Patent ID: 12261544

DETAILED DESCRIPTION

To begin with, examples of relevant techniques will be described.

A power converter according to a comparative example includes a busbar. The busbar is electrically connected to a positive electric potential of a battery and built in a resin case.

According to the comparative example, a current flows through the busbar built in the resin case at a high voltage. Therefore, an electromagnetic noise from the busbar may cause a malfunction in a circuit board inside the resin case or a peripheral device outside the resin case.

In contrast, according to an aspect of the present disclosure, a power converter includes semiconductor modules, a capacitor, a circuit board, a casing, a busbar and a shield layer. The capacitor is electrically connected to the semiconductor modules. The casing accommodates the circuit board, the semiconductor modules and the capacitor. The busbar has an input terminal portion, an output terminal portion and an electric pathway connecting the input terminal portion and the output terminal portion. The electric pathway is connected to at least one of electronic components including the semiconductor modules and the capacitor. The busbar has a built-in portion incorporated into the casing. The shield layer is electrically conductive and provided on an inner surface or an outer surface of the casing such that the shield layer covers the built-in portion.

According to this power converter, since the busbar is a current path, the built-in portion of the busbar incorporated in the casing can emit an electromagnetic noise. In this power converter, electromagnetic noises from various noise sources can propagate through the busbar and be emitted from the busbar. However, the shield layer is provided on the inner surface or the outer surface of the casing such that the shield layer covers the built-in portion. Therefore, the shield layer can prevent emission or diffusion of an electromagnetic noise or the like from the busbar via the casing. This power converter can suppress a propagation of the electromagnetic noise or the like in air from the busbar through the casing. Therefore, the power converter is capable of reducing noise interference to, for example, the circuit board or a peripheral device outside the casing.

Hereinafter, embodiments for implementing the present disclosure will be described referring to the drawings. In each embodiment, portions corresponding to the elements described in the preceding embodiments are denoted by the same reference numerals, and redundant explanation thereof may be omitted. When only a part of a configuration is described in an embodiment, the other preceding embodiments can be applied to the other parts of the configuration. It may be possible not only to combine parts the combination of which is explicitly described in an embodiment, but also to combine parts of respective embodiments the combination of which is not explicitly described if any obstacle does not especially occur in combining the parts of the respective embodiments.

First Embodiment

A first embodiment showing an example of a power converter will be described with reference toFIGS.1and2. The power converter can be applied to an in-vehicle power conversion device mounted on a vehicle such as an electric vehicle or a hybrid vehicle. The power converter capable of achieving the object disclosed in the specification can be applied to, for example, an inverter device, or a converter device. In this embodiment, the power converter applied to the inverter device will be described below.

The power converter1includes an inverter circuit200. As shown inFIG.1, the inverter circuit200includes semiconductor modules2. The semiconductor modules2include semiconductor elements20(e.g. insulated-gate bipolar transistor element). By switching the semiconductor elements20, the inverter circuit200converts DC power (i.e. direct current power) supplied from a DC power supply100into AC power (i.e. alternating current power). The vehicle runs by driving a three-phase motor110using the obtained AC power.

As shown inFIG.2, the power converter1includes the semiconductor modules2, a capacitor3, a circuit board4, and a casing5. The capacitor3is electrically connected to the semiconductor modules2. The power converter1includes a cooling member11that cools the semiconductor modules2. The cooling member11is in contact with the semiconductor modules2or thermally connected with the semiconductor modules2through a heat conductor. The cooling member11is in contact with the casing5or thermally connected with the casing5through a heat conductor. The cooling member11has a plate shape, and includes a flow path11ain which a cooling fluid flows. The cooling member11is fixed to an installation support13by a fixing member12such as a screw, or a bolt. The installation support13includes, for example, a vehicle member and a motor device. The installation support13is an example of a mount to which the casing5is fixed. Since the installation support13is electrically connected to the ground via a peripheral member, the casing5is electrically grounded.

