JP4569766B2 - Semiconductor device - Google Patents

Description

  The present invention relates to a semiconductor device, and more particularly, to a semiconductor device that cools by releasing heat generated from a heating element of a semiconductor module to a refrigerant in a cooling jacket.

  For example, a semiconductor module such as an IPM (intelligent power module) for industrial equipment such as an electric vehicle or a hybrid vehicle includes a semiconductor element that generates heat during operation, such as an IGBT (insulated gate bipolar transistor) or a power MOSFET. These semiconductor elements generate a large amount of heat with large current and high integration. Therefore, it is required to cool the semiconductor module efficiently. For this reason, as a conventional technique, it is conventionally known to cool a semiconductor module by attaching the semiconductor module to a cooling jacket holding a refrigerant (for example, Patent Document 1).

  Patent Document 1 includes a coolant jacket for forming a coolant flow passage and joining a semiconductor element to the flow passage outer surface directly or via an insulating substrate, on the inner surface of the flow channel that is the back side of the joint surface of the semiconductor element. A plurality of heat-dissipating protrusions are provided at predetermined intervals in a direction crossing the refrigerant flow, and each protrusion has a maximum protrusion length in a region corresponding to the approximate center of the semiconductor element, and protrudes toward the outside. A cooling device for a semiconductor device is disclosed in which the thickness is gradually reduced.

JP 2003-324173 A

  However, in the above-mentioned Patent Document 1, a semiconductor element that is a heat generating element is joined to the outer surface of the flow path of the coolant jacket directly or via an insulating substrate. That is, heat generated from the semiconductor element is radiated to the refrigerant through the refrigerant jacket or through the insulating substrate in addition to the refrigerant jacket, so that there is a problem that the cooling performance is limited.

  The present invention has been made in view of the above-described problems. With a simple configuration, the heat generated from the heating element of the semiconductor module can be efficiently radiated to the refrigerant, thereby improving the cooling performance for the semiconductor module. An object of the present invention is to provide a semiconductor device that can be used.

In order to achieve the above object, the semiconductor device according to claim 1 includes a semiconductor module having a heat generating element and a conductive member bonded thereto, and a cooling jacket having a coolant made of an insulating material therein. A plurality of the semiconductor modules are assembled in a watertight and integrated manner with a terminal block, an opening is formed in the water cooling jacket, and the terminal block is attached to the opening, thereby conducting electrical conductivity with the heating element of the semiconductor module. At least one of the members is immersed in a refrigerant.

According to the first aspect of the present invention, a plurality of the semiconductor modules are assembled in a watertight and integrated manner with a terminal block, an opening is formed in the water cooling jacket, and the terminal block is mounted in the opening. In the module, at least one of the heating element and the conductive member is directly immersed in a refrigerant made of an insulating material in a cooling jacket. Therefore, the heat generated from the heat generating element of the semiconductor module is radiated directly to the refrigerant or via the conductive member without being electrically short-circuited.

According to the present invention, assembled together with watertight a plurality of the semiconductor module to the terminal block, by attaching the terminal block opening formed in the water-cooling jacket, at least the heating elements or conductive the semiconductor module A part of the member can be immersed in a coolant made of an insulating material in a water-cooled jacket, and heat generated from the heating element of the semiconductor module can be radiated directly to the coolant or via a conductive member without being electrically short-circuited. Therefore, a semiconductor device with improved cooling performance for the semiconductor module can be provided.

One embodiment of a semiconductor device according to the present invention will be described in detail with reference to FIGS. 1 to 3 in the case of an intelligent power module (IPM) 1 used in an inverter control circuit of an electric vehicle such as an electric vehicle or a hybrid vehicle. Explained.
The semiconductor device 1 of the present invention generally has a semiconductor module 10 having a heating element (semiconductor element that generates heat) 11 and an electrode 12 as a conductive member joined thereto, and a refrigerant 21 made of an insulating material inside. And a plurality of semiconductor modules 10 are assembled in a watertight manner integrally with the terminal block 30, an opening 20 a is formed in the water cooling jacket 20, and the terminal block 30 is attached to the opening 20 a. it makes at least one of the heat generation element 11 and the electrode 12 as the conductive member of the semiconductor module 10 is immersed to contact directly the refrigerant 21.

  In the embodiment shown in FIG. 1, the cooling jacket 20 is constituted by a flow path 3 a that circulates and flows the refrigerant 21 formed inside the inverter case 3. In the cooling jacket 20, as the semiconductor device 1, the pressure-increasing IPM 1 a and the traveling IPM 1 b, the reactor 5, and the pump 6 as a circulation means for forcibly circulating the refrigerant 21 in the cooling jacket 20 are provided. And the heat exchanger 7 for cooling the refrigerant 21 are watertightly attached to the openings 20a formed to correspond to each other. Note that the pump 6 is not necessary when the refrigerant 21 is not forced to circulate in the cooling jacket 20, such as naturally convection.

