The present invention relates to an internal wiring structure of a power semiconductor module, and particularly relates to an effective technique to be applied to a power semiconductor module having a high output density in which a large current flows in a main circuit inside the module.
In recent years, because of a demand for higher output density of an inverter device as a power conversion device, reduction in size and in weight of a power conversion device is in progress, and there is also a strong demand for higher output density, reduction in size and in weight of a power semiconductor module mounted on a power conversion device.
The power conversion device has a function of converting DC power supplied from a DC power supply into AC power to be supplied to an AC electric load such as a rotating electrical machine, or a function of converting AC power generated by the rotating electrical machine into DC power to be supplied to the DC power supply. In order to achieve such a conversion function, the power conversion device includes an inverter circuit having a power semiconductor module, and the power semiconductor module repeats conduction operation and cutoff operation to perform power conversion from DC power to AC power or from AC power to DC power.
The power semiconductor module includes an input terminal that controls conduction operation and cutoff operation. For example, in a case of an element having an insulated gate control terminal such as a metal-oxide-semiconductor field effect transistor (Metal-Oxide-Semiconductor Field Effect Transistor, hereinafter MOSFET) or an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, hereinafter IGBT), it is possible to amplify and control a main voltage more than several tens of times to several hundreds of times and a main current more than several 1000 times by inputting a voltage signal of several V to several tens of V.
On the other hand, even a weak noise to the insulated gate control terminal greatly affects an output due to amplification, and thus countermeasures are required.
As a background art of the present technical field, for example, there is such a technique as recited in PTL 1. PTL 1 discloses “a power module including: a first control electrode 12 electrically connected to a control signal input electrode; and a second control electrode 11 electrically connected to a control signal reference electrode, in which a magnetic shield film is bonded to the first control electrode and the second control electrode so as to surround them”.
In addition, PTL 2 discloses “a power semiconductor module including a gate pattern 37 having an induction generation pattern 34 that is not shielded by an emitter pattern 28 and extends in a direction parallel to a direction in which a current of a main electrode terminal 20 flows”.
In a power semiconductor module mounted on such a power conversion device as described above, an induction magnetic field generated by a large current flowing through a main circuit in the power semiconductor module affects a signal wiring of a gate circuit or the like. In particular, in a case of positive feedback in which an induced current generated by an induction magnetic field is in the same direction as that of a gate drive signal, since turn-on is accelerated at the time of switching, a problem occurs that a voltage jumps due to transient response, or a transient current flows. Such influence of positive feedback increases the transient response, which causes malfunction of the power semiconductor module and breakdown due to excessive voltage and current.
Since such a magnetic shield film as described above is bonded later, PTL 1 has a problem that the number of manufacturing steps increases.
Further, while reciting the influence of positive feedback or negative feedback, PTL 2 mentions nothing about a shield structure that directly shields an induction magnetic field.
Therefore, an object of the present invention is to provide a highly reliable power semiconductor module in which a gate terminal and an emitter sense terminal are disposed adjacent to each other and a main circuit wiring is disposed in the vicinity thereof, the power semiconductor module being capable of effectively suppressing an influence of an induction magnetic field generated by a current flowing through the main circuit wiring on the gate terminal and the emitter sense terminal.
In order to solve the above problems, the present invention includes: a gate terminal to which a control signal is input; a reference potential terminal disposed adjacent to the gate terminal with a predetermined gap; a main circuit wiring disposed in the vicinity of the gate terminal and the reference potential terminal; and an electromagnetic shield that is disposed between the gate terminal and the reference potential terminal and shields an induction magnetic field generated by a current flowing through the main circuit wiring, in which the electromagnetic shield is formed integrally with at least one of the gate terminal and the reference potential terminal, and between the gate terminal and the reference potential terminal, a gap not shielded by the electromagnetic shield when viewed from a direction in which a magnetic flux of the induction magnetic field interlinks with the electromagnetic shield, is 1 mm or less.
According to the present invention, a highly reliable power semiconductor module can be realized in which a gate terminal and an emitter sense terminal are disposed adjacent to each other and a main circuit wiring is disposed in the vicinity thereof, the power semiconductor module being capable of effectively suppressing an influence of an induction magnetic field generated by a current flowing through the main circuit wiring on the gate terminal and the emitter sense terminal.
