DEVICE FOR THE TRANSFER OF HEAT

Abstract

The present invention relates to a device for transferring heat 116, comprising: a first heat sink 106 with a first surface 102; a second heat sink 114 with a second surface 110, wherein the second surface 110 faces the first surface 102; a first thermal conductivity material 118 with a low compressibility; and a second thermal conductivity material 120 with a higher compressibility than the first thermal conductivity material 118; wherein the first heat sink 106 and the second heat sink 114 can be moved relative to each other under the influence of force; wherein the second heat sink 114 has recesses 112 extending away from the first surface 102, the recesses 112 having at least an inner surface 113 and a bottom surface 113'; wherein the first heat sink 106 has projections 104 which extend into the recesses 112, the projections 104 having at least an outer surface 105 and a closing surface 105';wherein the first thermal conductivity material 118 is arranged between the first heat sink 106 and the second heat sink 114 such that the at least one inner surface 113 and the at least one outer surface 105 are thermally coupled to each other; wherein the second thermal conductivity material 120 is arranged between the first heat sink 106 and the second heat sink 114 such that the bottom surface 113' and the end surface 105' are thermally coupled to each other.

Description

Technical field

[0001] The present invention relates to the cooling of electronic components. In particular, the present invention relates to a device for transferring heat and a device for cooling a heat-generating component. Furthermore, the present invention relates to a vehicle. Technical background and task

[0002] Cooling electrical components, especially in vehicles, plays a crucial role in the performance, efficiency, and longevity of modern power electronics such as high-performance computing (HPC) units. Efficient thermal management is also essential for meeting the challenges of electromobility. Power electronics and electric motors in vehicles generate significant amounts of heat at high voltages and currents. Effective cooling is necessary to maintain these components within an optimal temperature range, ensuring their performance and extending their lifespan. Without adequate cooling, sensitive components can quickly suffer permanent damage.

[0003] The efficiency of a cooling system has a direct impact on the lifespan of the components being cooled. The more efficient the cooling, the less energy is required for thermal management.

[0004] Current technologies, however, have some drawbacks. Increased complexity due to multiple cooling circuits necessitates precise control via electric valves and sensors. This complexity not only increases costs but also the risk of malfunctions. Although modern cooling systems have become more efficient, they still consume a significant portion of the vehicle's available energy. This can negatively impact range, especially in extreme climates.

[0005] Conventional cooling systems often use passive cooling elements connected to liquid cooling circuits or air cooling. In these systems, heat transfer from the heat source through multiple elements to heat dissipation must be ensured to guarantee sufficient cooling.

[0006] Thermal interface materials (TIMs), such as pastes, pads, or elastomers, are frequently used for the transitions between individual elements during heat transfer. However, manufacturing tolerances and vehicle movement cause these transitions to shift relative to one another. This places a requirement on the cooling system to bridge any resulting gaps to prevent heat transfer from being impeded. Current cooling systems do not optimize heat transfer while simultaneously compensating for tolerances in all directions.

[0007] CN 1 07 197 588 A relates to a heat transfer device comprising a first heat sink with a first surface and a second heat sink with a second surface, the second surface facing the first surface. The device further comprises a thermal interface material. The first heat sink and the second heat sink can be moved relative to each other under the influence of force. The second heat sink has recesses extending away from the first surface, the recesses having at least an inner surface and a bottom surface. The first heat sink has projections extending into the recesses, the projections having at least an outer surface and a terminal surface. The thermal interface material is arranged between the first heat sink and the second heat sink such that the at least one inner surface and the at least one outer surface are thermally coupled to each other.It is therefore an object of the present invention to provide devices for transferring heat and for cooling a heat-generating component, which overcome at least one of the aforementioned disadvantages. Furthermore, it is an object of the invention to provide a corresponding vehicle. Disclosure of the invention

[0008] The problem is solved according to the invention by the features of the main claims. Advantageous embodiments can be found in the dependent claims.

[0009] According to a first aspect of the invention, a heat transfer device comprises a first heat sink with a first surface. The first heat sink can be designed, for example, as a finned heat sink, a pin heat sink, or extruded profiles. It can be designed as a passive heat sink or an active heat sink, for example, with an air or water cooling channel. The first surface does not necessarily describe a surface of the first heat sink. It can, for example, correspond to a reference surface of the first heat sink, such as a plane along two dominant axes of the first heat sink (e.g., in the plane of a width and length direction). However, the first surface does not have to be a plane, but can, for example, also be curved.

