KR102176925B1 - Cooling structure for water cooling type invertor module of vehicles - Google Patents

Abstract

The present invention relates to a cooling structure for a water-cooled inverter module of a vehicle. More specifically, the present invention relates to the cooling structure for the water-cooled inverter module of the vehicle wherein cooling fins are formed on a power module itself to allow direct heat exchange with cooling water, thereby improving cooling efficiency and reducing manufacturing costs. In the cooling structure for the water-cooled inverter module of the vehicle in accordance with the present invention, the cooling structure for the water-cooled inverter module of the vehicle includes: a cooling main body through which the cooling water is introduced and discharged; the power module installed in the cooling main body; a heat sink formed on the power module; a plurality of cooling fins formed on the heat sink; a fin insertion opening formed in the cooling main body so that the cooling fins are inserted and accommodated; and an airtight member installed in the fin insertion opening to maintain airtightness between the power module and the cooling main body.

Description

Cooling structure for automobile water-cooled inverter module {COOLING STRUCTURE FOR WATER COOLING TYPE INVERTOR MODULE OF VEHICLES}

The present invention relates to a cooling structure for an automobile water-cooled inverter module, and more particularly, by forming a cooling fin on the power module itself to allow direct heat exchange with cooling water, the cooling efficiency can be improved and the manufacturing cost can be reduced. It relates to a cooling structure for a vehicle water-cooled inverter module.

In general, a vehicle is equipped with an inverter system as a power conversion device for converting a high voltage DC power source generated from a battery or a fuel cell into a U, V, W three-phase AC power source.

The inverter system includes a power module made of an Insulated Gate Bipolar Transistor (IGBT) and a gate driving circuit.

During operation, the inverter system employs a cooling structure such as a heat sink for cooling due to severe heat generation from switching elements such as power modules.

For example, the cooling structure for an automobile water-cooled inverter module includes a cooler tube 110 through which cooling water is introduced, a cooler cover 120 fastened to seal the cooler tube 110, and a power module 130, as shown in FIG. Power Module) is equipped.

The cooler tube 110 has a plurality of cooling fins 140 integrally formed therein, and the power module 130 is in close contact with the outer surface of the portion where the cooling fins 140 is formed to Assembled by At this time, a thermal grease layer 160 formed by applying a thermal grease is provided between the contact surface of the heat sink 131 of the power module 130 and the cooler tube 110, the thermal grease layer 160 It fills in the fine pores of the metal surface to facilitate heat transfer, thereby improving cooling characteristics.

The cooling structure for a conventional automobile water-cooled inverter module shown in FIG. 1 is a water-cooled type, and thus has excellent cooling characteristics compared to an air-cooled type, but has the following problems.

First, in the conventional cooling structure for an automobile water-cooled inverter module, heat generated from the power module 130 is transferred to the cooler tube 110 through the thermal grease layer 160 and then heat exchanged with the cooling fins 140 disposed therein. As a method of cooling by action, since the power module 130 is indirectly cooled through the cooler tube 110, the cooling efficiency is low, and thus the stability and durability of the power semiconductor operation are deteriorated.

In addition, the conventional cooling structure for an automobile water-cooled inverter module has a disadvantage in that it is difficult to integrally form a plurality of cooling fins 140 on the cooler tube 110, and excessively high manufacturing costs are generated.

In addition, in the conventional cooling structure for a water-cooled inverter module of a vehicle, a predetermined number of cooling fins 140 are installed in the cooler tube 110 in consideration of the pressure loss of the cooling water, and the cooling fins 140 are formed in a round bar shape and There is a disadvantage in that the cooling efficiency is low because the heat exchange surface area with is small.

In addition, the conventional cooling structure for a water-cooled inverter module for automobiles has a poor contact relationship between the heat sink 131 of the power module 130 and the contact surface of the cooler tube due to deterioration and contamination of the thermal grease layer 160 when used for a long time. There is a disadvantage in that heat transfer characteristics are deteriorated, and therefore, a stable cooling operation cannot be performed.

