Light emitting module and surface light source

Abstract

To provide a light emitting module which has little luminance unevenness, and to provide a surface light source.SOLUTION: A light emitting module includes: a light source part; and a light guide part in which light emitted by the light source enters, and which has an upper surface, a lower surface positioned on the opposite side from the upper surface, and a side surface positioned between the upper surface and the lower surface. The light guide part includes a gap part defined by a surface including a first reflection region positioned below the upper surface and closer than the lower surface with respect to the upper surface, and a second reflection region extended to the lower surface side from the first reflection region. The surface roughness of the first reflection region is smaller than the surface roughness of the second reflection region.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a light emitting module and a surface light source. [Background technology]

[0002] Light-emitting modules in which a light-emitting element such as a light-emitting diode and a light guide plate are combined are widely used as planar light sources such as backlights for liquid crystal displays (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-137212 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a light-emitting module and a surface light source capable of reducing luminance unevenness. [Means for solving the problem]

[0005] The light emitting module according to the present disclosure comprises: A light source unit; a light guiding unit to which light emitted by the light source unit is incident and which has an upper surface, a lower surface located opposite to the upper surface, and a side surface located between the upper surface and the lower surface; the light guiding section includes a gap section including a first reflective area located below the upper surface and closer to the upper surface than the lower surface, and a second reflective area extending from the first reflective area toward the lower surface, The surface roughness of the first reflective area is smaller than the surface roughness of the second reflective area.

[0006] A surface light source according to the present disclosure includes a wiring board and a light emitting module according to the present disclosure disposed on the wiring board. Effect of the Invention

[0007] The light emitting module and surface light source of the present disclosure can reduce brightness unevenness. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic plan view of a surface light source according to a first embodiment. [Diagram 2] 2 is a schematic plan view of one light-emitting section of the surface light source of FIG. 1. [Diagram 3] FIG. 3 is a schematic cross-sectional view taken along line III-III in FIG. [Figure 4] 2 is a schematic cross-sectional view of a light source portion in the surface light source of FIG. 1. [Diagram 5] 2 is a schematic cross-sectional view of a light guiding section including a gap in the surface light source of FIG. 1. [Figure 6] 10 is a schematic plan view of a surface light source according to a second embodiment. FIG. [Figure 7] FIG. 11 is a schematic plan view of a surface light source according to a third embodiment. [Figure 8A] 8 is a schematic plan view of a gap portion of the surface light source of FIG. 7. [Figure 8B] 13 is a schematic plan view of a modified example of the gap portion in the surface light source of the third embodiment. FIG. [Figure 9] 11 is a schematic cross-sectional view of a surface light source according to a fourth embodiment. [Figure 10] 11 is a schematic cross-sectional view of a surface light source according to a fifth embodiment. [Figure 11] 13 is a schematic cross-sectional view of a surface light source according to a sixth embodiment. FIG. [Figure 12A] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing a surface light source according to an embodiment. [Figure 12B] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing a surface light source according to an embodiment. [Figure 12C] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing a surface light source according to an embodiment. [Figure 13A] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing a surface light source according to an embodiment. [Figure 13B]5A to 5C are schematic cross-sectional views illustrating a method for manufacturing a surface light source according to an embodiment. [Figure 14A] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing a surface light source according to an embodiment. [Figure 14B] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing a surface light source according to an embodiment. [Figure 14C] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing a surface light source according to an embodiment. [Figure 14D] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing a surface light source according to an embodiment. [Figure 14E] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing a surface light source according to an embodiment. [Figure 15A] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing a surface light source according to an embodiment. [Figure 15B] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing a surface light source according to an embodiment. [Figure 15C] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing a surface light source according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, with reference to the drawings, an embodiment for carrying out the invention according to the present disclosure will be described. The light-emitting module and the surface light source described below are for embodying the technical idea of ​​the invention according to the present disclosure, and unless otherwise specified, the invention according to the present disclosure is not limited to the following. In each drawing, the same reference numerals may be attached to members having the same functions. In consideration of the explanation or ease of understanding of the main points, the embodiments may be shown separately for convenience, but partial replacement or combination of the configurations shown in different embodiments is possible. In the embodiments described later, the description of matters common to the above will be omitted, and only the differences will be described. In particular, the same action and effect due to the same configuration will not be mentioned in each embodiment. The size and positional relationship of the members shown in each drawing may be exaggerated in order to clarify the explanation. In addition, an end view showing only the cut surface may be used as a cross-sectional view. In this specification, "upper" means the positive direction of the Z axis in the figure, and "lower" means the negative direction of the Z axis in the figure.

[0010] (Embodiment 1) A surface light source 301 according to a first embodiment of the present disclosure will be described with reference to Figs. 1 to 5. Fig. 1 is a schematic plan view of the surface light source 301. Fig. 2 is a schematic plan view of one light-emitting section of the surface light source 301. Fig. 3 is a schematic cross-sectional view of one light-emitting section of the surface light source 301. The schematic cross-sectional view shown in Fig. 3 shows a cross-section of the surface light source 301 taken along line III-III in Fig. 2. Fig. 4 is a schematic cross-sectional view of the light source section 1. Fig. 5 is a schematic cross-sectional view of an enlarged portion of the light guide section 2 including the gap section 5.

[0011] (Embodiment 1) A first embodiment according to the present disclosure relates to a surface light source 301. As shown in Fig. 3, the surface light source 301 includes a light emitting module 101 and a wiring board 201. The light emitting module 101 is disposed on the wiring board 201. The surface light source 301 may include a plurality of light emitting modules 101. The plurality of light emitting modules 101 are disposed in a matrix.

[0012] (Light Emitting Module) As shown in Figs. 1 to 3, the light emitting module 101 includes a light source unit 1 and a light guide unit 2. Light emitted by the light source unit 1 is incident on the light guide unit 2. The light guide unit 2 has an upper surface 21, a lower surface 22 located opposite to the upper surface 21, and a side surface 23 located between the upper surface 21 and the lower surface 22. As shown in Fig. 5, the light guide unit 2 includes a gap portion 5 defined by a surface including a first reflection region 51 located below the upper surface 21 and closer to the upper surface 21 than the lower surface 22, and a second reflection region 52 extending from the first reflection region 51 toward the lower surface 22. The surface roughness of the first reflection region 51 is smaller than the surface roughness of the second reflection region 52.

[0013] The light emitting module 101 may further include a light-transmissive member 3 (hereinafter also referred to as a first light-transmissive member) and a first light adjusting member 4.

[0014] The light emitting module 101 includes a light emitting section that is composed of one light guide section 2 and at least one light source section 1. When most of the light incident from the light source section 1 into the light guide section 2 reaches the outer side surface 23a, the luminance near the side surface 23a increases. As a result, in the light emitting section, the luminance of the intermediate section located between the central section and the peripheral section tends to be lower than the luminance of the central section where the light source section 1 exists and the luminance of the peripheral section near the side surface 23a. By disposing the void section 5 in the light guide section 2 and increasing the surface roughness of the second reflection area 52, the light incident from the light source section 1 into the light guide section 2 can be diffused in the second reflection area 52 of the void section 5 and extracted upward before reaching the side surface 23a. That is, the amount of light that enters the light guide section 2 from the light source section 1 and reaches the side surface 23a can be reduced. As a result, the luminance of the intermediate section of the light emitting section increases and the luminance of the peripheral section decreases, so that the luminance unevenness of the light emitting module 101 can be reduced.

