Energy beam welded structure and substrate

Abstract

To provide an energy beam welding structure capable of suppressing the dimension in the thickness direction of a substrate even when welding is performed by an energy beam, and to provide a substrate.SOLUTION: The energy beam welding structure includes a control substrate 100 and a first metal member 200. The control board 100 includes a board main body portion 1 in which a through hole 11 penetrating in a thickness direction is formed, and a second metal member 3 embedded in the through hole 11 of the board main body portion 1. The control substrate 100 includes a welded portion 4 in which the first metal member 200 and the second metal member 3 are welded by an energy beam La in a state where the first metal member 200 and the second metal member 3 are in contact with each other.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to energy beam welded structures and substrates. [Background technology]

[0002] BACKGROUND ART Energy beam welding structures and substrates are known in the art (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses a substrate. The substrate includes a conductor, a bus bar, a weld, and a substrate body. The conductor is attached to the surface of the substrate body. The bus bar is attached to the surface of the conductor opposite to the substrate body side. The weld is a portion where the conductor and the bus bar are welded by a laser. This electrically connects various components on the substrate to the bus bar via the conductor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-13800 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the substrate of Patent Document 1, a conductor is attached to the surface of the substrate body, and a bus bar is further attached to the surface of the conductor, and then the conductor and the bus bar are welded and joined together by a laser. As a result, the dimension of the substrate in the thickness direction increases due to the conductor and the bus bar being stacked on the surface of the substrate body and then welded by a laser. Therefore, it is desirable to suppress the increase in the dimension of the substrate in the thickness direction even when welding with a laser (energy beam).

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide an energy beam welding structure and a substrate that can reduce the thickness dimension of the substrate even when welding is performed using an energy beam. [Means for solving the problem]

[0007] In order to achieve the above object, an energy beam welding structure in a first aspect of the present invention comprises a substrate, and a first metal member including a base or a conductive member and joined to the substrate, the substrate including a substrate main body portion having a through hole penetrating in the thickness direction, a second metal member embedded in the through hole of the substrate main body portion, and a welded portion formed by welding the first metal member and the second metal member by an energy beam while the first metal member and the second metal member are abutted against each other.

[0008] In the energy beam welding structure according to a first aspect of the present invention, as described above, a substrate includes a substrate main body portion having a through hole formed therethrough in the thickness direction, a second metal member embedded in the through hole of the substrate main body portion, and a welded portion formed by welding the first metal member and the second metal member with an energy beam while the first metal member and the second metal member are in contact with each other. This allows the first metal member and the second metal member to be welded to each other with the energy beam using the second metal member embedded in the substrate main body portion. Therefore, compared to when a conductor or the like is laminated on the surface of the substrate main body portion and then welded with a laser, an increase in the thickness direction of the substrate can be suppressed. As a result, even when welding with an energy beam, an increase in the thickness direction of the substrate can be suppressed. Furthermore, the thickness of the second metal member embedded in the substrate main body portion is formed to be approximately the same as (the same as or slightly larger than) the thickness of the substrate main body portion, and the thickness of the second metal member irradiated with the energy beam is relatively large, thereby making it difficult for heat generated by the energy beam to be transferred to members adjacent to the second metal member. Similarly, the thickness of the second metal member embedded in the substrate body is formed to be approximately the same as (the same as or slightly larger than) the thickness of the substrate body, and the thickness of the second metal member irradiated with the energy beam is relatively large, so the allowable range of the laser output can be set wide, and as a result, the output of the energy beam can be easily adjusted.

[0009] In the energy beam welding structure according to the first aspect, the first metal member preferably includes a base that is welded to the second metal member by the energy beam and includes a joining protrusion that protrudes toward the second metal member, or a conductor member that includes a bus bar that is welded to the second metal member by the energy beam.

[0010] With this configuration, the base and the substrate can be directly joined by the joining protrusion melted by the energy beam and the weld formed by solidifying the second metal member, which reduces the increase in the combined dimension of the base and the substrate in the thickness direction and the number of parts compared to when the base and the substrate are fastened using bolts. Also, since the bus bar and the substrate can be directly joined by the bus bar melted by the energy beam and the weld formed by solidifying the second metal member, which reduces the increase in the combined dimension of the bus bar and the substrate in the thickness direction and the number of parts compared to when the bus bar and the substrate are fastened using bolts and terminal blocks.

[0011] In the aforementioned energy beam welding structure according to the first aspect, the substrate body portion preferably includes a ground pattern disposed around the through hole and electrically connected to the second metal member.

[0012] With this configuration, compared to when a bolt is used to electrically connect the grounding pattern to the base, the use of a second metal member embedded in the main body of the board reduces the increase in the number of parts required to connect the grounding pattern to the base.

