electronic device

Abstract

According to a first aspect of the invention, an electronic device is proposed comprising a base plate, wherein electronic components are arranged on a first side of the base plate, and wherein a formed part with recesses is arranged on a second side of the base plate opposite the first side, wherein the formed part and the base plate are materially bonded, and the formed part is shaped such that one or more cooling channels are formed in the area of ​​the recesses of the formed part. A cooling medium, e.g., water, can be passed through the cooling channel to cool the electronic components.

Description

[0001] The invention relates to an electronic device with electronic components and an assembly method for such an electronic device. State of the art

[0002] In many electronic applications, it is necessary to cool the power electronics assembly using liquid (usually cooling water). For this purpose, heat sinks are used, which are installed in a housing, which in turn must be sealed from the environment.

[0003] Complex cast parts with welded-in plates or multi-part soldered heat sinks are often used. These often require complex machining steps to achieve the necessary precision. Disclosure of the invention

[0004] It can therefore be considered an object of the invention to simplify the cooling of electronic components of an electronic device and to replace a complex and cost-intensive heat sink in a simple manner.

[0005] According to a first aspect of the invention, an electronic device is proposed which comprises a base plate, wherein electronic components are arranged on a first side of the base plate and wherein a formed part with recesses is arranged on a second side of the base plate opposite the first side, wherein the formed part and the base plate are materially connected and the formed part is shaped such that one or more cooling channels are formed in the region of the recesses of the formed part. A cooling medium for cooling the electronic components, e.g. water, can be conducted through the cooling channel. The base plate preferably has an inlet and an outlet for the cooling medium.

[0006] In a preferred embodiment, the base plate is formed from a metal and the formed part is welded to the base plate at least in the region of the cooling channel formed by the recess or recesses.

[0007] In particular, the base plate is connected at its edges to a housing for the electronic device. The formed part can advantageously form a cover for the housing. The base plate can advantageously be welded to the housing.

[0008] This advantageously results in a small number of components while maintaining a high level of sealing. The innovative design of a combination of only the absolutely necessary parts makes a separate heat sink and the usually complex cover seal (often liquid gasket) superfluous. This construction with fewer parts results in several advantages. Parts required in previous designs can be omitted and / or made simpler (e.g. seals, heat sinks). From a thermal point of view, the construction offers the advantage that, compared to previous designs, some heat transfers can be eliminated. Direct contact with the electronic components (e.g. for connecting an electric motor) is still possible even with an external heat sink because the cover is only fitted after the base plate has been fitted, meaning that electrical contact (e.g. with the stator wires of an electric motor) can be made in between.

[0009] In a preferred embodiment, a thermally conductive medium, in particular a thermally conductive adhesive, is arranged between the first side of the base plate and the electronic components. This ensures efficient heat conduction from the electronic components through the base plate to the cooling medium. Alternatively, the electronic components can be soldered to the base plate, for example.

[0010] The formed part can preferably be designed as a deep-drawn part and, in particular, has a thinner material thickness than the base plate. This design has the advantage that cooling channels with a comparatively narrow width can be realized. If the formed part is welded to the base plate in the area of ​​the recesses, the area on which the internal pressure acts can be kept as small as possible, thus reducing the resulting force on the base plate. The elimination of seals also reduces the forces acting on the base plate. This force reduction, combined with the possibility of additional weld seams between the channels, can prevent excessive deformation of the electronic device.

[0011] A further advantage of this design is that, in addition to the cooling channels, recesses can also be formed for contact between the stator wires and the electronic components, which in turn are sealed to the cooling channels by weld seams.

[0012] In one possible embodiment, the housing can have an additional heat sink, with the cooling channel conducting the cooling medium from the electronic components to this heat sink. Known heat sink designs can be used here, such as metallic heat sinks with cooling fins. Such a heat sink can be mounted on the formed part or mounted on the housing separately from the formed part. Further possible embodiments can provide for the formed part to form the heat sink and / or for the base plate to have an exposed section onto which a heat sink is mounted or on which a heat sink is formed.

