ELECTRICAL ASSEMBLY COMPLETING A SEMICONDUCTOR CIRCUIT DEVICE AND A CLAMPING DIODE, ELECTRONIC ASSEMBLY AND IGBT MODULE

Abstract

Electrical assembly comprising: a semiconductor switching device (510) configured to withstand a maximum breakdown voltage across two load terminals (L1, L2) in an off state; and a clamping diode (560) electrically connected to the two load terminals (L1, L2) and in parallel with the semiconductor switching device (510), wherein a semiconductor body (100) of the clamping diode (560) is made of silicon carbide and an avalanche breakdown voltage of the clamping diode (560) is lower than the maximum breakdown voltage of the semiconductor switching device (510), wherein the clamping diode (560) has a central region (610) in a vertical projection of both a metal anode (310) and a metal cathode (320) and a termination region (690) surrounding the central region (610), and wherein a breakdown voltage in the central region (610) is lower than a breakdown voltage in the termination region (690).

Description

BACKGROUND

[0001] In applications such as motor drives and power conversion circuits, semiconductor switches repeatedly switch a load current through an inductive load, such as transformer coils or motor windings, on and off. Typically, freewheeling diodes are electrically connected in parallel with the inductive load or in parallel with the semiconductor switch. After the load current is switched off, the freewheeling diode is biased forward, allowing the inductive load to dissipate the energy stored in its magnetic field.

[0002] In half-bridge circuits, for example in H-bridges for motor drives or on the primary side of half-bridge converters, a freewheeling diode, which is forward-biased when the high-side switch turns off, is typically connected and combined in parallel with the low-side switch, and a freewheeling diode, which is forward-biased when the low-side switch turns off, is typically connected and combined in parallel with the high-side switch. Device parameters such as the blocking capability of the freewheeling diode and the blocking capability of the semiconductor switch are typically matched, with device parameters such as reverse voltage, on-resistance, and switching losses being related to each other in such a way that, for example, a higher blocking capability implies a higher on-resistance and / or higher switching losses in the semiconductor switches.

[0003] It is desirable to create electrical assemblies that include semiconductor switches and combine low switching losses with high reliability. SUMMARY

[0004] The problem is solved by one of the independent claims. The dependent claims relate to further embodiments.

[0005] According to one embodiment, an electrical assembly comprises a semiconductor switching device that withstands a maximum breakdown voltage across two load terminals in an off state. A clamping diode is electrically connected to the two load terminals and in parallel with the switching device. The semiconductor body of the clamping diode is made of silicon carbide. The avalanche breakdown voltage of the clamping diode is lower than the maximum breakdown voltage of the switching device.

[0006] According to another embodiment, an electronic assembly comprises a low-side switch with a first electrical assembly and a high-side switch with a second electrical assembly. The low-side switch and the high-side switch are electrically arranged in a half-bridge configuration. At least one of the electrical assemblies comprises a semiconductor switching device that withstands a maximum breakdown voltage across two load terminals in an off state. A clamping diode is electrically connected to the two load terminals and in parallel with the switching device. The semiconductor body of the clamping diode is made of silicon carbide. The avalanche breakdown voltage of the clamping diode is lower than the maximum breakdown voltage of the switching device.

[0007] According to another embodiment, an insulated-gate bipolar transistor module comprises a half-bridge circuit including a low-side switch and a high-side switch. The low-side switch comprises a first electrical assembly, and the high-side switch comprises a second electrical assembly. At least one of the first and second electrical assemblies includes a semiconductor switching device that withstands a maximum breakdown voltage across two load terminals in an off state. A clamping diode is electrically connected to the two load terminals and in parallel with the switching device. The semiconductor body of the clamping diode is made of silicon carbide. The avalanche breakdown voltage of the clamping diode is lower than the maximum breakdown voltage of the switching device.

[0008] According to a further embodiment, an electrical assembly comprises a semiconductor switching device that withstands a maximum breakdown voltage across two load terminals in an off state. A clamping diode is electrically connected to the two load terminals and in parallel to the switching device. The avalanche breakdown voltage of the clamping diode is lower than the maximum breakdown voltage of the switching device. A feedback circuit electrically connects an anode electrode of the clamping diode to a gate electrode of the switching device. The feedback circuit increases or decreases a gate voltage at the gate electrode with increasing current through the reverse-biased or reverse-biased clamping diode.

[0009] The expert will recognize additional features and advantages after reading the following detailed description and examining the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying drawings are enclosed to provide a further understanding of the invention and are incorporated into the disclosure and form part thereof. The drawings illustrate exemplary embodiments of the present invention and, together with the description, serve to explain the principles of the invention. Other exemplary embodiments of the invention and intended advantages are immediately appreciated, as they are better understood with reference to the following detailed description.

[0011] Fig. Figure 1A is a schematic circuit diagram of an electrical assembly according to an embodiment comprising a semiconductor switching device and a clamping diode with an avalanche breakdown voltage lower than a maximum breakdown voltage value of the switching device.

[0012] Fig. Figure 1B is a schematic diagram illustrating a periodic load current to define an avalanche resistance capability or strength for the clamping diode of Fig. To illustrate 1A.

[0013] Fig. 1C is a schematic diagram representing an operating mode of the electrical assembly of Fig. 1A illustrates.

[0014] Fig. 1D is a schematic diagram that represents a safe operating range with respect to individual avalanche events in the clamping diode of Fig. 1A illustrated according to one embodiment.

[0015] Fig. Figure 2 is a schematic diagram showing voltage and current curves of an electrical assembly according to an embodiment comprising a Si-IGBT (silicon bipolar transistor with insulated gate) and a SiC-MPS (silicon carbide merged pin Schottky) diode.

[0016] Fig. Figure 3A is a schematic circuit diagram of an electrical assembly according to an embodiment comprising a Si-IGBT and a SiC clamping diode.

[0017] Fig. Figure 3B is a schematic circuit diagram of an electrical assembly according to an embodiment comprising a SiC-IGBT, a Si-FWD (silicon free-wheeling diode) and a SiC clamping diode.

[0018] Fig. 3C is a schematic diagram showing the voltage / current characteristics of a SiC clamping diode and a freewheeling diode for discussing the effects of the embodiment of Fig. 3B shows.

[0019] Fig. Figure 3D is a schematic circuit diagram of an electrical assembly according to an embodiment comprising a SiC clamping diode and a Si IGFET (silicon insulated gate field-effect transistor) with a body diode.

[0020] Fig. Figure 3E is a schematic circuit diagram of an electrical assembly according to an embodiment comprising a SiC clamping diode and an RC IGBT (reverse conducting IGBT).

[0021] Fig. 3F is a schematic circuit diagram of an electrical assembly according to an embodiment comprising a Si-IGBT, a Si-FWD, a SiC-SBD (Silicon Schottky barrier diode) and a SiC clamping diode.

[0022] Fig. 3G is a schematic circuit diagram of an electrical assembly according to an embodiment comprising a SiC clamping diode electrically connected in parallel to a plurality of semiconductor switching devices.

[0023] Fig. Figure 4A is a schematic diagram showing voltage / current characteristics for a Si-IGBT and a SiC clamping diode of an electrical assembly according to one embodiment.

[0024] Fig. Figure 4B is a schematic diagram showing voltage / current characteristics for a reference example comprising a Si-IGBT and a SiC-SBD (silicon carbide Schottky barrier diode and silicon carbide diode with Schottky barrier, respectively), to discuss effects of the embodiments.

