Mounting board, power supply unit, and lighting device

Abstract

To improve electrical reliability with a simple structure.SOLUTION: A mounting substrate 6 comprises a substrate body 60 and a liquid control unit 7. The substrate body 60 has a plurality of electronic components 61 mounted thereon, and includes a specific circuit region R1. The liquid control unit 7 is provided on the substrate body 60. The liquid control unit 7 controls the movement of liquid toward the specific circuit region R1 under the condition that liquid flows on one end surface of the substrate body 60 due to its own weight.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure generally relates to a mounting substrate, a power supply device, and a lighting device. More specifically, the present disclosure relates to a mounting substrate on which a plurality of electronic components are mounted, a power supply device including the mounting substrate, and a lighting device including the power supply device.

Background Art

[0002] Patent Document 1 discloses a tracking resistance material and a circuit board using the material. According to this circuit board, the comparative tracking index in the IEC method tracking resistance test of the surface layer and the back surface layer is sufficiently high, and the overall carbide generation rate is sufficiently small. Therefore, with this circuit board, carbonization of the entire board including the front and back surfaces and the inside can be well prevented, and tracking on the surface can be well prevented. As a result, according to this circuit board, both surface insulation breakdown due to the generation of a surface carbonization path and thickness-direction insulation breakdown due to carbonization erosion in the thickness direction can be well prevented.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the circuit board (mounting substrate) described in Patent Document 1, the manufacturing method may become complicated in order to enhance the tracking resistance (electrical reliability).

[0005] In view of the above reasons, the present disclosure is made, and an object thereof is to provide a mounting substrate, a power supply device, and a lighting device that can improve electrical reliability with a simple configuration.

Means for Solving the Problems

[0006] A mounting substrate according to one aspect of the present disclosure comprises a substrate body and a liquid control unit. The substrate body has a plurality of electronic components mounted on it and includes a specific circuit region. The liquid control unit is provided on the substrate body. The liquid control unit controls the movement of the liquid toward the specific circuit region when the liquid is flowing along one end surface of the substrate body due to its own weight. The liquid control unit includes one or more slits that penetrate the substrate body in the thickness direction. The one or more slits include a U-shaped slit having a U-shaped opening when viewed from the front. The U-shaped slits are arranged to surround the periphery of the specific region on the substrate body. A mounting substrate according to another aspect of the present disclosure comprises a substrate body and a liquid control unit. The substrate body has a plurality of electronic components mounted on it and includes a specific circuit region. The liquid control unit is provided on the substrate body. The liquid control unit controls the movement of the liquid toward the specific circuit region when the liquid flows along one end surface of the substrate body due to its own weight. The liquid control unit includes one or more recessed grooves in the one end surface of the substrate body. The one or more grooves include a U-shaped groove having a U-shaped opening when viewed from the front. The U-shaped groove is arranged to surround the periphery of the specific region on the substrate body. The liquid control unit includes one or more water-absorbing members having a water-absorbing function. A mounting substrate according to yet another aspect of the present disclosure comprises a substrate body and a liquid control unit. The substrate body has a plurality of electronic components mounted on it and includes a specific circuit region. The liquid control unit is provided on the substrate body. The liquid control unit controls the movement of the liquid toward the specific circuit region when the liquid is moving along one end surface of the substrate body due to its own weight. The liquid control unit includes one or more recessed grooves on the one end surface of the substrate body. The one or more grooves include a U-shaped groove having a U-shaped opening when viewed from the front. The U-shaped groove is arranged to surround the periphery of the specific region on the substrate body. The substrate body includes a first circuit region and a second circuit region. The first circuit region is a region with a higher potential than the second circuit region. The specific circuit region is either the first circuit region or the second circuit region. The liquid control unit controls the movement of the liquid so that the liquid bypasses the specific circuit region. A mounting substrate according to yet another aspect of the present disclosure comprises a substrate body and a liquid control unit. The substrate body has a plurality of electronic components mounted on it and includes a specific circuit region. The liquid control unit is provided on the substrate body. The liquid control unit controls the movement of the liquid toward the specific circuit region when the liquid flows along one end surface of the substrate body due to its own weight. The liquid control unit includes one or more recessed grooves on the one end surface of the substrate body. The one or more grooves include a U-shaped groove having a U-shaped opening when viewed from the front. The U-shaped groove is arranged to surround the periphery of the specific region on the substrate body. The specific electronic component among the plurality of electronic components includes a first terminal and a second terminal which is at a lower potential than the first terminal. The specific circuit region includes a first joint to which the first terminal is joined, or a second joint to which the second terminal is joined. At least a portion of the liquid control unit is located on the one end surface of the substrate body, between the first joint and the second joint.

[0007] A power supply device relating to one aspect of this disclosure is the above either The system includes a mounting board. The plurality of electronic components mounted on the board constitute a power supply circuit that generates power to supply to a load.

[0008] A lighting device according to one aspect of the present disclosure comprises the above-described power supply device, a light source unit, and a main body. The light source unit is the load, which is illuminated by power supplied from the power supply device. The main body houses or holds the power supply device and the light source unit. [Effects of the Invention]

[0009] According to this disclosure, there is an advantage in that electrical reliability can be improved with a simple configuration. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a perspective view of a lighting device (display device) according to one embodiment. [Figure 2] Figure 2 is an exploded perspective view of the same lighting device. [Figure 3] Figure 3 is an exploded perspective view of a power supply device according to one embodiment. [Figure 4] Figure 4 is a front view of a mounting substrate according to one embodiment. [Figure 5] Figure 5 is a cross-sectional view of the main part of the same mounting substrate. [Figure 6] Figure 6A is a cross-sectional view of a key part of a modified version of the same mounting substrate. Figure 6B is a cross-sectional view of a key part of another modified version of the same mounting substrate. [Modes for carrying out the invention]

[0011] A display device according to the embodiments of this disclosure will be described in detail with reference to the drawings. However, the figures described in the embodiments below are schematic diagrams, and the ratios of the size and thickness of each component do not necessarily reflect the actual dimensional ratios. The configurations described in the following embodiments are merely examples of this disclosure. This disclosure is not limited to the following embodiments, and various modifications are possible depending on the design, etc., as long as the effects of this disclosure can be achieved.

[0012] (1) Outline of the Embodiment As shown in Figures 3 and 4, the mounting substrate 6 according to this embodiment (hereinafter referred to as mounting substrate 6) comprises a substrate body 60 and a liquid control unit 7. In this embodiment, as an example, it is assumed that the liquid control unit 7 includes one or more (9 in Figure 4) slits 71 (through holes) provided in the substrate body 60.

[0013] A plurality of electronic components 61 are mounted on the substrate body 60. The substrate body 60 includes a specific circuit region R1. The "circuit region" referred to in the present disclosure is a region including a plurality of electronic components 61 that constitute a circuit (for example, the power supply circuit E1: see FIGS. 3 and 4), joints to which the terminals of each electronic component 61 are joined, and wiring patterns formed on the substrate body 60. The "joint" referred to in the present disclosure includes lands or pads and may include a part of the wiring pattern. The specific circuit region R1 is a part of the entire circuit region in the mounting substrate 6. The number of specific circuit regions R1 is one or more. In the example of FIG. 4, the number of specific circuit regions R1 is seven.

[0014] The liquid control unit 7 is provided on the substrate body 60. The liquid control unit 7 controls the movement of the liquid moving toward the specific circuit region R1 in a situation where the liquid travels on one end surface of the substrate body 60 by its own weight. The "one end surface of the substrate body 60" referred to in the present disclosure is one of the both end surfaces in the thickness direction of the substrate body 60, and is the first end surface 60A or the second end surface 60B (see FIG. 5) of the substrate body 60. Hereinafter, the first end surface 60A may be simply referred to as the "front surface", and the second end surface 60B may be simply referred to as the "back surface".

