JPH0510979A - Micro current sensor - Google Patents

Abstract

PURPOSE:To obtain a miniature micro current sensor capable of effectively detecting micro current without any use of an iron core 2. CONSTITUTION:A Hall element 13 is formed on a board 6 and an insulation film 7 is made on the Hall element 13. A coil pattern 5 is formed on the insulation film 7, then the coil pattern 5 is coated with another insulation film 8 and thus a drawing terminal 9 of the coil pattern 5 is formed on the surface of the insulation film 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a minute current sensor using a magnetic field detecting element.

[0002]

2. Description of the Related Art FIG. 6 is a schematic block diagram of a conventional minute current sensor. In the figure, a minute current sensor
Reference numeral 10 is a structure in which the Hall element 1 is arranged in the gap portion 11 of the C-shaped iron core 2, and a conductor 3 for flowing a minute current to the iron core 2
Is wound in a coil. This minute current sensor 10 is for generating a magnetic field in the iron core 2 by causing a current to flow through a conductor 3 of a coil 12 wound around the iron core 2, and detecting the magnetic field with a Hall element 1.

[0003]

[Problems to be Solved by the Invention] Conventional micro-current sensor
Reference numeral 10 is composed of a combination of an iron core 2 and a Hall element 1, and the iron core 2 is provided so that a large magnetic field is applied to the Hall element 1 so that it can detect even a minute current, and is essential. It is a component. However, the iron core 2 is much larger than the Hall element 1,
Therefore, there is a problem that the minute current sensor 10 also becomes large depending on the size of the iron core 2.

The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to provide a small-sized minute current sensor which can effectively detect a minute current without using an iron core.

[0005]

In order to achieve the above object, the present invention is configured as follows. That is, the present invention is characterized in that a coil pattern for generating a magnetic field by energization is integrally formed on at least one of the front and back sides of the magnetic field detecting element.

[0006]

In the present invention having the above-mentioned structure, when a minute current flows through the coil pattern, a magnetic field is generated by the Fleming's right-hand rule in a direction perpendicular to the current flow, that is, a direction penetrating the magnetic field detecting element. The magnetic field detection element receives this magnetic field and outputs a signal such as a voltage corresponding to the magnitude of the magnetic field as a current detection signal.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a structural diagram of a minute current sensor according to the present invention. In the figure, the minute current sensor 10 is a substrate 6
Hall element 13 as a magnetic field detecting element for detecting a magnetic field
Then, the Hall element 13 is covered with the insulating film 7.
Then, the spiral coil pattern 5 is formed on the insulating film 7, and the insulating film 8 is applied on the coil pattern 5.
A lead terminal 9 connected to the coil pattern 5 is provided on the insulating film 8. In FIG. 1A, the insulating films 7 and 8 are transparent so that the structure of the minute current sensor 10 can be easily understood, and the center lead-out terminal 9 of the coil pattern 5 is shown.
Are omitted.