[0025] Fig. 4C is a schematic diagram showing voltage / current characteristics of a silicon clamping diode for different temperatures to discuss the effects of the embodiments.

[0026] Fig. Figure 4D is a schematic diagram showing voltage / current characteristics of a SiC clamping diode for different temperatures to discuss the effects of the embodiments.

[0027] Fig. Figure 5A is a schematic vertical cross-sectional view of a SiC clamping diode in which an avalanche breakthrough takes place in an active area or region, according to one embodiment.

[0028] Fig. Figure 5B is a schematic horizontal cross-sectional view of a SiC clamping diode according to an embodiment, wherein an avalanche breakdown takes place in a central region of the SiC clamping diode.

[0029] Fig. Figure 6A is a schematic vertical cross-sectional view of a section of a SiC terminal diode with a pn junction according to an embodiment based on an MPS (merged pin Schottky) diode.

[0030] Fig. Figure 6B is a schematic vertical cross-sectional view of a section of a SiC clamping diode without a pn junction according to an embodiment based on a TMPS (trench MOS barrier Schottky) diode.

[0031] Fig. Figure 6C is a schematic vertical cross-sectional view of a section of a clamping diode with a pn junction according to an embodiment based on a TOPS (trench oxide pin Schottky) diode.

[0032] Fig. 6D is a schematic vertical cross-sectional view of a section of a clamping diode according to an embodiment based on an IDEE (inverse injection dependency of emitter efficiency) diode.

[0033] Fig. Figure 6E is a schematic vertical cross-sectional view of a section of a clamping diode according to an embodiment based on a SiC pin diode with an avalanche breakdown that is pinned in a device region which is laterally homogeneous except for pinning regions.

[0034] Fig. Figure 7 is a schematic circuit diagram of an electrical assembly with parasitic inductances for discussing effects of the embodiments.

[0035] Fig. Figure 8A is a schematic circuit diagram of an electrical assembly according to an embodiment which includes a feedback path utilizing a voltage drop across an inductor.

[0036] Fig. Figure 8B is a schematic circuit diagram of an electrical assembly according to an embodiment comprising a feedback path utilizing a voltage drop across an ohmic resistor.

[0037] Fig. Figure 9A is a schematic top view of a direct copper-bonded circuit board with an electrical assembly according to an embodiment with a feedback path comprising bonding wires.

[0038] Fig. Figure 9B is a schematic top view of a direct copper-bonded circuit board with an electrical assembly according to another embodiment having a feedback path comprising a looping strip conductor.

[0039] Fig. Figure 10 is a schematic diagram of a half-bridge circuit comprising SiC clamping diodes in parallel with semiconductor switching devices according to a further embodiment.

[0040] Fig. Figure 11 is a schematic diagram of a smart IGBT module comprising SiC clamping diodes in parallel to semiconductor switching devices according to a further embodiment. DETAILED DESCRIPTION

[0041] The following detailed description refers to the accompanying drawings, which form part of the disclosure and show specific embodiments for illustrative purposes in which the invention can be implemented. It is understood that other embodiments can be used and structural or logical modifications can be made without departing from the scope of the present invention. For example, features illustrated or described for one embodiment can be used in or in conjunction with other embodiments to arrive at yet another embodiment. It is intended that the present invention encompasses such modifications and changes. The examples are described using specific language, which should not be interpreted as limiting the scope of the appended claims.The drawings are not to scale and are for illustrative purposes only. Corresponding elements are marked with the same reference symbols in the various drawings unless otherwise stated.

[0042] The terms "have," "contain," "comprise," "exhibit," and similar terms are open-ended, indicating the presence of the identified structures, elements, or features, but not excluding the presence of additional elements or features. Indefinite and definite articles should encompass both the plural and singular unless the context clearly indicates otherwise.

[0043] The figures illustrate relative doping concentrations by indicating “–” or “+” next to the doping type “n” or “p”. For example, “n” means –“a doping concentration that is lower than the doping concentration of an “n” doping region, while an “n + A doping area with a relative concentration of n has a higher doping concentration than an n doping area. Doping areas with the same relative concentration doping do not necessarily have the same absolute concentration. For example, two different n doping areas can have the same or different absolute concentrations of doping.

[0044] Fig. 1A to Fig. 1D refers to an electrical assembly 500, which can, for example, be part of a single-sided or asymmetrical switching device or a half-bridge circuit, where the half-bridge circuit can be part of an H-bridge, a motor controller, or a power converter, for example, a DC / AC power converter, an AC / AC converter, or a DC / DC converter. The electrical assembly 500 can form or be part of a high-side switch, or can form or be part of a low-side switch of the half-bridge circuit.

[0045] Fig. 1A shows a semiconductor switching device 510 , which, in response to a signal applied to a control terminal Ctr, switches a load current between a first load terminal L1 and a second load terminal L2. The switching device 510This can be an IGFET, for example a MOSFET (metal-oxide-semiconductor field-effect transistor) in the usual sense, which includes metal gates and semiconductor gates, or an IGBT. One of the first and second load terminals L1, L2, for example the first load terminal L1, is on the input or supply side and can be electrically coupled to a power supply. The other of the first and second load terminals L1, L2, for example the second load terminal L2, is on the load side and can be electrically coupled to a load supplied by the power supply.

[0046] In the off state, the switching device locks 510 A positive voltage is applied across the first and second load terminals L1 and L2. If, starting from an off state, a signal applied to the control terminal Ctr rises above or falls below a threshold voltage, the switching device switches. 510and opens a low-resistance path between the first and second load terminals L1, L2 for a load current through the switching device 510 and the load. When the signal applied to the control terminal CTR returns to the level of the off state, the switching device switches. 510 out of.

[0047] An inductance in a load circuit or load current circuit, which is affected by the load current through the switched-on switching device. 510 The supply can generate an additional voltage drop. The effect of the load's inductance, which can be a motor winding or a transformer winding, can be dissipated by further devices such as freewheeling diodes. The effect of parasitic inductances within the commutation circuit, for example, the inductance of conductive paths within the electrical assembly, can also be mitigated. 500 or the inductance of wiring connections with the electrical assembly500 The overvoltage is typically not dissipated via external circuit elements. An overvoltage resulting from parasitic inductances on the supply or input side can cause the potential at the first load terminal L1 to exceed the positive supply voltage. Additionally or alternatively, parasitic inductances on the switched side can cause the potential at the second load terminal L2 to fall below the negative supply voltage. Current surges and grid overvoltages can be superimposed on the supply voltage and can be an alternative or additional source of overvoltage across the first and second load terminals L1 and L2.

[0048] If the resulting overvoltage causes the switching device to 510If the circuit begins to fail or break down, and the resulting breakdown current through the switching device has a sufficiently high current rise rate di / dt, or if an excessively high current is controlled on the breakdown branch, the overvoltage can trigger a destructive mechanism in the switching device. 510 , for example, trigger a destructive avalanche. For example, IGBTs designed for low resistance and low switching losses can be sensitive to overvoltage, since a design for low losses typically does not align with overvoltage withstand limitations.

[0049] A clamping diode 560 with a semiconductor body based on silicon carbide and an avalanche breakdown voltage that is lower than a maximum breakdown voltage value of the switching device 510 is, protects the switching device 510reliably protects against destructive overvoltage conditions. For example, the avalanche breakdown voltage of the clamping diode 560 at least 10%, for example at least 20% lower than a maximum breakdown voltage value of the switching device 510 within the complete nominal temperature range of the switching device 510 .

