Jet impingement cooling of electronic module

Abstract

The present disclosure relates to techniques of active cooling of electronic modules. Particularly, it is provided an electronic device, comprising at least one electronic module comprising a substrate having a first substrate main surface and a second substrate main surface opposite to the first substrate main surface, a plurality of electronic components mounted above the first substrate main surface and a plurality of fins formed on the second substrate main surface and a cooling device for removing heat generated by the electronic components, wherein the cooling device faces the second substrate main surface and the cooling device is configured to expel coolant jets towards the second substrate main surface. Alternatively, the substrate is attached to a base plate and it is the base plate that has fins formed on a surface thereof and the cooling device is configured to expel coolant jets towards the base plate surface comprising the fins.

Description

[0001] JET IMPINGEMENT COOLING OF ELECTRONIC MODULE

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to direct cooling of one or more electronic modules by coolant jets. For example, the present disclosure relates to an electronic device and a cooling device.

[0004] BACKGROUND

[0005] Electronic modules with substrates and electronic components mounted over the substrates are ubiquitous. In operation, the electronic components generate heat that has to be removed. The problem of heat removal is of particular importance in the context of high performance applications, for example, in the context of power modules.

[0006] Electronic modules can be passively cooled by natural convection, for example, through some heat exchanger, or actively by forced convection usually with the aid of a pump supplying the coolant. For high performance applications active cooling is mandatory. Active cooling schemes can be grouped into direct contact and indirect contact cooling wherein direct cooling requires contact between the coolant and the heat source and indirect cooling is facilitated by some intermediate medium.

[0007] Spray cooling and, particularly, jet impingement cooling are considered efficient active cooling mechanisms. Jet impingement cooling is similar to spray cooling but does not need droplet atomization and is performed with a lower nozzle pressure drop and a higher fluid flow rate. This lower pressure requirement, in conjunction with a high flow volume, reduces nozzle clogging and reduces noise levels.

[0008] However, a prohibitive factor in jet impingement assimilation as an effective cooling thermal management solution is the high pressure drop associated with it. Furthermore, when many heat sources exist, several jets are required leading to an increase in system pressure drop. This in turn requires a larger / more powerful pump and ancillary cooling system which results in increased system cost and weight.

[0009] The majority of existing jet impingement thermal management systems is focused on very few heat sources and a parallel configuration is usually adopted when multiple heat sources exist. This increases the module height and demand for available space for the integration in a system.

[0010] SUMMARY

[0011] In view of the above, it is an objective underlying the present application to provide techniques for reliably and efficiently cooling electronic modules at moderate costs and low spatial demands.

[0012] The foregoing and other objectives are achieved by the subject matter of the independent claims. Further implementation forms are apparent from the dependent claims, the description and the figures.

[0013] According to a first aspect, it is provided an electronic device (for example, a motor), comprising at least one electronic module comprising a substrate having a first substrate main surface and a second substrate main surface opposite to the first substrate main surface, a plurality of electronic components (for example, comprising transistors, capacitors, inductors, integrates circuits, processors, etc.) mounted above the first substrate main surface and a plurality of fins formed on the second substrate main surface. Further, the electronic device comprises a cooling device for removing heat generated by the electronic components, wherein the cooling device faces the second substrate main surface and the cooling device is configured to expel coolant jets towards the second substrate main surface. In this configuration, no base plate is present for mounting the substrate. The fins may be pin formed fins, for example, having cross sections perpendicular to the longitudinal extensions of the fins of regular shapes, for example, circular, elliptic, hexagonal, or rhombic shapes.

[0014] Due to the fins, the surface area of the second substrate main surface is increased and, therefore, heat dissipation is increased. Further, the coolant impinging the second substrate main surface can flow between the fins and effectively transport heat away from the substrate. Moreover, removal of heat by the coolant is efficient due to the absence of a base plate that conventionally is provided, since the coolant directly impinges on the second substrate main surface. In the case of a series arrangement of two or more electronic modules series cooling can easily and efficiently be realized by the cooling device extending along the series arrangement.

