Light emitting device

Abstract

To provide a light emitting device capable of changing the light distribution of light emitted from a light emitting element.SOLUTION: A light emitting device 1 has a light emitting element 20 and a sealing member 25 that encapsulates the light emitting element 20. The sealing member 25 includes a central part 26 that includes the optical axis O of the light emitting element 20 and a peripheral part 27 that is connected to the central part 26. The first light diffusion capacity of the central part 26 for light emitted from the light emitting element 20 is different from the second light diffusion capacity of the peripheral part 27 for light emitted from the light emitting element 20.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a light emitting device.

[0002] JP 2022-39128 A (Patent Document 1) discloses an electronic component including a substrate, a first electrode, a second electrode, a first pad, a second pad, a light-emitting diode, a bonding wire, and a sealing resin. The light-emitting diode is disposed on the first pad. The bonding wire is bonded to the light-emitting diode and the second pad. The sealing resin seals the light-emitting diode and the bonding wire. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-39128 A [Summary]

[0004] An object of the present disclosure is to provide a light emitting device capable of changing the light distribution of light emitted from a light emitting element.

[0005] The light emitting device of the present disclosure includes a light emitting element and a sealing member that seals the light emitting element. The sealing member includes a central portion including an optical axis of the light emitting element and a peripheral portion connected to the central portion. A first light diffusion ability of the central portion for light emitted from the light emitting element is different from a second light diffusion ability of the peripheral portion for the light. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a schematic perspective view of a light emitting device according to an embodiment. [Diagram 2] FIG. 2 is a schematic cross-sectional view of the light emitting device according to the embodiment taken along the cross-sectional line II-II shown in FIG. [Diagram 3] FIG. 3 is a flowchart illustrating an example of a method for manufacturing a light emitting device according to the embodiment. [Figure 4]FIG. 4 is a schematic enlarged partial cross-sectional view of a light emitting device according to a first modified example of the embodiment. [Diagram 5] 5 is a schematic partial enlarged cross-sectional view of a light emitting device according to a second modified example of the embodiment.

[0007] The details of the embodiments of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are given the same reference numerals, and the description thereof will not be repeated. At least some of the configurations of the embodiments described below may be arbitrarily combined.

[0008] A light emitting device 1 according to an embodiment of the present disclosure will be described with reference to Figures 1 and 2. The light emitting device 1 mainly includes a substrate 10, a first electrode 16, a first pad 17, a second electrode 18, a second pad 19, a light emitting element 20, a conductive wire 22, and a sealing member 25.

[0009] The substrate 10 includes a first main surface 11, a second main surface 12 opposite to the first main surface 11, a side surface 13, and a side surface 14 opposite to the side surface 13. The first main surface 11 and the second main surface 12 are both end surfaces in the thickness direction (z direction) of the substrate 10. The first main surface 11 and the second main surface 12 each extend in a first direction (x direction) perpendicular to the thickness direction of the substrate 10 and a second direction (y direction) perpendicular to the thickness direction and the first direction of the substrate 10. For example, the first direction may be the longitudinal direction of the substrate 10, the second direction may be the lateral direction of the substrate 10, and the side surfaces 13 and 14 may be both end surfaces in the longitudinal direction of the substrate 10. The substrate 10 is formed of an insulating material. The substrate 10 is, for example, a glass epoxy substrate formed of glass cloth and epoxy resin impregnated into the glass cloth.

[0010] The first electrode 16 is disposed on the first main surface 11, the side surface 13, and the second main surface 12. A portion of the first electrode 16 is exposed from the sealing member 25. The first pad 17 is connected to the first electrode 16. The first pad 17 protrudes from the first electrode 16 toward the second electrode 18. The second electrode 18 is disposed on the first main surface 11, the side surface 14, and the second main surface 12. The second electrode 18 is spaced apart from the first electrode 16 in the first direction (x direction). A portion of the second electrode 18 is exposed from the sealing member 25. The second pad 19 is connected to the second electrode 18. The second pad 19 protrudes from the second electrode 18 toward the first electrode 16. The second pad 19 is spaced apart from the first pad 17 in the first direction (x direction).

