JPH08191015A - Thin film skin effect element - Google Patents

Abstract

PURPOSE: To improve the low frequency characteristics by forming a magnetic member(s) made of a ferrite or amorphous magnetic passage on the entire surface or part of one or more windings of a plurality of turns formed adjacent ly on a base board. CONSTITUTION: A thin film skin effect element has one or more conductor windings of a plurality of turns are adjacently formed on a base board 10 and magnetic member 20 formed on the entire surface of part of, at least, one side of the board 10. The base boards 10 having these conductor windings are laminated into a laminate board and the magnetic member 20 is formed on the entire surface of part of, at least, one side of the laminate board or on a marginal area of the board 10. This improves the low frequency characteristics of the thin film element utilizing the skin effect of the conductor winding.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a film-like thin film substrate.
The present invention relates to a thin film skin effect element in which a plurality of or a plurality of conductor windings are closely wound and formed.

[0002]

2. Description of the Related Art In order to reduce the size and weight of a small capacity power source,
An air-core film type transformer utilizing the skin effect of the winding conductor has already been proposed. FIG. 15 is a diagram showing the already proposed film type transformer. The primary and secondary winding patterns are formed in a circular concentric axis shape by bringing two patterns close to each other on the film-shaped thin film insulating substrate 1 by a lithography technique, an etching technique, a printing technique or the like. As shown in FIG. 15A, if two patterns are used as a primary winding and a secondary winding, a film type thin film transformer is formed by this, and a transformer operation is possible even with this one film. It is convenient to stack two or more film transformers to improve the low frequency characteristics and change the transformation ratio.

Now, assuming that the pattern is formed in a circular concentric axis shape starting from the center, the pattern of FIG. 15A is wound clockwise and the pattern of FIG. 15B is wound counterclockwise. It will be. Then, assuming that the pitch and the number of turns are the same, in each of the turns shown in FIGS. 15 (a) and 15 (b), the winding located outside is always longer than the winding located inside. Therefore, for each turn in FIG. 15 (a), when the outer winding is always the primary winding 2 and the inner winding is the secondary winding 3, the reverse winding is shown in FIG. 15 (b). For each turn, the winding that is always located on the outside is the secondary winding 3 ′, and the winding that is located on the inside is the primary winding 2 ′.
5 (a) and the substrate of FIG. 15 (b) are laminated, the terminal 2b is connected to the terminal 2b ', and the terminal 3b is connected to the terminal 3b'.
When a'is a primary terminal, 3a, and 3a 'are secondary terminals, magnetic flux is added by the winding patterns of FIGS. 15 (a) and 15 (b), and the primary winding and the secondary winding are The lengths can be equal. In this way, a plurality of layers, each of which is a laminate of two sheets, are laminated and connected in series or in parallel to each other to form a film type transformer. When connected in series, the resistance value becomes large, and when connected in parallel, the resistance value becomes small. In the conventional film transformer, the low frequency characteristic was not sufficient.

[0004]

In such a thin film type transformer, the higher the frequency is, the more the skin current effect of the winding current becomes more remarkable, so that high efficiency can be achieved, but the characteristics in the low frequency region are not sufficient. However, improvement of characteristics in the low frequency region is desired.

The problem of improving the characteristics in the low frequency region is not limited to the film type transformer, but an element in which a conductor winding is formed close to a thin film substrate, for example, a single conductor is wound close to a plurality of turns. Related to all thin-film elements that utilize the inductance of the turned conductors, thin-film elements that utilize the resonance characteristics of a resonant circuit formed from the mutual inductance between conductors and distributed capacitance between conductors when multiple conductors are formed in close proximity, etc. It is also a task to do. The present invention has been made in view of the above circumstances, and an object thereof is to improve the characteristics of a thin film element in a low frequency region by utilizing the skin effect of a winding conductor.