A cooling side seal14that is electrically conductive is interposed between a lower case51of the casing5and the cooling member11. The cooling side seal14is provided at a joint between the lower case51and the cooling member11. The cooling side seal14is a gasket electrically conductive and is deformed between the lower case51and the cooling member11. The cooling side seal14seals the joint between the lower case51and the cooling member11. The cooling side seal14is in contact with the base-side outer layers61b,62b. The base-side outer layers61b,62bwill be described later. Since the cooling side seal14and the base-side outer layers61b,62bare electrically conductive, an electric current pass therebetween. The cooling side seal14may have thermal conductivity. The cooling side seal14may be a sheet shaped member, a grease, or a gel as long as the cooling side seal14is electrically conductive.

The casing5is a container for accommodating the circuit board4, the semiconductor modules2, and the capacitor3, for example. The casing5is formed by combining case members. The casing5includes at least a first case member and a second case member. The first case member and the second case member are resin molded products. For example, the first case member is a lower case51that surrounds the circuit board4, the semiconductor modules2, the capacitor3, and the like. The circuit board4, the semiconductor modules2, the capacitor3, and the like are housed in an internal space of the casing5, for example, in an internal space of the lower case51. For example, the second case member is a cover52that is attached to the lower case51such that the cover52covers the internal space of the lower case51. The cover52is fixed to and integrated with the lower case51such that the cover52is located over and covers the lower case51. A cover-side seal15is provided at a joint between the cover52and the lower case51. The cover-side seal15is a gasket electrically conductive and is interposed for sealing between the cover52and the lower case51. The cover-side seal15may be a sheet shaped member, a grease, or a gel as long as the cover-side seal15is electrically conductive.

The internal space of the casing5is, for example, divided by a partition wall into a capacitor accommodating space and a semiconductor-module accommodating space. The semiconductor-module accommodating space houses the semiconductor modules2and the circuit board4, for example.

The capacitor3is electrically connected to the semiconductor modules2. The capacitor3functions as a smoothing capacitor that smooths a DC voltage applied to the semiconductor modules2. The capacitor3includes a capacitor element, a sealing member31, and a terminal32. The capacitor element of the capacitor3is housed in a capacitor accommodating portion. The capacitor accommodating space is filled with the sealing member31, and the sealing member31seals the capacitor element. The sealing member31in the capacitor accommodating space encloses the capacitor element. The sealing member31forms an exterior of the capacitor3. The capacitor element is connected an electrode plate, for example. For example, a film capacitor can be adopted as the capacitor element.

The sealing member31is made of a thermosetting resin such as an epoxy resin. A gap between the capacitor element and the capacitor accommodating portion and a gap between a terminal32and the capacitor accommodating portion are filled with the sealing member31. With this configuration, the sealing member31seals the capacitor element, the terminal32, and the like. A part of the terminal32or the like protrudes from the sealing member31.

When manufacturing the capacitor3, the capacitor element is first housed in the capacitor accommodating space, and then an uncured sealing member31is injected into the capacitor accommodating space. Thereafter, the sealing member31is cured by a heat treatment to form the capacitor3. Further, the capacitor3may include an outer case for accommodating the capacitor element. The capacitor3may have a configuration having a film covering the capacitor element as an exterior.

The semiconductor modules2each include a body21incorporating the semiconductor elements20, a power terminal and a control terminal25. The power terminal and the control terminal25protrude from the body21. The semiconductor modules2are also called power modules. The power terminal includes an input terminal23to which DC voltage is applied, and an output terminal24connected to an output busbar72that is connected to the three-phase motor110. The input terminal23is connected to the terminal32of the capacitor3. Therefore, the input terminal23is electrically connected an output unit of the DC power supply100via an input busbar71. The control terminal25is connected to the circuit board4. The circuit board4constitutes a circuit board on which electronic components are mounted. The electronic components are, for example, arithmetic calculation elements controlling operations of the semiconductor elements20. The circuit board4controls turning on and off of the semiconductor element20. By switching the semiconductor element20, the DC power supplied from the DC power supply100is converted into AC power.

