JP4292913B2 - Semiconductor cooling unit - Google Patents

Description

  The present invention relates to a semiconductor cooling unit that includes a semiconductor module and includes cooling means for the semiconductor module.

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 AC motor that is a power source of an electric vehicle or a hybrid vehicle.
Generally, in an electric vehicle, a hybrid vehicle, or the like, a large driving torque needs to be obtained from an AC motor, and thus a large current is required as a driving current.
Therefore, in the power conversion circuit that generates the drive current for the AC motor, 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 tubes 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 tube parallel type power converter in which a semiconductor module is sandwiched between cooling tubes has been proposed (see, for example, Patent Document 1).
In this power converter, in order to improve the heat transfer efficiency between the cooling tube and the semiconductor module, a contact load is applied between the two to ensure a wide contact area.

However, the conventional power conversion device has the following problems. That is, since a mechanism or member for applying a contact load between the cooling tube and the semiconductor module is required, the structure is complicated and the size of the body may be increased.
Furthermore, since a dimensional change occurs in the direction of the load, there is a problem that it is difficult to maintain a high shape accuracy.
JP 2002-26215 A

  The present invention has been made in view of such conventional problems, and an object of the present invention is to provide an excellent semiconductor cooling unit having excellent heat radiation efficiency and high shape accuracy.

A first aspect of the present invention is a semiconductor cooling unit comprising a power semiconductor element and a pair of refrigerant flow paths for flowing a refrigerant, and the semiconductor element is disposed between the pair of refrigerant flow paths.
The semiconductor element has a pair of flat electrode plates arranged so as to sandwich the semiconductor element,
And the coolant channel is Ri at least a portion of the inner wall constitutes a part of the electrode plate Thea,
The pair of electrode plates and the semiconductor element are integrally covered with a mold resin, and each of the coolant channels is formed facing the electrode plate inside the mold resin. (Claim 1).

The semiconductor cooling unit according to the first aspect of the invention has the refrigerant flow path using the surface of the electrode plate as at least a part of the inner wall surface.
Therefore, according to the electrode plate, heat generated by the semiconductor element can be radiated directly and efficiently to the refrigerant flowing through the refrigerant flow path.

In the semiconductor cooling unit, it is not necessary to press a member such as a refrigerant pipe that forms the refrigerant flow path against the electrode plate.
Therefore, the semiconductor cooling unit according to the first aspect of the invention does not require a mechanism or a structure for applying a contact load, so that the structure is simple and a dimensional change due to the contact load may occur. There is no shape accuracy.

  As described above, the semiconductor cooling unit according to the first aspect of the invention is a unit having excellent heat dissipation efficiency and high shape accuracy.

Further, the pair of the electrode plate and the semiconductor element, Yes covers integrally by molding resin, each coolant channel, in the interior of the mold resin, Ru Thea formed facing the electrode plate .
Thereby , the said refrigerant | coolant which flows through the said refrigerant | coolant flow path shape | molded with the said mold resin can be made to contact the surface of the said electrode plate, and the heat transfer efficiency between both can be improved.

Further, the semiconductor cooling unit includes a pair of header portions for supplying and discharging a refrigerant, and the pair of headers sandwiching the semiconductor element are arranged in parallel in the pair of header portions. Are preferably connected (claim 2 ).
In this case, the plurality of semiconductor cooling units having the pair of refrigerant flow paths can be configured in a compact manner.

In the first invention, the coolant is preferably a refrigerant having an electrical insulation property (claim 3).
In this case, the electrical reliability of the semiconductor cooling unit can be improved by suppressing the possibility of an electrical short circuit through the refrigerant.

The surface of the electrode plate in contact with the refrigerant, it is preferable that is formed with an insulating film having an electrical insulation property (claim 4).
In this case, the possibility of causing an electrical short circuit through the refrigerant can be suppressed.
And since the said insulating film is arrange | positioned between the said refrigerant | coolant and the said electrode plate, the refrigerant | coolant which has electroconductivity can be employ | adopted as the said refrigerant | coolant.

