Liquid-cooled power electronic device

Abstract

A liquid-cooled power electronic device, which has a reduced mass and / or a reduced package size compared to a conventional module using die-cast materials, secondary machining, and / or welding operations. The power electronic module includes a housing, separate cooling channels positioned within the housing and having opposing cooling surfaces, and first and second printed circuit board assemblies disposed on opposite sides of the cooling channels.

Description

[0001] Cross - reference to related applications

[0002] This application claims the priority of Provisional Application No. 62 / 930,641, filed on November 5, 2019, the entire content of which is incorporated herein by reference. Technical field

[0003] The present disclosure relates to power electronic modules, and in particular to power electronic modules having integral cooling channels. Background art

[0004] Conventional power electronic modules typically use heavy and expensive liquid cooling channels, which are typically machined into one side of the main housing of the module and are sealed by welding to prevent leakage of the cooling fluid. Since the cooling channels are machined into one side of the housing, a single printed circuit board interfaces with the cooling surfaces of the cooling channels. As a result, a single large printed circuit board and large cooling channels are used in conventional power electronic modules, and the module has a large package size due to the inability to stack the printed circuit boards. Summary of the invention

[0005] Compared with conventional modules that employ die - cast materials, secondary machining operations, and / or welding operations, the disclosed power electronic module can have a reduced mass. Since the disclosed power electronic module is capable of positioning printed circuit boards on opposite sides of discrete cooling channels incorporated into the module, the disclosed power electronic module can have a reduced package size compared to conventional modules.

[0006] The disclosed power electronic module includes a housing, separate cooling channels positioned within the housing, the cooling channels having fluid inlets and outlets for coolant flow, and a first printed circuit board assembly and a second printed circuit board assembly, which are positioned on opposite sides of the separate cooling channels within the housing and are in thermal contact with opposite heat - absorbing surfaces of the separate cooling channels.

[0007] In certain aspects of the present disclosure, the housing has a partition defining a cutout portion, and the separate cooling channels are positioned within the cutout portion, wherein the partition includes an integral connector that facilitates attachment of the cooling channels to the housing via a retaining bracket.

[0008] In certain aspects of the present disclosure, the housing includes a core housing that is an injection - molded thermoplastic port, and the housing further includes an outer housing and a cover that together enclose the core housing, the printed circuit board assemblies, and the separate cooling channels. The outer housing and the cover can be made of stamped sheet metal (such as steel).

[0009] These and other advantages will be more fully understood in view of the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is an exploded perspective view showing the relationship of the components of the disclosed power electronics module.

[0011] Figure 2 is an exploded perspective view showing the parts of a separate cooling channel and how it is assembled to Figure 1 the core housing of the module.

[0012] Figure 3 is Figure 1 a cross-sectional perspective view of the device in the assembled state in

[0013] Figure 4 is Figures 1 to 3 a top perspective view of the partially assembled device in

[0014] Figure 5 showing the retaining bracket for securing the cooling channel to the core housing. Figures 1 to 4 is an exploded perspective view of the device in

[0015] DETAILED DESCRIPTION Figures 1 to 5 A liquid-cooled power electronics device 10 is shown in Figure 1 is an exploded view showing the relationship of the various components of the device 10. The device 10 includes a core or intermediate housing 12 that is configured to receive and hold a separate cooling channel 14 that has a downward-facing heat-absorbing surface 16 and an opposite upward-facing heat-absorbing surface 18 ( Figure 2 ), and these heat-absorbing surfaces are thermally interfaced with a first printed circuit board assembly 20 and a second printed circuit board assembly, respectively, to allow heat to be absorbed and carried away by a coolant fluid circulating through the separate cooling channel 14.

[0016] The separate cooling channel 14 is manufactured separately from the core housing 12, and the separate cooling channel 14 is fixed to the core housing after fabrication rather than being machined or formed as an integral part of the core housing. This allows the core housing 12 and the cooling channel 14 to be made of different lightweight materials to reduce the mass of the device, and allows the opposite surfaces 16, 18 of the cooling channel 14 to interface with two separate first printed circuit board assemblies 20 and second printed circuit board assemblies arranged on opposite sides of the cooling channel (i.e., in a stacked arrangement), whereby a more compact device can be produced.

[0017] Smaller electronic components (e.g., component 25) can be surface-mounted to the printed circuit board and fully supported by the printed circuit board. The attachment of larger or taller electronic components (e.g., inductor 26 and tall capacitor 28) can be strengthened by brackets 30, 32, which can be fixed to the core housing 12.

