Wiring board

Abstract

To provide a technique capable of improving bonding strength to a wiring pattern of a conductor part and easily moving a base material of the conductor part to an edge in a prescribed direction in a land part.SOLUTION: A wiring board 10 comprises a substrate part 11 and a conductor part 12. The substrate part 11 comprises a conductor layer 20 having a wiring pattern (first wiring pattern 21) and an insulation layer 30 including an insulation film 32 covering a part of the wiring pattern. A partial region of the wiring pattern is constituted as a land part 23. The conductor part 12 comprises a base material 40 and a plating layer 41. The base material 40 includes an opposed surface 42, a pair of first surfaces 43 and 44, and a pair of second surfaces 45 and 46. The opposed surface 42 and the pair of first surfaces 43 and 44 are covered by the plating layer 41. The pair of second surfaces 45 and 46 includes exposed surfaces 45A and 46A. The plating layer 41 covering the pair of first surfaces 43 and 44 is joined to the land part 23. The pair of second surfaces 45 and 46 is arranged to be superposed on the land part 23 in a thickness direction.SELECTED DRAWING: Figure 4

Description

【Technical Field】 【0001】 This disclosure relates to a wiring board. 【Background Art】 【0002】 Patent Document 1 discloses a heat dissipation structure for surface-mounted electronic components. Specifically, a heat-generating component surface-mounted on a printed circuit board and an SMT radiator disposed on a wiring pattern near the heat-generating component are disclosed. The SMT radiator is made of a metal with good thermal conductivity and functions as a heat dissipation component. The SMT radiator has a rectangular parallelepiped shape, and its lower surface is soldered to the wiring pattern. 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2003-188565 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 A conductor part such as the SMT radiator in Patent Document 1 is composed of, for example, a base material and a plating layer covering the base material, and the plating layer is soldered to the wiring pattern. Such a conductor part has higher bonding strength to the wiring pattern by joining not only the lower surface but also the four surfaces rising from the lower surface to the wiring pattern. However, in order to join the four surfaces to the wiring pattern, it is necessary to form a land part formed at the exposed part of the wiring pattern so as to protrude outside the outer peripheral edge of the lower surface of the conductor part, and join the four surfaces to the protruding part. For this reason, it becomes difficult to arrange the base material close to the end of the land part. 【0005】 One of the objectives of this disclosure is to provide a technique that makes it easy to bring the base material of the conductor part close to the end in a predetermined direction in the land part while improving the bonding strength of the conductor part to the wiring pattern. [Means for solving the problem] 【0006】 The wiring board disclosed herein is A substrate portion comprising a conductor layer having a wiring pattern and an insulating layer having an insulating film covering a portion of the wiring pattern, wherein a portion of the wiring pattern is configured as a land portion not covered by the insulating film, A conductive portion joined to the land portion by solder, A wiring board equipped with, The conductor portion comprises a conductive substrate and a plating layer covering a portion of the substrate. The substrate has an opposing surface facing the land portion on one side in the thickness direction of the substrate portion, a pair of first surfaces arranged on both sides in a first direction perpendicular to the thickness direction, and a pair of second surfaces arranged on both sides in a second direction perpendicular to the thickness direction and the first direction. The opposing surface and the pair of first surfaces are covered with the plating layer. The pair of the second surfaces have exposed surfaces in which the substrate is exposed without being covered by the plating layer, The plating layer covering the pair of first surfaces is joined to the land portion by the solder, The pair of the second surfaces are arranged to overlap with the land portion in the thickness direction. [Effects of the Invention] 【0007】 The technology disclosed herein improves the bonding strength of the conductor portion to the wiring pattern, while also making it easier to position the base material of the conductor portion towards the end in a predetermined direction within the land portion. [Brief explanation of the drawing] 【0008】 [Figure 1] Figure 1 is a plan view of the wiring board in the first embodiment. [Figure 2] Figure 2 is a front view of the wiring board in the first embodiment. [Figure 3] Figure 3 is a cross-sectional view of the area around the conductor, taken along line AA in Figure 1. [Figure 4]Figure 4 is a cross-sectional view of the conductor area, obtained by cutting along the BB line in Figure 1. [Figure 5] Figure 5 is an enlarged plan view of the area around the conductor portion of the wiring board in the second embodiment. [Figure 6] Figure 6 is a cross-sectional view along the CC line in Figure 5. [Figure 7] Figure 7 is an enlarged plan view of the area around the conductor portion of the wiring board in the third embodiment. [Figure 8] Figure 8 is a cross-sectional view of the DD line in Figure 7. [Modes for carrying out the invention] 【0009】 The embodiments of this disclosure are listed and illustrated below. 