JP7626932B2 - Light Emitting Module - Google Patents

Description

The present invention relates to a light-emitting module.

Light-emitting modules that combine light-emitting elements such as light-emitting diodes with light guide plates are widely used in planar light sources such as backlights for liquid crystal displays. For example, Patent Document 1 discloses a planar light source in which LEDs mounted on a flexible printed circuit board are placed in recesses in a light guide plate, and a reflective sheet with holes through which the LEDs pass is provided on the underside of the light guide plate.

JP 2010-8837 A

The present invention aims to provide a light-emitting module that can be made thin.

According to one aspect of the present invention, a light-emitting module includes a light-guiding member having a first surface and a second surface opposite to the first surface, the light-guiding member having a first region including a recess that opens into the second surface, a second region surrounding the first region in a planar view, and a third region surrounding the second region in a planar view, and a light source disposed in the recess. The first surface includes a concave surface disposed across the first region and the second region such that the deepest part is located in the first region. The second surface includes a convex surface in the second region that protrudes from the third region so as to follow the concave surface.

The present invention provides a light-emitting module that can be made thin.

1 is a perspective view of a first surface side of a light-emitting module according to an embodiment of the present invention; 2 is a perspective view of a second surface side of the light-emitting module according to one embodiment of the present invention; FIG. FIG. 1B is a cross-sectional view taken along line II-II in FIG. 1A. FIG. 2 is a top view of a light source in the light emitting module of one embodiment of the present invention. 2 is a bottom view of a light source in the light emitting module of the embodiment of the present invention. FIG. FIG. 3C is a cross-sectional view taken along line IIIC-IIIC in FIG. 3A. 4 is a cross-sectional view showing another example of a light source in the light-emitting module of one embodiment of the present invention. FIG. 1 is a cross-sectional perspective view showing a method for manufacturing a light-emitting module according to an embodiment of the present invention; 1 is a cross-sectional perspective view showing a method for manufacturing a light-emitting module according to an embodiment of the present invention; 1 is a cross-sectional perspective view showing a method for manufacturing a light-emitting module according to an embodiment of the present invention; 1 is a cross-sectional perspective view showing a method for manufacturing a light-emitting module according to an embodiment of the present invention; 1 is a cross-sectional perspective view showing a method for manufacturing a light-emitting module according to an embodiment of the present invention; 1 is a cross-sectional perspective view showing a method for manufacturing a light-emitting module according to an embodiment of the present invention; 1 is a cross-sectional perspective view showing a method for manufacturing a light-emitting module according to an embodiment of the present invention; 1 is a perspective view showing a manufacturing method of a light-emitting module according to an embodiment of the present invention;

The following describes the embodiments with reference to the drawings. Each drawing is a schematic representation of the embodiment, and therefore the size, spacing, or positional relationship of each component may be exaggerated, some components may not be shown, or end views showing only the cut surfaces may be used as cross-sectional views. Note that the same components are given the same reference numerals in each drawing. In addition, "planar view" in this disclosure refers to a view from the first surface side or the second surface side of the light-guiding member.

Figure 1A is a perspective view of the first surface 11 side of a light-emitting module 1 according to one embodiment of the present invention. Figure 1B is a perspective view of the second surface 12 side of the light-emitting module 1. Figure 2 is a cross-sectional view taken along line II-II in Figure 1A.

The light-emitting module 1 includes at least a light-guiding member 10, a light source 20, a first light-reflective member 41, a second light-reflective member 42, a third light-reflective member 43, a light-adjusting member 44, and a first light-transmissive member 31.

Light from the light source 20 is guided to the light-guiding member 10. The light-guiding member 10 is translucent to the light from the light source 20. The transmittance of the light-guiding member 10 to the light from the light source 20 is, for example, preferably 80% or more, and more preferably 90% or more. The light source 20 has at least a light-emitting element 22. The light from the light source 20 includes light emitted by the light-emitting element 22. In addition, when the light source 20 includes a phosphor, the light from the light source 20 also includes light emitted by the phosphor.

The light-guiding member 10 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.

The light guide member 10 has a first surface 11 which is the light emitting surface of the light emitting module 1, and a second surface 12 opposite to the first surface 11. The thickness of the light guide member 10 is preferably such that the shortest distance between the first surface 11 and the second surface 12 is, for example, 50 μm or more and 250 μm or less in the first region a1, 100 μm or more and 700 μm or less in the second region a2, and 200 μm or more and 800 μm or less in the third region a3. The light guide member 10 may be composed of a single layer in the thickness direction, or may be composed of a laminate of multiple layers. When the light guide member 10 is composed of a laminate, a translucent adhesive member can be disposed between each layer. The layers of the laminate can be made of the same or different materials, for example, from the materials of the light guide member 10 described above. The adhesive member can be made of, for example, a thermoplastic resin such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate, or polyester, or a thermosetting resin such as epoxy or silicone.

