KR100478710B1 - Method of manufacturing soft magnetic powder and inductor using the same - Google Patents

Abstract

The present invention relates to the production of shape-controlled soft magnetic powder having excellent high frequency characteristics and capable of firing even at low temperatures of 700 ° C. or lower, and a method of manufacturing an inductor using the same.

The shape-controlled soft magnetic powder according to the present invention is prepared by adding a surfactant to the soft magnetic powder and then performing a ball milling process. The soft magnetic powder prepared as described above is controlled to have a thickness: diameter ratio of 3 to 100. The method of manufacturing the wound inductor according to the present invention comprises the steps of: (a) coating the soft magnetic powder by adding a binder to the shape controlled soft magnetic powder; (b) molding the coated soft magnetic powder at room temperature; (c) heat treating the molded soft magnetic powder; And (d) winding the copper wire, wherein the method of manufacturing a chip inductor according to the present invention comprises the steps of: (a) coating a soft magnetic powder by adding a binder to the shape controlled soft magnetic powder; (b) casting the green sheet by the doctor blade method using the coated soft magnetic powder; (c) laminating the cast green sheet; (d) printing the internal electrodes on the stacked sheets and then stacking the green sheets again; (e) calcining it; And (f) forming an external electrode on the fired sintered body.

        Therefore, according to the present invention, it is possible to manufacture a shape-controlled soft magnetic material and an inductor using the same, which are capable of firing even at a low temperature of 700 ° C. or less, but have little change in electromagnetic properties to external stress, and have excellent high frequency characteristics.

Description

Preparation of soft magnetic powder and method of manufacturing inductor using same {Method of manufacturing soft magnetic powder and inductor using the same}

The present invention relates to a shape-controlled high frequency soft magnetic material used for a chip component such as a chip inductor, a chip bead, or a shielding component of electromagnetic waves such as a wound inductor, and a method for manufacturing a high frequency inductor using the same. It is about.

Today, the remarkable development of electronic and communication devices is based on the miniaturization of electronic components, thinning of film, and the improvement of mountability, and the construction of new industrial structure is developed. By causing the back has become a two-sided problem that causes social problems. In particular, the development of electromagnetic interference elimination (EMI / EMC) devices has been intensified due to the strengthening of electromagnetic interference regulations (FCC, CISPR, VDE, MIL, etc.) in each country regarding the electromagnetic environment worsened by the general commercialization of wireless communication devices and multi-environment. As the demand for parts increases, technology is being developed in terms of complexity, high integration, and high efficiency. Among them, the application range of soft magnetic materials applied to magnetic elements such as electromagnetic components such as electromagnetic interference elimination or electric power is also subdivided by magnetic characteristics and frequency bands, and the manufacturing method is different from the conventional powder metallurgy manufacturing method. Research is being actively conducted toward component manufacturing, and today, it has become a small chip component manufacturing technology in the ceramic electronic component manufacturing field.

In general, soft magnetic materials used in small chip components such as chip inductors, chip beads, chip arrays, chip LC filters, and chip transs require high inductance. The main soft magnetic materials used are manganese-zinc (Mn-Zn) ferrite, nickel (Ni) ferrite, nickel-zinc (Ni-Zn) ferrite or nickel-copper-zinc (Ni-Cu-Zn) ferrite. Etc. can be mentioned. Mn-Zn ferrite is used for magnetic core materials such as trans core for power supply and power line filter because of high permeability and very low power loss. There is a disadvantage that is difficult to do. Currently, magnetic ferrite materials for use in such high frequency bands include Ni ferrite, Ni-Zn ferrite, or Ni-Cu-Zn ferrite.

On the other hand, in the conventional method of manufacturing a small chip component using the soft magnetic material, in the firing process, the heat treatment is performed for about 1 to 5 hours at about 1,000 to 1,200 ℃. However, internal electrodes of electronic components such as chip inductors and chip bead filters usually use mercury (Ag) electrodes. The firing temperature is higher than the melting point (960 ° C) of mercury, an internal electrode. In addition, manufactured parts have the disadvantage of very high loss at high frequencies, which makes it very difficult to achieve the required inductance. Therefore, in order to lower the firing temperature of the soft magnetic material, in general, the particle size of the magnetic core material is pulverized to 0.01-0.5 μm to make the energy level of the particles in the ground state (quasi-potential state), and during sintering, the sintering is performed by increasing the material movement surface between the particles. The method of accelerating and achieving low temperature baking is performed. However, the manufacturing method through the pulverization process is accompanied by a price increase of the product due to the high cost of the equipment and the complexity of the manufacturing process.

