JP2021097170A - Light-emitting element and light-emitting device - Google Patents

Abstract

To provide a light-emitting element and a light-emitting device that can reduce thermal stress burden while the light extraction efficiency is maintained.SOLUTION: A light-emitting element includes a semiconductor stack including a plurality of exposure parts where a first semiconductor layer is exposed from a second semiconductor layer, a light-reflective electrode provided on and connected to the second semiconductor layer, a second electrode provided on the light-reflective electrode, an insulating film covering the semiconductor stack and the light-reflective electrode and having an opening over the exposure parts, a first electrode being connected to the first semiconductor layer at the opening and being partially disposed on the second semiconductor layer through the insulating film, a plurality of first external connection electrodes and second external connection electrodes disposed on the first electrode and the second electrode, and a first partition wall being disposed on the first electrode and surrounding the first external connection electrodes. In a plan view, an outer edge of the light-reflective electrode is disposed inside an outer edge of the second semiconductor layer and the first partition wall is disposed inside an outer edge of the light-reflective electrode.SELECTED DRAWING: Figure 1A

Description

The present invention relates to a light emitting element and a light emitting device.

The light emitting element is widely used in the general lighting field, the in-vehicle lighting field, and the like, while further improving the quality according to the application.
For example, there is known a light emitting device having a structure in which a light emitting element is flip-chip mounted on a mounting substrate using bumps and a light reflecting resin is further inserted between the light emitting element and the mounting substrate. (For example, Patent Document 1 etc.).

Japanese Unexamined Patent Publication No. 2015-188053

However, in a light emitting device having such a structure, the light-reflecting resin that has entered the gap corresponding to the height of the bump between the lower surface of the light emitting element and the upper surface of the mounting substrate may thermally expand and lift the light emitting element. is there. In such a case, the continuity between the light emitting element and the mounting substrate cannot be ensured, and the reliability of the light emitting device may be lowered.
One embodiment of the present invention aims to provide a light emitting element and a light emitting device capable of reducing a stress load due to heat while maintaining light extraction efficiency.

One embodiment of the present invention includes:
(1) A semiconductor laminate having a first semiconductor layer, a light emitting layer, and a second semiconductor layer in this order, and the first semiconductor layer is on the upper surface side of the second semiconductor layer from the second semiconductor layer to the first semiconductor. A semiconductor laminate having a plurality of exposed parts where the layers are exposed, and
A light-reflecting electrode provided on the second semiconductor layer and connected to the second semiconductor layer,
A second electrode provided on the light-reflecting electrode and
An insulating film that covers the semiconductor laminate and the light-reflecting electrode and has an opening above the plurality of exposed portions.
A first electrode connected to the first semiconductor layer at the opening and partially arranged on the second semiconductor layer via the insulating film.
A plurality of first external connection electrodes arranged on the first electrode,
A plurality of second external connection electrodes arranged on the second electrode,
A first partition wall arranged on the first electrode and surrounding the plurality of first external connection electrodes in a plan view is provided.
The outer edge of the light-reflecting electrode is arranged inside the outer edge of the second semiconductor layer in a plan view.
The first partition wall is a light emitting element arranged inside the outer edge of the light reflecting electrode in a plan view.
(2) A wiring board having a wiring pattern on the upper surface and
The above-mentioned light emitting element mounted by the plurality of first external connection electrodes and the plurality of second external connection electrodes on the wiring pattern,
A light emitting device including the light emitting element and a covering member that covers the outer surface of the first partition wall.

According to one embodiment of the present invention, it is possible to provide a light emitting element and a light emitting device capable of reducing a stress load due to heat while maintaining light extraction efficiency.

It is a schematic plan view which shows one Embodiment of the light emitting element of this invention. FIG. 1 is a cross-sectional view taken along the line I-I'of FIG. 1A. FIG. 2 is a cross-sectional view taken along the line II-II'of FIG. 1A. FIG. 5 is a schematic plan view showing the arrangement of the first external connection electrode, the second external connection electrode, the first partition wall, and the second partition wall in the light emitting element of FIG. 1A. It is an enlarged plan view of the main part of FIG. 1A. It is a schematic plan view which showed the arrangement of the 1st external connection electrode, the 2nd external connection electrode, and the 1st partition wall in another embodiment of the light emitting element of this invention. It is a schematic perspective view which shows one Embodiment of the light emitting device of this invention. FIG. 3A is a sectional view taken along line III-III'of FIG. 3A. It is the schematic sectional drawing which shows the other embodiment of the light emitting device of this invention. It is schematic cross-sectional view which shows the still another embodiment of the light emitting device of this invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. However, the forms shown below are examples for embodying the technical idea of the present invention, and the present invention is not limited to the following. In addition, the size and positional relationship of the members shown in each drawing may be exaggerated to clarify the explanation. Furthermore, with respect to the same name and code, in principle, members of the same or the same quality are shown, and duplicate description will be omitted as appropriate.

