JP2001159668A - Membrane electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly sensitive compact membrane electronic component, particularly a magnetic sensor. SOLUTION: In this membrane electronic component, a plurality of conductor line layers 11, 12, 13... and insulator layers 21, 22, 23... for electrically insulating the conductor line layers from one another are laminated inside the surface of a substrate substantially in a vertical direction, and the plurality of conductor line layers 11, 12, 13... are electrically connected in series.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to sputtering, vapor deposition,
The present invention relates to a small-sized thin-film electronic component using a conductor line layer, which is a thin film having a thickness of several tens of μm or less formed by plating or the like, as a functional layer, and particularly to a magnetic field sensor that converts an external magnetic field into an electric signal.

[0002]

2. Description of the Related Art For example, in a thin film electronic component such as an inductor or a magnetic field sensor, a conductor layer, which is a functional layer for supplying a current, is used by being patterned into various shapes for the purpose at present. is there.

[0003] Regarding the patterning form, IEEE Trans.
n. MAG-20, No. 5, p1804 (1984) states that spiral coils and meanders (m
Comparative studies on eander) coils have been reported.

[0004] Also, the Japan Society of Applied Magnetism Research Group, 107-
4, p25 (1998), a magnetic field sensor in which a permalloy (NiFe) thin film exhibiting a magnetoresistive effect is patterned in a meander pattern as a conductor layer, and further patterned in a line (strip) shape, and the end portion is made of another conductor. A structure in which some aluminum is electrically connected in series is also disclosed.

On the other hand, in a method for detecting a minute magnetic field such as terrestrial magnetism, Japanese Patent Laid-Open No.
There is a technique disclosed in Japanese Patent Application No. 1-109006. This technique relates to a magnetic impedance effect (MI effect) element in which a magnetic thin film is formed on a substrate and electrodes are provided at both ends in the longitudinal direction.

This magneto-impedance effect has been proposed by Prof. Toshio Mori, and is provided with magnetic anisotropy in the short side (width) direction and circumferential direction of a rectangular or linear ferromagnetic material in advance. There is a feature to keep. This uses the fact that the magnetic field from the longitudinal direction rotates the magnetization vector of the magnetic material, increasing the magnetic permeability in the width direction, thereby increasing the skin effect, thereby increasing the impedance of the ferromagnetic material. ing.

Further, JP-A-8-330744 discloses that
A structure in which a magnetic thin film exhibiting the MI effect is patterned in a meander shape is disclosed. This is because, in the MI effect element, the higher the absolute value of the impedance itself, the higher the voltage at both ends or the output of the LC oscillation circuit, which is advantageous for more stable operation.

[0008]

However, when the conductor layer is patterned in a meandering shape on a plane, the area occupied by the entire pattern naturally increases, and the number of elements manufactured from one wafer is naturally increased. Decrease. That is, there is a problem that the price becomes high. Further, when a conductor coil wound around a meander-shaped conductor is manufactured, the width of the wound coil is increased, and as a result, the efficiency of the wound coil is reduced. When the conductor layer is a magnetic material and is used as a magnetic field sensor for detecting an external magnetic field by the magnetization of the magnetic material,
This is equivalent to the fact that the magnetic material spreads in the width direction, and as a result, there is a problem that the spatial resolution of the magnetic field detection is reduced.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a highly sensitive and small-sized thin film electronic component, particularly a magnetic field sensor.

[0010]

SUMMARY OF THE INVENTION In order to solve such a problem, the present invention provides a method for manufacturing a semiconductor device, comprising the steps of:
An insulator layer for electrical insulation between the conductor line layers,
The plurality of conductor line layers are stacked in a direction substantially perpendicular to the plane of the base, and the plurality of conductor line layers are electrically connected in series.

In a preferred aspect of the present invention, the plurality of conductor line layers are composed of three or more conductor line layers.

In a preferred aspect of the present invention, the plurality of conductor line layers are made of a magnetic material.

In a preferred aspect of the present invention, the conductor coil is formed so that the plurality of conductor line layers and the insulator layer are sequentially laminated and wound around the outer periphery of a substantially integrated laminate structure. Is done.

In a preferred embodiment of the present invention, the plurality of conductor line layers are formed of a soft magnetic thin film,
It is configured as a magnetic field sensor that detects an external magnetic field in the longitudinal direction of the conductor line layer.

