KR101891775B1 - Soft magnetic core enhanced corrosion resistance and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a soft magnetic core having enhanced corrosion resistance. More specifically, the present invention relates to a soft magnetic core having enhanced corrosion resistance which provides a coating layer having corrosion resistance on a surface of the soft magnetic core to improve corrosion resistance under high temperature and high humidity corrosion conditions, and a manufacturing method thereof. The present invention can improve oxidation resistance and chemical resistance of the soft magnetic core through the coating layer and can be applied to electromagnetic component materials used in automobiles, home appliances, and computer and communication fields. An inductance holding rate of the core represented by formula 1 or formula 2 is more than or equal to 75%, and a core loss is less than or equal to 10%. The soft magnetic core includes a corrosion resistance reinforcing coating layer, wherein the corrosion resistance reinforcing coating layer includes Teflon (PTFE) or a water-soluble polymer. The formula 1 is Inductance holding rate = L2/L1×100, and the formula 2 is Inductance holding rate = L4/L3×100.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a soft magnetic core having enhanced corrosion resistance and a method of manufacturing the same.

The present invention relates to a soft magnetic core having enhanced corrosion resistance, and more particularly, to a soft magnetic core having a coating layer having corrosion resistance on the surface of an uncoated soft magnetic core and exhibiting improved corrosion resistance under high temperature and high humidity conditions, .

Soft magnetic materials are widely used in automotive, robotics, electronics, electricity, renewable energy, computer and telecommunication industries, and their usage is rapidly increasing due to the advanced functions, automation and miniaturization of their used devices. Various types of soft magnetic materials have been used for decades, such as electrical steel sheets, Fe, Ni-Zn / Mn-Zn ferrite, Fe-Ni, Fe-Si, Fe- , Nano crystalline, metallic glass, and the like. Until now, soft magnetic materials have been transforming our lives as core materials forming the cores of electromagnetic parts used in automobile, home appliances, computer and communication fields. In order to meet the demand, research and development on new soft magnetic materials capable of simultaneously satisfying low magnetic loss, high magnetic flux density and permeability are actively performed.

Iron-based alloys such as Fe-Ni, Fe-Ni-P, Fe-Si and Fe-Al-Si are the most widely used materials for soft magnetic cores. However, due to oxidation and corrosion There is a possibility that the efficiency of the magnetic material may be lowered, and when the oxidized and corroded iron-based alloy magnetic material is used as the structural material, the life of the product is shortened and there is a risk of safety problems.

On the other hand, U.S. Patent No. 8,610,532 B2 discloses a core using a corrosion-resistant coating layer, but the composition is different from that of the coating layer of the present invention by using inorganic zinc silicate, polysiloxane and room temperature vulcanized silicone rubber composition.

Japanese Patent Application Laid-Open No. 2005-295684 discloses a soft magnetic core using a Teflon (PTFE) coating layer. However, in order to insulate a core from a winding wire as an insulating layer, Is far from maintaining the magnetic body performance and improving the corrosion resistance.

The present invention relates to a soft magnetic core having enhanced corrosion resistance, and more particularly, to a soft magnetic core having a coating layer having corrosion resistance on the surface of the soft magnetic core and exhibiting improved corrosion resistance under high temperature and high humidity conditions, And to provide the above objects.

The present invention relates to a corrosion-resistant reinforcing coating layer containing a corrosion-resistant reinforcing coating layer having an inductance retention ratio of 75% or more of a core represented by the following formula (1) or (2) before and after being left for 1,000 hours or more at a temperature of 70 ° C or higher and a humidity of 70% A soft magnetic core is provided:

Inductance maintenance ratio = L ₂ / L ₁ x 100 ... (1) or L ₄ / L ₃ x 100 ... (2)

(In the above formula (1)

L ₁ is the inductance value measured before leaving for 1,000 hours at an applied current of 0 A, and L ₂ is the inductance value measured for 1,000 hours at the applied current of 30.6 A;

In the above formula (2)

L ₃ is the measured inductance value after 1,000 hours at 0 A, and L ₄ is the measured inductance value after 1,000 hours at 30.6 A applied current).

