Electronic assembly comprising at least one electronic component and a cooling device including a positioning element

Abstract

Title: Electronic assembly comprising at least one electronic component and a cooling device including a positioning member. The invention relates to an electronic assembly comprising at least one electronic component (6), a cooling device (2) for said electronic component comprising a cooling plate (4), said electronic component (6) being disposed on said cooling plate (4) in at least one heat exchange zone (Z, Z1, Z2, Z3), the heat exchange zone (Z, Z1, Z2, Z3) being a flat portion (10) of the cooling plate (4), the electronic assembly further comprising at least one thermal attachment means (8) interposed between the heat exchange zone (Z, Z1, Z2, Z3) and the electronic component (6),the cooling plate (4) being characterized in that centering means (12) are arranged on the periphery of the heat exchange zone (Z) so as to maintain the thermal attachment means (8) and / or the electronic component (6) within the heat exchange zone (Z). (figure 2),

Description

Title of the invention: Electronic assembly comprising at least one electronic component and a cooling device including a positioning element

[0001] The present invention relates to the field of electronic assemblies of motor vehicles, and in particular to cooling devices for electronic components associated with these electronic assemblies.

[0002] The electronic assemblies of motor vehicles, whether electric or hybrid, comprise a plurality of electronic components, such as power modules, coils, or capacitors, without this list being exhaustive. These electronic components generate heat during operation, and this temperature rise, when not controlled, risks damaging the electronic components and thus reducing the lifespan of the corresponding electronic system.

[0003] In particular, the power module is one of the electronic components that generates a large amount of heat. The power module comprises a housing within which electronic chips are arranged side by side. The housing includes a base for supporting the electronic chips and a cover plate that encloses the chips and, together with the base, forms an internal volume in which the chips are housed. The chips are connected to electrical connection pins that extend outside the power module, notably to allow the electronic chips, housed inside the casing, to be connected to an electrical network.

[0004] To prevent the risk of malfunction due to excessively high temperatures, it is known to associate with electronic components, and in particular with power modules, a cooling device configured to allow the dissipation of heat.

[0005] Such a cooling device may include a cooling plate on which the electronic components are arranged. A heat transfer fluid may circulate within the cooling plate, thus allowing heat exchange across the cooling plate between the electronic components and the heat transfer fluid.

[0006] It is known to secure power modules to a cooling plate by a brazing process with a thermal interface material interposed between each power module and the plate. These processes include a positioning step during which a means is placed A thermal attachment method, such as thermal grease or a preform, is applied to the cooling plate, followed by the placement of the power module onto this thermal attachment. The cooling plate is then placed in an oven and cooled to secure the power module in its initial position through appropriate deformation and hardening of the thermal attachment. When the thermal attachment is thermal grease, the pre-oven positioning operation involves the power module compressing and spreading the thermal grease across the surface of the cooling plate. The subsequent oven curing and cooling process polymerizes the thermal grease between the power module and the cooling plate.When this thermal attachment method is a preform, the pre-oven positioning operation involves correctly positioning the preform against the cooling plate and bringing the power module against this preform, the assembly then being brought into the oven to polymerize the preform when it is a thermal paste and to melt the metal when the preform is a metal attachment plate.

[0007] This mounting solution can be improved insofar as the inventors have observed that the thermal attachment means and the power modules can move during their movement for placement in an oven, and can thus imply a poor positioning of the power module relative to the cooling plate once the assembly is removed from the oven, i.e. a position of the power module which is not correctly centered on a fluid circulation channel within the cooling plate, this has the effect of generating a heat exchange which is not optimal during the temperature rise of the system and also generate mounting problems with respect to the control board via the control pins of the power modules.

[0008] The present invention falls within this context and aims to provide an electronic assembly equipped with a cooling device on which the thermal attachment means and / or the electronic component, in particular a power module, is held in a desired position.

[0009] The present invention provides an electronic assembly comprising at least one electronic component, a cooling device for said electronic component comprising a cooling plate, said electronic component being disposed on said cooling plate in at least one heat exchange zone, the heat exchange zone being a flat portion of the cooling plate, the electronic assembly further comprising at least one thermal attachment means interposed between the heat exchange zone and the electronic component, the cooling plate being characterized in that centering means are arranged around the perimeter of the heat exchange area so as to hold the thermal attachment means and / or the electronic component within the heat exchange area.

