Cooling device and module for electronic components

Abstract

Cooling Device and Module for Electronic Components The invention relates to a cooling device (1) for electronic components (6), comprising a cooling plate (2) which includes: - a heat transfer fluid inlet and outlet (9) and a heat transfer fluid circulation channel (29), - an upper face (22) intended to receive a first electronic component (4) and capable of cooling the first electronic component (4), the cooling device (1) comprising additional cooling means (3, 26), including a component (3) disposed on the upper face (22) and intended to receive a second electronic component (6) by being interposed between the upper face (22) and the second electronic component (6). (Figure 2)

Description

Title of the invention: Cooling device and module for electronic components

[0001] The present invention relates to the fields of mechanics and thermodynamics, and more specifically concerns a cooling device for electronic components, finding particular application in data storage centers for which certain electronic boards have increased cooling requirements.

[0002] Electronic boards requiring such cooling are often large, up to one meter long and, for example, 50 to 60 centimeters wide. They incorporate electronic components such as RAM (Random-Access Memory), digital-to-analog converters, regulators, processors, etc. These electronic components individually dissipate varying degrees of heat during operation, necessitating a cooling system capable of removing more heat from the components dissipating the most thermal power than from other electronic components.

[0003] Therefore, a cooling system for such an electronic board in a data center generally comprises: - a cooling plate in which glycol water circulates, located under the electronic board and in thermal contact with it, this cooling plate being for example arranged at the bottom of a sealed case containing the electronic board, - a dielectric liquid filling the case and in which the electronic board is immersed, the dielectric liquid being cooled by the cooling plate, and - glycol water circulating heat exchangers, fluidly connected with the cooling plate, and arranged on the electronic components of the electronic board dissipating the most heat, on the side opposite the cooling plate, these heat exchangers having greater cooling performance than the cooling plate.

[0004] To optimize the cooling of the electronic components on the circuit board, the cooling plate is designed according to the arrangement of these electronic components on the circuit board. In particular, the positions and dimensions of the cooling channels in the cooling plate depend on this arrangement of the electronic components. Therefore, a different cooling plate must be designed for each different type of circuit board.

[0005] Furthermore, the heat exchangers located on the electronic components of the circuit board that dissipate the most heat require tubular connections between the cooling plate and these heat exchangers in order to share the glycol water circulation. These tubular connections take up space in the enclosure containing the circuit board and can cause sealing problems, especially when they need to pass through the enclosure wall.

[0006] The present invention aims to remedy at least in part the aforementioned drawbacks by providing a cooling device for electronic components, a cooling module comprising such a cooling device and a method for assembling such a cooling device, making it possible in particular to simplify the design of cooling systems for electronic boards.

[0007] To this end, the invention proposes a cooling device for electronic components, comprising a cooling plate, the cooling plate comprising: - at least one inlet and outlet for the heat transfer fluid and at least one circulation channel for the heat transfer fluid, - an upper wall comprising an upper face intended to receive at least one first electronic component, and a lower wall comprising a lower face, at least one circulation channel being included between the lower wall and the upper wall, the upper wall thus being capable of cooling the first electronic component when it is received on the upper face, the cooling device being characterized in that it comprises additional cooling means, including at least one element extending over the upper face, the element comprising means for circulating the heat transfer fluid and being intended to receive at least one second electronic component by being interposed between the upper face and the second electronic component,The additional cooling means comprising a heat transfer fluid inlet and a heat transfer fluid outlet arranged in the upper wall and cooperating with the circulation means of the component.

[0008] It is understood that the second electronic component has greater cooling requirements than the first electronic component, the additional cooling means being capable of causing the heat transfer fluid to absorb more heat than the upper wall of the component, which is uninsulated, can. Thus, although the cooling provided by the upper wall of the cooling plate is sufficient to properly cool the first electronic component, it is not sufficient to properly cool the second electronic component. The additional cooling means compensate for this inadequacy of the cooling plate by allowing the characteristics to be locally adapted thermodynamics of the cooling plate, such as the circulation flow rate of the heat transfer fluid under the second electronic component or the heat exchange coefficient between the second electronic component and the heat transfer fluid.

[0009] The heat transfer fluid is, for example, glycol water, or even carbon dioxide in gaseous form. The cooling plate and the component are preferably metallic, for example aluminum, which gives them good thermal conductivity.

[0010] Thus, when the first electronic component is received on the upper face of the cooling plate, i.e. in thermal contact with it by direct contact or possibly by means of a thermal paste or equivalent material, the heat transfer fluid and the first electronic component are separated from each other only by materials with good thermal conductivity, which makes it possible to obtain a good heat transfer coefficient between the heat transfer fluid and the first electronic component.

[0011] Similarly, when the second electronic component is received on the organ, the second electronic component is separated from the heat transfer fluid only by means of thermally efficient materials, ensuring a good heat transfer coefficient with the heat transfer fluid, possibly better than the heat transfer coefficient between the first electronic component and the heat transfer fluid. The second electronic component is, for example, in direct contact with the organ or in contact with it via thermal paste or an equivalent material.