As another example, a method of promoting firing using a low temperature compound mainly composed of zinc oxide + bismuth oxide (ZnO + Bi ₂ O ₃ ) (Japanese Patent Laid-Open No. 59-67119), and boron oxide (B ₂ O ₃₎ ) And fluxes such as bismuth oxide (Bi ₂ O ₃ ), vanadium pentoxide (V ₂ O ₅ ) or lead oxide (PbO) as additives. A method of firing by inducing interfacial diffusion of particles is known and commercialized. However, methods of adding a low melting point compound interfere with the behavior of the cobalt (Co) component that improves high frequency characteristics, thereby reducing the effect of firing. In addition, since additives exist in the liquid phase in the temperature range lower than the sintering progress temperature of the soft magnetic material, which is the base material, and they act as a mechanism for promoting sintering by diffusing at the grain boundaries of the soft magnetic material, In addition to the reduction and loss of inductance, the product reacts with mercury, an internal electrode, or diffuses into the mercury electrode to deteriorate the electromagnetic characteristics (inductance, Q-factor) of the chip inductor. have.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a shape-controlled soft component powder having excellent high frequency characteristics.

Another object of the present invention is to (a) coating the soft magnetic powder by adding a binder to the shape-controlled soft magnetic powder; (b) molding the coated soft magnetic powder at room temperature; (c) heat treating the molded soft magnetic powder; And (d) winding the copper wire.

      Still another object of the present invention is to (a) coating the soft magnetic powder by adding a binder to the shape-controlled soft magnetic powder; (b) casting the green sheet by the doctor blade method using the coated soft magnetic powder; (c) laminating the cast green sheet; (d) printing the internal electrodes on the stacked sheets and then stacking the green sheets again; (e) calcining it; And (f) forming an external electrode on the calcined sintered body.

In order to achieve the above object, first, the shape-controlled soft magnetic material according to the present invention is added with a surfactant to various soft powders such as pure iron (Fe), cobalt (Co), nanocrystals (Finemet), Permalloy, amorphous, etc. It is then obtained by performing a ball milling process, the Aspect Ratio (thickness: ratio of diameter) is controlled to 3 to 100.

   In addition, the method of manufacturing a wound inductor according to the present invention comprises the steps of: (a) coating the soft magnetic powder by adding a binder to the shape-controlled soft magnetic powder in a total range of 0.2 ~ 3wt%; (b) molding the coated soft magnetic powder at room temperature; (c) heat-treating the shaped soft magnetic powder at a temperature of 50 to 700 ° C .; And (d) winding the copper wire, and provides a manufacturing method of the winding type inductor for low temperature firing.

       In addition, the method of manufacturing a chip-type inductor according to the present invention comprises the steps of: (a) coating the soft magnetic powder by adding a binder to the shape-controlled soft magnetic powder; (b) casting the green sheet by the doctor blade method using the coated soft magnetic powder; (c) laminating the cast green sheet; (d) printing the internal electrodes such as aluminum and conductive polymer on the stacked sheets, and then stacking the green sheets again; (e) calcining it at a temperature in the range from 50 to 700 ° C .; And (f) forming an external electrode on the fired sintered body.

Hereinafter, the present invention will be described in detail.

In general, magnetic materials have different characteristics according to their frequency, depending on their structure, composition, and shape.

The present invention utilizes a variety of shape-controlled magnetic powders (crystals, nanocrystals, amorphous, etc.) exhibiting excellent electromagnetic properties in the high frequency band of 10 kHz to several hundred MHz. When the shape is controlled, powders exhibiting excellent high frequency characteristics are pure iron (Fe), cobalt (Co), permalloy, and nanocrystals (Finemet: Fe-Si-Nb-B-Cu). And various amorphous magnetic powders can be used. Preferred soft powders include Fe ₈₀ Ni _20, Fe ₅₀ Ni _50, Fe (pure), Co (pure), Fe _84.1 Si _10.1 Al _5.8, Fe ₄₉ Co ₄₉ V _2, Fe _91.7 Si _5.3 B ₃ (amorphous powder), Co _83.9 Fe _5.34 Si _8.53 B _2.4 (amorphous powder), Fe _83.37 Si _7.7 Nb _5.66 B _1.98 Cu _1.29 (nanocrystalline powder).

