JP2015225910A - Light-emitting module and illumination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting module and an illumination device, capable of improving light extraction efficiency by suppressing color unevenness.SOLUTION: According to an embodiment, there is provided a light-emitting module comprising a laminate, a frame body, a sealing member, and a lens. The laminate includes a light-emitting element and a phosphor layer. The laminate further includes a thickness W1 in a first direction from the light-emitting layer toward the phosphor layer. The phosphor layer is provided on at least an upper surface of the light-emitting element. The frame body is provided around the laminate. The frame body includes a thickness W2 in the first direction larger than the thickness W1. The sealing member is charged in the inside of the frame body so as to cover the whole laminate. The lens is provided on the sealing member. The refractive index of the lens is equal to or smaller than the refractive index of the sealing member.

Description

  Embodiments described herein relate generally to a light emitting module and a lighting device.

  There is a light emitting module using an LED (Light Emitting Diode) as a light source. Such a light emitting module is used in a lighting device or the like, and can obtain higher luminance with less power consumption.

  In the light emitting module, the light emitting element and the phosphor layer are provided on the same substrate. The light emitting element and the phosphor layer are sealed with a sealing body such as a resin. The light emitting module emits light of a target color by mixing the light from the light emitting element and the light generated when the light from the light emitting element enters the phosphor. In such a light emitting module, it is desired to suppress uneven color and improve the light extraction rate.

JP 2013-239712 A

  Embodiments of the present invention provide a light emitting module and a lighting device in which uneven color is suppressed and the light extraction rate is improved.

  According to the embodiment of the present invention, a light emitting module including a laminate, a frame, a sealing member, and a lens is provided. The laminate includes a light emitting element and a phosphor layer. The stacked body has a thickness W1 in a first direction from the light emitting element toward the phosphor layer. The phosphor layer is provided on at least the upper surface of the light emitting element. The frame is provided around the laminated body. The frame has a thickness W2 in the first direction larger than the thickness W1. The sealing member is filled in the frame so as to cover the entire laminated body. The lens is provided on the sealing member. The refractive index of the lens is equal to or smaller than the refractive index of the sealing member.

  According to the embodiment of the present invention, it is possible to provide a light-emitting module and a lighting device in which uneven color is suppressed and the light extraction rate is improved.

It is a schematic plan view which shows the light emitting module which concerns on 1st Embodiment. It is a schematic cross section which shows the light emitting module which concerns on 1st Embodiment. It is a schematic cross section which shows another light emitting module which concerns on 1st Embodiment. It is a schematic cross section which shows the illuminating device which attached the light emitting module which concerns on 1st Embodiment. It is a schematic cross section which shows the light emitting module which concerns on 2nd Embodiment. FIGS. 6A and 6B are schematic cross-sectional views illustrating the adhesion between the sealing member and the lens according to the second embodiment.

The invention according to the embodiment includes a light-emitting element and a phosphor layer provided on at least an upper surface of the light-emitting element, and has a thickness W1 in a first direction from the light-emitting element toward the phosphor layer. A frame provided around the laminate and having a thickness W2 in the first direction larger than the thickness W1, and a sealing member filled inside the frame so as to cover the laminate A lens provided on the sealing member, wherein the refractive index of the lens is equal to or smaller than the refractive index of the sealing member. The light emitting module.
According to this light emitting module, color unevenness can be suppressed and the light extraction rate can be improved.

The light emitting element has a silicon substrate, and the refractive index of the light emitting element is larger than the refractive index of the phosphor layer, and the refractive index of the phosphor layer is equal to the refractive index of the sealing member. Or it is a light emitting module characterized by being larger than the refractive index of the said sealing member.
According to this light emitting module, the light extraction rate can be improved.

The lens is formed of a transmissive resin having a phosphor, the phosphor layer has a red phosphor, and the phosphor is at least one of a green phosphor and a yellow phosphor. This is a light emitting module.
According to this light emitting module, color unevenness can be suppressed and the light extraction rate can be improved.

In addition, the sealing member is a light emitting module that is bonded to the lens, and an uneven portion is provided on a bonding surface of either the sealing member or the lens.
According to this light emitting module, uneven color can be suppressed and the bonding strength between the sealing member and the lens can be increased.

The invention according to the embodiment is an illuminating device comprising: the light emitting module according to any one of the above; and a lighting circuit that supplies electric power to the light emitting module.
According to this lighting device, color unevenness can be suppressed and the light extraction rate can be improved.

