JP7196044B2 - Semiconductor equipment and power conversion equipment - Google Patents

Description

The present invention relates to the configuration and control of a semiconductor device, and more particularly to a technique effectively applied to a power semiconductor device mounted on a power converter.

The maximum voltage that can be applied to power semiconductor switching devices used in power converters such as DC-DC converters and inverters is specified from the viewpoint of reliability and destruction prevention.

In such a power conversion device, the current value changes due to the switching operation by turning on and off the main semiconductor switching element. For example, in the case of a turn-off operation that cuts off current, when the main semiconductor switching element cuts off the current by a control command to the control terminal, the inductance in the circuit changes according to the amount of current change per unit time. Therefore, a voltage higher than the power supply voltage is applied between the main terminals that control power.

At this time, if the electromotive voltage becomes excessive, an overvoltage exceeding the withstand voltage of the element is applied between the main terminals, a withstand voltage breakdown phenomenon occurs in the element, and the leakage current increases excessively. Therefore, in order to avoid such a situation, it is common to limit the switching operation speed to a certain extent to suppress the electromotive force. However, if the switching speed is simply set low, the switching loss tends to increase even under the condition that no overvoltage occurs, because the switching speed is low.

In order to avoid such problems, active clamping is widely used as a method of reducing the switching speed only under the condition that overvoltage occurs. As an example of an active clamp (active clamp circuit), there is a technique such as that disclosed in Patent Document 1, for example.

In this method, when a voltage above a certain level is applied between the main terminals, the voltage at the control terminal is changed in the ON direction, causing current to flow through the element. Overvoltage is prevented by limiting the voltage drop or exceeding a certain value, and suppressing the electromotive voltage of the inductance to a certain value or less.

JP 2001-245466 A JP-A-7-235674

A system such as that disclosed in Patent Document 1 requires a circuit for detecting overvoltage, and uses a circuit configuration in which a constant voltage diode is combined with the main semiconductor switching element. However, in such cases, it is necessary to consider variations in the judgment voltage for overvoltage and variations in the withstand voltage of the main semiconductor switching element. For voltage, it is necessary to suppress overvoltage to a lower voltage level. In this case, the switching speed is set too low, leading to increased losses.

For this reason, in the power conversion device, switching loss increases compared to the case where the overvoltage is suppressed until reaching the actual breakdown voltage of the element. In addition, in order to suppress heat generation due to switching loss, it is necessary to reduce total loss by using a large-area main semiconductor switching element with low conduction loss, or to suppress temperature rise with a cooling device with lower thermal resistance. As a result, it becomes difficult to reduce the size and improve the efficiency of the power converter.

As a method for reducing the influence of such variations in breakdown voltage and reducing loss while suppressing overvoltage, for example, a method disclosed in Patent Document 2 is known. In this method, overvoltage protection is performed by turning on the leakage current generated by breakdown of the junction termination region of the main semiconductor switching element due to overvoltage.

Since a portion for detecting overvoltage is provided in the main semiconductor switching element, the overvoltage judgment voltage fluctuates in the same manner as the breakdown voltage changes due to factors such as the chip thickness and impurity concentration of the main semiconductor switching element. The influence of variation is small, and the margin of the voltage for protection can be set low by judging the overvoltage with respect to the breakdown voltage of the main semiconductor switching element.

However, in the case of the method disclosed in Patent Document 2, the ON drive to the control terminal for overvoltage protection conflicts with the OFF output from the control circuit that controls the ON/OFF state of the main semiconductor switching element. A large leakage current is required to turn on. As a result, the delay time until the on state is increased, and the on-driving cannot be completed in time, making it difficult to suppress the overvoltage.

In addition, since excessive leakage current is required to prevent this delay, this leakage current generates high-energy charges that are injected into the gate oxide film of the device, etc., reducing the reliability of the main semiconductor switching device. It may let you.

In addition, a method of using an auxiliary drive circuit to improve such problems has been disclosed, but there are other problems such as an increase in the element area due to the installation of the auxiliary drive circuit and the need for a large current for the power supply of the auxiliary drive circuit. is difficult to apply.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a power semiconductor device excellent in reliability and low loss, capable of suppressing an electromotive voltage generated in a semiconductor switching element during switching, and a power converter using the same. It is in.

