Controller

Abstract

The invention relates to a control device having a housing (102) in which an electronic unit to be cooled is arranged, at least one space (130) being also arranged in the housing (102), said space being at least partially filled with a phase change material (132).

Description

Technical Field

[0001] The present invention relates to a controller, especially a controller for a motor vehicle. Background Art

[0002] A controller is an electronic module that is especially used in places where devices or processes are controlled and / or regulated. Controllers are used to control machines, equipment, and other technical processes. Controllers are widely used in motor vehicles.

[0003] A controller used in a motor vehicle is also called an automatic controller. An automatic controller set for automated or highly automated driving can be classified into three levels regarding its cooling. Devices with little waste heat (i.e., less than 30 W in the controller) can be passively cooled via fins according to the installation location. For this, reference can be made to Figure 1 .. Devices with high waste heat are cooled via external or internal ventilators that guide the cooling air through cooling fins. In addition, a water cooling system is used starting from a waste heat of approximately 100 W. In this regard, reference can be made to Figure 2 .

[0004] A system with external water cooling is especially important for highly automated driving functions because such systems usually require high computing power and thus also generate more system waste heat. As an additional requirement for such highly automated systems, a safety system still needs to be considered, which is used to rule out or sufficiently delay a fault situation in time, i.e., not exceed the critical temperature of the SoC (System on Chip) within a specified time period.

[0005] A typical fault situation for such a system is the failure of the cooling water flow (e.g., due to a blockage of the cooler pump). The corresponding application situation in automated driving should be ensured by appropriate measures so that the motor vehicle can enter a safe driving state through the motor vehicle software on the SoC within a certain time period, i.e., within a few seconds to half an hour. Therefore, the SoC of the ADAS unit (ADAS: Automated Driving and Steering) cannot be shut down or its frequency reduced during this time period because full functionality is required here until the stop state.

[0006] One measure is to install materials with high heat capacity, such as metals. However, the location and weight for the controller (ECU: electronic control unit) are restricted. Another feasibility is either through a separate pump or through a redundant cooling path with active air cooling. However, both methods are associated with significant expenses and costs. Additionally, this active air cooling presents a new potential source of failure due to hardly running, which also has to be structurally resolved. Summary of the Invention

[0007] Based on this background, a controller with the features of the present invention is proposed. The embodiments are derived from the description and the drawings.

[0008] The proposed controller has a housing in which an electronic unit to be cooled is arranged. The housing can have a controller front side and a controller rear side. In the housing, at least one space is also arranged, and the at least one space is at least partially (completely in the configuration) filled with a phase change material (PCM).

[0009] The phase change material (PCM: Phase Change Material) is a so-called latent heat storage, which stores a large share of thermal energy and cooling energy over a long time and can release it again without loss. Here, the reversible thermodynamic state change of the storage medium is utilized, for example, in the case of the phase change from the solid state to the liquid state.

[0010] The use of PCM in the automotive field has so far been limited to use in the battery thermal management of electric vehicles.

[0011] SoC (System-on-Chip) is an integrated circuit in which a large number of functions of a programmable electronic system are implemented. In the SoC, all functions are integrated on a semiconductor substrate. The system is understood in this case as a combination of different elements that together provide a certain function.

[0012] In the configuration, a low-cost solution is proposed for a time-limited heat sink inside the ADAS controller, which can receive a defined amount of heat within a defined time. Here, it is ideal that this process is reversible so that the controller does not have to be replaced in case of a cooler failure. Additionally, other actuators, such as pumps, ventilators, etc., which are other possible sources of failure, should not be installed.

[0013] In the configuration, a sufficient amount of PCM material is provided inside the water-cooled ADAS controller so that the time-limited heat through the phase change can be buffered.

[0014] The proposed controller has the following advantages in at least some embodiments:

[0015] There is the following feasibility: There is no external actuator to buffer the time-limited heat, so that the SoC of the ADAS function remains fully operational throughout its usage time.

[0016] For this solution, there is no need to install redundant external pumps or redundant heat transfer systems, such as additional ventilators in addition to the water cooling section.

