Chip laminated ferrite inductor and preparation method thereof

Abstract

The invention discloses a chip laminated ferrite inductor and a preparation method thereof, and relates to the field of inductor preparation. Comprising the following steps: grinding and pre-calcining a NiCuZnCo ferrite material, adding a casting agent, casting to form a film, cutting the film, punching, printing, laminating, laminating, cutting, discharging glue and sintering to obtain a cooked blank; chamfering the cooked blank, sealing the end, and carrying out silver firing treatment; and then electroplating a nickel layer and a tin layer on the end head of the semi-finished product to obtain a chip laminated ferrite inductor product. Liquid nitrogen dipping treatment is adopted after the silver firing procedure and before the electroplating procedure, the internal microstructure of the ferrite is induced to generate ordered arrangement and optimized recombination, the electrical property stability and the current resistance characteristic are enhanced, the long-term impedance value change amplitude is small, the method is easy and convenient to operate and easy to integrate into an existing production technological process, and the production cost is reduced. And the production cost is not obviously increased.

Description

Technical Field

[0001] The present invention relates to the field of inductor preparation, and particularly to a chip multilayer ferrite inductor and a preparation method thereof. Background Art

[0002] Inductors can be classified into wound inductors, thin film inductors, multilayer inductors, etc. according to their structures. Among them, multilayer inductors are widely used in small circuits that require high current due to their miniaturization, thinness, and small DC resistance.

[0003] Chip multilayer inductors generally have technical defects such as complex manufacturing processes, high costs, and unstable inductor product performance. Chip multilayer ferrite inductors are widely used in high-frequency circuits, and the stability of their performance directly affects the reliability and efficiency of the entire circuit. In the traditional production process, the magnetic properties of ferrite chip inductors may fluctuate over time, thus affecting their long-term stability. Therefore, finding effective methods to improve the performance stability of ferrite chip inductors has become an urgent problem to be solved. Summary of the Invention

[0004] The present invention provides a chip multilayer ferrite inductor and a preparation method thereof. By using liquid nitrogen impregnation treatment after the silver firing process and before the electroplating process in the preparation process of the multilayer ferrite inductor, the electrical stability of the ferrite material can be improved, and the change range of the long-term impedance can be reduced.

[0005] In order to solve the above technical problems, one of the purposes of the present invention is to provide a preparation method of a chip multilayer ferrite inductor, including the following steps:

[0006] (1) After grinding and pre-calcining the NiCuZnCo ferrite material, adding a casting aid and grinding to obtain a ferrite slurry, casting it into a film, cutting the film, punching holes, printing, stacking, laminating, cutting, debinding, and firing to obtain a green body;

[0007] (2) Chamfering and sealing the ends of the green body, and then performing silver firing treatment at 350-750°C;

[0008] (3) Making the semi-finished product after silver firing fully contact with liquid nitrogen, with an impregnation time of 3-5 minutes, and restoring to room temperature after impregnation;

[0009] (4) Electroplating a nickel layer and a tin layer on the ends of the semi-finished product after liquid nitrogen treatment to obtain a chip multilayer ferrite inductor product;

[0010] In step (1), the casting aid includes a binder, a solvent, and a dispersant with a mass ratio of (15-25):(25-35):(0.5-2).

[0011] In the ferrite inductor product of this application, after the silver firing process and before reaching the electroplating process, liquid nitrogen cryogenic impregnation treatment is adopted. The ultra-low temperature treatment can induce the ordered arrangement and optimized recombination of the internal microstructure of the ferrite, thereby reducing the density of defect states, enhancing the electrical stability and current-carrying characteristics. Whether it is low impedance or high impedance, the long-term impedance value changes less, and even in the low-impedance group, there is no electrical change amplitude exceeding 2%. The long-term impedance / inductance stability of the ferrite inductor is significantly improved.

[0012] In addition, control the liquid nitrogen impregnation time to avoid incomplete internal stress release caused by the inability to evenly reach the ultra-low temperature state of the entire product due to too short impregnation time, and at the same time avoid the product temperature being too low due to too long impregnation time, which may increase the thermal stress when returning to normal temperature, may cause microcracks or other structural defects, and will also increase the production cycle, reduce production efficiency, and increase costs.

[0013] As a preferred solution, the mass ratio of the NiCuZnCo ferrite material to the casting aid is 1:(0.8 - 1.2).

