JP2015211511A - Power semiconductor module and power conversion apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure water tightness in a division section in order to divide a heat radiation unit from a case, and to improve heat conductivity of a heat conduction path between a circuit body and the case.SOLUTION: A power semiconductor module includes a circuit body, a case for storing the circuit body, a first heat radiation member, a second heat radiation member, and a pressing member. A first aperture of the case is formed so that an outer peripheral length of an aperture face of the first aperture is shorter than an outer peripheral length of the first heat radiation member and a second aperture of the case is formed so that an outer peripheral length of an aperture face of the second aperture is longer than the outer peripheral length of the first heat radiation member and longer than an outer peripheral length of the second heat radiation member. The heat radiation member covers the first aperture so as to be brought into contact with the inner wall side of the case through a first seal material, the second heat radiation member closes the second aperture so as to be brought into contact with a wall, in the thickness direction of the case, forming the second aperture through a second seal material, and the pressing member presses the first heat radiation member, the circuit body and the second heat radiation member.

Description

  The present invention relates to a power semiconductor module including industrial and electric power and a power conversion device using the same, and more particularly to a power semiconductor module used in a hybrid vehicle and an electric vehicle and a power conversion device using the power semiconductor module.

  As the output increases, the cooling performance of the power conversion device is required to be improved. On the other hand, miniaturization of power converters is also required. Under such circumstances, development of a power conversion device of a type in which a circuit body including a power semiconductor element is housed in a metal case and the case is immersed in a flow path through which a refrigerant flows is underway (Patent Literature). 1).

  The case of the power semiconductor module mounted on such a submerged type power converter may divide the heat radiating portion and other parts.

JP 2010-110143 A

  An object of the present invention is to divide a heat radiating portion from a case, and to ensure water tightness in the divided portion and to increase the thermal conductivity of a heat conduction path between the circuit body and the case.

  A power semiconductor module and a power conversion device according to the present invention include a circuit body including a power semiconductor element, a case for housing the circuit body, and a first heat radiating member disposed on one side of the circuit body. A second heat radiating member disposed opposite to the first heat radiating member across the circuit body, and a pressing member, the case forming a first opening and a second opening, The first opening is formed such that an outer peripheral length of an opening surface of the first opening is smaller than an outer peripheral length of the first heat radiation member, and the second opening is an outer periphery of the opening surface of the second opening. The first heat radiating member is formed to have a length greater than an outer peripheral length of the first heat radiating member and larger than an outer peripheral length of the second heat radiating member, and the first heat radiating member is connected to an inner wall of the case via a first sealing material. Covering the first opening so as to contact the side, the second The heat member closes the second opening so as to contact the wall in the thickness direction of the case forming the second opening via the second sealing material, and the pressing member includes the outer surface of the case and the second heat radiation The first heat radiating member, the circuit body, and the second heat radiating member are pressed in a state in contact with the member.

  According to the present invention, it is possible to ensure water tightness and increase the thermal conductivity of the heat conduction path between the circuit body and the case.

1 is an external perspective view of a power semiconductor module 1 according to an embodiment. FIG. 2 is an exploded perspective view in which a power semiconductor module 1 is disassembled for each component. It is sectional drawing of the power semiconductor module 1 when it cut | disconnects in the cross section A shown in FIG. It is sectional drawing which showed the example of a flow-path structure of the power converter device using the power semiconductor module which concerns on this embodiment. It is sectional drawing which showed another example of attachment to the flow path of a power semiconductor module.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view of a power semiconductor module 1 according to this embodiment. FIG. 2 is an exploded perspective view in which the power semiconductor module 1 is disassembled for each component. FIG. 3 is a cross-sectional view of the power semiconductor module 1 taken along the cross-section A shown in FIG.

  The power semiconductor module 1 includes a circuit body 2 having a power semiconductor element. The circuit body 2 is inserted and installed in the case 3. In the present embodiment, the circuit body 2 is configured to include a power semiconductor element that constitutes the upper arm circuit of the inverter circuit and a power semiconductor element that constitutes the lower arm circuit. Only one power semiconductor element of the arm circuit may be included. The circuit body 2 may be configured to include a plurality of upper and lower arm circuits.

