Signal Transmission Circuit

Abstract

To provide a signal transmission circuit that can have a compact design.SOLUTION: A signal transmission circuit includes a multilayer substrate having a plurality of layers, and a pattern transformer that is provided on the multilayer substrate, the signal transmission circuit being a circuit for transmitting insulating signals. The pattern transformer has a primary winding including wound printed pattern wirings that are provided on a first planer region and a second planer region on the multilayer substrate, and a secondary winding including wound printed pattern wirings that are provided on a position in a layer direction different from the primary winding and provided on the first planer region and the second planer region. The primary winding and the secondary winding are configured to be electrically coupled and so that in one of the wound printed pattern wiring provided on the first planer region and the wound printed pattern wiring provided on the second planer region, a current flows clockwise, and in the other, the current flows counterclockwise.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a signal transmission circuit for transmitting an isolated signal. [Background technology]

[0002] A signal transmission circuit for transmitting an isolated signal has been proposed that includes a semiconductor switching element and a transformer. For example, Patent Documents 1 and 2 disclose a transformer having a laminated structure in which multiple layers provided with printed pattern wiring are stacked on top of each other. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-198246 A [Patent Document 2] JP 2019-146359 A Summary of the Invention [Problem to be solved by the invention]

[0004] The transformers disclosed in Patent Documents 1 and 2 are provided with an iron core, which is a magnetic material. The configuration with an iron core increases in size as a whole. However, if the iron core is omitted in these transformers, the leakage magnetic flux from the windings becomes large even in the planar area outside the windings, causing undesirable problems due to the leakage magnetic flux. Therefore, it is difficult to make these transformers compact by omitting the iron core.

[0005] In view of the above circumstances, an object of the present disclosure is to provide a signal transmission circuit that can be designed compactly. [Means for solving the problem]

[0006] The signal transmission circuit according to the present disclosure comprises: a multi-layer substrate including a plurality of layers; a pattern transformer provided on the multilayer substrate; A signal transmission circuit for transmitting an isolated signal, comprising: The pattern transformer is a primary winding including a winding-shaped printed pattern wiring provided on each of a first planar area and a second planar area of ​​the multilayer substrate; a secondary winding provided at a layer direction position different from that of the primary winding, the secondary winding including the printed pattern wiring in a winding shape provided in each of the first planar area and the second planar area of ​​the multilayer substrate; having the primary winding and the secondary winding are configured to be electromagnetically coupled; The printed pattern wiring is configured to have a winding shape provided in the first planar area and a winding shape provided in the second planar area, and a current flows in a clockwise direction in one of the printed pattern wiring and a counterclockwise direction in the other. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a signal transmission circuit that can be designed compactly. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a configuration of a signal transmission circuit according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a diagram illustrating a schematic configuration of a pattern transformer according to an embodiment. [Diagram 3] FIG. 2 is a plan view illustrating a schematic configuration of printed pattern wiring in a first pattern layer of a pattern transformer according to an embodiment. [Figure 4] FIG. 2 is a plan view illustrating a schematic configuration of printed pattern wiring in a second pattern layer of a pattern transformer according to an embodiment. [Diagram 5] FIG. 2 is a plan view illustrating a secondary winding of a pattern transformer according to an embodiment.

[0009] Hereinafter, some embodiments will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as the embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the invention. For example, expressions expressing relative or absolute configuration, such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," not only strictly express such a configuration, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions indicating that things are in an equal state, such as "identical," "equal," and "homogeneous," not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. For example, expressions describing shapes such as a rectangular shape or a cylindrical shape do not only refer to rectangular shapes, cylindrical shapes, etc. in the strict geometric sense, but also refer to shapes that include uneven portions, chamfered portions, etc., to the extent that the same effect is obtained. On the other hand, the expressions "comprise," "include," "have," "includes," or "have" of one element are not exclusive expressions excluding the presence of other elements.

[0010] (Configuration of signal transmission circuit) Hereinafter, a configuration of a signal transmission circuit 100 according to an embodiment of the present disclosure will be described with reference to Fig. 1. The signal transmission circuit 100 is a circuit for transmitting an isolated signal. Fig. 1 is a diagram showing a configuration of the signal transmission circuit 100 according to an embodiment of the present disclosure.

[0011] As shown in FIG. 1, the signal transmission circuit 100 includes a pattern transformer 10 and one or more FETs 40 and 50 serving as semiconductor switching elements. The pattern transformer 10 functions in the same manner as a normal transformer. A detailed configuration of the pattern transformer 10 will be described later. The FETs 40 and 50 are two N-type MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors). The source (S) terminal of the FET 40 is connected to the source (S) terminal of the FET 50.

[0012] The one or more semiconductor switching elements included in the signal transmission circuit 100 may be JFETs (Junction Field-Effect Transistors), transistors, etc., instead of MOSFETs. The one or more semiconductor switching elements included in the signal transmission circuit 100 are not limited to two semiconductor switching elements, and may be one semiconductor switching element, or three or more semiconductor switching elements.