[0013] According to a second aspect of the invention, a method for assembling an electronic device according to the first aspect is proposed. The method comprises the following steps: a) Mounting the electronic components on the first side of the base plate, in particular by placing a heat-conducting medium between the base plate and the electronic components, b) Mounting the formed part on the second side of the base plate, in particular in such a way that at least one recess of the formed part forms a channel between the inlet and outlet openings of the base plate, c) welding the formed part to the base plate adjacent to the recesses so that a sealed, closed area is formed between the second side of the base plate and the formed part, which is designed as a cooling channel, d) Optional: Circumferential welding of the formed part to the base plate and / or a housing.

[0014] For example, the electronic device can be designed as part of an inverter for an electric motor and can be used in a motor vehicle. In this case in particular, it may be advantageous to provide the following intermediate steps after step a) and before step b) of the assembly process: a1) Mounting the base plate on the motor a2) Electrical contacting of the motor stator wires to electronic components. Short description of the characters

[0015] Embodiments of the invention are described in detail with reference to the accompanying figures. Fig. 1 a) shows a section through an edge region of an electronic device according to the prior art. Fig. 1 b) shows a section through an edge region of an electronic device according to a first embodiment of the invention. Fig. 2a) and b) shows an electronic device according to a second embodiment of the invention with a housing Fig. 3 shows a section through an electronic device according to a third embodiment of the invention. Fig. 4 a)-e) show different designs of the formed part according to the invention and possible combinations with a heat sink. Preferred embodiments of the invention

[0016] In the following description of the exemplary embodiments of the invention, identical elements are designated by identical reference numerals, whereby a repeated description of these elements is omitted where appropriate. The figures only schematically illustrate the subject matter of the invention.

[0017] Fig. 1 a) shows a section through an edge region of an electronic device 100 according to the prior art. A group of electronic components 5 is attached to a first side 12 of a metallic base plate 10 by means of a solder layer 15. A cover 20 is arranged on the side 14 of the base plate 10 opposite the first side 12 and is thermally connected to the base plate 10 by means of a thermally conductive material 17. A channel 25 for a cooling medium 40 is formed in the cover 20. The channel 25 is sealed from the base plate 10 by means of an insert 22. According to this embodiment, all surfaces between the channel 25 and the insert 22, as well as between the insert 22 and the base plate 10, must be sealed.

[0018] Fig. 1 b) shows a section through an edge region of an electronic device 1 according to a first exemplary embodiment of the invention. A group of electronic components 5 is attached to a first side 12 of a metallic base plate 10 by means of a thermally conductive adhesive layer 16. A formed part 30 is arranged on the side 14 of the base plate 10 opposite the first side 12. The formed part 30 has a recess 36. In the region of the recess 36, the formed part 30 is tightly welded to the base plate along a circumferential weld seam 32. The recess 36 thus forms a cooling channel 35 through which a cooling medium 40, for example water, can be passed in order to dissipate heat from the electronic components 5.

[0019] It can be seen that the electronic device 1 in comparison with the prior art according to Fig. 1 a) has a simplified structure with fewer components and a simplified and thus more reliable sealing pattern. Furthermore, the electronic device 1 has, in comparison to the prior art according to Fig. 1 a) there is less heat transfer between the electronic components 5 to be cooled and the cooling medium 40, so that more efficient heat dissipation can take place.

[0020] Fig. 2 a) and b) show an electronic device 1 according to a second embodiment of the invention with a housing 50 in a perspective view. In Fig. 2 a), the housing 50 is shown without a cover. The base plate 10 arranged in the housing 50 and the electronic components 5 arranged on the side 12 of the base plate 10 facing the interior of the housing can be seen. The base plate 10 has an inlet opening 42 and an outlet opening 44 for the inlet and outlet of a cooling medium.