[0013] In addition, a substrate in a second aspect of the present invention includes a substrate main body portion having a through hole formed therethrough in the thickness direction, and a second metal member embedded in the through hole of the substrate main body portion and welded together with a first metal member including a base or a conductive member while being abutted against the first metal member.

[0014] In a second aspect of the present invention, a substrate includes a second metal member embedded in the through hole of the substrate main body portion, and welded to the first metal member while in contact with the first metal member, including a base or a conductor member. This allows the first metal member and the second metal member to be welded to each other using a laser using the second metal member embedded in the substrate main body portion. Therefore, compared to when a conductor or the like is laminated on the surface of the substrate main body and welded using a laser, the increase in the thickness direction of the substrate can be suppressed. As a result, a substrate can be provided that can suppress the increase in thickness direction of the substrate even when welding with an energy beam.

[0015] The energy beam welding structure in the first aspect is considered to have the following configuration.

[0016] (Additional note 1) In the energy beam welding structure according to the first aspect of the present invention, the thickness of the second metal member is equal to or greater than the thickness of the substrate main body portion and is close to the thickness of the substrate main body portion.

[0017] This configuration ensures that the second metal member has a sufficient thickness, allowing a weld of sufficient volume to be formed without melting the second metal member to the edge of the energy beam in the direction of irradiation. As a result, the joining strength of the weld can be ensured while preventing the energy beam from melting the second metal member and other adjacent members. Furthermore, because the thickness of the second metal member is close to the thickness of the substrate main body, it does not protrude significantly from the substrate main body. This minimizes the increase in the thickness of the substrate compared to when a conductor or the like is layered on the surface of the substrate main body and then welded with a laser.

[0018] (Additional note 2) In the energy beam welding structure according to the first aspect, the cross-sectional area of ​​the second metal member in the direction perpendicular to the thickness direction is configured to be an area that provides electrical resistance corresponding to the value of the current to be passed.

[0019] With this configuration, a current of an appropriate value can be passed through the second metal member.

[0020] (Additional note 3) In the energy beam welding structure of the first aspect described above, the welded portion is provided on the first metal member and the second metal member from the end on the side opposite to the irradiation direction of the energy beam to a position just before the end on the side in the irradiation direction of the energy beam.

[0021] With this configuration, the energy beam does not melt the second metal member to the edge to form a weld, so it is possible to prevent the energy beam from melting the second metal member as well as other adjacent members.

[0022] (Additional note 4) In the energy beam welding structure having a first metal member including the above-mentioned base, the base is welded to a second metal member by an energy beam, and includes a joining protrusion that protrudes toward the second metal member and a flow path through which a cooling liquid flows, and the substrate is configured to be cooled by the cooling liquid flowing through the flow path via the joining protrusion and the second metal member.

[0023] With this configuration, heat-generating elements such as switching elements on the substrate can be cooled, thereby suppressing the generation of noise caused by heat.

[0024] (Additional note 5) In the energy beam welding structure including the substrate including the above-described ground pattern, the ground pattern is provided on the substrate main body portion and includes a frame ground that serves as a reference for potential.

[0025] With this configuration, the frame ground and the base can be electrically connected via a welded joint, making it easier for current to flow from the frame ground to the base compared to when the frame ground and the base are electrically connected via a bolt.

[0026] (Additional note 6) In the energy beam welded structure according to the first aspect, the second metal member is a columnar metal member containing copper, silver, gold or aluminum.

[0027] With this configuration, a substrate for an energy beam welding structure can be formed simply by embedding a columnar metal member into the through hole of the substrate main body, making it easy to realize a substrate for an energy beam welding structure that can reduce the thickness dimension of the substrate.

[0028] (Additional note 7) In the energy beam welding structure according to the first aspect, the energy beam includes a blue laser or an infrared laser.

[0029] With this configuration, the first metal member and the second metal member can be easily welded by selectively using a blue laser or an infrared laser depending on the metal material, such as copper, silver, gold, or aluminum.

[0030] (Additional note 8) An energy beam welding method according to another aspect includes the steps of positioning and holding a substrate and a first metal member including a base or a conductor member and a second metal member fitted into a through hole formed in a substrate body of the substrate in a state in which the first metal member and the second metal member are in contact with each other, and welding the abutted first metal member and the second metal member with an energy beam.