[0013] A buffer 30 (buffer amplifier) ​​is provided on the input side of the signal transmission circuit 100. A pulse signal that alternates between +3.3V and 0V, for example, is input to the positive input terminal of the buffer 30. A pulse signal that alternates between 0V and -3.3V, for example, is input to the negative input terminal of the buffer 30. As a result, an AC voltage with a pulse waveform of 6.6V in total is applied between the positive and negative input terminals of the buffer 30.

[0014] The input voltage to the buffer 30 is not limited to such a voltage. For example, it may be a sinusoidal AC voltage. The pulse signal input to the buffer 30 may be a signal generated by a field-programmable gate array (FPGA) through PWM (Pulse Width Modulation) control.

[0015] One end of resistor R1 is connected to the positive output terminal of buffer 30, and the other end of resistor R1 is connected to one end of capacitor C1. One end of resistor R2 is connected to the negative output terminal of buffer 30, and the other end of resistor R2 is connected to one end of capacitor C2. Resistors R1 and R2 are designed to have resistance values ​​to prevent overload.

[0016] The other end of capacitor C1 is connected to the positive terminal of primary winding 11 of pattern transformer 10. The other end of capacitor C2 is connected to the negative terminal of primary winding 11 of pattern transformer 10. Capacitors C1 and C2 remove the DC component of the input signal. Therefore, an AC voltage from which the DC component has been removed is applied to primary winding 11 of pattern transformer 10.

[0017] One end of a coil L1 is connected to a positive terminal of a secondary winding 12 of the pattern transformer 10. The other end of the coil L1 is connected to one end of a capacitor C3. The other end of the capacitor C3 is connected to a negative terminal of the secondary winding 12 of the pattern transformer 10.

[0018] Thus, one end of the coil L1 is connected to one end of the secondary side of the pattern transformer 10, one end of a first capacitor (capacitor C3) is connected to the other end of the coil L1, and the other end of the first capacitor (capacitor C3) is connected to the other end of the secondary side of the pattern transformer 10. In addition, a second capacitor (capacitor C1) is connected to one end of the primary side of the pattern transformer 10, and a third capacitor (capacitor C2) is connected to the other end of the primary side of the pattern transformer 10.

[0019] Here, the coil L1 and the first capacitor (capacitor C3) are designed to form a resonant circuit that resonates with the AC signal output from the secondary side of the pattern transformer 10. That is, the inductance of the coil L1 and the capacitance of the capacitor C3 are parameter-designed to form a resonant circuit whose resonant frequency is close to the frequency of the AC signal output from the secondary side of the pattern transformer 10. The resonance of this resonant circuit can compensate for the voltage drop on the secondary side caused by losses in the pattern transformer 10.

[0020] The second capacitor (capacitor C1) and the third capacitor (capacitor C2) are configured to resonate in combination with the inductance of the primary winding of the pattern transformer 10. That is, the pattern transformer 10 is configured so that RLC resonance occurs on both the primary side and the secondary side.

[0021] Furthermore, the parameters of the second capacitor (capacitor C1) and the third capacitor (capacitor C2) are designed to have capacitances that act to increase the half-width of the resonant circuit formed by the coil L1 and the first capacitor (capacitor C3). In this case, since the half-width of the resonant circuit is increased, even if there is a slight deviation between the resonant frequency of the resonant circuit and the frequency of the AC signal due to the parameters of the elements, it is possible to suppress a reduction in the resonance effect.

[0022] One end of the capacitor C3 is connected to the anode terminal of the diode D1. The cathode terminal of the diode D1 is connected to one end of the capacitor C4. The other end of the capacitor C4 is connected to the other end of the capacitor C3. These constitute a first rectifier circuit that rectifies a half-wave component of the AC voltage, which is the secondary side voltage of the pattern transformer 10.

[0023] The other end of the capacitor C3 is connected to one end of the capacitor C5. The other end of the capacitor C5 is connected to the anode terminal of the diode D2. The cathode terminal of the diode D2 is connected to the anode terminal of the diode D1. These constitute a second rectifier circuit that rectifies a half-wave of the AC voltage, which is the secondary side voltage of the pattern transformer 10.

[0024] The other end of the capacitor C4 and one end of the capacitor C5 are connected to the negative terminal of the secondary winding 12 of the pattern transformer 10. Therefore, the charging voltage of the capacitors C4 and C5 becomes a DC voltage that has been full-wave rectified by the first rectifier circuit and the second rectifier circuit.

[0025] One end of the resistor R3 is connected to one end of the capacitor C4. The other end of the resistor R3 is connected to the other end of the capacitor C5. The resistor R3 is parameter-designed to have a resistance value suitable for discharging the charging voltage of the capacitors C4 and C5.

[0026] One end of resistor R3 is connected to one end of resistor R4 and one end of resistor R6. The other end of resistor R4 is connected to the gate (G) terminal of FET 40. The other end of resistor R6 is connected to the gate (G) terminal of FET 50. The other end of resistor R3 is connected to one end of resistor R5. The other end of resistor R5 is connected to the source (S) terminal of FET 40 and the source (S) terminal of FET 50.

