JP2018207647A - Power conversion device - Google Patents

Abstract

To provide a power conversion device improved in efficiency of cooling a semiconductor element which is a heat generation element.SOLUTION: In the power conversion device, six heat dissipation members 18A, 18B, 18C, 18D, 18E, and 18F provided for six semiconductor elements to be heat generation elements are mounted on a drive circuit-use printed circuit board 5 arranged in a flow channel 8. The heat dissipation members 18A, 18B, 18C, 18D, 18E, and 18F are arranged in three rows in the direction orthogonal to a plate-like member 6 constituting the flow channel 8 and in two stages in the direction along the plate-like member 6. Immediately under the heat dissipation member 18F located downstream of a main flow direction A of cooling air and located at the lowermost side, a plate-like connection terminal 15 is mounted on the drive circuit-use printed circuit board 5 at a predetermined inclination angle α with respect to the main flow direction A of cooling air. Cooling air A2 flowing in the main flow direction A at a position below the heat dissipation members 18C and 18F is reflected to the vertically upper side by the inclined connection terminal 15 to flow toward the heat dissipation member 18F.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a power conversion device in which a heating element on a printed circuit board disposed in a flow path is cooled by cooling air from a cooling fan.

  Patent Document 1 discloses a power conversion device in which a heat sink associated with a heating element (semiconductor element) is disposed in a cooling air flow path. In this power conversion device, the cooling fan is driven to allow cooling air to flow from the intake port to the exhaust port of the flow path, thereby forcibly cooling the heat sink portion to which heat from the heating element is transmitted. .

JP 2008-43047 A

  In order to improve the cooling efficiency of the heating element in the power conversion device as in Patent Document 1, it is generally considered that the heat sink portion is enlarged to increase the heat radiation area, or the cooling wind speed is increased. .

  When the heat sink portion is enlarged, the entire power conversion device is increased in size, which may increase the manufacturing cost associated with the power conversion device.

  On the other hand, when the wind speed of the cooling air is increased, a large amount of dust is taken into the flow path, and if this dust adheres to the charging part, there is a possibility that a short circuit of the charging part occurs. In addition, when the charging part is coated in order to suppress a short circuit of the charging part, an additional cost associated with the coating is generated.

The power converter of the present invention is
A flow path that has an intake port and an exhaust port formed in the housing, and allows cooling air to flow from the intake port to the exhaust port by a cooling fan;
A printed circuit board disposed in the flow path;
A heating element mounted on the printed circuit board and cooled by the cooling air;
A plate-like connection terminal mounted on the printed circuit board at a predetermined inclination angle with respect to the flow path so as to guide a part of the cooling air toward the heating element;
It has.

  Accordingly, the heating element is cooled by the cooling air guided by the inclined plate-like connection terminals in addition to the cooling air along the flow path.

  In a preferred aspect of the power conversion device, the flow path is formed in a duct shape by two plate-like members facing each other.

  Moreover, in another preferable aspect of the power conversion device, the connection terminal is located between one of the two plate-like members and the heating element.

  Furthermore, in another preferable aspect of the power conversion device, the connection terminal is located directly below the heating element.

  In another preferable aspect of the power conversion device, the power conversion device includes a plurality of heating elements mounted on the printed circuit board, and the plurality of heating elements are arranged in a direction orthogonal to the flow path. It is arranged in a plurality of stages in a row and in a direction along the flow path, and the connection terminal is provided directly below the heating element located in the lowermost row and the most downstream side.

  According to the present invention, since the heating element is further cooled by the cooling air guided by the plate-like connection terminals already mounted on the printed circuit board, it is possible to increase the size of the power converter and increase the wind speed of the cooling fan. Without being accompanied, the heating element can be efficiently cooled.

