KR102262900B1 - Coil component - Google Patents

Abstract

A coil component according to an embodiment of the present invention includes a body having a coil unit disposed therein and an external electrode connected to the coil unit, wherein the body includes metal particles made of a Fe-based nanocrystalline alloy therein, The Fe-based nanocrystalline alloy has one or two peaks in the differential scanning calorimetry (DSC) graph, but when it has two peaks, the size of the primary peak is smaller than the secondary peak.

Description

Coil Component {COIL COMPONENT}

The present invention relates to a coil component.

With the miniaturization and thinning of electronic devices such as digital TVs, mobile phones, and notebook computers, there is a demand for miniaturization and thinning of coil parts applied to these electronic devices, and in order to meet these needs, various types of winding type or thin film type are used. Research and development of coil parts is actively progressing.

A major issue due to the miniaturization and thinning of coil parts is to realize the same characteristics as the existing ones despite the miniaturization and thinning. In order to satisfy this requirement, it is necessary to increase the ratio of the magnetic material in the core in which the magnetic material is filled, but there is a limit to increasing the ratio due to the change in frequency characteristics according to the strength and insulation of the inductor body.

As an example of manufacturing a coil component, a method of realizing a body by laminating a sheet in which magnetic particles and a resin are mixed on a coil and then pressing is used. In the past, a lot of ferrite has been used as magnetic particles, but recently, attempts have been made to use Fe-based metal powder having excellent properties such as magnetic permeability and saturation magnetic flux density. However, in the case of such Fe-based metal powder, it is difficult to control the size of the nanocrystal grains, so it has been widely used in the form of a metal ribbon rather than a powder.

One of the several objects of the present invention is to provide a coil component having a Fe-based nanocrystalline alloy in powder form, and the Fe-based nanocrystalline alloy has excellent and stable magnetic properties. Such a coil component may have high magnetic permeability and DC bias characteristics.

As a method for solving the above problems, the present invention intends to propose a novel structure of a coil part through an example, and specifically, it includes a body in which the coil part is disposed and an external electrode connected to the coil part, , The body contains metal particles made of a Fe-based nanocrystalline grain alloy therein, wherein the Fe-based nanocrystalline grain alloy has one or two peaks in a differential columnar (DSC) graph. When having two peaks, 1 The size of the secondary peak is smaller than that of the secondary peak.

In an embodiment, the primary peak may be less than or equal to 80% of the secondary peak.

In an embodiment, the primary peak may be less than or equal to 50% of the secondary peak.

In an embodiment, the primary peak may be less than or equal to 20% of the secondary peak.

In an embodiment, the metal particles include nanocrystalline grains made of the Fe-based nanocrystalline alloy, and the size of the nanocrystalline grains may be 20-50 nm.

In one embodiment, the Fe-based nanocrystalline alloy is _{expressed by the composition formula of Fe (100-axyzpq)} Co _a Si _x B _y M _z Cu _p P _q , where 0≤a≤0.5, 2≤x≤17, 6≤y≤15, 0<z≤5, 0.5≤p≤1.5, 0≤q≤8, M is at least 1 selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W It may be more than one species.

In one embodiment, when the Fe-based nanocrystalline alloy has one peak, the peak may be 600 ~ 800 ℃.

In one embodiment, when the Fe-based nanocrystalline grain alloy has two peaks, the first peak may be 400 ~ 550 ℃.

In one embodiment, the secondary peak may be 600 ~ 800 ℃.

In the case of a coil component according to an embodiment of the present invention, magnetic permeability and DC bias characteristics can be improved by using a powder-type Fe-based nanocrystalline alloy having excellent and stable magnetic properties.

1 schematically shows an example of a coil component applied to an electronic device.
2 is a schematic perspective view showing a coil component according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view taken along line I-I' of FIG. 1 .
FIG. 4 is an enlarged view of a body region in the coil component of FIG. 3 .
FIG. 5 schematically shows crystal grains included in the metal particles of FIG. 4 .
6 to 9 are differential scanning calorimetry graphs showing the exothermic characteristics of Fe-based nanocrystalline grain alloys according to Comparative Examples and Examples, FIGS. 6 to 8 are Comparative Examples 1 to 3, respectively, and FIG. 9 is an Example.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to specific embodiments and the accompanying drawings. However, the embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. Further, the embodiments of the present invention are provided in order to more completely explain the present invention to those skilled in the art. Accordingly, the shapes and sizes of elements in the drawings may be exaggerated for clearer description, and elements indicated by the same reference numerals in the drawings are the same elements.

Electronics

1 schematically shows an example of a coil component applied to an electronic device.