[0018] Leaf springs 34, 36, 38, and 40 can be fixed to the core housing 12 to force the first printed circuit board assembly 20 and the second printed circuit board assembly into thermal contact with the external heat-absorbing surfaces 16, 18 of the cooling channels 14.

[0019] As Figure 3 shown in the cross-sectional view, the core housing 12 includes a generally flat partition 42 that extends from the sidewall 44 of the core housing 12 toward the opposite sidewall at approximately half the height between the upper edge 48 and the lower edge 50 of the sidewall. The partition 42 includes a cutout 54 in which the individual cooling channels 14 are positioned.

[0020] As indicated by reference numeral 56, the partition 42 of the core housing 12 includes a plurality of connectors for securing the cooling channels 14 in the cutout 54 by means of a retaining bracket 58 (as Figure 4 shown). Additional connectors 60 can be provided for securing the first printed circuit board assembly 20, the second printed circuit board assembly, the leaf springs 34, 36, 38, and 40, and the electronic component brackets 30, 32 to the core housing 12. The connectors can be integrally formed with the core housing during an injection molding process. Alternatively, the connectors and the core housing can be formed separately or together using die casting or sheet metal stamping processes.

[0021] To enhance the thermal contact between the heating and / or heat-generating components of the device 10, a thermal interface material 62 is provided between the first printed circuit board assembly 20 and the second printed circuit board assembly and the associated heat-absorbing surfaces 16, 18 of the individual cooling channels 14, and the thermal interface material 62 contacts both the first printed circuit board assembly 20, the second printed circuit board assembly, and the associated heat-absorbing surfaces 16, 18 of the individual cooling channels 14. The thermal interface material 62 can be in the form of a heat-conducting tape, pad, sheet, or paste, all of which are commercially available and commonly used to enhance heat transfer by conduction between surfaces. Suitable thermal interface materials include thermally conductive rubber materials used in the form of sheets, strips, or tapes.

[0022] As Figure 5 shown, the core housing 12 is mounted in an outer housing 64 having sidewalls 66, 67, 68, and 69 and a bottom or base wall 70. A cover 72 can be attached (e.g., with screws) to the outer housing 64 such that the core housing 12 and the various components mounted on the core housing are enclosed within the covered outer housing to provide an enclosed assembly 80.

[0023] As Figure 4 and Figure 5 shown, the inlet and outlet ports of the cooling passage 14 project or extend from the housing through slotted cutouts 83, 84 in the outer housing 64, which cutouts are closed with grommets 86, 87.

[0024] The foregoing description is intended to be illustrative and not restrictive. The scope of the invention should be determined with reference to the appended claims and the full scope of equivalents thereof. Future developments are expected and intended in the art, and the disclosed apparatus, kits and methods will be incorporated into these future embodiments. Accordingly, the invention is capable of modification and variation and is limited only by the appended claims.

Claims

1. A liquid-cooled power electronic device, the liquid-cooled power electronic device comprises: a housing; a separate cooling channel disposed in the housing, the separate cooling channel having a fluid coolant inlet and outlet passing through the wall of the housing; a first printed circuit board assembly having a first circuit board that defines conductive paths connecting electronic components mounted on the first circuit board, the first printed circuit board assembly being thermally coupled to a first heat-absorbing surface on one side of the separate cooling channel; and a second printed circuit board assembly having a second circuit board that defines conductive paths connecting electronic components mounted on the second circuit board, the second printed circuit board assembly being thermally coupled to a second heat-absorbing surface on a second side of the separate cooling channel; wherein the housing has: a substantially flat partition portion having a plurality of integrally formed connectors to facilitate the attachment of: at least one cooling channel retaining bracket; the first printed circuit board assembly and the second printed circuit board assembly; an electronic component bracket for holding electronic components not mounted on the first printed circuit board assembly and the second printed circuit board assembly; and a leaf spring assembly for forcing the first printed circuit board assembly and the second printed circuit board assembly into thermal contact with the first heat-absorbing surface and the second heat-absorbing surface of the separate cooling channel, wherein the housing includes: a core housing to which the separate cooling channel and the first printed circuit board assembly and the second printed circuit board assembly are attached; and an outer housing and a cover that together define an enclosure for the core housing, the separate cooling channel, the first printed circuit board assembly, and the second printed circuit board assembly.