    The ball milling process performed to manufacture the shape-controlled soft powder of the present invention is to control the shape of the powder using a chromium coated ball or iron ball, to determine the strength and weight of the ball to perform the process of the powder Agglomeration should be avoided as much as possible, and the shape of the powder is controlled by performing the process for an appropriate time to avoid the fracture of the powder [J. D. James, B. Wilshire and D. Cleaver, Powder Metall. 33 (3), 247 (1990)]. The ball milling process according to the present invention is preferably carried out for 5 hours.

      In addition, the present invention adds a surfactant to prevent agglomerate (agglomeration) of the magnetic powder during the ball milling process, stearic acid is most preferred.

The amount of the surfactant is preferably limited to 0.1 to 2.0 wt% of the total mass. "Gross mass" means the total mass of the soft powder component and surfactant manufactured, and does not include the mass of other organic solvents. Shape-controlled softening powder powder produced according to the present invention is adjusted to the aspect ratio (thickness: ratio of diameter) in the range of 3 to 100.

      After manufacturing the shape-controlled soft powder, remove the surfactant by heat treatment at a temperature of 200 ~ 400 ℃ as needed.

  When the device is fabricated by mixing the shape-controlled soft magnetic powder with low-temperature firing internal electrodes (aluminum, conductive polymers, etc.), the firing temperature is lowered to 700 ° C or less from the conventional high temperature process temperature (850-1,350 ° C). There are possible process advantages.

       The binder used in the method of manufacturing the wound inductor of the present invention is preferably a polyimide-based or phenol-based thermosetting resin.

   The binder such as polyimide can minimize the deterioration of the electromagnetic characteristics even when reacting with the main component of the soft magnetic material, and in particular, when the device is manufactured, the electrical resistance is increased in the magnetic layer to enable high frequency. There is this. In addition, high quality coefficient (Q) value can be obtained at high frequency (~ few GHz) by the binder added to the shape-controlled soft powder, while the inductance can be lowered. A chip having the characteristics can be obtained.

The amount of the binder is preferably limited to 0.2 to 3.0 wt% of the total mass. It is because when the amount of binder is too low, the bulking of the soft magnetic powder is difficult at 0.2 wt% or less. On the other hand, when the amount of the binder is too large, the bonding strength between the powder particles becomes strong, but the amount of powder in the molded body decreases, leading to deterioration of the soft magnetic properties. As used herein, the term "total mass" means the total mass of the shape-controlled soft powder and the binder to be produced, and does not include the mass of other organic solvents.

      After molding, heat treatment is performed at 50 to 700 ° C. for 0.1 to 1 hour to impart mechanical strength, and the temperature increase process is preferably performed within 10 ° C. per minute.

 According to the present invention, a wound inductor having good magnetic properties, having a high quality factor having a quality factor of at least 100, a peak range of at least about 10 MHz, and an inductance of at least 1.7 can be manufactured at a much lower temperature than before.

    The binder used in the manufacturing method of the chip type inductor of the present invention is one selected from organic polymers such as polyvinyl butyl (PVB), methylene chloride (MC), oleic acid, polyethylene glycol (PEG), toluene, mannitol or polyimide. It is preferable to use species or more.

      The mixing ratio of the soft magnetic powder and the binder is preferably 1: 1 to 1: 1.4 on a wt% basis.

      The internal electrode used is preferably at least one selected from aluminum, mercury, polypyrrole, polyacelylene or polyphenylene. The firing temperature of the firing step is preferably carried out at 50 to 700 ℃.

  According to the present invention, it is possible to manufacture chip inductors even below 700 ° C (300 ° C or less in the case of conductive polymers) which is much lower than the firing temperature of conventional chip inductors.

Hereinafter, the present invention will be described in detail with reference to the following examples, but the present invention is not limited thereto.