The present invention also provides a corrosion-resistant reinforcing coating layer having a core inductance retention of 85% or more expressed by the following formula (3) or (4) before and after being left for 1,000 hours or more at a temperature of 70 ° C or higher and a humidity of 70% The present invention provides a soft magnetic core comprising:

Inductance maintenance ratio = L ₃ / L ₁ × 100 ... (3) or L ₄ / L ₂ x 100 ... (4)

(In the above formula (3)

L ₁ is the inductance value measured before leaving for 1,000 hours at the applied current 0 A, L ₃ is the inductance value measured after 1000 hours at the applied current 0 A;

In the above formula (4)

L ₂ is the inductance value measured after leaving for 1,000 hours at the applied current of 30.6 A, and L ₄ is the inductance value measured after leaving for 1,000 hours at the applied current of 30.6 A.).

The present invention also provides an electronic component comprising a soft magnetic core having a surface modified with a corrosion-resistant reinforcing coating layer applied thereto.

The soft magnetic core of the present invention has a coating layer having corrosion resistance on the surface thereof, thereby improving the surface properties such as oxidation resistance and chemical resistance of the core. In particular, even in an environment of high temperature and humidity, Can be suppressed.

According to the present invention, a soft magnetic core coated with Teflon (PTFE) not only suppresses changes in appearance such as corrosion but also has a high inductance retention ratio and low core loss even in a high temperature and high humidity environment.

FIG. 1 is a photograph of a surface change observed after a Teflon-coated soft magnetic block core and an uncoated soft magnetic block core are left under a high-temperature and high-humidity condition.
FIG. 2 is a photograph of a surface observed before and after leaving the Teflon-coated and uncoated soft magnetic block cores under high-temperature and high-humidity conditions for 1,000 hours.
3 is a photograph of a soft magnetic block core coated with a different coating solution after being left in a high-temperature and high-humidity condition for 1,000 hours.
FIG. 4 is a photograph of the soft magnetic ring-block core of different materials coated with different coating liquids and then left in a high-temperature and high-humidity condition for 1,000 hours.

Hereinafter, embodiments and examples of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. It should be understood, however, that the present invention may be embodied in many different forms and is not limited to the embodiments and examples described herein. In order to clearly explain the present invention in the drawings, parts not related to the description are omitted.

Throughout this specification, when an element is referred to as "including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise.

Throughout this specification, a soft magnetic core means a soft magnetic core or an uncoated soft magnetic core comprising a corrosion-resistant hard coat layer.

Throughout the present application, the soft magnetic core may comprise a soft magnetic powder core or a soft magnetic block core.

Hereinafter, embodiments of the present invention are described in detail, but the present invention is not limited thereto.

An aspect of the present invention is to provide a method of manufacturing a semiconductor device having an inductance enhancement ratio of 75% or more of a core represented by the following formula (1) or (2) after being left for 1,000 hours or more at a temperature of 70 ° C or more and a humidity of 70% A soft magnetic core comprising a coating layer is provided:

Inductance maintenance ratio = L ₂ / L ₁ x 100 ... (1) or L ₄ / L ₃ x 100 ... (2)

(In the above formula (1)

L ₁ is the inductance value measured before leaving for 1,000 hours at an applied current of 0 A, and L ₂ is the inductance value measured for 1,000 hours at the applied current of 30.6 A;

In the above formula (2)

L ₃ is the measured inductance value after 1,000 hours at 0 A, and L ₄ is the measured inductance value after 1,000 hours at 30.6 A applied current).

The inductance retention of the core represented by the formula (1) or (2) may be 75% or more, preferably 80% to 100%, and more preferably 85% to 100%.

