Electronic assembly comprising a housing and a cover having a non-solded portion for implementing controlled

Abstract

The invention relates to an electronic assembly for a motor vehicle, comprising a housing (B) with at least one coolant duct (C) and a cover (F) closing the housing (B), the cover defining a controlled leakage space (E) relative to an inner wall (PI), allowing two parts of the duct (C) separated by the inner wall (PI) to communicate with each other. The assembly allows cooling to occur by contact with the housing (B) outside the duct (C). The invention also relates to a motor vehicle and a method based on such an assembly.

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of cooling plates for electronic power components, in particular for motor vehicles. BACKGROUND

[0002] Such a cooling plate comprises a housing equipped with at least one duct, and a substantially flat cover covering said duct, wherein the electronic components are attached to one face or the other, or to both faces, outside the duct. A coolant is introduced into the duct and then exits it again in order to cool the components.

[0003] The cooling plate directs the heat emitted by the power electronics to a cooling liquid circulating inside the cooling plate, in the duct. The duct wall in the housing directs the fluid along a given path determined to serve all locations of the heat-emitting components.

[0004] In the prior art, the housing and the cover are welded along the entire duct in order to ensure the sealing between the environment outside the housing and the two parts of the duct inside the housing. This is done for safety reasons and to maintain the cooling performance.

[0005] The surfaces of the housing and the cover to be welded need to be ground.

[0006] Furthermore, it has been proposed to add spirals to the duct in the plate, and to add raised portions in the duct, in order to improve the cooling.

[0007] Unfortunately, this makes the manufacturing of the plate more complex, and can lead to an increase in the length of the welds of more than 50%, due to the additional welds. SUMMARY

[0008] The aim of the present invention is therefore to remedy the drawbacks of the prior art, and in particular to propose a solution for improving the cooling made by the cooling plate, without significantly increasing the steps and materials required for the welds.

[0009] To achieve this aim, the present invention proposes an electronic assembly for a motor vehicle, said assembly comprising at least one plate equipped with electronic components, and a housing attached to the plate, the housing comprising at least one coolant duct, the housing defining an internal volume inside the housing, which is separate from an external volume outside the housing, the housing comprising an outer wall forming a separation between said duct and the external volume, and an inner wall forming a separation between the two parts of said duct in the internal volume, the housing also comprising a cover covering the outer wall, the inner wall and said duct, in order to achieve cooling by contact with the housing outside said duct, the cover being welded to the outer wall, characterized in that the cover and the internal wall define between them a controlled leakage space which allows the two parts of the duct separated by the internal wall to communicate with each other.

[0010] In particular, the internal wall between the two parts of the duct is no longer welded as in the prior art.

[0011] Preferably, the housing comprises a frame outside the duct, and the cover and the frame allow cooling by contact with the cover and / or the frame.

[0012] Advantageously, the invention makes it possible to manage the distance tolerance between the housing and the cover, and to limit leaks and use them in a controlled manner.

[0013] Preferably, the peripheral wall is still welded to ensure electrical safety.

[0014] Furthermore, the grinding in the non-welded areas also becomes optional.

[0015] According to a variant, the cover comprises a first blocking protruding part and the internal wall comprises a second blocking protruding part which cooperates by shape fit with the first blocking protruding part, and the first and second blocking protruding parts define between them a controlled leakage space.

[0016] This makes it possible to combine a controlled leakage with a blocking of the cover with respect to the housing.

[0017] According to a variant, the housing also comprises one or more welds between the cover and the internal wall. In particular, these are a limited number of spot welds.

[0018] This makes it possible to reinforce the binding between the cover and the internal wall, while providing a controlled leakage space.

[0019] According to a variant, the controlled leakage space has a size of between 0.05 mm and 0.15 mm, preferably 0.1 mm; and / or between 0.15 and 0.25 mm, preferably 0.2 mm.

[0020] This makes it possible to have a configuration perfectly adapted to the optimal cooling of the electronic power components.

[0021] According to a variant, the duct comprises at least two branches in the housing.

[0022] This makes it possible to align the path of the coolant with the areas to be cooled, and to increase the delivery speed to improve the cooling.