[0012] Thanks to the invention, the cooling improvement for certain critical electronic components is not achieved within the cooling plate itself, but rather on top of it, by means of a component attached to the plate according to the arrangement of these critical electronic components on the integrated circuit board. The cooling plate can therefore be generic to different types of circuit boards, while still providing differentiated cooling between critical electronic components and other, less critical electronic components.

[0013] Furthermore, interposing the additional cooling means organ between the upper face of the cooling plate and the second electronic component makes it possible to limit the size of the cooling device, in particular by not requiring tubular connections between the organ and the cooling plate.

[0014] The cooling plate is, for example, formed of two metal plates assembled together, the first of the plates forming the upper wall and The second of the plates forms the lower wall. At least one of the plates is embossed to guide the heat transfer fluid into the cooling plate and ensure homogenized circulation. Preferably, the first plate is flat and the second plate is embossed, to maximize the heat exchange surface area with the electronic components.

[0015] In one embodiment of the invention, the cooling plate has point bosses connecting the upper wall to the lower wall.

[0016] In the field of heat exchangers, these point bosses are called "hard dimples" in English. When the cooling plate is formed of two metal plates joined together, the point bosses are created, for example, by stamping the first and / or the second plate. This method of construction with point bosses allows for homogenized circulation of the heat transfer fluid within the cooling plate while limiting pressure losses related to this guidance.

[0017] Alternatively or in addition to these point bosses, the cooling plate includes one or more internal walls that at least partially delimit one or more baffles and / or U-shaped bends in at least one circulation channel. These internal walls are designed to guide the heat transfer fluid so as to homogenize its circulation within the cooling plate. The number of internal walls, baffles, and / or U-shaped bends in the circulation channel is adapted to the size of the cooling plate to ensure good thermal homogeneity. When the cooling plate includes both at least one internal wall and point bosses, the number of internal walls is limited compared to an embodiment without point bosses, as these also provide guidance for the heat transfer fluid.A design combining point bosses and at least one internal wall improves the thermal homogeneity of the cooling plate compared to a design with only point bosses, while limiting pressure losses.

[0018] In one embodiment of the invention, the means for circulating the heat transfer fluid comprise: - a sealed casing attached to the upper face, - cooling fins extending between the upper face and the casing, the heat transfer fluid outlet and the heat transfer fluid inlet opening into the casing, and the inlet opening being upstream of the outlet opening with respect to a direction of heat transfer fluid flow in at least one circulation channel.

[0019] The casing is preferably metallic and, for example, attached to the upper wall of the cooling plate by brazing. Alternatively, the casing may to be welded to the upper wall of the cooling plate, by laser, by a welding torch or by friction mixing.

[0020] It is understood that in this embodiment of the invention, at least a portion of the heat transfer fluid circulating in the cooling plate is diverted to circulate within the component and then return to the cooling plate. The fins extending from the upper surface to the casing increase the heat transfer coefficient between the heat transfer fluid and the casing, and therefore between the heat transfer fluid and the second electronic component. This component is separated from the heat transfer fluid only by the casing and possibly a thermal paste. The direction of flow of the heat transfer fluid in the circulation channel naturally refers to the direction of flow of the heat transfer fluid in the portion of the circulation channel located below the inlet and outlet ports of the heat transfer fluid, as originally provided in the cooling plate, that is to say, without considering the diversion of the heat transfer fluid within the component.

[0021] The cooling fins, for example, form channels parallel to the direction of flow of the heat transfer fluid, with the inlet orifice located opposite an inlet of the channels formed by the cooling fins, and the outlet orifice located opposite an outlet of the channels formed by the cooling fins. Thus, by forming several channels, the cooling fins limit the cross-sectional area of ​​the heat transfer fluid between the inlet and outlet orifices in the component, which increases the velocity of the heat transfer fluid in the component and consequently improves the absorption of heat by the heat transfer fluid.

[0022] The cooling fins are, for example, staggered-pitch fins, which further increases the heat transfer coefficient between the second electronic component and the heat transfer fluid. The staggered-pitch fins form several segmented channels parallel to the direction of flow of the heat transfer fluid. The staggered-pitch fins forming the segments of the same channel are offset from the channel axis, this offset alternating successively between two symmetrical positions with respect to the channel axis.

[0023] In an alternative embodiment, the cooling fins form non-segmented channels, the channels being formed by continuous walls parallel to the direction of flow of the flow channel from an outlet on the inlet port to an outlet on the outlet port.

[0024] In one embodiment of the invention, the additional cooling means further comprise a partition disposed in at least one circulation channel of the cooling plate, between the inlet and outlet ports, and extending at least from the lower wall to the upper wall of the cooling plate, the partition being capable of blocking the heat transfer fluid in at least one traffic channel on at least a portion of the at least one traffic channel which extends under the envelope.

[0025] This partition effectively diverts at least a portion of the heat transfer fluid circulating in the circulation channel towards the inlet of the component. The partition forms a means of at least partially obstructing the passage of the heat transfer fluid in the circulation channel. It can be flat and, for example, perpendicular to the direction of flow of the heat transfer fluid, or, for example, form a V-shaped dam to guide the heat transfer fluid towards the inlet.

[0026] The partition extends, for example, over the entire width of at least one circulation channel. Thus, the heat transfer fluid is forced to flow towards the inlet. However, the partition may have passages for the heat transfer fluid. Therefore, only a portion of the heat transfer fluid is diverted towards the component.

