Light-emitting module and manufacturing method thereof

Abstract

The invention provides a light-emitting module and a manufacturing method thereof, which can arrange a light-emitting device relative to a light guide plate with high position precision. The light-emitting module includes: a light guide plate having a first surface, a second surface on an opposite side of the first surface, and a through portion penetrating between the first surface and the second surface; a light-emitting device disposed on the second surface side of the through part; a translucent member provided on the light-emitting device and between the light-emitting device and a side wall of the through-hole portion on the first surface side in the through-hole portion; and a first reflective member provided between the upper surface of the light-emitting device and the translucent member and in contact with the upper surface of the light-emitting device.

Description

[0001] This application is a divisional application of a patent application for an invention named "Light-emitting Module and Manufacturing Method Thereof" with an application date of May 29, 2020, an application number of 202010473775.6. Technical Field

[0002] The present invention relates to a light-emitting module and a manufacturing method thereof. Background Art

[0003] A light-emitting module that combines a light-emitting element such as a light-emitting diode and a light guide plate is widely used as a surface light source such as a backlight for a liquid crystal display. For example, Patent Document 1 discloses a structure in which a light guide plate having a plurality of through holes is joined to a substrate on which a plurality of light sources are mounted, and the light sources are disposed in the through holes.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-211085 Summary of the Invention

[0005] An object of the present invention is to provide a light-emitting module and a manufacturing method thereof that can dispose a light-emitting device on a light guide plate with high positional accuracy.

[0006] According to an aspect of the present invention, a light-emitting module includes: a light guide plate having a first surface, a second surface opposite to the first surface, and a through portion penetrating between the first surface and the second surface; a light-emitting device disposed on the second surface side of the through portion; a light-transmissive member disposed on the first surface side within the through portion, on the light-emitting device, and between the light-emitting device and a side wall of the through portion; and a first reflective member disposed between an upper surface of the light-emitting device and the light-transmissive member and in contact with the upper surface of the light-emitting device.

[0007] In addition, according to another aspect of the present invention, a manufacturing method of a light-emitting module includes: forming a reflective member on the second surface of a light guide plate having a first surface and a second surface opposite to the first surface, and forming a through hole penetrating between the first surface and the second surface in the light guide plate so as to also penetrate the reflective member; pasting the second surface side of the light guide plate onto a sheet, and closing an opening on the second surface side of the through hole with the sheet; disposing a light-emitting device having an electrode portion in the through hole, and pasting the electrode portion onto the sheet closing the opening of the through hole; forming a light-transmissive member on the light-emitting device within the through hole and between the light-emitting device and a side wall of the through hole, and fixing the light-emitting device to the light guide plate through the light-transmissive member; separating the light guide plate on which the light-emitting device is fixed from the sheet, and exposing the electrode portion of the light-emitting device on the second surface side.

[0008] Further, according to another aspect of the present invention, a method for manufacturing a light emitting module includes: a step of preparing a light guide plate having a first surface and a second surface opposite to the first surface and having a through hole penetrating between the first surface and the second surface; a step of pasting the second surface side of the light guide plate onto a sheet and closing the opening on the second surface side of the through hole with the sheet; a step of disposing a light emitting device having an electrode portion in the through hole and pasting the electrode portion onto the sheet closing the opening of the through hole; a step of forming a light transmissive member on the light emitting device in the through hole and between the light emitting device and the side wall of the through hole, and fixing the light emitting device to the light guide plate through the light transmissive member; a step of separating the light guide plate fixed with the light emitting device from the sheet and exposing the electrode portion of the light emitting device on the second surface side.

[0009] According to one aspect of the present invention, a light emitting module and a method for manufacturing the same can be provided, which can dispose a light emitting device on a light guide plate with high positional accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a schematic cross-sectional view of a light emitting module according to an embodiment.

[0011] Figure 2 is a schematic cross-sectional view of a light emitting module according to an embodiment.

[0012] Figure 3A is a schematic cross-sectional view showing a method for manufacturing a light emitting module according to an embodiment.

[0013] Figure 3B is a schematic cross-sectional view showing a method for manufacturing a light emitting module according to an embodiment.

[0014] Figure 4A is a schematic cross-sectional view showing a method for manufacturing a light emitting module according to an embodiment.

[0015] Figure 4B is a schematic cross-sectional view showing a method for manufacturing a light emitting module according to an embodiment.

[0016] Figure 5A is a schematic cross-sectional view showing a method for manufacturing a light emitting module according to an embodiment.

[0017] Figure 5B is a schematic cross-sectional view showing a method for manufacturing a light emitting module according to an embodiment.

[0018] Figure 6A is a schematic cross-sectional view showing a method for manufacturing a light emitting module according to an embodiment.

[0019] Figure 6BIt is a schematic cross-sectional view showing a manufacturing method of a light-emitting module according to an embodiment.

[0020] Figure 7 It is a schematic cross-sectional view showing a manufacturing method of a light-emitting module according to an embodiment.

[0021] Figure 8A It is a schematic perspective view showing a manufacturing method of a light-emitting module according to an embodiment.

[0022] Figure 8B It is a schematic cross-sectional view showing a manufacturing method of a light-emitting module according to an embodiment.