Korean Patent Registration No. 10-1294077 "Cooling system for power conversion device" Korean Patent Registration No. 10-1746669 "Fin-fin and cooling device including the same" Korean Patent Laid-Open Patent No. 10-2017-0112812 "Water cooling inverter structure for electric vehicles"

The present invention has been proposed in light of the above, and by forming a cooling fin on the power module itself to allow direct heat exchange with the cooling water, the cooling efficiency can be improved and the manufacturing cost can be reduced. Its purpose is to provide a cooling structure.

Another object of the present invention is to provide a cooling structure for an automobile water-cooled inverter module in which a heat exchange area is increased and cooling efficiency is improved without causing a pressure loss.

Another object of the present invention is to provide a cooling structure for a water-cooled inverter module for an automobile, which is capable of improving manufacturability and durability by assembling cooling fins using ultrasonic welding and not using thermal grease.

In order to achieve the above object, the cooling structure for a vehicle water-cooled inverter module according to the present invention is a cooling structure for a vehicle water-cooled inverter module, comprising: a cooling body through which cooling water is introduced and discharged; And a power module installed on the cooling body, and a heat dissipation plate formed on the power module; A plurality of cooling fins formed on the heat sink; A fin insertion opening formed in the cooling body so that the cooling fins are inserted and received; And an airtight member installed in the pin insertion opening to maintain airtightness between the power module and the cooling body.

The heat sink is formed of a thermally conductive thin plate integrally coupled to the power module such that one surface is exposed, and the cooling fins may be integrally bonded to the thermally conductive thin plate by ultrasonic welding.

The pin insertion opening portion may have an airtight member insertion groove recessed along the periphery, and the airtight member may be formed as an O-ring inserted into the airtight member insertion groove.

The cooling fin may include a bonding flange portion bonded to the heat sink and a fin portion protruding from the bonding flange portion.

Meanwhile, the cooling fin may include a joint flange portion joined to the heat sink, a fin portion protruding from the joint flange portion, and a heat exchange groove concave in the fin portion to increase a heat exchange area.

Preferably, the fin portion is formed in a structure in which the outer diameter of the portion in contact with the joint flange portion is large and the outer diameter gradually decreases toward the free end, and the heat exchange groove may be concave in a spiral structure to facilitate the flow and processing of cooling water. .

The cooling structure for a vehicle water-cooled inverter module according to the present invention further comprises an auxiliary heat exchange member inserted into the plurality of cooling fins to expand the heat exchange area.

The auxiliary heat exchange member is composed of a thermally conductive thin plate having a plurality of pin insertion holes and a fixing protrusion extending in contact with the pin insertion hole so that the cooling fin is inserted, and the fixing protrusion is inserted for firm fixation with the cooling fin. It may protrude and be formed to provide a fitting hole having a small inner diameter in the direction.

According to the cooling structure for an automobile water-cooled inverter module according to the present invention, since the cooling fin integrally coupled to the power module performs a heat exchange process directly with the cooling water, the power module is in close contact with the cooler tube and indirectly cooled as in the prior art. In comparison, the cooling efficiency can be remarkably increased, so that the stability and durability of the power semiconductor operation can be improved.

And, according to the cooling structure for an automobile water-cooled inverter module according to the present invention, since the cooling fin integrally coupled to the power module is inserted into the cooling body, a thermal grease layer is not required, thereby improving fabrication, assembly, and durability. I can make it.

In particular, since the cooling fins are coupled to the heat sink by ultrasonic welding, they can be easily installed, and the spiral heat exchange grooves are provided in the conical fins, thereby minimizing the pressure loss of the cooling water and increasing the heat exchange area, thereby improving cooling efficiency. I can make it.