[0027] Alternatively, the partition extends only over a portion of the width of at least one circulation channel. For example, when the enclosure is smaller than the width of the circulation channel, the partition extends at least over the entire portion of the circulation channel extending under the enclosure.

[0028] In an alternative embodiment, the additional cooling means do not include a partition, the inlet port being shaped to channel the heat transfer fluid towards the component. In this embodiment, the inlet port is, for example, provided with suction means.

[0029] The invention also relates to a cooling module for an electronic board, comprising: - a cooling device according to the invention, - a support suitable for positioning an electronic board parallel to the cooling plate of the cooling device, and for positioning at least one electronic component of the electronic board against the upper face of the cooling plate, and at least one electronic component of the electronic board against the cooling device component, and - an inlet and outlet of heat transfer fluid connected fluidly to the inlet and respectively to the outlet of heat transfer fluid of the cooling plate.

[0030] These electronic circuit board supports in the cooling module according to the invention allow the first and second electronic components to be directly connected to the upper surface and, respectively, the cooling device, even though they are linked by the electronic circuit board. It is also possible to connect the first and second electronic components to the upper surface and, respectively, the cooling device by the intermediary of the electronic board support, but this reduces the cooling efficiency.

[0031] In the cooling module according to the invention, the upper surface or component may include at least one metallic protrusion, suitable for enabling thermal contact between the first or second electronic component and the upper surface or component. These protrusions allow the cooling device to be adapted to the different heights of the electronic components on the circuit board. These protrusions are made entirely of metal. They are, for example, metal pads, such as aluminum, brazed or welded to the upper surface or component.

[0032] In one embodiment of the invention, the cooling module according to the invention is sealed and further comprises a dielectric fluid inlet and outlet adapted to allow circulation of a dielectric fluid within the cooling module. The dielectric fluid is, for example, cooled by a heat exchanger external to the cooling module.

[0033] The cooling module according to the invention may of course comprise several electronic boards and several cooling plates, arranged for example in several tiers within the cooling module. The electronic boards are preferably also immersed in the dielectric liquid.

[0034] The invention also relates to a method for assembling a cooling device according to the invention, starting from a cooling plate comprising an upper wall having an upper face for receiving at least one first electronic component, a lower wall having a lower face, at least one heat transfer fluid circulation channel included between the lower wall and the upper wall, and a heat transfer fluid inlet and outlet, the assembly method comprising the steps of: - cutting of the inlet and outlet ports of the additional cooling means of the cooling device, in the upper wall of the cooling plate and opposite at least one circulation channel, so that the inlet port is upstream of the outlet port with respect to one direction of flow of the heat transfer fluid in at least one circulation channel, - positioning of the cooling fins of the component between the inlet and outlet ports, on the upper surface, - positioning of the organ casing on the upper face so as to completely cover the cooling fins, the inlet port and the outlet port, and - brazing of the entire cooling plate, cooling fins and casing thus positioned on the cooling plate.

[0035] The inlet and outlet ports are cut, for example, by drilling holes in the upper surface of the cooling plate. Furthermore, the brazing step can be replaced by welding steps, for example using a laser, or even by bonding steps. If bonding is used, the positioning steps can be performed in a different order and simultaneously with the bonding steps. For example, the process may include a step of positioning the fins in the casing by bonding the fins to the casing, followed by a step of positioning and bonding the casing to the upper surface of the cooling plate.

[0036] In one embodiment of the invention, the step of positioning the cooling fins is preceded by the steps of: - cutting a slot in the upper wall of the cooling plate, between the location of the inlet port and the location of the outlet port, the slot being positioned transversely to the direction of flow of the heat transfer fluid, and - insertion of the partition of the additional cooling means into the slot, the brazing step also including brazing the partition to the cooling plate.

[0037] The cutting of the slot can of course be done before the cutting of the inlet and outlet holes, or after this cutting of the inlet and outlet holes.

[0038] The cooling module according to the invention and the method of assembling a cooling device according to the invention have advantages similar to those of the cooling device according to the invention.

[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] represents in perspective a part of a cooling device according to the invention, in a first embodiment of the invention, the cooling device comprising a cooling plate on which a first electronic component is disposed, and the cooling device comprising an element disposed on the cooling plate and on which a second electronic component is disposed,

[0041] [Fig.2] shows in cross-section the cooling device of [Fig.1], at the level of the organ and the second electronic component, the section being made along a plane parallel to a direction of circulation of a heat transfer fluid in the organ, and perpendicular to a main extension plane of the cooling plate,

[0042] [Fig.3] shows in cross-section the cooling device of [Fig.1], according to the plan of section AA represented in [Fig.2], this section plane AA being orthogonal to the plane of section of [Fig.2] and to a main extension plane of the cooling plate of [Fig.1],

[0043] [Fig.4] shows in cross-section the cooling device of [Fig.1], according to the section plane BB represented in [Fig.3], this section plane BB being orthogonal to the section plane of [Fig.2], parallel to the main extension plane of the cooling plate of [Fig.1], and cutting the cooling device of [Fig.1] at the level of the organ,

[0044] [Fig.5] shows in cross-section according to the cooling device of [Fig.1], along a cutting plane parallel to cutting plane BB but cutting the cooling device of [Fig.1] at the level of the cooling plate,

[0045] [Fig.6] shows in cross-section a cooling device according to the invention, in a second embodiment of the invention, this cooling device also comprising a cooling plate and a component disposed on the cooling plate, the cut being made parallel to a main extension plane of the cooling plate, at the level thereof,

[0046] [Fig.7] shows a cross-section of a cooling module according to the invention, including the cooling device of [Fig. 6], and

[0047] [Fig.8] represents steps in a process for assembling a device cooling according to the invention, in one embodiment of the invention.