It is explanatory drawing which shows the power converter device of one Example seen from the side. It is a perspective view of a printed circuit board and a semiconductor element. FIG. 3 is a partially enlarged view of a fourth printed circuit board for a drive circuit from the left in FIGS. 1 and 2. It is a top view of a connection terminal. It is explanatory drawing of a switching element unit. FIG. 3 is an explanatory diagram showing the flow of cooling air in the fourth drive circuit printed board from the left in FIGS. 1 and 2.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an explanatory diagram illustrating an internal configuration of the power conversion device 1 when the power conversion device 1 of one embodiment is seen through from the side. The power converter 1 is, for example, an inverter that converts DC power into AC power, or a converter that converts AC power into DC power. The casing 2 of a board having a vertically long rectangular parallelepiped shape, For a plurality of drive circuits in which a cooling fan 3 disposed on the upper end surface and a drive circuit that is housed in the housing 2 and performs on / off control of a switching element unit 4 (see FIG. 5) (not shown) are mounted. The printed circuit board 5 is mainly configured.

  The housing 2 includes left and right side walls 2a (only the left side wall 2a is shown in FIG. 1), a bottom wall 2b, a ceiling wall 2c, a front wall 2d, and a back wall 2e. ing. As shown in FIG. 1, three plate-like members 6 extend horizontally from the front wall 2d of the housing 2 to a position spaced apart from the back wall 2e to the inside of the housing 2 to some extent, The housing 2 is partitioned into four sections except for a wind tunnel portion 7 described later between the rear end edge of the plate-like member 6 and the back wall 2e. In the first to third sections from the top in FIG. 1, the cooling air from the cooling fan 3 is formed as a rectangular parallelepiped space surrounded by two plate members 6 and the left and right side walls 2a facing each other. A duct-shaped flow path 8 is formed. Here, the uppermost channel 8 is configured as a rectangular parallelepiped space surrounded on all sides by the ceiling wall 2c, the uppermost plate-like member 6 and the left and right side walls 2a. The ceiling wall 2 c corresponds to the “plate member” described in the claims together with the plate member 6.

  Further, a space continuous in the vertical direction, that is, the wind tunnel portion 7 is formed between the rear end edge of the plate-like member 6 and the back wall 2e. The upper end of the wind tunnel portion 7 communicates with an exhaust port 9 formed in the ceiling wall 2c, and the cooling fan 3 is attached so as to cover the exhaust port 9. Although not shown in detail, the cooling fan 3 is a centrifugal fan that exhausts air in a direction perpendicular to the rotation axis. The cooling fan 3 blows air upward from the wind tunnel portion 7.

  An air inlet 10 is formed in the front wall 2d at a relatively lower position of each flow path 8. Through the air intake 10, the cooling air, which is outside air, flows when the cooling fan 3 is driven. 8 is taken in.

  In each flow path 8, as shown in FIG. 1, a rectangular mounting plate 11 is fixedly attached to the inner surface of the left side wall 2 a, and four rectangular printed circuit board 5 for drive circuits are attached to the mounting plate 11. It attaches at equal intervals along the shaped member 6 (or ceiling wall 2c).

  As shown in FIG. 2, a transformer printed circuit board 12 is attached to the upper half of the drive circuit printed circuit board 5. As shown in FIG. 1, the transformer printed circuit board 12 is provided at a position vertically above the air inlet 10, and a transformer 13 having a rectangular parallelepiped shape is mounted on the transformer printed circuit board 12. In the state in which the transformer 13 is mounted, the transformer 13 protrudes from the transformer printed board 12 to the side opposite to the mounting plate 11 as shown in FIG.

  As shown in the fourth printed circuit board 5 for drive circuit from the left in FIG. 2, six semiconductor elements 14 (14A, 14B, 14C, 14D, 14E, 14F), a plate-like connection terminal 15 for electrical connection to the switching element unit 4 (see FIG. 5), and two connectors 16 for electrical connection to the switching element unit 4 as well. , 17 are implemented.

  The semiconductor element 14 is, for example, a field effect transistor (FET). As shown in FIGS. 2 and 3, the semiconductor element 14 is 3 in the vertical direction, that is, in the direction orthogonal to the plate member 6 (or the ceiling wall 2 c) below the transformer 13. It is mounted on the drive circuit printed circuit board 5 in rows and in two stages in the horizontal direction, that is, in the direction along the plate-like member 6 (or the ceiling wall 2c). Here, as shown in FIG. 2 and FIG. 3, the semiconductor elements 14 aligned in the vertical direction at the first stage from the left are, in order from the top, the semiconductor element 14A, the semiconductor element 14B, and the semiconductor element 14C. The semiconductor elements 14 aligned in the vertical direction by eye are referred to as a semiconductor element 14D, a semiconductor element 14E, and a semiconductor element 14F in order from the top.

