SiO2 is at least one of quartz and fused quartz).

[0007] As a preferable technical solution, the composition of the main-phase ceramic material is Ca x SiO3 (where 0.9 ≦ x ≦ 1.0).

[0008] As a preferable technical solution, SiO2 is fused quartz.

[0009] To achieve the above second object, the present invention adopts the following technical means. A method for manufacturing a low dielectric constant wollastonite-based low-temperature co-fired ceramic material, 1) Synthesis of the main-phase ceramic Ca x SiO3: Weigh the raw materials CaCO3 and SiO2 according to the stoichiometric ratio of the chemical formula Ca x SiO3, use dehydrated ethanol as the solvent, mix them in a ball mill for 16 - 24 h and dry them. Then, pass them through a 40-mesh sieve, uniformly pulverize them, put them into an alumina crucible, and calcine them at 900 °C - 1300 °C for 2 - 4 h to synthesize the main-phase ceramic. After pulverizing, use it as a ceramic substrate. 2) Synthesis of the sintering aid: bwt%RO + cwt%Bi2O3 + dwt%B2O3 + ewt%MO (where 1 ≦ b ≦ 5, 0 < c ≦ 3, 0 < d ≦ 6, 0 ≦ e ≦ 10, and b, c, d, and e are the mass fractions of the RO, Bi2O3, B2O3, and MO phases with respect to Ca x SiO3 respectively). Weigh the raw materials of Li2CO3, K2CO3, Bi2O3, B2O3 or H3BO3, ZnO, MgO or Mg(OH)2, BaCO3, CoO or Co2O3, CuO, La2O3, MnO2 / MnCO3 according to the mass fraction ratio with respect to Ca 3) The manufactured main-phase Ca x SiO3 ceramic, SiO2, and the oxide sintering aid are mixed according to Ca x SiO3 + awt%SiO2 + bwt%RO + cwt%Bi2O3 + dwt%B2O3 + ewt%MO (where a, b, c, d, and e are Cax and mixing the resulting mixture in a ball mill using ZrO2 balls as a milling medium and ethanol as a solvent for 16 to 24 hours, drying the mixture, pulverizing and granulating the mixture with a polyvinyl alcohol binder content of 5 to 8% by weight, sieving the mixture, and then press-molding the mixture into an element having a diameter of 20 mm and a thickness of 10 mm at a pressure of 80 to 120 MPa, and firing the element in an air atmosphere at 850°C to 950°C for 1 to 3 hours to obtain the low dielectric constant wollastonite-based low-temperature co-fired ceramic material. Effect of the Invention

[0010] Compared with the prior art, the material of the present invention has the following advantages: 1. The present invention provides a simple, reliable, and low-cost manufacturing method. The main phase ceramic and sintering aid are synthesized separately, and then the low-temperature co-fired ceramic is manufactured. This method ensures that the composition of the main phase ceramic phase can be controlled, and the sintering aid can reliably synthesize compounds such as Li2O(K2O)-Bi2O3-B2O3 with a low eutectic point (less than 700°C). Compared with the prior art, the main phase ceramic phase synthesized by this method is easier to control, has a better temperature reduction effect of the eutectic point compound, and has excellent dielectric properties. 2. The present invention designs and optimizes the calcium to silicon ratio of the main phase ceramic and studies its influence on the dielectric properties of the material. In particular, the main phase ceramic Ca x When SiO3 has a value of 0.9≦x≦1, the material has excellent dielectric properties. This is because, in addition to the wollastonite phase (CaSiO3), the calcination process produces some Ca2SiO4 phase, which has a large dielectric loss, and excess SiO2 is advantageous in promoting the synthesis of the wollastonite phase, which further improves the dielectric properties of the material. 3. Fused quartz and Ca xWhen SiO3 ceramic is used in the compound, the dielectric constant of the material can be effectively reduced due to the small dielectric constant of fused quartz. At the same time, fused quartz is prone to forming a liquid phase during the sintering process, which has the effect of wetting the powder particles and promoting sintering. 4. The present invention uses composite oxides to synergistically lower the temperature, and controls the amount of alkali metal oxide and Bi2O3 added to prevent the risk of interlayer short circuit caused by silver migration, which is very likely to occur when simultaneously firing ceramic material and silver electrodes. In addition, in order to avoid the complicated manufacturing process of glass additives, which is difficult to control batch stability, the introduced various sintering additive oxides are pre-mixed and fired, solving the problem that the free hydroxyl groups in oxides such as B2O3 and powders crosslink with the hydroxyl groups in binders such as PVB during the production of ceramic casting slurry, increasing the viscosity of the slurry and making it difficult to obtain high-quality ceramic green sheets. 5. The present invention provides a low dielectric constant wollastonite-based low temperature co-fired ceramic material with a dielectric constant less than 7.5, a Q×f value greater than 20000GHz, and an absolute value of the frequency temperature coefficient less than 35ppm / ℃, which meets the requirements of low dielectric constant, low loss, and low frequency temperature coefficient required for millimeter wave devices. [Brief description of the drawings]

