KR101252139B1 - ZnCu FERRITE AND PREPARATION METHOD THEREOF - Google Patents

Abstract

The present invention relates to a ZnCu ferrite and a method for preparing the same, more specifically, 47-48 mol% in terms of Fe ₂ O ₃ Fe, 20-30 mol% in terms of ZnO and 20% Cu in terms of CuO as the main component 21 It comprises -34 mol%, 0.3-1 parts by weight of Bi in terms of Bi ₂ O ₃ as an additive, 0.3-2 parts by weight of Co in terms of Co ₃ O ₄ and Si in terms of SiO ₂ with respect to 100 parts by weight of the main component The present invention relates to a ZnCu ferrite and a method of manufacturing the same, which exhibits a permeability of 50 or more and a permeability of 0.1 or less in a frequency band of 13.56 MHz, and can effectively improve the recognition distance of RFID in a frequency band of 13.56 MHz.

Description

ＺｎＣｕ ferrite and preparation method thereof {ZnCu FERRITE AND PREPARATION METHOD THEREOF}

The present invention relates to a ZnCu ferrite having a high permeability and low permeability loss in the frequency band of 13.56MHz and a method for manufacturing the same.

RFID (Radio Frequency Identification) is a technology that can track the whole process from production to sale in a microchip (IC chip) and track it by radio frequency.It can be used for electronic tags, smart tags, electronic labels, and wireless identification. It is an important foundation technology for ubiquitous called.

RFID is widely used in fields such as logistics, warehouse management or mail management as well as mobile equipment such as cellular phones, RFID tags, and contactless IC cards. In particular, in the field of distribution, it is regarded as the next generation recognition technology to replace the bar code used for goods management.

RFID consists of a reader that provides reading and decryption functions and a tag that provides information. The RFID tag contains a variety of information in a tag attached to a product and allows the reader to read this information through an antenna. It is also used in conjunction with information systems in conjunction with satellites or mobile communication networks.

RFID has a slightly longer recognition distance than a bar code that can read information only within a few centimeters, but when the antenna contacts the reader with a metal plate, the recognition distance tends to decrease.

In order to solve this problem, a method of improving the recognition distance by placing a magnetic sheet having high performance characteristics between the antenna and the metal plate has been proposed. For example, the magnetic sheet includes a sheet made of metal magnetic powder such as Fe-Si, Fe-Si-Al, and a sheet made of ferrite such as NiZn and NiMn.

However, the conventional method using the magnetic sheet has a low permeability and a high permeability loss in the 13.56 MHz band in which RFID is used. For example, in the case of magnetic metal powders of Fe-Si and Fe-Si-Al, the magnetic permeability and the loss loss characteristics are inferior to those of NiZn and NiMn ferrite. In addition, in the case of Fe-Si and Fe-Si-Al metal magnetic powder, it is difficult to realize the magnetic permeability of 50 or more and the investment loss of 0.1 or less, so it is difficult to improve the recognition distance of RFID.

The present invention aims to provide a ZnCu ferrite having high permeability and low permeability characteristics in the frequency band of 13.56 MHz.

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

1. As a main component, Fe comprises 47-48 mol% in terms of Fe ₂ O ₃ , 20-30 mol% in terms of ZnO and 21-34 mol% in terms of CuO, and Zn is added to 100 parts by weight of the main component. ZnCu ferrite containing Bi 0.3-1 parts by weight in terms of Bi ₂ O ₃ , Co 0.3-3 parts by weight in terms of Co ₃ O ₄ , and 0.5-2 parts by weight of Si in terms of SiO ₂ .

2. In the above 1, ZnCu ferrite molar ratio of Zn and Cu is 26:26 in terms of ZnO and CuO.

3. ZnCu ferrite having a permeability of 50 or more and a loss of 0.1 or less in the frequency band of 13.56 MHz.

4. ZnCu ferrite according to the above 3, which has an investment loss of 0.03 or less in the frequency band of 13.56 MHz.