Example 1 Preparation of Shape Controlled Soft Magnetic Powder

Ball milling was performed by adding 0.5 wt% of stearic acid to the soft powder Fe ₈₀ Ni ₂₀ .

Ball milling was performed for 5 hours to control the shape of the powder. The shape-controlled powder had an aspect ratio of 5 (thickness: diameter ratio). This shape-controlled powder was heat treated at a temperature of about 300 ℃ to remove stearic acid. (Example 1-A)

According to the above process was carried out under the conditions of Table 1 to prepare a shape-controlled powder according to Example 1-B to Example 1-I.

TABLE 1

division Soft Magnetic Powder ^* Stearic acid (wt%) Ball milling time (H) Aspectratio Stearic acid removal temperature (℃) Example 1-A Fe ₈₀ Ni ₂₀ 0.5 5 5 300 Example 1-B Fe ₅₀ Ni ₅₀ 0.5 5 5 300 Example 1-C Fe (pure) 0.5 5 5 300 Example 1-D Co (pure) 0.5 5 5 300 Example 1-E Fe _84.1 Si _10.1 Al _5.8 0.5 5 5 300 Example 1-F Fe ₄₉ Co ₄₉ V ₂ 0.5 5 5 300 Example 1-G Fe _91.7 Si _5.3 B ₃ (amorphous powder) 0.5 20 5 300 Example 1-H Co _83.9 Fe _5.34 Si _8.53 B _2.4 (Amorphous Powder) 0.5 20 5 300 Example 1-I Fe _83.37 Si _7.7 Nb _5.66 B _1.98 Cu _1.29 (nanocrystalline powder) 0.5 20 5 300

* Shape-controlled soft-component powder [Aspect ratio (thickness: diameter ratio) = 3-100]

Example 2 Fabrication of Winding Inductor Using Shape-Controlled Soft Magnetic Powders

0.5 wt% polyimide binder was added to the improved controlled soft magnetic powder (Fe ₈₀ Ni ₂₀ ) prepared according to Example 1-A, mixed and dried, followed by 9.65 mm in outer diameter, 4.78 mm in inner diameter and 3.68 mm in height. It was molded into a toroidal core of and heat-treated for the expression of magnetic properties. The heat treatment temperature is about 700 ℃, the temperature increase rate was 10 ℃ / min, and the temperature was maintained at room temperature after maintaining the heat treatment temperature for about 1 hour. At this time, the cooling rate was 10 ° C / min. The enamelled copper wire with a diameter of 0.55 mm was wound 20 times on the material thus obtained by heat treatment. (Example 2-A)

According to the process of Example 2-A was carried out under the conditions of Table 2 to prepare a wound-type inductor according to Example 2-B to Example 2-I.

[Table 2]

division Used soft magnetic powder Binder type Binder (wt%) Heat treatment temperature after molding (℃) Example 2-A Shape controlled soft magnetic powder prepared according to Example 1-A (Fe ₈₀ Ni ₂₀ ) Polyimide 0.5 700 Example 2-B Shape controlled soft magnetic powder prepared according to Example 1-B (Fe ₅₀ Ni ₅₀ ) phenol 0.5 700 Example 2-C Shape-controlled soft powders [Fe (pure)] prepared according to Example 1-C Polyimide 0.5 300 Example 2-D Shape-controlled soft powders prepared according to Example 1-D [Co (pure)] Polyimide 0.5 500 Example 2-E Shape-controlled soft powders prepared according to Example 1-E (Fe _84.1 Si _10.1 Al _5.8 ) Polyimide 0.5 750 Example 2-F Shape controlled soft magnetic powder prepared according to Example 1-F (Fe ₄₉ Co ₄₉ V ₂ ) Polyimide 0.5 900 Example 2-G Shape controlled soft magnetic powder prepared according to Example 1-G [Fe _91.7 Si _5.3 B ₃ (amorphous powder)] phenol 1.0 350 Example 2-H Shape-controlled soft magnetic powder prepared according to Example 1-H [Co _83.9 Fe _5.34 Si _8.53 B _2.4 (Amorphous Powder)] Polyimide 1.0 400 Example 2-I Shape controlled _soft magnetic powder prepared according to Example 1-I [Fe _83.37 Si _7.7 Nb _5.66 B _1.98 Cu _1.29 (nanocrystalline powder)] Polyimide 1.0 620