[0050] If the clamping diode 560 on its breakthrough branch at least 500% or 400% of a maximum continuous or long-term load current value of the switching device 510 The clamping diode can withstand a time of at least 1 μs, 100 ns or 10 ns. 560 protected from being destroyed when the switching device 510 It is switched off after a short circuit condition is detected.

[0051] If the clamping diode 560 on its breakthrough branch at least 200% or 100% of a maximum long-term load current value of the switching device 510The clamping diode can withstand for at least 10 ns, 500 nm, 1 μm or 5 μs seconds. 560 to be protected from being destroyed by occasional overvoltage conditions that occur at a repetition rate of less than 0.1 Hz in applications such as flyback converters.

[0052] If the clamping diode 560 on its breakthrough branch at least 200%, 150% or 100% of a maximum long-term load current value of the switching device 510 The clamping diode can withstand a repetition rate of up to 16 kHz during a total overload period of at least 20 s, 1 s or 100 ms. 560 to protect against being destroyed by repeated overvoltage conditions that occur under overload conditions in servomotors with switching frequencies of typically up to 16 kHz and overload periods of up to 20 s.

[0053] Another definition of avalanche insensitivity or avalanche resistance can be defined with regard to applications in half-bridge circuits and a periodic load current flowing through an inductive load electrically connected to a network node between a high-side switch and a low-side switch.

[0054] Fig. Figure 1B shows the periodic load current ILD with a period T and a peak current IPK. The clamping can be active when the load current ILD exceeds 50%, 80%, or 90% of the peak current. If the clamping diode is not functioning during the clamping period... 560 on its breakthrough branch at least 150%, 120% or 100% of a maximum long-term load current value of the switching device 510 The clamping diode can withstand repeated pulses with a duration of at least 10 ns, 100 ns or 1 μs. 560protected from being destroyed by successive overvoltage states that occur around peaks of a periodic load signal at a repetition rate typical for switching frequencies up to 10 kHz, 20 kHz or 50 kHz.

[0055] Due to the material properties of silicon carbide, the clamping diode holds 560 comparatively high breakdown currents up to, for example, 5000 A / cm 2 or more without loss of blocking capacity immediately after the avalanche breakthrough ended.

[0056] Unlike silicon-based clamping diodes, such as Si-TVS (silicon transient voltage suppressor) diodes, a single clamping diode can withstand a reverse voltage of more than 650 V, 1200 V, 1700 V, or higher. In SiC diodes, the breakdown voltage is less temperature-dependent than in silicon diodes. As a result, the voltage across the load terminals L1 and L2 remains more stable. The steep I / V characteristic of SiC diodes means that the voltage increases only slightly after breakdown.

[0057] SiC diodes typically exhibit higher background doping, so that when the semiconductor body is flooded with charge carriers in an avalanche breakdown, the charge carrier distribution and current density are more uniform than in silicon. Local overheating can be avoided to a greater extent, resulting in higher avalanche insensitivity and resistance.

[0058] The electrical assembly 500 can be part of a one-sided or asymmetrical switch, wherein a freewheeling diode for dissipating energy stored in a magnetic field of an inductive load is typically connected to the semiconductor switching device 510 is connected in parallel. The clamping diode 560 can be effective like a freewheeling diode, or another diode that is essentially used as a freewheeling diode can be used with the clamping diode 560 be electrically connected in parallel.

[0059] According to other embodiments, the electrical assembly 500Part of a half-bridge circuit. In half-bridge circuits, a high-side switch and a low-side switch are electrically connected in series with respect to their load paths. A load is connected to an intermediate network node that connects the high-side and low-side switches. A gate driver circuit alternately turns the high-side and low-side switches on and off.

[0060] If the switching devices of the half-bridge circuit are IGFETs, a body diode of the high-side switch allows a current to flow that dissipates energy stored in the inductors on the switched load side after the low-side switch has turned off.

[0061] If the switching devices of a half-bridge circuit are IGBTs, after the low-side switch has turned off, a freewheeling diode connected in parallel with the high-side switch allows a current to flow, dissipating energy stored in the inductors on the switched load side. After the high-side switch has turned off, a freewheeling diode connected in parallel with the low-side switch allows a current to flow, dissipating energy stored in the inductors on the switched load side.

[0062] In both cases, the body diodes and the freewheeling diodes operate in forward or conduction mode. Since the body diodes and the freewheeling diodes are typically not avalanche-proof, their blocking capability is typically the same as or higher than that of the semiconductor switch to which they are assigned. In contrast, the clamping diode responds 560 According to the embodiments, this results in a reversed overvoltage state. The clamping diode 560 protects the switching device 510 before being exposed to a voltage exceeding the maximum breakdown voltage value. Since the clamping diode 560 at least 80% of a maximum long-term load current value of the switching device 510 The clamping diode can withstand at least 500 ns, 1 μs or 5 μs. 560protected from being destroyed by repeated overvoltage conditions occurring in switching cycles with a repetition rate of no more than 50 kHz.

[0063] Compared to conventional approaches that avoid destructive overvoltage conditions by selecting switching devices with a maximum voltage breakover value far beyond the highest supply voltage, i.e., by taking into account a high safety tolerance in terms of breakdown voltage at the expense of power efficiency, the clamping diode enables 560 the use of switching devices 510 with lower electrical losses.

[0064] For an application providing a voltage of no more than 600 V, a conventional half-bridge circuit, for example, might typically include switching devices with a maximum breakdown voltage of 1200 V, with 1200 V devices typically exhibiting significantly higher losses than 600 V devices. This is due to the high overvoltage insensitivity or resistance of the electrical assembly. 500 Can a 900 V switching device with inherently lower losses replace the 1200 V switching device without loss of reliability?

[0065] Due to the breakdown-resistant clamping diode 560 is the electrical assembly 500 Less sensitive to parasitic inductances. Wiring between components of the electrical assembly. 500 as well as the wiring of an electrical module that includes the electrical assembly 500It can do without expensive, low-inductance wiring connections. Design requirements for wiring to / from component carriers, such as a PCB (printed circuit board), are less stringent.

[0066] In Fig. 1C illustrates a reference voltage curve 411 as well as a reference current curve 412 the switching behavior of the switching device 510 from Fig. 1A without the clamping diode 560 After the shutdown process begins, the voltage V rises. L1L2 The voltage rises steeply between the first and second load connections L1, L2 at t = t0. After a certain time, the voltage begins to rise at V. L1L2 = V S (V DC ) the load current I L to drop steeply. Energy that is stored in the magnetic fields of parasitic inductances on the switched load side or between the voltage source, which supplies the voltage V SThe current supplied and stored at the load connection on the supply side induces a dissipation current that increases the potential on the supply side and / or the potential on the switched load side of the switching device. 510 below the lower potential of the supply voltage V S reduced. A significant overvoltage condition can occur. In half-bridge configurations, a turn-on overvoltage of a freewheeling diode in the complementary circuit can be superimposed on the potential at the switched side. The voltage V L1L2 can determine the maximum breakdown voltage value V BR the switching device 510 from Fig. exceed 1A.