【0010】 [1] A substrate portion comprising a conductor layer having a wiring pattern and an insulating layer having an insulating film covering a part of the wiring pattern, wherein a part of the wiring pattern is configured as a land portion not covered by the insulating film, A conductive portion joined to the land portion by solder, A wiring board equipped with, The conductor portion comprises a conductive substrate and a plating layer covering a portion of the substrate. The substrate has an opposing surface facing the land portion on one side in the thickness direction of the substrate portion, a pair of first surfaces arranged on both sides in a first direction perpendicular to the thickness direction, and a pair of second surfaces arranged on both sides in a second direction perpendicular to the thickness direction and the first direction. The opposing surface and the pair of first surfaces are covered with the plating layer. The pair of the second surfaces have exposed surfaces in which the substrate is exposed without being covered by the plating layer, The plating layer covering the pair of first surfaces is joined to the land portion by the solder, The pair of the aforementioned second surfaces are arranged to overlap with the land portion in the thickness direction. Wiring board. 【0011】 Since the plating layer covering the pair of first surfaces is joined to the land portion by solder, it is possible to improve the joining strength of the conductor portion to the land portion. On the other hand, the pair of second surfaces are configured to have exposed surfaces and are arranged to overlap the land portion in the thickness direction. That is, since at least a part of the pair of second surfaces is not covered with the plating layer, the wiring board is less likely to interfere with other members, and as a result, it is easy to move the base material closer to the end in the second direction at the land portion. 【0012】 〔2〕The distance in the second direction from at least any one of the second surfaces to the end of the land portion is shorter than the distance in the first direction from any one of the first surfaces to the end of the land portion The wiring board according to 〔1〕. 【0013】 The wiring board can bring at least one of the second surfaces closer to a position closer to the end in the second direction at the land portion than the distance from any one of the first surfaces to the end in the first direction at the land portion. 【0014】 〔3〕The conductor portion is arranged across a plurality of the land portions spaced apart from each other and is joined to each of the plurality of the land portions The wiring board according to 〔1〕 or 〔2〕. 【0015】 The wiring board can focus on joining a plurality of locations of the conductor portion. 【0016】 〔4〕Between the substrate portion and the opposing surface, the solder is continuously arranged so as to straddle a plurality of the land portions spaced apart from each other The wiring board according to 〔3〕. 【0017】 The wiring board can enhance the joining strength of the entire solder by continuously arranging the solder that focuses on joining a plurality of locations of the conductor portion and straddles a plurality of the land portions. 【0018】 〔5〕The entire opposing surface of the conductor portion is provided so as to overlap the land portion A wiring board as described in any of [1] through [4]. 【0019】 The above-mentioned wiring board tends to have uniform bonding strength with the land areas across the entire opposing surface. 【0020】 [6] The area of ​​each of the pair of first surfaces is greater than the area of ​​either of the pair of second surfaces. A wiring board as described in any of [1] through [5]. 【0021】 The above-mentioned wiring board makes it easier to improve the bonding strength between the first surface and the land area while keeping the size of the conductor portion to a minimum. 【0022】 [7] The conductor portion has an elongated shape that extends along the direction in which the current flows at the point where the conductor portion is joined. A wiring board as described in any of [1] through [6]. 【0023】 The above-mentioned wiring board allows current to flow more easily through the conductor, thereby improving the heat dissipation performance of the conductor. 【0024】 [8] The height of the solder fillet joined to at least one of the first surfaces and the land portion from the land portion is greater than the height of the first surface joined to the fillet from the land portion at the thickness-direction center position. A wiring board as described in any of [1] through [7]. 【0025】 The above-mentioned wiring board can further improve the bonding strength between at least one of the first surfaces and the land portion. 【0026】 <First Embodiment> The wiring board 10 shown in Figure 1 is mounted, for example, on a vehicle (not shown). The wiring board 10 is installed between a power supply unit 90 and a load 91 mounted on the vehicle and functions as a power path that supplies power from the power supply unit 90 to the load 91. 【0027】 As shown in Figures 1 and 2, the wiring board 10 comprises a board portion 11, a conductor portion 12, an input portion 13, an output portion 14, a switch portion 15, and solder 16. Note that in Figure 1, the solder 16 is omitted. 【0028】 The substrate portion 11 has a conductor layer 20 and an insulating layer 30. The conductor layer 20 is provided between the power supply unit 90 and the load 91 and functions as a power path that supplies power from the power supply unit 90 to the load 91. The conductor layer 20 is provided with an input section 13, an output section 14, and a switch section 15. 【0029】 The input section 13, output section 14, and switch section 15 are electrically connected to the conductor layer 20, for example, by soldering. The input section 13 is configured, for example, as a connector and is connected to the power supply section 90 via wiring 92. Power is supplied to the input section 13 based on the power supply section 90. The power supplied to the input section 13 is then supplied to the output section 14 via the conductor layer 20. 【0030】 The output unit 14 is configured, for example, as a connector and is connected to the load 91 via wiring 93. Power from the power supply unit 90 is supplied to the load 91 via the input unit 13, the conductor layer 20, and the output unit 14. 【0031】 The switch unit 15 may include a switch having physical contacts, or it may include a semiconductor switching element. The switch unit 15 is provided between the input unit 13 and the output unit 14. When the switch unit 15 is ON, it allows power to be supplied from the input unit 13 to the output unit 14. When the switch unit 15 is OFF, it cuts off power supply from the input unit 13 to the output unit 14. 