[0027] The drain (D) terminal of the FET 40 is connected to the positive output terminal of the signal transmission circuit 100. The drain (D) terminal of the FET 50 is connected to the negative output terminal of the signal transmission circuit 100. The FETs 40 and 50 each perform a switching operation because the voltage between their gate (G) terminal and source (S) terminal changes according to the secondary voltage of the pattern transformer 10.

[0028] In this way, one or more semiconductor switching elements (e.g., FETs 40, 50) provided on the secondary side of the pattern transformer 10 are configured to be turned on and off by the secondary side voltage of the pattern transformer 10 and output a contact output signal. In the above configuration, the FETs 40, 50 whose source (S) terminals are connected to each other are advantageous in that they can output a non-polar contact output signal. In other words, such a signal transmission circuit 100, as an IO module, outputs a contact signal without any restriction on the positive and negative sides, so that even solenoid valves that operate on AC voltage can be turned on and off.

[0029] (Configuration of pattern transformer 10) Hereinafter, the configuration of a pattern transformer 10 according to an embodiment will be described with reference to FIGS. 2 to 5. FIG. 2 is a diagram showing a schematic configuration of a pattern transformer 10 according to an embodiment. As shown in FIG. 2, the pattern transformer 10 is provided on a multilayer substrate 20 including a plurality of layers.

[0030] The multiple layers of the multilayer board 20 include a first pattern layer 21, a second pattern layer 22, a third pattern layer 23, and a fourth pattern layer 24. Printed pattern wiring is formed on these layers. The second pattern layer 22 is formed on one side of the first pattern layer 21. The third pattern layer 23 is formed on one side of the second pattern layer 22. The fourth pattern layer 24 is formed on one side of the third pattern layer 23.

[0031] In the example shown in Fig. 2, the one surface side is the lower side in the vertical direction (layer direction) in the figure, and the other surface side is the upper side in the vertical direction. One surface side of the first pattern layer 21 and the other surface side of the second pattern layer 22 face each other. One surface side of the second pattern layer 22 and the other surface side of the third pattern layer 23 face each other. One surface side of the third pattern layer 23 and the other surface side of the fourth pattern layer 24 face each other. In this way, multiple layers are arranged in the layer direction.

[0032] The multiple layers of the multilayer substrate 20 include a first insulating layer 27 (core layer) provided between the first pattern layer 21 and the second pattern layer 22, a second insulating layer 28 (prepreg layer) provided between the second pattern layer 22 and the third pattern layer 23, and a third insulating layer 29 (core layer) provided between the third pattern layer 23 and the fourth pattern layer 24. These layers are insulating layers having insulating properties.

[0033] The first insulating layer 27 and the third insulating layer 29 are each provided with a connection portion 60 that connects adjacent printed pattern wirings in the layer direction. The connection portion 60 includes a first connection portion 60 (60A, 60C) provided in the first planar region and a second connection portion 60 (60B, 60D) provided in the second planar region. On the other hand, the second insulating layer 28 (prepreg layer) is not provided with a connection portion 60.

[0034] The connection portion 60 is formed, for example, by injecting a conductive material into each of the through holes provided so as to penetrate the first insulating layer 27 and the third insulating layer 29. Note that the connection portion 60 may be a conductor provided so as to penetrate the first insulating layer 27 and the third insulating layer 29.

[0035] The first pattern layer 21, the second pattern layer 22, the third pattern layer 23, and the fourth pattern layer 24 are designed to have a thickness of, for example, 0.018 mm. The prepreg layer is preferably thicker than the core layer. For example, the first insulating layer 27 and the third insulating layer 29 may have a thickness of 0.1 mm, whereas the second insulating layer 28 may have a thickness of 0.3 mm. In this case, the printed pattern wirings can be easily connected to each other by the connecting portion 60 while ensuring the insulation between the primary winding 11 and the secondary winding 12.

[0036] 2, the multilayer substrate 20 may further include a fifth pattern layer 25, a sixth pattern layer 26, a fourth insulating layer (prepreg layer), and a fifth insulating layer (core layer) in addition to the four pattern layers and three insulating layers described above. For example, the thickness of the fourth insulating layer (prepreg layer) is 0.6 mm, and the thickness of the fifth insulating layer (core layer) is 0.1 mm.

[0037] 2, the pattern transformer 10 has a primary winding 11 including a winding-shaped printed pattern wiring provided in each of a first planar area and a second planar area of ​​a multilayer substrate 20, and a secondary winding 12 provided at a layer direction position different from that of the primary winding 11 and including a winding-shaped printed pattern wiring provided in each of the first planar area and the second planar area of ​​the multilayer substrate 20. The primary winding 11 and the secondary winding 12 are configured to be electromagnetically coupled.