[0010] The cooling device for an electronic system according to the invention, suitable for equipping an electric motor vehicle, has as its function, in particular, the transfer of heat generated by the operation of an electronic component of said system to a cooling circuit within the vehicle. This cooling device is characterized herein by the presence of a cooling plate within which a heat transfer fluid is able to circulate and which has a heat exchange zone against which an electronic component to be cooled is fixed, by means of a thermal attachment means which holds the electronic component in position and which enables, or improves, the heat exchange between the electronic component and the cooling plate.

[0011] The thermal attachment means and the associated electronic component are arranged on the cooling plate in a heat exchange zone. This heat exchange zone is chosen, in particular, by its proximity to a heat transfer fluid channel on the opposite side of the wall supporting this heat exchange zone. The heat exchange zone consists of at least one flat portion having dimensions equal to or greater than the corresponding dimensions of the thermal attachment means. The flatness of said flat portion allows the electronic component to be securely attached to the cooling plate.

[0012] According to another optional feature of the invention, the thermal attachment means is formed from a preform or a thermal paste.

[0013] The preform may be a plate, in particular a metal plate, especially a rigid metal plate, enabling the power module to be secured to the cooling plate after oven curing. The preform may be a plate made of a plastic or composite thermal interface material, for example silicone. The preform may have substantially constant dimensions, at least before oven curing.

[0014] The thermal paste ensures a contact surface free of air pockets between the cooling plate and the electronic component. The thermal paste is viscous within the temperature range of the assembly process. The thermal paste has a lower viscosity than a metal plate. The thermal paste can flow, particularly under stress applied by the electronic component. The paste can take the form of a thermal grease. This thermal paste is designed to be placed in the heat exchange zone, then compressed and spread by the electronic component onto the cooling plate, thus defining the heat exchange zone. When thermal paste is used, centering means are then configured to facilitate only the positioning and locking of the electronic component.

[0015] According to another optional feature of the invention, the cooling plate helps to define a cooling circuit. The cooling plate is then in contact with the heat transfer fluid.

[0016] The assembly of the cooling plate, the thermal attachment means, and the electronic component is achieved by placing the assembly in an oven at a temperature that, after cooling, allows the thermal attachment means to polymerize or be soldered. The thermal attachment means can expand when heated and adheres to the power module. When the assembly has cooled, the thermal attachment means is fixed between the power module and the cooling plate.

[0017] The assembly may be free of any means of attachment between the electronic component and the cooling device, other than the thermal attachment means, when said thermal attachment means is a metal plate. This type of attachment allows the electronic component and the cooling plate to be secured without adding any other fasteners such as screws or rivets. Furthermore, the thermal attachment means can improve thermal conductivity between the power module and the cooling plate.

[0018] The centering means present on the cooling plate are arranged around the perimeter of the heat exchange zone, which corresponds to the area where the electronic component is to be permanently positioned after oven drying, and for example the flat portion against which it is advantageous to rest the electronic component.

[0019] The centering means are arranged such that the thermal attachment means and / or the electronic component is held in position on the flat portion of the heat exchange zone during transport of the assembly to the oven, at a point in the assembly process when the electronic component, and where applicable the thermal attachment means, is not yet fixed to the cooling plate. In other words, the presence of the centering means makes it possible to reduce the risk of the thermal attachment means shifting within the heat exchange zone before the cooling plate has been placed in the oven.

[0020] In another embodiment, the electronic component is held in place by centering means. In particular, in an embodiment where the thermal attachment means is not a preform but thermal paste, or thermal grease, which is a viscous material. The thermal attachment means is then placed in the heat exchange zone without precise positioning, and is subsequently compressed by the electronic component. It is therefore important, according to this embodiment, to implementation, since the thermal attachment means can move, that the electronic component is blocked by the centering means.

[0021] According to an optional feature of the invention, the centering means block translational movements of the thermal attachment means and / or the electronic component, along two centering directions perpendicular to a coordinate system parallel to the planar portion. Alternatively, the centering means block translational movements of the thermal attachment means and / or the electronic component, along a single centering direction perpendicular to a coordinate system parallel to the planar portion.

