Board unit and power supply circuit

Abstract

To provide a board unit capable of suppressing generation of a solder bridge, and a power supply circuit.SOLUTION: A board unit comprises a board and an integrated circuit which is mounted on the board. The integrated circuit comprises a main body part including a first side face and a second side face which is directed to an opposite side of the first side face, a plurality of first leads provided so as to protrude from the first side face, and a plurality of second leads provided so as to protrude from the second side face. The board includes a board main body, a plurality of first pads provided in parallel on a surface of the board main body, and a plurality of second pads provided in parallel on the surface of the board main body. One first pad in the plurality of first pads extends in an oblique direction with respect to the first side face so as to extend in a direction, in which the one first pad is more separated from the first side face than the other first pad, and to extend in a direction along the first side face.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] FIELD An embodiment of the present invention relates to a board unit and a power supply circuit. [Background technology]

[0002] There is a substrate unit having a substrate and an integrated circuit mounted on the substrate. The substrate unit is used, for example, in a power supply circuit that supplies power to a load. The power supply circuit has a conversion circuit and a control circuit. The conversion circuit is connected to the load and a power supply, converts power supplied from the power supply to power appropriate for the load, and supplies the converted power to the load, thereby operating the load. The control circuit has a substrate unit and uses an integrated circuit to control the power conversion operation by the conversion circuit.

[0003] The integrated circuit has a rectangular parallelepiped main body and a plurality of leads protruding from each of two opposing side surfaces of the main body. The plurality of leads are arranged side by side on each of the two side surfaces of the main body. The substrate has a substrate main body and a plurality of pads arranged side by side on the surface of the substrate main body. The plurality of pads are arranged corresponding to each of the plurality of leads of the integrated circuit.

[0004] The integrated circuit is mounted on the substrate by placing the leads on the substrate so that they are positioned over the pads, respectively, and soldering the leads to the pads, respectively.

[0005] When soldering the leads of an integrated circuit to each of the pads, some of the solder may unintentionally connect two adjacent leads. This type of unintentional connection between two leads due to solder is called, for example, a solder bridge.

[0006] Solder bridges can cause malfunctions or breakdowns in integrated circuits. For example, if the board unit is used in the control circuit of a power supply circuit, the occurrence of solder bridges may prevent the conversion circuit from operating normally.

[0007] For this reason, it is desirable that the substrate unit and the power supply circuit using the same be able to suppress the occurrence of solder bridges when multiple leads of an integrated circuit are soldered to multiple pads on the substrate. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 6646841 Summary of the Invention [Problem to be solved by the invention]

[0009] The embodiments of the present invention provide a board unit and a power supply circuit that can suppress the occurrence of solder bridges. [Means for solving the problem]

[0010] According to an embodiment, a device includes a substrate and an integrated circuit mounted on the substrate, the integrated circuit having a main body portion having a first side surface and a second side surface facing opposite to the first side surface, a plurality of first leads provided to protrude from the first side surface, and a plurality of second leads provided to protrude from the second side surface, the substrate having a substrate main body, a plurality of first pads provided in a line on a surface of the substrate main body, and a plurality of second pads provided in a line on a surface of the substrate main body, the plurality of first pads provided corresponding to each of the plurality of first leads, and the plurality of second pads provided corresponding to each of the plurality of second leads, the integrated circuit A substrate unit is provided which is mounted on the substrate by positioning the plurality of first leads on each of the plurality of first pads and positioning the plurality of second leads on each of the plurality of second pads, soldering the plurality of first leads to each of the plurality of first pads, and soldering the plurality of second leads to each of the plurality of second pads, and wherein one of the plurality of first pads extends in a direction away from the first side surface more than the other first pads, and extends in a direction oblique to the first side surface so as to extend in a direction along the first side surface. [Effects of the Invention]

[0011] It is possible to provide a board unit and a power supply circuit that can suppress the occurrence of solder bridges. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a block diagram schematically illustrating a lighting fixture and a power supply circuit according to an embodiment. [Figure 2] FIG. 2 is a plan view schematically illustrating a substrate unit according to the embodiment. [Figure 3] FIG. 10 is a plan view schematically illustrating a modified example of the substrate unit according to the embodiment. [Figure 4] FIG. 10 is a plan view schematically illustrating a modified example of the substrate unit according to the embodiment. [Figure 5] FIG. 10 is a plan view schematically illustrating a modified example of the substrate unit according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Each embodiment will be described below with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Furthermore, even when the same part is shown, the dimensions and ratios may be different depending on the drawing. In the present specification and the drawings, elements similar to those described above with reference to the previous drawings are designated by the same reference numerals, and detailed descriptions thereof will be omitted as appropriate.

