Substrate connection structure, charger, and substrate connection method

Abstract

This substrate connection structure comprises a first wiring substrate (wiring substrate), a support member that supports the first wiring substrate, a first connection member that is attached to the first wiring substrate, and a first screw member that screws the support member and the first connection member together. The first wiring substrate has a first through-hole penetrating therethrough in a thickness direction, and a first conductor portion provided on the inner surface of the first through-hole. The support member has electrical conductivity and has a first screw hole. The first connection member has electrical conductivity, has a first screw passing-hole formed therein, and is attached to the first wiring substrate in a state of being inserted into the first through-hole and in electrical communication with the first conductor portion. The first screw member is screwed into the first screw hole through the first screw passing-hole, whereby the support member and the first connection member are screwed together in a state of electrical communication with each other.

Description

Substrate connection structure, charger, and substrate connection method

[0001] The present disclosure relates to a board connection structure, a charger, and a board connection method. More specifically, the present disclosure relates to a board connection structure including a wiring board, a support member, a connection member, and a screw member, a charger including the board connection structure, and a board connection method.

[0002] Patent Document 1 describes a conventional substrate connection structure in which a screw is passed through a second through-hole formed in an insulating substrate and a through-hole formed in an electronic component body, and the screw is fastened to a screw hole formed in a heat dissipation fin.

[0003] In the conventional board connection structure described above, the fastening force from the screw is applied directly to the resin part of the insulating board. As a result, the thickness of the part of the insulating board that comes into contact with the screw becomes thinner over time. This can lead to various problems, such as damage to the insulating board.

[0004] Japanese Patent Application Laid-Open No. 2020-181955

[0005] An object of the present disclosure is to provide a board connection structure, a charger, and a board connection method that can easily prevent a decrease in the conductivity between a wiring board and a support member.

[0006] A substrate connection structure according to one aspect of the present disclosure includes a wiring board, a support member that supports the wiring board, a first connection member attached to the wiring board, and a first screw member that screws together the support member and the first connection member. The wiring board has a first through hole that penetrates the wiring board in a thickness direction and a first conductor portion provided on the inner surface of the first through hole. The support member is conductive and has a first screw hole. The first connection member is conductive and has a first screw through hole formed therein, and is attached to the wiring board while being inserted into the first through hole and electrically connected to the first conductor portion. The first screw member is threaded through the first screw through hole and into the first screw hole, thereby electrically connecting the support member and the first connection member.

[0007] The first connecting member is preferably press-fitted into the first through hole.

[0008] It is preferable that the material of the first connecting member and the material of the first screw member are the same.

[0009] The first screw member is preferably a tapered screw.

[0010] The first conductor is preferably a plated layer formed on the inner surface of the first through hole.

[0011] It is preferable that the substrate connection structure further includes a second wiring substrate, and the support member is a spacer interposed between the first wiring substrate and the second wiring substrate.

[0012] The substrate connection structure preferably further comprises a second connecting member that is conductive and attached to the second wiring substrate, and a second screw member that screws together the support member and the second connecting member, wherein the second wiring substrate has a second through hole that penetrates in the thickness direction and a second conductor portion provided on the inner surface of the second through hole, the support member has a second screw hole, the second connecting member has a second screw through hole formed therein, is inserted into the second through hole and is attached to the second wiring substrate in a state of electrical conductivity with the second conductor portion, and the second screw member is screwed into the second screw hole through the second screw through hole, and the support member and the second connecting member are screwed together in a state of electrical conductivity.

[0013] A charger according to one aspect of the present disclosure includes a charging circuit including an electric circuit electrically connected by a board connection structure.

[0014] The charging circuit includes a first filter, an AC / DC converter, a DC / DC converter, a second filter, and a charge controller. The first filter passes an input AC voltage. The AC / DC converter converts the AC voltage that has passed through the first filter into a DC voltage. The DC / DC converter insulates the DC voltage and generates a charging voltage. The second filter passes the charging voltage generated by the DC / DC converter. The second filter charges the power storage unit with the charging voltage that has passed through the second filter. The charge controller controls the first filter, the AC / DC converter, the DC / DC converter, and the second filter. The first filter, the AC / DC converter, the DC / DC converter, the second filter, and the charge controller, which are electrical circuits that make up the charging circuit, are electrically connected to each other or to each other via a substrate connection structure.

[0015] A substrate connection method according to one aspect of the present disclosure includes first preparing a wiring board having a first through hole penetrating in a thickness direction and a first conductor portion provided on the inner surface of the first through hole, a conductive support member having a first screw hole, and a conductive first connecting member having a first screw through hole. The first connecting member is inserted into the first through hole of the wiring board and attached to the wiring board while being electrically connected to the first conductor portion of the wiring board. A first screw member is threaded through the first screw through hole of the first connecting member and into the first screw hole of the support member, and the support member and the first connecting member are fastened together while being electrically connected to each other.

[0016] The board connection structure, charger, and board connection method of the present disclosure make it easy to prevent a decrease in the conductivity between the wiring board and the support member.

