DE102021119213B4 - Helix channel cooler unit - Google Patents

Abstract

The invention relates to a helical channel cooler unit for electronic assemblies with three-dimensional channel routing, having a cooler body, a media inlet, a media outlet, a helical channel shape and at least one component that generates power loss, the cooler body containing the helical channel shape and media access and Media outlet are located on the surface of the heat sink and a medium enters the helix channel shape via the media access and leaves it again via the media outlet, wherein at least one component generating power loss is mounted on at least one surface of the heat sink; the helical channel shape has channel sections combined into a helix and the three-dimensional channel routing creates a forced helical flow movement of the medium and thus better heat transfer along the channel walls.

Description

The invention relates to a helical channel cooler unit for electronic assemblies with three-dimensional channel routing, having a heat sink, a media inlet, a media outlet, a helical channel shape and at least one component that generates power loss, the heat sink containing the helical channel shape and media access and Media outlet are on the surface of the heat sink and a medium enters the helix channel shape via the media access and leaves it again via the media outlet.

A medium, within the meaning of the invention, is understood to mean a fluid in the physical sense.

A three-dimensional helical flow of a medium in space, within the meaning of the invention, is understood to mean a helical turbulence forced by a three-dimensional channel geometry as a spiral secondary flow, which is superimposed on a main flow direction in the channel.

Two-dimensional flow baffles such as ShowerPower, 3D-ShowerPower from Danfoss Silicon Power are generally known from the prior art.

The known state of the art in liquid cooling shows a two-dimensional guidance of the liquid medium in a meandering form, which generates a rotation of the otherwise laminar flow threads (flow) in one plane by periodic changes of direction (meander channel). The effect of the liquid cooling consists in the desired reduction of the essentially stationary boundary layer of the cooling liquid on the boundary surface to be cooled. The heat supply is usually arranged on one side parallel to the flow threads on the boundary surface, for example a power semiconductor substrate DE 10 2005 058 780 A1 discloses a micro heat exchanger and the use of the same as a fluid cooler for electronic components with a planar comb-like or groove-like structure.

The pamphlet WO 2018/ 134 031 A1 shows a power electronics system and method for its manufacture. The power electronics are arranged on a first side of a base plate and a cooling structure is arranged on one side on the second side of the base plate.

The pamphlet WO 01/63667 A1 discloses a device for dissipating heat from heated elements, the device comprising a block of material having good thermal conductivity, on which the elements are arranged in thermal contact, and in which block channels are provided and a liquid, e.g. B. water, is forced to flow through the channels. The channels are made of thin-walled tubes and made of a material that is not corrosive to the flowing liquid.

Next is from the pamphlet U.S. 2016/0 313 390 A1 discloses a thermal control unit used to maintain a set temperature on an integrated circuit under test. This has at least one cooling plate configured to facilitate testing of integrated circuits when the device under test requires efficient cooling.

The pamphlet WO 2020/ 209 390 A1 discloses an arrangement that makes it possible to reduce the concentration of thermal stresses in the vicinity of a flow-restricted area of a plate heat exchanger and to prevent fatigue failures due to this concentration. The flow volume restricted area is provided with openings resembling those of a flow channel in order to reduce a rigidity difference with flow channel areas.

The main problems in the prior art are that in liquid cooling, a two-dimensional guidance of the liquid medium with a forced change of direction at the meander curves lying in a surface generates a swirl flow, which arises from a main direction and a cross flow. These laminar flow threads only have a moderate property of minimizing the boundary surface for the heat transfer from the boundary surface to the liquid medium, since there is no component in the direction of the wall to destroy the boundary layer.

The planar meandering of the canals leads to the rotation of the stream threads, as a kind of helical flow, but this is exclusively directed almost parallel to the canal walls. These flow threads thus show the classic flow profiles according to Bernoulli, which have a pronounced and stable boundary layer at the edges/boundaries. These boundary layers have little or no flow and reduce or prevent the interaction of the coolant with the wall.