[0031] In another aspect of the present invention, an energy beam welding method includes a step of welding the first metal member and the second metal member that are brought into contact with each other using an energy beam, as described above. This allows the first metal member and the second metal member to be welded to each other using a laser, using the second metal member embedded in the substrate main body. Therefore, compared to when a conductor or the like is laminated on the surface of the substrate main body and then welded using a laser, an increase in the thickness direction of the substrate can be suppressed. As a result, an energy beam welding method can be provided that can suppress an increase in the thickness direction of the substrate, even when welding using an energy beam. [Effects of the Invention]

[0032] According to the present invention, as described above, even when welding is performed using an energy beam, the dimension of the substrate in the thickness direction can be reduced. [Brief explanation of the drawings]

[0033] [Figure 1] FIG. 2 is a perspective view of a control board to which a bus bar according to the first embodiment is welded. [Figure 2] FIG. 2 is a perspective view of the control board before welding in the first embodiment. [Figure 3] FIG. 2 is a cross-sectional view taken along line III-III in FIG. [Figure 4] 3 is a flowchart showing a laser welding method according to the first embodiment. [Figure 5] FIG. 2 is a perspective view showing a state in which the control board and the bus bars of the first embodiment are positioned. [Figure 6] 4 is a perspective view showing a state in which a laser is irradiated onto the positioned control board and bus bars of the first embodiment. FIG. [Figure 7] FIG. 10 is a perspective view of a base to which a control board according to a second embodiment is welded. [Figure 8] FIG. 10 is a perspective view showing the control board and the base before welding in the second embodiment. [Figure 9] FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. [Figure 10] 10 is a flowchart showing a laser welding method according to a second embodiment. [Figure 11] FIG. 10 is a perspective view showing a state in which the control board and the base of the second embodiment are positioned. [Figure 12] FIG. 10 is a perspective view showing a state in which a laser is irradiated onto the positioned control board and base of the second embodiment. [Figure 13] FIG. 10 is a cross-sectional view showing a state in which a columnar copper member protrudes from a substrate body of a modified example of the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0034] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0035] [First embodiment] The configuration of a control board 100 according to the first embodiment will be described with reference to Figures 1 to 6. The control board 100 is a control board mounted on a vehicle. The control board 100 is a board on which various electronic components and control devices for controlling a power conversion device for a vehicle or other electric equipment for a vehicle are mounted. The control board 100 is an example of the "board" in the claims.

[0036] In each figure, the thickness direction of the control board 100 is the Z direction, one of the Z directions is the Z1 direction, and the other of the Z directions is the Z2 direction. A first direction perpendicular to the Z direction is the X direction. One of the X directions is the X1 direction, and the other of the X directions is the X2 direction. A second direction perpendicular to the X and Z directions is the Y direction. One of the Y directions is the Y1 direction, and the other of the Y directions is the Y2 direction.

[0037] Such a control board 100 is electrically connected to external vehicle electrical equipment (for example, a main battery) via a bus bar 200. The bus bar 200 is a plate-shaped member made of copper. For example, a plurality of bus bars 200 (three in number) are arranged. Note that the number of bus bars 200 may be one, two, or four or more. Furthermore, the bus bar 200 is an example of a "first metal member" and a "conductor member" in the claims.

[0038] The configuration including the control board 100 and the bus bar 200 described above is an example of the "energy beam welding structure" in the claims.

[0039] 1, the control board 100 includes a board main body 1, a control unit 2, a columnar copper member 3, and a welded portion 4. The columnar copper member 3 is an example of the "second metal member" in the claims.

[0040] (Explanation of the control board configuration) The substrate main body 1 is a member containing metal, such as a printed wiring board. Such substrate main body 1 is provided with a copper foil wiring pattern that electrically connects external vehicle electrical equipment, electronic components, and a control device to one another. One side of the copper foil wiring pattern is electrically connected to the columnar copper member 3. The other side of the copper foil wiring pattern is electrically connected to the electronic components and the control device. The copper foil wiring pattern is embedded in the substrate main body 1 in a state where it is alternately stacked with the resin portion of the substrate main body 1.

[0041] The control unit 2 is a control device that controls the vehicle electrical equipment. The control unit 2 includes a CPU (Central Processing Unit) and a storage unit such as a memory. The control unit 2 is electrically connected to the external vehicle electrical equipment via a copper foil wiring pattern and a bus bar 200. The control unit 2 is disposed on the surface of the board main body 1 on the Z1 direction side.

[0042] (Joining of busbar and board) 1, in the control board 100 of the first embodiment, the bus bar 200 and the columnar copper member 3 are electrically joined by welded portions 4 formed by welding the bus bar 200 and the columnar copper member 3 with a laser La. The laser La is, for example, a blue laser.