Another aspect of the present invention is to provide a method of manufacturing a semiconductor device having an inductance enhancement ratio of 85% or more with respect to a core represented by the following formula (3) or (4) after being left for 1,000 hours or more at a temperature of 70 ° C or higher and a humidity of 70% A soft magnetic core comprising a coating layer is provided:

Inductance maintenance ratio = L ₃ / L ₁ × 100 ... (3) or L ₄ / L ₂ x 100 ... (4)

(In the above formula (3)

L ₁ is the inductance value measured before leaving for 1,000 hours at the applied current 0 A, L ₃ is the inductance value measured after 1000 hours at the applied current 0 A;

In the above formula (4)

L ₂ is the inductance value measured after leaving for 1,000 hours at the applied current of 30.6 A, and L ₄ is the inductance value measured after leaving for 1,000 hours at the applied current of 30.6 A.).

The inductance retention of the core represented by the formula (3) or (4) may be 85% or more, preferably 90% to 100%, and more preferably 95% to 100%.

In one embodiment of the present invention, the soft magnetic core comprising the corrosion-resistant reinforcing coating layer has a current range of 40 amperes (A) or less, preferably 35 amperes or less at 100 kHz, 11 Ts, Lt; RTI ID = 0.0 > uH < / RTI > to 30 uH.

In one embodiment of the invention, the temperature may be at least 70 ° C, preferably from 70 ° C to 100 ° C, more preferably from 80 ° C to 90 ° C, and the humidity may be at least 70%, preferably at least 70% 100%, more preferably 80% to 90%.

In one embodiment of the invention, the core loss may be less than 10% after leaving for at least 1,000 hours at a temperature of 70 ° C or more and a humidity of 70% or more. Specifically, the soft magnetic core has a core loss of 18 mW / cc or less at a frequency of 25 kHz and a magnetic field of 300 Gauss. The core loss may be, for example, 25 mW / cc or less, preferably 20 mW / cc or less, more preferably 18 mW / cc or less under the above conditions.

In one embodiment of the present invention, the corrosion-resistant reinforcing coating layer may include at least one selected from the group consisting of Teflon (PTFE), epoxy, and water-soluble polymer. Teflon (PTFE) has a low coefficient of friction and is non-tacky. It has excellent thermal stability and corrosion resistance (chemical resistance) and is used in various industrial and household goods such as aviation, military, automobile, transportation, chemical, semiconductor, do. In particular, it exhibits excellent resistance to the corrosiveness of acids, alkalis, salts, fats and oils, and is therefore widely applied to parts requiring chemical resistance.

In one embodiment of the present invention, the water-soluble polymer is selected from the group consisting of polyethylene glycol, polyethylene oxide, polyoxyethylene-polyoxypropylene copolymer, polyvinyl alcohol-polyethylene glycol copolymer, hydroxypropylcellulose, hydroxypropylmethylcellulose, poly Polyvinyl pyrrolidone-vinyl acetate copolymer, polyvinyl alcohol, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxyethyl methyl cellulose, polyvinyl acetate, polyalkene oxide, polyalkeneglycol, diethylamino But are not limited to, at least one selected from the group consisting of acetate, aminoalkyl methacrylate copolymer, sodium alginate, gelatin, and combinations thereof.

In one embodiment of the present invention, the corrosion-resistant reinforcing coating layer is formed by a method selected from the group consisting of impregnation, coating, spray coating, spin coating, dip coating, die coating, roll coating, gravure coating, But it is not limited thereto.

In one embodiment of the present invention, the soft magnetic core comprising the corrosion-resistant reinforcing coating layer exhibits a DC voltage (DC-Bias) of 30 A or more.

In one embodiment of the present invention, the soft magnetic core is made of Fe-Si, Fe-Si-Al, Fe-Si-Cr, Fe-Ni, Fe-Ni-P, , But is not limited thereto. The soft magnetic core is an iron-based amorphous material containing Fe as a main component. Since the magnetic loss is small and the saturation magnetization is relatively large even when the magnetostriction is large, it is applied as a material for power and high frequency regions.