[0038] The first planar region and the second planar region are regions including the connection portion 60. The first planar region and the second planar region are different planar regions, and it is preferable that they do not overlap each other. "Provided in the first planar region" means that it is provided so as to overlap at least a part of the first planar region. The same applies to "provided in the second planar region." In other words, the winding-shaped printed pattern wiring of the primary winding 11 and the printed pattern wiring of the secondary winding 12 may be misaligned in a plan view, as long as they overlap a part of them.

[0039] 2, the printed pattern wiring of the primary winding 11 is formed on a third pattern layer 23 and a fourth pattern layer 24. The printed pattern wiring of the primary winding 11 includes a first winding portion 11A, a second winding portion 11B, a third winding portion 11C, and a fourth winding portion 11D.

[0040] The first winding portion 11A is wound inwardly in a clockwise direction from the positive electrode end in the first planar region of the fourth pattern layer 24 around the first connection portion 60 (60A) provided in the third insulating layer 29 and extends to be connected to the first connection portion 60 (60A). The second winding portion 11B is connected to the first winding portion 11A via the first connection portion 60 (60A) in the first planar region of the third pattern layer 23 and is wound outwardly in a clockwise direction from the first connection portion 60 (60A) in the third pattern layer 23.

[0041] The third winding portion 11C is connected to the negative end of the second winding portion 11B in the second planar region of the third pattern layer 23, and is wound inwardly in a counterclockwise direction around the second connection portion 60 (60B) starting from the negative end of the second winding portion 11B, and extends to be connected to the second connection portion 60 (60B). The fourth winding portion 11D is connected to the third winding portion 11C via the second connection portion 60 (60B) in the second planar region of the fourth pattern layer 24, and is wound outwardly in a counterclockwise direction around the second connection portion 60 (60B) starting from the second connection portion 60 (60B) in the fourth pattern layer 24, and is connected to the negative end.

[0042] 2, the printed pattern wiring of the secondary winding 12 is formed on a first pattern layer 21 and a second pattern layer 22. The printed pattern wiring of the secondary winding 12 includes a fifth winding portion 12A, a sixth winding portion 12B, a seventh winding portion 12C, and an eighth winding portion 12D.

[0043] The fifth winding portion 12A is wound inwardly in a clockwise direction from the positive end of the first pattern layer 21 around the second connection portion 60 (60D) provided on the first insulating layer 27, and extends to be connected to the second connection portion 60 (60D). The sixth winding portion 12B is connected to the fifth winding portion 12A via the second connection portion 60 (60D) in the second planar region of the second pattern layer 22, and is wound outwardly in a clockwise direction from the second connection portion 60 (60D) in the second pattern layer 22 around the second connection portion 60 (60D).

[0044] The seventh winding portion 12C is connected to the negative electrode end of the sixth winding portion 12B in the first planar region of the second pattern layer 22, and is wound inwardly in a counterclockwise direction around the first connection portion 60 (60C) starting from the negative electrode end of the sixth winding portion 12B, and extends to be connected to the first connection portion 60 (60C). The eighth winding portion 12D is connected to the seventh winding portion 12C via the first connection portion 60 (60C) in the first planar region of the first pattern layer 21, and is wound outwardly in a counterclockwise direction around the first connection portion 60 (60C) starting from the first connection portion 60 (60C) in the first pattern layer 21, and is connected to the negative electrode end.

[0045] The printed pattern wiring of the pattern transformer 10 will be described below from a different perspective than that of FIG. 2. FIG. 3 is a plan view that shows a schematic representation of the printed pattern wiring in the first pattern layer 21 of the pattern transformer 10 according to an embodiment. Here, the secondary winding 12 will be described by dividing it into the first pattern layer 21 and the second pattern layer 22. FIG. 4 is a plan view that shows a schematic representation of the printed pattern wiring in the second pattern layer 22 of the pattern transformer 10 according to an embodiment. FIG. 5 is a plan view that shows a schematic representation of the secondary winding 12 of the pattern transformer 10 according to an embodiment. Note that FIG. 5 shows a state in which multiple winding portions of the secondary winding 12 are overlapped with each other through the multilayer substrate 20.

[0046] 2 to 5, the fifth winding portion 12A in the second planar region and the eighth winding portion 12D in the first planar region are formed in the first pattern layer 21, and the sixth winding portion 12B in the second planar region and the seventh winding portion 12C in the first planar region are formed in the second pattern layer 22. The fifth winding portion 12A and the eighth winding portion 12D are connected to the sixth winding portion 12B and the seventh winding portion 12C via the connection portion 60, respectively. By forming the secondary winding 12 by connecting the winding portions provided in such two pattern layers, it is possible to increase the number of turns per unit area compared to a configuration in which the secondary winding 12 is formed in only one pattern layer.

[0047] 3 to 5, the primary winding 11 is also formed by connecting winding portions provided on the third pattern layer 23 and the fourth pattern layer 24. The primary winding 11 and the secondary winding 12 are overlapped as shown in FIGS.