[0017] Compared with typical structural materials (such as metals), the PCM provides 10 to 100 times higher heat storage capacity within a predefined temperature range.

[0018] The PCM can be shaped very flexibly and can fill a vast area of the cavity of the controller.

[0019] The heat reception and thus the phase conversion of typical PCMs (such as paraffin) are reversible. This means that in the case of such a fault situation, it is not mandatory to replace the controller and the controller can continue to be used.

[0020] Other advantages and configurations of the present invention can be derived from the description and the drawings.

[0021] It should be understood that the features mentioned above and to be explained below can be used not only in the combinations given respectively, but also in other combinations or alone, without departing from the framework of the present invention. Description of the Drawings

[0022] Figure 1 In the schematic diagram, a controller with a passively cooled housing according to the prior art is shown;

[0023] Figure 2 In the schematic diagram, a controller with a water-cooled housing according to the prior art is shown;

[0024] Figure 3 In the schematic diagram, an embodiment of the proposed controller is shown;

[0025] Figure 4 In the schematic diagram, another embodiment of the proposed controller is shown;

[0026] Figure 5 In the graph, the temperature change curves of blocks of different materials are shown.

[0027] Figure 6 Another embodiment of the proposed controller is shown;

[0028] Figure 7 Another embodiment of the proposed controller is shown. Detailed Description of the Invention

[0029] The present invention is schematically illustrated in the accompanying drawings according to an embodiment and will be described in detail hereinafter with reference to the drawings.

[0030] Figure 1 A controller according to the prior art is shown, which is generally identified by reference numeral 10. The controller 10 has a passively cooled housing 12, which has a controller front side 14 and a controller rear side 16. The controller front side 14 provides cooling fins 18 for cooling. In the housing 12, a printed circuit board (PCB) 20 with a SoC 22 arranged thereon is provided. The shown controller 10 generates little waste heat, typically less than 30 W, such that passive cooling with the cooling fins 18 is sufficient.

[0031] Figure 2 A controller 50 with a water-cooled housing 52 according to the prior art is shown. The housing 52 has a controller front side 54 and a controller rear side 56. Cooling fins 58 are molded on the controller front side 54 again, which provide passive cooling. A circuit board 60 and a SoC 62 arranged thereon are provided in the controller 50 or in the housing 52. In addition, a cooling channel 70 is provided above the SoC 62 in the housing 52, and a cooling liquid 72 is guided in the cooling channel.

[0032] The shown controller 50 generates typically about 100 W of waste heat, such that the cooling liquid 72 is used for sufficient cooling and thus water cooling is used in this case. It should be further noted that Figure 2 no external connectors are shown. The controller 50 is typically connected to an external cooling circuit.

[0033] Figure 3 An embodiment of the proposed controller is shown, which is generally identified by reference numeral 100. The controller 100 has a housing 102, which in turn includes a controller front side 104 and a controller rear side 106. Cooling fins 108 are molded on the controller front side 104, which provide passive cooling. A circuit board 110 and a SoC 112 arranged thereon are provided in the controller 100 or in the housing 102. In addition, a cooling channel 120 is provided above the SoC 112 in the housing 102, and a cooling liquid 122 is guided in the cooling channel.

[0034] In addition, two spaces or cavities 130 are provided on both sides of the SoC 112 in the controller 100, and these two cavities are at least partially or completely filled with a phase change material (PCM) 132. Since the phase change material can become liquid during its use, the phase change material is usually encapsulated, especially micro-encapsulated. It should be further noted that Figure 3The external connector is not shown. The controller 100 is typically connected to an external cooling circuit.

[0035] Figure 3 It is illustrated that the phase change material 132 is installed in the water-cooled controller 100, where the phase change material 132 is mounted laterally beside the SoC 112. For time-limited and previously calculated fault situations in particular, the phase change material 132 receives the waste heat that the controller 100 cannot discharge especially in the event of a fault. In addition, the phase change material 132 is selected such that the phase transition point (Phasenübergangspunkt) lies outside the operating point of the liquid cooling section. Thus, in the case of a maximum operating point of 50 °C in the cooling liquid, a phase change material 132 with a phase transition temperature of 60 °C can be envisaged.