[0011] The drawings in the specification which form a part of this invention are provided for the purpose of providing a further understanding of the invention. The illustrative examples of the invention and the description thereof are intended to illustrate the invention and are not intended to limit the invention. [Figure 1] 1 is an XRD diffraction pattern of the ceramic in Example 2. [Diagram 2] 1 is a SEM scanning electron microscope photograph of a fired ceramic sample of Example 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, embodiments of the present invention will be described in detail, examples of which are shown in the drawings. The embodiments described with reference to the drawings are illustrative and are intended merely to explain the present invention, and should not be construed as limiting the present invention.

[0013] In order to clarify and clarify the objectives, technical means and advantages of the present invention, the present invention will be described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are merely for the purpose of illustrating the present invention, and are not intended to limit the present invention.

[0014] Example 1 1) Synthesis of the main phase: Chemical formula Ca 0.98 The raw materials CaCO3 and quartz were weighed out in the ratio of SiO3, mixed in a ball mill for 24 hours using deethanol as a solvent, dried, sieved through a 40-mesh sieve, uniformly ground, placed in an alumina crucible, and fired at 1200°C for 3 hours to synthesize the main phase ceramic. 2) Synthesis of sintering aid: Weigh out raw materials such as Li2CO3, Bi2O3, H3BO3, and ZnO with a mass fraction ratio of 3wt%Li2O+2wt%Bi2O3+3wt%B2O3+3wt%ZnO to the main phase ceramic, add ethanol in a mass ratio of 1:1 to the mixed material and anhydrous ethanol, mix for 16h by wet method, and dry at 80℃. Sieve the dried mixed material through a 40 mesh sieve, put it into an alumina crucible, sinter at 600℃ for 3h, and grind it to use as sintering aid. 3) Main phase: Ca 0.98 SiO3 ceramic was mixed with 3.0wt% fused quartz and sintering aid synthesized in the previous process, respectively, based on the mass fraction of the main phase ceramic, and mixed in a ball mill using ZrO2 balls as milling medium and ethanol as solvent for 16h, dried, and then crushed and granulated with 8wt% polyvinyl alcohol binder, sieved, and manufactured into a body with a diameter of 20mm and a thickness of 10mm at a pressure of 100MPa. It was fired for 3h in an air atmosphere at 850℃ to obtain a low-temperature co-fired ceramic material, and its dielectric properties were evaluated.

[0015] Example 2 1) Synthesis of the main phase: The raw materials CaCO3 and quartz were weighed out in the ratio of the chemical formula CaSiO3, mixed in a ball mill for 24 hours using deethanol as a solvent, dried, sieved through a 40-mesh sieve, uniformly ground, placed in an alumina crucible, and fired at 1250℃ for 3 hours to synthesize the main phase ceramic. 2) Synthesis of sintering aid: The mass fraction ratio of the main phase ceramic is 1.5wt%Li2O+1wt%K2O+0.5wt%Bi2O3+2.5wt%B2O3+3wt%BaO+2wt%MnO2. The raw materials such as Li2CO3, K2CO3, Bi2O3, H3BO3, BaCO3, MnO2 are weighed, and the mixed materials and anhydrous ethanol are added in a mass ratio of 1:1. The mixed materials are mixed for 16h by wet method and dried at 80℃. The dried mixed materials are sieved through a 40 mesh sieve, put into an alumina crucible, fired at 650℃ for 3h, and crushed to be used as sintering aid. 3) The main phase CaSiO3 ceramic was mixed with 3.5wt% fused quartz and sintering aids synthesized in the previous process, respectively, based on the mass fraction of the main phase ceramic. The mixture was mixed in a ball mill using ZrO2 balls as milling media and ethanol as a solvent for 16h, dried, and pulverized with 8wt% polyvinyl alcohol binder. After sieving, a body with a diameter of 20mm and a thickness of 10mm was produced at a pressure of 100MPa. The mixture was fired for 3h in an air atmosphere at 900℃ to obtain a low-temperature co-fired ceramic material, and its dielectric properties were evaluated. Figure 1 shows the XRD pattern of the fired ceramic, in which the main phase of the ceramic is CaSiO3 and a small amount of SiO2 phase.

