Semiconductor device and semiconductor system

Abstract

The present invention aims to provide a semiconductor device that can suppress the influence of heat on a gate driver and also suppress the risk of overvoltage occurrence. [Solution] In a semiconductor device having at least a semiconductor element that is a switching element and a gate driver for the semiconductor element, the semiconductor element and the gate driver are arranged inside a common housing, and a heat shielding section is provided to block heat transfer from the semiconductor element to the gate driver.

Description

[Technical field]

[0001] The present invention relates to a semiconductor device and a semiconductor system incorporating a semiconductor element, and more particularly to a semiconductor device and a semiconductor system capable of suppressing the occurrence of an overvoltage while suppressing the influence of heat on a gate driver. [Background technology]

[0002] A so-called component-embedded modularization technology is known, which stacks circuit boards on which semiconductor elements are mounted to mount semiconductor devices three-dimensionally at high density. In particular, when semiconductor elements such as IGBTs (insulated gate bipolar transistors) and MOSFETs (metal-oxide-semiconductor field effect transistors) having a switching function are modularized, the semiconductor elements and components of the electric circuit generate a relatively large amount of heat. Therefore, when a gate driver that controls the switching operation of the semiconductor elements is embedded in a substrate together with the semiconductor elements, a device is required to prevent the influence of heat from reaching the gate driver. For example, the semiconductor device disclosed in Patent Document 1 discloses an invention in which a switching module 300 consisting of IGBTs and MOSFETs and a gate driver 320 that drives and controls the switching module 300 are connected by a gate wiring bar 108. By connecting the switching module 300 and the gate driver 320 by the gate wiring bar 108, it is intended to prevent the influence of heat from the switching module 300 from reaching the gate driver 320.

[0003] Patent Document 2 discloses an electronic device having a first conductive layer 11 electrically connected to a power element 11a that is thermally coupled to a heat dissipation member 20, a second conductive layer 12 electrically connected to control elements (gate drivers) 12a and 12b that control the switching operation of the power element 11a, and a resin layer 13 in which the power element 11a is embedded between the first conductive layer 11 and the second conductive layer 12. The first conductive layer 11, the resin layer 13, and the second conductive layer 12 are laminated in this order from the side closest to the heat dissipation member 20. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] WO2019 / 044832 publication [Patent Document 2] Patent No. 6308275 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the configuration of Patent Document 1, the use of gate wiring bar 108 results in a long wiring length in the electric circuit, which increases the parasitic inductance component of the electric circuit, causing problems such as overvoltage. Also, in the configuration of Patent Document 2, power element 11a and control elements 12a and 12b are arranged close to each other, so the length of the wiring electrically connecting them is short, but there is a problem in that the heat generated by power element 11a affects control elements 12a and 12b. SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, an object of the present invention is to provide a semiconductor device capable of suppressing the effect of heat on a gate driver while also suppressing the risk of overvoltage occurrence. [Means for solving the problem]

[0006] The present inventors have discovered that the following semiconductor device can solve the above-mentioned problems in the conventional technology. A semiconductor device according to an embodiment of the present invention is a semiconductor device having at least a semiconductor element which is a switching element and a gate driver for the semiconductor element, characterized in that the semiconductor element and the gate driver are disposed inside a common housing and a heat shield is provided to prevent heat transfer from the semiconductor element to the gate driver. Effect of the Invention