【0032】 The conductor layer 20 is made of, for example, metal foil (for example, copper foil). The conductor layer 20 has a first wiring pattern 21 and a second wiring pattern 22. The first wiring pattern 21 and the second wiring pattern 22 are spaced apart from each other. The first wiring pattern 21 has a longitudinal shape. An input section 13 is provided at one end of the first wiring pattern 21. One end of a switch section 15 is provided at the other end of the first wiring pattern 21. The other end of the switch section 15 and an output section 14 are provided on the second wiring pattern 22. 【0033】 The insulating layer 30 comprises a substrate body 31 and an insulating film 32. The substrate body 31 is insulating and is made of, for example, resin. The substrate body 31 is plate-shaped. The substrate body 31 is positioned on one side of the substrate portion 11 in the thickness direction relative to the conductor layer 20. Hereinafter, "thickness direction of the substrate portion 11" will also be simply referred to as "thickness direction". The conductor layer 20 (more specifically, a first wiring pattern 21 and a second wiring pattern 22) is provided on the other side of the substrate body 31 in the thickness direction. The insulating film 32 covers a portion of the other side of the conductor layer 20 (more specifically, the first wiring pattern 21 and the second wiring pattern 22) in the thickness direction. The insulating film 32 is made of, for example, solder resist. The insulating film 32 is insulating and is made of, for example, resin. 【0034】 A portion of the first wiring pattern 21 is configured as a land portion 23 that is not covered by the insulating film 32. The land portion 23 is surrounded by the insulating film 32. The land portion 23 is rectangular in shape. The land portion 23 has a longitudinal shape that extends along the direction in which the current flows. The land portion 23 has a longitudinal shape that extends along the longitudinal direction of the first wiring pattern 21. The land portion 23 is located between the input portion 13 and the output portion 14, and between the input portion 13 and the switch portion 15. Multiple land portions 23 are provided. Multiple land portions 23 are spaced apart from each other. Multiple land portions 23 are spaced apart in the direction in which the current flows. Multiple land portions 23 are spaced apart in the longitudinal direction of the first wiring pattern 21. 【0035】 The conductor portion 12 is a component that is joined to the land portion 23 by solder 16, as shown in Figures 3 and 4. The conductor portion 12 functions as a heat dissipation component. The conductor portion 12 is configured, for example, as a chip busbar. In this embodiment, the conductor portion 12 is rectangular parallelepiped, but it may take other forms. For example, the conductor portion 12 may be cubic, or it may have a curved surface. The conductor portion 12 has a conductive base material 40 and a plating layer 41 that covers a part of the base material 40. The base material 40 is a component that is not joined to the solder 16, or a component that is less likely to be joined to the solder 16 than the plating layer 41. The plating layer 41 is a component that is joined to the solder 16, and is more likely to be joined to the solder 16 than the base material 40. 【0036】 The base material 40 has an opposing surface 42, a pair of first surfaces 43 and 44, a pair of second surfaces 45 and 46, and a top surface 47. 【0037】 The opposing surface 42 faces the land portion 23 on one side in the thickness direction. The opposing surface 42 faces the conductor layer 20 either via the solder 16 or directly. The opposing surface 42 may or may not be in contact with the conductor layer 20. 【0038】 The pair of first surfaces 43 and 44 are positioned on both sides of the substrate 40 in a first direction. The first direction is perpendicular to the thickness direction. One first surface 43 is positioned on one side of the substrate 40 in the first direction. The other first surface 44 is positioned on the other side of the substrate 40 in the first direction. 【0039】 A pair of second surfaces 45 and 46 are positioned on both sides of the base material 40 in the second direction. The second direction is perpendicular to the thickness direction and the first direction. One second surface 45 is positioned on one side of the base material 40 in the second direction, and the other second surface 46 is positioned on the other side of the base material 40 in the second direction. 【0040】 The top surface 47 is positioned on the opposite side of the base material 40 from the opposing surface 42. The top surface 47 is positioned on the other side in the thickness direction of the base material 40. 【0041】 The length of the conductor portion 12 in the first direction is shorter than the length of the conductor portion 12 in the second direction. The length of the conductor portion 12 in the thickness direction is shorter than the length of the conductor portion 12 in the first direction and shorter than the length in the second direction. 【0042】 The opposing surface 42, the pair of first surfaces 43, 44, the pair of second surfaces 45, 46, and the top surface 47 are flat surfaces. Flat surfaces include not only strictly flat surfaces but also slightly curved surfaces. The opposing surface 42, the pair of first surfaces 43, 44, and the top surface 47 are covered with a plating layer 41. The plating layer 41 covering the opposing surface 42, the pair of first surfaces 43, 44, and the top surface 47 is continuous and forms an annular shape. The plating layer 41 covering the opposing surface 42 and the pair of first surfaces 43, 44 is joined to the land portion 23 by solder 16. In other words, the opposing surface 42 and the pair of first surfaces 43, 44 are joined to the solder 16 via the plating layer 41. 【0043】 In the projection plane obtained by projecting the opposing surface 42, solder 16, and land portion 23 onto a virtual plane perpendicular to the thickness direction, it is desirable that the ratio of the area of ​​the region where the opposing surface 42, solder 16, and land portion 23 overlap each other to the area of ​​the opposing surface 42 is 50% or more, and preferably 80% or more. With this configuration, the wiring board 10 can further improve the bonding strength between the conductor portion 12 and the land portion 23. In this embodiment, the above ratio is 100% (see Figures 1, 3, and 4). 