[0014] FIG. 1 is a block diagram schematically illustrating a lighting fixture and a power supply circuit according to an embodiment. 1, lighting device 2 includes a power supply circuit 10 and a light source 12. Power supply circuit 10 is connected to light source 12 and supplies power to light source 12, thereby turning on light source 12.

[0015] The light source 12 is provided, for example, separately from the power supply circuit 10 and connected to the power supply circuit 10 via wiring. The light source 12 is also detachably connected to the power supply circuit 10, for example, via a connector or the like. However, the light source 12 does not necessarily have to be detachable from the power supply circuit 10. The light source 12 may also be provided integrally with the power supply circuit 10.

[0016] The light source 12 is, for example, a light-emitting diode (LED). The light source 12 may be, for example, an organic light-emitting diode (OLED), an inorganic electroluminescence light-emitting element, an organic electroluminescence light-emitting element, or other electroluminescence-type light-emitting element. The light source 12 may be, for example, a light bulb. The light source 12 may be any light source that can emit light based on power supplied from the power supply circuit 10. Furthermore, the lighting device 2 may have multiple light sources 12 connected in series, parallel, or series-parallel. The number of light sources 12 provided in the lighting device 2 may be any number.

[0017] The power supply circuit 10 is installed, for example, in a space above the ceiling. The light source 12 is attached to the ceiling of a building, for example, through an opening in the ceiling, and emits light toward the room. The light source 12 is, for example, a downlight. However, the configuration of the lighting fixture 2 is not limited to the above. For example, the power supply circuit 10 may be attached to the ceiling of a building together with the light source 12. Furthermore, the installation position of the lighting fixture 2 is not limited to the ceiling, and may be any position where light needs to be emitted. The lighting fixture 2 may be attached, for example, to an exterior wall or a support pole outdoors.

[0018] The power supply circuit 10 includes a conversion circuit 20 and a control circuit 22. The conversion circuit 20 is connected to the light source 12 and also to a power source PS. The conversion circuit 20 converts the power supplied from the power source PS into power appropriate for the light source 12, and supplies the converted power to the light source 12, thereby lighting the light source 12.

[0019] The power supplied by the power source PS is, for example, AC power. The power source PS is, for example, a commercial power source. Furthermore, if the light source 12 is a light-emitting diode, the power supplied to the light source 12 is DC power. The conversion circuit 20 converts, for example, the AC power supplied from the power source PS into DC power appropriate for the light source 12, and supplies the converted DC power to the light source 12.

[0020] However, the power supplied by the power supply PS is not limited to AC power and may be DC power or the like. The power supplied to the light source 12 is not limited to DC power and may be any power suitable for the light source 12. The conversion circuit 20 may be configured in any way that can convert the power supplied from the power supply PS into power suitable for the light source 12 and supply the converted power to the light source 12. The configuration of the conversion circuit 20 may be set appropriately depending on the type of power supplied from the power supply PS, the configuration of the light source 12, etc.

[0021] The control circuit 22 controls the power conversion operation by the conversion circuit 20. The control circuit 22 has a board unit 30. The board unit 30 has a board 32 and an integrated circuit 34 mounted on the board 32. The integrated circuit 34 incorporates various circuits for controlling the operation of the conversion circuit 20. The control circuit 22 controls the power conversion operation by the conversion circuit 20 by using the integrated circuit 34.

[0022] The board unit 30 is not limited to one, and may have multiple integrated circuits 34. In other words, the number of integrated circuits 34 mounted on the board 32 may be two or more. The control circuit 22 may control the power conversion operation by the conversion circuit 20 by using multiple integrated circuits 34. The number of integrated circuits 34 provided on the board unit 30 is not limited to one, and may be any number. The number of integrated circuits 34 provided on the board unit 30 may be set appropriately depending on, for example, the configuration of the conversion circuit 20.

