JP4525615B2 - Power converter - Google Patents

Description

  The present invention relates to a power conversion device in which a semiconductor module and a cooling member for cooling the semiconductor module are stacked.

Conventionally, a power conversion circuit such as a DC-DC converter circuit or an inverter circuit is sometimes used to generate a drive current for energizing an electric motor that is a power source of an electric vehicle or a hybrid vehicle.
In general, an electric vehicle, a hybrid vehicle, or the like needs to obtain a large driving torque from an electric motor, and thus requires a large current as a driving current.
For this reason, in the power conversion circuit that generates the drive current for the electric motor, the heat generation from the semiconductor module including the power semiconductor element such as IGBT constituting the power conversion circuit tends to increase.

  Therefore, a large number of flat cooling pipes are arranged between a pair of headers that supply and discharge the cooling medium (refrigerant) so that the plurality of semiconductor modules constituting the power conversion circuit can be cooled with high uniformity. A cooling pipe parallel type power converter having a semiconductor module sandwiched between pipes has been proposed (see Patent Document 1).

Further, a structure is disclosed in which heat dissipation performance of an electronic component is improved by interposing a thermally conductive grease between the electronic component and a heat dissipation plate that dissipates heat from the electronic component (see Patent Document 2). ).
And by interposing grease between a semiconductor module and a cooling pipe and filling the space between both with grease, the cooling efficiency of the semiconductor module in the power converter mentioned above can be improved.

However, the grease is subjected to heat stress due to heat reception and cooling by the semiconductor modules and cooling pipes arranged on both sides thereof. In addition, when the power conversion device is disposed in an engine room of an automobile, thermal stress due to the use environment may be applied to the grease.
As a result, a bleed phenomenon in which the oil in the grease is separated may occur, and air may be mixed into the grease. As a result, the thermal conductivity of the grease decreases, and there is a risk that the heat radiation of the semiconductor module will be insufficient.

  In order to solve such a problem, it is conceivable to suppress the bleed phenomenon by cross-linking the oil component of the grease and gelling. However, since the gel has a high viscosity, it is difficult to dispose the gel thinly and uniformly between the semiconductor module and the cooling pipe. That is, when the gel is applied to the surface of the semiconductor module or the cooling pipe, the viscosity is high, so that it is inevitably blurred, and it is difficult to reliably fill the gel thinly between the semiconductor module and the cooling pipe. It is. Moreover, in order to apply | coat a gel to the surface of a semiconductor module or a cooling pipe so that it may not fade, there exists a problem that it is necessary to make an application | coating speed low and productivity will fall.

JP 2002-26215 A Japanese Patent Laid-Open No. 2005-5671

The present invention has been made in view of such a conventional problem , and is an electric power for generating a drive current for energizing an electric motor that is a power source of an electric vehicle or a hybrid vehicle having excellent heat dissipation efficiency and excellent productivity. It is an object of the present invention to provide a conversion device and a manufacturing method thereof.

The first invention includes a semiconductor module constituting a part of a power conversion circuit, Ri Na and stacked and a cooling member for cooling the semiconductor module from both sides,
A power conversion device for generating a drive current for energizing an electric motor that is a power source of an electric vehicle or a hybrid vehicle ,
Between the semiconductor module and the cooling member, a gel grease having thermal conductivity is interposed,
The gel grease is in a power converter having a crosslinking degree of 16 to 80% (Claim 1).

Next, the effects of the present invention will be described.
In the power conversion apparatus for generating a drive current for energizing an electric motor that is a power source of an electric vehicle or a hybrid vehicle according to the present invention, the gel grease is interposed between the semiconductor module and the cooling member. is doing. Therefore, the semiconductor module and the cooling member can be brought into close contact with each other without forming a gap between them. Therefore, the thermal resistance between the semiconductor module and the cooling member can be reduced, and the cooling efficiency of the semiconductor module can be improved.