[0017] FIG. 1 is a cross-sectional view of a board connection structure according to a first embodiment of the present disclosure. FIG. 2A is a cross-sectional view of a main portion of a first wiring board in the board connection structure according to the same. FIG. 2B is a plan view of a main portion of the first wiring board in the same. FIG. 3A is a cross-sectional view of a support member in the board connection structure according to the same. FIG. 3B is a plan view of the support member in the same. FIG. 4A is a cross-sectional view of a first connecting member in the board connection structure according to the same. FIG. 4B is a plan view of the first connecting member in the same. FIG. 5A is a side view of a first screw member in the board connection structure according to the same. FIG. 5B is a side view of a washer in the board connection structure according to the same. FIG. 6 is a cross-sectional view of a board connection structure according to a second embodiment of the present disclosure. FIG. 7 is a schematic view of a charger including the board connection structure according to the first embodiment of the present disclosure.

[0018] (1) Overview A board connection structure, a charger, and a board connection method according to the present disclosure will be described. The embodiments described below are merely a portion of various embodiments of the present disclosure. In the following embodiments, various modifications are possible depending on the design, etc., as long as the object of the present disclosure can be achieved. Furthermore, each figure described in the following embodiments is a schematic diagram. The ratios of the sizes and thicknesses of the components in the figures do not necessarily reflect the actual dimensional ratios.

[0019] FIG. 1 is a cross-sectional view of a board connection structure 92 according to a first embodiment of the present disclosure. As shown in FIG. 1 , the board connection structure according to the first embodiment includes a first wiring board 1 (wiring board), a support member 2 that supports the first wiring board 1, a first connection member 3 attached to the first wiring board 1, and a first screw member 4 that screws the support member 2 and the first connection member 3 together. The first wiring board 1 has a first through hole 13 that penetrates the first wiring board 1 in a thickness direction T0 and a first conductor portion 14 provided on the inner surface of the first through hole 13. The support member 2 is conductive and has a first screw hole 21. The first connection member 3 is conductive and has a first screw through hole 31 formed therein. The first connection member 3 is inserted into the first through hole 13 and attached to the first wiring board 1 in a state of electrical conductivity with the first conductor portion 14. The first screw member 4 is threaded through the first screw through hole 31 and screwed into the first screw hole 21, thereby electrically connecting the support member 2 and the first connection member 3 to each other.

[0020] 7 is a schematic diagram of a charger 90 including a board connection structure according to the first embodiment of the present disclosure. As shown in FIG. 7, the charger 90 according to the present disclosure includes a power storage unit 91, and a filter 98, an AC / DC converter 94, a DC / DC converter 95, a filter 96, and a charge controller 97 that form a charging circuit.

[0021] In the board connection method according to the present disclosure, a wiring board having a first through hole 13 penetrating in the thickness direction and a first conductor portion 14 provided on the inner surface of first through hole 13, a conductive support member 2 having a first screw hole 21, and a conductive first connecting member 3 having a first screw through hole 31 are prepared. The first connecting member 3 is inserted into the first through hole 13 of the wiring board and attached to the wiring board in a state of electrical conduction with the first conductor portion 14 of the wiring board. A first screw member 4 is threaded through the first screw through hole 31 of the first connecting member 3 and into the first screw hole 21 of the support member 2, and the support member 2 and the first connecting member 3 are screwed together in a state of electrical conduction.

[0022] In the above-described board connection structure 92, charger 90, and board connection method, it is easy to suppress a decrease in the conductivity between the wiring board (first wiring board 1) and support member 2.

[0023] (2) First Embodiment Hereinafter, a substrate connection structure and a substrate connection method according to a first embodiment will be described with reference to FIGS. 1 to 5B.

[0024] (2.1) Overview of the Board Connection Structure As shown in FIG. 1 , the board connection structure 92 includes a wiring board (first wiring board 1), a support member 2, a first connecting member 3, and a first screw member 4. As shown in FIG. 7 , the charger 90 includes a power storage unit 91 and a charging circuit including a filter 98, an AC / DC converter 94, a DC / DC converter 95, a filter 96, and a charging controller 97. The filter 98 passes the AC voltage of the power source input via the connection unit 93. The AC / DC converter 94 converts the AC voltage that has passed through the filter 98 into a high-voltage DC voltage. The DC / DC converter 95 insulates the high-voltage DC voltage and generates a charging voltage. The filter 96 passes the charging voltage generated by the DC / DC converter 95. The power storage unit 91 is charged with the charging voltage that has passed through the filter 96. The charge controller 97 controls the filter 98, the AC / DC converter 94, the DC / DC converter 95, and the filter 96. The filter 98, the AC / DC converter 94, the DC / DC converter 95, the filter 96, and the charge controller 97, which constitute the charging circuit, are electrically connected to each other or to each other via the board connection structure described above. The charger 90 is, for example, a charger for an electric vehicle. Energy for running the electric vehicle is stored in the power storage unit 91. The current used to run the electric vehicle flows through the electrical path formed by the board connection structure 92. Energy is supplied to the electric vehicle from the charger 90 via the connection unit 93.

