Patent Description:
A power converter including a terminal block that is arranged above a circuit board and to which wiring is connected from outside the power converter, and a bus bar connected to the terminal block is known in general, as disclosed in <CIT>, for example.

<CIT> discloses a power converter including a terminal block that is arranged above a circuit board and to which wiring is connected from outside the power converter and a bus bar connected to the terminal block. In this power converter, a semiconductor module containing a power conversion semiconductor element is connected (mounted) to the circuit board.

Although not clearly described in <CIT>, in a conventional power converter as described in <CIT>, the terminal block and the circuit board may be connected by a plurality of bus bars. In such a case, when a space over a surface of the circuit board in which the plurality of bus bars can be routed is narrow, the plurality of bus bars are spaced apart from each other in an upward-downward direction in order to prevent short circuits between the plurality of bus bars.

However, when the plurality of bus bars are spaced apart from each other in the upward-downward direction, it is necessary to space the bus bars apart from each other in the upward-downward direction by an air insulation distance (insulation distance in a case in which insulation is provided by air) in order to prevent short circuits between the plurality of bus bars, and the size of the power converter in the upward-downward direction disadvantageously increases over the circuit board. There is a method for reducing a distance between bus bars in an upward-downward direction by sandwiching an insulating member as a separate member between the bus bars and attaching the bus bars, but such a method increases the number of components and complicates assembly such that workability during assembly is decreased. Therefore, there is a demand for a power converter capable of significantly reducing or preventing an increase in the size of the power converter in an upward-downward direction while significantly reducing or preventing a decrease in workability during assembly.

<CIT> discloses a power conversion device including a power semiconductor module that converts a DC current into an AC current, a plate conductor that transfers the DC current or the AC current, a resin sealing material that seals the plate conductor and an electric component that is used to control the power semiconductor module, wherein the resin sealing material includes a supporting member that supports the electric component, and wherein the plate conductor is buried in a portion of the resin sealing material that is disposed to face the electric component.

The present invention has been proposed in order to solve the aforementioned problems, and an object of the present invention is to provide a power converter capable of significantly reducing or preventing an increase in the size of the power converter in an upward-downward direction while significantly reducing or preventing a decrease in workability during assembly.

The invention is defined by the features of claim <NUM>. The dependent claims recite advantageous embodiments of the invention.

In order to attain the aforementioned object, a power converter according to an aspect of the present invention includes a main circuit board configured to allow a power conversion semiconductor module to be mounted thereon, a terminal block arranged above the main circuit board, the terminal block being configured to allow wiring to be connected thereto from outside the power converter, and a resin molded bus bar integrally resin molded such that a plate-shaped first bus bar and a plate-shaped second bus bar, both of which are connected to the terminal block and are electrically connected to the main circuit board or the power conversion semiconductor module, are insulated by an insulating resin. The resin molded bus bar has an L-shape including a lateral portion configured to extend along the main circuit board and a vertical portion configured to extend upward from the lateral portion toward the terminal block.

In the aforementioned power converter according to this aspect, as described above, the resin molded bus bar has an L-shape including the lateral portion that extends along the main circuit board and the vertical portion that extends upward from the lateral portion toward the terminal block. Furthermore, the resin molded bus bar is integrally resin molded such that the first bus bar and the second bus bar are insulated by the insulating resin. Accordingly, the insulating resin insulates the first bus bar from the second bus bar, and thus even when the first bus bar and the second bus bar overlap in an upward-downward direction, a distance between the first bus bar and the second bus bar can be smaller in the lateral portion that extends along the main circuit board than that in a case in which insulation is provided by air (air insulation is provided). Consequently, an increase in the size of the power converter in the upward-downward direction over the main circuit board can be significantly reduced or prevented. Furthermore, the lateral portion of the resin molded bus bar including a single member in which the first bus bar, the second bus bar, and the insulating resin are integrally resin molded extends along the main circuit board such that both the first bus bar and the second bus bar can be easily electrically connected to the main circuit board or the power conversion semiconductor module. Furthermore, the vertical portion of the resin molded bus bar including a single member in which the first bus bar, the second bus bar, and the insulating resin are integrally resin molded extends from the lateral portion upward toward the terminal block such that both the first bus bar and the second bus bar can be easily electrically connected to the terminal block arranged above the main circuit board. Accordingly, both the first bus bar and the second bus bar can be easily electrically connected to the main circuit board or the power conversion semiconductor module and the terminal block arranged above the main circuit board by the resin molded bus bar as a single member having an L-shape including the lateral portion and the vertical portion. Consequently, unlike a case in which the first bus bar and the second bus bar are attached so as to sandwich an insulating member as a separate member, an increase in the number of components and complication of assembly can be significantly reduced or prevented. Thus, an increase in the size of the power converter in the upward-downward direction can be significantly reduced or prevented while a decrease in workability during assembly is significantly reduced or prevented.