[0015] In the present embodiment, it is assumed that the specific circuit region R1 is a region of a lower potential or a higher potential than the adjacent surrounding regions. The specific circuit region R1 is not limited to a region on the front surface side or the back surface side of the substrate body 60. The specific circuit region R1 may correspond to a region on the front surface side, a region on the back surface side, or a region on both surfaces in the front view of the substrate body 60. The "region on both surfaces" is located within the same projection region in the front view of the substrate body 60. In particular, the liquid may travel on the front surface or on the back surface. Therefore, it is preferable that the specific circuit region R1 corresponds to the "region on both surfaces" of the substrate body 60.

[0016] As used in this disclosure, the term "liquid" is not particularly limited. In the environment where the mounting substrate 6 is actually used (e.g., an indoor environment), the "liquid" may correspond to condensed water. Also, when a tracking resistance test is performed on the mounting substrate 6, the "liquid" may correspond to a solution of ammonium chloride used in the test.

[0017] When a liquid (such as condensed water) moves to a specific circuit region R1, abnormalities such as a short circuit may occur. In particular, when the liquid moves to a specific circuit region R1 that is at a lower potential (or higher potential) than the surroundings, it may cause abnormalities such as heat generation due to a short circuit. In contrast, in the mounting substrate 6, the movement of the liquid is controlled by the liquid control unit 7. Therefore, the mounting substrate 6 has the advantage that the electrical reliability can be improved with a simple configuration.

[0018] Also, as shown in FIG. 3, the power supply device 11 according to the embodiment (hereinafter abbreviated as the power supply device 11) includes a mounting substrate 6. A plurality of electronic components 61 mounted on the substrate body 60 constitute a power supply circuit E1 (see FIGS. 3 and 4) that generates electric power for supplying to the load L1 (see FIGS. 1 and 2). According to this configuration, a power supply device 11 with a simple configuration and improved electrical reliability can be provided.

[0019] In this disclosure, as an example, it is assumed that the load L1 is the light source unit A1 (see FIGS. 1 and 2). However, the type of the load L1 is not limited to the light source unit A1 (light source), and may be, for example, an electric motor.

[0020] Also, as shown in FIG. 2, the lighting device X1 according to the embodiment includes a power supply device 11, a light source unit A1, and a main body 1. The light source unit A1 is the load L1, and is lit by being supplied with electric power from the power supply device 11. The main body 1 houses or holds the power supply device 11 and the light source unit A1. According to this configuration, a lighting device X1 with a simple configuration and improved electrical reliability can be provided.

[0021] The type and usage of the lighting device X1 are not particularly limited. However, considering the improvement in electrical reliability obtained by the liquid control unit 7, it is preferable that the lighting device X1 is a lighting device that can be installed on the ceiling or wall of a facility, etc., with the thickness direction of the mounting substrate 6 facing horizontally. For example, it is preferable that the lighting device X1 is an emergency light or exit sign. Of course, even if the thickness direction of the mounting substrate 6 faces vertically, a considerable improvement in electrical reliability by the liquid control unit 7 can be expected. In the following description, it is assumed that the lighting device X1 is an emergency light (display device B1).

[0022] (2) Details of the embodiment (2-1) Configuration of the lighting device according to the embodiment The lighting device X1 (display device B1) will be described with reference to the drawings. The lighting device X1 described below is an emergency exit sign installed in an emergency exit or passageway to an emergency exit in a facility (a building such as an office or shop). As mentioned above, the lighting device X1 is not limited to an emergency exit sign. For example, the lighting device X1 may be used to indicate a specific location within a facility (such as a restroom). In the following description, unless otherwise specified, the up and down, front and back, and left and right directions indicated by arrows in Figure 1 are defined as the up and down, front and back, and left and right directions of the lighting device X1.

[0023] The lighting device X1 includes a light source unit A1 (load L1), a main body 1, a display block 2, a mounting plate 10, a power supply unit 11, a terminal block 12, a battery unit 13, and a connector 14, etc. (see Figures 1 and 2).

[0024] The main body 1 is formed from a synthetic resin material into a rectangular box shape with an opening on the front (see Figure 2). The main body 1 has a pair of left and right side walls 101. Each side wall 101 is formed into a rectangular plate shape. Each pair of side walls 101 has a wall surface 102 (inner wall surface). The wall surfaces 102 of the pair of side walls 101 face each other.

[0025] Multiple holding parts H1 are provided on the wall surfaces 102 of the pair of side walls 101. By sliding the display block 2 downward along the wall surfaces 102, the multiple holding parts H1 hold the display block 2 in a manner that restricts its movement along the thickness direction and further downward movement. In short, the main body 1 holds the display block 2.

[0026] As shown in Figure 2, the main unit 1 houses the power supply unit 11, battery unit 13, terminal block 12, connector 14, mounting plate 10, etc.

[0027] The mounting plate 10 is formed in a plate shape from a metal material (see Figure 2). The mounting plate 10 is screwed to the inner bottom surface of the main body 1. The power supply unit 11 and the terminal block 12 are screwed to the mounting plate 10 and housed inside the main body 1.

[0028] The battery unit 13 has a rechargeable battery. The battery unit 13 is detachably attached to the mounting plate 10.

[0029] The power supply unit 11 is configured to light up the light source unit A1 (load L1). The power supply unit 11 includes a mounting board 6 and a housing case 110.

[0030] As shown in Figures 3 and 4, the mounting board 6 comprises a board body 60 and a liquid control unit 7. The board body 60 is a printed circuit board in which conductive wiring (wiring patterns) are formed on the surface, back surface, and interior of a plate-shaped insulator. The type of board body 60 is not particularly limited. The board body 60 may be a single-sided board with wiring patterns formed on only one side, a double-sided board with wiring patterns formed on both sides, or a multilayer board consisting of multiple layers.

[0031] The substrate body 60 includes a first end face 60A (see Figures 3 to 5) and a second end face 60B (see Figure 5). Figure 5 is a schematic cross-sectional view of the main part along line AA in Figure 4. The first end face 60A (front surface) is the front surface in the illustrated example. The second end face 60B (back surface) is the rear surface in the illustrated example.

[0032] Multiple electronic components 61 include, for example, leaded components and chip components. Multiple electronic components 61 are mounted on the main board 60. Many electronic components 61 (especially high-profile components) are mounted on the first end face 60A, and some electronic components 61 (especially low-profile components) are mounted on the second end face 60B. Multiple electronic components 61 mounted on the main board 60 constitute a power supply circuit E1 that generates power to supply to the load L1.

[0033] The power supply circuit E1 is configured to light the light source unit A1 with normal power supplied from a regular power source (e.g., the commercial power grid) and to charge the battery unit 13. In the event of a power outage in the power grid, the power supply circuit E1 is configured to light the light source unit A1 with emergency power supplied (discharged) from the battery unit 13.

[0034] As shown in Figure 3, the housing case 110 has a cover 111 and a case 112. The cover 111 is formed in the shape of a rectangular box with an open rear. The case 112 is formed in the shape of a flat rectangular box with an open front. The housing case 110 houses the mounting substrate 6 inside.

[0035] A power supply side connector section 62 (see Figure 4) is provided at the upper left end of the first end face 60A. The power supply side connector section 62 is exposed from the housing case 110, and the terminals of the terminal block 12 are physically and electrically coupled to the power supply side connector section 62, enabling the power supply circuit E1 to receive AC power from the normal power supply.

