JP5155590B2 - Cooling system - Google Patents

Description

  The present invention relates to a cooling device.

Conventionally, power semiconductor modules using semiconductor elements such as IGBTs are used for driving electric motors and various power conversions.
In recent years, power semiconductor modules for industrial applications are required to have higher output against the background of the development of electric vehicles such as fuel cell vehicles. For this reason, both the rated current capacity and voltage have been expanded. Therefore, not only the design of the basic structure but also the heat dissipation measures due to the loss generated inside the module during operation has become a more serious problem. Yes.

As described in Patent Document 1, in-vehicle power semiconductor modules are required to have a small size and a high cooling capacity. Therefore, air cooling is not allowed, liquid cooling is generally used, and cooling performance is further improved. In order to improve, a structure has been proposed in which fins are provided on the metal base of the power semiconductor module and the coolant is directly applied to the metal base with fins.
In addition, since low power consumption is required in order to reduce size and improve fuel consumption, an electric pump that circulates coolant is used with a small capacity.
In order to improve the cooling performance, the pressure loss ΔP of the cooling liquid passage must also be small. Since the pressure loss ΔP and the cooling performance, that is, the heat transfer coefficient h are in a trade-off relationship, a sufficiently large heat transfer coefficient cannot be obtained simply by providing a fin on the metal base of the power semiconductor module and cooling it. For example, if the height of the fins is increased too much, the flow rate of the cooling liquid decreases, and there may be a case where a large heat transfer coefficient cannot be obtained as compared with the case where fins are not provided. Furthermore, consideration must be given to the manufacturing cost of manufacturing the fins on a metal base.

In order to improve the cooling performance, it is important to make the flow of the coolant in the heat generating portion passage portion turbulent. In Patent Documents 2 to 4, the flow of the coolant in the heat generating portion passage portion is referred to as turbulent flow. The shape of the fin for doing this is disclosed. Note that FIG. 9 of Patent Document 2 discloses a cooling liquid path in which a raised surface having an upwardly inclined surface on the upstream side and a downwardly inclined surface on the downstream side is formed on the bottom surface.
JP 2004-349324 A JP 2001-308246 A JP 2006-278735 A JP 2006-140390 A

However, the above-described conventional technology has the following problems.
As the metal base of the power semiconductor module, there may be used a casted product including a circuit mounting surface and striped fins formed on the opposite surface. In such a case, changing to a fin having a special structure as shown in Patent Documents 3 and 4 may increase costs and may not be preferable. Also, as shown in FIG. 10 of Patent Document 2, if a plurality of protrusions for causing turbulent flow are provided in the coolant path under the metal base of the power semiconductor module, the protrusions and the fins of the metal base Interfering with each other, making it difficult to fit the metal base having the fins into the cooling liquid passage. Therefore, a protrusion higher than the lower end of the metal-based fin cannot be provided, and cooling efficiency may not be pursued.

  The present invention has been made in view of the above problems in the prior art, and is a cooling device that cools a power semiconductor module by forming a cooling liquid path on a finned bottom surface of a heat dissipation base on which the power semiconductor module is mounted. It is an object of the present invention to provide a cooling device that can be applied regardless of the shape and size of the fins of the heat dissipation base and can improve the cooling performance with a simple structure that does not increase in size. .

The invention according to claim 1 for solving the above-described problems is a cooling device for cooling a power semiconductor module by forming a cooling liquid path on a bottom surface provided with fins of a heat dissipation base on which the power semiconductor module is mounted. ,
The fins are formed along the longitudinal direction of the heat dissipation base;
An inlet and an outlet of the cooling liquid path are respectively provided at opposite ends in the longitudinal direction;
A central axis of the inlet is along the longitudinal direction;
An opening formed in the upper surface of the cooling liquid path is covered with a bottom surface of the heat dissipation base, and the fins are disposed in the cooling liquid path,
A protrusion is provided on the bottom surface of the cooling liquid path,
The protrusion is a cooling device in which an upper end center portion of the protrusion is disposed between the upstream end portion of the fin and the inflow port so as to face the front surface of the center portion of the inflow port.

  The invention according to claim 2 is the cooling device according to claim 1, wherein an upper end of the protrusion is located above a lower end of the fin.

According to a third aspect of the present invention, an upstream portion of the bottom surface of the cooling liquid passage is formed on an ascending inclined surface and a downstream portion is formed on a descending inclined surface with reference to a predetermined boundary position. The cooling device according to claim 1 or 2.

The invention according to claim 4 is the cooling device according to claim 3 , wherein the predetermined boundary position is a center position of the heat dissipation base.