[0023] Figure 9 It is a schematic cross-sectional view of a light-emitting module according to another embodiment.

[0024] Figure 10A It is a schematic cross-sectional view showing a manufacturing method of a light-emitting module according to another embodiment.

[0025] Figure 10B It is a schematic cross-sectional view showing a manufacturing method of a light-emitting module according to another embodiment.

[0026] Figure 11 It is a schematic cross-sectional view of a light-emitting module according to still another embodiment.

[0027] Figure 12 It is a schematic cross-sectional view of a light-emitting module according to still another embodiment.

[0028] Figure 13 It is a schematic cross-sectional view of a light-emitting module according to still another embodiment.

[0029] Figure 14 It is a schematic cross-sectional view of a light-emitting module according to still another embodiment.

[0030] Figure 15 It is a schematic cross-sectional view of a light-emitting module according to still another embodiment.

[0031] Figure 16 It is a schematic cross-sectional view of a light-emitting module according to still another embodiment.

[0032] Figure 17 It is a schematic cross-sectional view of a light-emitting module according to still another embodiment.

[0033] Figure 18 It is a schematic cross-sectional view of a light-emitting module according to still another embodiment.

[0034] Figure 19A It is a schematic cross-sectional view of a light-emitting device according to still another embodiment.

[0035] Figure 19B It is a schematic cross-sectional view of a light-emitting device according to still another embodiment.

[0036] Figure 19C It is a schematic cross-sectional view of a light-emitting device according to another embodiment.

[0037] Figure 20 It is a schematic plan view of a light-emitting module according to one embodiment.

[0038] Figure 21 It is an exploded perspective view showing the structure of a liquid crystal display according to an embodiment.

[0039] Mark Explanation

[0040] 10: Light guide plate

[0041] 11: First surface

[0042] 12: Second surface

[0043] 13: Inclined surface

[0044] 15: Through-hole part

[0045] 15’: Through-hole

[0046] 20: Light-emitting device

[0047] 21: Light-emitting element

[0048] 22: Phosphor layer

[0049] 23: First reflective member

[0050] 24: Second reflective member

[0051] 25: Electrode part

[0052] 26: Rear electrode

[0053] 27: Conductive film

[0054] 30: Light-transmissive member

[0055] 31: Concave part

[0056] 40: Fourth reflective member

[0057] 50: Third reflective member

[0058] 61: Wiring

[0059] 70: Air layer

[0060] 100: Sheet

[0061] 120: Liquid crystal panel

[0062] 200: Light-emitting module

[0063] 1000: Liquid crystal display Detailed Embodiments

[0064] Hereinafter, embodiments will be described with reference to the drawings. In addition, in each drawing, the same reference numerals are assigned to the same elements.

[0065] Figure 1 is a schematic cross-sectional view of a light-emitting module according to an embodiment of the present invention. Figure 1 represents a cross-section cut at a position passing through the central axis of the through-hole 15 formed in the light guide plate 10.

[0066] The light-emitting module of the embodiment includes a light guide plate 10, a light-emitting device 20, and a light-transmissive member 30.

[0067] The light guide plate 10 has light transmissibility with respect to the light emitted from the light-emitting device 20. As the material of the light guide plate 10, for example, thermoplastic resins such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate, or polyester, thermosetting resins such as epoxy or silicone, or glass can be used. The thickness of the light guide plate 10 is preferably 100 μm to 1000 μm, and more preferably 200 μm or more and 800 μm or less.

[0068] The light guide plate 10 has a first surface 11 that serves as a light-emitting surface and a second surface 12 opposite to the first surface 11. Moreover, the light guide plate 10 has a through-hole 15 that penetrates between the first surface 11 and the second surface 12.

[0069] The light-emitting device 20 includes a light-emitting element 21 and a phosphor layer 22 as a light-transmissive member. The phosphor layer 22 is disposed on the upper surface of the light-emitting element 21. The phosphor layer 22 may be in contact with the upper surface of the light-emitting element 21, or may be joined by an adhesive or the like. The light-emitting element 21 has a semiconductor stack.

[0070] The semiconductor stack includes, for example, InxAlyGa1−x−yN (0 ≤ x, 0 ≤ y, x + y ≤ 1) and can emit blue light.

[0071] The phosphor layer 22 has a base material and phosphors dispersed in the base material. As the material of the base material of the phosphor layer 22, for example, silicone resin, epoxy resin, glass, etc. can be used. The phosphor is a wavelength conversion material that is excited by the light emitted from the light-emitting element 21 and emits light having a wavelength different from the wavelength of the light emitted from the light-emitting element 21. For example, as the phosphor, yttrium-aluminum-garnet-based phosphors (e.g., Y3(Al,Ga)5O 12 :Ce), lutetium-aluminum-garnet-based phosphors (e.g., Lu3(Al,Ga)5O 12 :Ce), terbium-aluminum-garnet-based phosphors (e.g., Tb3(Al,Ga)5O 12 :Ce), β-sialon-based phosphors (e.g., Si 6－z Alz O z N 8－z : Eu (0 < z < 4.2)), α - silicon aluminum oxynitride - based phosphor (e.g., Mz(Si, Al) 12 (O, N) 16 (where 0 < z ≤ 2, M is Li, Mg, Ca, Y, and lanthanum elements except La and Ce), nitride phosphors such as calcium aluminum silicon nitride (CASN or SCASN) - based phosphor (e.g., (Sr, Ca)AlSiN3:Eu), fluoride - based phosphors such as KSF - based phosphor (K2SiF6:Mn) or MGF - based phosphor (3.5MgO·0.5MgF2·GeO2:Mn), silicate - based phosphor (e.g., (Ba, Sr)2SiO4:Eu), chlorosilicate - based phosphor (e.g., Ca8Mg(SiO4)4Cl2:Eu), etc. The phosphor layer 22 may also contain a plurality of phosphors. In addition, a plurality of the above - mentioned phosphor layers may be stacked.