1 is an exploded perspective view for explaining a cooling structure for a conventional automobile water-cooled inverter module,
2 is a perspective view showing a cooling structure for a vehicle water-cooled inverter module according to the first embodiment of the present invention;
3A and 3B are exploded perspective views showing the cooling structure for a vehicle water-cooled inverter module according to the first embodiment of the present invention;
4 is an enlarged perspective view of essential parts for explaining the cooling structure for a vehicle water-cooled inverter module according to the first embodiment of the present invention;
5 is an enlarged front view of a cold fin of the cooling structure for a water-cooled inverter module for a vehicle according to the first embodiment of the present invention;
6 is a cross-sectional view showing a cooling structure for a vehicle water-cooled inverter module according to a first embodiment of the present invention;
7 is a front view showing another form of a cold fin of the cooling structure for a vehicle water-cooled inverter module according to the first embodiment of the present invention;
8 is an exploded perspective view showing a cooling structure for a vehicle water-cooled inverter module according to a second embodiment of the present invention;
9 is a perspective view of a main part showing an installed state of an auxiliary heat exchange member in the cooling structure for an automobile water-cooled inverter module according to a second embodiment of the present invention;
10 is a perspective view showing another form of an auxiliary heat exchange member applied to the cooling structure for an automobile water-cooled inverter module according to the second embodiment of the present invention.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS. 2 to 10 of the accompanying drawings, but the same reference numerals are assigned to the same components in FIGS. 2 to 10.

On the other hand, in each drawing, a detailed description of a configuration that can be easily recognized by a person of ordinary skill in the art from a general technique, and actions and effects therefor, will be simplified or omitted. In addition, since the present invention is characterized by a cooling structure for an automobile water-cooled inverter module, the related parts will be mainly shown and described, and the description of the remaining parts will be simplified or omitted.

2 is a perspective view showing a cooling structure for a vehicle water-cooled inverter module according to a first embodiment of the present invention, and FIGS. 3A and 3B are exploded perspective views showing a cooling structure for a vehicle water-cooled inverter module according to the first embodiment of the present invention. It shows the shape appearing in different directions (upper and lower). 4 is an enlarged perspective view of a main part for explaining a cooling structure for a water-cooled inverter module for a vehicle according to a first embodiment of the present invention, and FIG. 5 is a cold fin of the cooling structure for a water-cooled inverter module for a vehicle according to the first embodiment of the present invention. Figure 6 is an enlarged front view, a cross-sectional view showing a cooling structure for a vehicle water-cooled inverter module according to the first embodiment of the present invention.

2 to 6, the cooling structure for a vehicle water-cooled inverter module according to the first embodiment of the present invention includes a cooling body 1 through which cooling water is introduced and discharged, and a power module installed in the cooling body 1 ( 2), but the main feature is that the power module 2 itself has a cooling fin 3 formed to allow direct heat exchange with the cooling water.

The cooling body 1 is not particularly limited in structure and shape as long as the cooling water receiving space is provided to perform heat exchange while the cooling water is introduced and discharged, but in this embodiment, it is formed in a substantially rectangular cylindrical shape.

More specifically, the cooling body 1 is composed of a main case 11 formed in a rectangular frame shape so that a cooling water receiving space is provided therein, and a cover case 12 coupled to the main case 11. . The main case 11 and the cover case 12 have fastening holes 112 and 122 formed at the edge of the edge, and the sealing member 14 such as a screw is interposed with an airtight member 13 such as an O-ring. Are assembled together by

In addition, the main case 11 has connector connection holes 113 formed on both sides thereof to connect a connector 15 such as a nipple to which a cooling water supply line (not shown) and a cooling water discharge line (not shown) are connected. do.

In addition, the main case 11 has a first guide protrusion 114 that guides the flow of coolant therein, and the cover case 12 has a second guide protrusion 124 that guides the flow of coolant inside the cover case 12 Has been. The first and second guide protrusions 114 and 125 guide the cooling water introduced through the cooling water inlet side connector 15 to be discharged through the discharge side connector 15 after passing through a plurality of cooling fins 3 spaced apart from each other. Performs the function of

Meanwhile, the cooling body 1 is provided with a pin insertion opening 115 so that the cooling fins 3 are inserted and received in the main case 11 as shown in FIGS. 3 and 4. The pin insertion opening 115 is formed in plural so that a plurality of power modules 2 are installed, and each pin insertion opening 115 is capable of accommodating a plurality of cooling fins 3 formed in each power module 2. It is perforated in size and shape, and is formed in an approximately square hole in this embodiment. In addition, an airtight member insertion groove 116 for installing an airtight member is concave around the pin insertion opening 115

In addition, an airtight member 6 is installed in the pin insertion opening 115 to maintain airtightness between the power module 2 and the cooling body 1.