The object of the present invention is to reduce the disadvantageous, almost stationary boundary layers by means of a further forced change of direction by means of further swirl flows and to reduce them by means of impingement flows. The degraded boundary layers allow a significantly improved heat transfer from the boundary surface to the medium (the coolant). For this purpose, according to the invention, a further change in direction in the z-direction is imposed on the two-dimensional meandering by means of an xy channel guide. This creates a further cross-flow through changes in direction of the medium and thus a three-dimensional real helical flow in space. This additional flow component, together with the additional baffle surfaces of the flow guide, has a reducing effect on the thickness and extent of the boundary surface and thus has an increasing effect on the heat transfer. For example, improved cooling for power electronic semiconductor assemblies is then possible.

This problem is solved with a helix channel cooler unit according to the invention.

• - der Kühlkörper (10) die Helix-Kanalform (50) beinhaltet und sich Medienzugang (30) und Medienabgang (31) auf der Oberfläche des Kühlkörpers befinden; und
• - das Medium über den Medienzugang (30) in die Helix-Kanalform (50) gelangt und diese über den Medienabgang (31) wieder verlässt;
• - auf mindestens einer Oberfläche des Kühlkörpers (10) mindestens eine Verlustleistung erzeugende Komponente montiert ist; und
• - durch die dreidimensionale Kanalführung eine erzwungene helikale Strömungsbewegung des Mediums und somit ein besserer Wärmeübergang entlang der Kanalwände erzeugt wird;

und ist dadurch gekennzeichnet, dass
die Helix-Kanalform (50) zu einer Helix kombinierte Kanalabschnitte aufweist.
Weiter kann der Kühlkörper quaderförmig ausgebildet sein.The helix channel cooler unit for electronic assemblies with three-dimensional channel routing has: a heat sink, a media inlet, a media outlet, a helix channel shape (50), at least one component that generates power loss,
whereby

• - The heat sink (10) includes the helical channel shape (50) and media access (30) and media outlet (31) are located on the surface of the heat sink; and
• - The medium enters the helix channel shape (50) via the media access (30) and leaves it again via the media outlet (31);
• - At least one component generating power loss is mounted on at least one surface of the heat sink (10); and
• - A forced helical flow movement of the medium and thus a better heat transfer along the channel walls is generated by the three-dimensional channel guide;

and is characterized in that
the helical channel shape (50) has channel sections combined to form a helix.
Furthermore, the heat sink can be cuboid.

The heat sink can be designed in one piece or in two pieces with a first half-shell and a second half-shell.

The various surfaces of the heatsink can be equipped independently of one another with components that generate power loss.

The components that generate the power loss can include semiconductor components and/or capacitors.

The heat sink can be made of a metal, a metal alloy and/or ceramic materials, preferably copper alloys, aluminum alloys, silicon nitride, aluminum nitride, zirconium dioxide, nickel, stainless steels.

In a two-part design, the first half-shell and the second half-shell can be functionally expandable to form a first heat sink half-shell and a second heat sink half-shell.

In a two-part design, the helical channel shape can be obtained by forming sinks in the half-shells and then stacking the half-shells in pairs, the half-shells having the channel sections on different levels between the coordinate axes in the Cartesian coordinate system and the channel sections overlap so that a helical course is trained.

The helix channel cooler unit is specially designed for electronic assemblies with three-dimensional channel routing. It has a heat sink, a media inlet, a media outlet, a helical channel shape and at least one component that generates power loss, the heat sink containing the helical channel shape and the media inlet and media outlet are located on the surface of the heat sink and the medium via the media inlet into the helical channel shape and leaves it again via the media outlet, characterized in that at least one component that generates power loss is mounted on at least one surface of the heat sink, the helical channel shape has channel sections combined to form a helix and the three-dimensional channel routing causes a forced helical flow movement of the Medium and thus a better heat transfer is generated along the channel walls.

If the heat sink is cuboid, there are a total of six surfaces that can be given functions. Up to two surfaces each have a liquid inlet or media inlet and a liquid outlet or media outlet. The block-shaped design of the heat sink is the preferred variant. However, the heat sink can also have other geometries.