【0044】 The pair of second surfaces 45 and 46 have exposed surfaces 45A and 46A in which the substrate 40 is exposed without being covered by the plating layer 41. In this embodiment, the entirety of the second surfaces 45 and 46 is the exposed surface 45A and 46A. The exposed surfaces 45A and 46A are not joined to the solder 16 and are not joined to the land portion 23. The pair of second surfaces 45 and 46 are arranged to overlap the land portion 23 in the thickness direction. 【0045】 With this configuration, the wiring board 10 has a plating layer 41 covering a pair of first surfaces 43 and 44 which is joined to the land portion 23 by solder 16, thereby improving the bonding strength of the conductor portion 12 to the land portion 23. On the other hand, the pair of second surfaces 45 and 46 have an exposed surface configuration 45A and 46A and are arranged to overlap with the land portion 23 in the thickness direction. In other words, since at least a portion of the pair of second surfaces 45 and 46 of the wiring board 10 is not covered by the plating layer 41, it is less likely to interfere with other components, and as a result, it is easier to position the base material 40 towards the second-direction ends 23C and 23D of the land portion 23. In particular, in this embodiment, since the entirety of the second surfaces 45 and 46 of the wiring board 10 is exposed surface 45A and 46A, it is even easier to position the base material 40 towards the second-direction ends 23C and 23D of the land portion 23. 【0046】 The distance in the second direction from at least one of the second faces 45, 46 to the edge of the land portion 23 is shorter than the distance in the first direction from any of the first faces 43, 44 to the edge of the land portion 23. The "edge of the land portion 23" in "from the second face 45 to the edge of the land portion 23" refers to "the edge 23C of the land portion 23 positioned in the direction that the second face 45 faces." The "edge of the land portion 23" in "from the second face 46 to the edge of the land portion 23" refers to "the edge 23D of the land portion 23 positioned in the direction that the second face 46 faces." The "edge of the land portion 23" in "from the first face 43 to the edge of the land portion 23" refers to "the edge 23A of the land portion 23 positioned in the direction that the first face 43 faces." The "edge of the land portion 23" in "from the first face 44 to the edge of the land portion 23" refers to "the edge 23B of the land portion 23 positioned in the direction that the first face 44 faces." 【0047】 In the example shown in Figure 3, the distance in the first direction from the first surface 43 to the end 23A of the land section 23 is defined as distance L1, and the distance in the first direction from the first surface 44 to the end 23B of the land section 23 is defined as distance L2. In the example shown in Figure 4, the distance in the second direction from the second surface 45 to the end 23C of the land section 23 is defined as distance L3, and the distance in the second direction from the second surface 46 to the end 23D of the land section 23 is defined as distance L4. Distance L3 is shorter than distance L1 and shorter than distance L2. Distance L4 is shorter than distance L1 and shorter than distance L2. In other words, the distances L3 and L4 in the second direction from the second surfaces 45 and 46 to the ends 23C and 23D of the land section 23 are both shorter than the distances L1 and L2 in the first direction from the first surfaces 43 and 44 to the ends 23A and 23B of the land section 23. 【0048】 With this configuration, the wiring board 10 can bring its second surface 45 closer to the second edge 23C of the land portion 23 than the distances L1 and L2. In addition, the wiring board 10 can bring its second surface 46 closer to the second edge 23D of the land portion 23 than the distances L1 and L2. 【0049】 Note that distance L1 may be the same as or different from distance L2. Distance L3 may be the same as or different from distance L4. 【0050】 Fillets 51, 52, 53, and 54 are formed in the solder 16. Fillet 51 is located on one side of the solder 16 in the first direction. Fillet 51 is joined to the first surface 43 and the land portion 23. Fillet 52 is located on the other side of the solder 16 in the first direction. Fillet 52 is joined to the first surface 44 and the land portion 23. Fillet 53 is located on one side of the solder 16 in the second direction. In the example shown in Figure 4, fillet 53 is located below the exposed surface 45A of the second surface 45. However, fillet 53 does not have to be located below the exposed surface 45A of the second surface 45. For example, the upper end of fillet 53 may be located above the lower end of the exposed surface 45A. Fillet 54 is located on the other side of the solder 16 in the second direction. In the example shown in Figure 4, fillet 54 is positioned below the exposed surface 46A of the second surface 46. However, fillet 54 does not necessarily have to be positioned below the exposed surface 46A of the second surface 46. For example, the upper end of fillet 54 may be positioned above the lower end of the exposed surface 46A. The height of fillet 51 is the same as, or higher than, the height of fillets 53 and 54. The height of fillet 52 is the same as, or higher than, the height of fillets 53 and 54. The cross-sections of fillets 51 and 52 (more specifically, the cross-sections cut in a direction perpendicular to the second direction) are triangular (more specifically, isosceles triangles with two sides of equal length). The cross-sections of fillets 53 and 54 (more specifically, the cross-sections cut in a direction perpendicular to the first direction) are triangular (more specifically, isosceles triangles with two sides of equal length). "Two sides of the same length" includes not only cases where they are exactly the same, but also cases where they are substantially the same. "Substantially the same" means that the ratio of the difference between the two sides to the length of the longer side is 10% or less. 