JP3063417B2 - Electromagnetic coupling device between communication line and data terminal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic coupling device for connecting a communication line to a data terminal, and more particularly to an electromagnetic coupling device for transmitting a signal between a computer or other data terminal and a communication network such as a telephone line. .

[0002]

2. Description of the Related Art A central information processing device (computer) is connected to a terminal or a terminal by an analog signal telephone network, which is a communication line of a low frequency band, and systematically transmits and processes digital data. Communication systems have been developed.

In data transmission by this system, a modem (modulator / demodulator) plays a very important role in controlling input / output of transmission / reception signals. The modem converts the digital signal from the data terminal into an analog signal and sends it out to the telephone line, and also converts the analog signal transmitted from the telephone line back into a digital signal before the terminal or the center computer. Perform processing.

Here, transmission and reception can be performed only by the modem on a one-to-one dedicated line, but when a switched line is used, it is necessary to further incorporate a switching control mechanism such as dial signal transmission together with the modem. This is NCU
(Network control unit), which has an automatic call origination / reception function.

FIG. 6 shows a circuit configuration of a general NCU.
A transmission signal transmitted from a data terminal (not shown) via a terminal 5 is supplied to an input terminal of an amplifier 1 via a resistor R1, and an output thereof is passed through a resistor R2 to a transformer 2 which is an electromagnetic coupling device. Toward the primary coil 2a.

Normally, the frequency of an analog transmission / reception signal in such a data communication system is as low as 300 to 3400 Hz,
Also, the signal power is as wide as 0 dBm to -40 dBm. The transformer 2 has a function of transmitting an analog signal having such characteristics while performing DC isolation between the NCU and the data terminal in the data communication system.

The transmission signal induced in the secondary coil 2b of the transformer 2 is transmitted from the terminals 4a and 4b via the relay 3 to the communication system via the communication line.

The analog received signal transmitted from the communication line via terminals 4a and 4b
And enters the secondary coil 2b of the transformer 2. The received signal induced in the primary side coil 2a is supplied to the input terminal of the amplifier 10 via the resistor R3, and the output signal is supplied to the resistor R4.
Is supplied from the terminal 7 to the data terminal side.

The call signal from the exchange is applied to the photocoupler 9 via the resistor R5, the capacitor C1, and the Zener diode D1, and the terminals 8a and 8b are made conductive.
The data terminal detects a call when the terminals 8a and 8b are brought into conduction.

[0010] snubber circuit comprising a resistor R and a capacitor C, a Zener diode D, a capacitor C ₀ serves to remove a surge voltage, noise from the communication line.

When the relay 3 is connected to the data terminal, the communication line is connected to the telephone via the terminals 6a and 6b when the relay 3 is connected to the telephone so that the telephone can be used. To

The NCU configured as described above enables smooth signal transmission and reception between the data terminal and the communication line. However, it is usually difficult to reduce the size of this type of NCU due to the structure of the transformer. In the situation.

That is, a conventional transformer is generally formed by winding two types of copper wires around a single iron core. By supplying alternating current to one coil (primary coil), an alternating magnetic flux is generated in the iron core, and an induced electromotive force proportional to the square of the number of turns is generated in the other coil (secondary coil) interlinking with the magnetic flux. The configuration is such that power is excited and power is added to the load connected to the secondary coil.

This structure in which two types of copper wires are wound on an iron core causes an increase in the three-dimensional space occupation ratio in the NCU, which is one of the reasons why not only the NCU but also the modem cannot be downsized.

[0015]

SUMMARY OF THE INVENTION
In order to solve the problem that it is difficult to reduce the size of the transformer, a transformer in which a transformer 2 has a laminated structure has been proposed (Japanese Patent Laid-Open No. 2-105766). The proposed device is
Primary coil 2a and secondary coil 2 on a ceramic substrate
b, forming a pair of coil patterns by printing or the like,
A plurality of ceramic substrates on which the coil patterns are formed are laminated and integrated so that the coil patterns are located coaxially, and the coil patterns of the respective layers are connected using through holes or the like. According to this proposed device, there is no need to actually wind the copper wire,
Thus, the size of the device can be reduced.

