Power module

Abstract

The invention relates to a power module (300) comprising: - a first conductor (C+) comprising one or more portions (P+1, P+2); - a second conductor (C-) comprising one portion (P-1); - a third conductor (C~) comprising first and second portions (P~1, P~2); the portions of the conductors succeeding one another in a first direction (D1) in the following order: the portion (P-1) of the second conductor (C-), the second portion (P~2) of the third conductor (C~), the one or more portions (P+1; P+1, P+2) of the first conductor (C+) and the first portion (P~1) of the third conductor (C~); - a first switch formed of aligned first transistors (TLS), the first transistors (TLS) being pressed against the second portion (P~2) of the third conductor (C~) and electrically connected to the portion (P-1) of the second conductor (C-); - a second switch formed of aligned second transistors (THS), the second transistors (THS) being pressed against the one or more portions (P+1) of the first conductor (C+) and electrically connected to the first portion (P~1) of the third conductor (C~); and - between the first transistors (TLS) and the second transistors (THS), a control circuit (CMD) for controlling the transistors (TLS, THS).

Description

Description TITLE: POWER MODULE Technical field of the invention

[0001] The present invention relates to a power module. Technological background

[0002] It is known to use a power module implementing a switching arm with a high-side switch formed by several transistors, called high-side, and a low-side switch also formed by several transistors, called low-side. Generally, the transistors on each side are distributed in two parallel rows. The power module further comprises a control circuit with two parts, distant from each other, for controlling respectively the high-side transistors and the low-side transistors. Each of the two parts has pins projecting upwards or downwards to be connected to drivers.

[0003] Because of this configuration, at each switching, the electrical signals of the transistors exhibit oscillations which can lead to electrical instability which can lead to thermal runaway and / or electrical destruction of the transistors.

[0004] It may therefore be desirable to provide a power module which makes it possible to overcome at least some of the aforementioned problems and constraints. Summary of the invention

[0005] A power module is therefore proposed, characterized in that it comprises: a first conductor comprising one or more portions; a second conductor comprising a portion; a third conductor comprising first and second portions; the portions of the conductors following one another in a first direction in the order: the portion of the second conductor, the second portion of the third conductor, the portion(s) of the first conductor and the first portion of the third conductor; a first switch formed of aligned first transistors, the first transistors being pressed against the second portion of the third conductor and electrically connected to the portion of the second conductor; a second switch formed of aligned second transistors, the second transistors being pressed against the portion(s) of the first conductor and electrically connected to the first portion of the third conductor; and between the first transistors and the second transistors, a transistor control circuit.

[0006] Thus, thanks to the invention, oscillations can be reduced by aligning the high-side transistors and the low-side transistors, each time in a single alignment, and by positioning the control circuit between the two alignments, while allowing easy connections to be made. This is achieved by splitting the phase conductor to alternate a negative conductive portion, a phase conductive portion, a positive conductive portion, and again a phase conductive portion. This allows the connections to the high-side transistors to extend in one direction, while the low-side connections extend in the opposite direction, thus freeing up space between the transistors to accommodate the control circuit. This particularly concerns the high-current connections of the upper face of the high-side transistors.

[0007] Aligning the transistors also helps reduce the risk of oscillations during switching due to a phase shift between the switching times of the transistors.

[0008] The invention may further comprise one or more of the following optional features, in any technically possible combination.

[0009] Optionally, the portions of the conductors following one another in the first direction in the aforementioned order are done without any other intermediate conductor between said portions. That is to say that said portions following one another in the first direction are adjacent to each other. In other words, the portion of the second conductor is adjacent to the second portion of the third conductor which is itself adjacent to the portion(s) of the first conductor which is itself adjacent to the first portion of the third conductor.

[0010] Optionally, each switch is formed from a single row of aligned transistors.

[0011] Optionally, the power module includes only two switches.

[0001] Optionally, a conductor is formed from a single piece. That is, a conductor is formed from a single piece. In other words, a conductor is a single piece. It will be understood, in this example, that the conductor is not formed from different portions separated from each other. In particular, in an exemplary embodiment, the third conductor is formed from a single piece.

[0013] Optionally, the third conductor includes a connecting portion connecting the first portion of the third conductor and the second portion of the third conductor.