[0007] According to the embodiment of the present invention configured as described above, by providing a heat shield for blocking heat transfer from the semiconductor element to the gate driver, it is possible to mitigate the effect of heat on the gate driver. Furthermore, by providing a heat shield, the semiconductor element and the gate driver can be arranged in close proximity to each other. This makes it possible to arrange the semiconductor element and the gate driver inside a common housing. This eliminates the need to make the electric circuit length longer than necessary, making it possible to avoid overvoltage caused by increased inductance. [Brief description of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view of a semiconductor device according to a first embodiment of the present invention. [Diagram 2] 1 is an enlarged cross-sectional view of a main portion of a first embodiment of the present invention. [Diagram 3] 1 is a partial circuit diagram of a semiconductor device according to a first embodiment of the present invention. [Figure 4] FIG. 5 is an enlarged cross-sectional view of a main part of a semiconductor device according to a second embodiment of the present invention. [Diagram 5] FIG. 11 is an enlarged cross-sectional view of a main part of a semiconductor device according to a third embodiment of the present invention. [Figure 6] FIG. 11 is an enlarged cross-sectional view of a main part of a semiconductor device according to a fourth embodiment of the present invention. [Figure 7] 1 is a block diagram showing an example of a control system employing a semiconductor device according to an embodiment; [Figure 8]1 is a circuit diagram showing an example of a control system employing a semiconductor device according to an embodiment of the present invention. [Figure 9] FIG. 11 is a block diagram showing another example of a control system employing the semiconductor device according to the embodiment of the present invention. [Figure 10] FIG. 11 is a circuit diagram showing another example of a control system employing the semiconductor device according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, several embodiments of the present invention will be described with reference to the drawings. Note that the same components are designated by the same reference numerals to avoid redundant description.

[0010] FIG. 1 is a cross-sectional view showing a first embodiment of a semiconductor device according to the present invention. As shown in FIG. 1, a semiconductor device 110 has first and second semiconductor elements 2 and 3 arranged on a circuit board 1. In this embodiment, the first semiconductor element 2 is a switching element such as an IGBT (Insulated Gate Bipolar Transistor) or a MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor), which is a power semiconductor element (switching element) having a switching function. In addition, the second semiconductor element 3 may be a diode such as an SBD (Schottky Barrier Diode) or a PiN diode, which is a semiconductor component. In the embodiment of the present invention, the first and second semiconductor elements are not limited to the above elements. In addition, a gate driver 4 is further arranged on the circuit board 1. The gate driver 4 is composed of an IC incorporating a drive circuit for controlling the switching operation of a gate electrode provided in the first semiconductor element 2.

[0011] Between the first semiconductor element 2 and the gate driver 4, a separation portion 5, which is a region that is not directly connected to the circuit board 1, is formed by a predetermined length. The separation portion 5 is formed, for example, by partially drilling or removing the flat circuit board 1.

[0012] The upper surfaces of the first and second semiconductor elements 2, 3 are connected to an upper wiring layer 8 through vias 7. The lower surfaces of the first and second semiconductor elements 2, 3 are connected to a lower wiring layer 10 through vias 9, and further connected to a lower wiring layer 12 through vias 11. The upper wiring layer 8 and the lower wiring layer 12 are connected to each other through through holes 13.

[0013] Here, the vias 6, 7, 9, 11, the upper wiring layer 8, and the lower wiring layers 10 and 12 contain, as their main components, a material having excellent electrical conductivity and thermal conductivity, such as copper (Cu). Also, the blank portion in FIG. 1, including the spaced portion 5, is filled with an electrically insulating material, such as epoxy resin or prepreg. Specifically, after filling the inside of the semiconductor device 110 with an electrically insulating material, a laser process or a drill process is performed to form a plurality of holes, and the surfaces of these holes are further plated with copper to form vias and through-holes. By repeating this process, a plurality of stages of wiring layers and vias are formed in sequence. At the top of the semiconductor device 110, a housing wall 14 containing, as its main component, a material having excellent thermal conductivity, such as copper (Cu), is provided, and a heat dissipation means, such as a heat sink, is provided on the housing wall 14 as necessary. In the embodiment of the present invention, the housing is defined by the housing wall 14 and the lower wiring layer 12, and the thickness of the housing is about 200 μm to 500 μm. In the embodiment of the present invention, the dimensions of the housing are not limited to the above dimensions.

