阅读说明：本技术 一种高磁导率宽温功率型镍锌ltcf材料、其制备方法及应用 (High-magnetic-permeability wide-temperature-power type nickel-zinc LTCF material, and preparation method and application thereof ) 是由 刘兴 孙小龙 周永川 王福海 于 2020-07-23 设计创作，主要内容包括：本发明公开了一种高磁导率宽温功率型镍锌LTCF材料,属于铁氧体材料技术领域,其原料包括主成分和辅助成分,所述主成分含量：NiO(15～16)mol%、ZnO(29～30)mol%、CuO(6.5～7.5)mol%、Fe<Sub>2</Sub>O<Sub>3</Sub>(47～50)mol%,所述辅助成分含量：MnCO<Sub>3</Sub>(0.3～0.5)wt%、Bi<Sub>2</Sub>O<Sub>3</Sub>(0.2～0.4)wt%；本发明所得的材料,在900℃左右烧成后具有优异显微结构,磁导率(或电感量L)—T曲线出现K<Sub>1</Sub>≈0(补偿点)Ⅰ峰的温度位置已移至+125～150℃间,居里温度高(≥170℃),Ⅰ、Ⅱ峰间具有较平坦的磁导率(或电感量L)—T曲线,温度稳定性好,Ⅰ峰值后磁导率(或电感量L)的减落小,能够可靠地将应用工作温度范围拓展至-55～+150℃间,并满足芯片化LTCF微磁变压器用GM400材料电感量L变化率＜20%的使用要求。(The invention discloses a high-permeability wide-temperature power type nickel-zinc LTCF material, which belongs to the technical field of ferrite materials, and comprises the following raw materials in percentage by weight: NiO (15-16) mol%, ZnO (29-30) mol%, CuO (6.5-7.5) mol%, Fe 2 O 3 (47-50) mol%, and the content of the auxiliary components: MnCO 3 （0.3～0.5）wt%、Bi 2 O 3 (0.2-0.4) wt%; the material obtained by the invention has excellent microstructure after being sintered at about 900 ℃, and the magnetic permeability (or inductance L) -T curve appearsK 1 The temperature position of the peak I which is approximately equal to 0 (compensation point) is shifted to between +125 and 150 ℃, the Curie temperature is high (equal to or more than 170 ℃), a relatively flat magnetic conductivity (or inductance L) -T curve is formed between the peak I and the peak II, the temperature stability is good, the reduction of the magnetic conductivity (or inductance L) after the peak I is reduced, the application working temperature range can be reliably expanded to between-55 and +150 ℃, and the use requirement that the inductance L change rate of a GM400 material for a chip LTCF micro-magnetic transformer is less than 20% is met.)

1. A high-permeability wide-temperature power type nickel-zinc LTCF material is characterized in that: the raw materials comprise main components and auxiliary components, wherein,

the content of the main components is as follows: NiO (15-16) mol%, ZnO (29-30) mol%, CuO (6.5-7.5) mol%, Fe₂O₃（47～50）mol%，

The content of the auxiliary components is as follows: MnCO₃（0.3～0.5）wt%、Bi₂O₃（0.2～0.4）wt%。

2. The high permeability wide temperature power type nickel zinc LTCF material of claim 1, wherein: the content of the main components is as follows: NiO15.50mol%, ZnO 29.50mol%, CuO7.00mol%, Fe₂O₃48.00 mol%，

The content of the auxiliary components is as follows: MnCO₃0.40wt%、Bi₂O₃0.30wt%。

3. The preparation method of the high-permeability wide-temperature power type nickel-zinc LTCF material as claimed in claim 1 or 2, is characterized in that: and (3) carrying out dry mixing on the raw material oxide by adopting a high-frequency vibration mixing system, wherein the mixing time is 40-70 min.

4. The method of claim 3, wherein: and (3) presintering by adopting a sintering kiln, and controlling the temperature of the presintering temperature to be 830-860 ℃.

5. The method of claim 3, wherein: a large-flow circulating sand mill wet grinding material is adopted, wherein the first-stage grinding material is used for 3-5 hours, and the second-stage fine grinding material is used for 3-6 hours.

6. Use of a high permeability wide temperature power type nickel zinc LTCF material according to claim 1 or 2, characterized in that: the method is applied to the chip LTCF micro-magnetic transformer.

Technical Field

The invention relates to the technical field of ferrite materials, in particular to a high-permeability wide-temperature-power type nickel-zinc LTCF material, and a preparation method and application thereof.

Background

The chip LTCF micro-magnetic transformer is mainly applied to weaponry and civil power systems such as power converters, transformers and the like in aviation, aerospace, navigation, land and the like.