The circuit board4is fixed in a state of being supported by a boss41provided in the lower case51. The circuit board4is connected via wiring to a connector42protruding outward from the casing5. The connector42can be connected to a peripheral device installed outside the power converter1.

The power converter1includes busbars7. The busbars7include the input busbar71and the output busbar72. The busbars7are used for electric power input and output. The busbars7are electrically conductive. The busbars7each have an input terminal portion, an output terminal portion and an electric pathway connecting the input terminal portion and the output terminal portion. The busbars7are connected to an input side or an output side of at least one of components that include the semiconductor modules2and the capacitor3.

The input busbar71includes a first terminal portion71a, a built-in portion71band a second terminal portion71c. The first terminal portion71ais supplied with electric power from the DC power supply100. The built-in portion71bis incorporated into the lower case51. The first terminal portion71aand the second terminal portion71care exposed to an outside from the lower case51. The second terminal portion71cis electrically connected to the terminal32of the capacitor3and the input terminals23of the semiconductor modules2.

The output busbar72includes a first terminal portion72a, a built-in portion72band a second terminal portion72c. The first terminal portion72ais connected to the output terminal24. The built-in portion72bis incorporated into the lower case51. The first terminal portion72aand the second terminal portion72care exposed to the outside from the lower case51. The second terminal portion72cis a terminal that outputs electric power to the three-phase motor110. The output busbar72is also an electric pathway for an output current that has been controlled by a switching operation of a switch device such as a semiconductor device.

The power converter1has configuration that generates, transmits or radiates an electromagnetic noise that interferes with electrical components. Hereinafter, an electromagnetic noise may be referred to as a noise. The power converter1transmits a noise by a high-frequency current or the like flowing in the electric pathway. For example, a switching power supply is a source of noise. The switching power supply includes an electric circuit that converts voltage and frequency by conduction and interruption of a current with use of a semiconductor. A high frequency energy is generated in such a part where the current is conducted and interrupted. As a result, if the high frequency energy leaks to an outside by being transmitted or radiated, the high frequency energy may cause noise interference. Although the high frequency energy is absorbed by a capacitor or the like, the high frequency energy may be transmitted widely through the busbars7and thereby may leak to the outside. Further, the electromagnetic noise can be generated also by a type of switching surge phenomenon in which a current is conducted and interrupted with use of a commutator or the like.

Such electromagnetic noise is transmitted to the electric pathway via the input busbar71or the output busbar72. Further, the electromagnetic noise can be transmitted through the casing5from the built-in portion71bof the input busbar71and the built-in portion72bof the output busbar72. The electromagnetic noise can be emitted to an inside and an outside of the casing5.

The lower case51is integrated with the input busbar71and the output busbar72. The input busbar71and the output busbar72are provided in the lower case51by being inserted into a mold of the lower case51and integrally molded with a resin portion via solidification of a resin surrounding the lower case51.

The first terminal portion71aand the second terminal portion71cof the input busbar71are exposed to an outside from the resin portion of the lower case51. The first terminal portion71amay be integrally fixed and connected to a terminal block for power input. The built-in portion71bis a portion that is covered with the resin portion of the lower case51. The built-in portion71bis not exposed to the outside. The lower case51includes an inner resin51aand an outer resin51b. The built-in portion71bis covered with the inner resin51aon an inner side of the lower case51, and the built-in portion71bis covered with the outer resin51bon an outer side of the lower case51. The inner side of the lower case51faces the internal space of the lower case51, and the inner resin51ais exposed to the internal space. The outer side of the lower case51is an outer surface of the lower case51that is not exposed to the internal space, and the outer resin51bis exposed to an external space outside the lower case51.

The first terminal portion72aand the second terminal portion72cof the output busbar72are exposed to the outside from the resin portion of the lower case51. The first terminal portion72amay be integrally fixed and connected to a terminal block for power output. The built-in portion72bis a portion that is covered with the resin portion of the lower case51. The built-in portion72bis not exposed to the outside. The built-in portion72bis covered with the inner resin51aon the inner side of the lower case51, and an outside of the built-in portion72bis covered with the outer resin51bon the outer side of the lower case51.