[0015] According to an implementation, the cooling device is configured to expel the coolant jets towards the second substrate main surface between the fins. High heat dissipation rates might be achieved when orifices for expelling coolant jets are arranged such that the coolant jets are directed between the fins to impinge on the second substrate main surface between the fins. Particularly, the fins may be uniformly distributed over the second substrate main surface in a regular pattern. The fins may be distributed over the entire area of the second substrate main surface. Orifices for expelling coolant jets may, accordingly, also be arranged in a regular pattern complementarity to the regular pattern of the fins. Thus, the entire area of the second substrate main surface can be reached uniformly by the coolant for efficient heat dissipation and achieving a relatively uniform temperature across the substrate. However, according to another implementation, the orifices (jets) are distributed in the regular pattern over the entire breadth of the substrate but not over the entire length of the substrate. The extension of the regular distribution pattern of the orifices (coolant jets) in the length direction of the substrate may vary, for example, decrease, in series from one electronic module to another if more than one electronic module is provided.

[0016] According to an alternative implementation of the electronic device of the first aspect, the fins are exclusively formed on the second substrate main surface below areas of the first substrate main surface that are not covered by the electronic components and the cooling device is configured to direct the coolant jets exclusively towards areas of the second substrate main surface that are located below the areas of the first substrate main surface that are covered by the electronic components. Thus, the coolant is directly expelled toward the hottest regions of the (second substrate main surface of the) substrate for efficient heat dissipation. This configuration may result in a reduced pressure drop of the coolant over the cooling device and, therefore, a reduced pumping capacity of a pump supplying the coolant is needed. Further, due to the provision of fewer fins the overall module weight can be reduced as compared to the previously described implementation that is characterized by a uniform distribution of fins in a regular pattern over the entire second base plate main surface.

[0017] According to another implementation, the cooling device comprises a coolant inlet, a coolant outlet, a first chamber connected to the coolant inlet and comprising jet orifices, and a second chamber positioned closer to the second substrate main surface than the first chamber and comprising openings facing the jet orifices of the first chamber. The fins extend into the second chamber that is open towards the second substrate main surface. Such a configuration allows for an accurate flow management and distribution of the coolant over the substrate. Particularly, the coolant can be re-circulated from the coolant outlet to the coolant inlet via suitable means, for example, comprising pipes / tubes connected to a pump. The configuration can be manufactured with a compact size at relatively low costs. For example, the thus configured cooling device may be formed as a single molded piece, for example, made of some plastic material as polypropylene or any other appropriate high temperature resistant plastic material.

[0018] In the case of more than one electronic module, a first chamber may be provided for each of the electronic modules wherein only the first chamber associated with the first electronic module in series is connected to the coolant inlet and the second chamber may extend all along the electronic modules. According to an implementation, the cooling device further comprises a circulation chamber (plenum) connected to the coolant inlet and the first chamber. Provision of the circulation chamber allows for a uniform distribution of the coolant flow along the breadth of the first chamber. Again, in the case of more than one electronic module, a first chamber may be provided for each of the electronic modules wherein only the first chamber associated with the first electronic module in series is connected to the circulation chamber.

[0019] According to another implementation, the at least one electronic module comprises at least two electronic modules and the cooling device extends along the at least two electronic modules and comprises at least one bypass channel connecting another first chamber of the cooling device and the second chamber between the at least two electronic modules. The bypass channels may help to reduce the pressure drop and facilitate fluid mixing. In the case of more than electronic modules, a bypass channel for each of the electronic modules may connect the second chamber extending all along the electronic modules to a respective first chamber provided for each of the electronic modules.

[0020] According to another implementation, the at least one electronic module of the electronic device comprises a series of at least two electronic modules and the series of at least two electronic modules constitute a power module, for example, a power module for an electric motor. For example, the power module is constituted by 3-phase electronic modules. Power modules suffer from high heat production of their electronic components and, thus, the cooling device disclosed herein is particularly suitable for cooling such power modules.

[0021] According to a second aspect, it is provided an electronic device (for example, a motor), comprising at least one electronic module comprising a) a substrate having a first substrate main surface and a second substrate main surface opposite to the first substrate main surface, b) a plurality of electronic components mounted above the first substrate main surface and c) a base plate having a first base plate main surface and a second base plate main surface opposite to the first base plate main surface wherein the base plate is attached at the first base plate main surface to the second substrate main surface of the substrate and wherein the second base plate main surface comprises a plurality of fins formed thereon. Further, the electronic device comprises a cooling device for removing heat generated by the electronic components, wherein the cooling device faces the second base plate main surface and the cooling device is configured to expel coolant jets towards the second base plate main surface. The fins may be pin formed fins, for example, having cross sections perpendicular to the longitudinal extensions of the fins of regular shapes, for example, circular, elliptic, hexagonal, or rhombic shapes.

