Semiconductor module

Abstract

A semiconductor module according to the present invention comprises a substrate, a cooling plate, a housing (22), a sealing body, and a sealing material (25). The cooling plate (234) is joined to the back surface of the substrate. The housing (22) is provided to the cooling plate (234). An accommodation space (22v) formed by the housing (22) and the cooling plate (234) is filled with the sealing body (90). The interstices between the housing (22) and the cooling plate (234) are sealed with the sealing material (25). On the bottom surface (S) of the housing (22), a sealing surface (Sa), an inner groove (S1), and an outer groove (S2) are formed. The sealing material (25) which has leaked from the sealing surface (Sa) is collected in the inner groove (S1) and the outer groove (S2). The bottom surface (S) is provided with an open part (Sx) which terminates the inner groove (S1) so that the sealing material (25) leaked from the sealing surface (Sa) is released to the accommodation space (22v).

Description

Semiconductor Module CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2024-091736 filed in Japan on June 5, 2024, the contents of which are incorporated by reference in their entirety.

[0002] The disclosure herein relates to semiconductor modules.

[0003] The semiconductor module described in Patent Document 1 includes a substrate on which a semiconductor element is mounted, a resin case that houses the substrate, and a cooler that is thermally connected to the back surface of the substrate. The housing space formed by the cooler and the resin case is filled with a potting resin (sealant) that seals the substrate together with the semiconductor element. A sealant that adheres to the substrate is applied to the bottom surface of the resin case. This prevents the sealant from leaking from the housing space.

[0004] JP 2018-190894 A

[0005] However, it is difficult to control the amount of sealant applied so that only the minimum amount necessary is applied. If the amount applied is too small, leakage of the sealed body is insufficient, and if the amount applied is too large, the excess sealant may protrude from the bottom surface of the resin case, causing various problems.

[0006] One disclosed object is to provide a semiconductor module that reduces the risk of a sealant protruding and causing a problem.

[0007] One aspect of the disclosure is a semiconductor module comprising: a substrate having wiring; a semiconductor element mounted on one side of the substrate; a cooling plate thermally joined to the back side of the substrate, which is the side opposite to the one side; a housing mounted on the cooling plate and shaped like a ring to surround the substrate; a sealing body filled in the storage space formed by the housing and the cooling plate and sealing the semiconductor element and the substrate; and a sealing material that seals between the housing and the cooling plate, wherein a sealing surface to which the sealing material is applied is formed on the bottom surface of the housing, and the portion of the bottom surface facing the storage space with respect to the sealing surface is defined as an inner portion and a portion on the opposite side of the storage space is defined as an outer portion, and an outer groove is formed on the outer portion to collect sealing material that has leaked from the sealing surface, and a portion of the inner portion facing the outer groove is formed to have an inner groove that collects sealing material that has leaked from the sealing surface and an open portion where the inner groove is eliminated so that the sealing material that has leaked from the sealing surface is released into the storage space.

[0008] According to the disclosed semiconductor module, in the portion where the opening is provided, overflow to the inside of the bottom surface (toward the housing space) is encouraged through the opening. This inhibits overflow to the outside of the bottom surface S. Therefore, if there is a region (overflow prohibition region) where overflow to the outside of the housing is to be inhibited, providing an opening in the portion opposite that region can inhibit the sealing material from coming into contact with the overflow prohibition region. This reduces the risk of the sealing material overflowing and causing problems.

[0009] The various aspects disclosed in this specification employ different technical means to achieve their respective objectives. The reference numerals in parentheses in the claims and in this section are intended to exemplify correspondences with the following embodiments and are not intended to limit the technical scope. The objectives, features, and advantages disclosed in this specification will become more apparent by reference to the following detailed description and the accompanying drawings.

[0010] 4 is a diagram showing a circuit configuration of a power conversion device to which a semiconductor module according to a first embodiment is applied; FIG. 5 is a perspective view of the semiconductor module according to the first embodiment; FIG. 6 is a plan view of the semiconductor module according to the first embodiment; FIG. 7 is a cross-sectional view taken along line IV-IV in FIG. 3; FIG. 8 is a cross-sectional view of the semiconductor module according to the first embodiment; FIG. 9 is a plan view of the semiconductor module according to the first embodiment, showing a state in which the housing has been removed; FIG. 10 is a perspective view of the housing according to the first embodiment, seen from the cooling plate side; FIG. 11 is a perspective view of the housing according to a second embodiment, seen from the cooling plate side.

[0011] Hereinafter, several embodiments will be described with reference to the drawings. Note that in each embodiment, corresponding components are designated by the same reference numerals, and redundant description may be omitted. When only a portion of the configuration is described in each embodiment, the configuration of another embodiment described previously can be applied to the remaining portions of the configuration. Furthermore, in addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations of several embodiments can also be partially combined together even if not explicitly stated, as long as there is no particular problem with the combination. Note that the term "A and / or B" means at least one of A and B. In other words, it may include only A, only B, or both A and B.

[0012] The semiconductor module of this embodiment is applied to, for example, a power conversion device of a mobile body that uses a rotating electric machine as a drive source. The mobile body may be, for example, an electric vehicle such as a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV), an aircraft such as an electric vertical take-off and landing aircraft or a drone, a ship, construction machinery, or agricultural machinery. An example of application to a vehicle will be described below.

[0013] First Embodiment First, a schematic configuration of a vehicle drive system will be described with reference to FIG.

[0014] <Vehicle Drive System> As shown in FIG. 1 , a vehicle drive system 1 includes a DC power supply 2 , a motor generator 3 , and a power conversion device 4 .

[0015] The DC power supply 2 is a DC voltage source formed by a rechargeable secondary battery. The secondary battery is, for example, a lithium-ion battery or a nickel-metal hydride battery. The motor generator 3 is a three-phase AC rotating electric machine. The motor generator 3 functions as a drive source for the vehicle, i.e., an electric motor. The motor generator 3 functions as a generator during regeneration. The power conversion device 4 converts power between the DC power supply 2 and the motor generator 3.

[0016] <Power Conversion Device> Next, the circuit configuration of the power conversion device 4 will be described with reference to Fig. 1. The power conversion device 4 includes a power conversion circuit. The power conversion device 4 of this embodiment includes a smoothing capacitor 5 and an inverter 6, which is a power conversion circuit.

[0017] The smoothing capacitor 5 mainly smoothes the DC voltage supplied from the DC power supply 2. The smoothing capacitor 5 is connected to a P line 7, which is a power supply line on the high potential side, and an N line 8, which is a power supply line on the low potential side. The P line 7 is connected to the positive electrode of the DC power supply 2, and the N line 8 is connected to the negative electrode of the DC power supply 2. The positive electrode of the smoothing capacitor 5 is connected to the P line 7 between the DC power supply 2 and the inverter 6. The negative electrode of the smoothing capacitor 5 is connected to the N line 8 between the DC power supply 2 and the inverter 6. The smoothing capacitor 5 is connected in parallel to the DC power supply 2.