[0010] Furthermore, according to the first aspect, the device has a second heat sink with a second surface, the second surface facing the first surface. Analogously, what applies to the first heat sink and its first surface also applies to the second heat sink and its second surface.

[0011] The first and second surfaces face each other, meaning that the first heat sink is positioned opposite the second heat sink.

[0012] Furthermore, according to the first aspect, the device features a first thermal conductivity material with low compressibility. For example, the first thermal conductivity material exhibits a compression set of approximately 2%. Silicone elastomers are an example of such a material.

[0013] Furthermore, according to the first aspect, the device incorporates a second thermal conductivity material with a higher compressibility than the first thermal conductivity material. For example, the second thermal conductivity material is a silicone foam, which typically exhibits a compression set of approximately 25%.

[0014] The first and second heat sinks can be moved relative to each other under the influence of a force. This need not be an intentional relative movement, but can, for example, result from movement of the entire device. For instance, electronic components in vehicles and the cooling systems used to cool them are subject to vibrations and shocks caused by the vehicle's movement. Such vibrations, for example caused by the engine, and shocks, for example due to an uneven road surface, are transmitted through the vehicle's body to the components of the cooling systems.

[0015] Furthermore, the second heat sink has recesses extending away from the first surface. These recesses have at least one inner surface and one bottom surface. The cross-section of the recesses can have various geometries, such as round, square, rectangular, or triangular.

[0016] The first heat sink has protrusions that extend into the recesses. These protrusions have at least one outer surface and one end surface. The protrusions thus engage with the recesses as counterparts. They do not make contact, or at least not completely. Typically, the inner surface of the recesses and the outer surface of the protrusions are positioned opposite each other with a gap. The same applies to the base surface and the end surface.

[0017] The first thermal interface material is positioned between the first and second heat sinks such that at least one inner surface and at least one outer surface are thermally coupled. The first thermal interface material is thus located between the inner surface of the recesses and the outer surface of the projections. This allows heat to be transferred from the second heat sink to the first.

[0018] Although the first thermal interface material has low compressibility, some compensation is possible within a tolerance layer because sufficient free space can be provided for the first thermal interface material to expand when a force is applied. This free space can be located, for example, between the base surface and the end face. However, this typically reduces the thermal conductivity because it is filled with air. If the free space were filled with the first thermal interface material, significant tolerance compensation would no longer be possible due to its low compressibility.

[0019] Therefore, the second thermal interface material is positioned between the first and second heat sinks in such a way that the base and end surfaces are thermally coupled. This also enables thermal flow at this point, improving the overall heat transfer from the first to the second heat sink. Due to the higher compressibility of the second thermal interface material, tolerance compensation is maintained in all directions.

[0020] Advantageously, the recesses and / or projections have a round, square, rectangular, or triangular cross-section. Depending on the requirements of the device, the geometry and arrangement that exhibits the best thermal properties can therefore be selected.

[0021] Advantageously, the first thermal interface material is a silicone elastomer. This material is already used in a wide variety of applications. It is readily available and inexpensive.

[0022] Advantageously, the second thermally conductive material is a foam. For example, silicone foam, graphene foam, boron nitride / epoxy composite foam, or metal foam can be used. Foam has the advantage of conforming well to surfaces, even uneven ones. It can also absorb shocks and vibrations. Since the foam is also a thermally conductive material, it exhibits good thermal conductivity.

[0023] Advantageously, the first heat sink has a channel for guiding a cooling medium. This improves the heat conduction of the first heat sink. The cooling medium can be, for example, air, water, a dielectric fluid, or oil.

[0024] Advantageously, the device has a channel between the first and second heat sinks for guiding a cooling medium. This channel can be made of various materials; for example, it can be designed as a flexible pad.

[0025] Advantageously, the first heat sink is part of an enclosure. Electronic components can be mounted in enclosures. This has advantages, for example, regarding the shielding of electrical interference. If the first heat sink is part of the enclosure, this simplifies the design of the entire cooling system. Fewer parts are required, which can contribute to lower costs.

[0026] According to a second aspect of the invention, a device for cooling a heat-generating component comprises, in addition to the heat-generating component, a device for transferring heat as described above. The heat transfer device is arranged such that the heat-generating component is thermally coupled to the second cooling element.