  In a state in which the semiconductor elements 14A, 14B, 14C, 14D, 14E, and 14F are mounted, the semiconductor elements 14A, 14B, 14C, 14D, 14E, and 14F are printed circuit boards for drive circuits as shown in FIGS. 5 protrudes in the same direction as the transformer 13. In the semiconductor elements 14A, 14B, 14C, 14D, 14E, and 14F, the heat dissipating member 18 (18A, 18B, 18C, 18D, 18E, and 18F) is provided on the semiconductor element 14A, 14B from the side opposite to the drive circuit printed board 5. , 14C, 14D, 14E, and 14F, respectively. The heat radiating members 18A, 18B, 18C, 18D, 18E, and 18F are made of a metal material having excellent thermal conductivity, for example, copper, and are provided with a pair of cooling fins 30 as shown in FIG.

  The three semiconductor elements 14 and the heat radiating members 18 aligned in the vertical direction are arranged at equal intervals in the vertical direction, while the two semiconductor elements 14 and the heat radiating members 18 aligned in the horizontal direction are separated from each other in the horizontal direction. It is arranged as appropriate.

  In a state where the semiconductor element 14 and the heat radiating member 18 are mounted on the drive circuit printed board 5, the surface of the drive circuit printed board 5 (front side in FIG. 2) to the upper surface of the transformer 13 (front side in FIG. 2). ) Is longer than the distance from the surface of the printed circuit board 5 for drive circuit to the surface of the heat radiating member 18 (surface on the near side in FIG. 2). Therefore, as shown in FIG. 2, a relatively wide space is formed below the four transformers 13 in the flow path 8 so as to continue along the plate-like member 6 (or the ceiling wall 2c).

  In such a power conversion device 1, the cooling fan 3 is driven so that the cooling air, which is the outside air, is taken into the flow path 8 from the inlet 10, and a relatively wide space below the transformer 13 extends along the plate-like member 6. To the main. Then, the cooling air from the flow path 8 flows upward through the wind tunnel portion 7 and is discharged to the outside of the housing 2 through the exhaust port 9 formed in the ceiling wall 2c.

  Here, the main flow direction of the cooling air is indicated by an arrow A in FIG. The main flow direction A is the horizontal direction, that is, the direction along the plate-like member 6 (or the ceiling wall 2c) when the cooling air flows through the flow path 8, and when the cooling air flows through the wind tunnel portion 7, The vertical direction, that is, the direction orthogonal to the plate-like member 6 (or the ceiling wall 2c).

  The connection terminal 15 is, for example, a metal faston terminal, and as shown in FIG. 4, a base portion 15a having a substantially rectangular plate shape, and two protruding portions 15b protruding from the edge of the base portion 15a, I have.

  As shown in FIGS. 2 and 3, the connection terminal 15 configured in this way is connected to the drive circuit printed circuit board 5 directly below the semiconductor element 14 </ b> F and the heat radiating member 18 </ b> F positioned on the lowermost downstream side in the mainstream direction A. Has been implemented. Here, the plate-like base portion 15 a protrudes from the printed circuit board 5 for drive circuits at a right angle, and the two protruded portions 15 b penetrate through the through holes of the printed circuit board 5 for drive circuits. In the state where the connection terminal 15 is mounted, the connection terminal 15 is inclined at a predetermined inclination angle α with respect to the main flow direction A of the cooling air flowing through the flow path 8 as shown in FIG. That is, the connection terminal 15 has a predetermined inclination with respect to the plate-like member 6 constituting the flow path 8 at a position adjacent to the heat-radiating member 18F between the plate-like member 6 and the heat-dissipating member 18F attached to the semiconductor element 14F. It is inclined at an angle α. Here, the inclination angle α is an acute angle formed by the main flow direction A (direction of the plate-like member 6) of the cooling air flowing through the flow path 8 and the connection terminal 15, and is in the main flow direction A. The cooling air is set at an angle at which a part of the cooling air on the side of the heat radiating member 18F that flows can be guided toward the heat radiating member 18F. In this embodiment, the inclination angle α is 45 °.