[0015] The light emitting module 101 is provided with the second reflection region 52 and the gap portion 5 including the first reflection region 51 having a surface roughness smaller than that of the second reflection region 52, thereby improving the efficiency of extracting light upward in the middle portion of the light emitting section and reducing the brightness unevenness between the middle portion and the peripheral portion. In addition, since the surface roughness of the first reflection region 51 is small, the light incident from above the light guide unit 2 can be more efficiently reflected upward. For example, when the surface light source 301 is used for a liquid crystal backlight, the light reflected by a prism sheet or the like located above the light emitting module 101 and returning to the light emitting module 101 side can be efficiently reflected upward again. That is, the light recycling efficiency is improved, and the brightness of the light emitting module 101 is improved.

[0016] (Light guide section) The light guide section 2 is a member having translucency with respect to the light emitted by the light source section 1. The transmittance of the light guide section 2 with respect to the peak wavelength of the light source section 1 is, for example, preferably 60% or more, and more preferably 80% or more.

[0017] The light guide section 2 may be made of a material such as a thermoplastic resin, such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate, or polyester, a thermosetting resin, such as epoxy or silicone, or glass.

[0018] The thickness of the light guide section 2 is preferably, for example, 150 μm or more and 800 μm or less. In this specification, the thickness of the light guide section 2 is the maximum distance in the Z-axis direction from the upper surface 21 to the lower surface 22. The light guide section 2 may be composed of a single layer, or may be composed of a laminate of multiple layers. When the light guide section 2 is composed of a laminate, a light-transmitting adhesive member may be disposed between each layer. Each layer of the laminate may use a different type of main material. The material of the adhesive member may be, for example, a thermoplastic resin such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate, or polyester, or a thermosetting resin such as epoxy or silicone.

[0019] 3, the light guiding section 2 has an upper surface 21, a lower surface 22 located opposite to the upper surface 21, and a side surface 23 located between the upper surface 21 and the lower surface 22. As shown in FIG 1, the side surface 23 includes an outer side surface 23a and an inner side surface 23b.

[0020] 1 to 3, the light guide 2 has a hole 24 defined by the side surface 23b. That is, the hole 24 penetrates the light guide 2 from the upper surface 21 to the lower surface 22. The light source 1 is disposed in the hole 24. In the first embodiment, the hole 24 is circular in a plan view from the upper surface 21 side (hereinafter referred to as a top view). By making the shape of the hole 24 circular in a plan view, it is possible to reduce the bias of the light incident on the side surface 23b, and thus to reduce the brightness unevenness.

[0021] 3, the side surface 23a includes an inclined surface inclined at an acute angle with respect to the lower surface 22, i.e., an inclined surface inclined so as to approach the lower surface 22 as it approaches the outside of the light guide section 2 in the x-axis direction. The inclined surface may be a part of the side surface 23a or the entire side surface 23a. For example, the side surface 23a includes an extension portion 28 extending continuously from a part of the side surface 23a on the lower surface 22 side. Note that the side surface 23a is not limited to the above embodiment, and may include an inclined surface inclined at an obtuse angle with respect to the lower surface 22, or may include a surface perpendicular to the upper surface 21 and the lower surface 22.

[0022] 2, 3, and 5, the light guide section 2 includes a gap 5 defined by a surface including a first reflection region 51 located below the upper surface 21 and closer to the upper surface 21 than the lower surface 22, and a second reflection region 52 extending from the first reflection region 51 toward the lower surface 22. The surface roughness of the first reflection region 51 is smaller than the surface roughness of the second reflection region 52. The gap 5 is defined by the first reflection region 51 and a side surface extending from the first reflection region 51 toward the lower surface 22. The entire side surface may be the second reflection region 52, or only a part of the side surface may be the second reflection region 52.

[0023] The second reflection area 52 is preferably located on the light source unit 1 side when viewed from above. By arranging the second reflection area 52 on the light source unit 1 side when viewed from above, the light from the light source unit 1 can be scattered more efficiently.

[0024] The surface roughness of the first reflection region 51 may be preferably 40 nm or less, more preferably 20 nm or less, and even more preferably 5 nm or less. By making the surface roughness of the first reflection region 51 smaller, the specular reflectance can be increased, and light can be more efficiently reflected upward. The lower limit of the surface roughness of the first reflection region 51 is preferably substantially 0 nm at which specular reflection is possible, and may be, for example, 0.1 nm.

[0025] The surface roughness of the second reflective region 52 may be preferably 80 nm or more and 2000 nm or less, more preferably 100 nm or more and 1000 nm or less, and further preferably 115 nm or more and 300 nm or less. By setting the surface roughness of the second reflective region 52 within the above range, light can be scattered more efficiently.

[0026] The surface roughness of the second reflection region 52 is preferably equal to or greater than ¼ of the peak wavelength of the light emitted by the light source unit 1. By making the surface roughness of the second reflection region 52 equal to or greater than ¼ of the peak wavelength of the light emitted by the light source unit 1, the light can be scattered more efficiently.

[0027] The surface roughness is the surface roughness (Sa) specified by ISO25178. The surface roughness (Sa) can be measured using a white light interferometer. Specifically, a 50x lens is used to measure an area of ​​φ50 μm to 500 μm, and Sa is calculated from the data obtained. This measurement method allows the measurement to be performed by limiting the measurement area in accordance with the shapes of the first reflection area 51 and the second reflection area 52. When calculating the surface roughness (Sa), data from an area that does not include scratches or the like is used.

[0028] In the light guiding section 2 of the first embodiment, the gap 5 is open to the lower surface 22. By forming the gap 5 to be open to the lower surface 22, the formation of the gap 5 is facilitated. The gap 5 is not limited to being open to the lower surface 22, and may be formed at a position where at least a part of the gap overlaps with the light source section 1 in a direction parallel to the lower surface 22 and is spaced apart from the upper surface 21. For example, the gap 5 may be formed inside the light guiding section 2, that is, at a position spaced apart from both the upper surface 21 and the lower surface 22. The maximum distance of the gap in the vertical direction (Z-axis direction) is 0.1 times or more the thickness of the light guiding section.

[0029] In the light guide unit 2 of the first embodiment, the gap 5 includes gaps 5a, 5b, 5c, and 5d in the order of distance from the light source unit 1. The gap 5 has the lowest height, followed by gaps 5b, 5c, and the highest height, and the gap 5d. In other words, the height of the gap 5 increases as it is farther from the light source unit. The height of the gap 5 refers to the height from the lower end of the gap 5 to the first reflection region 51. When the gap 5 is open to the lower surface 22, the lower end of the gap 5 is flush with the lower surface 22. As shown in FIG. 5, by increasing the height of the gap 5 as it is farther from the light source unit, the light incident on the light guide unit 2 can be scattered stepwise in the gaps 5a to 5d. This makes it easier to reduce the bias of the light emitted from the upper surface 21 of the light-emitting module 101 toward the side surface 23a, and the luminance unevenness of the light-emitting module 101 can be further reduced.

[0030] In the light guiding section 2 of the first embodiment, the gap 5 is arranged rotationally symmetrically with respect to the light source section 1 in a top view. More specifically, the gap 5 is arranged in a circular ring shape around the light source section 1 in a top view. By arranging the gap 5 rotationally symmetrically, particularly in a circular ring shape, with respect to the light source section 1 in a top view, it is possible to further reduce the luminance unevenness of the light emitting module 101.

[0031] The shape of the gap 5 in top view may be substantially circular. The term "substantially circular" is not limited to a perfect circle, and may include a non-perfect circle, such as an ellipse. By making the shape of the gap 5 in top view substantially circular, there is no corner where stress concentrates, so that the gap 5 is less likely to deform and has high reliability.