In order to solve the above problems, the present invention includes a semiconductor switching element, and a control circuit connected to a gate terminal, a source terminal, or an emitter terminal of the semiconductor switching element for controlling on and off of the semiconductor switching element, The control circuit has a determination circuit for detecting a control terminal voltage between the gate terminal and the source terminal or the emitter terminal, and a gate drive circuit capable of controlling a voltage value of the control terminal voltage, and is detected by the determination circuit. When the increase value of the detected control terminal voltage exceeds a predetermined threshold, the control terminal voltage is increased to a level higher than the detected control terminal voltage, and the semiconductor switching element comprises an insulated gate switching element and an insulated gate switching element. A diode connected in parallel with the switching element and having a lower withstand voltage than the insulated gate type switching element is provided, and leakage current of the diode flows into the gate terminal, thereby increasing the control terminal voltage. do.

ADVANTAGE OF THE INVENTION According to the present invention, it is possible to realize a power semiconductor device excellent in reliability and low loss property capable of suppressing an electromotive voltage generated in a semiconductor switching element at the time of switching, and a power converter using the same. .

As a result, it is possible to reduce the size and improve the efficiency of the power converter.

Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

1 is a diagram showing a circuit configuration of a semiconductor device according to Example 1 of the present invention; FIG. 2 is a diagram showing an operating voltage and current sequence of the semiconductor device of FIG. 1; FIG. 2 is a diagram showing a cross-sectional structure of the main semiconductor switching element of FIG. 1; FIG. FIG. 5 is a diagram showing a cross-sectional structure of a main semiconductor switching element according to Example 2 of the present invention; It is a figure which shows the structure of the semiconductor device which concerns on Example 3 of this invention. It is a figure which shows the structure of the power converter device which concerns on Example 4 of this invention. FIG. 10 is a diagram showing the configuration of a main semiconductor switching element according to Example 5 of the present invention;

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in each drawing, the same configurations are denoted by the same reference numerals, and detailed descriptions of overlapping portions are omitted.

A semiconductor device according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. FIG. 1 is a diagram showing the circuit configuration of a semiconductor device according to this embodiment. The semiconductor device 1 of this embodiment is connected to a main semiconductor switching element 2, a gate terminal G (6) as its control terminal, and a source terminal S (4). It is configured.

The main semiconductor switching element 2 consists of an n-ch power MOSFET M1 (11), which is an insulated gate switching element, and a diode Di (12) having a common drain terminal D (5) and a cathode in the same semiconductor chip. ), a diode 14 provided between the anode of the diode Di (12) and the gate terminal G (6) of the power MOSFET M1 (11) in a direction connecting the anode terminal of the diode Di (12) and the diode Di (12) by a resistor Rs (13) connected between the anode terminal of (12) and the source terminal S (4).

Furthermore, the structure is set so that the withstand voltage of the diode Di (12) is lower than the withstand voltage of the power MOSFET M1 (11) by a certain amount. In addition, the gate resistor Rgin (15) incorporated in the power MOSFET M1 (11) is connected between the gate of the power MOSFET M1 (11) and the gate terminal G (6) in the form of a parasitic resistance or a limiting resistor to prevent oscillation. is provided in

The control circuit 3 includes an input circuit 21, a judgment circuit 22, a gate composed of a MOSFET M2 (23), a MOSFET M3 (24), a MOSFET M4 (25), a depletion type MOSFET M5 (26), and a gate resistor Rg (27). It is composed of a drive circuit 28 and is operated by a power supply applied between a power supply (Vcc) terminal 9 and an Ssense terminal 8. An input signal between a signal input terminal IN7 and an Ssense terminal 8 drives the power MOSFET M1 (11). on and off.

Here, when a voltage exceeding the withstand voltage of the diode Di (12) is applied between D and S of the power MOSFET M1 (11) due to the turn-off operation of the power converter, etc., the leakage current of the diode Di (12) increases. , due to the voltage drop across the resistor Rs due to the current, a leakage current flows through the diode 14 to the gate of the power MOSFET M1 (11), and the potential of the gate terminal G (6) increases.