[0018] The inverter 6 is a DC-AC conversion circuit. The inverter 6 converts DC voltage into three-phase AC voltage under switching control by a control circuit (not shown) and outputs the voltage to the motor generator 3. This drives the motor generator 3 to generate a predetermined torque. During regenerative braking of the vehicle, the inverter 6 converts the three-phase AC voltage generated by the motor generator 3 in response to rotational force from the wheels into DC voltage under switching control by the control circuit and outputs the DC voltage to the P line 7. In this way, the inverter 6 performs bidirectional power conversion between the DC power source 2 and the motor generator 3.

[0019] The inverter 6 is configured to include upper and lower arm circuits 9 for three phases. The upper and lower arm circuits 9 are sometimes referred to as legs. Each upper and lower arm circuit 9 has an upper arm 9H and a lower arm 9L. The upper arm 9H and the lower arm 9L are connected in series between the P line 7 and the N line 8, with the upper arm 9H on the P line 7 side.

[0020] The connection point between the upper arm 9H and the lower arm 9L is connected to the winding 3a of the corresponding phase in the motor generator 3 via an output line 10. Of the upper and lower arm circuits 9, the U-phase upper and lower arm circuit 9U is connected to the U-phase winding 3a via a corresponding output line 10. The V-phase upper and lower arm circuit 9V is connected to the V-phase winding 3a via a corresponding output line 10. The W-phase upper and lower arm circuit 9W is connected to the W-phase winding 3a via a corresponding output line 10. At least a portion of each of the P line 7, the N line 8, and the output lines 10 is formed of a conductive member such as a bus bar.

[0021] The inverter 6 has six arms. Each arm is configured with a switching element. The number of switching elements constituting each arm is not particularly limited. It may be one or more. When there are more than one switching elements, the multiple switching elements connected in parallel with each other are turned on and off at the same timing by a common gate drive signal (drive voltage).

[0022] In this embodiment, an n-channel MOSFET 11 is used as the switching element constituting each arm. MOSFET is an abbreviation for Metal Oxide Semiconductor Field Effect Transistor. In the upper arm 9H, the drain of the MOSFET 11 is connected to the P line 7. In the lower arm 9L, the source of the MOSFET 11 is connected to the N line 8. The source of the MOSFET 11 in the upper arm 9H and the drain of the MOSFET 11 in the lower arm 9L are connected to each other.

[0023] A freewheeling diode 12 is connected in antiparallel to each MOSFET 11. The diode 12 may be a parasitic diode (body diode) of the MOSFET 11, or may be provided separately from the parasitic diode. The anode of the diode 12 is connected to the source of the corresponding MOSFET 11, and the cathode is connected to the drain.

[0024] The switching element is not limited to the MOSFET 11. For example, an IGBT may be used. IGBT is an abbreviation for Insulated Gate Bipolar Transistor. In the case of an IGBT, a freewheeling diode is also connected in anti-parallel.

[0025] The inverter 6 includes a snubber circuit 13 in addition to the upper and lower arm circuits 9 described above. The snubber circuit 13 absorbs a transient high voltage that occurs during switching, a so-called switching surge. This enables high-speed switching. The snubber circuit 13 may be provided individually for the upper and lower arm circuits 9 and connected in parallel to the corresponding upper and lower arm circuits 9. The snubber circuit 13 may be provided individually for each arm 9H, 9L and connected in parallel to the corresponding arm 9H, 9L. As an example, the snubber circuit 13 in this embodiment is connected in parallel to the upper and lower arm circuits 9.

[0026] The snubber circuit 13 has at least a capacitor 131. The snubber circuit 13 may be, for example, a C snubber circuit having the capacitor 131, or an RC snubber circuit having the capacitor 131 and a resistor 132 as shown in Fig. 1. It may also be an RCD snubber circuit having the capacitor 131, the resistor 132, and a diode.

[0027] The power conversion device 4 may further include a converter as a power conversion circuit. The converter is a DC-DC conversion circuit that converts a DC voltage, for example, into a DC voltage of a different value. The converter is provided between the DC power source 2 and the smoothing capacitor 5. The converter is configured with, for example, a reactor and the above-mentioned upper and lower arm circuits 9. This configuration allows for voltage step-up and step-down. The power conversion device 4 may also include a filter capacitor that removes power supply noise from the DC power source 2. The filter capacitor is provided between the DC power source 2 and the converter.

[0028] The power conversion device 4 may include a drive circuit for the switching elements that constitute the inverter 6 and the like. The drive circuit supplies a drive voltage to the gate of the MOSFET 11 of the corresponding arm based on a drive command from the control circuit. The drive circuit drives the corresponding MOSFET 11, i.e., turns it on and off, by applying the drive voltage. The drive circuit is sometimes referred to as a driver.

[0029] The power conversion device 4 may include a control circuit for the switching elements. The control circuit generates a drive command for operating the MOSFET 11 and outputs it to the drive circuit. The control circuit generates the drive command based on, for example, a torque request input from a host ECU (not shown) and signals detected by various sensors. ECU is an abbreviation for Electronic Control Unit.

[0030] The various sensors include, for example, a current sensor, a rotation angle sensor, and a voltage sensor. The current sensor detects the phase current flowing through the winding 3a of each phase. The rotation angle sensor detects the rotation angle of the rotor of the motor generator 3. The voltage sensor detects the voltage across the smoothing capacitor 5. The control circuit outputs, for example, a PWM signal as a drive command. The control circuit is configured with, for example, a processor and a memory. PWM is an abbreviation for Pulse Width Modulation.

[0031] <Semiconductor Module> Fig. 2 is a perspective view showing an example of a semiconductor module. Fig. 3 is a top plan view of the semiconductor module shown in Fig. 2. Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3. Fig. 4 shows a simplified structure of the semiconductor module. The housing is omitted from Fig. 4.

[0032] In the following, the thickness direction of the substrate is referred to as the Z direction, and one direction perpendicular to the Z direction is referred to as the Y direction. The direction perpendicular to both the Z direction and the Y direction is referred to as the X direction. Unless otherwise specified, the shape viewed from the Z direction, in other words, the shape along the XY plane defined by the X and Y directions, is referred to as the planar shape. Furthermore, the planar view from the Z direction may be simply referred to as the planar view.