[0022] According to an optional feature of the invention, at least two centering means are arranged opposite each other on either side of the heat exchange zone along one of said centering directions. When each centering means blocks movement in a single direction, then four means are required. The centering means can thus block translation in both directions along a given direction.

[0023] In one embodiment, the centering means are arranged at the four corners of the heat exchange zone. In another embodiment, the centering means are arranged on each of the edges of the heat exchange zone. The edges can thus form the perimeter of the heat exchange zone.

[0024] In these variants, the heat exchange zone may in particular have a quadrilateral shape, the dimensions of which are similar to those of the quadrilateral shape of the thermal attachment means and / or the electronic component: Areas for material escape may be provided, in particular on one edge, in particular on several edges, in particular on all edges of the perimeter.

[0025] According to an optional feature of the invention, the thermal attachment means and / or the electronic component has at least one dimension slightly smaller than the corresponding distance between two opposing centering means.

[0026] In other words, the dimension of the thermal attachment means and / or the electronic component in a given direction, for example its length or width in the case of a quadrilateral shape, is defined by the spacing of the two centering means arranged opposite each other in that direction, so that it can be positioned against the flat portion of the cooling plate without being obstructed by the presence of the centering means. In this respect, the length and width of the thermal attachment means and / or the electronic component are less than those of the heat exchange area. Furthermore, since the centering means secure the thermal attachment means, or the electronic component respectively, and therefore the latter should move little or not at all during handling once it is positioned between the centering means, the length and width of the the means of thermal attachment and / or of the electronic component are only slightly lower, i.e. substantially equal, to those of the heat exchange zone.

[0027] According to an optional feature of the invention, at least one of the centering means comprises a main body which has a height, measured perpendicular to the flat portion of the heat exchange zone, which is greater than the corresponding height of the thermal attachment means:

[0028] In this way, it is ensured that the main body of the centering means blocks the thermal attachment means in its translational movement along the flat portion of the heat exchange zone, preventing it from passing over the centering means.

[0029] According to an optional feature of the invention, the electronic assembly has a stop finger. The stop finger extends between the electronic component and the flat portion of the cooling plate. In this way, it is ensured that the electronic component is at a given distance from the cooling plate when positioned in the heat exchange zone, this distance being determined for an optimal compression ratio of the thermal attachment means interposed between the electronic component and the cooling plate.

[0030] According to an optional feature of the invention, the centering means is formed from the material with the stop finger. The stop finger can project from the main body towards the center of the heat exchange zone of the cooling plate.

[0031] According to another optional feature of the invention, the main body of the centering means has a greater height than that of the stop finger.

[0032] By way of non-limiting example, the stop finger has a height of 200 microns. This dimension corresponds to the optimal height or thickness of the thermal attachment medium that should be retained after the electronic component has been placed on the heat exchange area, in particular so that sufficient thermal attachment medium is still interposed between the cooling plate and the electronic component before oven drying to allow the electronic component to be fixed and optimal heat exchange.

[0033] According to an optional feature of the invention, the electronic component includes at least one counter-form configured to receive the centering means.

[0034] The centering means can then allow the electronic component to be centered at the same time as it allows the thermal attachment means to be centered, and in particular when the electronic component has larger dimensions than the thermal attachment means.

[0035] According to an optional feature of the invention, the electronic component comprises at least two counter-forms, of which two counter-forms are made on opposite faces of the electronic component.

[0036] According to another feature of the invention, the centering means are elements attached to the cooling plate.

[0037] The centering means can, for example, take the form of lugs made separately from the cooling plate and configured to be inserted into holes made in the cooling plate and allowing the positioning of the centering means.

[0038] According to another optional feature of the invention, the centering means are made in one piece with the cooling plate.

