Cooling device configured to cool an electronic module

Abstract

The invention relates to a cooling device configured to cool an electronic module comprising an electronic board on which a plurality of electronic components are mounted, the cooling device comprising: - an enclosure configured to receive the electronic board and the electronic components, and to be filled with a dielectric fluid intended to immerse the electronic components, the enclosure comprising in particular at least one member for holding the electronic board, - a cover (14) configured to close the enclosure, - a dielectric fluid distributor (20) configured to distribute dielectric fluid into the enclosure in the form of at least one dielectric fluid jet, the distributor being in particular connected to the cover.

Description

DESCRIPTION TITLE: COOLING DEVICE CONFIGURED TO COOL AN ELECTRONIC MODULE [1] The present invention relates in particular to a cooling device configured to cool an electronic module. [2] It is known, in the context of cooling a power electronic card, such as that used in a DCDC converter (this converter being intended to transform a voltage of a direct current from a first voltage value to a second voltage value), to use a cooling liquid circulating in a plate which is in contact with the electronic card. Such a system involves a significant fluid flow rate and is energy-intensive. In addition, the architecture of the electronic card can complicate access, in terms of cooling, to the hottest components. [3] The present invention aims in particular to further improve the thermal regulation, in particular the cooling, of an electronic module. [4] The invention thus relates to a cooling device configured to cool an electronic module comprising an electronic card on which a plurality of electronic components are mounted, the cooling device comprising: - an enclosure configured to receive the electronic card and the electronic components, and to be filled with a dielectric fluid intended to immerse the electronic components, the enclosure comprising in particular at least one member for holding the electronic card, a cover configured to close the enclosure, - a dielectric fluid distributor configured to distribute dielectric fluid into the enclosure in the form of at least one jet of dielectric fluid, the distributor being in particular connected to the cover. [5] A "dielectric fluid jet" is a flow of dielectric fluid that is at a higher speed than the dielectric fluid that fills the enclosure, outside this jet. This jet makes it possible to locally create a speed differential that allows the jet to better cool the electronic components opposite the jet. The fluid distributor according to the invention is configured to distribute dielectric fluid without a drastic change in pressure losses, unlike spray systems. Spray systems require pressures of several bars (in any case, at least 1 bar) and the distributor according to the invention makes it possible in particular to generate only a few tens of millibars, or even a hundred millibars at most. [6] In the invention, the components are completely immersed, in particular without air or gas resulting from a phase change of dielectric fluid. [7] Thanks to the invention, the cooling of the electronic components is done by direct contact with the dielectric cooling fluid. This significantly improves the cooling capacity by the fluid, in particular compared to a conventional system using a plate within which cooling fluid circulates. [8] According to one aspect of the invention, the dielectric fluid dispenser is configured to generate a jet of dielectric fluid on only a portion of the electronic module, on a given area. [9] According to one aspect of the invention, the dielectric fluid dispenser is configured to generate a plurality of jets of dielectric fluid.

[0010] According to one aspect of the invention, the distributor is supplied with dielectric fluid by at least one tube formed on the cover.

[0011] According to one aspect of the invention, the cover comprises a fluid outlet pipe configured to discharge fluid that has circulated in the enclosure.

[0012] According to one aspect of the invention, the fluid inlet and outlet pipes extend perpendicular to a main wall of the cover. Other orientations are possible, for example the pipes could be inclined relative to the main wall of the cover. Optionally the pipes are integrated on the side walls of the housing.

[0013] According to one aspect of the invention, these fluid inlet and outlet pipes communicate with the enclosure through orifices made on the cover.

[0014] According to one aspect of the invention, the fluid inlet and outlet pipes are made in one piece with the cover.

[0015] Alternatively, the cover includes at least one channel configured to supply dielectric fluid to the dispenser.

[0016] According to one aspect of the invention, the cover comprises two plates, in particular made of metal such as aluminum, assembled together to form the dielectric fluid channel(s).

[0017] According to one aspect of the invention, the plates are brazed together.

[0018] According to one aspect of the invention, one of the plates is stamped to form the channel(s) and the other plate is flat.

[0019] According to one aspect of the invention, the fluid jet distributor is formed by orifices made on one of these plates.

[0020] According to one aspect of the invention, the cover is made of plastic, in particular by injection.