The invention according to claim 5 is the cooling device according to claim 3 , wherein the predetermined boundary position is an upstream position from a center position of the heat radiation base.

A sixth aspect of the present invention is the cooling device according to the third aspect , wherein the predetermined boundary position is a downstream position from a central position of the heat radiating base.

A seventh aspect of the present invention is the cooling device according to the sixth aspect, wherein the inclined surface of the upward gradient is composed of a relatively steep and short upstream portion and a relatively gentle gradient and a long downstream portion.

According to the present invention, a turbulent flow is generated by the protrusion provided on the bottom surface of the cooling liquid passage and arranged to face the inflow port, so that the cooling performance can be improved.
Further, according to the present invention, since the protrusion is disposed in a region between the upstream end of the fin and the inlet, the protrusion does not interfere with the fin of the heat dissipation base. Easy to apply regardless of shape and size.
Therefore, according to the present invention, compared to all conventional finned heat dissipating bases, it is possible to increase the size by simply installing a protrusion whose shape and size are selected for improving the cooling performance in the upstream portion of the bottom surface of the cooling liquid passage. The cooling performance can be improved.
Since there are no protrusions in the region directly below the fins of the heat dissipation base, a raised surface can be formed by the upstream ascending inclined surface and the downstream descending inclined surface. By controlling the upstream and downstream, further improvement of cooling efficiency can be pursued.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following is one embodiment of the present invention and does not limit the present invention.

[First Embodiment]
First, a cooling device according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of the cooling device. FIG. 2 is a right side view of the cooling device. FIG. 3 is an exploded perspective view of the cooling device. FIG. 4 is a perspective view of the present cooling device in which the power semiconductor module is not mounted. FIG. 5 is a plan view (a), a partially sectional front view (b), and a partially sectional side view (c) of the bottom part of the present cooling device. FIG. 6 is a plan view (a), a central longitudinal sectional view (b), and a back view (c) of the frame component of the cooling device. FIG. 7 is a left side view (a) and a right side view (b) of the frame component of the cooling device. FIG. 8 is a plan view (a), a front view (b), and a back view (c) of the protruding parts of the cooling device. FIG. 9 is a central longitudinal sectional view of the cooling device.

The cooling device of the present embodiment is a cooling device that cools the power semiconductor module 1, and is a liquid circulation type cooling device that circulates a coolant such as water.
The power semiconductor module 1 includes a circuit 1b on the heat dissipation base 1a via a ceramic insulating layer.
Is mounted, a resin-made outer case 1c is fitted on the periphery of the heat dissipation base 1a, and an external connection terminal is constituted by a terminal 1d embedded and held in the outer case 1c. The circuit 1b is a three-phase bridge type inverter that generates electric power for driving a three-phase motor. A drive circuit, a control circuit, and the like of the circuit 1b are mounted and housed, and a lid (not shown) is put on the upper end opening of the outer case 1c.

A circuit mounting surface on which the circuit 1b is mounted is formed on the surface of the heat dissipation base 1a, and fins 1e are formed on the bottom surface which is the opposite surface. The heat dissipating base 1a is an aluminum molded product that is integrally molded including the circuit mounting surface and the fin 1e, or the upper part including the circuit mounting surface and the lower part including the fin 1e are separately molded and joined together. Produced.
A plurality of fins 1e are formed in parallel along the longitudinal direction of the heat dissipation base 1a.

  As shown in FIG. 3 and the like, the frame part 2 and the bottom part 3 constitute a container having an upper surface opening 2a, and this internal space forms a cooling liquid path for bringing the cooling liquid into contact with the heat dissipation base 1a. The upper surface opening 2a is covered and sealed by the bottom surface of the heat dissipation base 1a, and the fins 1e are arranged in the cooling liquid passage.

As shown in FIG. 6, the frame part 2 is a frame-like part having openings 2a and 2d in the upper and lower sides, and an inlet hole 2b and an outlet hole 2c are respectively provided at the center of opposite ends in the longitudinal direction. Is provided. As shown in FIG. 1, FIG. 4, FIG. Is formed. The central axes of the inflow port 9 and the outflow port 10 are along the longitudinal direction of the heat dissipation base 1a and are arranged coaxially.
The upper surface opening 2a is formed in a rectangular shape. The lower surface opening 2d is formed in a boat shape, and the internal cavity of the frame part 2 is also formed in a boat shape.