[0014] An electric circuit connecting the first semiconductor element 2 and the gate driver 4 is extended through vias 6a and 6b to a resistor connection portion 15 provided at the height of a housing wall 14 arranged at a distance above the circuit board 1 in the thickness direction. Below the resistor connection portion 15, a space portion (heat shielding portion) 18 is provided in a part of the electrical insulating material filled in the spaced portion 5.

[0015] As shown in the partially enlarged view of FIG. 2, the space 18 has a substantially rectangular cross section. The space 18 extends in a direction perpendicular to the paper surface to have a predetermined depth, and is filled with a gas such as air (dry air). In the embodiment of the present invention, the space (heat shield) 18 is preferably a gas having a thermal conductivity of 0.1 W / m·K or less. It is particularly preferable that the length of the space 18 in the depth direction is the entire length of the opposing surface between the first semiconductor element 2 and the gate driver 4. It is also particularly preferable that the length of the space 18 in the vertical direction is the entire length of the opposing surface (thickness) between the first semiconductor element 2 and the gate driver 4.

[0016] The space 18 may be an open space or a closed space, and if it is an open space, it may have a conductive port leading to the outside of the case. The space 18 can be manufactured by a known process such as an etching process, a laser opening process, or a drill opening process in the semiconductor manufacturing process.

[0017] The resistor connection portion 15 is provided in a state where a gate resistor 16, which is an electronic component having an arbitrary resistance value, can be connected. That is, the resistor connection portion 15 is provided in a part of the electric circuit connecting the first semiconductor element 2 and the gate driver 4, and the resistor connection portion 15 is configured to be exposed from the housing. This also makes it possible to obtain a configuration in which at least a part of the wiring electrically connecting the first semiconductor element 2 and the gate driver 4 is disposed outside the housing. With this configuration, a heat shielding portion can be easily provided between the gate driver 4 and the first semiconductor element 2. By placing and fixing the gate resistor 16 on the resistor connection portion 15, electrical contacts are connected by the terminals 16a and 16b of the gate resistor 16, and the gate resistor 16 is configured to electrically connect a part of the electric circuit. The terminals 16a and 16b of the gate resistor 16 and the resistor connection portion 15 can be connected using a known connection method such as soldering. In addition, it is also possible to remove the gate resistor once connected from the resistor connection portion 15 by melting the solder, and then newly connect a gate resistor with a different resistance value.

[0018] FIG. 3 shows a circuit configuration of the semiconductor device 110 according to this embodiment. FIG. 3 shows the components shown in FIG. 2, that is, the first semiconductor element 2, the second semiconductor element 3, the gate driver 4, and the gate resistor 16. Here, a MOSFET is shown as an example of the semiconductor element 2, and the gate driver 4 supplies a control signal to the gate electrode G of the MOSFET to control the switching of the MOSFET 2. The second semiconductor element 3 is an SBD, and functions as a high-voltage free wheeling diode (FWD) for returning the current of the source electrode S of the MOSFET to the drain electrode D. A gate resistor (R1) 16 provided between the gate driver 4 and the MOSFET 2 is selected to have an appropriate resistance value for realizing a switching speed of the MOSFET 2 suitable for a control target (not shown). The resistor (R2) 17 is provided to set the voltage between the gate electrode G and the source electrode S to 0 V when the input signal of the gate electrode G is open.

[0019] Next, the operation of the present embodiment configured as described above will be described in detail.

[0020] The embodiment of the present invention is characterized by providing a heat shielding portion for blocking heat transfer from the semiconductor element to the gate driver. As the heat shielding portion, for example, a space portion 18 is provided between the semiconductor element 2 and the gate driver 4, and the space portion 18 is filled with air as a gas. The thermal conductivity of the thermosetting resin filled around the heat shielding portion is very high, for example, about 300 mW / m·K in the case of epoxy resin and about 400 mW / m·K in the case of prepreg. On the other hand, the thermal conductivity of air is about 25 mW / m·K at room temperature under normal pressure, which is more than 1 / 10 lower than that of thermosetting resin, and therefore the heat shielding effect is much higher. Therefore, the heat generated from the MOSFET 2 is finally dissipated to the outside of the housing by passing through the circuit board 1 and a route made of copper such as a via, or by passing through the thermosetting resin and the lower wiring layer 12 or the housing wall 14. The space 18, which has low thermal conductivity, functions as a heat shielding structure, thereby suppressing heat dissipation from the MOSFET 2 to the gate driver 4. Therefore, by providing the heat shielding portion, heat generated by the MOSFET 2 is less likely to be transmitted to the gate driver 4, and adverse effects on the gate driver can be suppressed.

