High-Q and high-Curie-temperature nickel-zinc LTCF material and preparation method thereof

Abstract

The invention discloses a high-Q and high-Curie-temperature nickel-zinc LTCF material and a preparation method, and belongs to the technical field of ferrite materials, raw materials of the material are composed of main materials and doping materials, the main materials are composed of 15-19mol% of NiO, 25-28mol% of ZnO, 7-11mol% of CuO and 46-48mol% of Fe2O3, the sum of the main materials and the doping materials is 100%, and the doping materials are composed of 0.1-0.3 wt% of Co2O3 and 0.3-0.9 wt% of Bi2O3; the preparation method comprises the steps of burdening, mixing, pre-sintering, grinding, granulating, forming, sintering and the like. By adjusting and optimizing the raw material composition and the preparation process, the Curie temperature Tc of the obtained low-temperature co-fired ferrite material is greater than 215 DEG C, the quality factor Q is greater than 200, the high Curie temperature is beneficial to expanding the upper limit of the use temperature range, and the high quality factor is beneficial to reducing the energy loss; therefore, the application of the chip device in energy conversion, power transmission and a wide temperature range is satisfied.

Description

Technical Field

[0001] The present invention relates to the technical field of ferrite materials, and in particular to a high-Q, high-Curie temperature nickel-zinc LTCF material and a preparation method thereof. Background Art

[0002] With the application and continuous improvement of microelectronic circuits and surface mount technology, a revolution in electronic assembly technology has been triggered worldwide. Light, thin, short and small have become important symbols and development trends for measuring electronic complete systems. The use of chip-based passive components can not only achieve the miniaturization of electronic products, but also facilitate the high automation of complete machine assembly. As a new generation of chip-based passive components, stacked chip devices (including inductors, magnetic beads, transformers, magnetic modules, etc.) are widely used in the fields of electronic complete systems such as communications, computers, industrial automation, and instrumentation. Stacked chip devices are produced by alternately coating low-temperature co-fired ferrite (LTCF) materials and electrode layers and co-firing. In order to obtain high-performance stacked chip devices, the magnetic properties of LTCF materials are the key. Nickel-zinc LTCF materials are mainly used in chip magnetic devices such as inductors, magnetic beads, transformers, and magnetic modules. Currently reported nickel-zinc LTCF materials, such as CN116283265A, CN104402428A, CN112979299A, etc., generally have problems such as low Curie temperature (Tc < 150°C) and high loss (quality factor Q < 150), which seriously limit the application of chip devices in energy conversion, power transmission and wide temperature range. Summary of the invention

[0003] One of the purposes of the present invention is to provide a high-Q, high-Curie temperature nickel-zinc LTCF material to solve the above-mentioned problems.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is as follows: a high-Q, high Curie temperature nickel-zinc LTCF material, the raw materials of which are composed of a main material and a doping material, wherein the main material is composed of NiO 15~19mol%, ZnO 25~28mol%, CuO 7~11mol%, and Fe2O346~48mol% in molar percentage, totaling 100%, and the doping material is composed of Co2O3 0.1~0.3wt% and Bi2O30.3~0.9wt% in mass percentage, and the mass percentage of the doping material is the mass proportion in the main material.

[0005] The second object of the present invention is to provide a method for preparing the above-mentioned high-Q, high Curie temperature nickel-zinc LTCF material, comprising the following steps: (1) Ingredients: Weigh the four main ingredients of NiO, ZnO, CuO and Fe2O3 according to the above ratio; (2) Mixing: dry-mix the main ingredients weighed in step (1); (3) Pre-sintering: Pre-sintering the powder mixed in step (2) to obtain pre-sintered powder; (4) Abrasive: Add the pre-sintered powder obtained in step (3) to Co2O3 and Bi2O3 in the above ratio, and grind the powder using a two-stage ball milling process to obtain ultra-fine micron-sized ferrite powder; (5) Granulation, molding and sintering: The powder obtained in step (4) is granulated, molded and then sintered to obtain the product.

[0006] As a preferred technical solution, in step (2), the mixing time is 40 to 60 minutes.

[0007] As a preferred technical solution, in step (3), the pre-firing is carried out in a sintering kiln at a pre-firing temperature of 790-840°C.

[0008] As a preferred technical solution, in step (4), the secondary ball milling is: primary ball milling for 3.5 to 4.5 hours, secondary fine ball milling for 3 to 5 hours; the wear-resistant ceramic medium grinding beads preferably have a diameter of 0.8 mm, the abrasive speed is preferably 1600 rpm, and the ratio of material to water is preferably 1:0.6.