【0051】 In the example shown in Figure 3, the height of the fillet 51 of the solder 16 joined to the first surface 43 and the land portion 23 from the land portion 23 is defined as height H1. Height H1 is the height at the highest point of the fillet 51. The height of the fillet 52 of the solder 16 joined to the first surface 44 and the land portion 23 from the land portion 23 is defined as height H2. Height H2 is the height at the highest point of the fillet 52. The height of the land portion 23 at the center position in the thickness direction of the first surface 43 is defined as height HC1. Height HC1 is the height at the center position in the second direction of the first surface 43. The height of the land portion 23 at the center position in the thickness direction of the first surface 44 is defined as height HC2. Height HC2 is the height at the center position in the second direction of the first surface 44. Height is synonymous with length in the thickness direction. 【0052】 In the example shown in Figure 3, height H1 is higher than height HC1, and height H2 is higher than height HC2. With this configuration, the wiring board 10 can further improve the bonding strength between the first surfaces 43 and 44 and the land portion 23. 【0053】 Note that height H1 may be the same as height HC1, or it may be lower than height HC1. Height H2 may be the same as height HC2, or it may be lower than height HC2. Height H1 may be higher than height HC1, and height H2 may be the same as height HC2, or lower than height HC2. Height H2 may be higher than height HC2, and height H1 may be the same as height HC1, or lower than height HC1. 【0054】 The conductor portion 12 is joined to one land portion 23. In a planar direction perpendicular to the thickness direction, the conductor portion 12 is positioned inward from the outer edge of the land portion 23. The entire opposing surface 42 of the conductor portion 12 is provided to overlap the land portion 23. With this configuration, the wiring board 10 tends to have uniform bonding strength with the land portion 23 across the entire opposing surface 42. 【0055】 The area of ​​each of the pair of first surfaces 43 and 44 is larger than the area of ​​either of the pair of second surfaces 45 and 46. With this configuration, the wiring board 10 can easily improve the bonding strength between the first surfaces 43 and 44 and the land portion 23 while suppressing an increase in the size of the conductor portion 12. 【0056】 The conductor portion 12 has a longitudinal shape that extends along the direction in which the current flows at the point where the conductor portion 12 is joined. The "direction in which the current flows" is the direction from the input portion 13 side to the output portion 14 side in the conductor layer 20. With this configuration, the wiring board 10 can improve the heat dissipation performance of the conductor portion 12 because current flows more easily through the conductor portion 12. 【0057】 The following description relates to a method for manufacturing a wiring board 10. The substrate portion 11 is formed by printing a conductive layer 20 on the surface of the substrate body 31 and applying an insulating film 32 so as to cover a portion of the conductive layer 20. The conductive portion 12 is formed by plating the surface of a prismatic metal member, and then cutting and dividing the metal member in a direction perpendicular to its own extension direction. The cut surfaces are configured as unplated second surfaces 45 and 46. Solder lubricant is applied to the substrate portion 11, and the conductive portion 12, input portion 13, output portion 14, and switch portion 15 are placed on it. Subsequently, the conductive portion 12, input portion 13, output portion 14, and switch portion 15 are joined to the conductive layer 20 by solder 16 using reflow soldering. In this way, the wiring board 10 is manufactured. 【0058】 <Second Embodiment> In the first embodiment, one conductor portion was joined to one land portion. In contrast, the second embodiment describes a configuration in which one conductor portion is joined to multiple land portions. In the description of the second embodiment, the same reference numerals are used for components that are the same as in the first embodiment, and detailed explanations are omitted. 【0059】 Figures 5 and 6 show a wiring board 210 of the second embodiment. The wiring board 210 comprises a substrate portion 211, a conductor portion 12, and solder 216. The substrate portion 211 has a conductor layer 20 and an insulating layer 230. Note that the solder 216 is omitted in Figure 5. 【0060】 As shown in Figures 5 and 6, the insulating layer 230 comprises a substrate body 31 and an insulating film 232. The insulating film 232 is insulating and is made of, for example, resin. The insulating film 232 covers a portion of the other side of the conductor layer 20 (more specifically, the first wiring pattern 21) in the thickness direction. 【0061】 A portion of the first wiring pattern 21 in the conductor layer 20 is configured as land portions 223A and 223B that are not covered by the insulating film 232. The land portions 223A and 223B are each surrounded by the insulating film 232. The land portions 223A and 223B are each rectangular in shape. The land portions 223A and 223B are arranged side by side with spacing in the direction of current flow. The land portions 223A and 223B are arranged side by side with spacing in the longitudinal direction of the first wiring pattern 21. The land portions 223A and 223B are located between the input section 13 and the output section 14 as described in the first embodiment, and between the input section 13 and the switch section 15. 【0062】 The conductor portion 12 is arranged across multiple (two in this embodiment) spaced-apart land portions 223A and 223B, and is joined to each of the multiple land portions 223A and 223B by solder 216. With this configuration, the wiring board 210 can focus on joining multiple locations of the conductor portion 12. The multiple (two in this embodiment) land portions 223A and 223B to which one conductor portion 12 is joined are composed of the same wiring pattern (specifically, the first wiring pattern 21). One land portion 223A is positioned to one side in the second direction compared to the other land portion 223B. The second surface 45 is positioned overlapping with the land portion 223A in the thickness direction. The second surface 46 is positioned overlapping with the land portion 223B in the thickness direction. 