5. Bi is Bi ₂ O ₃ in 100 parts by weight of the main component containing 47-48 mol% of Fe in terms of Fe ₂ O ₃ , 20-30 mol% in terms of ZnO and 21-34 mol% in terms of CuO. in terms of 0.3 to 1 part by weight, the first step of the mixed Co wet the additive comprises 0.5 to 2 parts by weight to 0.3 to 2 parts by weight of Si are SiO ₂ in terms of Co ₃ O ₄ conversion; A second step of drying and pulverizing the slurry prepared by wet mixing; And a third step of calcining the pulverized powder at 800-850 ° C. for 3-5 hours.

6. In the above 5, ZnCu ferrite manufacturing method further comprising the fourth step of wet grinding the calcined powder.

7. In the above 5, ZnCu 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.

The present invention can provide a ZnCu ferrite having a permeability of 50 or more and an investment loss of 0.1 or less, preferably 0.03 or less, in the frequency band of 13.56 MHz and a method of manufacturing the same.

In addition, the present invention can easily control the permeability and permeability loss in the frequency band of 13.56MHz by adjusting the content of ZnO, the main component of ferrite, and the content of Co and Si, which are additives.

In addition, the present invention can effectively improve the recognition distance of the RFID by exhibiting the above permeability and permeability characteristics in the frequency band of 13.56MHz.

In addition, the present invention can implement a passive device exhibiting high frequency characteristics when applied to a chip inductor because of excellent frequency characteristics relative to permeability.

1 is a graph showing the permeability characteristics of each frequency according to the content of ZnO,
2 is a graph showing the investment loss characteristics for each frequency according to the content of ZnO,
3 is a graph showing the permeability characteristics of each frequency according to the content of Co ₃ O ₄ ,
4 is a graph showing the investment loss characteristics for each frequency according to the content of Co ₃ O ₄ ,
5 is a graph showing the permeability characteristics of each frequency according to the content of SiO ₂ ,
6 is a graph showing the investment loss characteristics for each frequency according to the content of SiO ₂ .

The present invention relates to a ZnCu ferrite having a high permeability and low permeability loss in the frequency band of 13.56MHz and a method for manufacturing the same.

Hereinafter, the present invention will be described in detail.

ZnCu ferrite of the present invention comprises 47-48 mol% in terms of Fe ₂ O ₃ Fe, 20-30 mol% in terms of ZnO and 21-34 mol% Cu in terms of CuO as the main component, 100 weight of the main component It is characterized in that it contains 0.3-1 part by weight of Bi in terms of Bi ₂ O ₃ as an additive, 0.3-2 parts by weight in Co ₃ O ₄ and 0.5-2 parts by weight of Si in terms of SiO ₂ . .

In the present invention, the content of the metal component constituting the ZnCu ferrite is expressed in terms of oxide, but when a compound other than oxide is used, it may be converted accordingly.

The ZnCu ferrite of the present invention contains Fe, Zn and Cu as main components, and is characterized in that the content thereof is configured to be optimized. Specifically, Fe is 47-48 mol% in terms of Fe ₂ O ₃ , Zn is 20-30 mol% in terms of ZnO, and Cu is 21-34 mol% in terms of CuO with respect to 100 mol% of the main components constituting the ferrite. do.

Zn may be included in 20-30 mol% in terms of ZnO. 1 and 2 are graphs showing the permeability and permeability characteristics of each frequency according to the change of the content of ZnO. When the content of ZnO is 20-30 mol%, the permeability decreases slightly as the content decreases, but it can be seen that the width of the frequency band exhibiting a permeability of 50 or more, for example, 100 or more expands. In addition, it can be seen that as the ZnO content decreases, the investment loss is also lowered in the frequency band of 13.56MHz. In other words, in order to secure a high permeability in the frequency band of 13.56 MHz, the content of ZnO is preferably 26-30 mol%, and in order to secure a low permeability loss in the same frequency band, the content is preferably 20-26 mol%. Considering all these properties, it is most preferable that it is 26 mol%.

