JP2013101888A - Lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device capable of being soldered with good workability.SOLUTION: Wiring sections 24a, 24b are arranged on an LED substrate 22 in the lighting device, and ends of the wiring sections 24a, 24b exposed from insulating layers 25a, 25b become a terminal pair for supplying power to LEDs 23. Respective terminals are soldered to a wiring substrate 5, and are arranged by being close to each other on one side of a light source mounting surface of the LED substrate 22.

Description

  The present invention relates to an illumination device that can be soldered with good workability.

  LEDs (Light Emitting Diodes) are being adopted as light sources for lighting devices because they have advantages such as long life and low power consumption. Various lighting devices using LEDs as light sources are attracting attention as the next-generation energy-saving lighting that is kind to the earth.

  For example, Patent Document 1 discloses an illumination device (LED bulb) including an LED as a light source. FIG. 14 is a cross-sectional view showing a cross section in the vicinity of the LED module 101 in the illumination device 100 described in Patent Document 1. As shown in FIG. The lighting device 100 includes an LED module 101 as a light source. The LED module 101 is a so-called COB (chip on board) type light source in which an LED 103 sealed in a sealing body is mounted on an LED substrate 102. The LED module 101 includes a pair of terminals 104 and 104 on the emission surface of the LED substrate 102. Each terminal 104 is soldered to a lead wire (feeding path) 105 and is electrically connected to a lighting circuit or the like (not shown) provided on the back surface of the LED substrate 102.

JP2011-138785A (released on July 14, 2011)

  However, as shown in FIG. 14, in the lighting device 100, the terminal 104 of the LED module 101 is soldered to the lead wire 105. In addition, since this soldering is all performed manually, the soldering workability is poor.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an illumination device that can be soldered with good workability.

  In order to solve the above problems, an illumination device of the present invention includes a light source module having a light source and a light source substrate on which the light source is mounted, a power supply circuit unit that supplies power to the light source module, and the light source substrate. A lighting device including a wiring board disposed on a light source mounting surface side and wiring the light source module and the power supply circuit unit, wherein the light source board has a pair of terminals soldered to the wiring board. The pair of terminals are provided on one side of the light source mounting surface of the light source substrate so as to be close to each other.

  According to said structure, the terminal pair for electric power feeding provided in the light source board | substrate is soldered to the wiring board. That is, each terminal does not use a lead wire as in a conventional lighting device, but electrically connects the light source module and the power supply circuit unit using a wiring board. Therefore, soldering can be performed with better workability than when using lead wires. In particular, when a wiring board is used, solder bonding by a reflow process is possible. In the reflow process, since it is not necessary to perform soldering work manually, workability is improved as compared with the case of using a lead wire that requires soldering manually.

  In the lighting device of the present invention, the thermal expansion coefficient of the light source substrate and the thermal expansion coefficient of the wiring board may be different.

  When wiring a light source module using a wiring board as in the lighting device of the present invention, if power supply terminals are provided at both ends of the light source board (that is, the distance between the terminals is large) ), Solder cracks are likely to occur due to the difference in coefficient of thermal expansion between the wiring board and the light source board.

  However, as described above, the lighting device of the present invention is provided with the terminal pairs close to each other. As a result, even if the thermal expansion coefficients of the light source substrate and the wiring substrate are different, the stress applied to the soldered portion can be reduced, so that it is not easily affected by thermal expansion. Therefore, even if the difference in thermal expansion coefficient between the light source board and the wiring board is large, the light source module can be wired using the wiring board while preventing solder cracks. Therefore, a highly reliable lighting device can be provided.

  In the illuminating device of the present invention, it is preferable that the wiring board has a reflective surface on the side opposite to the light source mounting surface.

  According to said structure, the surface by the side of the light emission in a wiring board is a reflective surface. Thereby, the light incident on the reflecting surface is reflected in the light emitting direction of the illumination device. As a result, the reflectance of the light emitting side surface of the wiring board is increased. Therefore, the light use efficiency of the lighting device can be improved.

  In the lighting device of the present invention, it is preferable that the solder joint between the terminal and the wiring board is formed by a reflow process.

  According to said structure, the terminal and the wiring board are solder-joined by the reflow process. As a result, the working efficiency is dramatically improved as compared with manual soldering. Therefore, the manufacturing cost of the lighting device can be reduced. In addition, when solder bonding is performed by a reflow process, the size of the terminal can be significantly reduced as compared with the case where solder bonding is performed manually.

  In the illumination device of the present invention, it is preferable that at least one of the light source substrate and the wiring substrate is a metal substrate.

  According to said structure, at least one of a light source board | substrate and a wiring board is comprised from the metal substrate with high heat dissipation. Therefore, the heat dissipation effect of the lighting device can be enhanced.

  In the illuminating device of the present invention, a first heat radiating member in contact with the light source board and the wiring board may be provided between the light source board and the wiring board.

  According to said structure, the 1st heat radiating member is provided between a light source board and a wiring board so that a light source board and a wiring board may be contacted. Thereby, the heat generated in the light source board is conducted to the wiring board through the first heat radiating member. Therefore, the heat dissipation effect of the lighting device can be enhanced.

  In the lighting device of the present invention, it is preferable that the wiring board has an opening formed on the optical path of the light source.

  According to said structure, since the opening part formed in the wiring board is formed on the optical path, the emitted light of a light source is not obstruct | occluded by an opening part.