[0016] Example 3 1) Synthesis of the main phase: Chemical formula Ca 1.02 The raw materials CaCO3 and quartz were weighed out in the ratio of SiO3, mixed in a ball mill for 24 hours using deethanol as a solvent, dried, sieved through a 40-mesh sieve, uniformly ground, placed in an alumina crucible, and fired at 1300°C for 3 hours to synthesize the main phase ceramic. 2) Synthesis of sintering aid: Weigh out raw materials such as Li2CO3, Bi2O3, H3BO3, and MgO, with a mass fraction ratio of 2.5wt%Li2O+1wt%Bi2O3+2.5wt%B2O3+2wt%MgO to the main phase ceramic, add ethanol in a mass ratio of 1:1 between the mixed materials and anhydrous ethanol, mix for 16h by wet method, and dry at 80℃. Sieve the dried mixed material through a 40 mesh sieve, put it into an alumina crucible, sinter at 700℃ for 3h, and grind it to use as sintering aid. 3) Main phase: Ca 1.02 SiO3 ceramic was mixed with 5.0wt% fused quartz and sintering aid synthesized in the previous process, respectively, based on the mass fraction of the main phase ceramic, and mixed in a ball mill using ZrO2 balls as milling medium and ethanol as solvent for 16h, dried, pulverized and granulated with 8wt% polyvinyl alcohol binder, sieved, and then produced at a pressure of 100MPa with a diameter of 20mm and a thickness of 10mm. It was fired for 3h in an air atmosphere at 850℃ to obtain a low-temperature co-fired ceramic material, and its dielectric properties were evaluated.

[0017] Example 4 1) Synthesis of the main phase: The raw materials CaCO3 and quartz were weighed out in the ratio of the chemical formula CaSiO3, mixed in a ball mill for 24 hours using deethanol as a solvent, dried, sieved through a 40-mesh sieve, uniformly ground, placed in an alumina crucible, and fired at 1200℃ for 3 hours to synthesize the main phase ceramic. 2) Synthesis of sintering aid: Weigh out raw materials such as Li2CO3, Bi2O3, H3BO3, La2O3, and CuO with a mass fraction ratio of 4wt%Li2O+1.5wt%Bi2O3+4wt%B2O3+1wt%La2O3+2wt%CuO to the main phase ceramic, add ethanol in a mass ratio of 1:1 to the mixed materials and anhydrous ethanol, mix for 16h by wet method, and dry at 80℃. Sieve the dried mixed material through a 40 mesh sieve, put it into an alumina crucible, sinter at 600℃ for 3h, and grind it to use as sintering aid. 3) The main phase CaSiO3 ceramic was mixed with 2.0wt% fused quartz and sintering aids synthesized in the previous process, respectively, based on the mass fraction of the main phase ceramic. ZrO2 balls were used as milling media and ethanol was used as a solvent. The mixture was mixed in a ball mill for 16h and dried. A polyvinyl alcohol binder with a content of 8wt% was added, pulverized, granulated, and sieved to produce a body with a diameter of 20mm and a thickness of 10mm at a pressure of 100MPa. The material was fired for 3h in an air atmosphere at 880℃ to obtain a low-temperature co-fired ceramic material, and its dielectric properties were evaluated. Figure 2 shows a scanning electron microscope image of the cross section of the ceramic sample, which shows that the low-temperature co-fired ceramic has good density.