  In the state where the connection terminals 15 are mounted in an inclined manner as described above, the connection terminals 15 are printed from the drive circuit printed circuit board 5 toward the side opposite to the mounting plate 11 as shown in FIG. It protrudes longer than the distance from the surface of the substrate 5 to the surface of the heat dissipation member 18.

  The connection terminal 15 may be provided directly above the semiconductor element 14D or the heat dissipation member 18D positioned on the uppermost side in the mainstream direction A downstream side.

  Further, as shown in FIGS. 2 and 3, the connector 20 having the wiring 19 is attached to the base portion 15 a of the connection terminal 15. The connector 20 includes a metal plate-like portion 20a and two bent portions 20b bent inward from both side portions of the plate-like portion 20a. The connector 20 is attached to the connection terminal 15 such that the plate-like connection terminal 15 is inserted into the gap between the plate-like part 20a and the bent part 20b. Even when the connector 20 is mounted on the connection terminal 15 in this manner, the cooling air from the cooling fan 3 is reflected by the connection terminal 15 and guided toward the semiconductor element 14F and the heat dissipation member 18F.

  As shown in FIGS. 2 and 3, the connector 16 is mounted on the drive circuit printed board 5 above the semiconductor element 14D and the heat dissipation member 18D.

  As shown in FIGS. 2 and 3, the connector 17 is mounted on the drive circuit printed board 5 above the semiconductor element 14A and the heat dissipation member 18A.

  The drive circuit of the drive circuit printed circuit board 5 drives a switching element unit 4 (not shown) that performs power conversion. As shown in FIG. 5, the switching element unit 4 includes an upper arm 21 and a lower arm 22 that are similarly configured. These arms 21 and 22 include switching elements 21 a and 22 a such as IGBTs, for example. And diodes 21b and 22b connected in parallel with these.

  The connection terminal 15 of the drive circuit is electrically connected to the collector C of the switching element unit 4 via the connector 20. The collector voltage is monitored by the electrical connection between the connector 20 and the collector C.

  The drive circuit is electrically connected to the gate G1 and the emitter E1 of the switching element 21a of the upper arm 21 of the switching element unit 4 via the connector 16, and is further connected to the switching element unit 4 via the connector 17. The lower arm 22 is electrically connected to the gate G2 and the emitter E2 of the switching element 22a. Gate signals from the drive circuit are input to the gates G1 and G2 of the switching elements 21a and 22a, whereby the ON and OFF timings of the switching elements 21a and 22a are switched.

  When the cooling fan 3 is driven in the power conversion device 1, as shown in FIG. 1, the cooling air taken from the air inlet 10 flows in the main flow direction A in the flow path 8. At this time, the cooling air flowing in the main flow direction A at the same vertical position as each heat radiating member 18 is radiated from the heat radiating members 18A, 18B, and 18C located on the upstream side in the main flow direction A as shown by a thick arrow A1 in FIG. After cooling, the heat dissipating members 18D, 18E, 18F located on the downstream side in the main flow direction A are cooled.

  On the other hand, the cooling air flowing in the main flow direction A at a position below the heat radiating members 18C and 18F is reflected upward in the vertical direction by the inclined plate-like connection terminal 15 as shown by a thin arrow A2 in FIG. Then, the air flows toward the heat radiating member 18F adjacent to the connection terminal 15.