  In the illuminating device of this invention, it is preferable that the inner wall surface of the said opening part is a reflective surface.

  According to said structure, the inner wall face of the opening part formed on the optical path is a reflective surface. For this reason, the emitted light from the light source is emitted from the opening without being reflected by the inner wall surface of the opening, or is reflected from the inner wall surface of the opening and emitted from the opening. That is, light traveling straight from the light source and light traveling from the light source toward the inner wall surface of the opening are mixed and emitted from the opening. Thereby, for example, light having a long wavelength emitted from the light source toward the inner wall surface of the opening is reflected by the inner wall surface of the opening. Therefore, the emitted light of the light source is mixed and light emission with a uniform color can be realized.

  In the illuminating device of this invention, it is preferable that the optical member which covers the said opening part is provided.

According to said structure, the optical member is provided so that the opening part formed on the optical path may be covered. Thereby, the emitted light from the light source enters the optical member and is emitted from the optical member. Therefore, the light distribution of the emitted light from the light source can be controlled according to the design of the optical member.
It is characterized by doing.

  According to the present invention, it is possible to provide an illumination device that can be soldered with good workability.

It is sectional drawing of the LED module vicinity in the illuminating device which concerns on one Embodiment of this invention. It is a perspective view of the illuminating device which concerns on one Embodiment of this invention. It is a figure which shows the LED module in the said illuminating device, (a) is a top view by the side of an output surface, (b) is AA 'sectional drawing in (a), (c) is (a). It is BB 'sectional drawing. It is sectional drawing of the wiring part in the said LED module. It is a top view by the side of the outgoing surface of an LED module in the above-mentioned lighting device. It is sectional drawing of the LED module vicinity in the illuminating device which concerns on other one Embodiment of this invention. It is sectional drawing of the LED module vicinity in the illuminating device which concerns on other one Embodiment of this invention, (a) is a figure provided with a wiring board, (b) is a figure which is not provided with a wiring board. It is a figure which shows the illuminating device which concerns on other one Embodiment of this invention, and is a top view of the illuminating device provided with two or more LED modules. It is a top view which shows the LED module in the illuminating device of FIG. It is a top view which shows the back surface of the wiring board in the illuminating device of FIG. It is a top view of the illuminating device which concerns on other one Embodiment of this invention. It is the top view and sectional view which show the illuminating device which concerns on other one Embodiment of this invention, (a) is before wiring board wiring, (b) has shown after wiring by a wiring board. It is the top view and sectional view which show the illuminating device which concerns on other one Embodiment of this invention, (a) is before wiring board wiring, (b) has shown after wiring by a wiring board. It is sectional drawing which shows the cross section of the LED module vicinity in the illuminating device of patent document 1.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a perspective view of the illumination device 10 according to the embodiment of the present invention. As shown in FIG. 2, the lighting device 10 is a light bulb type lighting device. The illuminating device 10 has a configuration in which a globe cover 1, a light emitting unit 2 including an LED as a light source, and a base 3 are arranged in this order. In the following description, for the sake of convenience, the glove cover 1 side will be described as the upper side (upper) and the base 3 side will be described as the lower side (lower).

  The globe cover 1 has a dome shape, and accommodates a light source (LED module 21) provided in the light emitting unit 2 inside. The globe cover 1 has a function of transmitting light emitted from the light source and a function of protecting the light emitting unit 2 (particularly the LED module 21) by covering the light emitting unit 2. The globe cover 1 can be formed from, for example, transparent or light diffusing glass or synthetic resin. Since the LED generates a relatively large amount of heat when it is turned on, the globe cover 1 is preferably formed from a heat resistant material. For example, milky white polycarbonate resin is suitable as a constituent material of the glove cover 1 because it is excellent in impact resistance, heat resistance, and light diffusibility.

  The light emitting unit 2 is a main body of the lighting device 10. A glove cover 1 is attached to one end (upper end) of the light emitting unit 2, and a base 3 is attached to the other end (lower end). An LED module 21 having an LED as a light source is mounted on the upper end surface of the light emitting unit 2. On the other hand, a power supply module 27 is provided inside the light emitting unit 2. The power supply module 27 is a power supply circuit unit that supplies power to the LED module 21. The power supply module 27 is also a control circuit unit that controls the lighting state (light emission amount, etc.) of the LEDs. In addition, in the inside of the light emission part 2, the electronic component (circuit component) for the lighting control of LED, light control, or toning is provided.

  Since the illumination device 10 uses an LED as a light source, the amount of heat generated is relatively large. For this reason, it is preferable to comprise the exterior part of the light emission part 2 from a metal with favorable heat conductivity. For example, the exterior portion of the light emitting unit 2 is preferably made of a metal such as aluminum (Al), copper (Cu), iron (Fe), nickel (Ni), or an alloy thereof. Further, it may be composed of an industrial material such as aluminum nitride (AlN) or silicone carbide (SiC), or may be composed of a synthetic resin such as a high thermal conductive resin. Thereby, the light emission part 2 can thermally radiate the heat generated from the LED module 21 and the power supply module 27 effectively to the outside.