[0022] Due to the fins, the surface area of the second base plate main surface is increased and, therefore, heat dissipation is increased. Further, the coolant impinging the second base plate main surface can flow between the fins and effectively transport heat away from the substrate. In the case of a series arrangement of two or more electronic modules series cooling can easily and efficiently be realized.

[0023] According to an implementation, the cooling device is configured to expel the coolant jets towards the second base plate main surface between the fins. High heat dissipation rates might be achieved when orifices for expelling coolant jets are arranged such that the coolant jets are directed between the fins to impinge on the second base plate main surface between the fins. Particularly, the fins may be uniformly distributed over the second base plate main surface in a regular pattern. The fins may be distributed over the entire area of the second base plate main surface. Orifices for expelling coolant jets may, accordingly, also be arranged in a regular pattern complementarity to the regular pattern of the fins. Thus, the entire area of the second base plate main surface can be reached uniformly by the coolant for efficient heat dissipation. However, according to another implementation, the orifices (jets) are distributed in the regular pattern over the entire breadth of the base plate but not over the entire length of the base plate. The extension of the regular distribution pattern of the orifices (coolant jets) in the length direction of the base plate may vary, for example, decrease, in series from one electronic module to another, if more than one electronic module is provided. According to an alternative implementation of the electronic device of the second aspect, the fins are exclusively formed on the second base plate main surface below areas of the first substrate main surface that are not covered by the electronic components and the cooling device is configured to direct the coolant jets exclusively towards areas of the second base plate main surface that are located below the areas of the first substrate main surface that are covered by the electronic components. Thus, the coolant is directly expelled toward the areas of the base plate positioned below the hottest regions of the (second substrate main surface of the) substrate for efficient heat dissipation. This configuration may result in a reduced pressure drop over the cooling device and, therefore, a reduced pumping capacity of a pump supplying the coolant is needed. Further, due to the provision of fewer fins the overall module weight can be reduced as compared to the previously described implementation characterized by a uniform distribution of fins in a regular pattern over the entire second base plate main surface.

[0024] According to another implementation, the cooling device comprises a coolant inlet, a coolant outlet, a first chamber connected to the coolant inlet and comprising jet orifices, and a second chamber positioned closer to the second base plate main surface than the first chamber and comprising openings facing the jet orifices of the first chamber. The fins extend into the second chamber. Such a configuration allows for an accurate flow management and distribution of the coolant over the base plate. Particularly, the coolant can be re-circulated from the coolant outlet to the coolant inlet via suitable means, for example, comprising pipes / tubes connected to a pump. The configuration can be manufactured with a compact size at relatively low costs. For example, the thus configured cooling device may be formed as a single molded piece for example, made of some plastic material as polypropylene or any other appropriate high temperature resistant plastic material.

[0025] In the case of more than one electronic module, a first chamber may be provided for each of the electronic modules wherein only the first chamber associated with the first electronic module in series is connected to the coolant inlet and the second chamber may extend all along the electronic modules.

[0026] According to an implementation, the cooling device further comprises a circulation chamber (plenum) connected to the coolant inlet and the first chamber. Provision of the circulation chamber allows for a uniform distribution of the coolant flow along the breadth of the first chamber. Again, in the case of more than one electronic module, a first chamber may be provided for each of the electronic modules wherein only the first chamber associated with the first electronic module in series is connected to the circulation chamber.

[0027] According to another implementation, the at least one electronic module comprises at least two electronic modules and the cooling device extends along the at least two electronic modules and comprises at least one bypass channel connecting another first chamber of the cooling device and the second chamber between the at least two electronic modules. The bypass channels may help to reduce the pressure drop and facilitate fluid mixing

[0028] According to another implementation, the at least one electronic module of the electronic device comprises a series of at least two electronic modules and the series of at least two electronic modules constitute a power module, for example, a power module for an electric motor. For example, the power module is constituted by 3-phase electronic modules. Power modules suffer from high heat production of their electronic components and, thus, the cooling device disclosed herein is particularly suitable for cooling such power modules.