[0036] Furthermore, a connection terminal 63 (see Figure 4) is provided at the lower left end of the first end face 60A. The connection terminal 63 is exposed from the housing case 110, and the terminals of the battery unit 13 are physically and electrically coupled to the connection terminal 63, enabling the power supply circuit E1 to receive power from the battery unit 13 and to charge the battery unit 13.

[0037] Furthermore, a light source side connector section 64 (see Figure 4) is provided at the upper right end of the first end face 60A. The light source side connector section 64 is exposed from the housing case 110. The connector of the wire connected to the connector 14 is physically and electrically coupled to the light source side connector section 64, enabling the power supply circuit E1 to supply power for lighting to the light source unit A1 via the connector 14.

[0038] The liquid control unit 7 is located on the substrate body 60. The liquid control unit 7 controls the movement of the liquid toward a specific circuit region R1 when the liquid is flowing along one end surface (first end surface 60A or second end surface 60B) of the substrate body 60 due to its own weight. Details of the liquid control unit 7 will be described later.

[0039] The display panel 20 is illuminated by light emitted from a light source. The display block 2 includes the display panel 20, a light guide plate 21, and a holder 22 (see Figure 2).

[0040] The display panel 20 is illuminated by light emitted from an LED (Light Emitting Diode) 300 (see Figure 2), which is a light source. The display panel 20 is formed in the shape of a rectangular flat plate from a translucent synthetic resin material such as acrylic resin or polycarbonate resin. However, the display panel 20 may be formed from a translucent material other than synthetic resin, such as quartz glass. A pictogram 201 for evacuation guidance is displayed on the front surface (display surface 200) of the display panel 20 (see Figure 1).

[0041] The light guide plate 21 is formed in the shape of a rectangular flat plate from a light-transmitting synthetic resin material such as acrylic resin or polycarbonate resin. The light guide plate 21 is positioned behind the display panel 20 so that its front surface faces the rear surface of the display panel 20 (see Figure 2). Light emitted from the light source unit A1 is incident on the upper surface (incident surface 210) of the light guide plate 21. The light incident on the incident surface 210 is guided through the light guide plate 21 and emitted from the front surface (exit surface) of the light guide plate 21. The display panel 20 is then illuminated by the light emitted from the exit surface of the light guide plate 21.

[0042] The holder 22 is formed from a non-transparent synthetic resin material and is a rectangular box shape with an open front and top. The holder 22 holds the display panel 20 and the light guide plate 21 so that the display panel 20 is positioned in front of the light guide plate 21 (see Figure 2).

[0043] Furthermore, the retainer 22 has a plurality of plate-shaped sliding pieces Y1 protruding from its back surface. Each sliding piece Y1 is hook-shaped, allowing the corresponding retainer H1 to be slid into it from below.

[0044] The display block 2 is held in place by the main body 1 when multiple slide pieces Y1 are inserted into and hooked into multiple holding parts H1.

[0045] The display block 2 is attached to the main body 1 so as to cover the remaining portion of the opening in the main body 1, excluding the upper part where the light source unit A1 is mounted (see Figure 1). With the light source unit A1 attached to the main body 1, the incident surface 210 of the light guide plate 21 and the exit surface (bottom surface) of the light guide body 5 of the light source unit A1 (see Figure 2) face each other in the vertical direction. Therefore, almost all of the light emitted from the exit surface of the light guide body 5 enters the light guide plate 21 from the incident surface 210. The light that enters the light guide plate 21 travels through the light guide plate 21, undergoes total internal reflection at the rear surface of the holder 22, and exits forward from the exit surface of the light guide plate 21 to illuminate the display panel 20.

[0046] The light source unit A1 includes a light-emitting section, a light guide 5, and a housing 4 (see Figure 2).

[0047] The light-emitting section comprises an LED 300 (light source), which is a solid-state light source, and a substrate on which the LED 300 is mounted. The LED 300 is, for example, a package-type white LED for lighting. The substrate is a printed circuit board formed in a roughly T-shape when viewed from the left and right directions. The LED 300 is mounted on the surface of the wider portion of the substrate. A pair of electrodes is formed on the surface of the narrower portion of the substrate. The pair of electrodes are electrically connected one by one to the anode and cathode of the LED 300 via the printed circuit of the substrate. The light-emitting section is electrically connected to the power supply unit 11 by inserting the narrow portion of the substrate into the connector 14 inside the main body 1. Preferably, the light source unit A1 further includes a heat dissipation member that is thermally coupled to the substrate to dissipate heat from the LED 300, etc.

[0048] The light guide 5 is formed in a quadrangular prism shape from a translucent synthetic resin material such as acrylic resin or polycarbonate resin (see Figure 2). However, the shape of the light guide 5 is not limited to a quadrangular prism, and may be a quadrangular pyramidal shape or a quadrangular pyramidal truncated shape, etc.

[0049] Of the two bottom surfaces (left bottom surface and right bottom surface) of the light guide 5 that are opposite each other in the longitudinal direction (axial direction), one bottom surface (right bottom surface) becomes the incident surface. Also, of the four sides (front, rear, top, and bottom surfaces) of the light guide 5, one side surface (bottom surface) becomes the exit surface. Furthermore, the side surface (top surface) of the light guide 5 that is opposite the exit surface is provided with numerous grooves.

[0050] The housing 4 is formed in a box shape that is elongated in the left-right direction, with its rear and bottom surfaces open. As shown in Figure 2, the housing 4 has a pair of mounting pieces 46 and a pair of support pieces 47.

[0051] A pair of support pieces 47 protrude one to the rear from each of the left and right ends of the upper wall of the housing 4. A pair of mounting pieces 46 also protrude one to the rear from each of the left and right ends of the upper wall of the housing 4. The light source unit A1 is held in place by the pair of support pieces 47 and the way the pair of support pieces 47 are locked to predetermined locations on the main body 1.

[0052] The housing 4 houses the light-emitting unit at its rightmost end and the light guide 5 to its left. Specifically, the housing 4 houses the light guide 5 with its incident surface facing the LED 300 of the light-emitting unit, and with its exit surface exposed from below.

[0053] The installation procedure for display device B1 is briefly described below.

[0054] First, the worker performing the installation pulls the power wire through the power hole 15 (see Figure 2) located on the bottom of the main unit 1, and then attaches the main unit 1 to the structure of the facility (for example, the wall of a building) using wood screws or nails. Next, the worker electrically connects the power wire pulled through the power hole 15 to the terminal block 12.

[0055] Next, the worker attaches the display block 2 to the main body 1. Specifically, the worker brings the back surface of the display block 2 into contact with the front surface of the main body 1, so that the upper end of the display block 2 is at the same position as (or slightly below) the upper end of the main body 1, which is attached to the structure (wall) of the facility. Then, the worker slides the display block 2 downward along the pair of wall surfaces 102, so that the corresponding retaining parts H1 slide into the inside of each sliding piece Y1 of the display block 2. As a result, multiple sliding pieces Y1 slide into multiple retaining parts H1, and the display block 2 is held in place.

[0056] Finally, the worker attaches the light source unit A1 to the main body 1. Specifically, the worker inserts the narrow portion of the circuit board on which the LED 300 is mounted into the connector 14 of the main body 1, inserts the pair of support pieces 47 into the inside of the main body 1, and hooks the claws provided at the tips of the pair of mounting pieces 46 onto the edges of the holes provided on the top surface of the main body 1. As a result, the light source unit A1 is attached to the main body 1 in a manner that it is positioned on top of the display block 2.

[0057] With the above steps completed, the installation of the display device B1 is finished.

[0058] If it is necessary to replace the battery unit 13, first remove the light source unit A1 from the main unit 1, then slide the display block 2 upwards and then move it forward to remove the display block 2 from the main unit 1.

