JP2020174196A - Light emitting device - Google Patents

Abstract

To provide a light emitting device that can efficiently spread light in the lateral direction.SOLUTION: A light emitting device 100 comprises: a light emitting element 10 that includes a semiconductor laminate 11 including an electrode forming surface 11a, a light emitting surface 11b on the opposite side of the electrode forming surface, and a side surface 11c between the electrode forming surface and the light emitting surface, and a pair of electrodes 12 provided on the electrode forming surface; a covering member 20 that covers the side surface of the light emitting element; and an optical member 30 arranged over the light emitting surface of the light emitting element and the upper surface of the covering member. The optical member includes: a light reflecting unit 50 arranged above the light emitting element; and a translucent portion 40 that is arranged between the light reflecting unit and the covering member and forms a part of the outer surface of the light emitting device.SELECTED DRAWING: Figure 1B

Description

The present invention relates to a light emitting device.

There is known a light emitting device in which a reflective resin is provided on the upper surface of a transparent resin that seals a light emitting element, and light from the light emitting element is irradiated to the outside from the side surface of the transparent resin (for example, Patent Document 1). Such a light emitting device can easily spread light in the lateral direction, and can be used as, for example, a light source for a backlight.

Japanese Unexamined Patent Publication No. 2013-115280 Japanese Unexamined Patent Publication No. 2013-115088 Japanese Unexamined Patent Publication No. 2013-118244 Japanese Unexamined Patent Publication No. 2013-258175

In recent years, the backlight has become thinner and thinner, and the local dimming method, which adopts the direct type method and controls the brightness of the backlight according to the image, is spreading. Therefore, there is a demand for a light emitting device capable of efficiently spreading light in the lateral direction.

Embodiments of the present invention include the following configurations.
A light emitting device including a semiconductor laminate having a light emitting surface on the opposite side of the electrode forming surface and the electrode forming surface and a side surface between the electrode forming surface and the light emitting surface, and a pair of electrodes provided on the electrode forming surface. A light-reflecting coating member that covers the side surface of the light-emitting element, and an optical member that is arranged over the light-emitting surface of the light-emitting element and the upper surface of the coating member, and the optical member is arranged above the light-emitting element. A light emitting device including a light reflecting portion, a light transmitting portion arranged between the light reflecting portion and a covering member, and forming a part of an outer surface of the light emitting device.

As described above, the light from the light emitting device can be spread in the lateral direction more efficiently.

It is a schematic perspective view which shows an example of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view in the IB-IB cross section of FIG. 1A. It is a schematic bottom view which shows an example of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic perspective view of the optical member which shows an example of the light emitting device which concerns on Embodiment 1. FIG. It is the schematic sectional drawing which shows an example of the light emitting device which concerns on Embodiment 2. FIG. It is a schematic bottom view which shows an example of the light emitting device which concerns on Embodiment 2. FIG. It is the schematic sectional drawing which shows an example of the light emitting device which concerns on Embodiment 3. FIG. It is the schematic sectional drawing which shows the modification of the light emitting device which concerns on Embodiment 3. FIG. It is the schematic sectional drawing which shows the modification of the light emitting device which concerns on Embodiments 1-3. It is the schematic sectional drawing which shows the modification of the light emitting device which concerns on Embodiments 1-3. It is the schematic sectional drawing which shows the modification of the light emitting device which concerns on Embodiments 1-3. It is the schematic sectional drawing which shows the modification of the light emitting device which concerns on Embodiments 1-3. It is the schematic sectional drawing which shows the modification of the light emitting device which concerns on Embodiments 1-3. It is a figure which shows the manufacturing method of the light emitting device which concerns on Embodiments 1-3. It is a figure which shows the manufacturing method of the light emitting device which concerns on Embodiments 1-3. It is a figure which shows the manufacturing method of the light emitting device which concerns on Embodiments 1-3. It is a figure which shows the manufacturing method of the light emitting device which concerns on Embodiments 1-3. It is a figure which shows the manufacturing method of the light emitting device which concerns on Embodiments 1-3. It is a figure which shows the manufacturing method of the light emitting device which concerns on Embodiments 1-3. It is a figure which shows the manufacturing method of the light emitting device which concerns on Embodiments 1-3. It is a figure which shows the manufacturing method of the light emitting device which concerns on Embodiments 1-3. It is the schematic sectional drawing which shows an example of the light emitting device which concerns on Embodiment 4. FIG. It is a figure which shows the manufacturing method of the light emitting device which concerns on Embodiment 4. It is a figure which shows the manufacturing method of the light emitting device which concerns on Embodiment 4. It is a figure which shows the manufacturing method of the light emitting device which concerns on Embodiment 4. It is a figure which shows the manufacturing method of the light emitting device which concerns on Embodiment 4. It is the schematic sectional drawing which shows an example of the light emitting device which concerns on Embodiment 5. It is a figure which shows the manufacturing method of the light emitting device which concerns on Embodiment 5. It is a figure which shows the manufacturing method of the light emitting device which concerns on Embodiment 5. It is a figure which shows the manufacturing method of the light emitting device which concerns on Embodiment 5. It is a figure which shows the manufacturing method of the light emitting device which concerns on Embodiment 5. It is a figure which shows the modification of the manufacturing method of the light emitting device which concerns on Embodiment 5. It is a figure which shows the modification of the manufacturing method of the light emitting device which concerns on Embodiment 5. It is a figure which shows the modification of the manufacturing method of the light emitting device which concerns on Embodiment 5. It is a figure which shows the modification of the manufacturing method of the light emitting device which concerns on Embodiment 5. It is sectional drawing of an example of the light emitting device which concerns on Embodiment 6. It is sectional drawing of another example of the light emitting device which concerns on Embodiment 6. It is sectional drawing of the modification of the light emitting device which concerns on Embodiments 1-6.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, terms indicating a specific direction or position (for example, "upper", "lower", and other terms including those terms) are used as necessary. The use of these terms is to facilitate understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the invention. Parts having the same reference numerals appearing in a plurality of drawings indicate the same parts or members. The same name will be used before and after molding, solidification, curing, and individualization. That is, a member whose state changes depending on the stage of a process, such as a case where it is liquid before molding, becomes a solid after molding, and further becomes a solid whose shape is changed by dividing the solid after molding, is described by the same name. To do.

The light emitting device according to the embodiment includes a light emitting element, a covering member, and an optical member. The covering member is light reflective and is arranged so as to directly or indirectly cover the side surface of the light emitting element.
The optical member is a member arranged from above the light emitting element over the covering member. The optical member has at least a two-layer structure including a light reflecting portion and a light transmitting portion arranged below the light reflecting portion.

A light reflecting portion of an optical member is arranged above the light emitting element. As a result, the light from the light emitting element is unlikely to be emitted to the outside from above (directly above) the light emitting element. The translucent portion of the optical member is arranged between the light reflecting portion and the covering member. That is, the translucent portion of the optical member constitutes a part of the side surface of the light emitting device. The light from the light emitting element propagates in the translucent portion of the optical member and is mainly emitted to the outside from the side surface of the translucent portion.

As described above, the light from the light emitting device according to the embodiment is mainly emitted to the outside from the translucent portion which is a part of the side surface of the light emitting device. Further, by making a limited part of the side surface of the light emitting device a light emitting surface, it is possible to improve the light density of the light emitted to the outside. As a result, the light from the light emitting element can be efficiently emitted to the side. For example, when the light emitting device is arranged directly under the light guide plate as a light source for a backlight, it is possible to irradiate a wider range of light.
Hereinafter, each embodiment will be described in detail.

<Embodiment 1>
The light emitting device 100 according to the first embodiment is shown in FIGS. 1A to 1C. The light emitting device 100 has a substantially rectangular parallelepiped external shape. The shape of the lower surface 101 and the upper surface 102 of the light emitting device 100 is a quadrangle such as a square or a rectangle. Further, the shape of the side surface 103 of the light emitting device 100 is also substantially quadrangular.
Of the side surfaces 103, at least two side surfaces 103 located on opposite sides have the same size.
The light emitting device is not limited to the above shape, and the top view may be a polygon such as a hexagon.

The light emitting device 100 includes a light emitting element 10, a covering member 20, and an optical member 30. The covering member 20 is arranged so as to cover the side surface 11c of the light emitting element 10. The optical member 30 is arranged over the light emitting surface 11b of the light emitting element 10 and the upper surface 22 of the covering member 20.

(Light emitting element)
The light emitting element 10 includes a laminated structure 11 including a semiconductor layer and electrodes 12. The laminated structure 11 includes an electrode forming surface 11a and a light emitting surface 11b on the opposite side of the electrode forming surface 11a. The electrode 12 includes an electrode 12p on the positive electrode side and an electrode 12n on the negative electrode side. The electrode forming surface 11a of the laminated structure 11 is also an electrode forming surface of the light emitting element 10. The light emitting surface 11b of the laminated structure 11 is also a light emitting surface of the light emitting element 10.

The laminated structure 11 includes a semiconductor layer including a light emitting layer. Further, a translucent substrate such as sapphire may be provided. As an example of the semiconductor laminate, three semiconductor layers of a first conductive type semiconductor layer (for example, n-type semiconductor layer), a light emitting layer (active layer), and a second conductive type semiconductor layer (for example, p-type semiconductor layer) are included. Can be done. The semiconductor layer capable of emitting visible light from ultraviolet light or blue light to green light can be formed from a semiconductor material such as a group III-V compound semiconductor. Specifically, a nitride-based semiconductor material such as In _X Al _Y Ga _1-XY N (0 ≦ X, 0 ≦ Y, X + Y ≦ 1) can be used. As the semiconductor laminate capable of emitting red light, GaAs, GaAlAs, GaP, InGaAs, InGaAsP and the like can be used. The thickness of the laminated structure 11 can be, for example, 3 μm to 500 μm.

