Power module, power converter and electric drive for vehicle

Abstract

A power module (1) comprises: a carrier (2); -a plurality of dies (3, 3.1, 3.2, 3. N) connected in parallel and each forming a transistor (4) with a switching path, each die (3, 3.1, 3.2, 3. N) having a first terminal (5), a second terminal (6) and a control terminal (7), the switching path being formed between the first terminal (5) and the second terminal (6) and being switchable according to a voltage between the control terminal (7) and the second terminal (6), the first terminals (6) of the dies (3, 3.1, 3.2, 3. N) are connected to each other in order to form a parallel connection; -a connector (8) configured to connect a signal source (19) to the power module (1); and-an electrical conductor (9) made at least partially of an electrically conductive material and connecting the connector (8) to a specified terminal (D) of a respective one of the dies (3, 3.1, 3.2, 3. N), selected from the group consisting of the second terminal (6) and the control terminal (7), the electrical conductor (9) having a trace section (10) formed on the carrier (2) and an attachment section (11) connecting the trace section (10) with a specified terminal (D) of a respective one of the dies (3, 3.1, 3.2, 3. N); the carrier (2) and the trace section (10) are part of a substrate (13) on which the die (3, 3.1, 3.2, 3. N) and the connector (8) are mounted, where the trace section (10) and the attachment section (11) of the electrical conductor (9) provide a resistance (R1, R2, Rn) of at least 1 Omega between the connector (8) and a designated terminal (D) of a respective one of the die (3, 3.1, 3.2, 3. N).

Description

Field of the Invention

[0001] The present invention relates to a power module, comprising: a carrier; a plurality of dies, the plurality of dies being connected in parallel, and each die forming a transistor having a switching path, each die having a first terminal, a second terminal, and a control terminal, the switching path being formed between the first terminal and the second terminal and being switchable according to a voltage between the control terminal and the second terminal, the first terminals of the dies being connected to each other so as to form a parallel connection; a connector configured to connect a signal source to the power module; and an electrical conductor at least partially made of a conductive material and connecting the connector to a designated terminal of a corresponding one of the dies, the designated terminal being selected from the group comprising the second terminal and the control terminal, the electrical conductor having a trace section formed on the carrier and an attachment section connecting the trace section to the designated terminal of a corresponding one of the dies; the carrier and the trace section being part of a substrate, and the dies and the connector being mounted on the substrate.

[0002] Furthermore, the present invention relates to a power converter, an electric drive for a vehicle, and a vehicle comprising the electric drive according to the present invention.

[0003] The vehicle is for example a motorized ground vehicle, a train, an aircraft or a drone. The motorized ground vehicle is for example a motor vehicle, a motorcycle, a moped or a motorized wheelchair. Background Art

[0004] M. Wang, F. Luo and L. Xu, "Optimized Gate Loop Layout for Multi-Chip Silicon Carbide Metal Oxide Semiconductor Field Effect Transistor (SiCMOSFET) Power Modules", 2015 IEEE Third Wide Bandgap Power Devices and Applications Symposium (WiPDA), 2015, pp. 215 - 219 disclose a power module having parallel MOSFETs. A Kelvin source structure is employed in the power module, where fine wire bonding connects the gate and source pads of the MOSFETs to traces connected to a gate loop lead frame.

[0005] With the increasing power demand provided by the traction inverter of an electric vehicle, connecting a plurality of dies in parallel has become a suitable way to cope with the corresponding current and loss density. However, connecting the dies in parallel results in a very complex resonant system with unique feedback loops. In the VHF band, especially above 100 MHz, corresponding oscillations can be expected and different fault mechanisms can be triggered by the structure of the control terminals of the dies.

[0006] The above-mentioned literature by M. Wang, F. Luo, and L. Xu proposed suppressing the oscillation between gate circuits during switch transients by opening the trace between the gate circuit lead frame and the wire bond, thereby integrating individual discrete gate resistors into the power module. However, such a solution requires additional discrete components and additional manufacturing steps to place them on the substrate. SUMMARY OF THE INVENTION

[0007] The object of the present invention is to provide an improved possibility to reduce the oscillation during the operation of a power module with parallel dies, especially with less manufacturing effort and / or without re-designing the die.

[0008] According to the present invention, the above object is solved by the power module initially described, wherein the trace section and the attachment section of the electrical conductor provide a resistance of at least 1 Ω between the connector and the designated terminal of the corresponding one of the dies.

[0009] The power module according to the present invention includes a carrier and a plurality of dies. The dies are connected in parallel. Each die forms a transistor. The transistor has a switching path. Each die has a first terminal, a second terminal, and a control terminal. The switching path is formed between the first terminal and the second terminal. The switching path can be switched according to the voltage between the control terminal and the second terminal. The first terminals of the dies are connected to each other to form a parallel connection. The power module further includes a connector configured to connect a signal source to the power module. The power module further includes an electrical conductor. The electrical conductor is at least partially made of a conductive material. The electrical conductor connects the connector to the designated terminal of the corresponding one of the dies. The designated terminal is selected from the group including the second terminal and the control terminal. The electrical conductor has an attachment section. The trace section is formed on the carrier. The attachment section connects the trace section to the designated terminal of the corresponding one of the dies: The carrier and the trace section are part of the substrate. The dies are mounted on the substrate. The trace section and the attachment section of the electrical conductor provide a resistance of at least 1 Ω between the connector and the designated terminal of the corresponding one of the dies.