  For example, silicon oil can be used as the insulating fluid as the refrigerant 21 sealed in the cooling jacket 20. The refrigerant 21 fills the inside of the cooling jacket 20. Further, as the refrigerant, for example, a radiator cooling water (coolant) of an automobile or a refrigerant for an air conditioner can be supplied and circulated to the heat exchanger 7. In addition, although the inlet 6a and the outlet 6b which open to the cooling jacket 20 of the pump 6 are shown in a simplified manner so as to be arranged close to each other in FIG. 1, the refrigerant 21 is actually circulated and supplied to the entire cooling jacket 20. It is arranged so that it can be. Similarly, the inlet 7a and outlet 7b of the heat exchanger 7 are also shown in a simplified manner so as to be arranged close to each other in FIG. 1, but actually, the refrigerant can be circulated and supplied throughout the heat exchanger 7. So as to be spaced apart.

Next, the configuration 10 of the semiconductor module is a plate-like one (power card) provided in the IPM 1a for boosting, and the heating element 11 is an IGBT element (hereinafter referred to as the heating element 11 or the IGBT element 11 in some cases). Will be described in detail with reference to FIG. 2 and FIG. Each semiconductor module 10 includes, for example, an IGBT element as a heating element 11 and a pair of electrodes 12A and 12B as conductive members, and the electrodes 12A and 12B are directly surface-bonded to both surfaces of the IGBT element 11 by soldering or the like. The electrodes 12A and 12B are molded by the insulating resin 18 in a state where the electrodes 12A and 12B are exposed so as to constitute the surface of the semiconductor module 10, respectively. The semiconductor module (power card) 10 is attached to the terminal block 30 in a set of six for the purpose of controlling each phase of a three-phase AC motor, for example. Note that the electrodes 12 are not limited to being configured as a pair. For example, when the heating element 11 further includes a signal input terminal, an electrode connected to the signal input terminal is provided. Become. The electrode connected to the signal input terminal can be exposed on the surface of the semiconductor module 10 or can be disposed in the semiconductor module 10 without being exposed.
In the case of the embodiment shown in FIGS. 2 and 3, the IGBT element 11 has a two-stage shape having a part projecting partially on one surface of the plate-like main body, and the surface of the projecting part And the other surface of the main body each have a connection terminal. Each of the electrodes 12A and 12B includes a surface on which the connection terminal of the IGBT element 11 is provided, a joint portion 14 that is surface-bonded, and a terminal portion 15 that is connected to bus bars 16 and 17 having a predetermined polarity. . Of course, the electrode 12 has conductivity, but the joint 14 is made of a material having high thermal conductivity, and each of the connection terminals of the IGBT element 11 is provided via the solder layer 13. In order to directly bond the surfaces with each other, the surface of the IGBT element 11 is formed so as to have a larger area than each surface provided with the connection terminals. The terminal portion 15 of the electrode 12 protrudes from the base end face of the semiconductor module 10 and is connected to predetermined bus bars 16 and 17. In the present invention, since an insulating fluid is used as the refrigerant 21, for example, a lead is used instead of the electrode 12 having the plate-like joint portion 14 that is surface-joined to the connection terminals on both sides of the IGBT element 11 as the conductive member. It is also possible to use a linear element such as a wire so that the IGBT element 11 is directly exposed on the surface of the semiconductor module 10 and at least a part thereof is in contact with the refrigerant 21.