[0067] A voltage curve 401 as well as a current curve 402 illustrate the switching behavior of the electrical assembly 500 from Fig. 1A with the clamping diode 560After the shutdown begins at t = t0, the voltage V increases. L1L2 steeply rising. If the voltage across the electrical assembly is at t = t1 500 the avalanche breakthrough voltage V AV the clamping diode 560 If the voltage exceeds the threshold, the latter begins to conduct. The voltage across the switching device 510 does not exceed the avalanche breakthrough stress V AV , which is higher than the supply voltage V S and lower than the maximum breakdown voltage value V BR the switching device 510 is.

[0068] The clamping diode 560An avalanche diode is designed to safely handle the avalanche phenomenon without being destroyed. In an avalanche diode, the avalanche breakdown occurs in a central region, whereas in other diodes, the avalanche breakdown typically occurs in a terminal or termination region between the central region and an outer lateral surface of a semiconductor body. Avalanche diodes typically specify a maximum repetitive area-specific avalanche energy E. AR / A of at least 0.5 J / cm² 2 or at least 2 J / cm² 2 for impulses of 2 μs or at least 10 J / cm 2 for pulses of 20 μs at a pulse duty cycle of 0.1%. In contrast, in Schottky diodes the maximum electric field strength is close to the metal-semiconductor interface, meaning that Schottky diodes are typically not suitable avalanche diodes.

[0069] Fig. 1D shows the safe operating range of the clamping diode 560 from Fig. 1A for occasional avalanche events according to one embodiment. For example, for a SiC clamping diode with a chip size of 5 mm 2 the clamping diode 560 to remain in a state of avalanche breakthrough for 20 μs without being irreversibly damaged, provided that the avalanche flow I AV does not exceed 25 A.

[0070] Fig. 2 refers to an electronic assembly according to an embodiment which incorporates a 1200 V SiC MPS diode as a clamping diode with an avalanche breakdown voltage V AV = 1200 V, which is equipped with a 1700 V Si IGBT with a maximum breakdown voltage value V BR = 1700 V is electrically connected in parallel as a switching device.

[0071] At t = t0, the V decreases G -voltage curve 423 for the gate voltage V Gfrom above a threshold level to below the threshold level and switches off the 1700 V-Si-IGBT. A V CE -voltage curve 421 for the collector-emitter voltage V CE The voltage rises steeply via the first and second load connections L1 and L2. At V CE = V AS the 1200 V-Si-MPS diode breaks down, so that V CE The voltage does not exceed approximately 1600 V. The 1700 V Si IGBT is protected against any overvoltage conditions.

[0072] An egg L -current bend 422 for a load current I L The electronic assembly shows a less steep fall-off for the time the clamping diode is in the avalanche state. An E AR -Curve 424 for the dissipated avalanche energy E AR rises to a maximum value E during an avalanche cycle AS from about 150 mJ. The dissipated avalanche energy E ASheats up the 1200 V SiC MPS diode and exhibits a perceptible change in V CE as a result, although the change is significantly smaller than for silicon diodes.

[0073] The intrinsic charge carrier density in silicon carbide is low even at relatively high temperatures up to about 1000°C. As a result, the leakage current of a blocking SiC MPS diode, or any other silicon carbide diode, is low even immediately after recovering from an avalanche breakdown, whereas silicon diodes, for example silicon TVS (transient voltage suppressors), exhibit a significant leakage current immediately after recovering from an avalanche breakdown.

[0074] The switching device 510 from Fig. 1A can be a single semiconductor switch or it can comprise a multitude of semiconductor switches electrically connected in parallel. The electrical assembly 500It may also include components such as conventional Si-FWDs for dissipating energy temporarily stored in inductive loads and / or Schottky diodes to achieve a better compromise between noise and recovery current.

[0075] In Fig. 3A comprises an electrical assembly 500 a Si-IGBT 511 with a collector electrode C, which is electrically connected to the first load terminal L1, and an emitter electrode E, which is electrically connected to the second load terminal L2. A signal applied to a gate terminal G switches the Si IGBT. 511 On and off. A cathode electrode K of the clamping diode 560 is directly electrically connected to the first load electrode L1, to the collector electrode C, or to both. An anode electrode A of the clamping diode 560 The clamping diode is electrically connected to the second load terminal L2, to the emitter electrode E, or to both directly.560 is an avalanche diode with a SiC-based semiconductor body and an avalanche breakdown voltage below the maximum breakdown voltage value of the Si-IGBT 511 .

[0076] In Fig. 3B comprises the electrical assembly 500 furthermore, a freewheeling diode 519 The freewheeling diode 519 Can a silicon diode have a higher breakdown voltage than the avalanche breakdown voltage of the clamping diode? 560 be the freewheeling diode 519 can be part of a commutation circuit, which may include another semiconductor switch connected to the electrical assembly 500 electrically arranged in series.

[0077] A cathode electrode KF of the freewheeling diode 519 is connected to at least one of the cathode electrode C, the cathode electrode K of the clamping diode 560and the first load terminal L1 is directly electrically connected. An anode terminal AF of the freewheeling diode 519 is connected to at least one of the emitter electrode E, the anode electrode A of the clamping diode 560 or the second load connection L2 is directly electrically connected.

[0078] If the Si-IGBT 511 When in an off state, the freewheeling diode 519 operate in a forward-biasing mode when an inductive load reverses the polarity of the voltage across the first and second load terminals L1, L2 with respect to the polarity of the voltage across the first and second load terminals L1, L2 when the Si-IGBT 511 is in the on state.

[0079] Like the freewheeling diode 519 If it is conductive, a commutation current can flow between the freewheeling diode. 519 and the clamping diode 560 to be divided up.

[0080] The freewheeling diode 519can be selected to achieve a low forward voltage, so that the electrical assembly 500 exhibits both low ohmic losses during commutation and a steep clamping behavior, which is due to the characteristics of the SiC clamping diode. 560 is defined.

[0081] Furthermore, the freewheeling diode conducts 519 typically periodic, and the forward current heats the freewheeling diode. 519 instead, the clamping diode breaks. 560 Typically, this only happens in exceptional cases. Therefore, the clamping diode 560 with a smaller active area designed to withstand the same avalanche flow.

[0082] A bipolar current through the clamping diode 560This generates a dense charge carrier plasma in which significant recombination takes place. In SiC, the energy released during recombination can locally damage the crystal lattice, so that a bipolar current steadily degrades the SiC clamping diode. In combination with the freewheeling diode 519 can the SiC clamping diode 560 so that a bipolar current flows through the SiC terminal diode 560 can be avoided.

[0083] Fig. 3C shows the transmission characteristics 451 the freewheeling diode 519 and the passage characteristics 452 the SiC terminal diode 560 from Fig. 5A according to an embodiment with a nominal forward current of the freewheeling diode 519, which is selected such that the resulting forward voltage VFnom is lower than a minimum voltage VFmin at which the SiC clamping diode switches from the unipolar conducting mode, in which only one type of charge carrier flows, to a bipolar conducting mode, in which both types of charge carriers flow. To prevent the SiC clamping diode 560 switching to bipolar conducting mode simultaneously avoids deterioration of the SiC clamping diode 560 .

[0084] In Fig. 3D is the switching device 510 an IGFET 512 , whose internal body diode 512a can be effective as a freewheeling diode.

[0085] In Fig. 3E is the switching device 510 an RC-IGBT 511 , whose reverse-conducting diode 511a can be effective as a freewheeling diode.