[0036] The space 130 and thus the phase change material 132 should be arranged such that as high a heat flux as possible is introduced into the phase change material in the case of stationary cooling liquid. This can occur through direct mechanical contact between the phase change material and the cooling channels in the immediate vicinity of the SoC, for example as shown in Figure 3 Here, due to the smaller heat flux, the heat no longer flows through the possibly stationary liquid flow, but through the metal of the cooling channels 120 to the phase change material 132. The possibility of not increasing the heat flux is shown in Figure 4 In

[0037] Figure 4 An embodiment of the proposed controller is shown, which is generally identified by the reference numeral 150. The controller 150 has a housing 152, which in turn includes a controller front side 154 and a controller rear side 156. Cooling fins 158 are molded on the controller front side 154, and the cooling fins provide passive cooling. A circuit board 160 and a SoC 162 arranged thereon are provided in the controller 150 or in the housing 152. In addition, a cooling channel 170 is provided above the SoC 162 in the housing 152, and the cooling liquid 172 is directed through the cooling channel.

[0038] In addition, two spaces 180 are provided on both sides of the SoC 162 in the controller 150, and the two spaces are at least partially or completely filled with a phase change material (PCM) 182. It should also be noted that in Figure 4 the external connectors are not shown. The controller 150 is typically connected to an external cooling circuit. This also applies to Figure 6 and 7 other embodiments.

[0039] According to Figure 4A small metal cooling strip 184 protrudes into the phase change material 182 and in this way significantly improves the heat transfer into the space 180 filled with the phase change material 182. Attention should be paid to the ratio of the metal to the phase change material here. This construction method is mainly due to the low thermal conductivity of typical phase change materials (such as paraffin). This cooling strip 184 can also be arranged in Figure 6 and 7 embodiments.

[0040] In Figure 5 the working mode of the phase change material relative to the heat sink is shown. Figure 5 A diagram 200 is shown, on whose abscissa 202 time [s] is marked and on whose ordinate 204 temperature [°C] is marked. The first curve 210 shows the temperature change curve of a copper block of 4567 g, while the second curve 212 shows the temperature change curve of a phase change material block of 410 g.

[0041] According to Figure 5 , the same heat flow is conducted through the phase change material or blocks of the same size but different weights of copper. In this simulation, the phase change material has a phase change temperature of approximately 70 °C. Therefore, if the phase transition temperature of the material can be identified at approximately 70 °C, in this case the phase change material remains at almost a constant temperature for a long time. In addition, it can be seen that with the same volume and a time-limited cooling duration, a significant weight reduction is achieved by using the phase change material.

[0042] The phase change material can be installed everywhere in the controller at positions that reach a state of high heat flow in case of a fault, such that the critical temperature in the SoC, as an example of an electronic unit, cannot be exceeded. This is different according to the structure of the controller, however some exact mounting locations can be identified across variants.

[0043] Figure 6 An embodiment of the proposed controller is shown, which is generally identified by the reference numeral 250. The controller 250 has a housing 252, which in turn includes a controller front side 254 and a controller rear side 156. Cooling fins 258 are molded on the controller front side 254, which provide passive cooling. A circuit board 260 and an SoC 262 arranged thereon are provided in the controller 250 or in the housing 252. In addition, a cooling channel 270 is provided above the SoC 262 in the housing 252, through which a cooling liquid 272 is directed, and a heat dissipation strip 276 protrudes into the cooling liquid 272. In addition, in the housing 252, a second circuit board 280 is arranged on the controller front side 254.

[0044] The illustration also shows three spaces 290 filled with phase change material 292. Of these three spaces, two spaces are arranged on both sides of the SoC 262 and one space is arranged above the cooling channel 270. Thus, the controller 250 has a cooling channel 270 with phase change material 292 present above it. The cooling liquid 272 heats the upper side of the cooling channel 270 and thus the phase change material 292 by its own convection.

[0045] One basic variant is that the phase change material is directly constructed above the SoC. This is mainly practical for controllers mounted flat, since the cooling liquid heated by natural convection increasing heat heats the upper side of the cooling channel 270 and thus the controller 250. The amount of the corresponding phase change material can be placed here according to the thermal conductivity of the material of the cooling channel 270 and the material thickness.

