JPH10135040A - Thin-film magnetic element and its method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin-film magnetic element capable of keeping large Q value, regardless of the magnitude of high frequency current. SOLUTION: An insulating substrate 20 is formed by a semiconductor substrate 1 and an insulating film bed 2. A thin-film magnetic element 6 used as thin-film transformer and thin-film inductor is formed on the insulating film bed 2. The thin-film magnetic element 6 is formed by a first coil conductor 5a and a second coil conductor 5b consisting of a strip copper film and so on, the magnetic layer, the first soft magnetic layer 3a and the second soft magnetic layer 3b, arranged above and under the coil conductor 5a and 5b interposing them, an inter-layer insulating film 4 STORAGE (polyimide layer) filling up between the soft magnetic layer 3a and 3b, and the coil conductor 5a and 5b, and the metal pad 7 and 8 (external terminals) to which the both end of coil conductors 5a and 5b are connected together.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thin-film magnetic element, and more particularly, to a thin-film magnetic element formed on an insulating substrate by a thin-film forming technique and used as a small-capacity (about several watts) power supply component such as a DC / DC converter. And a method of manufacturing the same.

[0002]

2. Description of the Related Art Since the above-mentioned thin-film magnetic element is used as a small-capacity (about several watts) power supply component, the switching frequency used is 0.5 to 5 MHz and the occupied area is 4 MHz.
There is a restriction of about 25 m ² , and within this range,
It is desired that the Q value (= ωL / R: (= 2πf) be a used angular frequency and f be a used frequency) is large.

FIGS. 11A and 11B are main part configuration diagrams of a conventional thin film magnetic element. FIG. 11A is a sectional view, and FIG. 11B is a plan view.
FIG. 2A is a sectional view taken along line AA of FIG.
In FIG. 11, reference numeral 1 denotes a semiconductor substrate, and reference numeral 2 denotes a base insulating film 2 composed of an oxide film formed by thermally oxidizing the semiconductor substrate 1 and a nitride film formed on the oxide film by sputtering.
These constitute the insulating substrate 20. Reference numeral 6 denotes a thin-film magnetic element used as a thin-film transformer and a thin-film inductor, which is formed on the base insulating film 2. The thin-film magnetic element 6 insulates the coil conductors 5 made of a strip-shaped aluminum film or a copper film from each other.
And soft magnetic layers 3a and 3b formed with coil conductor 5 interposed therebetween
And soft magnetic layers 3a and 3b formed by sandwiching the coil conductor 5 from above and below both sides with the interlayer insulating film 4 interposed therebetween. Reference numerals 7 and 8 denote pads formed on both ends of the coil conductor 5.

[0004]

In the conventional spiral thin film coil conductor described above, when high frequency power is applied, the current flowing through the coil conductor is limited by the surface area of the coil conductor due to the skin effect. Therefore, in order to increase the surface area of the coil conductor to some extent, the coil conductor is made thick. Then, the interval between the soft magnetic layers sandwiching the coil conductor is widened, and the magnetic field generated by the coil current lowers the magnetic flux density across the soft magnetic layer, thereby reducing the inductance L.
Decrease, and the Q value decreases.

In a conventional spiral thin film coil conductor, since a coil conductor is formed in a spiral shape on the surface of a semiconductor substrate, a soft magnetic layer as a magnetic material as a magnetic core is provided on both sides of the coil conductor (see FIG. In this case, it was arranged vertically. For this reason, no magnetic core is arranged at the center of the coil where the lines of magnetic force are most concentrated and at the outer periphery of the coil conductor where the magnetic field tends to leak, and the characteristics of the coil have not been sufficiently derived.

An object of the present invention is to provide a thin-film magnetic element capable of increasing inductance by increasing a high-frequency current flowing through a coil conductor and increasing a magnetic flux density in a magnetic body, and a method of manufacturing the same. To provide.