[0021] According to one aspect of the invention, the cover comprises a plurality of dielectric fluid supply channels configured to supply dielectric fluid to the dispenser.

[0022] According to one aspect of the invention, the cover comprises at least two fluid supply channels, each channel opening onto one of the jet distributors.

[0023] According to one aspect of the invention, these distributors are arranged in parallel.

[0024] According to one aspect of the invention, the supply channels of the cover are supplied by a fluid inlet pipe made for example on the cover.

[0025] Thus the dielectric fluid from this inlet pipe is distributed in parallel to the distributors via parallel channels.

[0026] In this case, a fluid outlet, for example on one side of the enclosure, is provided to evacuate the fluid distributed by these distributors.

[0027] Alternatively, the cover has a single feed channel for the dispenser.

[0028] According to one aspect of the invention, the supply channel comprises a main section and branched sections which branch off from this main section and which each open onto an orifice distributing electrical fluid in the form of jets.

[0029] According to one aspect of the invention, the branched sections are arranged on only one side of the main section so as to generate jets on a single area to be cooled of the electronic module.

[0030] Alternatively, the branched sections are arranged on two opposite sides of the main section so that these branched sections allow two separate areas of the electronic module to be cooled.

[0031] According to one aspect of the invention, these branched sections are arranged, for example, in the manner of fish bones.

[0032] According to one aspect of the invention, the cover comprises an outlet for evacuating dielectric fluid that has circulated in the enclosure.

[0033] According to one aspect of the invention, this evacuation comprises at least one fluid outlet orifice formed on the cover.

[0034] According to one aspect of the invention, this fluid discharge connects to a discharge channel formed on the cover.

[0035] According to one aspect of the invention, the discharge channel may comprise a main section to which branched sections are connected and the fluid exits through orifices at one end of these branched sections. The fluid flows in these branched sections then join in the main section and are then discharged from the cover through an outlet pipe.

[0036] Different configurations are possible for the distributor(s) and the fluid outlet(s).

[0037] It is therefore possible to have one or more distributors generating the fluid jets in the enclosure and a single evacuation.

[0038] Alternatively, it is possible to have a single dispenser and a plurality of outlets at different locations on the cover.

[0039] According to one aspect of the invention, the fluid outlet(s) in the cover form areas with a higher flow rate, making it possible to cool the electronic components which are placed opposite this or these fluid outlet(s).

[0040] According to another aspect of the invention, the distributor is supplied with dielectric fluid by a conduit extending into the enclosure.

[0041] According to one aspect of the invention, the conduit comprises an orifice configured to generate the jet in the enclosure.

[0042] Depending on the areas to be cooled on the electronic module, it is possible to provide one or more conduits.

[0043] According to one aspect of the invention, this or these conduits are connected to fluid inlet and outlet connectors which can be placed on a side wall of the enclosure or on the cover.

[0044] According to one aspect of the invention, the conduit is a tube, for example a metal tube, in particular extruded.

[0045] According to one aspect of the invention, the conduit is assembled with the cover, for example by brazing or welding or gluing.

[0046] Alternatively, the cover and the conduit(s) may be made in one piece, for example by injection of a plastic material.

[0047] According to one aspect of the invention, the conduit comprises branches for bringing the fluid to several orifices to generate several jets.

[0048] According to one aspect of the invention, the cover comprises a main wall surrounded by a rim raised relative to this main wall, so that when the The cover is assembled with the enclosure, the main wall is recessed further into the enclosure than the raised edge of the cover. This means that the main wall of the cover is located closer to the circuit board and electronic components.

[0049] According to one aspect of the invention, the distributor comprises one or more outlet orifices for generating the leak jet(s) in the enclosure.

[0050] According to one aspect of the invention, the orifice(s) have an oblong shape, or alternatively a circular shape or any other shape.

[0051] The orifices of a single distributor may be identical or, alternatively, have different dimensions and orientations within a single group of orifices linked to the same distributor. For example, oblong-shaped orifices may be arranged aligned in the longitudinal direction. Alternatively, oblong-shaped orifices may be arranged parallel along their long side.

[0052] According to one aspect of the invention, each outlet orifice is surrounded by a collar allowing the fluid to be channeled towards the electronic component(s) to be targeted.

[0053] According to one aspect of the invention, the collar is made on the cover.