  The base 3 is a metal fitting for external connection, for example, a general E26 type metal fitting. That is, the base 3 supplies power from an external power source (not shown) to the power supply module 27. On the inner surface of the base 3, a thread that engages with a thread formed on the outer surface of the light emitting unit 2 is formed. Thereby, the light emission part 2 is screwed and connected. That is, the screw thread formed on the inner surface of the base 3 is a screwing mechanism for screwing the base 3 to the light emitting portion 2 and connecting it. A screw thread is also formed on the outer surface of the base 3. Thereby, the illuminating device 10 can be attached by being screwed into a socket provided on the ceiling or the like.

  With such a configuration, when the lighting device 10 is attached by screwing the base 3 into a socket or the like of a commercial power source (external power source), the power supply module 27 is connected via an electric wire (not shown) connected to the base 3. Is supplied with voltage. Then, an appropriate voltage is supplied to the LED module 21 via the power supply module 27, and the LED is lit. Light from the LED passes through the globe cover 1 and is diffused by the globe cover 1. As a result, substantially the entire globe cover 1 is brightened, and light having substantially uniform luminance is emitted to the outside. Since the illuminating device 10 includes an LED as a light source, a long life and low power consumption can be realized.

  Here, the LED module 21 provided in the illumination device 10 will be described. FIGS. 3A and 3B are diagrams showing the LED module 21 in the illumination device 10, where FIG. 3A is a plan view on the exit surface side, FIG. 3B is a cross-sectional view taken along line AA ′ in FIG. FIG. 4B is a sectional view taken along line BB ′ in FIG. 4A and 4B are diagrams showing the LED module 21 in the illumination device 10, where FIG. 4A is a plan view on the exit surface side, FIG. 4B is a cross-sectional view taken along line AA ′ in FIG. FIG. 4B is a sectional view taken along line BB ′ in FIG. FIG. 4 is a cross-sectional view of the wiring portions 24 a and 24 b in the LED module 21.

  As shown in FIG. 3, the LED module 21 includes an LED substrate (light source substrate) 22 and an LED 23 mounted on the LED substrate 22.

  The LED substrate 22 is a substrate on which the LEDs 23 are mounted. The board | substrate which comprises LED board 22 is not specifically limited. However, since the LED 23 generates a relatively large amount of heat, the LED substrate 22 is preferably a substrate with good thermal conductivity. For example, the LED board 22 can be comprised from a metal or its alloy. For example, the LED substrate 22 can be made of a metal such as aluminum (Al), copper (Cu), iron (Fe), nickel (Ni), or an alloy thereof. Further, it may be composed of an industrial material (ceramics) such as alumina, aluminum nitride (AlN), or silicone carbide (SiC), or may be composed of a synthetic resin such as a high thermal conductive resin. Thereby, the LED board 22 can effectively radiate the heat generated from the LED module 21 to the outside. Moreover, the heat dissipation effect of the lighting device 10 can be enhanced as the area of the LED substrate 22 increases.

  A pair of wiring portions (conductive portions) 24 a and 24 b for supplying power to the LEDs 23 are provided on the light source mounting surface of the LED substrate 22. The wiring portions 24a and 24b extend from the LED 23 to one side portion of the LED substrate 22 in parallel with each other. One end of each of the wiring portions 24 a and 24 b is connected to the LED 23, and the other end is exposed on the LED substrate 22. That is, as shown in FIGS. 3 and 4, only the other ends of the wiring portions 24a and 24b are exposed, and the remaining portions are covered with the insulating layers 25a and 25b. One of the end portions where the wiring portions 24a and 24b are exposed serves as an anode side terminal in the LED module 21, and the other serves as a cathode side terminal. Further, the wiring portions 24a and 24b are provided with end portions on the opposite side to the LED 23 (the other end) close to each other.

  The LED module 21 is a so-called COB type light source module. The LED 23 is a light source in the lighting device 10 (a light emitting unit in the LED module 21), and includes a plurality of LED elements connected in series, and is sealed with a resin in which a phosphor (not shown) is dispersed. The LED 23 emits light in a direction perpendicular to the mounting surface of the LED substrate 22.

  One LED module 21 is mounted on the illumination device 10. However, the number of LED modules 21 mounted on the lighting device 10 can be arbitrarily set. When a plurality of LED modules 21 are mounted, the LED substrate 22 may be mounted with LEDs 23 that emit a single color, or may be mounted with a plurality of LEDs 23 that emit different colors. Moreover, the illuminating device 10 may include a plurality of LED modules 21.

  Next, the feature point of the illuminating device 10 is demonstrated based on FIG.1, FIG3 and FIG.5. In the following description, reference is also made to the conventional lighting device 100 shown in FIG. 14 for comparison. FIG. 1 is a cross-sectional view of the vicinity of the LED module 21 in the lighting device 10. Specifically, FIG. 1 is a cross-sectional view in the optical axis direction (vertical direction) near the LED module 21. On the other hand, FIG. 5 is a plan view of the emission surface side of the LED module 21 in the illumination device 10.

  As shown in FIG. 14, in the lighting device 100 of Patent Document 1, the terminal 104 of the LED module 101 is soldered to the lead wire 105. That is, the LED module 101 is electrically connected to a lighting circuit or the like provided on the back surface of the LED substrate 102 using the lead wire 105. However, since solder joining between the terminal 104 and the lead wire 105 is all performed manually, workability is poor.

