SEMICONDUCTOR RELAY DEVICE

A semiconductor relay device includes: an oscillator unit configured to output an oscillation signal based on an input signal; a first inductor and a second inductor that are magnetically coupled to each other; a driving unit configured to drive the first inductor based on the oscillation signal output from the oscillator unit; a rectifier unit configured to rectify a signal output by the second inductor; and a connecting unit configured to electrically connect or disconnect a first terminal and a second terminal to or from each other based on a signal rectified by the rectifier unit.

TECHNICAL FIELD

The present invention relates to a semiconductor relay device.

BACKGROUND ART

There is known a semiconductor relay device including: an oscillator circuit that oscillates depending on an input signal; an inductor unit that converts a transmission signal from the oscillator circuit into an electromagnetic signal; a rectifier circuit that rectifies an output signal from the inductor unit; a charging and discharging circuit that charges and discharges a signal rectified by the rectifier circuit; and an output MOSFET of which switching is performed depending on potential difference generated between the ends of the charging and discharging circuit (Patent Literature 1).

CITATION LIST

Patent Literature

SUMMARY

Technical Problem

In the semiconductor relay device according to Patent Literature 1, the transmission signal from the oscillator circuit directly flows through the inductor unit which is a load of the oscillator circuit, and is converted into the electromagnetic signal. Thus, there is a possibility that the inductor unit cannot be supplied with sufficient current and switching of the output MOSFET cannot be appropriately performed.

Solution to Problem

According to a first aspect of the present invention, a semiconductor relay device includes: an oscillator unit configured to output an oscillation signal based on an input signal; a first inductor and a second inductor that are magnetically coupled to each other; a driving unit configured to drive the first inductor based on the oscillation signal output from the oscillator unit; a rectifier unit configured to rectify a signal output by the second inductor; and a connecting unit configured to electrically connect or disconnect a first terminal and a second terminal to or from each other based on a signal rectified by the rectifier unit.

Advantageous Effects of Invention

According to the present invention, switching can be appropriately performed.

DESCRIPTION OF EMBODIMENTS

Embodiment

FIG.1is a diagram illustrating a configuration example of a semiconductor relay device according to an embodiment. A semiconductor relay device1is a semiconductor relay having a first terminal11, a second terminal12, a third terminal13, and a fourth terminal14. The semiconductor relay device1includes an oscillator unit20, a driving unit30, an inductor unit40, a rectifier unit50, a smoothing/charging and discharging unit60, and a connecting unit90. The semiconductor relay device1switches between electrical connection and disconnection between the third terminal13and the fourth terminal14depending on a signal input to the first terminal11and the second terminal12.

The first terminal11and the second terminal12constitute an input unit to which an electrical signal can be input from outside of the semiconductor relay device1. In the semiconductor relay device1, each unit (oscillator unit20, driving unit30, or the like) of the semiconductor relay device1operates depending on a signal Vin supplied through the first terminal11and the second terminal12.

The third terminal13and the fourth terminal14constitute an output unit from which an electrical signal can be output to outside of the semiconductor relay device1. In the semiconductor relay device1, switching is performed depending on a signal Vin, and an electrical signal depending on the signal Vin is transferred (transmitted) to outside through the third terminal13and the fourth terminal14.

The oscillator unit20is constituted by an oscillator circuit (OSC) and generates a signal (hereinafter, referred to as an oscillation signal CLK) with a predetermined frequency and period on the basis of the signal Vin input through the first terminal11. When the signal level of the signal Vin supplied from the first terminal11changes from low level (for example, ground voltage or reference voltage) to high level (for example, power-supply voltage), the oscillator unit20generates an oscillation signal CLK and starts outputting the oscillation signal CLK. It can also be said that the oscillator unit20oscillates when the signal Vin is in an enabled state (at high level). The oscillator unit20outputs the generated oscillation signal CLK to the driving unit30.

The inductor unit40has a plurality of inductors (coils) that are magnetically coupled to each other and functions as a transformer that transmits energy. The inductor unit (transformer) is also a voltage-converter unit40that transforms voltage. Note that the method of transmitting energy from a primary side to a secondary side may be a flyback mode or a forward mode. That is, the inductor unit40may be a flyback transformer or a forward transformer. Furthermore, the inductor unit40may have a core (for example, iron core).