Embodiments of the present invention will be described below with reference to the drawings.
The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between the parts, and the like are not necessarily the same as actual ones. Further, even when the same part is represented, the dimensions and ratios may be represented differently depending on the drawings.
Note that, in the present specification and each drawing, the same elements as those described above with reference to the previous drawings are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

(First embodiment)
FIG. 1 is a schematic plan view illustrating a light emitting module 100 according to the first embodiment.
FIG. 2 is a schematic cross-sectional view illustrating the light emitting module 100 according to the first embodiment.
FIG. 3 is a schematic cross-sectional view illustrating another light emitting module 100 according to the first embodiment.
2 is a schematic cross-sectional view taken along line A1-A2 in FIG.

  The light emitting module 100 includes a substrate 10, a light emitting element 11 provided on the substrate 10, a phosphor layer 12 provided on at least the light emitting element 11, and the substrate 10 so as to surround the light emitting element 11 and the phosphor layer 12. The frame body 13 provided on the top, the sealing member 14, and the lens 15 provided on the frame body 13 and the sealing member 14 are provided.

  The direction from the substrate 10 toward the lens 15 is the Z-axis direction. One direction perpendicular to the Z-axis direction is taken as an X-axis direction. A direction perpendicular to the X-axis direction and perpendicular to the Z-axis direction is taken as a Y-axis direction. The Z-axis direction is the first direction.

  The substrate 10 can be formed of ceramics. Since ceramics has a high visible light reflectance, the luminous efficiency of the light emitting module 100 can be improved. Further, the substrate 10 may be formed using polycrystalline alumina, sapphire, aluminum nitride, silicon nitride, silicon oxide, or the like. The substrate 10 may be formed using glass, silicon, or the like.

  When a plurality of light emitting elements 11 are provided on the substrate 10, the light emitting elements 11 are arranged in parallel at a predetermined interval in the X axis direction of the substrate 10. For example, since the substrate 10 formed of ceramics has good heat dissipation, the thermal influence between the light emitting elements 11 provided on the substrate 10 can be suppressed. Therefore, the distance between the light emitting elements 11 can be shortened, and the light emitting module 100 can be downsized.

  The substrate 10 has, for example, a substantially rectangular shape. On the surface side of the substrate 10, a wiring pattern is formed by screen printing a paste of metal or the like, and the light emitting element 11 and the wiring pattern are electrically connected. A power supply terminal can be provided at the end of the substrate 10. The light emitting module 100 can be electrically connected to an element (for example, a lighting circuit) of the lighting device using such a power supply terminal. Note that there may be no wiring pattern on the substrate 10. A growth substrate such as silicon (Si) may be mounted and wire-connected to an electrode provided on the light emitting element 11.

  The light emitting element 11 is disposed on the upper surface of the substrate 10. The light emitting element 11 is a semiconductor light emitting element. The light emitting element 11 has, for example, a multilayer structure in which an n-type nitride semiconductor layer, an InGaN light emitting layer, and a p-type nitride semiconductor layer are sequentially stacked. The light emitting element 11 may be formed from a silicon substrate. The light emitting element 11 is, for example, a blue LED that emits blue light by supplying current.

  Hereinafter, although the light emitting element 11 is described as a blue LED, other light emitting elements that emit light of a predetermined color by supplying current may be used such as an organic EL (Organic Light Emitting Diode) or a semiconductor laser.

  The phosphor layer 12 converts the wavelength of part of the blue light emitted from the blue LED. That is, the phosphor layer 12 transmits the blue light emitted from the blue LED, excites the yellow phosphor by the blue light, converts it into yellow light, and mixes the transmitted blue light with the yellow light to produce white light. Emits light. White light L is irradiated from the phosphor layer 12 by wavelength conversion.

  The phosphor layer 12 is formed by dispersing and mixing a yellow phosphor in a transparent resin and applying it to a blue LED. The transparent resin is, for example, a silicone resin. The phosphor layer 12 may be formed by a molding machine or dipping. For example, an adhesive is provided between the phosphor layer 12 and the light emitting element 11 so that the phosphor layer 12 and the light emitting element 11 are bonded. The phosphor layer 12 is provided at least immediately above the light emitting element 11. The phosphor layer 12 may be provided so as to cover the upper surface and the side surface of the light emitting element 11 based on, for example, the type of the light emitting element 11.