[0010] In a conventional power module, the designer seeks to implement the trace section and the attachment section such that they provide a relatively low resistance, which is significantly less than the resistance proposed by the present invention. For example, by forming them from copper, aluminum, gold, or silver and / or having a relatively large cross-sectional area. In contrast, the present invention proposes to implement a relatively high resistance in the corresponding current path between the connector and the die. This resistance value allows suppressing the feedback loop that causes oscillation without adding discrete resistors in the current path. In other words, the present invention proposes to design the electrical conductor such that the trace section and / or the attachment section itself provides the desired resistance value. This allows suppressing VHF oscillation in a power module with parallel dies without the need to add the step of installing discrete resistors and / or re-designing the internal structure of the die during the general manufacturing process of the corresponding power module.

[0011] The number of dies can be at least two, preferably at least four, more preferably at least six. Preferably, the transistor is configured to block a voltage of at least 400 V, preferably at least 800 V, more preferably at least 1200 V on the switching path. However, the present invention can also be used in applications where the transistor is configured to block a voltage between 20 V and 400 V, or in high-voltage applications where the voltage is at least 10 kV. Of course, the die can have additional terminals, such as terminals for sensing internal voltage and / or terminals for an internal current mirror.

[0012] The transistor can be preferably a silicon carbide (SiC)-based metal oxide semiconductor field effect transistor (MOSFET), or preferably a gallium nitride-based high electron mobility transistor (HEMT). Regarding MOSFETs and HEMTs, the first terminal can be the drain terminal and the control terminal can be the gate terminal. Optionally, the transistor can be an insulated gate bipolar transistor (IGBT). In this case, the first terminal can be the collector terminal and the control terminal can be the gate terminal.

[0013] Specifically, the electrical connection between the dies can form a resonant circuit with a resonant frequency of at least 100 MHz and a feedback loop that forms an inductive coupling between the second terminal and the control terminal. Then, the resistance value is selected to suppress the inductive coupling to a level below which the switching of the transistor will damage the die. The resistance value can even be selected such that the oscillation is suppressed by the resonant circuit operating in an aperiodic state.

[0014] In particular, the resistance between the connector and the corresponding designated terminal can be at least 2 Ω, preferably at least 4 Ω, more preferably at least 6 Ω or even 10 Ω. Preferably, the resistance between the connector and the corresponding designated terminal can be at most 100 Ω, preferably at most 50 Ω.

[0015] Specifically, the attachment section can form different electrical connections between the trace section and the designated terminal in the corresponding die, and the resistance between the connector and the designated terminal is measured through the different electrical connections formed by the attachment section.

[0016] Regarding the power module according to the present invention, the trace section can be continuously formed between the connector and the attachment section. That is, the trace section can form a continuous path over the entire path from the connector to the attachment section. In particular, over the entire path from the connector to the attachment section, the trace section is integrally formed and / or extends on the carrier.

[0017] In addition, the attachment section can be attached to the trace section and the pad of the die forming the designated terminal. Preferably, the attachment section extends between the trace section and the pad by forming a gap with the carrier. In particular, one end of the attachment section attached to the trace section has a first distance from the carrier, and the other end of the attachment section attached to the pad has a second distance from the carrier, and the second distance is greater than the first distance. In particular, throughout the entire extent of the attachment section, there is no direct contact between the attachment portion and the carrier. The trace section and the attachment section can generally be different from each other because the trace section extends on the carrier, while the attachment section is attached to the trace section and the designated terminal and does not directly contact the carrier. Preferably, the attachment section is formed by wire bonding or a flat strip.

[0018] In particular, the conductive material has a resistivity of at least 2.0·10 -7 Ω m, preferably at least 3.5·10 -7 Ω m, more preferably at least 4.0·10 -7 Ω m. Such resistivity values may be large enough to achieve the above resistance by making the conductor at least partially made of this material.

[0019] The conductive material can be a copper-manganese-nickel alloy. Preferably, the alloy contains A wt.% copper, B wt.% manganese, and C wt.% nickel, where A + B + C ≤ 100, 81 ≤ A ≤ 88, 11 ≤ B ≤ 15, and 1 ≤ C ≤ 4. For example, Manganin® is a commercially available alloy. Alternatively, the alloy contains D wt.% copper, E wt.% nickel, F wt.% manganese, where D + E + F ≤ 100, 53 ≤ D ≤ 57, 42.5 ≤ E ≤ 45, and 0.5 ≤ F ≤ 1.2, and where, when D + E + F < 100, the alloy further contains G wt.% of other metals, such as iron, and D + E + F + G = 100. For example, Kon-Stantan® is commercially available.

[0020] Alternatively, the conductive material can be a nickel-chromium alloy. Preferably, the alloy contains H wt.% nickel, J wt.% chromium, where H + J ≤ 100, 75 ≤ H ≤ 85, 15 ≤ J ≤ 20, and where, when H + J < 100, the alloy also contains K wt.% of another metal, and H + J + K = 100. Alloys having such a composition are generally known, for example, nickel-chromium alloys.

[0021] Alternatively, the conductive material can be an iron-chromium-aluminum alloy, which has L wt.% chromium, M wt.% aluminum, and N wt.% iron, where L + M + N = 100, 20 ≤ L ≤ 30, and 4 ≤ M ≤ 7.5. For example, Kanthal® is a commercially available alloy.

[0022] Preferably, the attachment section is made of a conductive material. Alternatively, the attachment section may include a core and an outer cladding surrounding the core, with the core or the cladding made of a conductive material. In this case, the core may be made of a conductive material and the cladding made of aluminum, or in an alternative, the core may be made of an electrically insulating material, in particular a polymer, and the cladding may be made of a conductive material.