[0039] 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:

[0040] [Fig-1] is a partial schematic representation viewed from above of a device electronic component cooling, here for an electronic assembly forming a power switching system of a motor vehicle, making visible in particular a portion of a cooling plate and three adjacent heat exchange zones with one of the zones which includes an electronic component, another zone which includes only a thermal attachment means not covered by an electronic component, and another blank zone; [Fig.2] is a schematic representation seen from above of a formed heat exchange zone including a first embodiment of the arrangement of the centering means;

[0041] [Fig.3] is a schematic top-view representation of a second embodiment of the cooling device, with a heat exchange zone in which centering means are specifically arranged;

[0042] [Fig.4] is a schematic top-view representation of a third embodiment of the cooling device, with a heat exchange zone in which centering means are specifically arranged;

[0043] [Fig.5] is a schematic representation of a cross-sectional view of the assembly of the cooling plate, the thermal attachment means and the electronic component, making visible the interaction of the thermal attachment means and one of the centering means;

[0044] [Fig.6] is a schematic top-view representation of a heat exchange zone in an embodiment in which centering means come from material with a stop finger extending into the interior of the heat exchange zone;

[0045] [Fig.7] is a schematic representation of a cross-sectional view of the assembly of the cooling plate, the thermal attachment means and the power module with a counter form included in the power module.

[0046] Fig. 1 is a schematic representation of a cooling device 2 suitable for equipping a motor vehicle and in particular an electric or hybrid vehicle, although this application is not limiting of the invention.

[0047] The cooling device 2 includes a cooling plate 4 that helps to define a cooling circuit (not shown in the figures) and within which a heat transfer fluid is able to circulate. Heat exchange between the heat transfer fluid and electronic components of the electric vehicle takes place through the cooling plate 4. In other words, the electronic components are able to transfer heat to the heat transfer fluid via a wall of the cooling plate.

[0048] The cooling plate 4 here comprises three heat exchange zones Z1, Z2, Z3 configured to receive electronic components such as coils, capacitors, or, as illustrated here, power modules. Heat exchange is carried out between the heat transfer fluid and an electronic component at the level of the cooling plate 4 in a corresponding heat exchange zone Z1, Z2, Z3. In the cooling device 2 shown [Fig. 1], the three heat exchange zones Z1, Z2, Z3 are shown in a configuration that has been intentionally made different for each zone, to show a blank heat exchange zone Z1, a heat exchange zone Z3 covered by a thermal attachment means 8 prior to the positioning of an electronic component on top of it, and finally a heat exchange zone Z2 provided with an electronic component covering the thermal attachment means 8.

[0049] The first heat exchange zone Zl, shown here as blank, illustrates a flat portion 10 of the heat exchange zone. Each heat exchange zone comprises an identical flat portion 10 from one heat exchange zone to the next, but only that of the first heat exchange zone Zl, shown here as blank, is visible. The flat portion 10 has a quadrilateral shape, shown here as rectangular, which is substantially the same shape as that of the electronic components and thermal attachment means 8, without this being a limitation of the invention.

[0050] The second heat exchange zone Z2 is here covered by a power module forming the electronic component 6 to be cooled. The power module 6 comprises a housing 11 which has a rectangular shape. The housing 11 includes a face 13 opposite the cooling plate 4, visible in [Fig. 5].

[0051] The housing 11 contains electronic chips whose operation releases heat which must be dissipated through the wall of the housing 11 and the cooling plate 4 so that this heat can be captured by the heat transfer fluid circulating within the cooling plate 4.

[0052] The power module 6 is not in direct contact with the cooling plate 4, as a thermal attachment means 8, visible in the third heat exchange zone Z3 of [Fig. 1], is disposed between the power module 6 and the cooling plate 4. The thermal attachment means 8 serves to form a fastening system enabling the power module 6 to be secured to the cooling plate 4. In particular, the thermal attachment means 8 is configured to polymerize or to solder after and / or during curing in an oven. The thermal attachment means 8 also serves to increase the thermal conductivity between the housing 11 of the power module 6 and the cooling plate 4, notably by preventing the presence of air pockets between them. Thus, the heat exchange between the face 13 of the housing 11 of the power module 6 and the flat portion 10 of the heat exchange zone Z1, Z2, Z3 is optimal.

[0053] According to a first embodiment of the thermal attachment means 8, the thermal attachment means 8 is a preform whose dimensions remain substantially constant before the assembly formed by positioning the preform on the cooling plate 4 and then the power module 6 on the preform is placed in an oven. This preform may be a metal plate or a plate of a plastic or composite type thermal interface material, such as silicone. The preform may extend over the entire flat portion 10 of the heat exchange zone. The preform has a surface area at least greater than the surface area of ​​the face 13 of the power module 6 opposite the cooling plate 4.A plurality of preforms can be arranged on the flat portion 10 of a heat exchange zone such that the thermal attachment means 8 formed by this plurality of preforms has a surface area greater than the surface of the face 13 of the power module 6. According to a second embodiment of the thermal attachment means 8, the thermal attachment means 8 is a thermal paste.