In a preferred embodiment of the present invention, an external magnetic field is generated by applying a high-frequency current to the conductor line layer and applying a current for detection also to a wound conductor coil. It is configured to act to detect.

The present invention is preferably configured as a magnetic field sensor using a magneto-impedance effect.

According to the thin-film electronic component of the present invention, it is possible to increase the number of elements that can be manufactured from one wafer while having a conductor portion having the same length as the meander-shaped conductor layer. Inexpensive thin-film electronic components can be provided. Furthermore, since the width of the wound coil is small, efficient excitation can be realized, and high efficiency can be achieved. When using thin-film electronic components as magnetic field sensors,
Since the magnetic field detector is small, a sensor with high spatial resolution can be manufactured.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described in detail.

FIG. 1A is a plan view (top view) schematically showing a magnetic field sensor 1 which is a preferred example of the thin film electronic component of the present invention, and FIG. 2) is a cross-sectional view in the α-α direction. However, in the drawing of FIG. 1B, the dimensions in the thickness direction in the upper and lower directions are drawn in a form that is considerably expanded from the actual size so that the configuration of the present invention can be easily understood.

As shown in these figures, a magnetic field sensor 1 comprises a plurality of conductor line layers 11, 12, 13, 14, 15 and an electrical insulation between the conductor line layers on a substrate 40 as a base. Layers 22, 23, 24, 25 for
Is substantially perpendicular to the plane of the substrate 40 (the substrate 40
, And a plurality of the conductor line layers 11, 12, 13, 14, 15 are electrically connected in series.

That is, as shown in FIG.
Conductor line layers 11, 12, 13, 14, 15 made of a substantially rectangular magnetic thin film are formed on a substrate 40 by insulating layers 22, 2.
A so-called meander structure having a structure that is folded back in the vertical direction with 3, 24, and 25 interposed therebetween. Here, the connection between the conductor line layer 11 and the conductor line layer 12 is realized by the connection end portion 12a descending from the conductor line layer 12,
The connection between the conductor line layer 12 and the conductor line layer 13 is realized by a connection end 13a descending from the conductor line layer 13, and the connection between the conductor line layer 13 and the conductor line layer 14 is
The connection end 14a descending from the conductor line layer 14 is realized, and the connection between the conductor line layer 14 and the conductor line layer 15 is realized by the connection end 15a descending from the conductor line layer 15. As shown in FIG. 1B, the series connection of the conductor line layers is performed by the insulator layers 22 and 2 as shown in FIG.
It can be easily realized by devising the configurations of 3, 24 and 25.

The uppermost conductor line layer 15
Is connected to an electrode pad 52 formed on the substrate 40 by descending to the position of the substrate. The terminal end of the conductor line layer 11 located at the bottom is connected to an electrode pad 51 formed on the substrate 40.

Further, as shown in FIGS. 1A and 1B, the plurality of conductor line layers and the insulator layer are sequentially laminated, and are wound around the outer periphery of a substantially integrated laminate structure. In this manner, thin-film conductor coils 31 and 35 (these are integrated into a coil shape) are formed. More specifically, the thin-film coil is composed of a lower coil layer 31 and an upper coil layer 35 (these are integrated in a coil shape) in the direction in which the conductor line structure is wound. The line layer is insulated by insulating layers 21 and 26 disposed above and below, respectively. As described above, the electrode pads 51 and 52 are provided at both ends of the conductor line layer having the meander structure, respectively, and the electrode pads 53 and 54 are provided at the current introduction parts at both ends of the thin-film conductor coils 31 and 35, respectively. Is provided.

The case where the structure shown in FIG. 1 is used as an MI (magnetic impedance) sensor will be described in further detail. The MI sensor imparts magnetic anisotropy in the width direction of the rectangular magnetic body (the depth direction in FIG. 1B), and the magnetization direction changes due to a magnetic field from the longitudinal direction (the left-right direction in FIG. 1B). This is to detect a change in impedance caused by the operation. Therefore, the conductor line layer 11,
12, 13, 14, and 15 include NiFe, NiFeP, CoFe,
CoNiFe, CoFeP, NiFeMo, FeZr
Various known soft magnetic thin films such as N and FeN are used. Also, electrode pads 51, 5 which are end electrodes of the conductor line layer.
The high-frequency current is supplied from Step 2. Further, the conductor coil 3 substantially wound around the conductor line layer made of the ferromagnetic material
A bias current is supplied to the electrodes 1 and 35 from the electrode pads 53 and 54, which are end electrodes, and detected by a method such as canceling an external magnetic field.