[0043] (columnar copper member) FIG. 2 is a diagram of the control board 100 before the bus bar 200 and the columnar copper members 3 are welded together by laser La. As shown in FIG. 2, the columnar copper members 3 are cylindrical members. The columnar copper members 3 are embedded in through holes 11 in the board main body 1. The through holes 11 are holes that penetrate the board main body 1 in the Z direction. When viewed from the Z1 direction side, the through holes 11 are circular holes that have approximately the same shape as the columnar copper members 3. A plurality (three) of the through holes 11 are formed in the board main body 1. The columnar copper members 3 are embedded in each of the plurality (three) of through holes 11.

[0044] The copper columnar member 3 is a cylindrical metal member made of copper. However, instead of the copper columnar member 3, a metal member such as silver, gold, or aluminum may be used.

[0045] 3, the thickness Th1 of the columnar copper member 3 is approximately the same as the thickness Th2 of the substrate main body 1. The position of the end of the columnar copper member 3 on the Z1 direction side is approximately the same as the position of the end of the substrate main body 1 on the Z1 direction side. The position of the end of the columnar copper member 3 on the Z2 direction side is approximately the same as the position of the end of the substrate main body 1 on the Z2 direction side.

[0046] In a direction perpendicular to the Z direction, the cross-sectional area of ​​the columnar copper member 3 is configured to have an area that provides electrical resistance corresponding to the value of the current to be passed. Before the columnar copper member 3 is embedded in the through hole 11, the cross-sectional area of ​​the columnar copper member 3 in a direction perpendicular to the Z direction is slightly larger than the cross-sectional area of ​​the through hole 11. As a result, the columnar copper member 3 is embedded in the through hole 11 in a press-fit state.

[0047] The diameter R1 of the columnar copper member 3 is larger than the diameter R2 of the end of the welded portion 4 on the Z1 direction side. The difference between the diameter R1 of the columnar copper member 3 and the maximum diameter R2 of the end of the welded portion 4 on the Z1 direction side is the welding allowance. This prevents the substrate main body 1 around the columnar copper member 3 from melting.

[0048] (weld) As shown in FIG. 3, the welded portion 4 is a portion where the busbar 200 and the columnar copper member 3 are welded by a laser La (see FIG. 1) while the busbar 200 and the columnar copper member 3 are in contact with each other. The welded portion 4 is a portion where the busbar 200 melted by the laser La and the columnar copper member 3 melted by the laser La are mixed and solidified. The welded portion 4 is provided in the busbar 200 and the columnar copper member 3 from the end portion on the side opposite to the irradiation direction of the laser La (Z1 direction) to a position just before the end portion on the side on the irradiation direction of the laser La (Z2 direction). That is, the welded portion 4 is formed from the end face of the busbar 200 on the Z1 direction side of the portion where the busbar 200 is in contact with the columnar copper member 3 to the middle portion of the columnar copper member 3 in the Z direction. The welded portion 4 has a shape that tapers toward the Z2 direction.

[0049] The tapered welded portion 4 is formed by setting the focal position of the laser La at the middle portion in the Z direction of the columnar copper member 3. That is, in the irradiation direction, the diameter of the laser La is larger in the portion on the opposite side of the focal position of the laser La, and the diameter of the laser La is smaller in the portion on the focal position side of the laser La, resulting in such a tapered shape.

[0050] (Laser welding method) The laser welding method of the first embodiment will be described below with reference to Fig. 4 to Fig. 6. The laser welding method is a method of welding the bus bar 200 and the columnar copper member 3 embedded in the through hole 11 of the substrate main body 1 by using a laser La. Here, the type, output, focal position, etc. of the laser La are set in advance.

[0051] In step S1, the control board 100 and the bus bar 200 are held in a state in which the bus bar 200 and the columnar copper member 3 are aligned (see FIG. 5). That is, step S1 is a step in which the control board 100 and the bus bar 200 are positioned and held relative to each other in a state in which the bus bar 200 and the columnar copper member 3 fitted in the through hole 11 formed in the board main body 1 of the control board 100 are abutted against each other.

[0052] In step S2, the bus bar 200 and the columnar copper member 3 are welded by irradiating them with a laser beam La. That is, in step S2, the bus bar 200 and the columnar copper member 3 that are in contact with each other are welded by the laser beam La. Here, since there are multiple (three) bus bars 200 in contact with the columnar copper members 3, welding is performed at these three locations by the laser beam La (see FIG. 6). In step S2, the bus bar 200 and the columnar copper member 3 are welded by the laser beam La while the held control board 100 and the bus bar 200 are moved relative to the irradiation position of the laser beam La.

[0053] After step S2, the laser welding method ends.

[0054] (Effects of the first embodiment) In the first embodiment, the following effects can be obtained.