[0021] In Fig. 2 b) shows the same electronic device 1, but now arranged on the outward-facing side 14 of the base plate 10 is a formed part 30, which simultaneously serves as a cover for the housing 50. The formed part 30 has a recess 36 that runs from the inlet opening 42, along the electronic components 5, to the outlet opening 44 of the base plate 10, so that a cooling medium, e.g., water, can be conducted through the space between the base plate 30 and the recess 36 of the formed part, thus forming a cooling channel. For sealing, the formed part is welded 32 all the way around, at least in the area around the recess 36.

[0022] To manufacture the electronic device 1, the electronic components 5 are simply mounted on the metallic baseplate 10 (“baseplate”), instead of on the machined heat sink as in the prior art. For example, DBCs can be soldered or glued onto a stamped aluminum plate. For bonding, thermal interface material (TIM) is preferably used directly beneath the heat sources. The baseplate 10 is also provided with two openings, which, after assembly into the housing 50, form the inlet 42 and outlet 44 of the cooling medium.

[0023] Then, the metallic formed part 30 is mounted as the housing cover, which in a particularly advantageous embodiment is manufactured as a shell-shaped structure, e.g., by deep drawing. Its recessed area 36 now forms a channel between 42 and 44. The channel is then welded circumferentially to the base plate 10, so that a tight, enclosed area is created between the carrier plate 10 and the housing cover 30 - the cooling channel. During operation, the cooling medium flows through this channel and transports the waste heat from the electronics 5 introduced via the base plate 10 to a cooler (not shown, see Fig. 4).

[0024] In the final step, the housing cover is welded all the way around to the housing edge. This seals the interior of the housing from the environment without the need for an additional gasket.

[0025] The increased structural rigidity achieved through welding is particularly advantageous. Because the internal pressure in the cooling channel only causes deformation across the relatively narrow cooling channel width, and the deformation is further reduced by the increased rigidity of the assembly, very little deformation occurs in the electronics area.

[0026] Fig. Figure 3 shows a cross-section through an electronic device 1 according to a further embodiment of the invention. The electronic device 1 has a base plate 10, on the first side 12 of which two groups of electronic components 5, 5' are arranged. The base plate 10 has two openings 17, 18, which serve to pass through contact wires 62, 63 and a lead frame 65, wherein the lead frame 65 and / or the contact wires 62, 63 are in contact with the electronic components 5, 5'. The base plate is arranged in a housing 50.

[0027] On the side 14 of the base plate 10 opposite the first side 12, a formed part 30 is arranged. The formed part 30 has a plurality of recesses 36, 37, 38. The recess 36 is arranged directly above the electronic components 5, 5' and, together with the base plate 10, forms a cooling channel 35 through which a cooling medium 40 (e.g., water) can be passed. The recesses 37, 38 serve to protect the vias or the lead frame 65 and the contact wires 62, 63.

[0028] For sealing, the formed part 30 is welded in the region of the recess 36 along a weld seam 32. Furthermore, the formed part 30 is welded at its edge to the housing 50 along a weld seam 33.

[0029] The production of the weld seams 32, 33 can be carried out in particular by means of laser welding.

[0030] In the Fig. 4 a) to e) show various embodiments or combinations and arrangements of an electronic device 1 according to the invention in a housing 50, wherein in each case a formed part 30 according to the invention and in the Fig. 4 b) to e) an additional heat sink is provided.

[0031] In the execution according to Fig. 4 a), the base plate 10 is completely covered by the formed part 30. The formed part 30 thus forms a complete cover of the housing 50. The formed part 30 forms several parallel fins 39, which can, for example, be part of the cooling channel and improve the heat dissipation of the cooling medium.

[0032] In the execution according to Fig. 4 b), the formed part 30 has a recess 31. The base plate 10 forms a plurality of cooling fins 11 on the second side 14, which protrude through the recess 31 into the open and provide additional cooling for the electronic components 5. The cooling fins 11 are formed integrally with the base plate 10.