The light guide member 10 also has a first region a1, a second region a2 that surrounds the first region a1 in a planar view, and a third region a3 that surrounds the second region a2 in a planar view. In FIG. 1A, the boundaries between the first region a1 and the second region a2, and the boundaries between the second region a2 and the third region a3 are indicated by dashed lines.

The first region a1 includes a recess 13 (hereinafter referred to as the first recess) that opens to the second surface 12. The first surface 11 includes a concave surface 11a that is arranged across the first region a1 and the second region a2 so that the deepest part is located in the first region a1. The second surface 12 includes a convex surface 12a in the second region a2 that protrudes more than the third region a3 so as to follow the concave surface 11a of the first surface 11. The direction that connects the concave surface 11a and the convex surface 12a in the second region a2 at the shortest distance is inclined with respect to the direction that connects the first surface 11 and the second surface 12 at the shortest distance in the third region a3. Note that "along the concave surface 11a" means that it is parallel or approximately parallel to the concave surface 11a. Furthermore, "approximately parallel to the concave surface 11a" means that an inclination of within ±3° with respect to the concave surface 11a is permitted.

The first surface 11 and the second surface 12 in the third region a3 are parallel or approximately parallel. Note that the first surface 11 and the second surface 12 being approximately parallel means that it is acceptable for either the first surface 11 or the second surface 12 to have an inclination of within ±3° with respect to the other surface.

The light source 20 is disposed in the first recess 13 of the light-guiding member 10 via a first light-transmissive member 31. FIG. 3A is a top view of the light source 20. FIG. 3B is a bottom view of the light source 20. FIG. 3C is a cross-sectional view taken along line IIIC-IIIC in FIG. 3A.

The light source 20 may be a single light-emitting element 22, or may be a structure in which the light-emitting element 22 is combined with a second light-transmissive member 24 as shown in FIG. 3C. The light source 20 may further include a light-reflective covering member 25. Details of the second light-transmissive member 24 and covering member 25 will be described later.

The light emitting element 22 includes a semiconductor laminate and a pair of positive and negative electrodes electrically connected to the semiconductor laminate. The semiconductor laminate includes, for example, a support substrate such as sapphire or gallium nitride, an n-type semiconductor layer and a p-type semiconductor layer disposed on the support substrate, and a light emitting layer sandwiched between the n-type semiconductor layer and the p-type semiconductor layer. The pair of positive and negative electrodes includes an n-side electrode and a p-side electrode electrically connected to the n-type semiconductor layer and the p-type semiconductor layer, respectively. The semiconductor laminate may be one from which the support substrate has been removed. The structure of the light emitting layer may be a structure having a single active layer such as a double heterostructure or a single quantum well structure (SQW), or a structure having a group of active layers such as a multiple quantum well structure (MQW). The light emitting layer can emit visible light or ultraviolet light. The light emitting layer can emit visible light ranging from blue to red. Such a semiconductor laminate including a light emitting layer may include, for example, _{InxAlyGa1 -xyN (} 0≦x, 0≦y, x+y≦1).

The semiconductor laminate may include at least one light-emitting layer capable of emitting the above-mentioned light. For example, 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 sequence 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 may include light-emitting layers having the same emission peak wavelength. The same emission peak wavelength may have a variation of about several nm in the emission peak wavelength, for example. Such a combination of emission peak wavelengths 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. The light-emitting layer may include multiple active layers having different emission peak wavelengths, or may include multiple active layers having the same emission peak wavelength.

In the example shown in FIG. 3C, the second light-transmissive member 24 covers the top and side surfaces of the light-emitting element 22. The second light-transmissive member 24 is translucent to the light from the light source 20, and may be made of a light-transmissive resin such as silicone or epoxy. The second light-transmissive member 24 protects the light-emitting element 22 and may have functions such as wavelength conversion and light diffusion depending on the particles added to the second light-transmissive member 24.