[0055] In the first embodiment, as described above, the control board 100 includes the board main body 1 having the through hole 11 formed therein penetrating in the thickness direction (Z direction), the columnar copper member 3 embedded in the through hole 11 of the board main body 1, and the welded portion 4 formed by welding the bus bar 200 and the columnar copper member 3 with the laser La while the bus bar 200 and the columnar copper member 3 are in contact with each other. As a result, the bus bar 200 and the columnar copper member 3 are welded to each other with the laser La using the columnar copper member 3 embedded in the board main body 1. Therefore, compared to when a conductor or the like is stacked on the surface of the board main body 1 and then welded with the laser La, an increase in the dimension of the control board 100 in the thickness direction can be suppressed. As a result, even when welding with the laser La, an increase in the dimension of the control board 100 in the thickness direction can be suppressed. Furthermore, the thickness Th2 of the columnar copper member 3 embedded in the substrate main body 1 is formed to be approximately the same as (the same as or slightly larger than) the thickness Th1 of the substrate main body 1, and the thickness Th2 of the columnar copper member 3 irradiated with the laser La is relatively large, making it possible to prevent the heat generated by the laser La from being transferred to members adjacent to the columnar copper member 3. Similarly, the thickness Th2 of the columnar copper member 3 embedded in the substrate main body 1 is formed to be approximately the same as (the same as or slightly larger than) the thickness Th1 of the substrate main body 1, and the thickness Th2 of the columnar copper member 3 irradiated with the laser La is relatively large, making it possible to set a wide allowable range for the output of the laser La. As a result, the output of the laser La can be easily adjusted.

[0056] Furthermore, in the first embodiment, as described above, the laser-welded structure includes the bus bar 200 welded to the columnar copper member 3 by the laser La. This allows the bus bar 200 and the control board 100 to be directly joined together by the welded portion 4 formed by solidifying the bus bar 200 melted by the laser La and the columnar copper member 3. Therefore, compared to a case where the bus bar 200 and the control board 100 are fixed together using bolts and terminal blocks, it is possible to suppress an increase in the combined dimension of the bus bar 200 and the control board 100 in the thickness direction and to suppress an increase in the number of parts.

[0057] Furthermore, in the first embodiment, as described above, the control board 100 includes the columnar copper member 3 that is embedded in the through hole 11 of the board main body 1 and is welded together with the bus bar 200 while being in contact with the bus bar 200. This allows the bus bar 200 and the columnar copper member 3 to be welded to each other by laser La using the columnar copper member 3 embedded in the board main body 1. Therefore, compared to when a conductor or the like is stacked on the surface of the board main body 1 and welded by laser La, an increase in the dimension in the thickness direction of the control board 100 can be suppressed. As a result, it is possible to provide a control board 100 that can suppress an increase in the dimension in the thickness direction of the control board 100 even when welding by laser La.

[0058] [Second embodiment] A second embodiment will be described with reference to Figures 7 to 12. In this second embodiment, a control board 300 and a base 400 are welded together by a laser La using a columnar copper member 303 and a joining protrusion 402 (403, 404, 405). That is, unlike the first embodiment, the control board 100 and the bus bar 200 are not welded together. In the drawings, the same components as those in the first embodiment are denoted by the same reference numerals.

[0059] 7 to 12, the configurations of a control board 300 and a base 400 according to the second embodiment will be described. The control board 300 is a board on which various electronic components and control devices for controlling a power conversion device (for example, a DC-DC conversion device) for a vehicle are mounted. The control board 300 is an example of the "board" in the claims.

[0060] In each figure, the thickness direction of the control board 300 is the Z direction, one of the Z directions is the Z1 direction, and the other of the Z directions is the Z2 direction. A first direction perpendicular to the Z direction is the X direction. One of the X directions is the X1 direction, and the other of the X directions is the X2 direction. A second direction perpendicular to the X and Z directions is the Y direction. One of the Y directions is the Y1 direction, and the other of the Y directions is the Y2 direction.

[0061] (Base) The control board 300 is joined to a base 400. The base 400 is an aluminum member. The base 400 is an example of the "first metal member" in the claims.

[0062] The base 400 includes a main body 401 , a joining protrusion 402 , a joining protrusion 403 , a joining protrusion 404 , and a joining protrusion 405 .

[0063] A flow path 411 through which the coolant Cw flows is formed in the main body 401. The coolant Cw is configured to cool the control board 300 and electronic components such as the multiple switching elements 302 of the control board 300 via the joining protrusions 402, 403, 404, 405 and the columnar copper members 303.

[0064] Each of the joining protrusions 402, 403, 404, and 405 protrudes in the Z1 direction from the surface of the main body 401 on the Z1 direction side. Each of the joining protrusions 402, 403, 404, and 405 has a truncated cone shape that protrudes in the Z1 direction. Each of the joining protrusions 402, 403, 404, and 405 supports the control board 300 from the Z2 direction side.

