JPS61295602A - Amorphous core for common mode choke - Google Patents

Abstract

PURPOSE:To obtain an amorphous core for common mode choke, which is superior in characteristics to a low-level noise to a ferrite core for common mode choke and is equal or more with a Co group amorphous core for common mode choke in stability with time and is superior to the Co group amorphous more, by a method wherein an amorphous alloy having a specific composition is used as the material for the amorphous core for common mode choke. CONSTITUTION:An amorphous alloy having a composition, which is shown by a compositional formula =Fe100-x-y-zMxSiyBz (where the M is at least one kind of an element to be chosen out of the group of Ti, Zr, Hb, V, Nb, Ta, Cr, Mo, W, Mn, and Ni) and has the relations of 0.1<=x<=8, 10<=y<=18 and 8<=z<=9.5 (atomic %), is used as the material for the amorphous core for common mode choke. The Fe is essential in the composition and is needed for enhancing the magnetic properties of the amorphous alloy. The M is an essential element for improving the variation with time and for improving the noise attenuation characteristic. However, when the content (x) of the M is not more than 0.1 atomic %, the M has no effect on the improvement of the variation with time and the improvement of the noise attenuation characteristic and when the content (x) is larger than 8 atomic %, a marked drop in the saturated magnetic flux density and the Curie temperature is brought. Accordingly, it is not desirable for the content (x) to exceed 8 atomic %. When the amorphous alloy having a board thickness of 20mum or less is used, the noise attenuation characteristic of a high frequency (500kHz or more) is especially improved. As a result, more favorable results can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an amorphous magnetic core that is suitable for common mode chokes and has excellent frequency characteristics and high voltage noise attenuation characteristics.

[Conventional technology]

Conventionally, 7-elite, dust cores, and silicon steel plates have been mainly used as magnetic cores for common mode chokes.

The absolute value of magnetic permeability 1〃1 for powder magnetic cores and silicon steel plates is small;
There is a drawback α in that the amount of noise attenuation is small.

On the other hand, 7-elite has +f compared to powder magnetic cores and silicon steel plates.
Although it has a large i+ and good frequency characteristics, it has the disadvantage that the saturation magnetic flux density is low, making it less effective against high-voltage pulse noise, and the size of the magnetic core becomes large, which is undesirable.

Recently, Fe-based amorphous materials have attracted attention because of their excellent high-frequency magnetic properties, and are being used for magnetic cores for common motor chips.

[Problem that the invention seeks to solve]

However, because the saturation magnetic flux density of conventional Fe-based amorphous materials is higher than that of ferrite, etc., it has a large effect on high voltage pulsed common mode noise, but it is not effective against normal level common mode noise. The effect was comparable to that of 7elite, and the characteristics particularly below 500 kHz were insufficient.

Although the Co-based amorphous magnetic core has a large absolute value IAI of magnetic permeability below 500 kHz, the saturation magnetic flux density is lower than that of the Fe-based amorphous magnetic core, so it is inferior to the Fe-based amorphous magnetic core with respect to high voltage pulse noise.

Therefore, in the present invention, the common mode core has superior high-voltage pulse characteristics than the CO-based amorphous 1 magnetic core, has better characteristics against normal low-level noise than the 7-elite, and has excellent stability over time equivalent to or better than the Co-based amorphous magnetic core. The technical challenge is to obtain an amorphous magnetic core for chokes.

[Means to solve problems and problems]

In order to solve the above technical problems, the present invention has a compositional formula of Fe
Ioo-x-y-z Mx Si y B z (where M is Ti%Zr, Hf, ■, Nb.

At least one element selected from the group of Ta, Cr, Mo, W, Mn%Ni), 0.1≦X≦8.10≦y
An amorphous alloy having a composition having the relationship of ≦18, 8≦Z≦9.5 (atomic %) is used for the common mode choke core.

[For production]

In the present invention, Fe is an essential element and is necessary for making it ferromagnetic.

M is an essential element for improving aging and noise attenuation characteristics. However, if the content X is less than 0.1 at%, it will not be effective in improving the aging and noise attenuation characteristics, and if it is more than 8 at%, the saturation magnetic flux density and the Curie temperature will significantly decrease. Not inviting.

Si and B are necessary elements for amorphous formation and for improving magnetic properties, and Si-containing! ty is 1
0≦y≦18 (atomic %), B content 2 is 8≦2≦9.
5 (atomic %). That is, y is 10
If the content of 2 is less than 8 atomic %, the magnetic properties will deteriorate, which is not preferable. On the other hand, if y exceeds 18 atom%, the amorphous ribbon becomes brittle, which is undesirable;
If it exceeds atomic %, the change over time becomes large, which is not preferable.

It is particularly preferable to replace 0.1 to 3 atomic % of the Fe content with Cu because the magnetic properties are further improved and the noise attenuation properties are improved.

When the thickness of the amorphous alloy is 20 μm or less, the noise attenuation characteristics, especially at high frequencies (500 kHz or more), are improved, so even more favorable results can be obtained.7 In addition, the squareness ratio Br/Bs of the DC B-H curve When is 50% or less, the discount effect against high-voltage pulse-like noise becomes even greater, so it is preferable ν1° [Example] Hereinafter, the present invention will be described based on Examples.