As a result, it is possible to suppress an increase in transient response due to an influence of positive feedback at the time of switching and to prevent malfunction of the power semiconductor module and breakdown due to excessive voltage and current.
Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.
In the following, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and detailed description of overlapping parts is omitted.
A power semiconductor module according to a first embodiment of the present invention will be described with reference to
First, an internal wiring structure of the power semiconductor module according to the present embodiment will be described with reference to
As illustrated in
A diode chip 101 is connected in reverse parallel to each of the plurality of IGBT chips 100, and the diode chip 101 functions as a freewheeling diode.
In the upper arm part 20, a first insulating wiring board 5 of the upper arm part on which the plurality of IGBT chips 100 and the plurality of diode chips 101 are mounted and a second insulating wiring board 6 of the upper arm part on which the plurality of IGBT chips 100 and the plurality of diode chips 101 are mounted are connected in parallel to each other.
The first insulating wiring board 5 includes an emitter wiring part 22 for connecting an emitter part of the IGBT chip 100 and a collector wiring part 23 for connecting a collector part of the IGBT chip 100.
In addition, the second insulating wiring board 6 includes an emitter wiring part 24 for connecting the emitter part of the IGBT chip 100 and a collector wiring part 25 for connecting the collector part of the IGBT chip 100.
The collector wiring part 23 of the first insulating wiring board 5 and the collector wiring part 25 of the second insulating wiring board 6 are connected to a positive electrode terminal 3.
In addition, as control signal wirings for the IGBT chips 100 mounted on the first insulating wiring board 5 and the second insulating wiring board 6, connected to the upper arm part 20 are a gate terminal connection part 28a connected to a gate terminal 28 of the upper arm part and an emitter sense terminal connection part 29a connected to an emitter sense terminal 29 of the upper arm part.
In the lower arm part 10, a third insulating wiring board 7 of the lower arm part on which the plurality of IGBT chips 100 and the plurality of diode chips 101 are mounted and a fourth insulating wiring board 8 of the lower arm part on which the plurality of IGBT chips 100 and the plurality of diode chips 101 are mounted are connected in parallel to each other.
The third insulating wiring board 7 includes an emitter wiring part 12 for connecting the emitter part of the IGBT chip 100 and a collector wiring part 13 for connecting the collector part of the IGBT chip 100.
In addition, the fourth insulating wiring board 8 includes an emitter wiring part 14 for connecting the emitter part of the IGBT chip 100 and a collector wiring part 15 for connecting the collector part of the IGBT chip 100.
The emitter wiring part 12 of the third insulating wiring board 7 and the emitter wiring part 14 of the fourth insulating wiring board 8 are connected to a negative electrode terminal 4.
In addition, as control signal wirings for the IGBT chips 100 mounted on the third insulating wiring board 7 and the fourth insulating wiring board 8, connected to the lower arm part 10 are a gate terminal connection part 18a connected to a gate terminal 18 of the lower arm part and an emitter sense terminal connection part 19a connected to an emitter sense terminal 19 of the lower arm part.
Although the present embodiment and other embodiments are described with respect to an example in which an IGBT is used as the switching element, the present invention is not limited thereto, and a MOSFET may be used as the switching element.
In a case of a MOSFET, an emitter may be replaced with a source, and a collector may be replaced with a drain. The emitter sense terminal (19, 29) or a source sense terminal is also referred to as a reference potential terminal.
For comparison with the present embodiment (
In the power semiconductor module 1 of the present embodiment (
A difference between these shapes will be described with reference to
In the power semiconductor module, at the time of switching (turn-on) from the cutoff state to the conduction state, for example, in a case of an n-channel MOS gate, a current flows from a gate to an emitter in a gate-emitter circuit.
Therefore, in the conventional power semiconductor module 51, a loop current 104 is generated as indicated by a solid line in
In the conventional structure, since the induction magnetic field 103 passes through a gap G between the gate terminal 18 and the emitter sense terminal 19 of the loop current 104, an induced current flows.
Since a direction of the induced current is the same as a direction of the loop current 104 for a turn-on signal, positive feedback occurs to further accelerate the turn-on, so that the voltage jumps due to transient response or a transient current flows.
This causes a harmonic to be generated from strong distortion in inverter operation, or causes element breakdown due to a transient voltage or a transient current.
On the other hand, in the power semiconductor module 1 of the present embodiment, as illustrated in
The electromagnetic shield part 17 is desirably formed integrally with at least one of the gate terminal 18 and the emitter sense terminal 19.
