阅读说明：本技术 电路基板、半导体装置、电力转换装置及移动体 (Circuit board, semiconductor device, power conversion device, and moving object ) 是由 福岛裕太 于 2019-02-25 设计创作，主要内容包括：与第2电子部件是否发热无关地,独立地通过目视来容易地确认第1电子部件是否发热。或者,通过目视来容易地确认电路基板是否被暴露于热。第1电子部件以及第2电子部件安装于印刷基板之上。示温性树脂与第1电子部件接触,但不与第2电子部件接触。在温度上升的情况下,示温性树脂产生视觉性的变化。或者,电子部件安装于印刷基板之上。示温性树脂与印刷基板接触,但不与电子部件接触。在温度上升的情况下,示温性树脂产生视觉性的变化。(Whether or not the 1 st electronic component generates heat can be easily confirmed by visual observation independently of whether or not the 2 nd electronic component generates heat. Alternatively, whether or not the circuit board is exposed to heat can be easily confirmed by visual inspection. The 1 st electronic component and the 2 nd electronic component are mounted on the printed board. The temperature indicating resin is in contact with the 1 st electronic component but not in contact with the 2 nd electronic component. When the temperature rises, the temperature indicating resin changes visually. Alternatively, the electronic component is mounted on the printed board. The temperature indicating resin is in contact with the printed circuit board but not in contact with the electronic component. When the temperature rises, the temperature indicating resin changes visually.)

1. A circuit board (1) has:

a printed substrate (10);

a 1 st electronic component (101) mounted on the printed board (10);

a 2 nd electronic component (102) mounted on the printed board (10); and

and a temperature indicating resin (12) which is in contact with the 1 st electronic component (101) but not in contact with the 2 nd electronic component (102), and which undergoes a visual change when the temperature rises.

2. The circuit substrate (1) according to claim 1,

the 1 st electronic component (101) is an electronic component which does not generate heat during normal operation,

the 2 nd electronic component (102) generates heat during normal operation.

3. The circuit substrate (1) according to claim 1,

the 1 st electronic component (101) is a passive component.

4. A circuit board (2) has:

a printed substrate (10);

an electronic component (11) mounted on the printed circuit board (10); and

and a temperature indicating resin (12) which is in contact with the printed board (10) but not in contact with the electronic component (11), and which undergoes a visual change when the temperature rises.

5. Circuit substrate (1, 2) according to any one of claims 1 to 4,

the temperature indicating resin (12) has:

a resin (110); and

a wax (111) buried by the resin (110).

6. Circuit substrate (1, 2) according to claim 5,

the wax (111) is a granular wax.

7. Circuit substrate (1, 2) according to claim 5,

the wax (111) is a plate-like wax.

8. Circuit substrate (1, 2) according to claim 5,

the wax (111) is a flake-like wax.

9. A semiconductor device (3) has:

-a circuit substrate (1, 2) according to any of claims 1 to 4; and

and a housing (31) having an opening (300) facing the temperature indicating resin (12).

10. A semiconductor device (3) has:

-a circuit substrate (1, 2) according to any of claims 1 to 4; and

a semiconductor element (30) having a wide band gap semiconductor.

11. A power conversion device (41) has:

a main conversion circuit (400) having a semiconductor device, the main conversion circuit (400) converting and outputting input power;

a drive circuit (401) that outputs a drive signal for driving the semiconductor device to the semiconductor device; and

a control circuit (402) that outputs a control signal that controls the drive circuit (401) to the drive circuit (401),

at least one of the main conversion circuit (400), the drive circuit (401) and the control circuit (402) has the circuit substrate (1, 2) of any one of claims 1 to 4.

12. A mobile body (5) having the power conversion device (41) according to claim 11.

Technical Field

The present invention relates to a circuit board. The present invention also relates to a semiconductor device having a circuit board, a power conversion device, and a mobile object.

Background

In many cases, a circuit board includes a printed circuit board and a plurality of electronic components. A plurality of electronic components are mounted on the printed substrate.

In order to visually confirm the temperature of an object, a method of applying a material that changes visually when the temperature rises to the object has been proposed.