[0025] (2.2) Wiring Board FIG. 2A is a cross-sectional view of a main portion of a first wiring board 1 in a board connection structure 92 according to a first embodiment of the present disclosure. FIG. 2B is a plan view of a main portion of the first wiring board 1 in the board connection structure 92. As shown in FIG. 1 , a pair of wiring boards is used in this embodiment. A board connection structure according to the present disclosure is used in one of the wiring boards. A board connection structure according to the present disclosure is not used in the other wiring board. For convenience, a wiring board in which a board connection structure according to the present disclosure is used is referred to as a first wiring board 1, and a wiring board in which a board connection structure according to the present disclosure is not used is referred to as a second wiring board 6.

[0026] The first wiring substrate 1 has a substrate body 11 and a wiring portion 12. The substrate body 11 is formed of a non-conductive resin such as PCB (Poly Chlorinated Biphenyl). The thickness T1 of the substrate body 11 is, for example, 2 mm.

[0027] The substrate main body 11 is provided with a wiring portion 12. The wiring portion 12 is provided on the substrate main body 11 by forming a wiring pattern made of copper foil on one plate surface 101 of the substrate main body 11. The first wiring board 1 is a printed wiring board. The first wiring board 1 is a so-called single-sided board in which a wiring pattern is formed on one plate surface 101 of the substrate main body 11 and no wiring pattern is formed on the other plate surface 102. The plate surfaces 101 and 102 are configured as flat surfaces. The plate surfaces 101 and 102 have through holes and unevenness formed in parts thereof, and components such as electrical components are attached to them.

[0028] The first wiring substrate 1 has a first through hole 13 and a first conductor portion 14. The first through hole 13 penetrates the substrate body 11 in the thickness direction T0. The first conductor portion 14 is provided on the inner surface of the first through hole 13. The first through hole 13 has a circular shape when viewed in a direction perpendicular to the plate surface 101 (i.e., the thickness direction T0). The diameter W1 of the first through hole 13 is, for example, 10 mm. However, the specific size of the diameter W1 is not limited.

[0029] The first conductor portion 14 is provided on the inner surface facing the first through hole 13 of the substrate main body 11. The first conductor portion 14 is configured by a plating layer made of a metal such as copper, formed on the inner surface facing the first through hole 13 of the substrate main body 11. The first conductor portion 14 is formed on the entire inner surface facing the first through hole 13 of the substrate main body 11. The first conductor portion 14 is electrically connected to the wiring portion 12 formed on the plate surface 101 at the end of the first through hole 13 on the plate surface 101 side. In other words, the first conductor portion 14 is connected to the wiring portion 12 and serves as an electrical path for a current to be supplied to the first wiring board 1, etc.

[0030] The second wiring substrate 6 has a substrate body 61, a wiring portion 62, a second through hole 63, and a second conductor portion 64. The substrate body 61, the wiring portion 62, the second through hole 63, and the second conductor portion 64 are basically the same as the substrate body 11, the wiring portion 12, the first through hole 13, and the first conductor portion 14, respectively, of the first wiring substrate 1. Therefore, a description thereof will be omitted. The diameter of the second through hole 63 is smaller than the diameter W1 of the first through hole 13.

[0031] The second wiring board 6 is arranged in parallel with the first wiring board 1 in the thickness direction T0. That is, the direction in which the first wiring board 1 and the second wiring board 6 are arranged in parallel with the thickness direction T0.

[0032] (2.3) Support Member Fig. 3A is a cross-sectional view of the support member 2 in the board connection structure 92 according to the first embodiment of the present disclosure. Fig. 3B is a plan view of the support member 2 in the board connection structure 92. The support member 2 supports the first wiring board 1. The support member 2 is aligned with the first wiring board 1 in the thickness direction T0 and supports the first wiring board 1 in the thickness direction T0. The support member 2 has the strength and rigidity to support the first wiring board 1. The support member 2 is a spacer interposed between the first wiring board 1 and the second wiring board 6. The support member 2 has the strength and rigidity to function as a spacer.

[0033] The support member 2 is electrically conductive. The support member 2 is suitably formed from a metal or alloy such as copper, aluminum, or iron. By forming the support member 2 from a metal or alloy, not only is the support member 2 electrically conductive, but it also has sufficient strength and rigidity to support the first wiring substrate 1. By forming the support member 2 from a metal or alloy, heat dissipation (thermal conductivity) is improved.

[0034] The support member 2 has a circular shape when viewed in the thickness direction T0. The diameter W2 of the support member 2 is, for example, 8 mm. However, the specific size of the diameter W2 is not limited.

[0035] The thickness T2 of the support member 2 (length in the thickness direction T0) is, for example, 12 mm. Here, the thickness T2 of the support member 2 refers to the length in the thickness direction T0 of the portion of the support member 2 that functions as a spacer.

[0036] The support member 2 has a first screw hole 21. The first screw hole 21 is formed to extend in the thickness direction T0 from the surface of the support member 2 facing the first wiring substrate 1 in the thickness direction T0. The first screw hole 21 does not penetrate the support member 2. When viewed in the thickness direction T0, the center of the first screw hole 21 coincides with the center of the circular outer periphery of the support member 2.

