Composite co-fired material and preparation method thereof

Abstract

The invention relates to the field of co-fired materials, in particular to a composite co-fired material and a preparation method thereof. The composite co-fired material comprises a co-fired ceramic material layer, a middle layer and a co-fired ferrite material layer, one end of the middle layer is connected with the co-fired ceramic material layer, the other end of the middle layer is connected with the co-fired ferrite material layer, and the middle layer is of a laminated structure formed by at least two metal oxides. The laminated structure comprises at least three groups of middle barrier layers and connecting layers, and the connecting layers are arranged on the two surfaces of the middle barrier layers so as to connect the middle layers with the co-fired ferrite material layer or the co-fired ceramic material layer. According to the composite co-fired material, through the multi-layer middle layer structure, a path is physically prolonged, multiple material / interface barriers are arranged, high-barrier materials, potential chemical reaction capture, defect channel reduction and other synergistic action mechanisms are utilized, and the blocking capacity on various diffusion ions is greatly improved.

Description

Technical Field

[0001] The present application relates to the field of co-fired materials, and in particular to a composite co-fired material and a preparation method thereof. Background Art

[0002] The multilayer chip structure produced by low-temperature co-fired ceramic (LTCC) technology can effectively reduce device size. It is an important way to promote the miniaturization, integration, high reliability and low cost of components and has become one of the core technologies of the new generation of electronic information manufacturing industry. Low-temperature co-fired ferrite (LTCF) material technology is basically the same as the LTCC process, except that the LTCC material used in this process is ferrite. Based on the magnetic properties of ferrite, it can realize the integrated design of components such as inductors and transformers. However, with the increasing integration requirements of electronic systems, devices designed using only LTCC or LTCF materials have become difficult to meet the extreme demands of miniaturization and broadband. For example, using a single dielectric ceramic LTCC material, although small and high-performance embedded capacitors can be produced, embedded capacitors require a large number of turns to achieve the required inductance. Therefore, it is necessary to print wires on the multi-layer dielectric and connect these wires into multiple turns through through-holes. However, this increases the volume of the embedded capacitor module, and the use of a large number of through-holes increases the complexity of the preparation process. If a single ferromagnetic LTCF ceramic is used, although the volume of the inductor can be reduced, in order to increase the capacitance of the capacitor, the plate area needs to be increased, which is also not conducive to the miniaturization of the module.

[0003] Therefore, in order to optimize the design of circuit devices, both LTCC and LTCF materials can be used. For example, LTCF materials with higher magnetic permeability can be used to prepare the inductor and transformer parts, while dielectric ceramics with higher dielectric constant can be used to prepare the capacitor parts. The composite plates made of LTCC and LTCF materials are conducive to achieving the development needs of miniaturization, lightweighting, and high integration of capacitors. However, due to the large differences in the crystal structures of LTCC and LTCF materials, the compatibility of the two materials at the heterogeneous interface is poor. When connecting them through co-firing, there are difficulties such as difficulty in matching thermal expansion coefficients, difficulty in controlling sintering shrinkage, and uncontrollable interface reactions and interface diffusion. Once the thermal expansion coefficients and sintering shrinkage of LTCC and LTCF materials are mismatched, large internal stresses will be generated in the co-fired body, which can easily cause defects such as delamination, warping, and cracking in the co-fired body. These defects will cause mechanical performance problems such as deformation, cracking, and strength reduction in the composite plates made of LTCC and LTCF materials. Research on co-firing mismatch phenomena, such as shrinkage, stress defects, and delamination between different layers during co-firing, has investigated the interfacial interactions and co-firing behavior of Bi2O3-ZnO-Nb2O5 (BZN) dielectric ceramics and NiZnCu ferrite multilayers. Results indicate that interfacial element diffusion during co-firing leads to significant changes in the phase and microstructure of the materials near the interface. Furthermore, the kinetic mismatch between the two materials can cause defects such as cracks in the co-fired composite. While the complex interface formed by diffusion after co-firing is crucial for improving the mechanical and electromagnetic properties of the material, and proper diffusion can form new phases in the transition zone and covalent bonds at the interface, facilitating close co-firing of the ceramic and ferrite in the circulator composite substrate, excessive diffusion or excessive extension of the diffusion zone can introduce non-magnetic or fast-relaxing ions into the A- and B-site ferrites. These ions can affect the resistivity, saturation magnetization, and temperature stability of the magnetic ferrite.

[0004] Furthermore, for co-fired composites of LTCC and LTCF, proper diffusion of these materials is required during the low-temperature co-firing process. This ensures a certain degree of mutual wetting between the ceramic and high-frequency ferrite heterogeneous materials to ensure sufficient bonding strength. At the same time, the dielectric and magnetic properties of the materials must be minimized from the effects of diffused ions. However, the intermediate layer between the co-fired composites of LTCC and LTCF currently provides little protection against the effects of diffused ions. Summary of the Invention

[0005] The present application provides a composite co-fired material and a preparation method thereof to solve the following technical problem: how to improve the barrier capability of the intermediate layer between the co-fired materials to diffuse ions.

[0006] In the first aspect, an embodiment of the present application provides a composite co-fired material, which includes a co-fired ceramic material layer, an intermediate layer and a co-fired ferrite material layer, one end of the intermediate layer is connected to the co-fired ceramic material layer, and the other end of the intermediate layer is connected to the co-fired ferrite material layer, the intermediate layer is a laminated structure formed by at least two metal oxides, and the laminated structure includes at least three groups of intermediate barrier layers and connecting layers, and the connecting layers are arranged on both sides of the intermediate barrier layer to connect the intermediate layer with the co-fired ferrite material layer or the co-fired ceramic material layer.

[0007] Optionally, the metal oxide includes any one of the following: MgO2, Al2O3, TiO2, Y2O3, B2O3, ZnO, SiO2 and ZrO2.

[0008] Optionally, the metal oxide includes: SiO2 and ZrO2; wherein the metal oxide of the intermediate barrier layer is ZrO2, and the metal oxide of the connecting layer is SiO2.

[0009] Optionally, the thickness of the intermediate layer is 10 nm to 100 nm; and / or The thickness of the intermediate barrier layer is 5 nm to 10 nm; and / or The thickness of the connecting layer is 5 nm to 10 nm.