[Light emitting element 10]
As shown in FIGS. 1A to 1D, the light emitting element 10 of the present embodiment includes a semiconductor laminate 11, a light reflecting electrode 15, a second electrode 16 provided on the light reflecting electrode 15, and an opening. An insulating film 12 having 12a, a first electrode 18, a plurality of first external connection electrodes 19, a plurality of second external connection electrodes 20, and a first partition wall 21 are provided. As shown in FIGS. 1A and 1E, the outer edge 15a of the light-reflecting electrode 15 is arranged inside the semiconductor laminate 11, that is, the outer edge 11c of the second semiconductor layer 11p, and is arranged inside the outer edge 11c of the second semiconductor layer 11p. Is arranged inside the outer edge 15a of the light reflecting electrode 15 in a plan view.
The planar shape of the light emitting element 10 and / or the semiconductor laminate 11 is, for example, a polygon such as a quadrangle (approximately square, rectangle, etc.), a hexagon, a shape with rounded corners, a circle, an ellipse, or the like. , Can be in various shapes.

When the light emitting element having such a configuration is mounted on the wiring pattern 31 of the wiring board 32 described later by the plurality of first external connection electrodes 19 and the plurality of second external connection electrodes 20, that is, When mounting a so-called flip chip, the first partition wall 21 can effectively prevent the resin from entering between the light emitting element and the wiring board 32. This makes it possible to reduce the stress load on the light emitting element due to the thermal expansion of the resin due to the heat of the light emitting element. As a result, it is possible to effectively prevent the light emitting element from peeling off from the wiring board 32.
Further, the first partition wall 21 is arranged on the first electrode 18, surrounds the plurality of first external connection electrodes 19, and is mounted on the wiring pattern 31 to secure the heat dissipation path by the first partition wall 21 as well. Can be done. Therefore, the heat generated by the light emitting element can be effectively dissipated, and a more reliable light emitting element can be obtained.
Further, the first partition wall 21 allows the resin to be arranged outside the first partition wall 21 without allowing the resin to enter between the light emitting element and the wiring board 32. Therefore, a structure can be formed in which light leakage from the light emitting element that may occur outside the first partition wall 21 is suppressed by a resin having light diffusivity, that is, a covering member 33 described later. In particular, by arranging the outer edge 15a of the light reflecting electrode 15 on the outside of the first partition wall 21, light leakage of the light emitting element generated on the outer periphery of the light emitting element can be effectively reduced, and reliability and light extraction efficiency are improved. Can be made to.

(Semiconductor laminate 11)
The semiconductor laminate 11 is configured by laminating the first semiconductor layer 11n, the light emitting layer 11a, and the second semiconductor layer 11p in this order. The semiconductor laminate 11 is laminated on the substrate 13, for example. The substrate 13 may be removed from the semiconductor laminate 11.
The substrate 13 may be any as long as it can epitaxially grow the semiconductor layer. Examples of such a substrate 13 include an insulating substrate such as a sapphire (Al ₂ O ₃ ) substrate, a spinel (Mg A1 ₂ O ₄ ) substrate, and a conductive substrate such as a GaN substrate.
Examples of the first semiconductor layer 11n, the light emitting layer 11a, and the second semiconductor layer 11p include various semiconductors such as a group III-V compound semiconductor and a group II-VI compound semiconductor. Specific examples _{thereof include nitride-based semiconductor materials such as In X} Al _Y Ga _1-XY N (0 ≦ X, 0 ≦ Y, X + Y ≦ 1), and include InN, AlN, GaN, InGaN, AlGaN, and InGaAlN. Etc. can be used. As the film thickness and layer structure of each layer, those known in the art can be used.

