Cooler for cooling power semiconductors

Abstract

The invention relates to a cooler for cooling power semiconductors by means of a cooling fluid, comprising a cover plate, which can be provided on a power semiconductor; a channel plate, which is designed to form, together with the cover plate, a closed cooling channel for the cooling fluid; an insert, which is provided in the cooling channel, said insert being designed to increase the contact surface between the cooling fluid and the cooler; and a stiffening plate, which lies opposite the cover plate on a connection surface on the channel plate, said stiffening plate having a specified thickness which is designed to adapt the stiffness of the cooler in order to allow a constant stiffness for different cooling channel geometries.

Description

[0001] Description

[0002] title

[0003] Cooler for from

[0004] State of the art

[0005] The present invention relates to a cooler for cooling power semiconductors by means of a cooling fluid and to a vehicle with a power electronics module with the cooler according to the invention.

[0006] Power semiconductors in power electronics carry high electrical currents. Together with switching losses, the resulting conduction losses cause significant heat dissipation, which must be dissipated from a small area using a cooling system to prevent the component from overheating. Different cooler designs are sometimes necessary to meet varying pressure drop and power requirements. With a modular cooler design, its properties can be adjusted primarily through the shape of the cooling channel and any inserts placed within it. Changes in the height of the cooling channel or the insert can significantly affect the cooler's flexural stiffness and, consequently, the mechanical strength of the power module.

[0007] It would be desirable to have a cooler that can maintain a similar flexural stiffness for different performance variants.

[0008] Disclosure of the invention

[0009] The cooler according to the invention for cooling power semiconductors, comprising the features of claim 1, has the advantage that the bending stiffness of the cooler can be easily and flexibly adjusted. This is achieved according to the invention by the cooler comprising a cover plate and a channel plate. The cover plate can be arranged on a power semiconductor. The channel plate is configured to form a closed cooling channel for the cooling fluid together with the cover plate. Furthermore, the cooler comprises an insert element arranged in the cooling channel. The insert element is configured to increase the contact area between the cooling fluid and the cooler. In addition, the cooler comprises a stiffening plate arranged opposite the cover plate at a connecting surface on the channel plate.The stiffening plate has a predetermined thickness, designed to adjust the cooler's stiffness to ensure consistent stiffness across different cooling channel geometries. This allows for simple and cost-effective adaptation of the cooler's stiffness to the specific cooling channel geometry, guaranteeing consistent stiffness. Cooler stiffness refers specifically to its bending stiffness along the fluid flow direction within the cooling channel. The channel plate preferably fits flush with the channel sheet along the interface.

[0010] The dependent claims describe preferred embodiments of the invention.

[0011] Preferably, the connecting surface is arranged parallel to the cover plate. This allows the stiffness of the cooler to be easily adjusted to the height of the cooling channel or the insert perpendicular to the cover plate.

[0012] The cover plate preferably has a thickness of 0.5 mm or less. This thin wall thickness allows heat to be efficiently dissipated from the power semiconductors on the cover plate via the cooling channel.

[0013] A flat cover plate is preferred, while the channel plate has at least one bend to form the cooling channel. This allows for simple and cost-effective manufacturing of the cooler, and power semiconductors can be reliably arranged on the flat cover plate.

[0014] The sheet thickness of the channel plate is preferably greater than that of the cover plate. The thinner cover plate allows heat to be efficiently transferred from the power semiconductor to the cooling channel, while the greater thickness of the channel plate improves the cooler's rigidity.

[0015] It is further preferred that the sheet thickness of the channel plate be less than or equal to the thickness of the stiffening plate. Thus, the stiffening plate has a significant influence on the overall stiffness of the cooler, allowing the overall stiffness to be reliably adjusted by changing the thickness of the stiffening plate.

[0016] Preferably, the height of the cooling channel is 30% to 110% of the sum of the thickness of the stiffening plate and the thickness of the channel sheet.

[0017] Preferably, the height of the cooling channel is 60% to 105% of the stated sum, particularly preferably 100%. This ensures sufficient rigidity of the cooler while maintaining reliable cooling.

[0018] The cooler preferably comprises several stiffening plates arranged parallel to each other, one above the other. This allows the cooler's stiffness to be reliably adapted to the specific requirements.

[0019] Preferably, the stiffening plate incorporates a profile structure and / or a recess. The profile structure allows for efficient adjustment of the cooler's stiffness to the required specifications while minimizing material usage. A recess can additionally accommodate excess solder from the interface between the stiffening plate and the channel sheet, preventing it from oozing out laterally between the stiffening plate and the channel sheet.