( Reference Example 1 )
The semiconductor cooling unit 1 of this example will be described with reference to FIGS.
As shown in FIGS. 1 and 2, the semiconductor cooling unit 1 of the present example includes a power semiconductor element 11 and a pair of refrigerant channels 21 for flowing a refrigerant. A unit in which the semiconductor element 11 is disposed between them.
The semiconductor element 11 has a pair of flat electrode plates 151 and 152 disposed so as to sandwich the semiconductor element 11.
The refrigerant flow path 21 is constituted by at least a part of its inner wall surface by the surface of the electrode plate 15.
This content will be described in detail below.

The semiconductor cooling unit 1 of this example forms a part of a power conversion device (not shown) that generates a drive current for energizing a travel motor for an electric vehicle, for example.
As shown in FIG. 1, this semiconductor cooling unit 1 accommodates an IGBT element (hereinafter referred to as IGBT element 11) as a power semiconductor element 11, and a pair so as to sandwich the IGBT element 11. These electrode plates 151 and 152 are arranged.
The IGBT element 11 constitutes an inverter circuit or a DC-DC converter circuit of the power converter.

In the semiconductor cooling unit 1 of this example, as shown in FIG. 1, electrode plates 151 and 152 are soldered to both surfaces of the IGBT element 11. That is, the solder bonding layer 111 is formed between the IGBT element 11 and the electrode plates 151 and 152.
And the semiconductor cooling unit 1 of this example integrally covers the soldered IGBT element 11 and the pair of electrode plates 151 and 152 with the mold resin 100 as shown in FIGS.

In the semiconductor cooling unit 1, between the pair of electrode plates 151 and 152, as shown in FIG. 2, the IGBT element 11 and the flywheel diode element 12 necessary for smoothing the rotation of the motor are arranged. It is.
As shown in FIGS. 1 and 2, the semiconductor cooling unit 1 includes a power signal terminal that is integral with the electrode plates 151 and 152, and a control signal terminal that is a mold resin. And a control terminal 160 held therein.
The power terminal 150 and the control terminal 160 are disposed to face each other in a plane parallel to the electrode plate 15.

Moreover, the said electrode plates 151 and 152 are flat members which formed the hollow part 21 which makes a refrigerant | coolant flow inside, as shown in FIG. In this example, the cooling tube was formed from an aluminum alloy containing 97% aluminum.
According to the refrigerant flowing through the hollow portion 21, heat generated from the IGBT element 11 and transmitted to the electrode plates 151 and 152 can be absorbed efficiently.

A bonding portion 115 for connecting a bonding wire 116 that is a connection signal line to the control terminal 160 is formed at the end of one surface of the IGBT element 11.
Therefore, the width of the electrode plate 152 in the direction orthogonal to the flow direction of the refrigerant is narrower than that of the other electrode plate 151 so that the electrode plate 152 can be bonded to avoid the bonding portion 115.

In using the semiconductor cooling unit 1 of this example, for example, as shown in FIG. 3, the tank shape is made of 66 nylon containing glass fiber, and the pair of header portions 41 and 42 for supplying and discharging the refrigerant is used. A plurality of semiconductor cooling units 1 can be connected in parallel.
That is, both end portions of the electrode plates 151 and 152 of each semiconductor cooling unit 1 in the refrigerant flow direction are connected to the header portions 41 and 42.
Here, according to the header portions 41 and 42 made of 66 nylon with glass fiber having electrical insulation, electrical insulation between the electrode plates 151 and 152 is ensured, and each of the elements 11 and 12 is secured. An electrical short circuit can be prevented.

In addition, the semiconductor cooling unit 1 of the present example is configured such that an electrically insulating refrigerant flows through the hollow portion 21.
Therefore, there is little possibility that the elements 11 and 12 are electrically short-circuited through the refrigerant.
In addition, if an insulating coating film is formed on the inner wall surface of the hollow portion 21 of each of the electrode plates 151 and 152, it is possible to employ a conductive coolant.