The heat sink can be designed in one piece or in two pieces with a first half-shell and a second half-shell. The one-piece design has internal helical channels that can currently only be produced by one-piece additive manufacturing. In this embodiment, the components that generate the power loss can be built up on the larger, opposite plane surfaces. A two-part embodiment of the helical channel shape having baffle surfaces can be formed, for example, by a channel geometry that is produced by depressions in plates that are easy to produce and result in the complete medium channel by stacking them in pairs. The two plates complement each other on the channel side to form the cooler channel and also offer a surface on their two rear sides for the installation of components that generate power loss, such as power electronic components. The channel design in the two plates can be made by a variety of manufacturing processes, such as machining, embossing, deep drawing or additive metal manufacturing.

An advantage of the one-piece variant compared to the two-piece variant is the possibility of compensating for different heat flows with different loads on the power loss (heat)-generating components.

In contrast, the two-part variant is easier and cheaper to produce. This variant includes a new process for the production of liquid coolers with an internal duct, since the two half-shells are produced separately from one another and are only then assembled on top of each other to form the helix cooler duct. The heatsink can be equipped with electronic assemblies easily and independently on both sides.

The various surfaces of the heat sink can be equipped at least partially or completely and independently of one another with components that generate power loss.

Because the various surfaces of the heat sink can be fitted with components that generate power loss independently of one another, the helix channel cooler unit can be configured variably. The system is also easy to service and changes can be made relatively easily without having to completely rebuild the entire unit.

The components that generate power loss can preferably include electronic assemblies, in particular semiconductor components and/or capacitors.

The heat sink can preferably be made of a metal, a metal alloy and/or ceramic materials, preferably copper alloys, aluminum alloys, silicon nitride, aluminum nitride, zirconium dioxide, nickel, stainless steels, so that there is good heat conduction and, if necessary, corrosion-inhibiting materials can be added are. It is also an advantageous variant if the region of the channel formation consists of aluminum and a heat-spreading copper layer is inserted between the aluminum part and the components generating power loss in a materially connected manner.

The fact that in a two-part design the first half-shell and the second half-shell can be functionally expanded to form a first heatsink half-shell and a second heatsink half-shell, additional thermal contact surfaces are created on the heatsink for additional power loss-generating components. For example, in addition to semiconductor components on the base and top surfaces, capacitors or other components can also be mounted on two side surfaces.

In a two-part design, the helical channel shape can be obtained by forming sinks in the half-shells and then stacking the half-shells in pairs, the half-shells having the channel sections on different levels between the coordinate axes in the Cartesian coordinate system and the channel sections overlap so that a helical course is trained.

A simple, service-friendly, safe liquid cooler system that can be produced relatively inexpensively, namely the helix-channel cooler unit according to the invention, is provided via the possibility of constructing two half-shells, with which electronic assemblies can also be mounted independently on heat sinks.

Due to the helical channel shape present in the helix channel cooler unit, the medium is guided through the channel in a helical form, i.e. as rotating, migrating stream threads, three-dimensionally, whereby turbulent heat transfers are made possible by multiple wall contacts, which results in a significantly improved heat transfer from the boundary surface causes in the cooling liquid. The disadvantageous, almost stationary boundary layers are thereby reduced by the three-dimensional forced changes in direction by further swirl flows and degraded by impingement flows. For this purpose, according to the invention, a further change in direction in the z-direction is imposed on the two-dimensional meandering by xy channel routing. This creates a further transverse flow through a change in direction and thus a three-dimensional real helical flow. This additional flow component works together with the additional baffle surfaces of the flow control reducing the thickness and extent of the boundary surface and thus increasing the heat transfer.

The invention is described below using the accompanying illustrations in the description of the illustrations, which are intended to explain the invention and are not necessarily to be viewed as limiting:

• beispielhaft eine zweiteilige Ausführungsform einer Helix-Kanal-Kühler-Einheit für leistungselektronische Halbleiter-Baugruppen in perspektivischer Darstellung;
• beispielhaft eine zweiteilige Ausführungsform der Helix-Kanal-Kühler-Einheit für leistungselektronische Halbleiter-Baugruppen aus in perspektivischer Durchsicht-Darstellung (Röntgenbild);
• beispielhaft eine zweiteilige Ausführungsform der Helix-Kanal-Kühler-Einheit aus in perspektivischer Durchsicht-Darstellung (Röntgenbild), wobei die Strömungsvektoren der Helix dargestellt sind;
• beispielhaft einen Kanalbereich der Strömungsvektoren aus mit perspektivischer Durchsicht-Darstellung (Röntgenbild) ohne Helix-Kanalform;
• beispielhafte Kanalgestaltung einer zerlegten, zweiteiligen Ausführungsform einer Helix-Kanal-Kühler-Einheit für leistungselektronische Halbleiter-Baugruppen sowie resultierende mittlere Strömungsvektoren in Durchsicht-Darstellung;
• beispielhafte gruppierte und verbundene Kanalanordnung einer zerlegten, zweiteiligen Ausführungsform einer Helix-Kanal-Kühler-Einheit für leistungselektronische Halbleiter-Baugruppen sowie resultierende Strömungsvektoren in Durchsicht-Darstellung;
• eine beispielhafte zweiteilige Ausführungsform einer Helix-Kanal-Kühler-Einheit für leistungselektronische Halbleiter-Baugruppen mit beidseitigem Aufbau der leistungselektronischen Halbleiter-Baugruppen auf dem Kühlkörper, in Schnittdarstellung;
• eine beispielhafte zweiteilige Ausführungsform der Helix-Kanal-Kühler-Einheit für leistungselektronische Halbleiter-Baugruppen nach , wobei die Halbschalen zu funktionell erweiterten Kühlkörper-Halbschalen ausgebildet sind, in Schnittdarstellung.

Show it:

• an example of a two-part embodiment of a helix channel cooler unit for power electronic semiconductor assemblies in a perspective view;
• example, a two-part embodiment of the helix channel cooler unit for power electronic semiconductor assemblies in a perspective view (X-ray image);
• example, a two-part embodiment of the helix channel cooler unit in a perspective view (X-ray image), showing the flow vectors of the helix;
• shows a channel area of the flow vectors as an example with perspective see-through representation (X-ray image) without helical canal shape;
• exemplary channel design of a disassembled, two-part embodiment of a helix channel cooler unit for power electronic semiconductor assemblies and the resulting mean flow vectors in a see-through representation;
• exemplary grouped and connected channel arrangement of a disassembled, two-part embodiment of a helix channel cooler unit for power electronic semiconductor assemblies and resulting flow vectors in a see-through representation;
• an exemplary two-part embodiment of a helix-channel cooler unit for power electronic semiconductor assemblies with a double-sided structure of the power electronic semiconductor assemblies on the heat sink, in a sectional view;
• an exemplary two-part embodiment of the helix channel cooler unit for power electronic semiconductor assemblies , The half-shells being formed into functionally expanded heat sink half-shells, in a sectional view.

shows an example of a two-part embodiment of a helix channel cooler unit 1 for power electronic semiconductor assemblies in a perspective view. The helix-channel cooler unit 1 consists of a metallic heat sink 10 made up of a first half-shell 11 and a second half-shell 12 lying one on top of the other as well as semiconductor components 40 with power semiconductors 20 above the first half-shell 11. The medium becomes the helix-channel cooler unit 1 is fed through a media access 30 in the second half-shell 12 of the heat sink 10 and leaves the helix channel cooler unit via a media outlet 31 in the second half-shell 12. The metal heat sink 10 consists of a preferably good thermally conductive material. The half-shells are plate-shaped. The component (heat source) that generates power loss, here the power semiconductors 20, are constructed on one side in this example.

In becomes shown in a see-through view (X-ray image). After the medium has been supplied through the media inlet 30 , the medium flows through a helical channel shape 50 consisting of a number of channel sections which, when combined, form a helix before it exits again through the media outlet 31 . This helical channel shape 50 brings about an optimized 3-dimensional media guidance. In the illustration, the helix channel shape 50 is designed with baffles for the medium. In the illustration, the helical channel shape 50 is obtained, for example, by depressions that are easy to produce in the half-shells and then placed on top of each other in pairs. The first half-shell 11 carries the channel sections in the zx-direction and the second half-shell 12 carries the channel sections in the zy-direction. A zx section is overlapped with a zy section. The continued and alternating overlap ensures a helical course for liquid transport. The two half-shells complement each other on the channel side to form the helical channel shape 50 and also offer a surface on their two rear sides for installing heat-dissipating components, such as power semiconductors 20, which are mounted on one side as shown in the figure, or other electronic power components such as capacitors.