  Further, the circuit body 2 includes a conductor member connected to the power semiconductor element by a solder material and the like, and a resin sealing member for sealing the conductor member and the power semiconductor element.

  Case 3 forms a third opening 3C for inserting circuit body 2 therein. The case 3 also includes a first heat radiating member 5 and a second heat radiating member 6 each having a heat radiating surface formed in a direction substantially perpendicular to the opening surface of the third opening 3C.

  The first heat radiating member 5 and the second heat radiating member 6 include a large number of fins on the outer surface. In the present embodiment, a cylindrical pin fin is used as the fin, but a plate-like straight fin may be used. The first heat radiating member 5 and the second heat radiating member 6 are arranged to face each other so as to sandwich the circuit body 2.

  The pressing member 4 applies a compressive force for pressing the second heat radiating member 6 against the case 3 and applies a reaction force to the case 3 against the compressive force. As shown in FIG. 3, the compressive force of the pressing member 4 is also applied to the first heat radiating member 5 and the circuit body 2 via the case 3 or the second heat radiating member 6. That is, the pressing member 4 presses the first heat radiating member 5, the circuit body 2, and the second heat radiating member 6 while being in contact with the outer surface of the case 3 and the second heat radiating member 6.

  The pressing member 4 is disposed so as to be caught by a portion where the fins of the second heat radiating member 6 are not installed. Alternatively, the fins of the second heat radiating member 6 are formed so as to avoid the pressing member 4.

  In the present embodiment, four pressing members 4 are provided so as to respectively correspond to the four corners of the insulating sheet 9. However, two pressing members 4 are provided on the side of the case 3 close to the third opening 3C, and one pressing member 4 is provided on the bottom of the case 3 opposite to the side on which the third opening 3C is formed. It may be provided.

  The resin member 7 is filled in a gap between the case 3, the first heat radiating member 5 and the second heat radiating member 6 and the circuit body 2, and the resin member 7 is cured, so that the case 3, the first heat radiating member 5, the second heat radiating member The heat radiating member 6 and the circuit body 2 are fixed to each other.

  The case 3 forms a second opening 3B into which the first heat radiating member 5 and the second heat radiating member 6 are inserted. The case 3 also forms a first opening 3A for positioning the first heat radiating member 5.

  The first opening 3A is formed smaller than the outer shape of the first heat radiating member 5 and larger than the range where the fins of the first heat radiating member 5 are installed.

  The first seal member 8 is disposed between the case 3 and the first heat radiating member 5, and is configured by an elastic body. The first seal member 8 is formed smaller than the outer shape of the first heat radiating member 5 and larger than the first opening 3A.

  The first inner wall surface 3D of the case 3 is formed substantially parallel to the opening surface of the first opening 3A. The second opening 3B is formed larger than the outer shape of the first heat radiating member 5. The first seal member 8 is inserted from the second opening 3B and is disposed between the first heat radiating member 5 and the first inner wall surface 3D.

  The sheet 9 made of an insulating member is inserted from the second opening 3B and disposed on the surface of the first heat radiating member 5 opposite to the surface on which the first seal member 8 is installed.

  The circuit body 2 comes into contact with the sheet 9 after being inserted from the third opening 3C. The other sheet 9 is disposed so as to contact the other one surface of the circuit body 2. The other sheet 9 is inserted from the second opening 3B after the circuit body 2 is inserted.

  The second heat radiating member 6 is formed smaller than the second opening 3B. The second heat radiating member 6 is attached so as to contact the other sheet 9. A second seal member 10 is provided on a side surface of the second heat radiating member 6, and the second heat radiating member 6 and the second seal member 10 are inserted into the second opening 3B.

  The second seal member 10 is formed to be larger than the second opening 3B when attached to the second heat radiating member 6. The second seal member 10 is compressed and disposed between the second heat radiating member 6 and the second opening 3B.

