Power conversion device

Abstract

The reference potential pattern (20) of the printed circuit board (3) of the power conversion device (100) is connected to the housing (5), forming an electromagnetic shielding area (6A) surrounded by shielding walls (5B, 5C) of the housing (5) and the reference potential pattern (20). A power conversion circuit (1) is provided outside the electromagnetic shielding area (6A), and a conductive path (36) connected to the control circuit (2) and the power conversion circuit (1) is led from the outside of the electromagnetic shielding area to the electromagnetic shielding area via first connection holes (36H1, H2) of the printed circuit board (3) and is wired within the electromagnetic shielding area (6A).

Description

Technical Field

[0001] The present application relates to a power conversion device. Background Art

[0002] In recent years, power conversion devices have achieved high power and high density through miniaturization of components based on high-frequency switching and high-density component installation. The source of noise in power conversion devices is the switching noise of semiconductor elements. Filter circuits are usually used to prevent noise from propagating outside the device. However, the amount of noise increases due to high-frequency switching, and the electromagnetic coupling between components increases due to high-density installation. As a result, the noise propagating in the space between components that are not connected by electrical wiring becomes of a non-negligible magnitude. Therefore, it is necessary not only to simply set up a filter circuit, but also to design a method to reduce the electromagnetic coupling between the power conversion circuit and the filter circuit to suppress the noise propagating in the space.

[0003] Therefore, the following structure has been proposed in the past: within a metal casing, areas for accommodating a power conversion circuit and a filter circuit are separated, and shielding walls are provided in a manner that reduces electromagnetic coupling between the areas. When shielding the power conversion circuit and the filter circuit, it is necessary to accommodate the filter circuit in a shielded space surrounded by metal. The bottom and side surfaces of the shielded space can be easily shielded by using the bottom, outer wall, and inner wall of the metal casing of the power conversion device. The upper surface of the shielded space can be shielded by using a metal plate, but the addition of the metal plate causes the device to become larger and heavier. In order to solve such problems, for example, a power supply device as a power conversion device with the following structure is disclosed.

[0004] That is, the previous power supply device includes a shell, a first substrate, a rectifier, a transformer, a filter, and an output stabilizer. The shell body has a plurality of partitions to form a plurality of receiving sections. The receiving sections are divided by these partitions. The first shielding section is configured so as to be between the rectifier and the filter mechanism. The second shielding section is configured so as to be between the filter and the output stabilizer. The first and second shielding sections have the function of shielding noise. Slits for passing connecting wires are formed in the first and second shielding sections. The width and depth of these slits vary depending on the configuration of the busbars. The second and third substrates are multi-layer printed substrates, both of which are configured near the shell cover. In addition to having a configuration layer for configuring circuit elements, components, etc., the second and third substrates also have a ground layer as at least one layer other than the configuration layer, which shields noise on almost the entire surface of the substrate (for example, refer to patent document 1).

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2013-90533 (paragraphs

[0018] to

[0040] , Figures 1 to 5 ) Summary of the Invention

[0006] Problems to be solved by the invention

[0007] In power supply devices with this structure, it has been proposed to use the metal pattern of the printed circuit board to form a ground layer to shield the upper surface of the shielded space. However, since the wiring connecting from the outside of the shielded space to the inside is subject to electromagnetic coupling from outside the shielded space, it is impossible to prevent noise from propagating into the shielded space. Furthermore, there is a problem in preventing noise from leaking into the shielded space through gaps such as slits in the housing wall, which allow the wiring from outside to inside to pass through.

[0008] The present application discloses a technique for solving the above-mentioned problems, and an object of the present application is to provide a compact power conversion device that suppresses noise.

[0009] Solutions for solving problems

[0010] The power conversion device disclosed in this application is as follows.

[0011] A power conversion device includes a power conversion circuit for performing power conversion and a control circuit for controlling the power conversion circuit, and comprises:

[0012] a filter circuit connected to a control conductive path for controlling at least one of the control circuit and the power conversion circuit, and suppressing electromagnetic noise in the control conductive path;

[0013] a circuit wiring board which is a printed circuit board provided with the filter circuit and having a reference potential pattern formed on an inner layer; and

[0014] a housing holding the circuit wiring board,

[0015] The reference potential pattern is connected to the housing,

[0016] The housing has a shielding wall provided on a first main surface side of a surface layer on one side in a thickness direction of the circuit wiring board, forming an electromagnetic shielding area surrounded by the shielding wall and the reference potential pattern, and the control circuit and the power conversion circuit are arranged outside the electromagnetic shielding area.

[0017] The control conductive path is led from the control circuit into the electromagnetic shielding area through a first connection hole connecting wiring conductors of at least two layers of the circuit wiring board and is wired within the electromagnetic shielding area.

[0018] The filter circuit has:

[0019] a first capacitor provided in the electromagnetic shielding region of the circuit wiring board, having a first end connected to the control conductive path in the electromagnetic shielding region and a second end connected to the reference potential pattern; and

[0020] The second capacitor is provided outside the electromagnetic shielding area of ​​the circuit wiring board, has a first end connected to the control conductive path, and a second end connected to the reference potential pattern.

[0021] Effects of the Invention

[0022] According to the power conversion device disclosed in the present application, it is possible to obtain a compact power conversion device while suppressing noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a cross-sectional view showing a schematic configuration of a power conversion device according to the first embodiment.

[0024] Figure 2 This is a cross-sectional view showing a schematic configuration of a power conversion device according to the first embodiment.

[0025] Figure 3 This is a cross-sectional view showing a schematic configuration of a power conversion device according to the first embodiment.

[0026] Figure 4 This is a cross-sectional view showing a schematic configuration of a power conversion device according to the first embodiment.

[0027] Figure 5 This is a cross-sectional view showing a schematic configuration of a power conversion device according to the first embodiment.

[0028] Figure 6 This is a top view showing a schematic configuration of the power conversion device according to the first embodiment.

[0029] Figure 7 This is a top view showing a schematic configuration of the power conversion device according to the first embodiment.

[0030] Figure 8 This is a top view showing a schematic configuration of the power conversion device according to the first embodiment.

[0031] Figure 9 This is a cross-sectional view showing a schematic configuration of a power conversion device according to the second embodiment.

[0032] Figure 10 This is a cross-sectional view showing a schematic configuration of a power conversion device according to a third embodiment.

[0033] Figure 11 It is a top view showing a schematic configuration of a power conversion device according to a fourth embodiment.

[0034] Figure 12 It is a top view showing a schematic configuration of a power conversion device according to a fourth embodiment.

[0035] Figure 13 It is a top view showing a schematic structure of a power conversion device according to the fifth embodiment.

[0036] Figure 14 It is a top view showing a schematic structure of a power conversion device according to the sixth embodiment.

[0037] Figure 15 It is a top view showing a schematic structure of a power conversion device according to the seventh embodiment.

[0038] Figure 16 It is a top view showing a schematic structure of a power conversion device according to the eighth embodiment.

[0039] Figure 17 It is a top view showing a schematic structure of a power conversion device according to the ninth embodiment.

[0040] Figure 18 This is a cross-sectional view showing a schematic configuration of a power conversion device according to the tenth embodiment.

[0041] Figure 19 It is a top view showing a schematic structure of a power conversion device according to the eleventh embodiment.

[0042] (Explanation of Reference Numerals)

[0043] 1: Power conversion circuit; 2: Control circuit; 3: Printed circuit board (circuit wiring board); 5: Housing; 30, 530: First filter circuit; 38: Inductor; 5B: Housing wall (shielding wall); 5C: Bottom (shielding wall); 36H1, 36H2: Through hole (first connection hole); 31, 631a, 631b: First capacitor; 32, 33: Second capacitor; 739, 839: Stabilizing capacitor; 100, 100a, 100b, 100c, 100d, 100f, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100: Power conversion device. DETAILED DESCRIPTION

[0044] Implementation method 1.