[0014] Optionally, the conductor portions are flat. This improves the compactness of the power module and simplifies its manufacture.

[0015] Optionally, the flat portions also extend parallel to each other. This improves the compactness of the power module.

[0016] Also optionally, the first conductor comprises first and second planar portions, a portion of the second transistors being pressed against the first planar portion of the first conductor and the remainder of the second transistors being pressed against the second planar portion of the first conductor, and the third conductor comprises a connecting portion connecting the first and second planar portions by passing between the first and second planar portions of the first conductor.

[0017] Also optionally, one half of the second transistors are pressed against the first planar portion of the first conductor and the other half of the second transistors are pressed against the second planar portion of the first conductor.

[0018] Also optionally, the second transistors are pressed against the flat portion of the first conductor and the third conductor has a connecting portion connecting the first and second flat portions by passing over the flat portion of the first conductor. This makes it possible to simplify the connections between the conductors.

[0019] Optionally also, the first conductor comprises at least one first terminal located before the flat portion of the second conductor in the first direction and, for each first terminal, a connecting portion connecting the flat portion to the first terminal in question, passing next to the second flat portion of the third conductor and the flat portion of the second conductor.

[0020] Also optionally, the first conductor comprises at least one first terminal located before the flat portion of the second conductor in the first direction and, for each first terminal, a connecting portion connecting the flat portion to the first terminal in question by passing above the second flat portion of the third conductor and the flat portion of the second conductor.

[0021] Optionally also, the power module comprises first connections electrically connecting respectively the first transistors to the planar portion of the second conductor, these first connections being identical and extending parallel to each other and / or comprising second connections electrically connecting respectively the second transistors to the planar portion of the third conductor, these second connections being identical and extending parallel to each other. This makes it possible to simplify the power module by standardizing the connections and thus reduce its manufacturing cost.

[0022] Optionally also, each of the first transistors has a Kelvin terminal and the control circuit has a first Kelvin track to which all the Kelvin terminals of the first transistors are connected and / or each of the second transistors has a Kelvin terminal and the control circuit has a second Kelvin track to which all the Kelvin terminals of the second transistors are connected.

[0023] Also optionally, the control circuit includes a first Kelvin pin and a resistor connected between the first Kelvin track and the first Kelvin pin and / or a second Kelvin pin and a resistor connected between the second Kelvin track and the second Kelvin pin. The resistor helps reduce parasitic inductances in the control loop and provides better balance in transistor switching.

[0024] Also optionally, each of the first transistors comprises a control terminal and the control circuit comprises a first global control pin and, for each control terminal of the first transistors, a respective resistor connected between the control terminal in question and the first global control pin and / or each of the second transistors comprises a control terminal and the control circuit comprises a second global control pin and, for each control terminal of the second transistors, a respective resistor connected between the control terminal in question and the second global control pin. The resistor makes it possible to reduce the parasitic inductances in the control loop and to have a better balance in the switching of the transistors.

[0025] Also optionally, the power module comprises a so-called control substrate, for example pressed against the second portion of the third conductor, on which the control circuit extends.

[0026] Optionally, the control circuit also includes control electronics, such as a high-side transistor driver and / or a low-side transistor driver. Brief description of the figures

[0027] The invention will be better understood with the aid of the following description, given solely by way of example and with reference to the appended drawings in which: Figure 1 is a schematic view of a land motor vehicle in which the invention can be implemented, Figure 2 is an electrical diagram of a switching circuit that can be used in the land motor vehicle of Figure 1, Figure 3 is a three-dimensional view of a first example of a power module according to the invention, Figure 4 is a top view of the power module of Figure 3, Figure 5 is a top view of a second example of a power module according to the invention, Figure 6 is a three-dimensional view of a type of low-side switch connection strips of the power module, and Figure 7 is a three-dimensional view of a low-side switch connection clip of the power module. Detailed description of the invention

[0028] With reference to Figure 1, a motor land vehicle 100, in which the invention can be implemented, will now be described.

[0029] The vehicle 100 comprises one or more drive wheels 102 configured to put the vehicle 100 into motion.

[0030] To drive the drive wheel(s) 102, the mobility device 100 further comprises an electric drive device 104 and a direct voltage source 106, such as a battery, configured to electrically power the electric drive device 104.