In a device such as an MI sensor in which a high-frequency current flows through a conductor line layer, a conductive material is applied to the back surface of the device substrate in order to prevent high-frequency component noise from entering a wound conductor coil layer for detection. It is effective to perform the conversion process and connect to the ground terminal. For example, by forming a sputtered copper film on the entire back surface and bonding it to the ground part of the substrate to which the element is fixed by soldering, etc., it is possible to strengthen the fixing to the substrate simultaneously with the electrical connection to the ground line. is there.

Further, in order to prevent high-frequency noise, all the conductor line layers (HL) through which a high-frequency current flows are orthogonal to the wound coil layers for detection and the conductor lines (SL) such as their lead wires. It is preferable to arrange them so that If HL and SL must be arranged in a state close to parallel, it is preferable to increase the distance.

In the present invention, the substantial width (W) and the substantial line length (L) of the conductor line layer are not particularly limited, but are represented by length (L) / width (W). The aspect ratio is preferably 20 or more, and particularly preferably 40 or more. If the aspect ratio is less than 20, the overall resistance tends to be low and the efficiency of the device tends to decrease. When used as a magnetic field sensor, the sensitivity in a low magnetic field is deteriorated. The upper limit of the aspect ratio is not particularly limited,
If it is more than 300, it becomes difficult to reduce the size of the element, or it becomes difficult to manufacture the element. The number of stacked conductor line layers (five layers in FIG. 1), that is, the number of meander turns is two, and the effect of the present invention is small.
It is desirable to provide up to 30 turns. The upper limit of the number of times of three or more is not particularly limited. However, when the number of times is more than 30, the process becomes complicated and the yield tends to be reduced.

The conductor line layers 11, 12, 13, 14, 1
5 is preferably 0.1 to 50 μm. In particular, MI
When used as a sensor, the thickness is preferably 1 to 10 μm.
When the thickness of the conductor line layer is less than 0.1 μm, the resistance becomes high, and when it exceeds 50 μm, the production becomes difficult.

In the present invention, an insulator layer is formed between the stacked conductor line layers. As the insulator layer for the present invention, any material can be used as long as the material has higher resistance than the material constituting the conductor line layer. That is,
In addition to various known organic films, for example, thermosetting photoresists (novolak-based, polyimide-based), known inorganic films, for example, SiO ₂ and DLC (diamond-like carbon) films, and dielectric materials can be used. is there.

When a thermosetting novolak resin is used as the insulating layer for the MI magnetic field sensor, the thickness of the insulating layer is 0.1 mm.
5 to 100 μm, particularly preferably 1 to 30 μm is desirable. 0.
If the thickness is less than 5 μm, insulation is insufficient.
If it exceeds, the production becomes difficult.

As shown in FIG. 1, each conductor line layer of the present invention is substantially rectangular, and is electrically connected in series with the upper and lower conductor line layers at its longitudinal end as described above. This connection portion (the connection end portion 12, 1 in FIG. 1B)
3a, 14a, and 15a) are generally made of the same material as the conductor line layer, but may be made of another conductive material.

The meander structure of the conventional device will be briefly described for reference so that the structure and features of the present invention will be more clearly understood. In a conventional known plane meander pattern, a plurality of conductor line layers are arranged on a substrate in parallel at regular intervals, and these conductor line layers are electrically connected in series at each end. Therefore, in the conventional plane meander pattern, when the conductor pattern width W, the space between conductors S, and the number of times of folding are N,
For five diffraction returns (N = 5), the overall width is (5W + 4
S). On the other hand, in the present invention, it can be seen that the width is still W and constant even if it is turned 20 times.

Hereinafter, the case of the MI magnetic field sensor will be described in detail with comparison between the present invention and a conventional example. The conductor line layer is a NiFe film having a thickness of 5 μm, a line layer width W = 100 μm, a space S = 100 μm,
Diffraction return. The conductor coil for detection uses Cu film,
The thickness is set to 5 μm. The insulator layer is made of a thermosetting photoresist and has a thickness of 5 μm.