[0054] Alternatively, the collar is made at the outlet of the conduit.

[0055] According to one aspect of the invention, the collar and the associated orifice have an oblong shape.

[0056] According to one aspect of the invention, the collar is in the form of a lip which surrounds the orifice.

[0057] According to one aspect of the invention, the cover comprises at least one divergent placed on the outlet orifice.

[0058] According to one aspect of the invention, the divergent is configured to distribute the fluid over the electronic components. The divergent has a flare which opens towards the component(s) to be cooled, forming a hot zone.

[0059] According to one aspect of the invention, the divergent is inserted onto the outlet orifice on the cover.

[0060] Alternatively, the divergent is inserted at the end of a conduit when the dielectric fluid is supplied through a conduit.

[0061] According to one aspect of the invention, the divergent is made of plastic, in particular by injection. Alternatively, the divergent is made of metal, for example anodized aluminum to avoid short circuits.

[0062] According to one aspect of the invention, the divergent comprises a crenellated end configured to wedge the divergent on the electronic card of the electronic module.

[0063] By adjusting the width and number of notches in this notched end, it is possible to adjust the pressure drop for each zone to be cooled.

[0064] The invention thus makes it possible to generate a greater fluid flow on electronic components requiring greater cooling.

[0065] According to one aspect of the invention, the dispenser comprises a dispensing nozzle configured to allow high pressure dispensing of fluid to the electronic components to be cooled.

[0066] According to one aspect of the invention, the nozzle thus makes it possible to generate a high level of turbulence making it possible to improve the heat exchange coefficient.

[0067] The distribution nozzle(s) can be dedicated to a single electronic component or can be used to cool multiple electronic components in an area to be cooled.

[0068] According to one aspect of the invention, the nozzle comprises a single orifice or several orifices.

[0069] According to one aspect of the invention, the channel(s) formed on the cover or the conduit(s) may comprise means for disturbing the fluid, in particular flow disruptors (also called “Dimples” in English).

[0070] According to one aspect of the invention, the disruptors comprise bosses formed inside the channels or inside the conduits.

[0071] According to one aspect of the invention, the disruptors are present near the outlet orifice of the channel or conduit.

[0072] According to one aspect of the invention, the disruptors can be produced by stamping on one of the plates of the cover.

[0073] Alternatively, disruptors can be formed by injection.

[0074] According to one aspect of the invention, the disruptors are on side and / or top and / or bottom walls of the channel.

[0075] According to one aspect of the invention, the disruptors may have different shapes, for example a chevron shape, a circular shape, an oblong shape, a polygonal shape for example square or rectangle.

[0076] The invention also relates to a system comprising an electronic module and a cooling device as described above, configured to cool the electronic module.

[0077] According to one aspect of the invention, the cooling device comprises one or more fluid distributors or outlets configured to cool preferred areas of the electronic module.

[0078] According to one aspect of the invention, the zones to be cooled in a preferred manner comprise in particular transistors, in particular of the MOSFET type.

[0079] According to one aspect of the invention, the electronic module is part of a DCDC converter, in particular for a motor vehicle.

[0080] The invention thus makes it possible to cool in a preferential manner the areas which tend to heat up the most, in particular areas on the electronic card which group the transistors.

[0081] Such transistors in the case of a DCDC converter can generate more than half of the total heat loss.

[0082] The invention makes it possible to concentrate the cooling power mainly on the hot areas of the electronic card by increasing the flow rate of dielectric fluid circulating in these areas.

[0083] In other areas that require less cooling capacity, it is possible to have a lower leakage rate.

[0084] These components, which require less cooling capacity, are simply immersed in the dielectric fluid that bathes the enclosure.

[0085] The invention thus makes it possible to achieve differentiated cooling levels depending on the areas which have different cooling needs.

[0086] The enclosure comprises a member for holding the electronic card, this holding member being for example a hollow column, for example threaded, allowing the card to be fixed there, for example using a screw.