[0032] The shape of the cavity 5 as viewed from above is not limited to a substantially circular shape, and may be another shape, for example, a substantially polygonal shape such as a triangle, a rectangle, a pentagon, a hexagon, etc. By making the cross-sectional shape of the cavity 5 a substantially polygonal shape, the second reflection region 52 as a plane can be directed toward the light source unit 1, and the scattering efficiency of the light from the light source unit 1 can be improved.

[0033] The maximum width of the gaps 5 in top view may be preferably 5 μm to 300 μm, more preferably 10 μm to 200 μm, for example 20 μm to 150 μm, or 30 μm to 100 μm. By making the maximum width of the gaps 5 in top view 5 μm or more, the amount of light reflected per gap 5 increases. In addition, by making the maximum width of the gaps 5 in top view 300 μm or less, the degree of freedom in arranging the gaps 5 is improved.

[0034] The area of ​​the cross section perpendicular to the height direction of the void 5 is preferably smaller closer to the top surface 21. In other words, the void 5 has a shape that becomes thinner closer to the top surface 21. By making the shape of the void 5 thinner closer to the top surface 21, the formation of the void 5 becomes easier. For example, when the light guide 2 having the void 5 is formed by the imprint method, by making the void 5 thinner closer to the top surface 21, the light guide 2 is easily removed from the mold, and moldability is improved. In addition, by making the void 5 thinner closer to the top surface 21, the second reflection region 52 has a shape that is obliquely oriented toward the top surface 21, so that the light scattered by the second reflection region 52 is easily emitted from the top surface 21.

[0035] The light guide 2 may further include a recess that opens to the upper surface 21. By providing the light guide 2 with a recess that opens to the upper surface 21, the light from the light source 1 is diffused by the wall surface of the recess and taken out to the outside of the light guide 2. Therefore, by providing the recess in a low-luminance portion of the light-emitting module, it is possible to reduce luminance unevenness. In addition, the recess is preferably provided at a position that overlaps with the gap 5 in a direction parallel to the lower surface 22 in the low-luminance portion of the light-emitting module, and luminance unevenness can be further reduced. Furthermore, the recess is preferably provided at a position that does not overlap with the gap 5 in a top view so that the gap 5 can more efficiently reflect the light incident from above the light guide 2 upward. The shape of the recess as viewed from above is not particularly limited, and may be, for example, a V-shape, an L-shape, a substantially circular shape, or a substantially polygonal shape such as a triangle, a rectangle, a hexagon, or an octagon.

[0036] (Light source part) In the light-emitting module 101 of the first embodiment, the light source unit 1 is disposed in the hole 24. In the illustrated example, one light source unit is disposed in the hole 24. The light source unit 1 is not limited to this, and for example, a plurality of light source units may be disposed in the hole 24. The light source unit 1 is disposed such that each of the four side surfaces faces a corresponding corner of the light guiding unit 2. The light source unit 1 is not limited to this, and for example, the light source unit 1 may be disposed such that each of the side surfaces is parallel to the side surface 23a of the light guiding unit 2.

[0037] As shown in FIG. 4, the light source unit 1 includes a light emitting element 11. The light emitting element 11 includes a semiconductor laminate. The semiconductor laminate includes an n-type semiconductor layer, a p-type semiconductor layer, and a light emitting layer sandwiched between them. The light emitting layer may have a structure such as a double heterojunction or a single quantum well (SQW), or may have a structure including a plurality of well layers such as a multiple quantum well (MQW). The semiconductor laminate is configured to be capable of emitting visible light or ultraviolet light. Such a semiconductor laminate including a light emitting layer may be, for example, In x Al y Ga 1-x-y N (0≦x, 0≦y, x+y≦1).

[0038] The semiconductor laminate may have a structure including one or more light-emitting layers between an n-type semiconductor layer and a p-type semiconductor layer, or may have a structure in which a structure including an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer in order is repeated multiple times. When the semiconductor laminate includes multiple light-emitting layers, the semiconductor laminate may include light-emitting layers having different emission peak wavelengths, or light-emitting layers having the same emission peak wavelength. The same emission peak wavelength includes a case where the emission peak wavelength varies by about several nm. The combination of emission peak wavelengths between multiple light-emitting layers can be appropriately selected. For example, when the semiconductor laminate includes two light-emitting layers, the light-emitting layers can be selected from combinations such as blue light and blue light, green light and green light, red light and red light, ultraviolet light and ultraviolet light, blue light and green light, blue light and red light, or green light and red light. Each light-emitting layer may include multiple active layers having different emission peak wavelengths, or multiple active layers having the same emission peak wavelength.

[0039] 4, the light source unit 1 may further include a second light-transmissive member 12 (hereinafter also referred to as a light-source light-transmissive member). The light-source light-transmissive member 12 covers the upper surface and side surfaces of the light-emitting element 11. The light-source light-transmissive member 12 protects the light-emitting element 11 and has functions such as wavelength conversion and light diffusion depending on particles added to the light-source light-transmissive member 12.

[0040] For example, the light source transmissive member 12 may include a transmissive resin and may further include a phosphor. As the transmissive resin, for example, a silicone resin or an epoxy resin may be used. As the phosphor, an yttrium-aluminum-garnet phosphor (for example, Y3(Al,Ga)5O 12 :Ce), lutetium aluminum garnet phosphors (e.g., Lu3(Al,Ga)5O 12 :Ce), terbium aluminum garnet phosphors (e.g., Tb3(Al,Ga)5O 12 :Ce), CCA phosphors (e.g., Ca 10 (PO4)6Cl2:Eu), SAE phosphors (e.g., Sr4Al 14 O 25:Eu), chlorosilicate phosphors (e.g., Ca8MgSi4O 16 Cl2:Eu), silicate phosphors (e.g., (Ba,Sr,Ca,Mg)2SiO4:Eu), β - sialon phosphors (e.g., (Si,Al)3(O,N)4:Eu) or α - sialon phosphors (e.g., Ca(Si,Al) 12 (O,N) 16 :Eu) and other oxynitride phosphors, LSN phosphors (e.g., (La,Y)3Si6N 11 :Ce), BSESN phosphors (e.g., (Ba,Sr)2Si5N8:Eu), SLA phosphors (e.g., SrLiAl3N4:Eu), CASN phosphors (e.g., CaAlSiN3:Eu) or SCASN phosphors (e.g., (Sr,Ca)AlSiN3:Eu) and other nitride phosphors, KSF phosphors (e.g., K2SiF6:Mn), KSAF phosphors (e.g., K2(Si 1-x Al x )F 6-x :Mn where 0 < x < 1. ) or fluoride phosphors such as MGF phosphors (e.g., 3.5MgO·0.5MgF2·GeO2:Mn), quantum dots having a perovskite structure (e.g., (Cs,FA,MA)(Pb,Sn)(F,Cl,Br,I)3 where FA and MA represent formamidinium and methylammonium, respectively), II - VI group quantum dots (e.g., CdSe), III - V group quantum dots (e.g., InP), or quantum dots having a chalcopyrite structure (e.g., (Ag,Cu)(In,Ga)(S,Se)2) etc. can be used. As the phosphor contained in the light source light - transmissive member 12, one type of phosphor may be used, or a plurality of types of phosphors may be used.