The electrode 12 can be formed of any thickness by using a material and a structure known in the art.
Further, as the electrode 12, a good electric conductor can be used, and for example, Cu, Ni, Sn, Fe, Ti, Au, Ag, Pt and the like can be used. As the electrode 12, AuSn, SnAgCu, or SnPb solder may be specified. The electrode 12 can be formed by laminating a single layer or a plurality of these metals or solders, but preferably the main part is made of Cu, Ni, Fe, Sn materials having low material prices, and the most of the main parts. It is constructed by covering the surface with stable metals Au, Ag, and Pt. By forming the main part made of an inexpensive metal and a stable metal film covering the outermost surface thereof, the electrode 12 can be made inexpensive and the deterioration of the solder wettability due to oxidation can be suppressed. Further, an adhesion layer such as Ti, Ni, Mo, W, Ru or Pt may be formed between the surface layer composed of Au, Ag and Pt and the main portion composed of Cu, Ni, Fe and Sn. These adhesion layers can improve the adhesion with the main part as a base of the surface layer, control the diffusion of the solder, reduce the voids at the time of solder joining, and maintain stable strength for a long period of time.
The electrode 12 can be formed to a thickness of, for example, 1 μm to 300 μm, preferably in the range of 5 μm to 100 μm, and more preferably in the range of 10 μm to 50 μm. When forming the surface layer, for example, Au, Ag, Pt and the like are formed to a thickness of 0.001 μm to 1 μm, preferably 0.01 to 0.1 μm. By forming the surface layer in such a thickness range, it is possible to prevent the electrode surface from being oxidized while suppressing the cost increase, and it is possible to suppress the deterioration of the solder wettability. The adhesion layer such as Ti, Ni, Mo, W, Ru, Pt and the like formed between the surface layer and the main part has a thickness in the range of 0.001 to 1 μm, preferably 0.001 to 0.05 μm. Form to thickness. As the top view shape of the electrode 12, various shapes can be selected according to the purpose, application, and the like. In FIG. 1C, the electrodes 12n and 12p have the same shape and are rectangular. The electrodes 12n and 12p can have different shapes to show polarity. For example, it can be shaped like a notch on any side or corner of a rectangle. The lower surface of the electrode 12 is exposed from the covering member 20, and can function as an external connection terminal. Although only the lower surface of the electrode 12 is exposed from the covering member 20 here, a part or all of the side surface of the electrode 12 may be exposed from the covering member 20.

(Coating member)
The covering member 20 is light-reflecting and directly or indirectly covers the side surface 11c of the light emitting element 10. In other words, the inner side surface 24 of the covering member 20 is in contact with or faces the side surface 11c of the light emitting element 10. In the light emitting device 100 illustrated in FIG. 1B, the covering member 20 is in contact with the side surface 11c of the light emitting element 10.

The outer surface 23 of the covering member 20 constitutes the side surface 103 of the light emitting device 100 together with the side surface 33 of the optical member 30 described later. It is preferable that the outer surface 23 of the covering member 20 and the side surface 33 of the optical member 30 are the same surface.

The covering member 20 covers the electrode forming surface 11a of the laminated structure 11 so that at least a part of each of the pair of electrodes 12p and 12n of the light emitting element 10 is exposed. Specifically, in the covering member 20, the lower surface of the electrode 12p and the lower surface of the electrode 12n are exposed, and the side surface of the electrode 12p and the side surface of the electrode 12n are covered. The lower surface 21 of the covering member 20 constitutes a part of the lower surface 101 of the light emitting device 100. In the light emitting device 100 shown in FIG. 1B, the lower surface 21 of the covering member 20 and the lower surface of the electrode 12 are located on the same surface. The covering member that covers the lower surface of the laminated structure is, for example, the same as the thickness of the electrode 12 so that the lower surface 21 of the covering member 20 and the lower surface of the electrode 12 are located on the same surface, for example, in the range of 5 to 100 μm, preferably. Is formed to a thickness of 10 to 50 μm. When the lower surface of the laminated structure is covered with a covering member having a thickness in this range, the amount of light emitted from the lower surface of the laminated structure can be reduced (light leakage can be suppressed). The thickness of the covering member that covers the lower surface of the laminated structure can be appropriately set in consideration of, for example, the concentration of TiO2 contained in the covering member. As described above, for example, the lower surface 21 of the covering member 20 and the lower surface of the electrode 12 are located on the same surface, but in the present embodiment, between the lower surface of the electrode 12 and the lower surface 21 of the covering member 20. May have steps. In that case, the lower surface of the electrode 12 may protrude from the lower surface 21 of the covering member 20 or may be recessed. The step between the lower surface of the electrode 12 and the lower surface 21 of the covering member 20 is set to, for example, 0.1 to 30 μm, preferably 0.5 to 20 μm, in order to secure a stable connection having high connection strength and low connection resistance. More preferably, it is in the range of 0.5 to 10 μm. For example, if the electrode 12 is formed so as to protrude from the lower surface 21 of the covering member 20, the solder can be joined to the side surface of the protruding portion, so that the joining strength can be increased. Further, when the lower surface of the electrode 12 is recessed from the lower surface 21 of the covering member 20 to form the electrode 12, the inclination of the light emitting device at the time of mounting can be suppressed, and the variation in the orientation direction of the light emitting device after mounting can be reduced.

The upper surface 22 of the covering member 20 is in contact with the lower surface 31 of the optical member 30. In the light emitting device 100 shown in FIG. 1B, the upper surface 22 of the covering member 20 and the light emitting surface 11b of the light emitting element 10 are located on the same surface.

The covering member 20 is a member capable of reflecting light from the light emitting element 10, and for example, a resin material containing a light-reflecting substance can be used. The reflectance of the covering member 20 with respect to the light from the light emitting element 10 is preferably 70% or more, more preferably 80% or more, and more preferably 90% or more.

As the coating member 20, for example, it is preferable to use a resin material containing a thermosetting resin such as a silicone resin, a silicone-modified resin, an epoxy resin, or a phenol resin as a main component as a base material. As the light-reflecting substance contained in the resin material, for example, a white substance can be used. Specifically, for example, titanium oxide, silicon oxide, zirconium oxide, potassium titanate, aluminum oxide, aluminum nitride, boron nitride, mullite and the like are suitable.
As the light-reflecting substance, granular, fibrous, thin plate pieces and the like can be used.

(Optical member)
The optical member 30 is a member for controlling the light distribution characteristics of the light emitting device 100. FIG. 1D is a schematic perspective view of the optical member 30 of the light emitting device 100 shown in FIG. 1A as viewed from the lower surface side. The optical member 30 is a plate-shaped member arranged over the light emitting surface 11b of the light emitting element 10 and the upper surface 22 of the covering member 20. The optical member 30 has a two-layer structure at least in the vertical direction, and includes a light reflecting portion 50 on the upper side and a light transmitting portion 40 on the lower side. The upper surface 52 of the light reflecting portion 50 is the upper surface 32 of the optical member 30, and is also the upper surface 102 of the light emitting device 100. The side surface 53 of the light reflecting portion 50 is a part of the side surface 33 of the optical member 30, and is a part of the side surface 103 of the light emitting device 100. The side surface 43 of the light transmitting portion 40 is a part of the side surface 33 of the optical member 30, and is a part of the side surface 103 of the light emitting device 100. The lower surface 41 of the light transmitting portion 40 is a part or all of the lower surface 31 of the optical member 30, and is at least a surface facing the upper surface 22 of the covering member 20.

In the first embodiment, the translucent portion 40 is arranged above the light emitting element 10 in addition to above the covering member 20. In other words, the lower surface 41 of the translucent portion 40 faces the light emitting surface 11b of the light emitting element 10. As a result, the light emitting surface 11b of the light emitting element 10 and the lower surface 51 of the light reflecting portion 50 are arranged to face each other via the light transmitting portion 40, so that the light from the light emitting element 10 is directed to the lower surface of the light reflecting portion 50. The 51 can be used to efficiently reflect light so that light can be easily taken out from the light emitting surface on the side.

The thickness T _O of the optical member 30 may be the same thickness throughout. That is, the lower surface 31 and the upper surface 32 of the optical member 30 are both flat surfaces, and can be parallel to each other. By making the upper surface 32 of the optical member 30 a flat surface as shown in FIG. 1B, for example, when the optical member 30 is attracted by a collet or the like to transfer the light emitting device, the optical member 30 can be attracted with high accuracy. However, the upper surface 32 and the lower surface 31 of the optical member 30 may have some or all non-parallel surfaces. The thickness T _O of the optical member 30, the size and the light emitting device 100 of the size of the light emitting element 10 can be appropriately selected depending on the light distribution characteristics of the light emitting device 100. For example, the thickness _{T O} of the optical member 30 may be 20% to 80% of the thickness of the light emitting device 100.