[0009] As a preferred technical solution, in step (5), the sintering temperature is 890-910°C and the heat preservation time is 3.5-4.5h.

[0010] The present invention adds low melting point flux Bi2O3 to a high Cu content formula, cooperates with a two-stage ball milling process to obtain ultra-fine micron-level ferrite powder, and obtains a lower sintering temperature (890-910°C); by adjusting Fe and Zn in the formula, a high Curie temperature (Tc>215°C) is obtained; through combined doping of Co2O3 and Bi2O3, a trace amount of Co2O3 forms a uniaxial anisotropic and "frozen" domain wall, ensures that the magnetic permeability and Curie temperature do not change significantly, and realizes liquid phase sintering under the action of low melting point flux Bi2O3 to promote ferrite densification and grain size homogenization, and obtain a high quality factor (Q>200).

[0011] Compared with the prior art, the advantages of the present invention are: by adjusting and optimizing the raw material composition and the preparation process, the present invention obtains a low-temperature co-fired ferrite material with a Curie temperature Tc>215°C and a quality factor Q>200, thereby meeting the application of chip devices in energy conversion, power transmission and a wide temperature range. DETAILED DESCRIPTION

[0012] The preferred embodiments of the present invention are described below. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0013] Example 1

[0014] A high-Q, high-Curie temperature nickel-zinc LTCF material as described above, and its preparation method is: The main ingredients are NiO 19mol%, ZnO 26mol%, CuO 7mol%, and Fe2O3 48mol%. First, NiO, ZnO, CuO, and Fe2O3 are dry-mixed in the stated proportions for 40 minutes, and the mixture is pre-sintered in a sintering kiln at a pre-sintering temperature of 840°C. The pre-sintered powder is added with Co2O3 0.1wt% and Bi2O3 0.3wt% doping raw materials based on the mass of the powder for secondary ball milling (primary ball milling for 3.5h, secondary fine ball milling for 5h); the powder is granulated and formed into a 25×15×5 ferrite material sample ring, which is sintered at 910°C for 4.5h to obtain the product.

[0015] Example 2

[0016] A high-Q, high-Curie temperature nickel-zinc LTCF material as described above, and its preparation method is: The main materials are NiO 19mol%, ZnO 25mol%, CuO 9mol%, and Fe2O3 47mol%. First, NiO, ZnO, CuO, and Fe2O3 are dry-mixed in proportion for 45 minutes, and the mixture is pre-sintered in a sintering kiln at a pre-sintering temperature of 820°C. Co2O3 0.2wt% and Bi2O3 0.8wt% are added to the pre-sintered powder for secondary ball milling (primary ball milling for 4h, secondary fine ball milling for 4h); the powder is granulated and formed into a 25×15×5 ferrite material sample ring, and sintered at 900°C for 4h to obtain the product.

[0017] Example 3

[0018] A high-Q, high-Curie temperature nickel-zinc LTCF material as described above, and its preparation method is: The main materials are NiO 18mol%, ZnO 27mol%, CuO 8mol%, and Fe2O3 47mol%. First, NiO, ZnO, CuO, and Fe2O3 are dry-mixed in proportion for 50 minutes, and the mixture is pre-sintered in a sintering kiln at a pre-sintering temperature of 830°C. The pre-sintered powder is added with Co2O3 0.2wt% and Bi2O3 0.7wt% doping raw materials for secondary ball milling (primary ball milling for 4.5h, secondary fine ball milling for 3h). The powder is granulated and formed into a 25×15×5 ferrite material sample ring, which is sintered at 905°C for 4h.

[0019] Example 4

[0020] The main materials are NiO 17mol%, ZnO 26mol%, CuO9.5mol%, and Fe2O347.5mol%. First, NiO, ZnO, CuO, and Fe2O3 are dry-mixed in proportion for 55 minutes, and the mixture is pre-sintered in a sintering kiln at a pre-sintering temperature of 810°C. The pre-sintered powder is added with Co2O30.3wt% and Bi2O30.9wt% doping raw materials for secondary ball milling (primary ball milling for 4.5h, secondary fine ball milling for 3.5h). The powder is granulated and formed into a 25×15×5 ferrite material sample ring, which is sintered at 895°C for 4h.