[0023] Preferably, the trace section is made of a conductive material. If the attachment section is made of or includes a conductive material, the trace section may be made of a second conductive material. Alternatively, if the trace is made of a conductive material, the attachment section, in particular the cladding, may be made of a second conductive material.

[0024] Furthermore, the connector may be made of the said or the second conductive material. The resistivity of the first conductive material may be at least ten times the resistivity of the second conductive material. The second conductive material may be copper or aluminum.

[0025] The carrier may be made of ceramic, where a direct-bonded copper substrate (DBC), a direct-bonded aluminum substrate (DBA), or an active metal brazed substrate (AMB) is realized. Alternatively, the carrier may be made of a metal with a dielectric coating thereon. Such a carrier may realize an insulated metal substrate (IMS).

[0026] In some embodiments of the power module according to the present invention, the second terminals may be connected to each other to form a parallel connection. Alternatively, preferably, the second terminals are Kelvin terminals, and each die has a fourth terminal, with a switching path and a Kelvin terminal between the first terminal and the fourth terminal, and the fourth terminals of the dies are connected to each other to form a parallel connection. In the case where the transistor is a MOSFET or a HEMT, the fourth terminal may be the source terminal, or in the case where the transistor is an IGBT, the fourth terminal may be the emitter terminal.

[0027] Furthermore, the power module may also include a second connector mounted on the substrate and configured to connect a signal source to the power module; and a second electrical conductor connecting the second connector to the other terminal of the group, the second electrical conductor having a trace section formed on the carrier and an attachment section connecting the trace section to the other terminal of the corresponding one of the dies, and the trace section of the second electrical conductor being part of the substrate.

[0028] Wherein, the second electrical conductor may be at least partially made of a (first) conductive material, and the trace section and the attachment section of the second electrical conductor provide a resistance of at least 1 Ω between the second connector and the corresponding other terminal.

[0029] All statements regarding the first connector and the first electrical conductor and their connection to the dies may similarly apply to the second connector and the second electrical conductor, respectively.

[0030] The designated terminal may be the second terminal or the control terminal.

[0031] In particular, the following specific designs of the power module according to the present invention are preferred:

[0032] According to the first design, the second terminals are connected to each other to form a parallel connection, and the designated terminal is the control terminal. In this case, a resistor is formed between the connector and the control terminal. In this case, when the transistor is a MOSFET or a HEMT, the second terminal may be the source terminal, or when the transistor is an IGBT, the second terminal may be the emitter terminal.

[0033] According to the second design, the second terminal is a Kelvin terminal, and each die has a fourth terminal, with a switching path and the Kelvin terminal between the first terminal and the fourth terminal. The fourth terminals of the dies are connected to each other to form a parallel connection, where the designated terminal is the control terminal. In this case, a resistor is formed between the connector and the control terminal. The resistance between the second connector and the second terminal may be less than 0.5 Ω. In other words, the second electrical conductor may be formed conventionally, i.e., having a relatively low resistance and / or formed of a second conductive material.

[0034] According to the third design, the second terminal is a Kelvin terminal, and each die has a fourth terminal, with a switching path and the Kelvin terminal between the first terminal and the fourth terminal. The fourth terminals of the dies are connected to each other to form a parallel connection, where the designated terminal is the second terminal. In this case, a resistor is formed between the connector and the Kelvin terminal. The resistance between the second connector and the gate terminal may be less than 0.5 Ω. In other words, the second electrical conductor may be formed conventionally, i.e., having a relatively low resistance and / or formed of a second conductive material.

[0035] According to the fourth design, the second terminal is a Kelvin terminal, and each die has a fourth terminal. The switching path and the Kelvin terminal are between the first terminal and the fourth terminal. The fourth terminals of the dies are connected to each other to form a parallel connection. The power module further includes: a second connector mounted on the substrate and configured to connect a signal source to the power module; and a second electrical conductor connecting the second connector to the other terminal of the group. The second electrical conductor has a trace section formed on a carrier and an attachment section connecting the trace section to the other terminal of a corresponding one of the dies. The trace section of the second electrical conductor is part of the substrate. Wherein, the second electrical conductor is at least partially made of (first) conductive material. Wherein, the trace section and the attachment section of the second electrical conductor provide a resistance of at least 1 Ω between the second connector and the corresponding other terminal. In this case, a relatively high resistance is formed between the first connector and the control terminal and between the second connector and the Kelvin terminal. In this case, the designated terminal can be the control terminal.

[0036] Furthermore, regarding the power module according to the present invention, a plurality of dies, connectors, and electrical conductors, in particular the second connector and the second electrical conductor, can form a first arrangement. Wherein, the power module includes a corresponding second arrangement. One or more trace sections of the second arrangement are part of the substrate. The dies and one or more connectors of the second arrangement are mounted on the substrate. The first arrangement and the second arrangement can be connected to form a half-bridge. All statements regarding the first arrangement apply similarly to the second arrangement.

[0037] The above subject matter is also solved by a power converter including: a DC port for a DC voltage; an AC port having a plurality of phase conductors for an AC voltage; a power supply section including a plurality of switching elements interconnected to form a half-bridge for each phase conductor. Each half-bridge is connected to the DC port, and each phase conductor is connected to a center tap between the switching elements of one of the half-bridges; and a controller configured to provide switching signals to convert the DC voltage to an AC voltage by selectively turning on and off the switching elements; wherein, each switching element or each half-bridge is formed by a power module according to the present invention, and the signal source is formed by the controller.