In the device having the above structure, the conventional flat meander pattern has a total width of 1700 μm, whereas the present invention has a total width of 100 μm. The total thickness excluding the substrate is about 25 μm in the conventional method, and about 65 μm in the present invention. The cross-sectional area of the wound coil is 40,000 μm ² because the width of the coil is 2000 μm and the distance between the upper and lower coils is 20 μm in the conventional method. On the other hand, in the present invention, since the width is 200 μm and the distance between the upper and lower coils is 90 μm, it is 18,000 μm ² , which is less than half of the conventional method.

Further, a plurality of integrated conductor line layers having a vertically folded structure according to the present invention are arranged on a plane, and
Alternatively, they may be connected in parallel. For example, if two integrated members of the conductor line layer of the present invention having nine turns are arranged and connected in series, 18 turns are obtained. In this case, the entire width is 2W + S, but it goes without saying that there is a great effect as compared with the conventional planar pattern.

For applications other than the MI sensor in the present invention, see, for example, IEEE Trans. Magn. MAG-20, No. 5,
It is applicable to various thin-film electronic components such as small inductors and transformers as disclosed in p1804 (1984).

[0037]

The present invention will be described in more detail with reference to specific examples below.

Experimental Example 1

An MI magnetic field sensor was manufactured as a specific sample in the following manner.

A lower coil 31 was formed on a 3-inch φ silicon wafer substrate 40 having a thermal oxide film on the surface by a pattern electric Cu plating method. Next, a magnetic thin film magnetic core (conductive line layer 11) made of a NiFe plating film was formed on the lower insulating layer 21 made of a thermosetting novolak resin by a pattern electroplating method. Further, formation of an insulating layer made of a thermosetting novolak resin and formation of a magnetic thin-film magnetic core (conductive line layer) were alternately repeated to form a series-connected magnetic conductor line layer consisting of a multilayer meander pattern. After the upper coil 35 and the insulating layer between the uppermost conductor line layers are formed, the upper coil 3
5, and further, electrode pads 51 and 5 as electrode portions.
2, 53, 54 and a protective film were formed, and the wafer process was completed.

After cutting and separating the individual devices, the characteristics of each device were evaluated. Separately, a comparative MI sensor using a conventionally known plane meander pattern was prototyped.

Note that the magnetic sensing portions of both MI sensors are:
Conductor line part is magnetic material width 100μm, length 1500μ
m, the dimensions were exactly the same as the number of turns 9 times.

First, the number of elements manufactured from one wafer was 1500 in the sample of the present invention. On the other hand, in the comparative example sample, the number of elements manufactured from one wafer was 300.

Next, a high frequency current of 50 MHz was applied to the conductor line portion (magnetic core portion) of the completed magnetic field sensor, so that the MI effect was obtained. Then, as a method of detecting an external magnetic field, a detection experiment was performed by applying a current to the wound conductor coil so as to prevent an impedance change and canceling the external magnetic field by a negative feedback method.

First, the detection sensitivity was measured under a uniform magnetic field of 0.03 mT.
35 V / μT. On the other hand, in the sample of the example of the present invention, a value almost twice as large as 0.65 V / μT was obtained. This was because the efficiency of the exciting coil was extremely high.

Next, as shown in FIG.
Position detection was performed using a magnetic scale that was magnetized alternately by NS on the pitch. Position detection is performed by two types of methods: vertical placement with the substrate surface of the element perpendicular to the magnetization pitch of the magnetic scale (the pitch direction is the vertical direction of the drawing), and horizontal placement with the substrate surface horizontal. Was.

In the comparative sample, pitch detection was possible in the vertical position, but not in the horizontal position. This is because the magnetic material spreads over a width of 1700 μm. On the other hand, in the sample of the embodiment of the present invention, sufficient pitch detection is possible both in the vertical and horizontal positions, and the spatial resolution is 20 in both axes (horizontal direction and vertical direction).
It was confirmed that the thickness was 0 μm or less.

[Experimental example 2]

Next, in Examples and Comparative Examples in which the meander pattern is not a magnetic material but a normal conductor line layer (acting as a conductor coil), the magnetic material disposed above and below the conductor coil layer is closed. A shell-type inductor formed with a circuit structure was manufactured as a specific sample.