In particular, the molar ratio of Zn and Cu among the main components is preferably 26:26 in terms of ZnO and CuO, in that the permeability and permeability characteristics are excellent in the same frequency band.

ZnCu ferrite of the present invention includes Bi, Co and Si as an additive together with the above main components, it is characterized in that the content is configured to optimize. Specifically, Bi is 0.3-1 parts by weight in terms of Bi ₂ O ₃ , Co is 0.3-2 parts by weight in terms of Co ₃ O ₄ , and Si is 0.5-2 parts by weight in terms of SiO ₂ , based on 100 parts by weight of the main component. do.

More specifically, the grain growth of ferrite is induced by the addition of Bi ₂ O ₃ , and the growth of excessive grains is suppressed by the addition of SiO ₂ , leading to a decrease in investment loss, and the addition of Co ₃ O ₄ . By controlling the magnetic anisotropy less, it is possible to improve the frequency characteristics. Through this, it is possible to facilitate the implementation of the permeability and loss characteristics as in the present invention.

3 and 4 are graphs showing the permeability and permeability characteristics of each frequency according to the content of Co ₃ O _{4 in} the condition that the ratio of ZnO and CuO 26:26. As the content of Co ₃ O ₄ increases, the permeability decreases a little, but all the permeability was over 50 in the 13.56MHz frequency band. In addition, it can be seen that the investment loss is lower in the same frequency band as the content of Co ₃ O ₄ increases. Therefore, Co is preferably contained in an amount of 0.3-2 parts by weight in terms of Co ₃ O ₄ , and more preferably 1-2 parts by weight based on 100 parts by weight of the main component.

5 and 6 show that the ratios of ZnO and CuO are 26:26, respectively. This graph shows the permeability and permeability characteristics of each frequency according to the content of SiO ₂ . As the content of SiO ₂ increases, the permeability decreases slightly, but the permeability was over 50 in the 13.56MHz frequency band. In addition, it can be seen that the investment loss is lower in the same frequency band as the content of SiO ₂ increases. Therefore, Si is preferably contained in an amount of 0.5-2 parts by weight in terms of SiO ₂ with respect to 100 parts by weight of the main component, and more preferably 1-1.5 parts by weight.

The ZnCu ferrite of the present invention configured as described above has the most desirable permeability and permeability characteristics, in particular, the frequency band of 13.56 MHz by controlling the content of Zn in the above range and controlling the content of additives Co and Si in the optimum range. In a permeability of 50 or more and less than 0.1, preferably less than 0.03 investment loss characteristics can be implemented.

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

The method for producing ZnCu ferrite includes a first step of wet mixing 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, 100 parts by weight of Bi and Bi ₂ O ₃ containing 47-48 mol% of Fe in terms of Fe ₂ O ₃ , 20-30 mol% in terms of ZnO, and 21-34 mol% of Cu in terms of CuO. Prepare a raw material consisting of an additive comprising 0.3-1 parts by weight in terms of weight, 0.3-2 parts by weight in terms of Co ₃ O ₄ and 0.5-2 parts by weight of Si in terms of SiO ₂ , and wet mixing them to prepare a slurry. (Step 1). 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 800-850 ° C. for 2-5 hours in an atmospheric atmosphere (third step). If the calcination temperature is not in the above range, the ferrite crystal structure may not be formed completely, and the permeability may vary.

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).

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  1-9, Comparative example  1-6

Fe ₂ O ₃ (DAE SANG), ZnO (DAE JUNG) and CuO (JUNSEI) as the main components and Bi ₂ O ₃ (JUNSEI) and Co ₃ O ₄ (JUNSEI) as additives based on 100 parts by weight of the total content of the main components. And SiO ₂ (JUNSEI) were 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.