However, when a coil pattern is formed on a ceramic substrate by printing, the coil pattern is printed on the ceramic substrate before firing, and then laminated and fired. During the firing process, the ceramic substrate shrinks, and the variation in the shrinkage causes variations in the inductance value of the coil, causing a problem that it is difficult to obtain stable characteristics. In addition, when the ceramic substrate is sintered, the substrate is likely to be warped due to thermal strain, and the warpage causes poor sitting stability when the ceramic substrate laminate is surface-mounted on a circuit board. This is a problem in automating the implementation.

The method of printing and forming the coil pattern on a ceramic substrate before firing cannot be performed by etching, unlike a resin substrate. Therefore, a screen printing method using a silk screen is mainly used. , Screen clogging is likely to occur during printing,
Since there is a problem that the conductor pattern is blurred and the wire is easily broken, it is difficult to reduce the width of the printed conductor, and the printed conductor width of the coil pattern cannot be reduced to, for example, 300 μm or less. In addition, the spacing between the printed conductors is not high enough for silk screen, and the printed material is easy to spread around the ceramic substrate before firing, so to avoid contact between patterns, for example, 300 μm Since it must be wide, the area for forming the coil pattern becomes large, and it is still insufficient to reduce the size of the transformer.
There was room for further improvement.

Further, as a transformer mounting structure, a new method is provided in which the transformer is formed in a circuit board of an NCU or a modem, and the circuit board itself has the function of a transformer, thereby saving the trouble of mounting the transformer as a component. However, when a ceramic substrate is used as a circuit substrate of an NCU or a modem, it is difficult to form a large-area ceramic laminated substrate due to warpage deformation during sintering of the ceramic substrate. It is difficult to use the transformer as a circuit board for a modem, which hinders the implementation and deployment of this new transformer.

The present invention has been made to solve the above problems, and an object of the present invention is to solve the various problems caused by using a ceramic substrate as an insulating substrate for forming a coil pattern. It is an object of the present invention to provide an electromagnetic coupling device between a communication line and a data terminal, which can stabilize characteristics and at the same time reduce the size of the device.

[0020]

The present invention is configured as follows to achieve the above object. That is, in the electromagnetic coupling device of the present invention, one coil is on the communication line side,
The other coil is connected to the data terminal side, and furthermore, a coil pair consisting of two coils that are electromagnetically coupled to each other, and a primary coil of the coil pair by a transmission signal or a reception signal.
A modulator that modulates a carrier wave from a self-excited carrier wave generator using the coil as an inductance of an oscillator and supplies the modulated carrier wave to one of the coil pairs, and a modulated carrier wave output from the other one of the coil pairs. and a demodulator for demodulating a transmission signal or reception signal, the pair of coils are formed by stacking a plurality of resin insulation substrate obtained by forming a co-yl pattern so that the coil pattern is positioned coaxially, wherein The resin insulating substrate is characterized in that it is used as a resin circuit wiring substrate on which the modulator and the demodulator are mounted.

[0021]

In the present invention having the above-described structure, the coil pair for electromagnetically coupling the communication line and the data terminal is constituted by a resin insulating substrate having a coil pattern formed thereon or a laminate thereof. Since the substrate is a resin-insulated substrate, the warpage deformation that occurs in the case of a ceramic substrate is small, and the resin-insulated substrate can be used as an etching method as a main method when printing a coil pattern thereon. There is no problem such as blurring or disconnection of the conductor pattern generated at the time of printing on the ceramic substrate, the conductor width of the coil pattern and the interval between conductors of the coil pattern can be made smaller than that of the ceramic substrate, and the device can be downsized.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a circuit configuration of an embodiment according to the device of the present invention which is equivalent to the conventional device. In the figure, a signal transmitted from the other side via terminals t1 and t2 connected to the exchange is subjected to a bridge rectification by removing noise and surge voltage through a Suvana circuit composed of a resistor R1 and a capacitor C1 and a Zener diode Z1. The circuit Br is entered. One output of the bridge rectifier circuit Br goes to one input terminal of the amplifier 1 via the capacitor C2 and the resistor R2.