Furthermore, the second light-transmissive member 24 may further include a wavelength conversion material, such as a phosphor, that converts the light from the light-emitting element 22 into light with a different peak wavelength. Examples of phosphors include yttrium aluminum garnet phosphors (e.g., _Y3 (Al,Ga) _5O12 :Ce), lutetium aluminum garnet phosphors (e.g., _Lu3 (Al,Ga _{)5O12 :} Ce), terbium aluminum garnet phosphors (e.g., _Tb3 (Al, _Ga ) _5O12 :Ce), CCA phosphors (e.g., _Ca10 ( _PO4 ) _6Cl2 :Eu), SAE phosphors ( _e.g. , _{Sr4Al14O25 :} Eu), _{chlorosilicate} phosphors (e.g. _{, Ca8MgSi4O16Cl2} :Eu), β _- sialon phosphors (e.g., (Si _, Al) ₃ (O, _N ) ₄ :Eu), α-sialon phosphors (e.g., Ca(Si,Al) ₁₂ (O,N) ₁₆ :Eu), SLA phosphors (e.g., _SrLiAl3N4 :Eu), CASN phosphors (e.g., _CaAlSiN3 :Eu) or SCASN phosphors (e.g., (Sr,Ca) _AlSiN3 :Eu), nitride phosphors such as KSF phosphors (e.g., _K2SiF6 :Mn), KSAF phosphors (e.g., _K2 ( _Si ,Al) _F6 :Mn) or MGF phosphors (e.g., 3.5MgO.0.5MgF2.GeO2:Mn), fluoride phosphors such as KSF phosphors (e.g., _K2SiF6 :Mn), KSAF phosphors (e.g., K2(Si,Al)F6:Mn) or _MGF phosphors (e.g., _{3.5MgO.0.5MgF2.GeO2} :Mn), phosphors having a perovskite structure (e.g., CsPb(F,Cl,Br,I) ₃ ), or a quantum dot phosphor (e.g., CdSe, InP, _AgInS2 , or _AgInSe2 ), etc. may be used. As the phosphor to be added to the second light-transmissive member 24, one type of phosphor may be used, or multiple types of phosphors may be used.

The KSAF phosphor may have a composition represented by the following formula (I).
M ₂ [Si _p Al _q Mn _r F _s ] (I)

In formula (I), M represents an alkali metal and may contain at least K. Mn may be a tetravalent Mn ion. p, q, r, and s may satisfy 0.9≦p+q+r≦1.1, 0<q≦0.1, 0<r≦0.2, and 5.9≦s≦6.1. Preferably, 0.95≦p+q+r≦1.05 or 0.97≦p+q+r≦1.03, 0<q≦0.03, 0.002≦q≦0.02, or 0.003≦q≦0.015, 0.005≦r≦0.15, 0.01≦r≦0.12, or 0.015≦r≦0.1, and 5.92≦s≦6.05 or 5.95≦s≦6.025. For _example , the compositions represented by _K2 [ _{Si0.946Al0.005Mn0.049F5.995} ] _{, K2} [ _{Si0.942Al0.008Mn0.050F5.992} ], and _K2 [ _{Si0.939Al0.014Mn0.047F5.986} ] can be _mentioned . According to such a _KSAF phosphor, it is possible to obtain red light emission with _high brightness and a narrow _half - _width of _the emission _peak wavelength.

An electrode 23 electrically connected to the n-type semiconductor layer and the p-type semiconductor layer of the light-emitting element 22 is disposed on the underside of the light-emitting element 22. A covering member 25 is disposed on at least the underside of the light-emitting element 22. The covering member 25 is disposed so that at least a portion of the surface of the electrode 23 (the underside in FIG. 3C) is exposed from the covering member 25. The covering member 25 covers the underside of the second translucent member 24 and the side of the electrode 23.

The covering member 25 is reflective to the light from the light source 20. The covering member 25 is, for example, a resin member containing a light diffusing agent. Examples of the light diffusing agent include particles of _SiO2 , _CaF2 , _MgF2 , _TiO2 , _Nb2O5 , _BaTiO3 , _Ta2O5 , _{Zr2O3 , ZnO} , _Y2O3 , _Al2O3 , MgO, or _BaSO4 . Examples of the resin base material include silicone resin, epoxy resin _, or _acrylic resin. The covering member 25 may also be _, for example, ceramics, preferably fine ceramics.