[0065] Joining protrusion 402, joining protrusion 403, joining protrusion 404 and joining protrusion 405 are respectively arranged at a corner on the Y2 direction side and the X1 direction side, a corner on the Y2 direction side and the X2 direction side, a corner on the Y1 direction side and the X1 direction side and a corner on the Y1 direction side and the X2 direction side on the surface on the Z1 direction side of main body 401.

[0066] The configuration including the control board 300 and the base 400 described above is an example of the "energy beam welding structure" in the claims.

[0067] 7, the control board 300 includes a board main body 301, a plurality of switching elements 302, a copper columnar member 303, and a welded portion 304. The copper columnar member 303 is an example of the "second metal member" in the claims.

[0068] (Explanation of the control board configuration) The substrate main body 301 is a member containing metal, such as a printed wiring board. Such substrate main body 301 is provided with a copper foil wiring pattern that electrically connects electronic components such as external electrical equipment and multiple switching elements 302 to each other. That is, one side of the copper foil wiring pattern is electrically connected to the external electrical equipment. The other side of the copper foil wiring pattern is electrically connected to electronic components such as multiple switching elements 302. The copper foil wiring pattern is embedded in the substrate main body 301 in a state where it is alternately layered with the resin portion of the substrate main body 301.

[0069] The board main body 301 is also provided with a frame ground 312 that serves as a reference potential. The frame ground 312 is embedded in each of the multiple layers in the board main body 301 as a copper foil wiring pattern. The frame ground 312 is arranged around each of the multiple through holes 311 in the board main body 301. Ends of the frame ground 312 are arranged in a state where they are exposed on the inner circumferential surfaces of the multiple through holes 311 in the board main body 301. In this way, the frame ground 312 is electrically connected to the columnar copper members 303 embedded in each of the multiple through holes 311. The frame ground 312 is an example of a "ground pattern" in the claims.

[0070] The switching elements 302 are configured to output the supplied current as a current of a predetermined voltage. Each of the switching elements 302 is, for example, a power semiconductor. The switching elements 302 are electrically connected to external electrical equipment via a copper foil wiring pattern. Each of the switching elements 302 is disposed on the surface of the board main body 301 on the Z1 direction side.

[0071] (Joining of base and substrate) 7, in the control board 300 of the second embodiment, the joining protrusions 402 (joining protrusions 403, 404, and 405) of the base 400 are welded to the columnar copper member 303 by a laser La to form welds 304, which electrically join the joining protrusions 402 (joining protrusions 403, 404, and 405) and the columnar copper member 303. The laser La is, for example, an infrared laser.

[0072] (columnar copper member) FIG. 8 is a diagram of the control board 300 before the joining protrusions 402 (joining protrusions 403, 404, and 405) of the base 400 are welded to the columnar copper members 303 by laser La. As shown in FIG. 8, the columnar copper members 303 are cylindrical members. The columnar copper members 303 are embedded in through holes 311 of the board main body 301. The through holes 311 are holes that penetrate the board main body 301 in the Z direction. The through holes 311 are circular holes that have approximately the same shape as the columnar copper members 3 when viewed from the Z1 direction side. The through holes 311 are formed in a plurality (four) of the board main body 301. The columnar copper members 303 are embedded in each of the plurality (four) of through holes 311.

[0073] The copper pillar member 303 is a cylindrical metal member made of copper. Note that instead of the copper pillar member 303, a metal member such as silver, gold, or aluminum may be used.

[0074] 9, the thickness Th1 of the columnar copper member 303 is approximately the same as the thickness Th2 of the substrate main body 301. The position of the end of the columnar copper member 303 on the Z1 direction side is approximately the same as the position of the end of the substrate main body 301 on the Z1 direction side. The position of the end of the columnar copper member 303 on the Z2 direction side is approximately the same as the position of the end of the substrate main body 301 on the Z2 direction side.

[0075] In a direction perpendicular to the Z direction, the cross-sectional area of ​​the columnar copper member 303 is configured to have an area that provides electrical resistance corresponding to the value of the current to be passed. Before the columnar copper member 303 is embedded in the through-hole 311, the cross-sectional area of ​​the columnar copper member 303 in a direction perpendicular to the Z direction is slightly larger than the cross-sectional area of ​​the through-hole 311. As a result, the columnar copper member 303 is embedded in the through-hole 311 in a press-fit state.