[0048] According to a first embodiment of the invention shown in [Fig. 1], a cooling device 1 for electronic components, for example intended for use in a data center, comprises a cooling plate 2 having a heat transfer fluid inlet 21 and a heat transfer fluid outlet 23. The cooling plate 2 is configured to be traversed by a heat transfer fluid 9 (referenced, for example, in [Fig. 5]).

[0049] As shown in [Fig. 1], the cooling plate 2 is formed of two plates, which in this embodiment of the invention are brazed, welded, bonded, or laminated aluminum metal plates joined together around their edges. Alternatively, other types of thermally conductive materials may be used. One of the metal plates is flat and forms the upper wall of the cooling plate 2, this upper wall having a top face 22 for receiving a first electronic component 4. A second metal plate is stamped and forms the lower wall of the cooling plate 2, this lower wall having a bottom face 20.

[0050] The heat transfer fluid inlet 21 comprises a tube connected in a sealed manner, for example by brazing, to a first hole in a boss on the second metal plate, projecting from the lower face 20, the first hole being located at one end of the second metal plate. Similarly, the heat transfer fluid outlet 23 has a tube connected in a sealed manner, for example by brazing, to a second hole in another boss of the second metal plate, projecting from the lower face 20, this second hole being located at one end of the metal plate, distinct from the end having the first hole.

[0051] A circulation channel 29 extends between the inlet 21 and the outlet 23 of the heat transfer fluid, as shown in [Fig. 5]. This circulation channel 29, located between the lower and upper walls of the cooling plate 2, is formed by internal walls 28 stamped into the second metal plate of the cooling plate 2. These internal walls ensure homogenization of the circulation of the heat transfer fluid 9 within the cooling plate 2.

[0052] Referring back to [Fig. 1], this circulation of heat transfer fluid 9 in the cooling plate 2 is sufficient to cool the first electronic component 4 of an electronic board in the data storage center, when this first electronic component 4 is in contact with the upper surface 22 of the cooling plate. However, this circulation of the heat transfer fluid 9 in the cooling plate 2 is not sufficient to properly cool a second electronic component 6, which generates more heat during its operation than the first electronic component 4.

[0053] According to the invention, the cooling device 1 includes additional cooling means, capable of enabling the heat transfer fluid 9 to absorb more heat than only through the upper wall of the cooling plate 2. These additional cooling means include a member 3 interposed between the upper face 22 of the cooling plate 2 and the second electronic component 6 in contact with the member 3.

[0054] Figures 2 to 4 show how component 3 of the additional cooling means is implemented. The organ 3 comprises a metallic casing 30, here made of aluminum, brazed in a hermetic manner to the upper face 22 of the cooling plate 2. The second electronic component 6 is placed in contact with the casing 30, parallel to the main extension plane of the cooling plate 2.

[0055] The upper wall of the cooling plate 2 has a heat transfer fluid inlet 24 9 opening into the casing 30, and a heat transfer fluid outlet 25 9 also opening into the casing 30. This inlet 24 and outlet 25 are part of the additional cooling means. Indeed, they cooperate with means for circulating the heat transfer fluid 9 within the component 3, these circulation means also comprising at least the casing 30.

[0056] As can be seen in [Fig.4], the casing 30 covers the entire width of the circulation channel 29, delimited by two internal walls 28 of the cooling plate 2. The inlet 24 and outlet 25 ports are located opposite the circulation channel 29 between these two internal walls 28. The inlet 24 is arranged upstream of the outlet 25 with respect to the direction of flow of the heat transfer fluid 9 in the circulation channel 29, so that the inlet 24 draws at least a portion of the heat transfer fluid 9 to circulate it in the component 3 and then the heat transfer fluid 9 returns to the cooling plate 2 through the outlet 25.

[0057] It can be seen in [Fig.4] that the inlet orifices 24 and outlet orifices 25 extend over most of the width of the circulation channel 29, in order to facilitate the circulation of heat transfer fluid 9 between the cooling plate 2 and the component 3. The shape of the inlet orifices 24 and outlet 25 is here oblong, but can be any shape, for example rectangular.

[0058] The component 3 further comprises cooling fins 32 forming circulation channels within the component 3, each arranged parallel to the direction of flow of the heat transfer fluid 9 in the circulation channel 29. These cooling fins 32 extend from the upper face 22 of the cooling plate 2 to the casing 30. They are formed of a corrugated metal sheet, for example of aluminium, brazed with the casing 30 and the cooling plate 2.