The driving unit30drives the inductor unit40on the basis of the oscillation signal CLK output by the oscillator unit20. When the signal level of the signal Vin becomes high level and the oscillation signal CLK is input from the oscillator unit20, the driving unit30starts supplying electric power from the first terminal11to primary-side inductors of the inductor unit40. The driving unit30is an amplifier unit30and increases (amplifies) current and voltage to be supplied to the inductor unit40compared to a case where the oscillation signal CLK from the oscillator unit20is directly input to the inductor unit40.

The rectifier unit50has a rectifier element and functions to convert alternate current (AC) to direct current (DC). The rectifier unit50is electrically connected to secondary-side inductors of the inductor unit40, and rectifies AC voltage induced in the secondary-side inductors of the inductor unit40to DC voltage. The rectifier unit50outputs a signal V1obtained by the rectification to the smoothing/charging and discharging unit60.

The smoothing/charging and discharging unit60, to which the signal V1rectified by the rectifier unit50is input, smooths the signal V1. In addition, the smoothing/charging and discharging unit60charges or discharges the connecting unit90on the basis of the rectified and smoothed signal V1, and supplies a signal V2to the connecting unit90. The signal level of the signal V2applied to the connecting unit90changes depending on the signal level of the signal V1.

The connecting unit90has transistors controlled by the signal V2and electrically connects or disconnects the third terminal13and the fourth terminal14to or from each other. When the signal Vin becomes high level and the signal level of the signal V2becomes high level, the connecting unit (switching unit)90is switched to the ON state and electrically connects the third terminal13and the fourth terminal14to each other. When the signal Vin becomes low level and the signal level of the signal V2becomes low level, the connecting unit90is switched to the OFF state and electrically disconnects the third terminal13and the fourth terminal14from each other. The semiconductor relay device1according to the embodiment will be further described below with reference toFIG.2.

FIG.2is a diagram illustrating an example of a circuit configuration of the semiconductor relay device according to the embodiment. As an example, the inductor unit40has an inductor L1a, an inductor L1b, an inductor L2a, and an inductor L2bas illustrated inFIG.2. The inductors L1aand L1bare primary-side inductors and the inductors L2aand L2bare secondary-side inductors. The primary-side inductors and the secondary-side inductors are also referred to as primary-side windings (primary windings) and secondary-side windings (secondary windings), respectively. The primary-side inductors and the secondary-side inductors are electrically isolated from each other and make energy transmission from the primary side to the secondary side. It can also be said that the primary-side inductors and the secondary-side inductors are electromagnetically connected to each other.

The inductor L1ais arranged against the inductor L2aand is magnetically coupled to the inductor L2a. The inductor L1bis arranged against the inductor L2band is magnetically coupled to the inductor L2b. One end of each of the inductor L1aand the inductor L1bis electrically connected to the first terminal11, and the signal Vin is applied thereto. The other end of each of the inductor L1aand the inductor L1bis connected to the driving unit30.

One end of each of the inductor L2aand the inductor L2bis connected to the rectifier unit50. The other end of each of the inductor L2aand the inductor L2bis connected to a wiring102as illustrated inFIG.2. The electric potential of the wiring102is a reference potential for the signal V1and the signal V2(for example, ground potential).

When current is supplied to a primary-side inductor L1(L1a, L1b), magnetic flux is generated. The magnetic flux generated in the primary-side inductor L1is transmitted to a secondary-side inductor L2(L2a, L2b), so that electromotive force is induced in the secondary-side inductor L2. In the inductor unit40, electromagnetic induction occurs depending on the current input to the primary-side inductor L1, and electric power can thus be supplied to the secondary-side inductor L2.

The magnitude of voltage induced in the secondary-side inductor L2may vary according to a ratio between the number of turns of the primary-side inductor L1to the number of turns of the secondary-side inductor L2. The number of turns of the primary-side inductor L1may be fewer than the number of turns of the secondary-side inductor L2so that the voltage to be generated in the secondary-side inductor L2will be higher than the voltage input in the primary-side inductor L1. The ratio of the number of turns may be reversed, that is, the number of turns of the primary-side inductor L1may be more than the number of turns of the secondary-side inductor L2so that the voltage to be generated in the secondary-side inductor L2will be lower than the voltage input in the primary-side inductor L1. Alternatively, the same voltage as that in the primary-side inductor L1may be generated in the secondary-side inductor L2.

