Capacitor module, method for manufacturing same, and power conversion device

Abstract

A capacitor module (23) is provided with a primary molded body (30), a metal member (40), and a second resin portion (50). The primary molded body (30) has a capacitor element (31) and a first resin portion (33) that seals the capacitor element (31). The metal member (40) has a housing portion (41) that houses the primary molded body (30). The second resin portion (50) is filled into the housing portion (41) and seals the primary molded body (30). The second resin portion (50) is interposed at least between a bottom surface (331) of the first resin portion (33) and a bottom wall (411) of the housing portion (41), and between side surfaces (332) of the first resin portion (33) and side walls (412) of the housing portion (41).

Description

Capacitor Module, Method for Manufacturing Same, and Power Conversion Device Cross-Reference to Related Applications

[0001] This application is based on Japanese Patent Application No. 2025-28272 filed with Japan on February 25, 2025, and the entire content of the base application is incorporated herein by reference.

[0002] The disclosure in the present specification relates to a capacitor module, a method for manufacturing a capacitor module, and a power conversion device.

[0003] Patent Document 1 discloses a power conversion device including a capacitor module. The content described in the prior art document is incorporated herein by reference as an explanation of technical elements in the present specification.

[0004] Japanese Unexamined Patent Publication No. 2024-151749

[0005] In Patent Document 1, a smoothing capacitor is arranged in a housing portion of a metal casing, and the smoothing capacitor is sealed with an epoxy resin that is a thermosetting resin. For this reason, there is a risk that the epoxy resin may peel from the inner wall of the housing portion. From the above viewpoint or other viewpoints not mentioned, further improvements are demanded for capacitor modules, methods for manufacturing capacitor modules, and power conversion devices.

[0006] One of the objects of the present disclosure is to provide a technique capable of suppressing resin peeling.

[0007] A capacitor module according to one aspect of the disclosure comprises: a primary molded body having a capacitor element and a first resin portion that seals the capacitor element; a metal member having a housing portion that houses the primary molded body; and a second resin portion filled in the housing portion and sealing the primary molded body, wherein the second resin portion is interposed at least between a bottom surface of the first resin portion and a bottom wall of the housing portion and between a side surface of the first resin portion and a side wall of the housing portion.

[0008] According to the disclosed capacitor module, the sealing resin is divided into a first resin part and a second resin part. The first resin part constitutes the primary molded body together with the capacitor element, and the second resin part is filled into the housing part, sealing the primary molded body. Therefore, the shrinkage stress of the first resin part does not act at the interface with the housing part, but the shrinkage stress of the second resin part acts there. Thus, the shrinkage stress acting at the interface with the housing part can be reduced, and resin peeling can be suppressed.

[0009] A method for manufacturing a capacitor module, according to one aspect of the disclosure, comprises the steps of: encapsulating capacitor elements in resin to form a primary molded body; positioning and arranging the primary molded body in a housing portion of a metal member; and filling the housing portion with resin so as to be interposed at least between the bottom surface of the first resin portion that encapsulates the capacitor elements and the bottom wall of the housing portion, and between the side surface of the first resin portion and the side wall of the housing portion, thereby forming a second resin portion that encapsulates the primary molded body.

[0010] According to the disclosed manufacturing method, a primary molded body is first formed. Next, resin is filled into the housing with the primary molded body in place to form a second resin part. Therefore, the shrinkage stress of the first resin part does not act at the interface with the housing, but the shrinkage stress of the second resin part acts there. Thus, the shrinkage stress acting at the interface with the housing can be reduced, and resin peeling can be suppressed.

[0011] A power converter according to one aspect of the disclosure comprises a semiconductor module having semiconductor elements and a capacitor module electrically connected to the semiconductor module, wherein the capacitor module comprises a primary molded body having capacitor elements and a first resin part that seals the capacitor elements, a metal member having a housing part that houses the primary molded body, and a second resin part that fills the housing part and seals the primary molded body, wherein the second resin part is interposed at least between the bottom surface of the first resin part and the bottom wall of the housing part, and between the side surface of the first resin part and the side wall of the housing part.

[0012] According to the disclosed power conversion device, the encapsulating resin constituting the capacitor module is divided into a first resin part and a second resin part. The first resin part, together with the capacitor element, constitutes a primary molded body, and the second resin part is filled into the housing and encapsulates the primary molded body. Therefore, the shrinkage stress of the first resin part does not act at the interface with the housing, but the shrinkage stress of the second resin part acts. Thus, the shrinkage stress acting at the interface with the housing can be reduced, and resin peeling can be suppressed.

[0013] The various embodiments disclosed in this specification employ different technical means to achieve their respective objectives. The reference numerals in parentheses in the claims are illustrative in their correspondence with the embodiments described later and are not intended to limit the technical scope. The objectives, features, and effects disclosed in this specification will become clearer by referring to the subsequent detailed description and the accompanying drawings.

[0014] This figure shows a power conversion circuit and drive system to which a capacitor module according to the first embodiment is applied. This is a plan view showing an example of a power conversion device. This is a cross-sectional view along line III-III in Figure 2. This is a cross-sectional view showing another example of a power conversion device. This is a cross-sectional view showing an example of a capacitor module. This is a cross-sectional view showing another example of a capacitor module. This is a cross-sectional view showing another example of a capacitor module. This is a cross-sectional view showing a manufacturing method for a capacitor module. This is a cross-sectional view showing an example of heat curing. This is a cross-sectional view showing a modified example. This is a cross-sectional view showing a modified example. This is a cross-sectional view showing a manufacturing method for the power conversion device shown in Figure 12. This is a cross-sectional view showing an example of a capacitor module according to the second embodiment. This is a cross-sectional view showing an example of a capacitor module according to the third embodiment. This is a cross-sectional view showing an example of a capacitor module according to the fourth embodiment. This is a cross-sectional view showing a modified example. This is a cross-sectional view showing an example of a capacitor module according to the fifth embodiment. This is a cross-sectional view showing a modified example. This is a cross-sectional view showing an example of a capacitor module according to the sixth embodiment.

[0015] Several embodiments will be described below with reference to the drawings. In each embodiment, the same reference numerals are used for corresponding components, and redundant explanations may be omitted. If only a part of the configuration is described in each embodiment, the configuration of other embodiments described earlier can be applied to the other parts of that configuration. Furthermore, in addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations from multiple embodiments can be partially combined even if not explicitly stated, as long as there are no particular problems with the combination.

[0016] (First Embodiment) The capacitor module and power converter of this embodiment are applied, for example, to a mobile body that uses a rotating electric machine as a drive source. The mobile body is, for example, an electric vehicle such as an electric vehicle (BEV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV), an electric aircraft such as a drone or an eVTOL, a ship, construction machinery, or agricultural machinery. BEV is an abbreviation for Battery Electric Vehicle. HEV is an abbreviation for Hybrid Electric Vehicle. eVTOL is an abbreviation for electronic Vertical Take-Off and Landing aircraft. Examples of application to vehicles will be described below.

[0017] <Vehicle Drive System> Figure 1 shows an example of a drive system provided by a vehicle. The example drive system 1 includes a DC power supply 2, a motor generator 3, and a power conversion circuit 4.

[0018] DC power supply 2 is a DC voltage source. DC power supply 2 may be a rechargeable secondary battery such as a lithium-ion battery or a nickel-metal hydride battery. DC power supply 2 may also be a device that converts AC power to DC power for output.

[0019] The motor-generator 3 is a three-phase AC rotating electric machine. The motor-generator 3 functions as the vehicle's driving source, i.e., an electric motor. The motor-generator 3 also functions as a generator during regeneration. The power conversion circuit 4 performs power conversion between the DC power supply 2 and the motor-generator 3.

[0020] <Power Conversion Circuit> Figure 1 shows an example of a power conversion circuit 4. The example power conversion circuit 4 includes a smoothing capacitor 5 and an inverter 6.