In the plurality of conductor line layers constituting the meander pattern, each conductor line layer has a line width of 4
A copper plating film having a thickness of 0 μm, a line length of 2000 μm, and a layer thickness of 10 μm was obtained. Example 1 using such a conductor line layer,
The same thermosetting resist layer of 10 μm as above was interposed between a plurality of conductor line layers as an insulating layer to produce a vertically folded meander coil folded eight times. Before manufacturing this meander coil, a NiFe film of 5 μm
A film was formed, and an insulating layer was provided thereon. After the meander coil was manufactured, the upper magnetic layer was formed in the same manner as the lower magnetic layer via the insulating layer. The upper magnetic layer and the lower magnetic layer are directly joined at their widthwise ends to form a closed magnetic circuit structure. This shell-type inductor sample was used as Example 2 sample.

Similarly, one conductor line layer pattern is
Line width 40μm, line length 2000μm, layer thickness 20μ
An outer iron type inductor sample having a meander coil in which a m-th copper plating film was folded in a plane at an interval of 20 μm was prepared, and this was used as a comparative example 2 sample.
Incidentally, this comparative example 2 sample is IEEE Trans.Magn.
This corresponds to a small inductor disclosed in MAG-20, No. 5, p1804 (1984).

The magnetic path length of the inductor of the sample of the second embodiment is about 300 μm, whereas the magnetic path length of the sample of the second comparative example is about 1000 μm, which is three times or more. As a result, the value of the inductance of the sample of Example 2 was more than twice as high as that of the sample of Comparative Example 2.

[0053]

The effects of the present invention are clear from the above results. That is, the thin film electronic component of the present invention is
A plurality of conductor line layers and an insulator layer for electrical insulation between the conductor line layers are stacked in a direction substantially perpendicular to the plane of the base, and the plurality of conductor line layers are electrically Especially, it is necessary to increase the number of elements that can be manufactured from one wafer while having a conductor portion of the same length as the meander-shaped conductor layer. It is possible to provide an inexpensive thin-film electronic component. Furthermore, since the width of the wound coil is small, efficient excitation can be realized, and high efficiency can be achieved. Furthermore, when a thin film electronic component is used as a magnetic field sensor, a sensor having a high spatial resolution can be manufactured because the magnetic field detection unit is small.

[Brief description of the drawings]

FIG. 1A is a plan view (top view) schematically showing a magnetic field sensor which is a preferred example of a thin-film electronic component of the present invention, and FIG. 2) is a cross-sectional view in the α-α direction.

FIG. 2 is a drawing schematically showing an example of a usage example of a magnetic field sensor which is a preferred example of the thin-film electronic component of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Thin film electronic component (magnetic field sensor) 11, 12, 13, 14, 15 ... Conductor line layer (21), 22, 23, 24, 25, (26) ... Insulator layer 31, 35 ... Conductor coil 40 ... Substrate 51, 52, 53, 54 ... electrode pads

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hidehiko Yamaoka 1-13-1, Nihonbashi, Chuo-ku, Tokyo TDC Corporation F term (reference) 2G017 AA01 AC02 AD04 AD05 AD51 AD63 AD65 4E351 BB03 BB10 BB11 BB17 BB25 BB26 BB27 BB32 CC01 DD11 DD17 DD19 DD21 DD28 DD37 DD45 DD48 GG20

Claims (7)

[Claims] A plurality of conductor line layers and an insulator layer for electrical insulation between the conductor line layers are laminated on a substrate in a direction substantially perpendicular to the plane of the substrate. A thin-film electronic component, wherein the plurality of conductor line layers are electrically connected in series. 2. The thin-film electronic component according to claim 1, wherein the plurality of conductor line layers include three or more conductor line layers. 3. The thin-film electronic component according to claim 1, wherein the plurality of conductor line layers are made of a magnetic material. 4. The conductor coil according to claim 1, wherein said plurality of conductor line layers and said insulator layer are sequentially laminated, and a conductor coil is formed so as to wind around an outer periphery of a substantially integrated laminate structure. The thin-film electronic component according to claim 3. 5. The thin film according to claim 1, wherein the plurality of conductor line layers are formed of a soft magnetic thin film and configured as a magnetic field sensor for detecting an external magnetic field in a longitudinal direction of the conductor line layer. Electronic components. 6. A method for detecting an external magnetic field by applying a high-frequency current to the conductor line layer and applying a current for detection also to a wound conductor coil. Item 6. A thin film electronic component according to item 5. 7. The thin-film electronic component according to claim 4, which is configured as a magnetic field sensor using a magneto-impedance effect.