[0011] The first electrode 16, the second electrode 18, the first pad 17, and the second pad 19 are conductive members and are formed of a conductive material such as a metal. The first electrode 16, the second electrode 18, the first pad 17, and the second pad 19 are formed of, for example, copper (Cu) or aluminum (Al). The first electrode 16, the second electrode 18, the first pad 17, and the second pad 19 may be covered with a plating layer (not shown) such as a gold (Au) layer and a nickel (Ni) layer.

[0012] The light emitting element 20 is mounted on the first pad 17. Specifically, the light emitting element 20 is fixed to the first pad 17 using a bonding member (not shown) such as a conductive resin adhesive or solder. The light emitting element 20 is electrically connected to the first pad 17 through the bonding member. The light emitted from the light emitting element 20 has a light distribution. The light distribution of the light emitting element 20 is maximum on the optical axis O of the light emitting element 20. The optical axis O of the light emitting element 20 is, for example, parallel to the normal to the first main surface 11. The light emitting element 20 is, for example, a light emitting diode (LED). The light emitting element 20 may be a laser diode (LD).

[0013] The conductive wire 22 is bonded to the light emitting element 20 and the second pad 19. The conductive wire 22 may be a conductive connecting member such as a conductive ribbon. The conductive wire 22 is made of a conductive material such as a metal. The conductive wire 22 is made of, for example, copper (Cu), gold (Au) or aluminum (Al).

[0014] The sealing member 25 seals the light emitting element 20 and the conductive wire 22. The sealing member 25 includes a central portion 26 and a peripheral portion 27 connected to the central portion 26. The central portion 26 includes an optical axis O of the light emitting element 20. The light emitting element 20 may be sealed by the central portion 26. The top surface of the peripheral portion 27 may be flush with the top surface of the central portion 26. In this specification, the top surface of the central portion 26 is the surface of the central portion 26 opposite to the surface covering the light emitting element 20 or the substrate 10. The top surface of the peripheral portion 27 is the surface of the peripheral portion 27 opposite to the surface covering the light emitting element 20 or the substrate 10. The central portion 26 may cover at least a portion of the first pad 17. The peripheral portion 27 may cover a portion of the first electrode 16, a portion of the second electrode 18, and at least a portion of the second pad 19.

[0015] In the present embodiment, central portion 26 is sandwiched between two peripheral portions 27 in the longitudinal direction (first direction (x direction)) of substrate 10. In a cross section defined by the longitudinal direction of substrate 10 and optical axis O, the proportion of central portion 26 in sealing member 25 in the longitudinal direction of substrate 10 may be, for example, 20% or more and 80% or less, or 30% or more and 60% or less.

[0016] One of the central portion 26 and the peripheral portion 27 is formed of an insulating resin to which a light diffusing agent has been added. The other of the central portion 26 and the peripheral portion 27 includes an insulating resin. The other of the central portion 26 and the peripheral portion 27 may further include a light diffusing agent. The light diffusing agent is, for example, a light diffusing particle or a light diffusing filler. The light diffusing agent is, for example, a silicon filler. The insulating resin is, for example, an epoxy resin or a silicone resin. The central portion 26 and the peripheral portion 27 may further include fluorescent particles. The fluorescent particles convert the wavelength of the light emitted from the light emitting element 20.

[0017] A first light diffusing ability of the central portion 26 for light emitted from the light emitting element 20 is different from a second light diffusing ability of the peripheral portion 27 for the light. For example, the central portion 26 may differ from the peripheral portion 27 in the content of the light diffusing agent. In this specification, the unit of the content of the light diffusing agent is weight percent (wt%).

[0018] In one example, the content of the light diffusing agent in the central portion 26 is greater than the content of the light diffusing agent in the peripheral portion 27, and the first light diffusing ability of the central portion 26 is greater than the second light diffusing ability of the peripheral portion 27. Therefore, the intensity of the light radiated from the central portion 26 to the outside of the light emitting device 1 decreases, and the intensity of the light radiated from the peripheral portion 27 to the outside of the light emitting device 1 increases. The light distribution of the light radiated to the outside of the light emitting device 1 through the sealing member 25 can be made more uniform. Note that the peripheral portion 27 may contain a smaller content of the light diffusing agent than the central portion 26, or may not contain any light diffusing agent.