For example, in the technique described in patent document 1, in order to indicate whether or not the surface exceeds a threshold temperature, a composition is disposed in the vicinity of the surface (page 194, right lower column, lines 12 to 14). If the surface exceeds the threshold temperature, the composition becomes transparent, and if the surface is less than or equal to the threshold temperature, the composition becomes opaque (page 194, bottom right column, lines 14-16). The composition comprises a transparent flexible base material and an indicating material dispersed in the base material (page 195, upper right column, line 1-line 3). The indicating material is granular (page 196, upper left column, lines 7-8). The indicating material may be wax (page 196, upper right column, lines 5-6).

In addition, in order to improve insulation, moisture resistance, and the like of the circuit board, a method of coating the circuit board has been proposed.

For example, in the technique described in patent document 2, a portion of an electronic circuit constituted by a substrate, which lacks insulation and moisture resistance, is covered with a thermoplastic resin (page 186, upper right column, line 18 to page 186, lower left column, line 7).

Patent document 1: japanese laid-open patent publication No. 1-112123

Patent document 2: japanese laid-open patent publication No. 59-126643

Disclosure of Invention

It is sometimes required to visually confirm whether or not a specific electronic component included in a plurality of electronic components mounted on a printed circuit board generates heat. For example, in order to determine whether an electronic component that does not generate heat during normal operation is a normal component or an abnormal component, it is sometimes required to visually confirm whether the electronic component that does not generate heat during normal operation generates heat. In this case, by bringing a material that changes visually when the temperature rises into contact with a specific electronic component in advance, it is possible to visually confirm whether or not the specific electronic component generates heat. However, heat generated by electronic components other than the specific electronic component may be conducted to the material, and it may not be possible to appropriately confirm whether or not the specific component generates heat. For example, the heat generated by the electronic component that generates heat during normal operation may be transmitted to the material, and it may not be possible to appropriately confirm whether or not the electronic component that does not generate heat during normal operation generates heat.

The above-described problem is conspicuously manifested in the case where the circuit board is a control board for controlling the power semiconductor element. The above problem is remarkably manifested in the case where the circuit board is a control board for controlling the power semiconductor element because the control board for controlling the power semiconductor element is often a product produced in large numbers and in small numbers, and therefore, in the case where the circuit board is a control board for controlling the power semiconductor element, the mounting position of the electronic component often differs depending on the kind of the circuit board, and the time required for determining the presence or absence of a failure of the circuit board tends to become long.

In addition, it is sometimes required to visually confirm whether or not the circuit board is exposed to heat. For example, in order to identify whether or not a thermal stress test is performed on the circuit board, it is sometimes required to visually confirm whether or not the circuit board is exposed to heat. In this case, by bringing a material that changes visually when the temperature rises into contact with the circuit board in advance, it is possible to visually confirm whether or not the circuit board is exposed to heat. However, heat generated by any electronic component included in the plurality of electronic components may be conducted to the material, and it may not be possible to appropriately confirm whether or not the circuit board is exposed to heat. For example, heat generated by the electronic component, which generates heat during normal operation, may be conducted to the material, and it may not be possible to appropriately confirm whether or not the circuit board is exposed to heat.

The present invention has been made in view of these problems. The present invention aims to provide a circuit board which can easily confirm whether a 1 st electronic component generates heat by visual observation independently of whether a 2 nd electronic component generates heat. Another object of the present invention is to provide a circuit board that can easily confirm whether or not a circuit board is exposed to heat by visual observation independently of whether or not an electronic component generates heat.

The present invention is directed to a circuit board.

In the 1 st aspect of the present invention, the circuit board includes a printed circuit board, a 1 st electronic component, a 2 nd electronic component, and a temperature indicating resin. The 1 st electronic component and the 2 nd electronic component are mounted on the printed board. The temperature indicating resin is in contact with the 1 st electronic component but not in contact with the 2 nd electronic component. When the temperature rises, the temperature indicating resin changes visually.

In the 2 nd aspect of the present invention, the circuit board includes a printed circuit board, an electronic component, and a temperature indicating resin. The electronic component is mounted on the printed substrate. The temperature indicating resin is in contact with the printed circuit board but not in contact with the electronic component. When the temperature rises, the temperature indicating resin changes visually.

The present invention is also directed to a semiconductor device, a power conversion device, and a mobile body.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the 1 st aspect of the present invention, the temperature indicating resin does not visually change when the 2 nd electronic component generates heat, but visually changes when the 1 st electronic component generates heat. Therefore, whether or not the 1 st electronic component generates heat can be independently confirmed by visual observation regardless of whether or not the 2 nd electronic component generates heat.