At this time, if the determination circuit 22 determines that the amount of boosting of the potential of the gate terminal G (6), which is the control terminal (“first amount”), is greater than or equal to a certain amount, the control circuit 3 Another boosting scheme is provided by drive circuit 28 to increase the control terminal voltage Vg by an additional "second amount".

As a result, it is possible to increase the control terminal voltage Vg to a certain amount at high speed with a small amount of leakage current from the diode Di (12), and it is possible to suppress overvoltages at high speed and with higher accuracy. It is possible to reduce the loss of the element while avoiding the deterioration of the properties.

FIG. 2 shows the operating voltage and current sequence of the semiconductor device 1 of this embodiment during the turn-off operation. As shown in FIG. 2, the main terminal voltage Vds exceeds the withstand voltage Vds1 of the diode Di (12) while the control terminal voltage Vg of the control terminal G is decreasing when the current is interrupted, and the control terminal voltage Vg It rises by a certain amount ΔV1. Here, ΔV1 is generated by the leakage current flowing into the diode Di (12), which causes the current Ishink flowing into the off-drive circuit of the control circuit 3 to increase, and the voltage drop due to the resistance of the control circuit 3 to increase.

The determination circuit 22 detects this ΔV1, and the gate drive circuit 28 additionally increases the control terminal voltage Vg to ΔV2. At this time, the control terminal voltage Vg increases as shown in FIG. Although the slope of the decrease becomes gentle and the switching speed slows down, the gate voltage of is set to a range in which it does not change until it increases.

As a result, the current change rate of the main current Id flowing through the power MOSFET M1 (11), that is, the gradient of the current decreases as indicated by the dashed line in FIG. 2, thereby preventing overvoltage.

Also, when judging the overvoltage by this ΔV1, the main terminal voltage Vds between the source terminal S (4) and the drain terminal D (5) is within a certain range with respect to the withstand voltage Vds1 of the diode Di (12), for example, Vds≧ If the determination circuit 22 is set to determine overvoltage only when certain conditions such as Vds1×0.8 are met, the effects of noise and the like can be eliminated and overvoltage determination can be performed with higher accuracy, resulting in low loss and high reliability of the main terminal. It is possible to limit the overvoltage applied to

As a method of the judgment circuit 22 for judging the increase of ΔV1, for example, when the control terminal voltage Vg is differentiated by a differentiating circuit at the time of OFF operation, it is detected that the gradient of Vg is in an upward direction, and the control terminal from that time point is detected. The change amount ΔV of the voltage Vg is obtained by integrating the differential value of the control terminal voltage Vg with an integration circuit, and is compared with the set value of ΔV1 for determination.

In addition, as an equivalent and simple method, it is determined by detecting that the period in which the differential value (“first quantity”) of the control terminal voltage Vg is equal to or greater than a certain value continues beyond a certain period of time. You can

As a method of the gate drive circuit 28 for additionally increasing the control terminal voltage Vg by the "second amount", when it is determined that the amount of increase in the control terminal voltage Vg is a certain amount or more, the power MOSFET M1 is turned off during turn-off control. By turning off the MOSFET M3 (24) that flows the current Ishink1 that discharges the charge from the gate of (11) and turning on the MOSFET M4 (25), the MOSFET M4 (25) that discharges with a lower current Ishink2, depression The resistance of the discharge circuit may be increased by switching only to the current path consisting of the type MOSFET M5 (26).

Here, the depletion type MOSFET M5 (26) is a short circuit between the gate and source of the depletion type MOSFET. It functions as a constant current element and limits the current in the path of Ishink2. Di (12) leakage current can be reduced.

Further, as a method for further reducing the leakage current of the diode Di (12), the MOSFET M3 (24) is turned off when it is determined that the amount of increase in the control terminal voltage Vg is above a certain level, and the MOSFET M4 (25) is turned off. is turned on to switch to only the current path consisting of MOSFET M4 (25) and depletion type MOSFET M5 (26). Alternatively, the control terminal voltage Vg may be further increased by a certain amount by flowing a current from the power supply Vcc in the direction of increasing the control terminal voltage Vg.