[0031] The electric drive device 104 comprises an electric machine 108, in particular polyphase, for example three-phase, connected to the drive wheel(s) 102 to drive the latter. The electric drive device 104 further comprises an AC-DC electric voltage converter 110 connected between the DC voltage source 106 and the electric machine 108. The electric voltage converter 110 is configured to transfer electric power between the DC voltage source 106 and the electric machine 108. For example, the AC-DC converter 110 is configured to operate as an inverter to transfer electric power from the DC voltage source 106 to the electric machine 108 operating as an electric motor.The AC-DC converter 110 may also be configured to operate as a rectifier to transfer electrical power from the electrical machine 108 operating as an electrical generator to the DC voltage source 106, for example to recharge the latter.

[0032] With reference to FIG. 2, the electrical voltage converter 110 comprises a switching circuit 202 with switches HS, LS. The latter are transistor switches, such as metal-oxide gate field effect transistors (also designated by the acronym MOSFET) or silicon metal-oxide gate field effect transistors (also designated by the acronym Si MOSFET) or silicon carbide metal-oxide gate field effect transistors (also designated by the acronym SiC MOSFET) or insulated gate bipolar transistors (also designated by the acronym the acronym IGBT) or gallium nitride field effect transistors (also known by the acronym GaN FET).

[0033] The switching circuit 202 comprises at least one switching arm 206, for example, as many switching arms 206 as there are stator phases of the electric machine 108. Each switching arm 206 comprises a high-side switch HS and a low-side switch LS connected to each other at a midpoint. Each switching arm 206 is connected between terminals +, - of the DC voltage source 106. The midpoint is connected to one of the stator phases of the electric machine 108.

[0034] Each switching arm 206 is thus configured to switch between two configurations. In a first configuration, the high-side switch HS is closed and the low-side switch LS is open, so that a DC voltage is essentially applied to the midpoint and thus to the stator phase connected thereto. In a second configuration, the high-side switch HS is open and the low-side switch LS is closed, so that a zero voltage is applied to the midpoint and thus to the associated stator phase.

[0035] The electrical voltage converter 110 further comprises electronics 208 for controlling the switches HS, LS, generally via respective drivers (not shown). The control electronics 208 is for example designed to control the switches HS, LS in order to regulate phase currents transmitted to the stator phases from the midpoints.

[0036] With reference to FIG. 3, an example of a power module 300 implementing one of the switching arms 206 will now be described.

[0037] For the sake of clarity, the positions of the elements of the power module 300 will be described hereinafter with reference to a direct trihedron forming an X, Y, Z reference frame, in which the X direction is a right-left direction, the Y direction is a front-rear direction, and the Z direction is a vertical direction.

[0038] The power module 300 firstly comprises several electrical conductors: a first conductor intended to be connected to the positive terminal + of the voltage source 106 and therefore called the positive conductor C+, a second conductor intended to be connected to the negative terminal - of the voltage source 106 and therefore called positive conductor C-, and a third conductor intended to be connected to one of the phases and to present an alternating voltage and therefore called alternating conductor C-.

[0039] The conductors C+, C-, C- are arranged to present the following succession in a direction D1: a portion P-1 of the negative conductor C-, then a portion P-2 of the phase conductor C-, then at least one portion P+1, P+2 of the positive conductor C+, then another portion P-1 of the phase conductor C~. For example, as in the example illustrated, the direction D1 is parallel to the direction Y. Thus, the preceding portions follow one another from back to front.

[0040] For example, as in the illustrated example, the portions P-1 , P-2, P+1 , P+2, P-1 are planar and extend parallel to each other, i.e. parallel to the horizontal plane X,Y. For example, these portions P-1 , P-2, P+1 , P+2, P-1 are coplanar as in the illustrated example. Alternatively, these portions P- 1 , P-2, P+1 , P+2, P-1 could be offset in height by a few tenths of a millimeter.

[0041] The alternating conductor C- further comprises a connecting portion PL- connecting the portions P~i, P-2 passing between the portions P+i, P+2 of the first conductor C+. For example, as in the example illustrated, the connecting portion PL- is flat and parallel to the other portions P-1, P-2, P+1, P+2, P-1, for example coplanar with the latter.