[0007]

According to the present invention, in order to achieve the above object, a strip-shaped conductive metal layer having a function as a coil conductor is provided on an insulating substrate. A magnetic layer having a function as a magnetic core formed so as to sandwich the conductive metal layer with an interlayer insulating film interposed therebetween, wherein the conductive metal layer is laminated with an insulating film interposed therebetween. And

It is effective to electrically connect the stacked conductive metal layers. Further, on an insulating substrate, a strip-shaped conductive metal layer having a function as a coil conductor, and a magnetic core formed so as to sandwich the conductive metal layer via an interlayer insulating film above and below the conductive metal layer A thin-film magnetic element having a magnetic layer having a function may have a configuration in which the surface of the conductive metal layer has irregularities (trench structure).

Further, as a method of manufacturing the thin-film magnetic element, a step of laminating a first magnetic layer on an insulating substrate and then selectively removing the first magnetic layer, and a step of forming a first insulating layer on the first magnetic layer. After laminating the layer, the first metal fine particle layer and the second insulating layer, selectively removing the second insulating layer until the first metal fine particle layer is exposed; Forming the first conductive metal layer to the same thickness as the second insulating layer; and forming the third insulating layer and the second metal fine particles on the surface of the second insulating layer and the surface of the first conductive metal layer. Selectively removing the fourth insulating layer until the second metal fine particle layer is exposed after laminating the layer and the fourth insulating layer; and determining the thickness of the fourth insulating layer at the position where the fourth insulating layer is removed. Forming a second conductive metal film having the same thickness, forming a fifth insulating layer and a second magnetic layer on the second conductive metal layer and the fourth insulating layer; After stacking the door, the steps comprising a step of selectively removing the second magnetic layer.

In the above step, after the third insulating layer, the second metal fine particle layer and the fourth insulating layer are laminated, the fourth insulating layer is selectively removed until the second metal fine particle layer is exposed. A step of selectively removing the fourth insulating layer with an area smaller than the area on the first conductive metal layer until the first conductive metal layer is exposed; Forming a second conductive metal layer to have the same thickness as the insulating layer; and forming a fifth insulating layer and a second magnetic layer on the second conductive metal layer and the fourth insulating layer. And then selectively removing the second magnetic layer after lamination.

And a step of selectively removing the first magnetic layer after laminating the first magnetic layer on the insulating substrate; and forming a first insulating layer, a first metal fine particle layer, and a second metal layer on the first magnetic layer. A step of selectively removing the second insulating layer until the first metal fine particle layer is exposed after laminating the insulating layer, and a step of removing the second insulating layer at a position where the second insulating layer is removed. Forming a first conductive metal layer, and laminating a third insulating layer on the second insulating layer and the first conductive metal layer, and then forming a third conductive layer until the first conductive metal layer is exposed. A step of selectively removing the insulating layer; a step of forming a second conductive metal film at the same thickness as that of the third insulating layer at a position where the third insulating layer is removed; Stacking the fourth insulating layer and the second magnetic layer on the layer and the third insulating layer, and then selectively removing the second magnetic layer.

[0012] Further, the conductive metal layer is formed on the insulating substrate so as to sandwich the conductive metal layer via a strip-shaped conductive metal layer having a function as a coil conductor and an interlayer insulating film above and below the conductive metal layer. A thin-film magnetic element having a magnetic layer having a function as a magnetic core may be configured so that magnetic layers sandwiching a strip-shaped conductive metal layer from both sides are partially connected to each other.

It is effective if the magnetic layers sandwiching the strip-shaped conductive metal layer from both sides partially approach each other.
Further, it is preferable that the portions where the magnetic layers sandwiching the band-shaped conductive metal layer are sandwiched from both sides are connected or close to each other are the central portion and the outer peripheral portion of the conductive metal layer. A step of selectively removing the first magnetic layer after laminating the first magnetic layer on the insulating substrate; and a step of laminating the first insulating layer, the metal fine particle layer, and the second insulating layer on the first magnetic layer. After that, a step of selectively removing the second insulating layer until the metal fine particle layer is exposed, and a step of forming a conductive metal layer at a position where the second insulating layer is removed to the same thickness as the second insulating layer. Forming a third insulating layer and a second magnetic layer on the conductive metal layer and the second insulating layer, and partially forming the first magnetic layer and the second magnetic layer on the third magnetic layer. And a step of connecting at a time.