[0045] First, a power conversion device according to Embodiment 1 of the present application will be described.

[0046] Figure 1 This is a cross-sectional view schematically showing the structure of the power conversion device 100 according to the first embodiment.

[0047] The power conversion device 100 includes a power conversion circuit 1 having semiconductor switching elements (not shown) and performing power conversion, and a control circuit 2 for controlling the power conversion circuit 1 .

[0048] The power conversion device 100 further includes a first filter circuit 30 for suppressing electromagnetic noise in a control conductive path for controlling the control circuit 2 , a printed circuit board 3 on which the first filter circuit 30 is provided, and a conductive housing 5 for holding and housing the printed circuit board 3 .

[0049] The wide surface of the printed circuit board 3 on one side in the thickness direction Y is referred to as the first principal surface 3A, and the wide surface of the printed circuit board 3 on the opposite side to the first principal surface 3A is referred to as the second principal surface 3B.

[0050] The printed circuit board 3 is a multilayer board having the first main surface 3A, the second main surface 3B, and one or more inner layers. A ground pattern 20 serving as a reference potential pattern connected to the housing 5 is formed on the inner layer.

[0051] First ground pads 34P1 and 35P1 serving as connection pads are formed on the first main surface 3A of the printed circuit board 3, and second ground pads 35P2 serving as connection pads are formed on the second main surface 3B of the printed circuit board 3. These first ground pads 34P1 and 35P1 and second ground pads 35P2 on the surface layer of the printed circuit board 3 are connected to the ground pattern 20 on the inner layer via through-holes 34H and 35H serving as second connection holes that electrically connect the wiring conductors of each layer of the printed circuit board 3 to each other.

[0052] Next, the structure of the housing 5 will be described.

[0053] Figure 2 It means in Figure 1 The illustrated cross-sectional view shows a state in which the printed circuit board 3 is fixed by the case 5 in the power conversion device 100 .

[0054] The housing 5 includes a conductive outer wall 5A that surrounds the printed circuit board 3, a conductive housing wall 5B that serves as a shielding wall and is located on the lower side Y1 of the first principal surface 3A of the printed circuit board 3, a bottom surface 5C, and a cover 5D. The bottom surface 5C is formed substantially parallel to the first principal surface 3A of the printed circuit board 3. The outer wall 5A extends upward in the direction Y2 from the end of the bottom surface 5C, laterally surrounding the printed circuit board 3. The housing wall 5B is disposed inward of the outer wall 5A, extending from the bottom surface 5C toward the first principal surface 3A of the printed circuit board 3, with its end on the upper side Y2 abutting against the first principal surface 3A. The outer wall 5A and the housing wall 5B are each electrically connected to the bottom surface 5C.

[0055] The space within the housing 5, located on the lower side (direction Y1) of the printed circuit board 3, is divided by the housing wall 5B into a shielded area 6A, which serves as an electromagnetic shielding area, and another area 6B outside the shielded area 6A. Since the first principal surface 3A of the printed circuit board 3 is arranged so as to face the shielded area 6A, the upper side (direction Y2) of the shielded area 6A is covered by the printed circuit board 3.

[0056] The upper end surface of the housing wall 5B, facing the Y2 direction, is connected to the first ground pads 34P1 and 35P1. Furthermore, the printed circuit board 3 is secured to the housing wall 5B at at least one location using screws 8. The screws 8 penetrate the hollow portions of the through-holes 34H and 35H connecting the ground pattern 20 to the first ground pads 34P1 and 35P1. This secures the printed circuit board 3 to the housing 5. Furthermore, the ground pattern 20 formed on the inner layer of the printed circuit board 3 is electrically connected to the housing 5 via the first ground pads 34P1 and 35P1, thereby grounding the printed circuit board 3.

[0057] Thus, the following shielding area 6A is formed: the shielding area 6A is surrounded by the bottom surface 5C of the shell 5, the outer wall 5A, the shell wall 5B, the ground pattern 20, the first grounding pads 34P1, 35P1, the through hole 34H connecting the first grounding pad 34P1 and the ground pattern 20, and the through hole 35H connecting the first grounding pad 35P1 and the ground pattern 20, thereby shielding electromagnetic waves from the outside.

[0058] Here, the shield region 6A includes not only the spatial region on the lower side in the direction Y1 of the first main surface 3A of the printed circuit board 3 , but also the region from the first main surface 3A to the ground pattern 20 in the printed circuit board 3 .

[0059] The material of the housing 5 is, for example, aluminum, iron, or carbon fiber, but may also be an insulator with a conductive coating applied to the surface.

[0060] Outside shielded area 6A, control circuit 2 for controlling power conversion circuit 1 is mounted on first principal surface 3A, second principal surface 3B, or both surfaces of printed circuit board 3. In this embodiment, control circuit 2 is mounted on second principal surface 3B of printed circuit board 3.

[0061] Furthermore, power conversion circuit 1 is disposed within region 6B outside shielded region 6A. This allows components (not shown) such as capacitors, coils, and power semiconductor switching elements that make up power conversion circuit 1 to be housed within region 6B, separated from shielded region 6A by housing wall 5B. As long as these components for power conversion circuit 1 are located outside shielded region 6A, they can be mounted directly on printed circuit board 3 or connected to it via wiring.

[0062] The control circuit 2 operates based on a control signal or power supply voltage supplied from the outside of the power conversion device 100 via the external connection wiring 4 and the non-ground pattern 36. The external connection wiring 4 is a wiring that is inserted from the outside of the power conversion device 100 into the shielded area 6A as a control conductive path, and the non-ground pattern 36 is a pattern that is formed on the printed circuit board 3 and connected to the external connection wiring 4 as a control conductive path.

[0063] The non-ground pattern 36 inside the shield area 6A and the non-ground pattern 36 outside the shield area 6A are connected via through-holes 36H1 and 36H2 , which are first connection holes capable of connecting wiring conductors between at least two layers of the printed circuit board 3 .

[0064] The non-ground pattern 36 and the ground pattern 20 must be insulated to prevent electrical conduction. Therefore, the through-holes 36H1 through which the external connection wiring 4 passes, and the through-holes 36H2 connecting the non-ground pattern 36 inside the shield area 6A with the non-ground pattern 36 outside the shield area 6A, must pass through holes provided in the ground pattern 20. The ground pattern 20 seamlessly covers the shield area 6A except for the holes (slits) through which the through-holes 36H1 and 36H2 through which the external connection wiring 4 passes, thereby enhancing the electromagnetic shielding effect within the shield area 6A.

[0065] Furthermore, in this embodiment, the external connection wiring 4 is configured to penetrate the ground pattern 20 via the through-hole 31H1. This is because the external connection wiring 4 is configured to be a terminal of a connector component that penetrates the printed circuit board 3. For example, when the external connection wiring 4 is routed using a connector that can be surface-mounted on the printed circuit board 3, a configuration can be employed in which the through-hole H1 penetrating the ground pattern 20 is not provided.

[0066] As described above, the first filter circuit 30 is used to suppress electromagnetic noise in the control conductive path propagated from the control circuit 2 , and includes a first capacitor 31 and a second capacitor 32 .

[0067] First capacitor 31 is provided on first main surface 3A of printed circuit board 3 within shield region 6A. First capacitor 31 has a first end connected to non-ground pattern 36 within shield region 6A and a second end connected to first ground pad 34P1 for grounding.