In the aforementioned power converter according to this aspect, the resin molded bus bar is preferably configured to sandwich the insulating resin between the first bus bar and the second bus bar, and the first bus bar and the second bus bar are preferably stacked while being spaced apart from each other by a first separation distance that is smaller than an air insulation distance. Accordingly, even when the first bus bar and the second bus bar overlap in the upward-downward direction, the insulating resin is sandwiched between the first bus bar and the second bus bar, and thus the first bus bar and the second bus bar can be reliably insulated. Consequently, the distance between the first bus bar and the second bus bar can be smaller than the air insulation distance, and thus an increase in the size of the power converter in the upward-downward direction over the main circuit board can be significantly reduced or prevented.

In the aforementioned configuration in which the first bus bar and the second bus bar are stacked while being spaced apart from each other by the first separation distance that is smaller than the air insulation distance, the terminal block preferably includes a DC terminal block, the first bus bar preferably includes a positive electrode connector exposed from the insulating resin, the positive electrode connector being connected to a positive electrode terminal of the DC terminal block, the second bus bar preferably includes a negative electrode connector exposed from the insulating resin, the negative electrode connector being connected to a negative electrode terminal of the DC terminal block, and the first bus bar and the second bus bar are preferably configured to allow currents to flow therethrough in opposite directions to each other. Accordingly, currents flow through the first bus bar and the second bus bar in the opposite directions such that magnetic fields generated by the currents flowing through the first bus bar and the second bus bar can cancel each other out. Consequently, the inductances of the first bus bar and the second bus bar can be reduced.

In this case, the power converter preferably further includes a power supply board arranged above the main circuit board, the power supply board being configured to allow an electronic component configured to generate a control power supply to be mounted thereon, each of the first bus bar and the second bus bar of the resin molded bus bar preferably has an outer surface covered with the insulating resin, the first bus bar is preferably arranged between the main circuit board and the power supply board while being spaced apart by a second separation distance that is smaller than the air insulation distance from the power supply board in the lateral portion covered with the insulating resin, and the second bus bar is preferably arranged between the main circuit board and the power supply board while being spaced apart by a third separation distance that is smaller than the air insulation distance from the main circuit board in the lateral portion covered with the insulating resin. Accordingly, the first bus bar is arranged between the main circuit board and the power supply board while being spaced apart by the second separation distance that is smaller than the air insulation distance from the power supply board in the lateral portion covered with the insulating resin such that a distance between the first bus bar and the power supply board can be reduced. Furthermore, the second bus bar is arranged between the main circuit board and the power supply board while being spaced apart by the third separation distance that is smaller than the air insulation distance from the main circuit board in the lateral portion covered with the insulating resin such that a distance between the second bus bar and the main circuit board can be reduced. Consequently, a distance between the main circuit board and the power supply board arranged so as to sandwich the first bus bar and the second bus bar can be reduced, and thus an increase in the size in the upward-downward direction over the main circuit board can be significantly reduced or prevented.

In the aforementioned configuration including the power supply board, the first bus bar preferably includes a first main circuit board connector exposed from the insulating resin, the first main circuit board connector being connected to the main circuit board, and a power supply board connector exposed from the insulating resin, the power supply board connector being connected to the power supply board. Accordingly, the first bus bar having the outer surface covered with the insulating resin can be easily connected to the main circuit board by the first main circuit board connector exposed from the insulating resin. Furthermore, the first bus bar having the outer surface covered with the insulating resin can be easily connected to the power supply board by the power supply board connector exposed from the insulating resin.

In this case, the first bus bar preferably has a stepped shape that bends toward the main circuit board, the first main circuit board connector is preferably connected to the main circuit board from above, and the power supply board connector of the first bus bar preferably has a stepped shape that bends toward the power supply board, and is connected to the power supply board from below. Accordingly, even when the lateral portion in which the first bus bar is covered with the insulating resin is spaced apart from the main circuit board by the air insulation distance, due to the stepped shape of the first bus bar that bends toward the main circuit board, the first main circuit board connector of the first bus bar can be closer to the main circuit board (the height positions can be closer). Consequently, the first main circuit board connector of the first bus bar can be easily connected to the main circuit board. Furthermore, even when the lateral portion in which the first bus bar is covered with the insulating resin is spaced apart from the power supply board by the air insulation distance, due to the stepped shape of the power supply board connector that bends toward the power supply board, the power supply board connector can be closer to the power supply board (the height positions can be closer). Consequently, the power supply board connector of the first bus bar can be easily connected to the power supply board.

In the aforementioned power converter according to this aspect, the second bus bar preferably includes a second main circuit board connector exposed from the insulating resin, the second main circuit board connector being connected to the main circuit board, and the first bus bar is preferably arranged above the second bus bar in the lateral portion of the resin molded bus bar, and is preferably routed so as not to overlap the second main circuit board connector of the second bus bar, as viewed from above. Accordingly, even when the first bus bar is arranged above the second bus bar in the lateral portion of the resin molded bus bar, the second main circuit board connector of the second bus bar can be easily screwed (fastened) to the main circuit board from above.

In the aforementioned power converter according to this aspect, the vertical portion of the resin molded bus bar preferably has a thickness in a direction in which the first bus bar and the second bus bar overlap, the thickness decreasing upward from the lateral portion side. Accordingly, at the time of manufacturing the resin molded bus bar, the resin molded bus bar can be easily taken out from a casting mold.

An embodiment of the present invention is hereinafter described with reference to the drawings.