The light source 20 may also include a light-reflective member that covers the entire or part of the upper surface of the second translucent member 24. The light-reflective member is a resin member that is reflective and translucent to the light from the light-emitting element 22 and contains, for example, a light diffusing agent or air bubbles. The light-reflective member may also be, for example, a metal member such as Al or Ag, a DBR (Distributed Bragg Reflector), or ceramics (preferably fine ceramics). Such a light-reflective member can diffusely reflect a part of the light emitted from the upper surface of the second translucent member 24, thereby reducing uneven brightness within the light-emitting surface of the light-emitting module 1.

Figure 3D is a cross-sectional view showing another example of a light source. In this light source, a covering member 25 covers the side and bottom surfaces of the light-emitting element 22. A second light-transmissive member 24 covers the top surface of the light-emitting element 22 and the top surface of the covering member 25. The covering member 25 is arranged so that at least a part of the surface (bottom surface in Figure 3D) of the electrode 23 arranged on the bottom surface of the light-emitting element 22 is exposed. At this time, the covering member 25 covers the side surfaces of the electrode 23.

As shown in FIG. 2, a first light-transmissive member 31 is disposed in the first recess 13 of the light-guiding member 10. The first light-transmissive member 31 is translucent to the light from the light source 20, and is, for example, a translucent resin such as silicone or epoxy. The first light-transmissive member 31 may also contain a phosphor.

The first light-transmissive member 31 covers the top and side surfaces of the light source 20. The first light-transmissive member 31 also covers the inner surface (side and bottom surface) of the first recess 13. As shown in the example in FIG. 2, the first light-transmissive member 31 may be disposed only within the first recess 13, or a portion of the first light-transmissive member 31 may extend to further cover the convex surface 12a of the second surface 12 located around the first recess 13. The light source 20 is fixed to the light-guiding member 10 by the first light-transmissive member 31.

A light adjustment member 44 is disposed on the concave surface 11a of the first surface 11 of the light guide member 10. The light adjustment member 44 is disposed above the light source 20. The light adjustment member 44 is disposed across the first region a1 and the second region a2.

The light adjustment member 44 has reflectivity and translucency with respect to the light from the light source 20. The light adjustment member 44 may include a translucent resin and a light diffusing agent or air bubbles dispersed in the translucent resin. The translucent resin may be, for example, a silicone resin or an epoxy resin. The light diffusing agent may be, for example, particles of SiO ₂ , CaF ₂ , MgF ₂ , TiO ₂ , Nb ₂ O ₅ , BaTiO ₃ , Ta ₂ O ₅ , Zr ₂ O ₃ , ZnO, Y ₂ O ₃ , Al ₂ O ₃ , MgO, or BaSO _4. The light adjustment member 44 may be, for example, a metal member such as Al or Ag, a distributed Bragg reflector (DBR), or ceramics (preferably fine ceramics).

Such a light adjustment member 44 diffusely reflects a portion of the light emitted upward from the light source 20 and transmits the other portion. This prevents the brightness of the area directly above the light source 20 from becoming extremely high compared to the brightness of other areas, and reduces brightness unevenness within the light-emitting surface of the light-emitting module 1.

A first light reflecting member 41 is disposed on the convex surface 12a of the second surface 12 of the light guide member 10. The first light reflecting member 41 is a resin member containing a light diffusing agent. _Examples of the resin include silicone and epoxy. Examples of the light diffusing agent include particles of _SiO2 , CaF2, _MgF2 , _TiO2 , _Nb2O5 , _BaTiO3 , _{Ta2O5 , Zr2O3} , _ZnO , _{Y2O3 , Al2O3} , MgO, _{BaSO4 ,} or the _like .

The first light-reflective member 41 is also arranged at a position overlapping the first recess 13 in a plan view. In detail, the first light-reflective member 41 covers the lower surface of the first light-transmissive member 31 arranged in the first recess 13. A part of the light source 20 (e.g., a part including the electrode 23 and the covering member 25) is arranged outside the first recess 13, and the first light-reflective member 41 covers the side surface of the part of the light source 20.

The light-reflective member 40 is adhered to the third region a3 of the second surface 12, for example, via a translucent adhesive sheet. The adhesive sheet may contain a light diffusing agent. The light-reflective member 40 includes a second light-reflective member 42 and a third light-reflective member 43. The second light-reflective member 42 and the third light-reflective member 43 are also adhered to each other, for example, via an adhesive sheet.

The light-reflective member 40 includes a laminated portion of the second light-reflective member 42 and the third light-reflective member 43, and a single-layer portion of the third light-reflective member 43. In the laminated portion, the second light-reflective member 42 is located between the second surface 12 and the third light-reflective member 43. In addition, in the laminated portion, the second light-reflective member 42 and the third light-reflective member 43 surround the first light-reflective member 41 in a planar view. The single-layer portion of the third light-reflective member 43 surrounds the second light-reflective member 42 in a planar view.