[0072] A second reflective member 24 is provided on the side surface of the light - emitting element 21. A pair of positive and negative element electrodes are provided on the opposite side of the upper surface of the light - emitting element 21. The element electrodes may include an ohmic electrode in ohmic contact with the semiconductor layer and a columnar electrode (rear electrode 26) further connected to the ohmic electrode. A conductive film 27 is provided on the lower surface of the rear electrode 26 and the lower surface of the second reflective member 24. Hereinafter, the light - emitting element 21 having the rear electrode 26 will be described, but the rear electrode 26 may be omitted. In this case, the rear electrode 26 can be replaced as an element electrode.

[0073] The rear electrode 26 is connected to the conductive film 27. The rear electrode 26 is provided on the lower surface of the light - emitting element 21, and the conductive film 27 extends from the rear electrode 26 to a region outside the lower surface (side surface) of the light - emitting element 21. The rear electrode 26 and the conductive film 27 function as the electrode portion 25 of the light - emitting device 20. In addition, the conductive film 27 may only cover the lower surface of the rear electrode 26. Moreover, a light - emitting device without the conductive film 27 may also be provided.

[0074] The second reflective member 24 is provided between the conductive film 27 on the side of the light - emitting element 21 and the phosphor layer 22. The second reflective member 24 directly or indirectly covers the side surface of the light - emitting element 21. For example, an adhesive for connecting the phosphor layer 22 and the light - emitting element 21 may be disposed on the side surface of the light - emitting element 21. Moreover, the side surface of the light - emitting element 21 may be covered by the second reflective member 24 via this adhesive. The second reflective member 24 is also provided between the pair of rear electrodes 26 on the lower surface of the light - emitting element 21. That is, at least a part of the lower surface of the semiconductor laminate of the light - emitting element 21 is covered by the second reflective member 24.

[0075] The light-emitting device 20 is disposed on the second surface 12 side of the through-hole 15 of the light guide plate 10. That is, the light-emitting device 20 is disposed at a position closer to the second surface 12 than the first surface 11. The light-emitting element 21 is located on the side closer to the second surface 12 than the phosphor layer 22, and the phosphor layer 22 is located on the side closer to the first surface 11 than the light-emitting element 21.

[0076] A light-transmissive member 30 is provided in the through-hole 15 of the light guide plate 10. The light-transmissive member 30 has light transmissibility with respect to the light emitted by the light-emitting device 20. For example, a resin having the same material as the light guide plate 10 or a resin having a small refractive index difference from the material of the light guide plate 10 can be used. Alternatively, glass can also be used as the material of the light-transmissive member 30.

[0077] The light-transmissive member 30 is disposed on the light-emitting device 20 and between the side surface of the light-emitting device 20 and the side wall of the through-hole 15. The light-emitting device 20 is fixed to the light guide plate 10 by the light-transmissive member 30. No space such as an air layer is formed between the side surface of the light-emitting device 20 and the light-transmissive member 30, between the side wall of the through-hole 15 and the light-transmissive member 30, and between the upper surface of the light-emitting device 20 and the light-transmissive member 30. Herein, without being limited thereto, air may also be included in the light-transmissive member 30.

[0078] A concave portion 31 may be provided on the upper surface of the light-transmissive member 30. The concave portion 31 can be formed into a concave portion having a conical shape such as a cone or a pyramid, a frustum shape such as a frustum of a cone or a frustum of a pyramid, or a concave portion having a shape that allows light to be refracted only in one direction in a top view, such as a triangular prism shape or a semi-cylindrical shape. The opening diameter of the concave portion 31 can be made equal to the opening diameter of the through-hole 15. Alternatively, the opening diameter of the concave portion 31 can be made smaller than the opening diameter of the through-hole 15. In addition, the center of the concave portion 31 can coincide with the center of the through-hole 15 in a top view. Moreover, the center of the concave portion 31 can coincide with the center of the light-emitting device 20 in a top view. Alternatively, depending on the position of the through-hole 15, the center of the concave portion 31 may not coincide with the center of the through-hole 15 in a top view, or may not coincide with the center of the light-emitting device 20. In Figure 1 In the example shown, a concave portion 31 having a V-shaped cross section is provided. That is, an inclined surface inclined with respect to the first surface 11 is provided on the upper surface of the light-transmissive member 30. By reflecting and refracting light at the interface between the light-transmissive member 30 and air on this inclined surface, it is possible to suppress the luminance concentration in the directly above region of the light-emitting device 20. Alternatively, by providing a curved surface or a convex portion on the upper surface of the light-transmissive member 30, light diffusion or an improvement in light emission efficiency can be achieved.