[0033] 2, 3, and 4, the semiconductor module 20 may include a semiconductor device 21, a housing 22, and a cooler 23. The semiconductor module 20, together with a capacitor device that provides the smoothing capacitor 5, an input terminal block, an output terminal block, and the like, constitutes the power conversion device 4. The semiconductor module 20 may be housed in a case of the power conversion device 4 together with other elements such as the capacitor device.

[0034] The semiconductor device 21 is arranged on one surface of the cooler 23 in the Z direction. The semiconductor device 21 provides at least one arm of the inverter 6, which is a power conversion circuit. Each of the semiconductor devices 21 illustrated in FIG. 2 provides the upper and lower arm circuits 9 for one phase. The semiconductor module 20 includes three semiconductor devices 21 to provide the inverter 6. The three semiconductor devices 21 are arranged on the same surface of the cooler 23 and are lined up in the X direction. Each of the semiconductor devices 21 is fixed to the cooler 23.

[0035] One of the semiconductor devices 21, semiconductor device 21U, provides the U-phase upper and lower arm circuit 9U. Another of the semiconductor devices 21, semiconductor device 21V, provides the V-phase upper and lower arm circuit 9V. Another of the semiconductor devices 21, semiconductor device 21W, provides the W-phase upper and lower arm circuit 9W. In other words, the semiconductor module 20 provides the inverter 6. Details of the semiconductor device 21 will be described later.

[0036] The housing 22 is formed using an electrically insulating material such as resin. The housing 22 may be, for example, a resin molded body. The housing 22 may hold some of the components of the semiconductor device 21. Some of the components of the semiconductor device 21 may be integrally molded with the housing 22 as an insert part. The housing 22 may be fixed to the cooler 23. The housing 22 may be fixed to the case of the power converter 4 together with the cooler 23.

[0037] The housing 22 may be disposed on one side of the cooler 23, and together with the cooler 23, may provide an accommodation space 22v (see FIG. 5) for the semiconductor device 21. A seal 90 may be disposed in the accommodation space 22v formed by the housing 22 and the cooler 23. The seal 90 is filled up to a predetermined position lower than the top end of the housing 22.

[0038] The encapsulant 90 encapsulates the elements of the semiconductor device 21. The encapsulant 90 integrally encapsulates a portion of each of the semiconductor element 30, the substrate 40, the clip 50, and the external connection terminal 60. The encapsulant 90 also encapsulates the bonding wire 80 that electrically connects the pad 33 of the semiconductor element 30 to the signal terminal 62. In the example shown in FIG. 5 , a gel is used as the encapsulant 90. A potting resin may be used instead of the gel. The encapsulant 90 may be a resin molded body. The encapsulant 90 may be provided in the semiconductor device 21 or in the semiconductor module 20.

[0039] 2 and 3 , the housing 22 may include a frame 221 and a partition wall 222. The frame 221 has a predetermined height in the Z direction and is annular so as to surround the semiconductor device 21 in a plan view in the Z direction. The frame 221 may be referred to as an annular wall portion. The frame 221 may be substantially rectangular in shape. The rectangular annular frame 221 has four walls 221a, 221b, 221c, and 221d.

[0040] The walls 221a and 221b extend in the X direction. The walls 221a and 221b are arranged opposite each other with a predetermined gap in the Y direction. The wall 221a is arranged on one end side of the semiconductor device 21 in the Y direction, and the wall 221b is arranged on the other end side of the semiconductor device 21. The walls 221a and 221b include walls that define an area and extensions that extend outward from the walls in the Y direction. The walls 221c and 221d extend in the Y direction. The wall 221c is continuous with the walls 221a and 221b at one end side in the X direction. The wall 221d is continuous with the walls 221a and 221b at the other end side in the X direction.

[0041] The partition wall 222 has a predetermined height in the Z direction and is continuous with the frame body 221. The partition wall 222 divides the area defined by the frame body 221 into a plurality of areas. The partition wall 222 may divide the area into areas corresponding to the number of semiconductor devices 21, for example. The partition wall 222 divides the accommodation space 22v into the same number of areas as the number of substrates 40 in the X direction, which is the direction in which the substrates 40 are arranged. The partition wall 222 extends in the Y direction, which is perpendicular to the direction in which the substrates 40 are arranged, and both ends of the partition wall 222 are continuous with the wall portions 221a, 221b of the frame body 221.

[0042] The housing 22 may have two partition walls 222a and 222b as the partition wall 222. The partition walls 222a and 222b and the wall portions 221c and 221d are aligned in the X direction at a predetermined interval. The partition walls 222 divide the opposing area of ​​the frame body 221 into three regions. A semiconductor device 21 is housed in each of the three divided regions. The partition walls 222 are provided between adjacent boards 40 in the direction in which the boards 40 are arranged. The partition wall 222a is provided between the board 40 constituting the U-phase semiconductor device 21 and the board 40 constituting the V-phase semiconductor device 21. The partition wall 222b is provided between the board 40 constituting the V-phase semiconductor device 21 and the board 40 constituting the W-phase semiconductor device 21. The boards 40, i.e., the semiconductor devices 21 for each phase, are arranged in the three divided storage spaces 22v.

[0043] The cooler 23 cools the semiconductor devices 21. As illustrated in Fig. 4, the cooler 23 may have a flow path 231 therein. The flow path 231 is provided so as to overlap at least a portion of the semiconductor device 21 in a plan view so as to effectively cool the semiconductor device 21. The flow path 231 may be provided so as to encompass most of each semiconductor device 21 in a plan view.

[0044] The cooler 23 has a base member 233 and a cooling plate 234. The base member 233 and the cooling plate 234 are made of a metal with excellent thermal conductivity, such as aluminum or copper. The cooling plate 234 is attached to the base member 233 and covers an opening 233a of the base member 233. In the example shown in FIG. 3 , the cooling plate 234 is fastened to the base member 233 with bolts BT. As shown in FIG. 2 , the cooling plate 234 is formed with a plurality of bolt insertion holes 234a into which the bolts BT are inserted.

[0045] The portion of the cooling plate 234 where the bolt insertion holes 234a are formed corresponds to the fastening portion 234p that is fastened to the base member 233. As shown in Fig. 5, the fastening portion 234p is located outside the accommodation space 22v with respect to the frame body 221. The portion of the fastening portion 234p that surrounds the bolt insertion holes 234a and forms the seating surface of the bolt BT corresponds to the fastening seating surface 234b. Fig. 6 is a plan view showing the semiconductor module 20 with the housing 22 removed. The portion surrounded by the dashed line in Fig. 6 indicates the portion that functions as the fastening seating surface 234b.