[0037] An inset portion 22 is formed at the end of the support member 2 on the second wiring board 6 side in the thickness direction T0. When viewed in the thickness direction T0, the inset portion 22 has a circular shape. The diameter of the inset portion 22 is the same as or slightly smaller than the diameter of the second through hole 63. The inset portion 22 is inset into the second through hole 63 of the second wiring board 6. The support member 2 and the second wiring board 6 are connected by solder 60.

[0038] (2.4) Connecting Member Fig. 4A is a cross-sectional view of a first connecting member 3 in a board connection structure 92 according to the first embodiment of the present disclosure. Fig. 4B is a plan view of the first connecting member 3 in the same board connection structure 92. The first connecting member 3 is attached to the first wiring board 1 in a state where it is inserted into the first through hole 13 and is electrically connected to the first conductor 14.

[0039] The first connecting member 3 is electrically conductive. The first connecting member 3 is suitably formed from a metal or alloy such as copper, aluminum, or iron. The first connecting member 3 is formed from, for example, so-called SWCH12A (cold heading carbon steel). By forming the first connecting member 3 from a metal or alloy, not only is electrical conductivity obtained but heat dissipation is also improved.

[0040] The first connection member 3 has a circular shape when viewed in the thickness direction T0. The diameter W3 of the first connection member 3 is, for example, 10 mm, which is the same as the diameter W1 (see FIG. 2B ) of the first through hole 13 of the first wiring substrate 1. However, the specific size of the diameter W3 is not limited.

[0041] The first connection member 3 is attached to the first wiring board 1 by being press-fitted into the first through hole 13. The first connection member 3 is an inlay that is fitted into the first wiring board 1. The first connection member 3 is attached to the first wiring board 1 and is integrated with the first wiring board 1. The first connection member 3 attached to the first wiring board 1 is not intended to be removed from the first wiring board 1. When viewed in the thickness direction T0, the shape and size of the first connection member 3 are formed to be the same as the shape and size of the first through hole 13 formed in the board body 11.

[0042] The thickness T3 (length in the thickness direction T0) of the first connecting member 3 is, for example, 2 mm, which is the same as the thickness T1 (see FIG. 2A ) of the first wiring board 1. By forming the thickness T3 of the first connecting member 3 to be the same as the thickness T1 of the first wiring board 1, the first connecting member 3 can be housed inside the first through hole 13.

[0043] The first connection member 3 has a first screw through hole 31. The first screw through hole 31 is formed so as to extend in the thickness direction T0 from the surface of the first connection member 3 facing the first wiring board 1 in the thickness direction T0. The first screw through hole 31 penetrates the first connection member 3. No threaded portion is formed in the first screw through hole 31. When viewed in the thickness direction T0, the center of the first screw through hole 31 coincides with the center of the circular outer periphery of the first connection member 3.

[0044] (2.5) Screw Member and Washer Fig. 5A is a side view of the first screw member 4 in the board connection structure 92 according to the first embodiment of the present disclosure. Fig. 5B is a side view of the washer 5 in the same board connection structure 92. The first screw member 4 is a member that screws together the support member 2 and the first connection member 3. The first screw member 4 has a head 41 and a shank 42 on which a threaded portion is formed. The diameter W4 of the head 41 is, for example, 6 mm. However, the specific size of the diameter W4 is not limited.

[0045] A washer 5 is provided between the head 41 and the first connecting member 3. The shank 42 of the first screw member 4 passes through the hole in the washer 5 and the first screw-through hole 31 of the first connecting member 3, and is screwed into the first screw hole 21 of the support member 2. This allows the support member 2 and the first connecting member 3 to be screwed together in an electrically conductive state.

[0046] The first screw member 4 is preferably electrically conductive. However, the first screw member 4 does not have to be electrically conductive. The first screw member 4 is formed of, for example, SWCH12A. The material of the first screw member 4 is the same as the material of the first connecting member 3.

[0047] The diameter W5 of the washer 5 is, for example, 8 mm. However, the specific size of the diameter W5 is not limited. The diameter W5 of the washer 5 is preferably the same as or smaller than the diameter W3 of the first connecting member 3.

[0048] (2.6) Substrate Connection Method (Assembly of Substrate Connection Structure) As shown in Figure 1, when assembling the substrate connection structure 92, first, a first wiring substrate 1 having a first through hole 13 penetrating in the thickness direction T0 and a first conductor portion 14 provided on the inner surface of the first through hole 13, a conductive support member 2 having a first screw hole 21, and a conductive first connecting member 3 having a first screw-through hole 31 are prepared.

[0049] Next, the first connection member 3 is inserted into the first through hole 13 of the first wiring board 1 and attached to the first wiring board 1 in a state where it is electrically connected to the first conductor portion 14 of the first wiring board 1 .

[0050] Next, the second wiring board 6 is prepared. The fitting portion 22 of the support member 2 is fitted into the second through hole 63 of the second wiring board 6, and the support member 2 and the second wiring board 6 are fixed with solder 60.