[0059] (2-2) Liquid Control Unit The liquid control unit 7 controls the movement of the liquid toward a specific circuit region R1 when the liquid is flowing along the first end face 60A or the second end face 60B of the substrate body 60 due to its own weight. In this embodiment, "controlling the movement of the liquid" is assumed to mean, for example, changing the direction of the liquid's movement to a predetermined direction, but is not limited to changing the direction of movement. "Controlling the movement of the liquid" may also mean reducing the amount of liquid moving or stopping the movement of the liquid.

[0060] The liquid control unit 7 includes one or more slits 71 (see Figure 4) that penetrate the substrate body 60 in the thickness direction. In the example shown in Figure 4, nine slits 71 are provided.

[0061] The liquid control unit 7 is provided such that at least a portion of it overlaps with the projection area of ​​one or more electronic components 61 on one end face of the substrate body 60. Specifically, a portion or all of the area of ​​one of the nine slits 71 overlaps with the projection area of ​​one or more electronic components 61. Among the nine slits 71, there may be some slits 71 that do not overlap with the projection area of ​​any electronic component 61 at all.

[0062] In Figure 4, for ease of understanding, the area of ​​the slit 71 that is directly visible from the front of the first end face 60A is shown with a dark dot hatch, and the area that is hidden by the electronic component 61 and not directly visible is shown with a light dot hatch. In other words, the area of ​​the slit 71 shown with a light dot hatch is the area that overlaps with the projected area of ​​one or more corresponding electronic components 61.

[0063] The substrate body 60 includes one or more specific circuit regions R1 (see Figure 4). In the illustrated example, there are seven specific circuit regions R1 (referred to as the 1st to 7th specific regions R11 to R17). In Figure 4, the 1st to 7th specific regions R11 to R17 are shown enclosed in roughly rectangular frames when the substrate body 60 is viewed from the front. These roughly rectangular frames are illustrated to make it easy to intuitively understand the position of each specific circuit region R1, and are not intended to show the exact range of each specific circuit region R1. In this embodiment, nine slits 71 are arranged to correspond to the 1st to 7th specific regions R11 to R17.

[0064] A specific circuit region R1 is a region where it is undesirable for liquid to enter from the surrounding region. For example, if the surrounding region is a high-potential circuit region and the specific circuit region R1 is a low-potential circuit region, then if liquid enters the low-potential circuit region (specific circuit region R1) from the high-potential circuit region, it may cause a short circuit and lead to abnormalities such as overheating. Similarly, even if the surrounding region is a low-potential circuit region and the specific circuit region R1 is a high-potential circuit region, if liquid enters the high-potential circuit region (specific circuit region R1) from the low-potential circuit region, it may cause a short circuit and lead to abnormalities such as overheating. Conversely, even if liquid moves within a low-potential circuit region and causes a short circuit, while it may cause the circuit to malfunction, it is unlikely to lead to abnormalities such as overheating. Therefore, assuming a situation where liquid flows along one end surface of the substrate body 60 due to its own weight, the location and range where a short circuit is likely to cause abnormalities such as overheating are identified, and the location and range of the specific circuit region R1 on the substrate body 60 are set.

[0065] The vertical orientation of the circuit board body 60 shown in Figure 4 is the same as the vertical orientation when the lighting device X1 (display device B1) is actually installed in the facility.

[0066] Before further detailing the liquid control unit 7, we will now describe the power supply circuit E1, which is composed of multiple electronic components 61 mounted on the main board 60. The circuit configuration of the power supply circuit E1 is a conventionally known configuration, and therefore, a detailed explanation of the circuit configuration and operation will be omitted.

[0067] <Power supply circuit configuration> The power supply circuit E1 includes a protection circuit, a filter circuit, a rectifier circuit, a smoothing capacitor C2 (electrolytic capacitor: see Figure 4), a normal lighting circuit, an emergency lighting circuit, a charging circuit, a control circuit, and a power outage detection unit, etc.

[0068] The protection circuit is located in the circuit between the power supply connector 62 and the filter circuit, and includes a Zener diode ZD1 (surge absorption element: see Figure 4) as one of the electronic components 61.

[0069] The filter circuit is configured to remove harmonic noise from AC voltage and AC current supplied from a normal power source (e.g., a commercial power grid). The filter circuit includes a first filter LF1 (common mode choke coil), a capacitor C1, and a second filter LF2 (common mode choke coil), etc. (see Figure 4).

[0070] The rectifier circuit is placed after the filter circuit. The rectifier circuit consists of a diode bridge DB1 (see Figure 4) and full-wave rectifies the AC voltage input from the power supply (for example, a sinusoidal voltage with a frequency of 50Hz or 60Hz and an effective value of 100V). The smoothing capacitor C2 smooths the pulsating voltage output from the rectifier circuit.

[0071] The normal operation circuit is a power supply circuit that supplies power to the light source (LED300) during normal operation when the normal power supply is not experiencing a power outage. The normal operation circuit includes, for example, a switching power supply circuit, a so-called isolated flyback converter, which includes a transformer T1 (see Figure 4), a switching element, a diode, and a smoothing capacitor, and a converter control circuit that controls the switching of the switching element. The DC voltage smoothed by the smoothing capacitor C2 is input to the normal operation circuit. The normal operation circuit feedback-controls the switching element to match the current flowing through the light source (LED300) to a target value (for example, pulse width modulation control).

[0072] The charging circuit includes, for example, a switching power supply circuit, a so-called isolated flyback converter, which includes a transformer T1, a switching element, a diode, and a smoothing capacitor. However, the charging circuit shares part of the transformer T1 and the switching element with the normal lighting circuit. The charging circuit also includes a constant current circuit. The constant current circuit supplies a constant charging current to the battery unit 13. The battery unit 13 is charged by the charging current supplied from the constant current circuit during normal operation when the normal power supply is not experiencing a power outage.

[0073] The emergency lighting circuit is configured to light the LED 300 with power supplied from the battery unit 13 in the event of a power outage (emergency) of the normal power supply. The emergency lighting circuit includes, for example, a flyback converter equipped with a transformer and a switching element, and a converter control circuit that controls the switching of the switching element, and outputs the DC voltage supplied from the battery unit 13 after boosting or stepping it down. However, the emergency lighting circuit may also include a forward converter instead of a flyback converter.

[0074] The control circuit has a microcontroller. Based on a detection signal received from the power failure detection unit, the control circuit determines whether or not the normal power supply is experiencing a power failure. The power failure detection unit includes, for example, a Zener diode and a resistor. The power failure detection unit is electrically connected to the output terminal of the charging circuit. If the signal level of the detection signal is, for example, high, the control circuit determines that the normal power supply is not experiencing a power failure and operates in the normal operating mode. On the other hand, if the signal level of the detection signal is, for example, low, the control circuit determines that the normal power supply is experiencing a power failure and operates in the emergency operating mode.

[0075] In the normal operating mode, the control circuit operates the normal lighting circuit and the charging circuit, while keeping the emergency lighting circuit in a deactivated state. As a result, the LED 300 lights up (normal lighting) via the normal lighting circuit, and the battery unit 13 is charged via the charging circuit.

[0076] Furthermore, the control circuit activates the emergency lighting circuit in the emergency operation mode. The normal lighting circuit and charging circuit will shut down when power is cut off from the normal power supply. However, the LED300 will light up (emergency lighting) due to the emergency lighting circuit.

[0077] <Overall liquid control unit layout> The power supply connector 62 (one of the electronic components 61) to which AC power is input from the normal power supply is located at the upper left end of the mounting board 6. Therefore, the multiple electronic components 61 that constitute the protection circuit, filter circuit, and rectifier circuit of the power supply circuit E1 are located in approximately the upper half of the board body 60 in the vertical direction. The transformer T1 of the normal lighting circuit is located approximately in the center of the mounting board 6. As a result, the first to seventh specific regions R11 to R17 are also concentrated to some extent in the upper half (especially towards the left) of the board body 60 in the vertical direction.