[0046] The flow path 231 is formed in a space surrounded by a base member 233 and a cooling plate 234. An inlet pipe and an outlet pipe (not shown) are connected to the main body. A refrigerant 232 is supplied to the flow path 231 via the inlet pipe. The refrigerant 232 that has flowed through the flow path 231 is discharged to the outside of the cooler 23 via the outlet pipe. The refrigerant 232 may be a phase-change refrigerant such as water or ammonia, or a phase-non-change refrigerant such as an ethylene glycol-based refrigerant. The cooler 23 is not limited to the configuration having the flow path 231 described above. A heat dissipation member such as a heat sink may be used as the cooler 23. The heat dissipation member may include heat dissipation fins.

[0047] 4, a bonding material 24 is interposed between the semiconductor device 21 and the cooler 23. Specifically, the bonding material 24 is interposed between the conductor 43 and the cooling plate 234. As the bonding material 24, solder, a sintered material, or the like can be used.

[0048] The semiconductor module 20 includes a bonding material 24 disposed between the semiconductor device 21 and the cooler 23. The semiconductor device 21 is fixed to the cooler 23 by bonding. If insulation is required, an electrically insulating material may be disposed between the semiconductor device 21 and the cooler 23. For example, a ceramic plate or a resin sheet may be used as the insulating material. A TIM such as silicon gel may be used to improve thermal conductivity. TIM is an abbreviation for Thermal Interface Material.

[0049] The semiconductor module 20 may include a circuit board (not shown). The drive circuit described above is formed on the circuit board. The circuit board is arranged above the semiconductor devices 21 in the Z direction. The semiconductor module 20 may also include a cover that provides a housing together with the housing 22 and the cooler 23. The cover is arranged on the opposite side of the semiconductor devices 21 from the cooler 23. The cover may be arranged to cover the three semiconductor devices 21 as a whole.

[0050] <Semiconductor Device> As described above, the semiconductor device 21 may provide one phase of the upper and lower arm circuits 9. As illustrated in Figures 4 and 5, the semiconductor device 21 may include a semiconductor element 30, a substrate 40, a clip 50, and an external connection terminal 60.

[0051] The semiconductor element 30 is a vertical element formed on a semiconductor substrate made of silicon (Si) or a wide bandgap semiconductor having a wider bandgap than silicon. Examples of wide bandgap semiconductors include silicon carbide (SiC), gallium nitride (GaN), and gallium oxide (GaO). ２ O ３ ), diamond. The semiconductor element 30 may be called a power element, a semiconductor chip, or the like.

[0052] The vertical element is configured to pass a main current in the thickness direction of the semiconductor element 30 (semiconductor substrate). The semiconductor element 30 is disposed so that its thickness direction is substantially parallel to the Z direction. The semiconductor element 30 has main electrodes on both sides in the thickness direction. The semiconductor element 30 of this embodiment is formed by forming an n-channel MOSFET 11 as a vertical element on a semiconductor substrate made of SiC. As shown in FIG. 4 , the semiconductor element 30 has, as main electrodes, a drain electrode 31 on its lower surface facing the substrate 40 and a source electrode 32 on its upper surface opposite the lower surface.

[0053] When the MOSFET 11 is turned on, a current (main current) flows between the main electrodes, that is, between the drain electrode 31 and the source electrode 32. If the diode 12 is a parasitic diode, the source electrode 32 also serves as the anode electrode, and the drain electrode 31 also serves as the cathode electrode. The diode 12 may be formed on a chip separate from the MOSFET 11. The drain electrode 31 is the main electrode on the high potential side, and the source electrode 32 is the main electrode on the low potential side. The drain electrode 31 is formed over almost the entire bottom surface. The source electrode 32 is formed on a portion of the top surface.

[0054] The semiconductor element 30 has a generally rectangular shape in plan view. The semiconductor element 30 has, on its upper surface, pads 33 (see FIG. 5 ) that are signal electrodes. The pads 33 are formed at positions on the upper surface that are different from the source electrodes 32. The pads 33 include at least a gate pad.

[0055] As shown in Figure 3, the multiple semiconductor elements 30 include a semiconductor element 30H that constitutes the upper arm 9H and a semiconductor element 30L that constitutes the lower arm 9L. The semiconductor element 30H is sometimes referred to as an upper arm element. The semiconductor element 30L is sometimes referred to as a lower arm element. For example, the semiconductor elements 30H and 30L may have a common configuration. The semiconductor elements 30H and 30L are aligned in the Y direction.

[0056] The number of each of the semiconductor elements 30H, 30L is not particularly limited. There may be one of each, or multiple of each. In the example shown in FIGS. 2 and 3 , the semiconductor element 30 includes four of each of the semiconductor elements 30H, 30L. Four semiconductor elements 30H are connected in parallel to provide the MOSFET 11 of the upper arm 9H of one phase. Four semiconductor elements 30L are connected in parallel to provide the MOSFET 11 of the lower arm 9L of one phase. The four semiconductor elements 30H are lined up in the X direction. The four semiconductor elements 30L are lined up in the X direction.

[0057] The substrate 40 contains all of the semiconductor elements 30 (30H, 30L) in a plan view. The substrate 40 is disposed on the drain electrode 31 side of the semiconductor elements 30. As will be described later, the substrate 40 is electrically connected to the drain electrode 31 and provides a wiring function. The substrate 40 may also be referred to as a wiring board, a printed circuit board, or the like.

[0058] The substrate 40 has an insulating base material 41 and a conductor disposed on the insulating base material 41. The insulating base material 41 is formed using an electrically insulating material such as ceramic or resin. As shown in Fig. 4, the insulating base material 41 has one surface 41a that faces the semiconductor element 30 and a back surface 41b that is the surface opposite to the one surface 41a in the Z direction. The substrate 40 may be divided into units of semiconductor devices 21, or may be integrated into units of semiconductor modules 20.

[0059] The conductor is formed from a metal such as Cu or Al that has good electrical and thermal conductivity. The conductor may have a plating film of Ni-based metal or Au-based metal on its surface. The conductor may be disposed on only one surface 41a of the insulating substrate 41, or on both the one surface 41a and the back surface 41b. The conductor may be disposed inside the insulating substrate 41. In other words, the substrate 40 may be a single-sided substrate, a double-sided substrate, or a multilayer substrate having three or more layers of conductors. The conductor may include a via conductor. The via conductor is formed by disposing a conductor such as a plating in a through hole (via) formed in an insulating layer that constitutes the insulating substrate 41. The via conductor electrically connects conductors disposed on different layers.

[0060] The substrate 40 has conductors 42 arranged on one surface 41a. The conductors 42 are patterned. The patterned conductors 42 provide wiring, i.e., circuits. The conductors 42 include P wiring 421, N wiring 422, and O wiring 423. Each wiring is electrically separated by a predetermined interval (gap). The substrate 40 has a conductor 43 arranged on the back surface 41b.