[0087] Other characteristics, details and advantages of the invention will emerge more clearly on reading the description which follows on the one hand, and several examples of embodiment given for informational and non-limiting purposes with reference to the appended schematic drawings on the other hand, in which:

[0088] [Fig 1] Figure 1 is a schematic representation of a system according to an exemplary embodiment of the invention, with an electronic module in an enclosure of a cooling device;

[0089] [Fig. 2] Figure 2 is a side view of the system of Figure 1;

[0090] [Fig. 3] Figure 3 is a perspective representation, from above, of the cover of the cooling device illustrated in Figures 1 and 2;

[0091] [Fig. 4] Figure 4 is a perspective representation, from below, of the cover of the cooling device illustrated in Figures 1 and 2;

[0092] [Fig. 5] Figure 5 is a perspective representation of a cover according to another embodiment;

[0093] [Fig. 6] Figure 6 is a perspective representation, from below, of the cover of Figure 5;

[0094] [Fig. 7] Figure 7 is a perspective representation of a divergent for a cover according to another embodiment;

[0095] [Fig. 8] Figure 8 is a sectional representation of the divergent of Figure 7;

[0096] [Fig. 9] Figure 9 is a side view of a cover according to an exemplary embodiment of the invention, with nozzles.

[0097] The features, variants and different embodiments of the invention may be combined with each other in various combinations, provided that they are not incompatible or mutually exclusive. In particular, variants of the invention may be conceived comprising only a selection of features described below in isolation from the other features described, if this selection of features is sufficient to confer a technical advantage and / or to differentiate the invention from the prior art.

[0098] Figures 1 and 2 show a system 1 comprising an electronic module 2 and a cooling device 3 according to an exemplary embodiment of the invention, configured to cool the electronic module.

[0099] Electronic module 2 is part of a DCDC converter, particularly for motor vehicles.

[0100] The electronic module 2 comprises an electronic card 4 on which a plurality of electronic components 5 are mounted, including MOSFET type transistors present in zones 6.

[0101] Areas 6 should be cooled in a preferential manner because MOSFET transistors tend to heat up more than other components. Such transistors in the case of a DCDC converter can generate more than half of the total heat loss.

[0102] The cooling device 3 comprises an enclosure 10 configured to receive the electronic card 4 and the electronic components 5, and to be filled with a dielectric fluid intended to immerse the electronic components 5.

[0103] The enclosure comprises members 11 for holding the electronic card 4. The enclosure 10 is for example a single piece, made of plastic or metal, and is in the form of a tank.

[0104] The holding members 11 of the electronic card comprise hollow columns, for example threaded, allowing the card to be fixed there, for example using screws.

[0105] The screws pass through holes 12 formed in the board 4.

[0106] The cooling device 3 further comprises a cover 14 configured to close the enclosure 10, and a dielectric fluid distributor 20 configured to distribute dielectric fluid into the enclosure 10 in the form of jets of dielectric fluid.

[0107] The fluid distributor 20 is configured to preferentially cool one of the zones 6 of the electronic module 2.

[0108] In other areas that require less cooling capacity, it is possible to have a lower leakage rate.

[0109] The components 5 which require less cooling capacity are simply immersed in the dielectric fluid which bathes the enclosure 10.

[0110] The cover 14 comprises a channel 17 configured to supply dielectric fluid to the distributor 20.

[0111] The cover 14 may comprise two plates 16, in particular made of metal such as aluminum, assembled, by brazing, together to form the channel 17.

[0112] One of the plates 16 is stamped to form the channel and the other plate is generally flat.

[0113] The fluid jet distributor 20 is formed by orifices 18 made on one of these plates 16.

[0114] In the example of figures 1 to 3, the cover 14 has a single supply channel 17 for distributor 20. This channel 17 is supplied with fluid by an inlet pipe 19.

[0115] The supply channel 17 comprises a main section 21 and branched sections 22 (here three in number) which start from this main section 21 and which each open onto an orifice 18 distributing electrical fluid in the form of jets.

[0116] The branched sections 22 are arranged on only one side of the main section 21 so as to generate jets on a single zone 6 to be cooled of the electronic module.

[0117] Thus it is possible to have jets of fluid in the enclosure 10 through the orifices 18.

[0118] Alternatively, as illustrated in Figure 5, the branched sections 22 could be arranged on two opposite sides of the main section 21 so that these sections branched 22 allow two separate zones 6 of the electronic module to be cooled. The two cooled zones 6 are thus cooled by parallel flows of fluid.

[0119] The branched sections 22 are arranged, for example, in the manner of fish bones. Figure 6 shows the orifices 18 which produce jets towards two zones 6 to be cooled.

