JPH02236181A - Flux gate sensor - Google Patents

Abstract

PURPOSE:To eliminate the necessity of winding task, enable omitting of annealing process and manufacture a thin sensor by a method wherein an excitation coil and detecting coils are constituted with a foil magnetic core interposed into a print wiring board. CONSTITUTION:A core 1 wherein circular metallic foils made of amorphous alloy shaped by etching are laminated is interposed and adhered between a third and a fourth layers of a six-layered print wiring board. An excitation coil 2 is constituted of the third and fourth layers while the first and fifth layers and the second and sixth layers constitute two detecting coils 3. As a result actual winding is not necessary.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a manufacturing method and structure of a fluxgate sensor. (Note) The conventional fluxgate sensor consists of a core made of a magnetic material with high magnetic permeability, a primary winding for exciting it, and a secondary winding for detecting the saturation state. The magnetic field direction is measured by obtaining composite vectors in different directions using a secondary winding having magnetic field axes in at least two directions.
In conventional technology, it is common to use permalloy, ferrite, etc. as a core material, shape, anneale, and insulate the conductor to form the primary and secondary windings by hand or using a dedicated winding device. Ta. (c) Problems to be solved by the invention The above technology requires an annealing process depending on the magnetic core material, making it difficult to maintain the positional accuracy of the winding, and the structure of the sensor itself makes it difficult to manufacture thin. ．． Furthermore, since the windings overlap, disconnections and short circuits may occur.
The winding process takes a long time, and a dedicated winding machine is required for mass production. (Means for solving the phantom problem) Therefore, we printed wiring of two foil-like magnetic cores using high magnetic permeability materials such as amorphous alloys, which have little change in magnetic properties due to stress and do not require high-temperature annealing. An excitation coil and a detection coil are constructed by sandwiching the circuit board from above and below, and connecting the wiring on both sides with printed wiring and through holes. A core made of a magnetic material such as amorphous can be inserted inside the wiring, and a detection coil and a correction coil can be constructed by using a multilayer printed circuit board. I will explain.

(Example 1) A 6-layer printed wiring board 3 consists of a core [1] made by overlapping annular metal foils of amorphous alloy shaped by etching.
An example in which the 3rd and 4th layers constitute an excitation coil (2), and the 1st and 5th layers, and the 2nd and 6th layers constitute two detection coils (3). (Fig. 1) (Example 2) A core (1) made of overlapping annular metal foils of amorphous alloy shaped by etching is sandwiched from above and below between two single-sided printed circuit boards and glued together to form an excitation coil (2). is composed of printed wiring and through holes,
An example of a composite type in which the detection coil (3) is constructed of an insulated conductor. (Fig. 2) (g) Effects of the invention As mentioned above, there is no need for actual winding work, which greatly reduces work time. By utilizing the characteristics of amorphous alloy, the annealing process can be omitted, and if necessary,
Assembling and integrating other electronic components on the same board,
It also enables a sensor that is much thinner than conventional products. Furthermore, the possibility of disconnection or short-circuiting of the conducting wire is reduced, and the positioning of the coil can be made more accurate.

[Brief explanation of drawings]

Figure 1 is a perspective view of Embodiment 1, and Figure 2 is a perspective view of Embodiment 2. (1) is the core, ■ is the excitation coil, and (3) is the detection coil.

Claims (1)

[Claims] A foil-like magnetic core made of a high permeability material such as an amorphous alloy that has little change in magnetic properties due to stress and does not require high-temperature annealing, is sandwiched between two printed wiring boards from above and below, and printed wiring and through holes are used on both sides. A fluxgate sensor is characterized in that an excitation coil and a detection coil are configured by making the wiring conductive.