[0061] The P wiring 421 is connected to the drain electrode 31 of the semiconductor element 30H. The P wiring 421 is connected to a P terminal 611, which will be described later. The P wiring 421 electrically connects the drain electrode 31 of the semiconductor element 30H to the P terminal 611. The P wiring 421 may be referred to as a positive wiring, a high-potential power supply wiring, or the like.

[0062] The N wiring 422 is connected to the N terminal 612. The source electrode 32 of the semiconductor element 30L is electrically connected to the N wiring 422 via the clip 50L. The N wiring 422 electrically connects the source electrode 32 of the semiconductor element 30L and the N terminal 612. The N wiring 422 may be referred to as a negative wiring, a low-potential power supply wiring, or the like.

[0063] The O wiring 423 is connected to the drain electrode 31 of the semiconductor element 30L. The O wiring 423 is connected to an O terminal 613, which will be described later. The source electrode 32 of the semiconductor element 30H is electrically connected to the O wiring 423 via a clip 50H. The O wiring 423 electrically connects the source electrode 32 of the semiconductor element 30H, the drain electrode 31 of the semiconductor element 30L, and the O terminal 613. The O wiring 423 is sometimes referred to as an output wiring, etc.

[0064] The clip 50 may also be referred to as a bridging member, a relay member, a metal bridge, etc. The clip 50 is a metal plate material whose base material is a metal with good conductivity, such as Cu or a Cu alloy. The clip 50 may be formed by punching a metal plate of a predetermined thickness and then pressing it.

[0065] The clips 50 include a clip 50H connected to the semiconductor element 30H and a clip 50L connected to the semiconductor element 30L. The clip 50H electrically connects the source electrode 32 of the semiconductor element 30H to the O wiring 423. The clips 50H extend in the Y direction. The clips 50H may be provided individually for each semiconductor element 30H, or may be provided collectively for multiple semiconductor elements 30H. As shown in FIG. 3 and other figures, one clip 50H may be provided for two semiconductor elements 30H. The semiconductor device 21 includes two clips 50H. Each of the clips 50H is substantially Y-shaped in plan view.

[0066] The clip 50L electrically connects the source electrode 32 of the semiconductor element 30L and the N wiring 422. The clip 50L extends in the Y direction. The clip 50L may be provided individually for each semiconductor element 30L, or may be provided collectively for multiple semiconductor elements 30L. In the example shown in FIG. 3 and other figures, the clip 50L is provided individually for each semiconductor element 30L. The semiconductor device 21 includes four clips 50L.

[0067] The solder 81 joins the source electrode 32 and the clip 50H. The solder 81 joins the O wiring 423 and the clip 50H. The sintered member 82 joins the drain electrode 31 and the O wiring 423. The sintered member 82 further joins the drain electrode 31 and the P wiring 421. The sintered member 82 is made of Ag or Cu, and can be joined at a lower temperature than solder.

[0068] The external connection terminals 60 are terminals for electrically connecting the semiconductor device 21 to external devices. The external connection terminals 60 are formed using a metal material with good conductivity, such as copper. The external connection terminals 60 are, for example, a plate material. The external connection terminals 60 include a main terminal 61 and a signal terminal 62. The main terminal 61 is a terminal electrically connected to a main electrode of the semiconductor element 30. The signal terminal 62 is a terminal electrically connected to a pad 33 (see FIG. 5 ) of the semiconductor element 30. The main terminal 61 includes a P terminal 611 and an N terminal 612, which are power supply terminals, and an O terminal 613.

[0069] The P terminal 611 is the external connection terminal 60 electrically connected to the P line 7 described above. The P terminal 611 is electrically connected to the positive terminal of the smoothing capacitor 5. The P terminal 611 may also be referred to as a positive terminal, a high-potential power supply terminal, or the like. The P terminal 611 is connected to the terminal connection portion 421c of the P wiring 421. The P terminal 611 is electrically connected via the P wiring 421 to the drain electrode 31 of the semiconductor element 30H that constitutes the upper arm 9H.

[0070] As shown in FIGS. 2 and 3 , the P terminal 611 has a connection portion 611a for connecting to an external device and a connection portion 611b for connecting to the circuit board 40. The P terminal 611 generally extends in the Y direction. One of the Y-direction ends of the P terminal 611 forms the connection portion 611a, and the other Y-direction end forms the connection portion 611b. In the example shown in FIG. 2 , a portion of the P terminal 611 is held by the frame 221 of the housing 22. The connection portion 611a of the P terminal 611 protrudes outward from the wall portion 221a of the frame 221, and the connection portion 611b protrudes inward from the wall portion 221a, i.e., toward the partitioned area. The P terminal 611 has one connection portion 611a and one connection portion 611b. The connection portion 611b is connected to the terminal connection portion 421c of the P wiring 421. A capacitor device providing the smoothing capacitor 5 is connected to the connection portion 611a, for example, via a bus bar or the like.

[0071] The N terminal 612 is an external connection terminal 60 electrically connected to the above-described N line 8. The N terminal 612 is electrically connected to the negative terminal of the smoothing capacitor 5. The N terminal 612 may also be referred to as a negative terminal, a low-potential power supply terminal, or the like. The N terminal 612 is connected to the terminal connection portion 422c of the N wiring 422. The N terminal 612 is electrically connected to the source electrode 32 of the semiconductor element 30L constituting the lower arm 9L via the N wiring 422 and a clip 50L.

[0072] The N terminal 612 has a connection portion 612a for connecting to an external device and a connection portion 612b for connecting to the circuit board 40. The N terminal 612 extends generally in the Y direction. One of the Y-direction ends of the N terminal 612 forms the connection portion 612a, and the other Y-direction end forms the connection portion 612b. In this embodiment, as an example, a portion of the N terminal 612 is held by the frame 221 of the housing 22. The connection portion 612a of the N terminal 612 protrudes outward from the wall portion 221a of the frame 221, and the connection portion 612b protrudes inward from the wall portion 221a. The N terminal 612 has one connection portion 612a and two connection portions 612b. One of the connection portions 612b is connected to one of the terminal connection portions 421c of the N wiring 422, and the other connection portion 612b is connected to the other one of the terminal connection portions 421c. The smoothing capacitor 5 is connected to the connection portion 612a via, for example, a bus bar.

[0073] The O terminal 613 is an external connection terminal 60 electrically connected to the output line 10. The O terminal 613 is electrically connected to the winding 3a of the opposing phase of the motor generator 3. The O terminal 613 may also be referred to as an output terminal, an AC terminal, or the like. The semiconductor module 20 includes, as the O terminals 613, a U-phase O terminal 613U, a V-phase O terminal 613V, and a W-phase O terminal 613W.