[0059] The channels formed by the cooling fins 32 have a smaller cross-section than the cross-section of the circulation channel 29 under the casing 30, which makes it possible, on the one hand, to locally increase the exchange surface area between the heat transfer fluid 9 and the metal forming the cooling device 1, and on the other hand, to increase the circulation velocity of the heat transfer fluid 9 in the component 3 compared to the circulation velocity of the fluid 9 in the circulation channel 29. These characteristics allow the heat transfer fluid to absorb more heat dissipated by the second electronic component 6 than if the second electronic component 6 were directly in contact with the upper wall of the cooling plate 2. As an alternative embodiment, the cooling fins are staggered pitch fins, formed for example of several U-shaped sheets arranged in a staggered manner from each other.

[0060] The cooling fins 32 are arranged between the inlet port 24 and the outlet port 25. In this way, the inlet port 24 is located opposite at least one inlet of the channels formed by the cooling fins 32, and the outlet port 25 is located opposite at least one outlet of the channels formed by the cooling fins 32. The heat transfer fluid 9 exiting the cooling plate 2 through the inlet port 24 thus easily enters the channels formed by the fins. cooling 32, and can exit directly from the channels to the outlet port 25 to return to the cooling plate 2.

[0061] As can be seen in figures 2 to 5, a partition 26 is arranged in the cooling plate 2. It obstructs the circulation channel 29 by extending over the entire width of the circulation channel 29 between the two internal walls 28 extending under the component 3, and over the entire thickness of the cooling plate 2, that is to say from the lower wall of the latter to the upper wall of the latter.

[0062] This partition 26 forces the heat transfer fluid 9 to be diverted entirely towards the inlet orifice 24 of the heat transfer fluid 9 in the component 3, which ensures a good flow rate of heat transfer fluid 9 in the component 3. However, alternatively, passage orifices for the heat transfer fluid 9 can be provided in the partition 26, so that not all of the heat transfer fluid 9 is diverted towards the component 3.

[0063] Figure 5 is just one example of the implementation of the additional means of cooling, including component 3 and partition 26, at a portion of the circulation channel 29 located between two internal walls 28 of the cooling plate 2. It is noted that the internal walls 28 of the cooling plate 2 form several baffles and here several intertwined U-shaped bends. In particular, the first U-shaped bend, formed by a portion of these internal walls 28 and through which the heat transfer fluid 9 flows, brings the latter into a central portion of the cooling plate 2, and a second U-shaped bend, formed by another portion of the internal walls 28, distributes the heat transfer fluid 9 at the outlet of the first U-shaped bend, on either side of this central portion.This allows the temperature of the cooling plate 2 to be homogenized, compared to an embodiment in which the heat transfer fluid 9 progresses gradually through a width or length of the cooling plate 2 by tight turns, without going back in that length or width.

[0064] Figure 6 illustrates a second embodiment of the invention, in which The elements identical to those of the first embodiment according to the invention are referenced in the same way. In this second embodiment of the invention, a cooling device 1b according to the invention also comprises a cooling plate 2b having a heat transfer fluid inlet 21 and a heat transfer fluid outlet 23, as well as an additional cooling means 3, suitable for allowing better heat absorption by the heat transfer fluid than the upper wall of the cooling plate 2b alone.

[0065] The cooling plate 2b is also formed of two metal plates brazed together, the first of the metal plates being flat, forming an upper wall of the cooling plate 2b and having an upper face 22b (referenced [Fig. 7]) thereof. The second of the metal plates is stamped, forms a lower wall of the cooling plate 2b and has a lower face 20b of it. The upper and lower walls define a circulation channel 29b for the heat transfer fluid 9 in the cooling plate 2b.

[0066] Unlike the first embodiment of the invention, the second metal plate is stamped to form a single internal wall 28b, creating a single U-shape within the cooling plate 2b, as well as specific bosses 27, allowing the heat transfer fluid 9 to be distributed within the circulation channel 29. In other words, the width of the circulation channel 29b is approximately equal to half the width of the cooling plate 2b, with the internal wall 28b positioned at midpoint across the width of the cooling plate 2b. This embodiment of the invention makes it possible to limit pressure losses while maintaining acceptable thermal homogeneity of the cooling plate 2b.

[0067] Two additional cooling means 3, identical to that of the first embodiment of the invention, are arranged on the cooling plate 2b. These elements 3 are smaller in size than the circulation channel 29b.

[0068] A first component 3 is located above a first portion of the U formed by the circulation channel 29b. A first flat partition 26b extends in this first portion of the U from the inner wall 28b, orthogonally to the direction of flow of the heat transfer fluid 9 in this first portion of the U, and passes under the first component 3 until it passes beyond it, without completely closing the circulation channel 29b. In other words, the first partition 26b extends only over a portion of the width of the circulation channel 29b in the first portion of the U. The first partition 26b preferably extends over the entire thickness of the cooling plate 2b, that is, from the lower wall to the upper wall of the cooling plate 2b.The cooling plate 2b has an inlet orifice 24b opening under the casing 30 of the first component 3, and an outlet orifice 25b opening under the casing 30 of the first component 3, the inlet orifice 24b being arranged upstream of the outlet orifice 25b with respect to the direction of flow of the heat transfer fluid 9 in the circulation channel 29b. The inlet orifice 24b and the outlet orifice 25b are considered to be part of the additional cooling means of the cooling plate 2b, and cooperate with the means of circulating the heat transfer fluid 9 in the first component 3. Furthermore, the inlet orifice 24b and the outlet orifice 25b are located on either side of the first partition 26b.Thus, the heat transfer fluid 9 circulating in the circulation channel 29b is only partially diverted into the component 3 located in this first part of the U, to cool more efficiently than the cooling plate 2b, a second electronic component 6.