Referring to the drawings, it can be seen that various types of electronic components are used in electronic devices, for example, DC/DC, Comm. Processor, WLAN BT / WiFi FM GPS NFC, PMIC, Battery, SMBC, LCD AMOLED, Audio Codec, USB 2.0 / 3.0 HDMI, CAM, etc. can be used. At this time, among these electronic components, various types of coil components may be appropriately applied according to the purpose for the purpose of noise removal, etc. For example, a power inductor (Power Inductor, 1), a high frequency inductor (HF Inductor, 2) , a general bead (General Bead, 3), a high frequency bead (GHz Bead, 4), a common mode filter (Common Mode Filter, 5), and the like.

Specifically, the power inductor 1 may be used for stabilizing power by storing electricity in the form of a magnetic field to maintain an output voltage. In addition, the high frequency inductor 2 may be used for purposes such as securing a required frequency by matching impedance, or blocking noise and AC components. In addition, the general bead (General Bead, 3) may be used for the purpose of removing noise of power and signal lines, or removing a high-frequency ripple. In addition, the high-frequency bead (GHz Bead, 4) may be used for purposes such as removing high-frequency noise from signal lines and power lines related to audio. In addition, the common mode filter (Common Mode Filter, 5) may be used for purposes such as passing a current in the differential mode and removing only common mode noise.

The electronic device may typically be a smart phone, but is not limited thereto. For example, a personal digital assistant, a digital video camera, and a digital still camera. ), a network system, a computer, a monitor, a television, a video game, a smart watch, and the like. In addition to these, of course, it may be other various electronic devices well known to those skilled in the art.

coil parts

Hereinafter, the coil component of the present disclosure will be described, but for convenience, the structure of an inductor will be described as an example, but as described above, the coil component proposed in this embodiment may be applied to coil components for various other uses as well. to be.

Fig. 2 is a perspective view schematically showing an external shape of a coil component according to an embodiment of the present invention. Also, FIG. 3 is a cross-sectional view taken along line I-I' of FIG. 1 . 4 is an enlarged view of the body region in the coil component of FIG. 3 , and FIG. 5 schematically shows crystal grains included in the metal particles of FIG. 4 .

2 and 3 , the coil component 100 according to an embodiment of the present invention mainly includes a body 101 having a coil unit 103 disposed therein, and external electrodes 120 and 130 . is a structure that

The body 101 includes a coil unit 103 , and may include metal particles 111 as shown in FIG. 4 . Specifically, the metal particles 111 may be dispersed in the base 112 made of resin or the like. In this case, the metal particles 111 are made of a Fe-based nanocrystalline alloy, for example, may be made of a Fe-Si-B-Nb-Cu-based alloy, and the composition of the Fe-based nanocrystalline alloy will be described later. In addition, the Fe-based nanocrystalline grain alloy has only one peak or has two peaks in the differential scanning calorimetry (DSC) graph, and when it has two peaks, the size of the primary peak is smaller than the secondary peak. , exhibited magnetic properties suitable for use in an inductor by appropriately controlling the size and phase of nanocrystal grains when having these characteristics. Specific details of the exothermic properties of the alloy powder will be described later.

The coil unit 103 serves to perform various functions in the electronic device through characteristics expressed from the coil of the coil component 100 . For example, the coil component 100 may be a power inductor, and in this case, the coil unit 103 may store electricity in the form of a magnetic field to maintain an output voltage to stabilize power. In this case, the coil patterns constituting the coil unit 103 may be stacked on both surfaces of the support member 102 , and may be electrically connected through conductive vias passing through the support member 103 . The coil unit 103 may be formed in a spiral shape. At the outermost portion of the spiral shape, a lead-out portion (exposed to the outside of the body 101) for electrical connection with the external electrodes 120 and 130 is provided. T) may be included. The coil pattern constituting the coil unit 103 may be formed using a plating process used in the art, for example, pattern plating, anisotropic plating, isotropic plating, and the like, and a plurality of processes among these processes are used. Thus, it may be formed in a multi-layered structure.

In the case of the support member 102 supporting the coil unit 103, it may be formed of a polypropylene glycol (PPG) substrate, a ferrite substrate, or a metal-based soft magnetic substrate. In this case, a through-hole may be formed in the central region of the support member 102 , and a magnetic material may be filled in the through-hole to form a core region C. This core region C is formed by the body 101 . ) is part of As described above, the performance of the coil component 100 may be improved by forming the core region C in a form filled with the magnetic material.

