Power module and its manufacturing process

Abstract

Power Module and its Manufacturing Method The invention relates to a power module (1) intended to be connected to a connection grid, comprising: A power board (101) including a substrate (1011), two power portions (1012) arranged on the substrate, A signal board (11) mounted on the power board, Electrically conductive connection pads (12, 22), each connection pad comprising a first face (121, 221) and a second face (122, 222), the first face being connected to one of the power portions (1012) and the signal board (11), the second face being intended to be electrically connected to the connection grid, A housing enclosing the power board, the signal board and the connection pads, the second face of the connection pads being flush with an upper surface of the housing. (Figure 1)

Description

Title of the invention: Power module and its manufacturing process

[0001] The present invention relates to the field of power electronics and in particular to the field of electric motor power supply equipment. More specifically, the present invention relates to a power module and a method for manufacturing such a power module, as well as an associated current converter.

[0002] The invention can find its application, for example, in electronic systems for traction inverters, for on-board chargers, for electric cooling pumps, for example, for batteries, for heat pumps, for laser sensors, for example for autonomous driving, etc...

[0003] Electronic modules generally include contacts for connecting an auxiliary electronic board, such as an inverter control board. These contacts allow the transmission of signals, for example, control signals, between the power module and the auxiliary electronic board.

[0004] A power module typically comprises a power board and electrically conductive traces, at least one signal board. The set of electrically conductive traces forms the connection grid, also known by its Anglo-Saxon name "leadframe." The connection grid forms the external contacts of the module and ensures the connection with various elements of the power module as explained below.

[0005] The power board comprises power sections which are planar strips arranged on the power board substrate. These power sections are either at potential B-, potential B+, or Phase potential. The power board also comprises at least one power transistor. Power transistors enable the conversion of direct current into a polyphase current system and vice versa. For example, this could be an insulated-gate field-effect transistor, or MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor).

[0006] Each power portion is electrically connected to at least one electrically conductive track. Thus, each power portion is electrically connected to the connecting grid.

[0007] Finally, such a prior art power module includes a housing enclosing the power board, the signal board and the connection grid.

[0008] In prior art electronic modules, transistors are arranged on the power board with a predefined spacing to avoid thermal coupling. To meet space constraints, it is known to place the connection grid above the power and signal boards. Rigid electrical connection pillars link the transistors to the connection grid. This is referred to as a multi-stage power module. The connection grid is laser-welded to the rigid pillars.

[0009] Such an arrangement presents certain drawbacks. On the one hand, the rigid pillars subjected to mechanical stress can damage the transistors. On the other hand, during the soldering of the connection grid to the pillars, there is a risk of metallic spatter on the power and signal boards, which is hardly compatible with mass production. Furthermore, the encapsulated package is obtained by injecting epoxy resin into a mold containing the components to be encapsulated. Besides the fact that the resin flow is complex, the sealing of the power board and the connection grid must be ensured beforehand during the injection step. This leads to the use of special molds and / or laser ablation of the residual epoxy resin.Furthermore, in order to connect the module's elements together, the positioning possibilities for the different signal paths are limited, which can prove problematic depending on the pin integration requirements within the module.

[0010] The invention aims to overcome these drawbacks by providing a standard-design power module that does not require a special mold for its manufacture, nor even a laser ablation step. The invention proposes a connection to the remote connection grid and a judicious arrangement of the power portions leading to a compact power module directly applicable to various electronic systems, for example, for traction inverters.

[0011] To this end, the invention relates to a power module intended to be connected to a connection grid, comprising: - A power board comprising a power module substrate, two power portions arranged on the substrate, - A signal card mounted on the power card, - Electrically conductive connection pads, each pad of connection comprising a first face and a second face parallel to the first face, the first face being connected to one of the power portions and the signal card, the second face being intended to be electrically connected to the connection grid, - A housing containing the power board, the signal board, and the connection pads,

[0012] The power module is characterized in that the second face of the connection pads is flush with an upper surface of the housing. This means that the connection pads extend, preferably perpendicular to the plane of the substrate, from a power portion or the signal card to the upper surface of the housing. In other words, the second face is visible at the level of the upper surface of the housing. The second face lies in a plane parallel to the plane of the upper surface area onto which it is projected, this plane being preferably substantially coplanar with the plane of said surface area.