[0021] The smoothing capacitor 5 primarily smooths the DC voltage supplied from the DC power supply 2. The smoothing capacitor 5 is connected to the P line 7, which is the high-potential power line, and the N line 8, which is the low-potential power line. The P line 7 is connected to the positive terminal of the DC power supply 2, and the N line 8 is connected to the negative terminal of the DC power supply 2. The positive terminal of the smoothing capacitor 5 is connected to the P line 7 between the DC power supply 2 and the inverter 6. The negative terminal 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.

[0022] The inverter 6 is a DC-AC conversion circuit. The inverter 6 converts a DC voltage to a three-phase AC voltage according to the switching control of the control circuit and outputs it 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 the rotational force from the wheels to a DC voltage according to the switching control of the control circuit and outputs it to the P line 7. In this way, the inverter 6 performs bidirectional power conversion between the DC power supply 2 and the motor generator 3.

[0023] The inverter 6 is configured with three phase upper and lower arm circuits 9. The upper and lower arm circuits 9 are sometimes referred to as legs. The upper and lower arm circuits 9 have an upper arm 9H and a lower arm 9L. The upper arm 9H and 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.

[0024] The connection point between the upper arm 9H and the lower arm 9L is connected to the corresponding phase winding 3a in the motor generator 3 via the 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 the output line 10. The V-phase upper and lower arm circuit 9V is connected to the V-phase winding 3a via the output line 10. The W-phase upper and lower arm circuit 9W is connected to the W-phase winding 3a via the output line 10.

[0025] The inverter 6 has six arms. Each arm is equipped with a switching element. The number of switching elements constituting each arm is not particularly limited; there may be one or more. In the case of multiple switching elements, the multiple switching elements connected in parallel to each other are driven on and off at the same timing by a common gate drive signal (drive voltage).

[0026] The example switching element is an n-channel type MOSFET 11. MOSFET is an abbreviation for Metal Oxide Semiconductor Field Effect Transistor. In the upper arm 9H, the drain terminal of the MOSFET 11 is connected to the P line 7. In the lower arm 9L, the source terminal of the MOSFET 11 is connected to the N line 8. The source terminal of the MOSFET 11 in the upper arm 9H and the drain terminal of the MOSFET 11 in the lower arm 9L are interconnected.

[0027] Each MOSFET 11 has a freewheeling diode 12 connected in antiparallel. The diode 12 may be a parasitic diode (body diode) of the MOSFET 11, or it may be a separate diode. The anode terminal of the diode 12 is connected to the source terminal of the corresponding MOSFET 11, and the cathode terminal is connected to the drain terminal.

[0028] Note that the switching element is not limited to 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 antiparallel.

[0029] The power conversion circuit 4 may include a converter. The converter is a DC-DC converter circuit configured to convert a DC voltage to, for example, a DC voltage of a different value. The converter is placed between the DC power supply 2 and the smoothing capacitor 5. The converter is configured, for example, with a reactor and the above-described up-and-down arm circuit 9. With this configuration, step-up and step-down voltage conversion is possible.

[0030] The power conversion circuit 4 may include a snubber circuit. The snubber circuit is connected in parallel to the upper and lower arm circuit 9. The snubber circuit reduces the inductance of the upper and lower arm circuit 9. In other words, the snubber circuit absorbs transient high voltages, so-called switching surges, that occur when the switching elements (MOSFETs 11) constituting the upper and lower arm circuit 9 are switched. This enables the inverter 6 to perform high-speed switching.

[0031] The power conversion circuit 4 may include a filter circuit. The filter circuit may have a Y capacitor or the like to suppress common-mode noise. It may also have an X capacitor or the like to suppress normal-mode noise.

[0032] The power conversion circuit 4 may include a drive circuit for the switching elements that make up the inverter 6, etc. The drive circuit supplies a drive voltage to the gate of the corresponding arm's MOSFET 11 based on a drive command from the control circuit. The drive circuit drives the corresponding MOSFET 11, i.e., turns it on or off, by applying the drive voltage. The drive circuit is sometimes referred to as a driver.

[0033] The power conversion circuit 4 may include a control circuit for the switching element. 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 higher-level ECU (not shown) and signals detected by various sensors. ECU is an abbreviation for Electronic Control Unit.

[0034] The various sensors include, for example, current sensors, rotation angle sensors, and voltage sensors. The current sensor detects the phase current flowing through the windings 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 to include, for example, a processor and memory. PWM is an abbreviation for Pulse Width Modulation.

[0035] <Power Conversion Device> The power conversion device provides the power conversion circuit 4 described above. Figure 2 is a plan view showing an example of a power conversion device equipped with a capacitor module. Figure 3 is a cross-sectional view taken along line III-III in Figure 2. Figure 4 is a cross-sectional view showing another example of the power conversion device. Figure 4 corresponds to Figure 3.

[0036] The power converter 20 shown in Figures 2 and 3, and the power converter 20 shown in Figure 4, all include a support member 21, a semiconductor module 22, and a capacitor module 23. In addition to the above elements, the power converter 20 may also include at least one of the following: an input terminal block, an output terminal block, a current sensor, a semiconductor module constituting a converter, and an electrical element constituting a filter circuit.

[0037] In the following, the depth direction of the housing that accommodates the capacitor element is defined as the Z direction. The direction perpendicular to the Z direction is defined as the X direction, and the direction perpendicular to both the X and Z directions is defined as the Y direction. The X, Y, and Z directions are in a positional relationship that is orthogonal to each other. 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 defined as the planar shape. The view from the Z direction is sometimes simply referred to as the planar view.

[0038] In the power converter 20 (power converter 20A) illustrated in Figures 2 and 3, the support member 21 also serves as the metal member 40 of the capacitor module 23. The support member 21 also serves as the capacitor case.

[0039] The support member 21 supports at least a portion of the other elements constituting the power converter 20A. The exemplary support member 21 supports the other elements, a semiconductor module 22 and a capacitor module 23. The semiconductor module 22 and the capacitor module 23 are arranged on one side of the base 211, which will be described later. The support member 21 may be at least a part of the housing that houses the other elements constituting the power converter 20A, i.e., the housing of the power converter 20A, or it may be provided separately from the housing. The support member 21 is formed using a metal material such as aluminum. The support member 21 may be composed of a single member or may be composed of multiple members assembled together. The exemplary support member 21 is an aluminum die-cast product.

[0040] The support member 21 may have a function of cooling other elements that constitute the power converter 20A and are placed on the support member 21. The support member 21 that provides the cooling function may be called a cooler. The exemplary support member 21 comprises a base 211, a cover 212, a side wall 213, and a housing 214. The base 211 is provided with a flow path 215.

[0041] The flow path 215 opens to one surface of the base 211. A refrigerant inlet pipe and a refrigerant outlet pipe (not shown) are connected to the flow path 215. Refrigerant 216 flows through the flow path 215. The example flow path 215 is provided so as to overlap with the semiconductor module 22 and the capacitor module 23 in a plan view. The refrigerant 216 may be a phase-changing refrigerant such as water or ammonia, or a non-phase-changing refrigerant such as ethylene glycol. The refrigerant may be LLC, for example. LLC is an abbreviation for long life coolant.

[0042] The cover 212 closes the opening of the flow path 215. The cover 212 covers the opening of the flow path 215 in the base 211 and is liquid-tightly fixed to the peripheral area of the opening. The cover 212 may have fins extending from the back surface of the cover 212 and immersed in the refrigerant 216 within the flow path 215. Although an example in which the support member 21 includes the cover 212 is shown, the present invention is not limited thereto. The semiconductor module 22 may include a metal member (heat dissipation member) that covers the opening of the flow path 215. Note that the support member 21 may have a heat sink instead of the flow path 215 to provide a cooling function. The heat sink may have fins on the back side.

[0043] The side wall 213 extends in the Z direction from one surface of the base 211. The side wall 213 provides accommodation space for other elements constituting the power conversion device 20A. The side wall 213, together with the base 211 and a part of a side wall 2142 which will be described later, provides accommodation space for the semiconductor module 22.

