Electronic module, electronic system and associated manufacturing process.

Abstract

The invention relates to an electronic module (1) comprising: - a power assembly including a power board (101) and at least one electrically conductive track (102), - a first portion (1021) of the electrically conductive track (102), having a planar shape, and - a second portion (1022) of the electrically conductive track (102) having a three-dimensional shape and comprising a connection area (1023) forming a free end of the track (102), - a housing overmolded onto the power assembly, in which the connection area (1023) of the second portion (1022) of the track (102) is flush with an external surface of said housing. Figure to be published with the abbreviation: Fig. 2

Description

Title of the invention: Electronic module, associated electronic system and manufacturing process. FIELD OF INVENTION

[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 an electronic module, a method for manufacturing an electronic module, and an associated electronic system.

[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... STATE OF THE ART

[0003] In electronic modules, such as power modules, it may be necessary to know the voltage levels of the signals of the electronic module.

[0004] It is known to take representative voltage signals directly from the signal board of the electronic module using dedicated connectors. However, the space on this board is limited and does not allow for increasing the number of connection devices.

[0005] An object of the invention is in particular to correct all or part of the disadvantages of the prior art by proposing a solution allowing to take signals representative of the voltages in the electronic module taking into account the restricted surface of its signal card.

[0006] BRIEF DESCRIPTION OF THE INVENTION

[0007] To this end, the present invention relates to an electronic module comprising: - a power assembly including a power board; and at least one electrically conductive trace, • a first part of the electrically conductive track, having a flat shape, and • a second electrically conductive part of the track having a three-dimensional shape and comprising a connection area forming a free end of the track, - a casing enclosing the entire power assembly,

[0008] wherein the connection area of ​​the second part of the electrically conductive track is flush with an external surface of said housing.

[0009] The electronic module may also include one or more of the following features, considered individually or in all technically possible combinations: - the second part of the track comprises a folded strip of an electrically conductive material; and / or - at least one electrically conductive trace is located away from the power board; and / or - The power board comprises a substrate and at least one power portion deposited on said substrate, each power portion being electrically connected to at least one electrically conductive trace; and / or - the surface of the connection pad is flat, specifically parallel to the power board; and / or - the dimensions of the cross-sections of the first and second parts of the electrically conductive tracks are greater than a predefined value designed to allow the passage of a predetermined current intensity, in particular to ensure that the current density is less than 100 A rms / mm2; and / or - the electronic module includes a signal card mounted on the power card, the electrical module further including at least one electrically conductive connection device, at least one connection device comprising a first face and a second face parallel to each other, the first face being connected to the signal card and the second face being flush with the same external surface of the housing as the connection area; and / or - the electronic module includes at least two connection devices and at least a portion of the electrically conductive trace is disposed between two connection devices; and / or - the electronic module is a power electronic module; and / or - the casing's encapsulation material is an epoxy resin; and / or - the electronic module includes at least two devices connection, each connection device being aligned in a direction perpendicular to an edge of the signal card; and / or - the electronic module includes at least two connection devices, each connection device being aligned along a transverse direction of the electrically conductive tracks; and / or - the electronic module includes at least two connection ranges, each connection range being aligned in a direction perpendicular to an edge of the signal card; and / or - The electronic module comprises at least two connection areas, each connection area being aligned along a transverse direction of the electrically conductive tracks.

[0010] The invention also relates to a method for manufacturing an electronic module according to the invention comprising the following steps:

[0011] - provide a power assembly comprising a power board and at least an electrically conductive track, the electrically conductive track having: • a first part having a flat shape, and • a second part having a three-dimensional shape and comprising a connection area forming a free end of the electrically conductive track; - provide at least one injection mold;

[0012] - apply the mold, in contact with the connection area of ​​at least one track electrically conductive;

[0013] - Injecting a resin into the mold in order to coat a housing over the entire power, the power board and at least one electrically conductive track so that at least one connection area is flush with an external surface of said housing.