[0069] A second of the components 3 is located above a second portion of the U formed by the circulation channel 29b. A second partition 26c extends in this second portion of the U, from the lower wall to the upper wall of the cooling plate 2b, and over a portion of the width of the circulation channel 29b in the second portion of the U, so as to block the circulation of the heat transfer fluid 9 under the second component 3. The second partition 26c is formed of two metal plates connected to each other so as to form a V, the V forming an arrowhead directed in the direction of circulation of the heat transfer fluid 9 in the second portion of the U.The cooling plate 2b has an inlet orifice 24c in the upper wall of the cooling plate 2b and opening under the casing 30 of the second component 3, and an outlet orifice 25c in the upper wall of the cooling plate 2b and opening under the casing 30 of the second component 3. The inlet orifice 24c and the outlet orifice 25c are considered to be part of the additional cooling means of the cooling plate 2b, and cooperate with the means of circulating the heat transfer fluid 9 in the second component 3.

[0070] The tip of the V is arranged between the inlet port 24c and the outlet port 25c, the free ends of the V extending beyond the component 3 beneath it, into the cooling plate 2b. Thus, the heat transfer fluid 9 arriving at the second partition 26c is easily guided towards the center of the second partition 26c and then towards the inlet port 24c, to enter the second component 3 and then exit into the cooling plate 2b through the outlet port 25c. The second partition 26c allows a portion of the heat transfer fluid 9 circulating in the second part of the U to pass over its sides to reach the outlet 23 of the cooling plate, without passing through the component 3.

[0071] It is understood that the various embodiments of channels and partitions presented are adapted to the flow requirements of heat transfer fluid 9 passing through the component 3 and the cooling plate 2 or 2b in order to efficiently cool the first and second electronic components 4, 6. These various embodiments depend of course on the dimensions of the cooling plate 2, 2b and allow to obtain a thermal equilibrium at every point of the cooling plate 2, 2b, in order to limit the temperature gradient in the heat transfer fluid 9, and to limit to a minimum the temperature gradient between the thermal components arranged on the cooling plate 2, 2b.

[0072] It should be noted that two types of additional cooling means have been illustrated here on the same cooling plate 2b, including two partitions 26b, 26c of different shapes, to illustrate several embodiments, but Cooling devices with similar additional cooling means comprising separate components are, of course, also possible. A cooling module 5 according to the invention, comprising the cooling device 1b of the second embodiment of the invention, is now described with reference to [Fig. 7]. Alternatively, the cooling module 5 according to the invention comprises the cooling device 1 of the first embodiment of the invention.

[0073] The cooling module 5 comprises a housing 50, the bottom wall of the housing 50 being formed by the cooling plate 2b of the cooling device 1b. Alternatively, the cooling plate 2b may form a side wall of the housing 50 or be attached to it.

[0074] The inlet and outlet of the heat transfer fluid 9 of the cooling module therefore correspond respectively to the inlet 21 and the outlet 23 of the heat transfer fluid 9 of the cooling plate 2b.

[0075] The cooling module 5 includes an electronic board 8 on which are integrated first electronic components 4 and second electronic components 6. Supports 53, 54 fixed to side walls of the housing 50 allow the electronic board 8 to be held in the housing, so that the first and second electronic components 4, 6 are opposite the upper face 22b of the cooling plate 2b or of its components 3.

[0076] In order to allow the cooling of the first electronic components 4, metallic overthicknesses 11, 13 fill the space between the upper face 22b and the first electronic components 4, possibly supplemented by thermal paste.

[0077] In order to allow the cooling of a second electronic component 6, an overthickness 12 fills the space between the second organ 3 and the second electronic component 6. Another second electronic component 6 is for example in direct contact with the first organ 3 of the cooling device 1b.

[0078] The metallic overthicknesses 11, 13, 12 are for example aluminum blocks brazed onto the upper face 22b or onto the second component 3. They are not necessary when the first electronic components 4 or the second electronic component 6 touch the upper face 22b or respectively the second component 3, or when they are sufficiently close to the upper face 22b or respectively the second component 3, in which case the space between the upper face 22b and the first electronic components 4 or respectively between the second component 3 and the second electronic component 6, is filled only with thermal paste.

[0079] It is understood that these metallic overthicknesses allow good thermal contact between each of the electronic components to be cooled on the electronic board 8 and the cooling device 1b, despite the differences in height of these electronic components on the electronic board 8, and despite the steps created by the organs 3 on the cooling plate 2b.

[0080] The cooling module 5 may include several stages of electronic boards and cooling devices, arranged identically to the electronic board 8 and the cooling device 1b in the housing 50.