The overall configuration of a power converter <NUM> according to this embodiment is now described with reference to <FIG> and <FIG>. As shown in <FIG>, the power converter <NUM> is an inverter including an inverter circuit <NUM> including switching elements 1a, a rectifier circuit <NUM> including diode elements 2a, and a smoothing circuit <NUM> including a smoothing capacitor 3a.

As shown in <FIG>, the power converter <NUM> includes a terminal block <NUM> to which wiring is connected from outside the power converter. The terminal block <NUM> includes a DC terminal block <NUM>. Furthermore, the terminal block <NUM> includes an output terminal block <NUM> and an input terminal block <NUM>.

As shown in <FIG>, the power converter <NUM> includes a main circuit board <NUM> on which a semiconductor module <NUM> is mounted. The semiconductor module <NUM> is an example of a "power conversion semiconductor module" in the claims. Power conversion semiconductor elements (the switching elements 1a and the diode elements 2a) are housed in the semiconductor module <NUM>. The main circuit board <NUM> includes capacitors and relays (not shown).

As shown in <FIG>, the power converter <NUM> includes a power supply board <NUM> arranged above (Z1 direction side) the main circuit board <NUM> and configured to allow an electronic component (component <NUM>) configured to generate a control power supply to be mounted thereon. That is, a power supply for controlling a power conversion circuit (inverter circuit <NUM>) is generated by the power supply board <NUM> and the electronic component mounted on the power supply board <NUM>. Furthermore, electronic components that form a detection circuit (not shown) may be mounted on the power supply board <NUM>.

The main circuit board <NUM> and the power supply board <NUM> are printed circuit boards (PCB) on which a wiring pattern is formed by conductors and electronic components are mounted. The main circuit board <NUM> and the power supply board <NUM> extend along an X direction and a Y direction (XY plane). In this description, an upward-downward direction is defined as a Z direction, a direction orthogonal to the upward-downward direction (Z direction) is defined as the X direction, and a direction orthogonal to the Z direction and the X direction is defined as the Y direction. In <FIG>, only a portion of the power supply board <NUM> on the Y2 direction side is shown by a solid line, but in reality, the power supply board <NUM> extends to the vicinity of the end of the main circuit board <NUM> on the Y1 direction side, as shown by a broken line. The power supply board <NUM> covers the main circuit board <NUM> and a lateral portion 10a of a resin molded bus bar <NUM> described below.

As shown in <FIG>, the semiconductor module <NUM> is mounted on the rear surface side (Z2 direction side) of the main circuit board <NUM>. The main circuit board <NUM> includes a plurality of connection terminals <NUM> provided on the front surface side (Z1 direction side) of the main circuit board <NUM> to allow an electrical connection to the wiring pattern of the main circuit board <NUM> or the semiconductor module <NUM>.

The power converter <NUM> includes output bus bars <NUM> connected to the output terminal block <NUM> (see <FIG>) and input bus bars <NUM> connected to the input terminal block <NUM> (see <FIG>). The output bus bars <NUM> and the input bus bars <NUM> are connected to the connection terminals <NUM> of the main circuit board <NUM>, respectively.

As shown in <FIG>, the terminal block <NUM> is arranged above (Z1 direction side) the main circuit board <NUM>. The DC terminal block <NUM> and the output terminal block <NUM> are integrally formed. The terminal block <NUM> (the DC terminal block <NUM>, the output terminal block <NUM>, and the input terminal block <NUM>) is made of a polybutylene terephthalate (PBT) resin, and includes a terminal for connecting to wiring outside the power converter.

As shown in <FIG> and <FIG>, the power converter <NUM> includes the resin molded bus bar <NUM> integrally resin molded so as to insulate a plate-shaped first bus bar <NUM> and a plate-shaped second bus bar <NUM> with an insulating resin <NUM> (see <FIG>).

As shown in <FIG> and <FIG>, the resin molded bus bar <NUM> has a substantially L-shape including the lateral portion 10a that extends along the main circuit board <NUM> and a vertical portion 10b that extends upward (Z1 direction side) from the lateral portion 10a toward the terminal block <NUM>. The lateral portion 10a extends from the vertical portion 10b to the X2 direction side.

The first bus bar <NUM> and the second bus bar <NUM> are connected to the terminal block <NUM>, as shown in <FIG>. Furthermore, the first bus bar <NUM> and the second bus bar <NUM> are electrically connected to the main circuit board <NUM> (semiconductor module <NUM>). In this embodiment, the first bus bar <NUM> and the second bus bar <NUM> are electrically connected to the semiconductor module <NUM> through the connection terminals <NUM> (see <FIG>) of the main circuit board <NUM>.

As shown in <FIG>, the outer surfaces of the first bus bar <NUM> and the second bus bar <NUM> of the resin molded bus bar <NUM> are covered with the insulating resin <NUM>. The insulating resin <NUM> is a PBT resin, for example. In the resin molded bus bar <NUM>, the insulating resin <NUM> is also provided between the first bus bar <NUM> and the second bus bar <NUM>, as described below.

The first bus bar <NUM> is a bus bar provided in a current path P (see <FIG>) between the rectifier circuit <NUM> (diode element 2a) and a positive electrode terminal 41a (see <FIG>) of the DC terminal block <NUM>. The first bus bar <NUM> is a conductive plate-shaped member. The first bus bar <NUM> is a copper bar, for example.