[0042] The low-side switch LS is formed by several low-side transistors TLS pressed against the P-2 portion of the alternating conductor C- and electrically connected to the P-1 portion of the negative conductor C-, for example by respective RUBLS strips with for example two contact areas extending in the Y direction or in the X direction (see figure 6) on the connected low-side transistor TLS, or by one or more clips each connecting several low-side transistors TLS (see figure 7, in particular the reference CLP).

[0043] The high-side switch HS is formed by several high-side transistors THS pressed against the positive conductor C+ and electrically connected to the alternating conductor C-, for example by respective RUBHS strips (with for example two contact areas as for RUBLS strips) or by one or more clips each connecting several high-side transistors THS (as for the low-side transistors TLS). For example, as in the example illustrated in Figure 3, a part of the high-side transistors THS (for example, half) is pressed against the P+1 portion of the positive conductor C+, while the other part of the high-side transistors THS (e.g., the other half) is pressed against the P+2 portion of the positive conductor C+.

[0044] In order to connect the power module 300, the positive conductor C+ further comprises at least one terminal called positive B+1, B+2, the negative conductor C- further comprises at least one terminal called negative B-, and the alternating conductor C- comprises at least one terminal called alternating B~.

[0045] For example, as in the illustrated example, two positive terminals B+1, B+2 are provided. These two positive terminals B+1, B+2 are respectively electrically connected to the portions P+1, P+2 of the positive conductor C+. For this purpose, the positive conductor C+ comprises two connecting portions PL+1, PL+2 extending rearwardly from the portions P+1, P+2 respectively. These connecting portions PL+1, PL+2 bypass the portion P-2 of the alternating conductor C- from the right and the left. For example, as in the illustrated example, the connecting portions PL+1, PL+2 are planar and parallel to the other portions P-1, P-2, P+1, P+2, P-1, for example coplanar with the latter.

[0046] For example, as in the example illustrated, the positive terminals B+1, B+2 respectively comprise fixing lugs respectively attached to the connecting portions PL+1, PL+2, the negative terminal B- comprises a fixing lug attached to the portion P-1 of the negative conductor C-, and / or the alternative terminal B- comprises a fixing lug attached to the portion P-1 of the alternative conductor C~.

[0047] For example, the control module 300 comprises a substrate SUB carrying the portions P-1, P-2, P+1, P+2, P-1, as well as the portions PL-, PL+1, PL+2 if present. For example, the substrate SUB and the portions are formed by a directly bonded copper substrate (from the English "Direct Bonded Copper substrate" or "DBC substrate") or else an active metal brazed substrate (from the English "Active Metal Brazed substrate" or "AMB substrate"). Alternatively, the conductors C+, C-, C- could be formed with a rigid conductive frame (from the English "leadframe") and not require a substrate.

[0048] With reference to FIG. 4, the power module 300 further comprises, between the first transistors TLS and the second transistors THS, a control circuit CMD for the transistors TLS, THS. The power module 300 comprises, for example, a so-called control substrate SUB', for example pressed against the portion P~2 of the alternating conductor C~, on which the control circuit CMD extends. In particular when the control substrate SUB' comprises a thick film ceramic or an insulating organic material of the printed circuit type (PCB), this control substrate SUB' is naturally insulated and can thus extend over one or more neighboring portions, for example the portion PL+1 and / or PL+2.

[0049] For example, as in the illustrated example, each of the low-side transistors TLS and / or the high-side transistors THS has a Kelvin terminal KLS, KHS, for example a Kelvin source terminal. In this case, the control circuit CMD has for example a low-side Kelvin track PKLS to which all the Kelvin terminals of the low-side transistors TLS are connected and / or a high-side Kelvin track PKHS to which all the Kelvin terminals of the high-side transistors THS are connected.

[0050] Still for example, as in the example shown, the CMD control circuit has a low side Kelvin pin BKLS and a resistor RKLS connected between the low side Kelvin track PKLS and the low side Kelvin pin and / or the CMD control circuit has a high side Kelvin pin BKHS and a resistor RKHS connected between the high side Kelvin track PKHS and the high side Kelvin pin BKHS.