(Transparent part of optical member)
The translucent portion 40 arranged on the lower surface 31 side of the optical member 30 is a member for propagating the light from the light emitting element 10. A translucent resin material, glass, or the like can be used for the translucent portion 40. For example, a thermosetting resin such as a silicone resin, a silicone-modified resin, an epoxy resin, or a phenol resin can be used. Further, a thermoplastic resin such as a polycarbonate resin, an acrylic resin, a methylpentene resin, or a polynorbornene resin can be used. In particular, a silicone resin having excellent light resistance and heat resistance is preferable. The light-transmitting portion 40 preferably has a transmittance of 70% or more, more preferably 80% or more, and more preferably 90% or more with respect to the light from the light emitting element. The translucent portion 40 does not substantially contain the phosphor described later. Moreover, it does not include a diffusing material or the like. It consists only of the above-mentioned resin material or glass. As a result, the scattering of light inside the translucent portion 40 is suppressed, and the light reflected by the lower surface 51 of the light reflecting portion 50 and the upper surface 22 of the covering member 20 is efficiently transferred to the side surface 43 of the translucent portion 40. Can be emitted to the outside from.

The side surface 43 of the light transmitting portion 40 is a surface that emits light from the light emitting element 10 to the outside, and is a light emitting surface of the light emitting device 100. As shown in FIGS. 1A and 1B, the side surface 43 of the translucent portion 40 is arranged on all four side surfaces 103 of the rectangular light emitting device 100. That is, the light emitting device 100 includes light emitting surfaces on the four side surfaces 103. As a result, the light emitting device 100 includes a light emitting surface in the direction of 360 degrees with the light emitting device 100 as the center in the top view.

In this way, on the side surface 103 of the light emitting device 100, the light from the light emitting element 10 is emitted from the light emitting device 100 by using the light transmitting portion 40 sandwiched between the covering member 20 and the light reflecting portion 50 as the light emitting surface. It will be emitted to the outside from the light emitting surface having a small area compared to the thickness of. Therefore, the light emitted to the side of the light emitting device 100 can be emitted farther.

In the flat plate-shaped optical member 30 having the same thickness as a whole, the thickness of the light transmitting portion 40 or the thickness of the light reflecting portion 50 can be the same. That is, the flat plate-shaped light transmitting portion 40 and the flat plate-shaped light reflecting portion 50 can be formed. Preferably, as shown in FIG. 1B, in a cross-sectional view, the thickness of the light transmitting portion 40, than the thickness T _T2 at the center, it is preferable thicker towards the thickness T _T1 at the side surface 43. The thickness _{T T1} at the side surface 43 of the light transmitting portion 40, the thickness _{T O} of the optical member 30 may be 50% to 100%. That is, the thickness _{T T1} side 43 of the light transmitting portion 40, the thickness _{T O} of the optical element may be the same. The thickness _{T T2} at the center of the transparent portion 40, the thickness _{T O} of the optical member 30, can be 0% to 90%. That is, in the central portion of the light transmitting portion 40, the thickness T _T2 of the light reflecting portion 50, the thickness T _O of the optical member 30 may be the same.

(Light reflecting part of optical member)
The light reflecting portion 50 of the optical member 30 is a member for reflecting the light from the light emitting element 10 toward the side surface 43 of the light transmitting portion 40 which is a light emitting surface. For the light reflecting unit 50, for example, a resin material containing a light reflecting substance or a metal material can be used. Alternatively, an inorganic material using a dielectric multilayer film can be used. The light reflecting unit 50 preferably has a reflectance of 70% or more, more preferably 80% or more, and more preferably 90% or more with respect to the light from the light emitting element.

When a light-reflecting resin material in which a light-reflecting substance is dispersed in a resin material is used as the light-reflecting portion 50, for example, a white substance can be used as the light-reflecting substance. Specifically, for example, titanium oxide, silicon oxide, zirconium oxide, potassium titanate, aluminum oxide, aluminum nitride, boron nitride, mullite and the like are suitable. As the light-reflecting substance, granular, fibrous, thin plate pieces and the like can be used. As the base material, for example, a thermosetting resin such as a silicone resin, a silicone-modified resin, an epoxy resin, or a phenol resin can be used.

When a metal material having high light reflectance is used as the light reflecting portion 50, for example, silver, aluminum, rhodium, gold, copper and the like and alloys thereof can be mentioned, and one or two or more may be combined.

When a dielectric multilayer film is used as the light reflecting portion 50, for example, those using titanium oxide, silicon oxide, zirconium oxide, potassium titanate, aluminum oxide, aluminum nitride, etc. can be mentioned.

The light reflecting unit 50 includes a lower surface 51 that functions as a reflecting surface that reflects light incident on the light transmitting unit 40. The lower surface 51 of the light reflecting portion 50 can be a surface parallel to the light emitting surface 11b of the light emitting element 10. Preferably, it can also be a convex surface that is convex toward the light emitting surface 11b side. As a result, the light from the light emitting element 10 can be easily reflected in the direction of the light emitting surface (side surface 43 of the light transmitting portion 40) located on the side surface of the light emitting device.

Further, when the lower surface 51 of the light reflecting portion 50 is a convex surface, the top portion R, which is the portion closest to the light emitting surface 11b of the light emitting element 10, is arranged so as to coincide with the center of the light emitting element 10 in the top view. It is preferable to be done. As a result, it is possible to make it easier to evenly irradiate the light from the light emitting element 10 from all the light emitting surfaces on the side surface of the light emitting device to the outside.

The light reflecting portion 50 is preferably thick so that the transmittance of light from the light emitting element 10 is about 50% or less. As shown in FIG. 1B, when the light reflecting portion 50 is a member having a different thickness, the thickness is set so that the light transmittance from the light emitting element 10 is smaller than about 50% in the thinnest portion. Is preferable.

If the optical member 30 is flat, the thickness of the light reflecting portion 50, than the thickness T _R2 at the top R located at the center, it is preferable thinner towards the thickness T _R1 of the side surface 53.

When a resin material or the like containing a light reflecting substance is used as the light reflecting portion 50, the light transmittance changes depending on the composition and content of the light reflecting substance. Therefore, the thickness and the like are appropriately adjusted according to the material used. For example, in the case of the light reflecting portion 50 using a resin material containing about 70 wt% of titanium oxide and the light reflecting portion 50 having a thick central portion and a thin side surface 53 as shown in FIG. 1B, the thickness _{TR1 on the} side surface 53 Is preferably 0 μm to 300 μm, more preferably 20 μm to 100 μm, and even more preferably thick, for example, 20 μm to 500 μm, and even more preferably 50 μm to 300 μm.

The thickness _{T R2} at the top R of the light reflecting portion 50 may be the same as the thickness _{T O} of the optical member 30. That is, a region in which the light transmitting portion 40 does not exist may be provided in the thickness direction of the optical member 30.

The lower surface 51 of the light reflecting portion 50 may have a conical shape. For example, as shown in FIG. 1B, it is preferable that the central portion is the top portion R and the shape is a cone that is an inclined surface that is inclined from the top portion R to the side surface 53. The inclined surface can be an inclined surface that is a straight line in a cross-sectional view as shown in FIG. 1B. In that case, the angle θ (angle from the horizontal plane) of the inclined surface is preferably, for example, 10 degrees to 80 degrees, and more preferably 20 degrees to 60 degrees.

A modification of the light reflecting unit 50 will be described later.

<Embodiment 2>
The light emitting device 200 according to the second embodiment is shown in FIGS. 2A and 2B. The light emitting device 200 has the same external shape as the light emitting device 100 shown in FIG. 1A, and has a light guide member 60, a wavelength conversion member 70, and a metal layer 80 as compared with the light emitting device 100 of the first embodiment. It differs in that it has. The light guide member 60, the wavelength conversion member 70, and the metal layer 80 may include all of them, or may include any one or two of them. Hereinafter, the light guide member 60, the wavelength conversion member 70, and the metal layer 80 will be mainly described. Since other configurations can be the same as those in the first embodiment, the description thereof will be omitted as appropriate.

(Light guide member)
The light guide member 60 is a member arranged so as to cover the side surface 11c of the light emitting element 10, and is a member for guiding the light emitted from the side surface 11c of the light emitting element 10 to the optical member 30. As the light guide member 60, a translucent resin material can be used. For example, a resin material containing a thermosetting resin such as a silicone resin, a silicone-modified resin, an epoxy resin, or a phenol resin as a main component is preferable. The light guide member 60 preferably has a transmittance of 70% or more, more preferably 80% or more, and more preferably 90% or more with respect to the light from the light emitting element.

The light guide member 60 preferably covers 50% or more of the side surface 11c of the light emitting element 10.
Further, the light guide member 60 may cover the light emitting surface 11b of the light emitting element 10. The outer surface 63 of the light guide member 60 is covered with the covering member 20. Therefore, the light emitted from the side surface 11c of the light emitting element 10 is incident on the light guide member 60 and then reflected upward by the outer surface 63 of the light guide member 60 (direction of the light emitting surface 11b of the light emitting element 10). It is incident on the translucent portion 40 of the optical member 30. By providing such a light guide member 60, the light from the light emitting element 10 can be efficiently incident on the light transmitting portion 40 of the optical member 30.