The disintegrated powder was calcined at 840 ° 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 ZnO CuO Bi ₂ O ₃ Co ₃ O ₄ SiO ₂ Example 1 48 26 26 0.3 0.3 One Example 2 48 26 26 0.3 0.3 1.5 Example 3 48 26 26 0.3 0.5 One Example 4 48 26 26 0.3 0.5 1.5 Example 5 48 26 26 0.3 One 0.5 Example 6 48 26 26 0.3 2 0.5 Example 7 48 26 26 0.5 0.3 One Example 8 48 26 26 0.5 0.5 One Example 9 48 26 26 One 0.3 One Comparative Example 1 48 26 26 0.3 0.1 0.5 Comparative Example 2 48 26 26 0.3 3 0.5 Comparative Example 3 48 26 26 0.3 0.3 0.3 Comparative Example 4 48 26 26 0.3 0.3 2.5 Comparative Example 5 48 26 26 0.1 0.3 0.3 Comparative Example 6 48 26 26 1.5 0.3 0.5

Test Example

1. Measurement of Permeability and Loss

In order to measure the magnetic properties of the ZnCu ferrites prepared in Examples and Comparative Examples, 3 parts by weight of a polyvinyl alcohol (PVA) resin was mixed with 100 weight parts of the prepared ZnCu ferrite powders, and the mixture was made with an outer diameter of 18 mm and an inner diameter. The sintered compact of 6 mm and 3 mm height was manufactured.

Permeability (μ) and permeability loss (Tanδ) of the prepared sintered compacts were measured using an impedance analyzer.

division Permeability (μ) (13.56 MHz) Lost investment (Tanδ) (13.56MHz) Example 1 100 0.09 Example 2 60 0.02 Example 3 85 0.07 Example 4 50 0.02 Example 5 98 0.09 Example 6 62 0.02 Example 7 95 0.09 Example 8 80 0.07 Example 9 78 0.07 Comparative Example 1 200 0.72 Comparative Example 2 32 0.02 Comparative Example 3 160 0.52 Comparative Example 4 21 0.02 Comparative Example 5 128 0.27 Comparative Example 6 75 0.18

As shown in Table 2 and Figure 3-6, ZnCu ferrite of the present invention was confirmed that the investment loss is significantly lower than the conventional ferrite, and the permeability is also high in the range that the investment loss is maintained in this way.

In addition, as the content of Co ₃ O ₄ and SiO ₂ increases within the scope of the present invention, the investment loss is lower. Therefore, in order to significantly reduce the investment loss, it is preferable to adjust the content thereof in a large amount.

Claims (7)

47-48 mol% of Fe in terms of Fe ₂ O ₃ , 20-30 mol% of Zn in terms of ZnO, and 21-34 mol% of Cu in terms of CuO, respectively,
0.3-1 part by weight of Bi in terms of Bi ₂ O ₃ , 0.3-2 parts by weight of Co in terms of Co ₃ O ₄ , and 0.5-2 parts by weight of Si in terms of SiO ₂ with respect to 100 parts by weight of the main component, ,
ZnCu ferrites with a permeability of at least 50 and a permeability of less than 0.1 in the frequency band of 13.56 MHz.
The ZnCu ferrite of claim 1, wherein the molar ratio of Zn and Cu is 26:26 in terms of ZnO and CuO.
delete The ZnCu ferrite according to claim 1 having an investment loss of 0.03 or less in the frequency band of 13.56 MHz.
Bi to Bi ₂ O ₃ in 100 parts by weight of the main component containing Fe in the range of 47-48 mol% in terms of Fe ₂ O ₃ , 20-30 mol% in terms of Zn, and 21-34 mol% in terms of CuO A first step of wet mixing 0.3-1 parts by weight, an additive containing 0.3-2 parts by weight of Co in terms of Co ₃ O ₄ and 0.5-2 parts by weight of Si in terms of SiO ₂ ;
A second step of drying and pulverizing the slurry prepared by wet mixing; And
A third process of calcining the pulverized powder at 800-850 ° C. for 3-5 hours,
ZnCu ferrite manufacturing method having a permeability of 50 or more and a permeability of 0.1 or less in the frequency band of 13.56 MHz.
The method of claim 5, further comprising a fourth step of wet milling the calcined powder.
The method of claim 5, further comprising a fifth step of drying and pulverizing the slurry produced by wet milling at 150-200 ° C. for 12-15 hours.

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