[0079] A first reflective member 23 is provided between the upper surface of the light-emitting device 20, i.e., the upper surface of the phosphor layer 22, and the light-transmissive member 30. The first reflective member 23 is in contact with the upper surface of the light-emitting device 20 (in this example, the upper surface of the phosphor layer 22) and directly covers the upper surface of the light-emitting device 20. In addition, the first reflective member 23 may also be a part of the light-emitting device 20.

[0080] A third reflective member 50 is provided around the light-emitting device 20 disposed in the through-hole 15 on the second surface 12 side of the light guide plate 10. The third reflective member 50 is provided on the side surface of the second reflective member 24 and is not provided on at least a part of the side surface of the phosphor layer 22. A part or the whole of the side surface of the phosphor layer 22 is covered by the light-transmissive member 30. Preferably, the whole side surface of the phosphor layer 22 is in contact with the light-transmissive member 30.

[0081] The second surface 12 of the light guide plate 10 has a flat surface parallel to the first surface 11 and a concave portion with the inclined surface 13 as the inner side surface. In addition, the corner between the second surface 12 and the inclined surface 13 may also have a curvature. Also, a straight portion may be included between the second surface 12 and the inclined surface 13. A fourth reflective member 40 is provided between the second surface 12 and the inclined surface 13 (i.e., the inner side surface of the concave portion). The inclined surface 13 of the second surface 12 is the inner side surface of the concave portion provided on the second surface 12 so as to surround the through-hole in plan view. When the light guide plate 10 has a plurality of through-holes 15, the inclined surface 13 is, for example, Figure 2 disposed as shown on the inner side surface of the concave portion between the through-hole 15 and the adjacent through-hole 15. When the light guide plate 10 has a plurality of through-holes 15, the concave portions on the second surface 12 are arranged in a lattice shape, and one through-hole 15 is provided in the region surrounded by each lattice. In addition, the second surface 12 of the light guide plate 10 may not have the inclined surface 13. That is, the second surface 12 may be a flat surface. Also, the second surface 12 may only be an inclined surface and not have a flat surface. That is, the through-hole 15 and the inclined surface 13 may also be in contact.

[0082] The first reflective member 23, the second reflective member 24, the third reflective member 50, and the fourth reflective member 40 may be, for example, a white resin containing a reflective member (or a light-scattering member). The first reflective member 23, the second reflective member 24, the third reflective member 50, and the fourth reflective member 40 are, for example, a silicone resin or an epoxy resin containing fine particles such as TiO2, SiO2, Al2O3, and ZnO as a reflective member (or a light-scattering member). The first reflective member 23 and the fourth reflective member 40 may also use a reflective metal or a dielectric film (dielectric sheet). Also, when used as the first reflective member 23 and the fourth reflective member 40, in addition to the resin sheet made of the above-mentioned white resin, a resin sheet that is recognized as white by containing air bubbles may also be used.

[0083] The first reflective member 23 reflects a part of the light emitted directly above the light-emitting device 20 downward or laterally and transmits the other part. Thereby, in the light-emitting surface of the light-emitting module, it is possible to suppress the area directly above the light-emitting device 20 from becoming excessively bright compared to other areas.

[0084] The light emitted downward from the phosphor or the light emitted laterally and downward from the light-emitting element 21 is reflected upward by the second reflective member 24 and the third reflective member 50, and the brightness of the light extracted from the light-emitting surface, i.e., the first surface 11, can be increased.

[0085] In addition, the fourth reflective portion 40 provided on the second surface 12 and the inclined surface 13 of the light guide plate 10 reflects the light guided in the light guide plate 10 toward the first surface 11, and the brightness of the light extracted from the first surface 11 can be increased.

[0086] The lower surface of the fourth reflective member 40, the lower surface of the third reflective member 50, and the lower surface of the conductive film 27 are disposed on the same plane, and a metal-containing wiring 61 is provided on the lower surfaces of these fourth reflective member 40, third reflective member 50, and conductive film 27. The conductive film 27 is connected to the wiring 61. The light-emitting module is mounted on the wiring substrate via the wiring 61.

[0087] As Figure 2 shown, a plurality of through-holes 15 can be provided in one light guide plate 10, and a plurality of light-emitting devices 20 can be arranged. The light-emitting devices 20 are arranged in the respective through-holes 15, and each light-emitting device 20 is fixed to the light guide plate 10 by a light-transmissive member 30. This structure realizes a wide-surface light source with small brightness unevenness.

[0088] Next, with reference to Figures 3A to 8B a manufacturing method of a light-emitting module according to an embodiment will be described.

[0089] First, as Figure 3A shown, a light guide plate 10 is prepared. A recess is formed in the light guide plate 10 with the first surface 11, the second surface 12 on the opposite side of the first surface 11, and the inclined surface 13 that forms an obtuse angle with the second surface 12 as the inner side surfaces. The recess is formed in a lattice shape in a top view. Such a light guide plate 10 can be prepared, for example, by forming a flat light-transmissive member by purchasing or injection molding and then forming the recess using a processing tool. Alternatively, it can be prepared by purchasing a light guide plate with a recess in advance, or by forming a light guide plate with a recess by injection molding or the like.