The upper surface 62 of the light guide member 60 is connected to the lower surface 31 of the optical member 30 so as to be optically directly or indirectly continuous. Specifically, it is optically directly or indirectly connected to the lower surface 41 of the translucent portion 40 of the optical member 30. The light emitting device 200 shown in FIG. 2A includes a wavelength conversion member 70 between the light emitting surface 11b of the light emitting element 10 and the lower surface 31 of the optical member 30, and the upper surface 62 of the light guide member 60 is the lower surface of the wavelength conversion member 70. It is in contact with 71. Since the wavelength conversion member 70 is a translucent member as described later, the light emitted from the side surface 11c of the light emitting element 10 is incident into the light guide member 60 and then into the wavelength conversion member 70. After that, it is incident on the translucent portion 40 of the optical member 30. That is, the light guide member 60 and the optical member 30 are optically indirectly continuous with each other via the wavelength conversion member 70. When the wavelength conversion member 70 is provided, it is preferable that the light guide member 60 and the optical member 30 are connected to each other with the wavelength conversion member 70 interposed therebetween.

The outer shape of the upper surface 62 of the light guide member 60 can be substantially circular as shown in the lower surface view shown in FIG. 2B. The light guide member 60 having such a shape can be formed by forming a liquid light guide member 60 on a flat plate-shaped optical member 30 by potting or the like in the method for manufacturing a light emitting device described later. ..

(Wavelength conversion member)
The wavelength conversion member 70 includes a phosphor that absorbs light from the light emitting element 10 and converts it into light having a different wavelength. The wavelength conversion member 70 is arranged between the light emitting surface 11b of the light emitting element 10 and the lower surface 31 of the optical member 30. Specifically, the wavelength conversion member 70 is arranged between the light emitting surface 11b of the light emitting element 10 and the lower surface 41 of the light transmitting portion 40 of the optical member 30. By arranging the wavelength conversion member 70 between the light emitting element 10 and the light transmitting unit 40, the light from the light emitting element 10 and the mixed light of the light from the wavelength conversion member 70 are incident on the light transmitting unit 40. Will be done. The light guide member 60 may be arranged between the wavelength conversion member 70 and the light emitting element 10.

As shown in FIG. 2A and the like, the wavelength conversion member 70 preferably covers the entire surface of the light emitting surface 11b of the light emitting element 10. In other words, the width (area) of the lower surface 71 and the upper surface 72 of the wavelength conversion member 70 is preferably larger than the width (area) of the light emitting surface 11b of the light emitting element 10. When the light guide member 60 is provided on the side surface 11c of the light emitting element 10, the wavelength conversion member 70 preferably covers the entire surface of the light emitting surface 11b of the light emitting element 10 and the entire surface of the upper surface 62 of the light emitting element 60. In other words, the width of the lower surface 71 and the upper surface 72 of the wavelength conversion member 70 is larger than the width (area) obtained by adding the width (area) of the light emitting element 10 and the width (area) of the upper surface 62 of the light guide member 60. Is preferable. The lower surface 71 and the upper surface 72 of the wavelength conversion member 70 can have the same size or different sizes. Further, the side surface 73 of the wavelength conversion member 70 can be a vertical surface, an inclined surface, a curved surface, or the like.
The outer shape of the wavelength conversion member 70 (outer shape when viewed from above) is preferably similar to the outer shape of the light emitting surface of the light emitting element 10. By doing so, the central axis of the light emitting surface of the light emitting element 10 and the central axis of the wavelength conversion member 70 are arranged so as to substantially coincide with each other, so that the wavelength conversion member 70 located outside the light emitting surface of the light emitting element 10 The width of the outer peripheral portion can be made substantially constant, and color unevenness can be suppressed. That is, when the width of the outer peripheral portion of the wavelength conversion member 70 located outside the light emitting surface of the light emitting element 10 is not constant, the amount of light wavelength-converted by the wavelength conversion member differs depending on the direction, and color unevenness occurs. Although there is a risk, color unevenness can be suppressed by keeping the width of the outer peripheral portion of the wavelength conversion member 70 constant.

The side surface 73 of the wavelength conversion member 70 is preferably separated from the side surface 203 of the light emitting device 200. In other words, the width (area) of the first surface 71 and the second surface 72 of the wavelength conversion member 70 is preferably smaller than the width (area) of the light emitting surface 11b of the light emitting device 200. The top view shape of the wavelength conversion member 70 can be a quadrangle, a circle, a polygon, or the like. The thickness of the wavelength conversion member 70 can be appropriately selected according to the type and amount of the phosphor to be used, the target chromaticity, and the like. For example, the thickness of the wavelength conversion member 70 can be 20 μm to 200 μm, preferably 40 μm to 180 μm, and more preferably 60 μm to 150 μm.
Further, the wavelength conversion member 70 may be composed of a plurality of layers including different types of phosphors. By containing different types of phosphors in a plurality of layers, mutual absorption of the phosphors can be suppressed to improve the wavelength conversion efficiency, and a light emitting device having a high light output can be obtained. For example, when the wavelength conversion member 70 is composed of two layers, for example, the thickness of each layer is set in the range of 10 to 100 μm, more preferably 40 to 80 μm.

The wavelength conversion member 70 includes a translucent resin material, a base material such as glass, and a phosphor as a wavelength conversion material. As the base material, for example, a thermosetting resin such as a silicone resin, a silicone-modified resin, an epoxy resin, or a phenol resin can be used. Further, a thermoplastic resin such as a polycarbonate resin, an acrylic resin, a methylpentene resin, or a polynorbornene resin can be used. In particular, a silicone resin having excellent light resistance and heat resistance is preferable. The base material preferably has a transmittance of 70% or more, more preferably 80% or more, and more preferably 90% or more with respect to the light from the light emitting element.

A phosphor that absorbs light from the light emitting element 10 and converts it into light having a different wavelength is used. In other words, one that can be excited by light emission from the light emitting element 10 is used. For example, as a phosphor that can be excited by a blue light emitting element or an ultraviolet light emitting element, an yttrium / aluminum / garnet-based phosphor (YAG: Ce) activated with cerium; a lutetium / aluminum / garnet-based phosphor activated with cerium. (LAG: Ce); nitrogen-containing calcium aluminosilicate-based fluorophore (CaO-Al ₂ O _3- SiO ₂ ) activated with europium and / or chromium; silicate-based phosphor activated with europium ((Sr, Ba)) ₂ SiO ₄ ); Nitride-based phosphors such as β-sialon phosphors, CASN-based phosphors, and SCASN-based phosphors; KSF-based phosphors (K ₂ SiF ₆ : Mn); Sulfur-based phosphors, quantum dot phosphors And so on. By combining these phosphors with a blue light emitting element or an ultraviolet light emitting element, a light emitting device of various colors (for example, a white light emitting device) can be manufactured. One or more of these phosphors can be used. When a plurality of them are used, they may be mixed or laminated.
Further, the wavelength conversion member may contain various fillers or the like for the purpose of adjusting the viscosity or the like.

(Metal layer)
The metal layer 80 is a conductive member and can function as an external connection terminal of the light emitting device 200.

The metal layer 80 is electrically connected to the electrodes 12n and 12p of the light emitting element 10, respectively.
The metal layer 80 can be arranged so as to cover a part of the lower surface 21 of the covering member 20. In other words, on the lower surface of the light emitting device 200, the metal layer 80 can be arranged from the electrode 12 of the light emitting element 10 to the lower surface 21 of the covering member 20. As a result, the lower surface of the light emitting device 200 can be exposed to the outside as an external connection terminal having a larger area than the electrode 12 of the light emitting element 10. By making the area of the metal layer 80 larger than the electrode 12 of the light emitting element 10, when the light emitting device 200 is mounted on a wiring board or the like by using solder or the like, it can be mounted with high position accuracy. Further, the bonding strength between the wiring board and the light emitting device 200 can be improved.

It is preferable to select a metal layer 80 having better corrosion resistance and oxidation resistance than the electrode 12 of the light emitting element 10. The metal layer 80 may be composed of only one layer of a single material, or may be composed of layers of different materials laminated. In particular, it is preferable to use a metal material having a high melting point, and examples thereof include Ru, Mo, and Ta. Further, by providing these high melting point metal materials between the electrodes of the light emitting element and the outermost layer, it is possible to reduce the diffusion of Sn contained in the solder to the electrodes of the light emitting element and the layer close to the electrodes. It can be a possible diffusion prevention layer. Examples of the laminated structure provided with such a diffusion prevention layer include Ni / Ru / Au, Ti / Pt / Au and the like. The thickness of the diffusion prevention layer (for example, Ru) is preferably about 10 Å to 1000 Å.

The thickness of the metal layer 80 can be variously selected. The thickness of the metal layer 80 can be, for example, 10 nm to 3 μm. Here, the thickness of the metal layer 80 means the total thickness of the plurality of layers when the metal layer 80 is formed by laminating a plurality of layers.

The metal layer 80 can have a size that reaches the side surface 203 on the bottom surface of the light emitting device 200. Further, the metal layer 80 can be sized so as to be separated from the side surface 203 on the bottom surface of the light emitting device 200. The metal layer 80 can have the same shape, the same size, or a different shape and a different size in bottom view. For example, a notch or the like may be provided on either one of the metal layer 80 connected to the electrode 12n and the metal layer 80 connected to the electrode 12p so as to function as a cathode mark, an anode mark, or the like.

<Embodiment 3>
The light emitting device according to the third embodiment is shown in FIGS. 3A and 3B. The light emitting device 300A and the light emitting device 300B have the same external shape as the light emitting device 100 and the like shown in FIG. 1A. Further, in the above-described second embodiment, the light guide member 60 is arranged on the side surface 11c of the light emitting element 10, whereas in the third embodiment, the light guide member 60A is arranged on the side surface 73 of the wavelength conversion member 70. The difference is that they are.