(Exposure part 11b)
The first semiconductor layer 11n has a plurality of exposed portions 11b in which the second semiconductor layer 11p and the light emitting layer 11a are not formed, and the first semiconductor layer 11n is exposed from the second semiconductor layer 11p and the light emitting layer 11a. That is, the semiconductor laminate 11 has holes on the surface on the side of the second semiconductor layer 11p, and the first semiconductor layer 11n is exposed on the bottom surface of the holes. A second semiconductor layer 11p, a light emitting layer 11a, and optionally a first semiconductor layer 11n are exposed on the side surface of the hole.
The shape, size, position, and number of the exposed portion 11b can be appropriately set according to the size, shape, electrode pattern, and the like of the intended light emitting element. It is preferable that a plurality of exposed portions 11b are formed inside the edge portion of the semiconductor laminate 11. The exposed portions 11b are preferably arranged in a triangular lattice pattern or a square lattice pattern. As a result, uneven brightness of the light emitting element can be suppressed and light can be extracted uniformly.
Examples of the shape of the exposed portion 11b include polygons such as a circle or an ellipse, a triangle, a quadrangle, and a hexagon in a plan view. ) Is preferable. The size of the exposed portion can be appropriately adjusted depending on the size of the semiconductor laminate 11, the required output of the light emitting element, the brightness, and the like, and for example, the diameter may be several tens to several hundreds of μm. preferable. From another viewpoint, the diameter is preferably about 1/2 to 1/5 of one side of the semiconductor laminate 11.
The exposed portion 11b is electrically connected to the first electrode 18 described later. A part of the first electrode 18 connected to the exposed portion 11b is arranged on the second semiconductor layer 11p via an insulating film 12 described later. It is preferable that such exposed portions 11b are arranged apart from each other with a certain distance in a plan view. Specifically, it is preferable that the exposed portions 11b are arranged in a plurality of rows along the first direction. The first direction here refers to, for example, one direction parallel to one side of the semiconductor laminate 11 or the light emitting element 10. Further, it is preferable that the exposed portion 11b is arranged in several rows or more in the second direction orthogonal to the first direction. For example, it is preferable that several rows to a dozen rows are arranged in the second direction.
The plurality of exposed portions 11b may all have the same shape and size, or each or part of the exposed portions 11b may have different shapes and sizes. From the viewpoint of reducing the unevenness of brightness in the light emitting element, it is preferable that all of the plurality of exposed portions 11b have the same size and shape. Since the exposed portion 11b is a region that does not have the light emitting layer 11a, by regularly arranging a plurality of exposed portions of the same size in a regular arrangement, it is possible to suppress a bias in the light emitting area and the amount of current supplied. be able to. As a result, it is possible to suppress the uneven brightness of the light emitting element as a whole.
Although the exposed portion 11b is arranged inside the edge portion of the semiconductor laminate 11, the total area is preferably 30% or less and 25% or less of the flat area of the semiconductor laminate 11. By setting the total area of the exposed portion 11b to 30% or less of the flat area of the semiconductor laminate 11, it is possible to balance the current supply to the first semiconductor layer 11n and the second semiconductor layer 11p, and the supplied electric power can be achieved. Brightness unevenness due to bias can be suppressed.