[0019] In another example, the content of the light diffusing agent in the central portion 26 is smaller than the content of the light diffusing agent in the peripheral portion 27, and the first light diffusing ability of the central portion 26 is smaller than the second light diffusing ability of the peripheral portion 27. Therefore, the intensity of the light radiated from the central portion 26 to the outside of the light emitting device 1 increases, and the intensity of the light radiated from the peripheral portion 27 to the outside of the light emitting device 1 decreases. The light distribution of the light radiated to the outside of the light emitting device 1 through the sealing member 25 can be more concentrated. Note that the central portion 26 may contain a smaller content of the light diffusing agent than the peripheral portion 27, or may not contain a light diffusing agent.

[0020] An example of a manufacturing method for the light emitting device 1 of the present embodiment will be described with reference to Fig. 3. The manufacturing method for the light emitting device 1 of the present embodiment includes a die bonding step (S1), a wire bonding step (S2), a sealing step (S3), and a singulation step (S4).

[0021] In the die bonding step (S1), a bonding member (not shown) is used to bond the light emitting element 20 to the first pad 17. The bonding member is, for example, a conductive resin adhesive or solder.

[0022] In the wire bonding step (S2), the conductive wire 22 is bonded to the light emitting element 20 and the second pad 19 using a bonding tool (not shown).

[0023] In the sealing step (S3), the sealing member 25 is provided on the substrate 10 by molding. For example, the substrate 10 on which the light emitting element 20 is mounted is placed in a mold (not shown). A first sealing resin is poured into the mold. The first sealing resin is heated to harden the first sealing resin, thereby forming a central portion 26. Then, the substrate 10 covered with the central portion 26 is placed in a mold (not shown). A second sealing resin is poured into the mold. For example, the second sealing resin differs from the first sealing resin in the content rate of the light diffusing agent. The second sealing resin is heated to harden the second sealing resin, thereby forming a peripheral portion 27. In this manner, the sealing member 25 is provided on the substrate 10.

[0024] In the singulation step (S4), the substrate 10 on which the light emitting elements 20 are mounted and on which the sealing member 25 is provided is cut using a dicing saw or the like. In this manner, the light emitting devices 1 are singulated.

[0025] A light emitting device 1 according to a modified example of the present embodiment will be described.

[0026] As shown in FIG. 4, central portion 26 may be sandwiched between two peripheral portions 27 in the short-side direction (second direction (y direction)) of substrate 10. Central portion 26 may cover at least a part of first pad 17 and at least a part of second pad 19. Peripheral portion 27 may cover a part of first electrode 16 and a part of second electrode 18. In a cross section defined by the short-side direction of substrate 10 and optical axis O, the proportion of central portion 26 in sealing member 25 in the short-side direction of substrate 10 may be 20% or more and 80% or less, or may be 30% or more and 60% or less.

[0027] As shown in FIG. 5, the central portion 26 may be surrounded by the peripheral portion 27. The central portion 26 may cover at least a part of the first pad 17. The peripheral portion 27 may cover a part of the first electrode 16, a part of the second electrode 18, and at least a part of the second pad 19. In a cross section defined by the longitudinal direction (first direction (x direction)) of the substrate 10 and the optical axis O, the ratio of the central portion 26 to the sealing member 25 in the longitudinal direction of the substrate 10 may be 20% or more and 80% or less, or 30% or more and 60% or less. In a cross section defined by the lateral direction (second direction (y direction)) of the substrate 10 and the optical axis O, the ratio of the central portion 26 to the sealing member 25 in the lateral direction of the substrate 10 may be 20% or more and 80% or less, or 30% or more and 60% or less.

[0028] The light emitting device 1 does not necessarily have to include the substrate 10, and the conductive member (the first electrode 16, the second electrode 18, the first pad 17, and the second pad 19) may be a lead frame.

[0029] The effects of the light emitting device 1 of this embodiment will be described.

