COOLING FIN OF A COOLER, THROUGH WHICH FLUID CAN FLOW, FOR COOLING POWER ELECTRONICS

The present invention relates to a cooling fin (1) of a cooler (100), through which fluid can flow, for cooling power electronics (200). The cooling fin (1) comprises a profile (10) periodically repeating in a repeating direction (501), wherein the repeating direction (501) is perpendicular to an extending direction (500) of the profile (10). The invention also relates to a cooler (100), through which fluid can flow, for cooling power electronics (200), said cooler comprising a cooling fin (1) of said type, and to a power electronics assembly (1000), comprising power electronics (200) and a cooler (100) of said type, through which fluid can flow.

BACKGROUND

The present invention relates to a cooling fin of a cooler, through which fluid can flow, for cooling power electronics. In particular, the invention relates to a cooling fin which enables optimized cooling of power electronics. The invention further relates to a cooler, through which fluid can flow, and which comprises a cooling fin, in particular exactly one such cooling fin, and to an arrangement which comprises power electronics and a cooler of this type.

Power semiconductors in power electronics assemblies carry high electrical currents. Together with switching losses, the resulting conduction losses are the cause of high heat dissipation, which must be dissipated over a very small area. The maximum permissible semiconductor temperature is thereby critical to failure, for which reason minimizing the thermal resistance between the semiconductor and coolant is of central importance. For efficient cooling, the power substrates are applied to coolers through which fluid can flow. These coolers are made of aluminum, AlSiC, or copper alloys. Pins or fins are arranged inside the cooler to increase the heat transfer surface and intensify the heat transfer. In order to achieve a low thermal resistance between a power substrate, in particular an AMB/DBC power substrate (AMB: active metal braze; DBC: direct copper bonding), and the cooler, the power substrate is joined to the cooler by means of a soft soldering process or, optionally, a sintering process. For this purpose, these coolers can be surface-coated with materials suitable for a soft soldering process or a sintering process. In automotive engineering, aluminum coolers, also AlSiC or copper coolers, which consist of a plurality of components that are joined in particular by a brazing process, are frequently known.

Often, fins made of punched sheet metal are used in coolers through which fluid can flow. Existing fin geometries do not meet the requirements of a cooler, through which fluid can flow, for cooling power electronics. The thermal performance is essentially determined by the heat transfer between the fluid and the fin surface, the fin surface and the fin efficiency.

SUMMARY

The advantage of the cooling fin of a cooler, through which fluid can flow, for cooling power electronics assembly according to the invention is that it enables optimum cooling of the power electronics assembly. In particular, the cooling fin can achieve an advantageous ratio between the thermal performance of the cooling fin and the pressure loss caused in the cooler. The cooling fin according to the invention is therefore particularly suitable for use in coolers, through which fluid can flow for high-power electronic applications. This is achieved by the cooling fin of a cooler, through which fluid can flow in order to cool power electronics, comprising a profile which periodically repeats in a repeating direction, the repeating direction being perpendicular to an extending direction of the profile. It should be noted that, in the context of the invention, the term “profile” refers in particular to an element, especially a sheet-shaped element, whose cross-section is constant over its entire length. The direction of the length of the profile can be referred to as the longitudinal direction of the profile and corresponds to the extending direction of the profile. In particular, the extending direction of the profile corresponds to a flow direction.

The flow direction corresponds in particular to a main flow direction of a fluid used as a coolant, which flows through at least one passage channel formed at least by the repeating profile. In particular, the main flow direction is in this case the direction in which the fluid mainly flows, i.e., the direction in which a velocity component of the fluid is greater than a velocity component of the fluid in a direction parallel to the repeating direction. The main flow direction preferably corresponds to a direction in which the fluid enters the cooler, through which fluid can flow. The repeating direction corresponds in particular to a width direction of the cooler. The cooling fin serves as a surface-enlarging, flow-guiding and heat-transfer-enhancing structure, whereby increased heat dissipation and thus also improved cooling of power electronics can be achieved. The cooling fin can preferably be produced in a punching and/or roll forming process for ideal surface utilization with maximum fin efficiency. However, it is also possible for the cooling fin to be produced by an extrusion process for the same purpose, depending on the shape.

