JPH0673335B2 - Thin film magnetic element - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a thin film magnetic element used in a high frequency range.

[0002]

2. Description of the Related Art In a conventional magnetic thin film transformer, an example in which a primary coil and a secondary coil are laminated by interposing an insulating layer (Journal of Applied Magnetics, Vol. 12, No. 2, P. 385 (1988))
Is shown in FIG. This figure is a conceptual diagram for calculating the performance of the magnetic thin film transformer. 1 is the upper magnetic thin film, 2 is 1
Secondary coil, 3 is secondary coil, 4 is lower magnetic thin film, 6,
Insulating layers 7 and 8 are omitted from the support. A high-frequency current is passed through the primary coil 2 to excite the magnetic thin films 1 and 4, whereby an induced electromotive force is generated in the secondary coil 3 to operate as a thin film transformer.

[0003]

In the conventional example shown in FIG. 6, the lower magnetic thin film 4 and the upper magnetic thin film 1 are laminated at the same position on the outer peripheral portion. Generally, the film strain of each layer in the laminated state is strongest in the peripheral portion. Therefore, in the conventional example, the outer peripheral portion is easily affected by the strain, and in the process of manufacturing the thin film transformer, the outer peripheral portion is locally separated from the support or the lower layer and floats or becomes the starting point, and the laminated layer is formed. There is a problem such as peeling of the entire film.

In the conventional example shown in FIG. 6, the insulating layers 6, 7 and 8 are laminated at the same position in the peripheral edge portion, as in the magnetic thin film. In such a case, there is a problem for the same reason as the case of laminating the magnetic thin films described above. In particular, in order to improve performance, a magnetic thin film, an insulating layer, a conductor pattern layer, and the like are laminated in multiple layers. In the conventional example, there are many problems such as peeling and the manufacturing yield is poor. In order to solve the above problems, it is an object of the present invention to provide a thin film magnetic element in which peeling due to stacking strain is prevented and the production yield is significantly improved.

[0005]

In order to solve the above problems, the first means of the present invention is to provide a peripheral portion of an upper magnetic thin film and a lower magnetic thin film when sandwiching an insulating layer or a conductor pattern layer. In (2), the upper magnetic thin film is laminated so as to protrude to the peripheral edge of the lower magnetic thin film.

The second means is to insulate the magnetic thin film and the conductor pattern layer, so that when a plurality of insulating layers are laminated,
In the peripheral portion, the insulating layer is laminated so that the upper insulating layer extends outside the lower insulating layer.

[0007]

By the first means, only one layer of the portion of the magnetic thin film protruding to the outside at the peripheral portion comes into close contact with the support, so that the film strain is very small, and the magnetic strain between the support and the support is small. Strong adhesion. In addition, since the upper magnetic thin film, which has strong adhesion, presses the lower conductor pattern layer, insulating layer, lower magnetic thin film, etc. from above, the problem of peeling does not occur and the production yield is greatly improved. .

Further, by the second means, the upper insulating layer is protruded to the outside of the lower insulating layer at the peripheral portion, so that the peripheral insulating layer becomes one layer at the peripheral portion, and the strain at the peripheral portion is relieved and the adhesion is strengthened. . At the same time, the upper insulating layer wraps the lower conductor pattern layer and the insulating layer from the upper side and presses the lower conductive pattern layer from the upper side, so that the problem of peeling does not occur and the manufacturing yield is greatly improved.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a top view of a magnetic thin film transformer according to an embodiment of the present invention. 11 is an upper magnetic thin film, 12 is a primary coil, 13 is a secondary coil, and 17 and 18 insulate the magnetic thin film from the coil. Is a part of the insulating layer. 2 (a),
(B) shows the coil structure of the present invention, (a) is an overall view of the primary coil 12, and (b) is an overall view of the secondary coil 13. FIG. 3 is a cross-sectional view taken along the line AB of FIG.
11 is an upper magnetic thin film, 12 is a primary coil, 13 is a secondary coil, 14 is a lower magnetic thin film, 15 is a support, 16, 1
Reference numerals 7 and 18 are insulating layers. The upper magnetic thin film 11 is provided with a portion 19 protruding from the peripheral edge of the lower magnetic thin film 14. Further, the insulating layer 17 is provided with a portion 20 protruding to the peripheral edge of the insulating layer 16, and the insulating layer 18 is provided with a portion 21 protruding to the peripheral edge of the insulating layer 17.