The third light reflective member 43 extends from the single layer portion to cover the second light reflective member 42 and is in contact with the first light reflective member 41. The second light reflective member 42 is also in contact with the first light reflective member 41. In other words, there is no gap between the second light reflective member 42 and the first light reflective member 41, and there is no gap between the third light reflective member 43 covering the second light reflective member 42 and the first light reflective member 41.

The second light-reflective member 42 is, for example, a member in which multiple insulating films with different refractive indices are laminated. For example, a polyester resin can be used as this insulating film. The third light-reflective member 43 is, for example, a resin member containing multiple air bubbles. For example, polyethylene terephthalate can be used as the base resin.

The diffuse reflectance of the second light reflective member 42 is lower than that of the first light reflective member 41. The diffuse reflectance of the third light reflective member 43 is lower than that of the first light reflective member 41 and higher than that of the second light reflective member 42. The regular reflectance of the second light reflective member 42 is higher than that of the first light reflective member 41 and higher than that of the third light reflective member 43. The regular reflectance of the third light reflective member 43 is higher than that of the first light reflective member 41.

As shown in FIG. 1B, wiring 51 is disposed on the underside of the first light-reflective member 41. The underside of the electrode 23 electrically connected to the light-emitting element 22 is exposed from the first light-reflective member 41 and connected to the wiring 51. A pair of wiring 51 is disposed to connect to each of the pair of positive and negative electrodes 23, and the pair of wiring 51 is separated from each other on the underside of the first light-reflective member 41.

An insulating film 61 is disposed on the underside of the first light-reflective member 41. The insulating film 61 covers the outer periphery of the wiring 51. The part of the wiring 51 that is inside the outer periphery is exposed from the insulating film 61. The insulating film 61 is also disposed between a pair of wirings 51, improving the insulation between the pair of wirings 51.

Light from the light source 20 enters the light-guiding member 10 through the first light-transmissive member 31. The light that enters the light-guiding member 10 is guided through the light-guiding member 10 while repeatedly being totally reflected between the light-reflective member 40 and the first surface 11. Of the light guided through the light-guiding member 10, a portion of the light that is directed toward the first surface 11 is extracted from the first surface 11 to the outside of the light-guiding member 10.

In the third region a3, where the light-reflective members 40 (second light-reflective member 42 and third light-reflective member 43) having a higher specular reflectance than the first light-reflective member 41 are arranged, the light guided within the light-guiding member 10 is likely to be totally reflected on the second surface 12 side. This makes it easier for the light from the light source 20 to be guided within the light-guiding member 10 toward the ends and corners of the light-guiding member 10. As a result, the brightness of the region far from the light source 20 can be improved, and brightness unevenness within the light-emitting surface can be improved.

In the light-reflective member 40, a single layer portion of the third light-reflective member 43, which has a higher diffuse reflectance than the second light-reflective member 42, is arranged in the area farther from the light source 20. Therefore, in the area farther from the light source 20, light guided by total reflection is suppressed more than in the area where the second light-reflective member 42 is arranged, and light is mainly extracted from the first surface 11 by diffuse reflection, thereby improving the brightness in the area farther from the light source 20.

The second light-reflective member 42, which is disposed in an area closer to the light source 20 than the single-layer portion of the third light-reflective member 43, has a higher regular reflectance than the third light-reflective member 43. This makes it possible to prevent the light from the light source 20 from being diffusely reflected and being extracted to the outside from the first surface 11 before reaching the end or corner of the light-guiding member 10, and makes it easier to guide the light from the light source 20 to an area of the light-guiding member 10 farther from the light source 20.

In this way, by combining the second light-reflective member 42 and the third light-reflective member 43, which have different reflection characteristics, as the light-reflective member 40 arranged in the third region a3, it is possible to improve the efficiency of extracting light from the first surface 11 while ensuring light-guiding properties.

In the first region a1 and the second region a2, which are closer to the light source 20 than the third region a3, the first light-reflective member 41, which has a higher diffuse reflectance than the light-reflective member 40, can reflect the light traveling downward toward the first surface 11, thereby suppressing the light from escaping downward. Therefore, the brightness of the light extracted from the first surface 11 can be improved.