(Light reflective electrode 15)
The light-reflecting electrode 15 is provided on the second semiconductor layer 11p and is electrically connected to the second semiconductor layer 11p. The light reflective electrode 15 is directly arranged on the upper surface of the second semiconductor layer 11p.
As shown in FIGS. 1A to 1C and 1E, the outer edge 15a of the light reflecting electrode 15 is arranged inside the outer edge 11c of the second semiconductor layer 11p in a plan view. In a plan view, all of the light-reflecting electrodes 15 are arranged on the second semiconductor layer 11p. In order to improve the light extraction efficiency of the light emitting element, it is preferable that the light reflecting electrode 15 is formed in a wider area on the upper surface of the second semiconductor layer 11p. From this, for example, the distance between the outer edge 15a of the light reflecting electrode 15 and the outer edge 11c of the second semiconductor layer 11p is in the range of several μm to several tens of μm, preferably in the range of 1 μm to 20 μm, and is preferably in the range of 5 μm. A range of 15 μm is even more preferred. From another viewpoint, the outer edge 15a of the light reflecting electrode 15 is in the range of 0.1% to 20% from the outer edge 11c of the second semiconductor layer 11p with reference to the center (or the center of gravity) of the second semiconductor layer 11p. It suffices if it is arranged in the reduced position, and it is preferable that it is arranged in the reduced position in the range of 0.5% to 15%. The flat area of the light-reflecting electrode 15 is preferably 60% or more, more preferably 70% or more of the flat area of the second semiconductor layer 11p.
As the light-reflecting electrode 15, an alloy containing silver, aluminum or any of these metals as a main component can be used, and in particular, a silver or silver alloy having high light reflectivity with respect to light emitted from the light emitting layer. Is more preferable.
When the light-reflecting electrode 15 contains silver, a protective layer 17 may be provided to cover the upper surface, preferably the upper surface and the side surface thereof, in order to suppress the migration of silver. An insulating member can be used as the protective layer 17. Examples of the insulating member include the same materials as the insulating film 12 described later, and among them, SiN is preferably used. The thickness of the protective layer 17 is preferably about several hundred nm to several μm in order to effectively suppress the migration of silver. The protective layer 17 is provided with an opening above the light-reflecting electrode 15, and the light-reflecting electrode 15 and the second electrode described later are electrically connected through the opening. When the light emitting element 10 has the light-reflecting electrode 15 and the protective layer 17 on the second semiconductor layer 11p, the insulating film 12 covering the semiconductor laminate 11 covers the light-reflecting electrode 15 and the protective layer 17 and An opening 12a is provided in a region directly below the second electrode 16, and the second electrode 16 and the light-reflecting electrode 15 are electrically connected by the opening 12a.
The light-reflecting electrode 15 preferably has a thickness capable of reflecting the light emitted from the light emitting layer. The thickness of the light reflecting electrode 15 includes, for example, a range of 20 nm to 1 μm.

(1st electrode 18 and 2nd electrode 16)
The first electrode 18 and the second electrode 16 are arranged on the upper surface side of the semiconductor laminate 11 (that is, the side of the semiconductor laminate 11 opposite to the side on which the substrate 13 is provided). The first electrode 18 and the second electrode 16 may be in direct contact with the first semiconductor layer 11n and the second semiconductor layer 11p, respectively, or are electrically connected via the light-reflecting electrode 15 described above. You may.

The first electrode 18 and the second electrode 16 are formed of, for example, a single-layer film or a laminated film of a metal such as Au, Pt, Pd, Rh, Ni, W, Mo, Cr, Ti, Al, Cu or an alloy thereof. can do. Specifically, these electrodes are Ti / Rh / Au, Ti / Pt / Au, W / Pt / Au, Rh / Pt / Au, Ni / Pt / Au, Al—Cu alloy / Ti / from the semiconductor layer side. It can be formed by a laminated film of Pt / Au, Al—Si—Cu alloy / Ti / Pt / Au, Ti / Rh and the like. The film thickness of the first electrode 18 and the second electrode 16 described above may be within the film thickness range of the electrodes used in the art.
When the plan view shape of the semiconductor laminate 11 is rectangular, the plan view shape of the first electrode 18 is preferably rectangular or substantially rectangular. When the plan view shape of the semiconductor laminate 11 is rectangular, the plan view shape of the second electrode 16 is preferably rectangular or substantially rectangular. It is preferable that the first electrode 18 and the second electrode 16 provided on one semiconductor laminate 11 are alternately arranged in parallel in one direction in a plan view. For example, in a plan view, it is preferable that the first electrode 18 is arranged so as to sandwich the second electrode 16.

The first electrode 18 is electrically connected to the exposed portion 11b arranged on the second semiconductor layer 11p side of the semiconductor laminate 11 described above. The first electrode 18 preferably covers the plurality of exposed portions 11b integrally and is connected to the plurality of exposed portions 11b, and more preferably all the exposed portions 11b are integrally covered and connected. Therefore, the first electrode 18 is arranged not only on the first semiconductor layer 11n but also above the second semiconductor layer 11p. In this case, the first electrode 18 is arranged on the side surface of the hole forming the exposed portion 11b (that is, the side surface of the light emitting layer 11a and the second semiconductor layer 11p) and the second semiconductor layer 11p via the insulating film 12.