As shown in <FIG>, the first bus bar <NUM> includes a positive electrode connector 11a exposed from the insulating resin <NUM> and connected to the positive electrode terminal 41a (see <FIG>) of the DC terminal block <NUM>.

As shown in <FIG>, the first bus bar <NUM> includes a connector 11b exposed from the insulating resin <NUM> and connected to the main circuit board <NUM>. The connector 11b is an example of a "first main circuit board connector" in the claims.

As shown in <FIG>, the first bus bar <NUM> includes a connector 11c exposed from the insulating resin <NUM> and connected to the power supply board <NUM>. The connector 11c is an example of a "power supply board connector" in the claims.

The second bus bar <NUM> is a bus bar provided in a current path N (see <FIG>) to connect the inverter circuit <NUM> (switching element 1a) and the smoothing circuit <NUM> (smoothing capacitor 3a) to a negative electrode terminal 41b (see <FIG>) of the DC terminal block <NUM>. The second bus bar <NUM> is a conductive plate-shaped member. The second bus bar <NUM> is a copper bar, for example.

As shown in <FIG>, the second bus bar <NUM> includes a negative electrode connector 12a exposed from the insulating resin <NUM> and connected to the negative electrode terminal 41b (see <FIG>) of the DC terminal block <NUM>. The negative electrode connector 12a of the second bus bar <NUM> is arranged on the Y1 direction side with respect to the positive electrode connector 11a of the first bus bar <NUM>.

As shown in <FIG>, the second bus bar <NUM> includes a connector 12b exposed from the insulating resin <NUM> and connected to the main circuit board <NUM>. The connector 12b is an example of a "second main circuit board connector" in the claims.

As shown in <FIG>, the positive electrode connector 11a of the first bus bar <NUM> is fastened to the terminal block <NUM> (positive electrode terminal 41a) by a screw <NUM>. Furthermore, as shown in <FIG>, the negative electrode connector 12a of the second bus bar <NUM> is fastened to the terminal block <NUM> (negative electrode terminal 41b) by a screw <NUM>.

As shown in <FIG>, the connector 11b of the first bus bar <NUM> is arranged on the side (X2 direction side) opposite to the side on which the smoothing capacitor 3a is arranged with respect to the connector 12b of the second bus bar <NUM>, as viewed from above (Z1 direction side).

As shown in <FIG>, the first bus bar <NUM> is routed so as not to overlap the connector 12b of the second bus bar <NUM>, as viewed from above (Z1 direction side).

As shown in <FIG>, the resin molded bus bar <NUM> branches in the vicinity of the connector 12b of the second bus bar <NUM>. The first bus bar <NUM> bends to the Y2 direction side with the outer surface covered with the insulating resin <NUM> on the X1 direction side of the connector 12b of the second bus bar <NUM>. Furthermore, the first bus bar <NUM> is routed so as not to overlap the connector 12b of the second bus bar <NUM> and extends in an X2 direction.

As shown in <FIG>, the first bus bar <NUM> with the outer surface with the insulating resin <NUM> has a U-shape that is convex to the Y2 direction side, as viewed from above (Z1 direction side). The connector 12b of the second bus bar <NUM> is arranged inside a substantially U-shaped portion (portion U) of the first bus bar <NUM>, as viewed from above (Z1 direction side). The connector 11c extends from the outside (Y2 direction side) of the substantially U-shaped portion (portion U) of the first bus bar <NUM> to the Y2 direction side.

As shown in <FIG>, the first bus bar <NUM> is arranged above (Z1 direction side) the second bus bar <NUM> in the lateral portion 10a of the resin molded bus bar <NUM>. As shown in <FIG>, the second bus bar <NUM> is arranged on the terminal block <NUM> side (X1 direction side) with respect to the first bus bar <NUM> in the vertical portion 10b of the resin molded bus bar <NUM>.

As shown in <FIG>, the resin molded bus bar <NUM> is configured to sandwich the insulating resin <NUM> between the first bus bar <NUM> and the second bus bar <NUM>. The resin molded bus bar <NUM> sandwiches the insulating resin <NUM> between the first bus bar <NUM> and the second bus bar <NUM> in the lateral portion 10a and the vertical portion 10b. In the resin molded bus bar <NUM>, the first bus bar <NUM> and the second bus bar <NUM> are stacked while being spaced apart from each other by a separation distance D1 (see <FIG>) smaller than an air insulation distance. The separation distance D1 is an example of a "first separation distance" in the claims.

As described above, the first bus bar <NUM> is connected to the positive electrode terminal 41a (see <FIG>) of the DC terminal block <NUM> by the positive electrode connector 11a. The second bus bar <NUM> is connected to the negative electrode terminal 41b (see <FIG>) of the DC terminal block <NUM> by the negative electrode connector 12a. Currents flow through the first bus bar <NUM> and the second bus bar <NUM> in opposite directions to each other. In the vertical portion 10b and the lateral portion 10a of the resin molded bus bar <NUM>, the first bus bar <NUM> and the second bus bar <NUM> are stacked. Thus, in portions of the vertical portion 10b and the lateral portion 10a in which the first bus bar <NUM> and the second bus bar <NUM> are stacked, currents flow through the first bus bar <NUM> and the second bus bar <NUM> in opposite directions to each other such that magnetic fields generated by the currents flowing through the first bus bar <NUM> and the second bus bar <NUM> can cancel each other out. Consequently, in the resin molded bus bar <NUM>, the inductances of the first bus bar <NUM> and the second bus bar <NUM> can be reduced in the portions of the vertical portion 10b and the lateral portion 10a in which the first bus bar <NUM> and the second bus bar <NUM> are stacked.