The airtight member 6 is not particularly limited in shape or structure as long as it has excellent airtight properties, but in this embodiment, it is formed of an O-ring having a substantially rectangular shape.

Meanwhile, the power module 2 is commonly referred to as a power semiconductor module, and includes an insulated gate bipolar transistor (IGBT), a MOSFET, or a bipolar transistor, and is provided with a direct bonded copper (DBC) on the upper surface of the base plate. ) A substrate is placed, and a semiconductor chip is attached to the DBC substrate.

The power module 2 can be applied without any particular limitation on its shape or structure, but in this embodiment, a power semiconductor (not shown, IGBT), a soldering layer (not shown), a DBC substrate (not shown), an insulator from the top to the bottom in this embodiment The substrates (not shown) are stacked in order, and the molding layer 24 surrounds the outside. Here, as the insulator substrate, AIN and Si3N4 insulator substrates are applied.

Meanwhile, the power module 2 has a heat sink 4 installed on one surface of the insulator substrate so as to be exposed to the outside.

The heat dissipation plate 4 is not particularly limited in shape or structure as long as it is a thermally conductive thin plate integrally installed with the power module 2, but the present embodiment is made of a direct bonded copper (DBC) substrate having excellent heat dissipation characteristics.

In addition, the heat sink 4 is provided with a plurality of cooling fins 3 that are inserted into the cooling body 1 and directly contact the cooling water to perform heat exchange.

The cooling fin (3) is installed by a bonding method on the thermally conductive thin plate constituting the heat sink (4), but it is highly recommended to be bonded by ultrasonic welding to minimize the adverse effect on the heat resistance on the power module. It is important.

The cooling fin 3 is composed of a bonding flange portion 31 bonded to the heat sink 4 so as to be bonded through ultrasonic welding, and a fin portion 32 protruding from the bonding flange portion 31.

The bonding flange portion 31 is formed in an approximately disk shape, and the pin portion 32 is formed in an approximately round bar shape, and is integrally processed and manufactured by a thermally conductive material such as copper (Cu).

Here, the fin portion 32 is preferably formed in a conical structure in which the outer diameter of the portion in contact with the bonding flange portion 31 having a large amount of heat dissipation is large and the outer diameter gradually decreases toward the free end.

7 is a front view showing another form of a cold fin of the cooling structure for a vehicle water-cooled inverter module according to the first embodiment of the present invention.

Referring to FIG. 7, the cooling fin 3 is composed of a bonding flange portion 31 bonded to the heat sink 4 and a fin portion 32 protruding from the bonding flange portion 31, and heat exchange while installing a predetermined quantity. The heat exchange groove 33 is concave and formed in the fin 32 so that the area is increased.

Here, the heat exchange groove 33 should be able to minimize the resistance of the cooling water flowing into the cooling body 1, and the length of the cooling fin 3 is usually formed to be less than 10 mm (mm) and the diameter of the fin part It should be noted that commercialization is possible only when manufacturing properties are satisfied in consideration of the fact that this is a member of a small size formed to be several millimeters or less.

To this end, the heat exchange groove 33 has a characteristic concave in a spiral structure to facilitate the movement and processing of the cooling water. When the heat exchange groove 33 is formed in a helical structure as described above, the cooling water can be moved because it is not in the form of a concave groove having a clogged structure, so when the cooling water flows in, fluid resistance can be reduced and rapid circulation of cooling water is achieved. It can improve cooling performance. In addition, since the heat exchange groove 33 having a spiral structure is a groove that is connected to one after another, it is easy to cut and thus can be manufactured quickly and conveniently.

Hereinafter, the operation of the cooling structure for a vehicle water-cooled inverter module according to the first embodiment of the present invention will be briefly described.

First, a brief look at the assembly process of the main components is a power semiconductor (IGBT), a soldering layer, a DBC substrate, and an insulator substrate in that order, and the heat sink 4 is placed on the bottom of the insulator substrate and surrounds the outside. The power module 2 is configured by forming the molding layer 24. In this state, a certain number of cooling fins 3 are attached to the surface of the exposed heat sink 4 using ultrasonic welding, and tin (Sn) is plated on the outer surface of the power module to prevent oxidation. Complete assembly preparation.