In the second region a2 around the light source 20, the light adjustment member 44 is disposed on the concave surface 11a. Therefore, part of the light emitted upward in the second region a2 around the light source 20 is reflected by the concave surface 11a and directed laterally. In other words, part of the light directed upward in the second region a2 around the light source 20 is converted into a component that guides light within the light-guiding member 10, and the region above the light source 20 can be prevented from becoming too bright.

Next, a method for manufacturing the light-emitting module 1 of the embodiment will be described with reference to Figures 4 to 11.

The manufacturing method of the light-emitting module 1 of the embodiment includes a step of preparing a laminate 101 shown in FIG. 4. The step of preparing the laminate 101 includes a step of preparing a light-guiding member 10 and a step of arranging a light-reflective member 40 on the second surface 12 of the light-guiding member 10. The step of preparing the laminate 101 may be performed by purchasing the laminate 101 in which the light-reflective member 40 is arranged on the second surface 12 of the light-guiding member 10.

A recess 14 (hereinafter referred to as the second recess) is formed on the first surface 11 of the light-guiding member 10, and a first recess 13 is formed on the second surface 12 of the light-guiding member 10. In a plan view of the first surface 11, the first recess 13 is formed at a position overlapping the lower side of the second recess 14. In addition, the shape of the opening of the first recess 13 and the second recess 14 in a plan view is circular in this embodiment, but may be, for example, elliptical, or may be polygonal, such as triangular, rectangular, hexagonal, or octagonal.

For example, the first recess 13 and the second recess 14 can be formed by preparing a mold corresponding to the shape of the opening of the first recess 13 and the second recess 14, and sandwiching the plate-shaped light-guiding member 10 in the mold and pressing it to form the first recess 13 and the second recess 14. The first surface 11 and the second surface 12 are flat surfaces before pressing. Then, the pressing deforms a part of the light-guiding member 10 so that a part of the first surface 11 becomes a concave surface 11a and a part of the second surface 12 becomes a convex surface 12a. The deepest part of the concave surface 11a is located above the first recess 13. The convex surface 12a protrudes downward from the flat surface on the second surface 12 that is outside the convex surface 12a, so as to follow the concave surface 11a.

After processing the light-guiding member 10 in this manner, the light-reflective member 40 is adhered to the second surface 12. The light-reflective member 40 has an opening 40a that exposes the first recess 13 and the convex surface 12a. The light-reflective member 40 is adhered to the second surface 12 of the light-guiding member 10 by, for example, an adhesive sheet. For example, an epoxy resin, an acrylic resin, a silicone resin, or an olefin resin can be used as the adhesive sheet.

As described above, the light reflective member 40 includes the second light reflective member 42 and the third light reflective member 43. The second light reflective member 42 has a first opening 42a. A part of the third light reflective member 43 covers the second light reflective member 42. A step is formed between the part of the third light reflective member 43 that is bonded to the second surface 12 and the part that covers the second light reflective member 42 (the part that is laminated on the second light reflective member 42). A second opening 43a that overlaps with the first opening 42a of the second light reflective member 42 is formed inside the part of the third light reflective member 43 that covers the second light reflective member 42. The opening 40a of the light reflective member 40 is formed by communication between the first opening 42a and the second opening 43a.

As shown in FIG. 5, a light adjustment member 44 is formed in the second recess 14 of the first surface 11. For example, a translucent resin containing a light diffusing agent is supplied in an uncured state to the second recess 14 using a method such as dispensing or spraying, and then cured to form the light adjustment member 44.

As shown in FIG. 6, a first translucent member 31 is formed in the first recess 13 of the second surface 12. For example, the first translucent member 31 is supplied to the first recess 13 in an uncured state using a method such as dispensing or spraying. The first translucent member 31 may contain a phosphor. It is preferable to supply the first translucent member 31 to the first recess 13 in an amount equal to or smaller than the volume of the first recess 13.

As shown in FIG. 7, the light source 20 is disposed in the first recess 13. For example, after the first light-transmissive member 31 is supplied to the first recess 13, at least a part of the light source 20 is disposed in the uncured first light-transmissive member 31. After this, the first light-transmissive member 31 is cured. When the first light-transmissive member 31 is cured, the light source 20 sinks into the first light-transmissive member 31 by its own weight, or a load is applied to the light source 20 to sink it into the first light-transmissive member 31, so that, for example, the upper surface and side surface of the light source 20 are covered by the first light-transmissive member 31. At this time, the electrode 23 of the light source 20 is exposed from the first light-transmissive member 31. The light source 20 is fixed to the light-guiding member 10 by the first light-transmissive member 31.