2. The liquid-cooled power electronic device according to claim 1, wherein, a thermal interface material is disposed between the first printed circuit board assembly and the second printed circuit board assembly and the associated first heat-absorbing surface and second heat-absorbing surface of the separate cooling channel, and the thermal interface material is in contact with both the first printed circuit board assembly and the second printed circuit board assembly and the associated first heat-absorbing surface and second heat-absorbing surface of the separate cooling channel.

3. The liquid-cooled power electronic device according to claim 2, wherein, the thermal interface material is a thermally conductive tape, pad, sheet, or paste.

4. The liquid-cooled power electronic device according to claim 1, wherein, the separate cooling channel is made of aluminum or copper.

5. The liquid-cooled power electronic device according to claim 1, further comprising a cooling channel retaining bracket that secures the separate cooling channel to the substantially flat partition portion.

6. The liquid-cooled power electronic device according to claim 1, wherein, The first printed circuit board assembly and the second printed circuit board assembly are fixed to the core housing by the integrally formed connecting members.

7. The liquid-cooled power electronic device according to claim 1, wherein, the leaf spring assembly is fixed to the housing by the integrally formed connecting members, and the leaf spring assembly forces the first printed circuit board assembly and the second printed circuit board assembly into thermal contact with the first heat-absorbing surface and the second heat-absorbing surface of the separate cooling channels.

8. The liquid-cooled power electronic device according to claim 1, wherein, the substantially flat partition portion includes a cutout portion, and the separate cooling channels are positioned in the cutout portion.

9. The liquid-cooled power electronic device according to claim 1, wherein, the core housing is made of a thermoplastic material.

10. The liquid-cooled power electronic device according to claim 1, wherein, the outer housing and the cover are made of stamped metal.

11. The liquid-cooled power electronic device according to claim 1, wherein, the liquid-cooled power electronic device is an on-vehicle charger for an electric vehicle.

12. The liquid-cooled power electronic device according to claim 1, wherein, the liquid-cooled power electronic device is an electronic control unit for an advanced driver assistance system.

13. A liquid-cooled power electronic device, the liquid-cooled power electronic device comprising: a core housing having side walls; a substantially flat partition portion that at least partially extends between the side walls to define a first chamber and a second chamber within the core housing, the partition portion having a cutout portion; separate cooling channels having a fluid inlet, a fluid outlet, and a fluid passage therebetween for circulating coolant through the liquid-cooled power electronic device; the separate cooling channels are disposed in the cutout portion and have an external heat-absorbing surface for absorbing heat, the external heat-absorbing surface including heat-absorbing surfaces disposed in respective ones of the first chamber and the second chamber; a first printed circuit board assembly having a plurality of electronic components mounted on the first printed circuit board assembly and electrically connected by conduction paths, the first printed circuit board assembly being thermally coupled to the heat-absorbing surface disposed in the first chamber; and a second printed circuit board assembly having a plurality of electronic components mounted on the second printed circuit board assembly and electrically connected by conduction paths, the second printed circuit board assembly being thermally coupled to the heat-absorbing surface disposed in the second chamber; wherein the partition portion has a plurality of integrally formed connecting members to facilitate attachment of: at least one cooling channel retaining bracket; the first printed circuit board assembly and the second printed circuit board assembly; an electronic component holder for holding electronic components not mounted on the first and second printed circuit board assemblies; and a leaf spring assembly for forcing the first and second printed circuit board assemblies into thermal contact with the heat absorbing surface of the separate cooling channel.

14. The liquid-cooled power electronic device according to claim 13, wherein, the separate cooling channel is made of aluminum or copper, the core housing is made of a thermoplastic material, and the liquid-cooled power electronic device further includes an outer housing and a cover that together enclose the core housing, the separate cooling channel, the first printed circuit board assembly, and the second printed circuit board assembly.

15. The liquid-cooled power electronic device according to claim 14, wherein, a thermal interface material is provided between the first and second printed circuit board assemblies and the associated heat absorbing surface of the separate cooling channel, and the thermal interface material contacts both the first and second printed circuit board assemblies and the associated heat absorbing surface of the separate cooling channel.

16. The liquid-cooled power electronic device according to claim 15, wherein, the generally flat partition portion has a plurality of integral connectors that connect the first printed circuit board assembly, the second printed circuit board assembly, and the separate cooling channel to the core housing.

17. The liquid-cooled power electronic device according to claim 14, wherein, the outer housing and the cover include a stamped sheet metal material.

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