[0020] The maximum cooler height, measured perpendicular to the cover plate, is preferably between 7.5 mm and 9.5 mm. This cooler height allows for reliable cooling of the power semiconductor in a small installation space.

[0021] The height of the insert preferably corresponds to the height of the cooling channel. Thus, the insert extends from the cover plate to the channel plate, which can improve the rigidity of the cooler. In particular, the insert is bonded to the cover plate and / or channel plate. More preferably, the width of the insert corresponds to the width of the cooling channel, so that the insert utilizes the entire cross-section of the cooling channel, which can improve heat transfer to the cooling fluid.

[0022] Preferably, the thickness of the stiffening plate is adapted to the height of the insert and the thickness of the channel sheet, such that the sum of the stiffening plate thickness, the thickness of the channel sheet, and the height of the insert corresponds to a defined constant. This constant is, in particular, 8 mm. The constant ratio of the sum of the plate thickness, the thickness of the sheet, and the height of the insert ensures that the stiffness of the cooler remains constant for different cooling channel geometries.

[0023] Furthermore, the invention relates to a vehicle comprising a power electronics module with a power semiconductor and a previously described cooler. The defined rigidity of the cooler ensures reliable operation of the power electronics module and the vehicle. The cover plate, the channel plate, and the insert are preferably bonded together by means of a hard solder layer. The insert preferably has surface-enhancing, flow-guiding, and / or heat-transfer-enhancing properties. The insert is preferably a bent sheet metal part made of aluminum or another material with high thermal conductivity.

[0024] Brief description of the drawings

[0025] Exemplary embodiments of the invention are described in detail below with reference to the accompanying drawings. The drawing shows:

[0026] Figure 1 is a schematic sectional view of a

[0027] Power electronics module with a power semiconductor and a cooler according to a first embodiment,

[0028] Figure 2 is a schematic sectional view of a

[0029] Power electronics module with a power semiconductor and a cooler according to a second embodiment and Figure 3 a vehicle with the cooler according to the second embodiment of the invention.

[0030] Embodiments of the invention

[0031] Preferably, all identical components, elements and / or units in all figures are provided with the same reference numerals.

[0032] The following section describes in detail a cooler 1 for cooling power semiconductors 2 and a vehicle 100 with the cooler 1, with reference to Figures 1 to 3.

[0033] Figure 1 shows a power electronics module 3 comprising a power semiconductor 2 and the cooler 1. The power semiconductor 2 is directly applied to the cooler 1 by means of a compound layer 19.

[0034] The cooler 1 comprises a cover plate 11 and a channel plate 12. The cover plate 11 is flat and adjacent to the power semiconductor 2. The channel plate 12 has four bends 17 to form a cooling channel 13. The bends 17 run along a bending axis that is parallel to the flow direction of a cooling fluid in the cooling channel 13. The cover plate 11 is connected to the channel plate 12 by means of a hard solder layer 18, so that the cooling channel 13 is closed on its circumference.

[0035] An insert 14 is arranged in the cooling channel 13 and is connected to the cover plate 11 and the channel plate 12 by means of the brazing alloy layer 18. The height h6 of the cooling channel 13 corresponds to the height h5 of the insert 14. The insert 14 also extends along the width of the cooling channel 13, so that the insert 14 can act along the entire cross-section of the cooling channel.

[0036] The insert 14 is a sheet metal bent component with alternating bends, forming a meandering cross-section. This increases the contact area between the cooling fluid and the cooler 1. Furthermore, the insert 14 can precisely control the flow of the cooling fluid to improve the cooling performance of the cooler 1. The cooler 1 also features a stiffening plate 15, which is located opposite the cover plate 11 at a connecting surface 16 on the channel plate 12. The connecting surface 16 is flat and parallel to the cover plate 11. Thus, the stiffening plate 15 can precisely influence the stiffness of the cooler 1 to ensure consistent stiffness across different cooling channel geometries.

[0037] In the first embodiment, the thickness h1 of the stiffening plate 15 is greater than the thickness h3 of the channel plate 12. Furthermore, the thickness h2 of the cover plate 11 is less than the thickness h3 of the channel plate 12. The thinner thickness h2 of the cover plate 11 allows heat to be efficiently transferred from the power semiconductor 2 to the cooling channel 13, where it is then dissipated by the cooling fluid. The slightly thicker thickness h3 of the channel plate 12 provides improved structural rigidity to the cooler 1.

[0038] The thickness h1 of the stiffening plate 15, which is greater than the thickness h2 and h3 of the cover plate 11 and the channel plate 12, contributes significantly to the overall stiffness of the cooler 1. By adjusting the thickness h1 of the stiffening plate 15, the overall stiffness of the cooler 1 can therefore be easily adapted to different cooling channel geometries.