In other words, for example, when the control terminal voltage Vg rises above a predetermined threshold during OFF control of the main semiconductor switching element 2 (during the OFF control period), the control circuit 3 controls the power supply ( Vcc) or control to increase the resistance value of the discharge circuit that discharges the charge from the gate of the semiconductor switching element 2, thereby increasing the voltage value of the control terminal voltage Vg. configured with

If turning on the MOSFET M2 (23) causes an excessive rise in the control terminal voltage Vg, replace the MOSFET M2 (23) M2 with an on-side drive circuit using a MOSFET with a lower current drive capability. may be provided to raise the pressure.

As a result, it is possible to increase the control terminal voltage Vg to a certain amount at a higher speed with a small amount of leakage current from the diode Di (12). and loss reduction can be achieved to a higher degree.

FIG. 3 is a partial cross-sectional view of the main semiconductor switching element 2 in the semiconductor device 1 of this embodiment shown in FIG. 1, showing a power MOSFET as an example.

The main semiconductor switching element 32 includes a main MOSFET portion comprising a source electrode 42, a drain electrode 43, and a gate electrode (trench gate electrode) 41, a common drain electrode and gate electrode, and an independent sense electrode 51. A portion 54 corresponding to the diode Di (12) in FIG. 1 is provided.

In this example, the main MOSFET portion is a trench gate MOSFET with a stripe structure. 47 , a p + layer 48 is provided at the source electrode contact portion to the p-channel diffusion layer 46 , and a trench gate electrode 41 is provided via a gate oxide film 49 .

On the other hand, the portion 54 that becomes the diode Di consists of a p diffusion layer ps52 that is not in direct contact with the p-channel diffusion layer 46, and a high-concentration p+ layer 57 that serves as a contact portion between the sense electrode 51 and the p diffusion layer ps52. Prepare.

The p diffusion layer ps52 need only be separated (insulated) from the p-channel diffusion layer 46, and there is no problem even if they are formed in the same process with different layout patterns on the chip. A trench gate electrode is also provided, which is connected to the main MOSFET portion or provided independently, but the gate potential is common, or the same as the sense electrode 51 at the portion 54 that becomes the diode Di. It may be an electric potential. The resistor Rs 55 and the diode 56 may be formed using polysilicon or the like deposited on the insulating film.

Here, an n-diffusion layer 53 having a higher concentration than the drift layer (n- layer) 45 is provided at the boundary between the p-diffusion layer ps52 and the drift layer (n- layer) 45 in the portion 54 that becomes the diode Di.

With such a configuration, the strength of the electric field is increased by the n-layer, and the withstand voltage of the portion 54 that becomes the diode Di is lowered by a certain amount compared to the main MOSFET portion that does not have the n-layer. ) 45, even if the breakdown voltage of the main MOSFET part fluctuates due to fluctuations in the thickness of 45 and its concentration, the breakdown voltage can be set low by a certain amount with high accuracy.

In addition, even if a voltage exceeding the withstand voltage of this portion 54 is applied and the leakage current increases, the leakage current flows in the vicinity of the n-layer, so that high-energy electrons or holes due to the leakage current are generated in the gate oxide film of the trench gate electrode. Since it is hard to be injected into 49, it is hard to be damaged and high reliability can be obtained.

Note that a p-type diffusion layer may be provided instead of the n-layer in order to reduce the breakdown voltage of the portion 54 that becomes the diode Di by a certain amount.

Further, in this embodiment, an example of using an n-ch type power MOSFET M1 (11) as the main semiconductor switching element is shown. transistor) may be used. In this case, the control circuit 3 is connected to the gate and emitter terminals of the IGBT.

As described above, the semiconductor device 1 of this embodiment is connected to the main semiconductor switching element 2, the gate terminal G(6) of the main semiconductor switching element 2, and the source terminal S(4) (or the emitter terminal). , and a control circuit 3 for controlling on/off of the main semiconductor switching element 2. The control circuit 3 detects the control terminal voltage Vg between the gate terminal G (6) and the source terminal S (4) (or the emitter terminal). and a gate drive circuit 28 capable of controlling the voltage value of the control terminal voltage Vg. The control terminal voltage is increased to be higher than the control terminal voltage Vg.