[0074] The O terminal 613 is connected to the terminal connection portion 423c of the O wiring 423. The O terminal 613 is electrically connected to the drain electrode 31 of the semiconductor element 30L constituting the lower arm 9L via the O wiring 423. The O terminal 613 is electrically connected to the source electrode 32 of the semiconductor element 30H constituting the upper arm 9H via the O wiring 423 and the clip 50H.

[0075] The O terminal 613 has a connection portion 613a for connecting to an external device and a connection portion 613b for connecting to the circuit board 40. The O terminal 613 extends generally in the Y direction. One of the Y-direction ends of the O terminal 613 forms the connection portion 613a, and the other Y-direction end forms the connection portion 613b. In this embodiment, as an example, a portion of the O terminal 613 is held by the frame 221 of the housing 22. The connection portion 613a of the O terminal 613 protrudes outward from the wall portion 221b of the frame 221, and the connection portion 613b protrudes inward from the wall portion 221b. The O terminal 613 has one connection portion 613a and one connection portion 613b. The connection portion 613b is connected to the terminal connection portion 423c of the O wiring 423. The motor generator 3 is connected to the connection portion 613a via, for example, a bus bar or the like.

[0076] The signal terminals 62 electrically connect the semiconductor element 30 to a circuit board (not shown). The signal terminals 62 are electrically connected to the pads 33 of the semiconductor element 30 via connecting members such as bonding wires 80 (see FIG. 5). The number of signal terminals 62 is not particularly limited. The signal terminals 62 only need to include at least a terminal for applying a drive voltage to the gate electrode of the semiconductor element 30. The signal terminals 62 may include a terminal for detecting the source potential of the semiconductor element 30. The signal terminals 62 may include a terminal for detecting the drain potential of the semiconductor element 30. The signal terminals 62 may include a terminal for detecting the temperature of the semiconductor element 30.

[0077] 2 and other examples, a portion of the signal terminal 62 is held by the walls 221b and 221c and the partition walls 222a and 222b of the frame body 221. The signal terminal 62 on the upper arm 9H side is held by the frame body 221 and the partition wall 222. For example, the U-phase signal terminal 62 is held by the wall 221c of the frame body 221. The V-phase signal terminal 62 is held by the partition wall 222a, and the W-phase signal terminal 62 is held by the partition wall 222b. The signal terminal 62 on the lower arm 9L is held by the wall 221b of the frame body 221.

[0078] 7, a sealant 25 is provided between the housing 22 and the cooling plate 234. A material with excellent heat resistance, such as silicon, is used for the sealant 25. The sealant 25 seals between the housing 22 and the cooling plate 234, preventing the sealant 90 from leaking from the accommodation space 22v.

[0079] The sealant 25 is applied to the lower end surface (bottom surface S) of the frame 221, but not to the lower end surface of the partition wall 222. This is because there is no need to prevent the sealant 90 from moving between the multiple regions partitioned by the partition wall 222. The partition wall 222 may have through holes (not shown) that connect the multiple regions. This prevents variations in the amount of sealant 90 present in each of the multiple regions. Instead of through holes, gaps may be formed between the partition wall 222 and the cooling plate 234.

[0080] A seal surface Sa that comes into close contact with the cooling plate 234 is formed on the bottom surface S of the frame 221. A seal material 25 is applied to this seal surface Sa. The dotted areas in FIG. 7 correspond to the seal surface Sa and the openings Sx described below. The seal material 25 shown in FIG. 7 is the seal material 25 manually dispensed from a nozzle by an operator and is the seal material 25 immediately after being applied to the seal surface Sa. When the housing 22 is pressed against the cooling plate 234 in this state, the seal material 25 is crushed between the bottom surface S of the housing 22 and the cooling plate 234 and spreads across the entire seal surface Sa. The seal surface Sa has an annular shape that extends in an XY plane so as to surround the housing space 22v. In accordance with the rectangular annular shape of the frame 221, the seal surface Sa also has a rectangular annular shape in top view.

[0081] The portion of the bottom surface S that is on the side of the accommodation space 22v with respect to the sealing surface Sa is called the inner portion Sin. The portion of the bottom surface S that is on the opposite side of the accommodation space 22v with respect to the sealing surface Sa is called the outer portion Sout. An inner groove S1 is formed in the inner portion Sin, and an outer groove S2 is formed in the outer portion Sout. The inner groove S1 and the outer groove S2 are grooves that are recessed from the bottom surface S in a direction away from the cooling plate 234.

[0082] As described above, the sealing material 25 applied by the worker to any location on the sealing surface Sa is crushed between the bottom surface S and the cooling plate 234 and spreads over the sealing surface Sa. As the sealing material 25 spreads in this manner, excess sealing material 25 leaks out from the sealing surface Sa and is accumulated in the inner groove S1 and the outer groove S2 located on the outside of the sealing surface Sa.

[0083] The outer groove S2 has an annular shape extending along the seal surface Sa. In order to match the rectangular annular shape of the seal surface Sa, the outer groove S2 also has a rectangular annular shape when viewed from above. The inner groove S1 has an annular shape extending along the seal surface Sa. However, the inner groove S1 is not formed in an annular shape. In other words, there is an area on the bottom surface S where the formation of the inner groove S1 is prohibited, and this area corresponds to the open portion Sx. The inner groove S1 is eliminated in the open portion Sx. In other words, the inner groove S1 extending along the seal surface Sa is interrupted at the open portion Sx.

[0084] The open portion Sx has a flat shape that extends parallel to the sealing surface Sa. That is, the open portion Sx functions to bring the bottom surface S of the frame 221 and the cooling plate 234 into close contact with each other, similar to the sealing surface Sa. The open portion Sx, which does not have the inner groove S1, releases the sealing material 25 that leaks inward from the sealing surface Sa into the accommodation space 22v. In the open portion Sx, excess sealing material 25 is more likely to overflow into the inside of the frame 221 (i.e., the accommodation space 22v) without being trapped in the inner groove S1.

[0085] The fact that the sealing material 25 easily overflows into the accommodation space 22v in this way means that the excess sealing material 25 is less likely to overflow outside the frame body 221 from the outer groove S2 in the portion facing the open portion Sx. In other words, in the portion of the sealing surface Sa adjacent to the open portion Sx, the excess sealing material 25 is encouraged to overflow inside the frame body 221. As a result, the sealing material 25 is less likely to overflow outside the frame body 221.

[0086] 7 indicates the relative position of the fastening bearing surface 234b with respect to the bottom surface S of the frame body 221. The area of ​​the bottom surface S where the open portion Sx is formed is set on the opposite side of the sealing surface Sa from the fastening portion 234p. In other words, the position of the open portion Sx is set in a portion facing the fastening portion 234p in a top view. For example, the portion of the inner portion Sin closest to the fastening bearing surface 234b corresponds to the portion facing the fastening portion 234p.