  The frame 13 surrounds a stacked body in which the light emitting element 11 and the phosphor layer 12 are stacked. The frame 13 is formed of ceramic or resin. The frame 13 includes, for example, a material having high reflectivity. A reflective film may be provided on the surface of the frame 13. The dimension (thickness) W1 in the Z-axis direction of the laminate is smaller than the dimension W2 in the Z-axis direction of the frame body 13. The shape of the frame 13 is substantially circular (including a circular shape or an elliptical shape) in a plan view, and is substantially semicircular (including a semicircular shape or a semielliptical shape) in a sectional view.

  The sealing member 14 can be formed by filling a region surrounded by the substrate 10, the frame body 13, and the lens 15 with resin. The sealing member is formed of a resin such as an epoxy resin, a urea resin, or a silicone resin. The sealing member 14 is formed by filling and solidifying a member that transmits light emitted from the phosphor layer 12. The dimension W3 in the Z-axis direction of the sealing member 14 is substantially the same as the dimension W2 of the frame 13.

  The lens 15 is bonded to the upper surface of the sealing member 14. The lens 15 has a predetermined lens diameter and a curvature radius. For example, the lens 15 and the sealing member 14 have the same diameter. The lens 15 is formed of resin or the like. The shape of the lens 15 is substantially circular in a plan view, and is substantially semicircular in a cross-sectional view. The lens 15 and the sealing member 14 are joined by a transparent adhesive or the like. By providing the lens 15 on the upper surface of the sealing member 14, the extraction efficiency of light irradiated from the phosphor layer 12 is improved.

  When the refractive indexes of the light emitting element 11, the phosphor layer 12, the sealing member 14, and the lens 15 are n1, n2, n3, and n4, respectively, it is desirable to satisfy the following relational expression (1).

  n1> n2 ≧ n3 ≧ n4 (1)

  For example, when the light emitting element 11 is formed from a silicon substrate, the phosphor layer 12 is disposed only immediately above the blue LED. The light totally reflected at the interface between the sealing member 14 and the lens 15 may be repeatedly reflected in the sealing member 14 and absorbed by the side surface of the light emitting element 11 in some cases. As in the relational expression (1), the refractive index decreases in the order in which the light from the light emitting element 11 passes, so that the light can be extracted efficiently.

  The light refractive index n2 of the phosphor layer 12 and the light refractive index n3 of the sealing member 14 may be substantially the same. The light refractive index n3 of the sealing member 14 and the light refractive index n4 of the lens 15 may be substantially the same. The refractive index n3 and the refractive index n4 are preferably substantially the same as the refractive index of the adhesive that bonds the sealing member 14 and the lens 15. The light emitted from the light emitting element 11 through the phosphor layer 12 is taken out from the lens 15 through the sealing member 14.

  As shown in FIG. 3, a plurality of phosphors may be provided on the substrate 10. A light emitting element 11 including a silicon substrate 11a and a blue LED 11b is formed on the substrate 10, and a phosphor layer 12a including a first phosphor is provided immediately above the light emitting element 11. The light emitting element 11 and the phosphor layer 12a are surrounded by a sealing member 14 made of a transparent resin. A lens 15 made of a transmissive resin containing the second phosphor is provided on the sealing member 14.

  The first phosphor is a red phosphor having an emission peak at a wavelength of 620 to 650 nm. The second phosphor is a yellow phosphor or a green phosphor having an emission peak at a wavelength of 510 to 570 nm. In this case, a lens 15 including at least one of a yellow phosphor and a green phosphor may be provided on the sealing member 14.

  For example, when a red phosphor layer and a green phosphor layer or a yellow phosphor layer are stacked, light having a wavelength of 500 to 600 nm is easily absorbed by the red phosphor layer. That is, when light from the green phosphor layer or the yellow phosphor layer is absorbed by the red phosphor layer, a light emission loss is caused by the green phosphor layer or the yellow phosphor layer. As shown in FIG. 3, a phosphor layer 12 a containing a first phosphor is provided immediately above the light emitting element 11, and a lens 15 made of a resin containing a second phosphor is provided on the sealing member 14. With such a configuration, the light from the green phosphor layer or the yellow phosphor layer is prevented from being absorbed by the red phosphor layer. Further, color unevenness is also suppressed.

  FIG. 4 is a schematic cross-sectional view showing the lighting device to which the light emitting module according to the first embodiment is attached. In FIG. 4, a specific configuration of the lower part of the illumination device 150 is omitted.