[0021] 3, a gate resistor 16 is provided between the MOSFET 2 and the gate driver 4. In an actual circuit layout, the gate resistor is usually placed between the MOSFET 2 and the gate driver 4, that is, in the position of the space 18 in this embodiment. In contrast, in this embodiment, the gate resistor 16 of the MOSFET 2 is connected in a state where it is exposed from the housing, so that a region for providing a heat shield between the semiconductor element 2 and the gate driver 4 can be easily secured. At the same time, it is also possible to suppress adverse effects on the gate driver 4 due to heat generation from the gate resistor 16.

[0022] According to the first embodiment of the present invention having such a configuration, by providing a heat shielding portion that blocks heat transfer from the semiconductor element to the gate driver, it is possible to mitigate the effect of heat on the gate driver. Furthermore, by providing the heat shielding portion, the semiconductor element and the gate driver can be arranged close to each other, and therefore both can be arranged inside a common housing. This eliminates the need to make the electric circuit length longer than necessary, making it possible to avoid overvoltage caused by increased inductance.

[0023] Furthermore, the embodiments of the present invention are effective whether the semiconductor elements 2 and 3 are vertical devices, horizontal devices, or a combination of vertical and horizontal devices. That is, whether heat generation is predominant on the top or bottom surface of the semiconductor elements 2 and 3, the presence of the heat shielding portion makes it possible to mitigate the effect of heat on the gate driver.

[0024] In the following embodiments, since almost the same components as those of the semiconductor device 110 illustrated in FIG. 1 are provided, only the different parts will be described.

[0025] FIG. 4 is an enlarged cross-sectional view showing a main part of a semiconductor device according to a second embodiment of the present invention. As shown in FIG. 4, the semiconductor device 120 according to the second embodiment has a space 19 that is vertically holed up to the height of the resistor connection part 15 on which the gate resistor 16 is placed. The upper end part 19a of the space 19 is conductive to the outside of the housing. The space 19 is formed by processing from the upper end part 19a to the lower end part 19b toward the separation part 5 filled with resin or prepreg by a method such as drilling or dicing from the outside of the housing before the gate resistor 16 is placed on the resistor connection part 15. Although not shown in FIG. 4, the space 19 is formed so as to extend in a direction perpendicular to the paper surface, and the space 19 extends at least over the entire length of the opposing surfaces of the semiconductor element 2 and the gate driver 4.

[0026] According to the second embodiment of the present invention having such a configuration, the temperature of the upper end 19a of the open space 19 is lower than the temperature of the closed lower end 19b, so that air convection occurs in the space 19. Then, the air at the lower end 19b, which has become hot due to the heat generated by the semiconductor element 2, is carried by the convection to the upper end 19a and is easily discharged outside the housing, and the low-temperature air outside the housing can be taken in to replace the discharged high-temperature air. Therefore, it is possible to not only provide thermal insulation for the gate driver 4, but also to cool the vicinity of the separation portion 5, and to maintain stable operation of the gate driver 4.

[0027] Fig. 5 is an enlarged cross-sectional view showing a main part of a semiconductor device according to a third embodiment of the present invention. As shown in Fig. 5, a semiconductor device 130 according to the third embodiment has a space portion 20 that is provided by expanding laterally from the separation portion 5. In other words, the proportion of the space portion 20 in the separation distance between the semiconductor element 2 and the gate driver 4 is increased. This makes it possible to further reduce the influence of heat generated by the semiconductor element 2 on the gate driver 4.