[0014] As a preferred solution, in step (1), the NiCuZnCo ferrite material includes NiO, ZnO, CuO, Co3O4, and Fe2O3 with a molar ratio of (15 - 20):(25 - 30):(8 - 10):(3 - 6):(40 - 50).

[0015] As a preferred solution, the binder is a phenolic epoxy resin.

[0016] As a preferred solution, the organic solvent is n-propyl acetate and / or isobutanol.

[0017] As a preferred solution, the dispersant is dibutyl phthalate.

[0018] As a preferred solution, in step (1), the debinding temperature is 200 - 400°C.

[0019] As a preferred solution, in step (1), the sintering temperature is 500 - 900°C.

[0020] As a preferred solution, in step (1), the pre-calcination temperature is 850 - 900°C, and the pre-calcination time is 1 - 5 h.

[0021] As a preferred solution, in step (1), the ferrite slurry is cast into a film by a dry process, the film is cut into green blanks and punched, an inductor pattern and a designed dividing line are printed with silver paste, dried, and the dried wafers are stacked and pressed according to the inductor design structure. The stacked wafers are laminated again, and the laminated wafers are cut into individual green blank products with coils and lead-out ends using the dividing line as the alignment coordinate. After debinding and firing, a fired blank is obtained.

[0022] As a preferred solution, the temperature of the liquid nitrogen is below -196°C.

[0023] In order to solve the above technical problems, the second object of the present invention is to provide a chip multilayer ferrite inductor prepared by using the preparation method of the above chip multilayer ferrite inductor.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] In this application, after the silver firing process of the ferrite inductor product and before reaching the electroplating process, liquid nitrogen cryogenic impregnation treatment is adopted to induce the orderly arrangement and optimized recombination of the internal microstructure of the ferrite, enhance the electrical stability and current-carrying characteristics, and the long-term impedance value changes less significantly. The long-term impedance / inductance stability of the ferrite inductor is significantly improved. This method is simple to operate, easy to integrate into the existing production process flow, and will not significantly increase the production cost. Detailed Embodiments

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0027] It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention. In addition, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the range.

[0028] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this invention pertains. Although this invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of this invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the said documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0029] To further illustrate the present invention, the present invention will be described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention. The raw materials used in the following embodiments and comparative examples of this application, unless otherwise specified, can be obtained commercially, and the same raw materials are used in parallel experiments.

[0030] Example 1

[0031] A preparation method of a chip multilayer ferrite inductor, comprising the following steps:

[0032] (1) Grinding the NiCuZnCo ferrite material in a grinder. The NiCuZnCo ferrite material comprises NiO, ZnO, CuO, Co3O4 and Fe2O3 with a molar ratio of 18:27:9:5:46. Subsequently, calcining at 850 °C for 2 h to obtain a pre-calcined ferrite material. After adding 30 wt% of an organic solvent, 18 wt% of a binder and 2 wt% of a dispersant, grinding in a grinder to obtain a ferrite slurry. The organic solvent is n-propyl acetate, the dispersant is dibutyl phthalate, and the binder is a phenolic epoxy resin;

[0033] (2) Casting the ferrite slurry into a film by a dry process, cutting the film into green blanks and punching holes, printing an inductor pattern and a designed dividing line with silver paste, drying, stacking and pressing the dried blank sheets according to the inductor design structure, laminating the stacked blank sheets again to make the combination between layers more firm, using the dividing line as the alignment coordinate, cutting the laminated blank sheets into individual green blank products with coils and lead-out ends, and obtaining a sintered blank after debinding and sintering;

[0034] (3) Placing the sintered blank in a ball mill to chamfer the edges and corners into arcs for subsequent silver sintering, sealing the two ends of the chamfered sintered blank, dipping silver at the two ends of the sintered blank and drying to complete the end sealing;

[0035] (4) Sintering the silver on the semi-finished product after end sealing in a silver sintering furnace at 500 °C;

[0036] (5) Select the semi-finished product that has completed the silver firing process, cool it down to room temperature, place the semi-finished product into a liquid nitrogen container, ensure that the product surface is in full contact with liquid nitrogen (-196 °C), the impregnation time is 3 minutes, after the impregnation is completed, take out the semi-finished product and place it at room temperature to restore to normal temperature;

[0037] (6) Electroplate nickel layer and tin layer on the end of the semi-finished product after liquid nitrogen treatment to obtain the chip multilayer ferrite inductor product.