[0044] The accommodating portion 214 provides a space for accommodating the primary molded body 30 of the capacitor module 23. The accommodating portion 214 forms the accommodating portion 41 of the metal member 40. The accommodating portion 214 is filled with the second resin portion 50 of the capacitor module 23. The accommodating portion 214 is configured to include a part of the base 211. The accommodating portion 214 has a bottom wall 2141 and a side wall 2142. The bottom wall 2141 corresponds to the bottom wall 411 of the accommodating portion 41, and the side wall 2142 corresponds to the side wall 412. The bottom wall 2141 is provided by the base 211. The bottom wall 2141 is a wall portion facing the opening of the accommodating portion 214 among the wall portions that define the accommodation space.

[0045] The side wall 2142 extends in the Z direction from the base 211. The side wall 2142 extends on the same side as the side wall 213. The side wall 2142 forms an annular shape in a plan view. The illustrated side wall 2142 forms a substantially rectangular annular shape in plan view. In the base 211, a portion directly below the side wall 2142 and a portion surrounded by the side wall 2142 form the bottom wall 2141. The side wall 2142A is the side wall 2142 located between the same and the semiconductor module 22 in the X direction. The side wall 2142A corresponds to the side wall 412A.

[0046] The semiconductor module 22 configures the aforementioned upper and lower arm circuit 9, that is, the inverter 6. The semiconductor module 22 may also be referred to as a power module, a semiconductor device, or the like. In the illustrated power converter 20A, one semiconductor module 22 configures the upper and lower arm circuit 9 for one phase. The power converter 20 includes three semiconductor modules 22. The three semiconductor modules 22 are arranged in the Y direction. The semiconductor module 22 and the capacitor module 23 are arranged in the X direction.

[0047] The plurality of semiconductor modules 22, for example, have a common structure with each other. The illustrated semiconductor module 22 includes a main body portion 221 and an external connection terminal protruding from the main body portion 221. The main body portion 221 includes a semiconductor element 222, a sealing body 223, and the like.

[0048] The semiconductor element 222 is formed by forming a switching element on a semiconductor substrate made of a material such as silicon (Si) or a wide bandgap semiconductor having a wider bandgap than silicon. The switching element has a vertical structure such that a main current flows in the plate thickness direction of the semiconductor substrate. The wide bandgap semiconductor is, for example, silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga₂O₃), diamond, or the like.

[0049] The illustrated semiconductor element 222 is formed by forming the aforementioned n-channel MOSFET 11 and diode 12 on a semiconductor substrate made of SiC. The MOSFET 11 has a vertical structure such that a main current flows in the plate thickness direction of the semiconductor element 222 (semiconductor substrate). The semiconductor element 222 has main electrodes (not shown) on both sides in its own plate thickness direction. As the main electrodes, the semiconductor element 222 has a source electrode on the front surface and a drain electrode on the back surface. The source electrode is formed on a part of the front surface. The drain electrode is formed on almost the entire area of the back surface.

[0050] The main current flows between the drain electrode and the source electrode. The semiconductor element 222 has a pad (not shown) on the forming surface of the source electrode, which is a signal electrode. The semiconductor elements 222 are arranged so that their thickness direction is substantially parallel to the Z direction. One semiconductor module 22 includes, as semiconductor elements 222, a semiconductor element 222H that constitutes the upper arm 9H and a semiconductor element 222L that constitutes the lower arm 9L. The semiconductor elements 222H and 222L that constitute one upper and lower arm are aligned in the X direction. The semiconductor module 22 may have one of each of the semiconductor elements 222H and 222L, or it may have multiple of each of the semiconductor elements 222H and 222L.

[0051] The encapsulant 223 encapsulates some of the other elements that make up the semiconductor module 22. The remaining parts of the other elements are exposed outside the encapsulant 223. The encapsulant 223 encapsulates the semiconductor element 222 and some of the external connection terminals. Other parts of each of the external connection terminals protrude outside the encapsulant 223. The encapsulant 223 is made of, for example, resin. The illustrated encapsulant 223 is made of epoxy resin and molded by a transfer molding method. The encapsulant 223 has a substantially rectangular shape in plan. The encapsulant 223 forms the outer casing of the main body 221.

[0052] The sealing body 223 may be formed by potting. The sealing body 223 is filled into a housing space provided by, for example, a support member 21, and seals a semiconductor element 222 or the like that is placed in the housing space.

[0053] The external connection terminals are terminals for electrically connecting the semiconductor module 22 to external equipment. The external connection terminals include a P terminal 224P, an N terminal 224N, and an output terminal 224A, which are main terminals electrically connected to the main electrodes of the semiconductor element 222. The P terminal 224P is electrically connected to the drain electrode of the semiconductor element 222H. The N terminal 224N is electrically connected to the source electrode of the semiconductor element 222L. The output terminal 224A is electrically connected to the connection point between the source electrode of the semiconductor element 222H and the drain electrode of the semiconductor element 222L.

[0054] The P terminal 224P and N terminal 224N extend from the main body 221 toward the capacitor module 23. The P terminal 224P and N terminal 224N protrude outward from the surface of the main body 221 facing the capacitor module 23. The P terminal 224P and N terminal 224N are power terminals electrically connected to the capacitor module 23. The output terminal 224A extends from the main body 221 toward the side opposite to the capacitor module 23. The output terminal 224A protrudes outward from the side opposite to the surface facing the capacitor module 23. The output terminal 224A is a main terminal electrically connected to the winding 3a of the motor generator 3. In addition to the main terminal, the external connection terminals include signal terminals (not shown).

[0055] The semiconductor module 22 includes, in addition to the elements described above, a wiring member (not shown). The wiring member provides a wiring function to electrically connect the main electrode and the main terminal of the semiconductor element 222. The wiring member also provides a heat dissipation function to dissipate heat from the semiconductor element 222. The wiring member may be, for example, a substrate with metal bodies arranged on both sides of an insulating substrate, or a heat sink made of metal. The heat sink may be provided as part of the lead frame. The entire wiring member may be sealed by the sealant 223, or a part of the wiring member may be exposed from the main body 221. Exposing the wiring member can improve heat dissipation.

[0056] The semiconductor module 22 is placed on the support member 21. The main body 221 of the semiconductor module 22 may be thermally connected to the support member 21 via a bonding material such as solder, or it may be thermally connected via a thermal conductive member. The thermal conductive member is sometimes referred to as TIM. TIM is an abbreviation for Thermal Interface Material. GF may also be used as the thermal conductive member. GF is an abbreviation for Gap Filler. Details of the capacitor module 23 will be described later.

[0057] In the power converter 20 (power converter 20B) illustrated in Figure 4, the support member 21 and the metal member 40 of the capacitor module 23 are provided separately. The support member 21 and the capacitor case are provided separately.

[0058] In the power converter 20B, the side wall 213 is provided so as to surround the semiconductor module 22 and the capacitor module 23. The support member 21 does not have a housing portion 214. Instead of a housing portion 214, the support member 21 has a screw receiving portion 217. The screw receiving portion 217 has a screw hole provided in a boss that extends in the Z direction from the support portion 211. In a plan view, the support member 21 has a plurality of screw receiving portions 217 that are distributed amongst each other.

[0059] The capacitor module 23 includes a metal member 40 provided separately from the support member 21. The metal member 40 has a housing portion 41 for housing the primary molded body 30. The mounting portion of the metal member 40 is fixed to a screw receiving portion 217 by a screw 218. The screw 218 is inserted through a through hole (not shown) provided in the mounting portion and screwed into a screw hole in the screw receiving portion 217. The side wall 213 is provided so as to surround the semiconductor module 22 and the capacitor module 23. A heat conductive member 24 is interposed between the bottom wall 411 of the capacitor module 23 and the base 211. The capacitor module 23 is thermally connected to the base 211 via the heat conductive member 24. The heat conductive member 24 is, for example, TIM, GF, etc. The other configurations are the same as those of the power converter 20A.

[0060] <Capacitor Module> The capacitor module 23 provides the smoothing capacitor 5 described above. The capacitor module 23 is electrically connected to the semiconductor module 22 that constitutes the inverter 6 and to an input terminal block (not shown) that electrically connects the smoothing capacitor 5 to the DC power supply 2.

