JP4940777B2 - Semiconductor device - Google Patents

Description

  The present invention relates to a semiconductor device including a shield plate that shields electromagnetic waves from a semiconductor element, and more particularly to a heat dissipation structure thereof.

  As a semiconductor device, an inverter device that includes a semiconductor element such as an IGBT (Insulated Gate Bipolar Transistor) that performs a switching operation and a control board that controls the semiconductor element and converts a direct current into an alternating current is known. This type of inverter device is used, for example, to supply a drive current to an electric motor (motor) such as an electric vehicle or a hybrid vehicle. As an inverter device mounted on a vehicle, for example, as shown in Patent Document 1, an inverter device integrated with a motor is known. In this inverter device, in order to reduce the size, the control board is arranged separately above the semiconductor element.

  In this type of inverter device, heat is generated from the semiconductor element and the control board in accordance with the switching operation. In particular, since semiconductor elements generate a large amount of heat, heat dissipation is important. Therefore, the inverter device shown in Patent Document 1 includes a cooling unit below the semiconductor element, and dissipates heat generated from the semiconductor element in the lower cooling unit. On the other hand, since heat is generated from the control board, which is not as high as that of the semiconductor element, it is necessary to dissipate heat. The heat generated from the control board is dissipated through the side wall portion that supports the end of the control board and extends from the cooling section. The control board is disposed above the semiconductor element and is in a state separated from the cooling unit. For this reason, the heat generated from the control board cannot be directly conducted to the cooling unit and can be dissipated, and unavoidably radiated from the end of the control board through the side wall by the cooling unit.

  Note that an electromagnetic wave (switching noise) is generated from the semiconductor element along with the switching operation. The generated electromagnetic wave causes a malfunction or the like on the control board, and is shielded by a predetermined shield material. In Patent Document 1, electromagnetic waves are shielded using the side wall portion.

JP 2004-39749 A

  As described above, when the control board is arranged away from the cooling unit, it is difficult to efficiently transfer the heat generated from the control board to the cooling unit and cool the control board. In particular, in an inverter device that shields electromagnetic waves generated from a semiconductor element by interposing a plate-shaped shield material between the semiconductor element and the control board, the control board is further arranged at a location away from the cooling unit. As a result, it becomes difficult to cool the control board. In addition, in the inverter apparatus mounted in a vehicle, since a mounting space is limited, it is difficult to newly provide a cooling apparatus such as a cooling fan or a cooling plate.

  An object of the present invention is to provide a semiconductor device capable of effectively radiating heat in a semiconductor device provided with a shield plate.

The semiconductor device according to the present embodiment is integrated with a motor, and includes a cooling unit including a circulating cooling water storage chamber having a heat radiation fin inside, a side wall extending from the cooling unit, and a top surface of the side wall. A case having a lid plate placed thereon, a semiconductor element provided on the cooling unit in the case, a control board disposed in the case and controlling the semiconductor element, and the semiconductor in the case In a semiconductor device comprising an element and a shield plate interposed between the control board and shielding electromagnetic waves emitted from the semiconductor element, the shield plate is made of a heat conductive material, and an end portion is the cooling unit connect to cool the inside of the case at all times and, wherein the heat generated from the control board to move to the cooling unit.

  In the above semiconductor device, the end of the shield plate is sandwiched and fixed between the support member projecting on the cooling unit and the control board, and is connected to the cooling unit via the heat conducting member. It is preferable to have a conduction path.

  In the semiconductor device, the heat conducting member is preferably a metal fixing bolt for fixing the heat conducting path at the end of the shield plate to the cooling unit.

  ADVANTAGE OF THE INVENTION According to this invention, the semiconductor device which can be thermally radiated effectively in the semiconductor device provided with the shield board can be provided.

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

  FIG. 1 is a cross-sectional view showing a schematic configuration of a vehicle inverter device 10 which is a semiconductor device. A vehicle inverter device 10 (hereinafter simply referred to as an inverter device) is mounted on a vehicle using a motor such as an electric vehicle or a hybrid vehicle as a prime mover. The inverter device 10 is a device that converts electric power of a power source such as a battery provided in the vehicle into alternating current and supplies the electric power to the motor. The motor is driven to rotate by the electric power supplied from the inverter device 10, and the vehicle travels.

  The inverter device 10 includes a power board 12 on which a power circuit (not shown) through which a drive current flows, a control board 14 on which a control circuit (not shown) for controlling the power circuit is mounted, a power board 12, and a control circuit. A shield plate 16 is disposed between the substrate 14 and shields electromagnetic waves. Further, the inverter device 10 includes a cooling unit 18 for cooling the generated power board 12 and the like. The inverter device 10 according to the present embodiment is integrated with a motor (not shown), and a motor (not shown) is disposed below the cooling unit 18.