[0014] The method may also include one or more of the following features, considered individually or in all technically possible combinations: - The electronic module includes a signal card mounted on the power card, and the process further includes the following steps: • provide at least one connection device comprising a first face and a second face parallel to each other, • connect the first side of at least one connection device to at least one signal card; and in which: • during the step of applying the mold to the contact area, said mold is also in contact with the second face of at least one connection device, and • During the injection step, the resin also coats the housing on at least one connection device, and the second face of at least one connection device is also flush with the same external surface of the housing as the connection area; and / or - the method further includes a step of cleaning the connection area of ​​at least one electrically conductive track and / or the second face of at least one connection device; and / or - the cleaning step is carried out by laser ablation.

[0015] The invention also relates to an electronic system comprising at least one electronic module according to the invention and an interconnector comprising a plurality of pins, each pin being connected to a connection range or a second face of a connection means.

[0016] The electronic module of the electronic system may also include a first positioning element defining a reference position on said electronic module, and the interconnector may include a second positioning element configured to cooperate with the first positioning element. BRIEF DESCRIPTION OF THE FIGURES

[0017] The invention will be better understood in the light of the following description in the context of a displacement device, which is given by way of illustration only and is not intended to limit said invention, together with the figures below:

[0018] [Fig. 1] is a schematic representation of an example embodiment of an electronic module according to the invention;

[0019] [Fig.2] is exploded view of the embodiment of the electronic module illustrated in [Fig.1];

[0020] [Fig.3] is an exploded view of an example embodiment of an electronic system according to the invention.

[0021] In the various figures, analogous elements are designated by identical reference numerals. Furthermore, the various elements are not necessarily shown to scale in order to present a view that facilitates understanding of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] Figures 1 and 2 schematically represent an example of an embodiment of an electronic module 1 according to the invention.

[0023] According to a particular embodiment, the electronic module 1 is a power electronic module.

[0024] The electronic module 1 comprises a power assembly including a power board 101 and at least one electrically conductive track 102. The at least one electrically conductive track comprises a first portion 1021 having a planar shape and a second portion 1022 having a three-dimensional shape. The second portion 1022 of the at least one electrically conductive track 102 includes a connection area 1023 forming a free end of the track 102.

[0025] The set of electrically conductive tracks 102 forms the connection grid (or Icad frame “ according to Anglo-Saxon terminology).

[0026] Advantageously, the connection ranges 1023 allow a representative value of the voltage of the electrically conductive tracks 102 of the connection grid to be taken.

[0027] According to one embodiment, the second part 1022 of at least one electrically conductive track 102 comprises a ramp, formed in one piece with the first part 1021. The ramp comprises several bends, for example, a bend placed at the height of the connection area 1023 and a bend placed at the height of the first part 1021 of the track 102.

[0028] According to one embodiment, the second part 1022 of at least one electrically conductive track 102 comprises a folded strip of an electrically conductive material such as copper.

[0029] The electronic module 1 also includes a housing enclosing the power assembly so that at least one connection range 1023 of the second part 1022 of at least one electrically conductive track 102 is flush with an external surface of the housing.

[0030] According to one embodiment, the casing encapsulation material is an epoxy resin.

[0031] According to one embodiment, the surface of at least one connection area 1023 is flat, for example, parallel to the power board 101. Advantageously, the flatness of the connection area facilitates electrical connection, for example, by brazing, sintering or by electrically conductive bonding of a connection tab onto this connection area 1023.

[0032] The power board 101 further comprises a substrate 1011 and at least one power portion 1012 deposited on said substrate 1011. The power portions 1012 are flat strips directly arranged on the substrate 1011, parallel to each other and coplanar. Each power portion 1012 is electrically connected to at least one electrically conductive track 102. Thus, each power portion 1012 is electrically connected to the connecting grid.

