Power electronic submodule for mounting on a cooling unit

Abstract

Power electronic submodule (2) for mounting on a cooling device (3) having a first and a second surface section (300, 302) arranged side by side, with a substrate (4), with a housing (20) and with a connection element (50, 52) which is electrically connected to a contact section (510) with a conductor track (42) of the substrate (4) and has a connection section (500, 520) arranged parallel to the substrate (4), wherein the substrate (4) is provided to be arranged with a first main surface (400) on the first surface section (300), wherein the housing (20) has a housing section (200) having a first main surface (210) provided for arrangement on the second surface section (302) and a second main surface (220) opposite the first.and wherein, in the unmounted state of the submodule (2), a first main surface (502) of the connection section (500) in the housing area (204) of a fastening device (7) for mounting the housing section (200) on the second surface section (302) of the cooling device (3) has a first distance (800) from the second main surface (220) of the connection section (200), and wherein the housing section (200) has a deformation element (222, 224) in the area of ​​its second main surface (220) which interacts with the connection section (500) and defines the first distance (800).

Description

[0001] The invention describes a power electronic submodule for mounting on a cooling device, which has a first and a second surface portion arranged side by side, comprising a substrate, a housing, and a connection element that is electrically connected to a conductor track of the substrate via a contact portion and has a connection portion. The substrate is designed to be arranged with a first main surface on the first surface portion. The invention further describes a method for arranging such a submodule on a cooling device.

[0002] DE 10 2017 115 883 A1 discloses, as prior art, a submodule and an arrangement therewith, wherein the submodule comprises a switching device with a substrate and conductor tracks arranged thereon. The submodule comprises a first and a second DC voltage conductor track and, electrically connected thereto, a first and a second DC voltage connection element, as well as an AC voltage conductor track and, electrically connected thereto, an AC voltage connection element. The submodule further comprises a molded insulating body that encloses the switching device in a frame-like manner. The first DC voltage connection element rests with a first contact section on a first support body of the molded insulating body, and the AC voltage connection element rests with a second contact section on a second support body of the molded insulating body.A first clamping device is designed to extend in an electrically insulated manner through a first recess of the first support body and to form an electrically conductive clamping connection between the first DC voltage connection element and an associated first DC voltage connection element, and a second clamping device is designed to extend in an electrically insulated manner through a second recess of the second support body and to form an electrically conductive clamping connection between the AC voltage connection element and an associated AC voltage connection element.

[0003] DE 10 2018 204 473 A1 discloses a semiconductor device comprising a semiconductor component, a housing surrounding the semiconductor component, a spring terminal having a first connecting portion extending to a top side of the housing and a second connecting portion provided at the top side of the housing, and a control and / or regulating substrate provided at the second connecting portion, wherein the first connecting portion is connected to the semiconductor component, the second connecting portion has a first end connected to one end of the first connecting portion and a second end opposite to the first end, the second connecting portion is a flat plate and has an elastic force using the first end as a support point, the second end contacts the control and / or regulating substrate with an elastic force,and the second connecting portion has a constriction structure having a notch formed on a side surface along a longitudinal direction.,

[0004] JPH 09-55462 A discloses a method for reducing the manufacturing costs of a semiconductor module. A portion of an external connection element arranged in a housing is connected to a substrate on which a semiconductor chip is mounted by means of a connection board. The other portion of the external connection element protrudes from the housing and is bent at a right angle to contact the surface of the housing. An internal thread is provided in the housing, into which a screw engages, thus electrically connecting an external connection device to the external connection element.

[0005] In view of the prior art, the invention is based on the object of presenting a power electronic submodule of the above-mentioned type, wherein the thermal connection of the substrate to a cooling device in the region of the connection of a contact section of a connection element to a conductor track of the substrate is improved.

[0006] This object is achieved according to the invention by a power electronic submodule for mounting on a cooling device, which has a first and a second surface section that are arranged next to one another, with a substrate, with a housing and with a connection element that is electrically conductively connected to a conductor track of the substrate by a contact section and has a connection section that is arranged parallel to the substrate, wherein the substrate is intended to be arranged with a first main surface on the first surface section, wherein the housing has a housing section that has a first main surface that is intended to be arranged on the second surface section, and a second main surface opposite the first,and wherein, in the unassembled state of the submodule, a first main surface of the connection section in the housing region of a fastening device for mounting the housing section on the second surface section of the cooling device has a first distance from the second main surface of the connection section, and wherein the housing section has a deformation element in the region of its second main surface, which cooperates with the connection section and defines the first distance.