[0038] Comparative Example 1

[0039] A preparation method of a chip multilayer ferrite inductor, comprising the following steps:

[0040] (1) Grind the NiCuZnCo ferrite material in a grinder. The NiCuZnCo ferrite material includes NiO, ZnO, CuO, Co3O4 and Fe2O3 with a molar ratio of 18:27:9:5:46. Subsequently, calcine at 850 °C for 2 h to obtain the ferrite pre-sintered material. After adding 30 wt% of organic solvent, 18 wt% of binder and 2 wt% of dispersant, grind in a grinder to obtain the ferrite slurry. The organic solvent is n-propyl acetate, the dispersant is dibutyl phthalate, and the binder is phenolic epoxy resin;

[0041] (2) Cast the ferrite slurry into a film by a dry process, cut the film into green bodies, punch holes, print the inductor pattern and the designed dividing line with silver paste, dry it, stack and press the dried green bodies according to the inductor design structure, laminate the stacked green bodies again to make the combination between layers more firm, take the dividing line as the alignment coordinate, cut the laminated green bodies into individual green body products with coils and leads, and obtain the sintered green bodies after debinding and firing;

[0042] (3) Place the sintered green bodies in a ball mill to chamfer the edges and corners, chamfer the edges and corners into arcs for subsequent silver firing, seal the silver at both ends of the chamfered sintered green bodies, dip silver at both ends of the sintered green bodies and dry it to complete the end sealing;

[0043] (4) Fire the semi-finished product after end sealing in a silver firing furnace at 500 °C;

[0044] (5) Electroplate nickel layer and tin layer on the end of the semi-finished product after silver firing treatment;

[0045] (6) Place the electroplated semi-finished product into a liquid nitrogen container, ensure that the product surface is in full contact with liquid nitrogen (-196 °C), the impregnation time is 3 minutes, after the impregnation is completed, take out the semi-finished product and place it at room temperature to restore to normal temperature to obtain the chip multilayer ferrite inductor product.

[0046] Comparative Example 2

[0047] A preparation method of a chip multilayer ferrite inductor, comprising the following steps:

[0048] (1) Grind the NiCuZnCo ferrite material in a grinder. The NiCuZnCo ferrite material includes NiO, ZnO, CuO, Co3O4 and Fe2O3 with a molar ratio of 18:27:9:5:46. Then calcine it at 850 °C for 2 h to obtain a ferrite pre-sintered material. After adding 30 wt% of an organic solvent, 18 wt% of a binder and 2 wt% of a dispersant, grind it in a grinder to obtain a ferrite slurry. The organic solvent is n-propyl acetate, the dispersant is dibutyl phthalate, and the binder is a phenolic epoxy resin;

[0049] (2) Cast the ferrite slurry into a film by a dry process, cut the film into green blanks and punch holes, print an inductor pattern and a designed dividing line with silver paste, dry it. Stack and press the dried blank sheets according to the inductor design structure, and laminate the stacked blank sheets again to make the combination between layers more firm. Using the dividing line as the alignment coordinate, cut the laminated blank sheets into individual green blank products with coils and lead-out ends. After debinding and sintering, obtain a sintered blank;

[0050] (3) Place the sintered blank in a ball mill to chamfer the edges and corners, and chamfer the edges and corners into arcs for subsequent silver firing;

[0051] (4) Put the chamfered sintered blank into a liquid nitrogen container to ensure that the product surface is in full contact with liquid nitrogen (-196 °C), and the impregnation time is 3 min. After impregnation, take out the sintered blank and place it at room temperature to return to normal temperature;

[0052] (5) Seal the silver at both ends of the sintered blank after liquid nitrogen treatment, dip silver at both ends of the sintered blank and dry it to complete the end sealing;

[0053] (6) Fire the silver of the semi-finished product after end sealing in a silver firing furnace at 500 °C;

[0054] (7) Electroplate a nickel layer and a tin layer on the ends of the semi-finished product after silver firing treatment to obtain a chip multilayer ferrite inductor product.

