JP2016126971A - Light emitting device and wiring board used in light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emitting device which utilizes heat generated by light emitting components to efficiently heat a cover member, and to provide a wiring board.SOLUTION: A light emitting device includes: a mounting substrate on which light emitting components are mounted; and a cover member which is disposed spaced away from the heat components on the mounting substrate. The mounting substrate has a wiring board on which the light emitting components are mounted, and the wiring board includes a heat conductive member having flexibility and light transmissivity. The heat conductive member includes: a first portion which spreads along a surface of the wiring board on which the light emitting components are mounted; and a second portion contacting with an inner surface of the cover member.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a light emitting device using a light emitting component including a light emitting element that functions as a point light source, such as a light emitting diode. The present invention also relates to a wiring board on which a light emitting component is mounted, and relates to a wiring board used in a light emitting device.

  In recent years, it has been proposed to configure a light emitting device using a light emitting component including a light emitting element that functions as a point light source, such as a light emitting diode. For example, Patent Document 1 discloses a light emitting device including a mounting substrate on which a light emitting component is mounted and a cover member arranged with a space between the mounting substrate.

  The power consumption of light emitting elements such as light emitting diodes is generally lower than the power consumption of fluorescent and incandescent bulbs. For this reason, the amount of heat generated in a light emitting device using a light emitting element such as a light emitting diode is generally lower than the amount of heat generated in a light emitting device using a fluorescent lamp or an incandescent bulb. Such characteristics of light emitting elements such as light emitting diodes are preferable from the viewpoint of energy saving and environmental load reduction.

  By the way, when a light-emitting device is used as a signal light or a street light in a heavy snowy area, snow may adhere to the cover member of the light-emitting device. In the case of a light-emitting device using a conventional fluorescent lamp or incandescent lamp, a sufficient amount of heat is generated during light emission, and this heat can be used to melt the snow attached to the cover member. there were. However, in a light emitting device using a light emitting element such as a light emitting diode, the amount of heat generated at the time of light emission is small, so that the snow attached to the cover member cannot be sufficiently melted and visibility is deteriorated. Problems can arise.

  In order to solve such a problem, in Patent Document 1 described above, it is proposed to interpose a spacer between the mounting substrate and the cover member. In this case, the heat generated in the light emitting component of the mounting board can be efficiently conducted to the cover member via the spacer, so that it is possible to melt the snow attached to the cover member more efficiently.

JP 2012-256676 A

  In the invention described in Patent Document 1 described above, a spacer for conducting heat from the mounting substrate side to the cover member side extends between the mounting substrate and the cover member. For this reason, a part of the light emitted from the light emitting component is reflected by the spacer before reaching the cover member, and as a result, the influence of the arrangement of the spacer appears on the luminance distribution in the light emitting device. That is, it is conceivable that light unevenness occurs. Such unevenness of light becomes more prominent as the number of spacers is increased in order to increase the thermal conductivity between the mounting substrate and the cover member. Further, only the tip of the spacer contacts the cover member among the spacers. For this reason, it is difficult to efficiently heat the inner surface of the cover member over a wide area.

  The present invention has been made in consideration of such points, and an object of the present invention is to provide a light emitting device and a wiring board capable of efficiently heating a cover member using heat generated in a light emitting component. And

  The present invention includes a mounting board on which a light-emitting component is mounted, and a cover member disposed with a space between the light-emitting component of the mounting board, and the cover member is positioned on the mounting board side. The mounting board includes a wiring board on which the light emitting component is mounted, and the wiring board has flexibility and translucency. A heat conductive member, and the heat conductive member includes: a first portion extending along a surface of the wiring board on which the light emitting component is mounted; and a second portion in contact with the inner surface of the cover member. Including a light emitting device.

  In the light emitting device according to the present invention, when the region of the cover member that overlaps the light emitting component when viewed along the normal direction of the wiring board is referred to as an overlapping region, the second portion of the thermally conductive member. May be at least partially in contact with the inner surface of the cover member in the overlap region.

  In the light emitting device according to the present invention, the wiring board includes a first substrate and a base substrate including a second surface located on the opposite side of the first surface, and the thermally conductive member, and the light emitting component includes: It is mounted on the first surface side of the base substrate, and the first portion of the thermally conductive member may overlap the base substrate when viewed along the normal direction of the wiring substrate. .

  In the light emitting device according to the present invention, the thermal conductive member includes a support layer and a thermal conductive layer provided on the support layer, and the thermal conductive layer is a wire configured by a plurality of conductive particles. And / or a conductive wire arranged like a mesh, or a transparent conductive layer containing a metal oxide.

  In the light emitting device according to the present invention, the first portion of the thermally conductive member may be disposed on the second surface side of the base substrate, or disposed on the first surface side of the base substrate. It may be.