[0029] According to a third aspect, it is provided a cooling device for cooling at least one electronic module (for example, an electronic module of a motor) comprising a substrate having a plurality of electronic components mounted thereon, wherein the cooling device comprises a coolant inlet, a coolant outlet, a first chamber connected to the coolant inlet and comprising jet orifices, and a second chamber (to be positioned closer to the substrate than the first chamber) and comprising openings facing the jet orifices of the first chamber. Such a configuration allows for an accurate flow management and distribution of the coolant over the substrate to be cooled. Particularly, the coolant can be re-circulated from the coolant outlet to the coolant inlet via suitable means, for example, comprising pipes / tubes connected to a pump. The configuration can be manufactured with a compact size at relatively low costs. For example, the thus configured cooling device may be formed as a single molded piece for example, made of some plastic material as polypropylene or any other appropriate high temperature resistant plastic material.

[0030] According to an implementation, the cooling device further comprises a circulation chamber connected to the coolant inlet and the first chamber. Provision of the circulation chamber allows for a uniform distribution of the coolant flow along the breadth of the first chamber.

[0031] According to an implementation, the cooling device further comprises at least one bypass channel connecting another first chamber of the cooling device and the second chamber. The bypass channels may help to reduce the pressure drop and facilitate fluid mixing. Particularly, the cooling device may comprise a plurality of first chambers wherein only a first one of the plurality of first chambers is connected to the coolant inlet and the circulation chamber. A first bypass channel may connect the second chamber to a second first chamber, a second bypass channel may connect the second chamber to a third first chamber, etc.

[0032] Details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description, drawings, and claims.

[0033] BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In the following, embodiments of the present disclosure are described in more detail with reference to the attached figures and drawings, in which:

[0035] Figure 1 illustrates a substrate of an electronic module of an electronic device according to an embodiment, wherein the substrate comprises fins and electronic components representing heat sources are mounted over the substrate.

[0036] Figure 2 illustrates an electronic device comprising a series of electronic modules and a cooling device according to an embodiment.

[0037] Figure 3 is a side view of the electronic device shown in Figure 2.

[0038] Figure 4 is a three-dimensional view of an electronic device comprising a series of electronic modules and a cooling device according to an embodiment.

[0039] Figure 5 is a top view of the electronic device shown in Figure 4.

[0040] Figure 6 is a bottom view of the electronic device shown in Figure 4.

[0041] Figure 7 illustrates an electronic device comprising a series of electronic modules and a cooling device according to another embodiment.

[0042] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] Herein, techniques for cooling electronic components of an electronic device are provided. Particularly, it is provided an electronic device comprising one or more electronic modules and a cooling device configured for removing heat generated by electronic components of the one or more electronic modules by jet impingement. The electronic components are formed above a substrate comprising fins at the surface exposed to the coolant jets or above a substrate formed on a base plate comprising fins at the surface exposed to the coolant jets. According to an embodiment, the coolant jets are expelled between the fins. According to an alternative embodiment, the fins are only formed at areas above which no electronic components are arranged and the coolant jets are expelled at areas free of fins, i.e., areas above which the electronic components are arranged. Further, a cooling device for cooling at least one electronic module comprising a substrate having a plurality of electronic components mounted thereon is provided. Examples of the electronic device comprise an electric motor, for example, a Permanent Magnet Synchronous Motor, comprising a number of power modules.

[0044] Figure 1 illustrates a substrate 10 that might be used in an electronic module of an electronic device according to an embodiment. Electronic components 14, for example, comprising transistors, capacitors, inductors, integrates circuits, processors, etc., are mounted above a first (for example, upper) substrate main surface 10a of the substrate 10. The substrate 10 comprises fins 16 formed on a second (for example, lower) substrate main surface 10b of the substrate 10. According to an alternative, a substrate with electronic components 14, for example, comprising transistors, capacitors, inductors, integrates circuits, processors, etc., mounted above a first (for example, upper) substrate main surface is mounted at a second (for example, lower) substrate main surface on which no fins are formed to a first (for example, upper) base plate surface of a base plate and the base plate comprises fins formed on a second (for example, lower) base plate surface opposite to the upper base plate surface. In both alternatives, the fins may be pin formed fins, for example, having cross sections perpendicular to the longitudinal extensions of the fins of regular shapes, for example, circular, elliptic, hexagonal, or rhombic shapes. In both alternatives, the substrate may be formed of any suitable material known in the art. The fins, advantageously, increase the surface area of the second substrate main surface 10b and, therefore, heat dissipation is significantly increased.