The overlap is selected in such a way that, in the example, a channel cross section perpendicular to the central flow direction always remains constant (for example 6 mm ² ). Cross sections from 1 mm ² to more than 100 mm ² are also conceivable here; this depends on the cooling task and the permitted pressure drop in the channels and can be adapted to the specific task. On the side of the power dissipation generating component is the wall thickness of the cooler up to the channel inner top surface (heat transition zone) in the example not thicker (stronger) than 5 mm.

These geometric variants can be applied to other multi-part heat sinks with the same basic principle.

Figure 12 shows the extracted mean flow vectors of the two-part embodiment of the helix channel cooler unit in a perspective see-through representation (X-ray image), the flow vectors 60 of the helix being represented.

In becomes a channel region of the extracted mean flow vectors 60 from shown without drawn helix channel shape.

shows an example of a possible design of a helical channel shape 50 in a heat sink 10. The figure shows a plan view of the channel sections in the zx direction 70 of the second half-shell 12 with media access 30 and media outlet 31 on the left and in the middle a plan view of the channel sections in zy -Direction 71 of the first half-shell 11. On the right, the resulting (symbolic) mean flow vectors 60 in the helical channel shape 50 in the heat sink 10 consisting of the two half-shells are shown in a perspective view (X-ray image). In this example, the generated channel depth is at least the channel width.

The channel sections can be made using a variety of manufacturing processes, including combined ones, such as machining, embossing, deep-drawing or additive metal manufacturing.

The heat sink 10 consists of at least one metal, preferably a metal with good thermal conductivity, such as copper alloys, aluminum alloys or the like. Corrosion-inhibiting materials such as stainless steel are advantageous for use in a media/liquid cooler. A further advantageous variant consists in a channel formation made of aluminum and a materially connected, heat-spreading insertion of a copper layer between the aluminum part and the components generating power loss.

In addition, there is the possibility of providing thermal contact surfaces for further components that generate power losses on the narrow sides of the helix channel cooler unit 1 or its half-shells.

In a possible design of a grouped and connected channel arrangement of a helix channel shape 50 of a heat sink 10 as part of a helix channel cooler unit 1 is shown as an example. The figure shows a top view of the channel sections in the zx direction 70 of the second half-shell 12 with media access 30 and media outlet 31 on the left and a top view of the channel sections in the zy-direction 71 of the first half-shell 11 in the middle the channel sections are each lined up in several channel strips. Serial connections between the individual channel strips are provided in the middle. This is made clear by the partially enlarged channel sections in the zy direction 71 of the first half-shell 11. On the right are the resulting (symbolic) mean flow vectors 60 in the helix channel shape 50 in the heat sink 10 consisting of the two half-shells in a perspective view (X-ray image ) shown.

The chaining and arrangement of multiple ducts shown is particularly suitable for uniformly cooling a planar arrangement of heat-generating components. In this case, a serial connection of the duct strips, as shown by way of example, can advantageously be implemented in order to reduce temperature gradients. A further possibility offers a parallel flow through individual ducts. In a further variant, it is also possible to place media access 30 and media outlet 31 on the same side of the body, instead of on different or opposite sides.

shows an exemplary two-part embodiment of a helix channel cooler unit 1 for power electronic semiconductor assemblies with the power electronic semiconductor assemblies being built up on both sides on the heat sink 10 in a sectional view. The helix channel cooler unit 1 consists of a heat sink 10 having a first half-shell 11 and a second half-shell 12 arranged below the first half-shell 11, with the media inlet 30 and the media outlet 31 in the first half-shell 11 at the opposite ends of the half-shell lay. Media access 30 and media outlet 31 are connected to one another by a helical channel shape 50 . Semiconductor components 40 with power semiconductors 20 are mounted on the outwardly directed surfaces of the first half-shell 11 and the second half-shell 12 as an example of components that generate power losses. These components that generate power loss are preferably materially connected to the cooler metal of the half-shells, for example by soldering or low-temperature sintering.