[0068] Second capacitor 32 is provided on second main surface 3B of printed circuit board 3 outside shield region 6A. Second capacitor 32 has a first end connected to non-ground pattern 36 outside shield region 6A and a second end connected to second ground pad 35P2 for grounding.

[0069] Furthermore, the through hole 36H1 through which the external connection wiring 4 passes may also function as a via hole connecting the non-ground pattern 36 inside the shield region 6A and the non-ground pattern 36 outside the shield region 6A.

[0070] In the power conversion device 100 of the present embodiment, noise propagating from the control circuit 2 and the power conversion circuit 1 to the non-ground pattern 36 is bypassed to the housing 5 by the second capacitor 32 arranged outside the shield region 6A, thereby reducing the noise.

[0071] Furthermore, when a noise current flows through the second capacitor 32 , the second capacitor 32 generates a magnetic flux in an amount proportional to the noise current, and the shield region 6A functions to also shield the magnetic flux generated by the second capacitor 32 .

[0072] Furthermore, the non-ground pattern 36 outside the shielded area 6A is routed into the shielded area 6A via a through-hole 36H formed in the printed circuit board 3, rather than using wiring such as cables or busbars. This allows for the shortest possible connection between the non-ground pattern 36 outside the shielded area 6A and the non-ground pattern 36 inside the shielded area 6A via the printed circuit board 3. This reduces the potential for noise propagating into the shielded space due to electromagnetic coupling from outside the shielded space to the wiring connecting the wiring from outside the shielded area 6A to inside the shielded area 6A.

[0073] Furthermore, there is no need to provide a large-diameter hole, slit, or the like in the shell wall for connecting the non-ground pattern 36 outside the shielded area 6A with the non-ground pattern 36 inside the shielded area 6A, thereby preventing noise from leaking from gaps in the shell wall and propagating into the shielded space.

[0074] Furthermore, even when noise propagates into the shielded space, the noise is bypassed to the housing 5 by the first capacitor 31 disposed inside the shielded area 6A, thereby reducing the noise.

[0075] In this way, by reducing conducted noise and radiated noise, a highly reliable power conversion device can be realized.

[0076] Furthermore, by electrically connecting the upper surface of outer wall 5A to a conductive cover or the like, it is possible to reduce noise propagating through external connection wiring 4 and also to reduce noise leaking directly from power conversion circuit 1 and control circuit 2 as radio waves outside housing 5. In this case, in addition to housing wall 5B in contact with printed circuit board 3, a housing wall not in contact with printed circuit board 3 may also exist. Alternatively, the upper surface of the housing wall not in contact with printed circuit board 3 may be connected to the cover.

[0077] Furthermore, the through hole 34H connecting the first ground pad 34P1 and the ground pattern 20 and the through hole 35H connecting the first ground pad 35P1 and the ground pattern 20 may be formed of through holes having the same axis or may be formed separately.

[0078] Furthermore, the first ground pad 34P1 and the first ground pad 35P1 may be connected to each other in the same layer of the printed circuit board 3, or may be separated from each other in the same layer of the printed circuit board 3. Any structure is acceptable as long as the first ground pad 34P1 and the first ground pad 35P1 are each connected to the housing 5 and grounded.

[0079] Furthermore, the through holes 34H, 35H, 36H1 , and 36H2 are not limited to through holes connecting the wiring conductors on the first main surface and the wiring conductors on the second main surface, but may be via holes that can connect the wiring conductors of at least two layers of the printed circuit board 3 .

[0080] Furthermore, although an example is shown in which the printed circuit board 3 is fixed only to the case wall 5B with screws, it may be fixed only to the outer wall 5A of the case with screws, or may be fixed to both the outer wall 5A and the case wall 5B with screws.

[0081] Hereinafter, power conversion devices 100a, 100b, 100c, 100d, 100e, and 100f, which are modified examples of the power conversion device 100 of the present embodiment, will be described using Figures 3 to 8 Provide explanation.

[0082] Figure 3 This is a cross-sectional view schematically illustrating the configuration of a power conversion device 100 a that is a modified example of the power conversion device 100 according to the first embodiment.

[0083] like Figure 3 As shown, the second end of the first capacitor 31 may be configured such that it is not directly connected to the first ground pad 34P1 of the through hole 34H directly grounded to the housing wall 5B, but is connected to the ground pattern 20 via a via 20H1 and is grounded. Similarly, the second end of the second capacitor 32 may be configured such that it is not directly connected to the first ground pad 35P1 of the through hole 35H directly grounded to the housing wall 5B, but is connected to the ground pattern 20 via a via 20H2 and is grounded.

[0084] In addition, if Figure 3 As shown, the via 20H2 connecting the second ground pad 20P2 and the ground pattern 20 and the via 20H1 connecting the first ground pad 20P1 and the ground pattern 20 may be configured separately as long as they are connected via the ground pattern 20 .

[0085] Figure 4This is a cross-sectional view schematically illustrating the configuration of a power conversion device 100 b that is a modified example of the power conversion device 100 according to the first embodiment.

[0086] In the present power conversion device 100b, the power conversion circuit 1 may be arranged face-to-face with the second main surface 3B of the printed circuit board 3. In this case, the housing wall 5B need not define the region 6B for accommodating the power conversion circuit 1 as shown in the first embodiment, and a portion or all of the housing wall 5B may also serve as the outer wall 5A.

[0087] Figure 5 This is a cross-sectional view schematically illustrating the configuration of a power conversion device 100 c that is a modified example of the power conversion device 100 according to the first embodiment.

[0088] like Figure 5 As shown, the printed circuit board 3X on which the control circuit 2 is mounted and the printed circuit board 3 on which the first filter circuit 30 is mounted may be configured separately. In this case, the printed circuit boards 3 and 3X are connected to each other via a cable, a connector, or the like.

[0089] Figure 6 It is a top view showing a schematic configuration of a power conversion device 100d which is a modified example of the power conversion device 100 according to the first embodiment.

[0090] This figure is viewed from the second principal surface 3B of the printed circuit board 3, omitting the outline of the printed circuit board 3. The patterns and capacitors indicated by dashed lines are located below the ground pattern 20 in the direction Y1. A first ground pad 34P1 is formed on a portion or the entire surface of the area where the ground pattern 20 overlaps the housing wall 5B. Even when the power conversion circuit 1 and the filter circuit are mounted on the same substrate, and noise generated by the power conversion circuit 1 is high, reliably ensuring the area (region) where the ground pattern 20 overlaps the housing wall 5B can reduce noise generated by electromagnetic coupling.

[0091] Figure 7 This is a top view showing a schematic configuration of a power conversion device 100 e which is a modified example of the power conversion device 100 according to the first embodiment.

[0092] like Figure 7 As shown, the control circuit 2 operates based on the potential of the ground pattern 20, and the ground pattern 20 may extend to the location where the control circuit 2 is mounted. By arranging the second capacitor 32 directly above the housing wall 5B, the noise current can flow smoothly into the housing.

[0093] Figure 8 This is a top view showing a schematic configuration of a power conversion device 100 f that is a modified example of the power conversion device 100 according to the first embodiment.

[0094] Figure 8 1 shows a top view of a power conversion device according to a modified example of Embodiment 1. As described above, the second capacitor 32 does not necessarily need to be located directly above the case wall 5B.

[0095] The power conversion device of this embodiment configured as described above is as follows.

[0096] A power conversion device includes a power conversion circuit for performing power conversion and a control circuit for controlling the power conversion circuit, and comprises:

[0097] a filter circuit connected to a control conductive path for controlling at least one of the control circuit and the power conversion circuit, and suppressing electromagnetic noise in the control conductive path;

[0098] a circuit wiring board which is a printed circuit board provided with the filter circuit and having a reference potential pattern formed on an inner layer; and

[0099] a housing holding the circuit wiring board,

[0100] The reference potential pattern is connected to the housing,

[0101] The housing has a shielding wall provided on a first main surface side of a surface layer on one side in a thickness direction of the circuit wiring board, forming an electromagnetic shielding area surrounded by the shielding wall and the reference potential pattern, and the control circuit and the power conversion circuit are arranged outside the electromagnetic shielding area.