Preferably, the profile is repeated an integer or non-integer number of times. In other words, for an integer number of repetitions of the profile, the cooling fin corresponds to an integer multiple of the periodically repeating profile. On the other hand, a non-integer number of repetitions means that the cooling fin is not an integer multiple of the periodically repeating profile. How many times the profile repeats advantageously depends on a width of the power electronics assembly, in particular a power electronics unit, which is to be cooled by a cooler comprising the cooling fin.

Preferably, the cooling fin comprises at least one passage channel, in particular a plurality of passage channels. The at least one passage channel is at least partially formed by the repeating profile. The fluid used as a coolant flows through the at least one passage channel, to which heat generated by the power electronics assembly is transferred via the cooling fin and through which it is dissipated.

According to a first advantageous embodiment of the invention, the periodically repeating profile is a corrugated profile. In particular, the cooling fin is formed by a periodically repeating corrugated profile. As a result, a large surface area of the cooling fin and thus an improved cooling performance can be achieved without the cooling fin becoming too large in the repeating direction. In this embodiment, the cooling fin can preferably be produced by means of a punching and/or roll forming process.

It should be noted that the term “corrugated profile” refers to any profile that features a cross-section in the shape of a shaft, whereby the shaft can have any shape as long as it includes a region having a maximum height and a region having a minimum height. In particular, this means that the shaft need not necessarily be designed as a curve, but can also comprise only rectilinear sections or a combination of curved and rectilinear sections. In other words, within the scope of the invention, the corrugation profile of the cooling fin repeats in the repeating direction and extends in the extending direction. It is understood that the periodically repeating corrugated profile forms a larger corrugated profile in the repeating direction, which features a cross-section which is formed by the individual cross-sections of the repeating corrugated profile specified hereinabove. Therefore, within the scope of the invention, the cooling fin can in particular comprise a cooling fin corrugated profile which corresponds to the larger corrugated profile specified hereinabove.

Preferably, the cooling fin is meander-shaped. In other words, a cross-section of the cooling fin preferably features a meandering shape. In the context of the invention, a “meander” is in particular a shaft comprising rectilinear or substantially rectilinear sections situated perpendicular or substantially perpendicular to one another. In other words, the sections are arranged relative to each other such that rectangular or substantially rectangular deflections are formed between adjacent or directly interconnected sections. The expression “substantially perpendicular” means in particular a deviation of at most 10 degrees, preferably at most 8 degrees, from the perpendicular position.

The repeating corrugated profile or a repetition of the corrugated profile preferably in this case comprises a first bar, a second bar, a third bar, and a fourth bar. The first bar and second bar can be referred to as legs. The first bar and second bar extend in a height direction which is perpendicular to the repeating direction, whereby the third bar and the fourth bar extend parallel to the repeating direction. The first bar and the second bar are preferably connected to each other via the third bar, whereby the fourth bar is preferably connected to the second bar. Passage channels are in this case advantageously formed between adjacent bars. In particular, passage channels are defined alternately by a first bar, an adjacent second bar and an adjacent third bar as well as by a first bar, an adjacent second bar and an adjacent fourth bar.

It is understood that, due to the repetition of the repeating corrugated profile, the first bar and/or the second bar and/or the third bar and/or the fourth bar also repeat/repeat in an advantageous manner. In other words, the cooling fin can comprise a plurality of first bars and/or second bars and/or third bars, and/or fourth bars.

It should be noted that a region of the corrugated profile having a maximum height comprises in particular the third bar. Correspondingly, a region of the corrugated profile having a minimum height comprises in particular the fourth bar.

The third bar advantageously faces the power electronics assembly, whereby the fourth bar faces away from the power electronics assembly.

