JPS63193894A - Thin-film electromagnetic transducer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) This invention converts an output electrical signal from a semiconductor memory built into an IC card or the like into a magnetic signal, and transmits the signal to a magnetic head of a reading device. The present invention relates to a thin film electromagnetic transducer built into the card.

(Prior Art) In recent years, IC cards have been developed in which a non-magnetic card-like medium has a built-in large-capacity semiconductor memory and can be used for various data management. When reading information stored in the semiconductor memory, the conventional method is to mechanically connect an electrical terminal of an external device on the reading side and a terminal provided on the card. However, considering the number of times the card is used and the environment in which it is used, the mechanical connection method is
There is a problem with the reliability of the contacts.

As a method to solve this drawback, a contactless connection method has been proposed in which the electrical signal inside the card is once converted into a magnetic signal, and this signal is read by an external reading coil.

FIG. 4 shows a non-contact type signal transmission device, in which a plurality of coupling coils are provided on the card 11 side and the reading device 21 side in plane symmetry. Coils 12 and 22 are read coils, coils 13 and 23 are write coils, coils 14 and 24 are read/write coils for transmitting read/write switching signals, and coils 15 and 25 are power crotter coils. Used for power supply. FIG. 4B shows a state in which the coils in a vertical correspondence relationship are closest to each other.

(Problem to be solved by the invention) The electromagnetic conversion output by the electromagnetic conversion method of the above card is
When attempting to read a card with a magnetic stripe using the magnetic head of a current reader, the following problems arise.

That is, as shown in FIG. 4, the magnetic flux generated from one coil L has the same phase at the center of the coil L, so the magnetic path direction is within the half cores Ha and Hb of the reading magnetic head H. They are formed in a direction that weakens the playback output. As a result, if the reading magnetic head H is placed near the center of the coil L,
The reproduction output from the winding C becomes almost zero. In order to avoid such a phenomenon, if the read magnetic head H is placed outside the outermost periphery of the coil L, a half core Ha.

Since an asymmetrical magnetic flux flows through 1(b), the reproducing output does not become zero, but since only a small portion of the magnetic flux generated from the coil L acts effectively, the transmission efficiency is very poor.

Therefore, although this invention increases the ability to generate effective magnetic flux,
It is an object of the present invention to provide a thin film electromagnetic transducer that can generate effective magnetic flux with as little electric power as possible.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a non-magnetic substrate, a rod-shaped soft magnetic thin film formed on the non-magnetic substrate using thin film technology, and a rod-shaped soft magnetic thin film formed on the non-magnetic substrate using thin film technology. A thin film coil wound helically around the thin film in three dimensions, an electrical insulating film covering the thin film coil, a lead wire for energizing the coil, and a connection between the lead wire and other circuits. A magnetic field is generated from the rod-shaped soft magnetic thin film by energizing the helical coil.

(Function) With the above means, the arrangement relationship between the rod-shaped soft magnetic thin film and the reading magnetic head is set in the magnetic path direction in which the magnetic flux is efficiently transmitted, the coil resistance is small, and small electric power is required, and the generated magnetic flux is can be made into a thin film electromagnetic transducer with high utilization efficiency.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which 30 is a non-magnetic substrate, and the electromagnetic transducer section of the non-magnetic substrate 30 has a soft magnetic thin film 32 formed by helically winding a coil 31a section and a coil 31b section. It is configured as follows. Coil 31a and 31b
The helical coil 31 is formed using thin film technology. The lead wires 31c and 31d of this helical coil 31 are also formed by thin film technology,
The drawer ends are connected to connection pads 33, 34 for connection to other circuits. The helical coil 31 and the rod-shaped soft magnetic thin film 32 are insulated by insulating layers 35 and 36, as shown in FIG.

Next, the process of forming the thin film electromagnetic transducer will be explained with reference to FIG.