[0028] Fig. 6 is an enlarged cross-sectional view showing a main part of a semiconductor device according to a fourth embodiment of the present invention. As shown in Fig. 6, the semiconductor device 140 according to the fourth embodiment has a space 20 that is further expanded in the lateral direction of the separation portion 5. That is, the respective side surfaces of the semiconductor element 2 and the gate driver 4 are exposed to the space 20, and the lateral direction of the separation portion 5 is expanded to a size that is substantially occupied only by an air layer. This makes it possible to further reduce the influence of heat generated by the semiconductor element 2 on the gate driver 4.

[0029] The semiconductor device according to the embodiment of the present invention is useful when it includes a semiconductor element using silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga2O3), etc., which are widely known as semiconductor materials for power semiconductors. In particular, it is extremely useful when it includes a semiconductor element using gallium oxide (α-Ga2O3) with a corundum structure having a high band gap or gallium oxide (β-Ga2O3) with a β-gallium structure, and contributes not only to increasing the density of the semiconductor device but also to improving its reliability.

[0030] Of course, it is possible to combine a plurality of the above-described embodiments of the present invention, or to apply some of the components to other embodiments, and such combinations also belong to the embodiments of the present invention. For example, the extension length and shape of the space can be designed to have any structure depending on the internal structure of the case and the heat generation amount of the semiconductor element. In addition to filling the space with air, it may be filled with other gases or fluids (including liquids) with low thermal conductivity. The thermal conductivity is preferably 0.1 W / m·K or less, and in addition to the above-described air (dry air), gases such as argon (Ar) gas, nitrogen (N2) gas, oxygen (H2O), and carbon dioxide (CO2) may be selected. These gases are widely used in the semiconductor manufacturing process and are therefore easy to obtain.

[0031] In the embodiment of the present invention, in addition to the first semiconductor element 1 and the second semiconductor element, other semiconductor elements may be further built in. Also, other passive components (for example, a capacitor, a coil, a resistor, etc.) may be further built in the semiconductor device. In the embodiment of the present invention, the above-mentioned semiconductor device may be made into a submodule, and a module may be formed by combining a plurality of these submodules.

[0032] The semiconductor device according to the embodiment of the present invention described above can be applied to power conversion devices such as inverters and converters to achieve the above-mentioned functions. Fig. 7 is a block diagram showing an example of a control system using the semiconductor device according to the embodiment of the present invention, and Fig. 8 is a circuit diagram of the same control system, which is particularly suitable for installation in an electric vehicle.

[0033] As shown in Fig. 7, the control system 500 has a battery (power source) 501, a boost converter 502, a step-down converter 503, an inverter 504, a motor (driven object) 505, and a drive control unit 506, which are mounted on an electric vehicle. The battery 501 is a storage battery such as a nickel-metal hydride battery or a lithium-ion battery, and can store power by charging at a power supply station or by regenerative energy during deceleration, and can output a DC voltage required for the operation of the driving system and electrical equipment system of the electric vehicle. The boost converter 502 is a voltage conversion device equipped with a chopper circuit, for example, and can boost a DC voltage of, for example, 200 V supplied from the battery 501 to, for example, 650 V by the switching operation of the chopper circuit, and output the voltage to the driving system such as the motor. The step-down converter 503 is also a voltage conversion device equipped with a chopper circuit, and by stepping down a DC voltage of, for example, 200 V supplied from the battery 501 to, for example, about 12 V, it can output the voltage to an electrical system including power windows, power steering, or in-vehicle electrical equipment.

[0034] Inverter 504 converts the DC voltage supplied from boost converter 502 into a three-phase AC voltage by switching operation and outputs it to motor 505. Motor 505 is a three-phase AC motor that constitutes the driving system of the electric vehicle, and is rotationally driven by the three-phase AC voltage output from inverter 504, and transmits the rotational driving force to the wheels of the electric vehicle via a transmission (not shown) or the like.