The driving unit30has a control unit31and a supply unit35, and controls power supply to the inductor unit40to control operation of the inductor unit40. In the example illustrated inFIG.2, the supply unit35has a transistor36aand a transistor36bcontrolled by the control unit31. The transistor36aand the transistor36bare MOS transistors (MOSFETs) each having gate, source, and drain terminals. Note that the supply unit35may be configured using bipolar transistors.

The gate of each of the transistor36aand the transistor36bis connected to the control unit31. The drain of the transistor36ais connected to an end of the inductor L1a. The drain of the transistor36bis connected to an end of the inductor L1b. The source of each of the transistor36aand the transistor36bis electrically connected to the second terminal12via a wiring101as illustrated inFIG.2. A reference potential (for example, ground potential) for the signal Vin of the first terminal11is applied to the wiring101through the second terminal12.

The control unit31includes, for example, a buffer circuit, an inverter circuit, and the like, and generates, on the basis of the oscillation signal CLK output from the oscillator unit20, signals for controlling the supply unit35. The control unit31supplies the signals for controlling the supply unit35to the supply unit35and controls operation of each of the transistors (the transistor36aand the transistor36binFIG.2) of the supply unit35. The control unit31supplies the signal to the gate of each of the transistors of the supply unit35to turn the transistor to the ON state (connected state, conductive state, short-circuit state) or to the OFF state (disconnected state, non-conductive state, open state, cut-off state).

The control unit31performs ON/OFF control of the transistor36aand the transistor36bof the supply unit35by outputting the signals for controlling the supply unit35to the supply unit and thereby starts and stops supplying current to the inductor unit40. The control unit31can perform control of supplying current to the inductor L1aby the transistor36aand control of supplying current to the inductor L1bby the transistor36b. Note that the driving unit30may include the oscillator unit20.

The rectifier unit50is constituted by a rectifier circuit having a diode51aand a diode51b. The anode (terminal) of the diode51ais connected to the inductor L2a. The cathode (terminal) of the diode51ais connected to the smoothing/charging and discharging unit60. In addition, the anode of the diode51bis connected to the inductor L2b. The cathode of the diode51bis connected to the smoothing/charging and discharging unit60.

When the transistor36aof the supply unit35is turned to the ON state and the transistor36bto the OFF state, the inductor L1abecomes electrically connected to the second terminal12. Then, a voltage depending on the voltage between terminals, that is, between the first terminal11and the second terminal12is applied to the inductor L1a, so that current flows from the first terminal11to the inductor L1a. The current flowing through the inductor L1ainduces magnetic flux, which causes power supply to the inductor L2a. In this case, the diode51aof the rectifier unit50is turned to the ON state, and current from the inductor L2ais supplied to the smoothing/charging and discharging unit60.

When the transistor36aof the supply unit35is turned to the OFF state and the transistor36bto the ON state, the inductor L1bbecomes electrically connected to the second terminal12. Then, a voltage depending on the voltage between terminals, that is, between the first terminal11and the second terminal12is applied to the inductor L1b, so that current flows from the first terminal11to the inductor L1b. The current flowing through the inductor L1binduces magnetic flux, which causes power supply to the inductor L2b. In this case, the diode51bof the rectifier unit50is turned to the ON state, and current from the inductor L2bis supplied to the smoothing/charging and discharging unit60.

In this way, the inductor unit40is controlled by the driving unit30, and the inductor L1aand the inductor L1bare alternately supplied with electric power. Therefore, the inductor unit40can efficiently transmit power from the primary-side inductors L1to the secondary-side inductors L2. The rectifier unit50rectifies AC output generated by the inductor L2aand the inductor L2b, and outputs the rectified signal to the smoothing/charging and discharging unit60.

The smoothing/charging and discharging unit60has a smoothing unit70and a charging and discharging unit80. In the example illustrated inFIG.2, the smoothing unit70is constituted by a capacitor C. As illustrated inFIG.2, an end of the capacitor C is connected to the rectifier unit50and the charging and discharging unit80. The other end of the capacitor C is connected to the wiring102that is at the reference potential.

The signal V1is input to the capacitor C from the inductor L2aand the inductor L2bvia the rectifier unit50. The capacitor C accumulates electric charge depending on the voltage of the signal V1. The capacitor C suppresses fluctuations in the voltage of the signal V1. This makes it possible to supply steady-level signals to the latter circuit, especially, to the input gates of transistors91aand91bof the connecting unit90.