Comparative Example 1 Fabrication of Winding Inductor Using Conventional Soft Magnetic Powders

A wound inductor was manufactured in the same manner as in Example 2-C, except that the obtained spherical pure iron powder was used without the ball milling process, that is, without the shape control and the powder was used as it was. )

A wound inductor was manufactured in the same manner as in Example 2-A, except that the obtained spherical Fe ₈₀ Ni ₂₀ powder was used without the ball milling process, that is, without the shape control and the powder was used as it was. 1-B)

<Test Example 1>

The inductance of the wound inductor manufactured according to Example 2 and Comparative Example 1 was measured using an impedance analyzer (HP 4194A) in the frequency band of 10 kHz to several hundred MHz, and the results are shown in Table 3 below.

Table 3

division Inductance (μH) 10 kHz 1 MHz Example 2-A 2.6 2.5 Example 2-B 2.1 2.0 Example 2-C 1.7 1.5 Example 2-D 3.1 2.9 Example 2-E 2.2 2.0 Example 2-F 2.9 2.9 Example 2-G 2.2 2.2 Example 2-H 4.1 4.1 Example 2-I 3.4 3.4 Comparative Example 1-A 5.2 0.4 Comparative Example 1-B 9.1 0.8

As can be seen in Table 3, in Example 2 of the present invention, the inductance value of the calcined soft magnetic sintered body was hardly changed in the range of 10 kHz-1 MHz, and the inductance value was 1.7 μH or more. In particular, in Examples 2-H and 2-I, the inductance value was 3 μH or more, which is believed to be due to the amorphous phase and the nanocrystalline phase.

On the other hand, when the winding type inductor was manufactured using the powder without the shape control as in Comparative Example 1, the inductance value was higher in the low frequency region (10 kHz), but the inductance value rapidly decreased toward the high frequency region, which was much higher at 1 MHz. Low inductance value was shown. Therefore, when the shape-controlled powder is used, it can be seen that the high frequency characteristics of the device are greatly improved by the shape magnetic anisotropy.

Example 3 Fabrication of Chip Inductor Using Shape-Controlled Soft Magnetic Powders

After drying the shape-controlled soft magnetic powder (Fe ₈₀ Ni ₂₀ ) prepared as in Example 1-A, the polyvinyl butyl (PVB) binder was 1: 1 to 1: 1.4 (soft component powder: binder, wt% B), a green sheet having a thickness of 100 µm was cast by a doctor blade method.

About 5 layers of the cast green sheets were laminated, and internal electrodes made of polypyrrole, a conductive polymer, were printed on the laminated sheets, and the green sheets were laminated and fired. At this time, baking was performed at 650 degreeC for 2 hours. An external electrode was formed on the sintered body thus fired to manufacture a chip inductor. (Example 3-A)

The chip inductors according to Example 3-B to Example 3-I were prepared under the conditions of Table 4 according to the process of Example 3-A.

Table 4

division Softener Ingredients Used Kind of binder Amount of binder (wt%) Firing temperature (℃) Example 3-A Shape controlled soft magnetic powder prepared according to Example 1-A (Fe ₈₀ Ni ₂₀ ) PVB 52 650 Example 3-B Shape controlled soft magnetic powder prepared according to Example 1-B (Fe ₅₀ Ni ₅₀ ) Mannitol 52 650 Example 3-C Shape-controlled soft powders [Fe (pure)] prepared according to Example 1-C PVB and Mannitol Mix (wt% 1: 1) 52 300 Example 3-D Shape-controlled soft powders prepared according to Example 1-D [Co (pure)] PVB 52 650 Example 3-E Shape-controlled soft powders prepared according to Example 1-E (Fe _84.1 Si _10.1 Al _5.8 ) Mannitol 52 300 Example 3-F Shape controlled soft magnetic powder prepared according to Example 1-F (Fe ₄₉ Co ₄₉ V ₂ ) PVB and Mannitol Mix (wt% 1: 1) 52 650 Example 3-G Shape controlled soft magnetic powder prepared according to Example 1-G [Fe _91.7 Si _5.3 B ₃ (amorphous powder)] PVB 52 300 Example 3-H Shape-controlled soft magnetic powder prepared according to Example 1-H [Co _83.9 Fe _5.34 Si _8.53 B _2.4 (Amorphous Powder)]  Mannitol 52 650 Example 3-I Shape controlled _soft magnetic powder prepared according to Example 1-I [Fe _83.37 Si _7.7 Nb _5.66 B _1.98 Cu _1.29 (nanocrystalline powder)] PVB 52 300

Comparative Example 2 Fabrication of Chip Inductor Using Conventional Soft Magnetic Powders

A chip inductor was manufactured in the same manner as in Example 3-C, except that the obtained spherical pure iron powder was used without the ball milling process, that is, without the shape control, and the powder was used as it was.

