JP5440061B2 - Air-cooled power semiconductor device - Google Patents

Description

  The present invention relates to an air-cooled power semiconductor device applied to a semiconductor power conversion device such as a high-voltage inverter.

  As is well known, a power converter for a high-voltage inverter includes an input transformer, an inverter unit that is connected to the secondary side of the input transformer and constitutes an inverter circuit, and a control unit thereof separately stored. The inverter board corresponding to each phase of the inverter circuit is stored in the upper and lower stages in the converter board. Here, the inverter unit houses a plurality of power semiconductor modules (for example, IGBT modules) mounted on a heat sink in a unit case that also functions as a wind tunnel, and guides cooling air into the panel via the unit case. The power semiconductor module is cooled with air to cool it (see, for example, Patent Document 1).

  On the other hand, also for a general-purpose inverter device having a relatively small energization capacity, a plurality of power semiconductor modules 1 constituting an inverter circuit are mounted and accommodated in a heat sink 3 in a unit case in the same manner as described above, and cooling air is blown here. Thus, heat generated by the power semiconductor module 1 is radiated to the outside. Further, in the general-purpose inverter device, a smoothing capacitor, a printed circuit board, and the like are incorporated in the unit case together with the power semiconductor module 1, and air is cooled by flowing outside air by a fan separately from the cooling air of the heat sink 3.

  Next, an assembly structure of a conventional example of the power semiconductor device is shown in FIGS. In the figure, 1 is a power semiconductor module of two sets in which two sets of IGBT elements 2 are arranged side by side in a package 1a, and 3 is a heat sink in which a plate-like radiating fin row 3b is provided on the back side of the base plate 3a. In the center of the upper surface of the base plate 3a (made of a high heat transfer material such as aluminum) of the heat sink 3 having a rectangular outer shape, a plurality of (in the illustrated example) provided with a heat dissipation metal base (not shown) on the bottom surface. Three) power semiconductor modules 1 are mounted side by side in a line.

  The area of the base plate 3a is set such that the semiconductor modules 1 are spaced apart from each other in order to avoid the concentration of the temperature distribution rising due to the heat generated by each power semiconductor module 1, and a sufficient margin is transmitted to the left and right. Designed with a dimension width that ensures a hot surface. Although not shown in the figure, between the external terminals of each power semiconductor module 1 mounted on the heat sink 3 is inserted in accordance with the configuration of the inverter circuit, and the output conductor (bar conductor) has a shortest path so as to reduce its wiring inductance. It is wired linearly along.

  With the above configuration, the cooling air is blown along the radiating fin row 3b of the heat sink 3 while the power semiconductor device is energized, so that the generated heat of each power semiconductor element 2 is generated in the heat sink 3 via the bottom metal base of the module package. It is well known that heat is transferred to the base plate 3a and is transferred to the cooling air side by forced convection heat transfer with the cooling air flow flowing in the direction of the arrow along the radiating fin row 3b to dissipate heat outside the system. It is as follows.

  By the way, in the arrangement in which a plurality of power semiconductor modules 1 are arranged side by side on the base plate 3a along the flow direction of the cooling air flowing through the heat sink 3 as shown in FIG. When comparing the semiconductor module with the power semiconductor module arranged on the leeward side, the cooling air that has passed directly under the power semiconductor module on the leeward side receives heat radiated from the module, and the air temperature rises and flows to the leeward side. For this reason, in this state, the heat dissipation of the power semiconductor modules arranged on the leeward side due to the thermal interference is lowered as compared with the module on the leeward side.

  In this case, if the heat radiation area of the heat sink 3 is set large in advance or the amount of cooling air is increased, sufficient heat radiation performance can be ensured for the power semiconductor modules arranged on the leeward side. Increasing the heat dissipation area increases the envelope volume and space occupied by the heat sink, increasing the size of the semiconductor device. In addition, a large blower fan is required to increase the cooling air flow rate, and the cost increases. The problem of increased noise is also derived.