[0038] The DC port can have two lines, and each half-bridge is connected between these two lines. The power converter can be implemented as a two-level converter or a three-level converter.

[0039] The power converter can be an inverter.

[0040] The above subject matter is also solved by a drive for a vehicle (e.g., a car), which drive includes an electric machine configured to propel the vehicle and a power converter according to the invention, the electric machine being connected to the AC port of the power converter for supplying an AC voltage to the electric machine.

[0041] The above subject matter is also solved by a vehicle including an electric drive according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Further details and advantages of the invention are disclosed below,

[0043] with reference to the drawings, which schematically show:

[0044] Figure 1 is a perspective view of a first embodiment of a power module according to the invention;

[0045] Figure 2 is a schematic view of the power module according to the first embodiment;

[0046] Figure 3 is a perspective view of a second embodiment of a power module according to the invention;

[0047] Figure 4 is a schematic view of the power module according to the second embodiment;

[0048] Figure 5 is a schematic view of a power module according to a third embodiment;

[0049] Figure 6 is a perspective view of a fourth embodiment of a power module according to the invention;

[0050] Figure 7 is a schematic view of the power module according to the fourth embodiment;

[0051] Figure 8 is a block diagram of an embodiment of a power converter according to the invention; and

[0052] Figure 9 is a schematic diagram of an electric vehicle having an embodiment of an electric drive according to the invention. DETAILED DESCRIPTION

[0053] Figure 1 is a perspective view of a first embodiment of power module 1.

[0054] The power module 1 includes a carrier 2 and n dies 3, which are respectively represented by the numbers 3.1, 3.2, …, 3.n. The dies 3 are connected in parallel. Note that the number of the three depicted dies is only selected for illustrative purposes, and more than three dies can be connected in parallel, such as four, six, eight or even more.

[0055] Each die 3 forms a transistor 4 having a switching path (see Figure 2 ). Each die 3 has a first terminal 5, a second terminal 6 and a control terminal 7. The switching path is formed between the first terminal 5 and the second terminal 6. The switching path can be switched according to the voltage between the control terminal 7 and the second terminal 6. In this embodiment, each transistor 4 is a SiC-based MOSFET or a GaN-based HEMT, the first terminal 5 is a drain terminal, the second terminal 6 is a source terminal, and the control terminal 7 is a gate terminal. The first terminals 5 are connected to each other, and the second terminals 6 are connected to each other to form a parallel connection.

[0056] The power module 1 further includes a connector 8 and a conductor 9. The conductor connects the connector 8 to the designated terminal D which serves as the control terminal 7. The conductor 9 has a trace section 10 and an attachment section 11, and for illustrative purposes, the trace section 10 is shown shaded in Figure 1 . The trace section 10 is completely formed on and continuously extends on the carrier 2. The attachment section 11 connects the trace section 10 to the designated terminal D of the corresponding one of the dies 3. In this embodiment, the attachment section 11 is formed by a wire bond 12 for each die 3.

[0057] It can also be seen from Figure 1 that the carrier 2 and the trace section 10 are part of a substrate 13, and the dies and the connector 8 are mounted on the substrate 13. The connector 8 is exemplarily mounted on the substrate 13 by being attached to the trace section 10. Specifically, the substrate 13 further includes a first pad 14 and a second pad 15. The dies 3 are mounted on the first pad 14, and the first pad 14 connects the first terminals 5 to each other. The second terminals 6 are connected to the second pad 15 by another wire bond 16, and the other wire bond 16 is used to connect the second terminals 6 to each other.

[0058] Specifically, the attachment section 11 is attached to the trace section 10 and pads 17.1, 17.2, ……, 17.n, and the pads 17.1, 17.2, ……, 17.n form the designated terminal D of the corresponding one of the dies 3.1, 3.2, ……, 3.n, wherein the attachment section 11 extends between the trace section 10 and the pads 17.1, 17.2, ……, 17.n by forming a gap with the carrier 2. Therefore, the attachment section 11 forms different electrical connections between the trace section 10 and each of the pads 17.1, 17.2, ..., 17.n.

[0059] Optionally, the power module 1 includes another pair of connectors 18a, 18b mounted on the substrate 13. The other connector 18a is respectively connected to the first terminal 5 of the die 3 or to the first pad 14. The other connector 18b is respectively connected to the second terminal 6 of the die 3 or to the second pad 15.

[0060] Figure 2 is a schematic diagram of the power module 1 according to the first embodiment.

[0061] The connector 8 is configured to connect an external signal source 19 to the power module 1. The other connector 18b is also configured to connect the signal source 19 to the power module such that the voltage between the control terminal 7 for switching the switch path and the second terminal 6 can be supplied to the power module 1.

[0062] The trace section 10 and the attachment section 11 are made of a first conductive material and provide a resistance of at least 1 Ω, for example at least 10 Ω, between the connector 8 and the respective designated terminal D. That is, there is a resistance R1 between the connector 8 and the designated terminal D of the first one of the dies 3.1, a resistance R2 between the connector 8 and the designated terminal D of the second one of the dies 3.2, and so on, until there is a resistance R between the connector 8 and the designated terminal D of the nth one of the dies 3.n n , and each of the resistances R1, R2,..., R n has at least the above value. In particular, the resistance of the electrical connection formed by the trace section 10 and the attachment section 11 between the respective pads 17.1, 17.2,..., 17 of the corresponding one of the dies 3.1, 3.2,..., 3.n contributes to the resistances R1, R2,..., R between the connector 8 and the corresponding one of the dies 3.1, 3.2,..., 3.n n contributes.