[0033] In the execution according to Fig. 4 c), the formed part 30 has a recess 31. A separate heat sink 70 is mounted on the base plate 10 in the area of ​​the recess 31. The heat sink 70 can provide additional cooling for the electronic components 5. The heat sink 70 can be attached to the base plate 10, for example, using a thermally conductive adhesive.

[0034] In the execution according to Fig. 4 d), the base plate 10 is completely covered by the formed part 30. The formed part 30 thus forms a complete cover of the housing 50. A separate heat sink 71 is placed on the formed part 30. In this example, the heat sink 71 almost completely covers the surface of the formed part 30. The heat sink 71 can provide additional cooling for the electronic components 5 and / or promote heat dissipation of the cooling medium in a channel.

[0035] In the execution according to Fig.4 e), the formed part 30 has a recess 31. A separate heat sink 72 is mounted on the base plate 10 in the region of the recess 31. The heat sink 72 is wider than the recess 31 and also covers at least parts of the surface of the formed part 30. The heat sink 72 can thus provide additional cooling for the electronic components 5 and / or promote heat dissipation of the cooling medium in the channel 35. The heat sink 72 can be attached to the base plate 10, for example, by means of a thermally conductive adhesive.

Claims

[1] Electronic device (1) with a base plate (10), wherein electronic components (5, 5') are arranged on a first side (12) of the base plate (10) and wherein a formed part (30) with recesses (36, 37, 38) is arranged on a second side (14) of the base plate (10), wherein the formed part (30) and the base plate (10) are materially connected and the formed part (30) is shaped such that at least one cooling channel (35) is formed through at least one recess (36) of the formed part (30), through which channel a cooling medium (40) for cooling the electronic components (5, 5') can be conducted. [2] Electronic device (1) according to claim 1, characterized by that the base plate (10) has an inlet (42) and an outlet (44) for a cooling medium (40). [3] Electronic device (1) according to one of the preceding claims, characterized bythat the base plate (10) is formed from a metal and the formed part (30) is welded to the base plate (10) at least in the region of the cooling channel (35) formed by the recess (36) or recesses. [4] Electronic device (1) according to one of the preceding claims, characterized by that a thermally conductive medium (16) is arranged between the first side (12) of the base plate (10) and the electronic components (5), in particular a thermally conductive adhesive. [5] Electronic device according to one of the preceding claims, characterized by that the formed part (30) is designed as a deep-drawn part and has a lower material thickness compared to the base plate (10). [6] Electronic device (1) according to one of the preceding claims, characterized by that the formed part (30) is designed as a partial or complete cover of a housing (50) of the electronic device (1). [7] Electronic device (1) according to claim 6, characterized by that the formed part (30) is welded to the housing (50). [8] Electronic device (1) according to one of claims 6 or 7, characterized by that the electronic device (1) has an additional heat sink (11, 38, 70, 71, 72), wherein the cooling channel conducts the cooling medium from the electronic components to the heat sink and wherein the heat sink is connected in particular to the housing (50) and / or to the base plate (10). [9] A method for assembling an electronic device (1) according to any one of claims 1 to 8, comprising the following steps: a) mounting the electronic components (5, 5') on the first side (12) of the base plate (10), wherein in particular a heat-conducting medium (16) is applied between the base plate (10) and the electronic components (5, 5'), b) mounting the formed part (30) on the second side (14) of the base plate (14), in particular such that at least one recess (36) of the formed part forms a cooling channel between an inlet opening (42) and an outlet opening (44) of the base plate, c) welding the formed part (30) to the base plate adjacent to the recesses (36) so that a tight, closed area is formed between the second side (14) of the base plate (10) and the formed part (30), which is designed as a cooling channel (35). [10] Method according to claim 9, characterized by the additional step: d) Circumferential welding of the formed part (30) to the base plate and / or a housing (50). [11] Method according to one of claims 9 or 10, characterized by that after step a) and before step b), the following intermediate steps are carried out: a1) Mounting the base plate on a motor, a2) Electrical contacting of the motor stator wires to electronic components.

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