The casing5of the power converter1includes shield layers61,62. The shield layers61,62are electrically conductive. The shield layers61,62are provided on an inner surface of the casing5such that the shield layers61,62cover the built-in portions71b,72b. The shield layers61,62are provided on an outer surface of the casing5such that the shield layers61,62cover the built-in portions71b,72b. A shield layer61has a function of preventing an electromagnetic noise radiated from the built-in portion71bfrom leaking out of the casing5.

The shield layers61,62can be formed, for example, of a metal layer or an alloy layer obtained by plating of a surface of the casing5. The shield layers61,62may be, for example, copper layers obtained by plating of the surface of the casing5. According to this configuration, electrical conductivities of the shield layers61,62can be high, and thicknesses of the shield layers61,62can be small. As a result, weights of the shield layers61,62can be small, and the shield layers61,62can be made thinner. The shield layers61,62may be incorporated into the casing5. In this case, the shield layers61,62are integrally molded with the resin portion of the casing5by being inserted into a mold at the time of molding the casing5.

As shown inFIG.2, the lower case51is provided with a base-side inner layer61a. The base-side inner layer61ais provided on the inner surface of the casing5such that the base-side inner layer61acovers the built-in portion71b. The lower case51is provided with a base-side inner layer62a. The base-side inner layer62ais provided on the inner surface of the casing5such that the base-side inner layer62acovers the built-in portions72b. The lower case51is provided with a base-side outer layer61b. The base-side outer layer61bis provided on the outer surface of the casing5such that the base-side outer layer61bcovers the built-in portions71b. The lower case51is provided with a base-side outer layer62b. The base-side outer layer62bis provided on the outer surface of the casing5such that the base-side outer layer62bcovers the built-in portions72b.

The base-side inner layer61aand the base-side inner layer62amay be overlapped with an entire of an inner surface of the lower case51that defines the internal space of the lower case51. According to this, the base-side inner layers61a,62acan more reliably block the electromagnetic noise radiated from a wide area of the inner surface of the lower case51into the internal space. The base-side outer layer61band the base-side outer layer62bmay be overlapped with an entire of an outer surface of the lower case51that faces away form the internal space of the lower case51. According to this, the base-side outer layer61b,62bcan more reliably block the electromagnetic noise radiated from a wide area of the outer surface of the lower case51into an outer space of the casing5.

The second case member is the cover52. A cover-side layer that is electrically conductive is provided on the cover52. The cover-side layer covers an inner surface or an outer surface of the cover52. As shown inFIG.2, the cover52may be provided with a cover-side inner layer52aon the inner surface of the cover52, and a cover-side outer layer52bon the outer surface of the cover52. The cover-side inner layer52acovers the inner surface of the cover52facing the internal space. The cover-side outer layer52bcovers the outer surface of the cover52facing away from the internal space.

The cover-side layers52a,52bmay be incorporated into the cover52, In this case, the cover-side layers52a,52bare integrally molded with a resin portion of the cover52by being inserted into a mold at the time of molding the cover52.

The cover-side seal15is interposed between the cover-side inner layer52aand the base-side inner layers61a,62a. The cover-side seal15is sandwiched between the cover-side inner layer52aand the base-side inner layers61a,62aand is in contact with both the cover-side inner layer52aand the base-side inner layers61a,62aSince the cover-side seal15, the cover-side inner layer52a, and the base-side inner layers61a,62aare electrically conductive, an electric current passes between them. Since the cover-side inner layer52aand the base-side inner layer61a,62aform one conductive object, the electromagnetic noise can be dispersed, so that a noise intensity per unit volume can be reduced, By this action, the power converter1provides a configuration capable of reducing the electromagnetic noise emitted from the power converter1.