[0061] Figure 5 is a cross-sectional view showing an example of a capacitor module. Figure 5 shows a capacitor module corresponding to Figures 3 and 4. In Figure 5, a part of the capacitor module is shown in a simplified manner. The exemplary capacitor module 23 (capacitor module 23A) comprises a primary molded body 30, a metal member 40, and a second resin part 50. As described above, in the power converter 20A with the configuration shown in Figure 3, the support member 21 also serves as the metal member 40. In the power converter 20B with the configuration shown in Figure 4, the metal member 40 is provided separately from the support member 21.

[0062] The metal member 40 is formed using a metallic material such as aluminum. The metal member 40 has a housing section 41 for housing the primary molded body 30. The housing section 41 has a bottom wall 411 and side walls 412. The housing section 41 forms a so-called capacitor case. The bottom wall 411 is the wall section that defines the housing space and faces the opening of the housing section 41. The side walls 412 extend from the bottom wall 411 in the Z direction. The side walls 412 form an annular shape in plan view. The illustrated side wall 412 forms a roughly rectangular annular shape in plan view. The bottom wall 411 closes one of the opening ends of the side walls 412. Side wall 412A is the side wall 412 located between the metal member 411 and the semiconductor module 22 in the X direction.

[0063] The primary molded body 30 is a molded body formed before sealing by the second resin part 50, that is, before secondary molding. The primary molded body 30 has a capacitor element 31, a busbar 32, and a first resin part 33. The capacitor element 31 is, for example, a film capacitor element. The example capacitor element 31 is made by winding a film around an axis substantially parallel to the Z direction. The capacitor module 23A has at least one capacitor element 31. The capacitor module 23A has only one capacitor element 31.

[0064] The capacitor element 31 has, for example, a roughly rectangular shape in plan. The capacitor element 31 has electrodes (not shown). The electrodes are sometimes referred to as metallicon electrodes. The electrodes include a positive electrode (P electrode) and a negative electrode (N electrode) provided on the side opposite to the P electrode in the Z direction. In the example, the N electrode is provided on the side facing the bottom wall 411, and the P electrode is provided on the side facing the opening.

[0065] The busbar 32 is a metal plate made of a metal with good conductivity, such as Cu. The busbar 32 is connected to the corresponding electrode of the capacitor element 31. The busbar 32 includes a P busbar 32P connected to the P electrode and an N busbar 32N connected to the N electrode. The busbar 32 has a portion covered by the sealing resin, that is, a portion embedded in the sealing resin, and a portion that protrudes outward from the upper surface of the sealing resin. The protruding portion includes a terminal portion that is electrically connected to the power terminal of the semiconductor module 22, etc.

[0066] The illustrated busbar 32 extends in the Z direction from the junction with the corresponding electrode. Portions of the P busbar 32P and N busbar 32N are sealed by the first resin portion 33 and the second resin portion 50, respectively. Other portions of the P busbar 32P and N busbar 32N are sealed by the second resin portion 50. The remaining portions of the P busbar 32P and N busbar 32N protrude outward from the upper surface 501 of the second resin portion 50. The protruding portions of the P busbar 32P and N busbar 32N are electrically connected to the corresponding power terminals of the semiconductor module 22. The protruding portions may extend to a position overlapping the power terminals and be bonded to them. The protruding portions may also be connected to the power terminals via a connecting busbar provided separately from the busbar 32. The connecting busbar electrically connects the busbar 32 to the power terminals.

[0067] The example projection includes a Z-direction extension and an X-direction extension. The Z-direction extension is the portion extending in the Z direction from the upper surface 501. The X-direction extension extends in the X direction from the upper end of the Z-direction extension. The X-direction extension extends in the X direction across the side wall 412A. The X-direction extension is located near the upper end of the side wall 412A. The projection may have only the Z-direction extension. In addition to the Z-direction extension and X-direction extension described above, the projection may also include a Z-direction extension extending in the Z direction toward the base 211 from one end of the X-direction extension.

[0068] As illustrated, the primary molded body 30 may have an insulating member 34. The insulating member 34 is interposed between the P busbar 32P and the N busbar 32N, insulating and separating the P busbar 32P and the N busbar 32N. The insulating member 34 is, for example, a resin molded body. In order to reduce inductance, the P busbar 32P and the N busbar 32N are arranged so that their plate surfaces face each other for a portion of their total length, with the insulating member 34 interposed between the opposing surfaces.

[0069] The first resin part 33 seals the capacitor element 31. The first resin part 33 covers the entire capacitor element 31. The first resin part 33 seals a part of the busbar 32. The first resin part 33 is a resin molded body. The first resin part 33 is formed using an electrically insulating resin material. The example first resin part 33 is formed using a thermosetting resin. The first resin part 33 is formed using a heat-curing epoxy resin. The first resin part 33 has a substantially rectangular shape in plan. The first resin part 33 has a substantially rectangular parallelepiped shape. The first resin part 33 has a bottom surface 331, a side surface 332, and a top surface 333. The bottom surface 331 is the surface facing the bottom wall 411. The side surface 332 is the surface facing the side wall 412, including the side wall 412A. The top surface 333 is the surface facing the opening.

[0070] The first resin part 33 is formed to a size such that at least a portion of it fits inside the housing part 41. The bottom surface 331 of the first resin part 33 has a predetermined gap between it and the bottom wall 411, and the side surface 332 has a predetermined gap between it and the side wall 412. The second resin part 50 fills the gaps. The top surface 333 may be located closer to the bottom wall 411 than the opening end of the housing part 41, i.e., on the inside, or it may be located outside the opening end. In the example, the entire first resin part 33 is placed inside the housing part 41. The top surface 333 is located on the inside of the opening end.

[0071] The first resin part 33 may be configured to ensure various properties necessary for protecting the capacitor element 31, such as moisture barrier properties and electrical insulation properties, in its state before being covered by the second resin part 50, that is, in its state as the primary molded body 30. The first resin part 33 may also be configured to ensure barrier properties, electrical insulation properties, etc., by the first resin part 33 and the second resin part 50 when it is covered by the second resin part 50.

[0072] The second resin portion 50 is filled into the housing portion 41. The second resin portion 50 is in close contact with the bottom wall 411 and the side wall 412, including the side wall 412A. The second resin portion 50 seals the primary molded body 30. The second resin portion 50 is formed by comprising an electrically insulating resin material.

[0073] The illustrated second resin portion 50 is formed using a resin material with a lower glass transition temperature than the first resin portion 33. The second resin portion 50 is formed using a material with a lower elastic modulus than the first resin portion 33. The second resin portion 50 is formed using a room-temperature curable resin. The second resin portion 50 includes, for example, a room-temperature curable epoxy resin, a room-temperature curable silicone resin, and a room-temperature curable urethane resin. The second resin portion 50 covers the entire capacitor element 31 and the first resin portion 33, respectively. The second resin portion 50 seals a portion of the busbar 32. The second resin portion 50 fills the entire space of the housing portion 41. The upper surface 501 of the second resin portion 50 is substantially flush with the upper end 4121 of the side wall 412.

[0074] Figures 6 and 7 are cross-sectional views showing another example of a capacitor module. The capacitor module 23 shown in Figure 6 (capacitor module 23B) and the capacitor module 23 shown in Figure 7 (capacitor module 23C) have different arrangements of the capacitor elements 31. In capacitor modules 23B and 23C, the capacitor elements 31 are formed by winding a film around an axis substantially parallel to the X direction. The N electrode of the capacitor element is provided on the side facing the side wall 412A, and the P electrode is provided on the side opposite to the N electrode. The busbar 32P extends in the Z direction from the junction with the P electrode. The busbar 32N extends in the Z direction from the junction with the N electrode.

[0075] In capacitor module 23B, similar to capacitor module 23A, the second resin portion 50 covers the entire capacitor element 31 and the first resin portion 33 of the primary molded body 30. The upper surface 501 of the second resin portion 50 is substantially flush with the upper end 4121 of the side wall 412.