  Therefore, in the illuminating device 10 of the present embodiment, the LED module 21 and the power supply module 27 are electrically connected using a wiring board described later instead of a lead wire. Specifically, as shown in FIG. 1, in the lighting device 10 of the present embodiment, the wiring board 5 is disposed on the light source mounting surface (light emitting surface) side of the LED board 22, and the LED module 21 is wired. Soldered to the substrate 5. Specifically, the terminals of the wiring portions 24 a and 24 b provided on the LED substrate 22 are mounted on the wiring substrate 5 via the solder joint portions 26.

  More specifically, the wiring board 5 electrically connects the LED board 22 (LED module 21) and the power supply module 27 provided inside the light emitting unit 2. As shown in FIG. 1, in the lighting device 10, a metal base substrate that is a kind of metal substrate is applied as the wiring substrate 5. That is, the wiring board 5 is a metal base board in which the base metal 51, the insulating layer 53, and the wiring 52 are laminated in order from the light emitting side or the wiring board. Base metal 51 is formed of aluminum, iron, copper, or the like. The insulating layer 53 has a function of bonding the base metal 51 and the wiring 52 together with an insulating function. As will be described later, the wiring board 5 has an opening 54 formed on the optical path of the LED 23.

  The wiring 52 is formed from a wiring material such as copper foil. A part of the wiring 52 is joined to each terminal of the wiring parts 24 a and 24 b of the LED substrate 22 through the solder joint part 26. Thereby, the LED board 22 and the wiring board 5 are electrically connected to each other. Although not shown, the wiring board 5 is electrically connected to the power supply module 27 inside the light emitting unit 2. That is, for example, the wiring board 5 is connected to the power supply module 27 by a socket or a lead wire and is supplied with power. As a result, the LED board 22 is electrically connected to the power supply module 27 via the wiring board 5. Accordingly, power can be supplied to the LED 23 via the wiring board 5.

  Thus, the solder joint portion 26 is formed between each terminal of the wiring portions 24 a and 24 b provided on the LED substrate 22 and the wiring 52 formed on the back surface of the wiring substrate 5. Thereby, the LED module 21 and the wiring board 5 are electrically connected. Further, the wiring board 5 is connected to the power supply module 27. Therefore, the LED module 21 and the wiring board 5 are electrically connected by the solder joint portion 26.

  The type of solder used for the solder joint portion 26 is not particularly limited, but it is preferably so-called lead-free solder in consideration of the environment. Examples of the lead-free solder include Sn-Ag solder, Sn-Zn solder, Sn-Bi solder, Sn-In solder, Sn-Ag-Cu solder, but are particularly limited. It is not a thing. Further, the composition ratio of each solder component is not particularly limited.

  Further, the solder constituting the solder joint portion 26 may contain a flux or the like. Thereby, since the wettability and fluidity | liquidity of solder improve, the LED module 21 and the wiring board 5 can be joined reliably. The type of flux may be set according to the material of each terminal of the wiring portions 24a and 24b and the material of the wiring 52, and is not particularly limited. As will be described later, if soldering is performed by a reflow process, even if flux is mixed, scattering of the flux can be prevented.

  As described above, in the lighting device 10, the power supply terminal pairs (wiring portions 24 a and 24 b) provided on the LED substrate 22 are soldered to the wiring substrate 5. That is, each terminal of the wiring parts 24a and 24b does not use the lead wire as in the conventional lighting device, but the LED module 21 and the power supply module 27 are electrically connected using the wiring board 5. Therefore, soldering can be performed with better workability than when using lead wires. In particular, when the wiring board 5 is used, solder bonding by a reflow process is possible as will be described later. In the reflow process, since it is not necessary to perform soldering work manually, workability is improved as compared with the case of using a lead wire that requires soldering manually.

  When the LED module 21 is wired using the wiring board 5 as in the lighting device 10 of the present embodiment, the power supply terminals (wiring portions 24a and 24b) are provided at both ends of the LED board 22 separately. (Ie, when the distance between the terminals is large), solder cracks are likely to occur due to the difference in thermal expansion coefficient between the wiring board 5 and the LED board 22.

  Therefore, in the lighting device 10, as shown in FIG. 3, terminal pairs for feeding power to the LEDs 23 (terminals of the wiring portions 24 a and 24 b) are close to each other on one side of the light source mounting surface of the LED substrate 22. Is provided. That is, each terminal is disposed close to one side of the LED 23. For this reason, the distance between the wiring parts 24a and 24b (distance between the terminals) is shortened. Thereby, even if the thermal expansion coefficients of the LED substrate 22 and the wiring substrate 5 are different from each other, the stress applied to the solder joint portion 26 can be reduced, so that it is not easily affected by the thermal expansion. Therefore, even if the difference in thermal expansion coefficient between the LED substrate 22 and the wiring substrate 5 is large, the LED module 21 can be wired using the wiring substrate 5 while preventing solder cracks. Therefore, the lighting device 10 with high reliability can be provided.

For example, in the lighting device 10, the thermal expansion coefficient (linear expansion coefficient) of the wiring board 5 may be set larger than the thermal expansion coefficient (linear expansion coefficient) of the LED board 22. Specifically, the wiring substrate 5 may be an aluminum substrate (metal core substrate), and the LED substrate 22 may be alumina (ceramic substrate). The thermal expansion coefficient (linear expansion coefficient) of aluminum is 23 × 10 ⁻⁶ / ° C. On the other hand, the thermal expansion coefficient (linear expansion coefficient) of alumina is ≈8 × 10 ⁻⁶ / ° C. Thus, also when the LED board 22 and the wiring board 5 from which a thermal expansion coefficient differs are used, a solder crack can be prevented and the reliable illuminating device 10 can be provided.