After the light source 20 is fixed to the light guide member 10, the light reflective member 40 may be bonded to the second surface 12 of the light guide member 10. In addition, if heat treatment is performed, for example, at 40°C to 60°C to increase the adhesive strength after the light reflective member 40 is bonded to the second surface 12 of the light guide member 10, it is preferable to bond the light reflective member 40 to the second surface 12 of the light guide member 10, perform heat treatment, and then fix the light source 20 to the light guide member 10 in order to prevent thermal damage to the light source 20.

The light-reflective member 40 has an opening 40a that exposes the first recess 13. Therefore, even after the light-reflective member 40 is bonded to the second surface 12 of the light-guiding member 10, it is possible to form the first light-transmissive member 31 in the first recess 13 and to place the light source 20 therein.

In the opening 40a, the convex surface 12a of the second surface 12 is exposed so as to surround the light source 20 in a plan view. The first light reflective member 41 shown in FIG. 8 is formed on the second surface 12 in the opening 40a, including the convex surface 12a. For example, the opening 40a is filled with the first light reflective member 41 so as to cover the electrode 23 and the first translucent member 31 of the light source 20, and then the first light reflective member 41 is ground to expose the surface of the electrode 23 from the first light reflective member 41.

The inner side of the first light reflective member 41 contacts the covering member 25 of the light source 20, and the outer side of the first light reflective member 41 contacts the light reflective member 40. The thickness of the portion of the first light reflective member 41 that contacts the light reflective member 40 is thicker than the thickness of the portion of the first light reflective member 41 that contacts the covering member 25 of the light source 20. The thickness of the portion of the first light reflective member 41 that covers the convex surface 12a gradually becomes thinner as it approaches the light source 20.

After forming the first light-reflective member 41, as shown in FIG. 9, wiring 51 is formed on the surface of the first light-reflective member 41. For example, metal paste is supplied to the surface of the first light-reflective member 41 by a method such as printing and/or dispensing to form the wiring 51. The wiring 51 is connected to the electrodes 23 of the light source 20. The metal paste is formed continuously between the pair of electrodes 23, and then separated between the pair of electrodes 23 by, for example, laser etching. A pair of wiring 51 connected to each of the pair of electrodes 23 is formed.

After forming the wiring 51, as shown in FIG. 10, an insulating film 61 is formed on the surface of the first light-reflective member 41. The insulating film 61 is formed so as to cover at least the space between a pair of wirings 51, and can improve the insulation between the wirings 51. In the example shown in FIG. 10, the insulating film 61 is formed so as to cover the periphery of each of the pair of wirings 51, and can prevent the wirings 51 from peeling off from the first light-reflective member 41.

The above-described process is performed on the sheet-like light-guiding member 10 shown in FIG. 11. That is, a plurality of second recesses 14 are formed on the first surface 11 of the light-guiding member 10. A plurality of first recesses 13 are formed on the second surface 12 of the light-guiding member 10. A plurality of light-reflective members 40 are bonded separately to the second surface 12 of the light-guiding member 10. A light adjustment member 44 is formed in each of the plurality of second recesses 14. A first light-transmissive member 31 is formed in each of the plurality of first recesses 13. A light source 20 is disposed in each of the plurality of first recesses 13. A first light-reflective member 41 is formed in each of the openings 40a of the plurality of light-reflective members 40.

Then, the light-guiding member 10 is cut so as to include at least one light source 20 and at least one light-reflective member 40, thereby forming the light-emitting module 1 shown in Figures 1A, 1B, and 2. Note that one light-emitting module may include multiple light sources 20. The light-emitting module 1 may also be disposed on a wiring board to form a planar light source. The second surface 12 of the light-emitting module 1 faces the wiring board.

The first recess 13 for arranging the light source 20 is formed as a recess that opens into the second surface 12 in order to electrically connect the light source 20 to the outside. Like the first recess 13, the second recess for arranging the light adjustment member 44 can also be formed as a recess that opens into the first surface 11. However, as the light guide member 10 becomes thinner, the distance between the bottom surface of the first recess 13 and the first surface 11 becomes shorter, making it difficult to form a deep recess in the first surface 11 above the first recess 13.

According to this embodiment, by bending and deforming a portion of the light-guiding member 10, a portion of the first surface 11 formed as a flat surface is deformed into a concave surface 11a, forming a second recess 14 in which the light adjustment member 44 can be placed. Therefore, even if the light-guiding member 10 becomes thin, it is possible to ensure space for placing the light adjustment member 44. In addition, by storing the light adjustment member 44 in the second recess 14, it is possible to suppress an increase in the thickness of the entire light-emitting module 1.