[0027] The heat-generating component can be, for example, a CPU (central processing unit), a GPU (graphics processing unit), an ECU (electronic control unit), or an MCU (motor control unit). Any electronic component that generates significant heat can be cooled using the invention.

[0028] Advantageously, the heat-generating component is arranged on a circuit board and the second heat sink is positively connected to the circuit board by means of a fastening.

[0029] According to a third aspect of the invention, a vehicle has a device as described above. Summary of the characters

[0030] The invention is explained in more detail below using exemplary embodiments and the accompanying figures. The figures show: Fig. 1: An embodiment of a first heat sink; Fig. 2: An embodiment of a second heat sink; Fig. 3: An embodiment of a device for transferring heat; Fig. 4: Examples of recesses or projections; Fig. 5: An embodiment of a device for cooling a heat-generating component; and Fig. 6: A vehicle with the device made of Fig. 5. Detailed description of the figures

[0031] Fig. Figure 1 shows an embodiment of a first heat sink 106.

[0032] The first heat sink 106 is initially formed with a cuboid-shaped first base 100. This has a first surface 102.

[0033] Projections 104 are arranged on the first base 100. In the example of Fig. 1 from the first surface 102 outwards. The projections 104 can be arranged on the first base 100 in different ways. For example, they can be milled from a material to form a fit. Bending or gluing are also possible methods for arranging the projections 104 on the first base 100.

[0034] The projections 104, which in the example of Fig. The cylindrical components have an outer surface 105 and a top surface 105'. The top surface 105' corresponds to the bottom of the cylinder.

[0035] Fig. Figure 2 shows an embodiment of a second heat sink 114.

[0036] The second heat sink 114 is initially formed with a cuboid-shaped second base 108. This has a second surface 110.

[0037] Recesses 112 are arranged on the second base 108. These have, in the example of Fig. 2 from the second surface 110 into the interior of the second base 108. The recesses 112 can be arranged on the second base 108 in different ways, for example by milling, etching or cutting.

[0038] The exceptions 112, which in the example of Fig. The two cylindrical shapes have an inner surface 113 and a base surface 113'. The inner surface 113 corresponds to the inner surface of the cylinder.

[0039] Fig. Figure 3 shows an embodiment of a device for transferring heat 116. The device for transferring heat 116 is shown as a sectional drawing in a section plane and is formed with the first heat sink 106 made of Fig. 1 and the second heat sink 114 from Fig. 2.

[0040] In Fig. Figure 3 shows that the first surface 102 of the first heat sink 106 faces the second surface 110 of the second heat sink 114. It can also be seen that the recesses 112 of the second heat sink 114 extend away from the first surface 102. The projections 104 extend into the recesses 112 without contacting them.

[0041] A first thermally conductive material 118, which exhibits low compressibility, is arranged between the inner surface 113 and the outer surface 105, thus thermally coupling the first heat sink 106 and the second heat sink 114. In other words, this arrangement already allows heat to flow from the second heat sink 114 to the first heat sink 106. The first thermally conductive material 118 also enables a certain degree of tolerance compensation in a section plane along a section line 122, as it can expand into the existing cavities. The first thermally conductive material 118 can, for example, be a silicone elastomer.

[0042] The space between the end surfaces 105' of the projections 104 and the floor surfaces 113' of the recesses 112 is filled with a second thermally conductive material 120. This space usually contains only air, which has poor thermal conductivity. The second thermally conductive material 120, however, now also enables heat transfer across this space.

[0043] The second thermal conductivity material 120 has a higher compressibility than the first thermal conductivity material 118. This ensures that tolerance compensation perpendicular to the cutting plane along the cutting line 122 is also possible. The second thermal conductivity material 120 can, for example, be a graphene foam.

[0044] The first heat sink 106 may be provided with a channel for conveying a cooling medium such as water or air (not shown). Furthermore, the free space between the first heat sink 106 and the second heat sink 114 can be used to convey a cooling medium. This further increases the cooling capacity.

[0045] Fig. Figure 4 shows exemplary embodiments for recesses 112 or projections 104. The exemplary embodiments are shown in the section plane along the section line 122. Fig. 3 shown.