Figure m2 (a) shows a state in which the lower half of the helical coil 31, the coil 31a section, is formed by thin film technology. At this time, connection pads 33 and 34 and lead lines 31c and 31d are also formed at the same time. The coil 31a section is formed of a plurality of thin film wires arranged in parallel. Next, as shown in FIG. 3B, an insulating film 35 made of organic material or the like 8102 is formed to cover the coil 31a portion. Then, on top of this, a coil 31 is placed as shown in the same figure (C).
A soft magnetic thin film 32 is formed across the 8th line. In this example, PeNi was formed to a thickness of 5 μm by sputtering, and a width of 111111 μm was formed by ion milling. It was patterned to a length of 3 mm. Next, an insulating film 36 such as 5i02 and an organic material is formed to cover this, and the coil 3
A portion corresponding to the end of the wire forming part 1a is removed by etching to form a through hole. This through hole is connected to the helical coil 31 formed on the insulating film 36.
This is for connecting the upper half of the coil 31b and the coil 31a. The coil 31b section is also formed by sputtering and ion milling in the same manner as the coil 31b section. As a result, a thin film electromagnetic transducer as shown in FIG. 1 is formed. Although the coil 31b portion is shown exposed in this figure, a protective insulating film is further formed on this.

According to the thin film electromagnetic transducer configured as described above, when an input signal is supplied to the pads 33 and 34, the direction of the magnetic flux generated on the top surface of the substrate is as shown in FIG. 1(c). The current flows in one direction, and the current direction and the magnetic flux direction have a one-to-one relationship. If an alternating current signal is supplied to the spiral coil, the direction of the magnetic flux will change depending on the alternating current. In the conventional converter, magnetic flux is generated in the opposite direction to the core of the reading magnetic head as shown in FIG. 5, reducing the detection output to zero, but in the converter of the present invention, The magnetic flux flowing through the core of the head 40 is in a constant direction as long as the current flowing through the spiral coil is in one direction.

Therefore, the electromagnetic coupling to the read magnetic head 40 is in a highly efficient state, and the reproduction output of the magnetic head 40 can also be obtained at a high level. This means that it does not require as much driving power as the conventional one, and is also effective in reducing battery consumption of the IC card. In addition, as a method to achieve the above-mentioned one-to-one relationship between the coil current and the magnetic flux direction of the core, a pair of spiral coils wound in opposite directions are arranged side by side in a plane, and these are connected in series. death,
Another possible method is to form a magnetic path from the center of one spiral coil toward the center of the other spiral coil. In this method, the spiral coil is formed in a planar manner to obtain a predetermined number of turns, which requires a relatively long line length and a large amount of electric power. However, with the helical coil of the present invention, the line length is three-dimensionally wound compared to the planar spiral coil system, so a shorter line length is sufficient to obtain the same number of turns. This also
It contributes to generating effective magnetic flux with low power consumption.

FIG. 3 shows how to use the device of the invention. I
The C card 50 has the electromagnetic converter section 51 described in the embodiment, and the IC card 50 has the electromagnetic converter section 51 described in the embodiment.
The data from the IC memory 53 built into the amplifier 5
4. The data is converted into a current in the amplifier 54 and supplied to the spiral coil, whereupon it is converted into a magnetic signal in the electromagnetic transducer 52. The reading magnetic head 55 is sensitive to this magnetic signal, and a reproduced output signal corresponding to the data can be obtained between its output terminals 55a and 55b.

[Effects of the Invention] As described above, the present invention can provide a thin film electromagnetic transducer that can increase the effective magnetic flux generation capability and generate effective magnetic flux with as little electric power as possible.

[Brief explanation of the drawing]

FIG. 1 is a configuration explanatory diagram showing one embodiment of the present invention,
Figure (a) is an external view, Figure (b) is A-A in Figure (a).
2 is an explanatory diagram showing the manufacturing process of the electromagnetic transducer of the present invention, and Fig. 3 is a diagram showing the use of the electromagnetic transducer of the present invention. FIG. 4 is an explanatory diagram of the configuration of a conventional electromagnetic converter, and FIG. 5 is an explanatory diagram for explaining the problems of the conventional electromagnetic converter. 30... Nonmagnetic substrate, 31... Helical coil, 3
2... Soft magnetic thin film, 33.34... Connection pad. Applicant's representative Patent attorney Takehiko Suzue No. 2 Figure 2 Figure 3

Claims (1)

[Claims] A non-magnetic substrate, a rod-shaped soft magnetic thin film formed on the non-magnetic substrate using thin film technology, a thin film coil wound helically around the rod-shaped soft magnetic thin film in three dimensions; It consists of an electrical insulating film covering a thin film coil, a lead wire for energizing the coil, and a pad for connecting the lead wire to another circuit.By energizing the helical coil, the rod-shaped soft A thin film electromagnetic transducer characterized by being configured such that a magnetic field is generated from a magnetic thin film.