[0007] After mounting the power electronics submodule, in particular on a cooling device, the first main surface of the connection section rests on the second main surface of the connection section in the housing area of ​​the fastening device or is spaced from it by a distance that is less than the first distance. This exerts pressure on the contact section, improving the thermal connection of the substrate to the cooling device in the area where this contact section connects to a conductor track of the substrate. This improves cooling of this area and thus the connection element itself.

[0008] The term “parallel to the substrate” should not be understood in a mathematically precise way, but rather an angle of 10°, but at least an angle of 5°, is included between the connection section and the substrate.

[0009] For this purpose, it is advantageous if the connecting element is designed as a flat metal molded body with at least one bevel and this bevel or, better, a plurality of bevels are designed in such a way that an angle is formed between the connecting section and the substrate.

[0010] In this case, the connecting section can have a pressure element which is intended to deform the deformation element during assembly of the submodule.

[0011] For this purpose, the pressure element can protrude from the first main surface of the connecting section. This deformation element is advantageously cylindrical or frustoconical in shape. It is further advantageous if a base of the deformation element is arranged in a recess extending from the second main surface of the housing section.

[0012] In principle, the fastening device can be designed as a screw, rivet or clamp fastening device.

[0013] The above-mentioned object is further achieved according to the invention by a method for arranging a submodule on a cooling device according to one of the preceding claims with the following steps: a) providing the submodule and the cooling device with a first and a second co-planar and non-overlapping surface portion; b) applying the submodule to the cooling device, wherein the first main surface of the substrate lies on the first surface section and wherein the first main surface of the housing section of the housing of the submodule lies on the second surface section, wherein the first main surface of the connection section has a second distance from the second surface section of the cooling device; c) Attaching a fastening device; d) Formation of a clamping connection between the connecting section and the cooling device, wherein after the formation of the clamping connection the first main surface of the connecting section has a third smaller distance from the second surface section compared to the second.

[0014] As is customary in the art, a layer of a thermally conductive substance, in particular a thermally conductive paste, can be arranged between the first main surface of the substrate and the first surface section.

[0015] Preferably, in method step d), the contact section is pressed onto the substrate and the substrate is pressed onto the first surface section of the cooling device.

[0016] It may be preferred if a portion of the second main surface of the housing portion forms an abutment on which an associated sub-portion of the connection portion is supported during method step d) and thus exerts pressure on the substrate by means of the contact portion.

[0017] It is particularly advantageous if a deformation element of the housing section is deformed by a pressure element of the connecting section. In this case, it may be advantageous if the deformation element protrudes beyond the second main surface of the housing section and has a foot arranged in a recess of the second main surface of the housing section, wherein, during method step d), this foot is partially or completely deformed into this recess.

[0018] Of course, unless explicitly or per se excluded or contradicting the spirit of the invention, the features mentioned in the singular, in particular the connection element, may be present multiple times in the submodule according to the invention. Likewise, individual method steps may be present multiple times in the method according to the invention or its sequence.

[0019] It is understood that the various embodiments of the invention, regardless of whether they are disclosed in the description of the submodule or the method, can be implemented individually or in any combination to achieve improvements. In particular, the features mentioned and explained above and below can be used not only in the specified combinations, but also in other combinations or on their own, without departing from the scope of the present invention.

[0020] Further explanations of the invention, advantageous details and features, emerge from the following description of the Fig. 1 to 9 schematically illustrated embodiments of the invention, or of respective parts thereof. Fig. 1 shows, partially in exploded view, a first embodiment of a power electronic submodule according to the invention in the unassembled state as well as a cooling device. Fig. 2 shows an excerpt from Fig. 1. Fig. 3 partially shows the first embodiment of the power electronic submodule according to the invention mounted on a cooling device. Fig. 4 shows a section of Fig. 3. Fig. 5 partially shows a second embodiment of a power electronic submodule according to the invention mounted on a cooling device. Fig. 6 shows a section of Fig. 5. Fig. 7 shows, to explain the invention, partially a further embodiment of a power electronic submodule mounted on a cooling device. Fig. Figure 8 shows a three-dimensional view of part of a submodule. Fig. 9 shows a three-dimensional view of three submodules according to the invention mounted on a cooling device.

[0021] Fig. 1 shows, partially in exploded view, a first embodiment of a power electronic submodule 2 according to the invention in the unassembled state and a cooling device 3, here designed as a liquid cooling device. Fig. Figure 2 shows a section of this illustration. A substrate 4 of the submodule 2 is arranged on a first surface section 300 of this cooling device 3. This substrate 4 is designed in a conventional manner with an insulating body 40 and conductor tracks 42 arranged thereon. A power semiconductor component 44 is arranged on one of these conductor tracks 42 and is connected in a circuit-compatible manner by means of an internal connecting device 46. This connecting device 46 is also designed as a conventional foil composite.

