Electronic assembly with integrated cooling system and electronic unit comprising such assembly

Abstract

The invention relates to an electronic assembly (10) with an integrated cooling system (15), comprising:-a printed circuit board (20); an electronic component chamber (90) formed by the metal separator (70) and the printed circuit board (20); -at least two electronic components (30, 40), each mounted in the electronic component chamber (90) on the side of the printed circuit board (20) facing the metal separator (70); -fins (100) oriented parallel to each other in a transverse plane (T), the metal spacer (70) carrying the fins (100) on its side opposite to the side of the metal spacer (70) facing the electronic components (30, 40).

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of electronic units, in particular for the field of power electronics and in particular an electronic unit comprising electronic components and a cooling system for the electronic components. Such an electronic unit can be implemented in a motor vehicle. BACKGROUND

[0002] In the prior art, various electronic units or electronic assemblies are known, comprising a printed circuit board, bearing electronic components and a cooling system using a fan or natural convection. The cooling of the electronic components is not always optimal. Furthermore, the industry has been seeking to limit the size, weight and cost of such electronic units. SUMMARY

[0003] It is therefore an object of the present invention to propose an electronic assembly which is compact, light and inexpensive, as well as a unit comprising such an electronic assembly.

[0004] To achieve this object, the present invention proposes an electronic assembly with an integrated cooling system, comprising a printed circuit board; an electronic component chamber formed by the metal partition and the printed circuit board; In the electronic assembly, the transverse direction is defined as perpendicular to the printed circuit board; In the electronic assembly, the longitudinal direction is defined as parallel to the overall extension plane of the printed circuit board; A transverse plane is defined as perpendicular to the printed circuit board and extending in the longitudinal direction and the transverse direction.

[0005] The electronic assembly further comprises: - at least two electronic components, each mounted in the electronic component chamber on the side of the printed circuit board facing the metal partition; - fins (100) oriented parallel to each other in the transverse plane (T), the metal partition (70) carrying the fins (100) on the side opposite to the side of the metal partition (70) facing the electronic components (30, 40); Each of the at least two electronic components has a height equal to the maximum dimension of the respective electronic component from the printed circuit board in the transverse direction; The at least two electronic components are arranged such that the height of a first electronic component is less than the height of a second electronic component.

[0006] Thanks to this configuration, the cooling of the electronic components of the electronic assembly is improved.

[0007] Preferably, the electronic assembly comprises a cover, preferably made of plastic or metal, a metal partition interposed between the cover and the printed circuit board so as to delimit at least one air circulation channel between the metal partition and the cover, the electronic assembly further comprising at least one fan arranged at one end of the at least one air circulation channel and able to introduce air into the at least one air circulation channel, the rotation axis of said at least one fan being oriented in the longitudinal direction, the height of the first electronic component being arranged closer to said at least one fan than the second electronic component in the longitudinal direction.

[0008] Thus, the electronic assembly takes advantage of the fact that the smallest electronic components (MOSFETs, diodes, etc.) tend to require more cooling than the large components (induction coils, transformers, etc.). Here, the smallest components are arranged where the fins are the largest and benefit from the largest heat exchange area with the air. Conversely, the largest components are arranged further away from the air inlet, the further away from the air inlet the larger in order of increasing size, the size of the fins decreasing in the transverse direction but increasing in the longitudinal direction.

[0009] Thus, the total heat exchange with the air is substantially maintained and the heat flux per unit area of the metal partition is adapted to the cooling requirements of the components.

[0010] Furthermore, when a fan is used, the smallest components are arranged as close as possible to the fan and benefit from the coolest air at the inlet of the air circulation channel. Conversely, the largest components are arranged further away from the fan, the further away from the fan the larger in order of increasing size.

[0011] Thus, by arranging the fan in line with the air flow along the metal partition and the printed circuit board, the size of the electronic assembly is reduced, making it possible to reduce its weight and cost by limiting the volume of its constituent parts.

[0012] Advantageously, said at least one air circulation channel can converge substantially from said at least one fan to an outlet opening of the air circulation channel located at an end of said at least one air circulation channel opposite said at least one fan.