Further, the determination circuit 22 determines the main terminal voltage Vds between the source terminal S (4) and the drain terminal D (5) (or between the emitter terminal and the collector terminal) of the main semiconductor switching element 2 (power MOSFET M1 (11)). When the main terminal voltage Vds detected by the determination circuit 22 is within a predetermined voltage range and the control terminal voltage Vg detected by the determination circuit 22 exceeds a predetermined threshold, the control circuit 3 detects that the control terminal Increase the voltage Vg.

As a result, it is possible to realize a power semiconductor device excellent in reliability and low loss, capable of suppressing the electromotive voltage generated in the element when the semiconductor switching element is switched.

A semiconductor device according to a second embodiment of the present invention will be described with reference to FIG. FIG. 4 shows another embodiment of the cross-sectional structure of the main semiconductor switching element of the semiconductor device according to the present invention.

In this embodiment, as shown in FIG. 4, a portion 62 which becomes the diode Di of the main semiconductor switching element 34 is insulated under the gate pad electrode 61 for mounting and connecting the trench gate electrode 41 of the MOSFET by wire bonding or the like. A high-concentration p + layer 65 and a p diffusion layer (ps layer) 64 are provided with a film 63 interposed therebetween.

Incidentally, in FIG. 4, the contact portion of the wiring electrode of the portion 62 that becomes the diode Di is omitted. In this embodiment, since the trench gate electrode is not formed in the portion 62 that becomes the diode Di, the electric field relaxation by the trench gate electrode does not occur. The breakdown voltage of the portion 62 that becomes Di is adjusted. Needless to say, the breakdown voltage may be adjusted by providing an n-layer or the like.

In addition, since no trench gate electrode is provided in the formation region of the portion 62 to be the diode Di, the trench gate oxide film is not damaged by leakage current.

Furthermore, since the portion 62 that becomes the diode Di is provided under the gate pad electrode where no element is normally provided, the chip size can be reduced without increasing the element area. Also, by providing the p+ layer 65 with a high concentration, the series resistance of the portion 62 that becomes the diode Di is reduced, and the leak current can flow uniformly over a wide area under the gate pad electrode.

As a result, it is possible to prevent overvoltage detection level fluctuations due to excessive temperature rise due to concentration of leak current, deterioration of wiring due to local current concentration, and the like, and to achieve lower loss with higher accuracy and reliability.

Needless to say, the structure of the drain portion (drain electrode 43) of the MOSFET of this embodiment is changed to an IGBT collector structure, and the structure of the source portion (source electrode 42) is changed to an IGBT emitter structure. By doing so, a similar effect can be expected in the case of IGBTs.

A semiconductor device according to a third embodiment of the present invention will be described with reference to FIG. FIG. 5 shows an example of mounting a semiconductor device 71 according to the present invention, in which the semiconductor device according to the present invention is mounted in a three-terminal package, taking as an example the case where a MOSFET is used as the main semiconductor switching element 72 .

An IC chip 81 integrated with a control circuit 73 and a power supply circuit 74 is arranged on a circuit pattern 75 connected to the source terminal S (77) of the main semiconductor switching element 72, and a bonding wire 76 connects the drain terminal D. The potential of (78) is supplied to the control circuit 73 and the power supply circuit 74. FIG.

Here, the power supply circuit 74 is a circuit that generates a power supply voltage to the control circuit 73 from the drain-source voltage of the main semiconductor switching element 72 .

In the semiconductor device 71 of this embodiment, the main current is on/off controlled by applying a signal to the gate terminal G (79). By adopting such a configuration, it is possible to provide the intended function of the present invention in the form of a convenient three-terminal configuration and function that are the same as those of a widely used conventional element.

In addition, by mounting the main semiconductor switching element 72, the control circuit 73, and the power supply circuit 74 in the same package, the influence of noise due to parasitic wiring inductance can be avoided, and the voltage rise amount of the control terminal voltage Vg can be determined with high accuracy. The functions of the present invention can be realized with high precision.