[0081] The cooling module 5 further comprises an inlet 51 and an outlet 52 for dielectric fluid 7, suitable for circulating the dielectric fluid 7 within the cooling module 5. The dielectric fluid 7 is, for example, cooled by a heat exchanger external to the cooling module 5. Since the dielectric fluid inlet 51 is located in the upper part of the housing 50, above the electronic board 8, the support 53 has passage holes for the dielectric fluid 7, allowing it to flow between the electronic board 8 and the cooling device 1b before exiting the housing 50. The cooling module 5 according to the invention thus provides dielectric fluid cooling on both sides of the electronic board 8.

[0082] Alternatively, the dielectric liquid 7 is cooled solely by the cooling device 1b, i.e. the cooling module does not have either an inlet or outlet of dielectric liquid in this variant.

[0083] An assembly method 100 for the cooling device 1 according to the invention is now described with reference to [Fig. 8]. The assembly method 100 is readily applicable to the assembly of any embodiment of the cooling device 1, 1b according to the invention.

[0084] The assembly method uses the cooling plate 2 initially without the partition 26 and the inlet 24 and outlet 25 ports, this cooling plate 2 being pre-assembled for use with several distinct types of electronic boards.

[0085] A first step 102 of the assembly process 100 is the cutting, in the upper wall of the cooling plate 2, of the inlet port 24 of the heat transfer fluid 9 into the component 3 and of the outlet port 25 of the heat transfer fluid 9 from the component 3 to the cooling plate 2. These ports are cut one behind the other above a portion of the circulation channel 29, delimited by two internal walls 28, the inlet port 24 being made upstream of the outlet port 25 with respect to the direction of circulation of the heat transfer fluid 9 in this portion of the circulation channel 29, as initially provided in the cooling plate 2 without partition 26. These ports are made for example by drilling.

[0086] A second step 104 of the assembly process 100, which can take place before, after or in parallel with the first step 102, is the cutting of a slot in the upper wall of the cooling plate 2 between the location of the inlet port 24 and the location of the outlet port 25, the slot being arranged orthogonally to the direction of circulation of the heat transfer fluid 9 in the portion of the circulation channel 29 above which the inlet ports 24 and outlet ports 25 are or are to be made. The slot extends from one internal wall 28 delimiting this portion of the circulation channel 29 to the other internal wall 28 delimiting this portion of the circulation channel 29, and is of complementary shape to the cross-section of the partition 26.

[0087] A third step 106 of the assembly process 100, following the second step 104, is the insertion of the partition 26 into the slot previously made, so that the partition 26 touches the lower wall of the cooling plate 2. The partition 26 extends from the lower wall of the cooling plate 2 and into the thickness of the upper wall of the cooling plate 2, so as to stand vertically in the cooling plate 2 without yet being fixed there by brazing.

[0088] A fourth step 108 of the assembly process 100 is then the positioning of the cooling fins 32 on the upper face 22 of the cooling plate 2, the channels formed by the cooling fins 32 being arranged parallel to the direction of circulation of the heat transfer fluid 9 in the portion of the circulation channel 29, and between the inlet port 24 and the outlet port 25.

[0089] A fifth step 110 of the assembly process 100 is then the positioning of the envelope 30 on the upper face 22 of the cooling plate 2, so that the envelope 30 completely covers the cooling fins 32, the inlet port 24 and the outlet port 25.

[0090] Finally, a sixth step 112 of the assembly process 100 is the brazing of the assembly formed by the cooling plate 2, the partition 26, the cooling fins 32 and the casing 30, as previously positioned in or on the cooling plate 2. This brazing allows a tight connection between the casing 30 and the cooling plate 2 on the one hand, and between the partition 26 and the upper surface 22 of the cooling plate 2 on the other hand.

[0091] Of course, the invention is not limited to the examples just described, and many modifications can be made to these examples without departing from the scope of the invention. In particular, the features of the different variants or embodiments of the invention envisaged in this application can be combined to carry out the invention, provided that these variants or embodiments are not incompatible with each other.

Claims

Demands

1. Cooling device (1, 1b) for electronic components (4, 6), comprising a cooling plate (2, 2b), the cooling plate (2, 2b) comprising: - at least one inlet (21) and one outlet (23) of heat transfer fluid (9) and at least one circulation channel (29, 29b) for the heat transfer fluid (9), - an upper wall comprising an upper face (22, 22b) for receiving at least one first electronic component (4), and a lower wall comprising a lower face (20, 20b), the at least one circulation channel (29, 29b) being included between the lower wall and the upper wall, the upper wall thus being capable of cooling the first electronic component (4) when it is received on the upper face (22, 22b), the cooling device (1, 1b) being characterized in that it comprises additional cooling means (3, 26, 26b, 26c, 24, 24b, 24c, 25, 25b, 25c),comprising at least one component (3) extending over the upper face (22, 22b), the component (3) having means for circulating the heat transfer fluid (9) and being intended to receive at least one second electronic component (6) by being interposed between the upper face (22, 22b) and the second electronic component (6), the additional cooling means (3, 26, 26b, 26c, 24, 24b, 24c, 25, 25b, 25c) having an inlet port (24, 24b, 24c) for heat transfer fluid (9) and an outlet port (25, 25b, 25c) for heat transfer fluid (9) arranged in the upper wall and cooperating with the circulation means of the component (3).