  The distance between the terminals (between the wiring portions 24a and 24b) is preferably as close as possible while ensuring insulation between the terminals. In the present embodiment, as an example, the terminals are spaced apart by about 0.5 mm and are brought close together while ensuring insulation. Note that the shape of the terminal is not limited to a rectangle, and may be an arbitrary shape.

  Thus, according to the illuminating device 10 of this embodiment, while being able to suppress a solder crack, the illuminating device 10 which can be soldered with sufficient workability can be provided.

  Moreover, in the illuminating device 10, although the size of the LED module 21 is not specifically limited, If the size becomes large, the thickness of the LED board 22 will become thick. For this reason, when the size of the LED module 21 increases, the temperature difference between the light source mounting surface and the back surface of the LED substrate 22 cannot be ignored. The illuminating device 10 is excellent in heat dissipation because heat is directly released (dissipated) through the wiring substrate 5 from the light source mounting surface of the LED substrate 22 that is more likely to generate heat in the LED substrate 22.

  Moreover, in the illuminating device 10, it is preferable that at least one of the LED board 22 and the wiring board 5 is a metal substrate. The metal substrate (metal wiring substrate) is a printed wiring substrate having good heat dissipation (good thermal conductivity). On the other hand, the wiring substrate 5 may be a substrate having a wiring function, but is preferably a substrate having heat dissipation. For this reason, it is more preferable that at least the wiring substrate 5 is a metal substrate. Thus, if at least one of the LED board 22 and the wiring board 5 is comprised from the metal substrate with high heat dissipation, the heat dissipation effect of the illuminating device 10 can be improved.

  The metal substrate may be a metal base substrate such as the wiring substrate 5 of FIG. 1 or a metal core substrate. The metal base substrate is a substrate in which a circuit (outer layer circuit) made of copper foil is formed on the metal substrate and the metal substrate. On the other hand, the metal core substrate is a substrate in which a metal substrate is provided inside the substrate and both sides of the metal substrate are sandwiched between outer layer substrates (outer layer circuits). Note that both the metal base substrate and the metal core substrate are insulated by forming an insulating layer between the metal substrate and the outer layer circuit. Aluminum also has the advantages of being easy to handle, cheap, easy to process, light, and having a thermal conductivity about three times that of iron. Therefore, the metal substrate is preferably an aluminum base substrate or an aluminum core substrate.

  Moreover, in the illuminating device 10, the soldering method (the manufacturing method of the illuminating device 10) between the terminals of the power supply wiring portions 24a and 24b and the wiring substrate 5 (wiring 52) is not particularly limited. However, as described above, in the lighting device 10, the LED module 21 is wired using the wiring board 5. For this reason, it is preferable to use a reflow process of SMD (Surface Mounted Device) for forming the solder joint portion 26. That is, the solder joint portion 26 between the wiring portions 24a and 24b and the wiring board 5 is preferably formed by a reflow process. Specifically, in the wiring 52 formed on the back surface of the wiring substrate 5 on which the LED module 21 is mounted, the portions other than the portions corresponding to the ends (terminal portions) of the wiring portions 24a and 24b are masked, and the corresponding portions Only apply solder paste. Next, the heat dissipation sheet 4 is attached to the light source mounting surface of the LED substrate 22. Subsequently, after the LED module 21 is placed on the wiring board 5, it is soldered by heating in a reflow furnace.

  As described above, if the wiring portions 24a and 24b and the wiring board 5 are solder-bonded by the reflow process, the working efficiency is remarkably improved as compared with the manual soldering. Therefore, the manufacturing cost of the lighting device 10 can be reduced. In addition, when solder bonding is performed by a reflow process, the size of the terminals of the wiring portions 24a and 24b can be significantly reduced as compared with the case where solder bonding is performed manually.

  In the case of manual soldering, a trace of the soldering iron remains in the solder joint 26, whereas in the reflow process, such a trace does not remain. For this reason, it is possible to determine whether or not the solder joint portion 26 is formed by the reflow process. That is, the lighting device soldered by the reflow process can be distinguished from the lighting device soldered manually.

  Further, when simply applying a normal SMD reflow process, not only the power supply wiring portions 24a and 24b but also the heat radiation sheet 4 provided between the LED substrate 22 and the wiring substrate 5 is soldered. Become. However, in the lighting device 10, only the wiring portions 24a and 24b are soldered by the reflow process. That is, the heat dissipation sheet 4 is not fixed to the LED substrate 22 and is only in contact with the LED substrate 22 and the wiring substrate 5 (copper foil 53).

  In addition, when solder joining is performed manually as in the lighting device 100 of Patent Document 1, for example, when thread solder (solder including flux) is used, the flux may be scattered and attached to the light emitting portion of the LED module 21. is there. For this reason, it leads to the fall of the reliability of the illuminating device 100. FIG.

  On the other hand, when the solder joint portion 26 is formed by a reflow process as in the lighting device 10 of the present embodiment, it is only necessary to heat in a reflow furnace. Scattering can be prevented. Therefore, the highly reliable lighting device 10 can be provided.