The external electrodes 120 and 130 are formed on the body 101 to be respectively connected to the lead-out portion T. The external electrodes 120 and 130 may be formed using a paste containing a metal having excellent electrical conductivity, for example, nickel (Ni), copper (Cu), tin (Sn) or silver (Ag). It may be a conductive paste including alone or an alloy thereof. In addition, a plating layer (not shown) may be further formed on the external electrodes 120 and 130 . In this case, the plating layer may include any one or more selected from the group consisting of nickel (Ni), copper (Cu) and tin (Sn), for example, a nickel (Ni) layer and a tin (Sn) layer may be formed sequentially.

As described above, in the case of this embodiment, the metal particles 111 are made of a Fe-based nanocrystalline grain alloy, and the Fe-based nanocrystalline alloy has one or two peaks in a differential scanning calorimetry (DSC) graph, but two When it has a peak, the size of the primary peak is smaller than that of the secondary peak. In other words, it is a form in which the crystallization energy of a low temperature is smaller than the crystallization energy generated at a high temperature. In this case, as shown in FIG. 5 , the metal particles 111 include nanocrystal grains 140 , and the size (d) of the nanocrystal grains 140 is about 20-50 nm.

In addition, the Fe-based nanocrystal grain alloy has excellent properties such as saturation magnetic flux density and may be selected to have a composition range suitable for manufacturing in a powder form. Specifically, the Fe-based nanocrystalline alloy is _{expressed by the composition formula of Fe (100-axyzpq)} Co _a Si _x B _y M _z Cu _p P _q , where 0≤a≤0.5, 2≤x≤17, 6≤ y≤15, 0<z≤5, 0.5≤p≤1.5, 0≤q≤8, M is at least one selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W may be an element.

According to the research of the present inventors, even if the powder of the Fe-based nanocrystalline grain alloy having the same composition and size is different, the precipitation pattern of the actual grains is different and the inductance or efficiency of the coil component obtained therefrom is different, and this aspect is the heating characteristic of the alloy powder It was confirmed that it can be known by measuring In other words, it is difficult to accurately predict the characteristics expressed in the Fe-based nanocrystalline alloy powder only with the composition or size, and by revealing the exothermic characteristics through thermal analysis, the characteristics such as inductance when applying the inductor could be sufficiently predicted.

This will be described with reference to Comparative Examples 1 to 3 and Examples, and FIGS. 6 to 9 are differential scanning calorimetry graphs showing the exothermic characteristics of the Fe-based nanocrystalline alloy used in the experiment. Here, FIGS. 6 to 8 show Comparative Examples 1 to 3, respectively, and FIG. 9 shows Examples. First, the specific composition of the samples of the present inventors used in the experiments is a _{Fe 73 .5 Si 15 .5 B 7} Nb 3 Cu 1, samples are different from each other the same composition gatjiman microstructure.

In this way, alloy powders with different microstructures were prepared, and they were thermally analyzed. For thermal analysis, SDT600 manufactured by TA Instruments was used, and the temperature was increased at a rate of 40° C. per minute. And the measurement was performed in an argon (Ar) atmosphere so that the alloy powder is not oxidized. As a result, the exothermic properties of the alloy powder were different according to the comparative examples and the examples, which can be understood because the content or distribution of nanocrystal grains in each powder were different.

Table 1 below summarizes the characteristics (inductance, efficiency) of inductors manufactured according to Comparative Examples and Examples, grain size of alloy powder, and crystallization energy (W/g) during thermal analysis. In this case, the inductance can be evaluated using an impedance analyzer, and the inductance is determined according to the number of windings and the magnetic permeability. In the case of the same volume and number of turns, the higher the permeability, the higher the inductance. Efficiency can be evaluated, for example, by measuring changes in voltage and current before and after the circuit, and can also be calculated using a core loss value measured using an evaluation device such as a BH analyzer.

inductance
(uH) efficiency
(%) grain size
(nm) Crystallization energy (W/g) T _x1 T _x2 Comparative Example 1 0.35 80% 0 50 20 Comparative Example 2 0.45 82% 20 20 20 Comparative Example 3 0.35 80% 25 0 0 Comparative Example 4 0.41 81% 22 0 10 Example 1 0.475 89% 20 0 20 Example 2 0.45 85% 20 20 20

First, in the case of Comparative Example 1, two prominent exothermic peaks are shown, and the primary peak is larger than the secondary peak. From this thermal analysis result, it can be seen that Comparative Example 1 exhibits characteristics of an alloy in which nanocrystal grains are contained in very small amounts or not present. In other words, Comparative Example 1 has substantially amorphous properties. In this case, high crystallization energy is generated in the process of forming α-Fe (Si) at the primary exothermic peak near 500° C., and at the secondary exothermic peak near 600° C., relatively in the process of forming the Fe-B compound. A low crystallization energy appears to occur.

