Ferrite material as well as preparation method and application thereof

Abstract

The invention provides a ferrite material and a preparation method and application thereof, the raw materials of the ferrite material comprise main components and auxiliary components, the main components comprise Fe2O3, NiO, ZnO and CuO, the auxiliary components comprise B2O3, SnO2, TiO2 and SiO2, the ferrite material comprises 100 parts by weight of the main components and 0.66-2.45 parts by weight of the auxiliary components, and the auxiliary components comprise 0.1-0.7 part by weight of B2O3, 0.01-0.15 part by weight of SnO2, 0.05-0.2 part by weight of TiO2 and 0.5-1.4 parts by weight of SiO2. The ferrite material provided by the invention can maintain corresponding initial magnetic conductivity while having relatively high thermal shock resistance and relatively low magnetic conductivity temperature-resistant change rate, has relatively high saturation flux density, can meet the performance requirement of a ferrite inductor on a temperature-resistant material, and has a wide application prospect. And application of an integrated miniaturized inductor product in a high-temperature environment state is facilitated, and the high-temperature inductor has a good application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of magnetic materials, and in particular relates to a ferrite material and a preparation method and application thereof. Background Art

[0002] Nickel-copper-zinc ferrite (NICKEL) is a key application branch of traditional NiZn soft ferrite materials. Featuring high resistivity, high magnetic permeability, and high operating frequency, it is primarily used in fields such as computers, communications, power supplies, and consumer electronics, making it a significant new functional semiconductor material in the electronics industry. Currently, NICKEL is primarily used to manufacture various surface-mount components, such as surface-mount power inductors. This provides further development opportunities for circuits requiring high power transmission and thinner, more compact DC-DC power modules.

[0003] As electronic packaging technology evolves toward thinner and smaller designs, surface mount components face increasing thermal stress challenges during manufacturing and use. Traditional nickel-copper-zinc ferrite materials are susceptible to grain boundary structural degradation after repeated high-temperature soldering cycles. The differential thermal expansion between the internal CuO segregation phase and the matrix can easily lead to microscopic defects, resulting in insufficient thermal cycling stability.

[0004] Therefore, higher requirements are placed on the thermal shock resistance and temperature stability of nickel-copper-zinc ferrite materials and electronic components prepared therefrom. The development of a ferrite material with good temperature stability is of great significance to the field of electronic components. Summary of the Invention

[0005] In a first aspect, the present invention provides a ferrite material comprising the following raw materials, measured in parts by weight: 100 parts of a main component and 0.66-2.45 parts of auxiliary components. The auxiliary components include 0.1-0.7 parts of B2O3, 0.01-0.15 parts of SnO2, 0.05-0.2 parts of TiO2, and 0.5-1.4 parts of SiO2; and the main components include Fe2O3, NiO, ZnO, and CuO.

[0006] The present invention optimizes the design of ferrite materials and obtains ferrite materials with excellent magnetic properties and good temperature stability by regulating the ratio of each component in the main component and the auxiliary component. The inventors have found that the components in the auxiliary component can synergize and enhance efficiency within a certain range. By controlling the addition amount of each component within a certain range, the obtained ferrite material can take into account both excellent magnetic properties and good temperature stability. If the amount of the auxiliary component is added too much or too little, it will cause abnormal grain growth, resulting in a decrease in the magnetic properties and temperature stability of the ferrite material. The inventors have found through research that not any material doping can improve the magnetic properties and temperature stability of ferrite. The use of the specific main component and auxiliary component combination of the present invention can well take into account the magnetic properties and temperature stability. In addition, the inventors also found that controlling the addition amount of SnO2 and TiO2 in the auxiliary component within a certain ratio can also effectively improve the performance of the ferrite material.

[0007] In some embodiments, the auxiliary components include 0.1-0.5 parts of B2O3, 0.05-0.1 parts of SnO2, 0.15-0.2 parts of TiO2, and 0.7-1.2 parts of SiO2.

[0008] In some embodiments, the weight ratio of SnO2 to TiO2 in the auxiliary components is 1:(1.5-4).

[0009] In some embodiments, the weight ratio of SnO2 to TiO2 in the auxiliary components is 1:(1.5-3).

[0010] In some embodiments, the main components include, by mole percentage, 40-50 mol% of Fe2O3, 15-25 mol% of NiO, 18-35 mol% of ZnO, and 3.5-7 mol% of CuO.

[0011] In some embodiments, the main components include, by mole percentage, 45-50 mol% of Fe2O3, 15-20 mol% of NiO, 25-30 mol% of ZnO, and 5-7 mol% of CuO.

[0012] In a second aspect, the present invention provides a method for preparing a ferrite material, comprising the following steps: weighing raw materials in proportion, mixing, pre-burning, crushing, granulating, pressing, and sintering to obtain the ferrite material.

[0013] In some embodiments, the mixing comprises ball milling, and the ball milling time is 120-180 minutes.