[0018] Example 5 1) Synthesis of the main phase: Chemical formula Ca 0.95 The raw materials CaCO3 and fused quartz were weighed out in the ratio of SiO3, mixed in a ball mill for 24 hours using deethanol as a solvent, dried, sieved through a 40-mesh sieve, uniformly ground, placed in an alumina crucible, and fired at 1100°C for 3 hours to synthesize the main phase ceramic. 2) Synthesis of sintering aid: Weigh out raw materials such as Li2CO3, Bi2O3, H3BO3, CoO, and CuO with a mass fraction ratio of 3.75wt%Li2O+2.5wt%Bi2O3+3.75wt%B2O3+1wt%CoO+2wt%CuO to the main phase ceramic, add ethanol in a mass ratio of 1:1 to the mixed material and anhydrous ethanol, mix for 16h by wet method, and dry at 80℃. Sieve the dried mixed material through a 40 mesh sieve, put it into an alumina crucible, sinter at 650℃ for 3h, and grind it to use as sintering aid. 3) Main phase: Ca 0.95The SiO3 ceramic was mixed with 10.0 wt% fused quartz and the sintering aid synthesized in the previous process, respectively, based on the mass fraction of the main phase ceramic, and mixed in a ball mill using ZrO2 balls as the milling medium and ethanol as the solvent for 16 hours, dried, and then crushed and granulated with 8 wt% polyvinyl alcohol binder. After sieving, a body with a diameter of 20 mm and a thickness of 10 mm was produced at a pressure of 100 MPa. It was fired for 3 hours in an air atmosphere at 850°C to obtain a low-temperature co-fired ceramic material, and its dielectric properties were evaluated.

[0019] Example 6 The main phase Ca synthesized in Example 5 0.95 SiO3 ceramic was mixed with quartz with a mass fraction of 10.0 wt% of the main phase ceramic and the sintering aid synthesized in Example 5, and mixed in a ball mill using ZrO2 balls as milling media and ethanol as a solvent for 16 hours, dried, and then crushed and granulated with 8 wt% polyvinyl alcohol binder. After sieving, a body with a diameter of 20 mm and a thickness of 10 mm was produced under a pressure of 100 MPa. It was fired in an air atmosphere at 880°C for 3 hours to obtain a low-temperature co-fired ceramic material, and its dielectric properties were evaluated.

[0020] Example 7 The main phase CaSiO3 ceramic synthesized in Example 2 was mixed with fused quartz with a mass fraction of the main phase ceramic of 7.0 wt% and the sintering aid synthesized in Example 2, mixed in a ball mill using ZrO2 balls as milling media and ethanol as a solvent for 16 hours, dried, and pulverized with 8 wt% polyvinyl alcohol binder, sieved, and then manufactured into a body with a diameter of 20 mm and a thickness of 10 mm at a pressure of 100 MPa. It was fired in an air atmosphere at 850 °C for 3 hours to obtain a low-temperature co-fired ceramic material, and its dielectric properties were evaluated.

[0021] Comparative Example 1 The main phase CaSiO3 ceramic synthesized in Example 2 was mixed with the sintering aid synthesized in Example 2, mixed in a ball mill with ZrO2 balls as milling medium and ethanol as solvent for 16 hours, dried, and then crushed and granulated with 8% by weight of polyvinyl alcohol binder. After sieving, a body with a diameter of 20 mm and a thickness of 10 mm was manufactured under a pressure of 100 MPa. It was fired in an air atmosphere at 930°C for 3 hours to obtain a low-temperature co-fired ceramic material, and its dielectric properties were evaluated.

[0022] Table 1 shows the evaluation results of the dielectric properties of the materials corresponding to the comparative example and examples 1 to 7. The dielectric properties were measured using an Agilent 8719ET network analyzer to measure the dielectric constant ε r The values ​​of Q×f and frequency temperature coefficient τ f =(f110-f25) / (f25x85), where f110 and f25 are the resonant center frequencies of the sample at 110°C and 25°C, respectively. [Table 1] The low-temperature co-fired ceramic materials listed in the above table have a dielectric constant less than 7.5, a Q×f value greater than 20,000 GHz, and an absolute value of the frequency temperature coefficient less than 35 ppm / ℃. They meet the requirements of low dielectric constant, low loss, and low frequency temperature coefficient required for millimeter-wave devices. Compared with the comparative example, the introduction of fused quartz can reduce the sintering temperature, increase the Q×f value of the material, and improve the frequency temperature coefficient.

[0023] It should be noted that in describing the present invention, terms such as "comprises," "including," and the like are intended to cover a non-exclusive inclusion, further including certain other processes, methods, materials, etc. not expressly described. An "embodiment" or a "specific embodiment," etc., means that the specific feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention.