[0078] Furthermore, the connection terminal 63 (one of the electronic components 61) to which the terminals of the battery unit 13 are connected is located at the lower left end of the mounting board 6. Therefore, the multiple electronic components 61 constituting the charging circuit described above are located in approximately the lower half of the board body 60 in the vertical direction. In addition, the multiple electronic components 61 constituting the control circuit and the emergency lighting circuit are located near the right end of the board body 60. The light source side connector section 64 (one of the electronic components 61) to which the connector of the wires connected to the connector 14 is connected is located at the upper right end of the mounting board 6.

[0079] The charging circuit, control circuit, emergency lighting circuit, and normal lighting circuit (excluding the primary side of transformer T1) may have relatively lower voltages applied to them compared to the protection circuit, filter circuit, rectifier circuit, and the primary side of transformer T1. Hereinafter, the circuit region including the protection circuit, filter circuit, rectifier circuit, and the primary side of transformer T1 will be referred to as the "high-voltage region." Conversely, the circuit region including the charging circuit, control circuit, emergency lighting circuit, and normal lighting circuit (excluding the primary side of transformer T1) will be referred to as the "low-voltage region."

[0080] Furthermore, the first to seventh specific regions R11 to R17 are concentrated within the high-voltage region, and the liquid control unit 7 (9 slits 71) is provided accordingly. As a result, firstly, the possibility of a short circuit occurring due to liquid flowing from the high-voltage region to the low-voltage region or from the low-voltage region to the high-voltage region is reduced throughout the entire surface of the mounting substrate 6. As described above, the vertical orientation of the substrate body 60 shown in Figure 4 is the same as the vertical orientation when the lighting device X1 is actually installed in the facility, with the high-voltage region located in approximately the upper half. Therefore, by providing the liquid control unit 7, the possibility of a short circuit occurring due to liquid flowing from the high-voltage region to the low-voltage region mainly due to its own weight is reduced.

[0081] <Arrangement configuration of individual liquid control units> Next, we will explain each of the nine slits 71 (hereinafter sometimes referred to as the first to ninth slits 711 to 719).

[0082] The first specific region R11 is a region that includes the terminal on the low-potential side of the Zener diode ZD1 and the junction to which the terminal is joined. The first slit 711 is a hole with an elongated opening in the left-right direction and is located between the first circuit region on the high-potential side and the second circuit region (first specific region R11) on the low-potential side of the Zener diode ZD1. The first and second circuit regions of the Zener diode ZD1 are aligned vertically.

[0083] In other words, a specific electronic component 61 (Zener diode ZD1) among the multiple electronic components 61 includes a first terminal (on the high-potential side) and a second terminal that is on the lower potential side than the first terminal. A specific circuit region R1 (first specific region R11) includes a second junction (land) to which the second terminal is joined. At least a part of the liquid control unit 7 (first slit 711) is positioned on one end face of the substrate body 60 between the first junction (land) to which the first terminal of the specific electronic component 61 is joined and the second junction.

[0084] The Zener diode ZD1 is, for example, a leaded component, and the junctions (first and second junctions) to which its lead terminals are joined are located on the second end face 60B (back side) of the main board 60.

[0085] The first slit 711 controls the movement of the liquid so that it bypasses the second circuit region (first specific region R11) on the lower potential side of the Zener diode ZD1. In short, the substrate body 60 includes a first circuit region and a second circuit region in the circuit region including the Zener diode ZD1. The first circuit region is a region with a higher potential than the second circuit region. The specific circuit region R1 is the second circuit region. The liquid control unit 7 controls the movement of the liquid so that it bypasses the specific circuit region R1 (first specific region R11). As a result, the occurrence of short circuits caused by the movement of liquid from the first circuit region to the second circuit region in the circuit region including the Zener diode ZD1 is reduced.

[0086] The second specific region R12 is the region including the low-potential terminal of the capacitor C1 of the filter circuit and the junction to which the terminal is joined. The second slit 712 is a hole with an elongated opening in the left-right direction and is located between the first circuit region on the high-potential side and the second circuit region (second specific region R12) on the low-potential side of the capacitor C1. The first and second circuit regions of the capacitor C1 are aligned vertically.

[0087] In other words, a specific electronic component 61 (capacitor C1) among the multiple electronic components 61 includes a first terminal (on the high-potential side) and a second terminal that is on the lower potential side than the first terminal. A specific circuit region R1 (second specific region R12) includes a second junction (land) to which the second terminal is joined. At least a part of the liquid control unit 7 (second slit 712) is positioned on one end face of the substrate body 60 between the first junction (land) to which the first terminal of the specific electronic component 61 is joined and the second junction.

[0088] Capacitor C1 is, for example, a leaded component, and the joints (first and second joints) to which its lead terminals are joined are located on the second end face 60B (back side) of the main board body 60.

[0089] The second slit 712 controls the movement of the liquid so that it bypasses the second circuit region (second specific region R12) on the lower potential side of the capacitor C1. In short, the substrate body 60 includes a first circuit region and a second circuit region in the circuit region including the capacitor C1. The first circuit region is a region with a higher potential than the second circuit region. The specific circuit region R1 is the second circuit region. The liquid control unit 7 controls the movement of the liquid so that it bypasses the specific circuit region R1 (second specific region R12). As a result, the occurrence of short circuits caused by the movement of liquid from the first circuit region to the second circuit region in the circuit region including the capacitor C1 is reduced.

[0090] The third specific region R13 includes the output terminal of the secondary side (low potential side) winding of the second filter LF2 of the filter circuit, and the junction to which said output terminal is joined. Furthermore, the third specific region R13 also includes the low potential side input terminal of the diode bridge DB1, and the junction to which said input terminal is joined.

[0091] The third slit 713 is a hole with an elongated opening in the left-right direction, and is located between the first circuit region on the high-potential side, which includes the output terminal of the primary winding, and the second circuit region (third specific region R13) on the low-potential side, which includes the output terminal of the secondary winding, of the second filter LF2. The first and second circuit regions of the second filter LF2 are aligned vertically.

[0092] Furthermore, the third slit 713 is also located between the first circuit region of the diode bridge DB1, which includes the high-potential input terminal, and the second circuit region (third specific region R13), which includes the low-potential input terminal. The first and second circuit regions (on the input side) of the diode bridge DB1 are aligned vertically.

[0093] In other words, a specific electronic component 61 (second filter LF2, diode bridge DB1) among the multiple electronic components 61 includes a first terminal (on the high-potential side) and a second terminal that is on the lower potential side than the first terminal. A specific circuit region R1 (third specific region R13) includes a second junction (land, pad) to which the second terminal is joined. At least a part of the liquid control unit 7 (third slit 713) is positioned on one end face of the substrate body 60 between the first junction (land, pad) to which the first terminal of the specific electronic component 61 is joined and the second junction.

[0094] The second filter LF2 is, for example, a lead-type component, and the joints (first and second joints) to which its lead terminals are joined are located on the second end face 60B (back side) of the substrate body 60. On the other hand, the diode bridge DB1 is, for example, a chip-type component, and is surface-mounted on the second end face 60B (back side) of the substrate body 60. That is, the joints (first and second joints) to which the terminals of the diode bridge DB1 are joined are provided on the second end face 60B (back side).