[0076] In capacitor module 23C, the second resin portion 50 covers a part of the first resin portion 33. The illustrated second resin portion 50 covers the entire bottom surface 331 and side surface 332 of the first resin portion 33. The top surface 501 of the second resin portion 50 is located inward from the upper end 4121 and is substantially flush with the top surface 333 of the first resin portion 33. The top surface 333 is exposed from the second resin portion 50. The busbar 32 is not sealed by the second resin portion 50, but is sealed only by the first resin portion 33. The other configurations of capacitor modules 23B and 23C are the same as those of capacitor module 23A.

[0077] <Manufacturing Method for Capacitor Modules> Figure 8 shows an example of a manufacturing method for capacitor modules. In Figure 8, capacitor module 23B is shown as an example. Figure 9 shows an example of heat curing.

[0078] First, as shown in Figure 8(a), the capacitor element 31 is encapsulated in resin to form a primary molded body 30. The first resin part 33 in this example is a thermosetting resin. A busbar 32 is joined to the electrodes of the capacitor element 31, and this joined body is placed in the mold. Then, the resin injected into the mold to cover the joined body is heated and cured to form the first resin part 33, and subsequently the primary molded body 30. For example, the primary molded body 30 may be formed using a potting method.

[0079] For example, as shown in Figure 9, multiple primary molded bodies 30 before curing may be placed in a constant temperature bath 90 and cured all at once. For convenience, the mold is omitted in Figure 9. The curing process may also be carried out by sequentially feeding the primary molded bodies 30 into a transport-type heating furnace (not shown). Either a batch type or a continuous furnace type may be used. After the curing process, the primary molded bodies 30 that have been cured are obtained by removing them from the mold.

[0080] Next, as shown in Figure 8(b), the primary molded body 30 is positioned and placed in the housing portion 41 of the metal member 40. In the case of the example primary molded body 30, the busbar 32 is grasped by a device (not shown) and the primary molded body 30 is positioned relative to the housing portion 41 such that the bottom surface 331 does not contact the bottom wall 411 and the side surface 332 does not contact the side wall 412. The primary molded body 30 is positioned away from the bottom wall 411 and the side wall 412.

[0081] Next, as shown in Figure 8(c), resin is filled into the housing 41 to form the second resin part 50. The second resin part 50 in this example is a room-temperature curing resin. Resin is injected into the housing 41 so as to seal a part of the primary molded body 30, specifically the capacitor element 31 and the entirety of the first resin part 33. The injected resin is interposed between the bottom surface 331 and the bottom wall 411 of the first resin part 33, and between the side surface 332 and the side wall 412. In this state, the resin is cured at room temperature to form the second resin part 50. As a result, the capacitor module 23B can be formed. Other capacitor modules 23 (23A, 23C) can also be formed by the same manufacturing method.

[0082] <Summary of the First Embodiment> The capacitor module 23 of this embodiment comprises a primary molded body 30, a metal member 40, and a second resin part 50. The primary molded body 30 has a capacitor element 31 and a first resin part 33 that seals the capacitor element 31. The metal member 40 has a housing part 41 that houses the primary molded body 30. The second resin part 50 is filled into the housing part 41 and seals the primary molded body 30. The second resin part 50 is interposed at least between the bottom surface 331 of the first resin part 33 and the bottom wall 411 of the housing part 41, and between the side surface 332 of the first resin part 33 and the side wall 412 of the housing part 41.

[0083] In this way, the sealing resin of the capacitor element 31 is divided into a first resin part 33 and a second resin part 50. The first resin part 33, together with the capacitor element 31, constitutes the primary molded body 30. The curing shrinkage of the first resin part 33 is completed before it is covered by the second resin part 50. The second resin part 50 fills the housing part 41 and seals the primary molded body 30. At the interface between the sealing resin and the housing part 41, the shrinkage stress of the first resin part 33 does not act, but the shrinkage stress of the second resin part 50 acts. Therefore, compared to a configuration in which the sealing resin is made of a single material, the shrinkage stress acting at the interface with the housing part 41 can be reduced. This makes it possible to suppress the peeling of the resin from the wall surface of the housing part 41.

[0084] As illustrated, the second resin portion 50 may be positioned to cover the upper surface 333 of the first resin portion 33. Since the second resin portion 50 covers the entire first resin portion 33, the performance required of the capacitor element 31 can be improved. For example, barrier properties can be improved. For example, electrical insulation properties can be improved.

[0085] As illustrated, the first resin part 33 and the second resin part 50 may be formed using different materials. By allowing the selection of different materials, for example, a material suitable for the performance required for the capacitor element 31 can be used for the first resin part 33, and a material that easily suppresses peeling from the wall surface of the housing part 41 can be used for the second resin part 50. Even if the materials are different, the shrinkage stress of the first resin part 33 does not act at the interface with the housing part 41, but the shrinkage stress of the second resin part 50 acts. Therefore, it is possible to suppress the peeling of the resin from the wall surface of the housing part 41.

[0086] As illustrated, the first resin part 33 may be made of a thermosetting resin and the second resin part 50 may be made of a room-temperature curing resin. Room-temperature curing resins shrink less than thermosetting resins that harden when heated. By using a room-temperature curing resin as the second resin part 50, peeling from the housing part 41 can be effectively suppressed.

[0087] As illustrated, the glass transition temperature (Tg) of the second resin portion 50 may be set lower than that of the first resin portion 33. The second resin portion 50 becomes softer at a lower temperature than the first resin portion 33. Therefore, delamination from the housing portion 41 can be effectively suppressed by stress relaxation.

[0088] As illustrated, the elastic modulus of the second resin part 50 may be set to be lower than that of the first resin part 33. The second resin part 50 is softer than the first resin part 33. Therefore, stress relaxation can effectively suppress peeling from the housing part 41.

[0089] The manufacturing method of the capacitor module of this embodiment involves first encapsulating the capacitor element 31 in resin to form a primary molded body 30. Next, the primary molded body 30 is positioned and placed in the housing portion 41 of the metal member 40. Then, resin is filled into the housing portion 41 so as to be interposed at least between the bottom surface 331 of the first resin portion 33 and the bottom wall 411 of the housing portion 41, and between the side surface 332 and the side wall 412, thereby forming a second resin portion 50 that encapsulates the primary molded body 30.

[0090] Thus, the primary molded body 30 is first formed. Next, with the primary molded body 30 placed in the housing 41, resin is filled to form the second resin part 50. The curing shrinkage of the first resin part 33 is completed before the primary molded body 30 is placed in the housing 41. Therefore, the shrinkage stress of the first resin part 33 does not act at the interface with the housing 41, but the shrinkage stress of the second resin part 50 acts there. Thus, compared to a configuration in which a single resin is filled into the housing with the capacitor element placed in it and then cured, the shrinkage stress acting at the interface with the housing 41 is reduced, and the peeling of the resin from the wall surface of the housing 41 can be suppressed.

[0091] Furthermore, the primary molded body 30 is subjected to heat curing treatment. Therefore, when the primary molded body 30 is placed in a constant temperature bath 90 for heat curing, as illustrated in Figure 9, it is not necessary to place the metal member 40, or the support member 21 which also serves as the metal member 40, into the constant temperature bath 90. Thus, more products can be placed in the constant temperature bath 90 and subjected to heat curing treatment all at once. For example, production efficiency can be improved. In the case of a continuous furnace, the size of the products placed in the furnace can be reduced. For example, the size of the furnace can be reduced.

[0092] The power converter 20 of this embodiment includes a semiconductor module 22 and a capacitor module 23. The capacitor module 23 has the configuration described above. That is, the encapsulating resin of the capacitor element 31 is divided into a first resin part 33 and a second resin part 50. The first resin part 33 together with the capacitor element 31 constitutes the primary molded body 30. The curing shrinkage of the first resin part 33 is completed before it is covered by the second resin part 50. Therefore, the shrinkage stress of the first resin part 33 does not act on the interface between the encapsulating resin and the housing part 41, but the shrinkage stress of the second resin part 50 acts on it. This reduces the shrinkage stress acting on the interface with the housing part 41 and suppresses the peeling of the resin from the wall surface of the housing part 41.