[0010] Optionally, the number of groups of the intermediate barrier layer and the connecting layer is 3 to 4 respectively.

[0011] In a second aspect, an embodiment of the present application provides a method for preparing the composite co-fired material according to the first aspect, the method comprising: preparing a co-fired ceramic material layer and a co-fired ferrite material layer respectively; Using a precursor of a first metal oxide to perform a first extrusion atomization on the surfaces of the co-fired ceramic material layer and the co-fired ferrite material layer, respectively, to obtain a crude ceramic material product containing a crude connecting layer and a crude ferrite material product; Drying the crude ceramic material containing the crude connecting layer and the crude ferrite material to form a film to obtain a ceramic material matrix containing the connecting layer and a ferrite material matrix; Using a precursor of a second metal oxide to perform a second extrusion atomization on the surface of the ceramic material substrate or the ferrite material substrate containing the connecting layer to obtain a ceramic material or the ferrite material containing an intermediate barrier layer and a connecting layer; Pressing the ceramic material containing the intermediate barrier layer and the connecting layer with the ferrite material to obtain a heterogeneous composite green body; The heterogeneous composite green body is sintered to obtain a composite co-fired material.

[0012] Optionally, the first extrusion atomization and the second extrusion atomization flow rates are 0.4 cm 3 / s to 0.6cm 3 / s, and the time of the first extrusion atomization and the second extrusion atomization is 0.5s to 1.2s respectively.

[0013] Optionally, the drying film forming temperature is 105° C. to 115° C., and the drying film forming duration is 25 min to 35 min; and / or The pressing pressure is 300 MPa to 600 MPa, and the holding time of the pressing is 1.5 min to 2.5 min; and / or The sintering temperature is 900° C. to 950° C., and the sintering time is 2.5 hours to 3.5 hours.

[0014] Optionally, the preparation step of the precursor of the first metal oxide is: dissolving trimethoxymethylsilane, ethyl orthosilicate and oxalic acid solution in organic solvents respectively and mixing them to obtain a reaction mixture; hydrolyzing the reaction mixture to obtain a hydrolyzate; condensing the ammonium hydroxide solution and the hydrolyzate to obtain a precursor of the first metal oxide; and / or The preparation steps of the precursor of the second metal oxide are: mixing zirconium oxynitrate, ultrapure water and anhydrous ethanol to obtain a reaction solution; The citric acid, ethylene glycol and the reaction solution are subjected to a synthesis reaction to obtain a precursor of the second metal oxide.

[0015] In a third aspect, an embodiment of the present application provides a circuit device, which includes the composite co-fired material described in the first aspect.

[0016] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art: The present invention provides a composite co-fired material comprising at least three sets of intermediate barrier layers and connecting layers, with the connecting layers disposed on both sides of the intermediate barrier layer, to form a sandwich-like laminate structure with excellent barrier properties. This laminate structure encourages the repeated passage of diffusing ions within the different material layers, extending the diffusion path length of the diffusing ions. Furthermore, the laminate structure has a high energy barrier, which can reduce the diffusion efficiency of the diffusing ions. Furthermore, the intermediate barrier layer can be made of a metal oxide with an extremely low diffusion coefficient and high chemical stability, which enables the intermediate barrier layer to act as a high-energy barrier, effectively blocking the migration of diffusing ions. Furthermore, the various internal interfaces between the connecting layer and the intermediate barrier layer can form a natural energy barrier, significantly hindering the long-range migration of ions. Furthermore, the connecting layer of the laminate structure can match the thermal expansion coefficient of the co-fired ceramic material layer and the co-fired ferrite material layer and promote the sintering bonding of the intermediate barrier layer and the two material layers, thereby reducing the thermal stress on the laminate structure and avoiding the formation of defects such as micropores and microcracks. This can reduce the number of diffusion channels for the diffusing ions, forcing the diffusing ions to migrate only through bulk diffusion or grain boundary diffusion. In addition, the stacked structure uses different metal oxides between the intermediate barrier layer and the two material layers to form a discontinuous grain boundary interface, thereby interrupting the diffusion path of the diffused ions and reducing the diffusion efficiency of the diffused ions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0019] Figure 1 A schematic diagram of the structure of a composite co-fired material provided in an embodiment of the present application; Figure 2 A schematic flow chart of a method for preparing the composite co-fired material provided in an embodiment of the present application; Figure 3 A detailed flow chart of a method for preparing the composite co-fired material provided in an embodiment of the present application; Figure 4 A schematic diagram of a practical process of a method for preparing the composite co-fired material provided in an embodiment of the present application; Figure 5This is the SEM image of the bonding interface of the composite co-fired materials of Example 1, Example 2, Comparative Example 1, Comparative Example 2 and Comparative Example 3 of the present application; wherein, Figure 5 a is the SEM image of the bonding interface of the composite co-fired material of Comparative Example 1, Figure 5 b is the SEM image of the bonding interface of the composite co-fired material of Comparative Example 2, Figure 5 c is the SEM image of the bonding interface of the composite co-fired material of comparative example 3, Figure 5 d is the SEM image of the bonding interface of the composite co-fired material of Example 1, Figure 5 e is the SEM image of the bonding interface of the composite co-fired material of Example 2, Figure 5 f is a SEM image of the bonding interface of the composite co-fired material of Comparative Example 4; Figure 6 ion diffusion distribution curves of the composite co-fired materials of Example 1, Example 2, Comparative Example 1, Comparative Example 2 and Comparative Example 3 of the present application; wherein, Figure 6 a is the SEM image of the bonding interface of the composite co-fired material of Comparative Example 2, Figure 6 b is the SEM image of the bonding interface of the composite co-fired material of Comparative Example 3, Figure 6 c is the SEM image of the bonding interface of the composite co-fired material of Example 1, Figure 6 d is the SEM image of the bonding interface of the composite co-fired material of Example 2, Figure 5 e is a SEM image of the bonding interface of the composite co-fired material of Comparative Example 4; Figure 5 f is the SEM image of the bonding interface of the composite co-fired material of Comparative Example 1. DETAILED DESCRIPTION

[0020] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0021] Range descriptions used in this application, such as numerical ranges and ratio ranges, include all possible subranges and single numerical values ​​within that range. For example, the range description "1 to 6" or "1~6" encompasses all subranges between 1 and 6 (e.g., 1 to 3, 2 to 5, etc.) and single numbers (e.g., 1, 2, 3, 4, 5, 6). Unless otherwise specified, the terms "comprising" and "including" as used herein mean "including but not limited to," "first" and "second" are used solely to distinguish between different entities or operations and do not imply a specific order or relationship. "and / or" indicates that multiple instances can exist individually or simultaneously. Expressions such as "at least one," "a plurality," and "at least one" refer to any combination of the corresponding objects, including single or multiple objects. Proportional relationships mentioned herein, such as mass ratios and molar ratios, should be understood as the corresponding relationship between the first and second terms of the ratio formula in the order described. The raw materials, reagents, instruments, and equipment used herein can all be purchased commercially or prepared by existing methods.