Preferably, the third magnetic layer has a gap. It is also effective if the insulating layer is formed of at least one of a polyimide film, an oxide film and a nitride film. Further, the metal fine particle layer is made of platinum (P
t) or palladium (Pd).

As described above, by increasing the surface area of the coil conductor, the effective resistance due to the skin effect is reduced, and the high-frequency current is effectively increased, thereby increasing the magnetic flux density in the magnetic layer. , The inductance can be increased. Also, by forming a magnetic layer serving as a magnetic core at the center and the outer periphery of the coil conductor, the magnetic flux density in the magnetic layer can be increased and the inductance can be increased. Also,
By providing a gap in the magnetic layer, it is possible to prevent the magnetic flux in the magnetic layer from being saturated even with a large high-frequency current, and to secure a large inductance.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1A and 1B are sectional views of a main part of a first embodiment of the present invention. FIG. 1A is a sectional view and FIG. 1B is a plan view. FIG. 2A is a sectional view taken along line AA of FIG. In FIG. 1, reference numeral 1 denotes a semiconductor substrate (eg, a silicon substrate), 2 denotes an oxide film (eg, a silicon oxide film) formed by thermally oxidizing the semiconductor substrate 1, and a nitride film (eg, a silicon film) formed on the oxide film by sputtering. (A nitride film or the like). These constitute the insulating substrate 20. Reference numeral 6 denotes a thin-film magnetic element used as a thin-film transformer and a thin-film inductor, which is formed on the base insulating film 2. The thin-film magnetic element 6 includes a first coil conductor 5a made of a strip-shaped copper (Cu) film or a gold (Au) film, and a second coil conductor 5a.
A coil conductor 5b, a first soft magnetic layer 3a and a second soft magnetic layer 3b as magnetic layers arranged vertically so as to sandwich the coil conductors 5a and 5b, and the soft magnetic layers 3a and 3b
And an interlayer insulating film 4 (polyimide layer) filling the space between the coil conductors 5a and 5b, and metallic pads 7 and 8 (external lead terminals) to which both ends of the coil conductors 5a and 5b are connected together. It is configured. In this embodiment, the number of laminated coil conductors is two. However, more than two layers may be used.

When the coil conductor has two layers, the total surface area of the coil conductor is increased as compared with a single layer. Therefore, the effective resistance of the coil conductor due to the skin effect can be reduced, the high-frequency current increases, and the magnetic flux density of the soft magnetic layer generated thereby increases, and the inductance can be increased. That is, the Q value of the thin-film magnetic element can be increased.

FIGS. 2A and 2B are main part configuration diagrams of a second embodiment of the present invention. FIG. 2A is a sectional view, and FIG. 2B is a plan view.
FIG. 2A is a sectional view taken along line AA of FIG.
The difference from FIG. 1 is that the first coil conductor 5a and the second coil conductor 5b are partially connected by the connection conductor 9, and the surface area of the coil conductors 5a and 5b including the connection conductor 9 is increased. As a result, the resistance of the connection conductor 9 and the coil conductors 5a and 5b can be reduced, and the inductance can be increased.

FIGS. 3A and 3B are diagrams showing a main part of a third embodiment of the present invention. FIG. 3A is a sectional view and FIG. 3B is a plan view.
FIG. 2A is a sectional view taken along line AA of FIG.
The difference from FIG. 1 is that the surface of one coil conductor 5 is made uneven (a trench structure in which a groove is dug in the surface), so that the surface area of the coil conductor 5 can be increased. The effect is the same as in FIGS.

FIG. 4 shows a fourth embodiment of the present invention. FIGS. 4A to 4D are cross-sectional views showing the main parts of the thin film magnetic element shown in FIG. 1 in the main manufacturing steps. In FIG. 4, after a base insulating film 2 and a first soft magnetic layer 3a are formed on a semiconductor substrate 1, unnecessary portions of the first soft magnetic layer 3a (the outer peripheral portion where the coil conductor is not arranged) are photo-etched. To remove. This soft magnetic layer is formed by, for example, a sputtering method (FIG. 1A).