A primary coil 10a of a coil pair, which will be described later , is connected to the other input of the amplifier 1 through a resistor R3.
Self-excited carrier wave generator used as conductance
The carrier wave is supplied from the LC oscillator 7 functioning as a modulator, and the received signal is modulated.

The output of the amplifier 1 modulated and amplified as described above is a primary coil of a coil pair (hereinafter abbreviated as a coil pair) 10 of an electromagnetic coupling device which is a characteristic component in the present embodiment.
The signal output to 10a and induced in the secondary coil 10b by the inductive coupling action in the coil pair 10 is sent to both inputs of the amplifier 2. The carrier component superimposed on the received signal was removed by an integrating circuit including a resistor R4 and a capacitor C3 connected between one input and the output side of the amplifier 2, and demodulated via a resistor R5 and a terminal t3. A signal is sent to the modem.

On the other hand, when data is transmitted from the data terminal to the partner system, the resistance R
A transmission signal is supplied to one input of the amplifier 3 via 6. A primary coil 11b is emitted to the other input side of the amplifier 3.
Self-excited carrier wave used as inductance of shaker
A carrier wave is supplied from an LC oscillator 8 functioning as a generator, and a transmission signal having undergone a predetermined modulation and amplification operation in the amplifier 3 is sent to a coil pair 11, and the primary side coil 11b is subjected to electromagnetic coupling by a secondary side. The transmission signal induced in the coil 11a enters the amplifier 4.

The carrier signal is removed by an integrating circuit including a resistor R8 and a capacitor C4 connected to the input terminal and the output terminal of the amplifier 4, and the demodulated and amplified transmission signal is converted to a resistor R
9 and the capacitor C2 to the bridge rectifier circuit Br, and are sent out from the terminals t1 and t2 to the communication line via the exchange.

Similarly to the transmission signal, the tone dialer signal input from the terminal t5 is also transmitted by the same modulation / demodulation operation as described above, and is transmitted to the communication line.

When transmitting a pulse dial signal from the data terminal, this transmission signal is input from the terminal t6 to the base of the transistor Q1 via a resistor R10 through a modulation / demodulation circuit equivalent to each of the above transmission signals. . The transistor Q1 performs an on / off operation in response to a signal input to the base of the transistor Q1. As a result, the transistor Q2 is turned on / off, and the line current is interrupted to send a pulse dial signal to the exchange. The basic operation for transmitting the pulse dial signal to the transistor Q1 is not different from the case of the transmission signal, and a detailed description thereof will be omitted. The stabilized power supply circuit in FIG.
It functions to supply power to 4, 6, etc.

Next, referring to FIGS. 2 to 4, the structure of the laminated board type coil pair characteristic of the apparatus of this embodiment will be described in detail. The basic unit of this coil pair is that a coil pattern is printed and formed using a conductive material on a resin insulating substrate mainly composed of a resin such as a glass epoxy substrate, and the coil pattern is printed on the surface of the resin insulating substrate. For example, it is possible to increase the number of turns of a coil by forming a thermoplastic adhesive layer, laminating a plurality of the layers, and bonding them by heating, so that an electromagnetic coupling device having desired performance can be obtained. Note that the coil patterns of the respective layers that are stacked and integrated are connected by using through holes and the like.

FIG. 2A shows the relationship between the coil patterns on the plurality of resin insulating substrates thus stacked, but the substrate is not shown in the figure for the sake of easy understanding.