  And since the crosslinking degree of the said gel grease is 16-80%, while being able to ensure sufficient thermal conductivity, a gel grease can be easily formed between a semiconductor module and a cooling member. That is, by having the above degree of crosslinking, the gel grease can suppress a bleed phenomenon caused by thermal stress. As a result, a decrease in the thermal conductivity of the gel grease can be suppressed, and the heat dissipation efficiency of the semiconductor module can be ensured. Further, by having the above degree of crosslinking, the gel grease can be uniformly and easily applied to the main surface of the semiconductor module or the cooling member without causing a blur or the like without excessively high viscosity. Thereby, while being able to ensure the cooling efficiency of a semiconductor module, the productivity of a power converter device can be improved.

As described above, according to the present invention, it is possible to provide a power conversion device for generating a drive current for energizing an electric motor, which is a power source of an electric vehicle or a hybrid vehicle , having excellent heat dissipation efficiency and excellent productivity. Can do.

The second invention includes a semiconductor module constituting a part of a power conversion circuit, Ri Na and stacked and a cooling member for cooling the semiconductor module from both sides,
A method for manufacturing a power conversion device for generating a drive current for energizing an electric motor that is a power source of an electric vehicle or a hybrid vehicle ,
An application step of applying a gel grease having thermal conductivity and a crosslinking degree of 16 to 80% by screen printing on at least one main surface of the semiconductor module and the cooling member;
A method of manufacturing a power conversion device comprising: a laminating step of laminating the semiconductor module and the cooling member via the gel grease (claim 4).

Next, the effects of the present invention will be described.
The manufacturing method of the power converter includes the application process and the lamination process. Thereby, the said semiconductor module and the said cooling member can be closely_contact | adhered via gel grease, without forming a space | gap between both.
Therefore, in a power conversion device for generating a drive current for energizing an electric motor that is a power source of an electric vehicle or a hybrid vehicle, the thermal resistance between the semiconductor module and the cooling member is reduced, and the semiconductor module The cooling efficiency can be improved.

  And since the crosslinking degree of the said gel grease apply | coated to the at least one main surface of the said semiconductor module and the said cooling member in the said application | coating process is 16 to 80%, while being able to ensure sufficient thermal conductivity, The gel grease can be easily formed between the semiconductor module and the cooling member. That is, by having the above degree of crosslinking, the gel grease can suppress a bleed phenomenon caused by thermal stress. As a result, a decrease in the thermal conductivity of the gel grease can be suppressed, and the heat dissipation efficiency of the semiconductor module can be ensured. Further, by having the above degree of crosslinking, the gel grease can be uniformly and easily applied to the main surface of the semiconductor module or the cooling member without causing a blur or the like without excessively high viscosity.

In the application step, since the gel grease is applied by a screen printing method, the gel grease can be thinly and uniformly formed on the main surface of the semiconductor module.
Thereby, while being able to ensure the cooling efficiency of a semiconductor module, the productivity of a power converter device can be improved.

As described above, according to the present invention, there is provided a method for manufacturing a power conversion device for generating a drive current for energizing an electric motor that is a power source of an electric vehicle or a hybrid vehicle, which is excellent in heat dissipation efficiency and productivity. Can be provided.

A third invention is a semiconductor module constituting a part of a power conversion circuit, and a cooling member for cooling the semiconductor module from both sides, Ri Na and stacked via an insulating member therebetween,
A method for manufacturing a power conversion device for generating a drive current for energizing an electric motor that is a power source of an electric vehicle or a hybrid vehicle ,
Gel grease having thermal conductivity and a crosslinking degree of 16 to 80% is formed on at least one main surface of the semiconductor module and the insulating member and at least one main surface of the cooling member and the insulating member. An application step of applying by screen printing;
A method of manufacturing a power conversion device comprising: a laminating step of laminating the semiconductor module, the insulating member, and the cooling member via the gel grease (Claim 6).

Also in the case of the present invention, the same effect as that of the second invention can be obtained. That is, the power conversion device that needs to interpose the insulating member between the semiconductor module and the cooling member in manufacturing, it is possible to obtain the same effect as the second invention.
Therefore, according to the present invention, there is provided a method for manufacturing a power conversion device for generating a drive current that is excellent in heat dissipation efficiency and excellent in productivity, and that is used to generate an electric current that is applied to an electric motor that is a power source of an electric vehicle or a hybrid vehicle. be able to.