[0095] The third slit 713 controls the movement of the liquid so that it bypasses the second circuit region (third specific region R13) on the lower potential side of the second filter LF2 and diode bridge DB1. In short, the substrate body 60 includes a first circuit region and a second circuit region in the circuit region including the second filter LF2 and diode bridge DB1. The first circuit region is a region with a higher potential than the second circuit region. Specific circuit region R1 is the second circuit region. The liquid control unit 7 controls the movement of the liquid so that it bypasses specific circuit region R1 (third specific region R13). As a result, the occurrence of short circuits caused by the movement of liquid from the first circuit region to the second circuit region in the circuit region including the second filter LF2 and diode bridge DB1 is reduced.

[0096] The fourth specific region R14 is a region that includes the low-potential output terminal of the diode bridge DB1 and the junction to which the output terminal is joined. The fourth slit 714 is a hole with an elongated opening in the left-right direction and is located between the first circuit region of the diode bridge DB1, which includes the high-potential output terminal, and the second circuit region (fourth specific region R14), which includes the low-potential output terminal. The first and second circuit regions (on the output side) of the diode bridge DB1 are aligned vertically.

[0097] In other words, a specific electronic component 61 (diode bridge DB1) among the multiple electronic components 61 includes a first terminal (on the high-potential side) and a second terminal that is on the lower potential side than the first terminal. A specific circuit region R1 (fourth specific region R14) includes a second junction (pad) to which the second terminal is joined. At least a part of the liquid control unit 7 (fourth slit 714) is positioned on one end face of the substrate body 60 between the first junction (pad) to which the first terminal of the specific electronic component 61 is joined and the second junction.

[0098] The fourth slit 714 controls the movement of the liquid so that it bypasses the second circuit region (fourth specific region R14) on the lower potential side of the diode bridge DB1. In short, the substrate body 60 includes a first circuit region and a second circuit region in the circuit region including the diode bridge DB1. The first circuit region is a region with a higher potential than the second circuit region. Specific circuit region R1 is the second circuit region. The liquid control unit 7 controls the movement of the liquid so that it bypasses specific circuit region R1 (fourth specific region R14). As a result, the occurrence of short circuits due to the movement of liquid from the first circuit region to the second circuit region in the circuit region including the diode bridge DB1 is reduced.

[0099] The fifth specific region R15 is the region for the smoothing capacitor C2. As shown in Figure 5, the smoothing capacitor C2 is, for example, a leaded component and has a first terminal 611 (lead terminal) and a second terminal 612 (lead terminal). The first terminal 611 is the high-potential terminal and is connected to the first junction P1 (land) (see Figure 5). The second terminal 612 is the low-potential terminal and is connected to the second junction P2 (land) (see Figure 5).

[0100] The fifth specific region R15 is a region that includes the first terminal 611 on the high-potential side of the smoothing capacitor C2 and the first junction P1 to which the first terminal 611 is joined. The fifth slit 715 is a hole with a roughly U-shaped opening that is open on the left side when viewed from the front. The fifth slit 715 is arranged to surround the fifth specific region R15. The fifth slit 715 includes an upper hole portion 715A and a lower hole portion 715B (see Figure 5) that extend in the left-right direction, and a connecting hole portion that extends in the up-down direction to connect the upper hole portion 715A and the lower hole portion 715B. The upper hole portion 715A, the lower hole portion 715B and the connecting hole portion are in communication and constitute a single hole (slit). As a result, a portion of the fifth slit 715 (the lower hole portion 715B) is positioned between the first circuit region (fifth specific region R15) of the smoothing capacitor C2, which includes the first terminal 611 on the high-potential side, and the second circuit region, which includes the second terminal 612 on the low-potential side.

[0101] In other words, a specific electronic component 61 (smoothing capacitor C2) among the multiple electronic components 61 includes a first terminal 611 (on the high-potential side) and a second terminal 612 that is on the lower potential side than the first terminal 611. A specific circuit region R1 (fifth specific region R15) includes a first junction P1 to which the first terminal 611 is joined. At least a part of the liquid control unit 7 (the pilot hole 715B of the fifth slit 715) is positioned on one end face of the substrate body 60 between the first junction P1 and the second junction P2 of the specific electronic component 61.

[0102] The fifth slit 715 controls the movement of the liquid so that it bypasses the first circuit region (fifth specific region R15) on the high-potential side of the smoothing capacitor C2. In short, the substrate body 60 includes a first circuit region and a second circuit region in the circuit region including the smoothing capacitor C2. The first circuit region is a region with a higher potential than the second circuit region. Specific circuit region R1 is the first circuit region. The liquid control unit 7 controls the movement of the liquid so that it bypasses specific circuit region R1 (fifth specific region R15). As a result, the occurrence of short circuits due to the movement of liquid from the first circuit region to the second circuit region in the circuit region including the smoothing capacitor C2 is reduced.

[0103] In particular, the fifth slit 715 is formed to surround the first circuit region of the smoothing capacitor C2. Therefore, it is possible to suppress not only the movement of liquid from the first circuit region to the second circuit region of the smoothing capacitor C2, but also the movement of liquid from the fourth specific region R14 above the smoothing capacitor C2 to the first circuit region of the smoothing capacitor C2.

[0104] The sixth specific region R16 and the seventh specific region R17 are regions that include the terminals of multiple windings on the secondary side (low potential side) of the transformer T1, which is shared by the normal lighting circuit and the charging circuit, and the joints to which these terminals are joined. The seventh to ninth slits 717 to 719 are holes with elongated openings in the vertical direction. The sixth slit 716 is also a hole with an elongated opening in the vertical direction, however, its opening extends with an inclination relative to the vertical direction midway, and is formed in a roughly crank shape overall.

[0105] The 6th to 9th slits 716 to 719 are arranged to surround the terminals of multiple windings on the primary side (high potential side) of the transformer T1, and the joints to which these terminals are connected.

[0106] Specifically, the sixth slit 716 and the eighth slit 718 are located on either side of the multiple primary windings in transformer T1, respectively. The ninth slit 719 is located between the multiple primary windings in transformer T1. The seventh slit 717 is located directly above the ninth slit 719.

[0107] The provision of the 6th to 9th slits 716 to 719 allows the movement of liquid (e.g., condensation) as it flows downwards along the substrate 6 due to its own weight to be controlled by one of the 6th to 9th slits 716 to 719. This reduces the possibility of a short circuit occurring due to the liquid moving from the first circuit region on the high-potential side of the transformer T1 to the second circuit region on the low-potential side (specific region 6 R16 or specific region 7 R17).

[0108] Incidentally, increasing the length, width, and number of slits 71 improves the short-circuit suppression effect, but it may also reduce the strength of the mounting substrate 6. Therefore, in the mounting substrate 6 of this embodiment, the length, width, and number of slits 71 are kept to a certain extent while still suppressing short circuits. In particular, if slits 71 that extend long in the left-right direction, wide slits 71, or the number of slits 71 are increased to match the size of the relatively large transformer T1 located approximately in the center of the mounting substrate 6, there is a high possibility that the overall strength of the mounting substrate 6 will decrease. The length, width, and number of the 6th to 9th slits 716 to 719 are set to be kept to a minimum while considering the overall strength of the mounting substrate 6.

[0109] The dashed arrow LQ1 shown in Figure 4 illustrates an example of the expected flow path of liquid (e.g., condensed water) as it flows down the mounting substrate 6 from its upper end to its lower end (either on the first end face 60A or the second end face 60B) due to its own weight. From this arrow LQ1, it is easy to understand that the movement of the liquid is controlled by the fourth slit 714 and the fifth slit 715. In other words, the liquid is attracted to the periphery of the openings in the fourth slit 714 and the fifth slit 715 by surface tension and falls along that periphery. As a result, the liquid falls in a manner that bypasses the fourth specific region R14 and the fifth specific region R15 located directly below the fourth slit 714 and the fifth slit 715. Therefore, the occurrence of short circuits can be suppressed.