[0023] According to a variant, the duct comprises lugs or fins forming protrusions inside the duct.

[0024] This makes it possible to generate friction with the coolant flow in order to improve the cooling.

[0025] According to a variant, the cross section of the duct is configured to implement a Venturi effect, which modifies the static pressure of the coolant. In particular, the cross section for this purpose increases from the upstream portion of the duct to the downstream portion of the duct.

[0026] The application also relates to a motor vehicle comprising an electronic assembly according to the application.

[0027] Another object of the application relates to a method of manufacturing an electronic assembly according to the application, comprising the following steps: - mounting a cover to the housing so as to cover the outer wall, the inner wall and the duct; - arranging the cover with respect to the inner wall so that the cover and the inner wall define a controlled leak space between them, allowing the two portions of the duct separated by the inner wall to communicate with each other, - welding the cover to the outer wall, - mounting an electronic component board to the housing of the electronic assembly; - circulating a coolant in the duct.

[0028] The application also relates to a method of cooling electronic components by means of an electronic assembly according to the application, the cooling method comprising the following steps: - mounting an electronic component to the housing of the electronic assembly; - circulating a coolant in the duct. BRIEF DESCRIPTION OF DRAWINGS

[0029] The application is described in further detail in a non-limiting description of variants and on the basis of the drawings, in which: - Figure 1 a bottom view of the housing of the assembly according to a preferred variant of the application is schematically shown, without its cover; - Figure 2 a front view of a portion of the housing of Figure 1 is schematically shown, equipped with its cover; - Figure 3 a view similar to Figure 2 is schematically shown, for a variant of the electronic assembly comprising a blocking protruding portion; and - Figure 4 a close-up view of the controlled leak space is schematically shown, in which the pressure difference around said space is shown in detail. DETAILED DESCRIPTION

[0030] The application relates to a cooling plate, in particular for a printed circuit comprising electronic power components of a motor vehicle.

[0031] The cooling plate comprises a shell B and a lid F closing the shell B. The shell B is preferably parallelepiped-shaped, open on one face, and comprises at least one coolant duct C.

[0032] The shell B comprises an outer wall PE with respect to the outside and an inner wall PI between the two portions of duct C.

[0033] The lid F is welded to the outer wall PE by a weld S as illustrated in Figure 1

[0034] With reference to Figure 3 , the lid F can comprise a first blocking protrusion portion B1 forming a protrusion towards the shell B, and the inner wall can comprise a second blocking protrusion portion B2 forming a groove cooperating by shape with the first blocking protrusion portion B1 so as to block the lid F with respect to the shell B, in particular towards the left and right sides. Figure 3

[0035] When Figure 3 the height of the leakage path is comparable to its width, this allows the leakage length to be lengthened, thus reducing its flow rate.

[0036] According to the invention, the lid F and the inner wall PI define between them a controlled leakage space E, thus allowing the two portions of duct C separated by the inner wall PI to communicate with each other.

[0037] The invention provides an efficient solution for the cooling of power electronics devices, ensuring good efficiency without complex installation.

[0038] If a part of the leakage is too high, there are several ways to reduce it: - reducing the geometric tolerance between the shell B and the lid F, for example by grinding the surfaces; - adding welds on some inner walls in order to bind the lid F and the shell B together; - using a blocking mounting for the protrusion portions B1, B2 in the inner wall P1 Figure 3 in order to increase the length of the leakage path, thus increasing the friction in the leakage.

[0039] Preferably, a minimum leakage height can be defined in order to cool the components placed above the leakage.

[0040] If this is the case, since the leakage reduces the pressure drop, it is possible to increase the flow rate (by reducing the cross section of the duct C) in order to maintain the cooling performance.

[0041] In order to ensure electrical safety, the peripheral wall is still welded (weld S).

[0042] The controlled leakage allows the components arranged above the controlled leakage space to be cooled. ​​

[0043] For example, the space E is 0.1 mm above the simple inner wall PI, as Figure 2 indicated (in this case, the temperature is maintained and the pressure loss is reduced by 7.6%); or 0.2 mm above the inner wall PI with a barrier protruding portion (in this case, the temperature is maintained and the pressure loss is reduced by 32%).