  As shown in FIG. 5, raised portions 3 a and 3 b are formed on the upper surface of the bottom part 3 that forms the bottom surface of the coolant passage. The lower vertically raised portion 3 b is simply fitted into the lower surface opening 2 d of the frame component 2. The upper raised portion 3a is formed with an upstream ascending inclined surface 3c and a downstream descending inclined surface 3d, and the bottom surface of the cooling liquid passage is formed in a raised shape by the inclined surfaces 3c and 3d. In the present embodiment, the boundary position between the upstream ascending inclined surface 3c and the downstream descending inclined surface 3d is located upstream from the center position of the heat dissipating base 1a, and as shown in FIG. 9, the upstream end of the fin 1e. 1e-1 vicinity.

A protruding component 4 shown in FIG. 8 is attached and fixed to the center of the upstream rising slope 3c as shown in FIGS.
As shown in FIG. 8, the protruding component 4 includes an action body 4a and a mounting root 4b. The action body 4a is a protruding portion that is exposed to the coolant path and acts on the coolant flow. As shown in FIG. 8, the action body 4a has a substantially rhombic horizontal cross-sectional shape, is formed in a pseudo rhombus shape having a long downstream side and rounded corners. The bottom surface 4c of the acting body 4a is formed obliquely according to the gradient of the upward inclined surface 3c.
The mounting root portion 4b is fitted into a mounting hole 3e provided in the upward inclined surface 3c of the bottom part 3, and as shown in FIG. 9, the bottom surface 4c of the operating body 4a is aligned with the upward inclined surface 3c so as to project. 4 is attached to the bottom part 3 and fixed by bonding or the like.

As shown in FIG. 9, the action body 4 a of the protruding component 4, that is, the protrusion 4 a is disposed between the upstream end 1 e-1 of the fin 1 e and the inflow port 9.
Moreover, the protrusion 4a is arrange | positioned facing the inflow port 9, as shown in FIG.2 and FIG.9.
As shown in FIG. 2, the center of the upper end of the protrusion 4 a is arranged to face the front of the center of the inflow port 9.
Furthermore, as shown in FIG. 2, the upper end of the protrusion 4a is located above the lower end of the fin 1e.
As shown in FIG. 2, the center portion of the upper end of the protrusion 4 a is arranged so as to overlap the lower end portion of the fin 1 e-2 in the middle when viewed from the inflow direction 9.

  As shown in FIG. 3, the space between the heat dissipation base 1a and the frame part 2 is sealed by an O-ring 5. A holding groove 2e is formed on the upper peripheral edge of the upper surface opening 2a of the frame component 2, and an O-ring 5 is inserted into the holding groove 2e and held. The heat radiation base 1a and the frame part 2 are fastened together by bolts 11 and the like, and both are fixed, and the O-ring 5 is sandwiched and pressed between the heat radiation base 1a and the frame part 2 so that the upper surface opening 2a The space between the heat dissipation base 1a and the frame part 2 is sealed around.

On the other hand, the bottom part 3 and the frame part 2 are sealed by an O-ring 6. A holding groove 3f is formed in the bottom part 3 along the periphery of the raised portion 3b, and an O-ring 6 is inserted and held in the holding groove 3f. The bottom part 3 and the frame part 2 are fastened together by bolts 12 or the like, so that both are fixed, and the O-ring 6 is sandwiched and pressed between the bottom part 3 and the frame part 2 so that the lower surface opening 2d The space between the bottom part 3 and the frame part 2 is sealed around.
From the assembly structure via the O-ring 5 and the O-ring 6 described above, the hermeticity of the cooling liquid passage is maintained, and the leak-proof pressure is improved.

  An inlet 9 and an outlet 10 are connected to a coolant circulation system (not shown) and the present cooling device is incorporated.

Regardless of the present embodiment, the frame part 2 and the bottom part 3 may be produced as a single piece by molding or the like. In this case, the O-ring 6 is unnecessary, and the O-ring 5 only needs to be sealed with the heat dissipation base 1a.
When the frame part 2 and the bottom part 3 are separate parts as in this embodiment, the processing of each part is easy. Further, the bottom part 3 can be used as a common part by applying the frame part 2 having a different height according to the height of the fin 1e.

Regardless of the present embodiment, the protruding component 4 and the bottom component 3 may be formed as an integral product by molding or the like.
When the projecting part 4 and the bottom part 3 are separate parts as in the present embodiment, different projecting parts 4 can be applied to the common bottom part 3, and the bottom part 3 is replaced. The protruding component 4 can be replaced without doing so. For example, the protrusions can be changed independently according to the shape of the heat dissipation base 1a such as the fin 1e. That is, only the protruding part 4 can be changed and the bottom part 3 can be commonly used for different applications. However, it is necessary to sufficiently fix the bottom part 3 so that the protruding part 4 does not fall off during use. Therefore, when the bottom part 3 is not commonly used or the projection part 4 is not changed, it is also effective to integrate the projection part 4 and the bottom part 3 together.