[0045] Particularly, the substrate may be a multilayer substrate, for example, comprising a top layer made of or comprising copper, a middle layer made of or comprising ceramic and a bottom layer made of or comprising copper. The base plate according to the second alternative may be made of any suitable dielectric material known in the art. The substrate 10 shown in Figure 1 or the combination of a substrate and a base plate according to the second alternative may be used in the embodiments described below.

[0046] Figure 2 illustrates an electronic device 1000 according to an embodiment. The electronic device 1000 comprises a series of three electronic modules 100. Here and in the following no restriction to exactly three electronic modules 100 is intended but the number of electronic modules 100 is rather given as an example. Each of the electronic modules 100 comprises a substrate 10 attached to a base plate 20. The substrate 10 and the base plate 20 are attached to each other at a first base plate main surface of the base plate and a second substrate main surface of the substrate 10. Electronic components 14 (for example, comprising transistors, capacitors, inductors, integrates circuits, processors, etc.) are formed over a first substrate main surface of the substrate 10 and represent heat sources. The substrate may be a multilayer substrate, for example, comprising a top layer made of or comprising copper, a middle layer made of or comprising ceramic and a bottom layer made of or comprising copper. The base plate may be made of any suitable material known in the art. The base plate comprises fins formed on a second base plate main surface opposite to the first base plate main surface. According to an alternative embodiment, no base plate 20 is provided and fins are formed on the second substrate main surface of the substrate 10, for example, the substrate 10 shown in Figure 1. Absence of the base plate 20 may increase the thermal performance between the coolant and the heat sources. The fins may be formed in a uniform regular pattern populating the entirety of the second base plate main surface or in an irregular pattern leaving some areas of the second base plate main surface devoid of fins (see also description below).

[0047] The cooling device 200 may be formed of polypropylene or any other appropriate high temperature resistant plastic material. Particularly, the cooling device 200 may be formed in a single molded piece by mass production manufacturing processes.

[0048] Further, the electronic device 1000 shown in Figure 2 comprises a cooling device 200 for removing heat from the electronic modules 100 caused by operation of the electronic components 14. The cooling device 200 extends along the series of electronic modules 100 facing the second base plate main surface. The cooling device 200 is configured for generating coolant jets and directing the coolant jets towards the second base plate main surface. In the alternative embodiment without the base plate 20 the coolant jets impinge the second base plate surface. Additionally, Figure 2 shows bypass channels 230 and a circulation chamber 260 of the cooling device 200 (for details see description below). Figure 3 shows in a side view details of a cooling device 200 of the electronic device 1000 shown in Figure 2 according to an embodiment. The cooling device 200 comprises a coolant inlet 240 and a coolant outlet 250. A coolant may be supplied to the coolant inlet 240 by means of a pump, flows through the cooling device 200 and leaves it through the coolant outlet 250. The coolant may circulate between the coolant inlet 240 and the coolant outlet 250. The coolant fluid may be any appropriate liquid, such as (deionized) water, water-glycol, organic solvents, and inorganic solvents. Examples of such solvents may include commercial refrigerants that are conventionally used. The composition of the coolant used in association with the electronic module(s) may be selected taking account the boiling point, the density and the viscosity of the coolant.

[0049] The coolant enters a circulation chamber 260 for distributing the coolant into the first chamber 210. The first chamber 210 is provided with orifices for generating coolant jets J. The coolant jets J enter the second chamber 220 through openings associated with the orifices of the first chamber 210 and impinge on a lower base plate main surface of the base plate 20 (the second chamber 220 is open to the lower base plate main surface of the base plate 20). The coolant jets J may have diameters of about 0.5 to 1.2 mm and may originate at distances of about 3 to 4 mm, for example, to the lower base plate main surface of the base plate 20. The coolant jets J may be spaced apart from each other by distances of about 4 mm, for example.

[0050] After being impinged on the lower (second) base plate main surface of the base plate 20 the coolant flows along the second chamber guided by fins formed on the lower base plate main surface. The coolant meanders through the fins across the length of the substrate 10 (from left to right in Figure 3). The fins extend into the second chamber 220 and there is clearance between the tips of the fins and the bottom surface (facing the first chambers 210) of the second chamber 220, for example, a clearance of about 0.2 mm. The height of the second chamber may be about 1 mm.