The charging and discharging unit80has a plurality of diodes81(diodes81ato81cinFIG.2), a resistance82, and a transistor83. The diode81a, the diode81b, and the diode81care connected in series. The resistance82is connected to the diodes81ato81cin parallel. The signal V1is input to the gate of the transistor83. The signal V1is input from the rectifier unit via the smoothing unit70to the charging and discharging unit80, which outputs the signal V2based on the voltage of the signal V1to the connecting unit90.

When the voltage of the signal V1increases (gets higher), the diodes81ato81care turned to the ON state, the connecting unit90is charged, and the voltage of the signal V2input to the connecting unit90increases. When the voltage of the signal V1decreases (gets lower), the diodes81ato81care turned to the OFF state and the transistor83is turned to the ON state. In this case, the transistor83discharges the connecting unit90, resulting in a rapid fall in the voltage of the signal V2input to the connecting unit90.

The connecting unit90has a transistor91aand a transistor91bas illustrated inFIG.2. The transistor91aand the transistor91bare MOS transistors (MOSFETs) each having gate, source, and drain terminals. Note that the connecting unit90may be configured using bipolar transistors.

The gate of each of the transistor91aand the transistor91bis connected to the charging and discharging unit80, and the signal V2is input thereto. The drain of the transistor91aand the drain of the transistor91bare connected to the third terminal13and the fourth terminal14, respectively. The source of each of the transistor91aand the transistor91bis connected to the wiring102.

The transistor91aand the transistor91bare switched by the signal V2of which signal level changes depending on the signal Vin. The transistor91aand the transistor91belectrically connect or disconnect the third terminal13and the fourth terminal14to or from each other depending on the input signal V2.

When the signal V2becomes low level, the transistor91aand the transistor91bare both switched to the OFF state. In this case, the third terminal13and the fourth terminal14are electrically disconnected from each other by the transistor91aand the transistor91b.

When the signal V2becomes high level, the transistor91aand the transistor91bare both switched to the ON state. In this case, the third terminal13and the fourth terminal14are electrically connected to each other by the transistor91aand the transistor91b. Furthermore, the third terminal13and the fourth terminal14are both electrically connected to the wiring102, and a potential depending on the reference potential is applied to the third terminal13and the fourth terminal14. The connecting unit90outputs an electrical signal that serves as the reference potential from the third terminal13and the fourth terminal14to outside.

As described above, in the semiconductor relay device1according to the embodiment, the driving unit30controls power transfer from a primary-side inductor L1of the inductor unit40to a secondary-side inductor L2. It is possible to transfer electric power to the secondary-side inductor L2in a state where the primary-side inductor L1and the secondary-side inductor L2are electrically isolated from each other, and to set the voltage of the secondary-side inductor L2to a voltage raised or lowered from the voltage of the primary-side inductor L1or a voltage that is the same as the voltage of the primary-side inductor L1. It is possible to properly supply the connecting unit90with the signal V2with a voltage necessary for switching of the connecting unit90so that switching can be appropriately performed depending on the signal Vin.

Even in a case where transistors having a large current capacity and thus having a large gate capacitance are used for the connecting unit90, it is possible to supply the signal V2with large electric power that can charge the gate capacitance in a short time. Therefore, switching delays and malfunctions can be prevented.

FIG.3is a timing chart illustrating an operation example of the semiconductor relay device according to the embodiment. The timing chart inFIG.3shows, along the same time axis, the signal Vin, the oscillation signal CLK, the gate voltage Vg1of the transistor36a, the drain voltage Vd1of the transistor36a, the current Id1flowing through the inductor L1a, the gate voltage Vg2of the transistor36b, the drain voltage Vd2of the transistor36b, the current Id2flowing through the inductor L1b, and the signal V2.

At the time t1illustrated inFIG.3, the signal Vin becomes high level, and output of the oscillation signal CLK starts. In addition, at the time t1, while the gate voltage Vg1of the transistor36ais at low level, the gate voltage Vg2of the transistor36bbecomes high level. When the gate voltage Vg2of the transistor36bbecomes high level, the transistor36bis turned to the ON state and current is supplied to the inductor L1b, so that electric power is accumulated.

At the time t2, the gate voltage Vg1of the transistor36abecomes high level, and the gate voltage Vg2of the transistor36bbecomes low level. When the gate voltage Vg1of the transistor36abecomes high level, the transistor36ais turned to the ON state and current is supplied to the inductor L1a. The current flowing through the inductor L1ainduces magnetic flux, which causes energy supply to the secondary-side inductor L2, resulting in an increase in the voltage of the signal V1and an increase in the voltage of the signal V2.

