KR20120115810A - Nizncu ferrite and preparation method thereof - Google Patents

Abstract

PURPOSE: NiZnCu ferrite and a manufacturing method thereof are provided to easily lower the sintering temperature of the NiZnCu ferrite by controlling the content of MnO and V2O5. CONSTITUTION: NiZnCu ferrite includes Fe of 45 to 48 mol% as Fe2O3. The NiZnCu ferrite includes Ni of 9 to 40 mol% as NiO. The NiZnCu ferrite includes Zn of 7 to 37 mol% as ZnO. The NiZnCu ferrite includes Cu of 4 to 8 mol% as CuO. The NiZnCu ferrite includes V of 0.3 to 1 parts by weight as V2O5. The NiZnCu ferrite includes Mn of 3 to 7 parts by weight as MnO. [Reference numerals] (AA) Glass dielectric; (BB) Ferrite

Description

ＮｉＺｎＣｕ ferrites and preparation method thereof {NiZnCu FERRITE AND PREPARATION METHOD THEREOF}

The present invention relates to a NiZnCu ferrite capable of co-sintering with a glass dielectric at low temperature and a method of manufacturing the same.

Recently, as electronic devices are miniaturized and digitized, demands for noise removal are increasing, and components for countering electromagnetic interference (EMI) for this purpose are being used.

EMI components are provided with various shapes such as toroidal type and chip type, but chip type is mainly used according to the trend of surface mounting of these parts.

In the case of chip type EMI components, glass dielectric and ferrite are heterogeneously bonded to increase the noise removal effect in the high frequency band. In this case, at the sintering temperature of the glass dielectric near 800 ° C., the glass dielectric and the ferrite should be sintered simultaneously to minimize the defect of the product due to the shrinkage difference.

To this end, a method of lowering the sintering temperature of ferrite has been proposed by adding Bi ₂ O ₃ , V ₂ O ₅ , and the like, which are commonly known as additives for low temperature sintering. However, as the content of the low-temperature sintering additive is increased, the sintering temperature may be lowered, but they may cause a reaction with the silver (Ag) paste used as an internal electrode in chip manufacturing. This may impair the electromagnetic characteristics of the chip component, so it is difficult to be applied to the actual chip component manufacturing process. In order to secure stability against the reaction with the paste, the content of the low-temperature sintering additive should be 0.7 parts by weight or less based on 100 parts by weight of ferrite. However, in this case, it is difficult to sufficiently lower the sintering temperature of the ferrite, so that unstable sintering is performed at around 800 ° C, which is a temperature for simultaneous sintering with the glass dielectric. As a result, the sintering strength is lowered, thereby lowering the impact resistance of the product and causing defects in the product due to the difference in shrinkage rate.

In addition, in order to simultaneously sinter with ferrite at around 800 ° C., which is a sintering temperature of the glass dielectric, without using an additive for low temperature sintering, a method of manufacturing ferrite into nano-sized particles may be used. In this case, however, the manufacturing cost is high and the production volume is not high, so it is not economical, and the manufacturing of the chip parts is not easy to handle.

It is an object of the present invention to provide a NiZnCu ferrite capable of co-sintering with a glass dielectric at a low temperature of 800-810 ° C. due to a low sintering temperature.

Another object of the present invention is to provide a method for producing the NiZnCu ferrite.

Another object of the present invention is to provide a heterojunction in which a glass dielectric and a ferrite including NiZnCu ferrite are in contact with each other.

In addition, another object of the present invention is to provide a method for producing the heterojunction.

1.45-48 mol% of Fe in terms of Fe ₂ O ₃ , 9-40 mol% of Ni in terms of NiO, 7-37 mol% of Zn in terms of ZnO and 4-8 mol% of Cu in terms of CuO as main components NiZnCu ferrite comprising: 0.3-1 part by weight in terms of V ₂ O ₅ and 3-7 parts by weight of Mn in terms of MnO as additives based on 100 parts by weight of the main component.