[0021] Example 5

[0022] The main materials are NiO 15mol%, ZnO 28mol%, CuO 11mol%, and Fe2O3 46mol%. First, NiO, ZnO, CuO, and Fe2O3 are dry-mixed in proportion for 60 minutes, and the mixture is pre-sintered in a sintering kiln at a pre-sintering temperature of 790°C. The pre-sintered powder is added with Co2O3 0.2wt% and Bi2O3 0.6wt% doping raw materials for secondary ball milling (primary ball milling for 4h, secondary fine ball milling for 4h). The powder is granulated and formed into a 25×15×5 ferrite material sample ring, which is sintered at 890°C for 3.5h.

[0023] Comparative Example 1 This comparative example is based on the above-mentioned Example 2 (the best example), and the Fe2O3 is adjusted to 44 mol %, while the other conditions remain unchanged.

[0024] Comparative Example 2 This comparative example is based on the above-mentioned Example 2 (the best example), with ZnO adjusted to 30 mol %, and other conditions remaining unchanged.

[0025] Comparative Example 3 This comparative example is based on the above-mentioned Example 2 (the best example), with the CuO content adjusted to 5 mol %, and the other conditions remaining unchanged.

[0026] Comparative Example 4 This comparative example is based on the above-mentioned Example 2 (the best example), and Co2O is adjusted to 30wt%, while other conditions remain unchanged.

[0027] Performance Test: The materials prepared in the above-mentioned Examples 1-5 and Comparative Examples 1-4 were tested for conventional magnetic properties according to the requirements of the electronic industry military standard SJ20966-2006 "Measurement Methods for Soft Ferrite Materials", including: initial magnetic permeability, quality factor Q, Curie temperature, saturation magnetic flux density, and the results are shown in Table 1; Table 1 Test results of materials of Examples 1-5 and Comparative Examples 1-4 Initial magnetic permeability Quality factor@0.5MHz Curie temperature Saturation magnetic induction intensity (mT) Average particle size (μm) <![CDATA[Density (g / cm 3 ).]]> Shrinkage (%) Sintering temperature (℃) Example 1 182 215 229 382 0.32 5.22 15.89 910 Example 2 178 220 245 375 0.35 5.23 15.92 900 Example 3 192 218 232 366 0.36 5.22 15.91 905 Example 4 183 226 225 358 0.33 5.14 16.02 895 Example 5 190 215 218 363 0.34 5.15 16.13 890 Comparative Example 1 171 215 189 352 0.35 5.21 16.03 900 Comparative Example 2 323 172 175 359 0.34 5.20 16.23 900 Comparative Example 3 68 82 200 255 0.35 3.78 11.88 900 Comparative Example 4 195 173 238 372 0.35 5.28 15.98 900 The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-Q, high Curie temperature nickel-zinc LTCF material, characterized in that: The raw materials of the material consist of a main material and a doping material, wherein the main material consists of NiO 15~19mol%, ZnO 25~28mol%, CuO 7~11mol%, and Fe2O346~48mol% in molar percentage, totaling 100%, and the doping material consists of Co2O3 0.1~0.3wt% and Bi2O30.3~0.9wt% in mass percentage, and the mass percentage of the doping material is the mass proportion in the main material.

2. The high-Q, high Curie temperature nickel-zinc LTCF material according to claim 1, characterized in that: The main ingredients are NiO 15-19 mol%, ZnO 25-28 mol%, CuO 7-11 mol%, and Fe2O3 46-48 mol%.

3. The method for preparing the high-Q, high Curie temperature nickel-zinc LTCF material according to claim 1 or 2, characterized in that: The steps include: (1) Ingredients: Weigh the four main ingredients of NiO, ZnO, CuO and Fe2O3 according to the above ratio; (2) Mixing: dry-mix the main ingredients weighed in step (1); (3) Pre-sintering: Pre-sintering the powder mixed in step (2) to obtain pre-sintered powder; (4) Abrasive: Add the pre-sintered powder obtained in step (3) to Co2O3 and Bi2O3 in the above ratio, and grind the powder using a two-stage ball milling process to obtain ultra-fine micron-sized ferrite powder; (5) Granulation, molding and sintering: The powder obtained in step (4) is granulated, molded and then sintered to obtain the product.

4. The method according to claim 3, characterized in that In step (2), the mixing time is 40 to 60 minutes.

5. The method according to claim 3, characterized in that: In step (3), the pre-firing is carried out in a sintering kiln at a pre-firing temperature of 790 to 840°C.

6. The method according to claim 3, characterized in that In step (4), the secondary ball milling is as follows: primary ball milling for 3.5 to 4.5 hours and secondary fine ball milling for 3 to 5 hours.

7. The method according to claim 3, characterized in that In step (5), the sintering temperature is 890-910°C and the temperature is kept for 3.5-4.5 hours.