[0054] As mentioned, the preform forming the thermal attachment means 8 is configured to make the power module 6 integral with the cooling plate 4. Indeed, the assembly formed by the cooling plate 4, the thermal attachment means 8, and the power module 6 is configured to be placed in an oven to solidify the assembly. During transport of the cooling plate in the oven, the preform forming the thermal attachment means 8, as well as the power module 6, are likely to slide on the cooling plate 4, along two directions D1, D2 of an orthonormal coordinate system parallel to the planar portion 10 of the heat exchange zone Z1, Z2, Z3.

[0055] It is necessary to ensure that the thermal attachment means 8 and / or the power module 6 remain in the heat exchange zones Z1, Z2, Z3 before oven passage and in the heat exchange zones Z1, Z2, Z3 of a cooling device according to the invention include centering means 12 for blocking the translational movement of the preforms positioned in said heat exchange zones.

[0056] The centering means 12 are arranged around the heat exchange zone Z1, Z2, Z3 so that when the thermal attachment means is positioned against the cooling plate 4 and the power modules 6 are arranged against the thermal attachment means 8. The centering means 12 are configured to reduce the possible movements of the thermal attachment means 8 and in particular the movements of the thermal attachment means 8 along the cooling plate 4 before passing into the oven.

[0057] The centering means 12 are arranged around the perimeter of at least one heat exchange zone Z1, Z2, Z3, here around the perimeter of each of the heat exchange zones.

[0058] The centering means 12 are arranged around the perimeter of the heat exchange zone, and in particular around the perimeter of the flat portion 10 to delimit the area in which the thermal attachment means 8 and consequently the power module 6 must be positioned.

[0059] The centering means 12 are positioned at a distance from each other along a direction parallel to the plane in which the planar portion 10 of the heat exchange zone Z1, Z2, Z3 extends. This distance between the centering means 12 is slightly less than the corresponding dimension of a thermal attachment means 8, or of a power module 6, here of a thermal attachment means 8 as seen in [Fig.1] in the second heat exchange zone Z2.

[0060] In this way, the translation in this direction of the component disposed between the centering means 12, here the thermal attachment means 8, is blocked.

[0061] The centering means 12 can be produced by continuous material with the cooling plate 4. This manufacturing method ensures the precise positioning of the thermal attachment means 8 located on the cooling plate 4 on a larger scale. Since the cooling plate 4 is molded, the centering means 12 can be produced accurately as long as the same mold is used.

[0062] The centering means 12 can also be arranged on the cooling plate 4 by an operator, according to another manufacturing method. The centering means are made separately from the cooling plate, and the operator secures the centering means 12 to the cooling plate 4 by making each centering means cooperate with a lug on the cooling plate 4, for example. Such a manufacturing method allows the gap to be adjusted. between the centering means 12 so as to adapt to different sizes of the thermal fastening means 8 that one wishes to lock.

[0063] Various embodiments of the centering means 12 will be presented in figures 2 to 6.

[0064] Figure 2 shows a first embodiment of the centering means 12 in which the centering means 12 are arranged at the corner of the heat exchange zone Z, and these centering means 12 form stops for each of the corners 14 of the thermal attachment means 8 when the latter is attached to the cooling plate 4 on the heat exchange zone Z. The thermal attachment means 8 is shaped such that four centering means 12 are arranged around the periphery of the heat exchange zone Z. The centering means 12 are L-shaped.

[0065] Fig. 3 presents a second embodiment of the centering means 12 in which the number of centering means 12 is reduced while ensuring the positioning of the thermal attachment means 8.

[0066] According to the second embodiment, the centering means 12 are arranged at two corners 14 of the thermal attachment means 8. The two centering means 12 are opposite with respect to the thermal attachment means 8. As described in relation to [Fig. 2], the two centering means 12 have right-angled shapes, thus preventing the movement of the thermal attachment means 8 and / or the power module 6 along two directions D1, D2, and in both directions of each direction. This embodiment allows the amount of centering means 12 required to block the two degrees of freedom of the thermal attachment means 8 to be halved.