A first bar, which is connected to a third bar, can preferably merge into the third bar via a rounding radius (inner and outer radii). A third bar, which is connected to a second bar, can preferably merge into the second bar via a rounding radius (inner and outer radii). These rounding radii can preferably be the same and collectively referred to as the first rounding radius.

A second bar, which is connected to a fourth bar, can preferably merge into the fourth bar via a rounding radius (inner and outer radii). A fourth bar, which is connected to a first bar, can preferably merge into the fourth bar via a rounding radius (inner and outer radii). These rounding radii can preferably be the same and are collectively referred to as the second rounding radius.

Advantageously, the second rounding radius is larger than the first rounding radius, in particular twice as large as the first rounding radius. Advantageously, the first rounding radius is the same size as a profile thickness of the cooling fin.

When the profile is designed as a corrugated profile, the division of the cooling fin can preferably measure between 1.8 mm and 2.5 mm, preferably between 1.9 mm and 2.1 mm, in particular 2 mm. The division of the cooling fin corresponds to the period at which the periodically repeating corrugated profile is repeated to form the cooling fin.

According to a second advantageous embodiment of the invention, the periodically repeating profile is a cross-shaped profile. This embodiment of the cooling fin is advantageous, since the cross-shaped profile is firstly easy to manufacture and secondly comprises a large surface area for transferring heat to the fluid used as coolant. In particular, the cooling fin is formed by a periodically repeating cross-shaped profile. The cross-shaped profile preferably comprises a first bar, a second bar and a third bar, whereby the first bar and the second bar are each situated at a perpendicular angle to the third bar and protrude from the third bar. It is understood that the bars are arranged relative to each other such that the profile features the shape of a cross. Advantageously, the third bar extends in the repeating direction of the repeating profile. The at least one passage channel described hereinabove preferably comprises in this case at least one passage channel between adjacent first bars and a passage channel between adjacent second bars. In particular, at least one passage channel is defined by adjacent first bars and adjacent third bars, whereby at least one passage channel is defined by adjacent second bars and adjacent third bars. Preferably, the cooling fin according to this embodiment is produced by means of an extrusion process.

It is understood that, due to the repetition of the repeating cross-shaped profile, the first bar, and/or the second bar, and/or the third bar(s) also repeat in an advantageous manner. In other words, the cooling fin can comprise a plurality of first bars and/or second bars and/or third bars.

Preferably, the cooling fin can further comprise a fourth bar extending parallel to the third bar and connected to an end region of each first bar or each second bar. Advantageously, the fourth bar extends in the extending direction of the profile.

Alternatively, the cooling fin can further preferably comprise a fourth bar and a fifth bar extending parallel to the third bar. In this case, the fourth bar is connected to an end region of each first bar, whereby the fifth bar is connected to an end region of each second bar. Advantageously, the fourth bar and the fifth bar extend in the extending direction of the profile.

Advantageously, the fourth bar and/or the fifth bar extend(s) in the repeating direction of the repeating profile. Advantageously, the aforementioned at least one passage channel comprises at least one passage channel between adjacent first bars and at least one passage channel between adjacent second bars.

According to an advantageous variant of the second embodiment of the invention, a dimension of the first bar in the repeating direction can be the same as a dimension of the second bar in the repeating direction. The cooling fin can therefore be easily manufactured.

According to an alternative advantageous variant of the second embodiment of the invention, a dimension of the first bar in the repeating direction can be larger than a dimension of the second bar in the repeating direction. Heat dissipation through the cooling fin can therefore be further improved. In this case, it is advantageous if the first bar of the cross-shaped profile is arranged to face the power electronics assembly, whereby the second bar of the cross-shaped profile is arranged to face away from the power electronics. In other words, in this embodiment, the first bar is arranged to be closer to the power electronics assembly than the second bar. Due to the different dimensions of the first bar and the second bar, the flow, in particular the flow velocity, of the fluid used as coolant can be influenced such that a desired heat transfer coefficient of the fluid is achieved.

The dimension of the first bar or the second bar in the repeating direction corresponds in particular to a material thickness of the first bar or the second bar.