Furthermore, instead of the header parts 41 and 42 made of 66 nylon containing glass fiber, the header parts 41 and 42 are formed of a conductive material, for example, an aluminum alloy, while the header parts 41 and 42 and the electrodes are formed. A highly insulating member may be interposed between the plate 15 and the two in an insulated state.
Furthermore, in this example, the plurality of semiconductor cooling units 1 are configured in parallel. However, instead of this, one semiconductor cooling unit 1 can be connected to the pair of header portions 41 and 41.

In this example, the semiconductor cooling unit 1 is configured with the electrode plate 151 and the electrode plate 152 bonded to the IGBT element 11 as separate components. However, as shown in FIG. 4, the electrode plate 151 can be shared.
Although a deviation occurs at the tip position of the electrode terminal 150 for each electrode plate 150, there is no problem if the deviation can be absorbed on the socket side combined with the electrode terminal 150.

Further, the hollow portion 21 of the electrode plate 155 can be partitioned by ribs 210 as shown in FIG. In this case, it is possible to secure a large surface area of the electrode plate 155 in contact with the refrigerant and improve the heat transfer efficiency between them.
Furthermore, as shown in FIG. 6, the portion where the hollow portion 21 is formed can be formed with a plate thickness as compared with the electrode terminal 150. In this case, the cooling performance of the IGBT element 11 can be improved by increasing the flow rate of the refrigerant flowing through the hollow portion 21.

In the semiconductor cooling unit 1 in the figure, an electrode terminal 150 is joined to one surface side of the IGBT element 11 with a plate-shaped block 110 made of copper having good thermal conductivity. If the plate-like block 110 is interposed, interference between the electrode terminal 150 and the bonding wire 116 can be avoided.
Therefore, in this case, the electrode terminals 150 having substantially the same shape can be arranged on both surfaces of the IGBT element 11 without shifting along the element surface.

( Reference Example 2 )
In this example, the configuration of the electrode plate is changed based on Reference Example 1 . The contents of this example will be described with reference to FIGS.
As shown in FIG. 7, the electrode plate 17 of this example has a two-part structure of a terminal portion 171 and a refrigerant flow path portion 172. Both of them are previously joined together by brazing and formed in substantially the same shape as the electrode plate of Example 1.

Further, as shown in FIGS. 8 and 9, the terminal portions 181 and 191 and the refrigerant flow path portions 182 and 192 can be overlapped and joined to form the integrated electrode plates 18 and 19.
Here, regarding the positional relationship between the terminal portions 181 and 191 and the refrigerant flow passage portions 182 and 192, as shown in FIG. 8, the refrigerant flow passage portion 182 is disposed between the terminal portion 181 and the IGBT element 11. As shown in FIG. 9, it is possible to dispose the coolant channel portion 192 outside the terminal portion 191.
In addition, it can replace with the said brazing joining and can also be set as solder joining. Furthermore, it is also possible to interpose a heat conductive grease between the terminal portions 181 and 191 and the refrigerant flow path portions 182 and 192, and to cover them integrally with the mold resin 100 and join them together.

Furthermore, the shape of the hollow portion 21 can be changed based on the semiconductor cooling unit 1 shown in FIG. That is, as shown in FIG. 10, it is possible to use the refrigerant flow path portion 183 in which the hollow portion 21 is partitioned by the rib 210.
In the semiconductor cooling unit 1 in the figure, the refrigerant flow path portion 183 is joined to one surface side of the IGBT element 11 with a plate-like block 110 made of copper having good thermal conductivity. If the plate-shaped block 110 is interposed, interference between the refrigerant flow path portion 183 and the bonding wire 116 can be avoided.
Therefore, in this case, on both surfaces of the IGBT element 11, it is possible to dispose the refrigerant flow path portions 183 having substantially the same shape without shifting along the element surface.