[0041] Also, the wavelength conversion sheet containing the phosphor described above may be disposed above the light emitting module 101. In this case as well, the light that is wavelength converted and reflected by the wavelength conversion sheet and returns to the light emitting module 101 side can be reflected upward again by the first reflection region 51. The wavelength conversion sheet can be the light emitting module 101 that absorbs a part of the blue light from the light source unit 1, emits yellow light, green light and / or red light, and emits white light. For example, white light can be obtained by combining the light source unit 1 capable of emitting blue light with a wavelength conversion sheet containing a phosphor capable of emitting yellow light. Also, the light source unit 1 capable of emitting blue light may be combined with a wavelength conversion sheet containing a red phosphor and a green phosphor. Also, the light source unit 1 capable of emitting blue light may be combined with multiple wavelength conversion sheets. For the multiple wavelength conversion sheets, for example, a wavelength conversion sheet containing a phosphor capable of emitting red light and a wavelength conversion sheet containing a phosphor capable of emitting green light can be selected. In addition, a light source unit 1 having a light emitting element 11 capable of emitting blue light and a light source transmissive member 12 containing a phosphor capable of emitting red light may be combined with a wavelength conversion sheet containing a phosphor capable of emitting green light.

[0042] As the yellow phosphor used in the wavelength conversion sheet, for example, the above-mentioned yttrium-aluminum-garnet phosphor is preferably used. As the green phosphor used in the wavelength conversion sheet, for example, the above-mentioned β-sialon phosphor or quantum dots, which have a narrow half-width of the emission peak wavelength, are preferably used. As the red phosphor used in the wavelength conversion sheet, for example, the above-mentioned KSF phosphor, KSAF phosphor, or quantum dots, which have a narrow half-width of the emission peak wavelength like the green phosphor, are preferably used.

[0043] As shown in FIG. 4, the light source unit 1 may further include a second light adjustment member 13. The second light adjustment member 13 is disposed on the upper surface of the light source unit 1. The second light adjustment member 13 covers the upper surface of the light emitting element 11. The second light adjustment member 13 is disposed on the upper surface of the light source translucent member 12, and controls the amount and emission direction of light emitted from the upper surface of the light source translucent member 12. The second light adjustment member 13 has reflectivity and translucency with respect to the light emitted by the light emitting element 11. A part of the light emitted from the upper surface of the light source translucent member 12 is reflected by the second light adjustment member 13, and the other part is transmitted through the second light adjustment member 13. The transmittance of the second light adjustment member 13 with respect to the peak wavelength of the light emitting element 11 is, for example, preferably 1% or more and 50% or less, and more preferably 3% or more and 30% or less. This reduces the luminance directly above the light source unit 1, and reduces the luminance unevenness of the light emitting module 101.

[0044] The second light adjustment member 13 can be composed of a light-transmitting resin and a light scattering material contained in the light-transmitting resin. As the light-transmitting resin, for example, a thermoplastic resin such as an acrylic resin, a polycarbonate resin, a cyclic polyolefin resin, a polyethylene terephthalate resin, or a polyester resin, or a thermosetting resin such as an epoxy resin or a silicone resin can be used. As the light scattering material, for example, particles of titanium oxide, silicon oxide, aluminum oxide, zinc oxide, magnesium oxide, zirconium oxide, yttrium oxide, calcium fluoride, magnesium fluoride, niobium pentoxide, barium titanate, tantalum pentoxide, barium sulfate, or glass can be used. In addition, the second light adjustment member 13 may be, for example, a metal member such as aluminum or silver, or a dielectric multilayer film.

[0045] The light source unit 1 may further include a covering member 14. The covering member 14 is disposed on the lower surface of the light emitting element 11. The covering member 14 is disposed so that the lower surfaces of the electrodes 15 of the light source unit 1 are exposed from the covering member 14. The covering member 14 is also disposed on the lower surface of the light source translucent member 12 that covers the side surface of the light emitting element 11.

[0046] The covering member 14 may have reflectivity to the light emitted by the light source unit 1. The covering member 14 is, for example, a resin member including a light scattering material. For example, particles of titanium oxide, silicon oxide, aluminum oxide, zinc oxide, magnesium oxide, zirconium oxide, yttrium oxide, calcium fluoride, magnesium fluoride, niobium pentoxide, barium titanate, tantalum pentoxide, barium sulfate, or glass can be used as the light scattering material of the covering member 14. For example, a thermoplastic resin such as an acrylic resin, a polycarbonate resin, a cyclic polyolefin resin, a polyethylene terephthalate resin, or a polyester resin, or a thermosetting resin such as an epoxy resin or a silicone resin can be used as the resin material of the covering member 14.

[0047] The light source unit 1 is not limited to the illustrated example. For example, the light source unit 1 may not include the covering member 14. For example, the lower surface of the light source unit 1 may be formed by the lower surface of the light-emitting element 11 and the lower surface of the light-source translucent member 12. As another embodiment, the light source unit 1 may not include the second light adjustment member 13, and for example, the upper surface of the light source unit 1 may be formed by the upper surface of the light-source translucent member 12. As another embodiment, the light source unit 1 may be only the light-emitting element 11 alone. As another embodiment, the light source unit 1 may not include the covering member 14 and the light-source translucent member 12, and for example, the second light adjustment member 13 may be arranged on the upper surface of the light-emitting element 11. As another embodiment, the light source unit 1 may not include the light-source translucent member 12, and for example, the second light adjustment member 13 may be arranged on the upper surface of the light-emitting element 11, and the covering member 14 may be arranged on the lower surface of the light-emitting element 11.

[0048] (1st translucent member) The first light-transmissive member 3 has translucency for the light emitted by the light source section 1. The transmittance of the first light-transmissive member 3 for the peak wavelength of the light source section 1 is, for example, preferably 50% or more, and more preferably 70% or more. The material of the first light-transmissive member 3 may be, for example, a resin. For example, the same resin as the material of the light guiding section 2, or a resin having a small difference in refractive index from the material of the light guiding section 2 may be used as the material of the first light-transmissive member 3.

[0049] The first light-transmissive member 3 is disposed in the hole 24 so as to cover the light source unit 1. In other words, the first light-transmissive member 3 is disposed so as to be in contact with the light guide unit 2 and the light source unit 1 within the hole 24. By disposing the first light-transmissive member 3 in this manner, it becomes easier to guide the light from the light source unit 1 to the light guide unit 2.

[0050] The first light-transmissive member 3 may be composed of a single layer in the up-down direction (Z-axis direction), or may be composed of a laminate of multiple layers. The first light-transmissive member 3 may contain a phosphor and / or a light scattering material. When the first light-transmissive member 3 is a laminate, each layer may or may not contain a phosphor and / or a light scattering material. For example, the first light-transmissive member 3 may be composed of a layer containing a phosphor and a layer not containing a phosphor.

[0051] (First light adjustment member) The first light adjustment member 4 is disposed on the first light-transmissive member 3. The first light adjustment member 4 may be disposed on the first light-transmissive member 3 in contact with the first light-transmissive member 3, or may be disposed via an adhesive member. As shown in FIG. 1 to FIG. 3, the first light adjustment member 4 is disposed above the light source unit 1. In other words, the first light adjustment member 4 is disposed so as to overlap with the light source unit 1 in a top view. The first light adjustment member 4 has reflectivity and translucency for the light emitted by the light source unit 1. The transmittance of the first light adjustment member 4 with respect to the peak wavelength of the light source unit 1 is, for example, preferably 1% to 50%, more preferably 3% to 30%.

[0052] The first light adjusting member 4 may have through holes penetrating the upper and lower surfaces thereof. By appropriately changing the size, number, position, etc. of the through holes, the luminance directly above the first light adjusting member 4 can be easily adjusted.