  The present invention provides a mounting board having a wiring board on which a light-emitting component is mounted, a light-emitting component mounted on the wiring board, and a cover disposed with a space between the light-emitting component of the mounting board. A wiring board used in a light-emitting device comprising a member, wherein the cover member includes an inner surface located on the mounting substrate side and an outer surface located on the opposite side of the inner surface, A heat conductive member having flexibility and translucency, wherein the heat conductive member includes a first portion extending along a surface of the wiring board on which the light emitting component is mounted, and the cover member. And a second part in contact with the inner surface.

  According to the present invention, the cover member can be efficiently heated using heat generated in the light emitting component.

FIG. 1 is a front view showing a light emitting device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a light emitting device according to an embodiment of the present invention. 3 is an enlarged cross-sectional view of a mounting substrate of the light emitting device shown in FIG. FIG. 4 is a cross-sectional view showing a modified example of the mounting substrate. FIG. 5 is a cross-sectional view showing a light emitting component mounted on a wiring board. FIG. 6 is a cross-sectional view showing a stacked body used for manufacturing a wiring board. FIG. 7 is a cross-sectional view showing a wiring board obtained by patterning a conductive layer of the laminate shown in FIG. 8 is a cross-sectional view showing a mounting board obtained by mounting a light emitting component on the wiring board shown in FIG. FIG. 9 is a cross-sectional view showing a light emitting device according to a modification of the embodiment of the present invention. 10 is a plan view showing a mounting substrate used in the light emitting device shown in FIG. FIG. 11 is a cross-sectional view showing a light emitting device according to a modification of the embodiment of the present invention. FIG. 12 is a cross-sectional view showing a light emitting device according to a modification of the embodiment of the present invention. FIG. 13 is a front view showing a light-emitting device according to a modification of the embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. In the drawings attached to the present specification, for the sake of illustration and ease of understanding, the scale, the vertical / horizontal dimension ratio, and the like are appropriately changed and exaggerated from those of the actual ones. Further, in this specification, the terms “substrate” and “sheet” are not distinguished from each other based only on the difference in designation. For example, the “substrate” is a concept including a member that can be called a sheet or a film. Furthermore, as used in this specification, the shape and geometric conditions and the degree thereof are specified. For example, terms such as “parallel” and “orthogonal”, length and angle values, and the like are bound to a strict meaning. Therefore, it should be interpreted including the extent to which similar functions can be expected.

Emitting device Referring first to FIGS. 1 and 2, illustrates a light-emitting device 80 according to this embodiment. 1 and 2 are a front view and a cross-sectional view showing the light emitting device 80. FIG.

  The light emitting device 80 includes a mounting substrate 60 on which a plurality of light emitting components 61 are mounted, and a cover member 82 that is disposed with a space between the light emitting components 61 of the mounting substrate 60. The cover member 82 is located on the mounting substrate 60 side, and includes an inner surface 82a on which the light L1 emitted from the light emitting component 61 is incident, and an outer surface 82b located on the opposite side of the inner surface 82a. The light L1 incident on the inner surface 82a of the cover member 82 is diffused inside the cover member 82 and then exits from the outer surface 82b as indicated by reference numeral L2. The cover member 82 may have a diffusion function that changes the traveling direction of light.

  In FIG. 2, the area | region which overlaps with the light emitting component 61 when it sees along the normal line direction N of the wiring board 40 among the cover members 82 is represented by the code | symbol 82c. Hereinafter, the area | region of the cover member 82 represented with the code | symbol 82c is also called an overlapping area | region. In the present embodiment, the “normal direction N of the wiring board 40” is individually determined based on the direction in which the surface of the wiring board 40 where the light-emitting component 61 is mounted widens. For example, when the wiring board 40 has a curved surface and a plurality of light emitting components 61 are mounted on the curved surface, the normal direction N in each part of the wiring board 40 on which the plurality of light emitting components 61 are mounted is: Each will be different.

  In the present embodiment, an example is shown in which the inner surface 82a and the outer surface 82b of the cover member 82 are substantially flat, and therefore the plurality of overlapping regions 82c are also flat. However, the present invention is not limited to this, and as shown in a modification example described later, the inner surface 82a and the outer surface 82b of the cover member 82 are configured as curved surfaces, and therefore, the plurality of overlapping regions 82c may be curved respectively. .

  As long as light can be appropriately transmitted, the material constituting the cover member 82 is not particularly limited. For example, polypropylene, acrylic, or the like can be used as a material constituting the cover member 82.

Mounting Board Next, the mounting board 60 will be described with reference to FIGS. 2 and 3. FIG. 3 is an enlarged cross-sectional view showing the mounting substrate 60 of the light emitting device 80 shown in FIG.

  The mounting board 60 includes a wiring board 40 that has flexibility and functions as a so-called flexible board, and a plurality of light-emitting components 61 mounted on the wiring board 40. As long as a light emitting element that can function as a point light source is provided, the configuration of the light emitting component 61 is not particularly limited. For example, a light-emitting diode can be used as the light-emitting element, and a surface-mounted component including a light-emitting diode housed in a surface-mounted package can be used as the light-emitting component 61.