[0093] As illustrated, the metal member 40 may also be a support member 21 that supports the semiconductor module 22. In other words, the support member 21 may also serve as the metal member 40. In a configuration in which the capacitor element 31 is resin-sealed in the housing portion 214 of the support member 21, it is possible to suppress the peeling of the resin from the wall surface of the housing portion 41. In addition, the heat generated by the capacitor element 31 can be directly dissipated to the support member 21. The heat generated by the capacitor element 31 can be dissipated to the bottom wall 2141 and the side wall 2142. Therefore, heat dissipation can be improved. Since the support member 21 also serves as the metal member 40, the configuration can be simplified, and for example, the number of parts can be reduced.

[0094] As illustrated, the metal member 40 may be fixed to the support member 21 that supports the semiconductor module 22 and the capacitor module 23. In other words, the metal member 40 may be provided separately from the support member 21. In a configuration in which the capacitor element 31 is resin-sealed in the housing portion 41 of the metal member 40 fixed to the support member 21, it is possible to suppress the peeling of the resin from the wall surface of the housing portion 41. In addition, the heat generated by the capacitor element 31 can be directly dissipated to the support member 21. The heat generated by the capacitor element 31 can be dissipated to the support member 21 via the metal member 40.

[0095] <Modification> The number of capacitor elements 31 provided in the capacitor module 23 is not limited to one. Multiple capacitor elements 31 may be provided. For example, as shown in Figure 10, the capacitor module 23 (capacitor module 23D) may include a primary molded body 30 having multiple capacitor elements 31. In Figure 10, three capacitor elements 31 are integrally sealed by the first resin part 33.

[0096] As shown in Figure 11, the capacitor module 23 (capacitor module 23E) may comprise a plurality of capacitor elements 31, each individually sealed by a first resin portion 33. In other words, it may comprise a plurality of primary molded bodies 30. However, the busbar 32 is common to the plurality of primary molded bodies 30. In Figure 11, the capacitor module 23E comprises three primary molded bodies 30, and the three capacitor elements 31 are connected to a common busbar 32.

[0097] The arrangement of the housing section 214 (41), that is, the arrangement of the capacitor module 23, is not limited to the example described above. For example, as in the power converter 20 (power converter 20C) shown in Figure 12, the opening of the housing section 41 (214) of the capacitor module 23 may be arranged so that it faces the semiconductor module 22 in the Z direction, which is the depth direction of the housing section 41 (214). In Figure 12, as in Figure 3, the housing section 41 is constructed using a part of the support member 21. The base 211 also serves as a part of the side wall 412 of the housing section 41. This arrangement simplifies the routing of the busbar 32. For example, the length of the wiring portion that electrically connects the capacitor module 23 and the semiconductor module 22 can be shortened, thereby reducing the inductance.

[0098] The power converter 20C shown in Figure 12 can be formed, for example, by the manufacturing method shown in Figure 13. First, as shown in Figure 13(a), the support member 21 is positioned such that the bottom wall 411 of the housing 41 is vertically downward and the opening of the housing 41 is vertically upward. Then, the primary molded body 30 is placed inside the housing 41 and the room-temperature curable resin constituting the second resin part 50 is injected into the housing 41. After curing at room temperature, as shown in Figure 13(b), the base 211 is positioned vertically downward. Then, the semiconductor module 22 is placed on the base 211 and the power terminals of the semiconductor module 22 are joined to the corresponding busbars 32. In this way, after the capacitor module 23 is formed, the semiconductor module 22 may be mounted by laying it on its side.

[0099] (Second Embodiment) This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be applied by reference. In the preceding embodiment, the second resin part was constructed using a room-temperature curable resin. Alternatively, the second resin part may be constructed using a resin material with better thermal conductivity.

[0100] Figure 14 is a cross-sectional view showing an example of a capacitor module according to this embodiment. Figure 14 corresponds to Figure 6. In the capacitor module 23 (capacitor module 23F) shown in Figure 14, the second resin part 50 (second resin part 50A) is made of a room-temperature thermal conductive encapsulant, which is made by adding a filler with good thermal conductivity to a room-temperature curable resin. The filler includes, for example, at least one of a metal filler, a ceramic filler, or a carbon-based filler. As a result, the second resin part 50A has better thermal conductivity than the second resin part 50 described in the prior embodiment. The second resin part 50A has better thermal conductivity than the first resin part 33. The other configurations are the same as those described in the prior embodiment.

[0101] <Summary of the second embodiment> As illustrated, the thermal conductivity of the second resin part 50A may be made higher than that of the first resin part 33. This suppresses the peeling of the resin from the wall surface of the housing part 41 and improves heat dissipation.

[0102] Aside from the second resin part 50A, which has excellent heat dissipation properties, various configurations described in the prior embodiment can be applied to the other components.

[0103] (Third Embodiment) This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be referenced. In the preceding embodiment, the second resin part was constructed using a different material from the first resin part. Alternatively, the second resin part may be constructed using the same material as the first resin part.

[0104] Figure 15 is a cross-sectional view showing an example of a capacitor module according to this embodiment. Figure 15 corresponds to Figure 6. In the capacitor module 23 (capacitor module 23G) shown in Figure 15, the second resin part 50 (second resin part 50B) is made of the same material as the first resin part 33. The illustrated first resin part 33 and second resin part 50B are formed using a thermosetting resin, for example, a heat-curing epoxy resin. The other configurations are the same as those described in the prior embodiment.

[0105] <Summary of the Third Embodiment> As illustrated, the first resin part 33 and the second resin part 50B may be formed using the same material. Since the curing shrinkage of the first resin part 33 is completed before it is covered by the second resin part 50B, even when the same material is used, only the shrinkage stress of the second resin part 50B acts on the interface between the sealing resin and the housing part 41. Therefore, compared to a configuration in which the sealing resin is made of a single material, the shrinkage stress acting on the interface with the housing part 41 can be reduced, and peeling of the resin from the wall surface of the housing part 41 can be suppressed.

[0106] Aside from the second resin part 50B, which is made of the same material as the first resin part 33, various configurations described in the prior embodiment can be applied to the other components.

[0107] (Fourth Embodiment) This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be used by reference. In the preceding embodiment, the gap between the first resin part and the wall surface of the housing part was secured by suspending the primary molded body. Alternatively, the gap with respect to the wall surface of the housing part may be secured by providing a projection on the first resin part.

[0108] Figure 16 is a cross-sectional view showing an example of a capacitor module according to this embodiment. Figure 16 corresponds to Figure 6. In the capacitor module 23 (capacitor module 23H) shown in Figure 16, the first resin portion 33 has a bottom projection 334.

[0109] The bottom projections 334 are portions that support the bottom surface 331 at a position away from the inner surface of the bottom wall 411, such that the second resin portion 50 is interposed between the bottom surface 331 and the bottom wall 411. The bottom projections 334 protrude from the bottom surface 331 toward the bottom wall 411. The bottom projections 334 are connected to a part of the bottom surface 331 and protrude from the bottom surface 331, contacting a part of the bottom wall 411. The number and arrangement of the bottom projections 334 are not particularly limited. Any number and arrangement that can stably support the primary molded body 30 on the bottom wall 411 is acceptable. In the example, the bottom projections 334 are provided at each of the four corners of the bottom surface 331, which has a substantially planar shape. The other configurations are the same as those described in the prior embodiment.

[0110] <Summary of the Fourth Embodiment> As illustrated, the first resin portion 33 may have a bottom projection 334 that is connected to a part of the bottom surface 331 of the first resin portion 33 and protrudes from the bottom surface 331 to contact a part of the bottom wall 411 of the housing portion 41. With this, when the primary molded body 30 is positioned and placed in the housing portion 41, a gap can be secured between the bottom surface 331 and the bottom wall 411 that can be filled with resin. In addition, by positioning the primary molded body 30 so that the bottom projection 334 contacts the inner surface of the bottom wall 411, the position in the Z direction relative to the housing portion 41 can be determined.