The second electrode 16 is arranged on the second semiconductor layer 11p of the semiconductor laminate 11 described above, and is electrically connected to the second semiconductor layer 11p. The second electrode 16 is preferably arranged on the second semiconductor layer 11p via the light reflecting electrode 15. The second electrode 16 has, for example, a long shape in the first direction, has a length substantially equal to that of the light reflecting electrode 15 in the first direction, and has a length of 5 to 5 of the length of the semiconductor laminate 11 in the second direction. 20% length is mentioned.
The second electrode 16 is preferably arranged so as to be sandwiched between the first electrodes 18 provided along the first direction, for example. That is, in a plan view, it is preferable that the second electrode 16 has a shape longer in the first direction than the second direction, and the first electrode 18 is arranged so as to sandwich the second electrode 16. In this case, it is more preferable that the first electrode 18 is arranged line-symmetrically with respect to the center line of the second electrode 16 in the first direction. As a result, it is possible to reduce the bias of the stress applied to the first electrode 18 and the second electrode 16 when the light emitting element 10 is flip-chip mounted on the wiring board 32. As a result, the mounting accuracy when mounting the light emitting element 10 on the wiring board is stable. The first electrodes 18 arranged on both sides of the second electrode 16 may be electrically connected to each other.

(Insulating film 12)
The insulating film 12 covers the upper surface and side surfaces of the semiconductor laminate 11 and has an opening 12a above the exposed portion 11b. Since the insulating film 12 covers the semiconductor laminate 11 and has the opening 12a above the exposed portion 11b, the first electrode 18 can be formed over a wide range on the upper surface of the insulating film 12. The size of the opening 12a can be appropriately set depending on the size of the exposed portion 11b, the size of the light emitting element, and the like.
The insulating film 12 is made of a material known in the art, which is made of a material and a thickness capable of ensuring electrical insulation. Specifically, a metal oxide, a metal nitride, or the like can be used for the insulating film 12, and for example, at least one oxide selected from the group consisting of Si, Ti, Zr, Nb, Ta, and Al. Alternatively, it is preferable to use a nitride.

(1st external connection electrode 19 and 2nd external connection electrode 20)
The first external connection electrode 19 is electrically connected to the first electrode 18. The second external connection electrode 20 is electrically connected to the second electrode 16.
The first external connection electrode 19 is provided on the first electrode 18. That is, it is arranged so as to be electrically connected to the first electrode 18. The first external connection electrode 19 is provided on the first electrode 18 provided on the upper surface of the insulating film 12 above the second semiconductor layer 11p. The first external connection electrode 19 is arranged apart from the exposed portion 11b in a plan view. A plurality of the first external connection electrodes 19 are arranged along the first direction between the rows of the exposed portions 11b arranged along the first direction. The first external connection electrode 19 may have, for example, a plan view, a circular shape or an elliptical shape, a polygonal shape, or a shape close to these. The first external connection electrode 19 may have a part or all of them having a different size and shape. Of the first external connection electrodes 19, it is preferable that a plurality of first external connection electrodes 19 arranged along at least the same first direction have the same size and shape. It is preferable that a plurality of first external connection electrodes 19 are arranged between rows of exposed portions 11b arranged along the first direction.
Since the first external connection electrode 19 and the exposed portion 11b do not overlap in a plan view, the insulating film and the electrode in the vicinity of the exposed portion 11b due to the load generated at the time of mounting the light emitting element described later on the wiring board 32 Damage can be avoided.
In a plan view, the distance between the first external connection electrode 19 and the exposed portion 11b is, for example, 0.1% to 2% of the length of one side of the semiconductor laminate 11. Specifically, the distance between the first external connection electrode 19 and the exposed portion 11b is preferably 10 μm to 200 μm.
The second external connection electrode 20 is provided on the second electrode 16. As described above, when the first electrode 18 is arranged so as to sandwich the second electrode 16 in the second direction, the first external connection electrode 19 is placed on both sides of the second external connection electrode 20 in a plan view. Is preferably arranged.
The planar shape and size of the first external connection electrode 19 and the second external connection electrode 20 can be set to the extent normally used in the art. Examples of the planar shape of the first external connection electrode 19 or the second external connection electrode 20 include polygons such as a plan view, a circle, an ellipse, a quadrangle, and a hexagon, and a shape similar thereto. The maximum width of the first external connection electrode 19 and the second external connection electrode 20 in a plan view is preferably in the range of, for example, 10 μm to 300 μm, and more preferably in the range of 20 μm to 200 μm.
The thickness of the first external connection electrode 19 and the second external connection electrode 20 can be set to the extent normally used in the art. The thickness of the first external connection electrode 19 and the second external connection electrode 20 includes, for example, a thickness in the range of 10 μm to 100 μm. It is preferable that the upper surfaces of the first external connection electrode 19 and the second external connection electrode 20 are arranged at the same height from the surface of the second semiconductor layer 11p, for example.
The first external connection electrode 19 and the second external connection electrode 20 can be formed of gold, silver, copper, tin, platinum, zinc, nickel, aluminum or an alloy thereof in a single layer or laminated structure. The first external connection electrode 19 and the second external connection electrode 20 have at least the uppermost layer in order to prevent corrosion and improve the bondability with a wiring substrate using an Au alloy-based adhesive member such as Au—Sn eutectic solder. It is preferably formed with Au.
The first external connection electrode 19 and the second external connection electrode 20 can be formed by using these materials, for example, by a plating method, a sputtering method, or a method combining a vapor deposition method and a photoresist method.
For example, when the first external connection electrode 19 and the second external connection electrode 20 are formed by a plating method, a single layer or laminated structure of a metal such as Al, Ag, Al alloy and Ag alloy, Cu, Au, Ni is used. Can be done.
It is preferable that the first external connection electrode 19 and the second external connection electrode 20 are separated from the plurality of exposed portions 11b arranged on the semiconductor laminate 11 and arranged at a high density on the surface of the light emitting element. As a result, the current density supplied to the light emitting element 10 is dispersed, and uneven brightness is suppressed. Further, it is possible to increase the heat dissipation path for releasing the heat generated by the light emission of the light emitting element 10 to the wiring board 32 side via the first external connection electrode 19 and the second external connection electrode 20.