  The mounting board 60 may further include a heat radiating plate 81 attached to the wiring board 40 on the side of the wiring board 40 opposite to the side on which the light emitting component 61 is mounted. The heat radiating plate 81 is for efficiently releasing the heat generated in the light emitting component 61 of the mounting substrate 60 to the outside. As the heat radiating plate 81, a material having high thermal conductivity such as an aluminum plate can be used. Further, the base or housing of the light emitting device 80 may function as the heat radiating plate 81.

  In FIG. 3, reference numeral 62 denotes a space between the light emitting component 61 and the mounting electrode portion 41 for joining the light emitting component 61 to the mounting electrode portion 41 and electrically connecting the light emitting component 61 to the mounting electrode portion 41. Represents a bonding layer interposed between the two. Examples of the material constituting the bonding layer 62 include cream solder applied on the mounting electrode portion 41 in a reflow process. Cream solder includes a binder material such as a flux and metal powder that is dispersed in the binder material and melts during the reflow process. Although FIG. 2 shows an example in which the bonding layer 62 is clearly interposed between the light emitting component 61 and the mounting electrode portion 41, the present invention is not limited to this. The shape and arrangement of the bonding layer 62 are not particularly limited as long as the light emitting component 61 can be coupled to the mounting electrode portion 41 to electrically connect the light emitting component 61 to the mounting electrode portion 41.

  By the way, in the reflow process, at least the mounting electrode portion 41 and the peripheral portion of the wiring board 40 are heated to a temperature equal to or higher than the melting point of the solder contained in the bonding layer 62. In the following description, the maximum temperature reached by the heated wiring board 40 is also referred to as the reached temperature. In the case where the wiring substrate 40 contains a resin, if the ultimate temperature is high, oligomer precipitation and resin discoloration are likely to occur, and as a result, the reflectance of the wiring substrate 40 is considered to decrease. Therefore, it is preferable to set the temperature at the time of performing the reflow process as low as possible so that the temperature reached by the wiring board 40 is lowered.

  In consideration of such points, low melting point solder that melts at a temperature of 180 ° C. or lower, more preferably 150 ° C. or lower may be used as the solder included in the bonding layer 62. In this case, the ultimate temperature of the wiring board 40 can be set to 180 ° C. or lower, more preferably 150 ° C. or lower. As a result, oligomers are deposited on the surface of the wiring board 40 such as a base substrate 21 described later. In addition, discoloration of the base substrate 21 and the like can be suppressed.

  As long as melting is performed at a temperature of 180 ° C. or lower, the low melting point solder included in the bonding layer 62 is not particularly limited. For example, as the low melting point solder, a solder containing 42 wt% to 43 wt% tin and 57 wt% to 58 wt% bismuth can be used. In addition, a solder containing tin, bismuth, and silver can be used.

The wiring substrate wiring substrate 40 includes a flexible base substrate 21 and a mounting electrode portion 41 provided on the base substrate 21. The mounting electrode portion 41 is a portion for mounting the light emitting component 61 and is also referred to as a pad or a land. In the following description, the surface of the base substrate 21 on which the mounting electrode portion 41 is provided, that is, the surface on which the light emitting component 61 is mounted is referred to as a first surface 21a and is on the opposite side of the first surface 21a. A certain surface is referred to as a second surface 21b. The base substrate 21 is a substrate for supporting the light emitting component 61. Although not shown, the mounting electrode portion 41 is connected to wiring for supplying power and signals.

  In the present embodiment, “flexibility” refers to the degree that a fold does not occur in the wiring board 40 when the wiring board 40 is wound into a roll shape having a diameter of 30 cm in an environment of room temperature, for example, 25 ° C. Means flexibility. A “fold” is a deformation that appears on the wiring board 40 in a direction that intersects the winding direction of the wiring board 40, and even if the wiring board 40 is wound in the opposite direction so as to restore the deformation to the original state. Means deformation that does not return. In addition, as long as the wiring board 40 has flexibility as a whole, the degree of flexibility in each of the base substrate 21, the mounting electrode portion 41, and the wiring is not particularly limited.

(Base substrate)
The base substrate 21 is a flexible substrate that is made of an insulating resin material. The material constituting the base substrate 21 and the thickness of the base substrate 21 are appropriately determined according to characteristics such as flexibility and strength required for the wiring substrate 40. For example, the base substrate 21 may include a polyester resin such as polyethylene terephthalate or polyethylene naphthalate, an epoxy resin, or a polyimide resin as the base resin.

  Even if the base substrate 21 is configured to reflect the light that is radiated from the light emitting component 61 and then reflected by the cover member 82 or the like and returns to the mounting substrate 60, it can be directed again toward the cover member 82. Good. For example, a white pigment or bubbles may be dispersed in the resin constituting the base substrate 21. As a result, the light returning to the mounting substrate 60 can be directed again to the diffusion plate side and emitted to the outside of the light emitting device. For this reason, the utilization efficiency of the light in a light-emitting device can be improved.