[0046] The built-in cooling bar 276 can additionally be implemented, where heat conduction takes place particularly efficiently here and generates as little thermal resistance as possible for the opposite faces.

[0047] Providing a vertically mounted controller and circuit board as an alternative structural form, as shown in Figure 7 is shown.

[0048] Figure 7 Another embodiment of the proposed controller is shown, which is generally identified by the reference numeral 300. The controller 300 has a housing 302, which includes a controller front side 304 and a controller rear side 306. Cooling fins 308 are molded on the controller front side 304, and the cooling fins provide passive cooling. A first circuit board 310 and a SoC 312 arranged thereon are provided in the controller 300 or in the housing 302. In addition, a cooling channel 320 is provided above the SoC 312 in the housing 302, and the cooling liquid 322 is guided in the cooling channel and protrudes into the cooling liquid 322 by the heat dissipation bar 326. In addition, in the housing 302, a second circuit board 330 is arranged on the controller front side 304.

[0049] The schematic diagram also shows three spaces 340 filled with phase change material 342. Of the three spaces, two spaces are arranged on both sides of the SoC 312 and one space is arranged above the cooling channel 320.

[0050] In this case, the heat flow (arrow 400) goes upward into the interior of the cooling channel 320, so that the phase change material 342 should be configured above both sides of the cooling channel 320. Below the heat source, the SoC 312, conversely, no greater heat flow is expected.

[0051] Depending on the orientation of the controller and the installation position of the component to be cooled, different installation variants of the phase change material are obtained. The variants shown are only a partial view of the possible installation feasibility. All have in common the principle of action of the phase change material for buffering limited heat, especially in the emergency mode of the controller.

[0052] The proposed solution is particularly suitable for water-cooled controllers and for controllers that have extended safety requirements in the event of a fault.

Claims

1. A controller having a housing (102, 152, 252, 302), in which an electronic unit to be cooled is arranged, wherein: At least one space (130, 180, 290, 340) is also provided in the housing (102, 152, 252, 302), and the at least one space is at least partially filled with a phase change material (132, 182, 292, 342).

2. The controller according to claim 1, wherein at least one cooling channel (120, 170, 270, 320) for guiding a cooling medium is provided in the housing (102, 152, 252, 302).

3. The controller according to claim 2, in which a cooling liquid (122, 172, 272, 322) is used as a cooling medium.

4. A controller according to claim 2 or 3, in which direct contact is created between at least one space (130, 180, 290, 340) in the at least one space (130, 180, 290, 340) and at least one cooling channel (120, 170, 270, 320) in the at least one cooling channel (120, 170, 270, 320).

5. The controller according to claim 4, wherein the at least one cooling channel (120, 170, 270, 320) has a cooling strip (276, 326) which protrudes into the at least one space (130, 180, 290, 340).

6. A controller according to any one of claims 3 to 5, in which the phase change material (132, 182, 292, 342) selects at least one space (130, 180, 290, 340) so that the phase change point is outside the working point of the liquid cooling part set by the cooling channel (120, 170, 270, 320) and the cooling liquid (122, 172, 272, 322).

7. The controller according to any one of claims 1 to 5, in which at least one of the at least one spaces (130, 180, 290, 340) is arranged in the region of the electronic unit.

8. The controller according to claim 6, wherein spaces (130, 180, 290, 340) are respectively arranged on both sides of the electronic unit. 9 . The controller according to claim 1 , wherein the electronic unit is constructed as a system-on-chip (SoC) ( 112 , 162 , 262 , 312 ).

10. The controller according to any one of claims 1 to 9, in which at least one space (130, 180, 290, 340) of the at least one space (130, 180, 290, 340) is constructed in an encapsulated manner.

11. A controller according to any one of claims 1 to 10, in which at least one of the at least one spaces (130, 180, 290, 340) is installed at the following position, at which a high heat flow state is reached in the event of a fault, so that the critical temperature is not exceeded in the SoC (112, 162, 262, 312).

Images