According to a third advantageous embodiment of the invention, the periodically repeating profile is a V-shaped profile having a first bar and a second bar. The cooling fin can in this case preferably further comprise a third bar, whereby the third bar extends in the repeating direction and is arranged such that a triangular passage channel is formed for each repetition of the profile by the first bar, the second bar, and the third bar. The third bar extends advantageously in the extending direction of the profile. Alternatively, the cooling fin can preferably further comprise a third bar and a fourth bar, whereby the third bar and the fourth bar extend in the repeating direction and are arranged such that triangular passage channels are formed in the cooling fin. The third bar and the fourth bar extend advantageously in the extending direction of the profile. Preferably, the cooling fin according to the third advantageous embodiment is produced by means of an extrusion process.

It is understood that, due to the repetition of the repeating V-shaped profile, the first bar and/or the second bar also repeat in an advantageous manner. In other words, the cooling fin can comprise a plurality of first bars and/or second bars.

The shapes of the cooling fins according to the advantageous embodiments of the invention described above can in particular enable an advantageous ratio of a thermal performance to a pressure loss in the cooler caused by the cooling fin.

Particularly preferably, a height of the cooling fin can measure between 5 mm and 8 mm, preferably between 5.9 mm and 6.1 mm. The height is advantageously measured in a height direction that is perpendicular to the repeating direction and extending direction of the profile.

Particularly preferably, the material thickness of the cooling fin can measure between 0.3 mm and 0.6 mm, preferably between 0.35 mm and 0.45 mm. In the cooling fin according to the first embodiment described above, the material thickness of the cooling fin corresponds in particular to a profile thickness of the repeating corrugated profile. In the cooling fin according to the second embodiment described above, the material thickness of the cooling fin comprises in particular a profile thickness of the repeating cross-shaped profile and in particular also a material thickness of the fourth bar and/or the fifth bar. In the cooling fin according to the third embodiment described above, the material thickness of the cooling fin comprises in particular a profile thickness of the V-shaped profile and/or a material thickness of the fourth bar and/or the fifth bar.

Particularly preferably, a clear dimension between adjacent bars of the cooling fin in the repeating direction can measure between 0.6 mm and 1.2 mm, preferably between 0.85 mm and 0.95 mm. In the first advantageous embodiment, the clear dimension between adjacent bars is in particular a clear dimension between a first bar and an adjacent second bar. In the cooling fin according to the second advantageous embodiment described above, the clear dimension between adjacent bars comprises in particular a clear dimension between adjacent first bars and/or a clear dimension between adjacent second bars. In the cooling fin according to the third advantageous embodiment described above, the clear dimension between adjacent bars corresponds in particular to a maximum clear dimension between a first bar and an adjacent second bar.

In an advantageous manner, the cooling fin is designed as monobloc/monolithic.

The cooling fin is preferably made of a material and/or coated with a material that features a coefficient of thermal conductivity greater than 150 W/(m-K). Advantageously, the cooling fin can be made of aluminum or coated with aluminum or nickel.

The present invention further relates to a cooler, through which fluid can flow, for cooling power electronics, which comprises a cooling fin as described above.

The cooler, through which fluid can flow, preferably comprises exactly one cooling fin as described above and a cooling channel. The cooling fin is in this case arranged in the cooling channel. A length of the cooling fin in the extending direction of the repeating profile is equal to a dimension of the cooling channel in the extending direction of the repeating profile.

Preferably, the cooler, through which fluid can flow, comprises a housing. The housing can preferably be made of at least two metal parts, in particular aluminum parts, which are connected to each other and define the cooling channel. The cooling channel in this case corresponds in particular to an interior of the housing.

Further preferably, an inlet and an outlet for a fluid used as a coolant are arranged directly on the housing.