  When manufacturing the semiconductor module 10, the joint portions 14 of the electrodes 12A and 12B are directly joined to both surfaces of the IGBT element 11 by soldering or the like, and are not in contact with the IGBT elements 11 of both electrodes 12A and 12B. The electrode 12 can be molded so as to be exposed on the surface of the semiconductor module 10 by being placed in the mold and filled with the insulating resin 18 so that the surface is in contact with the inner surface of the mold. The base portion of each semiconductor module 10 is formed larger than the portion where the joint portion 14 of the electrode 12 located in the cooling jacket 20 is exposed. Each semiconductor module 10 is inserted into a hole 30 a formed in the terminal block 30, and a base portion is adhered by an adhesive and is injected and cured by being injected with a potting resin 31. It is assembled in one piece in a sealed state. The cooling jacket 20 is formed with an opening 20a having a shape into which the terminal block 30 can be fitted. Around the opening 20a, a concave groove for holding the seal member 8 such as an O-ring is formed. . The terminal block 30 is fitted to the cooling jacket 20 in a state where the terminal block 30 is fitted into the opening 20 a of the cooling jacket 20 and the flange 30 b is sealed by the sealing member 8. Therefore, the refrigerant 21 in the cooling jacket 20 does not leak out between each semiconductor module 10 and the hole 30a of the terminal block 30 and between the terminal block 30 and the opening 20a of the cooling jacket 20. Since the semiconductor module 10 is formed in a plate shape in this embodiment, if the surface is arranged in parallel with the flow direction of the refrigerant 21 in the cooling jacket 20, the flow resistance is reduced and the pump 6 The semiconductor module 10 can be uniformly cooled and the like. Furthermore, fins can be provided on the surface of the electrode 12 as necessary. In the present invention, since an insulating fluid is used as the refrigerant 21, the molded semiconductor module 10 has a portion where the refrigerant 21 passes from the inside of the cooling jacket 20 through the insulating resin 18 and the terminal portion 15 of the electrode 12. What is necessary is just to be able to mold so as not to leak outside from the space. As described above, the junction between the IGBT element 11 and the electrode 12 is configured without exposing only one of the junctions between the IGBT element 11 and the electrode 12 to the surface of the semiconductor module 10 and directly contacting the coolant 21. It is also possible to configure so that at least a part of both 11 and 14 is in direct contact with the coolant 21 without molding the periphery of the portion with the insulating resin 18.

  In the semiconductor device configured as described above, the coolant 21 made of an insulating fluid flows in the cooling jacket 20. The refrigerant 21 is cooled by the heat exchanger 7. The semiconductor module 10 is mounted so as to protrude into the cooling jacket 20, and at least a part of the joint portion 14 of the electrode 12 is immersed in the coolant 21 and is in direct contact with the joint portion 14 via the solder layer 13. The surface-bonded IGBT element 11 is located in the cooling jacket 20. Therefore, the heat generated from the IGBT element 11 is dissipated to the refrigerant 21 that is in direct contact with the two electrodes 12A and 12B through the joint portion 14. That is, the electrode 12 functions not only as an original function of electrically connecting the heat generating element 11 and the bus bars 16 and 17 but also as a heat radiating plate in which the joint portion 14 is interposed between the heat generating element 11 and the refrigerant 21. It is configured as follows. Moreover, since the joint portions 14 of the electrodes 12A and 12B are exposed on both surfaces of the semiconductor module 10, and the heat of the heating element 11 is radiated from both surfaces, the semiconductor module 10 can be efficiently and reliably cooled. . And since the refrigerant | coolant 21 is comprised with the insulating fluid, electrode 12A, 12B does not mutually short-circuit through the refrigerant | coolant 21. FIG. Therefore, the heat generated from the heating element 11 of the semiconductor module 10 can be efficiently and reliably radiated to the refrigerant 21 of the cooling jacket 20, and the cooling performance for the semiconductor module 10 can be improved. Further, as described above, a linear conductive member is used instead of the electrode 12 having the plate-like joint portion 14 so that the heating element 11 is directly exposed to the surface of the semiconductor module 10 and is immersed in the refrigerant 21. When configured, the heat generated from the heat generating element 11 can be directly radiated to the refrigerant 21, so that the cooling efficiency is further improved.

  The present invention is not limited to the above-described embodiment. The present invention can also be applied when the heat generating element 11 of the semiconductor module 10 is a semiconductor element other than the IGBT element. The semiconductor device 1 of the present invention can be applied as long as it is cooled by dissipating heat generated from the heating element 11 to the refrigerant 21 such as an inverter module of an industrial device other than an electric vehicle. The semiconductor module 10 is not limited to the case where a set of six power cards is used, and may be singular depending on the semiconductor device 1, or a plurality of sets other than six may be configured. Further, when the amount of heat generated by the heat generating element 11 is small, only one of the electrodes 12A and 12B may be exposed on the surface of the semiconductor joule 10 and immersed in contact with the refrigerant 21. Further, depending on the shape of the heating element 11, the semiconductor module 10 may be formed into a rod shape or the like without being formed into a plate shape.

It is the conceptual diagram shown in order to demonstrate one Embodiment of the whole semiconductor device of this invention. It is sectional drawing shown in order to demonstrate one Embodiment of a semiconductor module. It is an expanded sectional view of the semiconductor module shown in FIG.

Explanation of symbols

10: Power card (semiconductor module) 11: Heating element 12: Electrode 20: Cooling jacket 21: Refrigerant

Claims (1)

A semiconductor module having a heating element and a conductive member bonded thereto;
A cooling jacket holding a refrigerant made of an insulating material inside,
Assembling a plurality of the semiconductor modules to a terminal block in a watertight manner, forming an opening in the water-cooling jacket, and attaching the terminal block to the opening, so that at least the heating element and the conductive member of the semiconductor module A semiconductor device characterized in that one is immersed in a refrigerant.

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