  The power board 12 is disposed in contact with the upper surface 20 of the cooling unit 18. A shield plate 16 is disposed above the power substrate 12, and a control substrate 14 is disposed above the shield plate 16. The inverter device 10 has a hierarchical structure in which the power board 12 is disposed on the lower side and the control board 14 is disposed on the upper side away from the power board 12. The control board 14 and the shield plate 16 disposed above the power board 12 are supported and fixed by a resin support member 22 protruding from the upper surface 20 of the cooling unit 18. The support member 22 supports the end portions of the control board 14 and the shield plate 16 from the lower surface side. The support member 22 is a so-called resin mold, and includes a leg part 24 fixed to the upper surface 20 of the cooling part 18 and a standing wall part 26 standing on the leg part 24. The standing wall portion 26 of the support member 22 is in a state of surrounding the power substrate 12. The upper surface of the power substrate 12 is sealed with a resin 28. The resin 28 is filled in the upright wall portion 26 of the support member 22 that surrounds the power substrate 12 on the upper surface 16 of the cooling portion 18. The central portion of the shield plate 16 whose end is supported and fixed by the support member 22 is in a state of being recessed toward the power board 12 disposed on the lower side. A gap 30 is formed between the upper surface of the central portion of the recessed shield plate 16 and the control board 14. Further, a gap 32 is formed between the lower surface of the central portion of the recessed shield plate 16 and the power board 12.

  The power circuit mounted on the power board 12 is configured by a circuit including a three-phase bridge circuit having six switching elements (semiconductor elements) 34, for example. The switching element 34 is a semiconductor switching element and is made of, for example, an IGBT. The switching element 34 performs a switching operation (ON / OFF) according to a command from a control circuit included in the control board 14. By this switching operation, the power circuit can convert a direct current from the battery into an alternating current and supply a drive current to the motor. Note that heat is generated along with the switching operation of the switching element 34, and electromagnetic waves (switching noise) are generated.

  The control board 14 is a multilayer board on which a control circuit for issuing a switching operation command to the power circuit is mounted. The control circuit includes, for example, a control component (not shown) that generates heat, such as a drive IC and a transformer. The control circuit issues a switching operation command to the switching element 34 of the power circuit based on signals from an electronic control unit (ECU) that controls the motor or various detectors. The control circuit of the control board 14 and the power circuit of the power board 12 are connected by a lead frame (not shown).

  The shield plate 16 shields electromagnetic waves generated from the switching elements 34 on the power board 12 and prevents malfunction of the control circuit of the control board 14. The shield plate 16 is made of a material having excellent shielding properties such as aluminum and excellent thermal conductivity. The end portion of the shield plate 16 is sandwiched and fixed between the top surface of the standing wall portion 26 of the support member 22 and the back surface of the end portion of the control board 14. A heat conduction path 35 is extended at the end of the shield plate 16. The heat conduction path 35 is a part of the shield plate 16 (a part of the end) and is made of the same material. FIG. 2 is a plan view of the shield plate 16. The shield plate 16 has a substantially rectangular shape, and a heat conduction path 35 made of a strip-shaped flat plate member is provided at an end thereof. In the present embodiment, the heat conduction path 35 also has a function as a portion to be fixed to the support member 22 on the cooling unit 18. Therefore, the heat conduction path 35 is provided with a fixing hole 36 that is used when fixing.

  As shown in FIG. 1, the heat conduction path 35 is fixed on the leg portion 24 of the support member 22. The strip-shaped heat conduction path 35 is bent into a predetermined shape and fixed on the leg portion 24. The heat conduction path 35 and the leg portion 24 are fixed by a fixing means made of a member (heat conduction member) having excellent heat conductivity such as metal. In the present embodiment, a metal fixing bolt 38 (hereinafter simply referred to as a bolt) is used. The bolt 38 passes through the fixing hole 36 of the heat conduction path 35 and the fixing hole 40 provided in the leg portion 24. The tip of the bolt 38 reaches the cooling unit 18, and the bolt 38 and the cooling unit 18 are in contact with each other. The bolt 38 is also for fixing the support member 22 to the cooling unit 18.

  The cooling unit 18 includes a storage chamber 42 that stores cooling water (not shown), and a plurality of cooling fins 44 that are provided on the ceiling of the storage chamber 42. In the storage chamber 42, cooled cooling water that circulates in a predetermined radiator (not shown) and is cooled is stored. The cooling water in the storage chamber 42 is in contact with the cooling fins 44. The cooling unit 18 is made of a material having excellent thermal conductivity, and is made of a metal material such as aluminum, magnesium, or stainless steel, for example.