[0048] (Operation principle of pattern transformer 10) The operation of the pattern transformer 10 described above will be described when an AC voltage is applied to the pattern transformer 10 and a current flows from the positive electrode side of the primary winding 11. First, in the primary winding 11 and the secondary winding 12, a current flows clockwise in one of the winding-shaped printed pattern wiring provided in the first planar region and the winding-shaped printed pattern wiring provided in the second planar region, and a current flows counterclockwise in the other.

[0049] For example, as shown in Fig. 2, a current flows from the positive pole side of the primary winding 11 to the first winding portion 11A, and the current flows clockwise in the first winding portion 11A. This current flows into the second winding portion 11B via the connection portion 60, and the current flows clockwise in the second winding portion 11B. Furthermore, a current flows from the second winding portion 11B to the third winding portion 11C, and the current flows counterclockwise in the third winding portion 11C. This current flows into the fourth winding portion 11D via the connection portion 60, and the current flows counterclockwise in the fourth winding portion 11D.

[0050] According to the above configuration, currents flow in opposite directions in the winding-shaped printed pattern wiring provided in the first planar region and the winding-shaped printed pattern wiring provided in the second planar region. Therefore, magnetic circuits H1 and H2 are formed between the two winding-shaped printed wirings. The magnetic circuit H1 is a magnetic circuit of the magnetic flux in the primary winding 11, and the magnetic circuit H2 is a magnetic circuit of the magnetic flux due to the magnetic coupling between the primary winding 11 and the secondary winding 12. The magnetic flux generated by the induced current in the secondary winding 12 is also formed in the same manner as the magnetic circuit H1.

[0051] The magnetic circuits H1 and H2 guide the magnetic flux so that leakage flux from the windings is small in the flat areas outside the windings, making it possible to adopt a configuration that does not require an iron core and thus achieve a compact design.

[0052] In addition, since the primary winding 11 and the secondary winding 12 have a winding-shaped printed pattern wiring in the same planar area, electromagnetic coupling between them is possible. For example, as shown in Fig. 2, when a current flows through the primary winding 11, a magnetic circuit H2 is formed, and the magnetic flux generated in the primary winding 11 interlinks with the secondary winding 12. Therefore, a current flows through the secondary winding 12 due to electromagnetic induction of the AC current flowing through the primary winding 11. Therefore, the pattern transformer 10 functions as a transformer.

[0053] For example, as shown in Fig. 2, due to electromagnetic induction caused by a change in magnetic flux generated in the primary winding 11, a current flows from the positive pole of the secondary winding 12 to the fifth winding portion 12A, and the current flows clockwise in the fifth winding portion 12A. This current flows into the sixth winding portion 12B via the connection portion 60, and the current flows clockwise in the sixth winding portion 12B. Furthermore, a current flows from the sixth winding portion 12B to the seventh winding portion 12C, and the current flows counterclockwise in the seventh winding portion 12C. This current flows into the eighth winding portion 12D via the connection portion 60, and the current flows counterclockwise in the eighth winding portion 12D.

[0054] In this way, the primary winding 11 is configured so that a current flows clockwise in the winding-shaped printed pattern wiring provided in the first planar region, and a current flows counterclockwise in the winding-shaped printed pattern wiring provided in the second planar region. The secondary winding 12 is configured so that a current flows counterclockwise in the winding-shaped printed pattern wiring provided in the first planar region, and a current flows clockwise in the winding-shaped printed pattern wiring provided in the second planar region. When the polarity of the AC voltage is reversed, the current flows in the opposite direction to that described above.

[0055] (Modification) The present disclosure is not limited to the above-described embodiments, and includes modifications to the above-described embodiments and appropriate combinations of these modifications.

[0056] In the above embodiment, the primary winding 11 and the secondary winding 12 of the pattern transformer 10 are each provided across two pattern layers via the connection portion 60. However, the pattern transformer 10 is not limited to this configuration. The primary winding 11 and the secondary winding 12 may be provided across three or more pattern layers via the connection portion 60, or may be provided on one pattern layer.

[0057] In the above embodiment, the primary winding 11 and the secondary winding 12 of the pattern transformer 10 have winding portions in the first planar region and the second planar region, respectively. However, the pattern transformer 10 is not limited to this configuration. The primary winding 11 and the secondary winding 12 may have winding portions in three or more planar regions, respectively. That is, the magnetic circuit may be more complicated. However, it is preferable to design the primary winding 11 and the secondary winding 12 so that the magnetic flux generated by the currents in the primary winding 11 and the secondary winding 12 is small outside of those planar regions.

[0058] 2, the primary winding 11 is located below the secondary winding 12, and is provided on the third pattern layer 23 and the fourth pattern layer 24. However, the primary winding 11 may be located above the secondary winding 12, and is provided on the first pattern layer 21 and the second pattern layer 22. In other words, the positional relationship may be reversed as long as the two overlap in the layer direction.

[0059] The number of turns of the primary winding 11 and the secondary winding 12 is not limited to the example shown in the figure, and can be designed arbitrarily. The turn ratio can also be designed arbitrarily.

[0060] (summary) The contents described in each of the above embodiments can be understood, for example, as follows.