[0120] The fluid supply is via an inlet pipe 19, and the fluid outlet 25 is formed on the cover, directly connected to an outlet pipe not shown. Here, the outlet is formed by the pipe, and not by a channel made by two assembled plates of the cover.

[0121] Different configurations of the supply channel can be considered, depending on the zones 6 to be cooled in a preferred manner.

[0122] The cover 14 has an outlet 25 for evacuating dielectric fluid having circulated in the enclosure 10. Arrows F1 and F2 illustrate in Figure 3 respectively the direction of entry (into the distributor 20) and the direction of exit of the fluid (through the outlet 25).

[0123] The drain 25 has a fluid outlet orifice 26 formed on the cover 14.

[0124] This fluid outlet 25 connects to an outlet channel 27 formed on the cover 14.

[0125] The discharge channel 27 comprises a main section 28 to which branched sections 29 are connected and the fluid exits via orifices 30 at one end of these branched sections 29, as seen in FIGS. 3 and 4. The fluid flows in these branched sections 29 then join in the main section 28 to then be evacuated from the cover 14 via an outlet pipe 31.

[0126] Different configurations are possible for the distributor 20 and the fluid outlet 25.

[0127] Holes 18 and 30 have an oblong shape. Any other suitable shape is possible.

[0128] The groups of orifices 18, respectively 30, may be identical or, alternatively, have different dimensions and orientations within the same group of orifices. Here, the oblong-shaped orifices 30 are arranged aligned in the longitudinal direction. The oblong-shaped orifices 18 are arranged parallel along their long side, or in a slightly oblique manner.

[0129] Each orifice 18, 30 is surrounded by a collar 37, in the form of a lip, making it possible to channel the fluid towards the electronic components 5 to be targeted, as can be seen in Figure 4.

[0130] The collar 37 is made on the cover 14.

[0131] The evacuation of fluid 25 in the cover generates, thanks to the orifices 30, a greater flow rate, making it possible to cool in a preferential manner one of the hot zones 6 which is opposite the orifices 30.

[0132] The channels 17 and 27 formed on the cover 14 may comprise means for disturbing the fluid, in particular flow disruptors (also called “Dimples” in English). These disruptors 33 comprise bosses formed inside the channels 17 and 27, and are present near the inlet or outlet orifice.

[0133] The disruptors can be made by stamping on one of the plates 16 of the cover, and can have different shapes, for example a chevron shape, a circular shape, an oblong shape, a polygonal shape for example square or rectangle.

[0134] The cover 14 comprises a main wall 34 surrounded by a raised rim 35 relative to this main wall 34, so that when the cover 14 is assembled with the enclosure 10, the main wall 34 sinks further into the enclosure 10 than the raised rim 35 of the cover. Thus the main wall 24 of the cover is located as close as possible to the electronic card 4 and the electronic components 5, as illustrated in FIG. 2 in particular.

[0135] In an exemplary embodiment of the invention illustrated in figures 7 and 8, the cover 14 comprises a divergent 40 placed on the fluid outlet orifice 18.

[0136] The divergent 40 is configured to distribute the fluid over the electronic components 5. The divergent 40 has a flare which opens towards the components 40 to be cooled forming the hot zone 6.

[0137] The divergent 40 is inserted on the outlet orifice 18 on the cover 14.

[0138] The divergent 40 is made of plastic, in particular by injection. Alternatively, the divergent is made of metal, for example anodized aluminum to avoid short circuits.

[0139] The divergent 40 comprises a crenellated end 41 configured to wedge the divergent on the electronic card 4 of the electronic module.

[0140] By adjusting the width and number of notches of this notched end 41, it is possible to adjust the pressure drop for each zone to be cooled.

[0141] In an exemplary embodiment of the invention illustrated in FIG. 9, the distributor comprises a distribution nozzle 50 configured to allow high-pressure distribution of fluid to the electronic components 5 to be cooled.

[0142] The nozzle 50 thus makes it possible to generate a high level of turbulence, thereby improving the heat exchange coefficient.

[0143] The distribution nozzle(s) 50 may be dedicated to a single electronic component or may allow several electronic components to be cooled in a zone 6 to be cooled.