【0063】 Solder 216 is continuously arranged between the substrate portion 211 (more specifically, the substrate body 31) and the opposing surface 42, spanning multiple spaced land portions 223A and 223B. The insulating film 232 has an intermediate insulating film 232A arranged between the multiple land portions 223A and 223B to which one conductor portion 12 is joined. Solder 216 has a first solder portion 216A that joins the plating layer 41 covering the opposing surface 42 to the land portion 223A, a second solder portion 216B that joins the plating layer 41 covering the opposing surface 42 to the land portion 223B, and a third solder portion 216C arranged between the first solder portion 216A and the second solder portion 216B. The first solder portion 216A is arranged overlapping the opposing surface 42 and the land portion 223A in the thickness direction. The second solder portion 216B is positioned to overlap with the opposing surface 42 and the land portion 223B in the thickness direction. The conductor portion 12 is positioned with a gap in the thickness direction from the intermediate insulating film 232A. The third solder portion 216C is positioned between the conductor portion 12 and the intermediate insulating film 232A in the thickness direction and connects the first solder portion 216A and the second solder portion 216B. The third solder portion 216C is joined to the plating layer 41 covering the opposing surface 42. 【0064】 With this configuration, the wiring board 210 can strengthen the overall bonding strength of the solder 216 by concentrating the bonding of multiple points on the conductor portion 12 while continuously arranging the solder 216 across multiple land portions 223A and 223B. 【0065】 <Third Embodiment> In the second embodiment, an example was described in which a single conductor is joined to multiple land portions, and the multiple land portions are configured with the same wiring pattern. In the third embodiment, an example will be described in which the multiple land portions are configured with different wiring patterns. In the description of the third embodiment, the same reference numerals are used for components that are the same as in the first embodiment, and detailed explanations are omitted. 【0066】 Figures 7 and 8 show a wiring board 310 of the third embodiment. The wiring board 310 comprises a substrate portion 311, a conductor portion 12, and solder 316. The substrate portion 311 has a conductor layer 320 and an insulating layer 330. Note that the solder 316 is omitted in Figure 7. 【0067】 The conductor layer 320 has a plurality (two in this embodiment) of wiring patterns 321A and 321B that are joined to one conductor portion 12. The plurality of wiring patterns 321A and 321B constitute a path between the input portion 13 and the switch portion 15 as described in the first embodiment (see Figure 1). The plurality of wiring patterns 321A and 321B are spaced apart from each other in the second direction. A space is formed between the plurality of wiring patterns 321A and 321B. One wiring pattern 321A is positioned on one side in the second direction compared to the other wiring pattern 321B. 【0068】 As shown in Figures 7 and 8, the insulating layer 330 comprises a substrate body 31 and an insulating film 332. The insulating film 332 is insulating and is made of, for example, resin. The insulating film 332 covers a portion of the other side in the thickness direction of the conductor layer 320 (more specifically, the wiring patterns 321A and 321B). 【0069】 A portion of the wiring pattern 321A is configured as a land portion 323A that is not covered by the insulating film 322. A portion of the wiring pattern 321B is configured as a land portion 323B that is not covered by the insulating film 322. The land portions 323A and 323B are each rectangular in shape. The land portions 323A and 323B are spaced apart from each other in the direction of current flow. 【0070】 The conductor portion 12 is arranged across multiple (two in this embodiment) spaced-apart land portions 323A and 323B, and is joined to each of the multiple land portions 323A and 323B by solder 316. With this configuration, the wiring board 310 can focus on joining multiple locations of the conductor portion 12. The multiple (two in this embodiment) land portions 323A and 323B to which one conductor portion 12 is joined are composed of separate wiring patterns. One land portion 323A is positioned to one side in the second direction compared to the other land portion 323B. The second surface 45 is positioned overlapping with land portion 323A in the thickness direction. The second surface 46 is positioned overlapping with land portion 323B in the thickness direction. 【0071】 Between the substrate portion 311 (more specifically, the substrate body 31) and the opposing surface 42, solder 316 is continuously arranged so as to span multiple spaced land portions 323A and 323B. The solder 316 has a first solder portion 316A that joins the plating layer 41 covering the opposing surface 42 to the land portion 323A, a second solder portion 316B that joins the plating layer 41 covering the opposing surface 42 to the land portion 323B, and a third solder portion 316C arranged between the first solder portion 316A and the second solder portion 316B. The first solder portion 316A is arranged to overlap the opposing surface 42 and the land portion 323A in the thickness direction. The second solder portion 316B is arranged to overlap the opposing surface 42 and the land portion 323B in the thickness direction. The third solder portion 316C is arranged above the space between the multiple wiring patterns 321A and 321B. The third solder portion 316C connects the first solder portion 316A and the second solder portion 316B. The third solder portion 316C is joined to the plating layer 41 that covers the opposing surface 42. The solder 316 forms a bridge shape that spans multiple land portions 323A and 323B. 