WO2022228266A1 - Heat dissipation device, power module, and vehicle - Google Patents

Abstract

The present invention relates to the technical field of electronic components, and specifically relates to a heat dissipation device, a power module, and a vehicle. The heat dissipation device comprises a lower cooling plate, an upper cooling assembly, and an elastic fixing assembly; a first cooling flow channel is provided on a lower surface of the lower cooling plate; the upper cooling assembly is fixed above an upper surface of the lower cooling plate by means of the elastic fixing assembly; and the upper cooling assembly comprises a plurality of upper cooling plates, cooling channels are respectively provided within the plurality of upper cooling plates, the cooling channels communicate with one another to form a second cooling flow channel, and two ends of the second cooling flow channel sealingly communicate with the first cooling flow channel. By means of the elastic fixing assembly, the present invention can enable the upper cooling assembly to tightly press on a power device for follow-up deformation by means of the elastic deformation of the elastic fixing assembly, avoiding damage caused by reasonable deformation and excessive clamping force.

Description

A heat sink, a power module and a vehicle technical field

The invention relates to the technical field of electronic components, in particular to a heat dissipation device, a power module and a vehicle.

Background technique

In recent years, new energy vehicles have developed rapidly in the automotive industry, especially pure electric vehicles and hybrid vehicles. With the gradual improvement of new energy vehicles' requirements for battery life and energy saving, traditional IGBT motor controllers with a power density of about 15kW/L can no longer meet the needs of car manufacturers. New motor controllers with a power density of 30KW/L or even higher are developed. Imperative. Therefore, double-sided water-cooled SiC modules (power modules) have begun to be used in motor controllers. In order to give full play to the low loss performance of SiC and the high heat dissipation capability of double-sided water-cooled modules, it is necessary to develop a more efficient and reliable heat dissipation method for double-sided water-cooled SiC modules.

The prior art generally includes: bottom radiator, double-sided water cooling module, top radiator, radiator bead, and radiator fixing bolts in order from bottom to top. The whole scheme uses two radiator sandwich structure installation methods, and the two radiators and the bead are tightened by the upper bead through bolts to achieve the purpose of clamping the double-sided water-cooling module and dissipating heat. The installation sequence is performed from bottom to top.

Since the upper and lower radiators are made of hard metal, mostly cast aluminum and other materials, the deformation capacity is limited. The force of the three modules is bound to be uneven. Considering that the thickness of the module itself is also different, when the thickness of the middle module is too small, the two heat dissipation surfaces of the middle module will be greatly reduced, which will affect the heat dissipation capacity of the middle module and may cause the middle module to be overheated and damaged. When the difference in the clamping force of the module is reduced by increasing the bolt locking force, the clamping force of the modules on both sides will be too large, which may cause mechanical damage to the module in severe cases, affecting the reliability and life of the module.

On the other hand, during the use of the motor controller, due to the heating of the module, the local temperature difference between the upper and lower radiators will cause a reasonable deformation of the radiator. At this time, the stress difference between different modules will also be large, affecting the upper and lower parts of each module. effective heat dissipation, ultimately exacerbating the degree of overheating damage.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a heat dissipation device, a power module and a vehicle capable of adjusting the clamping force through self-adaptation.

In order to solve the above-mentioned technical problems, the first technical scheme adopted in the present invention is:

A heat dissipation device includes a lower cooling plate, an upper cooling assembly and an elastic fixing assembly, wherein a first cooling flow channel is opened on the lower surface of the lower cooling plate;

The upper cooling assembly is fixed above the upper surface of the lower cooling plate by an elastic fixing assembly; the upper cooling assembly includes a plurality of upper cooling plates, and cooling channels are respectively opened in the plurality of upper cooling plates, and a plurality of the cooling The channels communicate with each other to form a second cooling channel, and two ends of the second cooling channel are in sealing communication with the first cooling channel respectively.

In order to solve the above-mentioned technical problems, the second technical scheme adopted by the present invention is:

A power module, comprising a power device and the above cooling device;

The power device is located between the lower cooling plate and the upper cooling assembly.

In order to solve the above-mentioned technical problems, the third technical scheme adopted by the present invention is:

A vehicle includes the above-mentioned power module.