[0061] (1) A signal transmission circuit (100) according to an embodiment of the present disclosure includes: A multilayer substrate (20) including a plurality of layers; A pattern transformer (10) provided on the multilayer board (20); A signal transmission circuit (100) for transmitting an isolated signal, comprising: The pattern transformer (10) is a primary winding (11) including a winding-shaped printed pattern wiring provided on each of a first planar area and a second planar area of ​​the multilayer substrate (20); a secondary winding (12) provided at a layer direction position different from that of the primary winding (11) and including the printed pattern wiring in a winding shape provided in each of the first planar area and the second planar area of ​​the multilayer substrate (20); having The primary winding (11) and the secondary winding (12) are configured to be electromagnetically coupled to each other, The printed pattern wiring is configured to have a winding shape provided in the first planar area and a winding shape provided in the second planar area, and a current flows in a clockwise direction in one of the printed pattern wiring and a counterclockwise direction in the other.

[0062] According to the configuration described in (1) above, currents flow in opposite directions in the winding-shaped printed pattern wiring provided in the first planar region and the winding-shaped printed pattern wiring provided in the second planar region. Therefore, a magnetic circuit (H1, H2) is formed between the two winding-shaped printed wirings. This magnetic circuit (H1, H2) guides the magnetic flux so that leakage magnetic flux from the winding is reduced in the planar region outside the winding. Therefore, a compact design can be achieved by adopting a configuration without an iron core. Note that the primary winding (11) and the secondary winding (12) have winding-shaped printed pattern wiring in the same planar region, so electromagnetic coupling between them is possible.

[0063] (2) In some embodiments, in the configuration described in (1) above, The primary winding (11) is A current flows in a clockwise direction in the winding-shaped printed pattern wiring provided in the first planar region, and a current flows in a counterclockwise direction in the winding-shaped printed pattern wiring provided in the second planar region, The secondary winding (12) is A current is configured to flow counterclockwise in the winding-shaped printed pattern wiring provided in the first planar region, and a current is configured to flow clockwise in the winding-shaped printed pattern wiring provided in the second planar region.

[0064] Electromagnetic induction of a current flowing through the primary winding (11) causes a current to flow through the secondary winding (12), so that the pattern transformer (10) functions as a transformer.

[0065] (3) In some embodiments, in the configuration described in (1) or (2) above, One or more semiconductor switching elements (e.g., FETs 40 and 50 shown in FIG. 1) are provided on the secondary side of the pattern transformer (10), One or more of the semiconductor switching elements (for example, FETs 40, 50 shown in FIG. 1) are configured to be turned on and off by the secondary voltage of the pattern transformer (10) and to output a contact output signal.

[0066] According to the configuration described in (3) above, by controlling the current or voltage on the primary side of the pattern transformer (10), a semiconductor switching element (e.g., FETs 40 and 50 shown in FIG. 1) provided on the secondary side of the pattern transformer (10) can be turned on and off to output a contact output signal.

[0067] (4) In some embodiments, in the configuration described in any one of (1) to (3) above, One end of a coil (coil L1) is connected to one end of the secondary side of the pattern transformer (10), The other end of the coil (coil L1) is connected to one end of a first capacitor (capacitor C3), The other end of the first capacitor (capacitor C3) is connected to the other end of the secondary side of the pattern transformer (10), The coil (coil L1) and the first capacitor (capacitor C3) form a resonant circuit that resonates with an AC signal output from the secondary side of the pattern transformer (10).

[0068] According to the configuration described in (4) above, the voltage drop on the secondary side caused by the loss in the pattern transformer (10) can be compensated for by the resonance of the resonant circuit.

[0069] (5) In some embodiments, in the configuration described in (4) above, A second capacitor (for example, the capacitor C1 shown in FIG. 1) is connected to one end of the primary side of the pattern transformer (10), A third capacitor (for example, the capacitor C2 shown in FIG. 1) is connected to the other end of the primary side of the pattern transformer (10). The second capacitor (for example, the capacitor C1 shown in FIG. 1) and the third capacitor (for example, the capacitor C2 shown in FIG. 1) have a capacitance that acts to increase the half-width of the resonant circuit.

[0070] According to the configuration described in (5) above, the half-width of the resonant circuit is increased, so that even if there is a slight difference between the resonant frequency of the resonant circuit and the frequency of the AC signal due to the parameters of the element, it is possible to suppress a reduction in the resonance effect. Equipped with.

