JPS60154510A - Tape-wound magnet core for high frequency - Google Patents

Abstract

PURPOSE:To reduce the iron loss in a high frequency region and to obtain the tape-wound magnetic core having a small variation with time by a method wherein the tape-wound magnetic core is obtained using an amorphous ribbon of 3mm. width or less which is formed by performing a melted metal quenching method. CONSTITUTION:A tape-wound magnetic core single unit A is formed using an amorphous ribbon of 3mm. width or less. Said tape is laminated leaving a gap of 50mum or more, a non-magnetic plate D is interposed and arranged berween tape- wound magnetic cores, and then a non-magnetic thin metal strip is used. The tape-wound magnetic core may be wound around a bobbin E. According to this constitution, the iron loss in a high frequency region is small, heat dissipating effect is high, temperature rise can be suppressed at low extent, and the tape- wound magnetic core having a low variation with time can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a high frequency wound magnetic core using an amorphous ribbon.

Conventionally, permalloy wound magnetic cores using thin plates such as 50% Ni-F6 permalloy and 80% Ni-Fe permalloy have been used as high-frequency wound magnetic cores.

Recently, the miniaturization of electronic devices has progressed rapidly, and it has become necessary to make the power supplies used in these electronic devices smaller and more efficient.Magamp type switching power supplies are one of the methods for these power supplies. It has attracted attention and is being developed. In particular, in recent years, switching power supplies have tended to have higher frequencies in order to be more compact. However, as the frequency becomes higher, heat generation due to core loss of the control wound core used in the mag-amp type switching power supply increases, which becomes an obstacle to increasing the frequency. Currently, permalloy-wound magnetic cores are mainly used for this purpose, but for high frequencies, especially 100kHz,
Above z, iron loss is large and there is a practical problem.

In recent years, amorphous wound magnetic cores have attracted attention as an alternative to permalloy wound magnetic cores, and are attracting attention as suitable for high frequency applications. However, although the amorphous 71-thickness core generates less heat than the permalloy core, eddy current loss increases at high frequencies, and it generates considerably more heat than when used at low frequencies.

Furthermore, since amorphous metals are metastable substances, their changes over time increase as the temperature rises, which poses a major problem in actual use.

Therefore, in a high-frequency wound core using an amorphous ribbon, it is most important to further reduce iron loss in order to reduce changes over time, or to improve heat dissipation to suppress the temperature rise of the wound core.

It is an object of the present invention to improve the drawbacks of the above-mentioned prior art and to provide a wound magnetic core that is immersed in high frequency characteristics and exhibits little change over time.

The main points of the present invention are to produce a wound magnetic core using an amorphous ribbon made by the molten metal fish cooling method with a width of 3 mm or less, to lower iron loss in the high frequency range, to increase the heat dissipation effect, and to increase the temperature of the wound magnetic core for high frequencies. Keeping the temperature low and minimizing changes over time.
It's a good point.

When using a ribbon with a width of 31111111 or less, in order to maximize the effective cross-sectional area of the wound core, it is necessary to make the difference between the outer diameter and the inner diameter considerably large, which makes winding difficult. ■Controllability deteriorates when used in wound cores for power supply control. Problems such as this arise. In order to solve this problem, the present inventors tried stacking a large number of wound cores. However, it is not preferable to stack a large number of wound magnetic cores because the heat dissipation of the wound magnetic cores deteriorates and the temperature deteriorates over time. As a result of various studies, it was found that in order to improve heat dissipation, it is better to provide a gap of 50 μm or more. If the gap is smaller than 50 μm, heat dissipation inside the wound core is poor, and changes over time are large.

Furthermore, a similar effect can be obtained by inserting one or more non-magnetic plates in order to secure the space between the wound cores.

In particular, inserting one or more non-magnetic metal thin strips between the overlapping wound cores has a great heat dissipation effect (and is advantageous because it can keep changes over time to a minimum).

