Inter-board connection structure and power conversion device

Abstract

To improve versatility and a degree of freedom of an electrical connection structure of an electronic apparatus in which a plurality of circuit boards are laminated.SOLUTION: An inter-board connection structure comprises first and second boards and a key-shaped wire. The second board has a front face arranged so as to face a rear face of the first board. The key-shaped wire has a key part, and first and second terminal parts. The first terminal part extends from one end of the key part and has a length longer than a distance between the first and second boards. The second terminal part extends from the other one end of the key part in a direction in which the first terminal part extends and is shorter than the first terminal part. The key-shaped wire is formed from conductor material having an electrical conduction property. The key part protrudes on the front face side of the second board. Each of the first and second terminal parts protrudes on the rear face side of the second board. The first terminal part protrudes after extending on the rear face side of the first board and is electrically connected to a wiring pattern provided at least on the first board. The second terminal part is electrically connected to a wiring pattern provided on the second board.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a board-to-board connection structure and a power conversion device. [Background technology]

[0002] Conventionally, a power conversion device mounted on an electric vehicle or the like is provided with a plurality of circuit boards on which circuit configurations such as a DC / DC converter and an inverter are mounted, and the plurality of circuit boards are electrically connected to each other using, for example, connecting members.

[0003] For example, Patent Document 1 discloses a technique relating to electrical connection between devices to be connected that are provided inside a housing of a power conversion device mounted on a vehicle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-41576 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, in power conversion devices, multiple circuit boards are sometimes stacked to increase component packaging density. However, when electrically connecting two opposing circuit boards, the shape of the connecting member varies depending on, for example, the current value and the distance between the boards, resulting in low versatility and requiring design and evaluation for each connection. Furthermore, since the connection positions on the circuit boards and the connecting member must be aligned between the boards, problems arise, such as the complexity of the wiring patterns on the circuit boards and the difficulty of pattern configuration as the boards become smaller. For this reason, there is room for improvement in the electrical connection structures between or on boards in electronic devices such as power conversion devices.

[0006] One of the problems that the present disclosure aims to solve is to improve the versatility and flexibility of the electrical connection structure in an electronic device in which multiple circuit boards are stacked. [Means for solving the problem]

[0007] The board-to-board connection structure according to the present disclosure comprises a first substrate, a second substrate, and a hook-shaped wire. A first component is mounted on the first substrate. A second component is mounted on the second substrate, and the second substrate is disposed with its front surface facing the back surface of the first substrate. The hook-shaped wire has a hook portion, a first terminal portion, and a second terminal portion. The first terminal portion extends from one end of the hook portion and is longer than the distance between the first substrate and the second substrate. The second terminal portion extends from the other end of the hook portion in the same direction as the first terminal portion and is shorter than the first terminal portion. The hook-shaped wire is formed from an electrically conductive conductive material. The hook portion protrudes from the front surface of the second substrate, which is the side opposite to the first substrate. The first terminal portion and the second terminal portion each protrude from the back surface of the second substrate. The first terminal portion extends to a rear surface side of the first substrate opposite to the second substrate, protruding from the rear surface side of the first substrate, and is electrically connected to at least a wiring pattern provided on the first substrate, and the second terminal portion is electrically connected to a wiring pattern provided on the second substrate. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to improve the versatility and flexibility of the electrical connection structure in an electronic device in which multiple circuit boards are stacked. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing an example of the configuration of the front surface side of any circuit board of a power converter having a board-to-board connection structure according to an embodiment. [Figure 2] FIG. 2 is a perspective view showing an example of the arrangement of hook-shaped wires on the circuit board of FIG. [Figure 3]FIG. 3 is a perspective view showing an example of the configuration of the back side of the circuit board of FIG. [Figure 4] FIG. 4 is a diagram schematically illustrating an example of a board-to-board connection structure according to an embodiment. [Figure 5] FIG. 5 is a flowchart showing an example of the flow of a substrate-to-substrate connecting process according to the embodiment. [Figure 6] FIG. 6 is a diagram schematically showing another example of the inter-board connection structure according to the embodiment. [Figure 7] FIG. 7 is a diagram schematically showing another example of the inter-board connection structure according to the embodiment. [Figure 8] FIG. 8 is a diagram schematically showing another example of the inter-board connection structure according to the embodiment. [Figure 9] FIG. 9 is a diagram schematically showing another example of the inter-board connection structure according to the embodiment. [Figure 10] FIG. 10 is a diagram schematically illustrating another example of the inter-board connection structure according to the embodiment. [Figure 11] FIG. 11 is a diagram schematically showing another example of the inter-board connection structure according to the embodiment. [Figure 12] FIG. 12 is a diagram schematically illustrating another example of the inter-board connection structure according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of a board-to-board connection structure, a power conversion device, and a vehicle will be described with reference to the drawings.

[0011] In the description of the present disclosure, components having the same or substantially the same functions as those described above with respect to the previously-mentioned drawings may be given the same reference numerals, and descriptions thereof may be omitted as appropriate. Furthermore, even when the same or substantially the same parts are shown, the dimensions and proportions may be different depending on the drawing. Furthermore, for example, in order to ensure the visibility of the drawings, reference numerals may be given to only the main components in the description of each drawing, and reference numerals may not be given to components having the same or substantially the same functions as those described above with respect to the previously-mentioned drawings.

[0012] In the description of the present disclosure, components having the same or substantially the same functions may be distinguished by adding an alphanumeric character to the end of the reference symbol. Alternatively, when multiple components having the same or substantially the same functions are not distinguished, they may be collectively described by omitting the alphanumeric character at the end of the reference symbol.