According to the 2 nd aspect of the present invention, the temperature indicating resin does not visually change when the electronic component generates heat, but visually changes when the circuit board is exposed to heat. Therefore, whether or not the circuit board is exposed to heat can be independently confirmed by visual observation regardless of whether or not the electronic component generates heat.

The objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description and the accompanying drawings.

Drawings

Fig. 1 is a cross-sectional view schematically illustrating a circuit board according to embodiment 1.

Fig. 2 is an enlarged cross-sectional view schematically showing a part of the circuit board of embodiment 1.

Fig. 3 is an enlarged cross-sectional view schematically showing a part of the circuit board of embodiment 1.

Fig. 4 is an enlarged cross-sectional view schematically showing a part of the circuit board of embodiment 1.

Fig. 5 is a plan view schematically illustrating a circuit board according to embodiment 2.

Fig. 6 is a diagram schematically illustrating a semiconductor device according to embodiment 3.

Fig. 7 is a block diagram showing a configuration of a power conversion system according to embodiment 4.

Fig. 8 is a side view schematically illustrating the mobile unit according to embodiment 5.

Fig. 9 is a cross-sectional view schematically illustrating a circuit board of a reference example.

Detailed Description

1 embodiment mode 1

Fig. 1 is a cross-sectional view schematically illustrating a circuit board according to embodiment 1.

The circuit board 1 of embodiment 1 illustrated in fig. 1 includes a printed circuit board 10 and a plurality of electronic components 11.

A plurality of electronic components 11 are mounted on the printed substrate 10. The mounted electronic components 11 are electrically connected to a wiring pattern provided on the printed board 10. This makes it possible to configure an electronic circuit including a plurality of electronic components 11 and a wiring pattern provided on the printed circuit board 10.

The plurality of electronic components 11 are active components or passive components, respectively. The plurality of electronic components 11 are transistors, diodes, Integrated Circuits (ICs), capacitors, coils, resistors, inductors, transformers, and the like.

The plurality of electronic components 11 include a 1 st electronic component 101 and a 2 nd electronic component 102. The 1 st electronic component 101 and the 2 nd electronic component 102 have different heat generation characteristics from each other.

The circuit board 1 includes a temperature indicating resin 12.

When the temperature of the temperature indicating resin 12 increases, the visual change occurs. The temperature indicating resin 12 is applied on the 1 st electronic component 101 but not on the 2 nd electronic component 102. Therefore, the temperature indicating resin 12 is in contact with the 1 st electronic component 101 but not in contact with the 2 nd electronic component 102. Thus, even if the 2 nd electronic component 102 generates heat, the temperature indicating resin 12 does not change visually, but when the 1 st electronic component 101 generates heat, the temperature indicating resin changes visually. Therefore, whether or not the 1 st electronic component 101 generates heat can be independently confirmed by visual observation regardless of whether or not the 2 nd electronic component 102 generates heat.

The 1 st electronic component 101 is preferably an electronic component that does not generate heat during normal operation. The 2 nd electronic component 102 is preferably an electronic component that generates heat during normal operation.

When the 1 st electronic component 101 which does not generate heat during normal operation is a normal component, the 1 st electronic component 101 does not generate heat, and the temperature indicating resin 12 which is in contact with the 1 st electronic component 101 does not change visually. On the other hand, when the 1 st electronic component 101 that does not generate heat during normal operation is an abnormal component, the 1 st electronic component 101 may generate heat, and the temperature indicating resin 12 in contact with the 1 st electronic component 101 may change visually. However, the state of the temperature indicating resin 12 is not affected by heat generation of the 2 nd electronic component 102 that generates heat during normal operation. Thus, it is possible to visually confirm whether or not the 1 st electronic component 101 that does not generate heat during normal operation is an abnormal component. In addition, the confirmation of whether or not the 1 st electronic component 101 that does not generate heat during normal operation is an abnormal component is not affected by the heat generation of the 2 nd electronic component 102 that generates heat during normal operation.

When it is possible to visually confirm whether or not the 1 st electronic component 101 that does not generate heat during normal operation is an abnormal component, a defective product can be found as soon as possible in the middle of the production of the circuit board 1. This can improve the quality of the circuit board 1 and reduce the cost of the circuit board 1. In addition, the time required to investigate the cause of the failure of the circuit board 1 can be shortened, and the work for investigating the cause of the failure of the circuit board 1 can be simplified. These contribute to improving the productivity of the circuit substrate 1.