  A method for manufacturing the base substrate 21 having such a reflection characteristic is not particularly limited, and a known method can be appropriately used. For example, pellets as a raw material for the resin material and a white pigment are mixed and melted, the mixed material is formed by extrusion molding or the like, and fired as necessary. As the white pigment, white ceramic materials such as titanium oxide, calcium oxide, aluminum oxide, and zinc oxide can be used. In addition, various materials that can exhibit a white color, such as a white dye, can be used as the white pigment.

  When the base substrate 21 is provided with reflection characteristics, the base substrate 21 is preferably configured such that the total light reflectance in the light wavelength range of 380 nm to 780 nm is in the range of 60% to 99%. Here, the “total light reflectance” is the sum of regular reflectance and diffuse reflectance. The total light reflectance can be obtained in accordance with the total light reflectance measurement method of JIS K7375. Specifically, the total light reflectivity is 10 nm at a light wavelength of 380 nm to 780 nm using a spectrophotometer and an integrating sphere test stand when the light is incident on the base substrate 21 at an angle. It can be determined by measuring at intervals and calculating their average value. The total light reflectance is obtained as a relative value with the reflectance of a standard white plate containing barium sulfate as 100%.

(Thermal conductive member)
As shown in FIGS. 2 and 3, the wiring substrate 40 further includes a heat conductive member 22 disposed on the second surface 21 b side of the base substrate 21. Hereinafter, the heat conductive member 22 will be described.

  The heat conductive member 22 is a member provided to conduct heat generated in the light emitting component 61 to the cover member 82 and thereby melt snow attached to the cover member 82. As shown in FIG. 2, the heat conductive member 22 includes a first portion 22 x that extends along a surface on which the light emitting component 61 is mounted in the wiring board 40, and a second portion 22 y that contacts the inner surface 82 a of the cover member 82. , Including. As shown in FIG. 2, the first portion 22 x is a portion that overlaps the base substrate 21 when viewed along the normal direction N of the wiring substrate 40. The second portion 22y extends outward beyond the end portion 21c of the base substrate 21, and is bent along the contour of the inner surface 82a of the cover member 82 and is attached to the inner surface 82a. The heat conductive member 22 is flexible enough to withstand such bending. For example, the thickness of the heat conductive member 22 is in the range of 10 μm to 5 mm.

  The first portion 22x and the second portion 22y of the heat conductive member 22 are preferably configured integrally. That is, the part from the 1st part 22x to the 2nd part 22y among the heat conductive members 22 is continuously extended without a break. Accordingly, the heat generated in the light emitting component 61 can be more efficiently conducted to the second portion 22y via the base substrate 21 and the first portion 22x of the heat conductive member 22.

  In the present embodiment, the second portion 22y of the heat conductive member 22 is in contact with the inner surface 82a of the cover member 82 in the above-described overlapping region 82c of the cover member 82, as shown in FIG. In this case, the light L1 emitted from the light emitting component 61 passes through the second portion 22y of the heat conductive member 22 and enters the inner surface 82a of the cover member 82. Therefore, the second portion 22y of the heat conductive member 22 is required to have translucency. Here, “translucent” means that the total light transmittance of the second portion 22y of the heat conductive member 22 is 70% or more. Here, “total light transmittance” is defined as light transmittance including a diffusion component. The total light transmittance can be determined according to the total light transmittance measurement method of JIS K7375. Specifically, the transmittance is calculated by introducing the light transmitted through the test piece made of the heat conductive member 22 into the integrating sphere in a state where the dissipation from the end of the test piece is reduced as much as possible. Such measurement and calculation are performed at intervals of 10 nm at light wavelengths of 380 nm to 780 nm, and the total light transmittance can be obtained by calculating an average value thereof.

  The heat conductive member 22 is configured to have heat conductivity sufficient to conduct heat generated in the light emitting component 61 to the cover member 82 and thereby melt the snow attached to the cover member 82. . For example, the thermal conductivity of the thermal conductive member 22 in the direction from the first portion 22x to the second portion 22y is 1 W / (m · K) or more.

  Hereinafter, an example of a specific configuration of the heat conductive member 22 for realizing high heat conductivity in the heat conductive member 22 will be described. In the present embodiment, the heat conductive member 22 includes a support layer 24 and a heat conductive layer 23 provided on the support layer 24, as shown in FIG. The heat conductive layer 23 is a layer configured to have a heat conductivity of 1 W / (m · K) or more in a direction from the first portion 22x toward the second portion 22y. The support layer 24 is a layer that is flexible and configured to support the heat conductive layer 23. The support layer 24 includes, for example, a resin material. FIG. 3 shows an example in which the heat conductive layer 23 is positioned closer to the base substrate 21 than the support layer 24. However, the present invention is not limited to this, and although not shown, the support layer 24 is thermally conductive. It may be located closer to the base substrate 21 than the layer 23.

  As an example of the configuration of the heat conductive layer 23, a layer including a network formed by intertwining linear conductive wires formed of a plurality of conductive particles can be cited. This configuration is also called a so-called metal nanowire. For example, silver nanowires using silver particles as conductive particles and copper nanowires using copper particles are known. In addition, the material described as an example of the metal of a metal nanowire in Unexamined-Japanese-Patent No. 2014-63444 can be used. Further, a metal oxide material such as indium tin oxide or indium zinc oxide may be used as a material constituting the conductive particles.