[0013] The board-to-board connection structure according to the present disclosure is an electrical connection structure that electrically connects any opposing circuit boards among multiple stacked circuit boards mounted on an electronic device such as a power conversion device. This electrical connection structure is not limited to electrical connections between boards, but may also include wiring patterns formed on boards or combinations of such patterns. In other words, the board-to-board connection structure according to the present disclosure has a three-dimensional electrical path configuration formed across two circuit boards arranged opposite each other in an electronic device.

[0014] In the board-to-board connection structure according to the present disclosure, the circuit board is, for example, a printed circuit board (PCB), which is, for example, a glass epoxy board formed using an aluminum alloy or a copper alloy as a base material.

[0015] The circuit board may be a circuit board included in a magnetic component such as a transformer, a reactor, or a choke. This magnetic component has, for example, a substrate on which a conductor pattern forms a winding, and a magnetic core is passed through the inside and outside of the winding formed on the substrate to form a closed magnetic circuit, thereby functioning as a magnetic component. In other words, at least one of the circuit boards electrically connected in the board-to-board connection structure according to the present disclosure may be a printed circuit board transformer or a transformer-integrated printed circuit board.

[0016] The circuit board may be a circuit board constituting a board unit. Here, the board unit refers to a plurality of circuit boards that are joined together. In the board unit, the plurality of circuit boards may be electrically connected to each other using the inter-board connection structure according to the present disclosure, or may be joined together using adhesive, screws, bolts, or the like. In the board unit, the joined circuit boards may be electrically connected to each other or may be insulated from each other. The board unit may be a circuit board on which electronic components are mounted. In this case, the electronic components and the circuit boards may be electrically connected to each other, may be insulated from each other, or may only be thermally connected to each other.

[0017] The circuit board constituting the board-to-board connection structure according to the present disclosure has a wiring pattern (electrical path) formed of a conductor such as gold or copper. Electronic components may be mounted on the circuit board. For example, the electronic components (mounted components) mounted on the circuit board are electrically connected to the circuit board by, for example, soldering.

[0018] The electronic components (mounted components) mounted on the circuit board may be semiconductor elements, semiconductor modules, magnetic materials, capacitors, circuit breakers, and other components. A semiconductor module is, for example, composed of multiple semiconductor elements. Here, the magnetic materials include transformers, transformer-integrated printed circuit boards, transformers, reactors, and chokes. The circuit breakers include relays and fuses.

[0019] As an example, the inter-board connection structure according to the present disclosure is an electrical connection structure that electrically connects any two opposing circuit boards among a plurality of circuit boards stacked and mounted in an electronic device such as a power conversion device. The power conversion device is, for example, an on-board charger mounted in an electric vehicle or the like, that converts AC power supplied from a power source (external power source) into DC power of a predetermined voltage and outputs the converted DC power to a battery such as a lithium-ion battery. In such a power conversion device, a plurality of circuit boards, each mounted with a circuit configuration such as a DC / DC converter and an inverter, are stacked.

[0020] The board-to-board connection structure according to the present disclosure may be an electrical connection structure that electrically connects any one circuit board to two or more other circuit boards that are arranged opposite each other. This electrical connection is not limited to a connection between any two circuit boards, but may also be a connection between any three or more circuit boards. Furthermore, this electrical connection may be a connection via a wiring pattern on any circuit board.

[0021] As an example, the power conversion device according to the present disclosure may be mounted on a vehicle as, for example, an on-board charger. For example, the power conversion device may be an on-board charger that converts AC power supplied from an external single-phase or three-phase AC power source into DC power and supplies the converted DC power to a load mounted on the vehicle. The load may be, for example, a battery, an inverter, a motor, or various electrical components.

[0022] The vehicle may be any type of moving body configured to be driven or to drive its accessories (electrical components) using power from a battery, such as a passenger car, a freight vehicle, a van, a motorcycle, or an electric kick scooter. Examples of such electrical components include a navigation system, an audio system, an air conditioner, a power window, a defogger, an ECU (Electronic Control Unit), a GPS (Global Positioning System) module, and an on-board camera. The vehicle battery may be any battery capable of storing power for driving the traction motor (main motor) and electrical components mounted on the vehicle, and any battery, such as a lithium-ion battery, a nickel-metal hydride battery, or an all-solid-state battery, may be used. The power conversion device according to the present disclosure is not limited to vehicles, and may also be installed in, for example, aircraft, amusement facilities, uninterruptible power supplies, and the like.

[0023] (First embodiment) Fig. 1 is a perspective view showing an example of the configuration of the front side of any circuit board 2 of a power converter 1 having a board-to-board connection structure according to an embodiment. Fig. 2 is a perspective view showing an example of the arrangement of hook-shaped wires 7 on the circuit board 2 of Fig. 1. Fig. 3 is a perspective view showing an example of the configuration of the back side of the circuit board 2 of Fig. 1. Fig. 4 is a diagram schematically showing an example of the board-to-board connection structure according to an embodiment.

[0024] The circuit board 2b illustrated in Figures 1 to 3 is one of a pair of circuit boards 2 arranged opposite each other among the plurality of circuit boards 2 stacked in the power converter 1. The circuit board 2b illustrated in Figures 1 to 3 is a circuit board 2 on which a large electronic component (mounted component) such as a coil (winding) is mounted. In the power converter 1, by arranging the circuit boards 2 to be electrically connected among the plurality of stacked circuit boards 2 to face each other, the component mounting density of the power converter 1 can be increased.