  On the other hand, in the lighting device 10, as shown in FIG. 5, the LED module 21 is provided with a heat radiation sheet (first heat radiation member) 4 on the light source mounting surface of the LED substrate 22. The heat dissipating sheet 4 is provided in the vicinity of the LED 23 which is a main heat source in the lighting device 10. Specifically, the heat dissipation sheet 4 is provided around the LED 23, and is provided avoiding the LED 23, the wiring portions 24 a and 24 b and the insulating layers 25 a and 25 b. Since the heat dissipation sheet 4 is in contact with the LED substrate 22, the heat on the surface of the LED substrate 22 is conducted to the heat dissipation sheet 4. Furthermore, as shown in FIG. 1, the heat dissipation sheet 4 is in contact with the LED substrate 22 and the wiring substrate 5. Specifically, the heat dissipation sheet 4 is provided between the LED substrate 22 and the wiring substrate 5, and is in contact with the base metal 51 through the wiring 52 and the insulating layer 53. For this reason, the heat conducted to the heat dissipation sheet 4 can be conducted to the base metal 51 (wiring substrate 5). Therefore, the heat dissipation effect of the lighting device 10 can be enhanced.

  In addition, in the illuminating device 10, the thermal radiation sheet | seat 4 is not an essential structure. However, by providing the heat dissipation sheet 4, the heat generated on the LED 23 mounting surface of the LED substrate 22 can be effectively dissipated within the surface of the heat dissipation sheet 4. Therefore, the heat dissipation effect of the lighting device 10 can be enhanced.

  Further, the heat dissipation sheet 4 is not limited to a sheet shape, and may be a plate shape or a semi-solid shape such as heat dissipation grease. However, since the heat dissipation sheet 4 is in the form of a sheet, even if the LED substrate 22 and the wiring substrate 5 have some unevenness, they come into contact with the LED substrate 22 and the wiring substrate 5 in a state close to surface contact. Therefore, the heat dissipation effect of the lighting device 10 can be more reliably enhanced. Further, even if a shearing force is applied to the heat dissipation sheet 4, there is no problem such as peeling. On the other hand, when a plate-like heat radiating member is provided, the heat radiating member becomes thick, so the heat radiating effect is enhanced.

  As shown in FIG. 1, in the lighting device 10, the wiring substrate 5 has an opening 54 formed on the optical path of the LED 23. Since the opening 54 formed in the wiring board 5 is formed on the optical path of the LED 23, the light emitted from the LED 23 is not blocked by the opening 54.

  The illuminating device 10 of this embodiment can also be set as the following structures. In the following description, differences from the illumination device 10 will be mainly described, and description of similar configurations will be omitted. FIG. 6 is a cross-sectional view of the vicinity of an LED module in an illumination apparatus according to another embodiment of the present invention.

  The configuration of FIG. 6 is different from the lighting device 10 in that a plate-like heat dissipation member (second heat dissipation member) 7 is provided on the back surface of the LED substrate 22. That is, in the configuration of FIG. 6, the wiring board 5 is provided on the light source mounting surface of the LED substrate 22, and the heat radiating member 7 is provided on the surface (back surface) opposite to the light source mounting surface. That is, the LED board 22 is sandwiched between the wiring board 5 and the heat dissipation member 7. Thereby, the heat generated in the LED module 21 is radiated from both sides of the LED substrate 22. Therefore, it is possible to realize a lighting device having a higher heat dissipation effect. In addition, the heat radiating member 7 can be comprised from the metal substrate etc. with favorable heat dissipation (good heat conductivity) like the LED board 22 and the wiring board 5. FIG.

  In the configuration of FIG. 6, the inner wall surface 55 of the opening 54 is preferably a reflective surface. In this configuration, the inner wall surface 55 of the opening 54 formed on the optical path is a reflecting surface. For this reason, the light emitted from the LED 23 is emitted from the opening 54 without being reflected by the inner wall surface 55 of the opening 54, or is reflected from the inner wall surface 55 of the opening 54 and emitted from the opening 54. The That is, the light traveling straight from the LED 23 and the light traveling from the LED 23 toward the inner wall surface 55 of the opening 54 are mixed and emitted from the opening 54. Thereby, for example, light having a long wavelength emitted from the LED 23 toward the inner wall surface 55 of the opening 54 is reflected by the inner wall surface 55 of the opening 54. Therefore, the emitted light of the LED 23 is mixed and light emission with a uniform color can be realized.

  Further, in the configuration of FIG. 6, the wiring substrate 5 may have a reflection surface on a surface 51 a opposite to the mounting surface of the LED module 21. That is, the light emission side surface of the wiring board 5 may be a reflection surface. Thereby, the light incident on the reflecting surface is reflected in the light emitting direction of the illumination device. As a result, the reflectance of the light emitting side surface of the wiring board 5 is increased. Therefore, the light use efficiency of the lighting device can be improved.

  In addition, each said reflective surface may be a mirror surface process using the aluminum substrate as the wiring board 5, and may form a reflection film separately.

  FIG. 7 is a cross-sectional view of the vicinity of an LED module in a lighting device according to another embodiment of the present invention, where (a) is a diagram including a wiring board 5 and (b) is not including a wiring board 5. FIG. That is, the configuration of FIG. 7A is different from the configuration of FIG. 1 in that the optical member 6 is provided so as to cover the opening 54 of the wiring board 5 (striding across the opening 54). On the other hand, the configuration of FIG. 7B is a configuration in which the optical member 6 is provided on the optical path without providing the wiring board 5 in FIG.