[0086] In Fig. 3F includes the freewheeling diode 519 from Fig. 2B a Si-PND (silicon pn diode) 519x as well as a SiC-SBD (silicon carbide Schottky barrier diode) 519y The Si-PND 519x typically suffers from a large recovery current resulting from charge carriers that are stored and discharged in the diode during forward conduction mode when the Si-IGBT 511 switches on. The large recovery current results in high switching losses. On the other hand, the Si-SBD 519y A unipolar device with a very low recovery current. However, an excessively low recovery current can result in sharp changes in the load current, which, in combination with capacitance and inductance components, can induce noise in the load circuit. A freewheeling diode, the Si-PND 519x and the SiC-SBD 519yThis allows for the optimization of a compromise between noise and recovery current. The compromise can be adjusted by setting a suitable area ratio between the Si-PND. 519x and the SiC-SBD 519y is selected for the pass-through mode. The SiC-SBD 519a Reduces recovery losses. In contrast, the clamping diode protects 560 the Si-IGBT 511 , the SiC-SBD 519y and the Si-PND 519x against overvoltage.

[0087] In the lock mode of the SiC-SBD 519y The highest electric field at the metal-semiconductor interface is so effective that charge carriers are drawn directly into the semiconductor body. 100 They can be obtained without generating electron / hole pairs. The SiC-SBD 519y It breaks through or blocks without the avalanche phenomenon occurring. As a consequence, the reverse or blocking current remains comparatively low, and the SiC SBD 519y can the Si-IGBT 511They do not protect against overvoltage, even if the SiC-SBD 519y exhibiting a lower breakdown voltage. Instead, it generates voltage in the clamping diode. 560 the avalanche breakthrough electron / hole pairs, so that the reverse current is high and the clamping diode 560 the Si-IGBT 511 effectively protects against overvoltage.

[0088] In Fig. 3G includes the electrical assembly 500 a large number of semiconductor switches connected electrically in parallel, for example two, three or more Si-IGBTs 511a , 511b , 511c .... With every Si-IGBT 511a , 511b , 511c ... can a freewheeling diode 519a , 519b , 519c ...be electrically connected in parallel. A single clamping diode 560 can be used with the two, three or more Si-IGBTs 511a , 511b , 511c ...be electrically connected in parallel. The electrical assembly 500It can be integrated into an IHM (IGBT high-performance module) designed for load currents from 500 A to 4 kA. A housing 590 may include initial sets of load connections L1a, L1b, L1c, ... which connect to the individual Si-IGBTs 511a , 511b , 511c , ... are assigned, and second sets of load connections L2a, L2b, L2c, ..., the individual Si-IGBTs 511a , 511b , 511c ...are assigned. The electrical assembly 500 It could be the high-side part or the low-side part of a half-bridge circuit.

[0089] In Fig. 4A shows an I / V characteristic 431 a maximum breakdown voltage value V of a Si-IGBT BR , and an I / V characteristic 432 A SiC terminal diode of a switching assembly exhibits an avalanche breakdown voltage V AV , which are at least 10% lower than V BRis, in a current range for which the Si-IGBT is to be used, for example, for currents up to 20 A, 100 A, or 200 A. In an approximately linear section of the I / V characteristic. 432 The SiC clamping diode, with its maximum load current Imax, has a ΔV / ΔI ratio of at most 2 V / A for an active diode area of ​​2.5 mm². 2 in a steep section of the I / V characteristic, where the steep section is defined as the part of the I / V characteristic beyond a current density of 40 A / cm² 2 or with a current density per volt of at least 1 mA / mm 2 / V can be defined.

[0090] Fig. Figure 4B shows the I / V characteristic. 431 of the Si-IGBT of Fig. 4A and the I / V characteristic 433 a SiC-SBD. The I / V characteristic 433 The Si-SBD is significantly flatter than the I / V characteristic. 432the clamping diode according to the present embodiments. Even if the Si-SBD is subjected to a voltage similar to V AV from Fig. When the 4A circuit begins to break down or block, the voltage across the SiC-SBD can exceed the breakdown voltage V. BR The voltage of the Si-IGBT increases, so that the SiC-SBD cannot reliably protect the Si-IGBT from destruction by overvoltage events, because a breakdown occurs in a transition termination in the SiC-SBD or the Schottky barrier is breached.

[0091] The clamping diode 560 uses the avalanche breakthrough to increase the voltage via the switching device 510to limit. Typically, SiC diodes are designed to meet requirements regarding on-resistance and switching losses. If an avalanche breakdown occurs, it happens in an edge region of the SiC diode's semiconductor body, so that the entire avalanche current flows only in a comparatively small section of the semiconductor body. The semiconductor crystal can overheat locally and be irreversibly damaged.

[0092] In Fig. 4C shows curve 431 the I / V characteristic of a silicon clamping diode at T = 25 degrees Celsius and curve 432 The I / V characteristic of the same diode at a maximum operating temperature. The silicon clamping diode can be used to protect a switching device with a maximum breakdown voltage value of VBRIGBT1.

[0093] Fig. 4D shows equivalent curves 441 , 442For a SiC clamping diode at T = 25 degrees Celsius and at its maximum operating temperature. The smaller shift in the I / V characteristic with increasing temperature means that the switching device can be selected with a lower maximum breakdown voltage value (VBRIGBT2). Typically, an IGBT with a lower maximum breakdown voltage value can be implemented with lower conduction and switching losses.

[0094] Fig. 5A shows a clamping diode 560 , which is designed to withstand repeated avalanche breakthroughs in typical power conversion and motor control applications.

[0095] A metal anode 310 borders directly on a first surface 101 on a front side of a semiconductor body 100 The metal anode 310 can a Schottky barrier layer 311 a first metal and a contact layer 312comprise a second metal. The metal anode 310 forms an anode terminal A or is electrically connected to one.

[0096] A cathode metal 320 borders directly on a second surface on top of the first surface. 101 opposite back. A lateral outer surface 103 , which against the first and second surfaces 101 , 102 It is inclined, connecting the first and second surfaces 101 , 102 The metal cathode 320 forms a cathode terminal K or is electrically connected to one and borders directly on a highly n-doped cathode region 129 , which has an ohmic contact with the metal cathode 320 educates.

[0097] Between the first surface 101 and the cathode area 129 can the semiconductor body 100 a slightly or moderately n-doped drift zone 121and field-forming structures 130 include. If a reverse or blocking voltage exists between the metal anode 310 and the metal cathode 320 As it is created, the field-forming structures take shape. 130 the electric field such that the maximum electric field strength in one of the first surfaces 101 distant area is present. The semiconductor body 100 Highly p-doped anode zones can also be in ohmic contact with the metal anode. 310 include.

[0098] In a central area 610 Both the metal anode and the metal anode are bordered by 310 as well as the metal cathode 320 directly to the semiconductor body 100 , and the semiconductor body 100 is between the metal anode 310 and the metal cathode 320 Arranged in a sandwich-like fashion in the central area 610 A forward current I flows Fwd in a vertical direction through the semiconductor body100 In a concluding section 690 , which covers the central area 610 from the outer surface 103 separating, separates an interlayer dielectric 210 the metal anode 310 from the semiconductor body 100 In the final section 690 A forward current vector has a component horizontal to the first surface 101 , and no charge carriers pass through the first surface 101 .