[0022] It should be noted that the current preparation methods of the intermediate layer include: (1) Spin coating method: The buffer layer material is dissolved in an appropriate solvent to form a uniform buffer layer solution. The substrate of LTCC material or LTCF material is placed on a spin coating turntable, and then the buffer layer solution is dropped on the center of the substrate and the substrate is rotated at high speed. Under the action of centrifugal force, the buffer layer solution is evenly spread on the surface of the substrate. After the solvent evaporates, the buffer layer solution forms a buffer layer. The spin coating method can accurately adjust the thickness of the buffer layer by controlling parameters such as the rotation speed and solution concentration to prepare a buffer layer with uniform thickness and high surface flatness. However, the material utilization rate of the spin coating method is low, and most of the solution will be thrown to the edge of the equipment during the rotation process, resulting in waste. Moreover, for large-area substrate products, the spin coating method will cause a certain difference in thickness between the edge and center of the large-area substrate product, so it is necessary to optimize the process parameters to improve this difference phenomenon.

[0023] (2) Physical vapor deposition: Evaporation deposition is to heat the buffer layer material to an evaporating state, and the evaporated atoms or molecules condense on the surface of the LTCC material or LTCF material substrate to form a buffer layer; while sputtering deposition is to use high-energy particles to bombard the buffer layer target material, so that the target material atoms are sputtered out and deposited on the substrate surface. These deposition methods can produce high-purity buffer layers and improve the adhesion between the buffer layer and the substrate. Among the deposition methods, sputtering deposition can also control the quality and performance of the buffer layer by adjusting the sputtering parameters. However, the equipment used in physical vapor deposition is relatively expensive and the deposition rate is relatively slow. For evaporation deposition, the evaporation temperature and evaporation rate of the material need to be precisely controlled, otherwise the film quality may be poor.

[0024] (3) Chemical solution deposition method: Using a chemical solution containing buffer layer metal ions (such as calcium, titanium and other metal ions), the metal ions are precipitated on the surface of the LTCC material or LTCF material substrate through chemical reactions in the solution to form a buffer layer. For example, by reacting a metal salt solution with an appropriate precipitant, a precipitate of the target buffer layer material is generated. This process can control the composition and structure of the buffer layer at the molecular level and can produce a high-quality, uniform buffer layer. However, the process of chemical solution deposition is relatively complex and requires precise control of reaction conditions, such as solution concentration, temperature, pH value, etc. In addition, the post-reaction post-processing process (such as washing, drying, etc.) is also relatively cumbersome and may introduce impurities.

[0025] In summary, most existing methods for preparing the intermediate buffer layer are unable to easily and accurately obtain an intermediate buffer layer with uniform thickness. The uneven thickness of the intermediate layer will directly affect its barrier effect on diffusing ions.

[0026] Figure 1 The following is a schematic diagram of the structure of a composite co-fired material provided in an embodiment of the present application; like Figure 1 As shown, an embodiment of the present application provides a composite co-fired material, which includes a co-fired ceramic material layer, an intermediate layer and a co-fired ferrite material layer, one end of the intermediate layer is connected to the co-fired ceramic material layer, and the other end of the intermediate layer is connected to the co-fired ferrite material layer, the intermediate layer is a laminated structure formed by at least two metal oxides, and the laminated structure includes at least three groups of intermediate barrier layers and connecting layers, and the connecting layers are arranged on both sides of the intermediate barrier layer to connect the intermediate layer with the co-fired ferrite material layer or the co-fired ceramic material layer.

[0027] It should be noted that there are differences between the metal oxide of the intermediate barrier layer and the metal oxide of the connecting layer. Generally speaking, the capacity barrier of the intermediate barrier layer is significantly higher than that of the connecting layer, while the mechanical properties of the connecting layer are higher than those of the intermediate barrier layer.

[0028] It should be noted that the embodiments of the present application provide a composite co-fired material whose intermediate layer significantly improves its ability to block diffused ions through its unique multi-layer heterogeneous structure design and material selection. Its core mechanism is as follows: 1. Extending the diffusion path and increasing the difficulty of diffusion (tortuous path effect): In a single-layer barrier, ion diffusion only needs to overcome one material barrier, and the path is relatively direct. However, a multi-layer "sandwich" structure (at least three sets of intermediate barrier layers / connecting layers) forces the diffusing ions to repeatedly travel between different material layers. The ions need to pass through: Tie layer 1 → tie layer 2 → tie layer 3 → barrier layer 1 → barrier layer 2 → barrier layer 3 → tie layer 4 → tie layer 5 → tie layer 6.

[0029] Each time a diffusing ion crosses an interface between different materials, it faces an energy barrier (due to differences in lattice structure and chemical bonding), requiring it to overcome additional activation energy. This significantly extends the effective diffusion path length of the diffusing ion and significantly increases the total energy barrier that the diffusing ion must overcome, significantly slowing down its diffusion rate.

[0030] 2. Exploiting the inherent diffusion barrier properties of different materials (material selectivity): (1) Intermediate barrier layers: These layers are the core of the function of blocking diffused ions. Intermediate barrier layers are designed or selected to be resistant to target diffused ions (e.g. Zn in ferrite). 2+ , Fe 3+ or alkali metal ions in ceramics, etc.) are metal oxides with extremely low diffusion coefficients and high chemical stability.