In the light emitting device 300B, the light guide member 60 is arranged on the side surface of the light emitting element 10, and the light guide member 60A is arranged on the side surface of the wavelength conversion member 70. In such a case, it is preferable that the light guide member 60 and the light guide member 60B are arranged so as not to be optically continuous. If the light guide member 60 and the light guide member 60A are optically continuous, light that does not pass through the wavelength conversion member 70 is incident on the light transmitting portion 40, which is not preferable because it causes color unevenness.

The light guide member 60A arranged on the side surface 73 of the wavelength conversion member 70 is preferably arranged so as to be separated from the side surface 303 of the light emitting devices 300A and 300B. In other words, the light guide member 60A is preferably embedded by the covering member 20. Further, in the examples shown in FIGS. 3A and 3B, the metal layer 80 is provided, but this is not essential.

<Modification example of optical member>
The light emitting devices shown in FIGS. 4A to 4E show modifications of the optical members illustrated in the first to third embodiments. Here, as an example, a light emitting device provided with a wavelength conversion member, a light guide member, a metal layer, and the like is illustrated, but these members are not essential.

The optics shown in FIGS. 4A to 4E have in common that the lower surface of the light reflecting portion is convex downward at the center portion.

In the light emitting device 400A shown in FIG. 4A, the lower surface 51A of the light reflecting portion 50A of the optical member 30A is a curved surface. That is, it can be hemispherical or a rotating paraboloid. The lower surface 51A of the light reflecting portion 50A has a top portion R closest to the light emitting element 10 in the vicinity of the central portion thereof. The top R is a curved surface, and the lower surface 51B between the top R and the side surface 403 of the light emitting device 400A is a curved surface that is convex toward the side surface.

In the light emitting device 400B shown in FIG. 4B, the lower surface 51B of the light reflecting portion 50B of the optical member 30B has a curved surface shape that is convex toward the upper surface side with the top portion R in between, and has a shape similar to a modified example of a cone. is there. Specifically, the lower surface 51B of the light reflecting portion 50B is a curved surface that is concave with respect to the side surface 403 of the light emitting device 400B. As shown in FIG. 4B, by using a curved surface that is concave with respect to the side surface 403 as a reflecting surface, light can be spread farther than the light emitting device 400A shown in FIG. 4A.

Further, by making the lower surface of the light reflecting portion a curved surface as shown in FIGS. 4A and 4B, as compared with the light reflecting portion provided with an inclined surface which is a flat surface in a cross-sectional view as shown in FIG. 1B and the like. The orientation can be controlled while reducing the loss of brightness. When the lower surface of the light reflecting portion is a curved surface, the curvature of the curved surface is preferably 1 / (length of the wavelength conversion member L × 0.5) to 1 / (length L × 20 of the wavelength conversion member). Is in the range of 1 / (length L of the wavelength conversion member) to 1 / (length L × 10 of the wavelength conversion member). By making the curved surface in this range, light can be effectively reflected in the side surface direction, and a light emitting device having a high light output can be obtained.
Here, the length L of the wavelength conversion member is the length L of the wavelength conversion member, which is the diagonal length when the outer shape of the wavelength conversion member is rectangular, and the diameter when the outer shape of the wavelength conversion member is circular. To say.

In the light emitting device 400C shown in FIG. 4C, the light reflecting portion 50C of the optical member 30C includes a convex portion 50Ca near the central portion on the lower surface 51C side thereof, and a flat surface portion 50Cb around the convex portion 50Ca. That is, the lower surface 51 of the light reflecting portion 50 of the optical member 30 illustrated in FIG. 1B or the like has an inclined surface or a curved surface as a whole, whereas the lower surface 51C of the light reflecting portion 50C shown in FIG. 4C is a part thereof. The vicinity of the central portion is the lower surface 51Ca of the convex portion 50Ca, which is an inclined surface. Here, an example is shown in which the lower surface 51Ca of the convex portion 50Ca is an inclined surface that is a straight line in a cross-sectional view, but the present invention is not limited to this, and a convex curved surface as shown in FIGS. 4A and 4B. Alternatively, the lower surface 51Ca having a concave curved surface may be used.

The convex portion 50Ca of the light reflecting portion 50C is arranged above the light emitting element 10. The convex portion 50Ca is preferably arranged near the central portion of the optical member 30C. Further, it is preferable that the top R of the convex portion 50Ca and the center of the wavelength conversion member 70 coincide with each other in the top view. However, since light propagates inside the wavelength conversion member 70, even if the center of the light emitting element 10 and the center of the convex portion 50Ca are slightly deviated, the center of the wavelength conversion member 70 and the center of the convex portion 50Ca coincide with each other. lever, uniform protrusion 50Ca of the light reflecting portion 50C shown in light contagious Figure 4C, the width _{W R1} have shown smaller examples than the width _{W D} of the light emitting element 10. Is not limited to this, depending on the light distribution required, the width W _R1 of the convex portion 50Ca may be the same as the width W _D of the light emitting element 10, or may be larger than the width W _D of the light emitting element 10.

The flat surface portion 50Cb of the light reflecting portion 50C is a plane parallel to the lower surface 31C of the optical member 30C (the lower surface 41C of the transmitting portion 40C), and the thickness of the light reflecting portion 50C in this region is constant.

In the light emitting device 400D shown in FIG. 4D, the upper surface 32D of the optical member 30D (the upper surface 52D of the light reflecting portion 50D) has a concave shape. The translucent portion 40D of the light emitting device 400D has the same shape as the translucent portion 40 of the light emitting device 100 shown in FIG. 1B, but the shape of the upper surface 52D of the light reflecting portion 50D is different. Further, the light reflecting portion 50D is formed to have the same thickness as a whole. For example, when a metal film, an insulating reflective film formed by sputtering or the like is used as the light reflecting portion 50D, the light reflecting portion 50D can be formed so as to have the same thickness as a whole. Further, the light reflecting portion 50D shown in FIG. 4D may be a lower surface having a convex curved surface or a concave curved surface as shown in FIGS. 4A and 4B.

In the case of a light reflecting portion having a concave upper surface as shown in FIG. 4D, a filling member such as a resin material may be further provided on the light reflecting portion. For example, in the light emitting device 400E shown in FIG. 4E, the upper surface 52E of the light reflecting portion 50E is concave. Then, the filling member 54 is arranged on the upper surface 52E of the concave light reflecting portion 50E. The upper surface of the filling member 54 is the upper surface 32E of the optical member 30E. In this way, the upper surface 52E of the light reflecting portion 50E and the upper surface 32E of the optical member 30E may be different from each other. By making the upper surface of the filling member 54 a flat surface, it can be easily sucked by, for example, a collet or the like. The light reflecting portion 50E shown in FIG. 4E may also have a convex curved surface as shown in FIGS. 4A and 4B, or a lower surface provided with a concave curved surface.

<Manufacturing method>
The manufacturing method of the light emitting device according to the first to third embodiments will be described with reference to FIGS. 5A to 5H. Here, the light emitting device according to the second embodiment will be described as an example. That is, a method of manufacturing a light emitting device including a light guide member, a wavelength conversion member, a metal layer, and the like will be described. In order to obtain a light emitting device not provided with these members, the step of forming the members is omitted.

(Preparation of light reflector)
First, as shown in FIG. 5A, the light reflecting unit 50 is prepared. The light reflecting portion 50 is a plate-shaped member. The light reflecting portion 50 includes a second surface 52 which is a flat surface and a first surface 51 having a convex portion. One light reflecting portion 50 may include one or more convex portions. Here, a light reflecting portion 50 having two convex portions will be described as an example. In FIG. 5A, the second surface 52 is arranged on the lower side and the first surface 51 is arranged on the upper side. The first surface 51 is a surface corresponding to the lower surface 41 of the light reflecting portion 50 of the light emitting device 100, and the second surface 52 is a surface corresponding to the upper surface 52 of the light reflecting portion 50 of the light emitting device 100. In the manufacturing process, as shown in FIG. 5A and the like, the surface may be turned upside down. Therefore, for convenience of explanation, the first surface and the second surface are used instead of the lower surface and the upper surface.

The light reflecting unit 50 may be prepared by purchasing the light reflecting unit 50 having the above-mentioned shape, or may be prepared through a process such as molding using the following materials.

A case where the light reflecting portion 50 is formed by using a light reflecting resin material in which a light reflecting substance is dispersed in the resin material will be described. The light reflecting portion 50 made of a light reflecting resin material can be formed by a method such as injection molding, transfer molding, or compression molding using a mold or the like. Alternatively, a plate-shaped member as shown in FIG. 5A is prepared from another resin material or the like, and injection molding, transfer molding, and compression are performed on the first surface 51, which is a reflecting surface for reflecting the light from the light emitting element, in the same manner as described above. The light reflecting layer may be formed by a method such as molding, printing, spraying, sputtering, or the like to form the light reflecting portion 50.

A case where the light reflecting portion 50 is formed by using a metal material will be described. When a metal member is used, the entire light reflecting portion 50 may be made of a metal material having high light reflectance. In that case, the metal plate can be ground, bent, or the like to form a metal plate having a convex shape on one side as shown in FIG. 5A. Further, a plate-shaped member made of the above-mentioned resin material or the like and having the shape shown in FIG. 5A is prepared, and the first surface 51, which is a reflecting surface for reflecting the light from the light emitting element, has a high light reflectance by plating or the like. A plating film made of a metal material may be formed to serve as a light reflecting portion.