Another aspect of the present invention provides an electronic part made of a soft magnetic core comprising a corrosion-resistant reinforcing coating layer according to the present invention. The soft magnetic core including the corrosion-resistant reinforcing coating layer exhibits excellent physical properties even under high temperature and humidity conditions unlike the conventional uncoated soft magnetic core, thereby reducing time and economic loss for restoration of aesthetic and magnetic characteristics due to corrosion of the material However, by more efficiently reducing the economic loss and energy loss due to the replacement of the core and the reduction of the characteristics, it can be suitably applied as a core forming material for electromagnetic parts used in automobiles, household appliances, computers and telecommunication.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[Example]

The Fe-Si soft magnetic block core was coated with a Teflon (PTFE) coating solution by spraying and dipping method, and then heated and fired at a temperature of 150 ° C for 1 hour. The coating process was repeated two-coat to obtain a Fe-Si soft magnetic block core having a Teflon coating layer with a thickness of 20 mu m or less. The water-soluble polymer coating liquid and the epoxy coating liquid were also coated on the Fe-Si soft magnetic block core by the same method. As shown in Fig. 4, a water-soluble polymer coating layer, a Teflon coating layer and an epoxy coating layer were formed on the ring-block core made of different soft magnetic materials Fe-Ni, Fe-Ni-Co, Fe- Respectively.

[Comparative Example]

An uncoated Fe-Si soft magnetic block core was prepared for comparison with the above example.

[Experimental Example 1] Evaluation of corrosion resistance

The soft magnetic block cores of the above Examples and Comparative Examples were left for 1,000 hours at 85 ° C and 85% humidity conditions (constant temperature and humidity).

[Experimental Example 2] Measurement of inductance core loss of soft magnetic core according to corrosion resistance

The soft magnetic block core including the Teflon coating layer of the above example was left for 1,000 hours at 85 DEG C and 85% humidity. The inductance and core loss values measured before and after the abovementioned leaving are shown in Table 1 below. Measurement of inductance at DC voltage (DC-Bias) was performed under the conditions of frequency 100 kHz, magnetic flux density 11 Ts, and line speed 1.0 Φ. The core loss was measured at a frequency of 25 kHz and a magnetic field of 300 Gauss. The inductance after the corrosion-resistant strengthening coating was compared with the inductance before coating and the retention was calculated by the following formulas (1) to (4), and the measured results are shown in Table 1 below.

Inductance maintenance ratio = L ₂ / L ₁ x 100 ... (1) or L ₄ / L ₃ x 100 ... (2)

(In the above formula (1)

L ₁ is the inductance value measured before leaving for 1,000 hours at an applied current of 0 A, and L ₂ is the inductance value measured for 1,000 hours at the applied current of 30.6 A;

In the above formula (2)

L ₃ is the measured inductance value after 1,000 hours at 0 A, and L ₄ is the measured inductance value after 1,000 hours at 30.6 A applied current).

Inductance maintenance ratio = L ₃ / L ₁ × 100 ... (3) or L ₄ / L ₂ x 100 ... (4)

(In the above formula (3)

L ₁ is the inductance value measured before leaving for 1,000 hours at the applied current 0 A, L ₃ is the inductance value measured after 1000 hours at the applied current 0 A;

In the above formula (4)

L ₂ is the inductance value measured after leaving for 1,000 hours at the applied current of 30.6 A, and L ₄ is the inductance value measured after leaving for 1,000 hours at the applied current of 30.6 A.).

As can be seen from Table 1, the soft magnetic core including the corrosion-resistant reinforcing coating layer according to the present invention exhibits little change in inductance and core loss under high-temperature and high-humidity conditions. In addition, The change in inductance caused by the inductance is remarkably small.

It can be seen from FIG. 1 that (a) the soft magnetic block core coated with Teflon (PTFE) according to the present invention hardly causes corrosion, but (b) the uncoated soft magnetic block core has corrosion . Further, in the soft magnetic block core coated with Teflon (PTFE), in addition to the color change, there was almost no change in magnetism such as inductance and core loss.