[0033] According to one embodiment, the power board 101 also includes at least one transistor. The power transistors enable the conversion of direct current into a polyphase current system and vice versa. This could be, for example, an insulated-gate field-effect transistor, or MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) in Anglo-Saxon terminology.

[0034] According to one embodiment, at least one electrically conductive track 102 is located away from the power board 101. The electrically conductive track 102 is connected to a power portion via at least one pad of connection 103. Thus, each power portion 1012 is electrically connected to the connection grid.

[0035] The connection pads 103, arranged between the power portions 1012 and the connection grid, have in particular the role of transmitting power between the power portions 1012 and the electrically conductive tracks 102.

[0036] The connecting pads 103 can be cylindrical, as illustrated in figures 1 and 2, cubic, parallelepiped or any other volumetric shape.

[0037] Subsequently, the longitudinal direction of the electrically conductive tracks 102 will be considered to be the direction along the length of the substrate 1011 of the electronic module 1, and therefore the transverse direction will be considered to be the direction along the width of the substrate 1011.

[0038] According to another embodiment, the longitudinal direction of the electrically conductive tracks 102 will correspond to the direction of propagation of the signals on these tracks 102.

[0039] According to one embodiment, the dimensions of the cross-sections of the first part 1021 of the electrically conductive tracks 102 are greater than a predefined value designed to allow the passage of a predetermined current intensity, in particular so that the current density is less than 100 A rms / mm². In the example considered, the first part 1021 may have a cross-section of 3.5 mm by 0.8 mm.

[0040] According to one embodiment, the electronic module 1 comprises at least one signal card 11. The signal card 11 is mounted and electrically connected to the power card 101. It is connected to the various transistors of the power card 101 in order to send the signals enabling the control of the power electronics.

[0041] At least one electrically conductive connection device 12 is electrically connected to the power board 11. The connection device 12 comprises a first face 121 and a second face 122 parallel to each other and connected by elastic deformation means 123. The elastic deformation means 123 are arranged so as to maintain the parallelism of the first face 121 and the second face 122 during deformation of these means 123 along a direction perpendicular to the surface of the first face 121 and the second face 122 of the connection device 12.

[0042] The first face 121 of at least one connection device 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, sintering, electrically conductive bonding or any other equivalent means.

[0043] The second face 122 of at least one connection device 12 is flush with an external surface of the housing encapsulating the power assembly, the signal card 11 and at least one connection device 12 of the electronic module 1.

[0044] According to one embodiment, the second face 122 of at least one connection device 12 is flush with the same external surface of the housing as the connection area 1023 of at least one electrically conductive track 102.

[0045] According to one embodiment, at least one connection device 12 comprises a folded strip of an electrically conductive material such as copper.

[0046] The connecting devices 12 can have the shape of an S, as illustrated in [Fig.2], or any other shape such as a Z, a C or an S. Advantageously, these shapes allow elasticity of the connecting device 12 along a direction perpendicular to the surfaces of the first and second faces 121, 122 of the connecting devices 12.

[0047] According to one embodiment, the electronic module 1 comprises at least two connection devices 12, each connection device 12 being aligned in a direction perpendicular to an edge of the signal card 11.

[0048] According to one embodiment, the electronic module 1 comprises at least two connection ranges 1023, each connection range 1023 being aligned in a direction perpendicular to an edge of the signal card 11.

[0049] According to one embodiment, the electronic module 1 comprises at least two connection devices 12, each connection device 12 being aligned along a transverse direction of the electrically conductive tracks 102.

[0050] According to one embodiment, the electronic module 1 comprises at least two connection ranges 1023, each connection range 1023 being aligned along a transverse direction of the electrically conductive tracks 102.

[0051] According to one embodiment, the electronic module 1 comprises at least two connection devices 12 and at least a portion of an electrically conductive track 102 is disposed between two connection devices 12.

[0052] The invention also relates to a method for manufacturing an electronic module 1 according to the invention.