[0013] This convergence towards the outlet opening of the air circulation channel makes it possible to avoid the presence of a recess in which the air is poorly supplied by the fan. This improves the cooling of the electronic components.

[0014] Advantageously, the at least one air circulation channel can have no diverging cross section in the transverse plane and its protruding corners can be rounded.

[0015] More importantly, the configuration without a diverging cross section between the inlet and the outlet of the air circulation channel has the advantage of the absence of a fluid separation zone in which the cooling is poor, this omission of a diverging cross section making it possible to further improve the cooling of the components.

[0016] Advantageously, the metal partition can comprise a portion parallel to the overall extension plane of the printed circuit board, which faces at least one of the at least two electronic components in the transverse direction, preferably each of the at least two electronic components.

[0017] This portion parallel to the printed circuit board makes it possible to provide optimal proximity between the metal partition and the components to be cooled, thus providing improved heat exchange.

[0018] The fins improve the heat exchange between the metal partition 70 and the air flow. Moreover, their arrangement makes it possible to direct the air flow and ensure that it is distributed uniformly with respect to the metal partition 70, in order to achieve good heat exchange.

[0019] Advantageously, the first electronic component can be a semiconductor, such as a planar transistor, a diode or a planar transformer, and / or the second electronic component can be an inductive coil or a transformer or a capacitor.

[0020] The present application also relates to an electronic unit comprising an electronic assembly as described above. BRIEF DESCRIPTION OF DRAWINGS

[0021] The present application will be described in further detail by means of the description of non-limiting embodiments and on the basis of the attached drawings, which show variants of the present application and in which: Figure 1 An electronic assembly with integrated cooling system is schematically shown. DETAILED DESCRIPTION

[0022] With reference to Figure 1 , an electronic unit 5 comprising an electronic assembly 10 with integrated cooling system 15 is described.

[0023] The electronic assembly 10 comprises a printed circuit board 20, a plastic cover 80 and a metal partition 70.

[0024] The metal partition 70 is interposed between the plastic cover 80 and the printed circuit board 20 and delimits: - at least one air circulation channel 50 between the metal partition 70 and the plastic cover 80, and - an electronic component chamber 90 between the metal partition 70 and the printed circuit board 20.

[0025] The electronic component chamber 90 is designed to be watertight, in particular by means of the metal partition 70. One side of the metal partition 70 opens into the at least one air circulation channel 50, which also makes it possible to ensure cooling of the electronic component chamber 90 and of the electronic components 30, 40 located therein.

[0026] In the electronic assembly 10, the following geometric references are defined (see Figure 1 ): - a transversal direction Y perpendicular to the printed circuit board 20, - a longitudinal direction X parallel to the general extension plane P of the printed circuit board 20, - a transversal plane T perpendicular to the printed circuit board 20 and extending in the longitudinal direction X and in the transversal direction Y.

[0027] The electronic assembly 10 further comprises: - at least two electronic components 30, 40, each mounted in the electronic component chamber 90 on a side of the printed circuit board 20 facing the metal partition 70, - at least one fan 60 arranged at one end of the at least one air circulation channel 50 and able to introduce air into the at least one air circulation channel 50, the rotation axis of the at least one fan 60 being oriented in the longitudinal direction X.

[0028] Each of the at least two electronic components 30, 40 has a height LI, L2 equal to the largest dimension of the respective electronic component 30, 40 in the transversal direction Y from the printed circuit board 20. The at least two electronic components 30, 40 are arranged in such a way that the height LI of a first electronic component 30 arranged closer to the at least one fan 60 in the longitudinal direction X is smaller than the height L2 of a second electronic component 40.

[0029] The at least one air circulation channel 50 is substantially converging from the at least one fan 60 to an outlet opening 110 of the air circulation channel 50 located at an end 130 of the at least one air circulation channel 50 opposite the at least one fan 60. Preferably, the at least one air circulation channel 50 has no diverging cross section in the transversal plane T.

[0030] The metal partition 70 comprises a portion 120 parallel to the general extension plane P of the printed circuit board 20, the portion 120 facing at least one of the at least two electronic components 30, 40, preferably each of the at least two electronic components 30, 40, in the transversal direction Y, as Figure 1 shown.