The primary-side coils 40a and 42a and the secondary-side coils 44b and 46b each have a staggered four-stage configuration, and have a terminal end 44f of the first secondary-side coil 44b and a terminal end 46f of the second secondary-side coil 46b. , End of first primary coil 40a
The terminal 40f and the terminating end 42f of the second primary coil 42a are respectively connected through Thb and Tha of through holes formed in the resin insulating substrate.

FIG. 3B is a cross-sectional view of a coil pair composed of the above-described four-stage coils in a stacked state, in which two primary coils 40a and 42a and two secondary coils 44b and 46b are provided. The four coils are connected by through holes Tha and Thb, respectively, and the four coils are located in close contact with each other. The terminations may be connected to each other by an arbitrary method such as burying a pin made of a conductive material in the through hole.

The coil pair thus formed is not formed by winding a copper wire on an iron core like a conventional transformer, but by printing a two-dimensional coil pattern on a flat thin resin insulating substrate. Because of the stacking, the overall volume is significantly reduced and the coil pair can be provided in a compact form. Moreover, in the present embodiment, since the coil pattern is formed by printing on the resin insulating substrate by a method such as etching, compared to the case where the coil pattern is formed on the conventional ceramic substrate by silk screen printing, The conductor width of the coil pattern can be reduced to, for example, 100 μm, and the interval between the conductor patterns can also be reduced to, for example, 100 μm. With the same surface area, the number of turns of the coil can be further increased.

Further, when laminating and integrating a resin insulating substrate on which a coil pattern is formed by printing, the bonding heating temperature is sufficiently lower than the firing temperature of the ceramic substrate. There kuna Ru difficulty and warpage due to thermal distortion.

Further, as described above, since the resin insulating substrate is less likely to be warped, the shape of the coil pattern is not distorted, and therefore, the inductance of the coil is not varied, thereby greatly improving the characteristics of electromagnetic coupling. be able to.

Furthermore, in this embodiment, circuitry substrate is constituted by a laminate of a plurality of resin insulation substrate, a coil pattern is formed on a circuit board made of layers of the resin insulating substrate
The Tei Rukoto, coils pairs in laminated circuit board becomes to be embedded form, a new implementation deployment of the coil pairs FIG et al
That has been.

FIG. 3 shows another configuration example of the coil pair according to the device of the present invention. This embodiment is characterized in that a magnetic material is interposed between each coil pattern formed on each resin insulating substrate to be laminated, whereby a magnetic flux generated when a current flows through the coil is reduced. The magnetic material is attracted centripetically toward the center where the magnetic material is located, and the magnetic flux linkage rate is significantly improved.

In FIG. 3A, the primary side coil 50a
A magnetic material 54 is inserted between the coil 52b and the secondary coil 52b, and functions to collect the magnetic flux excited by the coil at the center thereof.

FIG. 7B is a cross-sectional view of a coil pair configuration in which the magnetic material 54 is mounted in such a two-layer type. In addition to the magnetic material 54 between the primary coil 50a and the secondary coil 52b, the upper and lower surfaces of the coil pair, that is, the upper surface of the upper resin insulating substrate 56 and the lower surface of the lower resin insulating substrate 58 in the example shown in FIG. Magnetic material sandwiching the whole
60 and 62 are adhesively fixed.

FIG. 4 shows another embodiment of the coil pair according to the present invention. This embodiment is characterized in that a guard pattern 64 for preventing electromagnetic induction from other circuit patterns is formed around a spiral coil pattern printed on each resin insulating substrate to be laminated. As a result, the S / N ratio of the transmission / reception signal induced in each coil can be remarkably improved. Note that one end of the guard pattern 64 is grounded, and has the same configuration for all coil patterns.