Next, a method of manufacturing the minute current sensor 10 will be described step by step with reference to the drawings. First, as shown in FIG. 2, a cross-shaped compound semiconductor 4 is formed on a substrate 6 by a vacuum evaporation three-temperature method, a MOCVD method, an MBE method, or the like,
The Hall element 13 is manufactured. For the purpose of improving the detection sensitivity of the Hall element 13, a semiconductor such as GaAs, InSb, InAs or the like having a large hole mobility is used as the material of the compound semiconductor 4. A portion 4a of the Hall element 13 is an input portion for the drive voltage, and a portion 4b is an output voltage take-out portion.
The insulating film 7 is formed on the Hall element 13 as shown in FIG. The material of the insulating film 7 is SiO ₂ , polyimide or the like, and as a film forming method, a film is formed by physical adhesion, chemical adhesion or coating. Next, this insulating film 7
As shown in FIG. 4, a spiral conductor layer is formed on the upper surface by vapor deposition or a printing technique such as photolithography to form a coil pattern 5. The film thickness of the insulating film 7 is extremely thin as long as the insulation between the Hall element 13 and the coil pattern 5 is maintained. By reducing the gap between the thin film, that is, the coil pattern 5 and the Hall element 13, the Hall element 13 can effectively detect the magnetic field even in the minute magnetic field generated by the minute current flowing in the coil pattern 5. The coil pattern 5 is formed in a spiral shape to generate a large magnetic field at the center of the element, and the material of this conductor is Cu, which has a large conductivity.
A metal such as Al is used. And this coil pattern 5
As shown in FIG. 5, an insulating film 8 is formed thereon. The insulating film 8 is formed by the same method as the insulating film 7 shown in FIG. 3, that is, by physical attachment, chemical attachment, coating, or the like. Then, as the material, SiO ₂ , polyimide or the like is used. A hole 15 is provided at the center of the insulating film 8 so as to face the terminal connecting portion 14 on the center side of the coil pattern. And
A conductor film of the lead-out terminal 9 is formed on the surface of the insulating film 8, and one end of the lead-out terminal 9 is electrically connected using the hole 15. Through the above steps, the coil pattern 5 as the magnetic field generating portion and the Hall element 13 as the magnetic field detecting portion are integrally formed on the same substrate 6.

According to the minute current sensor manufactured as described above, when a minute current flows through the lead wire (not shown) in the coil pattern 5, the Hall element 13 is penetrated by Fleming's right-hand rule. A magnetic field is generated. This magnetic field strongly acts on the Hall element 13 arranged close to the coil pattern 5. As a result of the Hall element 13 receiving the magnetic field and generating a voltage proportional to its magnitude, the minute current can be detected by detecting this voltage.

According to this embodiment, the coil pattern 5 and the Hall element 13 are formed on the same substrate 6 without using the iron core 2.
Since the and are formed, it is possible to obtain a small and lightweight epoch-making minute current sensor 10.

The present invention is not limited to the above-mentioned embodiments, and various embodiments can be adopted. For example, in the above embodiment, the Hall element 13 and the coil pattern 5 are arranged on the substrate 6
However, it may be formed on both sides of the substrate 6.

In the above embodiment, the Hall element 13 is formed on the substrate 6, the insulating film 7 is formed on the Hall element 13, and the coil pattern 5 is formed on the insulating film 7. ,
The coil pattern 5 may be provided on the substrate 6, and then the insulating film 7 and the Hall element 13 may be formed in this order.

Further, in the above-described embodiment, the minute current sensor has a structure in which one Hall element and one coil pattern are integrally combined, but a plurality of Hall elements and coil patterns are laminated by interposing an insulating film. It may have a multilayer structure.

Further, although the Hall element 13 is used as the magnetic field detecting element in the above embodiment, it may be used as a magnetic field detecting element such as a magnetoresistive element.

[0015]

According to the present invention, a coil pattern for magnetic field generation and a Hall element for magnetic field detection are integrally formed on the same substrate without using an iron core. The micro current sensor can be provided.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of a minute current sensor of the present invention.

FIG. 2 is a configuration diagram of a Hall element of the same example.

FIG. 3 is a configuration diagram in which an insulating film is formed on the Hall element of the same example.

FIG. 4 is a configuration diagram of a coil pattern according to the embodiment.

FIG. 5 is a configuration diagram showing a state in which an insulating film is formed on the coil pattern of the embodiment and lead terminals are attached.

FIG. 6 is a configuration diagram of a conventional minute current sensor.

[Explanation of symbols]

 1 Hall element 2 Iron core 4 Cross-shaped compound semiconductor 5 Coil pattern 6 Substrate 7 Insulating film 10 Micro current sensor 13 Hall element

Claims (1)

Claim: What is claimed is: 1. A micro-current sensor in which a coil pattern for generating a magnetic field by energization is integrally formed on at least one of the front and back sides of the magnetic field detection element.