  In FIG. 7, the optical member 6 is an optical lens in which the light incident surface 6a from the LED 23 is a convex surface and the light exit surface 6b is a flat surface. For this reason, in FIG. 7B, the optical member 6 condenses the LED light on the convex surface of the incident surface 6 a facing the LED 23. Then, the condensed light is emitted from the flat emission surface 6b. The shape of the optical member 6 is designed so that light emitted from the LED 23 in the lateral direction (perpendicular to the emission surface 6b) is totally reflected as much as possible at the interface between the emission surface 6b of the optical member 6 and air. . However, in this case, part of the light emitted from the LED 23 is not emitted from the emission surface 6 b of the optical member 6 and leaks in the lateral direction of the optical member 6. For this reason, the emitted light from the LED 23 cannot be refracted in the intended direction.

  On the other hand, when the wiring board 5 is provided as shown in FIG. 7A, the light emitted from the LED 23 in the lateral direction (perpendicular to the emission surface 6 b) is applied to the inner wall surface 55 of the opening 54. Head. As a result, the light is reflected by the inner wall surface 55, enters the optical member 6, and exits from the optical member 6. That is, light leakage of the LED 23 is suppressed. Therefore, the light utilization efficiency of the LED 23 can be increased. In particular, if the inner wall surface 55 is a reflecting surface, the light utilization efficiency can be further increased. Furthermore, the light distribution of the emitted light from the LED 23 can be controlled according to the design of the optical member 6. Therefore, it is possible to provide a lighting device suitable for a road lamp whose light distribution characteristics are strictly defined.

  In FIG. 7, in the optical member 6, the incident surface 6a is convex, and the exit surface 6b is flat. However, the shapes of the entrance surface 6a and the exit surface of the optical member 6 are not particularly limited. The shapes of the entrance surface 6a and the exit surface 6b of the optical member 6 can be arbitrarily set according to the required light distribution of the exit light. Further, the shape and type of the optical member 6 are not particularly limited. For example, as the optical member 6, various optical elements such as a convex lens and a Fresnel lens can be applied.

  On the other hand, FIG. 8 is a diagram showing a lighting device 10a according to another embodiment of the present invention, and is a plan view of the lighting device 10a including a plurality (12) of LED modules 21. FIG. 9 is a plan view showing the LED module 21 in the illumination device 10a of FIG. FIG. 10 is a plan view showing the back surface of the wiring board 5a in the illumination device 10a of FIG.

  Since the illumination device 10 is a light bulb type, the amount of light may be small. For this reason, the lighting device 10 includes one LED module 21. However, for example, a road lamp requires a light quantity of tens of thousands of lumens. Thus, when a large amount of light is required, it is preferable to provide a plurality of LED modules 21 as in the illumination device 10a of FIG.

  Specifically, in the lighting device 10 a, twelve LED modules 21 are mounted on the wiring board 5. Accordingly, it is possible to realize a lighting device 10a with a large amount of light.

  The illumination device 10a can be manufactured as follows, for example. That is, as shown in FIG. 9, twelve LED modules 21 are spaced apart from each other and evenly arranged on the base 8. Further, the heat dissipation sheet 4 is set on the light source mounting surface of the LED substrate 22. Next, as shown in FIG. 10, the wiring substrate 5a is masked, and a solder paste is applied only to the ends of the wiring portions 24a and 24b of the wiring 52a. Next, the base 8 on which the LED module 21 shown in FIG. 9 is mounted is set. At this time, alignment is performed so that the LED 23 is disposed in the opening 54 of the wiring board 5a. Next, it is heated and soldered in a reflow furnace. In FIG. 10, a copper foil 52b is also formed near the region where the opening 54 is formed. The copper foil 52b functions as a heat radiating member and has a different use from the wiring 52a solder-bonded to the LED substrate 22.

  In addition, the light distribution characteristic (irradiation position / irradiation amount) of the road lamp is strictly defined. For this reason, when applying the illuminating device 10a to a road light, the structure which makes the inner wall surface 55 of the opening part 54 of the wiring board 5 mentioned above a reflective surface, and the structure provided with the optical member 6 so that the opening part 54 may be straddled. It is preferable to combine at least one. Thereby, light distribution control becomes easy. Therefore, the desired light distribution characteristic can be realized.

  On the other hand, FIG. 11 is a plan view of a lighting apparatus 10b according to another embodiment of the present invention. The lighting device 10b also has a plurality (eight) of LED modules 21 mounted on the wiring board 5b. However, the wiring board 5 in FIG. 1 and the wiring board 5a in FIG. 8 are different in that the opening 54 is formed on the optical path, whereas the opening is not formed in the wiring board 5b in FIG. The wiring board 5b is a circular board, and the LED module wiring parts 24a and 24b are arranged on the inner peripheral part, while the LED 23 is arranged on the outer edge part. With such a configuration, two effects of reducing the weight of the lighting device 10b and improving the design of the lighting device 10b can be obtained. These effects will be described with reference to FIGS. 12 and 13 are a plan view and a cross-sectional view showing illumination devices 10c and 10d according to another embodiment of the present invention, respectively, (a) before wiring by wiring boards 5c and 5d, (b ) Shows after wiring by the wiring boards 5c and 5d. In FIG. 12 and FIG. 13, for simplicity of explanation, four COB type LED modules 21 are provided as lighting devices 10c and 10d mounted on the wiring boards 5c and 5d.