[0099] The clamping diode 560 According to the embodiments, the avalanche breakthrough is limited within the central area. 610 Since the central area 610 Because the terrain is relatively homogeneous, the avalanche flow can quickly spread across the entire central area. 610 Distribute the heat. Local overheating can be avoided, and the clamping diode... 560 demonstrates sufficient avalanche resistance against repeated, periodic avalanche breakthroughs.

[0100] If the reverse voltage in SiC-SBDs is high enough, so that the electric field in the semiconductor body 100 Overlapping with the metal-semiconductor interface, the electric field supports the transfer of charge carriers from the metal anode. 310 in the semiconductor body 100 In typical Schottky diodes, the maximum electric field strength is located at the metal-semiconductor interface on the anode side. Therefore, Si-SBDs suffer from a comparatively high leakage current. Instead, [the following occurs] in the semiconductor bodies. 100 the clamping diodes 560 of the present embodiments the field-forming structures 130 the electric field such that the maximum electric field strength is at a distance from the metal anode 310 occurs.

[0101] Fig. Figure 5B shows Schottky contacts SC, which have regularly arranged, separated hexagonal frames in the central area. 610form. Anode zones of MPS diodes or other field-forming structures. 130 can be formed between and / or within the hexagonal frames. A finishing area 690 is free of Schottky contacts SC and can be a JTE (Junction or Transition Termination Extension) 691 include. For clamping diodes with anode zones, the JTE can 691 It comprises one or more zones with a lower net dopant concentration than the anode zones. The maximum electric field strength occurs in the central region. 610 on.

[0102] The embodiments of Fig. 6A to Fig. 6C refers to field-forming structures 130 , which shape the electric field in such a way that the maximum electric field strength is achieved at a distance from the metal anode 310 is available.

[0103] Fig. 6A shows the central area of ​​an MPS diode 561 The field-forming structures130 are isolated anode zones 132 , which extend from the first surface 101 into the drift zone 121 extend. The anode zones 132 pn junctions pn0 form with the drift zone 121 The anode zones 132 They can be strip-shaped with one horizontal dimension significantly exceeding the second horizontal dimension, which is orthogonal to the first; they can be more point-like, with both horizontal dimensions being of the same order of magnitude; or they can form a hexagonal lattice. Between adjacent anode zones 132 border sections of the drift zone 121 directly to a metal anode 310 and form Schottky contacts SC with the metal anode 310 .

[0104] In forward bias mode, the Schottky contacts SC deliver a unipolar forward current, resulting in a low reverse recovery charge. In reverse bias mode, vertical pn junctions constrict the drift zone. 121 and the anode zones 132 the Schottky contacts SC, as indicated by the shape of the impoverishment zone 115 is displayed. As a consequence, the maximum field strength E appears. max at a distance d AV to the first surface 101 . As the blocking voltage increases, the maximum electric field strength E approximates max the avalanche field strength, and an avalanche breakthrough begins in the semiconductor body 100 at a distance from the first surface 101 .

[0105] In Fig. 6B includes the field-forming structures 130 a TMBS diode 562 polycrystalline silicon plugs or stoppers 134, which extend from the first surface 101 in the semiconductor body 100 extend. Horizontal cross-sections of the polysilicon plugs 134 They can be point-like, strip-like, or form a grid. An insulating layer. 135 isolates the polysilicon plugs 134 completely from the semiconductor body 100 Schottky contacts (SC) are located between adjacent polysilicon plugs. 134 trained.

[0106] If the TMBS diode 562 When the plug is biased in the blocking direction, the anode potential of the polysilicon plugs is depleted. 134 adjacent sections of the drift zone 121 With increasing blocking preload, depletion areas of adjacent plugs overlap. 134 The resulting area of ​​impoverishment 115 It constricts the Schottky contacts SC and suppresses any leakage current induced at the Schottky contacts SC. The electric field strength has a maximum E max at a distance dAV to the first surface 101 .

[0107] Fig. 6C refers to a TOPS diode 563 with field-forming structures 130 , the conductive plugs 134 include those that extend from the first surface 101 into the drift zone 121 extend. Insulator structures 135 line the vertical sidewalls of the conductive plugs 134 out. In the vertical projection of the conductive plugs 134 form separate, highly p-doped anode zones 132 pn transitions pn0 with a drift zone 121 The insulator structures 135 They prevent the diffusion of p-type dopants in a lateral direction and support the formation of the anode zones. 132 at a distance from the first surface 101 Schottky contacts (SC) are used between adjacent polysilicon plugs. 134 formed. The maximum electric field strength E maxoccurs at a distance d AV to the first surface 101 on.

[0108] In Fig. 6D comprises a semiconductor body 100 a SiC IDEE diode 564 , which is used as a clamping diode, anode zones 132 and oppositely endowed channels 138 between the anode zones 132 Highly doped channel contact zones 137 of the conductivity type of the channels 138 form ohmic contacts with the metal anode 310 Dopant concentrations and dimensions of the anode zones 132 and the canals 138 are selected in such a way that an electric field encircles the channels 138 in a reverse-biased state of the clamping diode 560 completely depleted of mobile load carriers.

[0109] In Fig. 6E comprises a semiconductor body 100 a SiC pin diode 565 , which act as a clamping diode 560 is used to create an anode zone 132, which has a pn junction pn0 with a slightly n-doped drift zone 121 forms. An n-doped field stop layer 128 with a net dopant concentration that corresponds to a mean net dopant concentration in the drift zone 121 exceeds at least five times, can be determined between the drift zone 121 and the cathode area 129 The anode zone should be arranged in a sandwich-like fashion. 132 defines a device area. Within the device area are the anode zones. 132 , the field stop zone 128 and the drift zone 121 outside one or more pinning areas 139 Laterally homogeneous. Within the pinning area. 139 The avalanche breakthrough stress is locally reduced. For example, in the pinning area 139 the anode zone 132 containing a higher-quality section, the drift zone can 121contain a higher-doped section and / or a vertical extension of the field stop layer 128 This can vary. An avalanche breakthrough begins in the pinning zone. 139 and spreads into the fixture area. For example, in the pinning area 139 the field stop layer 128 and / or the anode zone 132 locally deeper into the drift zone 121 than outside the pinning area 139 extend.

[0110] Fig. 7 refers to an electrical assembly 500 , which are a component carrier 590 includes, which can be a PCB. A clamping diode. 560 is as close as possible to a Si-IGBT 511 arranged so that a parasitic inductance exists between the clamping diode 560 and the Si-IGBT 511 and a freewheeling diode 519 The effective value is as low as possible. For example, the cathode K of the clamping diode560 , the cathode KF of the freewheeling diode 519 and the collector C of the Si-IGBT 511 directly connected by a conductive plate, so that there is virtually no inductance between the cathode K of the clamping diode 560 and the collector C of the Si-IGBT 511 is effective. Conductors on a circuit board can be used to control the collector electrode C of the Si-IGBT. 511 Connect the first load terminal L1 electrically, forming a first parasitic inductance Lpar1. Connecting or bonding wires can connect the emitter electrode E of the Si-IGBT. 511 They can be electrically connected to the second load terminal L2 and form a second parasitic inductance Lpar2.

[0111] A voltage drop across a bond wire or other connector between the anode terminal A of the clamping diode 560 and the second load connection L2 can be used for a feedback circuit 580 as in Fig. 8A and Fig. 8B can be used to illustrate this.