[0051] Bypass channels 230 are provided between individual electronic modules 100 to guide the coolant to a respective next first chamber 210. As shown in Figure 3 the bypass channels 230 may be altematingly arranged with respect to a front side and a back side of the cooling device 200. In the alternative embodiment without the base plate 20, the coolant jets impinge on a lower (second) substrate main surface of the substrate 10 (the second chamber 220 is open to the lower (second) substrate main surface of the substrate 10 on which the fins are formed).

[0052] Figure 4 illustrates in a three-dimensional view an electronic device 2000 according to an embodiment. Figures 5 and 6, respectively, show a top view and a bottom view of the electronic device 2000 shown in Figure 4. The electronic device 2000 comprises three electronic modules 100. Each of the electronic modules 100 comprises a substrate 10 formed on a base plate 20 provided with fins 16 or, alternatively, it comprises a substrate 10 provided with fins 16 without provision of a base plate 20. Further, the electronic device 2000 comprises a cooling device 200 for removing heat from the electronic modules 100 generated by electronic components (not shown in Figure 4) mounted above the substrate 10. The cooling device 200 comprises first chambers 210 and a second chamber 220 as illustrated in Figure 3, for example. Furthermore, the cooling device 200 comprises a coolant inlet 240, a coolant outlet 250 and a circulation chamber 250 connected to the coolant inlet 240.

[0053] Bypass channels 230 are provided between individual electronic modules 100 to guide the coolant to a respective next first chamber 210 (see Figures 5 and 6). The bypass channels 230 may be altematingly arranged with respect to a front side and a back side of the cooling device 200 / electronic modules 100 (see Figures 5 and 6).

[0054] According to the embodiment shown in Figures 4, 5 and 6 the (pin) fins are uniformly formed in a regular pattern on a lower main surface of the base plate 20 (if provided) or, alternatively, a lower main surface of the substrate 10. The fins may be pin formed fins, for example, having cross sections perpendicular to the longitudinal extensions of the fins of regular shapes, for example, circular, elliptic, hexagonal, or rhombic shapes. For example, the fins 16 have rhombic cross-sectional shapes with 2 mm x 2 mm extensions between opposing comers. A coolant can be expelled from the first chambers 210 to the second chamber 220 to impinge on the lower main surface of the base plate 20 or the lower main surface of the substrate 10 through openings 222 formed in the lower surface of the second chamber 220 (see Figure 5). The openings 222 face orifices of the first chambers 210 provided for generating coolant jets. As can be seen from Figure 6, the openings 222 and, thus, the orifices, are also arranged in a regular pattern complementary to the regular pattern of the fins 16 such that the coolant jets are nested between the fins 16 and are directed towards the lower main surface of the base plate 20 or the lower main surface of the substrate 10 between the fins 16. In the exemplary embodiment shown in Figure 6 the number of jets cover the breadth of the substrate 10 between the fins 16 and half the length (from left to right in Figure 6) of the substrate 10 for the first ((from left to right in Figure 6) substrate 10 of the first electronic module 100 in series. For subsequent substrates 10, the jet number may reduce by 20% across the length of the substrate 10 (unchanged across the breadth) and may be capped to 30% of the number of jets for the first substrate 10. Such a varying distribution of the jets may reduce the overall pressure drop and improve the flow control of the coolant across the series of electronic modules 100, in general.

[0055] Figure 7 shows an electronic device 3000 according to another embodiment. The electronic device 3000 comprises components similar to the components of the embodiment illustrated in Figures 4 to 6 but, contrary to that embodiment, the fins 16 are not distributed in a uniform regular pattern over the entire breadth of the lower surface of the substrate 10 or base plate 20 and they are not distributed below the electronic components 14.