A chip inductor was manufactured in the same manner as in Example 3-A, except that the obtained spherical Fe ₈₀ Ni ₂₀ powder was used as it was without ball milling, that is, without shape control. -B)

<Test Example 2>

The electromagnetic characteristics of the chip inductors manufactured according to Example 3 and Comparative Example 2 were measured using an impedance analyzer (HP 4194A), and the results are shown in Table 5 below.

Table 5

division Inductance (nH) Quality Factor Peak (Q) Example 3-A 210 45 Example 3-B 150 35 Example 3-C 140 39 Example 3-D 171 57 Example 3-E 164 54 Example 3-F 220 59 Example 3-G 250 61 Example 3-H 272 64 Example 3-I 263 59 Comparative Example 2-A 76 12 Comparative Example 2-B 82 17

As shown in Table 4 and Table 5, in the case of Example 3 of the present invention, unlike the firing temperature of the conventional chip inductor 1400-800 ℃ according to the internal electrode material, in particular in the case of using polypyrrole the firing temperature is 300 It was possible to control below ℃. In addition, the inductance value of the calcined soft magnetic sintered body was 140 nH or more and the quality factor (Q) value of the high frequency was about 39 or more. It can also be seen that the loss after firing also shows a characteristic of decreasing.

Example 4 Fabrication of Chip Inductor Using Shape-Controlled Soft Magnetic Powders

Except for using the shape-controlled powder (Fe ₈₀ Ni ₂₀ ) prepared according to Example 1-A exhibiting excellent high-frequency characteristics in Table 3 and using Al as the internal electrode agent A chip inductor was manufactured in the same manner as A (Example 4-A).

According to the conditions of the following Table 6 using the shape-controlled powder [Fe _83.37 Si _7.7 Nb _5.66 B _1.98 Cu _1.29 (nanocrystalline powder)] prepared according to Example 1-I showing excellent high frequency characteristics in Table 3 above. The chip inductor according to Example 4-B to Example 4-F was manufactured in the same manner as in Example 4-A.

Table 6

division Powder used Internal electrode material Firing temperature (℃) Example 4-A Shape controlled soft magnetic powder prepared according to Example 1-A (Fe ₈₀ Ni ₂₀ ) Al 650 Example 4-B Shape controlled soft magnetic powder prepared according to Example 1-A (Fe ₈₀ Ni ₂₀ ) polypyrrole 200 Example 4-C Shape controlled _soft magnetic powder prepared according to Example 1-I [Fe _83.37 Si _7.7 Nb _5.66 B _1.98 Cu _1.29 (nanocrystalline powder)] Al 650 Example 4-D Shape controlled _soft magnetic powder prepared according to Example 1-I [Fe _83.37 Si _7.7 Nb _5.66 B _1.98 Cu _1.29 (nanocrystalline powder)] polypyrrole 200 Example 4-E Shape controlled _soft magnetic powder prepared according to Example 1-I [Fe _83.37 Si _7.7 Nb _5.66 B _1.98 Cu _1.29 (nanocrystalline powder)] polyacelylene 200 Example 4-F Shape controlled _soft magnetic powder prepared according to Example 1-I [Fe _83.37 Si _7.7 Nb _5.66 B _1.98 Cu _1.29 (nanocrystalline powder)] polyphenylene 200

<Comparative Example 3> conventional soft magnetic powder _{[(Fe 2 O 3) 49.5} (NiO) 10.1 - (ZnO) 31.35 (CuO) 8.85] Preparation of a chip inductor using the

Conventional ferrite material, _{(Fe 2 O 3) 49.5 (} NiO) 10.1 - (ZnO) 31.35 (CuO) using the powder for without ball milling the course of _8.85 that is, without the formation control its original position as it is, as the inner electrode the mercury Chip inductor was manufactured in the same manner as in Example 3-A, except that the firing temperature was set to 1000 ° C.