A material for a chip LTCF micro-magnetic transformer belongs to the field of ferrite materials, realizes multilayer chip type, small light weight and integrated functionalization of a power magnetic device based on a low temperature co-fired ferrite technology (LTCF), solves the problems of size and weight of a traditional block discrete power magnetic device, and fundamentally solves the problems of large inductance of the chip LTCF micro-magnetic transformer and magnetic performance (magnetic permeability mu) under a high-temperature working environment of + 125-150 DEG C_iOr inductance L) is large compared with normal temperature (20-25 ℃), leakage inductance loss is effectively reduced, and stability and use reliability of magnetic performance of the chip LTCF micro magnetic transformer in the working temperature environment are realized. The material characteristics determine the performance and the working characteristics of the device, and the characteristics of the low-temperature co-fired GM400 material suitable for the application of the chip LTCF micro-magnetic transformer directly determine the large inductance of the chip LTCF micro-magnetic transformer and the magnetic performance stability and the use reliability under the high-temperature working environment of + 125-150 ℃, so that the GM400 material for the chip LTCF micro-magnetic transformer has the basic requirement of magnetic permeability mu_iMore than or equal to 400, and the power consumption Pv is less than or equal to 150kW/m³(100-300 KHz @30mT, 20 ℃), a sintering temperature of 850-910 ℃, and an inductance L change rate of less than 20% (a working temperature (125-150 ℃) is relative to a normal temperature (20-25 ℃)); and there is no material that can satisfy these conditions at present.

In general, the initial permeability μ of the soft magnetic ferrite material_iProportional to the square of the saturation magnetization Ms and to the magnetocrystalline anisotropy constant K₁Magnetostriction coefficient lambda s and internal stress sigma_iAre inversely proportional and these parameters are functions of temperature; due to K₁Ratio of change with temperature Ms²Large variation with temperature, K₁Is the influence of the permeability mu_iThe first factor of the temperature characteristic. Mu of different soft magnetic ferrites_iDifferent T characteristics, initial permeability μ_iThe soft magnetic ferrite material has one or two peaks along with the change of temperature, the first peak, namely the I peak, can appear on the soft magnetic ferrite material, and the second peak, namely the II peak, can appear on the soft magnetic ferrite material through the material formula design. The peak I appears due to the factor K around the Curie temperature₁The value drop is more rapid than Ms value, K₁The sharp zero trend, the peak value of II is caused by K at the temperature far lower than Curie temperature (such as normal temperature or negative temperature)₁Tending to zero, i.e. mu_iThe occurrence of the I and II peak values can be ascribed to K₁0 (compensation point) plays a major role. Compensation points for the position of the general term II peak, Co only²⁺When the ion compensation is carried out, the compensation point moves towards the high temperature direction along with the increase of the content; fe only²⁺When the ion compensation is carried out, the compensation point moves towards the low temperature direction along with the increase of the content; co²⁺、Fe²⁺When ions compensate simultaneously, the compensation results are just opposite if Co is controlled²⁺、Fe²⁺The ion proportion is proper, and a compensation point can be obtained at the negative temperature. Generally by means of material K₁And a T change rule, wherein the working temperature range of the material is controlled by controlling the temperature positions and peak heights of the I and II peaks, and a relatively flat area is formed between the I and II peaks to control the temperature stability of the magnetic conductivity of the material between the two peaks so as to meet practical requirements.

In the conventional high-permeability power type nickel-zinc LTCF material formula design, the power loss is reduced by adding a proper amount of high-Q ion Co freezing domain wall into a NiCuZn system iron-deficient formula and controlling Fe²⁺Content (Fe)₂O₃Content < 50 mol%); because of the limitation of the low-temperature co-firing temperature condition (about 900 ℃), in order to reduce the sintering temperature and consider the power loss of the material, the low melting point which is not beneficial to reducing the power loss and is beneficial to reducing the sintering temperature is not adoptedFluxing agent Bi₂O₃Usually, a high Cu formula is adopted to add a low melting point material V₂O₅The method of (1).

In the existing formula design of the known high-permeability wide-temperature power type nickel-zinc LTCF material, NiCuZn iron-rich (Fe) is adopted for reducing power loss₂O₃Content more than 50mol%) without adding Co and controlling Zn²⁺、Fe²⁺The method of content; the sintering temperature is reduced by adopting a formula with high Cu content and adding a proper amount of low-melting-point material V₂O₅And the material has excellent microstructure (fine, uniform and complete crystal grains, less and dispersed internal pores and the like) after being fired at the temperature of about 900 ℃, so that a compensation point at the position of a peak value II can move to a farther low-temperature direction (such as minus 55 ℃) and a relatively flat area is formed between the peak value I and the peak value II, and the temperature stability is good.