  Next, the flow of the cooling liquid in the cooling liquid path configured as described above will be described. FIG. 10 is a schematic diagram showing a flow in the cooling liquid path, and shows a horizontal cross section of the cooling liquid path at a position below the fins.

  The coolant flowing from the inlet 9 into the coolant passage 13 formed by being surrounded by the heat radiating base 1a, the frame component 2, and the bottom component 3 hits the projection 4a and flows into left and right parts (B and C portions in FIG. 10). A turbulent flow is generated including a flow escaping upward and a vortex behind the protrusion 4a (D portion in FIG. 10), and proceeds to a region where the fins 1e are disposed. The cross section of the turbulent flow generated by the protrusion 4a is limited and reduced to the upper part by the upstream rising slope 3c, and most of the turbulent flow proceeds to the fin 1e arrangement area while increasing the flow velocity. Therefore, turbulent flow in the fin 1e arrangement area can be efficiently promoted, and the cooling performance is improved.

  The flow path cross-sectional area of the coolant flow that has progressed to the fin 1e arrangement area is gradually expanded downward by the downstream inclined surface 3d and returns to the original area. The pressure loss is reduced by the flow path portion in which the downstream portion downward inclined surface 3d is formed, and the cooling performance is improved.

  After passing through the fin 1e arrangement area, the width of the coolant passage 13 decreases toward the outlet 10. Even in the portion A where the width immediately before the outlet 10 is reduced, a turbulent flow is generated as the flow path cross-section is reduced, and the coolant is discharged from the outlet 10.

As described above, according to the present embodiment, a turbulent flow is generated by the protrusions 4a provided on the bottom surface of the cooling liquid passage 13 and arranged to face the inflow port 9, so that the cooling performance can be improved.
Further, according to the present embodiment, since the protrusion 4a is disposed in the region between the upstream end 1e-1 of the fin 1e and the inflow port 9, it does not interfere with the fin 1e of the heat radiating base 1a. The present invention is applicable regardless of the shape and size of the fin 1e of the base 1a.
Therefore, with respect to all conventional finned heat dissipation bases, simply installing a projection whose shape and size are selected for improving the cooling performance on the upstream side of the bottom surface of the cooling liquid passage 13 does not increase in size. Cooling performance can be improved. The shape, size, structure, etc. of the protrusion 4a can be changed by simply replacing the protrusion component 4.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 11 is a central longitudinal sectional view of a cooling device according to the second embodiment of the present invention.

  The cooling device of the present embodiment is obtained by changing the inclined surface of the raised portion of the bottom part 3 as described below with respect to the first embodiment, and is otherwise the same as the first embodiment.

  In the raised portion of the bottom part 3 of the present embodiment, an upstream rising slope 3c-1 and a downstream falling slope 3d-1 are formed. In the first embodiment, the boundary position between the upstream ascending inclined surface 3c and the downstream descending inclined surface 3d is located upstream from the center position of the heat dissipation base 1a. The boundary position between the inclined surface 3c-1 and the downstream descending inclined surface 3d-1 is the center position of the heat dissipation base 1a.

In the first embodiment, the boundary position between the upstream ascending inclined surface 3c and the downstream descending inclined surface 3d is in the vicinity of the upstream end 1e-1 of the fin 1e. However, the downstream portion of the circuit 1b mounted on the heat dissipation base 1a is inferior in cooling efficiency compared to the upstream portion.
On the other hand, in the cooling device of the present embodiment, the boundary position between the upstream ascending inclined surface 3c-1 and the downstream descending inclined surface 3d-1 is the central position of the heat dissipation base 1a. Compared to one embodiment, downstream cooling is facilitated.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 12 is a central longitudinal sectional view of the cooling device according to the third embodiment of the present invention.

  The cooling device of the present embodiment is obtained by changing the inclined surface of the raised portion of the bottom part 3 as described below with respect to the first embodiment, and is otherwise the same as the first embodiment.

  In the raised portion of the bottom part 3 of the present embodiment, an upstream rising slope 3c-2, an intermediate rising slope 3c-3, and a downstream falling slope 3d-2 are formed. In the present embodiment, the boundary position between the ascending inclined surface 3c-3 and the downstream descending inclined surface 3d-2 is a downstream position from the center position of the heat dissipation base 1a.