The soft magnetic block core exhibits a reduction rate of about 20% or less of the inductance measured at a high current of DC-Bias of 30 amperes (A) or more to the initial inductance (0 amperes (A)). Left 0 ampere in Experimental Example 2 of the measured inductance is high temperature and humidity condition over (A) when 24.59 μH when in [L _1], 30.6 ampeeo (A) 20.92 μH [L _2] as a holding ratio [(L ₂ / L ₁ ) × 100] was about 85%, and the core loss at this time was 17 mW / cc. (L ₂ / L ₁ ) × 100 at 0 amperes (A) at 24.04 μH [L ₁ ] and at 30.6 amps (A) at 20.69 μH [L ₂ ] ] Was about 86%, and the core loss was 17 mW / cc. The core loss was found to be maintained at about 90% or more after leaving the soft magnetic core for 1,000 hours in hot and humid conditions and after leaving the measured values at all 17 mW / cc. In this measurement, a 100% retention value was obtained. In addition, the inductance values before and after the comparison with the same current were as high as 97.7% at 0 amperes (A), 24.04 μH after 1000 hours of initial inductance at 24.59 μH. Even at 30.6 amperes (A), the maintenance rate was 98.9% at 20.69 μH after 1,000 hours of initial inductance at 20.92 μH. Since the inductance and the core loss are values dependent on the properties of the soft magnetic core itself, it can be confirmed that the characteristics of the soft magnetic core are maintained through the above retention.

Fig. 2 is a soft magnetic block core observed before and after 1,000 hours in a high-temperature and high-humidity condition of 85 ° C and 85% humidity in accordance with Experimental Example 1, wherein (a) a Teflon (PTFE) (B) after leaving soft magnetic block cores coated with Teflon (PTFE) under conditions of high temperature and high humidity, and (c) subjecting soft magnetic block cores coated with PTFE to high temperature and high humidity conditions It shows the surface observed after leaving. 2 (c), corrosion resistance of the soft magnetic block core coated with Teflon (PTFE) can be confirmed.

3 is a photograph of a soft magnetic block core coated with a different coating solution after being left in a high-temperature and high-humidity condition for 1,000 hours. The Fe-Si soft magnetic block core was coated with a water-soluble polymer coating solution, a Teflon coating solution and an epoxy coating solution, and then allowed to stand for 1,000 hours at a temperature of 85 ° C and a humidity of 85% As a result, unlike the uncoated soft magnetic block core, the characteristics of the soft magnetic block core coated with the water soluble polymer coating liquid, the Teflon coating liquid and the epoxy coating liquid were not changed.

A water-soluble polymer coating layer, a Teflon coating layer and an epoxy coating layer are formed on the ring-block core made of different soft magnetic materials of Fe-Ni, Fe-Ni-Co, Fe-Si-Al and Fe- As a result of the application of the high humidity condition, the soft magnetic ring-block core in which the coating layer is formed shows no change in characteristics.

As the coating layer is applied to the special shape of the grooved shape of Figs. 2 and 3 and the O-ring-shaped block of Fig. 4, the corrosion-resistant reinforcing coating layer of the present invention is not limited to a specific shape and can be applied to various types of magnetic bodies Do.

In the non-coated soft magnetic block core of the comparative example, the above corrosion resistance was not confirmed. In the case of using the uncoated soft magnetic core, since the outer shape as well as the inherent physical properties are deteriorated or lost due to the corrosion, a large amount of money can be put into restoring the soft magnetic core. Although the composition of the soft magnetic core can be changed for the purpose of preventing oxidation, this may also deteriorate the characteristics of the magnetic material.

Since Teflon (PTFE) has the highest operating temperature (about 290 ° C) and excellent abrasion resistance and chemical resistance among the fluororesins, when used as a coating layer, PTFE maintains characteristics inherent to the soft magnetic core, that is, characteristics such as permeability and core loss It is possible to obtain a composite material exhibiting non-tackiness, thermal stability, and corrosion resistance (chemical resistance) of Teflon (PTFE) while preventing deterioration.