2. In the above 1, 45-48 mol% of Fe in terms of Fe ₂ O ₃ as the main component, 15-25 mol% in terms of NiO, 17-30 mol% in terms of ZnO and Cu in terms of CuO NiZnCu ferrite containing 4-8 mol%.

3. In the above 1, NiZnCu ferrite having a shrinkage rate of 15-17% when sintered at a low temperature of 800-810 ℃ and permeability of 25 or more in the frequency band of 1MHz.

4. In the above 1, Ni is contained 0.3-0.5 parts by weight in terms of V ₂ O ₅ , Mn is contained in 3-5 parts by weight in terms of MnO NiZnCu ferrite.

5. NiZnCu ferrite according to the above 4, the magnetic permeability is more than 40 in the frequency band of 1MHz.

6. 45-48 mol% of Fe in terms of Fe ₂ O ₃ , 9-40 mol% of Ni in terms of NiO, 7-37 mol% of Zn in terms of ZnO and 4-8 mol% of Cu in terms of CuO A first step of wet mixing an additive including 0.3-1 part by weight of V in terms of V ₂ O ₅ and 3-7 parts by weight of Mn in terms of MnO in 100 parts by weight of the main component; A second step of drying and pulverizing the slurry prepared by wet mixing; And a third step of calcining the pulverized powder at 750-760 ° C. for 3-5 hours.

7. According to the above 6, NiZnCu ferrite manufacturing method further comprising the fourth step of wet grinding the calcined powder.

8. According to the above 7, NiZnCu ferrite manufacturing method further comprises a fifth step of drying and pulverizing the slurry prepared by wet grinding at 150-200 ℃ for 12-15 hours.

9. A heterojunction in which the NiZnCu ferrite of any one of 1 to 5 is bonded to one side of a glass dielectric.

10. A method for producing a heterojunction comprising the step of co-sintering a glass dielectric and NiZnCu ferrite of any one of 1 to 5 at low temperature at 800-810 ° C.

The present invention can provide a NiZnCu ferrite and a method for manufacturing the same, which allows a stable sintering at a low temperature of 800-810 ° C. due to a low sintering temperature and has an appropriate shrinkage ratio, thereby enabling simultaneous sintering with a glass dielectric.

In addition, the present invention can easily lower the sintering temperature of NiZnCu ferrite by controlling the content of MnO together with V ₂ O ₅ , which is an additive for low temperature sintering.

In addition, the NiZnCu ferrite of the present invention is excellent in sintering strength even when co-sintering with a glass dielectric at a low temperature of 800-810 ° C. to ensure impact resistance, and there are no defects caused by the difference in shrinkage rate, and it is a silver paste used as an internal electrode. It does not cause any reactions with it, so it can secure electromagnetic characteristics.

In addition, since the NiZnCu ferrite of the present invention can be co-sintered with a glass dielectric, it is possible to manufacture a passive element in the form of a heterojunction.

1 is a graph showing the shrinkage (%) characteristics according to the content of V ₂ O ₅ at sintering at 800 ℃,
2 is a graph showing the shrinkage (%) characteristics according to the content of MnO during sintering at 800 ℃,
Figure 3 is a graph showing the permeability (permeability) characteristics of each frequency during sintering at 800 ℃ of NiZnCu ferrite prepared in Examples 1-2, 9-12,
Figure 4 is a photograph showing the degree of shrinkage of the heterojunction consisting of NiZnCu ferrite and glass dielectric prepared in Examples 5-6, Comparative Examples 3, 8,
5 is a cross-sectional view of a heterojunction according to an embodiment of the present invention.

The present invention relates to a NiZnCu ferrite and a method for manufacturing the same, which can simultaneously sinter with a glass dielectric at a low temperature of 800-810 ° C. due to a low sintering temperature.

Hereinafter, the present invention will be described in detail.