[0053] The shape of the first light adjustment member 4 in top view is not particularly limited, and may be, for example, a substantially circular shape or a substantially polygonal shape such as a triangle, a rectangle, a hexagon, or an octagon. The first light adjustment member 4 of the first embodiment has a substantially circular shape in plan view, and a plurality of voids 5 are arranged along its outer edge. This makes the distance between the first light adjustment member 4 and each void 4 equal in plan view, and can further reduce the luminance unevenness of the light emitting module 101.

[0054] The first light adjustment member 4 can be made of a light-transmitting resin and a light scattering material contained in the light-transmitting resin. Alternatively, the first light adjustment member 4 may be made of a light-transmitting resin having a plurality of voids, or may be made by further containing a light scattering material in a light-transmitting resin having a plurality of voids. As the light-transmitting resin, for example, a thermoplastic resin such as an acrylic resin, a polycarbonate resin, a cyclic polyolefin resin, a polyethylene terephthalate resin, or a polyester resin, or a thermosetting resin such as an epoxy resin or a silicone resin can be used. As the light scattering material, for example, particles of titanium oxide, silicon oxide, aluminum oxide, zinc oxide, magnesium oxide, zirconium oxide, yttrium oxide, calcium fluoride, magnesium fluoride, niobium pentoxide, barium titanate, tantalum pentoxide, barium sulfate, or glass can be used. In addition, the first light adjustment member 4 may be, for example, a metal member such as aluminum or silver, or a dielectric multilayer film.

[0055] The upper surface of the first light adjustment member 4 functions as the light emitting surface of the light emitting module 101 together with the upper surface 21 of the light guide unit 2. The first light adjustment member 4 reflects a part of the light emitted from the light source unit 1 toward the upward direction, and transmits the other part. This makes it possible to reduce the difference between the brightness of the area directly above and around the light source unit 1 and the brightness of the other areas on the light emitting surface of the light emitting module 101. This makes it possible to reduce the brightness unevenness on the light emitting surface of the light emitting module 101. It is preferable that the transmittance of the first light adjustment member 4 for the peak wavelength of the light source unit 1 is higher than the transmittance of the second light adjustment member 13 for the peak wavelength of the light source unit 1. In this way, it is possible to reduce the brightness unevenness of the area where the first light adjustment member 4 is provided and the surrounding area.

[0056] (wiring board) As shown in FIG. 3, wiring board 201 has insulating base material 60 and wiring layer 61 disposed on at least one of the upper and lower surfaces of insulating base material 60.

[0057] The insulating substrate 60 may be a rigid substrate or a flexible substrate. In order to reduce the thickness of the surface light source 301, it is preferable that the insulating substrate 60 is a flexible substrate. The insulating substrate 60 may be configured as a single layer in the vertical direction (Z-axis direction), or may be configured as a laminate of multiple layers. For example, the insulating substrate 60 may be configured as a single-layer flexible substrate, or may be configured as a laminate of multiple rigid substrates. For example, a resin such as polyimide can be used as the material of the insulating substrate 60.

[0058] The wiring layer 61 may be a metal film, for example a copper film.

[0059] (Intermediate parts) In the surface light source 301, the light emitting module 101 is disposed on the wiring board 201. The surface light source 301 may further include an intermediate member between the wiring board 201 and the light emitting module 101.

[0060] The intermediate member may be an adhesive member, a light reflecting member, an oxide layer, or the like.

[0061] The surface light source 301 may have, as intermediate members, a first adhesive member 73 arranged on the insulating substrate 60, a light reflecting member 72 arranged on the first adhesive member 73, and a second adhesive member 71 arranged on the light reflecting member 72.

[0062] The first adhesive member 73 is disposed between the insulating base material 60 and the light reflecting member 72, and bonds the insulating base material 60 and the light reflecting member 72 together.

[0063] The first adhesive member 73 is, for example, a resin layer containing a light scattering material. For example, particles of titanium oxide, silicon oxide, aluminum oxide, zinc oxide, magnesium oxide, zirconium oxide, yttrium oxide, calcium fluoride, magnesium fluoride, niobium pentoxide, barium titanate, tantalum pentoxide, barium sulfate, or glass can be used as the light scattering material. For example, thermoplastic resins such as acrylic resin, polycarbonate resin, cyclic polyolefin resin, polyethylene terephthalate resin, or polyester resin, or thermosetting resins such as epoxy resin or silicone resin can be used as the resin of the first adhesive member 73.

[0064] The light reflecting member 72 is disposed below the light guide section 2 and the light source section 1. The light reflecting member 72 has reflectivity to the light emitted by the light source section 1. For example, a resin having a plurality of voids, a resin containing a light scattering material, or a resin having a plurality of voids and containing a light scattering material can be used as the light reflecting member 72. For example, a thermoplastic resin such as an acrylic resin, a polycarbonate resin, a cyclic polyolefin resin, a polyethylene terephthalate resin, or a polyester resin, or a thermosetting resin such as an epoxy resin or a silicone resin can be used as the resin used for the light reflecting member 72. For example, particles of titanium oxide, silicon oxide, aluminum oxide, zinc oxide, magnesium oxide, zirconium oxide, yttrium oxide, calcium fluoride, magnesium fluoride, niobium pentoxide, barium titanate, tantalum pentoxide, barium sulfate, or glass can be used as the light scattering material. By including the light reflecting member 72 in the surface light source 301, the brightness of the light extracted from the light emitting surface of the surface light source can be improved.

[0065] The second adhesive member 71 is disposed between the light reflecting member 72 and the light guiding section 2, and bonds the light reflecting member 72 and the light guiding section 2. The light source section 1 is disposed on the second adhesive member 71. The second adhesive member 71 is translucent to the light emitted by the light source section 1. For example, an epoxy resin, an acrylic resin, or a cyclic polyolefin resin can be used as the material of the second adhesive member 71. The second adhesive member 71 can contain a light scattering material, and can improve the brightness of the light extracted from the light emitting surface of the planar light source.

[0066] The light source unit 1 is not limited to being disposed on the second adhesive member 71, and may be disposed on, for example, the first adhesive member 73. For example, a through hole penetrating the second adhesive member 71 and the light reflecting member 72 is provided, and the light source unit 1 is disposed on the first adhesive member 73 exposed from the through hole. With such a configuration, the light emitting module can be made thinner, and the surface light source can be made thinner.

[0067] The surface light source 301 may further include a conductive member 63. The conductive member 63 includes a connection portion 63a and a wiring portion 63b. The connection portion 63a penetrates the second adhesive member 71, the light reflecting member 72, the first adhesive member 73, and the insulating base material 60 in the up-down direction (Z-axis direction). The wiring portion 63b is disposed on the lower surface of the insulating base material 60. The wiring portion 63b connects the connection portion 63a and the wiring layer 61.

[0068] A pair of conductive members 63 are disposed apart from each other in correspondence with the pair of positive and negative electrodes 15 of the light source unit 1. The connection portion 63a of one conductive member 63 is connected to the positive electrode 15 below the light source unit 1, and the connection portion 63a of the other conductive member 63 is connected to the negative electrode 15 below the light source unit 1. The electrodes 15 of the light source unit 1 are electrically connected to the conductive members 63 and the wiring layer 61.

[0069] The conductive member 63 includes, for example, a resin and metal particles contained in the resin. For example, an epoxy resin or a phenol resin can be used as the resin of the conductive member 63. For example, copper or silver particles can be used as the metal particles.

[0070] The surface light source 301 may further include an insulating layer 62 to protect the conductive member 63 from short circuits and the like. The insulating layer 62 covers and protects the lower surface of the conductive member 63. The insulating layer 62 may be made of, for example, epoxy resin, urethane resin, or acrylic resin. reminder

[0071] The surface light source 301 and the light emitting module 101 of the first embodiment can be modified in various ways as described below.