[0111] In order to secure a gap between the first resin part 33 and the wall surface of the housing part 41, an insulating member that contacts the first resin part 33 and the wall surface of the housing part 41 may be placed separately from the primary molded body 30. If a bottom projection 334 is provided, a gap can be secured without placing a separate insulating member.

[0112] <Modification> As shown in Figure 17, the capacitor module 23 (capacitor module 23I) may have side projections 335. The side projections 335 are connected to a part of the side surface 332 of the first resin portion 33 and protrude from the side surface 332 toward the side wall 412 of the housing portion 41. The side projections 335 may be in contact with a part of the side wall 412. In the example capacitor module 23I, side projections 335 are provided on each of the side surfaces 332. With this, when the primary molded body 30 is positioned and placed in the housing portion 41, a gap can be secured between the side surface 332 and the side wall 412 that can be filled with resin. In addition, the position of the primary molded body 30 in a direction perpendicular to the Z direction with respect to the housing portion 41 can be determined.

[0113] In the capacitor module 23I, the first resin portion 33 has a bottom projection 334 and a side projection 335. Alternatively, the first resin portion 33 may have only the side projection 335.

[0114] Aside from the first resin portion 33 having a protrusion, various configurations described in the prior embodiment can be applied to the other components.

[0115] (Fifth Embodiment) This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be applied by reference. The capacitor module may further include an insulating member interposed between the second resin part and the wall surface of the housing part.

[0116] Figure 18 is a cross-sectional view showing an example of a capacitor module according to this embodiment. Figure 18 corresponds to Figure 5. The capacitor module 23 (capacitor module 23J) shown in Figure 18 includes an insulating member 60. The insulating member 60 is formed using an electrical insulating material. The insulating member 60 has better insulating properties than the second resin part 50. The insulating member 60 is arranged on at least a part of the wall surface of the housing part 41. The insulating member 60 is interposed between at least a part of the wall surface of the second resin part 50 and the housing part 41.

[0117] In the capacitor module 23J, the insulating member 60 is arranged throughout the entire area between the second resin part 50 and the wall surface of the housing part 41. The insulating member 60 is arranged across the entire wall surface of the housing part 41. The insulating member 60 has a base part 61 and an extension part 62. The base part 61 is arranged inside the housing part 41 and interposed between the second resin part 50 and the housing part 41. The extension part 62 extends from the base part 61 to the outside of the second resin part 50. The extension part 62 includes a portion that overlaps with the upper end 4121 of the side wall of the housing part 41. The extension part 62 is interposed between the busbar 32 and the upper end 4121. The other configurations are the same as those described in the prior embodiment.

[0118] <Summary of the Fifth Embodiment> As illustrated, an insulating member 60 may be provided interposed between the second resin part and the housing part. This further enhances the insulating properties. Even if at least one of the first resin part 33 and the second resin part 50 deteriorates, the insulating properties can be ensured by the insulating member 60.

[0119] As illustrated, the insulating member 60 may be arranged within the housing portion 41 and have a base portion 61 interposed between the second resin portion 50 and the housing portion 41, and an extension portion 62 extending from the base portion 61. The extension portion 62 may include a portion that overlaps with the upper end 4121 of the side wall 412. Because the extension portion 62 is interposed between the busbar 32 and the upper end 4121, the busbar 32 can be positioned closer to the upper end 4121. This makes it possible to reduce the size of the capacitor module 23, and consequently the power converter 20, in the Z direction.

[0120] <Modification> The arrangement of the insulating member 60 is not limited to the examples described above. For example, as in the power converter 20 (power converter 20D) shown in Figure 19, the base 61 may be placed only in a part of the space between the second resin part 50 and the wall surface of the housing part 41 (214). The insulating properties may be improved by considering the positions of the electrodes and busbars 32 of the capacitor element 31 and placing the base 61 on at least a part of the wall surface facing the electrodes and busbars.

[0121] As shown in the power converter 20D, the extension portion 62 may be provided on the outer surface of the side wall 412A (2142A). The extension portion 62 may be extended to a position that overlaps with the power terminals of the semiconductor module 22 in a plan view. In the power converter 20D, the extension portion 62 includes an X-direction extension portion that covers the upper end of the side wall 412A, a Z-direction extension portion that extends downward along the outer surface of the side wall 412A, and an X-direction extension portion that extends along one surface of the base 211.

[0122] With the exception of the insulating member 60, various configurations described in the prior embodiment can be applied to the other components.

[0123] (Sixth Embodiment) This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be incorporated by reference. The primary molded body may further include an insulating portion disposed on the surface of the first resin portion.

[0124] Figure 20 is a cross-sectional view showing an example of a capacitor module according to this embodiment. Figure 20 corresponds to Figure 6. In the capacitor module 23 (capacitor module 23K) shown in Figure 20, the primary molded body 30 has an insulating portion 35. The insulating portion 35 is located on at least a part of the surface of the first resin portion 33. The insulating portion 35 has better barrier properties than the first resin portion 33.

[0125] The example insulating portion 35 is formed by wrapping a barrier film, which is made by depositing AL2O3, SiO2, etc., onto a resin film such as PET, around the first resin portion 33. PET is an abbreviation for Polyethylene Terephthalate. The insulating portion 35 is arranged to cover the entire bottom surface 331 and side surface 332 of the first resin portion 33. The other configurations are the same as those described in the first embodiment.

[0126] <Summary of the 6th Embodiment> As illustrated, the primary molded body 30 may have an insulating portion 35 disposed on the surface of the first resin portion 33. By providing an insulating portion 35 with excellent barrier properties, the first resin portion 33 can be made smaller by the amount of the insulating portion 35. In other words, the size of the primary molded body 30 can be reduced.

[0127] With the exception of the insulating portion 35, various configurations described in the prior embodiment can be applied to the other components.

[0128] (Other Embodiments) The disclosures in this specification and drawings are not limited to the exemplary embodiments. The disclosures include the exemplary embodiments and variations thereof by those skilled in the art. For example, the disclosures are not limited to combinations of parts and / or elements shown in the embodiments. The disclosures are implementable in a variety of combinations. The disclosures may have additional parts that can be added to the embodiments. The disclosures include those in which parts and / or elements of an embodiment have been omitted. The disclosures include substitutions or combinations of parts and / or elements between one embodiment and another. The scope of the disclosed technical areas is not limited to the descriptions of the embodiments. Some of the scope of the disclosed technical areas are indicated by the descriptions of the claims and should be understood to include all modifications within the meaning and scope equivalent to the descriptions of the claims.

[0129] The disclosures in the specification and drawings are not limited by the claims. The disclosures in the specification and drawings encompass the technical ideas described in the claims and extend to a wider and more diverse range of technical ideas than those described in the claims. Therefore, a variety of technical ideas can be extracted from the disclosures in the specification and drawings without being bound by the claims.

[0130] When an element or layer is referred to as “on top of,” “connected to,” “linked to,” or “joined,” it may be directly on top of, connected to, or joined to another element or layer, and there may also be an intervening element or layer. In contrast, when an element is referred to as “directly on top of,” “directly connected to,” “directly linked to,” or “directly joined to” another element or layer, there is no intervening element or layer. Other words used to describe relationships between elements should be interpreted in a similar manner (e.g., “between” vs. “directly between,” “adjacent” vs. “directly adjacent,” etc.). As used in this specification, the term “and / or” includes any combination and all combinations relating to one or more of the enumerated items in question. That is, the statement A and / or B means at least one of A and B.

[0131] Spatially relative terms such as “inside,” “outside,” “back,” “below,” “low,” “above,” and “high” are used here to facilitate descriptions of the relationship between one element or feature and other elements or features, as illustrated. Spatially relative terms may be intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, if the device in the drawing is turned upside down, an element described as “below” or “directly below” another element or feature will be oriented “above” the other element or feature. Thus, the term “below” can encompass both up and down orientations. The device may also be oriented in other directions (it may be rotated 90 degrees or in other directions), and the spatially relative descriptors used in this specification will be interpreted accordingly.