  In the illuminating device 10c of FIG. 12, the LED 23 of the LED module 21 is arranged on the outer periphery of the wiring board 5c, similarly to the illuminating device 10b of FIG. On the other hand, in the illuminating device 10d of FIG. 12, the LED 23 of the LED module 21 is disposed in the opening 54 formed in the wiring board 5d, similarly to the illuminating device 10a of FIG.

  As apparent from a comparison between the illumination device 10c of FIG. 12 and the illumination device 10d of FIG. 13, the illumination device 10c has a small size (surface area) of the wiring board 5c and the heat dissipation member 7 (fixing member of the LED module 21). . Therefore, the illumination device 10c is advantageous in terms of mass compared to the illumination device 10d. For example, in a lamp that requires many LED modules 21 such as a chandelier, the mass per lighting device 10c is important. Therefore, the lighting device 10c (lighting device 10b) that can be reduced in weight is preferably applied to a chandelier or the like.

  On the other hand, the illumination device 10c is disadvantageous in terms of heat dissipation compared to the illumination device 10d. However, the LED substrate 22 may be formed from a material having good emissivity (thermal conductivity) such as ceramics (close to 1). Thereby, the temperature gradient in LED board 22 becomes small. As a result, even if the back surface of the light emitting portion (the portion where the LED 23 is formed) in the LED module 21 is not in contact with the heat radiating member 7, heat radiation by heat radiation and heat conduction from the portion in contact with the heat radiating member 7 Can sufficiently dissipate heat. The heat dissipation member 7 may be a metal plate (such as an aluminum plate) having a heat dissipation sheet formed on the LED module 21 side.

  On the other hand, the illuminating device 10c of FIG. 12 has a configuration in which the LEDs 23 (light emitting portions) are exposed from the outer edge portions of the wiring board 5c and the heat dissipation member 7. Furthermore, the heat radiating member 7 is not formed on the back surface of the LED substrate 22. In a COB type LED device like the LED module 21, when the LED board 22 on which the LED 23 is mounted is made of ceramics, a part of the light emitted by the LED 23 enters the LED board 22. In particular, when the LED 23 is formed of a general small chip (a kind of LED chip) that does not have a reflective layer for collecting light on the emission surface side, the emission side is also on the opposite side from the PN junction. The same amount of light is emitted. However, since the LED substrate 22 made of ceramics is not metal-bonded like metal, 100% of the surface cannot be reflected like metal. For this reason, light is also emitted from the back surface of the LED substrate 22. Therefore, in the illumination device 10c, not only can the light be emitted from the LED 23 to the wiring substrate 5c side (main emission surface), but also the back surface of the LED substrate 22 (the side opposite to the main emission surface) without using a special optical system. Also, light can be emitted. Thus, since the illuminating device 10c can also use the light which oozes out from the back surface of the LED board 22, the utilization efficiency of light improves and the design using a special light distribution characteristic is also attained. Therefore, the design of the illumination device 10c (illumination device 10b) is improved.

  In addition, in this embodiment, the illuminating device 10 provided with LED23 as a light source was demonstrated. However, the light source is not limited to the LED 23, and may be various light emitting elements such as a phosphor, an electroluminescence element, and a semiconductor light source. Moreover, what is necessary is just to set the color of a light source arbitrarily. However, LED (Light Emitting Diode) has advantages such as long life and low power consumption.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and the embodiments can be obtained by appropriately combining the technical means disclosed in the embodiments. The form is also included in the technical scope of the present invention.

4 Heat dissipation sheet (first heat dissipation member)
5 Wiring board 5a Wiring board 5b Wiring board 5c Wiring board 5d Wiring board 6 Optical member 10 Illuminating device 10a Illuminating device 10b Illuminating device 10c Illuminating device 10d Illuminating device 21 LED module (light source module)
22 LED board (light source board)
23 LED (light source)
24a / 24b Wiring section (one pair of terminals)
26 Solder joint 27 Power module (power circuit)
52 Wiring 54 Opening 55 Inner Wall

Claims (9)

A light source module having a light source and a light source substrate on which the light source is mounted;
A power supply circuit section for supplying power to the light source module;
An illumination device including a wiring board disposed on a light source mounting surface side of the light source board and wiring the light source module and the power supply circuit unit,
The light source board is provided with a pair of terminals soldered to the wiring board,
The pair of terminals are provided on one side of the light source mounting surface of the light source substrate so as to be close to each other.   The lighting device according to claim 1, wherein a thermal expansion coefficient of the light source substrate is different from a thermal expansion coefficient of the wiring substrate.   The lighting device according to claim 1, wherein the wiring board has a reflective surface on a surface opposite to the light source mounting surface.   The lighting device according to claim 1, wherein the solder joint between the terminal and the wiring board is formed by a reflow process.   The lighting device according to any one of claims 1 to 4, wherein at least one of the light source substrate and the wiring substrate is a metal substrate.   The illumination according to any one of claims 1 to 5, wherein a first heat radiating member in contact with the light source board and the wiring board is provided between the light source board and the wiring board. apparatus.   The lighting device according to claim 1, wherein the wiring board has an opening formed on an optical path of the light source.   The lighting device according to claim 7, wherein an inner wall surface of the opening is a reflective surface. The lighting device according to claim 7, wherein an optical member that covers the opening is provided.

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