The conventional high-permeability power type nickel-zinc LTCF material prepared by the prior art contains Co and Fe ions in a formula and K₁The optimal temperature position of the peak value compensation point of the T curve II can only reach about-20 ℃, the material is difficult to move to a farther low temperature direction (such as-55 ℃), the relatively optimal application temperature range of the material is between-20 ℃ and +85 ℃, and the problems of large change of magnetic performance (magnetic permeability or inductance) and poor temperature stability generally exist in the wide temperature application range of-55 ℃ to +85 ℃.

The high-permeability wide-temperature power type nickel-zinc LTCF material prepared by the prior art enables a compensation point at the position of a peak value II to move to a farther low-temperature direction (such as minus 55 ℃), a flat area is arranged between the peak values I and II, the temperature stability is good, the relatively better application temperature range of the material is between minus 55 ℃ and plus 85 ℃, and the problem of wide-temperature application of the conventional high-permeability wide-temperature power type nickel-zinc LTCF material is effectively solved. Whereas the above-mentioned high magnetic permeability (. mu.) was obtained by the prior art_iNot less than 400) common existing magnetic permeability (or inductance L) -T curve of conventional and wide-temperature power type nickel-zinc LTCF material₁The temperature positions of the I peak which are approximately equal to 0 (compensation point) are all between +80 ℃ and 100 ℃, the Curie temperature is low (less than or equal to 140 ℃), and the reduction of the magnetic conductivity (or inductance L) after the I peak is very large and cannot be fullThe inductance L change rate of the high-permeability low-temperature co-fired material for the chip LTCF micro-magnetic transformer is less than 20 percent (relative to normal temperature (20-25 ℃) at working temperature (+ 125-150 ℃)).

Disclosure of Invention

One of the objectives of the present invention is to provide a high magnetic permeability wide temperature power type nickel-zinc ltcc material to solve the above problems.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

in the formula design, a ceramic oxide dry method and wet method are combined in the process on the basis of taking a spinel NiCuZn soft magnetic ferrite material as a formula of a GM400 material; the material consists of main components and auxiliary components, wherein the main components are powdery oxides NiO, ZnO, CuO and Fe₂O₃The mol percentage content is adopted, and the auxiliary component is MnCO₃Low melting point additive Bi₂O₃And the like, and the mass percentage is adopted;

in the design of material properties, in order to enable the compensation point at which the I peak value appears to move to a farther high temperature region (such as + 125-150 ℃), and to have a high Curie temperature: the invention adopts NiCuZn slightly deficient iron (Fe) for reducing power loss₂O₃Content slightly less than 50mol%) without adding Co and controlling Zn²⁺、Fe²⁺The method of content;

in order to ensure that a compensation point at the position of the peak value I can move to a farther high-temperature area (such as + 125-150 ℃) and has high Curie temperature, the invention adopts a slightly-deficient iron formula to reduce non-magnetic Zn as far as possible²⁺The auxiliary component MnCO is added₃To suppress Fe²⁺And Ni²⁺A method for improving the super-exchange force formed by magnetic moments of magnetic ions occupying A, B bits in ferrite; the sintering temperature is reduced, and a low-melting-point Bi is added according to a formula of medium Cu content (CuO content is 5-8 mol percent)₂O₃And the method of refining powder particles (the particle size distribution D90 is less than 2.0 μm) by a wet grinding process is matched, so that the material has an excellent microstructure (the crystal grains are fine, uniform and complete, and the internal pores are few and dispersed and the like) after being fired at about 900 ℃;

specifically, NiCuZn is slightly deficient of iron (Fe) in terms of formula₂O₃The content is slightly less than 50mol percent), and the main components are powdered oxides NiO, ZnO, CuO and Fe₂O₃The auxiliary component is MnCO₃Low melting point additive Bi₂O₃(adding in wet grinding), and controlling the main component content of the GM400 material: NiO (15-16) mol%, ZnO (29-30) mol%, CuO (6.5-7.5) mol%, Fe₂O₃(47-50) mol%, content of auxiliary component MnCO₃（0.3～0.5）wt%、Bi₂O₃（0.2～0.4）wt%。

As a preferred technical scheme: the content of the main components is as follows: NiO15.50mol%, ZnO 29.50mol%, CuO7.00mol%, Fe₂O₃48.00 mol%，

The content of the auxiliary components is as follows: MnCO₃0.40wt%、Bi₂O₃0.30wt%。