[0022] On a second surface section 302 of the cooling device 3 arranged next to the first, there is a housing section 200 of a housing 20 not shown here, cf. for example Fig. 8. The housing 20 as such can enclose the entire submodule 200, but can also be designed as a partial housing or even in multiple parts.

[0023] The housing section 200 has a first main surface 210 arranged on the second surface section 302, as well as a second main surface 220 opposite the first and oriented parallel thereto. Furthermore, the housing section 200 has a recess 202 extending from the second to the first main surface for arranging a fastening device 7, or a part thereof.

[0024] A connection element 50, more precisely here a first DC load connection element, which is designed as a flat metal molded body, has a contact section 510, which is electrically conductively connected to a conductor track 42 of the substrate 4, and a connection section 500. The connection section 500 has a recess 504 aligned with the recess 202 of the housing section 200. A part of a fastening device 7 is arranged in this recess 504 during assembly. A second DC load connection element 52 is arranged here parallel to the first DC load connection element. The two DC load connection elements 50, 52 together form the electrical connection to a capacitor 6, see. Fig. 9, whose connection elements 60, 62 are also shown here. By means of the fastening device 7, the DC load connection elements 50, 52 are connected to these capacitor connection elements 60, 62 in a circuit-correct manner.

[0025] This fastening device 7 is designed as a screw 70 that engages in a threaded recess 76 of the cooling device 3. For electrical insulation, an insulating body 74 is also provided for placement in the recesses, if necessary. Furthermore, a spring element 72, in this case a disc spring, is provided for permanent and constant pressure application.

[0026] According to the invention, in the unassembled state of the submodule 2, a first main surface 502 of the connection section 500, facing the cooling device 3 and the housing section 200, in the housing region 204 of the fastening device 7 has a first distance 800 from the second main surface 220 of the connection section 200. The housing region 204 of the fastening device 7 is defined by the recess 202 of the housing section 200 and its immediate surroundings.

[0027] For the arrangement of the submodule 2 on the cooling device 3, a second distance 810 results between the first main surface 502 of the connection section 500 of the connection element 50 in that housing area 204 which is assigned to the fastening device 7.

[0028] In order to reliably form this first distance 800, or also the second distance 810, the housing section 200 has a deformation element 222 in the area, here starting from its second main surface 220, which interacts with the connection section 500. This deformation element 222 has a substantially cylindrical shape, with the base of the deformation element 222 being arranged in a recess 226 in the second main surface 220 of the housing section 200. This creates an angle, exaggerated here for reasons of clarity, between the plane of the substrate 4, precisely its first main surface 400, and that of the first main surface 502 of the connection section 500 of the connection element 50.

[0029] Fig. 3 partially shows the first embodiment of a power electronic submodule 2 according to the invention mounted on a cooling device 3. Fig. Figure 4 shows a section of this. Here, the result of the process for arranging submodule 2 on a cooling device 3 is shown.

[0030] By screwing the screw 70 of the fastening device 7 into the thread of the recess 76 of the cooling device 3, a portion of the connecting portion 500 deforms the deformation element 222 such that it is almost completely deformed into the recess of the housing portion. As a result, the distance between the first main surface 502 of the connecting portion 500 and the second main surface of the housing portion 20 in the housing region 204 of the fastening device 7 is significantly reduced compared to the first distance 800.

[0031] Advantageously, the connection element 500 rests with its first main surface 502 on the second main surface 220 of the housing section 200, whereby the distance between the two becomes zero within the scope of technical feasibility.

[0032] The second distance 810 of the unassembled assembly is also reduced, resulting in a third distance 812 that is less than the second.

[0033] Fig. 5 partially shows a second embodiment of a power electronic submodule 2 according to the invention mounted on a cooling device 3. Fig. 6 shows a section of this. In this embodiment, the fastening device 7 is basically similar to that according to the Fig. 1 and Fig. 3, however, the abutment of the screw here is a screw nut 78, which is not part of the cooling device.

[0034] Another difference to the arrangements under the Fig. 1 and Fig. 3 relates to the deformation element 224, which here is designed as a web, arranged in a recess of the housing section 200 and parallel to its second main surface 220. The connection section 500 here has a pronounced pressure element 524, which is intended to deform the deformation element 224 during assembly of the submodule 2, as shown here.

[0035] In addition, another part of the housing 20 is shown here. All other components correspond to those of the Fig. 1 to 4.

[0036] Fig. To explain the invention, Figure 7 partially shows a further embodiment of a power electronics submodule 2 mounted on a cooling device 3. Shown are again a cooling device 3 and a substrate 4 as already described above. However, the connection element 500 here has a contact section 510, which has a subsection parallel to the substrate 4, precisely its first main surface 400. The entire connection element 5 here has two bevels, through which the connection section 500 has an oblique course in the direction of the cooling device 3. This oblique course is not supported by any deformation element. The end of the connection section 500 is additionally located in a recess in the housing section 200, starting from its second main surface 220.