[0023] Furthermore, the components mounted on the substrate 32 are not limited to the integrated circuit 34, and any components necessary for the control circuit 22 may be mounted thereon. In other words, the control circuit 22 is composed of multiple components mounted on the substrate 32. However, the control circuit 22 may have multiple substrates connected via wiring, for example. The control circuit 22 may have multiple substrate units 30, for example. The control circuit 22 may have any configuration that includes at least one substrate unit 30 and uses at least one integrated circuit 34, thereby being able to control the operation of the conversion circuit 20.

[0024] Furthermore, the conversion circuit 20 may be mounted on a different board from the control circuit 22, or may be mounted on the board 32 of the board unit 30. The power supply circuit 10 may be configured, for example, by mounting the conversion circuit 20 and the control circuit 22 on a single board 32. The power supply circuit 10 may have any configuration that includes the conversion circuit 20 and the control circuit 22, and at least the control circuit 22 includes the board unit 30.

[0025] FIG. 2 is a plan view schematically illustrating the substrate unit according to the embodiment. 2, the integrated circuit 34 has a main body 40, a plurality of first leads 41, and a plurality of second leads 42. In other words, the main body 40 is a package that encapsulates a semiconductor chip and the like. In the main body 40, an insulating material such as ceramic or plastic is used as the encapsulant that encapsulates the periphery of the semiconductor chip.

[0026] The main body 40 has a first side surface 40a and a second side surface 40b facing the opposite side to the first side surface 40a. The main body 40 is, for example, rectangular parallelepiped-shaped. The first side surface 40a and the second side surface 40b are, for example, two side surfaces on the long sides of the rectangular parallelepiped-shaped main body 40. The second side surface 40b is, for example, a surface that is approximately parallel to the first side surface 40a. However, the second side surface 40b does not necessarily have to be parallel to the first side surface 40a. The first side surface 40a and the second side surface 40b may be, for example, surfaces that are inclined in the vertical direction. The shape of the two side surfaces on the short sides of the main body 40 may be, for example, trapezoid-shaped. The shape of the main body 40 may be, for example, a shape in which each corner of a rectangular parallelepiped has chamfered or rounded portions. The main body 40 may have any shape that has at least a first side surface 40a and a second side surface 40b facing the opposite side to the first side surface 40a.

[0027] The multiple first leads 41 are provided so as to protrude from the first side surface 40a of the main body portion 40. The multiple first leads 41 are provided side by side on the first side surface 40a so as to be aligned along the first side surface 40a and the surface of the substrate 32 when the main body portion 40 is placed on the substrate 32. The multiple second leads 42 are provided so as to protrude from the second side surface 40b of the main body portion 40. The multiple second leads 42 are provided side by side on the second side surface 40b so as to be aligned along the second side surface 40b and the surface of the substrate 32 when the main body portion 40 is placed on the substrate 32.

[0028] The integrated circuit 34 is a surface-mount type integrated circuit having a plurality of L-shaped (gull-wing shaped) leads protruding from two side surfaces of a main body 40 (package), such as an SOP (Small Outline Package), an SSOP (Shrink SOP), or a TSOP (Thin SOP). The plurality of first leads 41 and the plurality of second leads 42 are bent so as to contact the surface of the substrate 32 when the main body 40 is placed on the substrate 32.

[0029] The second leads 42 are arranged on the second side surface 40b at a predetermined interval P1. Meanwhile, the first leads 41 are arranged on the first side surface 40a at a predetermined interval P1, with some of them having an interval P2 wider than the interval P1. In other words, the wider interval is a portion where some of the first leads 41 have been thinned out. For this reason, in this example, the number of the first leads 41 is smaller than the number of the second leads 42.

[0030] More specifically, the first leads 41 include a first group of leads 41a arranged at a predetermined interval P1 on the first side surface 40a and a second group of leads 41b arranged at a predetermined interval P1 on the first side surface 40a. In other words, the first leads 41 are divided into the first group of leads 41a arranged at a predetermined interval P1 on the first side surface 40a and the second group of leads 41b arranged at a predetermined interval P1 on the first side surface 40a. A distance P2 between the first group of leads 41a and the second group of leads 41b is wider than the predetermined distance P1. In other words, the distance P2 is the shortest distance between the first group of leads 41a and the second group of leads 41b.