The first bus bar <NUM> and the second bus bar <NUM> are spaced apart from each other by the separation distance D1 (see <FIG>), but the separation distance D1 (the thickness of the insulating resin <NUM> between the first bus bar <NUM> and the second bus bar <NUM>) may be changed as appropriate according to the magnitudes of the currents flowing through the first bus bar <NUM> and the second bus bar <NUM> and the electrical characteristics of the insulating resin <NUM>. That is, the separation distance D1 (the thickness of the insulating resin <NUM> between the first bus bar <NUM> and the second bus bar <NUM>) may be substantially the same as the thickness t1 of the first bus bar <NUM> and the thickness t2 of the second bus bar <NUM>, as shown in <FIG>, or may be larger or smaller than the thickness t1 of the first bus bar <NUM> and the thickness t2 of the second bus bar <NUM>.

The first bus bar <NUM> is arranged between the circuit board <NUM> and the power supply board <NUM> while being spaced apart from the power supply board <NUM> by a separation distance D2 (see <FIG>) that is smaller than the air insulation distance in the lateral portion 10a covered with the insulating resin <NUM>. The separation distance D2 is an example of a "second separation distance" in the claims.

The first bus bar <NUM> has a stepped shape (see <FIG>) that bends toward the main circuit board <NUM> (Z2 direction side), and the connector 11b is connected to the main circuit board <NUM> from above (Z1 direction side). The connector 11b of the first bus bar <NUM> is connected to the connection terminal <NUM> of the main circuit board <NUM> from the Z1 direction side by a screw <NUM> (see <FIG>), and is electrically connected to the semiconductor module <NUM> through the connection terminal <NUM>. The first bus bar <NUM> is electrically connected to the positive electrode side of the semiconductor module <NUM>.

The connector 11c of the first bus bar <NUM> has a stepped shape (see <FIG> and <FIG>) that bends toward the power supply board <NUM> (Z1 direction side), and is connected to the power supply board <NUM> from below (Z2 direction side). The connector 11c is connected to the conductor pattern of the power supply board <NUM> from the Z2 direction side, and is fastened by a screw <NUM>.

The second bus bar <NUM> is arranged between the main circuit board <NUM> and the power supply board <NUM> while being spaced apart from the main circuit board <NUM> by a separation distance D3 (see <FIG>) that is smaller than the air insulation distance in the lateral portion 10a covered with the insulating resin <NUM>. The separation distance D3 is an example of a "third separation distance" in the claims.

The second bus bar <NUM> has a stepped shape (see <FIG>) that bends toward the main circuit board <NUM> (Z2 direction side), and the connector 12b is connected to the main circuit board <NUM> from above (Z1 direction side). As shown in <FIG>, the connector 12b of the second bus bar <NUM> is connected to the connection terminal <NUM> of the main circuit board <NUM> from the Z1 direction side by a screw <NUM>, and is electrically connected to the semiconductor module <NUM> through the connection terminal <NUM>. The second bus bar <NUM> is electrically connected to the negative electrode side of the semiconductor module <NUM>.

As shown in <FIG>, the vertical portion 10b of the resin molded bus bar <NUM> is configured such that the thickness thereof in the X direction (a direction in which the first bus bar <NUM> and the second bus bar <NUM> overlap) decreases (tapers) upward (Z1 direction side) from the lateral portion 10a side (Z2 direction side). That is, in the resin molded bus bar <NUM>, the thickness t4 of the vertical portion 10b on the upper side (Z1 direction side) is smaller than the thickness t3 of the vertical portion 10b on the lower side (Z2 direction side).

According to this embodiment, the following advantageous effects are achieved.