[0055] Comparative Example 3

[0056] A preparation method of a chip multilayer ferrite inductor, comprising the following steps:

[0057] (1) Grind the NiCuZnCo ferrite material in a grinder. The NiCuZnCo ferrite material includes NiO, ZnO, CuO, Co3O4, and Fe2O3 with a molar ratio of 18:27:9:5:46. Subsequently, calcine it at 850 °C for 2 h to obtain a pre-calcined ferrite material. After adding 30 wt% of an organic solvent, 18 wt% of a binder, and 2 wt% of a dispersant, grind it in a grinder to obtain a ferrite slurry. The organic solvent is n-propyl acetate, the dispersant is dibutyl phthalate, and the binder is a phenolic epoxy resin;

[0058] (2) Cast the ferrite slurry into a film by a dry process. Cut the film into green compacts and punch holes. Print the inductor pattern and the designed dividing lines with silver paste, and dry it. Stack and press the dried green compacts according to the inductor design structure. Laminate the stacked green compacts again to make the layers bond more firmly. Using the dividing lines as the alignment coordinates, cut the laminated green compacts into individual green compact products with coils and lead-out ends. After debinding and firing, obtain the fired compacts;

[0059] (3) Place the fired compacts in a ball mill to chamfer the edges and corners, chamfer the edges and corners into arcs for subsequent silver soldering. Seal the two ends of the chamfered fired compacts with silver, dip the two ends of the fired compacts with silver and dry them to complete the end sealing;

[0060] (4) Solder the silver on the end-sealed semi-finished products in a silver soldering furnace at 500 °C;

[0061] (5) Select the semi-finished products that have completed the silver soldering process, cool them to room temperature, place the semi-finished products in a liquid nitrogen container to ensure that the product surface is in full contact with liquid nitrogen (-196 °C), the impregnation time is 3 min. After impregnation, take out the semi-finished products and place them at room temperature to return to normal temperature;

[0062] (6) Electroplate nickel and tin layers on the ends of the liquid nitrogen-treated semi-finished products;

[0063] (7) Place the electroplated semi-finished products in a liquid nitrogen container to ensure that the product surface is in full contact with liquid nitrogen (-196 °C), the impregnation time is 3 min. After impregnation, take out the semi-finished products and place them at room temperature to return to normal temperature to obtain chip multilayer ferrite inductor products.

[0064] Comparative Example 4

[0065] A preparation method of a chip multilayer ferrite inductor, comprising the following steps:

[0066] (1) Grind the NiCuZnCo ferrite material in a grinder. The NiCuZnCo ferrite material includes NiO, ZnO, CuO, Co3O4, and Fe2O3 with a molar ratio of 18:27:9:5:46. Subsequently, calcine it at 850 °C for 2 h to obtain a pre-calcined ferrite material. After adding 30 wt% of an organic solvent, 18 wt% of a binder, and 2 wt% of a dispersant, grind it in a grinder to obtain a ferrite slurry. The organic solvent is n-propyl acetate, the dispersant is dibutyl phthalate, and the binder is a phenolic epoxy resin;

[0067] (2) Cast the ferrite slurry into a film by a dry process. Cut the film into green compacts and punch holes. Print the inductor pattern and the designed dividing lines with silver paste, and then dry it. Stack and press the dried green compacts according to the inductor design structure. Laminate the stacked green compacts again to make the layers bond more firmly. Using the dividing line as the alignment coordinate, cut the laminated green compacts into individual green compact products with coils and lead-out ends. After debinding and firing, obtain the fired compacts;

[0068] (3) Place the fired compacts in a ball mill to chamfer the edges and corners, and round the edges and corners for subsequent silver soldering. Seal the two ends of the chamfered fired compacts with silver. Dip the two ends of the fired compacts with silver and then dry them to complete the end sealing;

[0069] (4) Solder the silver on the semi-finished product after end sealing in a silver soldering furnace at 500 °C;

[0070] (5) Electroplate nickel and tin layers on the ends of the semi-finished product after silver soldering to obtain a chip multilayer ferrite inductor product.

[0071] Comparative Example 5

[0072] A method for preparing a chip multilayer ferrite inductor, where the reagents, equipment, and process parameters used in each step are the same as those in Example 1. The difference is that in step (1), the NiCuZnCo ferrite material is replaced with an equal amount of NiCuZnBi ferrite material. The NiCuZnBi ferrite material includes NiO, ZnO, CuO, Bi2O3, and Fe2O3 with a molar ratio of 18:27:9:5:41.