[0013] Thanks to the features of the invention, the power module contains the power sections and the signal board, each having connection areas on the second face of its associated connection pads. For each connection pad, the second face is located on the upper surface of the housing. Thus, all the elements of the power module form a first stage and are enclosed within the housing. The connection pads ensure the connection of the power sections and the signal board. They link the first stage to the upper surface of the housing.

[0014] The power module of the invention does not include the connection grid within its housing. The connection grid can be connected to the power sections and the signal board via connection pads whose second face is flush with the top surface of the housing. The connection to the power sections and the signal board is thus located on the top surface of the housing. Relocating the connection grid outside the power module allows, on the one hand, for a wide variety of possible element positions within the module, since the routing of electrically conductive traces within the housing no longer needs to be considered, and on the other hand, facilitates the manufacture of such a power module by making the resin injection step simpler and less expensive.

[0015] The module of the invention also offers another advantage: module standardization. The electrically conductive tracks form the contacts between the module and the inputs / outputs of the customer's electronic devices. Since the module does not include the connection grid, the power module can be used for various electronic devices. Only the connection grid needs to be adapted to the specific characteristics of the electronic device to which the power module is to be connected.

[0016] According to an optional feature of the invention, the two power portions are arranged on either side of the signal card. The two power portions and the signal card extend planarly on the substrate. The signal card is arranged between the two power portions. More precisely, the signal card is arranged on the power card along a central band, and the two portions of The power sections are arranged on the power board, each adjacent to the signal board, on one side and the other. The two power sections form two parallel bands between which the signal board is mounted.

[0017] Thanks to this arrangement of the two power sections around the signal board, crossings of power lines above the substrate are avoided. For example, it is possible to position the power lines at potential B+ and potential B- on the same power section, on the same side of the signal board. Thus, the central portion of the signal board is not affected by the positioning of the power lines.

[0018] It should be emphasized that the power module of the invention is a gateless module. Once connected to the power module, the gate forms the second stage, which is therefore located above the power module. It is thus understood that, being outside the power module, the gate does not affect the positioning of the connection pads. The power module of the invention therefore offers more space in the substrate plane for arranging the connection groups (power sections and signal board) along an X-axis of the substrate plane and for positioning a greater number of transistors along a Y-axis of the substrate plane, perpendicular to the X-axis.

[0019] According to an optional feature of the invention, the second face of at least one connection pad, preferably of each of the connection pads connected to the signal card, has a degree of freedom in translation about an axis perpendicular to the plane of the substrate. In other words, such a connection pad exhibits elasticity in a direction perpendicular to the faces of the connection pad. This makes it possible to keep the two faces of the connection pad parallel to each other when the connection pad is compressed in this direction. This is also referred to as a deformable pad.

[0020] According to an optional feature of the invention, the second face of at least one connection pad, preferably of each of the connection pads connected to the power sections, is at a constant distance from the first face of said connection pad. Such a connection pad is also called a rigid pillar. The rigid pillar does not deform. It is advantageously cylindrical but can take the form of any other polyhedron.

[0021] According to an optional feature of the invention, the first face of at least one connection pad is connected to the signal board by means including electrically conductive bonding, welding, or brazing. By using such electrically conductive means, the electrical connection of the connection pads to the power portion or signal board to which they are associated is ensured.

[0022] The invention also relates to a method for manufacturing a power module described above. The manufacturing method comprises the following steps: - Provide a power board comprising a power module substrate and two power portions arranged on the substrate, a signal board arranged on the substrate, the two power portions being preferably arranged on either side of the signal board, electrically conductive connection pads, each connection pad comprising a first face and a second face parallel to the first face, the first face being connected to one of the power portions and the signal board, - Place the substrate at the bottom of a mold configured to delimit at least one upper surface of the housing flush with the second face of the connection pads; - Press the substrate into the bottom of the mold; - Optionally, apply an insert to at least one of the connection pads; - Inject resin into the mold to coat the housing over the power board, signal board and connection pads.

[0023] According to an optional feature of the invention, the manufacturing process includes, during the resin injection step, a finger extraction step.

[0024] According to an optional feature, the substrate is held in place by means of fingers and / or by means of the connection pads. The pads have the advantage of holding the power board to the bottom of the mold, which prevents the generation of epoxy flashes.

[0025] At this stage of the manufacturing process, the resin injection has begun and keeps the substrate at the bottom of the mold. It is no longer necessary to press it against the bottom of the mold using fingers or pads. The finger removal step frees up a volume which is then filled with resin to complete the coating of the housing.