[0031] These blocking layers themselves act as high energy barriers and can effectively block the migration of ions.

[0032] (2) Interface as a diffusion barrier (interface energy barrier): There is an interface between every two adjacent layers (connecting layer-barrier layer, barrier layer-connecting layer).

[0033] The lattice mismatch and chemical bonding state changes at the interface of different materials will form a natural energy barrier. The migration of diffusing ions from one lattice structure to another different lattice structure needs to overcome this interfacial energy barrier.

[0034] The multilayer structure creates a large number of internal interfaces, and these continuous interfaces constitute multiple energy barriers, greatly hindering the long-range migration of ions.

[0035] (3) Absorption / reaction / capture of potential diffusing ions (chemical blocking): Specific connecting layer or barrier layer materials may react preferentially with the expected diffusing ions to form stable, non-mobile compounds, thereby "capturing" and fixing these diffusing ions and preventing them from continuing to diffuse deeper.

[0036] Certain layers can act as sacrificial layers, reacting preferentially with impurities to protect core functional layers (such as intermediate barrier layers) from being damaged by diffusants.

[0037] 3. Relieve thermal stress and reduce defect channels (physical integrity): The tie layer can match the coefficient of thermal expansion (CTE) and promote sintering bonding.

[0038] By selecting the right tie layer material, the CTE difference between the middle layer and the co-fired ceramic / ferrite layers on either side can be reduced. This helps reduce thermal stress during high-temperature co-firing and cooling, thereby minimizing the formation of defects such as microcracks and voids.

[0039] These defects are the "highways" for rapid ion diffusion. Reducing defects means blocking low-resistance diffusion channels, forcing diffusing ions to migrate only through more difficult bulk diffusion or grain boundary diffusion, and multilayer structures have a more significant blocking effect on these paths.

[0040] 4. Destruction of the continuous grain boundary network (grain boundary engineering): In polycrystalline materials, grain boundaries are usually the main fast pathways for ion diffusion.

[0041] In multilayer structures, the grain boundaries of different materials are discontinuous. Even if the grain boundaries within a layer allow for rapid diffusion, the diffusion path is interrupted when the diffusing ions reach the interface between that layer and the next. The ions must then re-enter the crystal lattice or grain boundary of the next layer, a process that requires additional energy.

[0042] The interfacial phase or amorphous phase formed between different material layers may also play a role in blocking the grain boundary channels and hinder the diffusion of diffusing ions.

[0043] In summary, the present invention provides a composite co-fired material that, through a multi-layer interlayer structure, significantly improves its barrier capability against diffusing ions through synergistic mechanisms such as physically extending the path length, establishing multiple material / interface barriers, utilizing high-barrier materials, capturing potential chemical reactions, and reducing defect channels. Rather than relying on the perfection of a single material, this material utilizes a carefully designed, coordinated mechanism to make the diffusion process extremely lengthy and difficult, effectively isolating the co-fired ceramic layer and the co-fired ferrite layer from harmful interdiffusion, ensuring their respective functionality and the overall performance and reliability of the device.

[0044] In some optional embodiments, the metal oxide includes any one of the following: MgO2, Al2O3, TiO2, Y2O3, B2O3, ZnO, SiO2 and ZrO2.

[0045] In these embodiments, the metal oxides used, such as MgO2, Al2O3, TiO2, Y2O3, B2O3, ZnO, SiO2 and ZrO2, can cover most of the metal oxide types of the intermediate layer, so that a continuous interface energy barrier can be formed between the intermediate barrier layer and the connecting layer to hinder the movement of diffused ions; at the same time, a discontinuous grain boundary network can also be formed between the intermediate barrier layer and the connecting layer to interrupt the diffusion channel of the diffused ions.

[0046] In some optional embodiments, the metal oxide includes: SiO2 and ZrO2; wherein the metal oxide of the intermediate barrier layer is ZrO2, and the metal oxide of the connecting layer is SiO2.

[0047] In these embodiments, ZrO2 is used as the metal oxide of the intermediate barrier layer, so that the intermediate barrier layer has a higher energy barrier and a diffusion channel distribution different from that of the connecting layer. The different energy barriers and discontinuous diffusion channel distribution between the intermediate barrier layer and the connecting layer can effectively block the diffusion of diffused ions and improve the blocking effect of the intermediate layer on diffused ions.

[0048] In some optional embodiments, the thickness of the intermediate layer is 10 nm to 100 nm; and / or The thickness of the intermediate barrier layer is 5 nm to 10 nm; and / or The thickness of the connecting layer is 5 nm to 10 nm.

[0049] In these embodiments, the intermediate layer having a thickness of 10 nm to 100 nm can provide the intermediate barrier layer and the connecting layer with sufficient thickness, thereby providing the intermediate layer with a sufficiently long diffusion path and a sufficiently high diffusion difficulty. Furthermore, the intermediate barrier layer having a thickness of 5 nm to 10 nm can have an extremely low diffusion coefficient and high chemical stability to effectively block the diffusion of diffusing ions, thereby improving the intermediate layer's barrier effect on diffusing ions. Furthermore, the connecting layer having a thickness of 5 nm to 10 nm can match the thermal expansion coefficients of the co-fired ceramic material layer and the co-fired ferrite material layer to minimize the formation of microcracks and pores, forcing the diffusing ions to migrate only through the more difficult bulk diffusion or grain boundary diffusion, thereby reducing the diffusion efficiency of the diffusing ions.

[0050] The thickness of the intermediate layer may be 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, or 100 nm.

[0051] The thickness of the intermediate barrier layer may be 5 nm, 6 nm, 7 nm, 8 nm, 9 nm or 10 nm.

[0052] The thickness of the connecting layer may be 5 nm, 6 nm, 7 nm, 8 nm, 9 nm or 10 nm.

[0053] In some optional embodiments, the number of groups of the intermediate barrier layer and the connecting layer is 3 to 4 respectively.

[0054] In these embodiments, groups of 3 to 4 intermediate barrier layers and connecting layers can form complex internal interfaces between the two. These internal interfaces constitute multiple energy barriers, greatly hindering the long-range migration of ions; in addition, discontinuous grain boundary distributions will be formed between these intermediate barrier layers and connecting layers, which can interrupt the diffusion path of the diffused ions and increase the diffusion difficulty of the diffused ions.