[0006]

To this end, the film type transformer of the present invention is provided with a partial region of at least one surface of a substrate on which one or a plurality of conductor windings are formed in close proximity and a plurality of turns are formed. It is characterized in that a magnetic material is provided on the entire surface. Further, according to the present invention, a plurality of substrates in which one or a plurality of conductor windings are closely arranged and formed by a plurality of turns are laminated, and a magnetic material is provided on a partial region or the entire surface of at least one surface of the laminated substrate. It is characterized by being provided. Further, the present invention is characterized in that the magnetic material is provided only in the peripheral portion of the substrate. The present invention also provides that the conductor winding forms a transformer.
It is characterized in that it is a secondary winding pattern and a secondary winding pattern. Further, the present invention is characterized in that the transformer formed by the primary winding pattern and the secondary winding pattern is a resonance type transformer.

[0007]

The thin film type skin effect element of the present invention is a magnetic material made of ferrite, an amorphous magnetic material or the like on the entire surface or a part of one or a plurality of windings formed by winding a plurality of times in close proximity to the substrate. By forming the body, it becomes possible to improve impedance characteristics, coupling coefficient, efficiency, etc. in the low frequency region.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. The thin film film type transformers in the embodiments of FIGS. 1 to 3 are transformers having the winding pattern as described in FIG. 15, and are either one or a plurality of laminated layers. May be. FIG. 1 is a diagram for explaining an embodiment of the film type transformer of the present invention. In FIG. 1A, a magnetic body 20 such as a ferrite or an amorphous magnetic body is provided on the entire surface of both sides of the film type transformer 10. When ferrite is used as the magnetic substance, it may be directly provided on the pattern because it is insulative.
When an amorphous magnetic material is used, it has conductivity, so it is provided via an insulating material. The magnetic body may be provided on the entire surface of only one side of the film type transformer 10 as shown in FIG. By providing a magnetic material in this way,
As will be described later, the characteristics in the low frequency region are improved.

FIG. 2 is a view showing another embodiment in which a magnetic material is provided in a partial area of a film type transformer. 2A shows an example in which strip-shaped magnetic bodies are provided on both sides so as to traverse the film type transformer, and FIG. 2B shows that strip-shaped magnetic bodies cross the transformer from the center of the film type transformer. These are examples provided on both sides, and any of them can improve low frequency characteristics. Of course, it may be provided on only one side. Since the magnetic body also has a function as a heat radiating plate, when it is provided on the entire surface as shown in FIG. 1, it is possible to suppress the temperature rise of the transformer and improve the efficiency. Further, the temperature of the central portion of the film type transformer is higher than that of the peripheral portion, but in the case of ferrite, there are some Curie points of about 110 ° C., so it is desirable to avoid providing it in the high temperature region as much as possible. Therefore, if a magnetic body is provided around the film transformer in an annular shape as shown in FIG. 3 or in a rectangular shape as shown in FIG. 3B, the influence of temperature rise can be avoided.

Next, the improvement of the low frequency characteristics by providing the magnetic material will be described. FIG. 4A shows a case where two film type transformers are stacked and connected in series and no magnetic material is provided, and FIG. 4B shows the same film type transformer as shown in FIG. 1A. As described above, the impedance characteristics and the phase characteristics when ferrite is provided on both surfaces are shown. As can be seen from FIG. 4, the resonance point is lowered and the low frequency characteristic is improved.

FIG. 5 shows the transformation ratio-frequency characteristics when there is no ferrite and when there is all ferrite. In the figure, ○ and □ are those without ferrite with different output impedance, and ● and ■ are those with corresponding ferrite. As can be seen from FIG. 5, the range of 10 kHz or more can be used without ferrite, while the range of 0.1 kHz can be obtained by adding ferrite.
It can be used to some extent, and the low frequency characteristics have been greatly improved.

FIG. 6 shows the efficiency-frequency characteristics with and without ferrite. In the figure, ○, △, and □ are without ferrite with different output impedance, and ●, ▲, and ■ are with corresponding ferrite. At about 1000 kHz, it is more efficient without ferrite, but below 100 kHz, especially 10
It can be seen that at frequencies below kHz, the one with ferrite is much more efficient and the low frequency characteristics are improved.

FIG. 7 shows the coupling coefficient-frequency characteristics with and without the amorphous magnetic material. In the figure, ◯ is the characteristic without an amorphous magnetic material, and Δ is the characteristic with the entire surface amorphous magnetic material. 1
At 000 kHz or higher, both cases are the same, but 1
At 00 kHz or less, the coupling coefficient is much larger with the amorphous magnetic material, and at 10 kHz, the coupling coefficient can be increased from 0.175 to 0.875 by adding the amorphous magnetic material.

