Insulating structure of electronic component

Abstract

To provide an insulating structure for electronic components that can ensure their insulation through a simple method.SOLUTION: An insulating structure of electronic component 10 in which at least a portion of the high-voltage area where high voltage from a conductor 14 is applied is exposed, ensures insulation between a metal protective member 50, which protects the electronic component 10, and the electronic component 10 by means of an insulating member 30 facing the electronic component 10 and an elastic member 42 attached to the insulating member 30 in a state where the electronic component 10 is supported on the substrate 20.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an insulating structure for an electronic component. [Background technology]

[0002] In recent years, automobiles equipped with motors as a driving source (such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), and fuel cell electric vehicles (FCEVs)) have become widespread. Hereinafter, these automobiles will be collectively referred to as electric vehicles. Electric vehicles have many devices that require cooling, such as motors (including internal combustion engines such as engines), batteries, air conditioners, and ECUs. Therefore, cooling circuits that circulate coolant, refrigerant, and oil are configured to cool these devices. In such cooling circuits, pumps are used to circulate the coolant and refrigerant.

[0003] Patent Document 1 discloses an electric compressor equipped with an inverter assembly. The inverter assembly includes a base member having an internal chamber with its open end attached to the surface of a housing through which a low-temperature, low-pressure refrigerant flows, and a circuit board mounted with electronic components and disposed within the chamber of the base member. A thermally conductive adhesive is disposed between the upper surface of the electronic components and the top plate of the base member, thereby fixing the electronic components to the base member. A thermally conductive elastic material is filled between the lower surface of the circuit board and the surface of the housing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-096297 Summary of the Invention [Problem to be solved by the invention]

[0005] In the inverter assembly for an electric compressor disclosed in Patent Document 1, electronic components are fixed to a base member and a housing with a heat-conductive adhesive and an elastic member. Therefore, heat generated by the electronic components is transferred to the base member via the adhesive and dissipated from the surface of the base member, and heat is exchanged with the refrigerant circulating inside the housing via the elastic member. This realizes an electric compressor with an inverter assembly that has high heat dissipation and vibration resistance, and is low-cost.

[0006] The electronic components used in the inverter assembly of the electric compressor disclosed in Patent Document 1 include components to which high voltages are applied, such as switching elements and choke coils. When the parts to which high voltages are applied (hereinafter simply referred to as high-voltage parts) of such electronic components to which high voltages are applied are exposed on the surface, the electronic components are required to have insulation properties to prevent short circuits between the high-voltage parts and other conductive parts. However, Patent Document 1 does not disclose any insulation properties for the inverter assembly of the electric compressor, leaving room for improvement.

[0007] Therefore, there is a demand for an insulating structure for electronic components that can ensure the insulation of electronic components in a simple manner. [Means for solving the problem]

[0008] One embodiment of the insulating structure for an electronic component according to the present disclosure is an insulating structure for an electronic component in which at least a portion of a high-voltage portion of a conductor to which a high voltage is applied is exposed, and in a state in which the electronic component is supported on a substrate, an insulating member facing the electronic component and an elastic member attached to the insulating member ensure insulation between the electronic component and a metallic protective member that protects the electronic component.

[0009] According to this embodiment, even in the case of an electronic component in which at least a part of a high-voltage portion of a conductor to which a high voltage is applied is exposed, the use of an insulating member and an elastic member ensures reliable insulation between the metallic protective member and the electronic component. Furthermore, since the insulating member faces the electronic component when the electronic component is supported on the substrate and the elastic member is attached to the insulating member, even if vibration is applied, the electronic component can be supported in a state in which the vibration is suppressed by the elastic member. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is an exploded perspective view showing the insulating structure of the choke coil. [Figure 2] FIG. 2 is a vertical cross-sectional view showing an insulating structure of the choke coil. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the insulation structure for electronic components according to the present disclosure will be described in detail with reference to the drawings. Note that the embodiments described below are merely examples for explaining the insulation structure for electronic components, and the insulation structure for electronic components is not limited to these embodiments. Therefore, the insulation structure for electronic components can be implemented in various forms without departing from the spirit of the invention.