  As shown in FIG. 4, the lighting device 150 includes the light emitting module 100, the instrument body 20, and the lighting circuit 30. The instrument body 20 includes a fixing member 21 that fixes the edge of the substrate 10. In addition, a recess 22 that houses the light emitting module 100 is provided in the instrument body 20. That is, the substrate 10 is accommodated in the recess 22 of the instrument body 20. The upper part of the lighting fixture 150 may be covered with a cover or the like.

  The edge of the substrate 10 is fixed by the pressing force below the fixing member 21 (−Z axis direction), and the light emitting module 100 is fixed to the instrument body 20. The light emitting module 100 is attached to the lighting device 150. The method for attaching the light emitting module 100 to the lighting device 150 is not limited to the method shown in FIG. 4, and any method such as adhesion, fitting, screwing, and locking may be used.

  The light emitting module 100 is electrically connected to the lighting circuit 30 of the lighting device 150. Electric power is supplied to the light emitting module 100 by electrical connection between the light emitting module 100 and the lighting circuit 30.

  Here, if the shape of the sealing member is hemispherical, the light extraction efficiency can be improved. However, when the sealing member is formed by solidifying the resin, it is difficult to process the sealing member into a predetermined shape.

  When a lens is provided in the light emitting module, the phosphor layer is formed in the vicinity of the light emitting element, for example, on the surface of the light emitting element, in order to take out the light irradiated from the phosphor layer to the outside. In such a case, if there is a variation in the thickness of the phosphor layer in the vertical direction (Z-axis direction), the color of the light emitted from the phosphor layer and the color difference for each angle (hereinafter referred to as the angle) May also be called color difference). An angular color difference occurs between the vertical direction (Z-axis direction) and the side surface direction (X-axis direction) of the light emitting element.

  In the present embodiment, the dimension W2 of the frame is larger than the dimension W1 of the laminate having the light emitting element 11 and the phosphor layer 12, and the frame 13 is provided on the substrate 10 so as to surround the laminate. The sealing member 14 is provided in a region surrounded by the substrate 10, the frame body 13, and the lens 15, and the lens 15 is provided on the upper surface of the sealing member 14. According to such a configuration of the light emitting module 100, a part of light irradiated in the side surface direction of the light emitting element 11 is blocked by the frame body 13. Moreover, the color temperature irradiated in the vertical direction of the light emitting element 11 is high, and the color temperature irradiated in the side surface direction is low. When a part of the light irradiated in the side surface direction of the light emitting element 11 is blocked by the frame body 13, the angular color difference can be reduced.

  According to the embodiment of the present invention, it is possible to provide a light-emitting module and a lighting device in which uneven color is suppressed and the light extraction rate is improved.

(Second Embodiment)
FIG. 5 is a schematic cross-sectional view illustrating the light emitting module 110 according to the second embodiment.
FIGS. 6A and 6B are schematic cross-sectional views illustrating the adhesion between the sealing member and the lens according to the second embodiment.
In FIG. 5, a cross-sectional view of the light emitting module 110 is shown. 6 (a) and 6 (b), enlarged sectional views for bonding the sealing member 14 and the lens 15 are shown.

  As illustrated in FIG. 5, the light emitting module 110 includes a substrate 10, a light emitting element 11 provided on the substrate 10, a phosphor layer 12 provided on the light emitting element 11, and the light emitting element 11 and the phosphor layer 12. A frame 13 provided on the substrate 10 so as to surround the sealing member 14, a sealing member 14, and a lens 15 provided on the upper surface of the sealing member 14.

  In the light emitting module 110, the lens 15 and the sealing member 14 are joined by the adhesive portion 16. For example, the bonding part 16 is a transparent adhesive. The lens 15 is bonded to the upper surface of the sealing member 14. Further, the sealing member 14 is provided with an uneven portion 17.

  The sealing member 14 is provided in a region surrounded by the substrate 10, the frame body 13, and the lens 15. The dimension W3 of the sealing member 14 in the Z-axis direction is substantially the same as the dimension W1 of the frame 13 in the Z-axis direction. A dimension W2 in the Z-axis direction of the frame body 13 is larger than a dimension W1 in the Z-axis direction of the laminated body.