[0055] The number of groups of the intermediate barrier layer and the connecting layer may be 3 or 4, respectively.

[0056] Figure 2 A schematic flow chart of a method for preparing the composite co-fired material provided in an embodiment of the present application is shown as an example; Based on a general inventive concept, such as Figure 2 As shown, the embodiment of the present application provides a method for preparing the composite co-fired material, the method comprising: S1. Prepare a co-fired ceramic material layer and a co-fired ferrite material layer respectively; S2. A first metal oxide precursor is respectively extruded and atomized on the surface of the co-fired ceramic material layer and the co-fired ferrite material layer to obtain a crude ceramic material containing a crude connecting layer and a crude ferrite material; S3. The connecting layer containing the crude ceramic material and the crude ferrite material is dried to form a film to obtain a ceramic material matrix and a ferrite material matrix containing a connecting layer; S4. performing a second extrusion atomization on the surface of the ceramic material substrate or the ferrite material substrate containing the connecting layer using a precursor of a second metal oxide to obtain a ceramic material or the ferrite material containing an intermediate barrier layer and a connecting layer; S5. The ceramic material containing the intermediate barrier layer and the connecting layer is pressed with the ferrite material to obtain a heterogeneous composite green body; S6. Sintering the heterogeneous composite green body to obtain a composite co-fired material.

[0057] This method is a method for preparing the above-mentioned composite co-fired material. The specific composition of the composite co-fired material can refer to the above-mentioned embodiment. Since this method adopts part or all of the technical solutions of the above-mentioned embodiment, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiment, which will not be repeated here.

[0058] It should be noted that the first extrusion atomization and the second extrusion atomization both extrude the precursor of the first metal oxide or the precursor of the second metal oxide through a nozzle to form an atomized precursor liquid, so that the precursor of the first metal oxide or the precursor of the second metal oxide can be evenly and densely covered on the surface of the co-fired ceramic material layer green body or the co-fired ferrite material layer green body to form a uniform and dense connecting layer and intermediate barrier layer.

[0059] It should be noted that the preparation process of the co-fired ceramic material layer green body is as follows: Commercial LTCC dielectric material (Al2O3) is used as the raw material powder. A combination of dry pressing and co-pressing is used. 0.15g of LTCC powder is weighed and held at 2.5 tons for 45 seconds to produce an Al2O3 green body with a diameter of 10mm and a thickness of approximately 1mm. Alternatively, tape can be produced using a tape casting process.

[0060] It should be noted that the preparation process of the co-fired ferrite material layer green body is as follows: Using NiCuZn ferrite as the raw material powder, 0.3g of NiCuZn ferrite oxide powder was weighed and mixed according to the stoichiometric ratio. The mixture was then pressed at 5 tons for 45 seconds to produce a NiCuZn ferrite green body with a diameter of 10mm and a thickness of approximately 1mm. Alternatively, a tape-casting process could be used to produce NiCuZn green ceramic tape.

[0061] In some optional embodiments, the flow rates of the first extrusion atomization and the second extrusion atomization are 0.4 cm 3 / s to 0.6cm 3 / s, and the time of the first extrusion atomization and the second extrusion atomization is 0.5s to 1.2s respectively.

[0062] In these embodiments, the flow rate is 0.4 cm 3 / s to 0.6cm 3 / s and the first extrusion atomization with a time of 0.5s to 1.2s and the second extrusion atomization can make the precursor of the first metal oxide and the precursor of the second metal oxide uniformly cover the surface of the co-fired ceramic material layer green body or the co-fired ferrite material layer green body to form a uniform and dense connecting layer and intermediate barrier layer.

[0063] The first extrusion atomization and the second extrusion atomization flow rates can be 0.40 cm 3 / s, 0.45cm 3 / s, 0.50cm 3 / s、0.55cm 3 / s or 0.60cm 3 / s.

[0064] The time of the first extrusion atomization and the second extrusion atomization can be 0.5s, 0.6s, 0.7s, 0.8s, 0.9s, 1.0s, 1.1s or 1.2s respectively.

[0065] In some optional embodiments, the temperature of the drying film is 105° C. to 115° C., and the duration of the drying film is 25 min to 35 min; and / or The pressing pressure is 300 MPa to 600 MPa, and the holding time of the pressing is 1.5 min to 2.5 min; and / or The sintering temperature is 900° C. to 950° C., and the sintering time is 2.5 hours to 3.5 hours.

[0066] In these embodiments, the drying film forming at a temperature of 105°C to 115°C and a duration of 25 minutes to 35 minutes can dry and shape the precursor of the first metal oxide on the surface of the crude ceramic material and the crude ferrite material, and form a connecting layer with uniform thickness and density. In addition, the pressing at a pressure of 300MPa to 600MPa and a holding time of 1.5 minutes to 2.5 minutes can fully merge the intermediate barrier layer, the connecting layer, the co-fired ceramic material layer green body and the co-fired ferrite material layer green body to form an integrated composite co-fired material, which is convenient for subsequent sintering. In addition, the sintering at a temperature of 900°C to 940°C and a duration of 2.5 hours to 3.5 hours can smoothly shape the composite green body to form a composite co-fired material with a significant laminated structure.

[0067] The drying temperature for film formation may be 105°C, 106°C, 107°C, 108°C, 109°C, 110°C, 111°C, 112°C, 113°C, 114°C or 115°C.

[0068] The duration of the drying film formation may be 25 min, 26 min, 27 min, 28 min, 29 min, 30 min, 31 min, 32 min, 33 min, 34 min or 35 min.

[0069] The pressing pressure may be 300 MPa, 350 MPa, 400 MPa, 450 MPa, 500 MPa, 550 MPa or 600 MPa.

[0070] The holding time of the pressing can be 1.5 min, 1.6 min, 1.7 min, 1.8 min, 1.9 min, 2.0 min, 2.1 min, 2.2 min, 2.3 min, 2.4 min or 2.5 min.

[0071] The sintering temperature may be 900°C, 905°C, 910°C, 915°C, 920°C, 925°C, 930°C, 935°C, or 940°C.