NiZnCu ferrite of the present invention as a main component 45-48 mol% in terms of Fe ₂ O ₃ Fe, 9-40 mol% in terms of NiO, 7-37 mol% in terms of ZnO and Zn 4 Cu in terms of CuO It contains -8 mol%, and 0.3 to 1 parts by weight in terms of V ₂ O ₅ and 3-7 parts by weight of Mn in terms of MnO as an additive with respect to 100 parts by weight of the main component.

In the present invention, the content of the metal component constituting the NiZnCu ferrite is expressed in terms of oxide, but it is natural that other types of compounds other than oxide may be converted accordingly.

NiZnCu ferrite of the present invention contains Fe, Ni, Zn and Cu as a main component, it is characterized in that the content is configured to optimize. Specifically, with respect to a total of 100 mol% of the main component constituting the ferrite Fe is 45-48 mol% in terms of Fe ₂ O ₃ , Ni is 9-40 mol% in terms of NiO, Zn is 7-37 mol% in terms of ZnO and Cu is contained 4-8 mol% in CuO conversion. Preferably, Fe is 45-48 mol% in terms of Fe ₂ O ₃ , Ni is 15-25 mol% in terms of NiO, Z-30 is 17-30 mol% in terms of ZnO, and Cu is CuO in terms of 100 mol% of the main components. It is preferable that 4-8 mol% is included in the case of low temperature sintering so that a permeability of 25 or more and a loss of 0.1 or less can be obtained in the frequency band of 1 MHz.

NiZnCu ferrite of the present invention includes V and Mn as additives together with the main components, and is characterized in that the content thereof is configured to be optimized. Specifically, V is 0.3-1 parts by weight in terms of V ₂ O ₅ , and Mn is 3-7 parts by weight in terms of MnO based on 100 parts by weight of the main component.

1 is in the condition that the proportion of the main component Fe ₂ O ₃ , NiO, ZnO and CuO is 47 mol%: 20 mol%: 29 mol%: 4 mol%, MnO is contained in 3 parts by weight based on 100 parts by weight of the main component It is a graph showing the shrinkage (%) characteristics according to the content of V ₂ O ₅ when sintering at 800 ℃. V ₂ O ₅ is a conventionally known additive for low temperature sintering and lowers the sintering temperature of NiZnCu ferrite, and it can be seen that the shrinkage rate increases as its content increases. V ₂ O ₅ is preferably included in 0.3-1 part by weight, more preferably 0.3-0.5 parts by weight based on 100 parts by weight of the main component. In the above content range, it is possible to secure a shrinkage rate of 15-17% when sintering at a low temperature of 800-810 ° C, and a glass dielectric having a shrinkage rate of 13-16% and a complementary shrinkage rate at the same time of sintering are complemented by the product. The defect of can be minimized. If the content is less than 0.3 parts by weight, the sintering temperature may not be sufficiently lowered, resulting in unstable sintering at low temperature sintering and it is difficult to secure an appropriate shrinkage rate. In addition, when the content is greater than 1 part by weight, it may react with the silver paste used as the internal electrode when co-sintering with the glass dielectric, thereby inhibiting electromagnetic characteristics.

FIG. 2 shows a ratio of Fe ₂ O ₃ , NiO, ZnO, and CuO of 47 mol%: 20 mol%: 29 mol%: 4 mol%, and 800 on condition that V ₂ O ₅ is 0.3 parts by weight with respect to 100 parts by weight of the main component. It is a graph showing the shrinkage (%) characteristics according to the content of MnO when sintered at ℃. MnO supplemented the difficulty of sufficiently lowering the sintering temperature of NiZnCu ferrite due to the limitation of its proper content when using V ₂ O ₅ alone, and worked together with small amounts of V ₂ O ₅ to increase the sintering temperature at 800-810. Allow to lower to about ℃. MnO is preferably included in 3-7 parts by weight based on 100 parts by weight of the main component. In the above content range, the sintering temperature is lowered to secure a shrinkage rate of 15-17% when sintered at a low temperature of 800-810 ° C., thereby minimizing product defects due to the difference in shrinkage rate when sintering simultaneously with the glass dielectric. If the content is less than 3 parts by weight, the effect of lowering the sintering temperature is insignificant, and if it is more than 7 parts by weight, there is no further effect of lowering the sintering temperature and there is no difference in shrinkage rate, which is uneconomical.