In the first to third inventions, as the gel grease, for example, a material in which an additive for promoting heat conduction is mixed can be used. And as this additive, metal powders, such as a zinc oxide, can be used, for example.
Moreover, when the degree of crosslinking of the gel grease is less than 16%, it is difficult to sufficiently suppress the bleed phenomenon caused by thermal stress. As a result, the thermal conductivity of the gel grease is lowered, and it may be difficult to ensure sufficient heat dissipation efficiency of the semiconductor module. On the other hand, when the degree of cross-linking exceeds 80%, the viscosity of the gel grease becomes too high, and there is a risk of causing blurring when applying the gel grease to the main surface of the semiconductor module, the cooling member, etc. It may be difficult to apply uniformly.

The power conversion equipment is for generating a driving current supplied to the electric motor as a power source for electric vehicles and hybrid vehicles, there is a DC-DC converter or an inverter or the like.
The semiconductor module includes, for example, a MOS FET element, an IGBT element, a diode, a transistor, a thyristor, a power integrated circuit, and the like.

Next, in the first invention (invention 1), the gel grease is preferably in direct contact with both the semiconductor module and the cooling member (invention 2).
In this case, only the gel grease is interposed between the semiconductor module and the cooling member. Therefore, it is possible to reduce the thermal resistance.

An insulating member is interposed between the semiconductor module and the cooling member, and the gel grease is between the insulating member and the semiconductor module and between the insulating member and the cooling member. It may be interposed in each of both (claim 3).
In this case, electrical insulation between the semiconductor module and the cooling member can be ensured. For example, when a heat sink or the like electrically connected to the electrode is disposed on the main surface of the semiconductor module, electrical insulation between the heat sink and the cooling member is ensured, It is necessary to ensure operation. Even in such a case, by applying the present invention, it is possible to obtain a power conversion device that is excellent in heat dissipation efficiency and excellent in productivity.

Next, in the second invention (invention 4) or the third invention (invention 6), the gel grease applied thickness before the laminating step is preferably 20 to 100 μm (invention). 5. Claim 7).
In this case, the cooling efficiency of the semiconductor module is improved by reducing the thermal resistance between the semiconductor module and the cooling member, or between the semiconductor module and the insulating member, and between the insulating member and the cooling member. be able to.

  That is, by setting the coating thickness of the gel grease in the coating step to 20 to 100 μm, in the stacking step, the semiconductor module and the cooling member, or the semiconductor module and the insulating member, or the insulating member and the cooling member are used. When the gel grease is crushed by applying pressure to each other, it becomes easy to extend the gel grease thinly and uniformly. As a result, the gel grease between the semiconductor module and the cooling member, or between the semiconductor module and the insulating member, and between the insulating member and the cooling member is made sufficiently thin and sufficiently widened as a whole. Can do. Therefore, the thermal resistance between the semiconductor module and the cooling member can be reduced, and the cooling efficiency of the semiconductor module can be improved.

  When the coating thickness of the gel grease is less than 20 μm, it may be difficult to sufficiently spread the gel grease on the contact surface such as between the semiconductor module and the cooling member. Thereby, there exists a possibility that air may intervene between a semiconductor module and a cooling member. On the other hand, when the coating thickness exceeds 100 μm, it is difficult to sufficiently crush the gel grease in the laminating step, and it may be difficult to reduce the final thickness of the gel grease. Thereby, the thermal resistance between the semiconductor module and the cooling member is increased, and it may be difficult to improve the cooling efficiency of the semiconductor module.

Example 1
A power converter according to an embodiment of the present invention and a manufacturing method thereof will be described with reference to FIGS.
As shown in FIGS. 1 and 2, the power conversion apparatus 1 of this example includes a semiconductor module 2 constituting a part of the power conversion circuit, and a cooling pipe 4 as a cooling member for cooling the semiconductor module 2 from both sides. Are laminated.