After the time t3, as in the period from the time t1to the time t3, energy supply from the inductor L1bto the secondary-side inductor L2and energy supply from the inductor L1ato the secondary-side inductor L2are alternately performed. In this way, when the signal Vin changes from low level to high level, the voltage of the signal V2increases. This results in switching of the transistors of the connecting unit90from the OFF state to the ON state, which leads to electrical connection between the third terminal13and the fourth terminal14.

According to the embodiment described above, the following advantageous effects can be obtained.

(1) A semiconductor relay device1includes: an oscillator unit20configured to output an oscillation signal CLK based on an input signal Vin; a first inductor and a second inductor (for example, the inductor L1aand the inductor L2a) that are magnetically coupled to each other; a driving unit30configured to drive the first inductor based on the oscillation signal CLK output from the oscillator unit20; a rectifier unit50configured to rectify a signal output by the second inductor; and a connecting unit90configured to electrically connect or disconnect a first terminal and a second terminal (the third terminal13and the fourth terminal14) to or from each other based on a signal rectified by the rectifier unit50. In the embodiment, the oscillation signal CLK from the oscillator unit20is input to the driving unit30, and the driving unit30controls power supply to the inductor unit40. The inductor unit40transfers power from the primary-side inductor L1ato the secondary-side inductor L2aand from the primary-side inductor L1bto the secondary-side inductor L2bin a state where the primary side and the secondary side are electrically isolated from each other. With this configuration, it is possible to supply the connecting unit90with the signal V2with a voltage necessary for switching of the connecting unit90. Switching can thus be appropriately performed depending on the signal Vin.
(2) In the embodiment, even in a case where transistors having a large current capacity are used for the connecting unit90, a large voltage for driving the transistors can be obtained. Furthermore, switching delays and malfunctions can be suppressed.

The following variations also fall within the scope of the present invention. It is also possible to combine one or more of the variations with the above-described embodiment.

FIG.4is a diagram illustrating an example of a configuration of a semiconductor relay device according to a first variation. In the example illustrated inFIG.4, the semiconductor relay device1has a detector unit22. The detector unit22detects current supplied to the primary side of the inductor unit40and outputs a signal indicating the detection result to the oscillator unit20. Note that the detector unit22may detect voltage based on the current supplied to the primary side of the inductor unit40and output a signal indicating the detection result to the oscillator unit20.

The oscillator unit20acquires the magnitude of current flowing on the primary side of the inductor unit40using the signal detected from the detector unit22, and changes the frequency of the oscillation signal CLK. For example, when the current flowing on the primary side of the inductor unit40is at or above a predetermined reference level (threshold), the oscillator unit20generates an oscillation signal CLK with a first frequency and outputs it. When the current flowing on the primary side of the inductor unit40drops below the predetermined reference level, the oscillator unit20generates an oscillation signal CLK with a second frequency lower than the first frequency and outputs it. In this case, the value of the second frequency may be adjusted such that the connecting unit90can stay in the ON state.

FIG.5is a diagram illustrating another configuration example of the semiconductor relay device according to the first variation. In the example illustrated inFIG.5, the detector unit22detects current flowing from the first terminal11through some parts of the semiconductor relay device1, such as current supplied to the oscillator unit20, the driving unit30, and a primary-side inductor L1of the inductor unit40inFIG.5, and outputs a signal indicating the detection result to the oscillator unit20. Note that the detector unit22may detect voltage based on the current supplied from the first terminal11and output a signal indicating the detection result to the oscillator unit20. Also in the example illustrated inFIG.5, the oscillator unit20can change the frequency of the oscillation signal CLK depending on the detection result by the detector unit22.

In this way, the semiconductor relay device1according to this variation shifts the frequency of the oscillation signal CLK depending on current flowing through the semiconductor relay device1. When the connecting unit90changes from the OFF state to the ON state and current flowing through a primary-side inductor drops, the frequency of the oscillation signal CLK can be lowered. Therefore, it is possible to mitigate electromagnetic radiation noise caused by the operation of the semiconductor relay device1. In addition, it is possible to reduce power consumption of the semiconductor relay device1.

FIG.6is a diagram illustrating a configuration example of a semiconductor relay device according to a second variation. In this variation, the semiconductor relay device1has a timing unit (TIMER)25. The timing unit (measuring unit)25starts timing when, for example, the signal Vin changes from low level to high level, and outputs a signal indicating the timing result to the oscillator unit20.