[0026] The invention also relates to a current converter, in particular DC / DC or AC / DC, comprising an electronic board, at least one power module as described above, signal connection lines between the electronic board and at least one power module, and a heat sink on which at least one power module is disposed.

[0027] In one embodiment, the current converter of the invention comprises an interconnector, per power module or per group of at least two power modules, comprising at least one electrically conductive trace forming the signal connection lines between the electronic board and the power module(s) to which it is connected. The interconnector is an overmolded part that allows the electrically conductive traces to be joined on the same part.

[0028] Thanks to the power module of the invention, the connection grid is separated from the power module. The connection grid is integrated into the interconnector. which manages the customer inputs and outputs. This combination allows for both more available space in the XY plane of the substrate for transistor placement and greater flexibility in routing the connection lines. Furthermore, separating the power and signal lines within the power module from the electrically conductive traces within the interconnector allows for a single type of power module to be used for various applications. The adaptation of the input and output connections to the customer interface is performed at the interconnector. As a result, the invention offers a compact and standardized power module suitable for any intended application.

[0029] The invention also relates to a motor vehicle comprising such a current converter.

[0030] Other features and advantages of the invention will become apparent from the following description on the one hand, and from several illustrative and non-limiting examples of embodiments given with reference to the accompanying schematic drawings on the other hand, in which:

[0031] [Fig.1] represents a view of a power module according to the invention;

[0032] [Fig.2] represents an external view of the power module housing according to the invention;

[0033] [Fig.3] schematically represents a cross-sectional view of the power module during its manufacture;

[0034] [Fig.4] schematically represents a view of a power module according to the invention connected to a connection grid.

[0035] The features, variants, and different embodiments of the invention, as described or as they will be presented in the detailed description that follows, can be combined in various ways, provided that they are not incompatible or mutually exclusive. In particular, variants of the invention may be conceived comprising only a selection of features described hereafter in isolation from the other described features, if this selection of features is sufficient to confer a technical advantage and / or to differentiate the invention from the prior art.

[0036] For the sake of clarity, the same elements are designated by the same references in the different figures.

[0037] Fig. 1 represents a view of a power module 1 according to the invention.

[0038] The power module 1 is intended to be connected to a connection grid 111 (visible in [Fig. 4]). The power module 1 comprises a power board 101 including a power module substrate 1011, two power portions 1012 arranged on substrate 1011. Substrate 1011 forms the main support for power module 1. Power module 1 includes a signal card 11 mounted on power card 101. Signal card 11 is electrically connected to power card 101.

[0039] The power module 1 comprises electrically conductive connection pads 12, 22. Each connection pad 12, 22 comprises a first face 121, 221 and a second face 122, 222, parallel to the first face 121, 221. The first face 121, 221 is connected to one of the power portions 1012 and the signal board 11. The second face 122, 222 is intended to be electrically connected to the connection grid 111. The substrate 1011 extending in an XY plane, the connection pads 122, 222 extend along a Z-axis perpendicular to the XY plane of the substrate 1011.

[0040] The power module 1 includes a housing 13 (visible in [Fig.2]) enclosing the power board 101, the signal board 11 and the connection pads 12, 22. According to one embodiment, the encapsulation material of the housing 13 is an epoxy resin.

[0041] According to the invention, the second face 122, 222 of the connection pads 12, 22 is flush with a top surface of the housing 13. In other words, the second face 122, 222 is located in the plane of a top surface of the housing 13 of the power module 1. The second face 122, 222 is free so as to allow an electrical connection with the connection grid.

[0042] The power module 1 of the invention differs from the prior art in that it does not include the connection grid within the housing. It thus provides a connection to the power sections 1012 and to the signal board 11, which is located on the upper surface of the housing 13. This arrangement is particularly advantageous since the power module does not include the connection grid 111 within its housing 13. The connection between the connection grid 111 and the power board 101 is made via connection pads, the second face of which is accessible from the upper surface of the housing. There are no electrically conductive traces 102 to be provided within the housing 13. This avoids the need for specific molds with complex resin flow within the mold during the resin injection phase to coat the housing.As will become apparent from the description of the manufacturing process for such a power module, the configuration of power module 1 according to the invention does not require laser ablation. The advantages are numerous compared to prior art processes: the manufacturing process includes one less step, and a smaller quantity of resin is required, thus resulting in lower production costs.