[0044] Preferably, the inner wall parallel to the flow in the duct C is not welded.

[0045] In a preferred variant illustrated in Figure 4 , in order to increase the static pressure (Venturi effect), the cross section Al, A2, A3 of the duct C is gradually increased between the two portions of the duct C separated by the non-welded inner wall PI.

[0046] The increase in the cross section of the duct C is dimensioned so that the static pressure ΔP upstream and downstream of the leakage path is equal along the entire non-welded inner wall PI. That is to say, the pressure drop in the main duct is compensated and the static pressure remains constant along the leakage path.

[0047] The result of this pressure balance is that there is no actual leakage: the action and reaction pressures of the first and second portions of the duct C are equal respectively.

[0048] According to other aspects of this preferred variant: - the gradual and controlled increase in the cross section of the duct C depends on the local losses of the main duct; - the pressure difference between the two successive portions is almost non-existent. The leakage is virtually non-existent. The impact of the leakage on the cooling performance is greatly reduced: in particular, the cross section of the duct C can be doubled in order to reduce the flow rate from 2 m / s to 1 m / s and this allows to compensate a pressure drop of 15 mbar.

[0049] The fluid is therefore slowed down when it flows. The electronic components with the highest dissipated power density are then preferably placed facing the fastest fluid, while the electronic components with less constraints are placed facing the least fast fluid.

[0050] The application also relates to a motor vehicle comprising a cooling plate as described above, and to a corresponding manufacturing and cooling method.

[0051] Furthermore, the application relates to a corresponding manufacturing method and to a corresponding cooling method.

Claims

1. An electronic assembly for a motor vehicle, comprising at least one board equipped with electronic components and a housing (B) attached to the board, the housing (B) defining an internal volume inside the housing (B) separate from an external volume outside the housing (B), the housing (B) comprising an outer wall (PE) forming a separation between the pipe (C) and the external volume, and an inner wall (PI) forming a separation between two portions of the pipe (C) in the internal volume, the housing (B) further comprising a cover (F) covering the outer wall (PE), the inner wall (PI) and the pipe (C) so as to achieve cooling by contact with the housing (B) outside the pipe (C), the cover (F) being welded to the outer wall (PE), characterized in that the cover (F) and the inner wall (PI) defining a controlled leak space (E) between them, allowing the two portions of the pipe (C) separated by the inner wall (PI) to communicate with each other, and wherein the housing (B) further comprises one or more welds between the cover (F) and the inner wall (PI).

2. The electronic assembly of claim 1, wherein, the cover comprising a first blocking raised portion (Bl) and the inner wall comprising a second blocking raised portion (B2) cooperating with the first blocking raised portion (Bl) by shape fit, characterized in that the first blocking raised portion (Bl) and the second blocking raised portion (B2) define a controlled leak space (E) between them.

3. The electronic assembly of any of claims 1 to 2, wherein, the controlled leak space (E) is between 0.05 and 0.15 mm, preferably 0.1 mm; and / or between 0.15 and 0.25 mm, preferably 0.2 mm.

4. The electronic assembly of any one of claims 1 to 3, wherein, the pipe (C) comprises at least two branches in the housing (B).

5. The electronic assembly of any one of claims 1 to 4, wherein, the pipe (C) comprises lugs (P) or fins forming protrusions inside the pipe (C).

6. The electronic assembly of any one of claims 1 to 5, wherein, the cross section of the pipe (C) is configured to achieve a Venturi effect that modifies the static pressure of the coolant.

7. A motor vehicle comprising an electronic assembly according to any one of claims 1 to 6.

8. A method of manufacturing an electronic assembly according to any one of claims 1 to 7, comprising the following steps: - mounting the cover (F) to the housing (B) so as to cover the outer wall (PE), the inner wall (PI) and the pipe (C); - arranging the cover (F) relative to the inner wall (PI) so that the cover (F) and the inner wall (PI) define a controlled leak space (E) between them, allowing the two portions of the pipe (C) separated by the inner wall (PI) to communicate with each other, - welding the cover (C) to the outer wall (PE), - mounting an electronic components board to the housing (B) of the electronic assembly; - circulating a coolant in the pipe (C).

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