[0056] Figure 7 shows two electronic modules 100 and a cooling device 200. Each of the electronic modules 100 comprises a substrate 10 formed on a base plate 20 provided with fins 16 or, alternatively, it comprises a substrate 10 provided with fins 16 without provision of a base plate (not shown in Figure 7). The fins are not formed in uniform regular pattern Electronic components 14 are mounted above the substrate 10 and represent heat sources 14. Heat generated by the electronic components 14 is to be removed by the cooling device 200 by means of coolant jets generated by the cooling device 200. The fins 16 of the substrate 10 or the base plate are exclusively formed below regions of the upper surface of the substrate 10 or the base plate that are devoid of electronic components 14. The fins may populate the entirety of the lower surface of the substrate 10 or the base plate except the regions directly underneath the heat sources 14. The number of fins 16 may be smaller than in the embodiment illustrated in Figures 4 to 6 and, thus, the weight of the electronic modules might be reduced. The fins 16 may be pin formed fins, for example, having cross sections perpendicular to the longitudinal extensions of the fins 16 of regular shapes, for example, circular, elliptic, hexagonal, or rhombic shapes. For example, the fins 16 have rhombic cross-sectional shapes with 2 mm x 2 mm extensions between opposing comers.

[0057] The openings 222 of the lower surface of the second chamber and the orifices formed in the upper surfaces of the first chambers, are exclusively arranged below regions of the upper surface of the substrate 10 or the base plate that are covered by the electronic components 14. Contrary to the embodiment illustrated in Figures 5 to 6, the coolant jets are not directed between the fins 16 but rather exclusively to the hottest regions of the lower surface of the substrate 10 or base plate below the electronic components 14. The coolant jets may have diameters of about 0.5 to 1.2 mm and may originate at distances of about 3 to 4 mm, for example, to the lower surface of the substrate 10 or the base plate. The number of coolant jets provided may depend on the number and size of heat sources 14, for example, with a jet count of 1 jet per 3 mm x 3 mm of heat source area. It might be ensured that all heat sources 14 have at least 1 coolant jet underneath with larger heat sources potentially having multiple jets.

[0058] The coolant flow along the second chamber in the direction toward the coolant outlet is again governed by the arrangement of the fins 16.

[0059] The embodiments illustrated in Figures 2 to 7 allow for high efficient cooling of the electronic modules 100 / substrates 10 with relatively low pressure drops of the coolant over the cooling device 200 across the series of electronic modules 100. Heat dissipation by jet impingement can be optimized by the finned impingement surfaces. Series cooling of planar module arrangements can be effectively achieved with relatively compact construction dimensions, in particular, construction heights, and at relatively low costs.

[0060] All previously discussed embodiments are not intended as limitations but serve as examples illustrating features and advantages of the invention. It is to be understood that some or all of the above-described features can also be combined in different ways.

Claims

CLAIMS1. An electronic device (1000, 2000, 3000), comprising: at least one electronic module (100) comprising a substrate (10) having a first substrate main surface (10a) and a second substrate main surface (10b) opposite to the first substrate main surface (10a), a plurality of electronic components (14) mounted above the first substrate main surface (10a) and a plurality of fins (16) formed on the second substrate main surface (10b); and a cooling device (200) for removing heat generated by the electronic components (14), wherein the cooling device (200) faces the second substrate main surface (10b) and the cooling device (200) is configured to expel coolant jets (J) towards the second substrate main surface (10b).

2. The electronic device (1000, 2000) according to claim 1, wherein the cooling device (200) is configured to expel the coolant jets (J) towards the second substrate main surface (10b) between the fins (16).

3. The electronic device (1000, 2000) according to claim 2, wherein the fins (16) are uniformly distributed over the second substrate main surface (10b) in a regular pattern.

4. The electronic device (3000) according to claim 1, wherein the fins (16) are exclusively formed on the second substrate main surface (10b) below areas of the first substrate main surface (10a) that are not covered by the electronic components (14); and the cooling device (200) is configured to direct the coolant jets (J) exclusively towards areas of the second substrate main surface (10b) that are located below the areas of the first substrate main surface (10a) that are covered by the electronic components (14).

5. The electronic device (1000, 2000, 3000) according to one of the preceding claims, wherein the cooling device (200) comprises: a coolant inlet (240); a coolant outlet (250); a first chamber (210) connected to the coolant inlet (240) and comprising jet orifices; and a second chamber (220) positioned closer to the second substrate main surface (10b) than the first chamber (210) and comprising openings (222) facing the jet orifices of the first chamber (210), and wherein the fins (16) extend into the second chamber (220).

6. The electronic device (1000, 2000, 3000) according to claim 5, wherein the cooling device (200) further comprises a circulation chamber (260) connected to the coolant inlet (240) and the first chamber (210).