[0030] The light emitting device 1 of the present embodiment includes a light emitting element 20 and a sealing member 25 that seals the light emitting element 20. The sealing member 25 includes a central portion 26 that includes the optical axis O of the light emitting element 20, and a peripheral portion 27 that is connected to the central portion 26. A first light diffusion ability of the central portion 26 for light emitted from the light emitting element 20 is different from a second light diffusion ability of the peripheral portion 27 for light emitted from the light emitting element 20.

[0031] Therefore, the light distribution of the light emitted from the light emitting element 20 can be changed by the sealing member 25.

[0032] In the light emitting device 1 of the present embodiment, the central portion 26 differs from the peripheral portion 27 in the content of the light diffusing agent.

[0033] Therefore, the light distribution of light emitted from the light emitting element 20 can be changed by the sealing member 25. Since it is only necessary to make the content of the light diffusing agent in the central portion 26 different from the content of the light diffusing agent in the peripheral portion 27, the light emitting device 1 can be easily manufactured.

[0034] In the light emitting device 1 of the present embodiment, the light emitting element 20 is sealed by the central portion .

[0035] Therefore, the light distribution of the light emitted from the light emitting element 20 can be changed by the sealing member 25.

[0036] In the light emitting device 1 of the present embodiment, the first light diffusing ability of the central portion 26 is greater than the second light diffusing ability of the peripheral portion 27 .

[0037] Therefore, the light distribution of the light that passes through the sealing member 25 and is emitted to the outside of the light emitting device 1 can be made more uniform.

[0038] In the light emitting device 1 of the present embodiment, one of the central portion 26 and the peripheral portion 27 is formed of an insulating resin to which a silicon filler is added. The other of the central portion 26 and the peripheral portion 27 contains an insulating resin. The insulating resin is an epoxy resin or a silicone resin.

[0039] Therefore, the light distribution of the light emitted from the light emitting element 20 can be changed by the sealing member 25.

[0040] Various aspects of the present disclosure are summarized below as appendices. (Appendix 1) A light-emitting element; a sealing member that seals the light-emitting element, the sealing member includes a central portion including an optical axis of the light-emitting element and a peripheral portion connected to the central portion, A light emitting device, wherein a first light diffusing ability of the central portion for light emitted from the light emitting element is different from a second light diffusing ability of the peripheral portion for the light. (Appendix 2) 2. The light emitting device of claim 1, wherein the central portion has a different content of light diffusing agent than the peripheral portion. (Appendix 3) 3. The light emitting device according to claim 1 or 2, wherein the light emitting element is sealed by the central portion. (Appendix 4) 4. The light emitting device of claim 1, wherein the first light diffusing ability is greater than the second light diffusing ability. (Appendix 5) one of the central portion and the peripheral portion is formed of an insulating resin to which a silicon filler is added; the other of the central portion and the peripheral portion includes the insulating resin, 5. The light emitting device according to claim 1, wherein the insulating resin is an epoxy resin or a silicone resin.

[0041] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0042] 1 light emitting device, 10 substrate, 11 first main surface, 12 second main surface, 13, 14 side surface, 16 first electrode, 17 first pad, 18 second electrode, 19 second pad, 20 light emitting element, 22 conductive wire, 25 sealing member, 26 central portion, 27 peripheral portion.

Claims

1. A light-emitting element; a sealing member that seals the light-emitting element, the sealing member includes a central portion including an optical axis of the light-emitting element and a peripheral portion connected to the central portion, A light emitting device, wherein a first light diffusing ability of the central portion for light emitted from the light emitting element is different from a second light diffusing ability of the peripheral portion for the light.

2. The light emitting device according to claim 1 , wherein the central portion differs from the peripheral portion in a content of the light diffusing agent.

3. The light emitting device according to claim 1 , wherein the light emitting element is encapsulated by the central portion.

4. The light emitting device of claim 1 , wherein the first light diffusing capacity is greater than the second light diffusing capacity.

5. one of the central portion and the peripheral portion is formed of an insulating resin to which a silicon filler is added; the other of the central portion and the peripheral portion includes the insulating resin, The light emitting device according to claim 1 , wherein the insulating resin is an epoxy resin or a silicone resin.

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