[0112] In Fig. 8A and Fig. 8B includes an electrical assembly 500 a semiconductor switching device, for example a Si-IGBT 511 , which withstands a maximum breakdown voltage across two load terminals L1, L2 in an off state. A clamping diode 560 It is electrically connected to the two load terminals L1 and L2, and in parallel to the switching device. An avalanche breakdown voltage of the clamping diode. 560 is lower than the maximum breakdown voltage of the switching device. A freewheeling diode 519 can be used with the clamping diode 560 be electrically connected in parallel.

[0113] For example, a semiconductor body of the clamping diode consists 560It is made of crystalline silicon and can include anode zones and oppositely doped channels between the anode zones. The dopant concentrations and dimensions of the anode zones and channels are selected such that the channels are in a reverse-biased state of the clamping diode. 560 are completely depleted of mobile charge carriers. According to another embodiment, the clamping diode 560 any of the SiC diodes discussed above.

[0114] If in Fig. 8A the clamping diode 560 When the electrode becomes conductive during the avalanche breakthrough, the increasing current can be used via a bond wire or a conductive path to increase the potential at the gate electrode G of the Si-IGBT. 511 to increase. The Si-IGBT 511 can become partially conductive, so that some of the power supplied by the overvoltage is transferred to the Si-IGBT 511 is dissipated.

[0115] For this purpose, a feedback path connects 582 an anode electrode A of the clamping diode 560 with a control 581 , which is connected to the gate electrode G of the Si-IGBT 511 is electrically connected. The control element 581 receives a potential via a feedback impedance 585 , which is connected between the anode electrode A and the second load terminal L2, wherein the control element 511 the inductance of the feedback impedance 585 , can take the resistance or both into account. The control element 581 It can be a voltage-controlled voltage, a current source, or a gate driver circuit that can be controlled by a signal applied to a control input. The feedback impedance 585 It can be a bond wire, a conductive path on a circuit board, a separate element, or any combination thereof. Since part of the clamping current in the Si-IGBT 511When dissipated, the clamping diode must 560 transmit or transport a lower avalanche flow and can have a smaller contour than without the feedback circuit. 580 exhibit.

[0116] In Fig. 8B receives and evaluates the control element 581 a potential via an ohmic feedback impedance 585 out of.

[0117] In Fig. 9A and Fig. 9B includes electrical assemblies 500 a carrier board 599 e.g., a PCB (printed circuit board) or a DCB (direct copper bonded) board. At least a first conductor structure. 591 and a second ladder structure 592 are on a mounting surface of the carrier board 599 trained. The first ladder structure 591 forms a first load connection L1 or is electrically connected to one. The second conductor structure 592forms a second load connection L2 or is electrically connected to one. The first and second conductor structures 591 , 592 These can be copper pads or contact points, or copper strips.

[0118] A Si-IGBT 511 , a freewheeling diode 519 and a clamping diode 560 are on the first ladder structure 591 mounted, for example soldered or bonded side by side, with the cathodes of the freewheeling diode 519 and the clamping diode 560 as well as the collector of the Si-IGBT 511 the first ladder structure 591 Contact us directly. Bond wiring 586 connect the exposed anode terminal AF of the freewheeling diode 519 and the exposed anode terminal A of the clamping diode 560 electrically with the second conductor structure 592 .

[0119] In Fig. 9A forms the bond wiring. 586 between the clamping diode 560and the second ladder structure 592 part of the feedback impedance 585 from Fig. 8A. The feedback impedance can be increased by increasing the number of bond wires in the bond wiring. 586 between the clamping diode 560 and the second ladder structure 592 is reduced or by lengthening the bond wires.

[0120] In Fig. 9B can create a loop 587 in the second ladder structure 592 between the Si-IGBT 511 and the clamping diode 560 the feedback impedance 585 increase.

[0121] Fig. 10 refers to a section of an electronic assembly 600, which could be, for example, a motor drive, a switched-mode power supply, a primary stage of a switched-mode power supply, a synchronous rectifier, a primary stage of a DC-AC converter, a secondary stage of a DC-AC converter, a primary stage of a DC-DC converter, or part of a solar power converter.

[0122] The electronic assembly 600 can two identical electrical assemblies 500 as described above, which are arranged as low-side and high-side switches in a half-bridge configuration. The electrical assemblies 500 can IGBTs 511 with parallel clamping diodes 560 include, and the load paths of the two electrical assemblies 500The two electrical components are connected in series between a first supply terminal A and a second supply terminal B. Supply terminals A and B can provide either a DC (direct current) or an AC (alternating current) voltage. An intermediate network node NN connects the two electrical components. 500 It can be electrically connected, for example, to an inductive load LD, which may be a winding of a transformer or a motor winding, or to a reference potential of an electronic circuit.

[0123] The electronic assembly 600 can be a motor drive, with the electrical assemblies 500 are electrically arranged in a half-bridge configuration, the network node NN is electrically connected to a motor winding, and the supply terminals A, B provide a DC voltage.

[0124] According to another embodiment, the electronic assembly 600 a primary-side stage of a switched power supply, wherein the supply terminals A, B provide an alternating voltage of an input frequency to the electronic assembly 600 Provide. The network node NN is electrically connected to a primary winding of a transformer.

[0125] The electronic assembly 600 can be a synchronous rectifier of a switched-mode power supply, wherein the supply terminals A, B are connected to a secondary winding of the transformer and the network node NN is electrically connected to a reference potential of an electronic circuit on the secondary side of the switched-mode power supply.

[0126] According to another embodiment, the electronic assembly 600a primary-side stage of a DC-DC converter, for example a power optimizer or a micro-inverter for applications including photovoltaic cells, wherein the supply terminals A, B provide a DC voltage to the electronic assembly 600 provide and the network node NN is electrically connected to an inductive storage element.

[0127] According to another embodiment, the electronic assembly 600 a secondary-side stage of a DC-DC converter, for example a power optimizer or a micro-inverter for applications including photovoltaic cells, wherein the electronic assembly 600 an output voltage is provided to the supply terminals A, B, and the network node NN is electrically connected to the inductive storage element.

[0128] Fig. 11 refers to an IGBT module 700 , the electronic assembly600 from Fig. 9 contains. The IGBT module 700 Furthermore, a control circuit can be used. 710 include, which is designed to provide a control signal for alternately switching the electronic assembly on and off 600 to provide, and a gate driver 720 , which is controlled by the control circuit 710 is controlled and connected to the gate terminals of the electronic assembly 600 is electrically connected.

[0129] Although specific embodiments are illustrated and described here, it is obvious to those skilled in the art that a multitude of alternative and / or equivalent designs can be used for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or modifications of the specific embodiments discussed herein. Therefore, it is intended that this invention is limited only by the claims and their equivalents.