  As shown in FIG. 1, a gel grease 5 having thermal conductivity is interposed between the semiconductor module 2 and the cooling pipe 4. In this example, the insulating member 3 is interposed between the semiconductor module 2 and the cooling pipe 4, and the gel grease 5 is provided between the insulating member 3 and the semiconductor module 2 and between the insulating member 3 and the cooling member 4. Are intervened in both sides. And the degree of crosslinking of this gel grease 5 is 16 to 80%.

  As the gel grease 5, silicone gel grease filled with metal powder such as zinc oxide as an additive for promoting heat conduction can be used. That is, the gel grease 5 is obtained by gelation by adding a crosslinking agent to the silicone grease to which the metal powder is added.

Said power converter 1, for generating a driving current supplied to the electric motor as a power source for electric vehicles and hybrid vehicles, a DC-DC converter and the inverter.
The semiconductor module 2 includes, for example, a semiconductor element such as a MOS type FET element, an IGBT element, a diode, a transistor, or a thyristor.
The semiconductor module 2 includes a module main body 20 containing a semiconductor element, a main electrode terminal 221 and a signal terminal 222 protruding from the module main body 20. Moreover, the heat sink 23 electrically connected to the main electrode terminal is exposed on both main surfaces of the module body 20.
The heat radiating plate 23 and the insulating member 3 are disposed to face each other, and the gel grease 5 is interposed therebetween.

The insulating member 3 is made of a ceramic plate, and the cooling pipe 4 is made of aluminum.
As shown in FIG. 1, the cooling pipe 4 has a refrigerant channel 41 inside thereof, and is configured so that a cooling medium can be circulated therein. Further, as shown in FIG. 2, a connection pipe 401 is arranged so as to connect both ends of the plurality of cooling pipes 4, and two header portions 402 are formed. In addition, a refrigerant inlet 403 and a refrigerant outlet 404 connected to the cooling pipe 4 are provided at one end of the two header portions 401 and 402, respectively. Thus, the cooler 40 formed by arranging a plurality of cooling pipes 4 in parallel is configured.
The semiconductor module 2 can be cooled from both sides by sandwiching the semiconductor module 2 between the adjacent cooling pipes 4 as described above and circulating the cooling medium in the cooling pipe 4.

  In manufacturing the power converter 1, the following coating process and laminating process are repeated as shown in FIGS. That is, in the application step, the gel grease 5 is applied to at least one main surface of the semiconductor module 2 and the insulating member 3 and at least one main surface of the cooling pipe 4 and the insulating member by a screen printing method. In the stacking step, the semiconductor module 2, the insulating member 3, and the cooling member 4 are stacked via the gel grease 5.

Below, it demonstrates concretely using FIGS. 3-7.
First, as shown in FIG. 3, the semiconductor module 2 is held by the chuck jig 61 with one main surface thereof facing upward. And the gel grease 5 is printed on the main surface (the surface of the heat sink 23) of the said semiconductor module 2 by the screen printing method. That is, the screen mask 62 having the print pattern 621 is covered on the main surface of the semiconductor module 2. Then, the gel grease 5 is placed on the upper surface of the screen mask 62, and the gel grease 5 is printed on the main surface of the semiconductor module 2 below the print pattern 621 of the screen mask 62 so as to be rubbed by the squeegee 63.

As a result, as shown in FIG. 4, the gel grease 5 is applied to a desired position and range of the semiconductor module 2. The coating thickness of the gel grease 5 at this time is approximately uniform between 20 and 100 μm.
Next, as shown in FIG. 5, the insulating member 3 is laminated on the main surface of the semiconductor module 2 to which the gel grease 5 is applied via the gel grease 5. At this time, by pressing the insulating member 3 against the main surface of the semiconductor module 2 with a predetermined pressure, the gel grease 5 is crushed and spread thinly and uniformly between the semiconductor module 2 and the insulating member 3. The film thickness of the gel grease 5 at this time is 10 μm or less.