[0102] The control conductive path is led from the control circuit into the electromagnetic shielding area through a first connection hole connecting wiring conductors of at least two layers of the circuit wiring board and is wired within the electromagnetic shielding area.

[0103] The filter circuit has:

[0104] a first capacitor provided in the electromagnetic shielding region of the circuit wiring board, having a first end connected to the control conductive path in the electromagnetic shielding region and a second end connected to the reference potential pattern; and

[0105] The second capacitor is provided outside the electromagnetic shielding area of ​​the circuit wiring board, has a first end connected to the control conductive path, and a second end connected to the reference potential pattern.

[0106] In this way, the second capacitor, located outside the shielded space, reduces noise propagating from the control circuit and power conversion circuit to the control conductive path. This reduces noise near the control circuit and power conversion circuit, which are the noise sources, effectively reducing noise propagating through the cable.

[0107] Furthermore, by providing the first capacitor, which is bypassed to the housing, within the electromagnetic shielding area, even if noise propagates into the shielded space, the noise propagating through the cable can be suppressed by shielding the magnetic flux around the first capacitor, thereby achieving a further noise reduction effect.

[0108] Furthermore, the control conductive path is not wired using cables, bus bars, or the like, but is led into the electromagnetic shielding area via the first connection hole formed in the printed circuit board.

[0109] In this manner, the inner wall of the first connection hole formed in the printed circuit board is plated with thin copper, eliminating the need for insertion of conductive wires such as cables and busbars. This allows for reliable electrical connection between layers of the printed circuit board while maintaining a small diameter. By employing a structure that utilizes a first connection hole in the printed circuit board with a smaller diameter than a hole formed in a metal plate or other housing, the propagation of noise from outside the electromagnetic shielding area to within the electromagnetic shielding area can be effectively suppressed.

[0110] Furthermore, the clearance between the first connection hole formed in the circuit wiring board, which serves as a control conductive path, and the ground pattern formed at a set distance from the first connection hole in a manner surrounding the first connection hole and functioning as a shielding member can be configured to be smaller than the gap, i.e., the clearance, between the inner wall of the hole formed in a general housing and the conductive wire inserted through the hole.

[0111] In this manner, the gap between the first connection hole serving as the control conductive path and the ground pattern functioning as a shield can be reduced, thereby further improving the electromagnetic shielding effect.

[0112] Furthermore, the control conductive path outside the electromagnetic shielding area is led into the electromagnetic shielding area via a first connection hole formed in the circuit wiring board, using a shortest connection equivalent to the thickness of the printed circuit board. Furthermore, by providing a connection via the first connection hole in the printed circuit board, the wiring length and path of the control conductive path from outside to inside the electromagnetic shielding area can be fixed.

[0113] This further reduces noise propagating into the shielded space due to electromagnetic coupling from outside the shielded space to the wiring connecting the shielded area to the inside of the shielded area. Furthermore, by suppressing noise variations that depend on changes in the wiring length and path of the conductive path, reliability can be further improved. This allows for a highly reliable power conversion device with reduced conducted and radiated noise.

[0114] Furthermore, since the electromagnetic shielding region is formed using the reference potential pattern formed on the inner layer of the circuit wiring board, a compact and lightweight power conversion device can be realized.

[0115] Furthermore, in the power conversion device of this embodiment configured as described above,

[0116] The reference potential pattern is connected to the housing via a second connection hole that connects the reference potential pattern to the wiring conductor on the first main surface of the circuit wiring board.

[0117] The electromagnetic shielding area is surrounded by the second connection hole in addition to being surrounded by the shielding wall and the reference potential pattern.

[0118] By forming the electromagnetic shielding region using the second connection holes connecting the reference potential pattern to the wiring conductors on the first main surface, a gapless electromagnetic shielding region can be formed, thereby preventing noise leakage and improving the electromagnetic shielding effect within the electromagnetic shielding region.

[0119] Furthermore, in the power conversion device of this embodiment configured as described above,

[0120] The first connection hole is a through hole connecting the wiring conductor on the first main surface and the wiring conductor on the second main surface which is the surface layer opposite to the first main surface, or a via hole connecting the wiring conductors of at least two layers of the circuit wiring board.

[0121] In this way, the controlled conductive path is led into the electromagnetic shielding area via via holes or through-holes formed in the printed circuit board, rather than using wiring such as cables or busbars. By using via holes or through-holes with a smaller diameter than holes in metal plates or other housings, noise propagation into the shielding area can be effectively suppressed.

[0122] Furthermore, the gap between the via holes or through holes that serve as the control conductive path and the ground pattern formed around the via holes or through holes and functioning as a shield can be made small, thereby further improving the electromagnetic shielding effect.

[0123] Furthermore, the control conductive path outside the electromagnetic shielding area can be connected to the control conductive path inside the electromagnetic shielding area by the shortest connection possible, equivalent to the thickness of the printed circuit board. By using via holes or through-holes in the printed circuit board, the wiring length and path of the control conductive path from outside to inside the electromagnetic shielding area can be fixed. This suppresses noise fluctuations that depend on changes in wiring length and path, thereby providing a highly reliable power conversion device.

[0124] Furthermore, in the power conversion device of this embodiment configured as described above,

[0125] The reference potential pattern is connected to the housing via the second connection hole and a connection pad formed at a contact portion between the second connection hole and the shield wall of the housing on the first main surface.

[0126] Furthermore, in the power conversion device of this embodiment configured as described above,

[0127] The shielding wall of the housing is configured to have:

[0128] a housing bottom formed in parallel with the first main surface of the circuit wiring board; and a housing wall portion extending from the housing bottom toward the first main surface side of the circuit wiring board and abutting against the first main surface,

[0129] The connection pad is formed on the first main surface at a contact portion between the case wall portion and the first main surface.

[0130] In this way, the second connection hole connected to the reference potential pattern is arranged to abut against the housing, thereby reducing the impedance of the reference potential pattern and improving the shielding effect in the electromagnetic shielding area. In addition, the electrical connection between the housing and the second connection hole is strengthened by the connection pad, further improving the shielding effect in the electromagnetic shielding area.

[0131] In this manner, a shielded space can be provided in a compact and lightweight manner using a printed circuit board, and noise propagation into the shielded space can be suppressed, thereby providing a power conversion device with less noise than conventional devices.

[0132] Implementation method 2.

[0133] Hereinafter, Embodiment 2 of the present application will be described with reference to the drawings, focusing on portions that are different from Embodiment 1. Components identical to those in Embodiment 1 are denoted by the same reference numerals, and description thereof will be omitted.

[0134] Figure 9 This is a cross-sectional view schematically showing the structure of a power conversion device 200 according to the second embodiment.

[0135] The power conversion device 200 according to the second embodiment has basically the same configuration as the power conversion device 100 according to the first embodiment, except that an inductor 38 is provided in series with the non-ground pattern 36 connecting the first capacitor 31 and the second capacitor 32 .

[0136] Inductor 38 is mounted on first main surface 3A of printed circuit board 3 within shielded area 6A. The combination of inductor 38 and first capacitor 31 forms an LC filter, effectively reducing noise propagating outside power converter 100 via external connection wiring 4. Inductor 38 can be a hollow magnetic body with a conductor extending through it, or a coil wound around a magnetic body. Mounting inductor 38 outside shielded area 6A may result in electromagnetic coupling from the power conversion circuit, increasing noise. However, mounting inductor 38 inside shielded area 6A prevents this increase in noise.