  As shown in FIG. 6A, the concavo-convex portion 17 is provided on the joint surface of the sealing member 14 with the lens 15. For example, the uneven portion 17 is provided on the sealing member 14 by processing the surface of the sealing member 14. The concavo-convex portion 17 is bonded to the lens 15 via the adhesive portion 16. By providing the fine uneven portion 17 on the sealing member 14, the white light L emitted from the phosphor layer 12 is scattered at the boundary surface between the sealing member 14 and the lens 15, and the scattered light L1 is generated. .

  For example, when the sealing member 14 is formed of a resin, there is a method of transferring the fine concavo-convex structure after injection molding or press molding as a method of providing the concave-convex portion 17 on the sealing member 14. Further, a fine uneven structure may be provided by irradiating the surface of the sealing member 14 with a laser.

  When the material of the sealing member 14 and the material of the lens 15 are different, the sealing member 14 and the lens 15 are easily peeled off because the two materials have different expansion coefficients. Since the uneven portion 17 is provided on the sealing member 14 as in this embodiment, the contact area between the sealing member 14 and the lens 15 increases. An anchor effect also occurs. For this reason, peeling of the sealing member 14 and the lens 15 is suppressed. Further, the uneven portion 17 scatters and mixes the white light L emitted from the phosphor layer 12. When the colors are mixed, the color unevenness is reduced.

  As shown in FIG. 6B, the concave and convex portion 17 may be provided on the lens 15 by processing the joint surface of the lens 15 with the sealing member 14. The uneven portion 17 is joined to the sealing member 14 via the adhesive portion 16. By providing the minute uneven portion 17 on the lens 15, the sealing member 14 and the lens 15 are prevented from being peeled off, and the color unevenness is reduced by the color mixture resulting from light scattering.

  According to the present embodiment, it is possible to provide a light emitting module and a lighting device in which uneven color is suppressed and the light extraction rate is improved.

  The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, specific elements such as a substrate, a light emitting element, a phosphor layer, a frame, a sealing member, a lens, an adhesive part, and an instrument body, a fixing member, and a lighting circuit included in the lighting device included in the light emitting module With respect to such configurations, those skilled in the art can appropriately select from the well-known ranges to implement the present invention in the same manner, and are included in the scope of the present invention as long as similar effects can be obtained. Moreover, what combined any two or more elements of each specific example in the technically possible range is also included in the scope of the present invention as long as the gist of the present invention is included.

  In addition, all light emitting modules and lighting devices that can be implemented by those skilled in the art based on the light emitting modules and lighting devices described above as embodiments of the present invention also include the gist of the present invention. It belongs to the scope of the present invention. In addition, in the category of the idea of the present invention, those skilled in the art can conceive of various changes and modifications, and it is understood that these changes and modifications also belong to the scope of the present invention. .

  DESCRIPTION OF SYMBOLS 10 ... Board | substrate, 11 ... Light emitting element, 11a ... Silicon substrate, 11b ... Blue LED, 12, 12a ... Phosphor layer, 13 ... Frame body, 14 ... Sealing member, 15 ... Lens, 16 ... Adhesion part, 17 ... Unevenness , 20 ... Appliance body, 21 ... Fixing member, 22 ... Recess, 30 ... Lighting circuit, 100, 110 ... Light emitting module, 150 ... Illuminating device, L, L1 ... Light

Claims (5)

A laminate having a light emitting element and a phosphor layer provided on at least an upper surface of the light emitting element, and having a thickness W1 in a first direction from the light emitting element toward the phosphor layer;
A frame provided around the laminate and having a thickness W2 in the first direction larger than the thickness W1;
A sealing member filled inside the frame so as to cover the entire laminate;
A lens provided on the sealing member;
Comprising
The light emitting module according to claim 1, wherein a refractive index of the lens is equal to or smaller than a refractive index of the sealing member. The light emitting element has a silicon substrate,
The refractive index of the light emitting element is greater than the refractive index of the phosphor layer, and the refractive index of the phosphor layer is equal to or greater than the refractive index of the sealing member. The light emitting module according to claim 1. The lens is formed of a transparent resin having a phosphor,
The phosphor layer has a red phosphor,
The light emitting module according to claim 1, wherein the phosphor is at least one of a green phosphor and a yellow phosphor. The sealing member is bonded to the lens,
The light emitting module according to any one of claims 1 to 3, wherein an uneven portion is provided on a joint surface of either the sealing member or the lens. A light emitting module according to any one of claims 1 to 4;
A lighting circuit for supplying power to the light emitting module;
An illumination device comprising:

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