<Test Example 3>

The electromagnetic characteristics of the chip inductors manufactured according to Example 4 and Comparative Example 3 were measured using an impedance analyzer (HP 4194A), and the results are shown in Table 7 below.

Table 7

division Inductance (nH) Q peak Example 4-A 221 47 Example 4-B 210 45 Example 4-C 271 61 Example 4-D 263 59 Example 4-E 257 53 Example 4-F 250 51 Comparative Example 3 240 59

As shown in Table 7, in the present invention, even when various conductive polymers and aluminum were used as internal electrode materials, there was almost no deterioration in characteristics compared to the conventional ferrite chip inductors (Comparative Example 3) using mercury as internal electrodes. For low temperature firing, which is an advantage of the present invention, it is preferable to use a new electrode material, aluminum and a conductive polymer, as the inner electrode, and in particular, when polypyrrole is used as the inner electrode material, it is possible to obtain the best high frequency characteristics among various conductive polymers. It is judged that it is a polymer for electrodes.

As described above, according to the present invention, a soft magnetic material having excellent high frequency characteristics can be sufficiently produced even at low temperature, and the present invention can use the existing soft magnetic manufacturing equipment as it is, thus eliminating the need for expensive manufacturing equipment investment and managing difficulties. In addition, it is possible to provide a low-cost soft magnetic material for the chip inductor due to the reduction of the process cost due to the simplification of the process and the decrease of the process temperature.

    In addition, it is possible to manufacture shape controlled soft magnetic materials and inductors using them, which can be fired at low temperature below 700 ℃ but have little change in electromagnetic characteristics against external stress and have excellent high frequency characteristics.

Claims (14)

1) adding a surfactant to the soft magnetic powder and performing a ball milling process to produce a soft magnetic powder having a shape-controlled thickness to diameter ratio of 3 to 100; 2) coating the soft magnetic powder by adding a binder to the shape controlled soft magnetic powder and molding the same at room temperature; 3) adding a low-temperature baking internal electrode to the molded soft magnetic powder and heat-treating it at a temperature of 50 to 700 ℃; And 4) winding a copper wire on the heat-treated material. The method of claim 1, 1-1) The method of manufacturing the wound inductor further comprising the step of removing the surfactant by heat-treating the prepared soft magnetic powder at a temperature of 200 to 400 ℃. The method of claim 1, The soft magnetic powder is at least one selected from pure iron (Fe), cobalt (Co) -based, permalloy-based, nanocrystalline or amorphous magnetic powder. delete delete delete The method of claim 1, The binder is a polyimide-based binder or a phenol-based binder manufacturing method of the winding inductor of any one or more selected. The method according to claim 1 or 7, The amount of the binder is 0.2 to 3wt% of the wire-type inductor manufacturing method of the total mass. The method of claim 1, The method of manufacturing a wound inductor in which the step of increasing the heat treatment temperature in step 3) is performed within 10 ° C. per minute. 1) adding a surfactant to the soft magnetic powder and performing a ball milling process to produce a soft magnetic powder having a shape-controlled thickness to diameter ratio of 3 to 100; 2) coating the soft magnetic powder by adding a binder to the shape controlled soft magnetic powder; 3) casting the green sheet by the doctor blade method using the coated soft magnetic powder; 4) laminating the cast green sheet and printing an internal electrode thereon; 5) re- laminating the green sheet on the green sheet printed with the internal electrode and firing it at a temperature between 50 and 700 ° C .; And 6) forming an external electrode on the sintered body fired in step 5). The method of claim 10, And said binder is at least one selected from polyvinylbutyl, mannitol, methylene chloride, oleic acid, polyethylene glycol, toluene or polyimide. The method according to claim 10 or 11, wherein The binder is a method of manufacturing a chip-type inductor is added in a 1: 1 to 1: 1.4 by wt% relative to the soft magnetic powder. The method of claim 10, The internal electrode is a method of manufacturing a chip-type inductor of at least one selected from aluminum, mercury, polypyrrole, polyacelylene or polyphenylene. delete