FIG. 5 shows another embodiment of the coil pair according to the present invention. The feature of this embodiment is that metal plates or metal foils for electromagnetic shielding are provided on both outer sides or one side of the laminated resin insulating substrates. Metal foils 74 , 74 printed on a resin insulating substrate 75 are laminated on one or both sides of a primary coil 72 and a secondary coil 73 printed via a resin insulating substrate 71 to form an electromagnetic shield. In FIG. 5 , each primary coil 72
And an example in which the secondary coil 73 is used, a configuration using a plurality of primary and secondary coils may be used.

It should be noted that the present invention is not limited to the above embodiments, but can take various embodiments. For example, in the above embodiment, the resin insulating substrate for forming the coil pattern is formed of a glass epoxy substrate, but various other types of resin insulating substrates can be used.For example, a phenol resin is used for a paper base material. An impregnated substrate can be used .

[0043]

According to the present invention, the coil pairs for electrically magnetically coupling a communication line and data terminal, since it is that constituted by the laminate of the resin insulating base plate coil pattern is formed, the ceramic Since the etching method, which is a method of printing a circuit pattern on a resin substrate, can be generally used instead of the silk-screen printing method, which is a conventional method of printing and forming a coil pattern on a substrate, the conductor width of the coil pattern and the coil conductor Can be narrowed, and the size of the apparatus can be further reduced.

Further, when a plurality of resin insulating substrates are laminated and integrated, they can be integrated at a temperature much lower than the firing temperature at which a conventional ceramic substrate is integrated. Warpage due to thermal strain at the time of formation can be reduced. For this reason, when the coil pair integrated by lamination is surface-mounted on the circuit board, the sitting stability is good, which is convenient for automating the surface mounting.

Further, as described above, since the warp deformation of the thermal strain and the shrinkage and variation during the heating and firing are small, the shape of the coil pattern is not collapsed. Can be suppressed, so that stable electromagnetic coupling characteristics can be obtained.

Further, when a conventional ceramic substrate is used, it is difficult to form a circuit board having a wide area that can be practically used due to warpage deformation at the time of sintering. Therefore, coil pairs are embedded in the circuit board. Although there is no significance in the formation, the coil pair of the present invention is less likely to be warped and deformed, so that it is easy to embed and form the coil pair on the circuit board, and to develop a new development of the coil pair mounting structure. The above is also advantageous. Further, since the stack of the plurality of resin insulation substrate which coil patterns are formed are those which are used as a resin circuit wiring board for mounting the demodulator and modulator, a coil pair on the circuit board as in the prior art The work of surface mounting becomes unnecessary, and the production efficiency of the electromagnetic coupling device according to the present invention can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of an embodiment of the device of the present invention.

FIG. 2 is an explanatory diagram of a structure of a transformer according to the example device.

FIG. 3 is an explanatory view showing another embodiment of the transformer according to the device of the present invention.

FIG. 4 is a coil pattern diagram of a transformer showing still another embodiment of the device of the present invention.

FIG. 5 is an explanatory view of a coil pair showing still another embodiment of the device of the present invention.

FIG. 6 is a circuit configuration diagram of a conventional device.

[Explanation of symbols]

 10, 11 coil pairs 10a, 11a Primary coil 10b, 11b Secondary coil

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) H04B 5/00 G06K 19/07 H01F 17/00 H05K 1/00

Claims (1)

(57) [Claims] A coil pair consisting of two coils, one of which is connected to a communication line and the other is connected to a data terminal, and which is electromagnetically coupled to each other; Emit the primary coil of the coil pair
A modulator that modulates a carrier wave from a self-excited carrier wave generator that is used as an inductance of a vibrator and supplies the modulated carrier wave to one of the coil pairs, and transmits a modulated carrier wave output from the other one of the coil pairs. and a demodulator for demodulating a signal or received signal, the pair of coils are formed by stacking a plurality of resin insulation substrate obtained by forming a co-yl pattern so that the coil patterns are positioned coaxially, the resin An electromagnetic coupling device between a communication line and a data terminal, wherein the insulating substrate is used as a resin circuit wiring substrate on which the modulator and the demodulator are mounted.