[0137] In the power conversion device of this embodiment configured as described above,

[0138] An inductor is provided. The inductor is connected in series with the control conductive path between the second end of the first capacitor and the second end of the second capacitor, and is arranged in the electromagnetic shielding region on the first main surface of the circuit wiring board.

[0139] By providing the inductor in the shielded region in this manner, it is possible to further reduce noise and provide a highly reliable power conversion device.

[0140] Implementation method 3.

[0141] Hereinafter, Embodiment 3 of the present application will be described with reference to the drawings, focusing on the parts that are different from Embodiments 1 and 2. The same parts as those in Embodiment 1 are denoted by the same reference numerals, and their description will be omitted.

[0142] Figure 10 It is a cross-sectional view showing a schematic configuration of a power conversion device 300 according to the third embodiment.

[0143] The power conversion device 300 according to the third embodiment has a structure substantially similar to that of the power conversion device 200 according to the second embodiment, except that a second capacitor 33 is further mounted on the first main surface 3A of the printed circuit board 3, facing the area 6B housing the power conversion circuit 1, outside the shielded area 6A. Consequently, the second capacitor 33 bypasses noise coupled from the power conversion circuit 1 near the power conversion circuit 1 to the housing 5, thereby reducing noise current flowing through the non-ground pattern 36 and enhancing the noise reduction effect.

[0144] In the power conversion device of this embodiment configured as described above,

[0145] The power conversion circuit is provided on one of the first main surface outside the electromagnetic shielding area of ​​the circuit wiring board and the second main surface which is a surface layer opposite to the first main surface.

[0146] comprising a plurality of the second capacitors,

[0147] At least one second capacitor is arranged on the first main surface or the second main surface on the side where the power conversion circuit is provided, the first end of the at least one second capacitor is connected to the control conductive path for controlling the power conversion circuit, and the second end of the at least one second capacitor is connected to the reference potential pattern.

[0148] In this manner, by providing the second capacitor in the housing near the power conversion circuit 1 that is a noise generation source, it is possible to further reduce noise and provide a highly reliable power conversion device.

[0149] Implementation method 4.

[0150] Hereinafter, Embodiment 4 of the present application will be described with reference to the drawings, focusing on the parts that are different from Embodiment 1. The same parts as those in Embodiment 1 are denoted by the same reference numerals, and their description will be omitted.

[0151] Figure 11 It is a top view showing a schematic configuration of a power conversion device 400 according to the fourth embodiment.

[0152] In the figure, components and patterns mounted and wired on the inner layer or first main surface 3A side of the printed circuit board 3 are indicated by dotted lines.

[0153] The power conversion device 400 involved in this embodiment 4 has basically the same structure as the power conversion device 100 involved in embodiment 1, except that the direction D1 from the first end to the second end of the first capacitor 31 is installed in a direction that is 45 degrees different from the direction D2 from the first end to the second end of the second capacitor 32.

[0154] When noise current flows through second capacitor 32, second capacitor 32 generates a magnetic flux proportional to the noise current. Shield region 6A also functions to block this magnetic flux. However, at frequencies where the thickness of ground pattern 20 is equal to or less than the skin depth of the pattern's conductive material, some of the magnetic flux intrudes into shield region 6A. This intruding magnetic flux then interlinks with first capacitor 31, increasing the noise propagating from external connection wiring 4 to the outside of the device.

[0155] For example, the skin depth of copper is 209μm at 100kHz, 66μm at 1MHz, and 21μm at 10MHz, while the thickness of the pattern is generally around 18μm, with the thickest being around 100μm. Consequently, noise from 100kHz to 10MHz can intrude into the shielded area 6A. Thus, simply using the ground pattern 20 to form a portion of the shielded area 6A is sometimes insufficient. By installing the first capacitor 31 and the second capacitor 32 so that their directions differ by 45 degrees, as in this embodiment, the magnetic flux that interlinks with the first capacitor 31 can be reduced to 1 / √2 of the magnetic flux intruding into the shielded area 6A. The same effect can be achieved even when the angle between the first capacitor 31 and the second capacitor 32 differs by 135 degrees, so it is sufficient to configure the first capacitor 31 so that the angle is within the range of 45 degrees to 135 degrees.

[0156] Figure 12 shows a top view of a power conversion device 400a according to a modified example of Embodiment 4. It is desirable that the direction from the first end to the second end of first capacitor 31 and the direction from the first end to the second end of second capacitor 32 be perpendicular to each other. In this case, the magnetic flux interlinking with first capacitor 31 can be minimized. In power conversion device 400 shown in this embodiment, even if magnetic flux intrudes into shielded area 6A, an increase in noise can be prevented.

[0157] Furthermore, the frequency of noise invading the interior of the shielding area 6A can be assumed based on the conductor thickness of the ground pattern 20 in the thickness direction of the printed circuit board 3 and the skin depth of the frequency of the noise signal flowing through the ground pattern 20. According to the invading noise, the angle formed by the direction from the first end to the second end of the first capacitor 31 and the direction from the first end to the second end of the second capacitor 32 is adjusted, thereby adjusting the magnetic flux interlinked with the first capacitor 31.

[0158] In the power conversion device of this embodiment configured as described above,

[0159] The first capacitor and the second capacitor are arranged so that a direction from the first end to the second end of the first capacitor forms an angle of not less than 45 degrees and not more than 135 degrees with respect to a direction from the first end to the second end of the second capacitor when viewed from a direction perpendicular to the first main surface.

[0160] By adjusting the angle between the first capacitor and the second capacitor, the magnetic flux that interlinks with the first capacitor 31 among the magnetic fluxes entering the shielded space can be reduced, thereby further improving the noise reduction effect and providing a highly reliable power conversion device.

[0161] Furthermore, in the power conversion device of this embodiment configured as described above,

[0162] The angle is adjusted based on a conductor thickness of the reference potential pattern in a thickness direction of the circuit wiring board and a skin depth of a frequency of a signal flowing through the reference potential pattern.

[0163] In this way, by adjusting the magnetic flux interlinked with the first capacitor 31 based on the conductor thickness of the ground pattern 20 in the thickness direction of the printed circuit board 3 and the skin depth of the frequency of the noise signal flowing through the ground pattern 20 , the noise reduction effect can be further improved.

[0164] Implementation method 5.

[0165] Hereinafter, Embodiment 5 of the present application will be described with reference to the drawings, focusing on the parts that are different from Embodiment 1. The same parts as those in Embodiment 1 are denoted by the same reference numerals, and their description will be omitted.

[0166] Figure 13 It is a top view showing a schematic configuration of a power conversion device 500 according to the fifth embodiment.

[0167] The reference potential pattern of this embodiment includes the ground pattern 20 as the first reference potential pattern, which is the same reference potential pattern as in the first embodiment, and the ground pattern 520 as the second reference potential pattern formed independently of the ground pattern 20 .

[0168] The ground pattern 20 is connected to the housing wall 5B as in the first embodiment, and the ground pattern 520 is also connected to the housing wall 5B. Figure 13 As shown by the dotted circle in the figure, the housing wall 5B functions as a slit. In this way, the housing 5 is interposed between the ground pattern 20 and the ground pattern 520, but the ground pattern 20 and the ground pattern 520 are not directly connected.

[0169] Furthermore, in addition to the first filter circuit 30 similar to that of Embodiment 1, this embodiment further includes a second filter circuit 530 for the power conversion circuit 1 having a second capacitor 532, located adjacent to the ground pattern 520. The second capacitor 532 of the second filter circuit 530 has a first end connected to a non-ground pattern 536 serving as a control conductive path for driving the power conversion circuit 1, and a second end connected to the ground pattern 520.