[0090] Next, as Figure 3BAs shown, a fourth light-reflecting member 40 is formed on the second surface 12 (the flat surface and the inner side surface of the concave portion, i.e., the inclined surface 13) of the light guide plate 10. When the fourth light-reflecting member 40 is made of a white resin material, as a forming method, there can be cited a method of forming a liquid or paste-like light-reflecting resin by printing, spraying, compression molding, transfer molding, etc. and curing it. Alternatively, a separately formed light-reflecting sheet can also be pasted. Further, when the fourth light-reflecting member 40 is a metal, there can be cited pasting of a metal foil, sputtering, evaporation plating, printing of a paste, etc. When the fourth light-reflecting member 40 is a dielectric, there can be cited pasting of a dielectric sheet, sputtering formation, etc.

[0091] After forming the fourth light-reflecting member 40, as Figure 4A shown, a plurality of through holes 15' penetrating between the first surface 11 and the second surface 12 are formed in the light guide plate 10 so as to also penetrate the fourth light-reflecting member 40. Figure 8A FIG. is a perspective view of the light guide plate 10 having a plurality of through holes 15' formed therein when viewed from the first surface 11 side. Figure 4A is Figure 8A a cross-sectional view taken along line IVA-IVA in Figure 8A In the example shown, the planar shape of the through hole 15' can be circular, or it can also be angular such as triangular, quadrilateral, etc. When it is angular, the corners can also be curved surfaces or chamfered shapes.

[0092] For example, the through holes 15' can be formed by machining such as drilling or punching. Alternatively, the through holes 15' can also be formed by etching or laser. When it is machining, as Figure 8B shown, the corners at the ends of the through holes 15' sometimes have a curvature. Further, when it is machining, irregularities are sometimes formed on the inner walls of the through holes 15'.

[0093] After forming the through holes 15', as Figure 4B shown, the second surface 12 side of the light guide plate 10 is pasted to the sheet 100. In this example, the surface of the fourth light-reflecting member 40 is pasted to the sheet 100. The openings on the second surface 12 side of the through holes 15' are blocked by the sheet 100. A part of the sheet 100 forms the bottom surface of the through holes 15'.

[0094] As Figure 5A shown, the above-described light-emitting device 20 is disposed in the through holes 15'. Specifically, the conductive film 27 constituting the Figure 1 shown electrode portion 25 in the light-emitting device 20 is pasted to the sheet 100 that blocks the openings on the second surface 12 side of the through holes 15'. There is a gap between the side surface of the light-emitting device 20 and the side wall of the through holes 15'.

[0095] After disposing the light-emitting device 20 in the through holes 15', asFigure 5B As shown, liquid resin 30' is supplied into the through-hole 15'. Examples of the supply method of the resin 30' include potting, spraying, dispensing, jet dispensing, printing, etc. The resin 30' contains a light-reflecting member including fine particles such as TiO2, SiO2, Al2O3, ZnO, etc.

[0096] Moreover, by the centrifugation method, the light-reflecting member contained in the resin 30' is settled on the upper surface of the light-emitting device 20 and on the sheet 100 that closes the opening on the second surface 12 side of the through-hole 15'. The light-reflecting member settled on the sheet 100 is settled in a region below the phosphor layer 22.

[0097] By the settlement of the light-reflecting member, as Figure 6A shown, a first light-reflective member 23 is formed on the upper surface of the phosphor layer 22 of the light-emitting device 20, and a third light-reflective member 50 is formed on the periphery on the second surface 12 side of the light-emitting device 20.

[0098] After the light-reflecting member is settled, the resin 30' is cured. For example, the resin 30' is thermally cured at a temperature of about 150°C. The sheet 100 has heat resistance with respect to this temperature.

[0099] By the curing of the resin 30', a light-transmissive member 30 is formed on the light-emitting device 20 in the through-hole 15' and between the light-emitting device 20 and the side wall of the through-hole 15', and the light-emitting device 20 is fixed to the light guide plate 10 through the light-transmissive member 30.

[0100] The upper surface of the light-transmissive member 30 is pressed by, for example, a forming die, and as

[0101] shown, a recess 31 is formed on the upper surface of the light-transmissive member 30. In addition, the recess 31 can also be formed by utilizing the volume reduction of the light-transmissive member 30 due to curing or by making the resin 30' climb on the inner side surface of the through-hole 15' by surface tension. Figure 6B After that, the light guide plate 10 fixed with the light-emitting device 20 and the sheet 100 are separated, and as

[0102] shown, the conductive film 27 constituting the electrode portion 25 of the light-emitting device 20 is exposed on the second surface 12 side. Figure 7 The wiring 61 shown is formed on the second surface 12 side so as to be connected to the exposed conductive film 27. Figure 1 shown.

[0103] According to the embodiment, after the fourth reflective member 40 is formed on the second surface 12, the through hole 15' is formed, and the light-emitting device 20 is disposed in the through hole 15', so the electrode portion 25 of the light-emitting device 20 is not covered by the fourth reflective member 40. In addition, since the resin 30' is supplied into the through hole 15' after the electrode portion 25 of the light-emitting device 20 is adhered to the sheet 100, the electrode surface of the light-emitting device 20 is not covered by the resin 30'. In this example, since the lower surface of the conductive film 27 is in contact with the sheet 100, it is not covered by the resin 30'. Further, after the resin 30' is cured, the sheet 100 is peeled off, whereby the electrode surface of the light-emitting device 20 is exposed. Therefore, there is no need to remove the fourth reflective member 40 or the resin 30' covering the electrode surface of the light-emitting device 20, and the wiring 61 can be easily connected to the electrode surface.