[0051] Still for example, as in the example described, each of the low-side transistors TLS has a control terminal BCLS, for example a gate terminal, and the control circuit CMD has a global low-side control pin BGLS and, for each low-side transistor TLS, a respective resistor RCLS connected between its control terminal BCLS and the global low-side control pin BGLS. Similarly, for example, each of the high-side transistors THS has a control terminal BCHS and the control circuit CMD has a global high-side control pin BGHS and, for each high-side transistor THS, a respective resistor RCHS connected between its control terminal BCLS and the global high-side control pin BGHS.

[0052] Furthermore, all or part of the resistors RKLS, RKHS, RCSL, RCHS can then be components mounted on the surface of the control substrate SUB' (from the English "Surface Mounted Device" or SMD). Alternatively, all or part of the RKLS, RKHS, RCSL, RCHS resistors can then be components directly printed on the ceramic SUB' control substrate.

[0053] The pins BKHS, BKLS, BGHS, BGLS project upwards, for example. Thus, it may be provided that the control electronics 208 extend above the CMD control circuit, with, for example, a low-side driver for the low-side transistors TLS and a high-side driver for the high-side transistors THS. Alternatively, all or part of the control electronics could be part of the CMD control circuit, for example by being interposed between the resistors RCLS, RCHS and the control pins BGLS, BGHS.

[0054] With reference to Figure 5, another example of a power module 500 according to the invention will now be described.

[0055] The 500 power module is similar to the 300 power module, except for the differences which will be detailed.

[0056] The positive conductor C+ has a single portion P+1 on which all the high-side transistors THS are plated. To connect the two portions P~1, P-2 of the AC conductor C- together, the connecting part PL- passes over the P+1 portion of the positive conductor C+.

[0057] Furthermore, the connecting portions PL+1, PL+2 pass over the P-2 portion of the AC conductor C- and the P-1 portion of the negative conductor C-. This solution allows the P+1 portion to have a large surface area for plating the high-side transistors THS.

[0058] In addition, the positive conductor C+ comprises, for example, a third connecting portion PL+3 connecting the two other connecting portions PL+1, PL+2.

[0059] In conclusion, it appears clearly that such as the one described previously allows a central placement of the control circuit, while keeping simple connections with the transistors.

[0060] It will also be noted that the invention is not limited to the embodiments described above. It will indeed appear to those skilled in the art that various modifications can be made to the embodiments described above, in light of the teaching which has just been disclosed to them.

[0061] In the detailed presentation of the invention given above, the terms used should not be interpreted as limiting the invention to the modes embodiments set forth in this description, but must be interpreted to include all equivalents which can be foreseen by those skilled in the art by applying their general knowledge to the implementation of the teaching just disclosed to them.