[0025] For example, the power conversion device 1 is provided with a power factor correction (PFC) circuit (not shown) that rectifies and smooths AC voltage from an external AC power supply to generate a DC voltage. Furthermore, for example, a DC-DC conversion circuit (not shown) is provided downstream of the PFC circuit in the power conversion device 1. The DC voltage generated by the PFC circuit is converted back into an AC voltage, and then rectified and smoothed to generate a DC voltage of an arbitrary set voltage. Furthermore, for example, a noise filter 5 is provided upstream of the PFC circuit in the power conversion device 1 to suppress (remove) noise from entering the power conversion device 1 from the external AC power supply and from leaking noise from the power conversion device 1 to the AC power supply.

[0026] In this embodiment, the explanation will be continued taking as an example a case where a plurality of electronic components constituting the noise filter 5 are mounted on circuit boards 2a and 2b arranged opposite to each other.

[0027] The noise filter 5 has a plurality of coils 5b (second components) provided on each of a plurality of power supply lines of the power conversion device 1. Each of the plurality of coils is, for example, a common mode choke coil or a normal mode choke coil. The coils 5b are held by a holding member 33 such as a resin mold and are mounted on the circuit board 2b. The holding member 33 determines the position of the coils 5b.

[0028] Furthermore, in the noise filter 5, a plurality of X capacitors 5a (first components) may be provided between each coil and the input terminal of the power conversion device 1. The plurality of X capacitors 5a are electrically connected between each of the plurality of power supply lines of the power conversion device 1 and the power supply line of the neutral wire (between the lines).

[0029] As an example, the multiple power supply lines include an electric wire through which a single-phase current from a single-phase AC power supply or, for example, a U-phase (first phase) current from a three-phase AC power supply flows, two electric wires that are not electrically connected to the single-phase AC power supply and through which, for example, a V-phase (second phase) current and a W-phase (third phase) current from the three-phase AC power supply flow, respectively, and a neutral electric wire that is electrically connected to each of the single-phase or three-phase AC power supply and a ground potential.

[0030] In the power conversion device 1 according to the embodiment, for example, with respect to the noise filter 5, as shown in FIG. 4, a coil 5b, which is a large component, is mounted on the circuit board 2b, and an X capacitor 5a (see FIG. 4) constituting a non-coil portion is mounted on the circuit board 2a (see FIG. 4). In other words, the circuit boards 2a and 2b on which the noise filter 5 is mounted are arranged opposite each other to form a two-layer structure. In addition, a support member 31 that physically supports the boards is provided between the opposing circuit boards 2. In other words, one of the opposing circuit boards 2 is supported by the other circuit board 2 via the support member 31. This support member 31 defines the distance between the opposing circuit boards 2. The number of support members 31 is arbitrary.

[0031] Furthermore, a plurality of hook-shaped wires 7, each electrically connecting the boards, are arranged between the opposing circuit boards 2. Each of the plurality of hook-shaped wires 7 has, for example, the same shape.

[0032] The hook-shaped wire 7 is made of an electrically conductive material such as copper, aluminum, an alloy, etc. As an example, the hook-shaped wire 7 is made of a general-purpose wiring (for example, a metal wire).

[0033] The hooked wire 7 has a first terminal portion 71 , a hook portion 73 and a second terminal portion 75 .

[0034] The first terminal portion 71 extends linearly from the hook portion 73. The first terminal portion 71 is shorter than the second terminal portion 75.

[0035] Hook portion 73 connects first terminal portion 71 and second terminal portion 75. Hook portion 73 is a bent portion formed, for example, in an arc shape (U-shape), but may be formed in other shapes such as a U-shape (angular U-shape) or a V-shape.

[0036] The second terminal portion 75 extends linearly from the opposite side of the hook portion 73 to the first terminal portion 71 in the same direction as the first terminal portion 71. The second terminal portion 75 is formed to be longer than the first terminal portion 71, for example, longer than the distance between the circuit boards 2 to be connected.

[0037] Furthermore, the hook-shaped wire 7 is provided with an insulating coating on the portion other than the portion connected to the wiring pattern 4. That is, the hook-shaped wire 7 is formed using a wire with an insulating coating, and the insulating coating is partially removed from the first terminal portion 71 and the second terminal portion 75 that penetrate the circuit board 2. Note that, of the portion of the hook-shaped wire 7 that penetrates the circuit board 2, the insulating coating is not removed from the portion that is not electrically connected to the wiring pattern 4.

[0038] In this way, the hook-shaped wire 7 according to the embodiment can be formed by bending a single wire. The wire forming the hook-shaped wire 7 may be a rectangular wire or a round wire. In other words, the cross section of the hook-shaped wire 7 may be circular or a polygonal shape such as a rectangle. In other words, the hook-shaped wire 7 according to the embodiment can be formed from a general-purpose wiring (metal wire), and can be easily shaped using a general-purpose wiring.

[0039] As shown in FIGS. 1 to 4, the hook-shaped wire 7 is inserted into the circuit board 2b so that its hook portion 73 is positioned on the front surface (+Z side) opposite to the other circuit board 2a that it faces. In other words, the hook-shaped wire 7 is hooked onto the circuit board 2b by the hook portion 73. In the example of FIGS. 1 to 4, the hook-shaped wire 7 penetrates the circuit board 2b twice. In other words, the hook-shaped wire 7 penetrates the installation surface (XY plane) of the circuit board 2b twice. Specifically, in the hook-shaped wire 7, the first terminal portion 71 and the second terminal portion 75 at both ends of the hook portion 73 each penetrate the circuit board 2b.

[0040] 4, the hook-shaped wire 7 passes through the circuit board 2a once. In other words, the hook-shaped wire 7 passes through the installation surface (XY plane) of the circuit board 2a once. Specifically, the portion of the hook-shaped wire 7 on the opposite side (-Z side) of the first terminal portion 71 from the hook portion 73 passes through the circuit board 2a arranged opposite to the circuit board 2b once.