A case where a dielectric multilayer film is used as the light reflecting portion 50 will be described. As described above, a plate-shaped member made of a resin material or the like and having the shape shown in FIG. 5A is prepared, and a dielectric multilayer film is formed on a first surface 51 which is a reflecting surface for reflecting light from a light emitting element by sputtering or the like. The light reflecting unit 50 may be used.

(Formation of translucent part)
Next, as shown in FIG. 5B, the light transmitting portion 40 is formed on the first surface 51 of the light reflecting portion 50. As a result, the first surface 41 of the light transmitting portion 40 is the first surface 31 of the optical member 30, and the second surface 52 of the light reflecting portion 50 is the second surface 32 of the optical member 30. The optical member 30 can be obtained. The translucent portion 40 may be formed by, for example, arranging the above-mentioned light reflecting portion 50 in a mold and then molding a translucent resin material by a method such as injection molding, transfer molding, or compression molding. it can. Alternatively, a translucent resin material can be formed on the first surface 51 of the light reflecting portion 50 by printing coating, spray coating, or the like. Since the first surface 41 of the light transmitting portion 40 will be the surface on which the light emitting element is placed in a later step, it is preferable that the first surface 41 is a flat surface.

(Preparation of optical member: deformation example)
The optical member 30 can be prepared by forming the light transmitting portion 40 after preparing the light reflecting portion 50 as described above, and first, after preparing the light transmitting portion 40, the light reflecting portion 50 is provided. It may be formed. In particular, when a metal film or a dielectric multilayer film is used as the light reflecting portion 50, the light transmitting portion 40 is prepared first, and these light reflecting portions 50 are formed on the first surface of the light transmitting portion 40, or the like. It is preferable to form using. Such a translucent part 40 may be purchased and prepared.

(Formation of wavelength conversion member)
Next, as shown in FIG. 5C, the wavelength conversion member 70 is arranged on the first surface 31 of the optical member 30 (on the first surface 41 of the translucent portion 40). In the manufacturing process of the light emitting device not provided with the wavelength conversion member, this step is omitted.

The wavelength conversion member 70 is located on the first surface 31 of the optical member 30 (on the first surface 31 of the light transmitting portion 40) at a position facing the top R of each convex portion of the light reflecting portion 50. Place it. The adjacent wavelength conversion members 70 are separated from each other between the tops R. It is preferable that the center of the wavelength conversion member 70 is arranged so as to coincide with the top R of the light reflecting portion 50.

The wavelength conversion member 70 can prepare a molded product and arrange it on the first surface 31 of the optical member 30 by using an adhesive or the like. When an adhesive is used, as shown in FIG. 3A and the like, the light guide member 60A can be formed by arranging the adhesive on the side surface 73 of the wavelength conversion member 70.

Further, the wavelength conversion member 70 forms a liquid resin material containing a phosphor in the resin material on the first surface 31 of the optical member 30 by printing, spraying, injection molding, compression molding, transfer molding, or the like. Can be done. For example, a mask or the like having an opening having a desired shape is provided in advance on the first surface 31 of the optical member 30 in a region facing the top R of the light reflecting portion, and the wavelength conversion member 70 is formed in the opening. Then, by removing the mask, the wavelength conversion members 70 separated from each other can be formed. Alternatively, the wavelength conversion member 70 is formed on the entire surface of the first surface 31 of the optical member 30, and then the other portion is formed so that the wavelength conversion member 70 having a desired shape remains in the region facing the top R of the light reflecting portion. By removing them, the wavelength conversion members 70 separated from each other can be formed. Alternatively, the wavelength conversion member 70 may be formed by potting a liquid resin material on the first surface 31 of the optical member 30 using a dispense nozzle or the like without using a mask.

The first surface 71 of the wavelength conversion member 70 is a surface on which a light emitting element is placed in a later step.
Therefore, it is preferable that the first surface 71 of the wavelength conversion member 70 includes at least a flat surface on which a light emitting element can be placed.

(Formation of light guide member)
Next, as shown in FIG. 5D, the light guide member 60 is arranged on the first surface 31 of the optical member 30. When the wavelength conversion member 70 is arranged on the first surface 31 of the optical member 30, the light guide member 60 is arranged on the first surface 71 of the wavelength conversion member 70. The light guide member 60 arranged here is liquid and functions as a joining member for joining the light emitting element described later with the optical member 30 or the wavelength conversion member 70, so that the hardness is preferably deformable. .. The size of the light guide member 60 arranged on the side surface of the light emitting element can be adjusted by the amount of the liquid light guide member 60. Therefore, it is preferable to adjust the amount of the light guide member 60 according to the size of the light emitting element, the height of the light emitting element, and the like. Further, when the liquid light guide member 60 is arranged on the first surface 71 of the wavelength conversion member 70, the light guide member 60 has a size smaller than the area of the first surface 71 of the wavelength conversion member 70. It is preferable to adjust the amount. Further, in the step of forming the liquid wavelength conversion member 70 before this step, the light emitting element may be placed before the liquid wavelength conversion member 70 is cured. That is, the liquid wavelength conversion member 70 itself may be used as the joining member. In such a case, the step of forming the light guide member can be omitted. Further, this step of forming the light guide member can be omitted even when the adhesive is applied to the light emitting element side or when the optical member and the light emitting element are directly joined.

(Placement of light emitting element)
Next, as shown in FIG. 5E, the light emitting element 10 is arranged on the light guide member 60. The light emitting element 10 is arranged so that the electrode 12 is on the upper side, that is, the laminated structure 11 side faces the light guide member 60. When the light guide member 60 is liquid, it crawls up to the side surface of the light emitting element 10 to form a fillet-shaped light guide member 60 as shown in FIG. 5E. The light guide member 60 is cured in such a state.

(Formation of covering member)
Next, as shown in FIG. 5F, the covering member 20 is formed on the optical member 30 so as to integrally cover the plurality of light emitting elements 10. The covering member 20 can be formed up to a height at which the electrode 12 of the light emitting element 10 is embedded. The covering member 20 is formed so as to embed the first surface 31 of the optical member 30 between the adjacent light emitting elements 10. The covering member 20 can be formed by, for example, injection molding, transfer molding, compression molding, printing, potting, spraying, or the like.

(Exposure of electrodes)
Next, as shown in FIG. 5G, the electrode 12 of the light emitting element 10 is exposed by removing a part of the covering member 20. It should be noted that this step is a step necessary after burying the electrode 12 when forming the covering member 20 as described above. That is, when the covering member 20 is formed so that the upper surface of the electrode 12 is not filled, this step is omitted. Examples of the method for removing a part of the covering member 20 include polishing, grinding, blasting and the like.

Next, as shown in FIG. 5H, a metal layer 80 is formed on the pair of exposed electrodes 12. The metal layer 80 may cover the covering member 20. The metal layer 80 includes sputter, thin-film deposition, atomic layer deposition (ALD) method, metallic organic chemical vapor deposition (MOCVD) method, and plasma CVD (Plasma-Enhanced Chemical Vapor Deposition; PECVD). ) Method, atmospheric pressure plasma deposition method, plating, etc.

The metal layer 80 can be formed by being formed so as to cover the entire surface including the covering member 20 and the electrode 12, and then patterned by, for example, laser light irradiation or etching. Alternatively, it can be formed by forming a mask or the like patterned in advance, then forming the metal layer 80 by using the above-mentioned method, and removing the mask. When the metal layer 80 is formed by laser ablation by laser light irradiation, the thickness of the metal layer 80 can be, for example, 10 nm to 3 μm, preferably 1 μm or less, and more preferably 1000 Å or less. Further, the thickness is preferably 5 nm or more, which can reduce the corrosion of the electrode 12.

(Individualization process)
Finally, the covering member 20 and the optical member 30 are cut between adjacent light emitting elements (the cutting line shown by the broken line C in FIG. 5H) and separated into individual pieces to emit light as shown in FIG. 2A. The device 200 can be obtained.

<Embodiment 4>
The light emitting device 600 according to the fourth embodiment is shown in FIG. In the fourth embodiment, the upper surface 72F and the side surface 73F of the wavelength conversion member 70F are covered with the translucent portion 40F of the optical member 30F. Therefore, the light from the light emitting element 10 is incident on the translucent portion 40F from the upper surface 72F and the side surface 73F of the wavelength conversion member 70F. Thereby, the light extraction efficiency can be improved.
Hereinafter, the points different from the first to third embodiments will be mainly described.

(Coating member)
In the fourth embodiment, the covering member 20F directly or indirectly covers the side surface 11c of the light emitting element 10 and does not cover the side surface 73F of the wavelength conversion member 70F. The upper surface 22F of the covering member 20F is flush with the lower surface 71F of the wavelength conversion member 70F.

(Optical member)
In the fourth embodiment, the optical member 30F has a recess 41F instead of a flush surface 31F. Specifically, the lower surface 41F of the translucent portion 40F of the optical member 30F is not flush with each other and includes a recess 41F. A wavelength conversion member 70F is arranged inside the recess 41F. The lower surface 41F of the light transmitting portion 40F and the lower surface 71F of the wavelength conversion member 70F are flush with each other. The width (area) of the recess 41F is preferably the same as the width (area) of the first surface 71F and the second surface 72F of the wavelength conversion member 70F. Depending on the method of forming the wavelength conversion member 70F, the widths of the first surface 71F and the second surface 72F of the wavelength conversion member 70F may be smaller than the width of the recess 41F. In top view, it is preferable that the center of the recess 41F and the center of the wavelength conversion member 70F coincide with each other. Further, in the top view, it is preferable that the center of the recess 41F and the top R of the light reflecting portion 50F coincide with each other. Further, the width of the recess 41F is preferably larger than the width (area) of the light emitting surface of the light emitting element 10. When the light guide member 60F is provided, the width of the recess 41F is larger than the width (area) of the width (area) of the light emitting element 10 and the width (area) of the upper surface 62F of the light guide member 60F. Is preferable. The depth of the recess 41F is preferably such that the desired wavelength conversion member 70F can be arranged.