(Example 1) Amorphous alloys of each composition shown in Table 1 with a thickness of approximately 12 μm and a width of 5 mm were produced by a single roll method, and the outer diameter was 19 mm.
, wound to an inner diameter of 15 mm, heat-treated in a N2 atmosphere, placed in a phenol resin case, wound 10 turns, and the absolute value of magnetic permeability at 100 kHz was 1β1. . , the absolute value of magnetic permeability at 5MHz was measured to be 11'15M.

Table 1 shows the results. Also, for comparison, conventional Fe
The base amorphous magnetic core, the Co-base amorphous magnetic core, and the ferrite 1, 11°, and 1115M are shown in the same table.

Table 1 From Table 1, it can be seen that the magnetic core of the present invention is more l ul took, 141 than the conventional Fe-based amorphous magnetic core, ferrite.
It can be seen that it is particularly excellent.

In addition, the l u l is equal to or higher than that of a Co-based amorphous magnetic core.
It can be seen that it has 15M.

In addition, especially the magnetic core containing Cu is ikl. . k is large,
It turns out that this is preferable.

(Example 2) Table 2 shows the rate of change over time Δlρ1 of the absolute value of magnetic permeability at 10kHz of the magnetic core according to the present invention and the conventional amorphous magnetic core, 1it+1°k. . A comparison of k is shown below.

Therefore, the rate of change over time ΔIul+. k was defined as follows.

Here, I/'l? . k: Initial absolute value of magnetic permeability l μl, OK. From the table of absolute values of magnetic permeability after being held at 120'c for 24 hours, the magnetic core according to the present invention is preferable because it has a smaller change over time than the conventional amorphous magnetic core. I understand.

(Example 3) Figure 1 shows Fe7. CulNb*, sS i13. sB
s The rate of change over time of the absolute value of the magnetic permeability at 120°C of the amorphous magnetic core, Δ1kl. FIG. 2 is a diagram showing the dependence of k on B content 2.

It can be seen that the range of the present invention in which Z is 8 to 9.5 FA% is preferable because the change over time is particularly small.

Table 2 (Example 4)
3, , Cu IMO) S i l 3 * s
The frequency dependence of the absolute value 1 = 1 of the magnetic permeability of the Bs amorphous magnetic core A is calculated using the following equations: 3F e4.t
S! 1sB +o) This is a diagram comparing the magnetic core radius.

The magnetic core A according to the present invention has a thicker +i1 on the low frequency side than the conventional Fe-based amorphous magnetic core C, and is 1.1 superior to the conventional Fe-based amorphous magnetic core C by a factor of 7 over a wide frequency range. Furthermore, it has frequency characteristics that are equal to or higher than those of the Go-based amorphous magnetic core.

(Example 5) Figure 3 shows Feyi, 5CulNb3S i according to the present invention.
+i, sB, the input characteristics for a common mode pulse (pulse width 1 μs) when an amorphous magnetic core (A) is used for a common mode choke are as follows. ,,F
e<, yS 115E31o) magnetic core (C) and Fe-based amorphous (Fe76S i, 5B-) magnetic core (D)
This is a comparison diagram.

The common moat chitsuk constructed with the magnetic core (A) according to the present invention is different from the conventional 7-elite (B) and C cores.

It is more effective and superior to high-voltage pulses than the Fe-based amorphous core (C), and is superior to the conventional Fe-based amorphous core (D).
) has almost the same characteristics as 1ζ.

However, as described above, the magnetic core according to the present invention has excellent frequency characteristics, and therefore is more suitable as a magnetic core for common mode chokes overall.

〔Effect of the invention〕

According to the present invention, it is possible to obtain good frequency characteristics and high-frequency pulse characteristics of an amorphous magnetic core for common mode chips, which were difficult to achieve in the past. Because it can be applied, its effect is extremely (manifest).

[Brief explanation of drawings]

Figure 1 shows FeysCuINb:+, sSi+z, sBs
FIG. 2 is a diagram showing the dependence of the B content fiz of the rate of change over time Δ+ /it lok of the absolute value of magnetic permeability at 120° C. of an amorphous magnetic core, and FIG. scu+M
O:lS i+ff, sB s A diagram comparing the frequency dependence of the absolute value of magnetic permeability of an amorphous magnetic core with that of a 7elite and a conventional amorphous magnetic core. The Pt53 diagram is according to the present invention. Fe73,5Cu+Nb:lS +I3.5B9
This is a diagram showing the input characteristics for common mode pulses when an amorphous magnetic core is used for common mode steering in comparison with conventional ferrite and amorphous magnetic cores of the same volume6 Agent Patent Attorney Takashi Honma Figure 1 7 8 ri /θ // /
2B content (atomic %) Output tip pressure (Y)

Claims (4)

[Claims] (1) Composition formula Fe_1_0_0_-_x_-_y_-_
zM_xSi_yB_z (where M is Ti
, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn
, at least one element selected from the group consisting of Ni), and an amorphous alloy having a composition having the following relationship. 0.1≦x≦8, 10≦y≦18, 8≦z≦9.5 (atomic%) (2) The amorphous magnetic core for a common mode choke according to claim 1, characterized in that an amorphous alloy in which 0.1 to 3 at % of the Fe content is replaced with Cu is used. (3) The amorphous magnetic core for a common mode choke according to claim 1 or 2, characterized in that the plate thickness of the amorphous alloy is 20 μm or less. (4) Claims 1 to 3, characterized in that the squareness ratio Br/Bs of the DC B-H curve is 50% or less.
An amorphous magnetic core for a common mode choke according to any one of the above.