Actions and effects produced by the power converter1according to the first embodiment will be described. The power converter1includes the semiconductor modules2, the capacitor3electrically connected to the semiconductor modules2, the circuit board4, and the casing5accommodating the circuit board4, the semiconductor modules2and the capacitor3. The power converter1includes the busbars7each having the input terminal portion, the output terminal portion and the electric pathway connecting the input terminal portion and the output terminal portion. The electric pathway connect to at least one of the semiconductor modules2or the capacitor3. The busbars7have the built-in portions71b,72bincorporated into the casing5. The power converter1includes the shield layers61,62electrically conductive and provided on the inner surface or the outer surface of the casing5such that the shield layers61,62cover the built-in portions71b,72b.

According to the power converter1, since the busbars7are a current paths, the built-in portions71b,72bof the busbars7can emit an electromagnetic noise. In the power converter1, electromagnetic noises from various noise sources can propagate through the busbars7and be emitted from the casing5. The shield layers61,62provided on the inner surface or the outer surface of the casing5such that the shield layers61,62cover the built-in portions71b,72b. According to this configuration, the shield layers61,62can prevent emission or diffusion of an electromagnetic noise or the like from the busbars7via the casing5. Therefore, the power converter1can suppress a propagation of the electromagnetic noise or the like in air from the busbars7through the casing5. The power converter1is capable of reducing noise interference given to, for example, the circuit board or a peripheral device outside the casing5.

The shield layers61,62are electrically grounded to the mount to which the casing5is fixed. According to this configuration, the electromagnetic noise transmitted to the shield layers61,62can be easily released to an outside through the mount. As a result, the effects of reducing noise interference can be enhanced.

In the power converter1, the shield layers include the base-side inner layers61a,62aprovided on the inner surface of the casing5such that the base-side inner layers61a,62acover the built-in portions71b,72b. According to this configuration, the base-side inner layers61a,62acan block the electromagnetic noise radiated from the busbars7into the internal space of the casing5. Therefore, the power converter1can suppress a propagation of the electromagnetic noise or the like to the inside of the casing5from the busbars7through the casing5. As a result, the power converter1is capable of reducing noise interference given to electrical components, for example, the circuit board4or the capacitor3.

In the power converter1, the shield layers include a base-side outer layers61b,62bprovided on the outer surface of the casing5such that the base-side outer layers61b,62bare located outward of and cover the built-in portion71b,72b. According to this configuration, the base-side outer layers61b,62bcan block the electromagnetic noise or the Ike radiated from the busbars7to the inside and the outside of the casing5. Therefore, the power converter1can suppress a propagation of the electromagnetic noise or the like to the outside of the casing5from the busbars7through the casing5. As a result, the power converter1is capable of reducing noise interference given to, for example, a peripheral device outside the casing5.

The shield layers are provided on both the inner surface and the outer surface of the casing5such that the shield layers cover the built-in portions71b,72b. According to this configuration, the base-side inner layers61a,62aand the base-side outer layers61b,62bcan block the electromagnetic noise radiated from the busbars7to the inside and outside of the casing5. The power converter1is capable of reducing noise interference given to electrical components, for example, the circuit board4, or the capacitor3in the casing5, or a peripheral device outside the casing5.

The power converter1includes the cooling member11that cools the semiconductor modules2, and the cooling side seal14electrically conductive that is interposed between the casing5and the cooling member11for sealing a gap therebetween. The cooling side seal14is in contact with the base-side outer layers61b,62bthat are provided on the casing5such that the base-side outer layers61b,62bare located outward of and cover the built-in portions71b,72b. According to this configuration, the cooling side seal14can ensure the sealing of the gap between the casing5and the cooling member11. Further, the base-side outer layers61b,62bare adhered to the cooling side seal14. The cooling side seal14is in contact with the base-side outer layers61b,62bthat are provided on the casing5such that the base-side outer layers61b,62bare located outward of and cover the built-in portions71b,72b.

According to this configuration, the cooling side seal14and the base-side outer layers61b,62bare capable of increasing a thickness of a member that blocks the electromagnetic noise on a surface of the casing5facing the installation support13. In this way, the power converter1is capable of increasing a shielding performance against the electromagnetic noise on the surface of the casing5that faces the installation support16. Further, since the cooling side seal14is electrically conductive, the electromagnetic noises accumulated in the base-side outer layer61b,62bcan flow to the cooling member11through the cooling side seal14. The electromagnetic noise that has flowed into the cooling member11is likely to be emitted to the outside from the cooling member11. Therefore, the power converter1is capable of suppressing propagation of the electromagnetic noise or the like to a peripheral device outside the casing5.