Similarly, the shape of the hollow portion 21 can be changed based on the semiconductor cooling unit 1 shown in FIG.
That is, as shown in FIG. 11, it is possible to use a refrigerant flow path portion 193 in which the hollow portion 21 is partitioned by the rib 210.
Other configurations and operational effects are the same as in Reference Example 1 .

( Example 1 )
In this example, the configuration of the refrigerant flow path is changed based on Reference Example 1 . The contents will be described with reference to FIG.
In the semiconductor cooling unit 1 of this example, the IGBT element 11 is sandwiched between a pair of electrode plates 15 and is integrally covered with a mold resin 100.

A coolant channel 211 is formed along the surface of each electrode plate 15 in the mold resin 100 covering the semiconductor cooling unit 1.
That is, the coolant channel 211 of this example is a channel in which the inner peripheral wall is formed by the surface of the mold resin 100 and the surface of the electrode plate 15.
Therefore, the refrigerant flowing through the refrigerant flow path 211 contacts the surface of the electrode plate 15 and can directly exchange heat with the electrode plate 15.

In addition, as a refrigerant | coolant made to flow through the said refrigerant | coolant flow path 211, it is necessary to use the refrigerant | coolant which has electrical insulation.
On the other hand, when an insulating film is formed on the surface of the electrode plate 15, a conductive coolant can be applied.
Other configurations and operational effects are the same as in Reference Example 1 .

( Reference Example 3 )
In this example, the configuration of the semiconductor cooling unit is changed based on Reference Example 1. The contents will be described with reference to FIGS.
As shown in FIG. 13, the semiconductor cooling unit 1 of this example is a unit in which a semiconductor module 2 containing an IGBT element 11 and the like is arranged inside a refrigerant pipe 4 through which a refrigerant flows.

The semiconductor module 2 is integrally formed with the mold resin 100 with the IGBT element 11 disposed between the pair of electrode plates 15 and the surface of the electrode plate 15 exposed.
And this semiconductor module 2 is arrange | positioned inside the refrigerant | coolant piping 4 to which the refrigerant | coolant provided with the electrical insulation was made to flow.
In the semiconductor cooling unit 1 of this example, since the semiconductor module 2 is immersed in the refrigerant, the performance of cooling the IGBT element 11 inside thereof is high.

As shown in FIG. 14, it is also effective to form heat transfer fins 159 on the surface of the electrode plate 15. In this case, the contact area between the refrigerant and the electrode plate 15 can be expanded to further improve the heat transfer efficiency.
In addition, an insulating film having electrical insulation can be formed on a portion of the outer surface of the semiconductor module 2 that comes into contact with the refrigerant. In this case, the semiconductor module 2 can be immersed in a conductive coolant.

Other configurations and operational effects are the same as in Reference Example 1 .
Furthermore, it can replace with the said refrigerant | coolant piping 4, and the semiconductor module 2 can also be immersed in the refrigerant | coolant tank which does not flow in and out of a refrigerant | coolant.
In this case, the semiconductor module 2 can be cooled using natural convection of the refrigerant in the tank.

( Reference Example 4 )
This example is an example in which the connection structure of the refrigerant flow path of the semiconductor cooling unit is changed based on Reference Example 1. The contents of this example will be described with reference to FIGS.
In the semiconductor cooling unit 1 of this example, the positions of the end portions of the electrode plates 151 and 152 are changed.

The semiconductor cooling unit 1 of this example is a unit formed by sandwiching an IGBT element 11 and the like between a pair of electrode plates 15 having a hollow portion, and then integrally covering with a mold resin 100.
In the semiconductor cooling unit 1 shown in FIG. 15, both end portions of the electrode plate 15 are located on the end face of the semiconductor cooling unit 1, and a hollow portion is opened on the end face.
In the semiconductor cooling unit 1 shown in FIG. 16, both end portions of the electrode plate 15 are located inside the mold resin 100 constituting the semiconductor cooling unit 1.
In the semiconductor cooling unit 1 shown in FIG. 17, one end of the electrode plate 15 protrudes from the mold resin 100 and the other end is inside the mold resin 100.