[0041] That is, when the front surface of the circuit board 2a and the back surface of the circuit board 2b are arranged opposite each other, the hook portion 73 of the hook-shaped wire 7 electrically connecting the circuit boards 2a and 2b protrudes toward the front surface side (+Z side) of the circuit board 2b. The first terminal portion 71 and the second terminal portion 75 each protrude toward the back surface side (-Z side) of the circuit board 2b. The second terminal portion 75 extends from the circuit board 2b to the back surface side (-Z side) of the circuit board 2a and protrudes toward the back surface side of the circuit board 2a.

[0042] 4, the second terminal 75 is electrically connected to a wiring pattern 4b provided on the circuit board 2b. A lead 51b of the coil 5b is electrically connected to this wiring pattern 4b. The first terminal 71 is electrically connected to, for example, a wiring pattern 4a provided on a circuit board 2a that is arranged opposite the circuit board 2b. A lead 51a of the X capacitor 5a is electrically connected to an arbitrary wiring pattern 4 provided on the circuit board 2a.

[0043] In this way, the hook-shaped wire 7 forms a three-dimensional electrical circuit that electrically connects the opposing circuit boards 2. In other words, the board-to-board connection structure according to the embodiment has a three-dimensional electrical circuit configuration in which the hook-shaped wire 7 is regarded as part of the wiring pattern 4.

[0044] With this structure, even when the width of wiring pattern 4 becomes large, such as when the current value is large, making it difficult to route within circuit board 2, it is possible to configure an electrical path by extending wiring pattern 4 three-dimensionally using hook-shaped wire 7. This improves the degree of freedom in the electrical connection structure and the heat dissipation effect, and also allows for the miniaturization of the entire device, compared to when wiring pattern 4 is configured only within circuit board 2.

[0045] Further, the hook portion 73 is provided with an insulating coating and is disposed above (on the +Z side of) the circuit board 2b at a distance from the circuit board 2b. That is, the first terminal portion 71 and the second terminal portion 75 at both ends of the hook portion 73 intersect with the circuit board 2b in the ZX plane, i.e., penetrate the circuit board 2b, while the hook portion 73 does not intersect with (or penetrate through) the circuit board 2b in the ZX plane. In other words, the hook portion 73 protrudes from the circuit board 2b on the side opposite the circuit board 2a. Therefore, on the circuit board 2b, below (on the -Z side of) the hook portion 73, another wiring pattern 4 that is not electrically connected to the hook-shaped wire 7 may be formed. In other words, the hook portion 73 of the hook-shaped wire 7 may three-dimensionally intersect with a wiring pattern 4 that is not electrically connected to the hook-shaped wire 7, among the wiring patterns 4 formed on the circuit board 2b. The wiring pattern 4 that is not electrically connected to the hook-shaped wire 7 is, for example, a wiring pattern 4 that has a different potential from the wiring pattern 4 that is electrically connected by the hook-shaped wire 7. It may also be arranged to cross over other wiring patterns at the same potential. This configuration improves the degree of freedom of the electrical connection structure.

[0046] Fig. 5 is a flowchart showing an example of the flow of a board-to-board connecting process according to an embodiment. Fig. 5 illustrates a case where an X capacitor 5a (first component) constituting a non-coil portion is mounted on one circuit board 2a of opposing circuit boards 2, and a coil 5b (second component) is mounted on the other circuit board 2b.

[0047] Prior to the flow of FIG. 5, wiring patterns 4 are formed on each of circuit boards 2a and 2b so that hook-shaped wires 7 inserted into circuit board 2b are perpendicular to each of circuit boards 2a and 2b.

[0048] First, the hook-shaped wire 7 is passed through the circuit board 2b (second board) (S1) as shown in Figures 1 to 3. Then, the hook-shaped wire 7 is soldered to the circuit board 2b together with the coil 5b (second component) (S2).

[0049] As illustrated in Figures 1 to 4, the coil 5b (second component) is arranged, for example, on the front surface side (+Z side) of the circuit board 2b, but it may also be arranged on the back surface side (-Z side) of the circuit board 2b.

[0050] Thereafter, the circuit board 2b on which the coil 5b and the hook-shaped wire 7 are arranged is assembled to the circuit board 2a (first board). Specifically, the hook-shaped wire 7 soldered to the circuit board 2b is passed through the circuit board 2a (S3). As an example, the hook-shaped wire 7 is passed through a predetermined position on the circuit board 2a while being held by a mold (not shown) with a positioning function or by using a jig. Then, the hook-shaped wire 7 is soldered to the circuit board 2a together with the X capacitor 5a (first component) (S4).

[0051] As illustrated in FIGS. 1 to 4, the X capacitor 5a (first component) is disposed on the front surface side (+Z side) of the circuit board 2a, for example, on the circuit board 2b side, but may also be disposed on the back surface side (-Z side) of the circuit board 2a.

[0052] As described above, the board-to-board connection structure according to the embodiment is a three-dimensional electrical circuit structure that electrically connects opposing circuit boards 2a, 2b with hook-shaped wires 7. Specifically, the board-to-board connection structure according to the embodiment is a wire bus bar type board-to-board connection structure in which a plurality of hook-shaped wires 7, each formed using a wire rod (wire), are used for electrical connection between opposing circuit boards 2, similar to when a bus bar is used, for example.