[0072] (Variation 1) Fig. 6 is a schematic plan view of the surface light source 302 of the modified example 1. As shown in Fig. 6, in the light-emitting module of the surface light source 302 of the modified example 1, the gap 5 is arranged in a substantially rectangular shape around the light source unit 1 in a plan view from the top surface side. In other words, the gap 5 is arranged so as to draw a substantially rectangular shape surrounding the light source unit 1 in a plan view from the top surface side. Each corner of the substantially rectangular shape does not need to be a right angle, and may be rounded, for example, as shown in the figure.

[0073] In the light-emitting module of the surface light source 302 of the first modification, the voids 5 are arranged in a substantially rectangular shape around the light source unit 1 in the top view, so that the voids 5 can be present up to the vicinity of the corners of the light-guiding unit 2. This makes it possible to reduce luminance unevenness at the corners of the light-guiding unit 2.

[0074] (Variation 2) Fig. 7 is a schematic plan view of the surface light source 303 of the modified example 2. As shown in Fig. 7, in the light-emitting module of the surface light source 303 of the modified example 2, the shape of the gap 5 when viewed from above is strip-shaped. The gap 5 is disposed in a substantially rectangular shape around the light source unit 1 when viewed from above. The strip-shaped shape means an elongated shape. The strip-shaped shape is not limited to a straight line shape, and may be a shape including a curved portion or a bent portion.

[0075] By making the shape of the gap 5 in a band shape when viewed from above, it is possible to increase the area of ​​the second reflection region 52. This increases the amount of scattered light in the second reflection region 52, making it easier to increase the luminance in the intermediate portion of the light-emitting section.

[0076] The aspect ratio of the length to the width of the cross section perpendicular to the height direction of the gap 5 can be preferably 1 to 100, more preferably 1 to 50. The length of the cross section means the length of the straight line between the most distant edges in the cross section. The width of the cross section means the length of the part where the perpendicular line that bisects the straight line between the most distant edges in the cross section intersects. For example, in FIG. 8A, the length of the cross section perpendicular to the height direction of the gap 5 is the length l1 of the straight line p1-p2 between the most distant edges in the cross section. The width of the cross section perpendicular to the height direction of the gap 5 is the length w1 of the part where the perpendicular line that bisects the straight line p1-p2 in the cross section intersects. The aspect ratio is l1 / w1. In FIG. 8B, the length of the cross section perpendicular to the height direction of the gap 5 is the length l2 of the straight line p3-p4 between the most distant edges. The width of the cross section perpendicular to the height direction of the gap 5 is the length w2 of the part where the perpendicular line that bisects the straight line p3-p4 in the cross section intersects. The aspect ratio is l2 / w2.

[0077] By setting the aspect ratio of the length to the width of a cross section perpendicular to the height direction of the gap 5 to 1 or more, the area of ​​the second reflection region 52 of the gap 5 can be increased. This increases the amount of scattered light in the second reflection region 52, making it easier to increase the brightness in the intermediate portion of the light-emitting section. By setting the aspect ratio of the length to the width of a cross section perpendicular to the height direction of the gap 5 to 100 or less, the width of the cross section increases, and therefore the area of ​​the first reflection region 51 of the gap 5 can be increased. This improves the recycling efficiency of light from above, and improves the brightness of the light-emitting module.

[0078] At least one void portion 5 can be present on any straight line connecting light source portion 1 and side surface 23a of light guide portion 2 in plan view from the top surface side.

[0079] In plan view from the top side, by providing at least one void 5 on any straight line connecting the light source unit 1 and the side surface 23a of the light guide unit 2, it becomes easy to reduce the amount of light that reaches the peripheral part of the light guide unit 2. In other words, the brightness of the peripheral part of the light-emitting section can be lowered, making it easy to reduce brightness unevenness.

[0080] (Variation 3) Fig. 9 is a schematic cross-sectional view of surface light source 304 of modification 3. As shown in Fig. 9, in the light-emitting module of surface light source 304 of modification 3, light guide unit 2 does not have hole 24, but has recess 26 opening on the lower surface 22 side of light guide unit 2, which is different from the light-emitting module of surface light source 301. Light source unit 1 is disposed in recess 26, and upper surface 16 of light source unit 1 contacts bottom surface 27 of the recess.

[0081] (Variation 4) 10 is a schematic cross-sectional view of a surface light source 305 of Modification 4. As shown in FIG.

[0082] (Variation 5) Fig. 11 is a schematic cross-sectional view of a surface light source 306 of Modification 5. As shown in Fig. 11, the surface light source 306 of Modification 5 has, between the wiring board 201 and the light emitting module 101, an adhesive member 79 arranged on the insulating base material 60, a light reflecting member 78 arranged on the adhesive member 79, an oxide layer 77 arranged on the light reflecting member 78, and a silicone resin layer 76 arranged on the oxide layer 77 as intermediate members.

[0083] The adhesive member 79 is, for example, a resin layer containing a light scattering material. For example, particles of titanium oxide, silicon oxide, aluminum oxide, zinc oxide, magnesium oxide, zirconium oxide, yttrium oxide, calcium fluoride, magnesium fluoride, niobium pentoxide, barium titanate, tantalum pentoxide, barium sulfate, glass, or the like can be used as the light scattering material. For example, thermoplastic resins such as acrylic resin, polycarbonate resin, cyclic polyolefin resin, polyethylene terephthalate resin, or polyester resin, or thermosetting resins such as epoxy resin or silicone resin can be used as the resin of the adhesive member 79.

[0084] The light reflecting member 78 is disposed below the light guiding section 2 and the light source section 1. The light reflecting member 78 has reflectivity to the light emitted by the light source section 1. As the light reflecting member 78, for example, a resin having a plurality of voids, a resin containing a light scattering material, or a resin having a plurality of voids and containing a light scattering material can be used.

[0085] The resin used for the light reflecting member 78 may be, for example, a thermoplastic resin such as an acrylic resin, a polycarbonate resin, a cyclic polyolefin resin, a polyethylene terephthalate resin, or a polyester resin, or a thermosetting resin such as an epoxy resin or a silicone resin.

[0086] As the light scattering material, for example, particles of titanium oxide, silicon oxide, aluminum oxide, zinc oxide, magnesium oxide, zirconium oxide, yttrium oxide, calcium fluoride, magnesium fluoride, niobium pentoxide, barium titanate, tantalum pentoxide, barium sulfate, glass, etc. can be used. By including the light reflecting member 78 in the surface light source 306, the luminance of the light extracted from the light emitting surface of the surface light source 306 can be improved.

[0087] The oxide layer 77 is disposed on the upper surface of the light reflecting member 78. The oxide layer 77 is disposed between the light reflecting member 78 and the silicone resin layer 76, and bonds the light reflecting member 78 and the silicone resin layer 76 together.

[0088] The oxide layer 77 may be made of, for example, silicon oxide, titanium oxide, or aluminum oxide.

[0089] The thickness of the oxide layer 77 may be, for example, 100 Å or more, preferably 120 Å or more. By making the oxide layer 77 80 Å or more thick, the adhesion between the light reflecting member 78 and the silicone resin layer 76 is improved. The upper limit of the thickness of the oxide layer 77 is not particularly limited, but may be, for example, 1000 Å or less, preferably 500 Å or less.

[0090] The silicone resin layer 76 is disposed between the oxide layer 77 and the light guide section 2 , and bonds the light reflecting member 78 and the light guide section 2 together.

[0091] (Manufacturing method 1) Next, an example of a method for manufacturing the surface light source 305 will be described with reference to FIGS. 12A to 14E.