[0144] According to another example of the invention (not shown), the distributor is supplied with dielectric fluid by a conduit extending into the enclosure. This conduit is separate from the cover. The conduit comprises an orifice configured to generate the jet in the enclosure. This or these conduits are connected to fluid inlet and outlet connectors which can be placed on a side wall of the enclosure 10 or on the cover 14. The conduit is for example a metal tube, in particular extruded. The conduit is assembled with the cover, for example by brazing or welding or gluing.

[0145] According to yet another example of the invention (not shown), the cooling device comprises a dielectric fluid outlet opposite, in particular above, a zone 6 to be cooled in a preferred manner, and a fluid distributor on one side of the enclosure 10. This fluid distributor may be opposite a zone 6 to be cooled in a preferred manner, or alternatively, be opposite a zone with components without the need for preferred cooling.

Claims

CLAIMS

1. Cooling device (3) configured to cool an electronic module (2) comprising an electronic card (4) on which a plurality of electronic components (5) are mounted, the cooling device comprising: - an enclosure (10) configured to receive the electronic card (4) and the electronic components (5), and to be filled with a dielectric fluid intended to immerse the electronic components, the enclosure (10) comprising in particular at least one holding member (11) for the electronic card, a cover (14) configured to close the enclosure (10), - a distributor (20) of dielectric fluid configured to distribute dielectric fluid in the enclosure (10) in the form of at least one jet of dielectric fluid, the distributor being in particular linked to the cover.

2. Cooling device (3) according to the preceding claim, in which the dielectric fluid distributor (20) is configured to generate a jet of dielectric fluid on only a portion of the electronic module, in an area (6).

3. Cooling device (3) according to one of the preceding claims, in which the cover (14) comprises at least one channel (17) configured to bring dielectric fluid to the distributor (20) and the cover (14) comprises two plates (16), in particular made of metal such as aluminum, assembled together to form the dielectric fluid channel(s) (17).

4. Cooling device (3) according to the preceding claim, in which the fluid jet distributor (20) is formed by orifices (18) made on one of these plates (16).

5. Cooling device (3) according to one of the preceding claims, in which the cover (14) comprises at least two fluid supply channels (17), each channel (17) opening onto one of the jet distributors (20).

6. Cooling device (3) according to one of claims 1 to 4, in which the cover (14) comprises a single supply channel (17) for a distributor.

7. Cooling device (3) according to claim 5 or 6, in which the supply channel (17) comprises a main section (21) and branched sections (22) which start from this main section (21) and which each open onto an orifice (18) distributing electrical fluid in the form of jets.

8. Cooling device (3) according to the preceding claim, in which the branched sections (22) are arranged on one side only of the main section (21) so as to generate jets on a single area to be cooled of the electronic module.

9. Cooling device (3) according to claim 7, in which the branched sections (22) are arranged on two opposite sides of the main section (21) so that these branched sections (22) make it possible to cool two separate zones of the electronic module.

10. Cooling device (3) according to one of the preceding claims, in which the cover (14) comprises an outlet (25) for evacuating dielectric fluid having circulated in the enclosure (10), in particular with an evacuation channel (27) comprising a main section (28) to which branched sections (29) are connected and the fluid exits via orifices at one end of these branched sections (29).

11. Cooling device (3) according to one of the preceding claims, in which the cover (14) comprises a main wall (34) surrounded by a raised rim (35) relative to this main wall (34), so that when the cover (14) is assembled with the enclosure (10), the main wall (34) sinks further into the enclosure than the raised rim (35) of the cover.

12. Cooling device (3) according to one of the preceding claims, in which the distributor comprises one or more outlet orifices (30) for generating the leak jet(s) in the enclosure, the orifice(s) (30) having for example an oblong shape.

13. Cooling device (3) according to the preceding claim, wherein the cover (14) comprises at least one divergent (40) placed on the outlet orifice.

14. System (1) comprising an electronic module (2) and a cooling device according to one of the preceding claims, configured to cool the electronic module.

15. System (1) according to the preceding claim, in which the cooling device is according to claim 5 with the cover (14) comprising at least two fluid supply channels (17), each channel (17) opening onto one of the jet distributors (20), or - the cooling device is according to claims 6 and 10, with the cover (14) comprising a single supply channel (17) for distributor and an outlet (25) for evacuating dielectric fluid having circulated in the enclosure (10).

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