FIG. 8 shows efficiency-frequency characteristics with and without an amorphous magnetic material. In the figure, ○ indicates no amorphous magnetic substance, △
Is a characteristic with the entire surface having an amorphous magnetic material. 600k
It can be seen that the efficiency is better without the amorphous magnetic material above Hz, but the efficiency is better with the amorphous magnetic material below 400 kHz, and the efficiency is significantly better with the amorphous magnetic material especially below 100 Hz. .

FIG. 9 shows the coupling coefficient-frequency characteristics with and without a strip-shaped ferrite as shown in FIG. 2A. In the figure, ○ means no ferrite, △ means ferrite (width 5 mm, length 9
5 mm). There is almost no difference at 1000 kHz or more, but at 50 kHz or less, the coupling coefficient with ferrite is significantly larger, and the coupling coefficient is 1.0 with ferrite and 5 Hz without ferrite.
Since it is 00 kHz, it can be seen that the frequency can be significantly lowered to obtain the same coupling coefficient.

FIG. 10 shows the efficiency-frequency characteristics with and without a strip of ferrite as shown in FIG. 2A. In the figure, ◯ is a characteristic without ferrite, Δ is a characteristic with a strip-shaped ferrite with a width of 5 mm, and □ is a characteristic with a strip-shaped ferrite with a width of 20 mm. 10
It can be seen that even at about 00 kHz, the strip-shaped ferrite is more efficient, but especially at 100 kHz or less, the efficiency is not so marked. Further, the wider the strip-shaped ferrite, the higher the efficiency.

The above-described frequency improving method is applicable not only to the resonance type and the non-resonance type but also to the thin film type film transformer in which windings are formed on the substrate. It is naturally applicable to the inductance thin film element in which the conductor of the above is wound in plural turns in close proximity so that the skin effect appears, and the thin film circuit element in which plural conductor windings are formed close to each other on the substrate. . Next, the resonance type film transformer will be briefly described. The primary and secondary windings of the film type transformer described in FIG. 15 have a structure in which conducting wires are wound in parallel, so that there is distributed capacitance between the conductors of each winding, and the resonance characteristics depend on the inductance of the windings. Present. Now, consider a case where two conductors are used for the primary winding and half of the primary voltage is applied between the primary conductors, as shown in FIG. Of course, the number of wires is not limited to two, and the number of wires may be increased.

Explaining the case where an alternating current is passed through a conductor having a conductor with a circular cross section as shown in FIG. 12, a current with a low frequency f is distributed almost uniformly over the cross section of the conductor as shown in FIG. 12 (a). To do. Therefore, the electric resistance R of the conductor is equal to the DC resistance R _{dc and} has a lower limit value. The inductance L of the conductor is composed of the sum L _in + L _{out of} the internal inductance L _in caused by the interlinkage of the current and the magnetic flux distributed inside the conductor and the external inductance L _out caused by the magnetic flux outside the conductor.

The current having a high frequency f is due to the skin effect.
As shown in FIG. 12B, it is distributed only around the conductor cross section. Therefore, the electric resistance R of the conductor becomes infinite because the frequency f is infinite and the cross-sectional area of the conductor through which the current flows is infinitesimally small. Since the frequency f is finite, the electrical resistance R is assumed to be an extremely large resistance R _max (>> R _dc ) for a sufficiently high frequency f. Since no current is distributed in the conductor in the inductance L, the internal inductance L _in becomes zero, so the inductance is the external inductance L
Only _out , and L = L _out .

For simplicity, as shown in FIG.
If two identical circular conductors are arranged in parallel and connected as shown in FIG. 13 (b), since there is a magnetic flux surrounding both conductors, a mutual inductance M exists between the conductor 1 and the conductor 2. . This mutual inductance M has a constant value irrespective of the frequency f, provided that the currents in both conductors are distributed symmetrically about their respective central axes. Actually, it is possible to distribute the currents symmetrically on the respective axes on average by a method of alternately arranging coils.