[0092] 12A is prepared by purchase or the like. The light guide plate 110 includes an upper surface 121 and a lower surface 122 located opposite the upper surface 121.

[0093] As shown in FIG. 12B, a void 5 is formed in the light guide plate 110. The void 5 is formed as a hole with a bottom that opens on the lower surface 122 side. The void 5 is formed by, for example, drilling or laser processing. The void 5 may be formed simultaneously with the light guide plate 110. For example, the light guide plate 110 having the void 5 may be formed by injection molding. Note that components in the middle of each process may be purchased. For example, the light guide plate 110 having the void 5 formed therein shown in FIG. 12B may be purchased.

[0094] 12C, holes 24 and grooves 25 are formed in light guide plate 110. Holes 24 can be formed by, for example, drilling, punching, laser processing, or the like. Groove 25 is formed as a groove that opens on upper surface 121 and lower surface 122. That is, groove 25 penetrates light guide plate 110 from upper surface 121 to lower surface 122. Groove 25 is formed by, for example, cutting or laser processing. Reduction

[0095] The laminated member 210 shown in FIG. 13A is prepared by purchase or the like. The laminated member 210 includes a wiring board 201, a first adhesive member 73 arranged on the wiring board 201, a light reflecting member 72 arranged on the first adhesive member 73, and a second adhesive member 71 arranged on the light reflecting member 72. The process of preparing the laminated member 210 may include, after preparing the wiring board 201 by purchase or the like, a process of arranging the first adhesive member 73 on the wiring board 201, a process of arranging the light reflecting member 72 on the first adhesive member 73, and a process of arranging the second adhesive member 71 on the light reflecting member 72. Note that the members in the middle of each process may be prepared by purchase. The laminated member 210 may further include an insulating layer covering the lower surface of the wiring board 201.

[0096] As shown in FIG. 13B, through holes 211 penetrating the second adhesive member 71, the light reflecting member 72, the first adhesive member 73, and the wiring board 201 are formed in the laminated member 210. The through holes 211 are formed by, for example, punching, drilling, laser processing, or the like. The shape of the through holes 211 in a plan view is circular. The shape of the through holes 211 in a plan view may be an ellipse or a polygon other than a circle. The through holes 211 are arranged so that one through hole 211 faces one electrode (for example, a positive electrode) of a pair of positive and negative electrodes of the light source unit 1 to be arranged later, and the other through hole 211 faces the other electrode (for example, a negative electrode). In a plan view, one through hole 211 is arranged so as to overlap at least a part of one electrode.

[0097] 14A, the light guide 2 is disposed on a laminated member 210 in which a through hole 211 is formed. A lower surface 22 of the light guide 2 is adhered to a second adhesive member 71 of the laminated member 210. The through hole 211 formed in the laminated member 210 is disposed so as to overlap with a hole 24 formed in the light guide 2. That is, in a plan view, the hole 24 and the two through holes 211 overlap with each other.

[0098] 14B, the light source unit 1 is disposed in the hole 24. For example, the lower surface of the covering member 14, which is the lower surface of the light source unit 1, may be adhered to the upper surface of the second adhesive member 71. The light source unit 1 is disposed such that the electrode 15 of the light source unit 1 and the through hole 211 formed in the laminate member 210 overlap with each other in a top view.

[0099] 14C, connection portion 63a is formed in through hole 211, and wiring portion 63b is formed on the lower surface of wiring substrate 201. For example, a conductive paste is placed in through hole 211 and on the lower surface of wiring substrate 201, and then cured, thereby forming connection portion 63a connected to electrode 15 of light source unit 1, and wiring portion 63b connected to wiring layer 61 of wiring substrate 201.

[0100] 14D, an insulating layer 62 is formed to cover the lower surface of the wiring portion 63b. The insulating layer 62 can be formed by, for example, printing, potting, spraying, inkjet, or laminating a resin sheet.

[0101] 14E, a first light-transmissive member 3 is formed to cover the light source unit 1 in the hole 24. The first light-transmissive member 3 is formed so as to cover the side and upper surface of the light source unit 1. For example, the first light-transmissive member 3 can be formed by supplying a liquid light-transmissive resin into the hole 24 and then heating and curing the light-transmissive resin.

[0102] Next, the first light adjusting member 4 is formed to cover the first light-transmitting member 3, thereby manufacturing the planar light source 305 shown in Fig. 10. The first light adjusting member 4 is formed by a method such as printing, potting, spraying, inkjet, or laminating a resin sheet.

[0103] (Manufacturing method 2) Alternatively, an example of a method for manufacturing a surface light source 306 will be described with reference to Figures 15A to 15C.

[0104] As shown in FIG. 15A, a silicone resin layer 76 is disposed on lower surface 22 of light guide section 2 prepared in the same manner as described with reference to FIGS. 12A to 12C, to prepare laminated member 220.

[0105] A laminated member 230 shown in FIG. 15B is prepared. The laminated member 230 includes a wiring board 201, an adhesive member 79 arranged on the wiring board 201, a light reflecting member 78 arranged on the adhesive member 79, and an oxide layer 77 arranged on the light reflecting member 78. The laminated member 230 includes the oxide layer 77, the light reflecting member 78, the adhesive member 79, and a through hole 212 penetrating the wiring board 201. The process of preparing the laminated member 230 may include, after preparing the wiring board 201 by purchase or the like, a process of arranging the adhesive member 79 on the wiring board 201, a process of arranging the light reflecting member 78 on the adhesive member 79, a process of arranging the oxide layer 77 on the light reflecting member 78, and a process of forming the through hole 212.

[0106] The step of disposing the oxide layer 77 on the light reflecting member 78 can be performed by using a known method such as a sputtering method or a vapor deposition method.

[0107] 15C, the lamination member 220 and the lamination member 230 are bonded together so that the silicone resin layer 76 of the lamination member 220 and the oxide layer 77 of the lamination member 230 are in contact with each other. The bonding can be performed by irradiating the surface of the silicone resin layer 76 and the surface of the oxide layer 77 with atmospheric pressure plasma, then bonding the lamination member 220 and the lamination member 230 together so that the silicone resin layer 76 and the oxide layer 77 are in contact with each other, and then applying pressure.

[0108] By bonding the silicone resin layer 76 and the oxide layer 77 in this manner, adhesion is improved.

[0109] Next, the surface light source 306 can be manufactured in the same manner as in FIGS. 14B to 14E.

[0110] The above-described method for manufacturing a surface light source is merely an example, and various modifications are possible as long as no technical contradiction occurs.