The beneficial effects of the present invention are: through the elastic fixing assembly, the upper cooling assembly can be tightly pressed on the power device, and each corner end of the upper cooling plate corresponds to an elastic body, so as to ensure that the module areas of the respective power devices are different from each other. The compression amount is used to adaptively compress the respective power devices, which not only meets the different clamping forces required by different power devices, but also ensures the reliable heat dissipation requirements of the power devices, avoids mechanical damage caused by excessive clamping force, and ensures the power The reliability and service life of the device; the reasonable deformation that occurs during the operation of the power device can also be followed by the elastic deformation of the elastic fixing component to avoid damage due to reasonable deformation.

Description of drawings

FIG. 1 is a schematic structural diagram of a power module according to a specific embodiment of the present invention;

Fig. 2 is the exploded view of Fig. 1;

Fig. 3 is another angle view of Fig. 2;

Figure 4 is a sectional view of a corrugated hose;

Numeral description: 1, lower cooling plate; 11, first cooling flow channel; 12, communication port; 13, heat sink; 2, upper cooling assembly; 21, upper cooling plate; 22, second cooling flow channel; 23, corrugation Hose; 231, pipe body; 232, connecting piece; 233, sealing groove; 3, elastic fixing component; 31, tray; 32, elastomer; 33, fixing piece; 34, limit post; 4, power device.

Detailed ways

In order to describe in detail the technical content, achieved objects and effects of the present invention, the following descriptions are given with reference to the embodiments and the accompanying drawings.

1 to 4, a heat dissipation device includes a lower cooling plate 1, an upper cooling component 2 and an elastic fixing component 3. A first cooling channel 11 is opened on the lower surface of the lower cooling plate 1; the Two ends of the first cooling channel 11 are respectively provided with communication ports 12;

The upper cooling assembly 2 is fixed above the upper surface of the lower cooling plate 1 by the elastic fixing assembly 3; the upper cooling assembly 2 includes a plurality of upper cooling plates 21, and cooling channels are respectively opened in the plurality of upper cooling plates 21 The cooling channels communicate with each other to form a second cooling channel 22 , and both ends of the second cooling channel 22 are in sealing communication with the communication port 12 of the first cooling channel 11 respectively.

Further, the cooling channels communicate with each other through corrugated hoses 23 to form a second cooling flow channel 22;

There is a connection part at the outlet of the cooling channel of the upper cooling plate 21;

The corrugated hose 23 includes a pipe body 231 and connecting pieces 232 at both ends, and the connecting pieces 232 are connected to the connecting parts.

Further, the connecting portion and the connecting piece 232 are threadedly connected;

The end of the tube body 231 has a first sealing cutout, the connecting piece 232 has a second sealing cutout corresponding to the first sealing cutout, and the first sealing cutout cooperates with the second sealing cutout to form a sealing groove 233, The sealing groove 233 has a sealing ring in it.

Further, the elastic fixing assembly 3 includes a tray 31, an elastic body 32 and a fixing member 33, the tray 31 is located above the upper cooling assembly 2 and is connected to the lower cooling plate 1 through the fixing member 33;

The elastic member is located between the upper cooling assembly 2 and the tray 31 to elastically press the upper cooling assembly 2 .

Further, there are multiple elastic bodies 32, and each corner end of the upper cooling plate 21 corresponds to one elastic body 32.

Further, the elastic body 32 is a spring, the tray 31 is provided with a limiting column 34 for limiting the position of the spring, and the length of the limiting column 34 is smaller than that of the spring.

Further, a plurality of cooling fins 13 are arranged in the first cooling channel 11 .

A power module, comprising a power device 4 and the above cooling device;

The power device 4 is located between the lower cooling plate 1 and the upper cooling assembly 2 .

Further, there are three power devices 4, and the upper cooling assembly 2 includes three upper cooling plates 21 corresponding to the power devices 4;

The upper surface and the lower surface of the power device 4 are coated with thermally conductive silicone grease.

A vehicle includes the above cooling device and/or the above power module.

It can be seen from the above description that the beneficial effects of the present invention are: through the elastic fixing assembly 3, the upper cooling assembly 2 can be tightly pressed on the power device 4, and each corner end of the upper cooling plate 21 corresponds to an elastic body 32, Ensure the different compression amounts of the module areas of the power devices 4 where they are located to adaptively compress the respective power devices 4, which not only satisfies the different clamping forces required by different power devices 4, but also ensures the reliable heat dissipation requirements of the power devices 4. Avoid mechanical damage caused by excessive clamping force, and ensure the reliability and service life of the power device 4; the reasonable deformation that occurs when the power device 4 is working can also be followed by the elastic deformation of the elastic fixing component 3. Reasonably deformed and damaged. Thermal grease can improve thermal conductivity.