Next, the gel grease 5 is similarly applied to the opposite main surface of the semiconductor module 2 and the insulating member 3 is laminated.
Next, as shown in FIG. 6, gel grease 5 is screen-printed on the main surface of the insulating member 3 laminated on the semiconductor module 2. The screen printing method is the same as that when printing on the main surface of the semiconductor module 2 (FIG. 3).
Thereby, as shown in FIG. 7, the gel grease 5 is formed on the main surface of the insulating member 3 with a substantially uniform thickness. The coating thickness of the gel grease 5 is 20 to 100 μm.

Next, the gel grease 5 is similarly screen-printed on the main surface of the insulating member 3 laminated on the main surface on the opposite side of the semiconductor module 2.
Next, as shown in FIG. 1, the semiconductor module 2 is disposed between the adjacent cooling pipes 4, and is sandwiched by the cooling pipes 4 from both main surfaces of the semiconductor module 2 via the gel grease 5. At this time, the gel grease 5 is crushed so that the film thickness becomes 10 μm or less.
And about the several semiconductor module 2, the power converter device 1 as shown in FIG. 2 is obtained by laminating | stacking with the cooling pipe 4 with the same assembly | attachment method.

Next, the function and effect of this example will be described.
In the power conversion device 1, the gel grease 5 is interposed between the semiconductor module 2 and the cooling pipe 4. Therefore, the semiconductor module 2 and the cooling pipe 4 can be brought into close contact via the gel grease 5 without forming a gap between them. Therefore, the thermal resistance between the semiconductor module 2 and the cooling pipe 4 can be reduced, and the cooling efficiency of the semiconductor module 2 can be improved.

  In this example, in particular, as described above, the insulating member 3 is interposed between the semiconductor module 2 and the cooling pipe 4, and between the semiconductor module 2 and the insulating member 3 and between the insulating member 3 and the cooling pipe 4. In each case, gel grease 5 is interposed. Therefore, the semiconductor module 2 and the insulating member 3 can be brought into close contact with each other via the gel grease 5 without forming a gap therebetween, and the gap between the insulating member 3 and the cooling pipe 4 can be reduced. It can be made to adhere through the gel grease 5 without forming. Therefore, the thermal resistance between the semiconductor module 2 and the cooling pipe 4 can be reduced, and the cooling efficiency of the semiconductor module 2 can be improved.

  Since the gel grease 5 has a crosslinking degree of 16 to 80%, sufficient thermal conductivity can be ensured, and between the semiconductor module 2 and the insulating member 3 and between the insulating member 3 and the cooling pipe 4. The gel grease 5 can be easily formed between the two. That is, by having the said crosslinking degree, the gel grease 5 can suppress the bleed phenomenon resulting from a thermal stress. As a result, a decrease in the thermal conductivity of the gel grease 5 can be suppressed, and the heat dissipation efficiency of the semiconductor module 2 can be ensured. Further, the gel grease 5 can be uniformly and easily applied to the main surface of the semiconductor module 2 or the cooling pipe 4 without causing blurring by having the above degree of crosslinking. it can. Thereby, while being able to ensure the cooling efficiency of the semiconductor module 2, the productivity of the power converter device 1 can be improved.

  Further, in manufacturing the power conversion device of this example, since the gel grease 5 is applied by the screen printing method in the application step, the gel grease 5 can be formed thinly and uniformly on the main surface of the semiconductor module 2 or the like. It becomes possible. Thereby, while being able to ensure the cooling efficiency of the semiconductor module 2, the productivity of the power converter device 1 can be improved.

  And the application | coating thickness of the gel grease 5 before the said lamination process is 20-100 micrometers. Thereby, the thermal resistance between the semiconductor module 2 and the insulating member 3 and between the insulating member 3 and the cooling member 4 can be reduced, and the cooling efficiency of the semiconductor module 2 can be improved.

  As described above, according to this example, it is possible to provide a power conversion device that is excellent in heat dissipation efficiency and excellent in productivity, and a manufacturing method thereof.

