JPS61275672A - Magnetic detector equipped with coil - Google Patents

Abstract

PURPOSE:To obtain a small-sized magnetic detector which performs magnetic detection with high sensitivity by connecting a lead wire to a terminal of a coil formed by laser cutting and vibrating a substrate at a high frequency. CONSTITUTION:An electrostrictive diaphragm is used as a substrate vibrating piece 1, a thin copper plate 4 is adhered to its top surface and irradiated with a YAG laser beam 14, which is scanned in a coil shape to cut the copper plate, manufacturing a spiral coil 3. An electrode plate 2 is formed of a copper vapor- deposited film on the reverse surface of the diaphragm 1 and a high frequency power source for electrostrictive vibration is connected between the coil 3 and electrode plate 2 by circuits 15 and 16. Then, a high frequency current is applied from the power source 5 to cause vibration. When magnetic detection is performed while the coil 3 is vibrated by the vibration of the diaphragm 1, magnetism is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of Industry] The present invention relates to a detector that detects magnetism by providing a coil on a substrate.

[Problems with conventional technology and means for solving the problems] Conventionally, for magnetic detection, an ultra-small coil is formed into an appropriate shape, for example, a spiral shape, and an external magnetic field is detected by the coil.
A changing magnetic field was generated in a coil to detect the approach of an external magnetic body. However, conventional detection has not been able to achieve high accuracy in a small size.

Therefore, the first challenge now is to precisely manufacture a small coil at low cost, and the second is to form a compact and highly sensitive detector by fixing the coil to a substrate without degrading its characteristics. This is an issue.

The third challenge is to provide a device that can perform even more sensitive detection by improving the substrate.

Although the detector coil of the present invention is ultra-small, we will explain how to make the coil and make it clear that conventional coils are also extremely small and highly effective. . In one embodiment, the coil is based on a ceramic thin plate of a minimum required thickness and a layer of conductive material of the required thickness is adhered to the substrate.

Next, the adhesive conductive layer of the ceramic thin plate is irradiated with a laser and scanned and cut into the desired shape using numerical (NC) control etc., and the required small coil is created with the required gap and the required width and height. To form something. In conventional conventional methods that do not use lasers, the width of each coil and gap is up to several U, but the laser cutting method described above can cut coils and gaps as small as several microns. I was able to get it. As the ceramic thin plate, for example, an electrostrictive material such as PZT crystal can be used for vibration detection.

Further, when a metal plate or the like is used as the substrate, an insulating coating layer is formed on the surface, and a conductor coil is formed on this.

A lead wire is connected to the terminal of the coil formed by laser cutting to detect a signal and cause the board to vibrate at high frequency.
Configure a magnetic detector.

〔Example〕

The present invention will be explained based on the drawings by giving an example. In FIG. 1, a substrate 1t is set at its end as a vibrating piece on a support 10, and a copper plate 4t made of a conductive material is bonded to the upper surface. A YAG laser 14 is irradiated onto the copper plate from an oscillator 11 through the entire reflecting mirror 12 and focusing lens 13, and then NC is performed by a device not shown.
Coil 3f which is controlled and scanned to have a highly accurate coil shape and dimensions: formed by laser cutting. Lead wires 7 and 8t are glued to both ends of the coil 3 and connected from the terminal 6 to an external meter 9. Electrode plate 2 is placed on the underside of the coil formation of vibrating piece 1.
A power source 5 is provided to apply a high frequency voltage between the coil 3 on the upper surface and the electrode plate 2. FIG. 2 is a top view of FIG. 1.

In the figure, an electrostrictive vibrating (PZT) plate 0°08 is attached to the vibrating piece 1.
A copper plate 4 having a thickness of B was used, and a copper plate 4 having a thickness of 0.04 mm was adhered to the upper surface thereof. The copper plate was irradiated with a YAG laser beam 14, scanned and cut into the coil shape shown in the figure, and the coil width was 10.
A spiral coil 3 shown in FIG. 2 with a coil spacing of 10 microns was manufactured. The coil was set to 40T. In this case, an electrode plate 2 made of a copper vapor deposited film with a thickness of 0.021 Ll was formed on the lower surface of the diaphragm 1, and a high frequency power source 5 for electrostrictive vibration was connected between the coil 3 and the electrode plate 2 through circuits 15 and 16. . A high frequency current of 40 kHz was applied by a power source 5 to cause vibration. Magnetism was detected while the coil 3 was vibrated by the vibration of the diaphragm 1, and a magnetic field of 40G could be detected at nine times, and the detection voltage of the coil 3 was 25 mV at that time.

It should be noted that, of course, detection can be performed without vibration using the high frequency power source 5, but it is better to vibrate in order to increase the detection sensitivity.

For the substrate, any ceramic material other than electrostrictive vibrating material, insulating film formed material, etc. can be used.

〔effect〕

As described above, since the present invention utilizes laser cutting,
Coils made using conventional methods can also be made extremely compact and with high precision, and a detector can be made compact using this ultra-small coil. We were able to use an electrostrictive vibrating piece on the coil substrate, and by detecting while generating high-frequency vibrations, we were able to perform highly sensitive magnetic detection. Such a detector is small, easy to manufacture, low cost, and capable of efficient detection.

[Brief explanation of the drawing]

FIG. 1 is a side view of a detector according to an embodiment of the present invention, and FIG. 2 is a top view thereof.

Claims (1)

[Claims] 1. A layer with a conductive material bonded to the surface of a ceramic or other insulating material or an insulating coating layer is provided, and a coil is cut into a desired shape by irradiating and scanning the conductive material layer with a focused laser beam. A magnetic detector equipped with a coil, characterized in that a detection lead wire is connected to a terminal of the coil. 2. A magnetic detector equipped with a coil according to claim 1, in which an electrostrictive material is used as an adhesive substrate of a conductive material.