[0087] The open portions Sx are provided in a plurality of locations. In other words, a plurality of inner grooves S1 separated by the open portions Sx are formed. The number of open portions Sx is the same as the number of fastening portions 234p. In the example shown in FIGS. 2 and 3, the fastening portions 234p are provided in eight locations, and therefore the open portions Sx are also provided in eight locations.

[0088] 7, the length L1 of the open portion Sx along the extension direction of the seal surface Sa is set to be larger than the diameter L2 of the fastening seat surface 234b. For example, the length L1 is the shortest distance between both ends of the open portion Sx along the extension direction of the seal surface Sa.

[0089] Here, the separation distance L3 between the outer groove S2 and the accommodation space 22v is not constant but varies depending on the annular position of the annularly extending outer groove S2. The portion of the bottom surface S where the separation distance L3 gradually narrows is called the narrow portion. The region of the bottom surface S where the open portion Sx is formed is set as the narrow portion.

[0090] Summary of First Embodiment In the semiconductor module 20 of this embodiment, an outer groove S2 that collects the sealing material 25 that has leaked from the sealing surface Sa is formed in an outer portion Sout of the bottom surface S of the frame body 221. Furthermore, an inner groove S1 and an open portion Sx are formed in a portion of the inner portion Sin of the bottom surface S that faces the outer groove S2. The inner groove S1 collects the sealing material 25 that has leaked from the sealing surface Sa. On the other hand, the open portion Sx does not have an inner groove so that the sealing material 25 that has leaked from the sealing surface Sa is released into the accommodation space 22v.

[0091] If a comparative structure in which the inner groove S1 is also formed in the open portion Sx were adopted, contrary to the present embodiment, excess sealing material 25 on the sealing surface Sa would leak from the sealing surface Sa to both the inner portion Sin and the outer portion Sout. The sealing material 25 leaking to the inner portion Sin would be accumulated in the inner groove S1, and the sealing material 25 leaking to the outer portion Sout would be accumulated in the outer groove S2. If the amount of excess sealing material 25 is greater than the capacity of the inner groove S1 and the outer groove S2 to accumulate, the sealing material 25 would overflow from the bottom surface S of the frame body 221.

[0092] In consideration of this point, according to the present embodiment, in the portion where the opening Sx is provided, overflow to the inside of the bottom surface S is encouraged through the opening Sx. This in turn suppresses overflow to the outside of the bottom surface S. Therefore, when there is a region (overflow prohibition region) where overflow to the outside of the frame body 221 should be suppressed, by providing the opening Sx in the portion opposite that region, it is possible to suppress the sealing material 25 from coming into contact with the overflow prohibition region.

[0093] Furthermore, in this embodiment, the cooling plate 234 has a fastening portion 234p that is fastened to the base member 233. The fastening portion 234p is located on the opposite side of the sealing surface Sa from the accommodation space 22v. At least a portion of the opening Sx is formed in a portion of the sealing surface Sa that faces the fastening portion 234p. This prevents the sealant 25 from adhering to the fastening portion 234p, reducing the risk of problems occurring in the fastening between the cooling plate 234 and the base member 233.

[0094] Furthermore, in this embodiment, the fastening portion 234p has a bolt insertion hole 234a into which the bolt BT is inserted and a fastening seating surface 234b that forms a seating surface for the bolt BT around the bolt insertion hole 234a. The length L1 of the open portion along the extension direction of the seal surface Sa is set to be larger than the diameter L2 of the fastening seating surface. This improves the reliability of preventing the sealing material 25 from adhering to the fastening portion 234p.

[0095] Furthermore, in this embodiment, the sealing surface Sa has an annular shape that extends to surround the accommodation space 22v. The outer groove S2 has an annular shape that extends along the sealing surface Sa. This improves the effect of preventing the sealing material 25 from spilling out of the frame body 221.

[0096] Furthermore, in this embodiment, the open portion Sx is formed in a narrow portion where the separation distance L3 between the outer groove S2 and the accommodation space 22v gradually narrows. In the narrow portion, the sealing surface Sa becomes smaller, so the amount of excess sealing material 25 on the sealing surface Sa tends to increase. As a result, the sealing material 25 tends to overflow from the bottom surface S of the frame body 221. According to this embodiment, in which the open portion Sx is formed in such a narrow portion, the effect of suppressing the sealing material 25 from overflowing outside the frame body 221 can be suitably exerted.

[0097] Furthermore, in this embodiment, the open portion Sx has a flat shape that extends parallel to the sealing surface Sa. Therefore, the open portion Sx can also exhibit the same sealing function as the sealing surface Sa, improving the sealing performance between the cooling plate 234 and the frame 221. In particular, since the open portion Sx has a sealing function in narrow portions, the effect of improving the sealing function by the open portion Sx is preferably exhibited in narrow portions where it is difficult to ensure a large sealing surface Sa.

[0098] Second Embodiment As shown in Fig. 8, a pilot hole S3 is formed in the bottom surface S of the frame body 221. The pilot hole S3 is a hole for fastening the frame body 221 and the cooling plate 234 with a screw (not shown). In the example shown in Fig. 8, the pilot hole S3 has a concave shape that does not penetrate through, but it may also have a through shape. For example, a tapping screw is used as the screw. The tapping screw is inserted into the pilot hole S3 while threading the inner wall surface of the pilot hole S3.

[0099] In the first embodiment, the open portion Sx is formed in a portion of the seal surface Sa facing the fastening portion 234p. In addition, in the present embodiment, an open portion Sx is also formed in a portion facing the pilot hole S3. The open portion Sx in the portion facing the fastening portion 234p is connected to the open portion Sx in the portion facing the pilot hole S3. In other words, the region Sy where the open portion Sx is formed includes regions facing both the fastening seat surface 234b and the pilot hole S3.

[0100] 8 are straight lines extending perpendicular to the direction in which the inner groove S1 extends and passing through the ends of the inner groove S1. The region between these two imaginary lines K is the region Sy where the opening Sx is formed.

[0101] According to this embodiment, the opening Sx is also formed in the portion facing the pilot hole S3, which prevents the seal material 25 from adhering to the pilot hole S3 and reduces the risk of problems occurring in fastening the frame 221 and the cooling plate 234 together.

[0102] (Other Embodiments) The disclosure in this specification and drawings, etc. is not limited to the exemplified embodiments. The disclosure encompasses the exemplified embodiments and modifications thereto by those skilled in the art. For example, the disclosure is not limited to the combinations of parts and / or elements shown in the embodiments. The disclosure can be implemented in various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure encompasses the omission of parts and / or elements from the embodiments. The disclosure encompasses the substitution or combination of parts and / or elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. Some disclosed technical scopes are defined by the claims, and should be interpreted as including all modifications within the meaning and scope equivalent to the claims.