[0063] In this embodiment, both the trace section 10 and the attachment section 11 are made of a first conductive material having a resistivity of at least 4.0 × 10 -7 Ω m. The resistances R1, R2,..., R are obtained through the respective geometries of each trace section 10 and each attachment section 11, i.e., the diameter and the length. n The conductive material may be a copper-manganese-nickel alloy such as Manganin® or Konstantan®, a nickel-chromium alloy such as Nichrome®, or an iron-chromium-aluminum alloy such as Kanthal®.

[0064] According to a first modification of the first embodiment, only the trace section 10 is made of a first conductive material, while the attachment section 11 is made of a second conductive material, and the resistances R1, R2, …, R between the connector 8 and the designated terminal D of the corresponding one of the dies 3.1, 3.2, …, 3.n n contribute less than 0.5 Ω. The second material can be, for example, copper or aluminum. Generally, the resistivity of the first conductive material is at least ten times the resistivity of the second conductive material.

[0065] According to a second modification of the first embodiment, only the attachment section 11 is made of a first conductive material, while the trace section 10 is made of a second conductive material, and the resistances R1, R2, R between the connector 8 and the designated terminal D of the corresponding one of the dies 3.1, 3.2, …, 3.n n contribute less than 0.5 Ω.

[0066] Figure 3 is a perspective view of a second embodiment of the power module 1.

[0067] The power module 1 includes a carrier 2 and n dies 3, which are respectively represented by the numbers 3.1, 3.2, …, 3.n. The dies 3 are connected in parallel. Note that the number of the three depicted dies is chosen for illustrative purposes only, and more than three dies can be connected in parallel, such as four, six, eight or even more.

[0068] Each die 3 forms a transistor 4 having a switching path (see Figure 4 ). Each die 3 has a first terminal 5, a second terminal 6, a control terminal 7 and a fourth terminal 20. The switching path is formed between the first terminal 5 and the second terminal 6. The switching path can be switched according to the voltage between the control terminal 7 and the second terminal 6. In the second embodiment, each transistor is a SiC-based MOSFET or a GaN-based HEMT, the first terminal 5 is a drain terminal, the second terminal 6 is a Kelvin terminal, the control terminal 7 is a gate terminal, and the fourth terminal 20 is a source terminal. The first terminals 5 are connected to each other, and the fourth terminals 20 are connected to each other, thus forming a parallel connection.

[0069] The power module 1 further includes a first connector 8, a second connector 8a, an electrical conductor 9 and a second electrical conductor 9a. The first electrical conductor 9 connects the first connector 8 to the designated terminal D. The designated terminal is selected from the group including the control terminal 7 and the second terminal 6. In this embodiment, the control terminal 7 is selected as the designated terminal D. Therefore, the other terminal O of the group is the second terminal 6.

[0070] In the present embodiment, the second electrical conductor 9a connects the second connector 8a to the other terminal O of the second terminal 6. Each of the electrical conductors 9, 9a has a trace section 10, 10a and an attachment section 11, 11a. For illustrative purposes, the trace sections 10, 10a are shown shaded in Figure 3 Each of the trace sections 10, 10a is formed entirely on and extends continuously over the carrier 2. The attachment section 11 of the first electrical conductor 9 connects the trace section 10 of the first electrical conductor 9 to the designated terminal D of a corresponding one of the dies 3. The attachment section 11a of the second electrical conductor 9a connects the trace section 10a of the second electrical conductor 9a to the other terminal O of the set. In the present embodiment, the attachment sections 11, 11a of the respective electrical conductors 9, 9a are formed by wire bonds 12, 12a of each die 3.

[0071] As can also be seen from Figure 3 the carrier 2 and the trace sections 10, 10a of the respective electrical conductors 9, 9a are part of the substrate 13, and the dies 3 and the connectors 8, 8a are mounted on the substrate 13. The first connector 8 is exemplarily mounted on the substrate 13 by being attached to the trace section 10 of the first electrical conductor 9. The second connector 8a is exemplarily mounted on the substrate 13 by being attached to the trace section 10a of the second electrical conductor 9a. Specifically, the substrate 13 further includes a first pad 14 and a second pad 15. The die 3 is mounted on the first pad 14, and the first pad 14 connects the first terminals 5 to each other. The fourth terminal 20 is connected to the second pad 15 by another wire bond 16 for connecting the fourth terminals 20 to each other.

[0072] Regarding the specific details of the first electrical conductor 9, the attachment section 11 is attached to the trace section 10 and pads 17.1, 17.2, …, 17.n, which form the designated terminal D of a corresponding one of the dies 3.1, 3.2, …, 3.n. Among them, the attachment section 11 extends between the trace section 10 and the pads 17.1, 17.2, …, 17 by forming a gap with the carrier 2. Thus, the attachment section 11 forms different electrical connections between the trace section 10 and a corresponding one of the pads 17.1, 17.2, ..., 17.n.

[0073] Accordingly, with respect to the second electrical conductor 9a, the attachment section 11a is attached to the trace section 10a and the pads 21.1, 21.2, 21.n, and the pads 21.1, 21.2, 21.n form the other terminal O of the group of the corresponding one of the dies 3.1, 3.2, ..., 3.n. Among them, the attachment section 11a extends between the trace section 10a and the pads 21.1, 21.2, …, 21.n by forming a gap with the carrier 2. Therefore, the attachment section 11a forms different electrical connections between the trace section 10a and the corresponding one of the pads 21.1, 21.2, …, 21.n.