The epoxy coating solution is an organic coating material that can prevent corrosion of iron. It has excellent adhesion with magnetic materials and is a reasonable coating for corrosion prevention considering economy, mechanical, chemical properties and applicability.

As described above, by forming the coating layer of Teflon (PTFE), epoxy and water soluble polymer on the soft magnetic core to improve the corrosion resistance of the soft magnetic core under high temperature and high humidity conditions, .

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereby. something to do.

Claims (8)

The inductance retention of the core represented by the following formula (1) or (2) is 75% or more and the core loss is 10% or less after being left for at least 1,000 hours at a temperature of 70 ° C or higher and a humidity of 70% And a corrosion-resistant reinforcing coating layer,
Wherein the corrosion-resistant reinforcing coating layer comprises Teflon (PTFE) or a water-soluble polymer.

Inductance maintenance ratio = L2 / L1 x 100 ... (1) or L4 / L3 x 100 ... (2)
(In the above formula (1)
L1 is the inductance value measured before leaving for 1,000 hours at the applied current of 0 A, L2 is the inductance value measured for 1,000 hours at the applied current of 30.6 A;
In the above formula (2)
L3 is the measured inductance value after 1,000 hours of application at 0 A, and L4 is the measured inductance value after 1,000 hours of application at 30.6 A). The inductance retention of the core represented by the following formula (3) or (4) is 85% or more and the core loss is 10% or less after being left for 1,000 hours or more at a temperature of 70 ° C or more and a humidity of 70% And a corrosion-resistant reinforcing coating layer,
Wherein the corrosion-resistant reinforcing coating layer comprises Teflon (PTFE) or a water-soluble polymer.

Inductance maintenance ratio = L3 / L1 x 100 ... (3) or L4 / L2 x 100 ... (4)
(In the above formula (3)
L 1 is an inductance value measured after 1,000 hours at an applied current of 0 A, and L 3 is an inductance value measured after leaving for 1,000 hours at an applied current of 0 A;
In the above formula (4)
L2 is the inductance value measured before leaving for 1,000 hours at an applied current of 30.6 A, and L4 is the inductance value measured after leaving for 1,000 hours at the applied current of 30.6 A.). delete 3. The method according to claim 1 or 2,
The water-soluble polymer may be selected from the group consisting of polyethylene glycol, polyethylene oxide, polyoxyethylene-polyoxypropylene copolymer, polyvinyl alcohol-polyethylene glycol copolymer, hydroxypropylcellulose, hydroxypropylmethylcellulose, polyvinylpyrrolidone, -Vinyl acetate copolymer, polyvinyl alcohol, hydroxymethylcellulose, hydroxyethylcellulose, hydroxyethylmethylcellulose, polyvinylacetate, polyalkenoxide, polyalkeneglycol, diethylaminoacetate, aminoalkyl methacrylate copolymer , Sodium alginate, gelatin, and combinations thereof. ≪ RTI ID = 0.0 > 11. < / RTI > 3. The method according to claim 1 or 2,
Wherein the soft magnetic core exhibits a DC voltage (DC-Bias) of 30 A or more. 3. The method according to claim 1 or 2,
The soft magnetic core may include at least one selected from the group consisting of Fe-Si, Fe-Si-Al, Fe-Si-Cr, Fe-Ni, Fe-Ni-P, Wherein the soft magnetic core comprises a soft magnetic core. 3. The method according to claim 1 or 2,
The coating layer of the soft magnetic core is formed by a coating method selected from an impregnation method, a coating method, a spray coating method, a spin coating method, a dip coating method, a die coating method, a roll coating method, a gravure coating method or a comma coating method Characterized by a soft magnetic core. An electronic component comprising the soft magnetic core of claim 1 or 2.

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