Thereafter, each component of the cooling body 1 is assembled, and the airtight member 6 is installed in the airtight member insertion groove 116 formed around the pin insertion opening 115 of the cooling body 1. In this state, the cooling fin 3 bonded to the power module 2 is positioned in the cooling water receiving space of the main case 11 and inserted into the cooling water receiving space, and the fastening member 14 is fastened to connect the power module 2 to the cooling body 1 ), the assembly process of the water-cooled inverter module is completed.

On the other hand, when the water-cooled inverter module assembled as described above is connected to the cooling water supply line and the cooling water discharge line branched from the engine cooling water line (not shown) of the vehicle in the state that the assembled water-cooled inverter module is installed at a predetermined position of the vehicle, the cooling body 1 Cooling water flows into the cooling water receiving space.

When the cooling water flows in this way, the heat exchange process with the cooling fin 3 inserted in the cooling water receiving space of the cooling body 1 is performed, and the cooling effect of the power module 2 is performed directly, so that the cooling efficiency is improved. There is this.

More specifically, in the cooling structure for a vehicle water-cooled inverter module according to the present invention, the cooling fin 3 integrally coupled to the power module 2 performs a heat exchange process directly with the cooling water, so that the power module is cooled as in the prior art. Compared to the method of indirectly cooling by being in contact with the outer surface of the main body 1, the cooling efficiency can be significantly increased. As a result, the thermal resistance of the power semiconductor is reduced, so that the maximum rated current can be maximized and used stably, and problems such as peeling of the soldering layer due to the thermal resistance can be prevented in advance, thereby improving durability. .

In addition, the cooling structure for a vehicle water-cooled inverter module according to the present invention must be formed on the contact surface of the power module as in the prior art as the cooling fins 3 integrally coupled to the power module 2 are inserted into the cooling water receiving space. Since a thermal grease layer is not required, there is an advantage of improving fabrication, assembly, and durability.

In particular, the cooling structure for a water-cooled inverter module for a vehicle according to the present invention is provided with a bonding flange portion 31 on the cooling fin 3 so that it can be conveniently installed on the heat sink 4 by ultrasonic welding, and the fin portion 32 The structure is formed in a conical structure that has a large outer diameter of the part with a large amount of heat dissipation and gradually decreases toward the free end, so that an effective heat exchange process is performed, while the heat exchange area is increased while the heat exchange area is increased as the spiral heat exchange groove 33 is provided. It is possible to minimize the pressure loss of the cooling water and improve the cooling efficiency through smooth circulation of the cooling water.

Hereinafter, another embodiment according to the present invention will be described, but detailed descriptions of components similar to the components shown in the above-described first embodiment will be omitted, and components having differences will be mainly described. Further, in the following other embodiments, as long as a structure that can be adopted among the elements shown in the first embodiment or the elements shown in different embodiments may be selectively applied, detailed descriptions or drawings will be omitted.

8 is an exploded perspective view showing a cooling structure for a vehicle water-cooled inverter module according to a second embodiment of the present invention, and FIG. 9 is a state in which an auxiliary heat exchange member is installed in the cooling structure for a vehicle water-cooled inverter module according to the second embodiment of the present invention. It is a perspective view showing the main part.

8 and 9, the cooling structure for a vehicle water-cooled inverter module according to the second embodiment of the present invention includes a cooling body 1 through which cooling water is introduced and discharged, and a power module installed in the cooling body 1 ( 2), a heat sink 4 formed on one side of the power module, a plurality of cooling fins 3 formed on the heat sink, and a fin insertion opening 115 formed in the cooling body 1 so that the cooling fins 3 are inserted and received. ), and an airtight member 6 installed to maintain airtightness between the power module and the cooling body, while an auxiliary heat exchange member 7 for expanding the heat exchange area is further configured.

The auxiliary heat exchange member 7 is formed of a heat conductive thin plate 71 such as a copper plate so as to be installed on the cooling fin 3, and at least one or more may be installed depending on the cooling capacity of the power module 2.

Preferably, the auxiliary heat exchange member 7 has a structure in which a plurality of pin insertion holes 72 are perforated so that the cooling fins 3 are inserted into the thermally conductive thin plate 71.