  The inverter device 10 is covered with a case 46. The case 46 includes a side wall 48 extending from the cooling unit 18 and a lid plate 50 that is placed on and fixed to the top surface of the side wall 48. The power board 12 and the control board 14 included in the inverter device 10 are accommodated in the case 46. The case 46 is made of a material having excellent thermal conductivity, and is made of a metal material such as aluminum, magnesium, stainless steel, for example. The case 46 may be manufactured integrally with the cooling unit 18.

  Here, the function of the heat dissipation structure of the inverter device 10 will be described. In the inverter device 10, the components that generate heat are mainly the switching elements 34 on the power board 12 and the control parts on the control board 14.

  The heat generated from the power board 12 including the switching element 34 and the like moves to the cooling unit 18 located below the power board 12. Since the upper side of the power substrate 12 is sealed with the resin 28 having a thermal conductivity inferior to that of the metal material, the heat generated from the power substrate 12 is transferred to the cooling unit 18 mainly made of the lower metal material. I can do it. The heat transferred to the cooling unit 18 is dissipated from the cooling fins 44 to the cooling water in the accommodation chamber 42. The cooling water in the storage chamber 42 is circulated through the radiator and cooled. In this way, the heat generated from the power board 12 moves to the cooling unit 18 and is dissipated into the cooling water.

  On the other hand, heat generated from the control board 14 including control components and the like is dissipated in the cooling unit 18 via the shield plate 16. In the present embodiment, a strip-shaped flat plate member that is a part of the end portion of the shield plate 16 and is a portion for fixing the shield plate 16 is used as the heat conduction path 35. Since the fixing means (bolt 38) made of a heat conductive member is used to fix the cooling unit 18, the shield plate 16 is thermally connected to the cooling unit 18. Therefore, the heat generated from the control board 14 can be moved from the end of the control board 14 to the shield plate 16 and further moved to the cooling section 18 via the heat conduction path 35 and the bolt 38. . The heat transferred to the cooling unit 18 is dissipated from the cooling fins 44 to the cooling water. In this way, the heat generated from the control board 14 moves to the cooling unit 18 via the shield plate 16 and is dissipated in the cooling unit 18.

  In the present embodiment, the shield plate 16 is always cooled by the cooling unit 18. Therefore, the shield plate 16 can be used as a so-called cooling device for purposes other than shielding electromagnetic waves. The shield plate 16 serves to cool not only the control board 14 but also the inside of the inverter device 10 (inside the case 46). According to the present embodiment, it is not necessary to newly provide a cooling device such as a cooling fan or a cooling plate in order to cool the control board 14 or the like, and cooling can be performed with a simple structure. Therefore, it is possible to cope with downsizing of the inverter device 10.

It is sectional drawing which shows schematic structure of the inverter apparatus for vehicles. It is a top view of a shield board.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Semiconductor device (vehicle inverter apparatus), 12 Power board, 14 Control board, 16 Shield plate, 18 Cooling part, 20 Upper surface of cooling part, 22 Support member, 24 Leg part, 26 Standing wall part, 28 Resin, 30, 32 Gap, 34 Semiconductor element (switching element), 36 Fixing hole, 38 Heat conduction member (Metal fixing bolt), 40 Fixing hole, 42 Storage chamber, 44 Cooling fin, 46 Case, 48 Side wall part, 50 Cover plate.

Claims (3)

A cooling unit including a circulating cooling water storage chamber that is integrated with the motor and has heat dissipation fins therein ;
A case having a side wall extending from the cooling unit and a cover plate placed on the top surface of the side wall;
A semiconductor element provided on the cooling unit in the case ;
A control board disposed in the case and controlling the semiconductor element;
In said case, said semiconductor element, and a shield plate interposed between the control board, shielding electromagnetic waves, wherein the semiconductor device is emitted,
In a semiconductor device comprising:
The shield plate, a semiconductor made of a heat conductive material, the inside of the case at all times to cool the end portion is connected to the cooling unit, and wherein the heat generated from the control board to move to the cooling unit apparatus. The semiconductor device according to claim 1,
End of the shield plate includes a support member which is protrudingly provided on said cooling portion, sandwiched between the control board, are fixed, and the thermal conductivity to be connected to the cooling unit via the heat conductive member A semiconductor device having a path. The semiconductor device according to claim 2,
The heat conductive member, wherein a said heat conduction path of the end of the shield plate is a metallic fixing bolt for fixing to the cooling unit.

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