A power converter according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 6 shows an embodiment of a power converter using a semiconductor device according to the present invention. As will be described later in Embodiment 5 (FIG. 7), a three-phase inverter 101 using IGBTs as main semiconductor switching elements 131 is shown as an example.

The power converter (three-phase inverter) 101 of this embodiment is an inverter composed of main circuits of a U-phase 107, a V-phase 108, and a W-phase 109 that supply power from a DC power supply 105 to a load 106 according to a command from a logic unit 102. , and semiconductor devices 111 and 121 of the present invention are provided on the upper and lower arms, as shown in detail in the main circuit of U-phase 107 .

The basic configuration and functions of these semiconductor devices 111 and 121 are the same as in the case of using the power MOSFET described above. A diode Di 141 provided in the IGBT for the IGBT is connected in series with a diode 145 formed by a pn junction on the collector side of the IGBT with its cathode facing each other.

Also in this case, if the withstand voltage of the diode Di141 is set lower than that of the IGBT section by a certain amount, the same effect as in the case of using the power MOSFET can be obtained. Further, in this case, by setting the withstand voltage of the diode Di136 connected in parallel to the IGBT to be higher than the withstand voltage of the diode Di141, application of overvoltage to the diode connected in parallel to the IGBT can be prevented.

A semiconductor device according to a fifth embodiment of the present invention will be described with reference to FIG. FIG. 7 shows an example in which all of the IGBTs, diodes Di, and resistance elements that constitute the main semiconductor switching element 131 are integrated on one chip.

As shown in FIG. 7, it is possible to integrate all of them on one chip, but the IGBT 135 and the diode Di 141 must be integrated on the same chip, but other parts are partially integrated. It is also possible to configure it in combination with another element.

With the configuration shown in FIG. 7, the electromotive voltage surge of the parasitic inductance Ls (see FIG. 6) of the main circuit applied to the turned-off IGBT 135 and the diode provided in parallel with the IGBT on the opposite arm of the turned-on IGBT 135 When overvoltage is applied such as electromotive voltage surge of parasitic inductance Ls during reverse recovery operation, load short circuit, and voltage surge due to high current cutoff due to protection operation when upper and lower arm short circuit occurs, less semiconductor Overvoltage can be prevented from being applied to the main semiconductor switching element by detecting the overvoltage with high accuracy from the leakage current of the switching element and increasing the control terminal voltage Vg by an appropriate amount.

In this way, by using the semiconductor device of the present invention, the electromotive voltage generated by the parasitic inductance Ls103 (FIG. 6) of the main circuit during switching can be controlled at high speed and with high accuracy so that the voltage is within an appropriate range. It is possible to provide a power converter that is controllable, has a simple configuration, and is highly reliable, low-loss, and small.

In the above, the semiconductor device according to the present invention and the method for appropriately controlling the overvoltage of the main semiconductor switching element in the power conversion device using the same with low loss have been described. Needless to say, the method can be applied to other types of power switching elements than those described above, and to other power conversion systems. For example, when applied to a DC-DC converter, in addition to the switching element that turns the current on and off, the same is true for the reverse recovery operation of the MOSFET of the synchronous rectifier circuit, which is widely used to reduce the loss of the diode rectification operation. effect can be expected.

In addition, the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. A part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Moreover, it is also possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