The casing5includes the first case member that incorporates the built-in portion and is covered with the shield layers, and the second case member that is attached to the first case member such that the second case member covers an internal space of the first case member. The shield layers include the cover-side layer that is electrically conductive and provided on and covers an inner surface or an outer surface of the second case member. According to this power converter1, the cover-side layer is capable of blocking the electromagnetic noise or the like propagating in the internal space of the casing5. As a result, the cover-side layer is capable of reducing radiation of the electromagnetic noise through the second case member to the outside of the casing5. In this power converter1, even if the shield layers61,62can not block the electromagnetic noise, and the electromagnetic noise is radiated into the internal space, the cover-side layer can block the electromagnetic noise or the like and prevent radiation of the electromagnetic noise from the internal space to the outside of the casing5.

The cover-side outer layer52bis provided on and covers the outer surface of the second case member. According to this power converter, the cover-side outer layer is capable of blocking the electromagnetic noise or the like transmitted in the second case member from the internal space of the casing5on the outer surface of the second case member.

The cover-side inner layer52ais provided on and covers the inner surface of the second case member. According to this power converter, the cover-side inner layer is capable of blocking the electromagnetic noise or the like propagating in the internal space on the inner surface of the second case member, thereby preventing transmission of the electromagnetic noise into the second case member.

The cover-side layers are provided on the inner surface and the outer surface of the second case member. This power converter is capable of blocking the electromagnetic noise or the like transmitted from the internal space of the casing5to the second case member on the inner surface and the outer surface of the second case member. That is, the power converter is capable of blocking the electromagnetic noise in two stages. Therefore, in the power converter, effects of reducing emission of the electromagnetic noise to the outside of the casing5through the second case member can be increased drastically.

The power converter1includes the cover-side seal15electrically conductive and interposed between the first case member and the second case member for sealing a gap therebetween. The shield layer includes the base-side inner layers61a,62athat are provided on an inner surface of the first case member such that the base-side inner layers61a,62acover the built-in portions71b,72b. The cover-side seal15is in contact with the base-side inner layers61a,62aand the cover-side inner layer52aprovided on the inner surface of the second case member.

According to this configuration, the cover-side seal15can ensure sealing of the gap between the first case member and the second case member. Further, the cover-side seal15is adhered to the cover-side inner layer52aand the base-side inner layers61a,62a. Therefore, the electromagnetic noise accumulated in the casing5can be blocked by the cover-side seal15, the cover-side inner layer52a, and the base-side inner layers61a,62aTherefore, the power converter1is capable of suppressing propagation of the electromagnetic noise or the like into the internal space of the casing5.

Second Embodiment

A second embodiment will be described with reference toFIG.3. A power converter101of the second embodiment is different from the first embodiment in a cover-side layer, a shield layer161and a shield layer162. Configurations, actions, and effects not specifically described in the second embodiment are the same as those in the first embodiment, and points different from the first embodiment will be described below.

As shown inFIG.3, a casing105includes a lower case151and a cover152. The cover-side layer includes the cover-side inner layer52aprovided on and covering an inner surface of the cover152. The cover152is not provided with a shield layer on an outer surface of the cover152. The shield layer161includes a base-side inner layer61aprovided on and covering an inner surface of the lower case151. The lower case151is not provided with the base-side outer layer provided on an outer surface of the lower case151. The shield layer162includes a base-side inner layer62aprovided on the inner surface of the lower case151. A cooling side seal14is provided between the lower case151and the cooling member11. The cooling side seal14is deformed to seal a gap between the lower case151and the cooling member11.