[0076] The diameter R1 of the columnar copper member 303 is larger than the diameter R2 of the end of the welded portion 304 on the Z1 direction side. The difference between the diameter R1 of the columnar copper member 303 and the maximum diameter R2 of the end of the welded portion 304 on the Z1 direction side is the welding allowance. This prevents the frame ground 312 and the board body 1 around the columnar copper member 3 from melting.

[0077] (weld) 9, the welded portion 304 is a portion where the joining protrusion 402 (joining protrusion 403, joining protrusion 404, and joining protrusion 405) of the base 400 is welded to the columnar copper member 303 by a laser La (see FIG. 7) while the joining protrusion 402 of the base 400 and the columnar copper member 303 are in contact with each other. Note that the welded portion 304 has the same configuration in the portion between the joining protrusion 403 and the columnar copper member 303, the portion between the joining protrusion 403 and the columnar copper member 303, the portion between the joining protrusion 403 and the columnar copper member 303, the portion between the joining protrusion 404 and the columnar copper member 303, and the portion between the joining protrusion 405 and the columnar copper member 303, and therefore only the welded portion 304 of the joining protrusion 402 of the base 400 will be described.

[0078] The welded portion 304 is a portion where the joining protrusion 402 melted by the laser La and the columnar copper member 303 melted by the laser La are mixed and solidified. The welded portion 304 is provided in the joining protrusion 402 and the columnar copper member 303 from the end portion on the side opposite to the irradiation direction of the laser La (Z1 direction) to a position just before the end portion on the side in the irradiation direction (Z2) of the laser La. That is, the welded portion 304 is formed from the end face on the Z1 direction side of the columnar copper member 303 to the middle portion in the Z direction of the joining protrusion 402. The welded portion 304 has a shape that tapers toward the Z2 direction.

[0079] The tapered welded portion 304 is formed by setting the focal position of the laser La at the middle portion in the Z direction of the columnar copper member 303. That is, in the irradiation direction, the diameter of the laser La is larger in the portion on the opposite side of the focal position of the laser La from the irradiation direction, and the diameter of the laser La is smaller in the portion on the focal position side of the laser La, resulting in such a tapered shape.

[0080] As described above, the control board 300 is configured to be cooled by the coolant Cw flowing through the flow path 411 via the joining protrusions 402 (joining protrusions 403, 404, and 405) and the columnar copper members 303. This cools the electronic components such as the multiple switching elements 302 on the board main body 301.

[0081] The other configurations of the second embodiment are the same as those of the first embodiment, and therefore the description thereof will be omitted.

[0082] (Laser welding method) The laser welding method of the second embodiment will be described below with reference to Figures 10 to 12. The laser welding method is a method of welding the joining protrusions 402 (joining protrusions 403, 404, and 405) of the base 400 to the columnar copper members 303 embedded in the through holes 311 of the substrate main body 301 with a laser La. Here, the type, output, focal position, etc. of the laser La are set in advance.

[0083] In step S201, the control board 300 and the base 400 are held in a state in which the joining protrusions 402 (joining protrusions 403, 404, and 405) of the base 400 are aligned with the columnar copper members 303 (see FIG. 11 ). That is, step S201 is a step in which the control board 300 and the joining protrusions 402 (joining protrusions 403, 404, and 405) of the base 400 are positioned and held relative to each other in a state in which the joining protrusions 402 (joining protrusions 403, 404, and 405) of the base 400 and the columnar copper members 303 fitted in the through holes 311 formed in the board main body 301 of the control board 300 are abutted against each other. Here, when viewed from the Z1 direction side, the center of the joining protrusion 402 (joining protrusion 403, joining protrusion 404, and joining protrusion 405) of the base 400 and the center of the columnar copper member 303 are aligned.

[0084] In step S202, a laser beam La is irradiated to weld the joining protrusions 402 (joining protrusions 403, 404, and 405) of the base 400 to the columnar copper member 303. That is, step S202 is a step in which the joining protrusions 402 (joining protrusions 403, 404, and 405) of the base 400, which are in contact with each other, are welded to the columnar copper member 303 by the laser beam La. Here, welding is performed by the laser beam La on each of the joining protrusions 402, 403, 404, and 405 of the base 400 that are in contact with the columnar copper member 303 (see FIG. 12 ). In step S202, the control board 300 and the base 400 are moved relative to the irradiation position of the laser La, and the joining protrusion 402 (joining protrusion 403, joining protrusion 404, and joining protrusion 405) is welded to the columnar copper member 303 by the laser La.

[0085] After step S202, the laser welding method ends.

[0086] (Effects of the second embodiment) In the second embodiment, the following effects can be obtained.