【0072】 With this configuration, the wiring board 310 can strengthen the overall bonding strength of the solder 316 by focusing on bonding multiple points of the conductor portion 12 while continuously arranging the solder 316 across multiple land portions 323A and 323B. Moreover, the conductor portion 12 also functions as a path connecting wiring pattern 321A and wiring pattern 321B. 【0073】 <Other Embodiments> This disclosure is not limited to the embodiments described above and in the drawings. For example, any combination of the features of the embodiments described above or below is possible as long as it does not contradict each other. Furthermore, any feature of the embodiments described above or below may be omitted unless explicitly stated as essential. In addition, the embodiments described above may be modified as follows. 【0074】 The length of the conductor portion 12 in the first direction may be longer than the length of the conductor portion 12 in the second direction, or it may be the same as the length of the conductor portion 12 in the second direction. Here, "same" does not mean strictly the same, but also includes substantially the same. Substantial identical means that the ratio of the difference between the length in the first direction and the length in the second direction to the longer length is 5% or less. 【0075】 The length of the conductor portion 12 in the thickness direction may be longer than the length of the conductor portion 12 in the first direction, or it may be the same as the length of the conductor portion 12 in the first direction. Here, "same" does not mean strictly the same, but also includes substantially the same. Substantially the same means that the ratio of the difference between the length in the thickness direction and the length in the first direction to the longer length is 5% or less. 【0076】 The length of the conductor portion 12 in the thickness direction may be longer than the length of the conductor portion 12 in the second direction, or it may be the same as the length of the conductor portion 12 in the second direction. Here, "same" does not mean strictly the same, but also substantially the same. Substantially the same means that the ratio of the difference between the length in the thickness direction and the length in the second direction to the longer length is 5% or less. 【0077】 Fillets 53 and 54 do not necessarily need to be formed on solder 16, 216, and 316. 【0078】 It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is not limited to the embodiments disclosed herein, and is intended to include all modifications within the scope set forth in the claims or equivalents thereof. [Explanation of Symbols] 【0079】 10…Wiring board 11... Circuit board section 12...Conductor part 13...Input section 14…Output section 15…Switch section 16... solder 20...Conducting layer 21...First wiring pattern (wiring pattern) 22...Second wiring pattern 23...Land Department 23A...end 23B...end 23C...edge 23D…edge 30…Insulating layer 31...Main board 32…Insulating film 40...Base material 41…Plating layer 42… Opposite side 43...Side 1 44...Side 1 45…Second side 45A…Exposed surface 46…Second side 46A…Exposed surface 47... Top surface 51… Fillet 52… Fillet 53… Fillet 54… Fillet 90...Power supply section 91... Load 92...Wiring 93...Wiring 210…Wiring board 211... Circuit board section 216... solder 216A...First solder joint 216B...Second soldering section 216C... Third solder joint 223A...Land section 223B...Land section 230...Insulating layer 232… Insulating film 232A…Intermediate insulating film 310…Wiring board 311... Circuit board section 316... solder 316A...First solder joint 316B...Second soldering section 316C... Third solder section 320...Conducting layer 321A...Wiring pattern 321B...Wiring pattern 322… Insulating film 323A...Land section 323B...Land section 330...Insulating layer 332… Insulating film H1...Height H2...height HC1…Height HC2…height L1…distance L2…distance L3... Distance L4... Distance

Claims

[Claim 1] A substrate portion comprising a conductor layer having a wiring pattern and an insulating layer having an insulating film covering a portion of the wiring pattern, wherein a portion of the wiring pattern is configured as a land portion not covered by the insulating film, A conductive portion joined to the land portion by solder, A wiring board equipped with, The conductor portion comprises a conductive substrate and a plating layer covering a portion of the substrate. The substrate has an opposing surface facing the land portion on one side in the thickness direction of the substrate portion, a pair of first surfaces arranged on both sides in a first direction perpendicular to the thickness direction, and a pair of second surfaces arranged on both sides in a second direction perpendicular to the thickness direction and the first direction. The opposing surface and the pair of first surfaces are covered with the plating layer. The pair of the second surfaces have exposed surfaces in which the substrate is exposed without being covered by the plating layer. The plating layer covering the pair of first surfaces is joined to the land portion by the solder, The pair of the aforementioned second surfaces are arranged to overlap with the land portion in the thickness direction, Multiple conductor sections are provided, At least two of the multiple conductor portions are arranged in a line along the direction in which the current flows, and the second surface is oriented in the direction in which the current flows. Wiring board. [Claim 2] A substrate portion comprising a conductor layer having a wiring pattern and an insulating layer having an insulating film covering a portion of the wiring pattern, wherein a portion of the wiring pattern is configured as a land portion not covered by the insulating film, A conductive portion joined to the land portion by solder, A wiring board equipped with, The conductor portion comprises a conductive substrate and a plating layer covering a portion of the substrate. The substrate has an opposing surface facing the land portion on one side in the thickness direction of the substrate portion, a pair of first surfaces arranged