Electronic assembly featuring an improved heat dissipation element

Abstract

The present invention relates to an electronic assembly (100) comprising a cooling circuit (6) and an electronic housing (20) in which at least one heat dissipation element (10) and an electronic module (1) are disposed, the heat dissipation element (10) being disposed between the electronic module (1) and a support surface (2) of the electronic housing (20) formed by the cooling circuit (6), the heat dissipation element (10) being formed by at least one electrically insulated, heat-conducting metallic plate (10), the thermal conductivity of the plate (10) being greater than that of the cooling circuit (6). Figure for the abstract: Fig. 1.

Description

Title of the invention: Electronic assembly comprising an improved heat dissipation element

[0001] The present invention relates to the cooling of the electronic assembly of an electrical machine of a motor vehicle, and for example a rotating electrical machine.

[0002] More particularly, the invention finds applications in the field of rotating electrical machines such as generators, alternators, alternator-starters, whose voltages are between 10 and 60V, and for example are equal to or greater than 48V.

[0003] The electronic assembly, arranged in an electronic housing, includes at least one electronic module whose temperature rises during its operation, the value of the rise in this temperature being linked to the sizing of the electronic module.

[0004] The temperature increase will cause significant damage to the electronic module itself and to the other elements of the electronic assembly.

[0005] To limit these thermal effects, it is known to use a cooling circuit for the electronic housing. The cooling circuit, generally made of aluminum, is located under the power module. In this type of electronic assembly, the power module is fixed to the substrate with thermal adhesive.

[0006] One drawback of using thermal adhesive is that it does not allow for proper heat dissipation under the power module. Indeed, due to its high power output, the power module generates a large amount of heat over a small area, resulting in a high temperature that is not dissipated effectively. Consequently, the temperature is not uniform under the power modules, causing hot spots in certain areas, disrupting their operation, and potentially leading to fires. Furthermore, when thermal adhesive is subjected to a temperature exceeding its maximum operating temperature, it disintegrates. The power module then comes into direct contact with the cooling circuit, which can cause damage to the power module and the electronic components.

[0007] The present invention therefore aims to overcome one or more of the drawbacks of prior art devices by proposing a cooling system comprising an improved cooling element, which consequently limits damage due to thermal effects.

[0008] For this purpose, the present invention proposes an electronic assembly comprising a cooling circuit and an electronic housing in which at least one heat dissipation element and an electronic module are disposed, the heat dissipation element being disposed between the electronic module and a support surface of the electronic housing formed by the cooling circuit, the heat dissipation element being formed by at least one electrically insulated heat-conducting metal plate, the thermal conductivity of the plate being greater than that of the cooling circuit.

[0009] Such a plate allows for better heat dissipation.

[0010] According to one embodiment of the invention, the heat dissipation element is an anodized aluminum metal plate.

[0011] Anodizing the plate provides a double insulation barrier and prevents any contact between the power module and the cooling circuit.

[0012] According to one embodiment of the invention, the plate is made of anodized 6060 aluminum.

[0013] According to one embodiment of the invention, the dissipation element has a thickness between 2 and 5 mm.

[0014] According to one embodiment of the invention, the dissipation element is fixed to the support and the electronic module with a thermal adhesive or equivalent.

[0015] According to one embodiment of the invention, the thickness of the thermal adhesive is between 0.1 mm and 0.5 mm.

[0016] The invention also relates to a machine assembly comprising an electrical machine and an electronic assembly according to the invention.

[0017] The invention also relates to the use of the assembly according to the invention in an electric or hybrid vehicle.

[0018] Other objects, features and advantages of the invention will be better understood and will become more apparent upon reading the description given below, with reference to the accompanying figures, given by way of example and in which:

[0019] - Fig. 1 is a schematic representation of a cross-sectional view of a electronic housing with a heat dissipation element according to an embodiment of the invention,

[0020] - [Fig. 2] is a schematic representation of a cross-sectional view of a electronic housing with a heat dissipation element according to another embodiment of the invention.

[0021] The [Fig.1] illustrates an electronic assembly 100 comprising an electronic housing 20 with a cooling circuit 6 and a heat dissipation element 10 according to the invention.

[0022] The electrical machine is, for example, a rotating electrical machine. By For example, rotating electrical machines are of the generator, alternator, alternator-starter type, whose voltages are between 10 and 60V, and for example are equal to or greater than 48V.

[0023] The electronic housing 20 comprises at least one electronic module 1.

[0024] According to one embodiment of the invention, the electronic module 1 is a module 1 of power.

[0025] In the context of the invention, a power module 1 is an electronic module containing semiconductor chips (for example, so-called power transistors), designed to carry out energy conversion circuits, such as those for example of a switching cell, an inverter or a rectifier bridge.

[0026] According to one embodiment of the invention, the electronic housing 20 comprises power electronics components. According to another embodiment of the invention, the electronic housing 20 comprises control electronics components.

[0027] According to one embodiment of the invention, the electronic assembly 100 includes a cooling circuit 6 arranged under the support surface 2 so as to allow the cooling of the electronic components and more particularly of the electronic module 1.

[0028] The cooling circuit 6 is formed by a channel 62 formed in the body 61 of the circuit 6.

[0029] According to one embodiment of the invention, the cooling circuit 6 is formed by a circular channel 62 or a parallelepiped-shaped channel or any shapes compatible with the operation of the cooling circuit 6.

[0030] According to one embodiment of the invention, the cooling circuit 6 is made of aluminum.