[0014] In some embodiments, the pre-firing temperature is 825-875° C., and the pre-firing time is 180-240 minutes.

[0015] In some embodiments, the sintering temperature is 910-930° C., and the sintering time is 180-200 minutes.

[0016] According to a third aspect of the present invention, a magnetic core is provided, comprising the above-mentioned ferrite material.

[0017] According to a fourth aspect of the present invention, an inductor is provided, comprising the magnetic core described above.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The ferrite material provided by the present invention has high thermal shock resistance and low temperature-resistant permeability change rate, while being able to maintain the corresponding initial magnetic permeability and having a high saturation magnetic induction intensity, which can meet the performance requirements of ferrite inductors for temperature-resistant materials and is conducive to the application of integrated miniaturized inductor products in high-temperature environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the magnetic ring sample.

[0021] Figure 2 This is an electron microscope image of the magnetic ring in Example 1. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below through specific examples. The specific examples do not limit the scope of protection of the present invention. Some non-essential modifications and adjustments made by others based on the concept of the present invention still fall within the scope of protection of the present invention. The raw materials, reagents or devices used in the examples can be obtained from conventional commercial channels or can be obtained by existing technical methods. Unless otherwise specified, the experiments or test methods are conventional methods in the art.

[0023] Preparation of ferrite materials

[0024] In the ferrite materials of Examples 1-5 and Comparative Examples 1-13, the main components, calculated in mole percentage, include 46.7 mol% of Fe2O3, 18.9 mol% of NiO, 28.2 mol% of ZnO, and 6.2 mol% of CuO.

[0025] The raw materials and addition amounts of the ferrite materials of Examples 1-5 and Comparative Examples 1-10 are shown in Table 1.

[0026] Table 1

[0027]

[0028] Comparative Example 11

[0029] The only difference between Comparative Example 11 and Example 1 is that the composition of the auxiliary components is different, and PbO is used to replace SnO2, specifically: 0.3 parts of B2O3, 0.05 parts of PbO, 0.15 parts of TiO2, and 1 part of SiO2.

[0030] Comparative Example 12

[0031] The only difference between Comparative Example 12 and Example 1 is that the composition of the auxiliary components is different, and ZrO2 is used instead of TiO2, specifically: 0.3 parts of B2O3, 0.05 parts of SnO2, 0.15 parts of ZrO2, and 1 part of SiO2.

[0032] Comparative Example 13

[0033] The only difference between Comparative Example 13 and Example 1 is that the composition of the auxiliary components is different, and ZrO2 and Co2O3 are used to replace TiO2, specifically: 0.3 parts of B2O3, 0.05 parts of SnO2, 0.1 parts of ZrO2, 0.05 parts of Co2O3, and 1 part of SiO2.

[0034] The preparation method of the ferrite material of Examples 1-5 and Comparative Examples 1-13 comprises the following steps:

[0035] (1) Ball milling: After the ingredients are prepared according to the above main ingredient ratio, dry mixing is performed for 180 minutes.

[0036] (2) Low-temperature pre-firing: The mixed materials are placed in a push-plate kiln for pre-firing. The pre-firing temperature is controlled at 850°C and the pre-firing time is 180 minutes to obtain the main component pre-firing material.

[0037] (3) Crushing: After adding the auxiliary components in the above ratio to the pre-calcined main component, wet crushing is carried out for 180 minutes, and the particle size is controlled at 0.8-1.3 μm to obtain the finished powder.

[0038] (4) Granulation: Add polyvinyl alcohol (PVA) equivalent to 15% of the weight of the finished powder to the finished powder, perform mechanical granulation, and obtain granular material.

[0039] (5) Pressing into rings: Use a powder forming machine to press the granular material to obtain a blank. The density of the pressed green blank is controlled at 3±0.3g / cm 3 .

[0040] (6) High temperature sintering: Sintering is carried out in a high temperature Nabertherm sintering furnace. The sintering temperature is controlled at 920℃ and kept warm for 180 minutes. The ambient atmosphere during sintering is air. After sintering, the furnace is cooled to room temperature to obtain a magnetic ring sample. The schematic diagram of the magnetic ring sample is shown in the figure. Figure 1 The magnetic ring electron microscope image of Example 1 is shown in FIG. Figure 2As shown, the grain size is 5-12um, and the grain cross section is mainly in the form of intergranular fracture.

[0041] Performance Testing: The prepared magnetic ring samples were tested for magnetic permeability using an E4991B impedance analyzer and a dedicated magnetic permeability fixture. The density of the magnetic rings was determined using the buoyancy method. The saturation magnetic induction intensity was measured using a BH tester. The temperature change rate of magnetic permeability was measured before and after the reflow oven test.