7A to 7D are diagrams showing a part of the steps of the method for manufacturing the light emitting device according to the fourth embodiment. First, as shown in FIG. 7A, the translucent portion 40F is prepared. The light transmitting portion 40F is provided with a recess 41F on the first surface 41F side on which a wavelength conversion member can be arranged. An inclined surface is provided on the second surface 42F side. The translucent part 40F may be purchased and prepared. Further, as the translucent portion 40F, a translucent portion 40F having a shape as shown in FIG. 7A may be prepared in advance by molding or the like, or a flat surface is provided as the first surface 41F and is inclined as the second surface 42F. The recess 41F may be formed in a separate step, such as forming the recess 41F after preparing the translucent portion provided with the surface. The second surface 42F may have the shapes shown in FIGS. 4A to 4C.

Next, as shown in FIG. 7B, a light reflecting portion 50F is formed on the second surface 42F side of the translucent portion 40F to obtain an optical member 30F.

Next, as shown in FIG. 7C, the wavelength conversion member 70F is arranged in the recess 41F of the first surface 31F of the optical member 30F (the first surface 41F of the translucent portion 40F). As the method of arranging the wavelength conversion member 70F, the same method as in the first to fourth embodiments can be used. In particular, it is preferable to form the liquid wavelength conversion member 70F in the recess 41F by printing or potting. The first surface 41F of the light transmitting portion 40F and the first surface 71F of the wavelength conversion member 70F have the same height, or the first surface 71F of the wavelength conversion member 70F is from the first surface 41F of the light transmitting portion 40F. Will be in a high position.

Next, as shown in FIG. 7D, the liquid light guide member 60F is arranged on the first surface 71F of the wavelength conversion member 70F. After that, the steps after the step of arranging the light emitting element 10 are the same as those of the first to third embodiments, and are omitted.

<Embodiment 5>
The light emitting device 800 according to the fifth embodiment is shown in FIG. In the fifth embodiment, the side surface 73G of the wavelength conversion member 70G is covered with the translucent portion 40G of the optical member 30G. The upper surface 72G of the wavelength conversion member 70G is covered with the light reflecting portion 50G of the optical member 30G. Therefore, the light from the light emitting element 10 is incident on the translucent portion 40G of the optical member 30G only from the side surface 73F of the wavelength conversion member 70F. As a result, the light can be spread more laterally. Hereinafter, the points different from the first to fourth embodiments will be mainly described.

(Coating member)
In the fifth embodiment, the covering member 20 directly or indirectly covers the side surface 11c of the light emitting element 10 and does not cover the side surface 73G of the wavelength conversion member 70G, as in the fourth embodiment.

(Optical member)
The fifth embodiment is the same as the first to fourth embodiments in that the light transmitting portion 40G and the light reflecting portion 50G of the optical member 30G form a part of the side surface 803 of the light emitting device 800. Of the lower surface 51G of the light reflecting portion 50G, a part of the lower surface 51G continuous from the side surface 803 of the light emitting device 800 is in contact with the translucent portion 40G, and the lower surface 51G of the light reflecting portion 50G located above the light emitting element 10 is It differs from the first to fourth embodiments in that the wavelength conversion member 70G is in contact with the wavelength conversion member 70G. In other words, the light transmitting portion 40G is not arranged above the wavelength conversion member 70G. This not only makes it possible to spread the light in the lateral direction, but also improves the color unevenness of the emitted light.

Here, as the light reflecting portion 50G, a light reflecting portion 50G having a convex portion 50Ga and a flat portion 50Gb is illustrated, but the light reflecting portion 50G also has a shape used in other embodiments. be able to.

The width (area) of the lower surface 71G of the wavelength conversion member 70G is preferably larger than the width (area) of the light emitting element 10. Further, when the light guide member 60G is provided as shown in FIG. 8, it is preferable that the wavelength conversion member 70G is also arranged on the upper surface of the light guide member 60G. The width (area) of the upper surface 72G of the wavelength conversion member 70G may be the same as that of the lower surface 71G, and may be large or small. That is, the side surface 73G of the wavelength conversion member 70G can be a vertical or inclined surface. Further, the side surface 73G of the wavelength conversion member 70G may be a surface having a step, a curved surface, or the like.

As shown in FIG. 8, the wavelength conversion member 70G shows an example in which all of the second surface 72G is in contact with the light reflecting portion 50G, but the present invention is not limited to this, and the second surface 72G of the wavelength conversion member 70G is not limited to this. A part of the light reflecting portion 50G may be in contact with the light reflecting portion 50G. Further, the wavelength conversion member 70G may be in contact with the convex portion 50Ga and the flat surface portion 50Gb of the light reflecting portion 50G, or may be in contact with only the convex portion 50Ga.

9A to 9D are diagrams showing a part of the steps of the method for manufacturing the light emitting device according to the fifth embodiment. First, as shown in FIG. 9A, the light reflecting unit 50G is prepared. The light reflecting portion 50G includes a convex portion 51Ga and a flat surface portion 50Gb on the first surface 51G side. The shape exemplified in other embodiments can be applied to the first surface 51G of the light reflecting portion 50G.

Next, as shown in FIG. 9B, a light transmitting portion 40G is formed on a part of the first surface 51G of the light reflecting portion 50G. Since the light transmitting portion 40G is arranged on the side surface 803 of the light emitting device 800, it is formed at a position where it is cut at the time of later individualization. Here, the light transmitting portion 40G is formed on the flat surface portion 50Gb at a position separated from the convex portion 50Ga of the light reflecting portion 50G. Although not shown, the light transmitting portion 40G is formed in a grid pattern in a top view. Therefore, a plurality of recesses 34G having the first surface 51G of the light reflecting portion 50G as the bottom surface and the light transmitting portion 40G as the side wall are formed. The top R of the convex portion 50Ga is arranged at the center of the bottom surface of the concave portion 34G.

Next, as shown in FIG. 9C, the wavelength conversion member 70G is arranged in the recess 34G.

Next, as shown in FIG. 9C, the liquid light guide member 60G is arranged on the first surface 71G of the wavelength conversion member 70G. After that, the steps after the step of arranging the light emitting element on the light guide member 60G are the same as those in the first to fourth embodiments, and are omitted.

10A to 10D are modified examples of the manufacturing method of the light emitting device 800 according to the fifth embodiment.
First, as shown in FIG. 10A, the light reflecting unit 50G is prepared. Next, as shown in FIG. 10B, the wavelength conversion member 70G is formed. After that, as shown in FIG. 10C, the flat portion 50Gb of the light reflecting portion 50G is exposed by removing the wavelength conversion member 70G arranged at the portion to be cut in the subsequent step. Next, as shown in FIG. 10D, a light transmitting portion 40G is formed on the light reflecting portion 50G between adjacent wavelength conversion members 70G. As described above, even if the wavelength conversion member 70G is formed before the light transmitting portion 40G, the same optical member 30G as shown in FIG. 9C can be formed.

<Embodiment 6>
The light emitting device of the sixth embodiment is configured in the same manner as the light emitting device of the first embodiment except that the side surface of the optical member is inclined with respect to the direction perpendicular to the upper surface of the optical member.
Specifically, in the light emitting device of one aspect according to the sixth embodiment, as shown in FIG. 11A, the side surface 33H of the optical member 30H is tilted inward at an inclination angle α with respect to the direction perpendicular to the upper surface of the optical member 30H. ing. Here, in the present specification, inward tilting means that the closer to the upper surface is closer to the central axis of the optical member, and the inward tilting angle is referred to as α.
In the light emitting device of this aspect, the optical member 30H includes a light reflecting portion 50H and a light transmitting portion 40H as in the first embodiment, and the side surface 33H of the optical member 30H is the side surface 43H of the light transmitting portion 40H and light. When the side surface 53H of the reflecting portion 50H is included, at least the side surface 43H of the translucent portion 40H may be inclined inward on the side surface 33H of the optical member 30H.

Further, in the light emitting device of another aspect according to the sixth embodiment, as shown in FIG. 11B, the side surface 33I of the optical member 30I is tilted outward at an inclination angle β with respect to the direction perpendicular to the upper surface of the optical member 30I. .. Here, in the present specification, "tilting outward" means tilting toward the upper surface so as to be farther from the central axis of the optical member, and the tilt angle when tilted outward is referred to as β.
In the light emitting device of the other aspect, the optical member 30I includes a light reflecting portion 50I and a light transmitting portion 40I as in the first embodiment, and the side surface 33I of the optical member 30I is the side surface 43I of the light transmitting portion 40I. When the side surface 53I of the light reflecting portion 50I is included, at least the side surface 43I of the light transmitting portion 40I may be inclined outward on the side surface 33I of the optical member 30I.