It is preferable that the electromagnetic shield part 17 is installed so as to close the gap G when viewed from a direction in which a magnetic flux of the induction magnetic field 103 interlinks with the electromagnetic shield part 17, and is installed between the gate terminal 18 and the emitter sense terminal 19 so that the gap G not shielded by the electromagnetic shield part 17 is 1 mm or less.
The reason for this will be described with reference to
In
In
Therefore, when the gap between the gate terminal 18 and the emitter sense terminal 19 is 1 mm or less, it is possible to suppress an increase in the transient response due to positive feedback. When the gap is-2 mm or less (overlap is 2 mm or more), a more stable effect of suppressing the transient response can be obtained.
In addition, when an actual module is designed to have the gap of 0 mm, the gap can be 1 mm or less even when an error of about +1 mm, for example, due to a processing tolerance or an assembly tolerance of a terminal, is included. Therefore, an effect of effective electromagnetic shielding can be obtained. Furthermore, when the gap is designed to be minus, a higher effect can be obtained.
In the case of negative feedback, as illustrated in
With the structure of the present embodiment, shielding a configuration of negative feedback of a gate-emitter sense circuit approaches absence of feedback (feedback zero), which causes no increase in a transient response unlike in positive feedback, and enables an increase in a switch loss to be suppressed.
Although in
With the configuration of the power semiconductor module 1 of the present embodiment described in the foregoing, it is possible to realize a highly reliable power semiconductor module capable of effectively suppressing an influence of an induction magnetic field generated by a current flowing through the main circuit wiring on the gate terminal and the emitter sense terminal.
In addition to the control signals for the gate terminals 18 and 28 and the like, for example, a sense signal terminal (temperature/current (di/dt) detection) such as a current detection terminal indicated by reference numeral 27 or a thermistor terminal indicated by reference numeral 16 in
A power semiconductor module according to a second embodiment of the present invention will be described with reference to
As illustrated in
In other words, as illustrated in
As in the present embodiment, the electromagnetic shield part 17 may have a bent shape, and may not necessarily be on the same plane as the gate terminal 18 and the emitter sense terminal 19.
Even in a case where the electromagnetic shield part 17 is disposed as illustrated in
A power semiconductor module according to a third embodiment of the present invention will be described with reference to
A difference from the second embodiment is that the electromagnetic shield part 17 is not bent unlike the second embodiment, but is integrally formed on the same plane as the gate terminal 18 and the emitter sense terminal 19 as illustrated in
For example, as illustrated in
Note that also in the third embodiment, the electromagnetic shield part 17 need only be configured to have a part where a part of at least one of the gate terminal 18 and the emitter sense terminal 19 integrally extends to the other side. Specifically, the electromagnetic shield part 17 may include only a part integrally formed with the gate terminal 18, or may include only a part integrally formed with the emitter sense terminal 19.
Even in a case where the electromagnetic shield part 17 is installed as illustrated in
Note that the effect of shielding by the electromagnetic shield part 17 is greater at an electrode close to the main current wiring. Since an induction magnetic field is inversely proportional to the square of a distance, for example, in the first embodiment (
Further, although in the first embodiment, the gap width between the gate terminal 18 and the emitter sense terminal 19 is defined, in essence, the effect is exerted by a gap with a small area. For example, even if there exists a part which is partially broad (e.g., a notch or an expansion of a termination part) in terms of structure, the effect is exerted in a narrowed part.
In addition, although in the first embodiment, the description has been made assuming a configuration of a 2-in-1 type power semiconductor module, the same effect can be obtained even in a module having a different wiring such as a 1-in-1 type or a 6-in-1 type.
In addition, a main current causing an induced current of signal wiring is not limited to a main current wiring inside the module, but an adjacent external bus bar wiring connected to the module is also applicable, and the structure of the present invention is also effective for shielding an induced current of this wiring.
Note that the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the described configurations. In addition, a part of the configuration of a certain embodiment can be replaced with the configuration of another embodiment, and to the configuration of a certain embodiment, the configuration of another embodiment can be added. In addition, it is possible to add, delete, and replace other configurations with respect to a part of the configuration of each embodiment.
Number | Date | Country | Kind |
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2021-118515 | Jul 2021 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2022/019782 | 5/10/2022 | WO |