[0104] By providing the conductive film 27 so as to extend from the rear electrode 26 provided on the lower surface of the light-emitting element 21 to a region outside the lower surface of the light-emitting element 21, the connection between the electrode portion 25 of the light-emitting device 20 and the wiring 61 becomes easy, and a highly reliable wiring connection can be performed.

[0105] In particular, when the light guide plate 10 having a plurality of through holes 15' formed therein is adhered to a structure in which a plurality of light-emitting devices 20 are first mounted on a wiring substrate, high precision is required between the mounting positions of the plurality of light-emitting devices 20 on the wiring substrate and the positions of the plurality of through holes 15' in the light guide plate 10.

[0106] In contrast, according to the embodiment, since the light-emitting device 20 is held on the light guide plate 10 instead of the wiring substrate and the light guide plate 10 and the light-emitting device 20 are integrated, the light-emitting device 20 can be arranged on the light guide plate 10 with high positional accuracy. The brightness unevenness in the light-emitting surface of the light guide plate 10 is suppressed.

[0107] In addition, by adhering, for example, a flexible printed circuit board to the wiring 61, the entire module including the wiring board can be thinned. Such a light-emitting module is suitable for, for example, a direct-lit backlight of a liquid crystal display.

[0108] Figure 9 It is a schematic cross-sectional view of a light-emitting module according to another embodiment.

[0109] The fourth reflective member 40 is not provided on the inclined surface 13 of the concave portion of the light guide plate 10, and the inclined surface 13 of the concave portion is in contact with the air layer 70 provided between the fourth reflective member 40 and the inclined surface 13. The refractive index of the material of the light guide plate 10 is higher than the refractive index of air. The refractive index here represents the refractive index with respect to the light emitted by the light emitting device 20. Therefore, the light guided in the light guide plate 10 can be totally reflected by the inclined surface 13 and directed toward the first surface 11, and the brightness of the light extracted from the first surface 11 can be improved.

[0110] When manufacturing Figure 9 the structure, as Figure 10A shown, after pasting the second surface 12 of the light guide plate 10 having the inclined surface 13 by processing or the like to the sheet-like fourth reflective member 40, a through hole 15' is formed in the light guide plate 10 so as to penetrate the fourth reflective member 40 as well. The air layer 70 is interposed between the inclined surface 13 and the fourth reflective member 40. As the sheet-like fourth reflective member 40, for example, a white resin containing a reflective member (or a light scattering member), or a multi-layer film of resin or ceramic, a dielectric multi-layer film, metal, etc. can be used.

[0111] Moreover, as Figure 10B shown, the fourth reflective member 40 is pasted to the sheet 100. After that, the light emitting device 20 is disposed in the through hole 15', and the same process as the above process is continued. In addition, Figure 10A and Figure 10B The cross-sectional view passing through the centers of a plurality of through holes 15' is shown in the same way as the cross-sectional view of other figures.

[0112] In addition, as Figure 11 shown, a light-transmitting resin 71 can also be provided on the inclined surface 13 of the light guide plate 10. The light-transmitting resin 71 is provided between the inclined surface 13 and the fourth reflective member 40. For the light-transmitting resin 71, a material having a refractive index smaller than that of the light guide plate is preferably used.

[0113] In addition, the inclined surface 13 may not be formed on the light guide plate 10, and as Figure 12 shown, the light guide plate 10 may also be in a flat plate shape.

[0114] In addition, irregularities for diffusing light or improving the light extraction efficiency may be formed on the first surface 11 of the light guide plate 10. For example, Figure 13 shows an example in which a plurality of convex portions 16 are formed on the first surface 11 of the light guide plate 10. The plurality of convex portions 16 are formed in a concentric circle shape around the through portion 15, for example. In addition, the convex portion 16 may also be in a dot shape.

[0115] For example, the height and width of the convex portion 16 on the outer peripheral side that is farther from the light-emitting device 20 are larger than the height and width of the convex portion 16 on the inner peripheral side that is closer to the light-emitting device 20. Additionally, the density of the convex portion 16 on the outer peripheral side may be higher than the density of the convex portion 16 on the inner peripheral side. On the first surface 11, not only the convex portion 16 can be formed, but also the concave portion can be formed.

[0116] Additionally, unevenness can also be formed on the second surface 12 of the light guide plate 10. For example, Figure 14 shows an example in which a plurality of concave portions 17 are formed on the second surface 12 of the light guide plate 10. On the second surface 12, not only the concave portion 17 can be formed, but also the convex portion can be formed. The uneven shape is not limited to having a curved surface in cross-section, and can also be an unevenness composed of continuous inclined surfaces.

[0117] As Figure 15 shown, the wiring 61 can also be formed on the side surface of, for example, the fourth reflective member 40 that constitutes the side surface of the light-emitting module. When the side surfaces are arranged adjacent to each other, the wirings 61 formed on the side surfaces of adjacent light-emitting modules can be directly connected to each other or connected via a conductive material.