  The heat conductive layer 23 including a conductive wire can be formed, for example, by applying a coating liquid in which conductive particles are dispersed on the support layer 24. As the liquid that acts as a solvent for dispersing the conductive particles, known solvents such as saturated hydrocarbons and aromatic hydrocarbons can be appropriately used. For example, the material described as an example of a dispersion medium in Unexamined-Japanese-Patent No. 2014-63444 can be used. In addition to the conductive particles and the solvent, the coating solution may contain a resin as necessary.

  As another example of the configuration of the heat conductive layer 23, a layer including metal conductive wires arranged in a mesh shape can be exemplified. This configuration is employed in electrodes of so-called mesh type touch panel sensors. As in the case of the conductive wire described above, the light transmittance in the heat conductive layer 23 is adjusted by appropriately adjusting the area ratio of the openings formed between the conductive wires arranged in a mesh pattern. Can do. Examples of the metal material constituting the conducting wire include silver, copper, aluminum, and alloys thereof.

  As a further example of the configuration of the heat conductive layer 23, a transparent conductive layer containing a metal oxide can also be mentioned. As an example of the metal oxide, a light-transmitting conductive material such as indium tin oxide or indium zinc oxide can be given.

(Mounting electrode and wiring)
As a material constituting the mounting electrode portion 41 and the wiring, a conductive material is used, and for example, a metal material such as copper or silver is used. In consideration of enhancing the reflection characteristics of the wiring board 40, silver is preferably used.

  The materials constituting the mounting electrode portion 41 and the wiring may be the same or different. For example, the mounting electrode portion 41 and the wiring may be formed simultaneously and continuously by patterning the same conductive layer 26 as will be described later. As long as the mounting substrate 60 is flexible in the desired direction, the dimensions such as the thickness and width of the mounting electrode portion 41 and the wiring 42 are not particularly limited.

(Reflective layer)
As described above, the wiring board 40 has a reflection characteristic that can reflect the light that is radiated from the light emitting component 61 and then reflected by the cover member 82 and returned to the mounting board 60. Is preferred. In the above-described embodiment, the example in which the base substrate 21 is provided with the reflection characteristic by dispersing the white pigment or the bubbles in the resin constituting the base substrate 21 has been described. However, the present invention is not limited to this, and as shown in FIG. 4, a reflective layer 44 is provided on the first surface 21 a side of the base substrate 21 so as not to overlap the light emitting component 61. The reflection characteristics of the substrate 40 may be realized.

  The configuration of the reflective layer 44 is not particularly limited as long as it can reflect light and thereby increase the light use efficiency in the light emitting device 80. For example, the reflective layer 44 may be configured as a layer including a white pigment having reflectivity such as a white ceramic material or metal powder. In this case, the reflective layer 44 is formed by first providing a paste containing a reflective white pigment, such as a white ceramic material or metal powder, on the first surface 21a of the base substrate 21, and then baking the paste. Is done. The method for providing the paste on the first surface 21a of the base substrate 21 is not particularly limited, and a screen printing method or the like can be used as appropriate. The reflective layer 44 may include a base material in which white pigments, bubbles, and the like are dispersed. In this case, the reflective layer 44 is formed by sticking a base material in which white pigments, bubbles, and the like are dispersed, to the first surface 21a of the base substrate 21 via an adhesive layer or an adhesive layer (not shown). As the white pigment, white ceramic materials such as titanium oxide, calcium oxide, aluminum oxide, and zinc oxide can be used as in the case of the white pigment dispersed in the base substrate 21.

  Preferably, the reflective layer 44 is configured so that the total light reflectance in the light wavelength range of 380 nm to 780 nm is in the range of 60% to 99%, as in the case of the base substrate 21. In addition, when the reflective layer 44 has a reflection characteristic, the base substrate 21 does not need to have the same reflection characteristic. That is, bubbles and white pigments need not be dispersed in the resin of the base substrate 21.

(Light-emitting parts)
Next, the light emitting component 61 will be described with reference to FIG. As shown in FIG. 5, the light emitting component 61 includes a light emitting element 66 and a terminal 67 that is electrically connected to the light emitting element 66 and at least partially exposed to the outside. The terminal 67 is connected via a bonding wire 67a. The terminal 67 is generally made of a metal material such as copper or silver. Heat generated in the light emitting component 61 is conducted to the mounting electrode portion 41 via the terminal 67.

  As shown in FIG. 5, a phosphor 68 for converting the wavelength of light emitted from the light emitting element 66 may be provided around the light emitting element 66. As shown in FIG. 5, a reflector 69 that reflects light may be disposed around the phosphor 68. Thereby, the light emitted from the light emitting element 66 can be extracted with high efficiency. A transparent resin 65 may be provided on the phosphor 68.