[0051] Next, the first screw member 4 is screwed into the first screw hole 21 of the support member 2 through the first screw-through hole 31 of the first connecting member 3, and the support member 2 and the first connecting member 3 are screwed together while being electrically connected to each other.

[0052] (2.7) Effects In the board connection structure 92 according to this embodiment, the first connection member 3 is inserted into the first through hole 13 formed in the board body 11. For this reason, the fastening force from the first screw member 4, i.e., the large pressure caused by being sandwiched between the head 41 of the first screw member 4 and the support member 2, is not locally applied to the board body 11.

[0053] To further explain, when a large pressure is locally applied to the substrate body 11, the thickness of the portion of the substrate body 11 where the large pressure is applied decreases due to aging. In such a case, if the first screw member 4 is fastened to the portion of the substrate body 11 where the wiring portion 12 is formed, as in the conventional substrate connection structure, and an electrical path including the first screw member 4 is formed, the thickness of the portion of the substrate body 11 where the first screw member 4 is fastened decreases, and the pressure at the portion where the first screw member 4 contacts the wiring portion 12 increases. This increases the contact resistance between the first screw member 4 and the wiring portion 12. In contrast, in the substrate connection structure according to this embodiment, the fastening force of the first screw member 4 is not applied to the substrate body 11 but to the first connection member 3. Therefore, the fastening force of the first screw member 4 does not thin the substrate body 11. This prevents the contact resistance from increasing. This makes it easier to prevent a decrease in the electrical conductivity between the first wiring board 1 and the support member 2. This is particularly effective when the substrate body 11 is made of resin.

[0054] The first connection member 3 is attached to the first wiring board 1 by being press-fitted into the first through-hole 13. This makes it easy to attach the first connection member 3 to the first wiring board 1.

[0055] The first connecting member 3 and the first screw member 4 are made of the same material. Therefore, when a current flows through the electrical path and the first connecting member 3 and the first screw member 4 thermally expand, the first connecting member 3 and the first screw member 4 have the same thermal expansion coefficient. Therefore, loosening of the first screw member 4 due to thermal expansion of the first connecting member 3 and the first screw member 4 is unlikely to occur.

[0056] The first conductor 14 is formed by a plating layer formed on the inner surface of the first through hole 13. Therefore, the first conductor 14 is less likely to fall off from the inner surface of the first through hole 13, and the first conductor 14 can be easily formed thin.

[0057] Support member 2 is a spacer interposed between wiring board 1 and second wiring board 6. Therefore, the spacer between two wiring boards (first wiring board 1, second wiring board 6) can be used to form a support member for the board connection structure.

[0058] A diameter W5 of the washer 5 is smaller than a diameter W3 of the first connecting member 3. Therefore, the fastening force of the first screw member 4 is not applied to the first wiring board 1 via the washer 5.

[0059] (3) Second Embodiment A board connection structure according to a second embodiment will be described below with reference to Fig. 6. Fig. 6 is a cross-sectional view of the board connection structure according to the second embodiment of the present disclosure. The board connection structure according to the second embodiment is largely the same as the board connection structure 92 according to the first embodiment, and therefore, redundant description will be omitted.

[0060] In the first embodiment, the substrate connection structure according to the present disclosure is not used for the second wiring board 6. In the second embodiment, the substrate connection structure according to the present disclosure is also used for the second wiring board 6. That is, the substrate connection structure according to the present disclosure is used for both the first wiring board 1 and the second wiring board 6.

[0061] The substrate connection structure further includes a second connecting member 7 that is conductive and attached to the second wiring substrate 6, a second screw member 8 that screws together the support member 2 and the second connecting member 7, and a washer 9. The second connecting member 7 is the same as the first connecting member 3 in terms of the component, and therefore its description will be omitted. The second screw member 8 is the same as the first screw member 4 in terms of the component, and therefore its description will be omitted.

[0062] The second wiring board 6 has a second through hole 63 that penetrates in the thickness direction T0 and a second conductor portion 64 that is provided on the inner surface of the second through hole 63. In the first embodiment, the fitting portion 22 of the support member 2 is fitted into the second through hole 63. In the present embodiment, a second connection member 7 is inserted into and attached to the second through hole 63. Inserting the second connection member 7 into the second through hole 63 and attaching the second connection member 7 to the second wiring board 6 is the same as inserting the first connection member 3 into the first through hole 13 and attaching the first connection member 3 to the first wiring board 1, and therefore a description thereof will be omitted.

[0063] The support member 2 has a second screw hole 23. The second screw hole 23 and the first screw hole 21 are formed in the same through hole formed in the support member 2 in the thickness direction T0.

[0064] The second connection member 7 has a second screw-through hole 71 formed therein, and is attached to the second wiring board 6 in a state where it is inserted into the second through-hole 63 and is electrically connected to the second conductor portion 64 .

[0065] The second screw member 8 is threaded through the second screw through-hole 71 and into the second screw hole 23, and the support member 2 and the second connecting member 7 are screwed together in a conductive state.

[0066] A washer 9 is provided between the head of the second screw member 8 and the first connecting member 3. The washer 9 is the same as the washer 5 as a component, and therefore a description thereof will be omitted.