NiZnCu ferrite of the present invention configured as described above can be co-sintered with a glass dielectric, preferably at a low temperature of 800-810 ° C by lowering the sintering temperature by including V in an appropriate amount and controlling Mn in an optimum range. It can be done.

NiZnCu ferrite of the present invention is prepared by the following method.

NiZnCu ferrite manufacturing method comprises the first step of wet mixing the raw materials; A second step of drying and pulverizing the slurry prepared by wet mixing; And a third step of calcining the pulverized powder.

First, Fe is 45-48 mol% in terms of Fe ₂ O ₃ , Ni is 9-40 mol% in terms of NiO, Zn is 7-37 mol% in terms of ZnO and Cu is 4-8 mol% in terms of CuO 100 parts by weight of the main component and V are prepared in the slurry consisting of additives containing 0.3-1 part by weight in terms of V ₂ O ₅ and 3-7 parts by weight in terms of MnO, and wet mixing them to prepare a slurry. ). Wet mixing may be carried out using a ball mill, for example, after adding purified water (ion exchange water) with an ion exchange filter to the raw material, which may be carried out for at least 6 hours, preferably 20-24 hours. Can be.

The slurry produced by wet mixing is then dried at 150-200 ° C. for 12-30 hours, preferably 15-25 hours, followed by disintegration (second step). The disintegration method is not particularly limited.

The pulverized powder is then calcined at 750-760 ° C. for 2-5 hours in an atmospheric atmosphere (third step). This calcination temperature is a temperature at least 40 ° C. low considering that the calcination temperature of conventional NiZnCu ferrite is 800 ° C. or higher, such as 800-900 ° C. Through this, it can be seen that the sintering temperature of the NiZnCu ferrite of the present invention is further lowered. If the calcination temperature is not in the above range, the crystal structure of the ferrite is not formed completely, the electromagnetic properties may be changed.

The calcined powder is then wet milled for 20-24 hours using a ball mill or the like to prepare a slurry (fourth step). At this time, the size of the wet pulverized particles can be carried out to 0.8 ㎛ or less, preferably 0.1-0.4 ㎛, more preferably 0.1-0.2 ㎛. The grinding process can improve particle size control, necking removal and additive dispersibility.

Then, it is dried for 12-15 hours at 150-200 ° C. prepared by wet grinding, and then disintegrated in the same manner as above (fifth step).

The present invention provides a heterojunction using the NiZnCu ferrite.

As shown in FIG. 5, the heterojunction may be in a form in which ferrite is bonded to one surface of the glass dielectric, and the shape thereof is not particularly limited.

In addition, the interface between the glass dielectric of the heterojunction and the ferrite may be bonded by low temperature sintering.

The ferrite constituting the heterojunction is not particularly limited as long as it is the NiZnCu ferrite of the present invention, and may be, for example, a molded body such as a sheet, a rod, or a block produced by a conventional compression molding method.

It is possible to prepare a heterojunction by arranging the surfaces where the ferrite and the glass dielectric are bonded to face each other and then co-sintering them at a low temperature of 800-810 ° C. In the above temperature range, the ferrite is stably sintered even at the sintering temperature of the glass dielectric to have excellent strength, imparting impact resistance to the heterogeneous bonded body, and the ferrite may have an appropriate shrinkage rate, thereby complementing the shrinkage of the glass dielectric. Can also be suppressed.