(Example 2)
In this example, as shown in FIG. 8, the power conversion has a configuration in which only the gel grease 5 is interposed between the semiconductor module 2 and the cooling pipe 4 without interposing an insulating member (see reference numeral 3 in FIG. 1). 2 is an example of the device 1;
The gel grease 5 is in direct contact with both the semiconductor module 2 and the cooling pipe 4.
Moreover, the semiconductor module 2 of this example does not expose the heat sink (see reference numeral 23 in FIG. 1) on the main surface. Therefore, it is not necessary to interpose an insulating member between the semiconductor module 2 and the cooling pipe 4.
Others are the same as in the first embodiment.

In the case of this example, since it is possible to adopt a configuration in which only one layer of gel grease 5 is interposed between the semiconductor module 2 and the cooling pipe 4, the thermal resistance between the semiconductor module 2 and the cooling pipe 4 is reduced. Reduction can be achieved. Thereby, the cooling efficiency of the semiconductor module 2 can be improved more.
In addition, the same effects as those of the first embodiment are obtained.

(Example 3)
In this example, as shown in FIG. 9, it was examined how the thermal resistance of a plurality of gel greases having different degrees of crosslinking changes due to a cooling test.
In the test, gel greases having a crosslinking degree of 0%, 50%, 60%, 70%, 80%, and 100% were prepared. The initial application thickness of the gel grease was 50 μm, sandwiched between two members, and crushed so as to have a film thickness of about 5 μm. And the thermal resistance between the front and back of the gel grease was measured. Note that the film thickness of the gel grease is somewhat reduced during the cold heat test.

The cold test was performed by repeating the process of 3,000 ° C. for one cycle in the gas phase in which the state of -30 ° C. was continued for 30 minutes and then the state of 110 ° C. was continued for 30 hours. And the thermal resistance of the gel grease was measured at the initial stage before the cooling test, during the cooling test, and after 3000 cycles.
The result is shown in FIG.

  In the figure, the thermal resistance before the cooling cycle (the number of cooling cycles 0) is high because the film thickness of the gel grease is large in the initial state, and then the film thickness is small during the cooling cycle. This is considered to be because it becomes stable. Therefore, if the film thickness of the gel grease is stable from the beginning, it can be considered that the thermal resistance is smaller than that at the 500th cycle by analogy with data of 500 cycles or more.

As can be seen from FIG. 9, the data after the 500th cycle is gradually increased in thermal resistance as the cooling cycle is performed, but the sample having a crosslinking degree of 0% has a particularly high thermal resistance. It has become. This is considered to be because a bleed phenomenon caused by thermal stress occurs. Conversely, for a sample with a degree of crosslinking of 50% or more, the thermal resistance can be kept relatively small.
From this result, when the degree of crosslinking is 0, that is, when the grease is not gelled, the thermal conductivity of the gel grease may be reduced due to the bleed phenomenon caused by thermal stress. It can be seen that the decrease in the resistance can be suppressed.

Example 4
In this example, as shown in FIG. 10, the relationship between the degree of crosslinking of the gel grease and the application state is examined.
That is, a plurality of gel greases having different degrees of crosslinking were screen-printed on the main surface of the semiconductor module at various printing speeds (squeegee speeds), and the printed state was visually confirmed.
The observation results are shown in FIG. In the same figure, a good one without fading was represented as ◯, a slight fading was represented as Δ, and a faint one was represented as x.

  From the test results, it can be seen that the lower the degree of crosslinking, the better the printing possible even if the printing speed is increased. And if a crosslinking degree is 80% or less, even if it sets a printing speed to 75 mm / sec, it turns out that favorable printing can be performed, without producing a blur. Therefore, it can be seen that by setting the degree of crosslinking to 80% or less, screen printing can be performed efficiently and productivity can be improved.

(Example 5)
This example is an example in which an appropriate range of the viscosity of the gel grease is considered from the viewpoint of durability and viscosity, as shown in FIG.
That is, the dependency of the degree of crosslinking on the rate of change in thermal resistance before and after the cooling test shown in Example 3 is represented by a solid line L1. The relationship between the degree of crosslinking and the viscosity is represented by a solid line L2. In FIG. 11, the left vertical axis represents the rate of change in thermal resistance before and after the cooling test, and the right vertical axis represents the viscosity scale. The viscosity was measured using a Malcolm viscometer.