[0024] Therefore, although the invention has been described above using specific examples, it should be understood that the above examples are used to understand the method and core matters of the invention and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above examples within the scope of the present invention without departing from the principles and gist of the present invention. Any simple modification, equivalent change, and modification made to the above examples in accordance with the technical essence of the present invention shall be regarded as falling within the protection scope of the present invention.

[0025] (Appendix) (Appendix 1) A low dielectric constant wollastonite-based low-temperature co-fired ceramic material, and the formulation of this low-temperature co-fired ceramic material is Ca x SiO3 + awt% SiO2 + bwt% R2O + cwt% Bi2O3 + dwt% B2O3 + ewt% MO (where 0.9 ≦ x ≦ 1.1, 0 < a ≦ 30, 1 ≦ b ≦ 5, 0 < c ≦ 3, 0 < d ≦ 6, 0 ≦ e ≦ 10, and a, b, c, d, and e are respectively the mass fractions of SiO2, RO, Bi2O3, B2O3, and MO phases with respect to Ca x SiO3, R2O is at least one of Li2O and K2O, MO is one or more of ZnO, MgO, BaO, CoO, CuO, La2O3, and MnO2, SiO2 is at least one of quartz and fused quartz). A low dielectric constant wollastonite-based low-temperature co-fired ceramic material, characterized in that.

[0026] (Appendix 2) The composition of the main phase ceramic material is Ca x SiO3 (where 0.9 ≦ x ≦ 1.0). The low dielectric constant wollastonite-based low-temperature co-fired ceramic material according to Appendix 1, characterized in that.

[0027] (Appendix 3) The SiO2 is fused quartz. The low dielectric constant wollastonite-based low-temperature co-fired ceramic material according to Addendum 1, characterized in that...

[0028] (Addendum 4) A method for manufacturing the low dielectric constant wollastonite-based low-temperature co-fired ceramic material according to Addendum 1, comprising: 1) Synthesis of the main phase ceramic Ca x SiO3: Weigh the raw materials CaCO3 and SiO2 according to the stoichiometric ratio of the chemical formula Ca x SiO3, use dehydrated ethanol as the solvent, mix them in a ball mill for 16 - 24 h and dry, then sieve through a 40-mesh sieve, uniformly pulverize, put them into an alumina crucible, and calcine at 900 °C - 1300 °C for 2 - 4 h to synthesize the main phase ceramic, and pulverize it for use as a ceramic substrate; 2) Synthesis of the sintering aid: bwt%RO + cwt%Bi2O3 + dwt%B2O3 + ewt%MO (where 1 ≤ b ≤ 5, 0 < c ≤ 3, 0 < d ≤ 6, 0 ≤ e ≤ 10, and b, c, d, and e are the mass fraction ratios of RO, Bi2O3, B2O3, and MO phases to Ca x SiO3 respectively), weigh the raw materials of Li2CO3, K2CO3, Bi2O3, B2O3 or H3BO3, ZnO, MgO or Mg(OH)2, BaCO3, CoO or Co2O3, CuO, La2O3, MnO2 / MnCO3 according to the mass fraction ratio, add ethanol at a mass ratio of the mixed material to anhydrous ethanol of 1:1 - 1:1.5, mix in a wet method for 16 - 24 h and dry at 80 °C, sieve the dried mixed material through a 40-mesh sieve, put it into an alumina crucible, calcine at 500 - 700 °C for 2 - 4 h, and pulverize it for use as a sintering aid; 3) The manufactured main phase Ca x SiO3 ceramic, SiO2 and the oxide sintering aid are mixed according to Ca x SiO3 + awt%SiO2 + bwt%RO + cwt%Bi2O3 + dwt%B2O3 + ewt%MO (where a, b, c, d, and e are the mass fraction ratios of Ca xthe mixture is mixed in a mixing ratio of 0.01 to 0.25 (the mass fraction of SiO2, RO, Bi2O3, B2O3 and MO phases relative to SiO3), mixed in a ball mill using ZrO2 balls as milling media and ethanol as a solvent for 16 to 24 hours, dried, pulverized and granulated with a polyvinyl alcohol binder content of 5% by weight to 8% by weight, sieved, and then press-molded into a body having a diameter of 20 mm and a thickness of 10 mm under a pressure of 80 to 120 MPa, and fired in an air atmosphere at 850°C to 950°C for 1 to 3 hours to obtain the low dielectric constant wollastonite-based low temperature co-fired ceramic material; A method for producing a low dielectric constant wollastonite-based low temperature co-fired ceramic material, comprising:

Claims

1. A low dielectric constant wollastonite-based low temperature co-fired ceramic material, the composition of which is: Ca ｘ SiO ３ + a wt% SiO ２ + bwt%R ２ O+cwt%Bi ２ O ３ + dwt% B ２ O ３ + e wt % MO, where 0.9≦x≦1.1; 0<a≦30, 1≦b≦5, 0<c≦3, 0<d≦6, 0≦e≦10, and a, b, c, d, and e are Ca ｘ SiO ３ SiO ２ , R.O., Bi. ２ O ３ , B ２ O ３ and the mass fraction of the MO phase, R ２ O is Li ２ O.K. ２ O, MO is ZnO, MgO, BaO, CoO, CuO, La ２ O ３ , MnO ２ and SiO ２ is at least one of quartz and fused silica; A wollastonite-based low-temperature co-fired ceramic material with a low dielectric constant.

2. The composition of the main phase ceramic material is Ca ｘ SiO ３ (Wherein, 0.9≦x≦1.0) 2. The low dielectric constant wollastonite-based low temperature co-fired ceramic material according to claim 1.

3. The SiO ２ is fused silica, 2. The low dielectric constant wollastonite-based low temperature co-fired ceramic material according to claim 1.

4. A method for producing the low dielectric constant wollastonite-based low temperature co-fired ceramic material according to claim 1, comprising the steps of: 1) Main phase ceramic Ca ｘ SiO ３ Synthesis of: ｘ SiO ３ The raw material CaCO ３ and SiO ２ weighing out the mixture, mixing and drying the mixture in a ball mill with deethanolic solvent for 16 to 24 hours, sieving the mixture through a 40 mesh sieve, uniformly grinding the mixture, placing the mixture in an alumina crucible, and firing the mixture at 900°C to 1300°C for 2 to 4 hours to synthesize a main phase ceramic, which is then ground and used as a ceramic substrate; 2) Synthesis of sintering aid: bwt% RO + cwt% Bi ２ O ３ + dwt% B ２ O ３ + e wt% MO (wherein 1≦b≦5, 0<c≦3, 0<d≦6, 0≦e≦10, b, c, d and e are Ca ｘ SiO ３ RO, Bi ２ O ３ , B ２ O ３ and the mass fraction of the MO phase), ２ CO ３ , K ２ CO ３ , Bi ２ O ３ , B ２ O ３ Or H ３ B.O. ３ , ZnO, MgO or Mg(OH) ２ , BaCO ３ , CoO or Co ２ O ３ , CuO, La ２ O ３ , MnO ２ / MnCO ３Weigh the raw materials, add ethanol in a mass ratio of 1:1 to 1:1.5 between the mixed material and anhydrous ethanol, mix for 16 to 24 hours by wet method, and dry at 80°C. Sieve the dried mixed material through a 40 mesh sieve, put it into an alumina crucible, sinter at 500 to 700°C for 2 to 4 hours, and crush it to use as a sintering aid; 3) Produced main phase Ca ｘ SiO ３ Ceramic, SiO ２ and the oxide sintering aid is Ca ｘ SiO ３ + a wt% SiO ２ +bwt%RO+cwt%Bi ２ O ３ + dwt% B ２ O ３ + e wt% MO (wherein a, b, c, d and e are Ca ｘ SiO ３ SiO ２ , R.O., Bi. ２ O ３ , B ２ O ３ and the mass fraction of the MO phase), and ２ Using balls as milling media and ethanol as a solvent, the mixture is mixed in a ball mill for 16 to 24 hours, dried, and then a polyvinyl alcohol binder having a content of 5% by weight to 8% by weight is added to the mixture, followed by pulverization and granulation. After sieving, the mixture is press-molded under a pressure of 80 to 120 MPa into a body having a diameter of 20 mm and a thickness of 10 mm, and then fired in an air atmosphere at 850°C to 950°C for 1 to 3 hours to obtain the low dielectric constant wollastonite-based low temperature co-fired ceramic material; A method for producing a low dielectric constant wollastonite-based low temperature co-fired ceramic material, comprising:

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