  If the connection terminal 15 is arranged in parallel with the plate-like member 6, that is, if the inclination angle α is 0 °, the connection terminal 15 is warmed through the heat dissipating members 18A, 18B, 18C on the upstream side in the mainstream direction A. The cooled air flows to the heat radiating members 18D, 18E, and 18F on the downstream side in the main flow direction A. Therefore, the cooling efficiency of the heat radiating members 18D, 18E, and 18F on the downstream side in the main flow direction A is lower than that on the heat radiating members 18A, 18B, and 18C on the upstream side in the main flow direction A. Generally, the cooling efficiency of the heat dissipating member 18E located at the center downstream of the mainstream direction A is the lowest, and accordingly, the temperature rise of the semiconductor element 14E that transfers heat to the heat dissipating member 18E is the highest. There is a risk of exceeding the allowable temperature for heat generation of 14E.

  However, in the above embodiment, since the connection terminal 15 inclined at 45 ° is disposed directly below the heat radiating member 18F, as shown by an arrow A2 in FIG. 6, cooling that flows in the mainstream direction A below the heat radiating member 18F. The flow of wind is guided by the inclined connection terminal 15 toward the heat radiating member 18F. Therefore, in addition to the cooling air (arrow A1) flowing in the main flow direction A at the same vertical position as the heat radiating members 18A, 18B, and 18C, the cooling air indicated by the arrow A2 not receiving heat from the upstream side in the main flow direction A Thus, the heat radiating members 18D, 18E, and 18F are cooled, so that the cooling efficiency of the semiconductor elements 14D, 14E, and 14F including the heat radiating members 18D, 18E, and 18F is improved. This cooling is most effective for the semiconductor element 14E having the highest temperature rise.

  Moreover, in the said Example, since the cooling efficiency of the heat radiating member 18 is improved using the connection terminal 15 which is an indispensable component of the printed circuit board 5 for drive circuits, the additional component and the large sized of the heat radiating member 18 are improved. Therefore, it is not necessary to increase the size of the entire power conversion device 1 and increase the wind speed of the cooling fan 3 in accordance with the conversion.

  In the above embodiment, the example in which the connection terminal 15 and the six semiconductor elements 14 mounted on the fourth printed circuit board 5 for the drive circuit from the left in FIGS. 1 and 2 are mounted has been described. The terminals 15 and the six semiconductor elements 14 can be mounted on the second printed circuit board 5 for the drive circuit from the left as shown in FIGS.

  In the above-described embodiment, the example in which the six semiconductor elements 14 are arranged in three rows in the direction orthogonal to the flow path 8 and in two stages in the direction along the flow path 8 is disclosed. This arrangement is not limited to this, and may be arranged in other plural rows and in other plural stages. In this case, the connection terminal 15 is provided directly below the semiconductor element 14 and the heat dissipation member 18 located in the lowermost row and the most downstream side.

DESCRIPTION OF SYMBOLS 1 ... Power converter 3 ... Cooling fan 5 ... Print circuit board 6 for drive circuits ... Plate-shaped member 8 ... Flow path 9 ... Exhaust port 10 ... Intake port 14 (14A ~ 14F) ... semiconductor element 15 ... connection terminal 18 (18A ~ 18F) ... heat dissipation member α ... inclination angle A ... mainstream direction A1 ... cooling air A2 ... cooling air

Claims (5)

A flow path that has an intake port and an exhaust port formed in the housing, and allows cooling air to flow from the intake port to the exhaust port by a cooling fan;
A printed circuit board disposed in the flow path;
A heating element mounted on the printed circuit board and cooled by the cooling air;
A plate-like connection terminal mounted on the printed circuit board at a predetermined inclination angle with respect to the flow path so as to guide a part of the cooling air toward the heating element;
The power converter provided with.   The power conversion device according to claim 1, wherein the flow path is configured in a duct shape by two plate-like members facing each other.   The power converter according to claim 2, wherein the connection terminal is located between one of the two plate-like members and the heating element.   The power converter according to claim 1, wherein the connection terminal is located immediately below the heating element.   A plurality of heating elements mounted on the printed circuit board, wherein the plurality of heating elements are arranged in a plurality of rows in a direction orthogonal to the flow path and in a plurality of stages in a direction along the flow path, The power converter according to any one of claims 1 to 3, wherein the connection terminal is provided in a lowermost row and directly below a heating element located on the most downstream side.

Images