The above-described effects are remarkably exhibited when the circuit board 1 is a control board for controlling the power semiconductor element. The above-described effect is remarkably exhibited when the circuit board 1 is a control board for controlling the power semiconductor element, because the control board for controlling the power semiconductor element is often a product produced in a large number of varieties and in a small amount, and therefore, when the circuit board 1 is a control board for controlling the power semiconductor element, the mounting position of the electronic component often differs depending on the variety, and the time required for determining the presence or absence of a failure of the circuit board 1 tends to become long.

The 1 st electronic component 101 is preferably a passive component. When the 1 st electronic component 101 is a passive component, the temperature indicating resin 12 only needs to be applied to the passive component, and therefore, the time required for the operation of applying the temperature indicating resin 12 can be shortened, and the amount of the temperature indicating resin 12 used can be reduced. This contributes to cost reduction of the circuit substrate 1.

Fig. 2, 3, and 4 are enlarged cross-sectional views schematically showing a part of the circuit board of embodiment 1. Fig. 2, 3 and 4 show examples 1, 2 and 3 of the temperature indicating resin, respectively.

As shown in fig. 2, 3, and 4, the temperature indicating resin 12 includes a resin 110 and a temperature indicating material 111. The temperature indicating material is also referred to as an indicating material or the like.

The temperature indicating material 111 is buried in the resin 110. The temperature indicating material 111 reacts at a temperature equal to or higher than a specific temperature higher than normal temperature. For example, the temperature indicating material 111 melts at a temperature greater than or equal to the particular temperature. When the 1 st electronic component 101 generates heat, the heat generated by the 1 st electronic component 101 is conducted to the temperature indicating material 111, the temperature of the temperature indicating material 111 becomes a temperature equal to or higher than the specific temperature, and the temperature indicating material 111 melts. As a result, when the temperature of the temperature indicating material 111 is returned to a temperature lower than the specific temperature and the temperature indicating material 111 is solidified, the temperature indicating resin 12 is visually changed.

The resin 110 is a polyolefin resin or the like.

The temperature indicating material 111 is wax or the like.

In example 1 illustrated in fig. 2, the temperature indicating material 111 is granular wax. When the temperature indicating material 111 is a granular wax, the temperature indicating material 111 is stirred into the resin before curing to prepare a mixture of the resin before curing and the temperature indicating material 111, and the prepared mixture is applied to cure the applied mixture.

In example 2 illustrated in fig. 3, the temperature indicating material 111 is wax in a plate shape. In this case, since it is not necessary to stir the temperature indicating material 111 into the resin before curing, the operation of applying the temperature indicating resin 12 can be simplified. This contributes to improvement in the productivity of the circuit substrate 1.

In example 3 illustrated in fig. 4, the temperature indicating material 111 is wax in a sheet form. When the temperature indicating material 111 is a wax in a sheet form, the temperature indicating resin 12 has an improved sensitivity to temperature changes.

2 comparison between embodiment 1 and reference example

Fig. 9 is a cross-sectional view schematically illustrating a circuit board of a reference example. Fig. 9(a) illustrates a state where neither the 1 st electronic component nor the 2 nd electronic component generates heat. Fig. 9(b) illustrates a state where the 1 st electronic component does not generate heat but the 2 nd electronic component generates heat.

In the circuit board 1 of embodiment 1 shown in fig. 1, the temperature indicating resin 12 is applied on the 1 st electronic component 101 but not applied on the 2 nd electronic component 102. Therefore, the temperature indicating resin 12 is in contact with the 1 st electronic component 101 but not in contact with the 2 nd electronic component 102. Thus, the temperature indicating resin 12 does not change visually when the 2 nd electronic component 102 generates heat, but the temperature indicating resin changes visually when the 1 st electronic component 101 generates heat. Therefore, whether or not the 1 st electronic component 101 generates heat can be independently confirmed by visual observation regardless of whether or not the 2 nd electronic component 102 generates heat.