10 is a perspective view showing another form of an auxiliary heat exchange member applied to the cooling structure for an automobile water-cooled inverter module according to the second embodiment of the present invention.

Referring to Figure 10, the auxiliary heat exchange member 7 is a plurality of pin insertion holes 72 perforated in the thermally conductive thin plate 71 so that the cooling fins 3 are inserted, and extend in contact with the pin insertion holes 72. A protruding fixing protrusion 73 is provided.

The fixing protrusion 73 has a fitting hole 73a of the upper narrow light structure formed with a small inner diameter at the upper side of the insertion direction and a larger inner diameter at the lower side so as to maintain a solid fixed state with the cooling fins 3 even if assembled by force fitting method. It is composed of a structure.

In addition, the fixing protrusion 73 may have an uneven portion (not shown) formed on the surface for a more robust fixation. This uneven portion is deformed when the cooling fin 3 is inserted and performs a role of pressing and fixing the cooling fin.

Meanwhile, the thermally conductive thin plate 71 may be formed with a plurality of through holes (not shown) for the movement of coolant, or a guide protrusion (not shown) protruding in the form of fins to induce the flow of fluid.

The cooling structure for a vehicle water-cooled inverter module according to the second embodiment of the present invention as described above has an auxiliary heat exchange member 7 additionally, so that the heat exchange area can be expanded to further improve cooling efficiency, and the power module 2 ), it has the advantage that it can be used interchangeably with the cooling structure for various inverter modules by installing the appropriate quantity according to the cooling capacity of ).

The configuration and operation of the cooling structure for a vehicle water-cooled inverter module according to an embodiment of the present invention has been described above, but this is only an example, and those of ordinary skill in the art will not depart from the technical spirit of the present invention. It will be understood that it is possible to substitute and modify some of the above-described embodiments.

Therefore, it should be understood that the scope of protection of the present invention extends to the invention and its equivalents described in the claims.

1: cooling body 11: main case
115: pin insertion opening 116: airtight member insertion groove
12: cover case 13: airtight member
14: fastening member 15: connector
2: power module 3: cooling pin
31: joint flange portion 32: pin portion
33: heat exchange groove 4: heat sink
6: airtight member 7; auxiliary heat exchange member
71: thermally conductive thin plate 72: pin insertion hole
73: Fixed protrusion

Claims (8)

In the cooling structure for an automobile water-cooled inverter module,
A cooling body through which cooling water is introduced and discharged; A power module installed in the cooling body; A heat sink formed on the power module; A plurality of cooling fins formed on the heat sink; A fin insertion opening formed in the cooling body so that the cooling fins are inserted and received; And an airtight member installed in the pin insertion opening to maintain airtightness between the power module and the cooling body,
The heat sink is formed of a thermally conductive thin plate integrally coupled to the power module so that one surface is exposed,
The cooling fin includes a joint flange portion integrally joined to the thermally conductive thin plate by ultrasonic welding, a fin portion protruding from the joint flange portion, and a heat exchange groove recessed into the fin portion to increase a heat exchange area, wherein the joint flange The portion is formed in a disk shape so that it can be joined through ultrasonic welding, and the fin portion is formed in a structure in which the outer diameter of the portion in contact with the joint flange portion is large and the outer diameter gradually decreases toward the free end, and the heat exchange groove is a flow of cooling water. It is concave in a helical structure for easy processing and
Further comprising an auxiliary heat exchange member inserted into the plurality of cooling fins to expand the heat exchange area, wherein the auxiliary heat exchange member includes a plurality of pin insertion holes so that the cooling fins are inserted, and a fixing protrusion extending in contact with the pin insertion hole. A cooling structure for an automobile water-cooled inverter module, comprising: a thermally conductive thin plate having, wherein the fixing protrusion protrudes so as to provide a fitting hole having a small inner diameter in the insertion direction for firm fixing with the cooling fin.
delete The method of claim 1,
The pin insertion opening has a concave airtight member insertion groove along the circumference,
The airtight member is a cooling structure for a vehicle water-cooled inverter module, characterized in that formed of an O-ring inserted into the airtight member insertion groove.
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