  Next, the operation and effect of the present embodiment having such a configuration will be described. Here, the laminated body is processed to produce the above-described wiring board 40, the light-emitting component 61 is mounted on the wiring board 40 to produce the above-mentioned mounting board 60, and the mounting board 60 and the cover member 82 are combined. A method for manufacturing the above-described light emitting device 80 will be described.

(Method for manufacturing a wiring board)
First, the laminate 20 shown in FIG. 6 is prepared. The stacked body 20 includes a base substrate 21, a conductive layer 26 provided on the first surface 21 a side of the base substrate 21, and a heat conductive member 22 provided on the second surface 21 b side of the base substrate 21. It is out. As shown in FIG. 6, the thermal conductive member 22 includes a first portion 22 x that overlaps the base substrate 21 and a second portion 22 y that extends beyond the end portion 21 c of the base substrate 21. In addition, the laminated body 20 may be prepared by a sheet | seat, or the elongate laminated body 20 may be supplied by a roll-to-roll.

  Next, the wiring board 40 is manufactured by processing the laminated body 20 described above. FIG. 7 is a cross-sectional view showing the wiring substrate 40 including the mounting electrode portion 41 obtained by patterning the conductive layer 26 of the stacked body 20.

  As a method of patterning the conductive layer 26, a method of etching the conductive layer 26 using a photosensitive layer provided on the conductive layer 26 in a pattern corresponding to the mounting electrode portion 41 as a mask, or a method corresponding to the mounting electrode portion 41. A known method such as a laser ablation method in which the conductive layer 26 is irradiated with a laser in a pattern can be appropriately used.

  Thereafter, although not shown, the above-described reflective layer 44 may be provided on the first surface 21 a side of the base substrate 21. Although not shown, an adhesive layer may be provided on the surface of the heat conductive member 22 opposite to the surface on the base substrate 21 side. The adhesive layer is for attaching the wiring board 40 and the mounting board 60 to the heat sink 81 and the cover member 82. By providing the adhesive layer in advance, the mounting process of the wiring board 40 and the mounting board 60 can be facilitated. On the adhesive layer, a release sheet for protecting the adhesive surface of the adhesive layer may be provided. As a material constituting the adhesive layer, for example, acrylic, epoxy, urethane or the like can be used. The adhesive layer may be included in the laminate 20 in advance.

  Moreover, although the example in which the heat conductive member 22 was previously contained in the laminated body 20 was shown, it is not restricted to this, After producing the wiring board 40 and the mounting board 60 mentioned later, the wiring board 40 and the mounting board 60 are shown. The heat conductive member 22 may be attached to the second surface 21 b side of the base substrate 21.

(Manufacturing method of mounting substrate)
Next, the bonding layer 62 is provided on the mounting electrode portion 41 of the wiring board 40. For example, cream solder for forming the bonding layer 62 is applied on the mounting electrode portion 41. Thereafter, a mounting process for mounting the light emitting component 61 on the mounting electrode part 41 provided with the bonding layer 62, a so-called reflow process is performed. Specifically, first, the light emitting component 61 is placed on the mounting electrode portion 41 provided with the bonding layer 62, and then the mounting electrode portion on which at least the light emitting component 61 of the wiring board 40 is placed. The portion 41 is heated to melt the bonding layer 62. As a result, as shown in FIG. 8, it is possible to obtain a mounting substrate 60 on which the light emitting component 61 is mounted.

(Method for manufacturing light emitting device)
Next, the light emitting device 80 is manufactured by combining the mounting substrate 60 and the cover member 82. Specifically, the mounting substrate 60 and the cover member 82 are combined so that the light emitting component 61 of the mounting substrate 60 and the inner surface 82a of the cover member 82 face each other with a space therebetween. At that time, the second portion 22y of the heat conductive member 22 of the wiring substrate 40 of the mounting substrate 60 is bent along the inner surface 82a of the cover member 82 and attached to the inner surface 82a. Thereby, the light emitting device 80 shown in FIG. 2 can be obtained. As shown in FIG. 2, a heat radiating plate 81 may be attached to the wiring board 40 on the opposite side of the wiring board 40 from the side on which the light emitting component 61 is mounted.

  According to the light emitting device 80 according to the present embodiment, the heat generated in the light emitting component 61 is conducted to the first portion 22x of the heat conductive member 22 through the mounting electrode portion 41 and the base substrate 21. . Thereafter, heat is conducted from the first portion 22 x to the second portion 22 y with high thermal conductivity in the heat conductive member 22, and is transferred to the cover member 82. As described above, according to the present embodiment, by using the heat conductive member 22 configured to overlap the light emitting component 61 in the thickness direction and extend to contact with the inner surface 82a of the cover member 82, the light emitting component 61 generates the heat. The conducted heat can be efficiently conducted to the cover member 82. For this reason, snow attached to the cover member 82 can be melted without providing an additional heat source such as a heater in the light emitting device 80. Of course, an additional heat source such as a heater may be provided in the light emitting device 80. Even in that case, the load applied to the additional heat source can be reduced by using the above-described heat conductive member 22, and thus the power consumption of the entire light emitting device 80 can be reduced. .