[0072] The sintering time may be 2.5 h, 2.6 h, 2.7 h, 2.8 h, 2.9 h, 3.0 h, 3.1 h, 3.2 h, 3.3 h, 3.4 h or 3.5 h.

[0073] Figure 3 A detailed flow chart of a method for preparing the composite co-fired material provided in an embodiment of the present application is exemplarily shown; In some optional embodiments, such as Figure 3 As shown, the preparation steps of the first metal oxide precursor are: S101. Dissolving trimethoxymethylsilane, ethyl orthosilicate, and oxalic acid solution in an organic solvent, respectively, and mixing to obtain a reaction mixture; S102. hydrolyzing the reaction mixture to obtain a hydrolyzate; S103. condensing the ammonium hydroxide solution and the hydrolyzate to obtain a precursor of a first metal oxide; and / or The preparation steps of the precursor of the second metal oxide are: S111. Zirconium oxynitrate, ultrapure water and anhydrous ethanol are mixed to obtain a reaction solution; S112. Conducting a synthesis reaction between citric acid, ethylene glycol and the reaction solution to obtain a precursor of a second metal oxide.

[0074] In these embodiments, the first metal oxide precursor uses trimethoxymethylsilane, ethyl orthosilicate, and oxalic acid solution as raw materials, and undergoes a hydrolysis reaction and a condensation reaction to form a first metal oxide precursor gel product, which facilitates the subsequent first extrusion atomization. The second metal oxide precursor uses zirconium oxynitrate, ultrapure water, and anhydrous ethanol as raw materials, and then adds citric acid and ethylene glycol for a synthesis reaction to form the second metal oxide precursor gel product.

[0075] It should be noted that the organic solvent may be methanol.

[0076] Based on a general inventive concept, an embodiment of the present application provides a circuit device, which includes the composite co-fired material.

[0077] The circuit device is realized based on the above-mentioned composite co-fired material. The specific composition of the composite co-fired material can be referred to the above-mentioned embodiment. Since the circuit device adopts part or all of the technical solutions of the above-mentioned embodiment, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiment, which will not be described one by one here.

[0078] The present application is further described below with reference to specific examples. Experimental methods in the following examples where specific conditions are not specified are generally measured in accordance with national / industry standards. If there are no corresponding national / industry standards, the methods are carried out in accordance with commonly used international standards, conventional conditions, or conditions recommended by the manufacturer.

[0079] Example 1 like Figure 1 As shown, an embodiment of the present application provides a composite co-fired material, which includes a co-fired ceramic material layer, an intermediate layer and a co-fired ferrite material layer. One end of the intermediate layer is connected to the co-fired ceramic material layer, and the other end of the intermediate layer is connected to the co-fired ferrite material layer. The intermediate layer is a laminated structure formed by at least two metal oxides. The laminated structure includes at least three groups of intermediate barrier layers and connecting layers. The connecting layers are arranged on both sides of the intermediate barrier layer to connect the intermediate layer with the co-fired ferrite material layer or the co-fired ceramic material layer.

[0080] The thickness of the middle layer is 45 nm; The thickness of the intermediate barrier layer is 5 nm; The thickness of the connecting layer is 5 nm.

[0081] The number of groups of the intermediate barrier layer and the connecting layer is 3.

[0082] like Figure 3 As shown, the embodiment of the present application provides a method for preparing a composite co-fired material, comprising: S101. Dissolve 1 mL of trimethoxymethylsilane (MTMS), 0.2 mL of tetraethyl orthosilicate (TEOS), and 0.5 mL of a 0.001 M oxalic acid solution in 10 mL of methanol in a volume ratio of 10:2:5, and mix to obtain a reaction mixture. S102. The reaction mixture was stirred continuously and vigorously at room temperature in a constant temperature heated magnetic stirrer for 3 h to promote hydrolysis of the reaction mixture to obtain a hydrolyzate; S103. A condensation reaction was carried out between 0.61 mL of 11.2 M ammonium hydroxide solution and the hydrolyzate. The reaction mixture was stirred at room temperature for 30 min, and then allowed to stand for gelation and aging at room temperature for 24 h to obtain a Si-based gel as a precursor of the first metal oxide. The preparation steps of the second metal oxide precursor are: S111 according to the mass ratio of 1:9.6:6 6g of zirconium oxynitrate, 57.6g of ultrapure water and 36g of anhydrous ethanol were fully dissolved and mixed at a temperature of 25 ° C under the action of a constant temperature heating magnetic stirrer to obtain a reaction solution; S112. 6 g of citric acid and 24 g of ethylene glycol were fully dissolved at a mass ratio of 3:12 at 25° C., and the reaction solution was slowly added to the solution to carry out a synthesis reaction at 80° C. for 1 h. Finally, the reaction was allowed to stand at room temperature for 24 h to obtain a Zr-based gel as a precursor of the second metal oxide. S1. Prepare a co-fired ceramic material layer and a co-fired ferrite material layer respectively; S2. A first metal oxide precursor is applied to the surfaces of the co-fired ceramic material layer and the co-fired ferrite material layer by extrusion atomization. During the first extrusion atomization, the nozzle is 3 cm away from the co-fired ceramic material layer and the co-fired ferrite material layer to obtain a crude ceramic material and a crude ferrite material containing a connecting layer; S3. The connecting layer containing a crude ceramic material and a crude ferrite material is dried to form a film to obtain a ceramic material matrix and a ferrite material matrix containing a connecting layer; S4. A second metal oxide precursor is subjected to a second extrusion atomization on the surface of a ceramic material substrate or a ferrite material substrate containing a connecting layer to obtain a ceramic material or a ferrite material containing an intermediate barrier layer and a connecting layer; S5. The ceramic material containing the intermediate barrier layer and the connecting layer is pressed with the ferrite material to obtain a heterogeneous composite green body; S6. Sintering the heterogeneous composite green body to obtain a composite co-fired material.

[0083] The inlet flow rates of the first extrusion atomization and the second extrusion atomization were 0.5 cm 3 / s, and the time for the first extrusion atomization and the second extrusion atomization were 1.0s respectively.

[0084] The drying temperature for film formation is 110°C and the duration for drying film formation is 30 min; The pressing pressure is 500 MPa, and the holding time is 2.0 min. The sintering temperature is 920°C and the sintering time is 3.0h.