[0046] In addition to a triangular cross-section, square, round, or rectangular cross-sections are shown. Oval cross-sections or combinations of the geometries shown are also possible. In the example of Fig. 4. The geometries of the projections 104 are identical to those of the recesses 112, which is why the first thermal conductivity material 118 also has the same geometry. However, it is also possible to provide different geometries for the projections 104 and recesses 112, for example, round recesses 112 and triangular projections 104. The first thermal conductivity material 118 must then be adapted to the resulting free space.

[0047] Fig. Figure 5 shows an embodiment of a device for cooling a heat-generating component 124.

[0048] A component 126 to be cooled, for example a processor or an ECU (electronic control unit), is arranged on a printed circuit board 128. The component 126 to be cooled is further thermally connected to the heat transfer device 116 by means of a thermal paste 130. Fig. 3 coupled. To stabilize the thermal coupling, the heat transfer device 116 is positively connected to the circuit board 128 by means of a fastening 132. The fastening 132 can be implemented, for example, by screws or soldering.

[0049] In the example of Fig. 5 is the first heat sink 106, part of a cover component. The printed circuit board 128 is arranged in the housing, which can be closed by the cover. The housing, the cover, and thus the first heat sink 106 are made of an electrically conductive material, so that when the cover is closed, the printed circuit board and all components arranged on it are shielded from interference radiation. The cover thus fulfills several purposes: cooling and electrical shielding.

[0050] Fig. Figure 6 shows a vehicle 134 with the device 124 made of Fig.5. The device for cooling a heat-generating component 124 can be used, for example, in an HPC (high-performance computer), i.e., a central computer, a zone control unit, an infotainment system, or a HUD (head-up display). Virtually all electronic components in the vehicle 134 can be cooled using the device for cooling a heat-generating component 124. Reference symbol list 100 First Base 102 First area 104 lead 105 outdoor area 105' end area 106 First heat sink 108 Second Base 110 Second area 112 Exclusion 113 interior surface 113' floor area 114 Second heat sink 116 Device for transferring heat 118 First thermal conductivity material 120 Second thermal conductivity material 122 Section line 124 Device for cooling a heat-generating component 126 Component to be cooled 128 circuit boards 130 thermal paste 132 Fastening 134 vehicles

Claims

[1] Heat transfer device (116) comprising: - a first heat sink (106) with a first surface (102), - a second heat sink (114) with a second surface (110), wherein the second surface (110) faces the first surface (102), - a first thermal conductivity material (118) with low compressibility, and - a second thermal conductivity material (120) with a higher compressibility than the first thermal conductivity material (118), - wherein the first heat sink (106) and the second heat sink (114) can be moved relative to each other under the influence of force, - wherein the second heat sink (114) has recesses (112) extending away from the first surface (102), the recesses (112) having at least an inner surface (113) and a bottom surface (113'), - wherein the first heat sink (106) has projections (104) which extend into the recesses (112), the projections (104) having at least an outer surface (105) and a end surface (105'), - wherein the first thermal conductivity material (118) is arranged between the first heat sink (106) and the second heat sink (114) such that the at least one inner surface (113) and the at least one outer surface (105) are thermally coupled to each other, - wherein the second thermal conducting material (120) is arranged between the first heat sink (106) and the second heat sink (114) such that the bottom surface (113') and the end surface (105') are thermally coupled to each other. [2] Device according to claim 1, characterized in that the recesses (112) and / or the projections (104) have a round, square, rectangular or triangular cross-section. [3] Device according to claim 1 or 2, characterized in that the first thermal conductivity material (118) is a silicone elastomer. [4] Device according to one of the preceding claims, characterized in that the second heat-conducting material (120) is a foam. [5] Device according to one of the preceding claims, characterized in that the first cooling element (106) has a channel for guiding a cooling medium. [6] Device according to one of the preceding claims, characterized in that a channel for guiding a cooling medium is provided between the first cooling element (106) and the second cooling element (114). [7] Device according to one of the preceding claims, characterized in that the first heat sink (106) is part of a housing. [8] Device for cooling a heat-generating component (124), comprising: - the heat-generating component (126), and - the device for transferring heat (116) according to one of the preceding claims, arranged such that the heat-generating component (126) is thermally coupled to the second heat sink (114). [9] Device according to claim 8, characterized in that the heat-generating component (126) is arranged on a printed circuit board (128) and the second heat sink (114) is positively connected to the printed circuit board (128) by means of a fastening (132). [10] Vehicle (134) comprising a device (116,124) according to one of the preceding claims.

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