  In the present embodiment, the second portion 22y of the heat conductive member 22 is attached to the inner surface 82a of the cover member 82 as a surface. Specifically, the surface of the second portion 22 y continuously extending from the surface of the first portion 22 x extending along the plurality of light emitting components 61 of the heat conductive member 22 is attached to the inner surface 82 a of the cover member 82. It has been. In this case, the heat conductive member for the contact area between the heat conductive member 22 and the inner surface 82a of the cover member 82 as compared with the case where the spacer-shaped heat conductive member as in the invention described in Patent Document 1 is used. The volume ratio of 22 can be reduced. That is, heat can be efficiently transferred to the cover member 82 by using the heat conductive member 22 having a smaller volume.

  According to the present embodiment, since the second portion 22y of the heat conductive member 22 has flexibility, the second portion 22y can be brought into close contact with the inner surface 82a of the cover member 82 without a gap. For this reason, heat can be more efficiently conducted from the second portion 22y of the heat conductive member 22 to the cover member 82.

  Further, according to the present embodiment, since the second portion 22y of the heat conductive member 22 has high translucency, as shown in FIG. The second portion 22y of the member 22 can be attached. For this reason, it can suppress that the nonuniformity of light arises compared with the case where the spacer exists locally like the invention of the above-mentioned patent document 1. In addition, the second portion 22y of the heat conductive member 22 can be disposed so as to overlap the overlapping region 82c of the cover member 82.

  Note that various modifications can be made to the above-described embodiment. Hereinafter, modified examples will be described with reference to the drawings as necessary. In the following description and the drawings used in the following description, the same reference numerals as those used for the corresponding parts in the above embodiment are used for the parts that can be configured in the same manner as in the above embodiment. A duplicate description is omitted. In addition, when it is clear that the operational effects obtained in the above-described embodiment can be obtained in the modified example, the description thereof may be omitted.

(Modification of arrangement of heat conductive member)
In the above-described embodiment, the example in which the first portion 22x of the heat conductive member 22 is disposed on the second surface 21b side of the base substrate 21 has been described. However, the present invention is not limited to this, and the first portion 22x of the heat conductive member 22 may be disposed on the first surface 21a side of the base substrate 21 as shown in FIG.

  FIG. 10 is a plan view showing a case where the mounting substrate 60 used in the light emitting device 80 shown in FIG. 9 is viewed from the side where the light emitting component 61 is mounted. When the first portion 22x of the heat conductive member 22 is disposed on the first surface 21a side of the base substrate 21, as shown in FIG. 10, an opening is provided at a position corresponding to the light emitting component 61 in the first portion 22x. 22c may be formed. When the light transmittance of the first portion 22x of the heat conductive member 22 is sufficiently high, the first portion 22x of the heat conductive member 22 may be overlapped with the light emitting component 61, although not illustrated.

  9 and 10 also, the surface of the second portion 22y continuously extending from the surface of the first portion 22x extending along the plurality of light emitting components 61 of the heat conductive member 22 is covered by the cover. The member 82 is attached to the inner surface 82a. For this reason, the heat generated in the light emitting component 61 can be efficiently conducted to the cover member 82.

(Modification of the configuration of the heat conductive member)
Further, in the above-described embodiment and modification, the heat conductive member 22 for conducting the heat generated in the light emitting component 61 to the cover member 82 is provided separately from the base substrate 21 that supports the light emitting component 61. An example is given. However, the present invention is not limited to this, and the heat conductive member 22 may further fulfill the function of supporting the light emitting component 61 in addition to the function of conducting the heat generated in the light emitting component 61 to the cover member 82. . For example, as illustrated in FIG. 11, the heat conductive member 22 may include a first portion 22 x that supports the light emitting component 61 and a second portion 22 y that contacts the inner surface 82 a of the cover member 82.

In the modification shown in FIG. 11, the mounting electrode portion 41 and the wiring described above are formed on the first portion 22 x of the heat conductive member 22. In this case, at least the surface of the heat conductive member 22 on which the light emitting component 61 is mounted is made of an insulating material.
For example, the surface of the thermally conductive member 22 on which the light emitting component 61 is mounted can be configured using the support layer 24 including a resin material. Further, the above-described heat conductive layer 23 may be provided on the side of the support layer 24 opposite to the side on which the light emitting component 61 is mounted, thereby ensuring the heat conductivity of the heat conductive member 22.
In addition, the heat conductive member 22 may be configured by extending a resin substrate in which a white pigment or the like is dispersed, such as the above-described base substrate 21, and attaching the resin substrate to the inner surface 82 a of the cover member 82.

(Modification of the second part of the heat conductive member)
Further, in the above-described embodiment and the modification, the example in which the second portion 22y of the heat conductive member 22 is in contact with the inner surface 82a of the cover member 82 in the overlapping region 82c of the cover member 82 has been described. However, the present invention is not limited to this, and the second portion 22y of the heat conductive member 22 may be disposed so as not to contact the overlapping region 82c of the cover member 82 as shown in FIG. Even in this case, as shown in FIG. 12, the second portion 22 y of the heat conductive member 22 partially contacts the inner surface 82 a of the cover member 82, thereby efficiently covering the heat generated in the light emitting component 61. The member 82 can be conducted.