[0042] Magnetic permeability determines the performance value (inductance value or impedance value, etc.) of the product under the same design. Under the same design, the Ls inductance value is proportional to the magnetic permeability ui value. In practical applications, the inductance value must be accurately selected based on comprehensive considerations such as the specific function of the circuit, operating frequency, current requirements, size restrictions, efficiency targets, etc. If the inductance value is too low, problems such as excessive ripple, reduced efficiency, core saturation, filter failure, or resonance point shift will occur. If the inductance value is too high, problems such as slow response, reduced SRF, or resonance point shift will occur. All multilayer chip ferrite inductor products currently on the market have a nominal value of inductance Ls or impedance Z at a specific frequency and its tolerance range. A multilayer chip inductor that limits the nominal inductance value and the DC resistance of the internal electrode requires the initial magnetic permeability of the matrix material to be in the range of 130μi±10μi. In the magnetic permeability performance test of the present invention, materials that meet this range are considered qualified.

[0043] The performance test results of Examples 1-5 and Comparative Examples 1-13 are shown in Table 2 below.

[0044] Table 2

[0045]

[0046] The results show that in the ferrite material of the present invention, when the amount of one or more components in the auxiliary components exceeds a certain range, the magnetic permeability of the ferrite material will be significantly reduced, the saturation magnetic induction intensity will be significantly reduced, and it will be unable to meet the actual application requirements (Comparative Examples 1-4). When B2O3 or SnO2 is missing in the auxiliary components, the magnetic permeability of the ferrite material will be reduced and the saturation magnetic induction intensity will be reduced (Comparative Examples 5-6). When TiO2 is missing in the auxiliary components, the magnetic permeability of the ferrite material will be too high, which will not meet the actual application requirements (Comparative Example 7). When too much SiO2 is added to the auxiliary components, the magnetic permeability of the ferrite material will be too high, which will not meet the actual application requirements (Comparative Example 8). When the addition ratio of SnO2 and TiO2 in the auxiliary components exceeds or is less than 1: (1.4-5), the magnetic properties and temperature stability of the ferrite material will be reduced (Comparative Examples 9-10). When PbO is used to replace SnO2 in the auxiliary components, the saturation magnetic induction intensity of the ferrite material will be reduced (Comparative Example 11). When ZrO2 or ZrO2-doped Co2O3 is used to replace TiO2 in the auxiliary component, the magnetic permeability of the ferrite material will be significantly reduced and the temperature resistance change rate of the magnetic permeability will increase (Comparative Examples 12-13).

[0047] It can be seen that the present invention optimizes the design of the ferrite material. By regulating the ratio of each component in the main component and the auxiliary component, a ferrite material with excellent magnetic properties and excellent temperature stability can be obtained. The components in the auxiliary component can synergistically enhance the effect within a certain range. By controlling the addition amount of each component within a certain range, the obtained ferrite material can take into account both excellent magnetic properties and excellent temperature stability.

[0048] The ferrite material provided by the present invention has high thermal shock resistance and low temperature-resistant permeability change rate, while being able to maintain the corresponding initial magnetic permeability and having high saturation magnetic induction intensity, and can meet the performance requirements of ferrite inductors for temperature-resistant materials, and has good application prospects.

[0049] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A ferrite material, characterized in that: The invention comprises the following raw materials in parts by weight: 100 parts of a main component and 0.66-2.45 parts of auxiliary components; wherein the auxiliary components comprise 0.1-0.7 parts of B2O3, 0.01-0.15 parts of SnO2, 0.05-0.2 parts of TiO2 and 0.5-1.4 parts of SiO2; and the main components comprise Fe2O3, NiO, ZnO and CuO.

2. The ferrite material according to claim 1, wherein The auxiliary components include 0.1-0.5 parts of B2O3, 0.05-0.1 parts of SnO2, 0.15-0.2 parts of TiO2 and 0.7-1.2 parts of SiO2.

3. The ferrite material according to claim 1, wherein Among the auxiliary components, the weight ratio of SnO2 and TiO2 is 1:(1.5-4); preferably, among the auxiliary components, the weight ratio of SnO2 and TiO2 is 1:(1.5-3).

4. The ferrite material according to claim 1, wherein The main components, in terms of molar percentage, include 40-50 mol% of Fe2O3, 15-25 mol% of NiO, 18-35 mol% of ZnO and 3.5-7 mol% of CuO; preferably, include 45-50 mol% of Fe2O3, 15-20 mol% of NiO, 25-30 mol% of ZnO and 5-7 mol% of CuO.

5. A method for preparing the ferrite material according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: weighing raw materials in proportion, mixing, pre-burning, crushing, granulating, pressing and sintering to obtain the ferrite material.

6. The preparation method according to claim 5, wherein The mixing includes ball milling mixing, and the ball milling mixing time is 120-180 minutes.

7. The preparation method according to claim 5, wherein The pre-firing temperature is 825-875° C., and the pre-firing time is 180-240 minutes.

8. The preparation method according to claim 5, wherein The sintering temperature is 910-930° C., and the sintering time is 180-200 minutes.

9. A magnetic core, characterized in that: The invention comprises the ferrite material as described in any one of claims 1 to 4.

10. An inductor, characterized in that: Comprising the magnetic core as claimed in claim 9.

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