[0053] According to one embodiment, the manufacturing process comprises the following steps: - provide a power assembly comprising a power board 101 and at least one conductive electrical trace 102, the electrically conductive trace having: - a first part 1021 having a flat shape, and - a second part 1022 having a three-dimensional shape, the second part 1022 of the electrically conductive track having a connection area 1023 forming a free end of the track 102; - provide at least one injection mold, - apply the injection mold to the contact area 1023 of at least one electrically conductive track 102, - Inject resin into the mold to coat a housing on the power board 101 and at least one electrically conductive track 102 so that the connection area 1023 is flush with an external surface of said housing.

[0054] Advantageously, the action of the mold on the connection area 1023 of at least one electrically conductive track 102 makes it possible to limit, or even avoid, the deposition of resin on this connection area 1023. This makes it possible to limit the reworking of the surface of these connection areas 1023 in order to remove the resin after the encapsulation of the housing.

[0055] According to one embodiment, the electronic module 1 comprises a signal card 11 and the manufacturing process for such an electronic module 1 further comprises the following steps: - provide at least one connection device 12 comprising a first face 121 and a second face 122 parallel to each other; - connect the first face 121 of at least one connection device 12 to at least the signal card 11; - during the step of applying the mold to the contact area 1023, said mold is also in contact with the second face 122 of at least one connection device 12, and - during the injection step, the resin also coats the housing on at least one connection device 12 and the second face 122 of at least one connection device 12 is also flush with the same external surface of the housing as the connection range 1023.

[0056] Advantageously, the action of the mold on the connection devices 12 makes it possible to limit, or even avoid, the deposition of resin on the second face 122 of these devices 12. This makes it possible to limit the surface treatment of these second faces 122 in order to remove the resin after the encapsulation of the housing.

[0057] During the injection of the resin, at least one connecting device 12 is compressed in a direction perpendicular to the first and second faces 121, 122 of the connecting device 12. After cooling and polymerization, the resin will fix the position of at least one connecting device 12.

[0058] According to one embodiment, the manufacturing process of an electronic module 1 according to the invention further includes a step of cleaning at least one connection area 1023 of an electrically conductive track 102 and / or at least one second face 122 of a connection device 12.

[0059] According to one embodiment, the cleaning step is carried out by laser ablation.

[0060] The invention also relates to an electronic system 3 comprising an electronic module 1 as described above and an interconnector 31. [Fig.3] illustrates an example of an embodiment of such a system 3.

[0061] The interconnector 31 is an overmolded part allowing different connection pins 310 to be gathered on the same part.

[0062] According to one embodiment, the interconnector 31 comprises a plurality of legs 311, each of these legs 311 being electrically connected to a first end of the various pins 310. The legs 311 of the interconnector are intended to be electrically connected to connection areas of the electronic module 1 such as the connection areas 1023 of electrically conductive track 102 and / or the second faces 122 of connection devices 12. The connection can be made by welding, brazing, sintering, electrically conductive bonding or any other equivalent means.

[0063] According to one embodiment, the various legs 311 of the interconnector 31 are aligned in one or more rows.

[0064] In the example illustrated in [Fig. 3], the tabs 311 of the interconnector are arranged in two rows. A first row is arranged along an outer edge of the interconnector 31. A second row is arranged inside the interconnector 31. Openings 313 are made in the overmolding of the interconnector 31 to provide access to the tabs 311 of the second row. In this example, the tabs of the first row are intended to be electrically connected with the second faces 122 of the connection devices 12. The tabs of the second row are intended to be electrically connected with the connection areas 1023 of the electrically conductive tracks 102.

[0065] According to one embodiment, the various pins 310 of the interconnector 31 are oriented perpendicularly to the surface of said interconnector 31.