In contrast, in the circuit board 9 of the reference example shown in fig. 9, the temperature indicating resin 12 is applied on the 1 st electronic component 101 and on the 2 nd electronic component 102. Therefore, the temperature indicating resin 12 is in contact with the 1 st electronic component 101 and the 2 nd electronic component 102. As a result, when the 2 nd electronic component 102 generates heat, the temperature indicating resin 12 visually changes as illustrated in fig. 9(b) regardless of whether the 1 st electronic component 101 generates heat. Therefore, it is not possible to appropriately check whether or not the 1 st electronic component 101 generates heat by visual inspection independently of whether or not the 2 nd electronic component 102 generates heat.

3 embodiment 2

Fig. 5 is a plan view schematically illustrating a circuit board according to embodiment 2. Fig. 5(a) shows a state before the thermal stress test is performed on the circuit board. Fig. 5(b) shows a state after the thermal stress test was performed on the circuit board.

The circuit board 2 of embodiment 2 shown in fig. 5 is different from the circuit board 1 of embodiment 1 shown in fig. 1 mainly in the following points of difference. As for points not described, the circuit board 2 according to embodiment 2 also has the same configuration as that of the circuit board 1 according to embodiment 1.

In the circuit board 1 of embodiment 1, the temperature indicating resin 12 is applied on the 1 st electronic component 101 included in the plurality of electronic components 11, but is not applied on the 2 nd electronic component 102 included in the plurality of electronic components 11. Therefore, the temperature indicating resin 12 is in contact with the 1 st electronic component 101 but not in contact with the 2 nd electronic component 102.

In contrast, in the circuit board 2 of embodiment 2, the temperature indicating resin 12 is applied on the printed board 10, but not on the plurality of electronic components 11. Therefore, the temperature indicating resin 12 is in contact with the printed board 10 but not in contact with the plurality of electronic components 11.

As a result, when any of the plurality of electronic components 11 generates heat, the temperature indicating resin 12 does not change visually, but when the circuit board 1 is exposed to heat, the temperature indicating resin 12 changes visually as illustrated in fig. 5 (b). Therefore, whether or not the circuit board 1 is exposed to heat can be independently checked visually regardless of whether or not any of the plurality of electronic components 11 generates heat.

The temperature indicating resin 12 is in contact with the printed substrate 10 but not in contact with the plurality of electronic components 11. Therefore, the temperature indicating resin 12 is in contact with a portion where the temperature rises when the thermal stress test is performed on the circuit board 1, but is not in contact with a portion where the temperature may rise other than when the thermal stress test is performed. Therefore, when the circuit board 1 is subjected to the thermal stress test, the heat applied to the circuit board 1 by the thermal stress test is conducted to the temperature indicating material 111, the temperature of the temperature indicating material 111 becomes higher than the normal temperature, and the temperature indicating material 111 melts. As a result, when the temperature of the temperature indicating material 111 returns to the normal temperature and the temperature indicating material 111 solidifies, the temperature indicating resin 12 changes visually. Therefore, whether or not the circuit board 1 is exposed to heat can be visually checked, and whether or not the circuit board 1 is subjected to the thermal stress test can be recognized. This helps prevent the process of performing the thermal stress test from being omitted when the circuit substrate 1 is manufactured.

Embodiment 3

Fig. 6 is a diagram schematically illustrating a semiconductor device according to embodiment 3.

The semiconductor device 3 of embodiment 3 illustrated in fig. 6 is a power semiconductor, and as illustrated in fig. 6(a), is a semiconductor module, a semiconductor discrete component, or the like having a semiconductor element 30. The semiconductor element 30 is a switching element, a diode, or the like.

The semiconductor device 3 includes the circuit board 2 of embodiment 2. The semiconductor device 3 may have the circuit board 1 of embodiment 1 instead of the circuit board 2 of embodiment 2. The circuit board 2 is built in the semiconductor device 3.

The semiconductor device 3 has a housing 31. The case 31 preferably has an opening 300 facing the temperature indicating resin 12. The opening 300 is an opening for checking the state of the temperature indicating resin 12. Therefore, the temperature indicating resin 12 can be visually confirmed from the outside of the case 31 through the opening 300. Thus, after the semiconductor device 3 is assembled and the circuit board 2 is built in the semiconductor device 3, the state of the temperature indicating resin 12 can be checked, and whether or not the circuit board 1 is exposed to heat can be checked visually, whereby whether or not the thermal stress test is performed on the circuit board 1 can be recognized. Therefore, the state of the temperature indicating resin 12 can be used as proof of showing that the thermal stress test has been performed on the circuit board 1 to the shipment destination of the semiconductor device 3.