Example 1

A heat dissipation device includes a lower cooling plate, an upper cooling assembly and an elastic fixing assembly, wherein a first cooling channel is opened on the lower surface of the lower cooling plate; two ends of the first cooling channel are respectively provided with communication ports ;

The upper cooling assembly is fixed above the upper surface of the lower cooling plate by an elastic fixing assembly; the upper cooling assembly includes a plurality of upper cooling plates, and cooling channels are respectively opened in the plurality of upper cooling plates, and the cooling channels are mutually A second cooling flow channel is formed in communication, and both ends of the second cooling flow channel are respectively in sealing communication with the communication port of the first cooling flow channel.

The cooling channels are communicated with each other through corrugated hoses to form a second cooling flow channel;

A connection part is provided at the outlet of the cooling channel of the upper cooling plate;

The corrugated hose includes a pipe body and connecting pieces at both ends, and the connecting pieces are connected to the connecting parts.

The connecting part and the connecting piece are screwed;

The end of the pipe body has a first sealing cutout, the connecting piece has a second sealing cutout corresponding to the first sealing cutout, the first sealing cutout cooperates with the second sealing cutout to form a sealing groove, and the sealing There is a sealing ring in the groove.

The elastic fixing assembly includes a tray, an elastic body and a fixing member, the tray is located above the upper cooling member and is connected to the lower cooling plate through the fixing member;

The elastic member is located between the upper cooling assembly and the tray to elastically press the upper cooling assembly.

There are multiple elastic bodies, and each corner end of the upper cooling plate corresponds to an elastic body.

The elastic body is a spring, the tray is provided with a limit column for limiting the position of the spring, and the length of the limit column is smaller than the length of the spring.

A plurality of cooling fins are arranged in the first cooling channel.

Embodiment 2

A power module, comprising three power devices (SiC) and the heat dissipation device described in Embodiment 1;

The power device is located between the lower cooling plate and the upper cooling assembly.

The upper cooling assembly includes three upper cooling plates corresponding to the power devices;

The upper surface and the lower surface of the power device are coated with thermally conductive silicone grease.

The upper cooling plate is a rounded rectangular plate, and there are 12 springs;

The installation process is:

(1), prepare the cooling plate;

(2) Place three SiC power devices (model: MD800HFC120N3S) on the lower cooling plate, and the upper and lower sides of the power devices are pre-coated with thermal grease to improve thermal conductivity;

(3) Prepare three upper cooling plates of the controller corresponding to the power devices;

(4) Install corrugated flexible connecting pipes between the three upper cooling plates;

(5) Place 12 non-standard compression springs on the upper cooling assembly;

(6) Install the circuit board tray on the lower cooling plate with bolts (the controller box structure is described in the accompanying drawings, the design of this application is to adopt the integrated design of the lower cooling plate and the control box), and then the tray is compressed 12 non-standard springs tightly press the three upper cooling plates on the three and power devices.

From the above introduction, due to the thickness deviation of different batches in the production process of various workpieces themselves, these production process control factors need to be added to the design input. Moreover, in the vehicle environment, the power module is affected by factors such as environmental temperature changes and local differences in its own heating. The stress effect of the deformation of hardware components also needs to be added to the design input.

According to the module specification, the typical clamping force of SiC power device (model: MD800HFC120N3S) is 700N, and the maximum is 850N. In order to make the thermal resistance of the three modules more consistent, it is necessary to make the clamping force deviation between modules as small as possible. In this case, we design the target according to the clamping force of the module as Ftotal=700N+100N. As shown in Figure 10, a single module is exerted by 4 springs, so the elastic force requirement of a single spring is:

F=Ftotal/4=175N+25N, ΔF=25N Formula 1

by Hooke's law

F=K*Δx Formula 2

It can be seen that the actual pressure is directly determined by the spring deformation and elastic coefficient. The difference in the amount of spring deflection between the three modules is determined by the tolerances of the parts. The thickness of the SiC power device (model: MD800HFC120N3S) is h=4.7mm±0.3, the maximum thickness difference between the three modules is Δh=0.6mm, and the machining accuracy of the upper water-cooled plate is h1=26.5mm+0.3, Δh1=0.3mm , The machining accuracy requirements of the mounting surface of the spring pressure plate in the box are h2=62.5mm+0.3, Δh2=0.3mm, so considering the extreme value of tolerance, the maximum deviation of the spring deformation between the three modules is:

ΔΔx=Δh+Δh1+Δh2=1.2mm Equation 3

From formula 1, formula 2 and formula 3, K=ΔF/ΔΔx=25N/1.2mm=20.83N/mm Equation 4

It can be obtained from formula 4 and company 1, spring stroke Δx=F/K=175/20.83=8.4mm Formula 5

By K=G*d ⁴ /8*n*D ³ formula 6

In this design, G=79000N/mm ² , d=2mm, D=9.6mm, can be calculated by formula 4 and formula 6:

n=G*d ⁴ /8*K*D ³ =8.5 Equation 7

Where: G: transverse elastic coefficient (Young's modulus), d: wire diameter, n: effective number of turns, D: average coil diameter

Fmax=K*(Δx+ΔΔx)=20.83*9.6=199.7N Equation 8

Therefore, in this design, by selecting G=79000N/mm ² , L=16mm, which can be obtained from formula 5, the strain is 50%, the wire diameter is 2mm, the diameter is 9.6mm, and the non-standard spring with 8.5 turns can also be used in the actual production process. The method of controlling the spring tolerance (<+0.7mm) can further balance the stress difference between the three-phase modules and reduce the spring strain.

Embodiment 3

A vehicle includes the heat sink described in Embodiment 1 and/or the power module described in Embodiment 2.

The above descriptions are only examples of the present invention, and are not intended to limit the scope of the present invention. Any equivalent transformations made by using the contents of the description and drawings of the present invention, or directly or indirectly applied in related technical fields, are similarly included in the within the scope of patent protection of the present invention.

Claims (10)

1. A heat dissipation device is characterized in that it comprises a lower cooling plate, an upper cooling assembly and an elastic fixing assembly, and a first cooling flow channel is opened on the lower surface of the lower cooling plate;

   The upper cooling assembly is fixed above the upper surface of the lower cooling plate by the elastic fixing assembly; the upper cooling assembly includes a plurality of upper cooling plates, and cooling channels are respectively opened in the plurality of upper cooling plates, A plurality of the cooling channels communicate with each other to form a second cooling channel, and both ends of the second cooling channel are in sealing communication with the first cooling channel respectively.
2. The heat dissipation device according to claim 1, wherein the cooling passages communicate with each other through corrugated hoses to form the second cooling flow passages;

   A connection part is provided at the outlet of the cooling channel of the upper cooling plate;

   The corrugated hose includes a pipe body and connecting pieces located at both ends of the pipe body, and the connecting pieces are connected to the connecting parts.
3. The heat dissipation device according to claim 2, wherein the connecting portion and the connecting piece are screwed together;

   The end of the pipe body has a first sealing cutout, the connecting piece has a second sealing cutout corresponding to the first sealing cutout, the first sealing cutout cooperates with the second sealing cutout to form a sealing groove, and the sealing There is a sealing ring in the groove.
4. The heat dissipation device according to claim 1, wherein the elastic fixing component comprises a tray, an elastic body and a fixing member, the tray is located above the upper cooling member and is connected to the lower cooling member through the fixing member cooling plate;

   The elastic member is located between the upper cooling assembly and the tray to elastically press the upper cooling assembly.
5. The heat dissipation device according to claim 4, wherein there are multiple elastic bodies, and each corner end of the upper cooling plate corresponds to one elastic body.
6. The heat dissipation device according to claim 4, wherein the elastic body is a spring, a limit post for limiting the position of the spring is provided on the tray, and the length of the limit post is less than the length of the spring .
7. The heat dissipation device according to claim 1, wherein a plurality of heat dissipation fins are provided in the first cooling channel.
8. A power module, characterized in that it comprises a power device and the heat dissipation device according to any one of claims 1-7;

   The power device is located between the lower cooling plate and the upper cooling assembly.
9. The power module according to claim 8, wherein there are three power devices, and the upper cooling assembly includes three upper cooling plates corresponding to the power devices;

   The upper and lower surfaces of the power device are coated with thermally conductive silicone grease.
10. A vehicle, characterized by comprising the power module according to claim 8 or 9.

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