With the above configuration, the first heat radiating member 5 passes without interfering with the second opening 3B. The second heat radiating member 6 is inserted without interfering with the second opening 3B. The second seal member 10 is compressed between the second heat radiating member 6 and the second opening 3B, and no load is generated in the contact surface direction of the circuit body 2, the sheet 9, and the second heat radiating member 6. Thereby, the first heat radiating member 5 forms a face seal structure with the case 3, and the second heat radiating member 6 can generate a shaft seal with the case 3, so that the circuit body 2, The repulsive force of the first seal member 8 and the compressive force due to the pressing of the pressing member are applied to the contact surfaces of the sheet 9, the first heat radiating member 5, and the second heat radiating member 6.
In addition, the outer peripheral side wall of the first heat radiating member 5 is formed obliquely, and the wall in the thickness direction of the case 3 forming the first opening 3A is formed obliquely in the same direction as the side wall of the first heat radiating member 5, The first heat radiating member 5 may be fitted into the first opening 3A. In this case, the first seal member 8 is housed in a groove formed in the wall in the thickness direction of the case 3. Further, when the wall in the thickness direction of the case 3 is formed obliquely in this way, the wall in the thickness direction is defined as the inner wall side of the case 3.

  The pressing member 4 is attached to three or more places so as to sandwich the case 3 and the second heat radiating member 6 (four places in this embodiment).

  The pressing member 4 includes a first pressing portion 4A that presses the second heat radiating member 6, a second pressing portion 4B that presses the case 3, a coupling portion 4C that connects the first pressing portion 4A and the second pressing portion 4B, Consists of.

  In the present embodiment, the first seal member 8 is disposed at a position sandwiched between the first pressing portion 4A and the second pressing portion 4B. In other words, the first pressing portion 4A and the second pressing portion 4B are projections of the first pressing portion 4A and the second pressing portion 4B when viewed from the direction perpendicular to the fin forming surface (heat radiating surface) of the second heat radiating member 6. The part is formed so as to overlap the projected part of the first seal member 8. As a result, the first sealing member 8 is pressed by the first pressing portion 4A and the second pressing portion 4B, and the sealing performance is improved. The first seal member 8 may be in the vicinity of the space between the first pressing part 4A and the second pressing part 4B.

  In the pressing member 4, the product of the load generated at the time of attachment and the number of attachments is a load that compresses the first seal member 8 by 10% or more over the entire circumference.

  A convex portion 3G is formed on the outer side surface of the case 3. The convex portion 3G prevents the pressing member 4 from falling off by engaging the connecting portion 4C of the pressing member 4. Further, a protrusion 3H is formed in the vicinity of the bottom of the outer side surface of the case 3. The protrusion 3H prevents the pressing member 4 from falling off by engaging the connecting portion 4C of the pressing member 4.

As shown in FIG. 3, the first heat radiating member 5 has a first inner surface 5B facing the circuit body 2 via the sheet 9, and a first outer surface 5A on the surface facing the first inner surface 5B.
A plurality of first fins 5D are arranged on the first outer surface 5A. Further, the first outer surface 5A has a first flat surface 5C on the outer periphery.

  The first opening inner surface 3D forms a groove shape. The first seal member 8 is compressed between the first opening inner surface 3D and the first plane 5C to close the first opening 3A.

  A groove 6B is formed on the side surface of the second heat radiating member 6. The second seal member 10 is inserted into the groove 6B. The second seal member 10 is compressed between the groove 6B and the second opening 3B to close the second opening 3B.

  The second heat radiating member 6 has a second inner surface 6D facing the circuit body 2 through the sheet 9, and a second outer surface 6A on the surface facing the second inner surface 6D.

  A plurality of second fins 6E are arranged on the second outer surface 6A. Furthermore, the second outer surface 6A has a second flat surface 6C on the outer periphery. The second plane 6C is formed to be the same plane as the case 3 or lower. The second plane 6C is formed to be lower than the tips of the second fins 6E.

The pressing member 4 sandwiches the second plane 6C and the first opening outer surface 3E. The first opening outer surface 3E is made lower than the tip of the first fin 5D.
The pressing member 4 applies a compressive force to the second heat radiating member 6 and the circuit body 2 via the sheet 9. Further, the pressing member 4 applies a compressive force to the circuit body 2 and the first heat radiating member 5 via the sheet 9.

  The pressing member 4 compresses the first seal member 8 disposed between the first heat radiating member 5 and the first opening inner surface 3D.

  The pressing member 4 is formed to be lower than the tip of the first fin 5D. The pressing member 4 is formed to be lower than the tip of the second fin 6E.