[0053] For example, when electrically connecting opposing circuit boards using pin headers or blades, the shapes of the pin headers or blades vary depending on the current value and the distance between the boards, making it difficult to form them as general-purpose components. This requires design and evaluation for each case, resulting in a problem of low design versatility. Furthermore, when connecting a mounted component to a circuit board using a bus bar, the cost of the mold used to form the bus bar is high. Furthermore, because the shape of the bus bar differs for each connection point (e.g., each pole of the coil 5b), multiple types of molds are required. Furthermore, when connecting a mounted component to a circuit board by extending the leads (wires) of the mounted component, the wire paths become complicated, requiring design and evaluation for each case, resulting in a problem of low design versatility.

[0054] In this regard, the hook-shaped wire 7 according to the embodiment can be easily formed using wire material, and can therefore be realized as a low-cost general-purpose component. Furthermore, if the wiring pattern 4 can be routed on the circuit board 2, each of the multiple hook-shaped wires 7 can be made to have the same shape, making it possible to create a lower-cost general-purpose component. Furthermore, even when the wiring pattern 4 is routed on the circuit board 2, the hook portion 73 can be made to intersect three-dimensionally with other wiring patterns 4 on the circuit board 2b, and therefore, even if each of the multiple hook-shaped wires 7 has the same shape, it is possible to prevent a decrease in the degree of freedom in their placement.

[0055] Furthermore, for example, in electrical connection structures using pin headers or blades, the surface-mounted pin headers or blades can interfere with soldering electronic components to a circuit board, thereby affecting the connection process. For example, in electrical connection structures using blades, the precision of the mounting position of a pair of mating blades and sockets can lead to connection failures, and a mating status confirmation process is required to prevent connection failures. Furthermore, it is necessary to configure the wiring patterns of the opposing circuit boards so that the terminal positions to be connected coincide. However, as the current value increases, the pattern width increases, limiting the degree of freedom. Especially when miniaturization is required, it can be difficult to configure the layout pattern so that the terminal positions to be connected coincide. Furthermore, while increasing the number of layers in a circuit board increases the degree of freedom in the configuration of wiring patterns per circuit board, there is a risk of insufficient heat dissipation when the current value is high. Furthermore, for example, when a mounted component such as a coil is connected to a circuit board on which electronic components constituting the non-coil portion are mounted by extending its wire (lead), the electrical circuit structure becomes complicated depending on the route of the wire, and if the wire is long, there is a risk that heat may not be dissipated sufficiently.

[0056] In this situation, according to the board-to-board connection structure of the embodiment, a three-dimensional electrical circuit can be configured using a hook-shaped wire 7. This three-dimensional electrical circuit structure using the hook-shaped wire 7 can improve the versatility and flexibility of the electrical connection structure in electronic devices. Specifically, according to the board-to-board connection structure of the embodiment, the flexibility of the configuration of the wiring pattern 4 on the circuit board 2 can be improved. Furthermore, as the flexibility of the wiring pattern 4 is improved, the flexibility of the arrangement of electronic components mounted on the circuit board 2 can also be improved. The improved flexibility of the arrangement of the wiring pattern 4 and mounted components on the circuit board 2 improves the packaging density per circuit board 2, suppresses an increase in the number of layers of the circuit board 2, suppresses an increase in the size of the power conversion device 1, and improves the efficiency of heat dissipation.

[0057] Furthermore, the hook-shaped wire 7 can accommodate different current values ​​and inter-substrate distances by changing the wire diameter and the length of the first terminal portion 71, making it easy to standardize and highly expandable.

[0058] Furthermore, the area of ​​the circuit board 2a where the hook-shaped wire 7 is connected to the wiring pattern 4 is occupied only by the through-hole through which the first terminal portion 71 passes. Therefore, compared to electrical connection structures that use pin headers, blades, or bus bars, or electrical connection structures that extend leads, the effect of miniaturization can be achieved.

[0059] (Second embodiment) The shape of the hook-shaped wire 7 can be changed as appropriate to suit the arrangement of electronic components mounted on the circuit board 2.

[0060] 6 is a diagram schematically illustrating another example of a board-to-board connection structure according to the embodiment. As shown in FIG. 6, the hook portion 73 of the hook-shaped wire 7 according to the embodiment extends in the direction along the circuit board 2 (X direction) and is formed so as to straddle the X capacitor 5a. That is, the hook portion 73 extends along the circuit board 2b beyond at least a portion of the electronic components mounted on the circuit board 2a. The hook-shaped wire 7 electrically connects the wiring pattern 4b provided on the circuit board 2b with the wiring pattern 4a provided on the circuit board 2a. The connection portion between the hook-shaped wire 7 and the wiring pattern 4b is on the opposite side of the X capacitor 5a from the connection portion between the hook-shaped wire 7 and the wiring pattern 4a in the direction along the circuit board 2.

[0061] According to this configuration, the hook-shaped wire 7 forms a three-dimensional electrical path, and the wiring patterns 4a, 4b can be electrically connected to each other. In other words, by changing the shape of the hook portion 73 of the hook-shaped wire 7, the position of the wiring pattern 4 to be connected in the direction along the circuit board 2 (XY plane) can be shifted between the circuit boards 2 to be connected. Therefore, compared to when the wiring pattern 4 is formed inside the circuit board 2, the degree of freedom of the electrical connection structure is further improved, and the power conversion device 1 can be made more compact.

[0062] (Third embodiment) The first terminal portion 71 may be further electrically connected to, for example, a wiring pattern 4b provided on the circuit board 2b.