Claims

Claims [1] Power module (300; 500) characterized in that it comprises: a first conductor (C+) comprising one or more portions (P+1; P+1, P+2); a second conductor (C-) comprising a portion (P-1); a third conductor (C~) comprising first and second portions (P-1, P-2); the portions of the conductors following one another in a first direction (D1) in the order: the portion (P-1) of the second conductor (C-), the second portion (P-2) of the third conductor (C~), the portion(s) (P+1; P+1, P+2) of the first conductor (C+) and the first portion (P-1) of the third conductor (C~); a first switch formed of aligned first transistors (TLS), the first transistors (TLS) being pressed against the second portion (P-2) of the third conductor (C~) and electrically connected to the portion (P-1) of the second conductor (C-);a second switch formed of aligned second transistors (THS), the second transistors (THS) being pressed against the portion(s) (P+i) of the first conductor (C+) and electrically connected to the first portion (P~i) of the third conductor (C~); and between the first transistors (TLS) and the second transistors (THS), a control circuit (CMD) for the transistors (TLS, THS).; [2] Power module (300; 500) according to claim 1, in which the portions of the conductors (C+, C-, C~) are flat. [3] Power module (300; 500) according to claim 1 or 2, wherein the planar portions extend parallel to each other. [4] Power module (300) according to any one of claims 1 to 3, in which the first conductor (C+) comprises first and second planar portions (P+1, P+2), a portion of the second transistors (THS) being pressed against the first planar portion (P+1) of the first conductor (C+) and the remainder of the second transistors (THS) being pressed against the second planar portion (P+2) of the first conductor (C+), and in which the third conductor (C~) comprises a connecting portion (PL-) connecting the first and second planar portions (P-1, P-2). passing between the first and second flat portions (P+1, P+2) of the first conductor (C+). [5] Power module (300) according to claim 4, wherein one half of the second transistors (THS) is pressed against the first planar portion (P+1) of the first conductor (C+) and the other half of the second transistors (THS) is pressed against the second planar portion (P+2) of the first conductor (C+). [6] Power module (500) according to any one of claims 1 to 3, in which the second transistors (THS) are pressed against the flat portion (P+1) of the first conductor (P+) and in which the third conductor (C~) comprises a connecting portion (PL~) connecting the first and second flat portions (P~1, P~2) by passing above the flat portion (P+1) of the first conductor (C+). [7] Power module (300) according to any one of claims 1 to 6, wherein the first conductor (C+) comprises at least one first terminal (B+i, B+2) located before the flat portion (Pi) of the second conductor (C-) in the first direction (D1) and, for each first terminal (B+i, B+2), a connecting portion (PL+i, PL+2) connecting the flat portion (P+1) to the first terminal (B+1, B+2) considered by passing next to the second flat portion (P~2) of the third conductor (C~) and the flat portion (P-1) of the second conductor (C-). [8] Power module (500) according to any one of claims 1 to 6, wherein the first conductor (C+) comprises at least one first terminal (B+1, B+2) located before the flat portion (P-1) of the second conductor (C-) in the first direction (D1) and, for each first terminal (B+1, B+2), a connecting portion (PL+1, PL+2) connecting the flat portion (P+1) to the first terminal (B+1, B+2) in question by passing above the second flat portion (P~2) of the third conductor (C~) and the flat portion (P-1) of the second conductor (C-). [9] Power module (300; 500) according to any one of claims 1 to 8, comprising first connections (RUBLS) electrically connecting respectively the first transistors (TLS) to the planar portion (P-1) of the second conductor (C-), these first connections (RUBLS) being identical and extending parallel to each other and / or comprising second connections (RUBHS) electrically connecting respectively the second transistors (THS) to the flat portion (P~) of the third conductor (C~), these second connections (RUBHS) being identical and extending parallel to each other. [10] Power module (300; 500) according to any one of claims 1 to 9, wherein each of the first transistors (TLS) comprises a Kelvin terminal and wherein the control circuit (CMD) comprises a first Kelvin track (PKLS) to which all the Kelvin terminals of the first transistors (TLS) are connected and / or wherein each of the second transistors (THS) comprises a Kelvin terminal and wherein the control circuit (CMD) comprises a second Kelvin track (PKHS) to which all the Kelvin terminals of the second transistors (THS) are connected. [11] Power module (300; 500) according to claim 10, wherein the control circuit (CMD) comprises a first Kelvin pin (BKLS) and a resistor (RKLS) connected between the first Kelvin track (PKLS) and the first Kelvin pin (BKLS) and / or a second Kelvin pin (BKHS) and a resistor (RKHS) connected between the second Kelvin track (PKHS) and the second Kelvin pin (BKHS). [12] Power module (300; 500) according to any one of claims 1 to 11, wherein each of the first transistors (TLS) comprises a control terminal and wherein the control circuit (CMD) comprises a first global control pin (BCLS) and, for each control terminal of the first transistors (TLS), a respective resistor (RCLS) connected between the control terminal in question and the first global control pin (BCLS) and / or wherein each of the second transistors (THS) comprises a control terminal and wherein the control circuit (CMD) comprises a second global control pin (BCHS) and, for each control terminal of the second transistors (THS), a respective resistor (RCHS) connected between the control terminal in question and the second global control pin (BCHS). [13] Power module (300; 500) according to any one of claims 1 to 12, comprising a so-called control substrate (SUB'), for example pressed against the second portion (P~2) of the third conductor (P~), on which the control circuit (CMD) extends. [14] Power module (300; 500) according to any one of claims 1 to 13, wherein the control circuit (CMD) comprises control electronics, such as for example a driver of the high side transistors (THS) and / or a driver of the low side transistors (TLS).

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