In the case of the semiconductor cooling unit 1 shown in FIGS. 16 and 17, when the end portion of the electrode plate 15 is disposed inside the mold resin 100, the opening shape communicating with each hollow portion is set for each hollow portion. The opening part 105 (FIG. 18) may be provided, and the single opening part 106 (FIG. 19) which gathered each hollow part may be provided.
Other configurations and operational effects are the same as in Reference Example 1 .

Sectional drawing which shows the cross-section of the semiconductor cooling unit in the reference example 1. FIG. The top view which shows the semiconductor cooling unit in the reference example 1. FIG. Sectional drawing which shows the connection structure of the semiconductor cooling unit in the reference example 1. FIG. Sectional drawing which shows the cross-section of the other semiconductor cooling unit in the reference example 1. FIG. Sectional drawing which shows the cross-section of the other semiconductor cooling unit in the reference example 1. FIG. Sectional drawing which shows the cross-section of the other semiconductor cooling unit in the reference example 1. FIG. Sectional drawing which shows the cross-section of the semiconductor cooling unit in the reference example 2. FIG. Sectional drawing which shows the cross-section of the other semiconductor cooling unit in the reference example 2. Sectional drawing which shows the cross-section of the other semiconductor cooling unit in the reference example 2. Sectional drawing which shows the cross-section of the other semiconductor cooling unit in the reference example 2. Sectional drawing which shows the cross-section of the other semiconductor cooling unit in the reference example 2. Sectional drawing which shows the cross-section of the semiconductor cooling unit in Example 1. FIG. Sectional drawing which shows the cross-section of the semiconductor cooling unit in the reference example 3. FIG. Sectional drawing which shows the cross-section of the other semiconductor cooling unit in the reference example 3 . The top view which shows the semiconductor cooling unit 1 in the reference example 4. FIG. The top view which shows the semiconductor cooling unit 2 in the reference example 4. FIG. The top view which shows the semiconductor cooling unit 3 in the reference example 4. FIG. The side view which shows the semiconductor cooling unit 2 in the reference example 4 (the 3). The side view which shows the other semiconductor cooling unit 2 in the reference example 4 (the 3).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor cooling unit 100 Mold resin 11 IGBT element 110 Thermal buffer board 150 Power terminal 160 Control terminal 151,152,17,18,19 Electrode plate 171,181,191 Terminal part 172,182,192 Coolant flow path part 2 Semiconductor module 21, 211 Hollow part

Claims (4)

In a semiconductor cooling unit comprising a semiconductor element for electric power and a pair of refrigerant passages for flowing a refrigerant, and the semiconductor element is disposed between the pair of refrigerant passages,
The semiconductor element has a pair of flat electrode plates arranged so as to sandwich the semiconductor element,
And the said refrigerant | coolant flow path comprises at least one part of the inner wall surface by a part of said electrode plate,
The pair of electrode plates and the semiconductor element are integrally covered with a mold resin, and each of the coolant channels is formed facing the electrode plate inside the mold resin. A semiconductor cooling unit.   2. The semiconductor cooling unit according to claim 1, wherein the semiconductor cooling unit includes a pair of header parts for supplying and discharging a refrigerant, and the pair of header parts includes a plurality of the pair of refrigerant flow paths sandwiching the semiconductor element. The semiconductor cooling unit is connected in parallel. 3. The semiconductor cooling unit according to claim 1, wherein the refrigerant is an electrically insulating refrigerant. The semiconductor cooling unit according to any one of claims 1 to 3, wherein an insulating film having electrical insulation is formed on a surface of the electrode plate in contact with the refrigerant.

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