According to this embodiment, the resin molded bus bar <NUM> has an L-shape including the lateral portion 10a that extends along the main circuit board <NUM> and the vertical portion 10b that extends upward (Z1 direction side) from the lateral portion 10a toward the terminal block <NUM>. Furthermore, the resin molded bus bar <NUM> is integrally resin molded such that the first bus bar <NUM> and the second bus bar <NUM> are insulated by the insulating resin <NUM>. Accordingly, the insulating resin <NUM> insulates the first bus bar <NUM> from the second bus bar <NUM>, and thus even when the first bus bar <NUM> and the second bus bar <NUM> overlap in the upward-downward direction (Z direction), a distance between the first bus bar <NUM> and the second bus bar <NUM> can be smaller in the lateral portion 10a that extends along the main circuit board <NUM> than that in a case in which insulation is provided by air (air insulation is provided). Consequently, an increase in the size of the power converter <NUM> in the upward-downward direction over the main circuit board <NUM> can be significantly reduced or prevented. Furthermore, the lateral portion 10a of the resin molded bus bar <NUM> including a single member in which the first bus bar <NUM>, the second bus bar <NUM>, and the insulating resin <NUM> are integrally resin molded extends along the main circuit board <NUM> such that both the first bus bar <NUM> and the second bus bar <NUM> can be easily electrically connected to the main circuit board <NUM> (semiconductor module <NUM>). Furthermore, the vertical portion 10b of the resin molded bus bar <NUM> including a single member in which the first bus bar <NUM>, the second bus bar <NUM>, and the insulating resin <NUM> are integrally resin molded extends from the lateral portion 10a upward (Z1 direction side) toward the terminal block <NUM> such that both the first bus bar <NUM> and the second bus bar <NUM> can be easily electrically connected to the terminal block <NUM> arranged above the main circuit board <NUM>. Accordingly, both the first bus bar <NUM> and the second bus bar <NUM> can be easily electrically connected to the main circuit board <NUM> (semiconductor module <NUM>) and the terminal block <NUM> arranged above the main circuit board <NUM> by the resin molded bus bar <NUM> as a single member having an L-shape including the lateral portion 10a and the vertical portion 10b. Consequently, unlike a case in which the first bus bar <NUM> and the second bus bar <NUM> are attached so as to sandwich an insulating member as a separate member, an increase in the number of components and complication of assembly can be significantly reduced or prevented. Thus, an increase in the size of the power converter in the upward-downward direction can be significantly reduced or prevented while a decrease in workability during assembly is significantly reduced or prevented.

According to this embodiment, as described above, the resin molded bus bar <NUM> sandwiches the insulating resin <NUM> between the first bus bar <NUM> and the second bus bar <NUM>, and the first bus bar <NUM> and the second bus bar <NUM> are stacked while being spaced apart from each other by the separation distance D1 that is smaller than the air insulation distance. Accordingly, even when the first bus bar <NUM> and the second bus bar <NUM> overlap in the upward-downward direction (Z direction), the insulating resin <NUM> is sandwiched between the first bus bar <NUM> and the second bus bar <NUM>, and thus the first bus bar <NUM> and the second bus bar <NUM> can be reliably insulated. Consequently, the distance between the first bus bar <NUM> and the second bus bar <NUM> can be smaller than the air insulation distance, and thus an increase in the size of the power converter <NUM> in the upward-downward direction (Z direction) over the main circuit board <NUM> can be significantly reduced or prevented.

According to this embodiment, as described above, the first bus bar <NUM> includes the positive electrode connector 11a exposed from the insulating resin <NUM> and connected to the positive electrode terminal 41a of the DC terminal block <NUM>. Furthermore, the second bus bar <NUM> includes the negative electrode connector 12a exposed from the insulating resin <NUM> and connected to the negative electrode terminal 41b of the DC terminal block <NUM>. Moreover, the first bus bar <NUM> and the second bus bar <NUM> are configured to allow currents to flow therethrough in the opposite directions to each other. Accordingly, currents flow through the first bus bar <NUM> and the second bus bar <NUM> in the opposite directions such that the magnetic fields generated by the currents flowing through the first bus bar <NUM> and the second bus bar <NUM> can cancel each other out. Consequently, the inductances of the first bus bar <NUM> and the second bus bar <NUM> can be reduced.

According to this embodiment, as described above, the outer surfaces of the first bus bar <NUM> and the second bus bar <NUM> of the resin molded bus bar <NUM> are covered with the insulating resin <NUM>. Furthermore, the first bus bar <NUM> is arranged between the main circuit board <NUM> and the power supply board <NUM> while being spaced apart by the separation distance D2 that is smaller than the air insulation distance from the power supply board <NUM> in the lateral portion 10a covered with the insulating resin <NUM>. Moreover, the second bus bar <NUM> is arranged between the main circuit board <NUM> and the power supply board <NUM> while being spaced apart by the separation distance D3 that is smaller than the air insulation distance from the main circuit board <NUM> in the lateral portion 10a covered with the insulating resin <NUM>. Accordingly, the first bus bar <NUM> is arranged between the main circuit board <NUM> and the power supply board <NUM> while being spaced apart by the separation distance D2 that is smaller than the air insulation distance from the power supply board <NUM> in the lateral portion 10a covered with the insulating resin <NUM> such that a distance between the first bus bar <NUM> and the power supply board <NUM> can be reduced. Furthermore, the second bus bar <NUM> is arranged between the main circuit board <NUM> and the power supply board <NUM> while being spaced apart by the separation distance D3 that is smaller than the air insulation distance from the main circuit board <NUM> in the lateral portion 10a covered with the insulating resin <NUM> such that a distance between the second bus bar <NUM> and the main circuit board <NUM> can be reduced. Consequently, a distance D4 (see <FIG>) between the main circuit board <NUM> and the power supply board <NUM> arranged so as to sandwich the first bus bar <NUM> and the second bus bar <NUM> can be reduced, and thus an increase in the size in the upward-downward direction (Z direction) over the main circuit board <NUM> can be significantly reduced or prevented.