[0132] (Disclosure of Technical Ideas) This specification discloses several technical ideas as described in the following paragraphs. Some paragraphs may be written in a multiple dependent form, where subsequent paragraphs optionally refer to preceding paragraphs. Furthermore, some paragraphs may be written in a multiple dependent form, where they refer to other multiple dependent forms. These paragraphs written in multiple dependent forms define several technical ideas.

[0133] <Technical Concept 1> A capacitor module comprising: a primary molded body (30) having a capacitor element (31) and a first resin part (33) that seals the capacitor element; a metal member (40) having a housing part (41) that houses the primary molded body; and a second resin part (50) that is filled in the housing part and seals the primary molded body, wherein the second resin part is interposed at least between the bottom surface of the first resin part and the bottom wall of the housing part, and between the side surface of the first resin part and the side wall of the housing part.

[0134] <Technical Concept 2> The capacitor module described in Technical Concept 1, wherein the second resin part covers the upper surface of the first resin part.

[0135] <Technical Concept 3> A capacitor module according to Technical Concept 1 or Technical Concept 2, wherein the first resin part and the second resin part are formed using different materials from each other.

[0136] <Technical Concept 4> The capacitor module according to Technical Concept 3, wherein the first resin part is formed using a thermosetting resin, and the second resin part is formed using a room-temperature curing resin.

[0137] <Technical Concept 5> The capacitor module according to Technical Concept 3 or Technical Concept 4, wherein the second resin part has a lower glass transition temperature than the first resin part.

[0138] <Technical Concept 6> The capacitor module described in any one of Technical Concepts 3 to 5, wherein the second resin part has a lower elastic modulus than the first resin part.

[0139] <Technical Concept 7> The capacitor module described in any one of Technical Concepts 3 to 6, wherein the second resin part has a higher thermal conductivity than the first resin part.

[0140] <Technical Concept 8> A capacitor module according to Technical Concept 1 or Technical Concept 2, wherein the first resin part and the second resin part are formed using the same material.

[0141] <Technical Concept 9> The capacitor module according to any one of Technical Concepts 1 to 8, wherein the first resin part has a bottom projection (334) that is connected to a part of the bottom surface of the first resin part, protrudes from the bottom surface and contacts a part of the bottom wall of the housing part.

[0142] <Technical Concept 10> The capacitor module according to any one of Technical Concepts 1 to 9, wherein the first resin part has a side projection (335) that is connected to a part of the side surface of the first resin part and protrudes from the side surface toward the side wall of the housing part.

[0143] <Technical Concept 11> A capacitor module according to any one of technical concepts 1 to 10, comprising an insulating member (60) interposed between the second resin part and the housing part.

[0144] <Technical Concept 12> The capacitor module according to technical concept 11, wherein the insulating member is disposed within the housing and has a base portion (61) interposed between the second resin portion and the housing, and an extended portion (62) extending from the base portion and including a portion that overlaps with the upper end of the side wall of the housing.

[0145] <Technical Concept 13> The capacitor module according to any one of Technical Concepts 1 to 12, wherein the primary molded body has an insulating portion (35) disposed on the surface of the first resin portion.

[0146] <Technical Concept 14> A method for manufacturing a capacitor module, comprising: a step of resin-encapsulating a capacitor element (31) to form a primary molded body (30); a step of positioning and arranging the primary molded body in a housing portion (41) of a metal member (40); and a step of filling the housing portion with resin such that it is interposed at least between the bottom surface of the first resin portion (33) that encapsulates the capacitor element and the bottom wall of the housing portion, and between the side surface of the first resin portion and the side wall of the housing portion, thereby forming a second resin portion (50) that encapsulates the primary molded body.

[0147] <Technical Concept 15> A power conversion device comprising: a semiconductor module (22) having a semiconductor element (222); a capacitor module (23) electrically connected to the semiconductor module, wherein the capacitor module comprises: a primary molded body (30) having a capacitor element (31) and a first resin part (33) that seals the capacitor element; a metal member (40) having a housing part (41) that houses the primary molded body; and a second resin part (50) that is filled in the housing part and seals the primary molded body, wherein the second resin part is interposed at least between the bottom surface of the first resin part and the bottom wall of the housing part, and between the side surface of the first resin part and the side wall of the housing part.

[0148] <Technical Concept 16> The power conversion device according to technical concept 15, wherein the metal member is a support member for supporting the semiconductor module.

[0149] <Technical Concept 17> The power conversion device according to technical concept 15, comprising a support member (21) that supports the semiconductor module and the capacitor module, wherein the metal member is fixed to the support member.

Claims

1. A capacitor module comprising: a primary molded body (30) having a capacitor element (31) and a first resin part (33) that seals the capacitor element; a metal member (40) having a housing part (41) that houses the primary molded body; and a second resin part (50) that fills the housing part and seals the primary molded body, wherein the second resin part is interposed at least between the bottom surface of the first resin part and the bottom wall of the housing part, and between the side surface of the first resin part and the side wall of the housing part.

2. The capacitor module according to claim 1, wherein the second resin part covers the upper surface of the first resin part.

3. The capacitor module according to claim 1 or claim 2, wherein the first resin part and the second resin part are formed using different materials from each other.

4. The capacitor module according to claim 3, wherein the first resin portion is formed using a thermosetting resin, and the second resin portion is formed using a room-temperature curing resin.

5. The capacitor module according to claim 3, wherein the second resin portion has a lower glass transition temperature than the first resin portion.

6. The capacitor module according to claim 3, wherein the second resin portion has a lower elastic modulus than the first resin portion.

7. The capacitor module according to claim 3, wherein the second resin portion has a higher thermal conductivity than the first resin portion.

8. The capacitor module according to claim 1 or claim 2, wherein the first resin part and the second resin part are formed using the same material.

9. The capacitor module according to claim 1, wherein the first resin portion has a bottom projection (334) that is connected to a part of the bottom surface of the first resin portion and protrudes from the bottom surface and contacts a part of the bottom wall of the housing portion.

10. The capacitor module according to claim 1 or claim 9, wherein the first resin portion has a side projection (335) that is connected to a part of the side surface of the first resin portion and protrudes from the side surface toward the side wall of the housing portion.

11. The capacitor module according to claim 1, further comprising an insulating member (60) interposed between the second resin portion and the housing portion.

12. The capacitor module according to claim 11, wherein the insulating member is disposed within the housing and has a base portion (61) interposed between the second resin portion and the housing, and an extended portion (62) extending from the base portion and including a portion that overlaps with the upper end of the side wall of the housing.

13. The capacitor module according to claim 1, wherein the primary molded body has an insulating portion (35) disposed on the surface of the first resin portion.

14. A method for manufacturing a capacitor module, comprising: a step of resin-encapsulating a capacitor element (31) to form a primary molded body (30); a step of positioning and arranging the primary molded body in a housing portion (41) of a metal member (40); and a step of filling the housing portion with resin so as to be interposed at least between the bottom surface of the first resin portion (33) that encapsulates the capacitor element and the bottom wall of the housing portion, and between the side surface of the first resin portion and the side wall of the housing portion, thereby forming a second resin portion (50) that encapsulates the primary molded body.

15. A power conversion device comprising: a semiconductor module (22) having a semiconductor element (222); a capacitor module (23) electrically connected to the semiconductor module, wherein the capacitor module comprises: a primary molded body (30) having a capacitor element (31) and a first resin part (33) that seals the capacitor element; a metal member (40) having a housing part (41) that houses the primary molded body; and a second resin part (50) that fills the housing part and seals the primary molded body, wherein the second resin part is interposed at least between the bottom surface of the first resin part and the bottom wall of the housing part, and between the side surface of the first resin part and the side wall of the housing part.

16. The power conversion device according to claim 15, wherein the metal member is a support member for supporting the semiconductor module.

17. The power conversion device according to claim 15, comprising a support member (21) for supporting the semiconductor module and the capacitor module, wherein the metal member is fixed to the support member.

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