[0043] Such a power module 1 thus has power and signal connections which extend along the Z axis perpendicular to the XY plane of the substrate.

[0044] According to an optional feature of the invention, the two power portions 1012 are arranged on either side of the signal card 11. The power portions 1012 are flat strips directly arranged on the substrate 1011, parallel to each other and coplanar. Put another way, the signal card 11 is interposed between the two power sections 1012. The signal card 11 is placed on the power card 101 in a central position and the two power sections 1012 are placed on the power card 101, each being adjacent to the signal card 11. The two power sections 1012 and the signal card 11 thus form three parallel alternating bands: a first power section 1012 placed contiguous to the signal card 11, itself placed contiguous to the second power section 1012.This distribution of power portions around the signal map, forming parallel bands, is symbolized by means of dotted lines on [Fig. 1].

[0045] According to the embodiment illustrated in [Fig. 1], the power card includes power portions 1012 which are either at potential B, or at potential B+ or at Phase potential.

[0046] The power board 101 also includes at least one power transistor 131, 132. In the power module 1 of [Fig. 1], eight transistors are shown: four are on a first power section and four others are on a second power section. Of course, a different number of transistors and / or a different arrangement does not depart from the scope of the invention. The power transistors enable the conversion of direct current into a polyphase current system and vice versa. They may be, for example, insulated-gate field-effect transistors, or MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors).

[0047] In a known manner, each transistor 131, 132 is connected by electrical connection means 133, 134 to a power portion 1012 and the signal board 11.

[0048] Each power portion 1012 is intended to be electrically connected to at least one electrically conductive track of the connecting grid via at least one connecting pad 22. The connecting pads 22, arranged between the power portions 1012 and the connecting grid, serve to transmit power between the power portions 1012 and the electrically conductive tracks of the connecting grid. In [Fig. 1], the connecting pads 22 are cylindrical in shape. This representation is not limiting. The connecting pads can be of various shapes such as cubes, parallelepipeds, or any other volumetric shape.

[0049] The signal card 11 is electrically connected to the power card 101. The signal card 11 is connected to the various power transistors of the power card. power 101 by the connection means 134 in order to send the signals enabling the control of the power transistors.

[0050] Electrically connected on the signal card 11 are connection pads 12. These connection pads 12 allow electrical control signals to pass between the signal card 11 and the outside of the power module 1.

[0051] The arrangement of the two power portions 1012 around the signal card 11 has the advantage of avoiding power line crossings above the substrate.

[0052] The invention thus proposes a module with power and signal connections extending upwards from the power substrate, i.e. from the substrate and perpendicular to the plane of the substrate, assembled in three groups and molded without a connection grid with the upper surface outside the housing of the power module. A first group forms an output contact on one side of the module via a power portion 1012 (for example, the phase), a second group forms a signal contact in the middle of the substrate via the signal board, a third group forms all the power input and output contacts on a second side (for example, B+, B-, phase).

[0053] This configuration significantly simplifies the design of a mixed interconnector intended to cooperate with such a power module. The power module design is simplified since it is not impacted by specific interfaces and can be the same for all traction inverter applications, resulting in a significant reduction in development costs. Since the mixed interconnector handles all customer inputs and outputs, more space is available in the XY plane of the substrate for transistor placement. With this invention, only the mixed interconnector is modified, without impacting the power module design. Consequently, the invention provides a compact and standardized power module regardless of the intended application.

[0054] According to an optional feature of the invention, the second face 122 of at least one connection pad 12 connected to the signal card 11 has a translational degree of freedom about a Z-axis perpendicular to the XY plane of the substrate 1011. The first face 121 and the second face 122 are connected by elastic deformation means. The elastic deformation means of the connection pads 12 are arranged so as to ensure the parallelism of the first and second faces 121, 122 when these means are deformed along a Z-direction perpendicular to the surfaces of the first and second faces 121, 122.

[0055] The connection pads 12 are elastically deformable. These pads therefore exhibit a certain elasticity which allows them to compensate for the vertical play (along the Z axis) in the relative positioning of the power module and the interconnector.

[0056] The first face 121 of at least one connection pad 12 is electrically connected to the signal card 11. The connection is made by an electrically conductive means such as welding, for example laser or ultrasonic welding, brazing, electrically conductive gluing or any other equivalent means.