According to this embodiment, as described above, the first bus bar <NUM> includes the connector 11b exposed from the insulating resin <NUM> and connected to the main circuit board <NUM>, and the connector 11c exposed from the insulating resin <NUM> and connected to the power supply board <NUM>. Accordingly, the first bus bar <NUM> having the outer surface covered with the insulating resin <NUM> can be easily connected to the main circuit board <NUM> by the connector 11b exposed from the insulating resin <NUM>. Furthermore, the first bus bar <NUM> having the outer surface covered with the insulating resin <NUM> can be easily connected to the power supply board <NUM> by the connector 11c exposed from the insulating resin <NUM>.

According to this embodiment, as described above, the first bus bar <NUM> has a stepped shape that bends toward the main circuit board <NUM> (Z2 direction side), and the connector 11b is connected to the main circuit board <NUM> from above. Furthermore, the connector 11c of the first bus bar <NUM> has a stepped shape that bends toward the power supply board <NUM> (Z1 direction side), and is connected to the power supply board <NUM> from below. Accordingly, even when the lateral portion 10a in which the first bus bar <NUM> is covered with the insulating resin <NUM> is spaced apart from the main circuit board <NUM> by the air insulation distance, due to the stepped shape of the first bus bar <NUM> that bends toward the main circuit board <NUM>, the connector 11b of the first bus bar <NUM> can be closer to the main circuit board <NUM> (Z2 direction side) (the height positions can be closer). Consequently, the connector 11b of the first bus bar <NUM> can be easily connected to the main circuit board <NUM>. Furthermore, even when the lateral portion 10a in which the first bus bar <NUM> is covered with the insulating resin <NUM> is spaced apart from the power supply board <NUM> by the air insulation distance, due to the stepped shape of the connector 11c that bends toward the power supply board <NUM>, the connector 11c can be closer to the power supply board <NUM> (Z1 direction side) (the height positions can be closer). Consequently, the connector 11c of the first bus bar <NUM> can be easily connected to the power supply board <NUM>.

According to this embodiment, as described above, the second bus bar <NUM> includes the connector 12b exposed from the insulating resin <NUM> and connected to the main circuit board <NUM>. Furthermore, the first bus bar <NUM> is arranged above the second bus bar <NUM> (Z1 direction side) in the lateral portion 10a of the resin molded bus bar <NUM>, and is routed so as not to overlap the connector 12b of the second bus bar <NUM>, as viewed from above. Accordingly, even when the first bus bar <NUM> is arranged above the second bus bar <NUM> in the lateral portion 10a of the resin molded bus bar <NUM>, the connector 12b of the second bus bar <NUM> can be easily screwed (fastened) to the main circuit board <NUM> from above.

According to this embodiment, as described above, the vertical portion 10b of the resin molded bus bar <NUM> has a thickness in the direction (X direction) in which the first bus bar <NUM> and the second bus bar <NUM> overlap that decreases upward (Z1 direction side) from the lateral portion 10a side. Accordingly, at the time of manufacturing the resin molded bus bar <NUM>, the resin molded bus bar <NUM> can be easily taken out from a casting mold.

The embodiment disclosed this time must be considered as illustrative in all points and not restrictive. The scope of the present invention is not shown by the above description of the embodiment but by the scope of claims for patent, and all modifications (modified examples) within the meaning and scope equivalent to the scope of claims for patent are further included.

For example, while the first bus bar <NUM> and the second bus bar <NUM> are connected to the terminal block <NUM>, are connected to the connection terminals <NUM> of the main circuit board <NUM>, and are electrically connected to the semiconductor module <NUM> through the connection terminals <NUM> of the main circuit board <NUM> in the aforementioned embodiment, the present invention is not restricted to this. For example, the first bus bar and the second bus bar may alternatively be connected to the terminal block and may be connected to terminals of the power conversion semiconductor module not through the main circuit board (the connection terminals of the main circuit board).

While in the resin molded bus bar <NUM>, the first bus bar <NUM> and the second bus bar <NUM> (two bus bars) are integrally resin molded so as to be insulated by the insulating resin <NUM> in the aforementioned embodiment, the present invention is not restricted to this. In the present invention, the resin molded bus bar may alternatively include three or more bus bars integrally resin molded.

While in the resin molded bus bar <NUM>, the first bus bar <NUM> connected to the positive electrode terminal 41a of the DC terminal block <NUM> and the second bus bar <NUM> connected to the negative electrode terminal 41b of the DC terminal block <NUM> are integrally resin molded in the aforementioned embodiment, the present invention is not restricted to this. In the present invention, in the resin molded bus bar, any two or more of the bus bar connected to the DC terminal block, the bus bar connected to the input terminal block, and the bus bar connected to the output terminal block may alternatively be integrally molded, or these bus bars may alternatively be combined and integrally molded. That is, the first bus bar may be any of the bus bar connected to the DC terminal block, the bus bar connected to the input terminal block, and the bus bar connected to the output terminal block. Furthermore, the second bus bar may be any of the bus bar connected to the DC terminal block, the bus bar connected to the input terminal block, and the bus bar connected to the output terminal block.

While the lateral portion 10a of the resin molded bus bar <NUM> is arranged between the main circuit board <NUM> and the power supply board <NUM> in the aforementioned embodiment, the present invention is not restricted to this. In the present invention, the power supply board may alternatively be shifted in a direction (the X direction or Y direction) along the main circuit board so as not to cover the upper side of the lateral portion of the resin molded bus bar.