[0110] (3) Advantages of the mounting board according to the embodiment When the lighting device X1 is installed in a facility, for example, as indoor lighting, condensation may occur inside the lighting device X1. As a result, the condensed water may travel along one end surface (first end surface 60A or second end surface 60B) of the substrate body 60 due to its own weight. As described above, in this embodiment, since the liquid control unit 7 is provided on the substrate body 60, the movement (for example, direction of travel) of liquid such as condensed water is controlled by the liquid control unit 7. In particular, the possibility of a short circuit occurring due to the movement of liquid such as condensed water to a specific circuit region R1 is reduced. Consequently, the mounting substrate 6 of this embodiment has the advantage of improving electrical reliability with a simple configuration. In other words, it also improves tracking resistance.

[0111] Furthermore, compared to the circuit board described in Patent Document 1, the mounted board 6 can reduce costs while improving tracking resistance (electrical reliability). Also, compared to the circuit board described in Patent Document 1, the mounted board 6 can suppress abnormalities such as heat generation in the entire circuit area, including wiring patterns.

[0112] Furthermore, in this embodiment, the movement of the liquid is controlled by providing one or more (nine in the illustrated example) slits 71 as the liquid control unit 7, thus improving electrical reliability with a simpler configuration. In particular, since the slits 71 penetrate the substrate body 60 in the thickness direction, a single slit 71 can reduce the occurrence of short circuits for liquids flowing on either the first end face 60A or the second end face 60B.

[0113] Furthermore, at least a portion of each of the first to fifth slits 711 to 715 is positioned between the first and second junctions (first junction P1 and second junction P2 in Figure 5) relating to the corresponding electronic component 61 in a plan view of the substrate body 60. Therefore, the occurrence of short circuits due to the movement of liquid from the first junction to the second junction (or from the second junction to the first junction) is reduced.

[0114] Furthermore, the first to seventh specific regions R11 to R17 are concentrated within the high-voltage region (the upper left half of Figure 4), and the liquid control unit 7 (9 slits 71) is provided accordingly. As a result, even when looking at the entire surface of the mounting substrate 6, the possibility of a short circuit occurring due to liquid flowing from the high-voltage region to the low-voltage region (or from the low-voltage region to the high-voltage region) is reduced.

[0115] (4) Variations The following lists some variations of the mounting substrate 6 according to the above-described embodiment. The above-described embodiment and the following variations may be combined with each other as appropriate.

[0116] In the embodiment described above, the number of slits 71 is 9, but is not limited to 9. However, if the number of slits 71 increases too much, the strength of the mounting substrate 6 may decrease, so it is preferable that the number of slits 71 be in the range of 1 to 10.

[0117] In the embodiments described above, each slit 71 has a substantially constant width. At least one slit 71 may be formed not with a constant width, but for example, with a gradually increasing width along one direction.

[0118] In the embodiments described above, the liquid control unit 7 includes one or more slits 71. The liquid control unit 7 may include, instead of or in addition to, one or more slits 71, one or more grooves 72 (see Figure 6A) recessed in one end face (first end face 60A or second end face 60B) of the substrate body 60. Figure 6A illustrates a smoothing capacitor C2, similar to Figure 5. In the example of Figure 6A, the groove 72 is formed in the second end face 60B instead of the fifth slit 715 in Figure 5. The shape, length, and width of the groove 72 in front view are assumed to be the same as, for example, the fifth slit 715, but are not particularly limited. The depth of the groove 72 is assumed to be about half the thickness of the substrate body 60, for example, but are not particularly limited. Other slits (711-714, 716-719) other than the fifth slit 715 may also be replaced with grooves 72.

[0119] Even when the groove 72 is provided in the substrate body 60 as the liquid control unit 7, the movement of the liquid flowing along the second end face 60B is controlled, thereby reducing the occurrence of short circuits. As a result, electrical reliability can be improved with a simpler configuration. To reduce the occurrence of short circuits for liquid flowing along the first end face 60A, the groove 72 should be provided on the first end face 60A.

[0120] Alternatively, the liquid control unit 7 may include one or more water-absorbing members 73 (see Figure 6B) having a water-absorbing function. Figure 6B also illustrates a smoothing capacitor C2, similar to Figure 5. In the example of Figure 6B, a sheet-like water-absorbing member 73 is attached to the second end face 60B instead of the fifth slit 715 in Figure 5. The material of the water-absorbing member 73 is not particularly limited as long as it has a water-absorbing function, but a flame-retardant material is preferred, for example, a glass fiber material such as glass wool, or a flame-retardant silicone sponge. The shape, length, and width of the water-absorbing member 73 in a front view are assumed to be the same as, for example, the fifth slit 715, but are not particularly limited. The thickness of the water-absorbing member 73 is assumed to be about half the thickness of the substrate body 60, for example, but are not particularly limited. The other slits (711-714, 716-719) other than the fifth slit 715 may also be replaced with water-absorbing members 73.

[0121] Even when the water-absorbing member 73 is provided on the substrate body 60 as the liquid control unit 7, the movement of the liquid flowing along the second end face 60B is controlled, thereby reducing the occurrence of short circuits. As a result, electrical reliability can be improved with a simpler configuration. In particular, with the slit 71 and groove 72, "controlling the movement of the liquid" meant changing the direction of the liquid's movement. With the water-absorbing member 73, "controlling the movement of the liquid" could mean absorbing (capturing) the liquid with the water-absorbing member 73 to reduce the amount of liquid moved or to stop the liquid's movement. To reduce the occurrence of short circuits with respect to the liquid flowing along the first end face 60A, the water-absorbing member 73 can be provided on the first end face 60A. Alternatively, the water-absorbing member 73 may be embedded in the slit 71 or groove 72.

[0122] The mounting substrate 6 may include two or more of the following as the liquid control unit 7: slits 71, grooves 72, and water-absorbing members 73.

[0123] In the embodiment described above, the light source unit A1 has one light-emitting part. However, for example, the light source unit A1 may have two light-emitting parts. The two light-emitting parts may be arranged one at each end in the longitudinal direction of the light guide 5.

[0124] In the embodiment described above, the display device B1 is a so-called single-sided display device in which the display block 2 is attached only to the front of the main body 1 and the rear of the main body 1 is installed facing the wall of the structure. However, for example, the display device B1 may also be a so-called double-sided display device in which the display block 2 is attached to both the front and rear of the main body 1.

[0125] (summary) Based on the embodiments described above, the following aspects are disclosed.

[0126] The first embodiment of the mounting substrate (6) comprises a substrate body (60) and a liquid control unit (7). The substrate body (60) has a plurality of electronic components (61) mounted on it and includes a specific circuit region (R1). The liquid control unit (7) is provided on the substrate body (60). The liquid control unit (7) controls the movement of the liquid moving toward the specific circuit region (R1) when the liquid is flowing along one end face (first end face 60A or second end face 60B) of the substrate body (60) due to its own weight.

[0127] According to the above embodiment, since the movement of the liquid is controlled by the liquid control unit (7), the possibility of a short circuit occurring due to the movement of the liquid (condensed water, etc.) to a specific circuit region (R1) is reduced. As a result, the mounting board (6) has the advantage of improving electrical reliability with a simple configuration.

[0128] With respect to the mounting substrate (6) according to the second embodiment, in the first embodiment, the liquid control unit (7) includes one or more slits (71) that penetrate the substrate body (60) in the thickness direction.

[0129] According to the above embodiment, the movement of the liquid is controlled by providing a slit (71), thus improving electrical reliability with a simpler configuration.