[0118] As Figure 16 shown, a phosphor layer 122 can be provided on the second surface 12 of the light guide plate 10 around the light-emitting device 20. The light wavelength-converted by the phosphor layer 122 can be diffused in the surface direction through the light guide plate 10, and color unevenness within the surface of the light guide plate 10 can be suppressed.

[0119] As Figure 17 shown, a reflective member 72 can be provided on, for example, a V-shaped cross-section concave portion 31 on the upper surface of the light-transmissive member 30. The reflective member 72 reflects a part of the light emitted by the light-emitting device 20 and allows the other part to pass through. Thereby, on the light-emitting surface of the light-emitting module, it is possible to suppress the area directly above the light-emitting device 20 from becoming too bright compared to other areas. Additionally, there is the light-transmissive member 30 between the first reflective member 23 and the reflective member 72, so that it is possible to suppress the area directly above the light-emitting device 20 from becoming darker than the periphery.

[0120] Figure 18 is a schematic cross-sectional view of a light-emitting module of still another embodiment.

[0121] A fourth reflective member 140 is provided on the second surface 12 of the light guide plate 10 via an adhesive sheet 92. The adhesive sheet 92 can be, for example, an acrylic resin. The fourth reflective member 140 can be, for example, polyethylene terephthalate that is recognized as white by forming many bubbles. The thickness of the fourth reflective member 140 is preferably 35 μm or more and 350 μm or less.

[0122] The lower surface of the reflective member 140 is bonded to the wiring substrate 80 via the adhesive sheet 93. The adhesive sheet 93 includes, for example, an acrylic resin. The wiring substrate 80 has an insulating substrate 81, a wiring layer 82, and pads 83 connected to the wiring layer 82.

[0123] The light-emitting device 20 has a light-emitting element 21 and a phosphor layer 22 that covers the upper surface and the side surfaces of the light-emitting element 21. The light-emitting device 20 is disposed in the through-hole 15. In the through-hole 15, a light-transmissive member 30 is provided on the light-emitting device 20 and between the side surface of the light-emitting device 20 and the side wall of the through-hole 15.

[0124] A first reflective member 23 is provided between the upper surface of the light-emitting device 20, that is, the upper surface of the phosphor layer 22, and the light-transmissive member 30. The first reflective member 23 is in contact with the upper surface of the light-emitting device 20 (in this example, the upper surface of the phosphor layer 22) and directly covers the upper surface of the light-emitting device 20.

[0125] A reflective member 124 is provided on the lower surface of the light-emitting element 21 and the lower surface of the phosphor layer 22. A reflective member 150 is provided on the surface of the wiring substrate 80 around the light-emitting device 20 in the through-hole 15. The reflective member 124 and the reflective member 150 are, for example, a silicone resin or an epoxy resin containing fine particles such as TiO2, SiO2, Al2O3, ZnO, etc. as reflective members.

[0126] The electrode 26 of the light-emitting element 21 is joined to the pad 83 of the wiring substrate 80 via a joining member (for example, solder) 91. As the light source of the light-emitting module, only the light-emitting element can be used instead of the light-emitting device using a light-transmissive member such as the phosphor layer 22 as described above. In addition, as Figure 19A shown, as the light-emitting device, a light-emitting device including the light-emitting element 21 and the first reflective member 23 can be used. In this case, the first reflective member 23 is disposed on the upper surface of the light-emitting element 21.

[0127] As Figure 19B shown, the light-emitting device can also have a structure including the light-emitting element 21, a light-transmissive member 29 that covers the upper surface and the side surfaces of the light-emitting element 21, and a reflective member 124 that covers the lower surface of the light-emitting element 21 and the lower surface of the light-transmissive member 29. The light-transmissive member 29 can be a phosphor layer containing a phosphor, or can be a layer not containing a phosphor. The first reflective member 23 is disposed on the upper surface of the light-transmissive member 29.

[0128] As Figure 19CAs shown, as a light-emitting device, it can have a structure including a light-emitting element 21, a phosphor layer 22, a light-transmitting member 129 that does not contain a phosphor, and a reflective member 24. The phosphor layer 22 covers the upper surface of the light-emitting element 21. The light-emitting element 21 is bonded to the phosphor layer 22 via a bonding member 28. The reflective member 24 covers the side surface, the lower surface of the light-emitting element 21, and the side surface of the phosphor layer 22. The light-transmitting member 129 is disposed on the upper surface of the phosphor layer 22. The first reflective member 23 is disposed on the upper surface of the light-transmitting member 129.

[0129] When the light-emitting device does not contain a phosphor, a phosphor sheet can be provided on the first surface 11 of the light guide plate 10.

[0130] Figure 20 It is a schematic top view of the light-emitting surface (the first surface 11 of the light guide plate 10) side of the light-emitting module of the embodiment. When viewed from above, the first surface 11 of the light guide plate 10 is formed in a quadrilateral shape having four corner portions, and the light-emitting device 20 is also formed in a quadrilateral shape having four corner portions.