[0031] The widely spaced portions are not limited to the plurality of first leads 41, and may be provided on each of the plurality of first leads 41 and the plurality of second leads 42. The number of widely spaced portions provided on the plurality of first leads 41 is not limited to one, and may be two or more. In other words, the plurality of first leads 41 may include three or more groups divided by widely spaced portions. When multiple widely spaced portions are provided, the spacing between each portion (the number of thinned leads) may be different. The plurality of first leads 41 do not necessarily have to have widely spaced portions. The plurality of first leads 41 may be arranged side by side on the first side surface 40a at a predetermined spacing P1.

[0032] The predetermined interval P1 is, for example, 0.4 mm or more and 1 mm or less. The interval P2 is, for example, 2 mm or more. However, the interval P2 may be any interval wider than the interval P1.

[0033] The substrate 32 has a substrate body 50, a plurality of first pads 51 arranged side by side on a surface 50a of the substrate body 50, and a plurality of second pads 52 arranged side by side on the surface 50a of the substrate body 50. The plurality of first pads 51 are arranged corresponding to the plurality of first leads 41 of the integrated circuit 34, respectively. The plurality of second pads 52 are arranged corresponding to the plurality of second leads 42 of the integrated circuit 34, respectively.

[0034] In Figure 2, for ease of illustration, only a portion of the multiple first leads 41, multiple second leads 42, multiple first pads 51, and multiple second pads 52 are labeled with symbols for convenience.

[0035] One first pad 51a of the multiple first pads 51 extends in a direction away from the first side surface 40a more than the other first pads 51, and also extends in a direction oblique to the first side surface 40a so as to extend in a direction along the first side surface 40a.

[0036] One first pad 51a has, for example, a first portion 511 extending in a direction perpendicular to the first side surface 40a, and a second portion 512 extending in a direction diagonal to the first side surface 40a from the end of the first portion 511 opposite the first side surface 40a so as to extend in a direction away from the first side surface 40a and in a direction along the first side surface 40a.

[0037] The extending direction of the first portion 511 does not have to be strictly the same as the direction perpendicular to the first side surface 40a. The extending direction of the first portion 511 may be inclined with respect to the direction perpendicular to the first side surface 40a. The extending direction of the first portion 511 only needs to have at least a component extending in the direction perpendicular to the first side surface 40a.

[0038] The length LP1 of the first portion 511 from the first side surface 40a is, for example, not less than one time and not more than two times the length LL1 of the first lead 41 from the first side surface 40a.

[0039] The length LP2 of the second portion 512 in the direction along the first side surface 40a is, for example, 1.5 times or more the length LL2 of the first lead 41 in the direction along the first side surface 40a. In other words, the length LL2 of the first lead 41 in the direction along the first side surface 40a is the width of the first lead 41.

[0040] The first pad 51a is, for example, a first pad 51 corresponding to one of the first group leads 41a that is arranged at a position closest to the second group leads 41b among the multiple first pads 51. In this case, the first pad 51a extends in a direction oblique to the first side surface 40a so as to extend in a direction toward the second group leads 41b. In other words, the first pad 51a extends in a direction where the spacing is wide.

[0041] Among the multiple first pads 51, one first pad 51e located at the edge extends in the opposite direction to the adjacent first pads 51. A width W12 of the first pad 51e in the direction in which the multiple first pads 51 are arranged is wider than a width W11 of the other first pads 51.

[0042] The first pad 51e is, for example, one of the multiple first pads 51 that corresponds to one lead 41b of the second group that is located at a position farthest from the multiple leads 41a of the first group. In other words, the first pad 51e extends in the opposite direction to the adjacent lead 41b of the second group. In the direction along the first side surface 40a, the extension direction of the first pad 51e is the same as the extension direction of the first pad 51a. In the example shown in FIG. 2, both the first pad 51a and the first pad 51e extend toward the right side of the paper.

[0043] Of the multiple second pads 52, one second pad 52e located at the end on the same side as the first pad 51e extends in the opposite direction to the adjacent second pads 52. The width W22 of the second pad 52e in the direction in which the multiple second pads 52 are arranged is wider than the width W21 of the other second pads 52.

[0044] The integrated circuit 34 is mounted on the substrate 32 by placing the multiple first leads 41 on each of the multiple first pads 51 and the multiple second leads 42 on each of the multiple second pads 52 on the substrate 32 (substrate body 50), soldering the multiple first leads 41 to each of the multiple first pads 51, and soldering the multiple second leads 42 to each of the multiple second pads 52.