By the way, when two conductors are connected in series and a voltage V is applied as shown in FIG. 13B, the potential difference between the two conductors is the same potential difference V / 2 from the left end to the right end,
The directions of the currents are the same. Therefore, the connection of FIG. 13B is represented by a lumped constant equivalent circuit as shown in FIG. 14C in the process as shown in FIG. 14A, FIG. 14B, and FIG. 14C. It can be seen that the connection in FIG. 13 (b) forms a parallel resonant circuit of inductance and capacitance.

In the equivalent circuit shown in FIG. 14 (c), the resonance angular frequency ω _r (= 2πf _r ) and the impedance Z _r at resonance are obtained.
Is given by ω _r = 1 / {(L + M) C} ^1/2 (1) Z _r = R + {(L + M) / RC} = R + {1 / Rω _r ² C ² } ...... (2) To be From the equation (1), the reduction of the resonance frequency either increases the inductance or the capacitance. Further, the impedance at resonance increases as the inductance increases, and decreases as the capacitance increases. Therefore, lower the resonance frequency,
In addition, it is most preferable to increase the inductance in order to increase the impedance at resonance.

Thus, the windings formed close to each other are
As can be seen from the equations (1) and (2), the resonance characteristic is exhibited, and therefore, the present invention can be used as a circuit element such as a filter or an inductor utilizing the resonance characteristic. It can be used as a characteristic improvement in the low frequency region.

[0024]

As described above, according to the present invention, by providing a thin film element utilizing the skin effect with a magnetic material such as ferrite or amorphous magnetic material, characteristics in a low frequency region such as impedance characteristics and coupling coefficient are obtained. It is possible to greatly improve efficiency and the like.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a film type transformer of the present invention.

FIG. 2 is a diagram showing another embodiment of the film type transformer of the present invention.

FIG. 3 is a diagram showing another embodiment of the film type transformer of the present invention.

FIG. 4 is a diagram showing impedance characteristics.

FIG. 5 is a diagram showing a transformation ratio-frequency characteristic with and without ferrite.

FIG. 6 is a diagram showing efficiency-frequency characteristics with and without ferrite.

FIG. 7 is a diagram showing a coupling coefficient-frequency characteristic with and without an amorphous magnetic material.

FIG. 8 is a diagram showing efficiency-frequency characteristics with and without an amorphous magnetic material.

FIG. 9 is a diagram showing coupling coefficient-frequency characteristics with and without strip-shaped ferrite.

FIG. 10 is a diagram showing efficiency-frequency characteristics with and without strip-shaped ferrite.

FIG. 11 is a diagram illustrating a resonance type transformer.

FIG. 12 is a diagram illustrating a current flowing through a conductor having a circular cross section.

FIG. 13 is a diagram illustrating a wiring system.

FIG. 14 is a diagram illustrating a resonance circuit formed by the wiring system of FIG.

FIG. 15 is a diagram illustrating a film type transformer.

[Explanation of symbols]

 10 ... Film type transformer, 20 ... Magnetic material.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical indication location H01F 19/00 Z 4230-5E 9375-5E H01F 31/00 D (72) Inventor Hideki Kishimoto Kyoto, Kyoto Prefecture Higashi-Horikawa-dori, Ichijo-Kami, Ken 436-5, Tomitacho Photographic Chemical Co., Ltd.

Claims (5)

[Claims] 1. A thin film type in which a magnetic material is provided on a partial region or the entire surface of at least one surface of a substrate on which one or a plurality of conductor windings are closely wound and formed. Skin effect element. 2. A plurality of substrates, each having one or a plurality of conductor windings formed in close proximity to each other and having a plurality of turns formed thereon, are laminated, and a magnetic material is provided on a partial region or the entire surface of at least one surface of the laminated substrate. A thin film type skin effect element characterized by the above. 3. The device according to claim 1 or 2, wherein
A thin film type skin effect element characterized in that a magnetic material is provided only on the peripheral portion of the substrate. 4. The thin-film type skin effect according to claim 1, wherein the conductor windings are a primary winding pattern and a secondary winding pattern forming a transformer. element. 5. The thin-film skin effect element according to claim 4, wherein the transformer formed by the primary winding pattern and the secondary winding pattern is a resonance type transformer.