The oscillator unit20changes the frequency of the oscillation signal CLK depending on the signal input from the timing unit25. When a predetermined time has elapsed after the change of the signal Vin from low level to high level, the oscillator unit20lowers the frequency of the oscillation signal CLK. Note that the timing unit25may start time keeping when the oscillator unit20starts outputting the oscillation signal CLK, and output a signal indicating the timing result to the oscillator unit20. In this case, the oscillator unit20may lower the frequency of the oscillation signal CLK when a predetermined time has elapsed after the start of the output of the oscillation signal CLK.

The semiconductor relay device1according to this variation shifts the frequency of the oscillation signal CLK depending on the timing result by the timing unit25. Therefore, it is possible to mitigate radiation noise by lowering the frequency of the oscillation signal CLK. In addition, it is possible to reduce power consumption of the semiconductor relay device1.

Although configuration examples of the inductor unit40and the driving unit30have been described in the above embodiment and variations, they are merely examples. For example, the number of inductors of the inductor unit40and the arrangement thereof, and the number of transistors of the driving unit30and the arrangement thereof are not limited to the above examples. As illustrated inFIG.7, four inductors L1ato L1dmay be arranged as primary-side inductors L1, and four transistors36ato36dmay be arranged for controlling the four inductors, respectively. Furthermore, the control unit31may change control of the inductor unit40by the supply unit35depending on the timing result by the timing unit25.

When the signal Vin changes from low level to high level, the control unit31may turn only the transistor36aand the transistor36damong the four transistors to the ON state so as to perform, for a first period, power supply to the inductors L1aand L1bby the transistor36aand power supply to the inductors L1cand L1dby the transistor36d. In this first period, the four primary-side inductors L1are driven and thereby sufficient current is supplied to the secondary side. Thus, it is possible to quickly charge the gates of the transistors of the connecting unit90to switch the connecting unit90to the ON state. It is possible to shorten the time from when the signal Vin changes to high level until the connecting unit90is switched to the ON state.

For a second period following the first period, the control unit31may turn only the transistor36band the transistor36camong the four transistors to the ON state so as to perform power supply to the inductor L1bby the transistor36band power supply to the inductor L1cby the transistor36c. In this second period, the two primary-side inductors L1supply power to the two secondary-side inductors L2and thereby higher voltage can be generated on the secondary side than in the first period, so that higher voltage is applied to the gates of the transistors of the connecting unit90. This makes it possible to lower the on-resistance of the transistors of the connecting unit90and to stably maintain the ON state.

Note that, as illustrated inFIG.8, two inductors L1aand L1dmay be arranged as primary-side inductors L1. In this configuration, energy may be accumulated in the primary-side inductors L1when the transistors36are in the ON state, and the energy may be transmitted to the secondary-side inductor L2when the transistors36are turned to the OFF state. In the example illustrated inFIG.8, the inductor unit40can function as a flyback transformer.

FIG.9is a diagram illustrating a configuration example of a semiconductor relay device according to a fourth variation. The semiconductor relay device1includes a sealing portion110and a wiring layer120. The sealing portion (sealing layer)110is in contact with the wiring layer120and is provided to insulate at least a part of each of a first semiconductor element201and a second semiconductor element202. The first semiconductor element201is, for example, a semiconductor chip provided with the oscillator unit20and the driving unit30. The second semiconductor element202is, for example, a semiconductor chip provided with the smoothing unit70and the charging and discharging unit80.

The wiring layer120includes a first wiring layer114provided with the primary-side inductor L1of the inductor unit40, an isolating layer115, and a second wiring layer116provided with the secondary-side inductor L2of the inductor unit40. The first wiring layer114and the second wiring layer116are laminated with the isolating layer115interposed between the first wiring layer114and the second wiring layer116.

The primary-side inductor L1and the secondary-side inductor L2may be spiral inductors (coils). In the example illustrated inFIG.9, the inductor unit40functions as a so-called coreless transformer. The primary-side inductor L1and the secondary-side inductor L2can be formed in a wiring process when the first semiconductor element201and the second semiconductor element202are mounted, allowing miniaturization of the semiconductor relay device1. The inductor unit40also functions with a configuration using a magnetic body.

The various embodiments and variations have been described above, but the present invention is not limited to the details thereof. Another mode conceivable within the technical idea of the present invention also falls within the scope of the present invention.

REFERENCE SIGNS LIST