[0066] The second ends 312 of the pins 310 of the interconnector 31 are intended to be electrically connected to at least one printed circuit board ancillary to the electronic module 1, for example by plugging, for example, by press-fitting into vias of the printed circuit board

[0067] According to one embodiment of the electronic system 3, the interconnector 31 is indexed with respect to the electronic module 1. For this purpose, the electronic module 1 may include at least one first positioning element 1025 defining a reference position on said electronic module 1. The interconnector 31 includes at least one second positioning element 315 configured to cooperate with the at least one first positioning element 1025.

[0068] In the example illustrated in [Fig. 3], a first positioning member 1025 is formed on an electrically conductive track 102 in the form of a female element, namely, a cylindrical hole. A second positioning member 315 is formed in the overmolding of the interconnector in the form of a male element, namely, a cylindrical pin.

Claims

Demands

1. Electronic module (1) comprising: - a power assembly including a power board (101) and at least one electrically conductive track (102), - a first part (1021) of the electrically conductive track (102), having a planar shape, and - a second part (1022) of the electrically conductive track (102) having a three-dimensional shape and comprising a connection area (1023) forming a free end of the track (102), - a housing enclosing the power assembly, in which the connection area (1023) of the second part (1022) of the track (102) is flush with an external surface of said housing.

2. Electronic module (1) according to the preceding claim, wherein the second part (1022) of the track (102) comprises a folded strip of an electrically conductive material.

3. Electronic module (1) according to any one of the preceding claims, wherein the dimensions of the cross sections of the first part (1021) and second part (1022) of the electrically conductive tracks (102) are greater than a predetermined value dimensioned to permit the passage of a predetermined current intensity.

4. Electronic module (1) according to any one of the preceding claims, comprising a signal card (11) mounted on the power card (101), the electrical module (1) further comprising at least one electrically conductive connection device (12), the at least one connection device (12) comprising a first face (121) and a second face (122) parallel to each other, the first face (121) being connected to the signal card (11) and the second face (122) being flush with the same external surface of the housing as the connection range (1023).

5. Electronic module (1) according to the preceding claim, comprising at least two connection devices (12) and wherein at least a portion of the electrically conductive track (102) is disposed between two connection devices (12).

6. Electronic module (1) according to any one of the preceding claims, wherein said electronic module (1) is a power electronic module.

7. A method for manufacturing an electronic module (1) according to any one of the preceding claims comprising the following steps: - providing a power assembly comprising a power board (101) and at least one electrically conductive track (102), the electrically conductive track having: - a first part (1021) having a planar shape, and - a second part (1022) having a three-dimensional shape, the second part (1022) of the track having a connection area (1023) forming a free end of the electrically conductive track (102); - providing at least one injection mold, - applying the mold to the contact area (1023) of at least one electrically conductive track (102), - injecting a resin into the mold to encapsulate a housing on the power board (101) and the at least one electrically conductive track (102) such that the connection area (1023) is flush with an external surface of said housing.

8. Method of manufacturing an electronic module (1) comprising a signal card (11) mounted on the power card (101), according to the preceding claim further comprising the following steps: - providing at least one connection device (12) comprising a first face (121) and a second face (122) parallel to each other, - connecting the first face (121) of at least one connection device (12) to at least the signal card (11); in which: - during the step of applying the mold to the contact area (1023), said mold is also in contact with the second face (122) of at least one connection device (12), and - during the injection step, the resin also coats the housing on the at least one connection device (12) and the second face (122) of at least one connection device (12) is also flush with the same external surface of the housing as the connection area (1023).

9. A method for manufacturing an electronic module (1) according to claim 7 or 8 further comprising a cleaning step the connection range (1023) of at least one electrically conductive track (102) and / or of the second face (122) of at least one connection device (12).

10. Electronic system (3) comprising at least one electronic module (1) according to any one of claims 1 to 7 and an interconnector (31) comprising a plurality of pins (311), each pin (311) being connected to a connection range (1023) or a second face (122) of a connection means (12).

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