[0063] 7 is a diagram schematically illustrating another example of the inter-board connection structure according to the embodiment. As shown in FIG. 7, the second terminal 75 of the hook-shaped wire 7 according to the present embodiment is electrically connected to a wiring pattern 41b provided on the circuit board 2b. A lead 51b of the coil 5b is electrically connected to this wiring pattern 41b. The first terminal 71 is electrically connected, for example, to a wiring pattern 4a provided on the circuit board 2a that is disposed opposite the circuit board 2b. The first terminal 71 is further electrically connected, for example, to another wiring pattern 42b of the same potential that is provided on the circuit board 2b.

[0064] According to this configuration, the hook-shaped wire 7 can further be used as an electrical path that connects the wiring patterns 4 at the same potential on the circuit board 2b. In other words, according to the inter-board connection structure of this embodiment, the degree of freedom of the electrical connection structure can be further improved.

[0065] (Fourth embodiment) The hook portion 73 may be disposed beyond the outer edge of the circuit board 2b.

[0066] 8 is a diagram schematically illustrating another example of a board-to-board connection structure according to an embodiment. As shown in FIG. 8, the hooked wire 7 is inserted into the circuit board 2b so that the hook portion 73 is located on the opposite side (+Z side) from the other circuit board 2a that it faces. The hooked wire 7 penetrates the surface (XY plane) on which the circuit board 2b is located twice. Specifically, in the hooked wire 7, the first terminal portion 71 and the second terminal portion 75 at both ends of the hook portion 73 each penetrate the surface on which the circuit board 2b is located, i.e., the installation surface (XY plane) of the circuit board 2b.

[0067] 8, the hook-shaped wire 7 penetrates once through the installation surface (XY plane) of the circuit board 2a. Specifically, the portion of the hook-shaped wire 7 on the opposite side (-Z side) of the second terminal portion 75 from the hook portion 73 penetrates once through the circuit board 2a arranged opposite to the circuit board 2b.

[0068] That is, in the hook-shaped wire 7 electrically connecting the opposing circuit boards 2a and 2b, the hook portion 73 protrudes from the installation surface of the circuit board 2b opposite the circuit board 2a (+Z side). The second terminal portion 75 is located inside the circuit board 2b. On the other hand, the first terminal portion 71 is located outside the circuit board 2b. That is, the hook portion 73 extends from the inside to the outside of the circuit board 2b on the front surface side (+Z side) of the circuit board 2b. The first terminal portion 71 and the second terminal portion 75 each protrude from the installation surface of the circuit board 2b toward the circuit board 2a (-Z side). The second terminal portion 75 extends from the circuit board 2b to the side of the circuit board 2a opposite the circuit board 2b (-Z side). That is, the second terminal portion 75 protrudes from the side of the circuit board 2a opposite the circuit board 2b (-Z side).

[0069] According to this configuration, it is not necessary to extend the circuit board 2b up to above (on the +Z side of) the wiring pattern 4a of the circuit board 2a, which makes it possible to reduce the size of the circuit board 2b, that is, the size of the power conversion device 1. Furthermore, according to the configuration in which the hook portion 73 extends to the outside of the circuit board 2b, the degree of freedom of the electrical connection structure can be further improved.

[0070] (Fifth embodiment) In the inter-board connection structure according to the second embodiment, large electronic components such as the coil 5b (wound material) may be mounted on the circuit board 2a side, not limited to the circuit board 2b.

[0071] 9 is a diagram schematically illustrating another example of the inter-board connection structure according to the embodiment. The inter-board connection structure illustrated in FIG. 9 corresponds to the inter-board connection structure illustrated in FIG. 6 in which the coil 5b is mounted on the circuit board 2a and the X capacitor 5a is mounted on the circuit board 2b. In the example illustrated in FIG. 9, the second terminal 75 is electrically connected to a wiring pattern 4b provided on the circuit board 2b. The first terminal 71 is electrically connected to, for example, a wiring pattern 4a provided on the circuit board 2a that is arranged opposite the circuit board 2b. A lead 51b of the coil 5b is electrically connected to this wiring pattern 4a.

[0072] Even with this configuration, the same effects as in the second embodiment can be obtained.

[0073] (Sixth embodiment) In the board-to-board connection structure according to the third embodiment, large electronic components such as the coil 5b (wound material) may be mounted on the circuit board 2a side, not limited to the circuit board 2b.

[0074] 10 is a diagram schematically illustrating another example of the inter-board connection structure according to the embodiment. The inter-board connection structure illustrated in FIG. 10 corresponds to the inter-board connection structure illustrated in FIG. 7 in which the coil 5b is mounted on the circuit board 2a and the X capacitor 5a is mounted on the circuit board 2b. In the example illustrated in FIG. 10, the second terminal 75 is electrically connected to a wiring pattern 41b provided on the circuit board 2b. The first terminal 71 is electrically connected to the wiring pattern 42b provided on the circuit board 2b and to a wiring pattern 4a provided on the circuit board 2a that faces the circuit board 2b. A lead 51b of the coil 5b is electrically connected to the wiring pattern 4a.

[0075] Even with this configuration, the same effects as in the third embodiment can be obtained.

[0076] (Seventh embodiment) In the board-to-board connection structure according to the fourth embodiment, large electronic components such as the coil 5b (wound material) may be mounted on the circuit board 2a side, not limited to the circuit board 2b.

[0077] 11 is a diagram schematically illustrating another example of the inter-board connection structure according to the embodiment. The inter-board connection structure illustrated in FIG. 11 corresponds to the inter-board connection structure illustrated in FIG. 8 in which the coil 5b is mounted on the circuit board 2a and the X capacitor 5a is mounted on the circuit board 2b. In the example illustrated in FIG. 11, the hook-shaped wire 7 penetrates the installation surface (XY plane) of the circuit board 2b twice. The hook-shaped wire 7 also penetrates the installation surface (XY plane) of the circuit board 2a once. The second terminal 75 is electrically connected to the wiring pattern 41b provided on the circuit board 2b. The first terminal 71 is electrically connected to the wiring pattern 4a provided on the circuit board 2a that is disposed opposite the circuit board 2b. The lead 51b of the coil 5b is electrically connected to the wiring pattern 4a.