While the first bus bar <NUM> includes the connector 11b (first main circuit board connector) exposed from the insulating resin <NUM> and connected to the main circuit board <NUM>, and the connector 11c (power supply board connector) exposed from the insulating resin <NUM> and connected to the power supply board <NUM> in the aforementioned embodiment, the present invention is not restricted to this. In the present invention, the bus bar connected to the positive electrode terminal of the DC terminal block and connected to the power supply board may alternatively be provided separately from the resin molded first bus bar.

While the first bus bar <NUM> has a stepped shape that bends toward the main circuit board <NUM> (Z2 direction side), and the connector 11b (first main circuit board connector) is connected to the main circuit board <NUM> from above in the aforementioned embodiment, the present invention is not restricted to this. In the present invention, the connection terminal provided on the main circuit board may alternatively extend toward the first main circuit board connector of the first bus bar, and the first main circuit board connector of the first bus bar may alternatively be connected by the connection terminal provided on the main circuit board without bending toward the main circuit board.

While the connector 11c (power supply board connector) of the first bus bar <NUM> has a stepped shape that bends toward the power supply board <NUM> (Z1 direction side), and is connected to the power supply board <NUM> from below in the aforementioned embodiment, the present invention is not restricted to this. In the present invention, a connection terminal provided on the power supply board may alternatively extend toward the power supply board connector of the first bus bar, and the power supply board connector of the first bus bar may alternatively be connected by the connection terminal provided on the power supply board without bending toward the power supply board.

While the first bus bar <NUM> is arranged above (Z1 direction side) the second bus bar <NUM> in the lateral portion 10a of the resin molded bus bar <NUM> in the aforementioned embodiment, the present invention is not restricted to this. In the present invention, the first bus bar may alternatively be arranged below the second bus bar in the lateral portion of the resin molded bus bar.

While the first bus bar <NUM> connected to the positive electrode terminal 41a of the DC terminal block <NUM> is arranged above (Z1 direction side) the second bus bar <NUM> connected to the negative electrode terminal 41b of the DC terminal block <NUM> in the lateral portion 10a of the resin molded bus bar <NUM> in the aforementioned embodiment, the present invention is not restricted to this. In the present invention, the bus bar connected to the positive electrode terminal of the DC terminal block may alternatively be arranged below the bus bar connected to the negative electrode terminal of the DC terminal block in the lateral portion of the resin molded bus bar.

While the first bus bar <NUM> is covered with the insulating resin <NUM> up to the vicinity of the connection terminal <NUM> (see <FIG>) in the aforementioned embodiment, the present invention is not restricted to this. In the present invention, the first bus bar may alternatively be exposed from the insulating resin in a portion of the resin molded bus bar in which a distance corresponding to the air insulation distance can be ensured (spaced apart) between the first bus bar and the power supply board. That is, the first bus bar may be covered with the insulating resin only in a portion of the resin molded bus bar in which a distance corresponding to the air insulation distance cannot be ensured (spaced apart) between the first bus bar and the power supply board. Alternatively, the second bus bar may alternatively be exposed from the insulating resin in a portion of the resin molded bus bar in which a distance corresponding to the air insulation distance can be ensured between the second bus bar and the main circuit board.

Claim 1:
A power converter (<NUM>) comprising:
a main circuit board (<NUM>) configured to allow a power conversion semiconductor module (<NUM>) to be mounted thereon;
a terminal block (<NUM>) arranged above the main circuit board, the terminal block being configured to allow wiring to be connected thereto from outside the power converter; and
a resin molded bus bar (<NUM>, <NUM>) integrally resin molded such that a plate-shaped first bus bar (<NUM>) and a plate-shaped second bus bar (<NUM>), both of which are connected to the terminal block and are electrically connected to the main circuit board, are insulated by an insulating resin (<NUM>, <NUM>); wherein
the resin molded bus bar has an L-shape including a lateral portion (10a) configured to extend along the main circuit board and a vertical portion (10b) configured to extend upward from the lateral portion toward the terminal block,
wherein the power converter (<NUM>) is characterized by further comprising
a power supply board (<NUM>) arranged above the main circuit board, the power supply board being configured to allow an electronic component (<NUM>) configured to generate a control power supply to be mounted thereon; wherein
each of the first bus bar and the second bus bar of the resin molded bus bar has an outer surface covered with the insulating resin;
the first bus bar is arranged between the main circuit board and the power supply board while being spaced apart by a second separation distance (D2) that is smaller than the air insulation distance from the power supply board in the lateral portion covered with the insulating resin; and
the second bus bar is arranged between the main circuit board and the power supply board while being spaced apart by a third separation distance (D3) that is smaller than the air insulation distance from the main circuit board in the lateral portion covered with the insulating resin,
wherein the first bus bar (<NUM>) and the second bus bar (<NUM>) are electrically connected to the semiconductor module (<NUM>) through connection terminals (<NUM>),
wherein the first bus bar includes a first main circuit board connector (11b, 211b) exposed from the insulating resin, the first main circuit board connector being connected to the main circuit board, and a power supply board connector (11c) exposed from the insulating resin, the power supply board connector being connected to the power supply board.