[0045] The board unit 30 is soldered by, for example, a jet-type flow soldering device. The jet-type flow soldering device sprays molten solder while transporting the board 32 with the integrated circuit 34 mounted thereon, causing the molten solder to adhere to each lead and each pad, thereby soldering the integrated circuit 34 to the board 32.

[0046] 2, the board unit 30 is set in a jet flow soldering device so that the first side surface 40a and the second side surface 40b of the integrated circuit 34 extend along the conveyance direction of the board 32. The board unit 30 is set in the jet flow soldering device so that the first side surface 40a and the second side surface 40b of the integrated circuit 34 are parallel to the conveyance direction of the board 32.

[0047] After the board unit 30 is set in the device as described above, when the board 32 is transported toward the left side of the paper as shown in Fig. 2, the leads and pads are soldered in order starting from those arranged on the left side of the paper. In other words, the first pad 51a, the first pad 51e, and the second pad 52e are provided so as to extend toward the downstream side in the transport direction of the board 32.

[0048] In this way, when soldering the substrate unit 30 using a jet-type flow soldering device, solder bridges tend to occur more easily in the leads and pads located downstream in the transport direction of the substrate 32 than in the leads and pads located upstream in the transport direction of the substrate 32.

[0049] In areas where multiple leads and pads are lined up consecutively, molten solder supplied in excess to a pad flows onto the next pad. Therefore, solder bridges are less likely to occur in areas where multiple leads and pads are lined up consecutively. In contrast, the leads and pads located furthest downstream in the transport direction of the board 32 have no escape route for excess molten solder, so the excess molten solder may flow into the upstream leads and pads, potentially forming a solder bridge between them. This is thought to make downstream leads and pads more susceptible to solder bridges than upstream leads and pads.

[0050] In the board unit 30 according to this embodiment, the first pads 51e and second pads 52e located downstream in the transport direction of the board 32 are extended toward the downstream side in the transport direction of the board 32, and have larger areas than the other first pads 51 and second pads 52. This makes it possible to prevent molten solder from flowing toward the upstream leads and pads in the first pads 51e and second pads 52e. Even when soldering the board unit 30 using a jet-type flow soldering device, it is possible to prevent solder bridges from occurring in the downstream first pads 51e and second pads 52e.

[0051] Furthermore, solder bridges caused by molten solder flowing upstream can also occur in areas where the spacing between leads is large. For example, this can also occur in the lead 41a located furthest downstream of the leads 41a of the first group. In this case, simply extending the pad 51e downstream in the transport direction, like the first pad 51e, may not provide a sufficient area due to its relationship with the lead 41b of the second group located furthest upstream, and may not be effective in suppressing solder bridges.

[0052] In contrast, in the substrate unit 30 according to this embodiment, the first pad 51a corresponding to one of the first group leads 41a arranged at a position closest to the plurality of second group leads 41b extends in a direction away from the first side surface 40a more than the other first pads 51 and extends in a direction oblique to the first side surface 40a so as to extend in a direction along the first side surface 40a. In other words, in the substrate unit 30, the first pad 51a extends in a diagonal direction so as to face the downstream side in the transport direction of the substrate 32.

[0053] As a result, in the board unit 30 according to this embodiment, even when there are widely spaced portions among the multiple first leads 41, it is possible to prevent molten solder from flowing toward the upstream leads and pads. Even when soldering the board unit 30 using a jet-type flow soldering device, it is possible to prevent solder bridges from occurring on the first pads 51 a located in the widely spaced portions among the multiple first leads 41.

[0054] In this way, in the substrate unit 30 of this embodiment and the power supply circuit 10 using it, the occurrence of solder bridges can be suppressed even when multiple first leads 41 and multiple second leads 42 of the integrated circuit 34 are soldered to multiple first pads 51 and multiple second pads 52 of the substrate 32.

[0055] Furthermore, in the substrate unit 30, if the length of the first portion 511 is excessively long, the molten solder will have difficulty flowing toward the second portion 512 extending in the diagonal direction. Therefore, the length LP1 of the first portion 511 from the first side surface 40a is set to be at least one time and at most two times the length LL1 of the first lead 41 from the first side surface 40a. This makes it easier for the molten solder to flow toward the second portion 512, and makes it possible to more appropriately suppress the occurrence of solder bridges.