[0035] Meanwhile, using various sensors (not shown), actual values ​​such as the number of rotations of the wheels, torque, and the amount of depression of the accelerator pedal (acceleration amount) are measured from the electric vehicle while it is running, and these measurement signals are input to the drive control unit 506. At the same time, the output voltage value of the inverter 504 is also input to the drive control unit 506. The drive control unit 506 has the function of a controller equipped with a calculation unit such as a CPU (Central Processing Unit) and a data storage unit such as a memory, and generates a control signal using the input measurement signal and outputs it to the inverter 504 as a feedback signal to control the switching operation by the switching element. As a result, the AC voltage that the inverter 504 gives to the motor 505 is instantly corrected, so that the driving control of the electric vehicle can be accurately performed, and the safe and comfortable operation of the electric vehicle is realized. It is also possible to control the output voltage to the inverter 504 by giving a feedback signal from the drive control unit 506 to the boost converter 502.

[0036] 8 shows the circuit configuration in FIG. 7 excluding the step-down converter 503, that is, the circuit configuration showing only the configuration for driving the motor 505. As shown in the figure, the semiconductor device according to the embodiment of the present invention is used as, for example, a Schottky barrier diode in a step-up converter 502 and an inverter 504 to perform switching control. In the step-up converter 502, it is incorporated in a chopper circuit to perform chopper control, and in the inverter 504, it is incorporated in a switching circuit including an IGBT to perform switching control. Note that an inductor (such as a coil) is interposed in the output of the battery 501 to stabilize the current, and a capacitor (such as an electrolytic capacitor) is interposed between the battery 501, the step-up converter 502, and the inverter 504 to stabilize the voltage.

[0037] 8, a calculation unit 507 consisting of a CPU (Central Processing Unit) and a storage unit 508 consisting of a non-volatile memory are provided in the drive control unit 506. A signal input to the drive control unit 506 is provided to the calculation unit 507, which performs programmed calculations as necessary to generate feedback signals for each semiconductor element. The storage unit 508 also temporarily holds the results of calculations performed by the calculation unit 507, and accumulates physical constants and functions necessary for drive control in the form of a table and outputs them to the calculation unit 507 as appropriate. The calculation unit 507 and the storage unit 508 can be configured as known in the art, and their processing capabilities can be selected as desired.

[0038] As shown in FIG. 7 and FIG. 8, in the control system 500, a thyristor, a power transistor, an IGBT, a MOSFET, etc., which are diodes or switching elements, are used for the switching operations of the boost converter 502, the buck converter 503, and the inverter 504. The switching characteristics are significantly improved by using gallium oxide (Ga2O3), particularly corundum-type gallium oxide (α-Ga2O3), as the material for these semiconductor elements. Furthermore, by applying the semiconductor device according to the embodiment of the present invention, extremely good switching characteristics can be expected, and further miniaturization and cost reduction of the control system 500 can be realized. That is, the boost converter 502, the buck converter 503, and the inverter 504 can each be expected to achieve the effects of the present invention, and the effects of the present invention can be expected in any one of them, any combination of two or more of them, or in any form including the drive control unit 506.

[0039] The above-mentioned control system 500 can be applied to the semiconductor device according to the embodiment of the present invention not only to the control system of an electric vehicle, but also to control systems for various purposes such as stepping up / down the power from a DC power source, converting DC to AC, etc. Also, a power source such as a solar cell can be used as the battery.

[0040] FIG. 9 is a block diagram showing another example of a control system employing a semiconductor device according to an embodiment of the present invention, and FIG. 10 is a circuit diagram of the same control system. The control system is suitable for installation in infrastructure equipment, home appliances, and the like that operate on power from an AC power source.