[0057] According to an optional feature of the invention, the second face 222 of at least one connection pad 22 connected to the power portions 1012 is at a constant distance from the first face 221 of said connection pad 222. In other words, the connection pad 22 is a rigid pillar.

[0058] Figure 2 shows an external view of the housing 13 of the power module 1 according to the invention. This view highlights the substrate 1011, which supports the power module 1, and the encapsulation by the housing 13 of all the elements constituting the power module. It is also visible that the second faces 122 and 222 are flush with the upper surface of the housing 13. Thus, it is sufficient to place an interconnector on the upper surface of the housing 13 to allow the connection of the power module's inputs / outputs.

[0059] Figure 3 schematically represents a cross-sectional view of the power module 1 during its manufacture. The manufacturing process for such a power module 1 includes the steps described below.

[0060] The first step is the provision of a power board 101 comprising a power module substrate 1011 and two power portions 1012 arranged on the substrate 1011, a signal board 11 arranged on the substrate, the two power portions 1012 being preferably arranged on either side of the signal board 11, electrically conductive connection pads 12, 22, each connection pad comprising a first face 121, 221 and a second face 122, 222 parallel to the first face, the first face 121, 221 being connected to one of the power portions 1012 and the signal board 11. The elements provided correspond to the constituent elements of the power module 1 which must be embedded in resin, typically epoxy resin, in order to encapsulate them in a housing 13.

[0061] The second step is the arrangement of the substrate 1011 at the bottom of a mold 40 configured to delimit at least one upper surface of the housing 13 flush with the second face 122 of the connection pads 12. The mold is composed of a lower part 41 and an upper part 42. The substrate 1011 (and the elements mounted on the substrate supplied in the first step) is placed at the bottom of the lower part 41 of the mold 40, the external face of the substrate being in contact with the bottom of the mold.

[0062] The third step is the plating of the substrate 1011 in the bottom of the mold by means of fingers 350. This step ensures that there is no free space between the substrate and the bottom of the mold in order to prevent resin from passing into such a space.

[0063] The fourth, optional step, which can take place before, during or after the third step, is the application of an insert 312, 322 on at least one of the connecting pads 12, 22.

[0064] A connecting pin 12, 22 is associated with an insert 312, 322 comprising a first end 3121, 3221 in contact with the second face 122, 222 of said pin 12, 22. An assembly formed by a connecting pin and its insert has one degree of freedom in translation about an axis perpendicular Z to the plane of the substrate XY. In other words, the insert 312 associated with the connecting pin 12, which exhibits elasticity, is a fixed insert, while the insert 322 associated with the connecting pin 22, which is a rigid support, is a movable insert. This degree of freedom allows for height adjustment along the Z-axis. Since the upper part 42 of the mold has a shape complementary to the shape of the upper surface of the housing 13 to be obtained, the presence of the inserts 312, 322 allows for local compensation of any height differences in Z when the mold is closed.

[0065] The fifth step is the injection of the resin into the mold in order to coat the housing 13 on the power board 101, the signal board 11 and the connection pads 12, 22.

[0066] During the resin injection step, the manufacturing process advantageously includes a finger extraction step 350. Once the resin injection step has begun, the substrate is already coated in resin and thus held against the bottom of the mold. The fingers 350 are retracted, and resin fills the space left by the fingers 350.

[0067] The manufacturing process just described allows obtaining the power module 1 shown in [Fig.2].

[0068] Figure 4 schematically represents a view of a power module 1 according to the invention connected to a connection grid 111. The connection grid 111 is formed by the set of electrically conductive tracks 102. As can be seen in Figure 2, the upper surface of the power module 1 exposes the second faces 122, 222 of the connection pads. These second faces, flush with the upper surface of the housing 13, are the connection point between the connection grid (comprising the electrically conductive tracks 102) and the power portions 1012 and the signal board 11.

[0069] One end of an electrically conductive track 102 can then be connected to a second face of a connection pad by laser welding. Generally, the tracks 102 are arranged in a thermoplastic part serving as a support for the tracks 102. This is then referred to as an interconnector.

[0070] According to one possible variant shown in [Fig. 4] by way of example, at least one electrically conductive track 102 comprises a first part 1021 having a planar shape and a second part 1022 having a three-dimensional shape. The The second portion 1022 of the electrically conductive track 102 includes a connection area 1023 forming a free end of the electrically conductive track 102. The connection area 1023 of the second portion 1022 of the electrically conductive track 102 is flush with an outer surface of the housing 13 when it is positioned above the power module. It is the connection area 1023 that is welded to its associated second face. This is an example of an embodiment, and the invention is by no means limited to this configuration of tracks 102.