The semiconductor element 30 is preferably a semiconductor element having a wide band gap semiconductor. The wide band gap semiconductor is silicon carbide (SiC), gallium nitride (GaN), diamond (C), or the like. Wide band gap semiconductors such as silicon carbide (SiC), gallium nitride (GaN), and diamond (C) have a band gap wider than that of semiconductors such as silicon (Si). In addition, the semiconductor element having a wide band gap semiconductor can stably ensure the ultrasonic bonding life of the electrode even when used in a high-temperature environment. In addition, the space occupied by the semiconductor element 30 can be reduced, and the semiconductor device 3 can be made smaller and lighter.

5 embodiment 4

In the present embodiment, the circuit board 1 according to embodiment 1, the circuit board 2 according to embodiment 2, or the semiconductor device 3 according to embodiment 3 described above is applied to a power conversion device. The application of the circuit board 1 according to embodiment 1, the circuit board 2 according to embodiment 2, or the semiconductor device 3 according to embodiment 3 is not limited to a specific power conversion device, but hereinafter, as embodiment 4, a case will be described in which the circuit board 1 according to embodiment 1, the circuit board 2 according to embodiment 2, or the semiconductor device 3 according to embodiment 3 is applied to a three-phase inverter.

Fig. 7 is a block diagram showing a configuration of a power conversion system according to embodiment 4.

The power conversion system shown in fig. 7 includes a power source 40, a power conversion device 41, and a load 42. The power source 40 is a dc power source and supplies dc power to the power conversion device 41. The power supply 40 may be configured by various power supplies, for example, a DC system, a solar cell, and a storage battery, or may be configured by a rectifier circuit or an AC/DC converter connected to an AC system. The power supply 40 may be configured by a DC/DC converter that converts DC power output from the DC system into predetermined power.

The power conversion device 41 is a three-phase inverter connected between the power source 40 and the load 42, and converts dc power supplied from the power source 40 into ac power and supplies the ac power to the load 42. As shown in fig. 7, the power conversion device 41 includes: a main converter circuit 400 that converts dc power into ac power and outputs the ac power; a drive circuit 401 that outputs a drive signal for driving each switching element of the main converter circuit 400; and a control circuit 402 that outputs a control signal for controlling the drive circuit 401 to the drive circuit 401. At least one of the main converter circuit 400, the driver circuit 401, and the control circuit 402 may have the circuit board 1 of embodiment 1 or the circuit board 2 of embodiment 2.

The load 42 is a three-phase motor driven by ac power supplied from the power conversion device 41. The load 42 is not limited to a specific application, and is an electric motor mounted on various electric devices, for example, a motor for a hybrid car, an electric car, a railway vehicle, an elevator, or an air conditioner.

The power converter 41 will be described in detail below. The main converter circuit 400 includes a switching element and a flywheel diode (not shown), and converts dc power supplied from the power source 40 into ac power by turning on and off the switching element, and supplies the ac power to the load 42. Although there are various specific circuit configurations of the main converter circuit 400, the main converter circuit 400 according to the present embodiment is a 2-level three-phase full bridge circuit and can be configured with 6 switching elements and 6 freewheeling diodes connected in reverse parallel to the switching elements. Each switching element of the main converter circuit 400 may have the circuit board 1 according to embodiment 1 or the circuit board 2 according to embodiment 2. The semiconductor device 3 according to embodiment 3 described above may be applied to each switching element of the main converter circuit 400. The 6 switching elements 2 by 2 are connected in series to constitute upper and lower arms, and each of the upper and lower arms constitutes each phase (U-phase, V-phase, W-phase) of the full bridge circuit. Further, 3 output terminals of main converter circuit 400, which are output terminals of the upper and lower arms, are connected to load 42.

The drive circuit 401 generates a drive signal for driving the switching elements of the main converter circuit 400, and supplies the drive signal to the control electrodes of the switching elements of the main converter circuit 400. Specifically, a drive signal for turning the switching element on and a drive signal for turning the switching element off are output to the control electrode of each switching element in accordance with a control signal from a control circuit 402 described later. When the switching element is maintained in the on state, the drive signal is a voltage signal (on signal) greater than or equal to the threshold voltage of the switching element, and when the switching element is maintained in the off state, the drive signal is a voltage signal (off signal) less than or equal to the threshold voltage of the switching element.