According to the second embodiment, the power converter101includes, as shield layers, the base-side inner layers61a,62aprovided on the inner surface of the lower case151such that the base-side inner layers61a,62acover the built-in portions71b,72b. According to this configuration, the base-side inner layers61a,62acan block an electromagnetic noise radiated from the busbars7into an internal space of the casing105. Therefore, the power converter101is capable of suppressing propagation of the electromagnetic noise or the like to an inside of the casing105from the busbars7through the casing105. As a result, the power converter101is capable of reducing noise interference to electrical components, for example, a circuit board4or a capacitor3.

The cover-side inner layer52ais provided on and covers the inner surface of the cover152. According to this power converter101, the cover-side inner layer52ais capable of blocking the electromagnetic noise or the like propagating in the internal space of the casing105on the inner surface of the cover152. As a result, transmission of the electromagnetic noise in the cover152can be prevented.

Third Embodiment

A third embodiment will be described with reference toFIG.4. A power converter201of the third embodiment is different from the first embodiment in a cover-side layer, a shield layer261and a shield layer262. Configurations, actions, and effects not specifically described in the third embodiment are the same as those in the first embodiment, and points different from the first embodiment will be described below.

As shown inFIG.4, a casing205includes a lower case251and a cover252. The cover-side layer includes a cover-side outer layer52bprovided on and covering an outer surface of the cover252. The cover252is not provided with a shield layer provided on an inner surface of the cover252. The shield layer261includes a base-side outer layer61bprovided on and covering an outer surface of the lower case151. The lower case251is not provided with a base-side inner layer provided on an inner surface of the lower case251. The shield layer262includes a base-side outer layer62bprovided on and covering an outer surface of the lower case151.

According to the third embodiment, the power converter201includes, as the shield layers, the base-side outer layers61b,62bprovided on the outer surface of the lower case251such that the base-side outer layers61b,62bcover the built-in portions71b,72b. According to this configuration, the base-side outer layers61b,62bcan block radiation of an electromagnetic noise from the busbars7to surroundings of the casing205. Therefore, the power converter201is capable of suppressing propagation of the electromagnetic noise or the like to an outside of the casing205from the busbars7through the casing205. As a result, the power converter201is capable of reducing noise interference given to, for example, a peripheral device outside the casing205.

The cover-side outer layer52bis provided on and covering the outer surface of the cover252. According to this power converter201, the cover-side outer layer is capable of blocking the electromagnetic noise or the like transmitted in the cover252from the internal space of the casing205on the outer surface of the cover252.

Other Embodiments

The disclosure of this specification is not limited to the illustrated embodiment. The disclosure encompasses the illustrated embodiments and variations based on the embodiments by those skilled in the art. For example, the disclosure is not limited to the combinations of components and elements shown in the embodiments, and various modifications and implementations can be performed. The disclosure may be implemented in various combinations. The disclosure may have additional portions that may be added to the embodiments. The disclosure includes the embodiments from which the parts and the components are omitted. The disclosure encompasses the replacement or combination of components, elements between one embodiment and another. The disclosed technical scope is not limited to the description of the embodiment. It should be understood that the disclosed technical scope is defined in claims and includes meanings equivalent to the claims and all modifications in the scope of the claims.

The power converter and shield layer disclosed in the specification is not limited to the examples shown in the above embodiments. For example, the power converter includes a device having the following configurations. The cover of the second embodiment may not be provided with the cover-side inner layer52aon the inner surface of the cover. The cover of the third embodiment may not be provided with the cover-side outer layer52bon the outer surface of the cover. The cover of the first embodiment may not be provided with the cover-side inner layer52aon the inner surface of the cover. The cover of the first embodiment may not be provided with the cover-side outer layer52bon the outer surface of the cover. The cover of the first embodiment may not be provided with the shield layer.

While the present disclosure has been described with reference to embodiments thereof, it is to be understood that the disclosure is not limited to the embodiments and constructions. To the contrary, the present disclosure is intended to cover various modification and equivalent arrangements. In addition, while the various elements are shown in various combinations and configurations, which are exemplary, other combinations and configurations, including more, less or only a single element, are also within the spirit and scope of the present disclosure.