  As can be seen from the solid line L1 in FIG. 11, the rate of change in thermal resistance before and after the cooling test can be made 100% or less by setting the degree of crosslinking to 16% or more. This indicates that if the degree of cross-linking is 16% or more, it is possible to prevent the thermal resistance from becoming larger than the initial state by the cold test, and it is possible to ensure durability.

  Further, as can be seen from the solid line L2 in FIG. 11, when the degree of crosslinking is increased to about 70% or more, the viscosity gradually increases. Then, considering the manufacturing variation of the gel grease, it can be seen that the degree of crosslinking is preferably 80% or less from the viewpoint of printing workability.

Sectional explanatory drawing which shows a part of power converter device in Example 1. FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 3 is an explanatory diagram of a screen printing method of gel grease on a semiconductor module in Example 1. FIG. 3 is an explanatory diagram illustrating a state where gel grease is applied to the semiconductor module in the first embodiment. Explanatory drawing which shows the state which laminated | stacked the insulating member on the semiconductor module through the gel grease in Example 1. FIG. FIG. 3 is an explanatory diagram of a screen printing method of gel grease on an insulating member in Example 1. Explanatory drawing which shows the state which laminated | stacked the insulating member on the insulating member through the gel grease in Example 1. FIG. Sectional explanatory drawing which shows a part of power converter device in Example 2. FIG. The diagram which shows the change of the thermal resistance by the cold test in Example 3. FIG. The diagram which shows the relationship between the crosslinking degree of gel grease in Example 4, and an application state. The diagram which shows the appropriate range of the crosslinking degree of the gel grease in Example 5. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power converter 2 Semiconductor module 3 Insulation member 4 Cooling pipe 5 Gel grease

Claims (7)

A semiconductor module constituting a part of a power conversion circuit, Ri Na with a cooling member for cooling the semiconductor module from both sides and stacked,
A power conversion device for generating a drive current for energizing an electric motor that is a power source of an electric vehicle or a hybrid vehicle ,
Between the semiconductor module and the cooling member, a gel grease having thermal conductivity is interposed,
The gel grease has a degree of cross-linking of 16 to 80%.   2. The power conversion device according to claim 1, wherein the gel grease is in direct contact with both the semiconductor module and the cooling member.   2. The insulating member is interposed between the semiconductor module and the cooling member according to claim 1, and the gel grease is provided between the insulating member and the semiconductor module, and between the insulating member and the cooling member. The power converter characterized by interposing both in between. A semiconductor module constituting a part of a power conversion circuit, Ri Na with a cooling member for cooling the semiconductor module from both sides and stacked,
A method for manufacturing a power conversion device for generating a drive current for energizing an electric motor that is a power source of an electric vehicle or a hybrid vehicle ,
An application step of applying a gel grease having thermal conductivity and a crosslinking degree of 16 to 80% by screen printing on at least one main surface of the semiconductor module and the cooling member;
A method for manufacturing a power conversion device, comprising: a laminating step of laminating the semiconductor module and the cooling member via the gel grease. 5. The method of manufacturing a power conversion device according to claim 4, wherein a coating thickness of the gel grease before the laminating step is 20 to 100 [mu] m. A semiconductor module constituting a part of a power conversion circuit, and a cooling member for cooling the semiconductor module from both sides, Ri Na and stacked via an insulating member therebetween,
A method for manufacturing a power conversion device for generating a drive current for energizing an electric motor that is a power source of an electric vehicle or a hybrid vehicle ,
Gel grease having thermal conductivity and a crosslinking degree of 16 to 80% is formed on at least one main surface of the semiconductor module and the insulating member and at least one main surface of the cooling member and the insulating member. An application step of applying by screen printing;
The manufacturing method of the power converter device which has a lamination process which laminates | stacks the said semiconductor module, the said insulating member, and the said cooling member via the said gel grease. 7. The method of manufacturing a power converter according to claim 6, wherein the gel grease is applied in a thickness of 20 to 100 [mu] m before the laminating step.

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