[0012] As an example of an insulation structure for an electronic component according to this embodiment, the following describes an insulation structure for a choke coil mounted in a drive circuit of an electric water pump, which is an example of a water pump used in an electric vehicle. An electric water pump is used, for example, to circulate coolant for cooling an FC stack in a fuel cell vehicle. However, the insulation structure for an electronic component according to this embodiment is not limited to choke coils and can be applied to any electronic component that requires insulation. Furthermore, the insulation structure for an electronic component according to this embodiment can be applied to products other than electric water pumps, and can also be applied to electrical circuits other than drive circuits. Since the structure of an electric water pump is publicly known, a detailed description thereof will be omitted.

[0013] 1 and 2, a drive circuit 1 of an electric water pump A is disposed in a circuit accommodating space 2 formed in the electric water pump A. The circuit accommodating space 2 is a closed space formed by a body 3 of the electric water pump A, a holder 50 (an example of a protective member) disposed inside the body 3 and spatially separating a pump section (not shown) of the electric water pump A, and a lid section 4 fixed to the body 3.

[0014] The drive circuit 1 is configured by mounting various electronic components (choke coils, capacitors, switching elements, etc.) on a substrate 20. The choke coil 10 of this embodiment is an example of an electronic component. The choke coil 10 is mounted and supported on the substrate 20. The substrate 20 on which the choke coil 10 is supported is placed in the circuit accommodating space 2 while being supported by a holder 50 (see FIG. 2). The holder 50 protects the choke coil 10. In the following description, the direction perpendicular to the surface of the substrate 20 is defined as the Z direction, and the direction parallel to the Z direction when looking at the choke coil 10 from the substrate 20 is defined as the Z1 direction, and the opposite direction is defined as the Z2 direction.

[0015] As shown in FIG. 1, choke coil 10 includes core 12, two coils 14 (an example of a conductor) wound around core 12, four terminals 16 connected to both ends of coil 14, and base 17. That is, choke coil 10 is configured with four terminals. Core 12 has a cylindrical shape. Hereinafter, the central axis of core 12 will be referred to as axis X. Choke coil 10 is supported on substrate 20 with axis X parallel to the Z direction.

[0016] The core 12 has protrusions 12a, 12a that are U-shaped when viewed in a direction perpendicular to the Z direction (hereinafter also referred to as a side view) on the outer edge at two locations that are point-symmetrical with respect to the central axis X in the circumferential direction. Two coils 14 are wound around one side and the other side of the core 12 in the circumferential direction that are partitioned by the two protrusions 12a. That is, the two coils 14 are wound in positions that do not overlap when viewed in the direction along the Z direction (hereinafter also referred to as a plan view).

[0017] A base 17 made of an insulating material such as resin is disposed on the substrate 20 side of the choke coil 10. The base 17 has a rectangular plate shape in a plan view, and is formed with through-holes 17a through which the four terminals 16 pass. Of the plate surfaces of the base 17 perpendicular to the Z direction, a first plate surface 17c facing the core 12 is formed with a pair of protrusions 17b that protrude toward the protrusions 12a of the core 12. The base 17 is fixed to the core 12 by placing the tips of the protrusions 17b on the protrusions 12a of the core 12 and fixing them by a method such as adhesive. Therefore, the first plate surface 17c is spaced apart from the core 12.

[0018] A second plate surface 17d of the base 17 opposite the first plate surface 17c faces the substrate 20, and the second plate surface 17d and the surface of the substrate 20 are fixed together by a first adhesive 41 or the like. Furthermore, the four terminals 16 of the choke coil 10, which pass through the through holes 17a of the base 17, pass through the first through holes 20a of the substrate 20 and are electrically connected and fixed to the substrate 20 by soldering or the like. In this way, the choke coil 10 is supported in a fixed state on the substrate 20 by the first adhesive 41 and soldering or the like. The second plate surface 17d and the surface of the substrate 20 may be fixed together by any method other than the first adhesive 41.