[0056] Furthermore, if the length of the second portion 512 is short in the board unit 30, the effect of suppressing solder bridges will be reduced. Therefore, the length LP2 of the second portion 512 in the direction along the first side surface 40a is set to be 1.5 times or more the length LL2 of the first lead 41 in the direction along the first side surface 40a. This ensures that the first pad 51a has a sufficient area required to receive molten solder, making it possible to more appropriately suppress the occurrence of solder bridges.

[0057] FIG. 3 is a plan view schematically illustrating a modified example of the substrate unit according to the embodiment. 3, in the board unit 30a, the first side surface 40a and the second side surface 40b of the integrated circuit 34 are inclined with respect to the transport direction of the board 32. In this manner, the first side surface 40a and the second side surface 40b of the integrated circuit 34 do not necessarily have to be parallel to the transport direction of the board 32. The board unit 30a may be set in a jet-type flow soldering device so that the first side surface 40a and the second side surface 40b of the integrated circuit 34 have at least a component extending along the transport direction of the board 32.

[0058] FIG. 4 is a plan view schematically illustrating a modified example of the substrate unit according to the embodiment. As shown in FIG. 4, the substrate unit 30b further includes a third portion 513 extending from the end of the second portion 512 opposite the first side surface 40a in a direction perpendicular to the first side surface 40a, so that the first pad 51a faces away from the first side surface 40a.

[0059] In this example, the first pad 51a has a shape obtained by bending linear first portion 511, second portion 512, and third portion 513. The first pad 51a may have, for example, a curved portion. The shape of the first pad 51a is not limited to the above, and may be any shape that extends in a direction away from the first side surface 40a more than the other first pads 51 and in a direction oblique to the first side surface 40a so as to extend in a direction along the first side surface 40a.

[0060] FIG. 5 is a plan view schematically illustrating a modified example of the substrate unit according to the embodiment. As shown in FIG. 5, in the substrate unit 30c, the first leads 41 of the integrated circuit 34 do not have any widely spaced portions, and are arranged side by side at predetermined intervals on the first side surface 40a.

[0061] In the substrate unit 30c, the first pad 51a extending in a direction oblique to the first side surface 40a is replaced with a first pad 51e. In the substrate unit 30c, the first pad 51a is the first pad 51 located at the edge of the multiple first pads 51, and extends in a direction oblique to the first side surface 40a so as to face in the opposite direction to the adjacent first pads 51.

[0062] Furthermore, in the substrate unit 30c, of the multiple second pads 52, one second pad 52 located at the end on the same side as the first pad 51a is replaced from the second pad 52e of the above embodiment with a second pad 52a having a configuration similar to that of the first pad 51a.

[0063] In this way, the first pad 51a extending in a direction oblique to the first side surface 40a may be used for the first pad 51 located at the end of the multiple first pads 51 arranged at a predetermined interval. The configuration of the first pad 51a extending in a direction oblique to the first side surface 40a may also be used for the second pad 52.

[0064] Also, for example, when the multiple first leads 41 have widely spaced portions, the multiple first pads 51 may have two first pads 51a: a first pad 51a provided in the widely spaced portion and a first pad 51a provided at the end. Furthermore, when the multiple first leads 41 have multiple widely spaced portions, the multiple first pads 51 may have three or more first pads 51a.

[0065] In the above embodiments, the power supply circuit 10 that supplies power to the light source 12 is shown as an example of a power supply circuit. However, the power supply circuit is not limited to this and may be a power supply circuit that supplies power to any load. The power supply circuit (conversion circuit 20) may have any configuration that is connected to a load and a power source, converts power supplied from the power source into power appropriate for the load, and supplies the converted power to the load.

[0066] In addition, in each of the above embodiments, an example in which the substrate unit is applied to a power supply circuit is shown. The substrate unit is not limited to a power supply circuit, but can be applied to any circuit (device) that requires a substrate and an integrated circuit.