[0078] Even with this configuration, the same effects as in the fourth embodiment can be obtained.

[0079] (Eighth embodiment) In the inter-board connection structures according to the above-described embodiments, the hook-shaped wire 7 is not limited to the wiring pattern 4 on the circuit board 2, and may cross other hook-shaped wires 7 at different levels.

[0080] 12 is a diagram schematically illustrating another example of the board-to-board connection structure according to the embodiment. In the example illustrated in FIG. 12, each of the hook-shaped wires 7a and 7b is inserted into the circuit board 2b so that the hook portion 73 is located on the opposite side (+Z side) from the other circuit board 2a that it faces. That is, each of the hook-shaped wires 7a and 7b penetrates the installation surface (XY plane) of the circuit board 2b twice. Specifically, in the hook-shaped wires 7a and 7b, the first terminal portion 71 and the second terminal portion 75 at both ends of the hook portion 73 each protrude from the circuit board 2b toward the circuit board 2a. Furthermore, each of the hook-shaped wires 7a and 7b penetrates the installation surface (XY plane) of the circuit board 2a once. Specifically, in the hook-shaped wires 7a and 7b, the first terminal portion 71 protrudes from the circuit board 2a opposite the circuit board 2b (-Z side). Here, the hook-shaped wire 7a according to the embodiment is an example of a first hook-shaped wire, and the hook-shaped wire 7b according to the embodiment is an example of a second hook-shaped wire.

[0081] Moreover, the hook portions 73 of the hook-shaped wires 7a and 7b intersect on the front surface side (+Z side) of the circuit board 2b. Specifically, the hook-shaped wire 7b is held by a holding member 81 and inserted into a through-hole of the circuit board 2b so that the hook portion 73 is positioned above (on the +Z side of) the hook portion 73 of the hook-shaped wire 7a.

[0082] The holding member 81 is formed of, for example, an insulating material. The holding member 81 may hold the hook-shaped wires 7a, 7b and fix them relative to each other, or may hold at least one of the hook-shaped wires 7a, 7b and fix it to the circuit board 2b. For example, the size of the holding member 81 may be determined according to the insulation distance between the intersecting hook-shaped wires 7a, 7b. This holding member 81 can ensure the insulation distance between the intersecting hook-shaped wires 7a, 7b.

[0083] In the example shown in FIG. 12, the second terminal portion 75 of the hook-shaped wire 7a is electrically connected to the wiring pattern 41b on the circuit board 2b. The first terminal portion 71 of the hook-shaped wire 7a is electrically connected to the wiring pattern 4a on the circuit board 2a. Meanwhile, the second terminal portion 75 of the hook-shaped wire 7b is electrically connected to the wiring pattern 43b on the circuit board 2b. This wiring pattern 43b is at a different potential from the wiring pattern 41b on the circuit board 2b and is a wiring pattern 4 that is not electrically connected to the wiring pattern 41b. The second terminal portion 75 of the hook-shaped wire 7b is electrically connected to the wiring pattern 4 (not shown) on the circuit board 2a. This wiring pattern 4 is also at a different potential from the wiring pattern 4a on the circuit board 2a and is a wiring pattern 4 that is not electrically connected to the wiring pattern 4a.

[0084] In this way, the configuration in which the hook-shaped wires 7 are crossed can further improve the degree of freedom of the electrical connection structure compared to the inter-board connection structures according to the above-described embodiments.

[0085] Furthermore, if insulation between each hook portion 73 of the intersecting hook-shaped wires 7 can be ensured and the wires are held with sufficient strength by being fixed to the circuit board 2b, the holding member 81 does not need to be provided even when the hook-shaped wires 7 are crossed.

[0086] It is also possible to have one hook-shaped wire 7 cross two or more hook-shaped wires 7 .

[0087] Note that multiple hook-shaped wires 7 connected to wiring patterns 4 at the same potential may be electrically connected while crossing each other. This electrical connection may be made via a holding member 81. With this configuration, an electric path can be formed via multiple crossing hook-shaped wires 7, further improving the degree of freedom of the electrical connection structure.

[0088] According to at least one of the embodiments described above, it is possible to improve the versatility and flexibility of the electrical connection structure in an electronic device in which a plurality of circuit boards are stacked.

[0089] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents.