  The first fin 5D has the same height as the second fin 6E. The first fin 5D has the same range as the second fin 6E when viewed from the fin axis direction. The case 3 has a case upper surface 3F that is perpendicular to the third opening 3C.

2 is bonded to the circuit body 2 before insertion in the case 3, and the circuit body 2 integrated with the sheet 9 is attached to the case 3 using an insulating member having adhesiveness. You may comprise so that it may insert in. As a result, the sheet 9 is fixed to both surfaces of the circuit body 2 and is less likely to be displaced due to external force, so that the position of the sheet 9 can be accurately placed at a predetermined position.
FIG. 4 is a cross-sectional view showing a flow path configuration example of a power conversion device using the power semiconductor module according to the present embodiment.
The power semiconductor module 1 is disposed in a storage space formed by the upper flow path forming body 11 and the lower flow path forming body 12. The upper flow path forming body 11 includes an opening portion 11A, and the interface portion 2A of the circuit body 2 protrudes from the opening portion 11A.

  The upper flow path forming body 11 forms an upper flow path outer surface 11B perpendicular to the opening 11A in the flow path. The joint 13 connects the upper flow path outer surface 11B and the case upper surface 3F. Further, the joint portion 13 closes the opening portion 11A.

  The opening 11D is formed in the upper flow path outer surface 11E on the side facing the opening 11A. A groove 11F is formed in the upper flow path outer surface 11E. Further, the opening 11D is formed at a position near the first heat radiating member 5 and the second heat radiating member 6 that does not come into contact therewith.

  The lower flow path forming body 12 forms a flow path recess 12A. The lower flow path forming body 12 has a lower flow path outer surface 12B facing the upper flow path outer surface 11E.

  The third seal member 14 is inserted into the groove 11F and compressed between the lower flow path outer surface 12B, and the third seal member 14 closes the first flow path lower opening 11D.

  The first flow path 15 is formed by the surface of the opening 11D adjacent to the first heat radiating member 5. The first flow path 15 includes a gap between the first fins 5D and a gap between the front end of the first fin 5D and the surface of the opening 11D. The clearance area between the first fins 5D is secured at least twice the clearance area between the front end of the first fin 5D and the surface of the opening 11D.

  The second flow path 16 is formed by the surface of the opening 11D adjacent to the second heat radiating member 6. The second flow path 16 includes a gap between the second fins 6E and a gap between the front end of the second fin 6E and the surface of the opening 11D. The gap area between the second fins 6E is secured at least twice the gap area between the tip of the second fin 6E and the surface of the opening 11D.

  In the present embodiment, the refrigerant flowing in one flow path is divided into the first flow path 15 and the second flow path 16 when it collides with the pressing member 4 side of the power semiconductor module 1. The divided refrigerant flows on the outer surface of the first heat radiating member 5 and the outer surface of the second heat radiating member 6, and takes heat from the outer surface of the first heat radiating member 5 and the outer surface of the second heat radiating member 6. As a result, the heat generated by the semiconductor element is efficiently radiated from both sides of the circuit body 2. Since the amount of heat of the semiconductor element is dissipated, the temperature rise of the semiconductor element is suppressed.

  The channel recess 12A is formed so as to be adjacent to the second plane 6C and the first opening outer surface 3E. The first flow path 15 and the second flow path 16 merge in the vicinity of the lower flow path forming body 12. The channel recess 12A forms a channel where the first channel 15 and the second channel 16 merge.

  When projected from the vertical direction of the opening surface of the opening 11D, the opening 11D is such that the projection of the opening 11D is a projection of the fin of the first heat radiating member 5 and a projection of the fin of the second heat radiating member 6. It is formed to overlap.

  Similarly, when projected from the vertical direction of the opening surface of the opening 11D, the flow detour prevention wall surface 11C is the projection of the flow detour prevention wall surface 11C and the projection portion of the fin portion of the first heat radiating member 5 and the second heat radiating member 6. It is formed so as to overlap with the projected part of the fin part. The flow detour prevention wall surface 11C is formed smaller than the shape formed by the opening 11D.

  FIG. 5 is a cross-sectional view showing another example of attaching the power semiconductor module to the flow path.