The second purpose of the invention is to provide the preparation method of the high-permeability power type nickel-zinc LTCF material, on the basis of the traditional preparation process of ceramic oxides, firstly, a high-frequency vibration mixing system is adopted to effectively improve the mixing uniformity of the oxides of the raw materials, a high-speed primary crushing effect is achieved, dry mixing is completed, the mixing time is controlled to be 40-70 minutes, then, a sintering kiln is further adopted for pre-sintering, and the pre-sintering junction temperature is controlled to be (830-860);

further adopts a wet grinding material of a large-flow circulating sand mill to refine powder particles so as to improve the activity of the powder, reduce the activation energy of reaction, effectively reduce the sintering temperature and control the particle size distribution D of the powder particles₉₀The ultra-fine ferrite particles are obtained below 2.0 mu m.

The invention improves the raw material formula and the preparation process, and adopts a dry method and a wet method of ceramic oxide to obtain the ultra-fine ferrite particles with the particle size of 2.0 mu m by using a scheme. Because the traditional dry process (adopting a high-frequency vibration mixing system to mix materials D90: 20-50 μm, large particle size, wide distribution range and poor uniformity) or wet process technology (adopting a primary sanding or ball milling grinding material D90: 3-15 μm, large particle size, wide distribution range and poor uniformity, which is not suitable for the multilayer lamination process of LTCF devices) can not meet the particle size distribution requirement that D90 is less than 2.0 μm, the invention adopts a combined scheme of the dry process and the wet process of the ceramic oxide which can meet the requirement of smaller particle size distribution.

Specifically, a high-frequency vibration mixing system is adopted to effectively improve the mixing uniformity of oxides of raw materials, a high-speed primary crushing effect is achieved, dry mixing is completed, the mixing time is controlled to be 40-70 minutes, and further, large-flow circulation sand mill wet grinding materials (primary grinding materials for 3-5 hours and secondary fine grinding materials for 3-6 hours) are adopted to refine powder particles, so that the activity of the powder is improved, the reaction activation energy is reduced, the sintering temperature is effectively reduced, and the particle size distribution D90 of the powder particles is controlled to be less than 2.0 microns, so that ultra-fine ferrite particles are obtained.

The third purpose of the invention is to provide the application of the material, in particular to the application of the material in a chip LTCF micro magnetic transformer, because the material has excellent microstructure after being fired at the temperature of 900 ℃ or so, and the permeability (or inductance L) -T curve shows K₁The temperature position of a peak I which is approximately 0 (compensation point) is shifted to be between +125 and 150 ℃, the Curie temperature is high (equal to or more than 170 ℃), a relatively flat magnetic conductivity (or inductance L) -T curve is formed between the peak I and the peak II, the temperature stability is good, the reduction of the magnetic conductivity (or inductance L) after the peak I is small, the reliable application working temperature range is expanded to be between-55 and +150 ℃, and the use requirement that the inductance L change rate of a GM400 material for a chip LTCF micro-magnetic transformer is less than 20% (relative to normal temperature (20 to 25 ℃) when the working temperature is (+ 125 to 150 ℃) is met.

Compared with the prior art, the invention has the advantages that: the material obtained by the invention has magnetic permeability mu_iMore than or equal to 400, and the power consumption Pv is less than or equal to 150kW/m³(100-300 KHz @30mT, 20 ℃), a sintering temperature of 850-910 ℃, and an inductance L change rate of less than 20% (a working temperature (125-150 ℃) is relative to a normal temperature (20-25 ℃)); after being sintered at about 900 ℃, the material has excellent microstructure and K appears in a magnetic permeability (or inductance L) -T curve₁The temperature position of the peak which is approximately equal to 0 (compensation point) I is shifted to between +125 and 150 DEG CThe internal temperature is high (more than or equal to 170 ℃), a relatively flat magnetic conductivity (or inductance L) -T curve is formed between the I peak value and the II peak value, the temperature stability is good, the reduction of the magnetic conductivity (or inductance L) after the I peak value is small, the reliable application working temperature range is expanded to be between 55 ℃ below zero and 150 ℃, and the use requirement that the inductance L change rate of a GM400 material for a chip LTCF micro-magnetic transformer is less than 20% (relative to normal temperature (20-25 ℃) at the working temperature (+ 125-150 ℃) is met.

Drawings

FIG. 1 is a typical inductance L-T curve for a material of example 1 of the present invention;

FIG. 2 is a typical inductance L-T curve of a conventional wide temperature power type nickel zinc LTCF material;

FIG. 3 is a L-T curve of inductance of typical high permeability wide temperature power type nickel-zinc LTCF materials with different ZnO contents.

Detailed Description

The present invention will be further described with reference to the following examples.