[0085] Example 2 Compared with Example 1, this embodiment has the following differences, and the rest are the same: The number of groups of the intermediate barrier layer and the connecting layer is 4.

[0086] Example 3 Compared with Example 1, this embodiment has the following differences, and the rest are the same: The thickness of the middle layer is 60 nm; The thickness of the intermediate barrier layer is 6 nm; The thickness of the connecting layer is 7 nm.

[0087] Example 4 Compared with Example 1, this embodiment has the following differences, and the rest are the same: The thickness of the middle layer is 90 nm; The thickness of the intermediate barrier layer is 10 nm; The thickness of the connecting layer is 10 nm.

[0088] Comparative Example 1 Compared with Example 1, the differences of this comparative example are as follows, and the rest are the same: The ceramic material is laminated with the ferrite material without using an intermediate layer.

[0089] Comparative Example 2 Compared with Example 1, the differences of this comparative example are as follows, and the rest are the same: The number of groups of the intermediate barrier layer and the connecting layer is 1.

[0090] Comparative Example 3 Compared with Example 1, the differences of this comparative example are as follows, and the rest are the same: The number of groups of the intermediate barrier layer and the connecting layer is 2.

[0091] Comparative Example 4 Compared with Example 1, the differences of this comparative example are as follows, and the rest are the same: The number of groups of the intermediate barrier layer and the connecting layer is 5.

[0092] Related experiments and effect data: 1. Morphology analysis: The composite co-fired materials of Example 1, Example 2, Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4 were collected and the bonding interface between the LTCC material and the LTCF material was observed under a scanning electron microscope. The results are as follows: Figure 5 shown.

[0093] 2. Ion diffusion: The element distribution at the interface between LTCC material and LTCF material was statistically analyzed for the composite co-fired materials of Example 1, Example 2, Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4. The results are as follows: Figure 6 As shown, the ion diffusion distances of the diffused ions of the composite co-fired materials of each embodiment and comparative example were counted respectively, and the results are shown in Table 1.

[0094] Table 1 Ion diffusion distance distribution of diffused ions in various embodiments and comparative examples

[0095] As shown in Table 1, the composite co-fired material provided in the embodiment of the present application has a multi-layer intermediate layer structure, which greatly improves the barrier capability to various diffused ions by means of a synergistic mechanism such as physically extending the path, setting multiple material / interface barriers, utilizing high barrier materials, potential chemical reaction capture, and reducing defect channels. 3+ The ion diffusion distance is reduced to below 8μm, while Fe 3+ The ion diffusion distance is reduced to below 5.5μm, while Ni + The ion diffusion distance of Cu 2+ The ion diffusion distance is reduced to below 1.8μm and Zn 2+ The ion diffusion distance is reduced to below 4.00 μm, which shows that the stacked structure with the intermediate barrier layer and the connecting layer can play a good chemical barrier role, thereby reducing the impurity phase caused by ion diffusion.

[0096] Compare Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4, Figure 5 and Figure 6 It can be seen that the number of different intermediate barrier layers and connecting layers in the laminated structure can give the composite co-fired material a blocking effect on various diffused ions. However, when the number of intermediate barrier layers and connecting layers in the laminated structure is insufficient, the blocking effect of the laminated structure is not obvious. When the number of intermediate barrier layers and connecting layers in the laminated structure is too many, the blocking effect of the laminated structure is difficult to continue to improve, and will also increase the diffusion distance of the diffused ions in reverse. This may be because the thickness of the intermediate barrier layer and the connecting layer is too large, which makes it difficult to stabilize the interface between the co-fired ceramic material layer and the co-fired ferrite material layer. A large amount of external impurity elements will be introduced into the composite co-fired material and provide a large number of diffusion channels for the diffused ions, thereby increasing the ion diffusion distance of some diffused ions.

[0097] In summary, the embodiment of the present application provides a composite co-fired material, which greatly improves the blocking ability of various types of diffusing ions through the synergistic mechanisms of this multi-layer intermediate layer structure, such as physically extending the path, setting multiple material / interface barriers, utilizing high-barrier materials, potential chemical reaction capture, and reducing defect channels.

[0098] In addition, the present invention provides a composite co-fired material, which can buffer the difference in sintering shrinkage between LTCC material and LTCF material through a unique intermediate layer, and can selectively block specific diffusion ions, such as dark Fe 3+ ion.

[0099] In addition, an embodiment of the present application provides a composite co-fired material, which can reduce the co-firing stress between the heterogeneous interface of LTCC material and LTCF material through a unique intermediate layer, and can inhibit the mutual diffusion of ions between the heterogeneous interfaces, breaking through the key technology of low-temperature co-firing of LTCC material and LTCF material, and can obtain an LTCC / LTCF heterogeneous composite substrate with stable and reliable connection.

[0100] In addition, the embodiments of the present application provide a composite co-fired material, and the specific characteristics of the composite co-fired material are as follows: 1. The core advantage of the sandwich-type buffer layer between heterogeneous composite materials lies in its excellent chemical barrier properties: Due to the mutual diffusion of impurity elements at the heterogeneous interface, impurity phases will be generated, which will cause abnormal electromagnetic properties of the composite substrate. The sandwich-like multilayer structure formed by the stacked structure can disrupt the diffusion channels of the diffusing elements, forcing the diffusing elements to take a longer path through the intermediate layer, thereby increasing the diffusion resistance of the diffusing elements. At the same time, the interfaces between the layers of the stacked structure can also play a role in hindering the diffusion of substances, further improving the barrier performance of the intermediate layer. The single-layer intermediate layer generally has a relatively simple structure and a relatively direct material diffusion channel, which makes the barrier performance of the intermediate layer relatively weak. In addition, the sandwich-type stacked structure can form a more effective barrier to prevent external impurity elements from mutually diffusing and penetrating between the heterogeneous materials of LTCC materials and LTCF materials. Each layer of heterogeneous material can be selected from materials with different barrier properties. For example, the intermediate barrier layer can use a dense inorganic material, such as zirconium oxide, which has good impurity element barrier properties and reduces the formation of impurity phases in the interface area.