[0074] Optionally, the power module 1 includes another connector 18a, 18b mounted on the substrate 13. The other connector 18a is respectively connected to the first terminal 5 or the first pad 14 of the die 3. The other connector 18b is respectively connected to the fourth terminal 20 or the second pad 15 of the die 3.

[0075] Figure 4 is a schematic diagram of the power module 1 according to the second embodiment.

[0076] The connectors 8, 8a are configured to connect the external signal source 19 to the power module 1 such that the voltage between the control terminal 7 and the second terminal 6 for switching the switch path can be supplied to the power module 1.

[0077] With respect to the first electrical conductor 9, the trace section 10 and the attachment section 11 are made of a first conductive material and provide a resistance of at least 1 Ω, for example at least 10 Ω, between the connector 8 and the corresponding designated terminal D. That is, there is a resistance R1 between the first connector 8 and the designated terminal D of the first one of the dies 3.1, a resistance R2 between the first connector 8 and the designated terminal D of the second one of the dies 3.2, and so on, until there is a resistance R between the first connector 8 and the designated terminal D of the nth one of the dies 3.n n , and each resistance R1, R2, ..., R n has at least the above value. In particular, the resistance of the electrical connection formed by the attachment section 11 between the trace section 10 and the pads 17.1, 17.2, …, 17.n of the corresponding one of the dies 3.1, 3.2, …, 3.n contributes to the resistance R1, R2, …, R between the connector 8 and the corresponding one of the dies 3.1, 3.2, …, 3.n n contributes.

[0078] In this embodiment, both the trace section 10 and the attachment section 11 of the first electrical conductor 9 are made of a first conductive material. The resistances R1, R2, …, R are obtained by the respective geometries of each trace section 10 and each attachment section 11, that is, the diameter and the length. n。The trace section 10a and the attachment section 11b of the second electrical conductor are made of a second conductive material. The attachment sections 11, 11a may additionally be clad with aluminum. The statements regarding the first and second conductive materials of the first embodiment also apply to the second embodiment.

[0079] According to a first modification of the second embodiment, only the trace section 10 is made of a first conductive material, while the attachment section 11 is made of a second conductive material, and the resistances R1, R2,..., R between the connector 8 and the designated terminal D of the corresponding one of the dies 3.1, 3.2,..., 3.n n contribute less than 0.5 Ω. Another material may be, for example, copper or aluminum.

[0080] According to a second modification of the second embodiment, only the attachment section 11 is made of a first conductive material, while the trace section 10 is made of a second conductive material, and the resistances R1, R2,..., R between the connector 8 and the designated terminal D of the corresponding die of the dies 3.1, 3.2,..., 3.n n contribute less than 0.5 Ω.

[0081] Figure 5 is a schematic diagram of the power module 1 according to the third embodiment. Except for the differences described below, the third embodiment corresponds to the second embodiment. Among them, the same or equivalent components are denoted by the same reference numerals.

[0082] In the third embodiment, the trace section 10a and the attachment section 11a of the second electrical conductor 9a are also made of a first conductive material, and a resistance of at least 1 Ω (for example, at least 10 Ω) is provided between the second connector 8a and the corresponding second terminal. That is, there is a resistance R between the second connector 8a and the other terminal O of the first die 3.1 a,1 , there is a resistance R between the second connector 8a and the other terminal O of the second die 3.2 a,2 , and so on, until there is a resistance R between the second connector 8a and the other terminal O of the nth die 3.n a,n , and each resistance R a,1 、R a,2 、…、R a,n has at least the aforementioned value. In particular, the resistance of the electrical connection formed by the attachment section 11a between the trace section 10a and the pads 21.1, 21.2,..., 21.n of the corresponding one of the dies 3.1, 3.2,..., 3.n contributes to the resistances R a,1 、R a,2 、…、R a,n between the second connector 8a and the other terminal O of the corresponding one of the dies 3.1, 3.2,..., 3.n.

[0083] In this embodiment, both the trace section 10a and the attachment section 11a of the second electrical conductor 9a are made of a first conductive material. The resistance R is achieved by the respective geometries of each trace section 10a and each attachment section 11a, i.e., the diameter and the length. a,1 R a,2 ,... a,n .

[0084] According to a first modification of the third embodiment, only the trace section 10 and / or the trace section 10a are made of a first conductive material, while the attachment section 11 and / or the attachment section 11a are made of a second conductive material, and the resistances R1, R2,... n or the resistance R a,1 , a,2 ,... a,n contribute less than 0.5 Ω respectively to the resistance between the connector 8, 8a and the corresponding one of the designated terminals D or the other terminal O of the dies 3.1, 3.2,...

[0085] According to a second modification of the third embodiment, only the attachment section 11 and / or the attachment section 11a are made of a first conductive material, while the trace section 10 and / or the attachment section 10a are made of a second conductive material, and the resistances R1, R2, R n or the resistance R a,1 , a,2 , a,n contribute less than 0.5 Ω respectively to the resistance between the connector 8, 8a and the corresponding one of the designated terminals D or the other terminal O of the dies 3.1, 3.2,...

[0086] Figure 6 is a perspective view of a fourth embodiment of the power module 1. Except for the differences described below, the fourth embodiment corresponds to the second embodiment. Among them, the same or equivalent components are denoted by the same reference numerals.