[0071] Similar to the electrically conductive tracks 102, the connecting grid also includes conductors 202 associated with the power portions 1012.

[0072] It is clear from the description of the invention that the power module 1 offers a high degree of adaptability in the connections between the power module and the customer interface. It is sufficient to adapt the interconnector and the routing of its electrically conductive tracks 102.

[0073] The invention also relates to a current converter, in particular DC / DC or AC / DC, comprising an electronic board, at least one power module as described above, signal connection lines between the electronic board and the power module(s), and a heat sink on which the power module(s) are arranged. The heat sink ensures the dissipation of heat produced by the power module(s).

[0074] In one variant, the current converter includes an interconnector, per power module or per group of at least two power modules, comprising at least one electrically conductive track forming the signal connection lines between the electronic board and the power module(s) to which it is connected.

[0075] Of course, the invention is not limited to the examples just described, and many modifications can be made to these examples without departing from the scope of the invention. In particular, the features of different embodiments of the invention can be combined to carry out the invention, provided that these embodiments are not incompatible with each other.

Claims

Demands

1. A power module (1) intended to be connected to a connection grid (111), comprising: - A power board (101) including a power module substrate (1011), two power portions (1012) arranged on the substrate (1011), - A signal board (11) mounted on the power board (101), - Electrically conductive connection pads (12, 22), each connection pad (12, 22) comprising a first face (121, 221) and a second face (122, 222) parallel to the first face (121, 221), the first face (121, 221) being connected to one of the power portions (1012) and the signal board (11), the second face (122, 222) being intended to be electrically connected to the connection grid (111), - A housing (13) enclosing the board power (101), the signal card (11) and the connection pads (12, 22), the power module (1) being characterized in that the second face (122,222) of the connection pads (12, 22) is flush with an upper surface of the housing (13).

2. Power module (1) according to claim 1, wherein the two power portions (1012) are arranged on either side of the signal card (11).

3. Power module (1) according to claim 1 or 2, wherein the second face (122) of at least one connection pad (12), preferably of each of the connection pads connected to the signal card (11), has a degree of freedom in translation about an axis (Z) perpendicular to the plane (XY) of the substrate (1011).

4. Power module (1) according to any one of claims 1 to 3, wherein the second face (222) of at least one connection pad (22), preferably of each of the connection pads connected to the power portions (1012), is at a constant distance from the first face (221) of said connection pad (222).

5. Power module (1) according to any one of claims 1 to 4, wherein the first face (121) of at least one pad of connection (12) is connected to the signal card (11) by a means taken from electrically conductive gluing, welding or brazing.

6. A method for manufacturing a power module (1) according to any one of claims 1 to 5, comprising the following steps: - Providing a power board (101) comprising a power module substrate (1011) and two power portions (1012) disposed on the substrate (1011), a signal board (11) disposed on the substrate, the two power portions (1012) preferably being disposed on either side of the signal board (11), electrically conductive connection pads (12, 22), each connection pad comprising a first face (121, 221) and a second face (122, 222) parallel to the first face, the first face (121, 221) being connected to one of the power portions (1012) and the signal board (11), - Disposing the substrate (1011) at the bottom of a mold (40) configured to delimit at least one upper surface of the housing (13) flush with the second face (122) of the connection pads (12);- Press the substrate (1011) into the bottom of the mold; - Optionally, apply an insert (312, 322) to at least one of the connection pads (12, 22); - Inject resin into the mold to coat the housing (13) over the power board (101), the signal board (11) and the connection pads (12, 22).

7. A manufacturing method according to the preceding claim, comprising, during the resin injection step, a finger extraction step (350).

8. Current converter, in particular DC / DC or AC / DC, comprising an electronic board, at least one power module according to any one of claims 1 to 5, signal connection lines between the electronic board and the at least one power module, and a heat sink on which the at least one power module is disposed.

9. 15 Current converter according to the preceding claim, comprising an interconnector, per power module or per group of at least two power modules, comprising at least one electrically conductive track forming the signal connection lines between the electronic board and the power module(s) to which it is connected.

10. Motor vehicle comprising a current converter according to any one of claims 8 to 9.