[0067] The present embodiment includes the following aspects. (Appendix 1) A substrate; an integrated circuit mounted on the substrate; Equipped with The integrated circuit comprises: a main body having a first side and a second side facing opposite to the first side; a plurality of first leads provided so as to protrude from the first side surface; a plurality of second leads provided so as to protrude from the second side surface; and The substrate is A substrate body, a plurality of first pads arranged side by side on the surface of the substrate body; a plurality of second pads arranged side by side on the surface of the substrate body; and the first pads are provided corresponding to the first leads, respectively; the second pads are provided corresponding to the second leads, respectively; the integrated circuit is mounted on the substrate by placing the first leads on the substrate so as to be located on the first pads, respectively, and the second leads on the substrate so as to be located on the second pads, respectively, and soldering the first leads to the first pads, respectively, and soldering the second leads to the second pads, respectively; A substrate unit characterized in that one of the plurality of first pads extends in a direction away from the first side surface more than the other first pads, and also extends in a direction oblique to the first side surface so as to extend in a direction along the first side surface.

[0068] (Appendix 2) the first leads include a first group of leads arranged at predetermined intervals on the first side surface, and a second group of leads arranged at the predetermined intervals on the first side surface, a spacing between the first group of leads and the second group of leads is greater than the predetermined spacing; the one first pad is a first pad corresponding to one lead of the first group that is arranged at a position closest to the leads of the second group, among the plurality of first pads; The substrate unit described in Appendix 1, characterized in that the one first pad extends in a direction oblique to the first side so as to extend in a direction toward the leads of the multiple second groups.

[0069] (Appendix 3) Among the plurality of first pads, one of the first pads corresponding to one of the second group leads located at the end and disposed at a position farthest from the plurality of first group leads extends in a direction opposite to the adjacent first pads, A substrate unit as described in Appendix 2, characterized in that among the multiple second pads, one second pad located at the farthest end on the same side as one first pad located at the farthest end extends in the opposite direction to the adjacent second pad.

[0070] (Appendix 4) A substrate unit as described in Appendix 1, characterized in that the one first pad is the first pad located at the farthest end among the multiple first pads, and extends in a diagonal direction relative to the first side surface so as to face in the opposite direction to the adjacent first pads.

[0071] (Appendix 5) The one first pad is a first portion extending in a direction perpendicular to the first side surface; a second portion extending from an end of the first portion opposite the first side surface in a direction oblique to the first side surface so as to extend in a direction away from the first side surface and in a direction along the first side surface; 5. The substrate unit according to any one of claims 1 to 4, comprising:

[0072] (Appendix 6) 6. The substrate unit according to claim 5, wherein the length of the first portion from the first side surface is between one and two times the length of the first lead from the first side surface.

[0073] (Appendix 7) A substrate unit as described in Appendix 5 or 6, characterized in that the length of the second portion in the direction along the first side surface is 1.5 times or more the length of the first lead in the direction along the first side surface.

[0074] (Appendix 8) A substrate unit as described in any one of Appendices 5 to 7, characterized in that one of the first pads further has a third portion extending from an end of the second portion opposite the first side surface in a direction perpendicular to the first side surface, facing away from the first side surface.

[0075] (Appendix 9) a conversion circuit connected to a load and a power source, converting power supplied from the power source into power appropriate for the load, and supplying the converted power to the load; a control circuit having a substrate unit including a substrate and an integrated circuit mounted on the substrate, the control circuit controlling the operation of power conversion by the conversion circuit by using the integrated circuit; Equipped with The integrated circuit comprises: a main body having a first side and a second side facing opposite to the first side; a plurality of first leads provided so as to protrude from the first side surface; a plurality of second leads provided so as to protrude from the second side surface; and The substrate is A substrate body, a plurality of first pads arranged side by side on the surface of the substrate body; a plurality of second pads arranged side by side on the surface of the substrate body; and the first pads are provided corresponding to the first leads, respectively; the second pads are provided corresponding to the second leads, respectively; the integrated circuit is mounted on the substrate by placing the first leads on the substrate so as to be located on the first pads, respectively, and the second leads on the substrate so as to be located on the second pads, respectively, and soldering the first leads to the first pads, respectively, and soldering the second leads to the second pads, respectively; A power supply circuit characterized in that one of the plurality of first pads extends in a direction away from the first side surface relative to the other first pads, and extends in a direction oblique to the first side surface so as to extend in a direction along the first side surface.