[0067] Figure 4 shows a third embodiment of the centering means 12. In the third embodiment, the centering means 12 has a rectangular prism shape.

[0068] The centering means are arranged around the perimeter of the heat exchange zone, each centering means being parallel to an edge of the flat portion of the heat exchange zone. The centering means 12 are positioned opposite edges 16 of the thermal attachment means 8 when the latter is positioned on the heat exchange zone. Thus, four centering means 12 are arranged around the thermal attachment means 8. The longer sides of the rectangular block are parallel to the edges 19 of the thermal attachment means 8 against which the centering means 12 extend. According to the third embodiment, the centering means 12 are positioned opposite each other in pairs, and are therefore capable of blocking the thermal attachment means 8, and / or, where applicable, the power module 6, in two directions D1, D2 and in both directions of each of these directions.

[0069] Figure 5 is a cross-sectional view of any embodiment described above, which notably shows the vertical dimension of the elements described previously. The centering means 12 has a height equal to or greater than the height of the thermal attachment means 8, the height being defined along the direction perpendicular to the planar portion 10 of the heat exchange zone Z. Since the centering means 12 has a height equal to or greater than the thermal attachment means 8, the latter is blocked because it is impossible for it to pass over the centering means 12. Furthermore, in this embodiment, the surface area of ​​the face 13 of the housing 11 of the power module 6 is smaller than the surface area of ​​the thermal attachment means 8.Thus, the power module 6 can also be blocked by the centering means 12 when the latter has a thickness greater than the thermal attachment means 8, the power module 6 resting against the thermal attachment means.

[0070] The [Fig.6] is a schematic representation of a second aspect of the invention which can be applied to either of the embodiments described above.

[0071] At least one centering means 12, here all centering means 12, has a main body 16 in accordance with what has been described in the previously mentioned embodiments. A stop finger 18 extends from the main body 16 of each centering means 12 towards the center of the heat exchange zone Z.

[0072] The stop fingers 18 form a vertical stop for the power module 6 when the latter is positioned on the heat exchange zone Z and comes to rest against the stop fingers 18. The stop fingers 18 maintain the power module 6 parallel to the flat portion 10 of the heat exchange zone Z, and at a determined distance from this flat portion 10 which corresponds to the height of the stop fingers 18.

[0073] Each of the stop fingers 18 associated with a heat exchange zone and the support of a power module 6 has the same height as the other stop fingers so that the face of the power module 6 opposite the flat portion 10 is parallel to the latter and exerts a constant pressure on the thermal attachment means 8.

[0074] Thus, this embodiment with a stop finger is particularly advantageous when the thermal attachment means 8 consists of a thermal paste, or thermal grease, with a lower viscosity, especially lower than that of a preform in the form of a metal plate whose dimensions are substantially constant during the assembly process. The thermal grease is distributed in the heat exchange zone Z1, Z2, Z3 by means of the compression of the power module 8, and the vertical positioning of the power module 6 and the thickness of the thermal attachment means 8 are determined according to this arrangement. It is necessary for proper For the electronic components to function correctly, they must be positioned at the intended height, and for proper cooling, the thermal grease thickness must be optimal. Therefore, the fingers of the stop 18 of the centering means 12 allow for defining a vertical positioning of the power module 6 that most closely matches a theoretical positioning, thus ensuring optimal compression of the thermal grease.

[0075] By maintaining the power module 6 at a defined distance from the cooling plate 4 via these stop fingers 18, the thermal attachment means 8 can also have a defined and continuous thickness over the entire heat exchange area Z, so that the thermal attachment means 8 is as efficient as possible. The optimal thickness of the thermal attachment means 8 is 200 microns, and this thickness can be substantially constant over the entire heat exchange area Z due to the homogeneous compression of the thermal attachment means 8 by the power module 6. This controlled thickness of the thermal attachment means 8 makes it possible to obtain the best possible attachment of the power module 6 to the cooling plate 4 while providing the best possible heat exchange between the power module 6 and the cooling plate 4.After oven curing, the thickness remains optimal since there is a sufficient quantity of the thermal bonding medium 8 under the power module 6 without the latter being too thick.