The light emitting module of this embodiment has the following configuration.
[Appendix 1]
a light guiding member having a first surface and a second surface opposite to the first surface;
a light source disposed on the second surface side of the light guiding member;
a light adjustment member disposed on the first surface side at a portion overlapping with the light source in a plan view;
A light reflective member disposed on the second surface side;
Equipped with
The light reflective member is
a first light reflective member disposed near the light source and overlapping with the light adjustment member in a plan view;
a second light reflective member disposed outside the first light reflective member in a plan view and having a lower diffuse reflectance than the first light reflective member;
a third light reflective member disposed outside the second light reflective member in a plan view and having a higher diffuse reflectance than the second light reflective member;
A light emitting module having
[Appendix 2]
2. The light-emitting module according to claim 1, wherein the second light-reflective member includes a plurality of insulating films.
[Appendix 3]
3. The light-emitting module according to claim 1, wherein a portion of the third light-reflective member extends so as to cover the second light-reflective member.
[Appendix 4]
4. The light-emitting module according to claim 1, wherein the diffuse reflectance of the third light-reflecting member is lower than the diffuse reflectance of the first light-reflecting member.

The above describes the embodiments of the present invention with reference to specific examples. However, the present invention is not limited to these specific examples. All forms that a person skilled in the art can implement by appropriately modifying the design based on the above-described embodiments of the present invention also fall within the scope of the present invention as long as they include the gist of the present invention. In addition, a person skilled in the art can come up with various modifications and amendments within the scope of the concept of the present invention, and these modifications and amendments also fall within the scope of the present invention.

1...light emitting module, 10...light guide member, 11...first surface, 11a...concave surface, 12...second surface, 12a...convex surface, 13...concave (first concave), 14...concave (second concave), 20...light source, 22...light emitting element, 23...electrode, 24...second light transmissive member, 25...covering member, 31...first light transmissive member, 40...light reflective member, 41...first light reflective member, 42...second light reflective member, 43...third light reflective member, 44...light adjustment member, 51...wiring, a1...first region, a2...second region, a3...third region

Claims (9)

a light guiding member having a first surface and a second surface opposite to the first surface, the light guiding member having a first region including a recess that opens into the second surface, a second region surrounding the first region in a plan view, and a third region surrounding the second region in a plan view;
A light source disposed in the recess;
Equipped with
the first surface includes a concave surface disposed across the first region and the second region such that a deepest portion is located in the first region,
the second surface includes a convex surface in the second region that protrudes from the third region so as to be aligned with the concave surface,
a first light reflective member disposed on the convex surface;
a second light reflecting member disposed in the third region of the second surface and having a lower diffuse reflectance for light from the light source than the first light reflecting member;
The light emitting module further comprises : The light-emitting module according to claim 1, further comprising a light adjustment member disposed on the concave surface. The light emitting module according to claim 1 , wherein the first light reflective member is a resin member containing a light diffusing agent. 4. The light emitting module according to claim 1, wherein the second light reflective member is a laminated member made of a plurality of insulating films. The light-emitting module described in any one of claims 1 to 4, further comprising a third light-reflective member disposed in the third region of the second surface, surrounding the second light-reflective member in a planar view, and having a diffuse reflectance lower than that of the first light-reflective member and higher than that of the second light-reflective member for light from the light source. The light emitting module according to claim 5 , wherein the third light reflective member extends so as to cover the second light reflective member. The light emitting module according to claim 6 , wherein the third light reflective member is in contact with the first light reflective member. The light emitting module according to claim 5 , wherein the third light reflective member is a resin member containing a plurality of bubbles. a light guiding member having a first surface and a second surface opposite to the first surface, the light guiding member having a first region including a recess that opens into the second surface, a second region surrounding the first region in a plan view, and a third region surrounding the second region in a plan view;
A light source disposed in the recess;
Equipped with
the first surface includes a concave surface disposed across the first region and the second region such that a deepest portion is located in the first region,
the second surface includes a convex surface in the second region that protrudes from the third region so as to be aligned with the concave surface,
Further comprising a light adjusting member disposed on the concave surface,
The light-emitting module, wherein the light adjustment member includes a light-transmitting resin and a light diffusing agent contained in the light-transmitting resin, and is disposed across the first region and the second region above the light source.

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