FIG. 4 is a sectional view taken along the line C--D in FIG. 1, which shows an insulating layer portion for insulating the primary coil 12 from the magnetic thin films 11 and 14. Reference numeral 15 is a support, and 17 and 18 are insulating layers. The insulating layer 18 has a portion 2 protruding from the periphery of the insulating layer 17.
Two are provided.

FIG. 5 is a sectional view taken along the line EF of FIG. 1 and shows an insulating layer portion for insulating the secondary coil 13 from the magnetic thin films 11 and 14. Reference numeral 15 is a support, and 16 and 17 are insulating layers. The insulating layer 17 has a portion 2 protruding from the periphery of the insulating layer 16.
3 is provided.

As can be seen from FIG. 3, the insulating layer 17 encloses the secondary coil 13 and the insulating layer 16 inside, and the protruding portion 20 adheres to the lower magnetic thin film 14 and seems to be glued. It is in the form. Further, the insulating layer 18 is glued to the lower magnetic thin film 14 at the portion 21 protruding to the outside thereof, and the upper magnetic thin film 11 is attached to the inner insulating layers 16 to 16.
18, the coils 12, 13 and the lower magnetic thin film 14 are all wrapped up, and the protruding portion 19 is in close contact with and glued to the support 15. The same applies to FIGS. 4 and 5, in which the inside is wrapped with the upper insulating layers 18 and 17, and the protruding portions 22 and 23 at the peripheral edges are adhered to the support 15 in such a manner as to be glued.

As described above, the feature of the present invention is that the upper layer wraps the inside to reduce the number of laminated layers at the peripheral edge, and the layer is adhered to the lower layer or the support in a state where the laminating strain of the film is small. That is.

In the above embodiments, the case of the magnetic thin film transformer was described, but in the case where the above method is applied to a magnetic thin film inductor having a so-called closed magnetic circuit structure, which has a magnetic thin film formed so as to enclose an exciting conductor coil. It is clear that also produces the same effect.

[0016]

As described above, according to the present invention, it is possible to minimize the number of laminated layers in the peripheral portion, and thus it is possible to minimize the lamination strain in the peripheral portion. As a result, in the conventional example, in the ultrasonic cleaning process, the magnetic thin film transformer may be gradually lifted up from the peripheral portion and may be peeled off. However, according to the present invention, in the ultrasonic cleaning process, The problem is gone. Further, in the conventional example, in the process of developing the photoresist and the process of washing with running water, the liquid may infiltrate and peel off gradually from the locally defective adhesion portion due to the stacking distortion of the peripheral portion of the magnetic thin film transformer. However, the present invention has solved such a problem. As described above, the present invention significantly improves the production yield.

[Brief description of drawings]

FIG. 1 is a top view showing an embodiment of the present invention.

FIG. 2 is a configuration diagram showing an example of a coil according to the present invention.

3 is a cross-sectional view taken along the line AB of FIG.

4 is a cross-sectional view taken along the line CD of FIG.

5 is a cross-sectional view taken along the line EF of FIG.

FIG. 6 is a partially cutaway perspective view showing a conventional magnetic thin film transformer.

[Explanation of symbols]

11 ... Upper magnetic thin film, 12 ... Primary coil, 13 ... Secondary coil, 14 ... Lower magnetic thin film, 15 ... Support, 16, 1
7, 18 ... Insulating layer.

Claims (2)

[Claims] 1. In a thin film magnetic element such as a magnetic thin film transformer or a magnetic thin film inductor, when a plurality of magnetic thin films are laminated with an insulating layer and a conductor pattern layer interposed therebetween, an upper magnetic thin film is a lower layer at a peripheral portion of the magnetic thin film. A thin film magnetic element characterized by being stacked so as to extend outside a magnetic thin film. 2. In a thin film magnetic element such as a magnetic thin film transformer or a magnetic thin film inductor, in order to insulate the magnetic thin film and the conductor pattern layer, the upper insulating layer is laminated so as to extend outside the lower insulating layer. Thin film magnetic element.