[0041] As shown in FIG. 9, the control system 600 receives power supplied from, for example, an external three-phase AC power source (power source) 601, and includes an AC / DC converter 602, an inverter 604, a motor (drive target) 605, and a drive control unit 606, which can be mounted on various devices (described later). The three-phase AC power source 601 is, for example, a power generation facility (thermal power plant, hydroelectric power plant, geothermal power plant, nuclear power plant, etc.) of a power company, and its output is supplied as an AC voltage while being stepped down via a substation. In addition, it is installed in a building or a nearby facility in the form of, for example, a private generator, and is supplied with power via a power cable. The AC / DC converter 602 is a voltage conversion device that converts AC voltage to DC voltage, and converts an AC voltage of 100V or 200V supplied from the three-phase AC power source 601 into a predetermined DC voltage. Specifically, the voltage is converted into a desired DC voltage that is generally used, such as 3.3V, 5V, or 12V. If the drive target is a motor, conversion to 12V is performed. It is also possible to use a single-phase AC power supply instead of a three-phase AC power supply, in which case a similar system configuration can be achieved by using an AC / DC converter that accepts single-phase input.

[0042] The inverter 604 converts the DC voltage supplied from the AC / DC converter 602 into a three-phase AC voltage by switching operation and outputs it to the motor 605. The form of the motor 604 differs depending on the controlled object, but it is a three-phase AC motor for driving wheels when the controlled object is a train, pumps and various power sources when the controlled object is a factory facility, and compressors and the like when the controlled object is a home appliance, and is rotationally driven by the three-phase AC voltage output from the inverter 604 and transmits the rotational driving force to a driven object (not shown).

[0043] For example, in home appliances, there are many objects to be driven that can be supplied with the DC voltage output from AC / DC converter 602 as is (for example, personal computers, LED lighting equipment, video equipment, audio equipment, etc.), in which case inverter 604 is not required in control system 600, and the DC voltage is supplied to the object to be driven from AC / DC converter 602 as shown in Fig. 9. In this case, for example, a personal computer is supplied with a DC voltage of 3.3V, and an LED lighting equipment is supplied with a DC voltage of 5V.

[0044] Meanwhile, various sensors (not shown) are used to measure actual values ​​such as the rotation speed and torque of the object to be driven, or the temperature and flow rate of the surrounding environment of the object to be driven, and these measurement signals are input to the drive control unit 606. At the same time, the output voltage value of the inverter 604 is also input to the drive control unit 606. Based on these measurement signals, the drive control unit 606 provides a feedback signal to the inverter 604 to control the switching operation of the switching element. As a result, the AC voltage provided by the inverter 604 to the motor 605 is instantly corrected, so that the operation control of the object to be driven can be performed accurately, and stable operation of the object to be driven is realized. Also, as described above, when the object to be driven can be driven by a DC voltage, it is also possible to feedback control the AC / DC converter 602 instead of feedback to the inverter.

[0045] Fig. 10 shows the circuit configuration of Fig. 9. As shown in the figure, the semiconductor device according to the embodiment of the present invention is used as, for example, a Schottky barrier diode in an AC / DC converter 602 and an inverter 604 to perform switching control. The AC / DC converter 602 uses, for example, a Schottky barrier diode configured in a bridge circuit, and performs DC conversion by converting and rectifying the negative voltage of the input voltage into a positive voltage. In the inverter 604, the switching control is performed by incorporating the diode into a switching circuit in the IGBT. Note that the voltage is stabilized by interposing a capacitor (such as an electrolytic capacitor) between the AC / DC converter 602 and the inverter 604.

[0046] 10, the drive control unit 606 includes a calculation unit 607 made up of a CPU and a storage unit 608 made up of a non-volatile memory. A signal input to the drive control unit 606 is provided to the calculation unit 607, which performs programmed calculations as necessary to generate feedback signals for each semiconductor element. The storage unit 608 also temporarily holds the results of calculations performed by the calculation unit 607, and accumulates physical constants and functions necessary for drive control in the form of a table and outputs them to the calculation unit 607 as appropriate. The calculation unit 607 and the storage unit 608 can be configured as known units, and their processing capabilities can be selected as desired.