[0031] The cooling circuit 6 is traversed by a cooling fluid, and for example water or a water-glycol mixture.

[0032] In the context of the invention, a heat dissipation element 10 is disposed under the electronic module 1 and on a support surface 2 of the electronic housing 20 formed by the cooling circuit 6. More specifically, the heat dissipation element 10 is disposed between the electronic module 1 and the support surface 2 of the electronic housing 20 formed by the body 61 of the cooling circuit 6. The heat dissipation element 10 is thus disposed of to allow the dissipation of heat emanating from the electronic components and more particularly from the electronic module 1.

[0033] In the context of the invention, the heat dissipation element 10 is formed by at least one anodized, heat-conducting metallic plate 10. More specifically, the plate 10 is electrically insulated, and its thermal conductivity is greater than that of cooling circuit 6.

[0034] Such a plate allows for better heat dissipation.

[0035] According to one embodiment of the invention, the plate is made of anodized aluminum. According to another embodiment of the invention, the plate is fully anodized on all its faces. The complete anodization of the plate, that is, on both faces, provides a double insulation barrier and prevents any contact between the power module and the cooling circuit.

[0036] According to one embodiment of the invention, the plate is made of anodized 6060 aluminum.

[0037] Aluminium 6060 is composed of Si 0.30-0.60, Fe 0.10-0.30, Cu 0.1 max, Mn 0.1 max, Mg 0.35-0.60, Cr 0.05 max, Zn 0.15 max, Ti 0.10 max, Al the rest.

[0038] According to one embodiment of the invention, the conductivity of the metallic plate 10 is greater than or equal to 150 W / mK

[0039] According to one embodiment of the invention, the conductivity of the metallic plate 10 is greater than or equal to 200 W / mK

[0040] According to one embodiment of the invention, the conductivity of the metallic plate 10 is equal to 200 W / mK

[0041] The plate thus allows for greater conductivity, enabling better heat exchange and preventing hot spots

[0042] According to one embodiment of the invention, the metal plate 10 has a thickness of between 2 and 5 mm.

[0043] According to one embodiment of the invention, the metal plate 10 has a thickness of 4 mm.

[0044] The thicker the plate, the greater the conductivity. Such a thickness thus allows for a compromise between conductivity and the plate's size. In this way, the plate provides a larger heat exchange surface and avoids hot spots. According to one embodiment of the invention, the metal plate 10 is fixed to the support 2 and the electronic module 1 with a thermal adhesive 3, 3' or an equivalent. There are thus two layers of thermal adhesive 3, 3'. A layer 3 between the plate 10 and the electronic module 1, and a layer 3' between the plate and the support 2. The thickness of the thermal adhesive 3, 3' is between 0.1 mm and 0.5 mm. According to one embodiment of the invention, the thickness of the thermal adhesive 3, 3' is 0.2 mm.

[0045] According to one embodiment of the invention, the electronic assembly 100 comprises at least one plate 10 under each electronic module 1

[0046] According to one embodiment of the invention, the electronic assembly 100 comprises more than one plate 10 under each electronic module 1.

[0047] According to one embodiment of the invention, the electronic assembly 100 comprises a plate 10 common to several electronic modules 1, that is to say arranged under several electronic modules 1.

[0048] According to an embodiment of the invention illustrated [Fig. 2], the cooling circuit 6 comprises on its internal surface 63 primary protrusions 64 and / or secondary turbulatory protrusions 65, also called bumps. The internal surface 63 is defined as the surface of the circuit 6 in contact with the cooling fluid.

[0049] According to one embodiment of the invention, the cooling circuit 6 is closed by a hood 66.

[0050] The primary and secondary protrusions are arranged in such a way as to force the water to turbulate and allow the cooling fluid to detach from the internal surface. This increases heat exchange.

[0051] The invention also relates to a machine assembly comprising an electrical machine and an electronic assembly according to the invention.

[0052] The invention also relates to the use of assembly 100 according to the invention in a thermal, electric or hybrid vehicle.

[0053] The scope of the present invention is not limited to the details given above and allows for embodiments in many other specific forms without departing from the field of application of the invention. Therefore, the present embodiments should be considered by way of illustration and may be modified without, however, departing from the scope defined by the claims.

Claims

Demands

1. Electronic assembly (100) comprising a cooling circuit (6) and an electronic housing (20) in which are disposed at least one heat dissipation element (10) and an electronic module (1), the heat dissipation element (10) being disposed between the electronic module (1) and a support surface (2) of the electronic housing (20) formed by the cooling circuit (6), characterized in that the heat dissipation element (10) of thickness between 2 and 5 mm is formed by at least one electrically insulated, heat-conducting anodized aluminum metal plate (10), the thermal conductivity of the plate (10) being greater than that of the cooling circuit (6).

2. Electronic assembly (100) according to claim 1, wherein the plate is made of anodized 6060 aluminum.

3. Electronic assembly (100) according to any one of claims 1 or 2, wherein the dissipation element (10) is fixed to the support (2) and to the electronic module (1) with a thermal adhesive (3).

4. Electronic assembly (100) according to claim 3, wherein the thickness of the thermal adhesive (3) is between 0.1 mm and 0.5 mm

5. iliili. Machine assembly comprising an electrical machine and an electronic assembly (100) according to any one of claims 1 to 4.

6. Use of the assembly (100) according to any one of claims 1 to 4 in an electric or hybrid vehicle.