Next, the alloys of the other comparative examples and the examples contained nanocrystal grains as the microstructure was controlled, but there was a difference to the extent that characteristics such as thermal analysis results and inductance were clearly distinguished. Specifically, as a result of thermal analysis of Comparative Example 2 ( FIG. 7 ), two peaks were shown, and the primary peak and the secondary peak had almost the same size. In the case of Comparative Example 2, the size of the nanocrystal grains was analyzed to be at the level of 20 nm, but there was a problem in that the efficiency was lowered compared to the Example, which could be explained by the small amount of nanocrystal grains contained in the powder. In addition, in the case of Comparative Example 3 ( FIG. 8 ), no exothermic peak was observed and the nanocrystal grains had a size of 25 nm, but properties such as inductance and efficiency were not good, and the sample of Comparative Example 4 also showed similar results. This may be explained by the fact that, in the samples of Comparative Examples 3 and 4, a large number of Fe-B compounds were formed, resulting in a decrease in magnetic permeability and an increase in loss.

In the embodiment of the present invention, as shown in the graph of FIG. 9 , only a single peak, ie, one exothermic peak, is shown and corresponds to a peak near about 600°C. From the fact that there is no peak near 500 °C and the peak appears only at 600 °C, it can be seen that a large amount of α-Fe (Si) phase is present and Fe-B compound is absent or is present in a trace amount, and both inductance and efficiency were excellent in these alloys. .

From the above experimental results, it can be seen that the powdery Fe-based nanocrystalline alloy has excellent inductance and efficiency when it has a single peak in the differential scanning calorimetry (DSC) graph. In this case, the size of the nanocrystalline grains contained in the powder is about 20-50 nm. In this case, in the embodiment, the single peak was 600° C. However, when expressed more generally, the single peak may have a range of 600 to 800° C.

In addition, the above-described Fe-based nanocrystalline grain alloy in powder form does not necessarily have a single peak in the differential scanning calorimetry (DSC) graph, but may have two peaks. However, even in this case, the size of the primary peak should be smaller than that of the secondary peak, and specifically, the primary peak may be 80% or less of the secondary peak. Furthermore, the primary peak may be 50% or less of the secondary peak, and most preferably, the primary peak may be 20% or less of the secondary peak. In the case of the alloy powder having such thermal properties, it does not contain the Fe-B compound or contains only a very small amount, so that the magnetic properties are excellent. Here, when the Fe-based nanocrystalline grain alloy has two peaks, if the exothermic characteristics related to the precipitation of different phases are generalized and described, the first peak may be 400 ~ 550 °C, and the second The peak may be 600-800°C.

As such, the Fe-based nanocrystal grain alloy proposed in this embodiment has a large amount of α-Fe (Si) phase, so there is no or very low primary peak occurring during precipitation of the α-Fe (Si) phase. The secondary peak that occurs when the Fe-B compound is not included or is included in an extremely small amount during precipitation of the Fe-B compound shows a relatively large characteristic. In addition, this Fe-based nanocrystalline alloy includes nanocrystalline grains when manufactured as a powder, and can exhibit excellent and stable magnetic properties. And in the case of a coil component implemented therefrom, it may exhibit high magnetic permeability and DC bias characteristics.

The present invention is not limited by the above-described embodiments and the accompanying drawings, but is intended to be limited by the appended claims. Therefore, various types of substitution, modification and change will be possible by those skilled in the art within the scope not departing from the technical spirit of the present invention described in the claims, and it is also said that it falls within the scope of the present invention. something to do.

1: Power Inductor
2: high frequency inductor
3: Normal bead
4: Bead for high frequency
5: Common mode filter
100: coil part
101: body
102: support member
103: coil unit
111: metal particles
112: base
113: nano crystal grains
120, 130: external electrode
140: nano crystal grains
C: core area

Claims (7)

a body having a coil unit disposed therein; and
and an external electrode connected to the coil unit;
The body includes metal particles made of a Fe-based nanocrystalline alloy therein,
The Fe-based nanocrystalline alloy has two peaks in a differential scanning calorimetry (DSC) graph,
The first peak of the two peaks is 400 ~ 550 ℃,
The second peak of the two peaks is 600 ~ 800 ℃,
The crystallization energy of the first peak is 20% or less of the crystallization energy of the second peak,
The Fe-based nanocrystalline alloy is _{expressed by a compositional formula of Fe (100-axyzpq)} Co _a Si _x B _y M _z Cu _p P _q , where 0≤a≤0.5, 2≤x≤17, 6≤y≤15 , 0<z≤5, 0.5≤p≤1.5, 0≤q≤8, M is a coil that is at least one element selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W part.
According to claim 1,
The metal particles include nanocrystal grains made of the Fe-based nanocrystal grain alloy, and the size of the nanocrystal grains is 20-50 nm.
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