[0131] When viewed from above, the quadrilateral light-emitting device 20 is disposed by rotating, for example, 45 degrees with respect to the quadrilateral of the first main surface 11 of the light guide plate 10, and the diagonal line connecting the corner portions of the first surface 11 intersects the side surface (or edge portion) of the light-emitting device 20. For example, when the light guide plate 10 is square, the corner portions of the light-emitting device 20 do not lie on the diagonal line connecting the corner portions of the first surface 11.

[0132] When viewed from above, in the quadrilateral light-emitting device 20, the side surface has a larger area than the corner portion, and there is a tendency that the brightness of the light emitted from the side surface of the light-emitting device 20 is higher than the brightness of the light emitted in the diagonal direction of the light-emitting device 20.

[0133] In addition, on the quadrilateral first surface 11 of the light guide plate 10, the distance between the central portion of the light-emitting device 20 and the corner portion of the first surface 11 is longer than the distance between the central portion and the edge portion of the first surface 11, and there is a tendency that light is difficult to spread to the four corners of the first surface 11.

[0134] According to Figure 20 In the embodiment shown, the light-emitting device 20 is disposed with respect to the light guide plate 10 such that the diagonal line connecting the corner portions of the first surface 11 intersects the side surface (edge portion) of the light-emitting device 20, and the side surface of the light-emitting device 20 faces the corner portion of the first surface 11, so that the light emitted from the light-emitting device 20 can be easily spread to the four corners of the first surface 11 of the light guide plate 10. Among them, not limited to this, the light guide plate 10 that is quadrilateral when viewed from above and the light-emitting device 20 that is quadrilateral when viewed from above can also be used to dispose the light-emitting device 20 such that one side of the light guide plate 10 is parallel to one side of the light-emitting device 20.

[0135] Figure 21It is an exploded perspective view showing the structure of a liquid crystal display 1000 including a light-emitting module 200 according to an embodiment.

[0136] The liquid crystal display 1000 sequentially includes a liquid crystal panel 120, two lens sheets 110a and 110b, a diffusion sheet 110c, and a light-emitting module 200 from the upper side.

[0137] The light-emitting module 200 has the above-mentioned Figure 1 , Figure 9 , Figures 11 to 20 structures or a structure combining them. Moreover, the light-emitting module 200 includes a plurality of through-holes 15 and a plurality of light-emitting devices 20 disposed in the through-holes 15.

[0138] The liquid crystal display 1000 is a so-called direct-lit type liquid crystal display in which the light-emitting module 200 that functions as a backlight is stacked below (inside) the liquid crystal panel 120. The liquid crystal display 1000 irradiates the light emitted from the light-emitting module 200 onto the liquid crystal panel 1205. The diffusion sheet 110c overlaps on the light-emitting surface, i.e., the first surface 11, of the light guide plate 10, and can suppress the brightness unevenness within the light-emitting surface. In addition, in addition to the above-described components, the liquid crystal display 1000 may further include components such as a polarizing film or a color filter.

[0139] As described above, the embodiments of the present invention have been described with reference to specific examples. However, the present invention is not limited to these specific examples. Based on the above-described embodiments of the present invention, all modes that can be appropriately designed and implemented by those skilled in the art as long as they include the gist of the present invention also fall within the scope of the present invention. In addition, it should be understood that within the scope of the idea of the present invention, various modification examples and correction examples can be conceived by those skilled in the art, and these modification examples and correction examples also fall within the scope of the present invention.

Claims

1. A light-emitting module, wherein, Comprising: A light guide plate, a light emitting device, and a second light transmissive member; The light guide plate has a first surface, a second surface opposite to the first surface, and a through portion penetrating between the first surface and the second surface; The light emitting device is disposed on the second surface side of the through portion, and the light emitting device comprises: A light emitting element; A first light transmissive member that covers the upper surface and the side surface of the light emitting element; A reflective member that covers the lower surface of the light emitting element and the lower surface of the first light transmissive member; A first reflective member that is disposed on the upper surface of the first light transmissive member; The second light transmissive member is disposed on the light emitting device within the through portion and between the light emitting device and the side wall of the through portion; The light emitting device is fixed to the light guide plate through the second light transmissive member, The upper surface of the second light transmissive member has a recess.

2. The light emitting module according to claim 1, wherein, The first light transmissive member contains a phosphor.

3. The light emitting module according to claim 2, wherein, The phosphor contains a KSF-based phosphor.

4. The light emitting module according to claim 2 or 3, wherein, The phosphor contains a β-sialon-based phosphor.

5. The light emitting module according to claim 1, wherein, The first light transmissive member does not contain a phosphor.

6. The light emitting module according to claim 1, wherein, A phosphor sheet is provided on the first surface of the light guide plate.

7. The light emitting module according to any one of claims 1 to 3, wherein, The second surface of the light guide plate comprises: A flat surface parallel to the first surface; A recess having an inclined surface as an inner side surface.

8. The light emitting module according to any one of claims 1 to 3, wherein, A resin sheet containing bubbles and recognized as white is provided on the second surface of the light guide plate via an adhesive sheet.

9. The light emitting module according to claim 8, wherein, The resin sheet is polyethylene terephthalate containing bubbles and recognized as white.

10. The light emitting module according to claim 8, wherein, The thickness of the resin sheet is 35 μm or more and 350 μm or less.

Images