Preferably, one region of the cooling fin corresponds to at least part of the housing of the cooler. In other words, a region of the cooling fin is formed at least as part of the housing of the cooler. In an advantageous manner, the fourth bar an—depending on the design of the cooling fin—in particular also the fifth bar in the cooling fin according to the advantageous fourth embodiment described above each correspond to at least a part of the housing. In particular, the fourth bar can partially or completely correspond to a metal part of the at least two metal parts of the housing. If a fourth bar and a fifth bar are provided in the cooling fin, the fourth bar can partially or completely correspond to a first metal part of the at least two metal parts of the housing and the fifth bar can correspond to a second metal part of the at least two metal parts of the housing.

The present invention further relates to a power electronics assembly comprising a cooler, through which fluid can flow, as described hereinabove, and power electronics. The power electronics assembly is in this case arranged on the cooler. As a result, the power electronics assembly can be cooled by means of the cooler. In particular, the power electronics assembly is fixed to the cooler.

Preferably, the power electronics can comprise (exactly) one power electronics unit or a plurality of power electronics units. The power electronics units can be arranged on one or both sides of the cooler, through which fluid can flow, or its housing. In other words, the cooler, through which fluid can flow, can be equipped with power electronics units on one or both sides.

The power electronics can preferably comprise at least a first power electronics unit and a second power electronics unit. In the main flow direction of the fluid used as coolant, the first power electronics unit is preferably arranged upstream of the second power electronics unit. Furthermore, the power electronics can preferably comprise a third power electronics unit. Preferably, the third power electronics unit is in this case arranged downstream of the second power electronics unit in the main flow direction of the fluid.

In the context of the invention, a power electronics unit can in particular also be referred to as a power module. The power electronics unit preferably comprises a printed circuit board and/or conductor tracks and/or one or a plurality of power semiconductors.

DETAILED DESCRIPTION

Referring toFIGS.1and2, a power electronics assembly1000according to the invention comprising power electronics200and a cooler100according to a first exemplary embodiment of the invention is described below.

As shown inFIG.1, the power electronics200comprises a power electronics unit210, which can also be referred to as a power module. The power electronics unit210comprises a printed circuit board204, conductor tracks203,205and power semiconductors201. The conductor tracks203,205are designed in particular as copper conductor tracks, whereby the printed circuit board204is preferably made of ceramic.

The power semiconductors201are applied to the trace203by a layer202. In particular, the layer202is in this case designed as a solder or sintered layer.

The conductor tracks203,205together with the printed circuit board204form a power substrate. The power substrate is joined to the cooler100, in particular to a first metal part101of a housing110of the cooler100, by means of a layer206produced by a soft soldering process or a sintering process, which is thus correspondingly a soft soldering layer or sintering layer.

The housing110of the cooler100further comprises a second metal part102, which is connected to the first metal part101by means of a layer103, which is in particular designed as a brazing solder layer. Both the first metal part101and the second metal part102are preferably aluminum parts.

FIG.1also shows that the first metal part101is an upper part and the second metal part102is a lower part of the housing110. The first metal part101faces the power electronics unit210, whereby the second metal part102faces away from the power electronics unit210. Furthermore, in this exemplary embodiment, the first metal part101is plate-shaped, whereby the second metal part102comprises a plate-shaped region and a trapezoidal region in cross-section. However, it is also possible for the first metal part101and the second metal part102to feature other shapes. The second metal part102can advantageously be produced by a deep-drawing process.

A mediation layer107is advantageously located between the layer206and the cooler100(in particular the first metal part101), which layer is firmly connected to the first metal part101and enables wetting of the layer206. The mediation layer107is an optional feature of the power electronics assembly1000and can in particular be considered either as a separate part or as part of the housing110of the cooler100.

The first metal part101and the second metal part102, which form the housing110of the cooler100when joined together, define an interior space which serves as the cooling channel111of the cooler100.

Exactly one cooling fin1is arranged in the cooling channel111, which serves as a surface-enlarging, flow-guiding, and heat-transfer-enhancing structure for a fluid used as a coolant. The cooling fin1is advantageously joined to the first metal part101and second metal part102by means of the layer103.