[0170] As described above, in this embodiment, the second capacitor is configured to include the second capacitor 32 as the second A capacitor similar to that in the first embodiment and the second capacitor 532 as the second B capacitor.

[0171] A noise current greater than that of the second capacitor 32 flows through the second capacitor 532 of the second filter circuit 530, which is disposed near the power conversion circuit 1. If this noise current flows through the ground pattern 20, the noise may intrude into the shielded area 6A. Therefore, by providing a slit by interposing the housing wall 5B between the ground pattern 20 and the second ground pattern 520 as in this embodiment, the noise current flowing through the second capacitor 532 of the second filter circuit 530 can be prevented from flowing through the ground pattern 20. This prevents noise from intruding into the shielded area 6A, thereby preventing an increase in noise.

[0172] In the power conversion device of this embodiment configured as described above,

[0173] The reference potential pattern is configured to include a first reference potential pattern and a second reference potential pattern that are independently formed and connected to the housing.

[0174] The housing is interposed between a connection point between the first reference potential pattern and the housing and a connection point between the second reference potential pattern and the housing.

[0175] The second capacitor has:

[0176] a second A capacitor having a first end connected to the control conductive path for driving the control circuit and a second end connected to the first reference potential pattern; and

[0177] The second B capacitor has a first end connected to the control conductive path for driving the power conversion circuit, and a second end connected to the second reference potential pattern.

[0178] By configuring the ground patterns of the second capacitor for the power conversion circuit and the second capacitor for the control circuit separately in this manner, it is possible to prevent noise from entering the shielded space, thereby providing a highly reliable power conversion device.

[0179] Implementation method 6.

[0180] Hereinafter, Embodiment 6 of the present application will be described with reference to the drawings, focusing on the parts that are different from Embodiment 1. The same parts as those in Embodiment 1 are denoted by the same reference numerals, and their description will be omitted.

[0181] Figure 14 It is a top view showing a schematic configuration of a power conversion device 600 according to the sixth embodiment.

[0182] In the power conversion device 600 according to the sixth embodiment, the control conductive path for controlling the control circuit 2 includes a differential communication signal pattern 636a serving as a first conductive path for transmitting a positive first signal, and a differential communication signal pattern 636b serving as a second conductive path for transmitting a negative second signal forming a differential signal paired with the first signal. Furthermore, a differential communication IC 637 is provided on the second main surface 3B, which relays the signals of these differential communication signal patterns 636a and 636b, and a third conductive path 636c serving as a control conductive path for supplying power to the differential communication IC 637 is also provided.

[0183] Since differential communication signals have positive and negative polarities, the first capacitors disposed within the shielded area 6A include two types: a first A capacitor 631a on the positive side and a first B capacitor 631b on the negative side. The first A capacitor 631a has a first end connected to the differential communication signal pattern 636a and a second end connected to the ground pattern 20. Furthermore, the first B capacitor 631b has a first end connected to the differential communication signal pattern 636b and a second end connected to the ground pattern 20.

[0184] The second capacitor 32, which is disposed outside the shield region 6A, has its first end connected to the third conductive path 636c and its second end connected to the ground pattern 20. This results in a configuration in which the first end of the second capacitor 32 is connected to the third conductive path 636c, which supplies power to the differential communication IC 637, and is not directly connected to the differential communication signal patterns 636a and 636b.

[0185] The inductor 38 is connected to the differential communication signal patterns 636 a and 636 b in the shield region 6A between the differential communication IC 637 and the first A capacitors 631 a and 631 b .

[0186] The inductor 38 may not be provided, but the noise reduction effect can be enhanced by inserting the inductor 38 between the differential communication IC 637 and the first A capacitors 631 a and 631 b.

[0187] The inductor 38 may be provided separately on the positive electrode side and the negative electrode side, or an inductor such as a common mode inductor may be provided in which the positive electrode side and the negative electrode side are integrated.

[0188] Even if the second capacitor 32 is directly connected to the differential communication signal patterns 636a and 636b on the second main surface 3B, a noise reduction effect can be achieved. However, if the capacitance of the capacitor connected to the differential communication signal patterns 636a and 636b is increased excessively, signal waveform degradation may occur, leading to malfunction. By connecting the second capacitor 32 to the third conductive path 636c, which serves as the power supply pattern for the differential communication IC 637, as in this embodiment, the noise reduction effect is not degraded, and the number of capacitors connected to the differential communication signal patterns 636a and 636b can be reduced, thereby preventing signal waveform degradation.

[0189] Furthermore, if a second capacitor is provided, which has a smaller capacitance than the second capacitor 32 and has a capacitance that does not affect the signal waveforms in the differential communication signal patterns 636a and 636b, the second capacitor may be directly connected to the differential communication signal patterns 636a and 636b. In this case, the noise reduction effect is not degraded, and degradation of the signal waveform can be prevented.

[0190] In the power conversion device of this embodiment configured as described above,

[0191] The control conductive path is configured to include: a first conductive path for transmitting a first signal; a second conductive path for transmitting a second signal forming a differential signal in pair with the first signal; and a third conductive path for supplying power to a differential communication circuit portion that relays the first and second signals between the control circuit and the control circuit.

[0192] The first capacitor includes a first A capacitor having a first end connected to the first conductive path and a first B capacitor having a first end connected to the second conductive path.

[0193] A first terminal of the second capacitor is connected to the third conductive path.

[0194] This prevents degradation of the waveform of a signal for controlling the control circuit without deteriorating the noise reduction effect, thereby providing a power conversion device that operates with high reliability.

[0195] Implementation method 7.

[0196] Hereinafter, Embodiment 7 of the present application will be described with reference to the drawings, focusing on the parts that are different from Embodiment 6. The same parts as those in Embodiment 1 are denoted by the same reference numerals, and their description will be omitted.

[0197] Figure 15 It is a top view showing a schematic configuration of a power conversion device 700 according to the seventh embodiment.

[0198] The reference potential pattern of this embodiment includes the ground pattern 20 as the first reference potential pattern, which is the same reference potential pattern as in the first embodiment, and a ground pattern 720 as the third reference potential pattern formed independently of the ground pattern 20 .

[0199] The ground pattern 720 is given a reference potential in a drive signal for driving the control circuit 2 , and has a potential different from that of the ground pattern 20 .

[0200] In the power conversion device 700 of the present embodiment, the second end of the second capacitor 32 is not connected to the ground pattern 20 but is connected to the ground pattern 720 .

[0201] Furthermore, in this embodiment, a stabilizing capacitor 739 is provided separately from the second capacitor 32 to suppress potential fluctuations in the ground pattern 720. The stabilizing capacitor 739 has a first end connected to the ground pattern 720 and a second end connected to the ground pattern 20.

[0202] The control circuit 2 operates based on the potential of the reference potential pattern 720. However, since the reference potential pattern 720 has a different potential from the ground pattern 20, if noise propagates from the power conversion circuit 1 to the reference potential pattern 720, the noise is superimposed on the differential communication IC 637 due to the fluctuation of the reference potential, resulting in an increase in the noise of the differential communication signal patterns 636a and 636b.

[0203] In this embodiment, a dedicated stabilizing capacitor 739 is provided for the reference potential pattern 720 to bypass the noise propagating to the reference potential pattern 720 to the housing 5, thereby preventing fluctuations in the reference potential pattern 720 and preventing an increase in noise in the differential communication signal patterns 636a and 636b.

[0204] In the power conversion device of this embodiment configured as described above,

[0205] The reference potential pattern includes a third reference potential pattern to which a reference potential is given in a drive signal for driving the control circuit, and a first reference potential pattern formed independently of the third reference potential pattern.