[0071] (6) In some embodiments, in the configuration described in any one of (1) to (5) above, The plurality of layers include A first pattern layer (21) on which the printed pattern wiring is formed; A second pattern layer (22) on which the printed pattern wiring is formed, the second pattern layer (22) being formed on one side of the first pattern layer (21); a third pattern layer (23) on which the printed pattern wiring is formed, the third pattern layer (23) being formed on one surface side of the second pattern layer (22); a fourth pattern layer (24) on which the printed pattern wiring is formed, the fourth pattern layer (24) being formed on one surface side of the third pattern layer (23); a first insulating layer (27) having insulating properties and provided between the first pattern layer (21) and the second pattern layer (22); a second insulating layer (28) having insulating properties and provided between the second pattern layer (22) and the third pattern layer (23); a third insulating layer (29) having insulating properties and provided between the third pattern layer (23) and the fourth pattern layer (24); Including, The first insulating layer (27) and the third insulating layer (29) are provided with a connection portion (60) that connects adjacent printed pattern wirings in the layer direction, the connection portion (60) including a first connection portion (60A, 60C) provided in the first planar region and a second connection portion (60B, 60D) provided in the second planar region.

[0072] According to the configuration described in (6) above, the connection portion (60) can be used to form the primary winding (11) by extending the printed pattern wiring to the third pattern layer (23) and the fourth pattern layer (24), and the secondary winding (12) can be formed by extending the printed pattern wiring to the first pattern layer (21) and the second pattern layer (22). In addition, the primary winding (11) and the secondary winding (12) can be insulated by the second insulating layer (28). This is suitable for forming a pattern transformer (10).

[0073] (7) In some embodiments, in the configuration described in (6) above, The printed pattern wiring of the primary winding (11) is formed on the third pattern layer (23) and the fourth pattern layer (24), a first winding portion (11A) that is wound inwardly in a clockwise direction around the first connection portion (60A) provided on the third insulating layer (23) from an end portion on a positive electrode side in the first planar region of the fourth pattern layer (24) and extends so as to be connected to the first connection portion (60A); a second winding portion (11B) that is connected to the first winding portion (11A) via the first connection portion (60A) in the first planar region of the third pattern layer (23) and that is wound clockwise outwardly around the first connection portion (60A) in the third pattern layer (23), starting from the first connection portion (60A); a third winding portion (11C) that is connected to a negative electrode side end of the second winding portion (11B) in the second planar region of the third pattern layer (23), that is wound inwardly in a counterclockwise direction around the second connection portion (60B) from the negative electrode side end of the second winding portion (11B) as a starting point, and that extends so as to be connected to the second connection portion (60B); a fourth winding portion (11D) that is connected to the third winding portion (11C) via the second connection portion (60B) in the second planar region of the fourth pattern layer (24), that is wound counterclockwise outwardly around the second connection portion (60B) in the fourth pattern layer (24) starting from the second connection portion (60B), and that is connected to an end portion on the negative electrode side; Includes.

[0074] According to the configuration described in (7) above, the four winding portions can be formed by a continuous printed wiring pattern, so that the primary winding (11) can be easily formed.

[0075] (8) In some embodiments, in the configuration described in (6) or (7) above, The printed pattern wiring of the secondary winding (12) is formed on the first pattern layer (21) and the second pattern layer (22), a fifth winding portion (12A) that is wound inwardly in a clockwise direction around the second connection portion (60D) provided on the first insulating layer (27) from an end portion on a positive electrode side in the second planar region of the first pattern layer (21) and extends so as to be connected to the second connection portion (60D); a sixth winding portion (12B) that is connected to the fifth winding portion (12A) via the second connection portion (60D) in the second planar region of the second pattern layer (22) and that is wound clockwise outwardly around the second connection portion (60D) in the second pattern layer (22), starting from the second connection portion (60D); a seventh winding portion (12C) that is connected to a negative electrode side end of the sixth winding portion (12B) in the first planar region of the second pattern layer (22), that is wound inwardly in a counterclockwise direction around the first connection portion (60C) from the negative electrode side end of the sixth winding portion (12B) as a starting point, and that extends so as to be connected to the first connection portion (60C); an eighth winding portion (12D) that is connected to the seventh winding portion (12C) via the first connection portion (60C) in the first planar region of the first pattern layer (21), that is wound counterclockwise toward the outside around the first connection portion (60C) in the first pattern layer (21) with the first connection portion (60C) as a starting point, and that is connected to an end portion on the negative electrode side; Includes.

[0076] According to the configuration described in (8) above, the four winding portions can be formed by a continuous printed wiring pattern, so that the secondary winding (12) can be easily formed. [Explanation of symbols]

[0077] 10 Pattern Transformer 11 Primary winding 11A First Winding 11B Second winding section 11C 3rd winding section 11D 4th winding section 12 Secondary winding 12A 5th winding 12B 6th winding 12C 7th winding 12D 8th winding section 20 Multilayer board 21 First pattern layer 22 2nd pattern layer 23 3rd pattern layer 24 4th pattern layer 25 5th pattern layer 26 6th pattern layer 27 First insulating layer 28 Second insulating layer 29 Third insulating layer 30 buffers 60 Connection 60A, 60C 1st connection part 60B, 60D Second connection part 100 Signal transmission circuit C1, C2, C3, C4, C5 capacitors D1, D2 diode H1, H2 magnetic circuit L1 coil R1,R2,R3,R4,R5,R6 resistance