Claims

[1] Electrical assembly comprising: a semiconductor switching device ( 510 ), which is designed to withstand a maximum breakdown voltage across two load terminals (L1, L2) in an off state; and a clamping diode ( 560 ), which are connected to the two load terminals (L1, L2) and in parallel to the switching device ( 510 ) is electrically connected, wherein a semiconductor body ( 100 ) the clamping diode ( 560 ) consists of silicon carbide and has an avalanche breakdown voltage of the clamping diode ( 560 ) lower than the maximum breakdown voltage value of the switching device ( 510 ) is. [2] Electrical assembly according to claim 1, wherein the clamping diode ( 560 ) is designed to ensure at least 400 of a maximum long-term load current value of the switching device ( 510 ) to withstand for at least 10 ns. [3] Electrical assembly according to one of claims 1 to 2, wherein the clamping diode ( 560 ) has a pn junction (pn0) that connects a metal anode ( 310 ) and a metal cathode ( 320 ) is effective. [4] Electrical assembly according to one of claims 1 to 3, wherein the clamping diode ( 560 ) Field-forming structures ( 130 ) which are configured such that in a blocking mode of the clamping diode ( 560 ) an electric field strength has a maximum value at a distance from a metal-semiconductor interface between the semiconductor body ( 100 ) and a metal anode ( 310 ) the clamping diode ( 560 ) exhibits. [5] Electrical assembly according to claim 4, wherein the clamping diode ( 560 ) has a Schottky contact (SC) that connects the semiconductor body ( 100 ) and the metal anode ( 310 ) is effective. [6] Electrical assembly according to any one of claims 1 to 5, wherein the clamping diode ( 560 ) a central area ( 610 ) in a vertical projection of both a metal anode ( 310 ) as well as a metal cathode ( 320 ) as well as a closing area ( 690 ) exhibits the central area ( 610 ) surrounds, and wherein a breakdown voltage in the central region ( 610 ) lower than a breakdown voltage in the termination region ( 690 ) is. [7] Electrical assembly according to any one of claims 1 to 6, wherein the clamping diode ( 560 ) a merged-pin Schottky (MPS) diode ( 561 ) is. [8] Electrical assembly according to any one of claims 1 to 6, wherein the clamping diode ( 560 ) a trench MOS barrier Schottky diode ( 562 ) is. [9] Electrical assembly according to any one of claims 1 to 6, wherein the clamping diode ( 560 ) a trench oxide pin (TOPS) diode (563 ) is. [10] Electrical assembly according to any one of claims 1 to 6, wherein the clamping diode ( 560 ) a merged-pin Schottky diode ( 564 ) is. [11] Electrical assembly according to any one of claims 1 to 6, wherein the clamping diode ( 560 ) a SiC pin diode ( 565 ) is. [12] Electrical assembly according to any one of claims 1 to 10, further comprising: a freewheeling diode ( 519 ), which run between the two load terminals (L1, L2) in parallel to the switching device ( 510 ) and to the terminal diode ( 560 ) is switched, with an avalanche breakdown voltage of the clamping diode ( 560 ) is lower than the breakdown voltage of the freewheeling diode. [13] Electrical assembly according to claim 12, wherein the freewheeling diode ( 519 ) a silicon pin diode ( 519x ) includes. [14] Electrical assembly according to one of claims 12 and 13, wherein the freewheeling diode (519 ) a silicon carbide Schottky diode ( 519y ) includes. [15] Electrical assembly according to any one of claims 1 to 14, further comprising: at least one further semiconductor switching device connected in parallel to the switching device ( 510 ) is electrically arranged. [16] Electrical assembly according to any one of claims 1 to 15, wherein the switching device ( 510 ) a silicon bipolar transistor with an insulated gate (Si-IGBT) ( 511 ) includes. [17] Electrical assembly according to any one of claims 1 to 16, further comprising: a feedback circuit ( 580 ), which is an anode electrode (A) of the clamping diode ( 560 ) with a gate electrode (G) of the switching device ( 510 ) electrically connects, with the feedback circuit ( 580) is set up to apply a gate voltage to the gate electrode (G) with increasing current through the reverse-biased clamping diode ( 560 to increase. [18] Electrical assembly according to claim 17, further comprising: a feedback impedance ( 585 ), which are located between the anode electrode (A) of the clamping diode ( 560 ) and the second load connection (L1, L2) is electrically switched, wherein the feedback circuit ( 580 ) a feedback path ( 582 ) includes the anode electrode (A) of the clamping diode ( 560 ) with a control element ( 581 ) electrically connects to the gate electrode (G) of the switching device ( 510 ) is electrically connected, with the control element ( 581 ) is set up to apply a gate voltage to the gate electrode (G) with increasing current through the reverse-biased clamping diode ( 560 to increase. [19] Electrical assembly according to claim 18, wherein the control element ( 581 ) is selected from a group that includes a voltage-controllable voltage, a current source, and a gate driver circuit. [20] Electrical assembly according to any one of claims 1 to 19, wherein the avalanche breakdown voltage of the clamping diode ( 560 ) lower than the maximum breakdown voltage value of the switching device ( 510 ) for an entire nominal temperature range and for a maximum current value of the switching device ( 510 ) is. [21] Electrical assembly according to any one of claims 1 to 20, wherein the avalanche breakdown voltage of the clamping diode ( 560 ) is at least 300 V. [22] Electronic assembly comprising: a low-side switch with a first electrical assembly ( 500 ) and a high-side switch with a second electrical assembly ( 500), wherein the low-side switch and the high-side switch are electrically arranged in a half-bridge configuration and at least one of the electrical assemblies ( 500 ) includes a semiconductor switching device ( 510 ), which is designed to withstand a maximum breakdown voltage across two load terminals (L1, L2) in an off state; and a clamping diode ( 560 ), which are connected to the two load terminals (L1, L2) and in parallel to the switching device ( 510 ) is electrically connected, wherein a semiconductor body ( 100 ) the clamping diode ( 560 ) consists of silicon carbide and has an avalanche breakdown voltage of the clamping diode ( 560 ) lower than the maximum breakdown voltage value of the switching device ( 510 ) for a nominal temperature range of the switching device ( 510 ) is. [23] Bipolar transistor module with insulated gate, comprising: a half-bridge circuit comprising a low-side switch with a first electrical assembly ( 500 ) and a high-side switch with a second electrical assembly ( 500 ) includes, where at least one of the electrical assemblies ( 500 ) includes: a semiconductor switching device ( 510 ), which is designed to withstand a maximum breakdown voltage across two load terminals (L1, L2) in an off state; and a clamping diode ( 560 ), which are connected to the two load terminals (L1, L2) and in parallel to the switching device ( 510 ) is electrically connected, wherein a semiconductor body ( 100 ) the clamping diode ( 560 ) consists of silicon carbide and has an avalanche breakdown voltage of the clamping diode ( 560 ) lower than the maximum breakdown voltage value of the switching device ( 510 ) for a nominal temperature range of the switching device ( 510 ) is. [24] Bipolar transistor module with insulated gate according to claim 23, further comprising: a gate driver ( 720 ), which is connected to the gate terminals of the electrical assemblies ( 500 ) is electrically connected. [25] Electrical assembly comprising: a semiconductor switching device ( 510 ), which is designed to withstand a maximum breakdown voltage across two load terminals (L1, L2) in an off state; a clamping diode ( 560 ), which are connected to the two load terminals (L1, L2) and in parallel to the switching device ( 510 ) is electrically connected, with an avalanche breakdown voltage of the clamping diode ( 510 ) lower than the maximum breakdown voltage value of the switching device ( 510 ) is; and a feedback circuit ( 580 ), which is an anode electrode (A) of the clamping diode ( 560 ) with a gate electrode (G) of the switching device (510 ) electrically connects, with the feedback circuit ( 580 ) is set up to apply a gate voltage to the gate electrode (G) with increasing current through the reverse-biased clamping diode ( 560 to increase or decrease. [26] Electrical assembly according to claim 25, wherein a semiconductor body ( 100 ) the clamping diode ( 560 ) consists of silicon carbide.

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