[0076] Due to the presence of the stop fingers 18, the thermal attachment means 8 includes cutouts resembling cavities in which the stop fingers 18 are able to extend. In this way, the stop fingers 18 also allow the thermal attachment means 8 to be centered.

[0077] Fig. 7 is a schematic cross-sectional representation of a third aspect of the invention in which the power module 6 includes counter forms 20. The counter forms 20 are arranged on the face 13 of the housing 11 of the power module 6 opposite the cooling plate 4 and on one of the lateral faces of the power module 6. The counter forms 20 extend into the interior of the housing 11 of the power module 6, thus forming respectively a receiving area for one of the centering means.

[0078] The counter form 20 is configured to cooperate with the main body 16 of the centering means 12 and with the stop fingers 18. This embodiment allows the housing 11 of the power module to have a dimension slightly smaller than that of the spacing between two centering means 12 and the stop fingers 18 ensure the function of blocking the movement of the thermal attachment means 8 and / or the movement of the power module 6.

[0079] This third aspect of the invention is particularly advantageous when the second embodiment of the thermal attachment means 8 is implemented since thermal grease does not have a constant shape and it is necessary to ensure that the thickness of the thermal grease after compression by the power module 6 is substantially homogeneous and thick enough to ensure its role as a thermal bridge.

[0080] At least two counter-forms 20 are included under the power module 6, these being opposed to each other with respect to the power module 6. These two counter-forms 20 make it possible to block the degrees of freedom of the power module 6 along the two directions D1, D2 parallel to the planar portion 10 of the heat exchange zone Z and to block the direction D3 perpendicular to the planar portion 10 along one direction of D3.

[0081] The invention, as described above, achieves its intended purpose and provides a cooling device for electronic components that ensures the positioning of the thermal attachment means. Variations not described here could be implemented without departing from the scope of the invention, provided that, in accordance with the invention, they include means for centering the thermal attachment means in accordance with the invention.

Claims

Demands

1. Electronic assembly comprising at least one electronic component (6), a cooling device (2) for said electronic component comprising a cooling plate (4), said electronic component (6) being disposed on said cooling plate (4) in at least one heat exchange zone (Z, Z1, Z2, Z3), the heat exchange zone (Z, Z1, Z2, Z3) being a flat portion (10) of the cooling plate (4), the electronic assembly further comprising at least one thermal attachment means (8) interposed between the heat exchange zone (Z, Z1, Z2, Z3) and the electronic component (6), the cooling plate (4) being characterized in that centering means (12) are disposed on the periphery of the heat exchange zone (Z) so as to maintain the thermal attachment means (8) and / or the electronic component (6) within the heat exchange zone (Z).

2. Electronic assembly according to claim 1, wherein the centering means (12) block translational movements of the thermal attachment means (8) and / or the electronic component (6), along two centering directions (D1, D2) perpendicular to a frame parallel to the planar portion (10).

3. Electronic assembly according to any one of the preceding claims, wherein at least one of the centering means (12) comprises a main body (16) which has a height, measured perpendicular to the planar portion (10) of the heat exchange zone (Z, Z1, Z2, Z3), which is greater than the corresponding height of the thermal attachment means (8).

4. Electronic assembly according to claim 3, wherein the centering means (12) has a stop finger (18) projecting from the main body (16) towards the center of the heat exchange zone (Z, Z1, Z2, Z3) of the cooling plate (4).

5. Electronic assembly according to the preceding claim, wherein the main body (16) of the centering means (12) has a greater height than that of the stop finger (18).

6. Electronic assembly according to any one of the preceding claims, wherein the power module (6) comprises at less a counter form (20) configured to receive the centering means (12).

7. Electronic assembly according to any one of claims 1 to 6, wherein the centering means (12) are elements attached to the cooling plate (4).

8. Electronic assembly according to any one of claims 1 to 6, wherein the centering means (12) are made in one piece with the cooling plate (4).

9. Electronic assembly according to any one of the preceding claims, wherein the thermal attachment means (8) is formed of a thermal paste or a preform, in particular a plate.

10. Electronic assembly according to any one of the preceding claims, wherein the cooling plate (4) participates in delimiting a cooling circuit.

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