The cooling fin1is formed by a profile10periodically repeating in a repeating direction501. The repeating direction501is perpendicular to an extending direction500of the profile10and corresponds in particular to a width direction of the cooler100. The extending direction500is the direction in which the repeating profile10or the cooling fin1extends as a unit. The extending direction500corresponds in this case to a flow direction500, in particular a main flow direction, of a fluid used as coolant when it flows through the cooling channel111, in particular through passage channels16(FIGS.1and3), which are formed by the repeating profile10. The single cooling fin1extends in the extending direction500over an entire length of the cooling channel111of the cooler100in the extending direction500. In other words, a length607of the cooling fin1is the same as the entire length of the cooling channel111.

In this exemplary embodiment, the repeating corrugated profile10is a corrugated profile. In particular, the cooling fin1is meander-shaped. The cooling fin1is designed to be monobloc or monolithic and is preferably manufactured by means of a stamping process.

The repeating corrugated profile, or rather each repetition of the corrugated profile, comprises a first bar11, a second bar12, a third bar13, and a fourth bar14.

The first bar11and second bar12of the repeating corrugated profile extend in a height direction502that is perpendicular to the repeating direction501and extending direction500, whereby the third bar13and fourth bar14extend parallel to the repeating direction501. The cooling fin1therefore comprises a plurality of first bars11, second bars12, third bars13, and fourth bars14. A first bar11is connected to an adjacent second bar12via a third bar13or a fourth bar14. A transition from one of the bars11to14to an adjacent bar is formed at a right angle (not rounded).

Passage channels16are in this case formed between adjacent bars11,12. A clear dimension602between adjacent bars11,12in the repeating direction501, which corresponds to the dimension of the corresponding passage channel16formed, measures between 0.6 mm and 1.2 mm, preferably between 0.85 mm and 0.95 mm.

A division601of the cooling fin1can measure between 1.8 mm and 2.5 mm, preferably between 1.9 mm and 2.1 mm. The division601of the cooling fin1in this case corresponds to the period at which the periodically repeating profile10is repeated to form the cooling fin1.

A height604of the cooling fin1measures between 5 mm and 8 mm, preferably between 5.9 mm and 6.1 mm.

Furthermore, a material thickness605of the cooling fin1can measure between 0.3 mm and 0.6 mm, preferably between 0.35 mm and 0.45 mm. The material thickness605of the cooling fin1in this case corresponds to a profile thickness of the repeating corrugated profile or a material thickness of the bars11to14.

By means of the cooling fin1, heat generated during operation of the power electronics unit210can be efficiently transferred from the power electronics unit210first to the first metal part101and from there to a fluid flowing through the cooling fin10and dissipated. Furthermore, an optimum ratio between thermal performance and the pressure loss caused in the cooler100is achieved.

In order to achieve advantageous heat transfer and at the same time enable simple manufacture, the cooling fin1is advantageously made of aluminum. Alternatively, the cooling fin1can be provided with an aluminum layer. It is also possible that the cooling fin1is coated with nickel. However, it is also possible that other thermally conductive materials are used for the cooling fin1and/or the layer thereof, which in particular have a coefficient of thermal conductivity greater than 150 W/(m-K).

The cooler100can further preferably comprise coolant nozzles,which can also be joined together by means of a hard solder in the manufacturing step of joining the two metal parts101,102.

FIG.3relates to a cooling fin1according to a second exemplary embodiment of the invention.

The structure of the cooling fin1according to the second exemplary embodiment is basically identical to the structure of the cooling fin1according to the first exemplary embodiment.

The only difference is the shape of the transitions between adjacent bars.

In particular, in the cooling fin1according to the second exemplary embodiment, the first bars11, which are each connected to a third bar13, merge into the corresponding third bar13via a first rounding radius (inner and outer radii). Furthermore, the third bars13, which are each connected to a second bar12, merge into the corresponding second bar12via the first rounding radius608(inner and outer radii). The second bars12, which are each connected to a fourth bar14, merge into the corresponding fourth bar14via a second rounding radius609(inner and outer radii). Furthermore, the fourth bars14, which are each connected to a first bar11, merge into the corresponding first bar11via the second rounding radius609(inner and outer radii).