[0087] In the fourth embodiment, the designated terminal D is the second terminal 6, i.e., the Kelvin terminal, and the other terminal O of the group is the control terminal. Accordingly, the first electrical conductor 9 connects the first connector 8 to the second terminal 6, and the second electrical conductor 9a connects the second connector 8a to the control terminal 7. Specifically, the attachment section 11a of the second electrical conductor 9a connects the trace section 10a of the second electrical conductor 9a to the control terminal 7. Corresponding to the second embodiment, the pads 17.1, 17.2,...

[0088] Figure 7 is a schematic diagram of the power module 1 according to the fourth embodiment.

[0089] As can be seen in Figure 7 As can be seen in Figure 7 , the resistors R1, R2, and R3 are still between the first connector 8 and the designated terminals D of the dies 3.1, 3.2, ..., 3.n. However, in this embodiment, the designated terminals D are the second terminals 6 or the Kelvin terminals, respectively, and the other terminals O of the group are the control terminals 7. Accordingly, the trace segments 10 and the attachment segments 11 of the first conductors 9 that connect the first connector 8 to the designated terminals D (i.e., the second terminals 6 or the Kelvin terminals) are made of a first conductive material, while the trace segments 10a and the attachment segments 11a of the second conductors 9a that connect the second connector 8a to the other terminals O of the group (i.e., the control terminals 7) are made of a second conductive material.

[0090] The first and second modifications to the second embodiment are similarly applicable to the fourth embodiment.

[0091] Regarding further modifications to the above embodiments, the transistor can be an IGBT. In this case, the first terminal 5 is the collector terminal. Regarding the first embodiment, the second terminal 6 is the emitter terminal. Regarding the second to fourth embodiments, the fourth terminal is the emitter terminal. The control terminal 7 is the gate terminal of the IGBT.

[0092] Regarding further modifications to the above embodiments, the attachment segments 11, 11a or the corresponding attachment segments 11, 11a are formed by conductive bars instead of wire bonds 12, 12a.

[0093] In the above embodiments and their modifications, the LC resonator is formed by the inductance L, the gate-drain capacitance, and the gate-source capacitance or the gate-collector capacitance and the gate-emitter capacitance that are electrically connected in parallel to the die 3, respectively. On the one hand, the resistance between the connector 8 or the corresponding connector 8a and the designated terminal D and / or the Kelvin terminal in the embodiments and their variants is higher than the corresponding resistance of a conventional power module. The resistance attenuates or even suppresses the oscillation of the LC resonator in the VHF range without the need to redesign the die 3 or add additional discrete resistance components to the power module 1.

[0094] According to another embodiment corresponding to the above embodiments, wherein the attachment segments 11, 11a are made of a first conductive material, only the core of the attachment segments 11, 11a is made of a first conductive material, and the cladding surrounding the core is made of a second conductive material, such as aluminum.

[0095] According to another embodiment corresponding to the above embodiments, wherein the attachment segments 11, 11a are made of a first conductive material, the core of the attachment segments 11, 11a is made of an electrically insulating material (e.g., polymer), and the cladding surrounding the core is made of a first conductive material or a second conductive material.

[0096] Figure 8 is a block diagram of an embodiment of a power converter 100.

[0097] The power converter 100 forms an inverter and includes a DC port 101 having two lines 102a, 102b for a DC voltage, an AC port 103 having a plurality of phase conductors 104u, 104v, 104w for an AC voltage, and a power section 105.

[0098] The power section 105 includes a plurality of switching elements, each switching element being formed by a power module 1 according to any of the above embodiments. The switching elements are interconnected to half - bridges 106u, 106v, 106w for each phase conductor 104u, 104v, 104w. Each half - bridge 106u, 106v, 106w is connected between the lines 102a, 102b, and each phase conductor 104u, 104v, 104w is connected to a center tap 107u, 107v, 107w between the switching elements of one of the half - bridges 106u, 106v, 106w.

[0099] Furthermore, the power converter 100 includes a controller 108 configured to provide switching signals in order to convert the DC voltage to an AC voltage by selectively turning on and off the switching elements. The controller 108 forms a signal source 19.

[0100] Although not shown in Figures 1 to 8 According to another embodiment, the power module 1 may include another arrangement of a plurality of dies 3, a first connector 8 and / or a second connector 8a, and a first electrical conductor 9 and / or a second electrical conductor 9a, one or more trace sections 10, 10a of which are part of a substrate 13, and the dies 3 and one or more connectors 9, 9a of the other arrangement are mounted on the substrate 13. Then, these arrangements can be connected to form one of the half - bridges 106u, 106v, 106w.

[0101] Figure 9 is a schematic diagram of an electric vehicle 110 having an electric drive 111 according to an embodiment.

[0102] The electric drive 111 includes an electric motor 112 configured to propel the vehicle 110 and a power converter 100 according to the above embodiments. The electric motor 112 is connected to the AC port 103 for supplying power to the electric motor 112. Furthermore, the DC port 101 is connected to a high - voltage battery 113 of the vehicle 110.

[0103] The electric vehicle 110 includes wheels 114 which are coupled directly or indirectly to an electric drive 111, for example via a transmission, so as to rotate the wheels 114. According to this embodiment, the electric vehicle 110 is a battery electric vehicle (BEV). Alternatively, the electric vehicle 110 may additionally include an internal combustion engine, thus forming a hybrid vehicle. Furthermore, the electric vehicle 110 may include a fuel cell that powers the power converter 100.