Hereinafter, preferred examples are provided to aid the understanding of the present invention, but these examples are merely illustrative of the present invention and are not intended to limit the scope of the appended claims. It is apparent to those skilled in the art that various changes and modifications can be made to the present invention, and such modifications and changes belong to the appended claims.

Example

Example  1-12, Comparative example  1-8

Main components Fe ₂ O ₃ (DAE SANG), NiO (IN CO), ZnO (DAE JUNG) and CuO (JUNSEI), and V ₂ O ₅ (JUNSEI) and MnO as additives based on 100 parts by weight of the main component (JUNSEI) was weighed as shown in Table 1, respectively, and ion-exchanged water was added thereto, followed by wet mixing for 20 hours using a ball mill.

The slurry prepared by wet mixing was completely dried and crushed at 150 ° C. for 12 hours.

The disintegrated powder was calcined at 750-760 ° C. for 4 hours to produce a spinel crystal phase.

Ion-exchanged water was added to the calcined powder and wet milled for 20 hours using a ball mill.

The slurry produced by wet milling was again completely dried and crushed at 150 ° C.

division Main ingredient (mol%) Additive (part by weight) Fe ₂ O ₃ NiO ZnO CuO V ₂ O ₅ MnO Example 1 47 19 29 5 0.3 3 Example 2 47 19 29 5 0.3 5 Example 3 47 18 28 7 0.5 3 Example 4 47 18 28 7 0.5 5 Example 5 47 20 26 7 0.3 3 Example 6 47 20 26 7 0.3 5 Example 7 47 20 26 7 0.5 3 Example 8 47 20 26 7 0.5 5 Example 9 47 20 26 7 0.5 7 Example 10 47 20 29 4 0.5 5 Example 11 47 22 26 5 0.7 3 Example 12 47 22 26 5 0.7 5 Comparative Example 1 47 20 26 7 0.7 - Comparative Example 2 47 20 26 7 - 5 Comparative Example 3 47 20 26 7 0.1 5 Comparative Example 4 47 20 26 7 0.1 7 Comparative Example 5 47 20 26 7 0.2 5 Comparative Example 6 47 20 26 7 0.2 7 Comparative Example 7 47 20 26 7 0.3 2.5 Comparative Example 8 47 20 26 7 0.3 7.8

Test Example

1. Permeability ( permeability , μ measurement

3 parts by weight of polyvinyl alcohol (PVA) resin was mixed with 100 parts of NiZnCu ferrite powder prepared in Examples and Comparative Examples, and the mixture was sintered into a toroidal form having an outer diameter of 18 mm, an inner diameter of 6 mm, and a height of 3 mm. Prepared.

Permeability of the prepared sintered compact was measured using an impedance analyzer.

2. Shrinkage of Ferrite (%)

3 parts by weight of a polyvinyl alcohol (PVA) resin was mixed with 100 parts of NiZnCu ferrite powder prepared in Examples and Comparative Examples, and the mixture was compression molded in a toroidal form and sintered at 800 ° C.

The outer diameter before and after sintering the compression molded body was measured, and the shrinkage ratio was calculated using Equation 1 below.

[Wherein, A is the outer diameter before sintering of the compact and B is the outer diameter after sintering of the compact.]

division Permeability (μ) (1MHz) Shrinkage (%) Example 1 102 15.8 Example 2 130 16.2 Example 3 122 16.4 Example 4 126 16.7 Example 5 49 15.4 Example 6 58 16.1 Example 7 43 16.3 Example 8 48 16.4 Example 9 51 16.5 Example 10 50 16.2 Example 11 30 16.5 Example 12 33 16.7 Comparative Example 1 16 8.2 Comparative Example 2 13 6.2 Comparative Example 3 19 9.7 Comparative Example 4 21 10.4 Comparative Example 5 23 11.8 Comparative Example 6 24 12.4 Comparative Example 7 43 14.8 Comparative Example 8 67 17.5

As shown in Table 2 and Figure 3, the NiZnCu ferrite of the present invention is stable sintering even at low temperature sintering, showing a permeability of 25 or more even in the frequency band of 1MHz, can be applied as an EMI component, 15-17% By showing the shrinkage ratio of the glass dielectric and the sintering at the same time, it can be seen that the appropriate strength can be secured and defects due to the shrinkage difference can be suppressed.