on both sides in a first direction perpendicular to the thickness direction, and a pair of second surfaces arranged on both sides in a second direction perpendicular to the thickness direction and the first direction. The opposing surface and the pair of first surfaces are covered with the plating layer. The pair of the second surfaces have exposed surfaces in which the substrate is exposed without being covered by the plating layer. The plating layer covering the pair of first surfaces is joined to the land portion by the solder, The pair of the aforementioned second surfaces are arranged to overlap with the land portion in the thickness direction, The conductor portion is arranged across a plurality of land portions that are spaced apart from each other, and is joined to each of the plurality of land portions. Between the substrate portion and the opposing surface, the solder is continuously arranged so as to span across a plurality of spaced-apart land portions. The plurality of land portions include a first land portion and a second land portion, The insulating film has an intermediate insulating film disposed between the first land portion and the second land portion to which one of the conductor portions is joined, The solder has a first solder portion that joins the plating layer covering the opposing surface to the first land portion, a second solder portion that joins the plating layer covering the opposing surface to the second land portion, and a third solder portion disposed between the first solder portion and the second solder portion. The first solder portion is arranged to overlap with the opposing surface and the first land portion in the thickness direction, The second solder portion is arranged to overlap with the opposing surface and the second land portion in the thickness direction, The conductor portion is arranged with a gap between it and the intermediate insulating film in the thickness direction. The third solder portion is positioned between the conductor portion and the intermediate insulating film in the thickness direction, connects the first solder portion and the second solder portion, and is joined to the plating layer covering the opposing surface. Wiring board. [Claim 3] A substrate portion comprising a conductor layer having a wiring pattern and an insulating layer having an insulating film covering a portion of the wiring pattern, wherein a portion of the wiring pattern is configured as a land portion not covered by the insulating film, A conductive portion joined to the land portion by solder, A wiring board equipped with, The conductor portion comprises a conductive substrate and a plating layer covering a portion of the substrate. The substrate has an opposing surface facing the land portion on one side in the thickness direction of the substrate portion, a pair of first surfaces arranged on both sides in a first direction perpendicular to the thickness direction, and a pair of second surfaces arranged on both sides in a second direction perpendicular to the thickness direction and the first direction. The opposing surface and the pair of first surfaces are covered with the plating layer. The pair of the second surfaces have exposed surfaces in which the substrate is exposed without being covered by the plating layer. The plating layer covering the pair of first surfaces is joined to the land portion by the solder, The pair of the aforementioned second surfaces are arranged to overlap with the land portion in the thickness direction, The conductor portion is arranged across a plurality of land portions that are spaced apart from each other, and is joined to each of the plurality of land portions. Between the substrate portion and the opposing surface, the solder is continuously arranged so as to span across a plurality of spaced-apart land portions. The plurality of land portions include a first land portion and a second land portion, The conductor layer has a first wiring pattern and a second wiring pattern that are spaced apart from each other. A portion of the first wiring pattern is configured as the first land portion, A portion of the second wiring pattern is configured as the second land portion, The solder has a first solder portion that joins the plating layer covering the opposing surface to the first land portion, a second solder portion that joins the plating layer covering the opposing surface to the second land portion, and a third solder portion disposed between the first solder portion and the second solder portion. The first solder portion is arranged to overlap with the opposing surface and the first land portion in the thickness direction, The second solder portion is arranged to overlap with the opposing surface and the second land portion in the thickness direction, The third solder portion is positioned above the space between the first and second wiring patterns, connects the first and second solder portions, and is joined to the plating layer covering the opposing surfaces. Wiring board. [Claim 4] The distance in the second direction from at least one of the second surfaces to the edge of the land portion is shorter than the distance in the first direction from any of the first surfaces to the edge of the land portion. A wiring board according to any one of claims 1 to 3. [Claim 5] The entire opposing surface of the conductor portion is provided so as to overlap the land portion. A wiring board according to any one of claims 1 to 3. [Claim 6] The area of ​​each of the pair of first surfaces is greater than the area of ​​either of the pair of second surfaces. A wiring board according to any one of claims 1 to 3. [Claim 7] The conductor portion has an elongated shape that extends along the direction in which the current flows at the point where the conductor portion is joined. A wiring board according to any one of claims 1 to 3. [Claim 8] The height of the solder fillet joined to at least one of the first surfaces and the land portion from the land portion is greater than the height of the first surface joined to the fillet at the center position in the thickness direction from the land portion. A wiring board according to any one of claims 1 to 3.

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