(Modification of cover member)
Further, in the above-described embodiment and modification examples, the inner surface 82a and the outer surface 82b of the cover member 82 are substantially flat, and therefore, the plurality of overlapping regions 82c are also flat. However, as shown in FIG. 13, the inner surface 82a and the outer surface 82b of the cover member 82 are configured as curved surfaces, and therefore, the plurality of overlapping regions 82c may be curved respectively. Thus, even if the cover member 82 has a curved surface, according to the present embodiment, since the heat conductive member 22 is flexible, the second portion of the heat conductive member 22 is provided. 22y can be easily attached to the inner surface 82a of the cover member 82. For this reason, the heat generated in the light emitting component 61 can be efficiently conducted to the cover member 82.

  Although not shown, the wiring board 40 may have a curved surface, and a plurality of light emitting components 61 may be mounted on the curved surface. Even in this case, the surface of the second portion 22y continuously extending from the surface of the first portion 22x extending along the plurality of light emitting components 61 in the heat conductive member 22 is changed to the inner surface 82a of the cover member 82. By attaching to the cover member 82, heat generated in the light emitting component 61 can be efficiently conducted to the cover member 82.

(Other variations)
In the above-described embodiment, the example in which the heat radiating plate 81 is attached to the wiring board 40 after the light emitting component 61 is mounted, that is, the mounting board 60 is shown. However, the present invention is not limited to this. Absent. For example, the heat radiating plate 81 may be attached to the wiring substrate 40 before the light emitting component 61 is mounted, and then the light emitting component 61 may be mounted on the mounting electrode portion 41 of the wiring substrate 40.

  In the present embodiment, an example in which the wiring board 40 has flexibility as a whole has been shown. For example, an example in which the base substrate 21 supporting the light emitting component 61 has flexibility has been shown. However, as long as the heat conductive member 22 attached to the inner surface 82a of the cover member 82 has flexibility, the wiring board 40 does not need to have flexibility as a whole. For example, a hard material used for a so-called rigid substrate may be used as the material constituting the base substrate 21.

  In addition, although some modified examples with respect to the above-described embodiment have been described, naturally, a plurality of modified examples can be applied in combination as appropriate.

DESCRIPTION OF SYMBOLS 20 Laminated body 21 Base substrate 22 Thermal conductive member 22x 1st part 22y 2nd part 23 Thermal conductive layer 24 Support layer 40 Wiring board 41 Mounting electrode part 60 Mounting board 61 Light emitting component 62 Bonding layer 80 Light emitting apparatus 81 Heat sink 82 Cover member 82a inner surface 82b outer surface 82c overlap region

Claims (7)

A mounting board on which light emitting components are mounted;
A cover member disposed with a space between the light emitting component of the mounting substrate, and
The cover member includes an inner surface located on the mounting substrate side, and an outer surface located on the opposite side of the inner surface,
The mounting board has a wiring board on which the light emitting component is mounted,
The wiring board includes a heat conductive member having flexibility and translucency,
The heat conductive member includes a first portion that extends along a surface of the wiring board on which the light emitting component is mounted, and a second portion that contacts the inner surface of the cover member.   In the cover member, when the region overlapping the light emitting component when viewed along the normal direction of the wiring board is referred to as an overlapping region, the second portion of the heat conductive member is at least partially, The light emitting device according to claim 1, wherein the light emitting device is in contact with the inner surface of the cover member in the overlapping region. The wiring board includes a base substrate including a first surface and a second surface located on the opposite side of the first surface, and the thermally conductive member.
The light emitting component is mounted on the first surface side of the base substrate,
3. The light emitting device according to claim 1, wherein the first portion of the thermal conductive member overlaps the base substrate when viewed along a normal direction of the wiring substrate. The thermally conductive member includes a support layer and a heat conductive layer provided on the support layer,
The thermal conductive layer includes at least one of a linear conductive wire composed of a plurality of conductive particles, a conductive wire arranged in a mesh shape, or a transparent conductive layer containing a metal oxide. Item 4. The light emitting device according to Item 3.   5. The light emitting device according to claim 3, wherein the first portion of the thermal conductive member is disposed on the second surface side of the base substrate.   5. The light emitting device according to claim 3, wherein the first portion of the thermal conductive member is disposed on the first surface side of the base substrate. A wiring board on which a light emitting component is mounted; and a light emitting component mounted on the wiring board; a mounting board;
A wiring board used in a light-emitting device comprising: a cover member arranged with a space between the light-emitting component of the mounting board;
The cover member includes an inner surface located on the mounting substrate side, and an outer surface located on the opposite side of the inner surface,
The wiring board includes a heat conductive member having flexibility and translucency,
The heat conductive member includes a first portion that extends along a surface of the wiring substrate on which the light emitting component is mounted, and a second portion that contacts the inner surface of the cover member.

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