[0087] In the second embodiment, as described above, the control board 300 includes a board main body 301 in which a through hole 311 penetrating in the thickness direction (Z direction) is formed, a columnar copper member 303 embedded in the through hole 311 of the board main body 301, and a welded portion 304 formed by welding the joining protrusions 402 (joining protrusions 403, 404, and 405) of the base 400 to the columnar copper member 303 with a laser La while the joining protrusions 402 (joining protrusions 403, 404, and 405) of the base 400 are in contact with the columnar copper member 303. This makes it possible to suppress an increase in the dimension of the control board 300 in the thickness direction even when welding is performed with the laser La.

[0088] Furthermore, in the second embodiment, as described above, the laser-welded structure includes the base 400, which is welded to the columnar copper member 303 by the laser La and includes the joining protrusions 402 (joining protrusions 403, 404, and 405) that protrude toward the columnar copper member 303. This allows the base 400 and the control board 300 to be directly joined by the joining protrusions 402 (joining protrusions 403, 404, and 405) melted by the laser La and the welded parts 304 formed by solidifying the columnar copper member 303. Therefore, compared to when the base 400 and the control board 300 are fixed using bolts, it is possible to suppress an increase in the combined dimension of the base 400 and the control board 300 in the thickness direction and to suppress an increase in the number of parts.

[0089] Furthermore, in the second embodiment, as described above, the board main body 301 includes the frame ground 312 (grounding pattern) disposed around the through-hole 311 and electrically connected to the columnar copper member 303. As a result, compared to the case where the frame ground 312 (grounding pattern) and the base 400 are electrically connected using bolts, the use of the columnar copper member 303 embedded in the board main body 301 makes it possible to suppress an increase in the number of parts required to connect the frame ground 312 (grounding pattern) to the base 400.

[0090] The other effects of the second embodiment are the same as those of the first embodiment, and therefore a description thereof will be omitted.

[0091] [Variations] The above-described embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the description of the above-described embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0092] For example, in the first embodiment described above, the thickness Th1 of the columnar copper member 3 (second metal member) is approximately the same as the thickness Th2 of the substrate main body 1, but the present invention is not limited to this. In the present invention, the thickness Th2 of the second metal member 503 may be larger than the thickness Th1 of the substrate main body 1, as in the modified example shown in FIG.

[0093] In the first and second embodiments, the columnar copper member 3 (second metal member) is a cylindrical member, but the present invention is not limited to this. In the present invention, the second metal member may be a rectangular columnar member.

[0094] Furthermore, in the above-described first embodiment, an example was shown in which the focal position of the laser La (energy beam) was set to the middle part in the Z direction of the columnar copper member 3 (second metal member). Furthermore, in the above-described second embodiment, an example was shown in which the focal position of the laser La (energy beam) was set to the middle part in the Z direction of the joining protrusion 402 (joining protrusion 403, joining protrusion 404, and joining protrusion 405: first metal member). However, the present invention is not limited to this. In the present invention, the focal position of the energy beam may be aligned with the boundary part between the first metal member and the second metal member.

[0095] Furthermore, in the first and second embodiments, examples have been shown in which a laser La (energy beam) is used in welding, but the present invention is not limited to this. In the present invention, an electron beam may be used as the energy beam.

[0096] In the first and second embodiments, the laser welded structure is used in a vehicle, but the present invention is not limited to this. In the present invention, the laser welded structure may be used in a configuration other than a vehicle. [Explanation of symbols]

[0097] 1, 311: Board main body, 3, 303: Columnar copper member (second metal member), 4, 304: Welding portion, 11, 311: Through hole, 100, 300: Control board (board), 200: Bus bar (first metal member, conductor member), 312: Frame ground (grounding pattern), 400: Base (first metal member), 402, 403, 404, 405: Jointing protrusion, La: Laser (energy beam)

Claims

1. A substrate; a first metal member including a base or a conductive member and joined to the substrate; The substrate is a substrate body portion having a through hole formed therein that penetrates the substrate body portion in a thickness direction; a second metal member embedded in the through hole of the substrate main body; An energy beam welding structure including a welded portion where the first metal member and the second metal member are welded by an energy beam while the first metal member and the second metal member are in contact with each other.

2. 2. The energy beam welding structure according to claim 1, wherein the first metal member is welded to the second metal member by the energy beam and includes the base including a joining protrusion that protrudes toward the second metal member, or the conductor member includes a bus bar that is welded to the second metal member by the energy beam.

3. The energy beam welding structure according to claim 1 , wherein the substrate body portion includes a ground pattern disposed around the through hole and electrically connected to the second metal member.

4. a substrate body portion having a through hole formed therein that penetrates the substrate body portion in a thickness direction; A substrate comprising a second metal member embedded in the through hole of the substrate main body portion and welded together with a first metal member including a base or a conductive member while being in contact with the first metal member.

Images