First polyimide layer 4a and first Pt layer 10a
After forming the second polyimide layer 4b (a layer in which fine particles of platinum are dispersed and the size of the fine particles is several Å), the second polyimide layer 4b is etched by a photoetching technique until the first Pt layer 10a appears. (Figure (b)).
A metal thin film (not shown) is fixed (plated) to the etched concave portion of the second polyimide layer 4a by an electroless plating method, and then the first coil conductor 5a is electrolytically plated to a thickness equal to that of the second polyimide layer 4b. The third polyimide layer 4c and the second Pt layer 10b (first P
After forming the fourth polyimide layer 4d, the second Pt layer 1 is formed by a photo-etching technique.
The fourth polyimide layer 4d is etched until 0b appears (FIG. 3C).

The fourth polyimide layer 4 is formed by an electroless plating method.
A metal thin film is fixed to the etched concave portion of d, and then a second coil conductor 5b is formed by electrolytic plating until the film thickness becomes the same as that of the fourth polyimide layer 4d (until the surface is flush), The fifth polyimide layer 4e and the second
After laminating the soft magnetic layer 3b, the unnecessary second magnetic layer 3b (at least the soft magnetic layer on the pad) is removed by a photo-etching technique (FIG. 4D).

Although not shown, there is a subsequent step of connecting both ends of the first coil conductor 5a and the second coil conductor 5b to the metal pads 7, 8 (see FIG. 1B). The material of the metal thin film and the coil conductors 5a and 5b (not shown) is Cu or A, which can employ an electrolytic plating method.
u and the like, and the same applies to the following description. FIG.
5A to 5D show a fifth embodiment of the present invention. FIGS. 6A to 6D are cross-sectional views of main parts in a main manufacturing process of the thin-film magnetic element shown in FIG.

In FIG. 5, after a base insulating film 2 and a first soft magnetic layer 3a are formed on a semiconductor substrate 1, unnecessary portions of the first soft magnetic layer 3a are removed by a photo-etching technique (FIG. )). First polyimide layer 4a and first Pt layer 1
After the formation of the first polyimide layer 4a and the second polyimide layer 4b, the second polyimide layer 4b is etched by a photo etching technique until the first Pt layer 10a appears (FIG. 2B).

The second polyimide layer 4 is formed by an electroless plating method.
A metal thin film (not shown) is fixed to the etched concave portion of d, and then the first coil conductor 5a is formed by electrolytic plating until the film thickness becomes the same as the second polyimide layer 4b.
After forming the third polyimide layer 4c, the second Pt layer 10b, and the fourth polyimide layer 4d, the fourth polyimide layer 4d is etched by the photo-etching technique until the second Pt layer 10b appears, and then the first polyimide conductor 4a is formed on the first coil conductor 5a. A connection hole 9b having a size smaller than that of the first coil conductor 5a and a depth reaching the first coil conductor 5a is formed in the third polyimide layer 4c by a photo-etching technique (FIG. 3C).

The connection hole 9b formed in the third polyimide layer 4c by the combination of the electroless plating method and the electrolytic plating method and the etched concave portion of the fourth polyimide layer 4d
A coil conductor 5b is formed until the film thickness becomes the same as that of the fourth polyimide layer 4d, and the fifth polyimide layer 4e and the second
After forming the soft magnetic layer 3b, the unnecessary second soft magnetic layer 3b is removed by a photo-etching technique (FIG. 4D).

The connection hole 9b filled with the second coil conductor 5b becomes the connection conductor 9. 6A and 6B show a sixth embodiment of the present invention. FIGS. 6A to 6D are cross-sectional views of a main part of the device shown in FIG. 3 in main manufacturing steps. In FIG.
After the base insulating film 2 and the first soft magnetic layer 3a are formed on the semiconductor substrate 1, unnecessary portions of the first soft magnetic layer 3a are removed by a photo-etching technique (FIG. 1A).

The first polyimide layer 4a, the Pt layer 10, and the second
After the formation of the polyimide layer 4b, the second polyimide layer 4b is formed until the Pt layer 10 appears by a photo etching technique.
Is etched (FIG. 2B). A metal thin film (not shown) is fixed to the etched concave portion of the second polyimide layer 4b by electroless plating, and then the first coil conductor 5a is formed by electrolytic plating until the film thickness becomes the same as that of the second polyimide layer 4b. Then, after forming the third polyimide layer 4c, the third polyimide layer is selectively etched by the photo-etching technique until the first coil conductor 5a appears (FIG. (C)).