  Therefore, as one countermeasure against the above problem, a wind direction deflector is disposed in the ventilation path inside the unit case containing the power semiconductor device, and the wind speed of the cooling air flow passing directly under the power semiconductor modules arranged on the leeward side is determined. A configuration in which the heat dissipating performance of the power semiconductor module is enhanced locally by the forced convection heat transfer has been proposed earlier than the same applicant as the present invention (see Patent Document 2).

JP 2007-174851 A JP 2004-128439 A

  In the air-cooled power semiconductor device having a configuration in which a plurality of power semiconductor modules are arranged in a line in the front and rear and mounted side by side on the base plate of the heat sink, including the configuration of FIG. 2 and Patent Document 2 described above, the air is guided to the heat sink. The influence of heat generated by the semiconductor modules disposed on the leeward side of the cooling air flow interferes with the semiconductor modules arranged on the leeward side as they are, and deteriorates the heat dissipation performance. For this reason, the conventional device uses a heat sink with a large heat dissipation area, or uses a large blower fan to increase the amount of cooling air to be blown to the heat sink to ensure the required heat dissipation performance. However, this countermeasure still has problems such as an increase in the space occupied by the semiconductor device due to an increase in the envelope volume of the heat sink, an increase in the capacity of the blower fan, and fan noise. In addition, the configuration of Patent Document 2 in which a wind direction deflector is additionally installed in the ventilation path of the unit case increases the space occupied by the unit, increases the size of the device, and increases the windage loss. In addition, the generation of noise increases.

  The present invention has been made in view of the above points, and an object thereof is to change the arrangement of power semiconductor modules mounted on a heat sink without using additional parts such as a wind direction deflector, and lead wiring between modules. To provide a power semiconductor device that is improved so as to reduce the thermal interference between modules with respect to the cooling air flow without reducing the performance and to reduce the size of the heat sink and the size and noise of the blower fan. is there.

In order to achieve the above object, according to the present invention, a plurality of power semiconductor modules are aligned and mounted side by side on a base plate of a heat sink provided with a plate-like heat radiation fin array, In the air-cooled power semiconductor device in which cooling air is ventilated to the fin side to dissipate the generated heat of the power semiconductor module,
The power semiconductor module is disposed obliquely with respect to the flow direction of the cooling air that is guided along the radiating fin row of the heat sink,
The plurality of power semiconductor modules are mounted side by side in a line in the diagonal direction of the base plate with respect to the base plate of the heat sink having a rectangular shape.

  According to the above configuration, for a plurality of power semiconductor modules arranged on the base plate of the heat sink in an alignment posture inclined in the same direction, the modules arranged on the windward side of the heat sink and the modules arranged on the leeward side are arranged along the radiation fins. It will be aligned to the right with respect to the direction of the flowing cooling air flow. This reduces the cumulative thermal effect of the cooling air on the leeward modules due to the heat generated by the modules aligned on the leeward side of the heat sink, and the heat generated by the modules aligned on the upstream side immediately below each module aligned on the leeward side. Cooling air in a relatively low temperature state is ventilated without receiving much thermal interference from the heated cooling air. In addition, the diagonal distance of the base plate of the heat sink can be effectively used to ensure a wide space between the multiple semiconductor modules. The power semiconductor module can be effectively air-cooled and cooled.

As a result, it is not necessary to design a heat dissipation area of the heat sink to be larger than necessary or to use a large fan in order to increase the blown air volume, thereby achieving downsizing and low noise of the device.
In addition, since the power semiconductor modules are aligned in a line, the wiring properties of the connecting conductors that are wired between the modules are not impaired.