[0039] The sum of the thickness h1 of the stiffening plate 15, the thickness h3 of the channel plate 12, and the height h5 of the insert 14 preferably corresponds to a defined constant. For example, if the height h5 of the insert 14 is reduced to adjust the cooling capacity of the cooler 1, the thickness h1 of the stiffening plate 15 is preferably increased by the same amount as the height h5 of the insert 14 is reduced.

[0040] The sum of the thickness h1 of the stiffening plate 15, the thickness h3 of the channel plate 12, and the height h5 of the insert 14 is preferably a constant 8 mm, although this value may exhibit tolerance-related variations. The thickness h2 of the cover plate 11 is preferably 0.5 mm. The sum of the thickness h3 of the channel plate 12 and the thickness h1 of the stiffening plate 15 can vary by ±1 mm. Thus, the maximum cooler height h4, as the sum of all layers of the cooler 1 measured perpendicular to the cover plate 11, is between 7.5 mm and 9.5 mm. Figure 2 shows the power electronics module 3 with the power semiconductor 2 and the cooler 1 according to a second embodiment. The second embodiment differs from the first embodiment in particular in that the cooler 1 in the second embodiment has two stiffening plates 15, which are arranged parallel and adjacent to each other.The thickness h1 and width of the two stiffening plates 15 are the same. The additional stiffening plate 15 increases the stiffness of the cooler 1.

[0041] The two stiffening plates 15 are joined together by means of a brazing layer 18. Furthermore, the stiffening plate 15 is mounted on the channel sheet 12 by means of the brazing layer 18. The width of the stiffening plates 15 corresponds essentially to the width of the insert 14.

[0042] Figure 3 shows the vehicle 100 with the power electronics module 3. The power electronics module 3 comprises the power semiconductor 2 and the cooler 1.

[0043] By providing the cooler 1, which can be adapted independently of the design of the cooling channel 13 in order to have a constant stiffness, it can be ensured that the cooler 1 and the power electronics module 3 have the required structural stiffness to be able to withstand the loads in the operation of the vehicle 100 permanently.

Claims

Claims 1. Cooler for cooling power semiconductors (2) by means of a cooling fluid, comprising - a cover plate (11) which can be arranged on a power semiconductor (2), - a channel plate (12) which is designed to form a closed cooling channel (13) for the cooling fluid together with the cover plate (11), - an insert (14) which is arranged in the cooling channel (13), wherein the insert (14) is configured to increase the contact area between the cooling fluid and the cooler (1), - a stiffening plate (15) which is arranged opposite the cover plate (11) on a connecting surface (16) on the channel plate (12), - wherein the stiffening plate (15) has a predetermined plate thickness (h1), wherein the predetermined plate thickness (h1) is configured to adjust the stiffness of the cooler (1) to allow for consistent stiffness across different cooling channel geometries.

2. Cooler according to claim 1, wherein the connecting surface (16) is arranged parallel to the cover plate (11).

3. Cooler according to one of the preceding claims, wherein the cover plate (h2) has a sheet thickness (h2) less than or equal to 0.5 mm.

4. Cooler according to one of the preceding claims, wherein the sheet thickness (h3) of the channel sheet (12) is greater than the sheet thickness (h2) of the cover sheet (11).

5. Cooler according to one of the preceding claims, wherein the sheet thickness (h3) of the channel sheet (12) is less than or equal to the plate thickness (h1) of the stiffening plate (15).

6. Cooler according to one of the preceding claims, wherein the height (h6) of the cooling channel (13) is 30% to 110% of the sum of the plate thickness (h1) of the stiffening plate (15) and the sheet thickness (h3) of the channel sheet (12), preferably 60% to 105%, particularly preferably 100%.

7. Cooler according to one of the preceding claims, wherein the cooler (1) comprises several stiffening plates (15) which are arranged parallel to one another and adjacent to each other.

8. Cooler according to one of the preceding claims, wherein the stiffening plate (15) comprises a profile structure and / or a recess.

9. Cooler according to one of the preceding claims, wherein a maximum cooler height (h4), measured perpendicular to the cover plate (11), is between 7.5 mm and 9.5 mm.

10. Cooler according to claim 9, wherein the plate thickness (h1) of the stiffening plate (15) is adapted to the height (h5) of the insert (14) and the sheet thickness (h3) of the channel sheet (12), such that the sum of the plate thickness (h1) of the stiffening plate (15), the sheet thickness (h3) of the channel sheet (12) and the height (h5) of the insert (14) corresponds to a defined constant, in particular the constant is 8 mm.

11. Vehicle (100) comprising a power electronics module (3) with a power semiconductor (2) and a cooler (1), according to one of the preceding claims.

Images