[0111] The present disclosure includes the following aspects. [Section 1] A light source unit; a light guiding unit to which light emitted by the light source unit is incident and having an upper surface, a lower surface located opposite to the upper surface, and a side surface located between the upper surface and the lower surface; the light guiding section includes a gap defined by a surface including a first reflective area located below the upper surface and closer to the upper surface than the lower surface, and a second reflective area extending from the first reflective area toward the lower surface, A light-emitting module, wherein the surface roughness of the first reflective area is smaller than the surface roughness of the second reflective area. [Section 2] 2. The light emitting module according to item 1, wherein the second reflection area is located on the light source side in a plan view from the top surface side. [Section 3] 3. The light-emitting module according to item 1 or 2, wherein the surface roughness of the first reflective region is 40 nm or less. [Section 4] 4. The light-emitting module according to any one of items 1 to 3, wherein the first reflective region has a surface roughness of 5 nm or less. [Section 5] 5. The light emitting module according to any one of items 1 to 4, wherein the second reflective region has a surface roughness of 80 nm to 2000 nm. [Section 6] 6. The light-emitting module according to any one of items 1 to 5, wherein the second reflective region has a surface roughness of 115 nm to 300 nm. [Section 7] 7. The light-emitting module according to any one of items 1 to 6, wherein the gap is open to the lower surface. [Section 8] 8. The light-emitting module according to any one of items 1 to 7, wherein the height of the gap increases as it is farther from the light source unit. [Section 9] 8. The light emitting module according to any one of items 1 to 7, wherein at least one of the gaps is present on any straight line connecting the light source section and a side surface of the light guiding section in a plan view from the top surface side. [Section 10] 9. The light-emitting module according to any one of items 1 to 8, wherein, in a plan view from the upper surface side, the gap portion is disposed rotationally symmetric with respect to the light source portion. [Section 11] 10. The light emitting module according to any one of items 1 to 9, wherein, in plan view from the upper surface side, the gap portion is disposed in a circular ring shape around the light source portion. [Section 12] 10. The light-emitting module according to any one of items 1 to 9, wherein the gap is arranged in a substantially rectangular shape in plan view from the upper surface side. [Section 13] Item 13. The light-emitting module according to any one of items 1 to 12, wherein the cavity has a substantially circular shape when viewed from above. [Section 14] Item 13. The light-emitting module according to any one of items 1 to 12, wherein the cavity has a substantially polygonal shape when viewed from above. [Section 15] Item 15. The light-emitting module according to any one of items 1 to 14, wherein the maximum width of the gap in top view is 5 μm to 300 μm. [Section 16] Item 16. The light-emitting module according to any one of items 1 to 15, wherein an aspect ratio of a length to a width of the cross section perpendicular to a height direction of the cavity is 1-100. [Section 17] Item 17. The light-emitting module according to any one of items 1 to 16, wherein the area of ​​a cross section perpendicular to a height direction of the gap decreases toward the upper surface. [Section 18] Item 18. The light emitting module according to any one of items 1 to 17, wherein the light source section is covered with a first light-transmissive member. [Section 19] Item 19. The light emitting module according to any one of items 1 to 18, further comprising a light adjusting member on the light source unit. [Section 20] A wiring board; A light emitting module according to any one of items 1 to 19, which is disposed on the wiring board; A surface light source comprising: [Section 21] Item 21. The surface light source according to item 20, further comprising a light reflecting member between the wiring board and the light emitting module. [Section 22] Item 22. The surface light source according to item 21, further comprising an oxide layer on the light reflecting member, a silicone resin layer on the oxide layer, and the light emitting module on the silicone resin layer. [Section 23] Item 22. The surface light source according to item 21, further comprising an adhesive member between the light reflecting member and the light emitting module. [Section 24] Item 24. The surface light source according to item 23, wherein the adhesive member contains a light diffusing agent. [Section 25] Item 25. The surface light source according to any one of items 20 to 24, comprising a plurality of the light emitting modules. [Section 26] Item 26. The surface light source according to item 25, wherein the plurality of light emitting modules are arranged in a matrix. [Explanation of symbols]

[0112] 101...light emitting module, 201...wiring board, 301,302,303,304,305,306...Surface light source, 1...Light source section, 2...Light guide section, 3...Translucent member (first translucent member), 4...First light adjustment member, 5...Void part, 5a,5b,5c,5d...Void part, 11...light emitting element, 12...second light transmissive member (light source transmissive member), 13...second light adjustment member, 14: covering member; 15: electrode; 16: upper surface of light source unit; 21...upper surface of light guiding portion, 22...lower surface of light guiding portion, 23...side surface of light guiding portion, 23a, 23b... Side surface of light guide portion, 24... Hole portion, 25... Groove portion, 26: recess; 27: bottom surface of recess; 28: extension; 51...first reflective area, 52...second reflective area, 60: insulating substrate; 61: wiring layer; 62: insulating layer; 63...conductive member, 63a...connection portion, 63b...wiring portion, 71: second adhesive member; 72: light reflecting member; 73: first adhesive member; 76: silicone resin layer, 77: oxide layer, 78: light reflecting member, 79: adhesive member, 110...light guide plate; 111...upper surface of the light guide plate; 112...lower surface of the light guide plate; 210...lamination member, 211...through hole, 212...through hole, 220...lamination member, 230...Laminated member

Claims

1. A light source unit; a light guiding unit to which light emitted by the light source unit is incident and having an upper surface, a lower surface located opposite to the upper surface, and a side surface located between the upper surface and the lower surface; the light guiding section includes a gap defined by a surface including a first reflective area located below the upper surface and closer to the upper surface than the lower surface, and a second reflective area extending from the first reflective area toward the lower surface, The surface roughness of the first reflective area is smaller than the surface roughness of the second reflective area, A light-emitting module, wherein, in a plan view from the top surface side, the gap portion is arranged rotationally symmetrical with respect to the light source portion.

2. The light emitting module according to claim 1 , wherein the second reflection area is located on the light source side in a plan view from the upper surface side.

3. The light-emitting module according to claim 1 , wherein the surface roughness of the first reflective region is 40 nm or less.

4. The light emitting module according to claim 1 , wherein the first reflective region has a surface roughness of 5 nm or less.

5. The light emitting module according to claim 1 , wherein the surface roughness of the second reflective area is 80 nm to 2000 nm.

6. The light-emitting module according to claim 1 , wherein the surface roughness of the second reflective area is 115 nm to 300 nm.

7. The light-emitting module according to claim 1 , wherein the cavity is open to the lower surface.

8. The light-emitting module according to claim 1 , wherein the height of the gap increases as the gap becomes farther from the light source unit.

9. The light emitting module according to claim 1 , wherein at least one of the gaps is present on any straight line connecting the light source section and a side surface of the light guiding section in a plan view from the top surface side.

10. The light emitting module according to claim 1 , wherein the gap portion is disposed in a circular ring shape around the light source portion in a plan view from the upper surface side.

11. The light-emitting module according to claim 1 , wherein the gap is arranged in a substantially rectangular shape in a plan view from the upper surface side.

12. The light-emitting module according to claim 1 , wherein the cavity has a substantially circular shape when viewed from above.

13. The light-emitting module according to claim 1 , wherein the cavity has a generally polygonal shape when viewed from above.

14. 2. The light-emitting module according to claim 1, wherein the maximum width of the gap in a top view is 5 μm to 300 μm.

15. 2. The light-emitting module according to claim 1, wherein an aspect ratio of a length to a width of a cross section perpendicular to a height direction of the cavity is 1 to 100.

16. The light-emitting module according to claim 1 , wherein the area of ​​a cross section perpendicular to a height direction of the gap decreases toward the upper surface.

17. The light emitting module according to claim 1 , wherein the light source portion is covered with a light-transmitting member.

18. The light emitting module according to claim 1 , further comprising a light adjusting member on the light source unit.

19. A wiring board; A light emitting module according to any one of claims 1 to 18, which is disposed on the wiring board; A surface light source comprising:

20. The surface light source according to claim 19 , further comprising a light reflecting member between the wiring board and the light emitting module.

21. The surface light source according to claim 20 , further comprising an oxide layer on the light reflecting member, a silicone resin layer on the oxide layer, and the light emitting module on the silicone resin layer.

22. The surface light source according to claim 20 , further comprising an adhesive member between the light reflecting member and the light emitting module.

23. The surface light source according to claim 22 , wherein the adhesive member includes a light diffusing agent.

24. The surface light source according to claim 19 , comprising a plurality of the light emitting modules.

25. The surface light source according to claim 24 , wherein the plurality of light emitting modules are arranged in a matrix.

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