[0067] In the second embodiment, the substrate connection structure of the present disclosure can be used for both the first wiring substrate 1 and the second wiring substrate 6. The second wiring substrate 6 also provides the same effects as those obtained in the first wiring substrate 1 in the first embodiment.

[0068] (4) Modifications The charger 90 in which the board connection structure is provided is not limited to a charger for an electric vehicle. The board connection structure according to the present disclosure does not have to be provided in a device other than the charger 90, and is not limited to a charger.

[0069] First wiring board 1 does not have to be a printed wiring board. First wiring board 1 may be a so-called double-sided board or a multi-layer board. Board surfaces 101 and 102 are preferably flat. However, they do not have to be flat.

[0070] The substrate body 11 may be formed of a resin other than PCB. The substrate body 11 does not have to be formed of a resin, and the material is not particularly limited as long as it is formed of a material that is not conductive. The specific size of the thickness T1 of the substrate body 11 is not limited. The shape, size, etc. of the substrate body 11 are not particularly limited.

[0071] The first through hole 13 formed in the substrate body 11 may have a polygonal shape such as a triangle, a rectangle, or a pentagon when viewed in the thickness direction T0, and is not limited to a circle. The size (area) of the first through hole 13 when viewed in the thickness direction T0 is not particularly limited. The inner surface of the substrate body 11 facing the first through hole 13 does not necessarily have to be a surface extending parallel to the thickness direction T0.

[0072] There is no particular limitation on the magnitude of the current flowing through the first conductor 14. The first conductor 14 may be configured as a separate conductor attached to the inner surface of the substrate body 11 facing the first through hole 13. The first conductor 14 may be formed only on a part of the inner surface of the substrate body 11 facing the first through hole 13, rather than on the entire surface.

[0073] The support member 2 does not have to function as a spacer interposed between two wiring substrates. The support member 2 does not have to be formed solely of a metal or alloy. That is, it may contain a non-metal in part. For example, the base of the support member 2 may be formed from a non-metal such as resin, and a metal may be provided on the surface of the support member 2. That is, it is sufficient if it contains at least a conductive material in part and can serve as an electrical path for current supplied to the first wiring substrate 1. The specific size of the thickness T2 of the support member 2 is not limited. The shape, size, etc. of the support member 2 are not particularly limited.

[0074] A first screw hole 21 may pass through the support member 2 .

[0075] The attachment of the first connection member 3 to the first wiring board 1 is not limited to press-fitting the first connection member 3 into the first through hole 13 of the first wiring board 1. For example, the first connection member 3 may be inserted into the first through hole 13 and fixed to the first wiring board 1 by soldering, screwing, adhesive, or the like.

[0076] The first connecting member 3 does not have to be made of only a metal or an alloy, that is, it may contain a non-metal in part.

[0077] The first connection member 3 attached to the first wiring board 1 may be detachable from the first wiring board 1 .

[0078] The first connecting member 3 may have a polygonal shape such as a triangle, a rectangle, or a pentagon when viewed in the thickness direction T0, and is not limited to a circle. The size (area) and shape of the first connecting member 3 when viewed in the thickness direction T0 are not particularly limited. The first connecting member 3 only needs to be insertable into the first through hole 13 formed in the substrate body 11. Even if the size of the first connecting member 3 when viewed in the thickness direction T0 is slightly larger than the size of the first through hole 13, it is sufficient that the first connecting member 3 can be press-fitted into the first through hole 13. The first connecting member 3 does not need to be formed to have the same shape as the first through hole 13.

[0079] The specific size of the thickness T3 of the first connecting member 3 is not limited. The thickness T3 of the first connecting member 3 may be larger than the thickness T1 of the first wiring board 1. The surface of the first connecting member 3 opposite the support member 2 may protrude beyond the plate surface 101 of the first wiring board 1. However, it is preferable that the surface of the first connecting member 3 opposite the support member 2 does not protrude beyond the plate surface 101. The shape, size, etc. of the first connecting member 3 are not particularly limited.

[0080] The first screw member 4 is preferably formed from a metal or alloy such as iron. However, the material of the first screw member 4 is not particularly limited. The material of the first screw member 4 is preferably the same as the material of the first connecting member 3. However, the material of the first screw member 4 is not limited to SWCH12A. The material of the first screw member 4 does not have to be the same as the material of the first connecting member 3. The material of the first screw member 4 preferably has the same or similar thermal expansion coefficient as the material of the first connecting member 3.

[0081] The first screw member 4 preferably has a tapered thread. In this case, if the first screw through-hole 31 has a diameter equivalent to the diameter of the large-diameter portion of the shank 42 of the first screw member 4, when the first screw member 4 is fastened, the large-diameter portion of the first screw member 4 pushes open the first screw through-hole 31, thereby expanding the diameter W3 of the first connecting member 3. This increases the pressure at the contact portion with the first conductor 14. Therefore, it is easy to prevent an increase in contact resistance between the first connecting member 3 and the first conductor 14 and a decrease in conductivity.

[0082] Washer 5 and washer 9 may not be provided.