[0073] Comparative Example 6

[0074] A method for preparing a chip multilayer ferrite inductor, where the reagents, equipment, and process parameters used in each step are the same as those in Example 1. The difference is that in step (1), the ferrite slurry includes 20 wt% of a binder, 25 wt% of a solvent, 5 wt% of a dispersant, and the balance of the pre-calcined ferrite material.

[0075] Performance Detection Test

[0076] 1. The low-impedance group 1 (coil turns: 3.5 turns) and the high-impedance group 2 (coil turns: 6.5 turns) were respectively used to conduct 100pcs of test verification on the chip multilayer ferrite inductors of the examples and comparative examples. The impedance value was intermittently tested over a period of 24 days (test equipment: Keysight E4982A, test fixture: Keysight 16192A, test frequency: 100Mhz) to confirm the maximum electrical property change amplitude △Z of each group Max and the product ratio P (△Z>2%) showing such changes (test instrument equipment error δ≤2%). The test results are shown in Table 1 below.

[0077] Table 1 - Impedance value test results of the chip multilayer ferrite inductors of the examples and comparative examples of this application

[0078]

[0079]

[0080] As shown in Table 1, for the ferrite inductor products of Example 1 of this application, after the silver sintering process and before reaching the electroplating process, liquid nitrogen cryogenic impregnation treatment can induce an orderly arrangement and optimized recombination of the internal microstructure of the ferrite, thereby reducing the density of defect states and enhancing the electrical stability and current-carrying characteristics. Whether it is low impedance or high impedance, compared with the products of Comparative Example 4 without liquid nitrogen cryogenic treatment, the change amplitude over more than 20 days is relatively small, and the product ratio with an electrical change exceeding 2% in the high-impedance group is lower, and there is no electrical change exceeding 2% in the low-impedance group, significantly improving the long-term impedance / inductance stability of the ferrite inductor.

[0081] Compared with Example 1, the preparation process of the ferrite inductor in Comparative Example 1 is to conduct liquid nitrogen cryogenic impregnation treatment after the silver sintering and electroplating processes of the semi-finished product, resulting in a larger electrical change amplitude of the ferrite inductor products, especially in the high-impedance group. The maximum electrical change amplitude has increased by more than 1 time, and the product ratio with an electrical change exceeding 2% has increased by nearly 4 times. Moreover, the product ratio with a change exceeding 2% in the low-impedance group has increased from none to 15%, indicating that the long-term impedance / inductance stability of the ferrite inductor in Comparative Example 1 is significantly worse. The reason may be that the electroplating layer hinders the grain optimization and stress release of the ferrite matrix, and the thermal expansion mismatch between the coating and the matrix causes interface defects.

[0082] Compared with Example 1, the preparation process of the ferrite inductor in Comparative Example 2 is to use liquid nitrogen low-temperature impregnation treatment after the chamfering process and before reaching the capping process. There is a certain degree of increase in the maximum electrical property change range of the ferrite inductor product, and there is also a small increase in the proportion of products with a change exceeding 2%. This shows that the long-term impedance / inductance stability of the ferrite inductor in Comparative Example 2 is significantly worse. The reason is that chamfering processing may introduce large residual stresses, and the drastic temperature change (from room temperature to -196°C) during liquid nitrogen low-temperature impregnation will exacerbate the internal stress release of the material, resulting in local deformation or cracks, affecting stability. In Example 1, part of the stress has been released through high-temperature treatment during the silver sintering process, and the material structure is more stable, and the stress response to subsequent low-temperature treatment is more controllable.

[0083] Compared with Example 1, the preparation process of the ferrite inductor in Comparative Example 3 is to use liquid nitrogen low-temperature impregnation treatment between the silver sintering and electroplating processes and after the electroplating process. There is a small increase in the maximum electrical property change range of the ferrite inductor, but the proportion of products with a change exceeding 2% in the low-impedance group has increased from zero to 22%, and the proportion of products with an electrical property change exceeding 2% in the high-impedance group has increased by 2 times. This shows that the ferrite inductor in Comparative Example 3 also has insufficient long-term impedance / inductance stability. The reason is that the electroplating layer hinders the direct optimization of the matrix by liquid nitrogen, induces interface stress, and the secondary liquid nitrogen treatment destroys the stable magnetic domain structure and introduces oxidation risk.