[0103] In the above-described embodiments, the open portion Sx has a flat shape extending parallel to the sealing surface Sa, but is not limited thereto. For example, the open portion Sx may have a shape that slopes away from the cooling plate 234 as it approaches the accommodation space 22v from the sealing surface Sa. Alternatively, the open portion Sx may have a curved shape that curves away from the cooling plate 234 as it approaches the accommodation space 22v from the sealing surface Sa.

[0104] In each of the above embodiments, an example was shown in which the outer groove S2 was formed in an annular shape, but this is not limited thereto, and there may be a portion of the outer portion Sout where the outer groove S2 is not formed. However, the outer groove S2 is required in the portion facing the open portion Sx. In other words, the open portion is formed in the portion facing the outer groove S2. It is also desirable that the inner groove S1 be formed in the portion facing the outer groove S2. The "portion facing the outer groove S2" also refers to the portion of the inner portion Sin that is closest to the outer groove S2.

[0105] The sealing material 25 may function as an adhesive that solidifies and adheres in addition to its sealing function. In each of the above embodiments, the base member 233 to which the cooling plate 234 is fastened is a part of the cooler 23, but this is not limiting. For example, the base member to which the cooling plate 234 is fastened may be a part of the case of the power conversion device 4.

[0106] In each of the above embodiments, the power conversion device 4 includes the inverter 6 as a power conversion unit, but is not limited to this. For example, the power conversion device 4 may include a plurality of inverters. The power conversion device 4 may include at least one inverter and a converter. The power conversion device 4 may include only a converter.

[0107] (Disclosure of Technical Ideas) This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be described in a multiple dependent form, with the subsequent clause alternatively referring to the preceding clause. Furthermore, some clauses may be described in a multiple dependent form, with the subsequent clause referring to another multiple dependent clause. These multiple dependent clauses define multiple technical ideas.

[0108] (Technical Idea 1) A semiconductor device (40) comprising: a substrate (40) having wiring (42); a semiconductor element (30) mounted on one surface of the substrate; a cooling plate (234) thermally joined to a back surface of the substrate opposite to the one surface; a housing (22) mounted on the cooling plate and having an annular shape extending to surround the substrate; a seal (90) filled in an accommodating space (22v) formed by the housing and the cooling plate and sealing the semiconductor element and the substrate; and a seal material (25) sealing between the housing and the cooling plate, wherein a seal surface (Sa) to which the seal material is applied is formed on a bottom surface (S) of the housing; a portion of the bottom surface on the side of the accommodating space relative to the seal surface is defined as an inner portion (Sin) and a portion on the opposite side of the accommodating space is defined as an outer portion (Sout); and an outer groove (S2) is formed in the outer portion to collect the seal material leaking from the seal surface, A semiconductor module in which an inner groove (S1) for collecting the sealing material leaking from the sealing surface and an open portion (Sx) in which the inner groove is eliminated so that the sealing material leaking from the sealing surface is released into the storage space is formed in the inner portion of the semiconductor module facing the outer groove.

[0109] (Technical Idea 2) A semiconductor module according to Technical Idea 1, wherein the cooling plate has a fastening portion (234p) that is fastened to a base member (233), the fastening portion is located on the opposite side of the accommodating space with respect to the sealing surface, and at least a portion of the opening is formed in a portion that faces the fastening portion with respect to the sealing surface.

[0110] (Technical Idea 3) A semiconductor module according to Technical Idea 2, wherein the fastening portion has a bolt insertion hole (234a) into which a bolt (BT) is inserted and a fastening seat surface (234b) that forms a seat surface for the bolt around the bolt insertion hole, and the length (L1) of the open portion along the direction in which the sealing surface extends is set to be larger than the diameter (L2) of the fastening seat surface.

[0111] (Technical Idea 4) A semiconductor module described in any one of Technical Ideas 1 to 3, wherein the sealing surface has a shape that extends in an annular shape so as to surround the accommodating space, and the outer groove has a shape that extends in an annular shape along the sealing surface.

[0112] (Technical Idea 5) A semiconductor module according to any one of Technical Ideas 1 to 4, wherein the open portion is formed in a narrow portion where the separation distance (L3) between the outer groove and the accommodation space gradually narrows.

[0113] (Technical Concept 6) The semiconductor module according to any one of Technical Concepts 1 to 5, wherein the open portion has a flat shape extending parallel to the sealing surface.

Claims

1. A substrate (40) having wiring (42), a semiconductor element (30) mounted on one side of the substrate, a cooling plate (234) thermally bonded to the back surface of the substrate opposite the one side, a housing (22) mounted on the cooling plate and having an annular shape so as to surround the substrate, a sealing body (90) filled in an accommodation space (22v) formed by the housing and the cooling plate and sealing the semiconductor element and the substrate, and a sealing material (25) sealing between the housing and the cooling plate, wherein a sealing surface (Sa) to which the sealing material is applied is formed on a bottom surface (S) of the housing, a portion of the bottom surface on the accommodation space side relative to the sealing surface is defined as an inner portion (Sin) and a portion on the opposite side of the accommodation space is defined as an outer portion (Sout), and an outer groove (S2) is formed in the outer portion to collect the sealing material leaking from the sealing surface, The semiconductor module has an inner groove (S1) formed in the part of the inner portion facing the outer groove for collecting the sealing material leaked from the sealing surface, and an open portion (Sx) in which the inner groove is eliminated so that the sealing material leaked from the sealing surface is released into the storage space.

2. A semiconductor module as described in claim 1, wherein the cooling plate has a fastening portion (234p) that is fastened to a base member (233), the fastening portion is located on the opposite side of the storage space from the sealing surface, and at least a portion of the opening is formed in a portion that faces the fastening portion from the sealing surface.

3. A semiconductor module as described in claim 2, wherein the fastening portion has a bolt insertion hole (234a) into which a bolt (BT) is inserted and a fastening seat surface (234b) that forms a seat surface for the bolt around the bolt insertion hole, and the length (L1) of the open portion along the direction in which the sealing surface extends is set to be larger than the diameter (L2) of the fastening seat surface.

4. A semiconductor module according to any one of claims 1 to 3, wherein the sealing surface has an annular shape extending to surround the accommodating space, and the outer groove has an annular shape extending along the sealing surface.

5. A semiconductor module according to any one of claims 1 to 3, wherein the open portion is formed in a narrow portion where the distance (L3) between the outer groove and the housing space gradually narrows.

6. The semiconductor module according to any one of claims 1 to 3, wherein the open portion has a flat shape extending parallel to the sealing surface.

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