The control circuit 402 controls the switching elements of the main converter circuit 400 to supply a desired power to the load 42. Specifically, the time (on time) at which each switching element of the main converter circuit 400 should be turned on is calculated based on the power to be supplied to the load 42. For example, the main converter circuit 400 can be controlled by PWM control for modulating the on time of the switching element in accordance with the voltage to be output. Then, a control command (control signal) is output to the drive circuit 401 so that an on signal is output to the switching element to be turned on at each time point, and an off signal is output to the switching element to be turned off. The drive circuit 401 outputs an on signal or an off signal as a drive signal to the control electrode of each switching element in accordance with the control signal.

In the power converter according to the present embodiment, at least one of the main converter circuit 400, the driver circuit 401, and the control circuit 402 has the circuit board 1 according to embodiment 1 or the circuit board 2 according to embodiment 2 described above, and therefore, it is possible to achieve an effect of visually checking whether or not the 1 st electronic component 101 generates heat independently of whether or not the 2 nd electronic component 102 generates heat, or visually checking whether or not the circuit board 2 is exposed to heat independently of whether or not any of the plurality of electronic components 11 generates heat.

In the present embodiment, an example in which the circuit board 1 of embodiment 1, the circuit board 2 of embodiment 2, or the semiconductor device 3 of embodiment 3 is applied to a 2-level three-phase inverter has been described, but the application of the circuit board 1 of embodiment 1, the circuit board 2 of embodiment 2, or the semiconductor device 3 of embodiment 3 is not limited thereto, and can be applied to various power conversion devices. In the present embodiment, a 2-level power converter is used, but a 3-level or multi-level power converter may be used, and when power is supplied to a single-phase load, the circuit board 1 of embodiment 1, the circuit board 2 of embodiment 2, or the semiconductor device 3 of embodiment 3 may be applied to a single-phase inverter. In addition, when power is supplied to a DC load or the like, the circuit board 1 according to embodiment 1, the circuit board 2 according to embodiment 2, or the semiconductor device 3 according to embodiment 3 may be applied to a DC/DC converter or an AC/DC converter.

The power conversion device to which the circuit board 1 according to embodiment 1, the circuit board 2 according to embodiment 2, or the semiconductor device 3 according to embodiment 3 is applied is not limited to the case where the load is a motor, and may be used as a power supply device for an electric discharge machine, a laser machine, an induction heating cooker, or a non-contactor power supply system, and may also be used as a power conditioner for a solar power generation system, a power storage system, or the like.

When a semiconductor device that is small and light in weight is applied to the power converter 41 according to embodiment 4, the cooler and the like of the main converter circuit 400 can be made small and light in weight, the reliability of the power converter 41 can be improved, and the energy consumed by the main converter circuit 400 can be reduced.

6 embodiment 5

Fig. 8 is a side view schematically illustrating the mobile unit according to embodiment 5.

The moving body 5 illustrated in fig. 8 is a train. The mobile body 5 may be a mobile body other than a train. For example, the moving body 5 may be an automobile, a ship, an airplane, an electric power assisted bicycle, an electric wheelchair, or the like.

The mobile body 5 includes the power conversion device 41 of embodiment 4. The moving body 5 drives a motor or the like with the electric power converted by the power conversion device 41.

When the semiconductor device that is reduced in size and weight is applied to the power conversion device 41 according to embodiment 4, the mobile body 5 can be reduced in size and weight, the efficiency of the mobile body 5 can be improved, and the performance of the mobile body 5 can be improved.

The present invention can be freely combined with or appropriately modified or omitted from the respective embodiments within the scope of the present invention.

The present invention has been described in detail, but the above description is illustrative in all aspects, and the present invention is not limited thereto. It is understood that numerous modifications, not illustrated, can be devised without departing from the scope of the invention.

Description of the reference numerals

The circuit board comprises a circuit board 1, a printed circuit board 10, a plurality of electronic components 11, a temperature indicating resin 12, a temperature indicating material 101, a circuit board 1, an electronic component 2 102, a resin 110, a temperature indicating material 111, a circuit board 2, a semiconductor device 3, a shell 31, an opening 300, a power conversion device 41, a main conversion circuit 400, a driving circuit 401, a control circuit 402 and a moving body 5.