The second rounding radius609is larger than the first rounding radius608, in particular twice as large as the first rounding radius608. In an advantageous manner, the first rounding radius608is the same size as the profile thickness605of the cooling fin1.

The cooling fin1according to the second exemplary embodiment can replace the cooling fin1according to the first exemplary embodiment in the cooler100inFIG.1. In this case, the cooling fin1is arranged in the cooling channel111of the cooler100such that the third bars13are closer to the power electronics unit210than the fourth bars14.

FIG.4refers to a cooling fin1according to a third exemplary embodiment of the invention.

The cooling fin1is in this case formed by a periodically repeating profile10, which is a cross-shaped profile. Preferably, the cooling fin1is an extrusion product.

The cross-shaped profile comprises a first bar11, a second bar12and a third bar13. The first bar11and the second bar12are in this case each situated at a perpendicular angle to the third bar30and protrude from the third bar13. The third bar13extends in the repeating direction501of the repeating profile10. The cooling fin1therefore comprises a plurality of first bars11, second bars12, and third bars13.

Passage channels16for the fluid used as coolant are formed between adjacent first bars11, whereby further passage channels16for the fluid are formed between adjacent second bars12.

A dimension (material thickness)603of the first bar11in the repeating direction501is equal to a dimension (material thickness)606of the second bar12in the repeating direction501. Therefore, a clear dimension610between adjacent first bars11in the repeating direction501is also equal to a clear dimension611between adjacent second bars12in the repeating direction501. In particular, the clear dimension610or611measures between 0.6 mm and 1.2 mm, preferably between 0.85 mm and 0.95 mm. Both the clear dimension610and the clear dimension611correspond to the dimension of the respective passage channel16formed in the repeating direction501.

A height604of the cooling fin1measures between 5 mm and 8 mm, preferably between 5.9 mm and 6.1 mm.

FIG.5relates to a cooling fin1according to a fourth exemplary embodiment of the invention.

The cooling fin1according to the fourth exemplary embodiment of the invention differs from that according to the third exemplary embodiment in that the dimension (material thickness)603of the first bars11in the repeating direction501is greater than the dimension (material thickness)606of the second bars12in the repeating direction501. Therefore, the clear dimension610between adjacent first bars11in the repeating direction501is also smaller than the clear dimension611between adjacent second bars12in the repeating direction501.

The cooling fin1according to the third exemplary embodiment of the invention can be provided in the housing110of the cooler100inFIG.1. In particular, the cooling fin1is then arranged in the cooling channel111such that the first bars11face the power electronics200, whereby the second bars12face away from the power electronics200.

FIG.6shows a cooling fin1according to a fifth exemplary embodiment of the present invention.

The cooling fin1according to the fifth exemplary embodiment differs from that according to the third exemplary embodiment in that the cooling fin1in this case additionally comprises a fourth bar14and a fifth bar15, which extend parallel to the third bar13. The fourth bar14and the fifth bar15therefore extend parallel to the repeating direction501and extend in the extending direction500.

The fourth bar14is arranged at end regions18of the first bars11and is connected thereto. The fifth bar15is arranged at end regions18of the second bars12and is connected thereto.

Due to this design of the cooling fin1, passage channels16for the fluid used as coolant are formed between adjacent first bars11and the fourth bar14and between adjacent second bars12and the fifth bar15.

The cooling fin1according to the fifth exemplary embodiment of the invention can replace the cooling fin1according to the first exemplary embodiment. Furthermore, it is possible that the fourth bar14forms the first metal part101and the fifth bar15forms the second metal part102of the housing100inFIG.1, in whole or in part.

FIG.7shows a cooling fin1according to a sixth exemplary embodiment of the present invention.

Here, the cooling fin1comprises a periodically repeating profile10, which is a V-shaped profile. Preferably, the cooling fin1is produced by means of an extrusion process.

The repeating V-shaped profile comprises a first bar11and a second bar12, which are arranged relative to each other such that the profile10features a V-shape. The cooling fin1therefore comprises a plurality of first bars11and second bars12.