The light emitting device of the sixth embodiment configured as described above can control the direction of the light emitted from the side surfaces 33H and 33I by adjusting the inclination angles α and β of the side surfaces 33H and 33I of the optical members 30H and 30I. Therefore, it has the following advantages.
First, in addition to being able to spread and emit light over a wide range in the lateral direction, it is possible to more appropriately control the light distribution characteristics of the light emitted in the lateral direction.
Further, for example, different light distribution characteristics can be realized by adjusting the inclination angles α and β of the side surfaces 33H and 33I of the optical members 30H and 30I at the final stage of the manufacturing process, and a light emitting device having different light distribution characteristics can be realized. Can be efficiently manufactured. This makes it possible to inexpensively provide a wide variety of light emitting devices having different light distribution characteristics.

In the above-described light emitting device of the sixth embodiment, the side surfaces 33H and 33I of the optical members 30H and 30I have been described by an example in which the side surfaces 33H and 33I are inclined at a constant inclination angle α and β. It may be configured by a curved surface, or may be configured by a side surface formed of a curved surface that is projected or recessed instead of the side surfaces 33H and 33I. Even in this way, the light distribution characteristics of the light emitted in the lateral direction can be controlled.

The light emitting device of the sixth embodiment has been described by an example configured in the same manner as the light emitting device of the first embodiment except that the side surfaces 33H and 33I of the optical members 30H and 30I are inclined at constant inclination angles α and β. However, in the light emitting device of the sixth embodiment, in the light emitting device of the second to fifth embodiments, for example, the side surfaces 33H and 33I of the optical members 30H and 30I may be tilted at constant tilt angles α and β.

As can be understood from the above description, in the light emitting devices of the first to sixth embodiments, the angle or shape of the lower surface of the light reflecting portion and the surface direction of the side surface of the light transmitting portion are appropriately set from the side surface of the light transmitting portion. Light can be emitted in a desired direction. However, in the light emitting devices of the first to sixth embodiments, it is possible to control the light distribution characteristics by further controlling the surface roughness of the side surface of the light transmitting portion. FIG. 12 schematically shows an example in which the surface roughness of the side surface 43 of the translucent portion 40 is increased in the light emitting device of the first embodiment. For example, if the surface roughness Ra of the side surface of the translucent portion is set to a relatively large surface roughness in the range of 0.1 to 50, preferably 1 to 20, light scattering on the side surface of the transmissive portion It can be made larger, and the light distribution characteristics of the light emitted from the side surface of the light transmitting portion can be made into a wide light distribution characteristic. Here, the broad light distribution characteristic is realized by the angle of the lower surface of the light reflecting portion and the surface direction of the side surface of the light transmitting portion, and is assumed that there is no light scattering on the side surface of the light transmitting portion. It means that the attenuation rate of the intensity of light emitted in a direction different from the center of light distribution is smaller than that of the light characteristics. As described above, assuming that the light distribution characteristic of the light emitted from the side surface of the light transmitting portion has a broad light distribution characteristic, for example, when a plurality of light emitting devices are arranged in a matrix, the irradiation is arranged at close positions. It becomes possible to uniformly irradiate the object with light, and for example, a thinner backlight can be realized. Further, by increasing the surface roughness of the side surface of the translucent portion, the total reflection on the side surface of the translucent portion can be reduced, and the light extraction efficiency can be increased. Further, for example, when the surface roughness Ra of the side surface of the light transmitting portion is set to a relatively small range of 0.001 to 0.1, preferably 0.005 to 0.05, the side surface of the light transmitting portion is set. The scattering of light in the light can be reduced, and light is emitted based on the light distribution characteristics set by the angle or shape of the lower surface of the light reflecting portion and the surface direction of the side surface of the light transmitting portion. When the surface roughness Ra on the side surface of the light transmitting portion is reduced, the total reflection on the side surface of the light transmitting portion tends to increase as the surface roughness Ra decreases. It is preferably at least the lower limit of the above range.
As described above, in the light emitting devices of the first to sixth embodiments, by appropriately changing the surface roughness Ra of the side surface of the light transmitting portion, the angle of the lower surface of the light reflecting portion and the surface direction of the side surface of the light transmitting portion can be determined. It is possible to change the light distribution characteristics of the light emitted from the side surface of the light transmitting portion, which is realized.
Therefore, for example, by appropriately changing the surface roughness Ra of the side surface of the light transmitting portion at the final stage of the manufacturing process, various different light distribution characteristics can be realized, and a light emitting device having different light distribution characteristics can be efficiently manufactured. can do. This makes it possible to inexpensively provide a wide variety of light emitting devices having different light distribution characteristics.
The surface roughness Ra of the side surface of the light-transmitting portion is determined by the size of the abrasive grains of the cutting blade when the side surface is polished to the desired surface roughness by the individualized light emitting device or is individualized. / Or the desired surface roughness can be easily adjusted by appropriately selecting the rotation speed.

100, 200, 300A, 300B, 400A, 400B, 400C, 400D, 400E, 600, 800 ... Light emitting device 101 ... Lower surface of light emitting device 102 ... Upper surface of light emitting device 103, 203, 303, 403, 803 ... Side surface of light emitting device 10 ... Light emitting element 11 ... Laminated structure 11a ... Electrode forming surface of laminated structure (light emitting element) 11b ... Light emitting surface of laminated structure (light emitting element) 11c ... Side surface of laminated structure (light emitting element) 12, 12p, 12n ... Electrode 20 ... Covering member 21 ... Lower surface (first surface) of the covering member
22 ... Upper surface (second surface) of the covering member
23 ... Outer surface of the covering member 24 ... Inner surface of the covering member 30, 30A, 30B, 30C, 30D, 30E, 30F, 30G ... Optical member 31, 31C ... Lower surface of the optical member (first surface)
32, 32D ... Upper surface (second surface) of the optical member
33 ... Side surface of optical member 34G ... Recessed portion 40, 40A, 40B, 40C, 40D, 40E, 40F, 40G ... Translucent part 41, 41F ... Lower surface of translucent part (first surface)
41Fa ... Recessed portion on the lower surface of the translucent part 42 ... Upper surface of the translucent part (second surface)
43 ... Side surface of the translucent part (light emitting surface)
50, 50A, 50B, 50C, 50D, 50E, 50F, 50G ... Light reflecting part 50Ca, 50Ga ... Convex part of light reflecting part 50Cb, 50Gb ... Flat part of light reflecting part R ... Top of light reflecting part 51, 51A, 51B, 51C, 51G ... Lower surface (first surface) of the light reflecting portion
51Ca, 51Ga ... Lower surface of the convex portion of the light reflecting portion 51Cb, 51Gb ... Lower surface of the flat surface portion of the light reflecting portion 52, 52D ... Upper surface of the light reflecting portion (second surface)
53 ... Side surface of light reflecting portion 54 ... Filling member 60, 60A, 60F, 60G ... Light guide member 62, 62F, 62G ... Upper surface of light guide member 63 ... Outer surface of light guide member 70, 70A, 70G ... Wavelength conversion member 71, 71F, 71G ... Lower surface (first surface) of the wavelength conversion member
72, 72F, 72G ... Upper surface (second surface) of wavelength conversion member
73,73F, 73G ... side thickness T _{R1 ...} reflection portion at the center of the thickness T _{T2 ...} transparent portion of the side surface 80 ... metal layer T O _... side thickness T _{T1 ...} transparent portion of the optical member of the wavelength conversion member the thickness W O _... width W D _... width of the inclined portion of the width W _{R1 ...} reflective portion of the light emitting element of the optical member at the center of the thickness T _{R2 ...} reflection portion in

Claims (12)

A semiconductor laminate having an electrode forming surface, a light emitting surface on the opposite side of the electrode forming surface, and a side surface between the electrode forming surface and the light emitting surface, and a pair of electrodes provided on the electrode forming surface. With a light emitting element
A light-reflecting coating member that covers the side surface of the light emitting element,
An optical member arranged over the light emitting surface of the light emitting element and the upper surface of the covering member, and
With
The optical member includes a light reflecting portion arranged above the light emitting element, a light transmitting portion arranged between the light reflecting portion and the covering member, and forming a part of an outer surface of the light emitting device. With
A light emitting device including a light guide member that covers a side surface of the light emitting element and whose outer surface is covered with the covering member. The light emitting device according to claim 1, wherein the light guide member covers 50% or more of the side surface of the light emitting element. The light emitting device according to claim 1 or 2, wherein the light guide member covers the light emitting surface of the light emitting element. The light emitting device according to any one of claims 1 to 3, wherein the light guide member is directly or indirectly connected to the lower surface of the light transmitting portion. The light emitting device according to any one of claims 1 to 4, further comprising a wavelength conversion member arranged between the light emitting surface of the light emitting element and the light transmitting member. The light emitting device according to claim 5, wherein the wavelength conversion member covers the upper surface of the light emitting element and the upper surface of the light guide member. The light emitting device according to claim 5 or 6, wherein the width of the wavelength conversion member is larger than the width obtained by adding the width of the light emitting element and the width of the upper surface of the light guide member. The light emitting device according to claim 5 or 6, wherein the side surface of the wavelength conversion member is a vertical surface. The light emitting device according to claim 5 or 6, wherein the side surface of the wavelength conversion member is an inclined surface. The light emitting device according to any one of claims 5 to 9, wherein the side surface of the wavelength conversion member is separated from the side surface of the light emitting device. The light emitting device according to any one of claims 5 to 10, wherein the light guide member is arranged on a side surface of the wavelength conversion member. The light emitting device according to claim 11, wherein the light guide member arranged on the side surface of the wavelength conversion member is separated from the side surface of the light emitting device.