3. Shrinkage degree of heterozygotes

3 parts by weight of a polyvinyl alcohol (PVA) resin was mixed with respect to 100 prepared NiZnCu ferrite powders, and the mixture was compression molded into chips.

Heterogeneous composites were prepared by arranging the chip-shaped glass dielectric and chip-shaped compression molded ferrite as shown in FIG.

4A-D are photographs showing the degree of shrinkage of the heterojunction prepared using the NiZnCu ferrites of Examples 5-6 and Comparative Examples 3 and 8, respectively. The ferrite of Example 5-6 had a shrinkage of 15-17%, so that there was almost no difference in shrinkage even when co-sintering with the glass dielectric, which did not cause a defect. On the other hand, the ferrite of Comparative Example 3 is too small shrinkage compared to the glass dielectric is bent as shown in Figure 4 (C), the ferrite of Comparative Example 8 is so large that the shrinkage of the ferrite occurs a warping phenomenon as shown in Figure 4 (D) It was confirmed that causing the defect.

Claims (10)

As the main component contains 45-48 mol% of Fe in terms of Fe ₂ O _3, 9-40 mol% Ni as NiO, Zn 4-8 mol% in terms of ZnO and 7-37 mol% of Cu in terms of CuO in the ,
NiZnCu ferrite containing 0.3-1 part by weight in terms of V ₂ O ₅ and 3-7 parts by weight of Mn in terms of MnO as an additive based on 100 parts by weight of the main component.
The method according to claim 1, the main component in a 45-48 mol% of Fe in terms of Fe ₂ O _3, 15-25 mol% Ni as NiO, 17-30 mol% of Zn in terms of ZnO and Cu in terms of CuO 4 NiZnCu ferrite containing 8 mol%.
The NiZnCu ferrite according to claim 1, wherein the shrinkage is 15-17% upon sintering at a low temperature of 800-810 ° C. and the permeability is 25 or more in the frequency band of 1 MHz.
The NiZnCu ferrite according to claim 1, wherein V is contained in an amount of 0.3-0.5 parts by weight in terms of V ₂ O ₅ , and Mn is contained in an amount of 3-5 parts by weight in terms of MnO.
The NiZnCu ferrite according to claim 4 having a permeability of 40 or more in the frequency band of 1 MHz.
100 main components containing 45-48 mol% of Fe in terms of Fe ₂ O ₃ , 9-40 mol% of Ni in terms of NiO, 7-37 mol% of Zn in terms of ZnO and 4-8 mol% of Cu in terms of CuO V is 0.3 to 1 part by weight of the V ₂ O ₅ in terms of parts by weight of a first step of wet mixing the Mn is an additive containing 3-7 parts by weight in terms of MnO;
A second step of drying and pulverizing the slurry prepared by wet mixing; And
Method for producing NiZnCu ferrite comprising the third step of calcining the pulverized powder at 750-760 ℃ for 3-5 hours.
The method of claim 6, further comprising a fourth step of wet milling the calcined powder.
The method of claim 7, further comprising a fifth step of drying and pulverizing the slurry produced by wet milling at 150-200 ° C. for 12-15 hours.
A heterojunction wherein the NiZnCu ferrite of any one of claims 1 to 5 is bonded to one surface of a glass dielectric.
A method for producing a heterojunction comprising the step of co-sintering a glass dielectric and the NiZnCu ferrite of any one of claims 1 to 5 at low temperature at 800-810 ° C.

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