Furthermore, the cooling fin1additionally comprises a third bar13and a fourth bar14. The third bar13and the fourth bar14extend in the repeating direction501and are arranged relative to the first bars11and the second bars12such that triangular passage channels16are formed in the cooling fin1.

A clear dimension602between adjacent bars11,12in the repeating direction501corresponds to a maximum dimension of the corresponding passage channel16formed, and measures between 0.6 mm and 1.2 mm, preferably between 0.85 mm and 0.95 mm.

A height604of the cooling fin1measures between 5 mm and 8 mm, preferably between 5.9 mm and 6.1 mm.

Furthermore, a material thickness605of the cooling fin1can measure between 0.3 mm and 0.6 mm, preferably between 0.35 mm and 0.45 mm. The material thickness605of the cooling fin1in this case corresponds to a profile thickness of the repeating corrugated profile or a material thickness of the bars11to14.

The cooling fin1according to the sixth exemplary embodiment of the invention can replace the cooling fin1according to the first exemplary embodiment. Furthermore, it is possible that the third bar14forms the first metal part101and the fourth bar14forms the second metal part102of the housing100inFIG.1, in whole or in part.

FIG.8shows a power electronics assembly1000according to a seventh exemplary embodiment of the present invention.

The power electronics assembly1000according to the seventh exemplary embodiment differs from that according to the first exemplary embodiment in that the first metal part101, which is the upper part and thus faces the power electronics unit210, comprises a plate-shaped region and a trapezoidal region in cross-section, whereby the second metal part102, which is the lower part and thus faces the power electronics unit210, is plate-shaped.

This design of the housing110can be advantageous in the event of a lack of space in the immediate vicinity of the power electronics unit210.

It should be noted that the housing110of the cooler100according to the seventh exemplary embodiment can also be combined with a cooling fin1according to one of the exemplary embodiments two to six.

FIG.9refers to a power electronics assembly1000according to an eighth exemplary embodiment of the present invention.

Similar to the power electronics assembly1000according to the seventh exemplary embodiment, the power electronics assembly1000according to the eighth exemplary embodiment differs from that according to the first exemplary embodiment in the design of the housing110of the cooler100.

As can be seen fromFIG.9, a third metal part104is provided in addition to the first metal part101and the second metal part102, which together with the first metal part101and the second metal part102form the housing110of the cooler100. The third metal part104, which in particular is also designed as an aluminum part, is arranged between the first metal part101and the second metal part102. The first metal part101is joined to the third metal part104by means of a first layer105, which is connected to the second metal part102by means of a second layer106. The first layer105and/or the second layer106is/are preferably each designed as a brazing solder layer.

It is understood that the cooling channel111is defined by the first metal part101, the second metal part102, and the third metal part104.

This design of the housing110offers the advantage that it can be manufactured very easily.

It should be noted that the housing110of the cooler100according to the eighth exemplary embodiment can also be combined with a cooling fin1according to one of the exemplary embodiments two to six. If the cooling fins1inFIG.6or7are used, the first metal part101and the second metal part102can in this case also be replaced by the corresponding bars of the cooling fins.

FIG.10shows a power electronics assembly1000according to a ninth exemplary embodiment of the present invention.

The power electronics200of the power electronics assembly1000according to the ninth exemplary embodiment comprises a first power electronics unit210, a second power electronics unit211and a third power electronics unit212.

In the flow direction, or rather the main flow direction, of the fluid used as coolant, the first power electronics unit210is arranged upstream of the second power electronics unit211, which in turn is arranged upstream of the third power electronics unit212in the flow direction500. The flow direction advantageously corresponds to a direction from an inlet108to an outlet109of the cooler100.

The cooling fin1is associated with all power electronics units210,211,212. In other words, heat generated by the power electronics units210,211,212during their operation is transferred to the single cooling fin1and from there to the fluid flowing through it. For this purpose, the cooling fin1extends in its extending direction500over an entire length1110of the cooling channel111of the cooler100.