[0090] (Addendum) The above description of the embodiments discloses the following techniques. (1) a first substrate on which a first component is mounted; a second substrate on which a second component is mounted and whose front surface is disposed opposite to the back surface of the first substrate; a hook-shaped wire made of an electrically conductive conductive material, the hook-shaped wire having a hook portion, a first terminal portion extending from one end of the hook portion and longer than the distance between the first substrate and the second substrate, and a second terminal portion extending from the other end of the hook portion in the same direction as the first terminal portion and shorter than the first terminal portion; the hook portion protrudes from a surface side of the second substrate opposite to the first substrate, the first terminal portion and the second terminal portion each protrude to a rear surface side of the second substrate, the first terminal portion extends to a rear surface side of the first substrate opposite to the second substrate, protrudes from the rear surface side of the first substrate, and is electrically connected to at least a wiring pattern provided on the first substrate; The second terminal portion is electrically connected to a wiring pattern provided on the second substrate. Board-to-board connection structure. (2) The hooked wire penetrates the second substrate twice and the first substrate once. The board-to-board connection structure according to (1) above. (3) the hook portion extends beyond at least a portion of the first component mounted on the first substrate in a direction along the first substrate and the second substrate; a connection portion between the hook-shaped wire and the wiring pattern provided on the first substrate is on the opposite side of the first component from a connection portion between the hook-shaped wire and the wiring pattern provided on the second substrate in a direction along the first substrate and the second substrate; The board-to-board connection structure according to (1) or (2) above. (4) The first terminal portion is further electrically connected to a wiring pattern provided on the second substrate. The substrate-to-substrate connection structure according to any one of (1) to (3) above. (5) the hook portion extends to an outside of the second substrate on the front surface side of the second substrate, The hooked wire passes through each of the first substrate and the second substrate once. The substrate-to-substrate connection structure according to any one of (1), (3), and (4) above, which does not cite (2) above. (6) The hook portion is formed in a U-shape or a square U-shape. The substrate-to-substrate connection structure according to any one of (1) to (5) above. (7) The hook-shaped wire is formed by bending a single metal wire. The substrate-to-substrate connection structure according to any one of (1) to (6) above. (8) The hook portion is provided with an insulating coating and intersects with another wiring pattern having a different potential provided on the surface side of the second substrate on the surface side of the second substrate. The substrate-to-substrate connection structure according to any one of (1) to (7) above. (9) a first hook-shaped wire electrically connected to a wiring pattern at a first potential, and a second hook-shaped wire connected to a wiring pattern at a second potential different from the first potential; the hook portion of the first hook-shaped wire and the hook portion of the second hook-shaped wire intersect on the front surface side of the second substrate; The substrate-to-substrate connection structure according to any one of (1) to (8) above. (10) The wire harness further includes a holding member made of an insulating material, disposed between the hook portion of the first hook-shaped wire and the hook portion of the second hook-shaped wire, and holding at least one of the first hook-shaped wire and the second hook-shaped wire. The board-to-board connection structure according to (9) above. (11) The substrate-to-substrate connection structure according to any one of (1) to (10) above, the first component being one of a coil and an X capacitor; the second component being the other of the coil and the X capacitor; Power conversion device. (12) The power conversion device according to (11) above, which converts AC power from an external AC power source into DC power; a battery that is charged using the DC power converted by the power conversion device. vehicle. [Explanation of symbols]

[0091] 1 Power conversion device 2, 2a, 2b Circuit board 31 Support member 33 Retaining member 4, 4a, 4b, 41b, 42b, 43b Wiring pattern 5 Noise Filter 5a x capacitor 5b coil 51a, 51b Lead 7, 7a, 7b Hooked wire 71 1st terminal section 73 Key section 75 2nd terminal section 81 Retaining member

Claims

1. a first substrate on which a first component is mounted; a second substrate on which a second component is mounted and whose front surface is disposed opposite to the back surface of the first substrate; a hook-shaped wire made of an electrically conductive conductive material, the hook-shaped wire having a hook portion, a first terminal portion extending from one end of the hook portion and longer than the distance between the first substrate and the second substrate, and a second terminal portion extending from the other end of the hook portion in the same direction as the first terminal portion and shorter than the first terminal portion; the hook portion protrudes from a surface side of the second substrate opposite to the first substrate, the first terminal portion and the second terminal portion each protrude to a rear surface side of the second substrate, the first terminal portion extends to a rear surface side of the first substrate opposite to the second substrate, protrudes from the rear surface side of the first substrate, and is electrically connected to at least a wiring pattern provided on the first substrate; The second terminal portion is electrically connected to a wiring pattern provided on the second substrate. Board-to-board connection structure.

2. The hooked wire passes through the second substrate twice and the first substrate once. The substrate-to-substrate connection structure according to claim 1 .

3. the hook portion extends beyond at least a portion of the first component mounted on the first substrate in a direction along the first substrate and the second substrate; a connection portion between the hook-shaped wire and the wiring pattern provided on the first substrate is on the opposite side of the first component from a connection portion between the hook-shaped wire and the wiring pattern provided on the second substrate in a direction along the first substrate and the second substrate; The substrate-to-substrate connection structure according to claim 1 .

4. The first terminal portion is further electrically connected to a wiring pattern provided on the second substrate. The board-to-board connection structure according to claim 2 .

5. the hook portion extends to an outside of the second substrate on the front surface side of the second substrate, The hooked wire passes through each of the first substrate and the second substrate once. The substrate-to-substrate connection structure according to claim 1 .

6. The hook portion is formed in a U-shape or a square U-shape. The substrate-to-substrate connection structure according to claim 1 .

7. The hook-shaped wire is formed by bending a single metal wire. The substrate-to-substrate connection structure according to claim 1 .

8. the hook portion is provided with an insulating coating, and intersects with another wiring pattern having a different potential provided on the surface side of the second substrate on the surface side of the second substrate; The substrate-to-substrate connection structure according to claim 1 .

9. a first hook-shaped wire electrically connected to a wiring pattern of a first potential, and a second hook-shaped wire connected to a wiring pattern of a second potential different from the first potential, the hook portion of the first hook-shaped wire and the hook portion of the second hook-shaped wire intersect on the front surface side of the second substrate; The substrate-to-substrate connection structure according to claim 1 .

10. The wire harness further includes a holding member made of an insulating material, disposed between the hook portion of the first hook-shaped wire and the hook portion of the second hook-shaped wire, and configured to hold at least one of the first hook-shaped wire and the second hook-shaped wire. The board-to-board connection structure according to claim 9 .

11. The substrate-to-substrate connection structure according to any one of claims 1 to 10; the first component being one of a coil and an X capacitor; the second component being the other of the coil and the X capacitor; Power conversion device.

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