[0206] The filter circuit includes a stabilizing capacitor having a first end connected to the third reference potential pattern and a second end connected to the first reference potential pattern.

[0207] This prevents fluctuations in the reference potential pattern, reduces noise in the control conduction path that controls the control circuit, and provides a power conversion device that operates with high reliability.

[0208] Furthermore, in the power conversion device of this embodiment configured as described above,

[0209] The reference potential pattern includes a third reference potential pattern to which a reference potential is given in a drive signal for driving the control circuit, and a first reference potential pattern formed independently of the third reference potential pattern.

[0210] A first end of the second capacitor is connected to the third conductive path, and a second end of the second capacitor is connected to the third reference potential pattern.

[0211] This prevents degradation of the waveform of a signal for controlling the control circuit without deteriorating the noise reduction effect, thereby providing a power conversion device that operates with high reliability.

[0212] Furthermore, similar to the sixth embodiment, a configuration may be employed in which a second capacitor is provided. This second capacitor has a smaller capacitance than the second capacitor 32 and has a capacitance that does not affect the signal waveforms in the differential communication signal patterns 636a and 636b, and is directly connected to the differential communication signal patterns 636a and 636b. In this case, the noise reduction effect is not degraded, and degradation of the signal waveform can be prevented.

[0213] Implementation method 8.

[0214] Hereinafter, Embodiment 8 of the present application will be described with reference to the drawings, focusing on the parts that are different from Embodiment 7. The same parts as those in Embodiment 7 are denoted by the same reference numerals, and their description will be omitted.

[0215] Figure 16 It is a top view showing a schematic structure of a power conversion device 800 according to the eighth embodiment.

[0216] In this embodiment, similarly to Embodiment 7, a ground pattern 720 is formed independently of the ground pattern 20. In this embodiment, a power pattern 836 for supplying power to the control circuit 2 is provided as a control conductive path for controlling the control circuit 2.

[0217] A first end of the first capacitor 31 provided on the first principal surface 3A side of the printed circuit board 3 is connected to the power pattern 836 as a control conductive path, and a second end of the first capacitor 31 is connected to the ground pattern 20 as a reference potential pattern.

[0218] Furthermore, a first end of the second capacitor 32 provided on the second main surface 3B side of the printed circuit board 3 is connected to the power pattern 836 as a control conductive path, and a second end of the second capacitor 32 is connected to the ground pattern 20 as a reference potential pattern.

[0219] As in the seventh embodiment, the stabilizing capacitor 739 for suppressing potential fluctuations in the ground pattern 720 has a first end connected to the ground pattern 720 and a second end connected to the ground pattern 20 .

[0220] In this embodiment, a stabilizing capacitor 839 is provided on the first main surface 3A within the shield region 3A of the printed circuit board 3 to suppress potential fluctuations in the ground pattern 720. A first end of the stabilizing capacitor 839 is connected to the ground pattern 720, and a second end of the stabilizing capacitor 839 is connected to the ground pattern 20.

[0221] Inductors 38a and 38b do not need to be present, but by inserting them between first capacitor 31 and second capacitor 32, and between stabilizing capacitor 839 and stabilizing capacitor 739, respectively, the noise reduction effect can be enhanced. Alternatively, inductors 38a and 38b can be integrated by using common-mode inductors.

[0222] The control circuit 2 operates based on the potential of the reference potential pattern 720. However, since the reference potential pattern 720 has a different potential from the ground pattern 20, if noise propagates from the power conversion circuit 1 to the reference potential pattern 720, this increases the noise propagating to the outside of the device via the external connection wiring 4. In this embodiment, capacitors are not provided only in the power supply pattern 836, but also in the reference potential pattern 720, stabilizing capacitors 739 and 839. This bypasses the noise propagating to the reference potential pattern 720 to the housing 5. This reduces noise in the power supply line and in the reference potential pattern 720, thereby reducing noise propagating to the outside of the device.

[0223] In the power conversion device of this embodiment configured as described above,

[0224] The reference potential pattern includes a third reference potential pattern to which a reference potential is given in a drive signal for driving the control circuit, and a first reference potential pattern formed independently of the third reference potential pattern.

[0225] A first end of the second capacitor is connected to a power supply line serving as the control conductive path for supplying power to the control circuit, and a second end of the second capacitor is connected to the first reference potential pattern.

[0226] This can reduce noise in the power supply line and reduce noise propagating to the outside of the device.

[0227] Implementation method 9.

[0228] Hereinafter, Embodiment 9 of the present application will be described with reference to the drawings, focusing on the parts that are different from Embodiment 8. The same parts as those in Embodiment 8 are denoted by the same reference numerals, and their description will be omitted.

[0229] Figure 17 It is a top view showing a schematic configuration of a power conversion device 900 according to the ninth embodiment.

[0230] The power conversion device involved in embodiment 9 has a structure basically the same as the power conversion device involved in embodiment 8, except that: the second capacitor 32 whose first end is connected to the power supply pattern 836 serving as a control conductive path has a second end that is not connected to the ground pattern 20 but is connected to the reference potential pattern 720.

[0231] In the power conversion device of this embodiment configured as described above,

[0232] The reference potential pattern includes a third reference potential pattern to which a reference potential is given in a drive signal for driving the control circuit, and a first reference potential pattern formed independently of the third reference potential pattern.

[0233] A first end of the second capacitor is connected to a power supply line serving as the control conductive path for supplying power to the control circuit, and a second end of the second capacitor is connected to the third reference potential pattern.

[0234] Thus, while maintaining the effects obtained by the eighth embodiment, it is possible to reduce noise generated by the magnetic flux generated by the power conversion circuit 1 interlinking between the power supply pattern 836 and the reference potential pattern 720 .

[0235] Implementation method 10.

[0236] Hereinafter, Embodiment 10 of the present application will be described with reference to the drawings, focusing on portions that are different from Embodiment 1. Portions identical to those in Embodiment 1 are denoted by the same reference numerals, and description thereof will be omitted.

[0237] Figure 18 This is a top view showing a schematic configuration of a power conversion device 1000 according to the tenth embodiment.

[0238] The power conversion device according to Embodiment 10 has a configuration substantially similar to that of the power conversion device according to Embodiment 1, and includes multiple non-ground patterns as control conductive paths for controlling the control circuit 2. In this embodiment, two non-ground patterns 1036a and 1036b are shown. Furthermore, unlike Embodiment 1, a pair of first and second capacitors 31a and 32a, and a pair of first and second capacitors 31b and 32b are provided for each of these multiple non-ground patterns 1036a and 1036b.

[0239] In this embodiment, two types of non-ground patterns 1036a and 1036b are shown, but three or more types may be used. Non-ground patterns 1036a and 1036b may be power supply patterns for supplying power to the control circuit, signal patterns for transmitting signals to the control circuit, or reference potential patterns for providing a reference potential for the control circuit.

[0240] Here, first capacitor 31b for non-ground pattern 1036b and second capacitor 32b for non-ground pattern 1036b are mounted so that directions D1 and D2 from their respective first ends to their second ends are orthogonal to each other. However, first capacitor 31a for non-ground pattern 1036a and second capacitor 32a for non-ground pattern 1036a are not mounted so that directions D3 and D4 from their respective first ends to their second ends are orthogonal to each other.

[0241] If the noise superimposed on non-ground pattern 1036a is smaller than that on non-ground pattern 1036b, the magnetic flux intruding into shield area 6A is primarily generated in second capacitor 32b for non-ground pattern 1036b. Therefore, even without arranging second capacitor 32a for non-ground pattern 1036a and first capacitor 31a for non-ground pattern 1036a orthogonally, the noise reduction effect can be achieved by arranging second capacitor 32b for non-ground pattern 1036b and first capacitor 31b for non-ground pattern 1036b orthogonally.