[0083] The diameter W5 of the washer 5 may be larger than the diameter W3 of the first connecting member 3. In this case, the fastening force of the first screw member 4 is applied to the first wiring board 1 via the washer 5, but if the contact area between the washer 5 and the first wiring board 1 is small, the fastening force applied to the first wiring board 1 is suppressed, and no particular problem occurs.

[0084] The first screw hole 21 and the second screw hole 23 may be formed as separate holes (recesses) or separate through holes.

[0085] (Summary) As described above, the board connection structure of the first aspect includes a first wiring board 1 (wiring board), a support member 2 that supports the first wiring board 1, a first connecting member 3 attached to the first wiring board 1, and a first screw member 4 that screws together the support member 2 and the first connecting member 3. The first wiring board 1 has a first through hole 13 that penetrates in the thickness direction T0 and a first conductor portion 14 provided on the inner surface of the first through hole 13. The support member 2 is conductive and has a first screw hole 21. The first connecting member 3 is conductive and has a first screw through hole 31 formed therein. The first connecting member 3 is inserted into the first through hole 13 and attached to the first wiring board 1 in a state of electrical conductivity with the first conductor portion 14. The first screw member 4 is threaded through the first screw through hole 31 and screwed into the first screw hole 21, so that the support member 2 and the first connecting member 3 are screwed together in a state of electrical conductivity.

[0086] In the first aspect, the first connection member 3 is inserted into the first through hole 13 formed in the substrate body 11. Therefore, no fastening force from the first screw member 4 is applied to the substrate body 11. This prevents the substrate body 11 from becoming thinner due to the fastening force of the first screw member 4, and makes it easier to prevent the fastening force of the first screw member 4 from loosening, increasing contact resistance, and deteriorating electrical conductivity.

[0087] The second aspect can be realized by combining the first aspect with the first aspect. In the second aspect, the first connecting member 3 is press-fitted into the first through hole 13 .

[0088] In the second aspect, first connection member 3 can be easily attached to first wiring board 1 .

[0089] The third aspect can be realized by combining the first or second aspect. In the third aspect, the first connecting member 3 and the first screw member 4 are made of the same material.

[0090] In the third aspect, the first connecting member 3 and the first screw member 4 have the same thermal expansion coefficient, so that loosening of the first screw member 4 due to thermal expansion of the first connecting member 3 and the first screw member 4 is less likely to occur.

[0091] The fourth aspect can be realized by combining with any one of the first to third aspects. In the fourth aspect, the first screw member 4 is a tapered thread.

[0092] In the fourth aspect, the pressure at the contact portion with the first conductor 14 increases, making it easier to prevent a decrease in the conductivity between the first connecting member 3 and the first conductor 14 .

[0093] The fifth aspect can be realized by combining with any one of the first to fourth aspects. In the fifth aspect, the first conductors 14 are plated layers formed on the inner surfaces of the first through holes 13.

[0094] In the fifth aspect, the first conductors 14 are less likely to fall off from the inner surfaces of the first through holes 13, and the first conductors 14 can be easily formed thin.

[0095] The sixth aspect can be realized by combining with any one of the first to fifth aspects. In the sixth aspect, the substrate connection structure further includes a second wiring substrate 6. The support member 2 is a spacer interposed between the first wiring substrate 1 and the second wiring substrate 6.

[0096] In the sixth aspect, a spacer between two wiring boards (first wiring board 1, second wiring board 6) can be used to form a support member for the board connection structure.

[0097] The seventh aspect can be realized by combining the sixth aspect. In the seventh aspect, the board connection structure further includes a second connecting member 7 that is conductive and attached to a second wiring board 6, and a second screw member 8 that screws together the support member 2 and the second connecting member 7. The second wiring board 6 has a second through hole 63 that penetrates in the thickness direction T0 and a second conductor portion 64 that is provided on the inner surface of the second through hole 63. The support member 2 has a second screw hole 23. The second connecting member 7 has a second screw through hole 71 formed therein, and is inserted into the second through hole 63 and attached to the second wiring board 6 in a state of electrical conductivity with the second conductor portion 64. The second screw member 8 is threaded through the second screw through hole 71 and screwed into the second screw hole 23, so that the support member 2 and the second connecting member 7 are screwed together in a state of electrical conductivity.

[0098] In the seventh aspect, the substrate connection structure can be used for both the first wiring substrate 1 and the second wiring substrate 6 .

[0099] The eighth aspect can be realized by combining with any one of the first to seventh aspects. The eighth aspect includes a charger 90 and a charging circuit including an electric circuit electrically connected by the board connection structure 92 of any one of the first to seventh aspects.

[0100] In a ninth aspect, the charging circuit charger 90 shown in the eighth aspect includes a filter 98, an AC / DC converter 94, a DC / DC converter 95, a filter 96, and a charge controller 97. The filter 98 passes the input AC voltage. The AC / DC converter 94 converts the AC voltage that has passed through the filter 98 into a DC voltage. The DC / DC converter 95 insulates the DC voltage and generates a charging voltage. The filter 96 passes the charging voltage generated by the DC / DC converter 95. The power storage unit 91 is charged with the charging voltage that has passed through the filter 96. The filter 98, the AC / DC converter 94, the DC / DC converter 95, the filter 96, and the charge controller 97 are electrically connected to each other or to each other by the board connection structure 92 of any one of the first to seventh aspects. The charge controller controls the filter 98, the AC / DC converter 94, the DC / DC converter, and the filter 96.