Claims

1. A power module (1), comprising: - A carrier (2); - A plurality of dies (3, 3.1, 3.2, 3.n), the plurality of dies (3, 3.1, 3.2, 3.n) being connected in parallel, and each die forming a transistor (4) having a switching path, each die (3, 3.1, 3.2, 3.n) having a first terminal (5), a second terminal (6) and a control terminal (7), the switching path being formed between the first terminal (5) and the second terminal (6) and being switchable according to the voltage between the control terminal (7) and the second terminal (6), the first terminals (5) of the dies (3, 3.1, 3.2, 3.n) being connected to each other to form the parallel connection; - A connector (8), the connector (8) being configured to connect a signal source (19) to the power module (1); and - A conductor (9), the conductor (9) being at least partially made of a conductive material and connecting the connector (8) to a designated terminal (D) of a corresponding one of the dies (3, 3.1, 3.2, 3.n), the designated terminal (D) being selected from the group comprising the second terminal (6) and the control terminal (7), the conductor (9) having a trace section (10) formed on the carrier (2) and an attachment section (11) connecting the trace section (10) to the designated terminal (D) of a corresponding one of the dies (3, 3.1, 3.2, 3.n); The carrier (2) and the trace section (10) are part of a substrate (13), and the dies (3, 3.1, 3.2, 3.n) and the connector (8) are mounted on the substrate (13), characterized in that The trace section (10) of the electrical conductor (9) and the attachment section (11) provide a resistance (R1, R2, R) of at least 1 Ω between the connector (8) and the designated terminal (D) of the respective one of the dies (3, 3.1, 3.2, 3.n). n ) 2. The power module according to claim 1, wherein The trace section (10) is continuously formed between the connector (8) and the attachment section (11).

3. The power module according to claim 1 or 2, wherein The attachment section (11) is attached to the trace section (10) and pads (17.1, 17.2, 17.n) of the die (3, 3.1, 3.2, 3.n) forming the designated terminal (D), wherein the attachment section (11) extends between the trace section (10) and the pads by forming a gap with the carrier (2).

4. The power module according to any one of the preceding claims, wherein - The attachment section (11) is made of the conductive material, or comprises a core and an outer cladding surrounding the core, the core or the cladding being made of the conductive material, and / or - The trace section (10) is made of the conductive material.

5. The power module according to claim 4, wherein - The core is made of a conductive material and the cladding is made of aluminum, or - The core is made of an electrically insulating material, in particular a polymer, and the cladding is made of the conductive material.

6. The power module according to any one of the preceding claims, wherein The conductive material - having a resistivity of at least 2.0·10 -7 Ω m, preferably at least 3.5·10 -7 Ω m, more preferably at least 4.0·10 -7 Ω m and / or - is a copper-manganese-nickel alloy, a nickel-chromium alloy, or an iron-chromium-aluminum alloy.

7. The power module according to any one of the preceding claims, wherein the substrate (13) is a direct-bonded copper substrate, a direct-bonded aluminum substrate, an active metal brazed substrate, or an insulated metal substrate.

8. The power module according to any one of the preceding claims, wherein the second terminal (6) is a Kelvin terminal, and each die has a fourth terminal (20), the switching path and the Kelvin terminal being between the first terminal (5) and the fourth terminal (20), the fourth terminals (20) of the dies (3, 3.1, 3.2, 3.n) being connected to each other to form the parallel connection.

9. The power module according to claim 8, further comprising: - a second connector (8a) mounted on the substrate (13) and configured to connect the signal source (19) to the power module (1); and - a second electrical conductor (9a) connecting the second connector (8a) to the other terminal (O) of the group, the second electrical conductor (8a) having a trace section (10a) formed on the carrier (2) and an attachment section (11a) connecting the trace section (10a) to the other terminal (O) of a corresponding one of the dies (3, 3.1, 3.2, 3.n), the trace section (10a) of the second electrical conductor (9a) being part of the substrate (13).

10. The power module according to claim 9, wherein the second electrical conductor (9a) is at least partially made of the conductive material, wherein the trace section (10a) and the attachment section (11a) of the second electrical conductor (9a) provide a resistance of at least 1 Ω between the second connector (9a) and the corresponding other terminal (O).

11. The power module according to any one of claims 1 to 9, wherein the designated terminal (D) is the second terminal (6).

12. The power module according to any one of claims 1 to 7, wherein the second terminals (6) are connected to each other to form the parallel connection.

13. The power module according to any one of claims 1 to 10 or according to claim 12, wherein, The designated terminal (D) is the control terminal (7).

14. A power converter (100) comprising: - a DC port (101) for a DC voltage; - an AC port (103) having a plurality of phase conductors (104u, 104v, 104w) for an AC voltage; - A power supply section (105) including a plurality of switching elements interconnected to form half-bridges (106u, 106v, 106w) for each phase conductor (104u, 104v, 104w), each half-bridge (106u, 106v, 106w) being connected to the DC port (101), and each phase conductor (104u, 104v, 104w) being connected to a center tap (107u, 107v, 107w) between the switching elements of one of the half-bridges (106u, 106v, 106w); and - A controller (108) configured to provide switching signals for converting the DC voltage to the AC voltage by selectively turning on and off the switching elements; wherein each switching element or each half-bridge (106u, 106v, 106w) is formed by the power module (1) according to any one of the preceding claims, and wherein the signal source (19) is formed by the controller (108).

15. An electric drive (111) for a vehicle, such as a vehicle (110), comprising an electric machine (112) configured to propel the vehicle and a power converter (100) according to claim 14, the electric machine (112) being connected to the AC port of the power converter for supplying an AC voltage to the electric machine (112).

16. A vehicle comprising the electric drive (111) according to claim 15.

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