[0019] The holder 50 is made of a metal such as aluminum and has a base 52 (an example of a second portion) extending in a direction perpendicular to the Z direction, and a plurality of (two in this embodiment) support posts 54 (an example of a first portion) extending from the base 52 in the Z2 direction. Each support post 54 has a female thread 54a formed from its tip end toward its base end (in the Z1 direction). The substrate 20 has a second through hole 20b formed in a location corresponding to the support post 54. In this embodiment, the second through hole 20b of the substrate 20 is aligned with the female thread 54a of the support post 54 of the holder 50, and the bolt 54b is inserted into the second through hole 20b of the substrate 20 and fastened to the female thread 54a of the support post 54, thereby supporting the substrate 20 on which the choke coil 10 is mounted on the support post 54. When the substrate 20 is supported by the holder 50, the surface of the substrate 20 and the base 52 of the holder 50 are parallel to each other. At this time, the choke coil 10 is disposed between the substrate 20 and the base 52 (see FIG. 2).

[0020] In the choke coil 10 of the drive circuit 1 of the electric water pump A, a high voltage is applied to two coils 14, at least a portion of which is exposed to the holder 50. That is, at least a portion of the high-voltage portion of the coil 14 to which the high voltage is applied is exposed. Conventionally, an insulating second adhesive 42 (an example of an elastic member or elastic adhesive) made of an elastic silicone or urethane material, or the like, is disposed between the choke coil 10 and the base 52 of the holder 50 to support the choke coil 10 relative to the holder 50. However, the second adhesive 42 alone is sometimes insufficient to ensure a creepage distance to insulate the coil 14 from the holder 50 and prevent short circuits. Therefore, in this embodiment, an insulating plate 30 (an example of an insulating member) made of an insulator such as resin is disposed between the choke coil 10 and the second adhesive 42 to ensure a creepage distance to insulate the coil 14 from the holder 50. In this embodiment, a structure in which the insulating plate 30 is used to ensure an insulating creepage distance between the choke coil 10 and the holder 50 is an "insulating structure for electronic components."

[0021] The insulating plate 30 of this embodiment includes a disk-shaped bottom plate portion 32, an annular peripheral wall portion 34 extending from the outer edge of the bottom plate portion 32, and a rod-shaped connecting portion 36 extending from the center of the bottom plate portion 32 in the same direction as the peripheral wall portion 34. The insulating plate 30 has a dish shape. The insulating plate 30 is fixed to the choke coil 10 by inserting the connecting portion 36 into the center of the core 12 of the choke coil 10 along the axis X. At this time, the choke coil 10 is spaced apart from the bottom plate portion 32 of the insulating plate 30. The inner diameter of the peripheral wall portion 34 of the insulating plate 30 is larger than the outer diameter of the choke coil 10 (see FIG. 2). In other words, the choke coil 10 is in contact only with the connecting portion 36 of the insulating plate 30, and is not in contact with the bottom plate portion 32 or the peripheral wall portion 34. In addition, the peripheral wall portion 34 of the insulating plate 30 does not overlap the core 12 of the choke coil 10 in a side view (see FIG. 2).

[0022] In this embodiment, the second adhesive 42 is disposed between the bottom plate portion 32 of the insulating plate 30 and the base 52 of the holder 50, thereby supporting the choke coil 10 relative to the holder 50. With this configuration, the creepage distance between the choke coil 10 and the holder 50 can be increased, ensuring insulation, compared to a conventional case in which the second adhesive 42 is disposed directly between the choke coil 10 and the base 52 of the holder 50.

[0023] In particular, in this embodiment, the bottom plate portion 32 of the insulating plate 30 has a peripheral wall portion 34 that stands up from the outer edge, so that the creepage distance can be made longer compared to when the insulating plate 30 is composed of only the bottom plate portion 32, and excess second adhesive 42 can be prevented from getting between the insulating plate 30 and the choke coil 10.

[0024] [Another embodiment] The present disclosure may be configured as follows in addition to the above-described embodiments (common numbers and symbols as in the embodiments are used to designate components having the same functions as in the embodiments).

[0025] (1) In the above embodiment, the peripheral wall portion 34 of the insulating plate 30 and the core 12 of the choke coil 10 do not overlap in side view, but they may be configured to overlap.

[0026] (2) In the above embodiment, an elastic adhesive is used for the second adhesive 42. However, an inelastic adhesive may be used for the second adhesive 42, and an elastic adhesive may be used for the first adhesive 41. Alternatively, an elastic adhesive may be used for both the second adhesive 42 and the first adhesive 41. Alternatively, the second adhesive 42 may be made of a flexible material such as rubber, and the second adhesive 42 may be fixed to the insulating plate 30 and the holder 50 with an inelastic adhesive.