  In the first embodiment and the second embodiment, the ascending inclined surface is an inclined surface having a uniform gradient. However, in this embodiment, the ascending inclined surface is a relatively steep and short upstream portion 3c-2. And a relatively slow gradient and a long downstream portion 3c-3. The uppermost position of the upstream rising surface 3c-2 is in the vicinity of the upstream end 1e-1 of the fin 1e, and the uppermost position of the intermediate rising surface 3c-3 is the downstream end 1e-3 of the fin 1e. It is said to be near.

In the first embodiment, the portion with the highest cooling efficiency tends to be relatively upstream, and in the second embodiment, the portion with the highest cooling efficiency tends to be relatively downstream.
On the other hand, in the cooling device of the present embodiment, the upstream cooling efficiency is increased by the upstream upstream slope 3c-2 of the first stage, and the downstream of the downstream intermediate slope 3c-3 is increased by the second intermediate slope 3c-3. Since the cooling efficiency is increased, a relatively uniform cooling efficiency can be achieved, and the temperature deviation of the circuit 1b can be reduced.

There may be a portion of the circuit 1b that is locally hot.
Depending on the distribution of heat generation in the circuit 1b, the shape of the inclined surface is selected from the first to third embodiments, or the inclined surface is designed with reference to the first to third embodiments, so that the circuit 1b It is preferable not to generate a local high temperature part. In the said embodiment, although the inclined surface was comprised combining several planes, you may employ | adopt a curved surface as a whole or a part for an inclined surface.

It is a perspective view of the cooling device concerning a 1st embodiment of the present invention. It is a right view of the cooling device concerning a 1st embodiment of the present invention. It is a disassembled perspective view of the cooling device concerning a 1st embodiment of the present invention. 1 is a perspective view of a cooling device not mounted with a power semiconductor module according to a first embodiment of the present invention. It is a top view (a) of a bottom part of a cooling device concerning a 1st embodiment of the present invention, a partial section front view (b), and a partial section side view (c). It is the top view (a), center longitudinal cross-sectional view (b), and back view (c) of the frame components of the cooling device which concern on 1st Embodiment of this invention. It is the left view (a) and right view (b) of the frame components of the cooling device which concern on 1st Embodiment of this invention. It is the top view (a) of the protrusion component of the cooling device which concerns on 1st Embodiment of this invention, a front view (b), and a back view (c). It is a center longitudinal cross-sectional view of the cooling device which concerns on 1st Embodiment of this invention. It is a schematic diagram which shows the flow in the cooling fluid path which concerns on this invention, and shows the horizontal cross section of the cooling fluid path in the position below a fin. It is a center longitudinal cross-sectional view of the cooling device which concerns on 2nd Embodiment of this invention. It is a center longitudinal cross-sectional view of the cooling device which concerns on 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power semiconductor module 1e Fin 1a Heat radiation base 2 Frame component 3 Bottom component 4 Protrusion component 4a Protrusion (action body)
9 Inlet 10 Outlet 13 Cooling liquid passage

Claims (7)

In the cooling device for cooling the power semiconductor module by forming a cooling liquid path on the bottom surface provided with the fin of the heat dissipation base on which the power semiconductor module is mounted,
The fins are formed along the longitudinal direction of the heat dissipation base;
An inlet and an outlet of the cooling liquid path are respectively provided at opposite ends in the longitudinal direction;
A central axis of the inlet is along the longitudinal direction;
An opening formed in the upper surface of the cooling liquid path is covered with a bottom surface of the heat dissipation base, and the fins are disposed in the cooling liquid path,
A protrusion is provided on the bottom surface of the cooling liquid path,
The projection is in between the inlet and the upstream end portion of the fin, the top center portion of the projection is disposed so as to face the central portion front of the inlet cooler.   The cooling device according to claim 1, wherein an upper end of the protrusion is located above a lower end of the fin. Upstream portion of the bottom surface of the predetermined said coolant channel relative to the boundary position is formed on the inclined surface of the upward gradient, claim portions of the downstream side is formed on the inclined surface of the downward slope 1 or claim 2 the cooling device according to. The cooling device according to claim 3 , wherein the predetermined boundary position is a center position of the heat dissipation base. The cooling device according to claim 3 , wherein the predetermined boundary position is an upstream position from a center position of the heat dissipation base. The cooling device according to claim 3 , wherein the predetermined boundary position is a downstream position from a central position of the heat dissipation base. The cooling device according to claim 6 , wherein the inclined surface having an upward slope includes a relatively steep and short upstream portion and a relatively gentle slope and a long downstream portion.

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