[0037] During assembly, the screw 70, as described above, is screwed into the thread of the recess 76 of the cooling device 3. Due to the force occurring in the housing area 204 of the fastening device 7, the connection section 500 is pressed toward the second main surface 220 of the housing section 200 and thus also toward the cooling device 3. At the same time, pressure is exerted on the connecting section 510 of the connection element 50, pressing it onto the substrate 4, which then presses it onto the cooling device 3. This provides excellent heat transfer, which cools the entire connection element 5 during operation.

[0038] Fig. Figure 8 shows a three-dimensional view of part of a submodule 2, with the details described above being illustrated again for illustrative purposes. The housing 20 here comprises a plurality of sub-housings that are not directly connected to one another.

[0039] Fig.Figure 9 shows a three-dimensional sectional view of three submodules 2 according to the invention mounted on a cooling device 3. A capacitor 6 is also shown here. Within the scope of the method according to the invention, the connection elements 60, 62 of the capacitor 6 were also connected in a circuit-correct manner to the connection elements 50, 52 of the submodules 2.

Claims

[1] Power electronic submodule (2) for mounting on a cooling device (3), which has a first and a second surface section (300, 302) arranged next to one another, with a substrate (4), with a housing (20) and with a connection element (50, 52) which is electrically conductively connected to a conductor track (42) of the substrate (4) by a contact section (510) and has a connection section (500, 520) arranged parallel to the substrate (4), wherein the substrate (4) is intended to be arranged with a first main surface (400) on the first surface section (300), wherein the housing (20) has a housing section (200) which has a first main surface (210) which is intended to be arranged on the second surface section (302), and a second main surface (220) opposite the first,and wherein, in the unassembled state of the submodule (2), a first main surface (502) of the connecting section (500) in the housing region (204) of a fastening device (7) for mounting the housing section (200) on the second surface section (302) of the cooling device (3) has a first distance (800) from the second main surface (220) of the connecting section (200), and wherein the housing section (200) has a deformation element (222, 224) in the region of its second main surface (220), which cooperates with the connecting section (500) and defines the first distance (800). [2] Submodule according to claim 1, wherein the connecting element (50, 52) is designed as a flat metal shaped body with at least one bevel. [3] Submodule according to claim 1 or 2, wherein the connecting portion (500) comprises a pressure element (524) which is intended to deform the deformation element (224) during assembly of the submodule. [4] Submodule according to claim 3, wherein the pressure element (524) protrudes from the first main surface (502) of the connecting portion (500). [5] Submodule according to claim 1, wherein the deformation element (222) is cylindrical or frustoconical in shape. [6] Submodule according to claim 5, wherein a foot of the deformation element (222) is arranged in a recess (226) starting from the second main surface (220) of the housing section (200). [7] Submodule according to one of the preceding claims, wherein the fastening device (7) is designed as a screw, rivet or clamp fastening device. [8] Method for arranging a submodule (2) on a cooling device (3) according to one of the preceding claims, comprising the following steps: a) providing the submodule (2) and the cooling device (3) with a first and a second surface section (300,302) lying in one plane and not overlapping; b) applying the submodule (2) to the cooling device (3), wherein the first main surface (400) of the substrate (4) comes to lie on the first surface section (300) and wherein the first main surface (210) of the housing section (200) of the housing (20) of the submodule (2) comes to lie on the second surface section (302), wherein the first main surface (502) of the connection section (500) has a second distance (810) from the second surface section (302) of the cooling device (3); c) attaching a fastening device (7); d) forming a clamping connection between the connecting section (500) and the cooling device (3), wherein after the formation of the clamping connection, the first main surface (502) of the connecting section (500) has a third smaller distance (812) from the second surface section (302) compared to the second. [9] Method according to claim 8, wherein in the course of method step d) the contact section (510) is pressed onto the substrate (4) and this is pressed onto the first surface section (300) of the cooling device (3). [10] Method according to claim 8 or 9, wherein a portion of the second main surface (220) of the housing portion (200) forms an abutment on which an associated sub-portion of the connection portion (500) is supported during method step d) and thus exerts pressure on the substrate (4) by means of the contact portion (510). [11] Method according to one of claims 8 to 10, wherein the deformation element (222,224) of the housing portion (200) is deformed by the pressure element (524) of the connection portion (500). [12] Method according to one of claims 8 to 10, wherein the deformation element (222) projects beyond the second main surface of the housing section and has a foot which is arranged in a recess (226) of the second main surface (220) of the housing section (200), wherein during method step d) this foot is partially or completely deformed into this recess (226).

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