2. Cooling device (1b) according to claim 1, wherein the cooling plate (2b) has point bosses (27) connecting the upper wall to the lower wall.

3. Cooling device (1, 1b) according to claim 1 or 2, wherein the cooling plate (2, 2b) has one or more internal walls (28, 28b) delimiting at least in part one or more U-shaped turns of at least one circulation channel (29, 29b).

4. A cooling device (1, 1b) according to any one of claims 1 to 3, wherein the means for circulating the heat transfer fluid (9) comprise: - a casing (30) sealed onto the upper face (22, 22b), - cooling fins (32) extending between the upper face (22, 22b) and the casing (30), the heat transfer fluid (9) outlet (25, 25b, 25c) and the heat transfer fluid (9) inlet (24, 24b, 24c) opening into the casing (30), and the inlet (24, 24b, 24c) being located upstream of the outlet (25, 25b, 25c) with respect to one direction of circulation of the heat transfer fluid (9) in at least one circulation channel (29, 29b).

5. Cooling device (1, 1b) according to claim 4, wherein the cooling fins (32) form channels parallel to the direction of flow of the heat transfer fluid (9), the inlet port (24, 24b, 24c) is located opposite an inlet of the channels formed by the cooling fins (32), and the outlet port (25, 25b, 25c) is located opposite an outlet of the channels formed by the cooling fins (32).

6. Cooling device according to claim 4 or 5, wherein the cooling fins are offset pitch fins.

7. Cooling device (1, 1b) according to any one of claims 4 to 6, wherein the additional cooling means (3, 26, 26b, 26c, 24, 24b, 24c, 25, 25b, 25c) further comprise a partition (26, 26b, 26c) disposed in at least one circulation channel (29, 29b) of the cooling plate (2, 2b), between the inlet port (24, 24b, 24c) and the outlet port (25, 25b, 25c), and extending at least from the lower wall to the upper wall of the cooling plate (2, 2b), the partition (26, 26b, 26c) being capable of blocking the heat transfer fluid (9) in at least one circulation channel (29, 29b) on at least a portion of at least one circulation channel (29, 29b) which extends under the envelope (30).

8. Cooling device according to claim 7, wherein the partition has passage holes for the heat transfer fluid.

9. Cooling device (1) according to claim 7 or 8, wherein the partition (26) extends over a whole width of at least one circulation channel (29).

10. Cooling module (5) for electronic board (8), comprising: - a cooling device (1b) according to any one of claims 1 to 9, - a support (53, 54) suitable for positioning an electronic board (8) parallel to the cooling plate (2b) of the cooling device (1b), and for positioning at least a first electronic component (4) of the electronic board (8) against the upper face (22b) of the cooling plate (2b), and at least a second electronic component (6) of the electronic board (8) against the element (3) of the cooling device (1b), and - a heat transfer fluid inlet and outlet (9) fluidically connected to the inlet (21) and respectively to the outlet (23) of heat transfer fluid (9) of the cooling plate (2b).

11. Cooling module (5) according to claim 10, the cooling module (5) being sealed, and further comprising an inlet (51) and an outlet (52) of dielectric fluid (7) suitable for permitting circulation of a dielectric fluid (7) in the cooling module (5).

12. Cooling module (5) according to claim 10 or 11, wherein the upper face (22b) or the member (3) has at least one metallic overthickness (11, 12, 13), suitable for permitting thermal contact between the first (4) or respectively the second electronic component (6) and the upper face (22b) or respectively the member (3).

13. A method for assembling (100) a cooling device (1) according to any one of claims 7 to 9, from a cooling plate (2) comprising an upper wall having an upper face (22) for receiving at least one first electronic component (4), a lower wall having a lower face (20), at least one circulation channel (29) for the heat transfer fluid (9) included between the lower wall and the upper wall, and an inlet (21) and an outlet (23) for the heat transfer fluid (9), the assembly method (100) comprising the steps of: - cutting (102) the inlet orifice (24) and outlet orifice (25) of the additional cooling means (3, 26, 24, 25) of the cooling device (1), in the upper wall of the cooling plate (2) and opposite at least one circulation channel (29), such that the inlet orifice (24) is upstream of the outlet orifice (25) with respect to one direction of flow of the heat transfer fluid (9) in at least one circulation channel (29), - positioning (108) of the cooling fins (32) of the component (3) between the inlet orifice (24) and the outlet orifice (25), on the upper face (22), - positioning (110) of the casing (30) of the component (3), on the upper face (22), so as to completely cover the cooling fins (32), the orifice inlet (24) and outlet (25), and - brazing (112) of the cooling plate assembly (2),cooling fins (32) and casing (30) thus positioned on the cooling plate (2).

14. Method of assembling (100) a cooling device (1) according to claim 13, wherein the positioning step (108) of the cooling fins (32) is preceded by the steps of: - cutting (104) a slot in the upper wall (22) of the cooling plate (2), between the location of the inlet port (24) and the location of the outlet port (25), the slot being arranged transversely with respect to the direction of flow of the heat transfer fluid (9), and - inserting (106) the partition (26) of the additional cooling means (3, 26) into the slot, the brazing step (112) also comprising brazing the partition (26) to the cooling plate (2).

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