[0031] The electronic assembly 10 preferably comprises heat sinks 100, the heat sinks 100 being oriented parallel to each other in the transversal plane T. The metal partition 70 carries the heat sinks 100 on a side of the metal partition 70 opposite the side of the metal partition 70 facing the electronic components 30, 40.

[0032] Preferably, in a non-limiting manner, the first electronic component 30 is a transistor or a diode and / or the second electronic component 40 is an inductive coil or a transformer.

[0033] According to an alternative, the electronic assembly 10 comprises a first electronic component of the MOSFET, IGBT, diode or planar transformer type having a first height LI, a second electronic component of the inductive coil, capacitor or transformer type having a second height L2, and a third electronic component of the inductive coil or transformer type having a third height L3, such that L3>L2>LI.

[0034] The cooling system 15 comprises in particular a fan 60, a metal baffle 70, a cover 80 and fins 100. Thanks to the above-described configuration, the cooling system 15 is integrated into the electronic assembly 10 and / or the electronic unit 5, thus being in particular compact, lightweight and inexpensive.

Claims

1. An electronic assembly (10) having an integrated cooling system (15), said electronic assembly comprising: - a printed circuit board (20); - an electronic component chamber (90) formed by a metal partition (70) and the printed circuit board (20); in said electronic assembly (10), a transverse direction (Y) is defined as perpendicular to said printed circuit board (20); in said electronic assembly (10), a longitudinal direction (X) is defined as parallel to a general extension plane (P) of said printed circuit board (20); a transversal plane (T) is defined as perpendicular to said printed circuit board (20) and extending in said longitudinal direction (X) and said transverse direction (Y); said electronic assembly (10) further comprising: - at least two electronic components (30, 40), each mounted in said electronic component chamber (90) on a side of said printed circuit board (20) facing said metal partition (70); - fins (100) oriented parallel to each other in said transversal plane (T), said metal partition (70) carrying said fins (100) on a side opposite to a side of said metal partition (70) facing said electronic components (30, 40); each of said at least two electronic components (30, 40) has a height (LI, L2) equal to a maximum dimension of the respective electronic component (30, 40) from said printed circuit board (20) in said transverse direction (Y); said at least two electronic components (30, 40) are arranged so that a height (LI) of a first electronic component (30) is smaller than a height (L2) of a second electronic component (40), and wherein said electronic assembly (10) comprises a cover (80), preferably made of plastic or metal, said metal partition (70) being interposed between said cover (80) and said printed circuit board (20) so as to delimit at least one air circulation channel (50) between said metal partition (70) and said cover (80), said electronic assembly (10) further comprising at least one fan (60) arranged at one end of said at least one air circulation channel (50) and capable of introducing air into said at least one air circulation channel (50), a rotation axis of said at least one fan (60) being oriented in said longitudinal direction (X), said height (LI) of said first electronic component (30) being arranged closer to said at least one fan (60) in said longitudinal direction (X) than said second electronic component (40), and wherein said at least one air circulation channel (50) is substantially converging from said at least one fan (60) to an outlet opening (110) of said air circulation channel (50) located at an end of said at least one air circulation channel (50) opposite to said at least one fan (60), and said metal partition (70) carries fins (100) on a side opposite to a side of said metal partition (70) facing said electronic components (30, 40).

2. The electronic assembly (10) according to claim 1, characterized in that Said at least one air circulation channel (50) has no diverging cross section in said transversal plane (T).

3. The electronic assembly (10) according to any one of claims 1 and 2, characterized in that, Said metal spacer (70) comprises a portion (120) parallel to said overall extension plane (P) of said printed circuit board (20), which faces at least one of said at least two electronic components (30, 40) in said transversal direction (Y), preferably each of said at least two electronic components (30, 40).

4. The electronic assembly (10) according to any one of claims 1 to 3, characterized in that Said first electronic component (30) is a semiconductor, such as a planar transistor, a diode or a planar transformer.

5. The electronic assembly (10) according to any one of claims 1 to 4, characterized in that Said second electronic component (40) is an inductive coil, a transformer or a capacitor.

6. An electronic unit (10) comprising an electronic assembly (10) according to any one of claims 1 to 5.

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