[0101] 2. Optimize the stress transfer path: The heterogeneous materials of LTCC materials and LTCF materials are prone to interfacial stress due to the difference in thermal expansion coefficients. The sandwich-type laminated structure achieves thermal expansion gradient buffering through the intermediate barrier layer, which can reduce the risk of heterogeneous interface cracking caused by hot and cold cycles. In addition, the sandwich-type laminated structure can be designed with different thicknesses and material combinations to optimize the stress transfer path. When the heterogeneous materials are subjected to external forces, the stress can be reasonably distributed and transferred between the layers of the laminated structure to avoid stress concentration in a certain area, thereby improving the overall stability and reliability of the heterogeneous material structure. However, during the stress transfer process, the single-layer intermediate layer may lack the synergistic effect of this laminated structure, resulting in a more obvious stress concentration phenomenon, affecting the performance and service life of the heterogeneous material. In contrast, the single-layer buffer layer is relatively poor in flexibility and accuracy of stress adjustment due to its single material.

[0102] 3. Enhanced Heterogeneous Interface Bonding Strength: Heterogeneous materials often exhibit differences in physical and chemical properties, which can lead to poor interfacial compatibility. Sandwich-type laminated structures can improve interfacial compatibility by selecting an appropriate metal oxide material for the connecting layer. The metal oxide material in the connecting layer exhibits good compatibility with both heterogeneous materials, thereby reducing defects and gaps at the interface and improving interfacial bonding quality. However, a single intermediate layer has relatively limited ability to improve interfacial compatibility and cannot simultaneously meet the diverse requirements of both heterogeneous materials. The different layers of a sandwich-type laminated structure can form different types of bonding interfaces with the heterogeneous materials, such as chemical bonding, physical adsorption, and mechanical occlusion. By rationally designing the materials of each layer in the laminated structure, the diversity and strength of interfacial bonding can be increased. For example, materials with active functional groups in the connecting layer, which contacts the heterogeneous material, can react with the heterogeneous material surface to form chemical bonds. By selecting appropriate materials for the intermediate barrier layer, physical adsorption and mechanical occlusion between the intermediate barrier layer, connecting layer, and the heterogeneous material can be enhanced, significantly improving interfacial bonding strength. In contrast, a single interlayer usually provides only one or limited bonding mechanism, and the interfacial bonding strength is relatively low.

[0103] The foregoing is merely a detailed description of the present invention, intended to enable those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein, but rather is intended to conform to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A composite co-fired material, comprising a co-fired ceramic material layer, an intermediate layer, and a co-fired ferrite material layer, wherein one end of the intermediate layer is connected to the co-fired ceramic material layer, and the other end of the intermediate layer is connected to the co-fired ferrite material layer, wherein the intermediate layer is a laminated structure formed of at least two metal oxides, and the laminated structure comprises at least three groups of intermediate barrier layers and connecting layers, wherein the connecting layers are provided on both sides of the intermediate barrier layer to connect the intermediate layer with the co-fired ferrite material layer or the co-fired ceramic material layer.

2. The composite co-fired material according to claim 1, characterized in that: The metal oxide includes any one of the following: MgO2, Al2O3, TiO2, Y2O3, B2O3, ZnO, SiO2 and ZrO2.

3. The composite co-fired material according to claim 1 or 2, characterized in that: The metal oxide includes: SiO2 and ZrO2; wherein the metal oxide of the intermediate barrier layer is ZrO2, and the metal oxide of the connecting layer is SiO2.

4. The composite co-fired material according to claim 1, characterized in that: The thickness of the intermediate layer is 10 nm to 100 nm; and / or The thickness of the intermediate barrier layer is 5 nm to 10 nm; and / or The thickness of the connecting layer is 5 nm to 10 nm.

5. The composite co-fired material according to claim 1, characterized in that: The number of groups of the intermediate barrier layer and the connecting layer is 3 to 4 respectively.

6. A method for preparing the composite co-fired material according to any one of claims 1 to 5, the method comprising: preparing a co-fired ceramic material layer and a co-fired ferrite material layer respectively; Using a precursor of a first metal oxide to perform a first extrusion atomization on the surfaces of the co-fired ceramic material layer and the co-fired ferrite material layer, respectively, to obtain a crude ceramic material product containing a crude connecting layer and a crude ferrite material product; Drying the crude ceramic material containing the crude connecting layer and the crude ferrite material to form a film to obtain a ceramic material matrix containing the connecting layer and a ferrite material matrix; Using a precursor of a second metal oxide to perform a second extrusion atomization on the surface of the ceramic material substrate or the ferrite material substrate containing the connecting layer to obtain a ceramic material or the ferrite material containing an intermediate barrier layer and a connecting layer; Pressing the ceramic material containing the intermediate barrier layer and the connecting layer with the ferrite material to obtain a heterogeneous composite green body; The heterogeneous composite green body is sintered to obtain a composite co-fired material.

7. The method according to claim 6, characterized in that The flow rates of the first extrusion atomization and the second extrusion atomization are 0.4 cm 3 / s to 0.6cm 3 / s, and the time of the first extrusion atomization and the second extrusion atomization is 0.5s to 1.2s respectively.

8. The method according to claim 6, characterized in that The drying film forming temperature is 105° C. to 115° C., and the drying film forming duration is 25 min to 35 min; and / or The pressing pressure is 300 MPa to 600 MPa, and the holding time of the pressing is 1.5 min to 2.5 min; and / or The sintering temperature is 900° C. to 950° C., and the sintering time is 2.5 hours to 3.5 hours.

9. The method according to claim 6, characterized in that The steps for preparing the precursor of the first metal oxide are: dissolving trimethoxymethylsilane, ethyl orthosilicate and oxalic acid solution in organic solvents respectively and mixing them to obtain a reaction mixture; hydrolyzing the reaction mixture to obtain a hydrolyzate; condensing the ammonium hydroxide solution and the hydrolyzate to obtain a precursor of the first metal oxide; and / or The preparation steps of the precursor of the second metal oxide are: mixing zirconium oxynitrate, ultrapure water and anhydrous ethanol to obtain a reaction solution; The citric acid, ethylene glycol and the reaction solution are subjected to a synthesis reaction to obtain a precursor of the second metal oxide.

10. A circuit device comprising the composite co-fired material according to any one of claims 1 to 5.

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