[0047] In the control system 600, as in the control system 500 shown in FIG. 7 and FIG. 8, diodes and switching elements such as thyristors, power transistors, IGBTs, and MOSFETs are used for the rectification and switching operations of the AC / DC converter 602 and the inverter 604. The switching characteristics are improved by using gallium oxide (Ga2O3), particularly corundum-type gallium oxide (α-Ga2O3), as the material for these semiconductor elements. Furthermore, by applying the semiconductor device according to the embodiment of the present invention, extremely good switching characteristics can be expected, and further miniaturization and cost reduction of the control system 600 can be realized. That is, the effects of the present invention can be expected for each of the AC / DC converter 602 and the inverter 604, and the effects of the present invention can be expected for any one of them, a combination of them, or a form including the drive control unit 606.

[0048] 9 and 10, a motor 605 is shown as an example of a driven object, but the driven object is not necessarily limited to mechanically operated objects, and can be many devices that require AC voltage. The control system 600 can be applied as long as it inputs power from an AC power source to drive the driven object, and can be installed for drive control of equipment such as infrastructure equipment (for example, power equipment in buildings and factories, communication equipment, traffic control equipment, water and sewage treatment equipment, system equipment, labor-saving equipment, trains, etc.) and home appliances (for example, refrigerators, washing machines, personal computers, LED lighting equipment, video equipment, audio equipment, etc.). [Explanation of symbols]

[0049] 1 Circuit Board 2, 3 Semiconductor elements 4 Gate Drivers 5 Separation part 6a, 6b, 7, 9, 11 vias 13 Through Hole 15 Resistor connection 16 Gate resistor 18 Space (heat shield) 110, 120, 130, 140 Semiconductor device 500 Control System 501 Battery (power source) 502 Boost Converter 503 Buck Converter 504 Inverter 505 Motor (Driven object) 506 Drive control unit 507 Arithmetic section 508 Storage section 600 Control System 601 Three-phase AC power supply (power supply) 602 AC / DC Converter 604 Inverter 605 Motor (Driven object) 606 Drive control unit 607 Arithmetic section 608 Storage section

Claims

1. A semiconductor device having at least a semiconductor element serving as a switching element and a gate driver for the semiconductor element, a semiconductor device comprising: a first insulating material that is electrically insulating between the first and second wiring layers and an upper wiring layer; a first insulating material that is electrically insulating between the first and second wiring layers and an upper wiring layer; and a second insulating material that is electrically insulating between the first and second wiring layers and an upper wiring layer.

2. 2. The semiconductor device according to claim 1, wherein the heat shield is a space provided in the electrically insulating material.

3. 2. The semiconductor device according to claim 1, wherein the thermal conductivity of the heat shielding portion is 0.1 W / m·K or less.

4. 3. The semiconductor device according to claim 2, wherein the space is filled with a gas.

5. 5. The semiconductor device according to claim 4, wherein the space is filled with air.

6. 3. The semiconductor device according to claim 2, wherein the space is electrically connected to the outside of the case.

7. 2. The semiconductor device according to claim 1, wherein at least a part of wiring electrically connecting said semiconductor element and said gate driver is located outside said housing.

8. 2. The semiconductor device according to claim 1, further comprising a substrate on which the semiconductor element and the gate driver are mounted, and a gate resistor electrically connected to the semiconductor element and the gate driver is disposed at a position spaced apart in a thickness direction of the substrate.

9. 9. The semiconductor device according to claim 8, wherein the gate resistor is disposed outside the housing.

10. 3. The semiconductor device according to claim 2, wherein said electrical insulating material is a thermosetting resin.

11. 3. The semiconductor device according to claim 2, wherein the electrically insulating material is a prepreg.

12. A power conversion device using the semiconductor device according to claim 1.

13. A control system using the semiconductor device according to claim 1.

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