The third polyimide layer 4c is formed by electrolytic plating.
After the second coil conductor 5b is formed in the etched concave portion until the film thickness becomes the same as that of the third polyimide layer 4c, the fourth polyimide layer 4d and the second soft magnetic layer 3b are formed thereon. Unnecessary second soft magnetic layer 3b is removed by an etching technique (FIG. 4D). FIGS. 7A and 7B are main part configuration diagrams of a seventh embodiment of the present invention. FIG. 7A is a sectional view, and FIG.
Is a plan view. It should be noted that FIG. 3A is a view taken along the line AA in FIG.
FIG.

In FIG. 7, a soft magnetic layer 3 serving as a magnetic core is formed at the center and the outer periphery of the coil conductor 5, and the coil conductor 5 is surrounded by the soft magnetic layer 3 via an interlayer insulating film.
With this configuration, the magnetic flux density in the soft magnetic layer 3 is increased by the soft magnetic layer 3 disposed at the center and the outer periphery of the coil conductor 5, and the inductance can be increased.

FIGS. 8A and 8B are diagrams showing the main parts of an eighth embodiment of the present invention. FIG. 8A is a sectional view and FIG. 8B is a plan view.
FIG. 2A is a sectional view taken along line AA of FIG.
The difference from FIG. 7 is that the soft magnetic layer 3 is partially separated and has a gap. Of course, this gap is filled with the interlayer insulating film 4. This gap prevents the magnetic flux density in the soft magnetic layer 3 surrounding the coil conductor 5 from saturating, and ensures a large inductance even when the current flowing through the coil conductor 5 is large.

FIG. 9 shows a ninth embodiment of the present invention. FIGS. 9A to 9D are cross-sectional views showing the main parts of the thin film magnetic element shown in FIG. 7 in the main manufacturing steps. In FIG. 9, after forming a base insulating film 2 and a first soft magnetic layer 3a on a semiconductor substrate 1, unnecessary portions of the first soft magnetic layer 3b are removed by a photoetching technique (FIG. 9A).

The first polyimide layer 4a, the Pt layer 10, and the second
After the formation of the polyimide 4b, the second polyimide layer 4b is etched by the photo-etching technique until the Pt layer 10 appears (FIG. 2B). A metal thin film (not shown) is fixed to the etched concave portion of the second polyimide layer 4b by an electroless plating method, and then the coil conductor 5 is formed by electrolytic plating until the film thickness becomes the same as that of the second polyimide layer 4b. After the third polyimide layer 4c is formed thereon, the third polyimide layer 4c and the second polyimide layer 4 at the center and the outer periphery of the coil conductor 4 are formed by a photo-etching technique.
b and the first polyimide layer 4a with the connection opening 9b in the first
It is provided by etching so as to reach the soft magnetic layer 3a (FIG. 3 (c)).

The second soft magnetic layer 3b is replaced with a third polyimide layer 4c.
At the same time, the connection opening 9b is filled with the second soft magnetic layer 3b and connected to the first soft magnetic layer 3a, and then the unnecessary second soft magnetic film 3b is removed by a photo-etching technique (FIG. (D)). 10A and 10B show a tenth embodiment of the present invention. FIGS. 10A to 10D are cross-sectional views of main parts in the main manufacturing steps of the thin-film magnetic element shown in FIG.

The difference from FIG. 9 is that after the third polyimide layer 4d is formed in the step of FIG. 9C, the third polyimide layer 4c at the center and the outer periphery of the coil conductor 5 and the third polyimide layer 4d are formed by photoetching technology. The second polyimide layer 4b is provided with an opening 9c by etching so as to form the first polyimide layer 4a, and in the step of FIG. 9D, the opening 9c is formed in the second soft magnetic layer 3b.
c. In other words, a gap is formed without connecting the first soft magnetic layer 3a and the second soft magnetic layer 3b, and the first polyimide layer 4a is formed in the gap. Of course, the opening 9c may be formed so as to enter into the first polyimide layer 4a.