1 shows an exemplary two-part embodiment of the helix channel cooler unit 1 for power electronic semiconductor assemblies in sectional view, with the first Half-shell 11 and the second half-shell 12 are functionally expanded to form the first heatsink half-shell 90 and the second heatsink half-shell 91 .

In the figure, in addition to the components in two capacitors, namely a first capacitor 80 and a second capacitor 81 are shown. The two capacitors are each installed next to the media inlet 30 and the media outlet 31 of the end faces of the heat sink 10 . The helix channel cooler unit 1 is in thermal contact with the capacitors of the power electronic system in this example, and the first half-shell 11 and the second half-shell 12 thus become the first heat sink half-shell 90 and the second heat sink half-shell 91 functionally expanded. According to the figure, the first capacitor 80 is partially integrated into the half-shells of the heat sink and the second capacitor 81 is, for example, fully integrated into the half-shells of the heat sink. In principle, such contacting of components to be cooled is not limited to semiconductor components.

The cuboid volume of the two-part helix channel cooler unit 1 has a total of up to six surfaces that can be given functions: Up to two surfaces each have a media inlet 30 and a media outlet 31.

In addition to the two-piece embodiment shown in the figures, a one-piece embodiment is also possible. The one-piece embodiment has internal helical channels of a type that can only be made by one-piece additive manufacturing. In this embodiment, too, the components that generate the power loss can be built up on the larger, opposite planar surfaces. The additional advantage of the one-piece variant compared to the two-piece variant is the possibility of compensating for different heat flows with different loads on the components that generate heat (power loss).

Reference List

1

Helix channel cooler unit

10

heatsink

11

first half shell

12

second half shell

20

power semiconductors

30

media access

31

media outlet

40

semiconductor components

50

Helix channel shape

60

flow vectors

70

Channel sections in the z-x direction

71

Channel sections in the z-y direction

80

first capacitor

81

second condenser

90

first heatsink half shell

91

second heat sink half shell

Claims (8)

Helix channel cooler unit (1) for electronic assemblies with three-dimensional channel routing having - a heat sink (10); - a media access (30); - a media outlet (31); - a helical channel shape (50); - At least one power loss generating component; - the heat sink (10) includes the helical channel shape (50) and the media inlet (30) and media outlet (31) are located on the surface of the heat sink; and - a medium enters the helix channel shape (50) via the media access (30) and leaves it again via the media outlet (31); - At least one component generating power loss is mounted on at least one surface of the heat sink (10); and - a forced helical flow movement of the medium and thus a better heat transfer along the channel walls is generated by the three-dimensional channel guidance, characterized in that - the helical channel shape (50) has channel sections combined into a helix. Helix channel cooler unit (1) after claim 1 , characterized in that the heat sink (10) is cuboid. Helix channel cooler unit (1) after claim 1 or 2 , characterized in that the heat sink (10) - is formed in one piece or - in two parts with a first half-shell (11) and a second half-shell (12). Helix channel cooler unit (1) according to any one of the preceding claims, characterized in that the different surfaces of the heat sink (10) are at least partially or completely and are equipped independently of one another with components that generate power loss. Helix-channel cooler unit (1) according to one of the preceding claims, characterized in that components generating power losses comprise semiconductor components (40) and/or capacitors. Helix channel cooler unit (1) according to one of the preceding claims, characterized in that the heat sink (10) is made of a metal, a metal alloy and/or ceramic materials, preferably copper alloys, aluminum alloys, silicon nitride, aluminum nitride, zirconia, nickel, stainless steels. Helix channel cooler unit (1) after claim 3 , characterized in that in a two-part design, the first half-shell (11) and the second half-shell (12) are functionally expandable to form a first heat sink half-shell (90) and a second heat sink half-shell (91). Helix channel cooler unit (1) after claim 3 , characterized in that in a two-part design the helical channel shape (50) is obtained by forming depressions in the half-shells and then placing the half-shells on top of one another in pairs, the half-shells having the channel sections on different levels between the coordinate axes in the Cartesian coordinate system and the channel sections overlap so that a helical course is formed.

Images