1, 31, 71, 111, 121... semiconductor device 2, 32, 34, 72, 112, 122, 131... main semiconductor switching element 3, 33, 73, 113, 123... control circuit 4, 77... source terminal S
5, 78... Drain terminal D
6, 79, 134 --- Gate terminal G
7... Signal input terminal 8... Ssense terminal 9... Power supply (Vcc) terminal 11... Power MOSFET
12, 54, 62, 141... Diodes (Di)
DESCRIPTION OF SYMBOLS 13,55,142... Resistor 14,56,143... Diode 15,144... Built-in gate resistance 21... Input circuit 22... Judgment circuit 23, 24, 25... MOSFET
26 Depletion type MOSFET
27 Gate resistance Rg
28... Gate drive circuit 41... Gate electrode (trench gate electrode)
42... Source electrode 43... Drain electrode 44... Substrate n+ layer 45... Drift layer (n- layer)
46... p-channel diffusion layer 47... source diffusion layer (n+ layer)
48, 57, 65 p+ layer 49 gate oxide film 51 sense electrode 52, 64 p diffusion layer (ps layer)
53...n diffusion layer 61...gate pad electrode 63...insulating film 74...power supply circuit 75...circuit pattern 76...bonding wire 81...IC chip 101...power converter (three-phase inverter)
102... Logic part 103... Parasitic inductance Ls (of the main circuit)
104... Smoothing capacitor 105... DC power supply 106... Load 107, 108, 109... Inverter main circuit (U phase, V phase, W phase)
132... Emitter terminal 133... Collector terminal 135... IGBT
136... Parallel diode 145... Collector side pn diode

Claims (10)

a semiconductor switching element;
A control circuit connected to the gate terminal and the source terminal or the emitter terminal of the semiconductor switching element and controlling on and off of the semiconductor switching element,
The control circuit has a determination circuit that detects a control terminal voltage between the gate terminal and the source terminal or the emitter terminal, and a gate drive circuit that can control the voltage value of the control terminal voltage,
When the increase value of the control terminal voltage detected by the determination circuit exceeds a predetermined threshold, the control terminal voltage is increased to be higher than the detected control terminal voltage ,
the semiconductor switching element includes an insulated gate switching element and a diode connected in parallel with the insulated gate switching element and having a lower withstand voltage than the insulated gate switching element;
1. A semiconductor device according to claim 1, wherein leakage current of said diode flows into said gate terminal, thereby increasing a control terminal voltage . The semiconductor device according to claim 1 ,
A semiconductor device, wherein the insulated gate switching element is a MOSFET or an IGBT. The semiconductor device according to claim 1,
The semiconductor device, wherein the control circuit increases the control terminal voltage when a voltage gradient of the control terminal voltage detected by the determination circuit continues to exceed a predetermined threshold value for a certain period of time. The semiconductor device according to claim 1,
The control circuit controls the supply of current from a power supply connected to the gate drive circuit and turns off the semiconductor switching element when the increase value of the control terminal voltage exceeds a predetermined threshold during OFF control of the semiconductor switching element. A semiconductor device, wherein the voltage value of the control terminal voltage is increased by performing at least one of control to increase a resistance value of a discharge circuit that discharges charges from a gate. The semiconductor device according to claim 1 ,
The semiconductor switching element has a trench gate electrode,
The diode is formed in a portion of the trench gate electrode in the channel width direction, and has a high-concentration diffusion layer of n-type or p-type conductivity at the boundary between the channel diffusion layer and the drift layer at that portion. A semiconductor device characterized by: The semiconductor device according to claim 1 ,
The semiconductor device according to claim 1, wherein the diode is arranged under the gate pad electrode. The semiconductor device according to claim 1,
A semiconductor device, wherein the semiconductor switching element and the control circuit are integrated within the same mounting structure. The semiconductor device according to claim 7 ,
A semiconductor device, wherein a power supply circuit for generating a power supply for said control circuit from a terminal voltage of said semiconductor switching element is integrated within the same mounting structure. a semiconductor switching element;
A control circuit connected to the gate terminal and the source terminal or the emitter terminal of the semiconductor switching element and controlling on and off of the semiconductor switching element,
The control circuit has a determination circuit that detects a control terminal voltage between the gate terminal and the source terminal or the emitter terminal, and a gate drive circuit that can control the voltage value of the control terminal voltage,
When the increase value of the control terminal voltage detected by the determination circuit exceeds a predetermined threshold, the control terminal voltage is increased to be higher than the detected control terminal voltage,
the determination circuit detects a main terminal voltage between the source terminal and the drain terminal or between the emitter terminal and the collector terminal of the semiconductor switching element;
The control circuit increases the control terminal voltage when the main terminal voltage detected by the determination circuit is within a predetermined voltage range and the control terminal voltage detected by the determination circuit exceeds a predetermined threshold. A semiconductor device characterized by: A power conversion device using the semiconductor device according to claim 1 .

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