[0076] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0077] 2...Lighting fixture, 10...Power supply circuit, 12...Light source, 20...Conversion circuit, 22...Control circuit, 30, 30a to 30c...Board unit, 32...Board, 34...Integrated circuit, 40...Main body, 40a...First side surface, 40b...Second side surface, 41...First lead, 41a...First group of leads, 41b...Second group of leads, 42...Second lead, 50...Board main body, 50a...Surface, 51, 51a, 51e...First pad, 52, 52e...Second pad, 511...First portion, 512...Second portion, 513...Third portion, PS...Power supply

Claims

1. A substrate; an integrated circuit mounted on the substrate; Equipped with The integrated circuit comprises: a main body having a first side and a second side facing opposite the first side; a plurality of first leads provided so as to protrude from the first side surface; a plurality of second leads provided so as to protrude from the second side surface; and The substrate is A substrate body, a plurality of first pads arranged side by side on the surface of the substrate body; a plurality of second pads arranged side by side on the surface of the substrate body; and the first pads are provided corresponding to the first leads, respectively; the second pads are provided corresponding to the second leads, respectively; the integrated circuit is mounted on the substrate by placing the first leads on the substrate such that the first leads are located on the first pads, respectively, and the second leads are located on the second pads, respectively, and soldering the first leads to the first pads, respectively, and soldering the second leads to the second pads, respectively; A substrate unit characterized in that one of the plurality of first pads extends in a direction away from the first side surface more than the other first pads, and also extends in a direction oblique to the first side surface so as to extend in a direction along the first side surface.

2. the first leads include a first group of leads arranged at predetermined intervals on the first side surface, and a second group of leads arranged at the predetermined intervals on the first side surface, a spacing between the first group of leads and the second group of leads is greater than the predetermined spacing; the one first pad is a first pad corresponding to one lead of the first group that is arranged at a position closest to the leads of the second group, among the plurality of first pads; 2. The substrate unit according to claim 1, wherein the one first pad extends in a direction oblique to the first side surface so as to extend in a direction toward the leads of the second group.

3. Among the plurality of first pads, one of the first pads corresponding to one of the second group leads located at the end and disposed at a position farthest from the plurality of first group leads extends in a direction opposite to the adjacent first pads, The substrate unit according to claim 2, characterized in that, among the plurality of second pads, one second pad located at the farthest end on the same side as one of the first pads located at the farthest end extends in the opposite direction to the adjacent second pad.

4. The substrate unit according to claim 1, characterized in that the one first pad is the first pad located at the farthest end among the plurality of first pads, and extends in a diagonal direction relative to the first side surface so as to face in the opposite direction to the adjacent first pads.

5. The one first pad is a first portion extending in a direction perpendicular to the first side surface; a second portion extending from an end of the first portion opposite the first side surface in a direction oblique to the first side surface so as to extend in a direction away from the first side surface and in a direction along the first side surface; 2. The substrate unit according to claim 1, further comprising:

6. 6. The substrate unit according to claim 5, wherein the length of the first portion from the first side surface is equal to or greater than one time and equal to or less than two times the length of the first lead from the first side surface.

7. 6. The substrate unit according to claim 5, wherein the length of the second portion in the direction along the first side surface is 1.5 times or more the length of the first lead in the direction along the first side surface.

8. The substrate unit of claim 5, characterized in that one of the first pads further has a third portion extending from the end of the second portion opposite the first side surface in a direction perpendicular to the first side surface, facing away from the first side surface.

9. a conversion circuit connected to a load and a power source, converting power supplied from the power source into power appropriate for the load, and supplying the converted power to the load; a control circuit having a substrate unit including a substrate and an integrated circuit mounted on the substrate, the control circuit controlling the operation of the power conversion by the conversion circuit by using the integrated circuit; Equipped with The integrated circuit comprises: a main body having a first side and a second side facing opposite the first side; a plurality of first leads provided so as to protrude from the first side surface; a plurality of second leads provided so as to protrude from the second side surface; and The substrate is A substrate body, a plurality of first pads arranged side by side on the surface of the substrate body; a plurality of second pads arranged side by side on the surface of the substrate body; and the first pads are provided corresponding to the first leads, respectively; the second pads are provided corresponding to the second leads, respectively; the integrated circuit is mounted on the substrate by placing the first leads on the substrate such that the first leads are located on the first pads, respectively, and the second leads are located on the second pads, respectively, and soldering the first leads to the first pads, respectively, and soldering the second leads to the second pads, respectively; A power supply circuit characterized in that one of the plurality of first pads extends in a direction away from the first side surface relative to the other first pads, and extends in a direction oblique to the first side surface so as to extend in a direction along the first side surface.

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