  In addition to the cooling air flow that blows along the heat sink fin rows of the heat sink, even when cooling air is blown to the module mounting surface side of the heat sink to ventilate the air around the module, it is aligned in an oblique position. The package peripheral wall surface of each module lined up becomes a wind direction guide, and the cooling air can be smoothly guided without creating a blind spot between the modules, thereby further improving the air cooling effect.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the power semiconductor device by the Example of this invention, (a) is a top view, (b) is a front view, (c) is a side view. FIG. 2 is a schematic configuration diagram of a conventional power semiconductor device corresponding to FIG. 1, in which (a) is a plan view, (b) is a front view, and (c) is a side view.

  Hereinafter, embodiments of the present invention will be described based on the examples shown in FIGS. In addition, in the figure of an Example, the same code | symbol is attached | subjected to the same member corresponding to FIG.2 (a)-(c), and the description is abbreviate | omitted.

  In this embodiment, as shown in the figure, a plurality of power semiconductor modules 1 are arranged in parallel with each other in an oblique direction with the diagonally oriented direction with respect to the base plate 3a of the heat sink having a substantially square shape. Yes. In the figure, an arrow A indicated by a one-dot chain line indicates a cooling air flow to be blown along the radiation fins 3b of the heat sink 3, and a broken arrow B indicates a flow of the cooling air for ventilation flowing to the module mounting side of the base 3a. Yes.

  As is apparent from the illustrated arrangement, a plurality of power semiconductor modules 1 mounted on the base plate 3a of the heat sink 3 are arranged side by side aligned in the diagonal direction of the base plate, thereby allowing ventilation along the radiating fin row 3b. The respective power semiconductor modules 1 are aligned in the left-right direction with respect to the flowing direction of the cooling air flow A. Thereby, as compared with the conventional arrangement of the front and rear rows shown in FIG. 2, the cumulative thermal influence on the leeward module due to the heat generated by the modules arranged on the leeward side of the heat sink 3 is reduced. Cooling air in a low temperature state flows directly under each module arranged in a row without receiving much thermal interference from the cooling air passing through the modules arranged on the windward side. Further, the diagonal distance of the base plate 3a of the heat sink 3 (√2 times the length of one side) can be effectively utilized to ensure a wide mutual interval between the semiconductor modules 1. Thereby, the plurality of power semiconductor modules 1 mounted thereon can be effectively air-cooled and cooled by making the best use of the heat radiation area and heat radiation function of the heat sink 3.

  As a result, it is not necessary to design the heat dissipation area of the heat sink 3 to be larger than necessary, or to use a large fan to increase the air flow rate of the cooling air as in the prior art. Miniaturization and low noise can be achieved. In addition, since the power semiconductor modules 1 are aligned in a line, the wiring property of the connection conductor (bar conductor) wired between the modules is not impaired.

  In addition to the cooling air A that is blown along the radiating fin row 3b of the heat sink 3 as shown in the example, the cooling air B is also blown to the module mounting surface side of the heat sink 3 to raise the temperature rising air around the power semiconductor module. Even when the air is ventilated, the cooling air B can be smoothly guided so that the package peripheral wall surface of each power semiconductor module 1 aligned in an oblique posture according to the illustrated arrangement serves as a wind direction guide and sews between the modules. The air cooling effect is further improved.

DESCRIPTION OF SYMBOLS 1 Power semiconductor module 2 IGBT element 3 Heat sink 3a Base board 3b Radiation fin row

Claims (1)

A plurality of power semiconductor modules are aligned and mounted side by side on a base plate of a heat sink having a plate-like heat radiation fin array, and cooling air is blown to the module mounting side and the heat radiation fin side of the heat sink to generate a power semiconductor module. In an air-cooled power semiconductor device that dissipates heat,
The power semiconductor module is disposed obliquely with respect to the flow direction of the cooling air that is guided along the radiating fin row of the heat sink,
The air-cooled type, wherein the plurality of power semiconductor modules are mounted side by side on the base plate of the heat sink so as to be aligned in a line in the diagonal direction of the base plate with respect to the base plate of the heat sink having a rectangular shape. Power semiconductor device.