[0027] In the above-described embodiment, the following configurations are envisioned.

[0028] <1> The insulating structure of the electronic component in which at least a part of the high-voltage portion of the conductor (14) to which a high voltage is applied is exposed ensures insulation between the electronic component (10) and a metallic protective member (50) that protects the electronic component (10) by an insulating member (30) facing the electronic component (20) and an elastic member (42) attached to the insulating member (30) when the electronic component (10) is supported on a substrate (20).

[0029] According to this configuration, even if the electronic component 42 has at least a portion of the high-voltage portion of the conductor 14 exposed, where a high voltage is applied, the use of the insulating member 30 and the elastic member 42 ensures reliable insulation between the metallic protective member 50 and the electronic component 10. Furthermore, since the insulating member 30 faces the electronic component 42 when the electronic component 42 is supported on the substrate 20 and the elastic member 42 is attached to the insulating member 30, even if vibration is applied, the elastic member 42 can support the electronic component 42 while suppressing the vibration.

[0030] <2> <1> In the insulating structure for electronic components described above, the elastic member (42) is preferably a fluid elastic adhesive applied to the insulating member (30).

[0031] According to this configuration, since the elastic member 42 is an elastic adhesive, simply applying the elastic adhesive can ensure the insulation of the electronic component 10. Furthermore, when the electronic component 20 is supported via the elastic member 42, even if an external force such as vibration or impact acts on the electronic component 10, simply applying the fluid elastic adhesive allows the elastic member 42 to attenuate the external force, thereby enabling stable support of the electronic component 10.

[0032] <3> <1> or <2> In the insulating structure for electronic components, it is preferable that the insulating member (30) is configured in a dish shape including a bottom plate portion (32) and a peripheral wall portion (34) erected from the outer edge of the bottom plate portion (32).

[0033] According to this configuration, compared to when the insulating member (30) is composed of only the bottom plate portion (32), the creepage distance can be increased and excess elastic member (42) can be prevented from getting between the insulating member (30) and the electronic component (10).

[0034] <4> the above <1> from <3> In the insulating structure for an electronic component described in any one of the above, it is preferable that the substrate (20) is supported by the first portion (54) of the protective member (50), the electronic component (10) is sandwiched between the substrate (20) and the second portion (52) of the protective member (50), and an insulating member (30) and an elastic member (42) are arranged between the electronic component (10) and the second portion (52).

[0035] According to this configuration, the electronic component (10) is sandwiched between the substrate (20) and the second portion (52) of the protective member (50). The insulating member (30) and the elastic member (42) are disposed between the electronic component (10) and the second portion (52). Therefore, even if an external force such as vibration or impact acts on the protective member (50), the elastic member (42) attenuates the external force, making it difficult for the external force to be transmitted to the electronic component (20). Furthermore, the electronic component (10) can be stably supported by the substrate (20) and the second portion (52) of the protective member (50). [Industrial Applicability]

[0036] The present disclosure can be used in insulating structures for electronic components. [Explanation of symbols]

[0037] 10: choke coil (electronic component), 14: coil (conductor), 20: substrate, 30: insulating plate (insulating member), 32: bottom plate portion, 34: peripheral wall portion, 42: adhesive (elastic member, elastic adhesive), 50: holder (protective member), 52: base (second portion), 54: support (first portion)

Claims

1. An insulating structure for an electronic component in which at least a part of a high-voltage portion of a conductor to which a high voltage is applied is exposed, An insulating structure for an electronic component that, when the electronic component is supported on a substrate, ensures insulation between the electronic component and a metallic protective member that protects the electronic component, using an insulating member that faces the electronic component and an elastic member attached to the insulating member.

2. 2. The insulating structure for an electronic component according to claim 1, wherein the elastic member is a fluid elastic adhesive applied to the insulating member.

3. 2. The insulating structure for an electronic component according to claim 1, wherein the insulating member has a dish shape including a bottom plate portion and a peripheral wall portion extending from an outer edge of the bottom plate portion.

4. the substrate is supported by a first portion of the protection member; the electronic component is sandwiched between the substrate and the second portion of the protective member, The insulating structure for an electronic component according to claim 1 , wherein the insulating member and the elastic member are disposed between the electronic component and the second portion.

Images