If the metal ribbon is placed outside the wound core, heat radiation will be greater, and changes over time can be reduced.

The present invention is particularly effective for CO-based amorphous wound cores that have small magnetostriction and low iron loss at high frequencies.

The sewage invention will be explained according to examples.

Embodiment 1 FIG. 1 is a diagram showing an example of the construction of a wound magnetic core for high frequency according to the present invention.

The wound core is composed of an amorphous ribbon with a width of 31111111 or less, and is made of a single (a) or multiple wound cores of 50
They are constructed by stacking each other with a gap of μm or more (b to 11).

The wound magnetic core may be constructed by (h) winding an amorphous ribbon around a bobbin. Alternatively, a non-magnetic plate may be inserted between the overlapping wound cores to ensure a gap (d, e, f, g, h).
.

Furthermore, even better results can be obtained if a non-magnetic metal ribbon is used to provide a heat dissipation effect as shown in Figures (e, f).

Example 2 Table 1 shows the iron loss W%o of the high-frequency wound core according to the present invention and the conventional wound core at a frequency of 10σkHz and a peak value of magnetic flux density of 2KG.
0 (10 square ill Frequency 10 after being held at 100℃
Iron loss W at 0kHz, peak value of magnetic flux density 2KG1-
This is a table showing an example of θ.

The iron loss of the high-frequency wound magnetic core according to the present invention is smaller than that of the conventional wound magnetic core using an amorphous alloy with the same composition, and 10
It can be seen that the iron loss after 1000 hours at 0°C is also small, and the change over time is small.

Embodiment 3 FIG. 2 shows the wound magnetic core G shown in FIG. 1 (d >) according to the present invention.
This is a diagram comparing an example of the change in iron loss over time of the wound magnetic core [1 shown in (l) and the conventional wound magnetic core F.The temperature is 100 ° C.
It is. In particular, it can be seen that the change over time of the wound magnetic core 1 (with a heat sink) is smaller than that of the conventional wound magnetic core F.

Example 4 FIG. 3 is a diagram showing the change in iron loss over time when the gap between the wound cores is changed when two wound magnetic cores are overlapped to form a high frequency wound core. ■The gap is 10μm, J is 20. czm, K is 50μlll, L is 300μ
It can be seen that when m and lvl are i ooo μm and the gap is 50 μm or more, the change over time becomes considerably small.

According to the present invention, it is possible to reduce the iron loss of the high-frequency wound magnetic core, which was a problem in the past, and improve heat dissipation, so that the change over time, which is a problem with the amorphous wound magnetic core C, can be reduced.1

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing an example of a wound magnetic core for high frequency according to the present invention, Fig. 2 is a diagram comparing an example of changes in iron loss over time of a wound magnetic core according to the present invention and a conventional wound magnetic core, and Fig. 3 is a diagram showing the difference in the change in iron loss over time when considering the gap between the wound magnetic cores. A, ~A: Wound magnetic core prepared by winding an amorphous ribbon having a width of 3ml or less, B: Adhesive, D+~D. Non-magnetic plate, [; Bopin Figure 1 (a) (b) M temple tl (Aour) Rule 15 (Aθpir)

Claims (1)

[Claims] 1. A wound magnetic core for high frequency, characterized in that it is wound using an amorphous ribbon produced by a molten metal quenching method with a width of 3IIli1 or less. 2. The high-frequency wound magnetic core according to claim 11, characterized in that a large number of wound magnetic cores are stacked one on top of the other with a gap of 50 μm or more between the amorphous magnetic cores. 3. A wound magnetic core for high frequency according to claim 2, characterized in that one or a plurality of non-magnetic plates are inserted between the wound magnetic cores to be overlapped to ensure a gap of 50 μm or less between the wound magnetic cores. . 4. The high-frequency wound magnetic core according to claim 4, characterized in that one or more non-magnetic metal ribbons are inserted between the overlapping wound magnetic cores to provide a heat dissipation effect.