[0101] In the eighth and ninth aspects, a charger 90 is obtained that includes a board connection structure 92 that can easily prevent the fastening force of the first screw member 4 from loosening, increasing contact resistance, and reducing electrical conductivity.

[0102] In the board connection method of the tenth aspect, a wiring board having a first through hole 13 penetrating in the thickness direction T0 and a first conductor portion 14 provided on the inner surface of the first through hole 13, a conductive support member 2 having a first screw hole 21, and a conductive first connecting member 3 having a first screw through hole 31 are prepared. The first connecting member 3 is inserted into the first through hole 13 of the wiring board and attached to the wiring board in a state of electrical conduction with the first conductor portion 14 of the wiring board. The first screw member 4 is threaded through the first screw through hole 31 of the first connecting member 3 and into the first screw hole 21 of the support member 2, and the support member 2 and the first connecting member 3 are screwed together in a state of electrical conduction.

[0103] In the ninth aspect, it is possible to configure a board connection structure that can easily prevent the fastening force of the first screw member 4 from loosening, increasing contact resistance, and reducing electrical conductivity.

[0104] The board connection structure, charger, and board connection method according to the present disclosure can be used in various products in which electric motors are mounted.

[0105] REFERENCE SIGNS LIST 1 First wiring board (wiring board) 13 First through hole 14 First conductor portion 2 Support member 21 First screw hole 23 Second screw hole 3 First connecting member 31 First screw through hole 4 First screw member 6 Second wiring board 63 Second through hole 64 Second conductor portion 7 Second connecting member 71 Second screw through hole 8 Second screw member 90 Charger 91 Power storage portion 92 Board connection structure 93 Connection portion 94 AC / DC converter 95 DC / DC converter 96 Filter 97 Charging controller 98 Filter T0 Thickness direction

Claims

1. A first wiring substrate; a support member having electrical conductivity and supporting the first wiring substrate; a first connection member having electrical conductivity and attached to the first wiring board; A first screw member that screws together the support member and the first connection member, the first wiring board has a first through hole penetrating in a thickness direction and a first conductor portion provided on an inner surface of the first through hole, The support member has a first screw hole formed therein, the first connection member is attached to the first wiring board in a state in which a first screw through-hole is formed, the first connection member is inserted into the first through-hole, and is electrically connected to the first conductor portion; The first screw member is screwed into the first screw hole through the first screw through hole, and the support member and the first connection member are screwed together in a conductive state. Board connection structure.

2. The first connection member is press-fitted into the first through hole. The substrate connection structure according to claim 1 .

3. The material of the first connecting member is the same as the material of the first screw member. The substrate connection structure according to claim 1 or 2.

4. The first screw member is a tapered screw. The substrate connection structure according to claim 1 or 2.

5. The first conductor portion is a plating layer formed on the inner surface of the first through hole. The substrate connection structure according to claim 1 or 2.

6. Further comprising a second wiring board, the support member is a spacer interposed between the first wiring board and the second wiring board; The substrate connection structure according to claim 1 or 2.

7. a second connection member having electrical conductivity and attached to the second wiring board; A second screw member that screws together the support member and the second connection member, the second wiring board has a second through hole penetrating in a thickness direction and a second conductor portion provided on an inner surface of the second through hole, The support member has a second screw hole, the second connection member is attached to the second wiring board in a state in which a second screw through-hole is formed, the second connection member is inserted into the second through-hole, and is electrically connected to the second conductor portion; The second screw member is screwed into the second screw hole through the second screw through hole, and the support member and the second connection member are screwed together in a conductive state. The substrate connection structure according to claim 6 .

8. A charger comprising: a power storage unit; and a charging circuit including an electric circuit electrically connected by the board connection structure according to claim 1 or 2.

9. The charging circuit includes a first filter, an AC / DC converter, and a DC / DC converter, a second filter, and a charge controller; the first filter passes an input AC voltage; the AC / DC converter converts the AC voltage that has passed through the first filter into a DC voltage; The DC / DC converter insulates the DC voltage and generates a charging voltage; the second filter passes the charging voltage generated by the DC / DC converter and charges the power storage unit with the charging voltage that has passed through the second filter; The charge controller controls the first filter, the AC / DC converter, the DC / DC converter, and the second filter. The charger of claim 8.

10. preparing a wiring board having a first through hole penetrating in a thickness direction and a first conductor portion provided on an inner surface of the first through hole, a conductive support member having a first screw hole, and a conductive first connection member having a first screw through hole; the first connection member is inserted into the first through hole of the wiring board and attached to the wiring board in a state of being electrically connected to the first conductor portion of the wiring board; a first screw member is screwed into the first screw hole of the support member through the first screw through hole of the first connection member, and the first screw member is screwed into the first screw hole of the support member while the support member and the first connection member are electrically connected to each other; Board connection method.