7. The electronic device (1000, 2000, 3000) according to claim 5 or 6, wherein the at least one electronic module (100) comprises at least two electronic modules (100) and the cooling device (200) extends along the at least two electronic modules and comprises at least one bypass channel (230) connecting another first chamber (210) of the cooling device and the second chamber (220) between the at least two electronic modules (100).

8. The electronic device (1000, 2000, 3000) according to any of the preceding claims, wherein the cooling device (200) is formed as a single molded piece.

9. The electronic device (1000, 2000, 3000) according to any of the preceding claims, wherein the at least one electronic module (100) comprises a series of at least two electronic modules (100) and wherein the series of at least two electronic modules (100) constitute a power module.

10. An electronic device (1000, 2000, 3000), comprising: at least one electronic module (100) comprising a) a substrate (10) having a first substrate main surface (10a) and a second substrate main surface (10b) opposite to the first substrate main surface (10a), b) a plurality of electronic components (14) mounted above the first substrate main surface (10a) and c) a base plate having a first base plate main surface and a second base plate main surface opposite to the first base plate main surface and wherein the base plate is attached at the first base plate main surface to the second substrate main surface (10b) of the substrate (10) and wherein the second base plate main surface comprises a plurality of fins (16) formed thereon; and a cooling device (200) for removing heat generated by the electronic components (14), wherein the cooling device (200) faces the second base plate main surface and the cooling device (200) is configured to expel coolant jets (J) towards the second base plate main surface.

11. The electronic device (1000, 2000) according to claim 10, wherein the cooling device (200) is configured to expel the coolant jets (J) towards the second base plate main surface between the fins (16).

12. The electronic device (1000, 2000) according to claim 11, wherein the fins (16) are uniformly distributed over the second base plate main surface in a regular pattern.

13. The electronic device (3000) according to claim 10, wherein the fins (16) are exclusively formed on the second base plate main surface below areas of the first substrate main surface (10a) that are not covered by the electronic components (14); and the cooling device (200) is configured to direct the coolant jets (J) exclusively towards areas of the second base plate main surface that are located below the areas of the first substrate main surface (10a) that are covered by the electronic components (14).

14. The electronic device (1000, 2000, 3000) according to one of the claims 10 to 13, wherein the cooling device (200) comprises: a coolant inlet (240); a coolant outlet (250); a first chamber (210) connected to the coolant inlet (240) and comprising jet orifices; and a second chamber (220) positioned closer to the second base plate main surface than the first chamber (210) and comprising openings (222) facing the jet orifices of the first chamber (210); and wherein the fins (16) extend into the second chamber (220).

15. The electronic device (1000, 2000, 3000) according to claim 14, wherein the cooling device (200) further comprises a circulation chamber (260) connected to the coolant inlet (240) and the first chamber (210).

16. The electronic device (1000, 2000, 3000) according to claim 14 or 15, wherein the at least one electronic module (100) comprises at least two electronic modules (100) and the cooling device extends along the at least two electronic modules (100) and comprises at least one bypass channel (230) connecting another first chamber (210) of the cooling device and the second chamber between the at least two electronic modules (100).

17. The electronic device (1000, 2000, 3000) according to any of the claims 10 to 16, wherein the cooling device (200) is formed as a single molded piece.

18. The electronic device (1000, 2000, 3000) according to any of the claims 10 to 17, wherein the at least one electronic module (100) comprises a series of at least two electronic modules (100) and wherein the series of at least two electronic modules (100) constitute a power module.

19. Cooling device (200) for cooling at least one electronic module (100) comprising a substrate (10) having a plurality of electronic components (14) mounted thereon, wherein the cooling device (200) comprises: a coolant inlet (240); a coolant outlet (250); a first chamber (210) connected to the coolant inlet (240) and comprising jet orifices; and a second chamber (220) and comprising openings (222) facing the jet orifices of the first chamber (210).

20. The cooling device (200) according to claim 19, wherein the cooling device (200) comprises a circulation chamber (260) connected to the coolant inlet (240) and the first chamber (210).

21. The cooling device (200) according to claim 19 or 20, further comprising at least one bypass channel (230) connecting another first chamber (210) of the cooling device and the second chamber.

22. The cooling device (200) according to any of the claims 19 to 21, wherein the cooling device (200) is formed as a single molded piece.

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