[0130] With respect to the mounting substrate (6) according to the third embodiment, in the first or second embodiment, the liquid control unit (7) includes one or more recessed grooves (72) in one end face (first end face 60A or second end face 60B) of the substrate body (60).

[0131] According to the above embodiment, the movement of the liquid is controlled by providing a groove (72), thus improving electrical reliability with a simpler configuration.

[0132] With respect to the mounting substrate (6) according to the fourth embodiment, in any one of the first to third embodiments, the liquid control unit (7) includes one or more water-absorbing members (73) having a water-absorbing function.

[0133] According to the above embodiment, the movement of the liquid is controlled by providing the water-absorbing member (73), thus improving electrical reliability with a simpler configuration.

[0134] With respect to the mounting substrate (6) according to the fifth embodiment, in any one of the first to fourth embodiments, the substrate body (60) includes a first circuit region and a second circuit region. The first circuit region is a region with a higher potential than the second circuit region. The specific circuit region (R1) is either the first circuit region or the second circuit region. The liquid control unit (7) controls the movement of the liquid so that the liquid bypasses the specific circuit region (R1).

[0135] According to the above embodiment, the occurrence of short circuits caused by the movement of liquid, for example, from a high-potential region to a low-potential region (or from a low-potential region to a high-potential region) is reduced.

[0136] With respect to the mounting substrate (6) according to the sixth embodiment, in any one of the first to fifth embodiments, a specific electronic component (61) among the plurality of electronic components (61) includes a first terminal (611) and a second terminal (612) which is at a lower potential than the first terminal (611). The specific circuit region (R1) includes a first joint (P1) to which the first terminal (611) is joined, or a second joint (P2) to which the second terminal (612) is joined. At least a part of the liquid control unit (7) is arranged between the first joint (P1) and the second joint (P2) on one end face of the substrate body (60).

[0137] According to the above embodiment, the occurrence of short circuits due to the movement of liquid from the first joint (P1) to the second joint (P2), or from the second joint (P2) to the first joint (P1), is reduced.

[0138] With respect to the mounting substrate (6) according to the seventh embodiment, in any one of the first to sixth embodiments, the liquid control unit (7) is provided such that at least a part of it overlaps with the projection area of ​​one or more electronic components (61) among the plurality of electronic components (61) on one end face of the substrate body (60).

[0139] According to the above embodiment, the occurrence of short circuits around the circuit region on which the electronic component (61) is mounted is reduced.

[0140] The power supply device (11) according to the eighth embodiment comprises a mounting board (6) according to any one of the first to seventh embodiments. Multiple electronic components (61) mounted on the board body (60) constitute a power supply circuit (E1) that generates power to be supplied to a load (L1).

[0141] According to the above embodiment, a power supply device (11) can be provided that can improve electrical reliability with a simple configuration.

[0142] The lighting device (X1) according to the ninth embodiment comprises a power supply device (11) according to the eighth embodiment, a light source unit (A1), and a main body (1). The light source unit (A1) is a load (L1) that is lit by power supplied from the power supply device (11). The main body (1) houses or holds the power supply device (11) and the light source unit (A1).

[0143] According to the above embodiment, a lighting device (X1) can be provided that can improve electrical reliability with a simple configuration.

[0144] The configurations relating to the second to seventh aspects are not essential to the mounting board (6) and can be omitted as appropriate. [Explanation of Symbols]

[0145] A1 Light source unit 1 Main unit 11 Power supply 6. Implemented circuit board 60 Main board 61 Electronic Components 611 1st terminal 612 2nd terminal 7. Liquid Control Unit 71 Slits 72 Groove 73 Water-absorbing material E1 power supply circuit L1 load P1 1st joint P2 2nd joint R1 Specific circuit region X1 lighting device

Claims

1. Multiple electronic components are mounted on the main board, which includes a specific circuit area, The substrate body is provided with a liquid control unit that controls the movement of the liquid as it moves toward a specific circuit region, under the condition that the liquid flows along one end surface of the substrate body due to its own weight. The liquid control unit includes one or more slits that penetrate the substrate body in the thickness direction, The one or more slits include a U-shaped slit having a U-shaped opening when viewed from the front, and the U-shaped slit is arranged to surround a specific area on the substrate body. Implemented circuit board.

2. The liquid control unit includes one or more water-absorbing members having a water-absorbing function, The mounting substrate according to claim 1.

3. The substrate body includes a first circuit region and a second circuit region, The first circuit region is a region with a higher potential than the second circuit region. The aforementioned specific circuit region is the first circuit region or the second circuit region. The liquid control unit controls the movement of the liquid so that the liquid bypasses the specific circuit region. The mounting substrate according to claim 1.

4. A specific electronic component among the plurality of electronic components includes a first terminal and a second terminal which is at a lower potential than the first terminal, The aforementioned specific circuit region includes a first junction to which the first terminal is joined, or a second junction to which the second terminal is joined. At least a portion of the liquid control unit is located on one end face of the substrate body, between the first joint and the second joint, The mounting substrate according to claim 1.

5. A substrate body on which multiple electronic components are mounted and which includes a specific circuit region, The substrate body is provided with a liquid control unit that controls the movement of the liquid as it moves toward a specific circuit region, under the condition that the liquid flows along one end surface of the substrate body due to its own weight. The liquid control unit includes one or more recessed grooves on one end face of the substrate body, The one or more grooves include a U-shaped groove having a U-shaped opening when viewed from the front, and the U-shaped groove is arranged to surround a specific area on the substrate body. The liquid control unit includes one or more water-absorbing members having a water-absorbing function. Implemented circuit board.

6. A substrate body on which multiple electronic components are mounted and which includes a specific circuit region, The substrate body is provided with a liquid control unit that controls the movement of the liquid as it moves toward a specific circuit region, under the condition that the liquid flows along one end surface of the substrate body due to its own weight. The liquid control unit includes one or more recessed grooves on one end face of the substrate body, The one or more grooves include a U-shaped groove having a U-shaped opening when viewed from the front, and the U-shaped groove is arranged to surround a specific area on the substrate body. The substrate body includes a first circuit region and a second circuit region. The first circuit region is a region with a higher potential than the second circuit region. The aforementioned specific circuit region is the first circuit region or the second circuit region. The liquid control unit controls the movement of the liquid so that the liquid bypasses the specific circuit region. Implemented circuit board.

7. A substrate body on which multiple electronic components are mounted and which includes a specific circuit region, The substrate body is provided with a liquid control unit that controls the movement of the liquid as it moves toward a specific circuit region, under the condition that the liquid flows along one end surface of the substrate body due to its own weight. The liquid control unit includes one or more recessed grooves on one end face of the substrate body, The one or more grooves include a U-shaped groove having a U-shaped opening when viewed from the front, and the U-shaped groove is arranged to surround a specific area on the substrate body. A specific electronic component among the plurality of electronic components includes a first terminal and a second terminal that is at a lower potential than the first terminal. The aforementioned specific circuit region includes a first junction to which the first terminal is joined, or a second junction to which the second terminal is joined. At least a portion of the liquid control unit is located on one end face of the substrate body, between the first joint and the second joint, Implemented circuit board.

8. The liquid control unit is provided such that at least a portion of it overlaps with the projection area of ​​one or more of the plurality of electronic components on one end face of the substrate body. The mounting substrate according to claim 1.

9. A power supply device comprising the mounting board described in Claim 1, The plurality of electronic components mounted on the aforementioned circuit board constitute a power supply circuit that generates power to be supplied to a load. power supply.

10. The power supply device according to claim 9, The load includes a light source unit that is lit when power is supplied from the power supply device, The power supply unit and the light source unit are housed in or held in a main body, Equipped with, Lighting device.

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