[0242] In this manner, when there are multiple non-ground patterns and a pair of first and second capacitors is provided for each non-ground pattern, it is not necessary for all pairs of first and second capacitors 32 to be orthogonal to each other. Furthermore, when the orientations of the first and second capacitors are altered, the angle does not necessarily need to be 90 degrees; a noise reduction effect can be achieved as long as the orientations differ by 45 to 135 degrees.

[0243] In the power conversion device of this embodiment configured as described above,

[0244] A plurality of control conductive paths are provided, and a pair of the first capacitor and the second capacitor is provided for each control conductive path.

[0245] At least one of the plurality of pairs of the first capacitor and the second capacitor is arranged so that, when viewed from a direction perpendicular to the first main surface, a direction from the first end to the second end of the first capacitor forms an angle of greater than 45 degrees and less than 135 degrees with respect to a direction from the first end to the second end of the second capacitor.

[0246] Thus, the first and second capacitors can be determined to form an angle of at least 45 degrees and at most 135 degrees based on the noise propagating toward the non-ground pattern. This eliminates the need for all pairs of first and second capacitors 32 to form the aforementioned angle, thereby reducing the wiring area on the printed circuit board and miniaturizing the power converter.

[0247] Implementation method 11.

[0248] Hereinafter, Embodiment 11 of the present application will be described with reference to the drawings, focusing on portions that are different from Embodiment 1. Portions identical to those in Embodiment 1 are denoted by the same reference numerals, and description thereof will be omitted.

[0249] Figure 19 This is a cross-sectional view schematically showing the structure of a power conversion device 1100 according to the eleventh embodiment.

[0250] The power conversion device 100 according to the eleventh embodiment has basically the same structure as the power conversion device 1000 according to the first embodiment, except that a conductive gasket 1040 is provided on the contact surface between the first ground pads 34P1 and 35P1 and the case wall 5B.

[0251] This allows the first ground pads 34P1 and 31B to be seamlessly connected to the housing wall 5B, thereby enhancing the shielding effect and the noise reduction effect. Examples of gaskets include metal mesh, metal shielding fingers, rubber containing carbon fibers, sponge, conductive rubber containing metal particles, sponge, and a sponge wrapped with conductive cloth.

[0252] This application describes various illustrative embodiments and examples, but the various features, methods, and functions described in one or more embodiments are not limited to application in specific embodiments, and can be applied to the embodiments alone or in various combinations.

[0253] Therefore, numerous variations not shown in the examples are conceivable within the scope of the technology disclosed in this application, including, for example, variations, additions, or omissions of at least one structural element, and extraction and combination of at least one structural element with structural elements from other embodiments.

Claims

1. A power conversion device comprising a power conversion circuit for converting power and a control circuit for controlling the power conversion circuit, the power conversion device comprising: a filter circuit connected to a conductive path driving at least one of the control circuit and the power conversion circuit, and suppressing electromagnetic noise in the conductive path; a circuit wiring board, which is a printed circuit board provided with the filter circuit and having a reference potential pattern formed on an inner layer; and a housing holding the circuit wiring board, The reference potential pattern is connected to the housing, The housing has a shielding wall provided in an area on the first main surface side of the surface layer on one side in the thickness direction of the circuit wiring board, an electromagnetic shielding area surrounded by the shielding wall and the reference potential pattern is formed, and the power conversion circuit is arranged outside the electromagnetic shielding area. The conductive path is led from the outside of the electromagnetic shielding area into the electromagnetic shielding area through a first connection hole connecting wiring conductors of at least two layers of the circuit wiring board and is wired within the electromagnetic shielding area. The first connection hole is a through hole connecting the wiring conductor on the first main surface and the wiring conductor on the second main surface which is the surface layer opposite to the first main surface, or a via hole connecting the wiring conductors of at least two layers of the circuit wiring board.

2. The power conversion device according to claim 1, wherein: The filter circuit has: The first capacitor is provided in the electromagnetic shielding region of the circuit wiring board, has a first end connected to the conductive path in the electromagnetic shielding region, and a second end connected to the reference potential pattern.

3. The power conversion device according to claim 1, wherein: The filter circuit has: The second capacitor is provided outside the electromagnetic shielding region of the circuit wiring board, has a first end connected to the conductive path, and a second end connected to the reference potential pattern.

4. The power conversion device according to claim 2, wherein: The filter circuit has: The second capacitor is provided outside the electromagnetic shielding region of the circuit wiring board, has a first end connected to the conductive path, and a second end connected to the reference potential pattern.

5. The power conversion device according to claim 3, wherein: The reference potential pattern is connected to the housing via a second connection hole that connects the reference potential pattern to the wiring conductor on the first main surface of the circuit wiring board. The electromagnetic shielding area is surrounded not only by the shielding wall and the reference potential pattern, but also by the second connection hole.

6. The power conversion device according to claim 4, wherein: The reference potential pattern is connected to the housing via a second connection hole that connects the reference potential pattern to the wiring conductor on the first main surface of the circuit wiring board. The electromagnetic shielding area is surrounded not only by the shielding wall and the reference potential pattern, but also by the second connection hole.

7. The power conversion device according to claim 5, wherein: The reference potential pattern is connected to the housing via the second connection hole and a connection pad formed at a contact portion between the second connection hole and the shield wall of the housing on the first main surface.

8. The power conversion device according to claim 6, wherein: The reference potential pattern is connected to the housing via the second connection hole and a connection pad formed at a contact portion between the second connection hole and the shield wall of the housing on the first main surface.

9. The power conversion device according to any one of claims 4, 6, and 8, wherein: An inductor is provided, the inductor being connected in series to the conductive path between the first end of the first capacitor and the first end of the second capacitor.

10. The power conversion device according to any one of claims 3 to 8, wherein: The reference potential pattern is configured to include a first reference potential pattern and a second reference potential pattern that are independently formed and connected to the housing. The housing is interposed between a connection point between the first reference potential pattern and the housing and a connection point between the second reference potential pattern and the housing. The second capacitor has: a second A capacitor having a first end connected to the conductive path for driving the control circuit and a second end connected to the first reference potential pattern; as well as The second B capacitor has a first end connected to the conductive path driving the power conversion circuit and a second end connected to the second reference potential pattern.

11. The power conversion device according to any one of claims 3 to 8, wherein: The reference potential pattern includes a third reference potential pattern to which a reference potential is given in a drive signal for driving the control circuit, and a first reference potential pattern formed independently of the third reference potential pattern. The filter circuit includes a stabilizing capacitor having a first end connected to the third reference potential pattern and a second end connected to the first reference potential pattern.

12. The power conversion device according to any one of claims 3 to 8, wherein: The reference potential pattern includes a third reference potential pattern to which a reference potential is given in a drive signal for driving the control circuit, and a first reference potential pattern formed independently of the third reference potential pattern. A first end of the second capacitor is connected to a power line serving as the conductive path for supplying power to the control circuit, and a second end of the second capacitor is connected to the first reference potential pattern or the third reference potential pattern.

13. The power conversion device according to claim 7 or 8, wherein: The shielding wall of the housing is configured to include: a housing bottom formed in parallel with the first main surface of the circuit wiring board; and a housing wall portion extending from the housing bottom toward the first main surface side of the circuit wiring board and abutting against the first main surface. The connection pad is formed on the first main surface at a contact portion between the case wall portion and the first main surface.

14. The power conversion device according to claim 13, wherein: A conductive gasket is provided on a contact surface between the connection pad and the housing wall.

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