The method of forming the soft magnetic layer according to the first to tenth embodiments is based on CoFeBSiO, CoHfTa and CoFeBSiO.
In addition to the method of forming HfTaPd or the like by a sputtering method, it may be formed by an organic magnet which is a pure inducing compound. Since the organic magnet is generated by recrystallization from a solvent, a soft magnetic layer can be easily formed even when there is a concave portion as shown in the above-described embodiment.

[0037]

According to the present invention, the inductance can be increased and the Q value can be increased by increasing the surface area of the coil conductor, reducing the resistance of the coil conductor, and increasing the high-frequency current. Further, by partially connecting the soft magnetic layer sandwiching the coil conductor, the magnetic flux density in the soft magnetic layer can be increased, and a large inductance can be secured even in a range where the high-frequency current flowing through the coil conductor is small. By providing a gap without connecting the soft magnetic layer, even when the high-frequency current flowing through the coil conductor is large, the magnetic flux density does not saturate and a large inductance can be secured.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a main part of a first embodiment of the present invention, and FIG.
Is a sectional view, and (b) is a plan view.

FIGS. 2A and 2B are main part configuration diagrams of a second embodiment of the present invention, wherein FIG.
Is a sectional view, and (b) is a plan view.

FIGS. 3A and 3B are main part configuration diagrams of a third embodiment of the present invention, wherein FIG.
Is a sectional view, and (b) is a plan view.

FIGS. 4A to 4D show a fourth embodiment of the present invention.
Is a fragmentary cross-sectional view of the main manufacturing process of the thin-film magnetic element shown in FIG.

FIGS. 5A to 5D show a fifth embodiment of the present invention.
Is a cross-sectional view of a main part in a main manufacturing process of the thin-film magnetic element shown in FIG.

FIGS. 6A to 6D show a sixth embodiment of the present invention.
Is a cross-sectional view of a principal part in a main manufacturing process of the thin-film magnetic element shown in FIG.

FIGS. 7A and 7B are main part configuration diagrams of a seventh embodiment of the present invention, wherein FIG.
Is a sectional view, and (b) is a plan view.

FIG. 8 is a diagram showing a main part of an eighth embodiment of the present invention;
Is a sectional view, and (b) is a plan view.

FIGS. 9A to 9D show a ninth embodiment of the present invention.
Is a fragmentary cross-sectional view of the main manufacturing process of the thin-film magnetic element shown in FIG.

10 (a) to 10 (d) are cross-sectional views of main parts in a main manufacturing process of the thin-film magnetic element shown in FIG. 8 in a tenth embodiment of the present invention.

11A and 11B are configuration diagrams of a main part of a conventional thin film magnetic element, and FIG.
Is a sectional view, and (b) is a plan view.

[Explanation of symbols]

 Reference Signs List 1 semiconductor substrate 2 base insulating film 3 soft magnetic layer 3a first soft magnetic layer 3b second soft magnetic layer 4 interlayer insulating film 4a first polyimide layer 4b second polyimide layer 4c third polyimide layer 4d fourth polyimide layer 4e fifth Polyimide layer 5 coil conductor 5a first coil conductor 5b second coil conductor 6 thin film magnetic element 7 pad 8 pad 9 connection conductor 9a connection hole 9b connection opening 9c opening 10 Pt layer 10a first Pt layer 10b second Pt layer 20 insulation substrate

Claims (13)