  The power semiconductor module 1 is disposed inside the upper flow path forming body 11 and the lower flow path forming body 12. The upper flow path forming body 11 includes an opening 11A. The interface part 2A constituting the terminal of the circuit body 2 protrudes from the opening part 11A. That is, the case 3 covers the opening 11A with the terminal protruding from the opening 11A. The upper flow path forming body 11 forms the upper flow path inner surface 11G. An upper flow path groove 11H is formed in the upper flow path inner surface 11G.

The fourth seal member 17 is inserted into the upper flow path groove 11H and compressed between the case seal surface 3G. That is, the case 3 is fixed to the upper flow path forming body 11 by the fixing screw 18 (fixing member) with the fourth seal member 17 sandwiched between the case 3 and the upper flow path forming body 11. 18 fixes the case 3 to the upper flow path forming body 11. The fixing screw 18 generates an axial force that compresses the fourth seal member 17. The fixing screws 18 are installed at two places on both ends of the case 3. The fixing screw 18 is installed inside the fourth seal member 17. In other words, the fourth seal member 17 is formed in an annular shape surrounding the fixing screw 18.

  The case 3 forms a screw hole 3I for tightening the fixing screw 18. The screw hole 3I is installed so as not to penetrate the flow path 19.

  Thereby, the power semiconductor module is firmly fixed to the flow path forming body while suppressing the occurrence of refrigerant leakage from the flow path.

2 ... Circuit body
3 ... Case
3A ... 1st opening
3B… Second opening
3C… 3rd opening
3D ... 1st inner wall
3G ... Convex
3H ... Projection
3I ... Screw hole
4 ... Pressing member
4A ... 1st pressing part
4B ... Second pressing part
4C ... Connection
5… First heat dissipation member
6 ... Second heat dissipation member
8… First seal member
9 ... Sheet
10… Second seal member

Claims (5)

A circuit body including a power semiconductor element;
A case for storing the circuit body;
A first heat dissipating member disposed on one side of the circuit body;
A second heat dissipating member disposed opposite to the first heat dissipating member across the circuit body;
A pressing member,
The case forms a first opening and a second opening,
The first opening is formed such that the outer peripheral length of the opening surface of the first opening is smaller than the outer peripheral length of the first heat radiating member,
The second opening is formed such that the outer peripheral length of the opening surface of the second opening is larger than the outer peripheral length of the first heat radiating member and larger than the outer peripheral length of the second heat radiating member,
The first heat radiating member covers the first opening so as to be in contact with the inner wall side of the case through a first sealing material,
The second heat radiating member closes the second opening so as to be in contact with a wall in the thickness direction of the case forming the second opening via a second sealing material,
The pressing member is a power semiconductor module that sandwiches the outer surface of the case and the second heat radiating member and presses the first heat radiating member and the circuit body disposed inside the pressing member. A power semiconductor module according to claim 1,
The pressing member includes a first pressing portion on a side in contact with the outer surface of the case, and a second pressing portion on a side in contact with the second heat radiating member,
When projected from the direction perpendicular to the heat radiating surface of the second heat radiating member facing the circuit body, the first pressing part and the second pressing part are the projection parts of the first pressing part and the second pressing part. A power semiconductor module formed so as to overlap with a projected portion of the first seal member. In the power semiconductor module according to claim 1 or 2,
A power semiconductor module comprising an insulating member disposed between the first heat radiating member or the second heat radiating member and the circuit body and having adhesiveness. A power conversion device comprising any one of the power semiconductor modules according to claim 1,
A flow path forming body for forming a flow path for flowing a coolant for cooling the power semiconductor module;
The said flow path is a power converter device comprised including a 1st flow path between the said 1st heat radiating members, and a 2nd flow path between the said 2nd heat radiating members. A power conversion device comprising any one of the power semiconductor modules according to claim 1,
A flow path forming body for forming a flow path for flowing a coolant for cooling the power semiconductor module;
The flow path forming body forms an opening for penetrating a terminal protruding from the circuit body,
The case is fixed to the flow path forming body by a fixing member in a state where a third seal portion is sandwiched between the case and the flow path forming body,
Furthermore, the case covers the opening in a state where the terminal protrudes from the opening,
The third seal portion is a power conversion device formed in an annular shape surrounding the fixing member.