[0084] Compared with Example 1, the preparation process of the ferrite inductor in Comparative Example 4 is not to perform liquid nitrogen low-temperature impregnation treatment. There is a significant increase in the maximum electrical property change range of the ferrite inductor. The proportion of products with a change exceeding 2% in the low-impedance group has increased from zero to 42%, and the proportion of products with an electrical property change exceeding 2% in the high-impedance group has increased to 58%. This shows that the ferrite inductor in Comparative Example 4 also has insufficient long-term impedance / inductance stability, and the reasons are attributed to grain disorder, stress residue, and micropore defects.

[0085] Compared with Example 1, the preparation process of the ferrite inductor in Comparative Example 5 is to use NiCuZn powder doped with Bi. There is a significant increase in the maximum electrical property change range of the ferrite inductor. The proportion of products with a change exceeding 2% in the impedance group has increased from zero to 35%, and the proportion of products with an electrical property change exceeding 2% in the high-impedance group has increased to 50%. This shows that the ferrite inductor in Comparative Example 5 also has insufficient long-term impedance / inductance stability, and the reasons are attributed to the influence of the introduction of Bi on the ferrite lattice, magnetic permeability, and temperature characteristics.

[0086] Compared with Example 1, the dispersant in the ferrite slurry of Comparative Example 6 is excessive, and the maximum electrical property change range of the ferrite inductor shows an obvious increase. The proportion of products with a change exceeding 2% in the impedance group increases from zero to 28%, and the proportion of products with an electrical property change exceeding 2% in the high-impedance group increases to 45%. This shows that the ferrite inductor of Comparative Example 6 also suffers from insufficient long-term impedance / inductance stability. The reason is attributed to the excessive dispersant inhibiting grain growth, and the liquid nitrogen treatment cannot repair the defects.

[0087] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. In particular, for those skilled in the art, any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a chip-type laminated ferrite inductor, characterized in that: The following steps are involved: (1) grinding and pre-calcining the NiCuZnCo ferrite material, adding a casting agent to grind to obtain a ferrite slurry, casting into a film, cutting, punching, printing, laminating, cutting, debinding, and firing to obtain a cooked blank; (2) chamfering the cooked blank and sealing the ends, followed by silver firing at 350-750°C; (3) fully contacting the semi-finished product after silver burning with liquid nitrogen for 3-5 minutes, and returning to room temperature after the impregnation is completed; (4) electroplating a nickel layer and a tin layer on the end of the semi-finished product treated with liquid nitrogen to obtain a chip-type laminated ferrite inductor product; In step (1), the casting agent comprises a binder, a solvent and a dispersant in a mass ratio of (15-25): (25-35): (0.5-2).

2. The method for preparing a chip-type multilayer ferrite inductor according to claim 1, characterized in that: The mass ratio of the NiCuZnCo ferrite material to the casting agent is 1:(0.8-1.2).

3. The method for preparing a chip-type multilayer ferrite inductor according to claim 1, characterized in that: In step (1), the NiCuZnCo ferrite material comprises NiO, ZnO, CuO, Co3O4 and Fe2O3 in a molar ratio of (15-20):(25-30):(8-10):(3-6):(40-50).

4. The method for preparing a chip-type multilayer ferrite inductor according to claim 3, characterized in that: The adhesive is phenolic epoxy resin.

5. The method for preparing a chip-type multilayer ferrite inductor according to claim 3, characterized in that: The organic solvent is n-propyl acetate and / or isobutyl alcohol.

6. The method for preparing a chip-type multilayer ferrite inductor according to claim 3, characterized in that: The dispersant is dibutyl phthalate.

7. The method for preparing a chip-type multilayer ferrite inductor according to claim 1, characterized in that: In step (1), the debinding temperature is 200-400°C.

8. The method for preparing a chip-type multilayer ferrite inductor according to claim 1, characterized in that: In step (1), the sintering temperature is 500-900°C.

9. The method for preparing a chip-type multilayer ferrite inductor according to claim 1, characterized in that: In step (1), the pre-calcination temperature is 850-900° C., and the pre-calcination time is 1-5 hours.

10. A chip-type multilayer ferrite inductor prepared by the method for preparing a chip-type multilayer ferrite inductor according to any one of claims 1 to 9.

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