[Claims] 1. A belt-shaped conductive metal layer having a function as a coil conductor is formed on an insulating substrate so as to sandwich the conductive metal layer via an interlayer insulating film above and below the conductive metal layer. And a magnetic layer having a function as a magnetic core, wherein the conductive metal layer is laminated with an insulating film interposed therebetween. 2. The thin-film magnetic element according to claim 1, wherein the stacked conductive metal layers are electrically connected. 3. A strip-shaped conductive metal layer having a function as a coil conductor is formed on an insulating substrate so as to sandwich the conductive metal layer via an interlayer insulating film above and below the conductive metal layer. A magnetic layer having a function as a magnetic core, wherein the surface of the conductive metal layer has an unevenness (trench structure). 4. After laminating a first magnetic layer on an insulating substrate,
Selectively removing the first magnetic layer; laminating the first insulating layer, the first metal fine particle layer, and the second insulating layer on the first magnetic layer, and removing the first magnetic fine particle layer until the first metal fine particle layer is exposed. A step of selectively removing the second insulating layer; a step of forming a first conductive metal layer at the same thickness as the second insulating layer at a position where the second insulating layer is removed; After the third insulating layer, the second metal fine particle layer, and the fourth insulating layer are laminated on the surface of the first conductive metal layer and the surface of the first conductive metal layer, the fourth insulating layer is selectively formed until the second metal fine particle layer is exposed. Removing the fourth insulating layer, forming a second conductive metal film at the same thickness as that of the fourth insulating layer at a position where the fourth insulating layer has been removed, Stacking a fifth insulating layer and a second magnetic layer on the layer, and then selectively removing the second magnetic layer. The method of production. 5. After the step of laminating the third insulating layer, the second metal fine particle layer, and the fourth insulating layer, selectively removing the fourth insulating layer until the second metal fine particle layer is exposed, Selectively removing the fourth insulating layer with an area smaller than the area on the first conductive metal layer until the first conductive metal layer is exposed; and removing the fourth insulating layer at a location where the fourth insulating layer has been removed. Forming a second conductive metal layer to have the same thickness as that of the first conductive metal layer, and laminating a fifth insulating layer and a second magnetic layer on the second conductive metal layer and the fourth insulating layer 5. The method according to claim 4, further comprising the step of selectively removing the second magnetic layer after the step. 6. After laminating a first magnetic layer on an insulating substrate,
Selectively removing the first magnetic layer; laminating the first insulating layer, the first metal fine particle layer, and the second insulating layer on the first magnetic layer, and removing the first magnetic fine particle layer until the first metal fine particle layer is exposed. A step of selectively removing the second insulating layer; a step of forming a first conductive metal layer at the same thickness as the second insulating layer at a position where the second insulating layer is removed; Selectively stacking the third insulating layer until the first conductive metal layer is exposed, after laminating the third insulating layer on the first and the first conductive metal layers, and removing the third insulating layer. Forming a second conductive metal film at the same thickness as that of the third insulating layer at the place where the second insulating layer and the fourth insulating layer are formed on the second conductive metal layer and the third insulating layer. A step of selectively removing the second magnetic layer after laminating the layers, and a method of manufacturing a thin-film magnetic element. 7. A strip-shaped conductive metal layer having a function as a coil conductor is formed on an insulating substrate so as to sandwich the conductive metal layer via an interlayer insulating film above and below the conductive metal layer. A magnetic layer having a function as a magnetic core, wherein the magnetic layers sandwiching a strip-shaped conductive metal layer from both sides are partially connected to each other. . 8. The thin film magnetic element according to claim 7, wherein the magnetic layers sandwiching the strip-shaped conductive metal layer from both sides are partially close to each other. 9. The conductive layer according to claim 7, wherein the magnetic layers sandwiching the strip-shaped conductive metal layer from both sides are connected or close to each other at the center and the outer periphery of the conductive metal layer. 9. The thin-film magnetic element according to 8. 10. A step of selectively removing the first magnetic layer after laminating a first magnetic layer on an insulating substrate; and forming a first insulating layer, a metal fine particle layer and a second insulating layer on the first magnetic layer. Selectively removing the second insulating layer until the metal fine particle layer is exposed after stacking the layers, and conducting the conductive layer to the same thickness as the second insulating layer at the position where the second insulating layer is removed. Forming a conductive metal layer, laminating a third insulating layer and a second magnetic layer on the conductive metal layer and the second insulating layer, and partially forming the first magnetic layer and the second magnetic layer. And a step of connecting with a third magnetic layer. 11. The method according to claim 10, wherein the third magnetic layer has a gap. 12. The method according to claim 4, wherein the insulating layer is formed of at least one of a polyimide film, an oxide film and a nitride film. . 13. The method according to claim 4, wherein the metal fine particle layer is formed of platinum (Pt) or palladium (Pd).