Claims

1. A multilayer substrate including a plurality of layers that are constantly connected to each other; a pattern transformer provided on the multilayer substrate; A signal transmission circuit for transmitting an isolated signal, comprising: The pattern transformer is a primary winding including a winding-shaped printed pattern wiring provided on each of a first planar area and a second planar area of ​​the multilayer substrate; a secondary winding provided at a layer direction position different from that of the primary winding, the secondary winding including the printed pattern wiring in a winding shape provided in each of the first planar area and the second planar area of ​​the multilayer substrate; having the primary winding and the secondary winding are configured to be electromagnetically coupled; a current flows clockwise through one of the winding-shaped printed pattern wiring provided in the first planar region and the winding-shaped printed pattern wiring provided in the second planar region, and a current flows counterclockwise through the other of the winding-shaped printed pattern wiring provided in the first planar region; The plurality of layers include a first pattern layer on which the printed pattern wiring is formed; A second pattern layer on which the printed pattern wiring is formed, the second pattern layer being formed on one surface side of the first pattern layer; a third pattern layer on which the printed pattern wiring is formed, the third pattern layer being formed on one surface side of the second pattern layer; a fourth pattern layer on which the printed pattern wiring is formed, the fourth pattern layer being formed on one surface side of the third pattern layer; A first insulating layer (core) having insulating properties and provided between the first pattern layer and the second pattern layer; A second insulating layer (prepreg) having insulating properties provided between the second pattern layer and the third pattern layer; A third insulating layer (core) having insulating properties and provided between the third pattern layer and the fourth pattern layer; Including, the first insulating layer and the third insulating layer are provided with connection portions that connect the printed pattern wirings adjacent to each other in a layer direction, the connection portions including a first connection portion provided in the first planar region and a second connection portion provided in the second planar region; the first pattern layer, the second pattern layer, the third pattern layer, and the fourth pattern layer are always contiguous with one another; One or more semiconductor switching elements are provided on the secondary side of the pattern transformer, The one or more semiconductor switching elements are turned on and off by a secondary voltage of the pattern transformer, and are configured to output a contact output signal.

2. The primary winding is A current flows in a clockwise direction in the winding-shaped printed pattern wiring provided in the first planar region, and a current flows in a counterclockwise direction in the winding-shaped printed pattern wiring provided in the second planar region, The secondary winding is A current flows counterclockwise in the winding-shaped printed pattern wiring provided in the first planar region, and a current flows clockwise in the winding-shaped printed pattern wiring provided in the second planar region.

2. The signal transmission circuit according to claim 1.

3. One end of the coil is connected to one end of the secondary side of the pattern transformer, One end of a first capacitor is connected to the other end of the coil, the other end of the first capacitor is connected to the other end of the secondary side of the pattern transformer, The coil and the first capacitor form a resonant circuit that resonates an AC signal output from the secondary side of the pattern transformer.

3. The signal transmission circuit according to claim 1.

4. the printed pattern wiring of the primary winding is formed on the third pattern layer and the fourth pattern layer; a first winding portion that is wound inwardly in a clockwise direction around the first connection portion provided on the third insulating layer, starting from an end portion on the positive electrode side in the first planar region of the fourth pattern layer, and extends so as to be connected to the first connection portion; a second winding portion that is connected to the first winding portion via the first connection portion in the first planar region of the third pattern layer and that is wound clockwise outwardly around the first connection portion in the third pattern layer starting from the first connection portion; a third winding portion connected to a negative end of the second winding portion in the second planar region of the third pattern layer, wound inwardly in a counterclockwise direction around the second connection portion from the negative end of the second winding portion as a starting point, and extending so as to be connected to the second connection portion; a fourth winding portion that is connected to the third winding portion via the second connection portion in the second planar region of the fourth pattern layer, that is wound counterclockwise outwardly around the second connection portion in the fourth pattern layer starting from the second connection portion, and that is connected to an end portion on the negative electrode side; Includes 2. The signal transmission circuit according to claim 1.

5. the printed pattern wiring of the secondary winding is formed on the first pattern layer and the second pattern layer; a fifth winding portion that is wound inwardly in a clockwise direction around the second connection portion provided on the first insulating layer, starting from an end portion on the positive electrode side in the second planar region of the first pattern layer, and extends so as to be connected to the second connection portion; a sixth winding portion that is connected to the fifth winding portion via the second connection portion in the second planar region of the second pattern layer and that is wound clockwise outwardly around the second connection portion in the second pattern layer starting from the second connection portion; a seventh winding portion connected to a negative electrode side end of the sixth winding portion in the first planar region of the second pattern layer, wound inwardly in a counterclockwise direction around the first connection portion from the negative electrode side end of the sixth winding portion as a starting point, and extending so as to be connected to the first connection portion; an eighth winding portion that is connected to the seventh winding portion via the first connection portion in the first planar region of the first pattern layer, that is wound counterclockwise outwardly around the first connection portion in the first pattern layer starting from the first connection portion, and that is connected to an end portion on the negative electrode side; Includes 5. The signal transmission circuit according to claim 4.

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