(1st partition wall 21, 41 and 2nd partition wall 22)
As shown in FIGS. 1A and 1D, the first partition wall 21 is arranged on the first electrode 18 and surrounds a plurality of first external connection electrodes 19 in a plan view. As described above, when the first external connection electrode 19 is arranged on both sides of the second external connection electrode 20 in a plan view, the first partition wall 21 is located on both sides of the second external connection electrode 20, respectively. Two first partition walls 21 can be included so as to surround the plurality of first external connection electrodes 19.
Further, as in the light emitting element 40 shown in FIG. 2, the first partition wall 41 may cover a part or all of the plurality of second external connection electrodes 20 as long as it surrounds the plurality of first external connection electrodes 19. It may be surrounded together with the external connection electrode 19.
The first partition walls 21 and 41 may be in contact with the first electrode 18, or may be, for example, provided with an insulating film on the first electrode 18 and arranged in a non-contact manner via the insulating film. In order to increase the conduction path between the first electrode 18 and the wiring board 32, the first partition walls 21 and 41 are preferably arranged in contact with the first electrode 18. The first partition walls 21 and 41 are preferably formed by the same process as the first external connection electrode 19 from the viewpoint of simplifying the manufacturing method. In this case, the first partition walls 21, 41 and the first external connection electrode 19 preferably contain the same material or are formed of the same material, and more preferably formed of the same metal material.
In a plan view, the first partition walls 21 and 41 are preferably arranged inside the outer edge 15a of the light reflecting electrode 15, as shown in FIGS. 1B, 1C, 1E and 2. In other words, it is preferable that all of the first partition walls 21 and 41 are arranged on the light reflecting electrode 15. Further, it is preferable that the bottom surfaces of the first partition walls 21 and 41 are arranged on the same light reflecting electrode 15 or the same first electrode 18 arranged on the same light reflecting electrode 15. In a plan view, the distance between the first partition walls 21, 41 (for example, the outer surfaces 21a, 41a of the first partition walls 21, 41) and the outer edge 15a ranges from several μm to several tens of μm, and ranges from 1 μm to 30 μm. Can be a range.

The second partition wall 22 is preferably arranged separately from the first partition wall 21 so as to surround the plurality of second external connection electrodes 20 as shown in FIG. 1D in a plan view. In this case, the second partition wall 22 can be arranged on the second electrode 16 as shown in FIGS. 1A, 1B and 1C. The second partition wall 22 may be in contact with the second electrode 16, or may be, for example, provided with an insulating film on the second electrode 16 and arranged in a non-contact manner via the insulating film. In order to increase the conduction path between the second electrode 16 and the wiring board 32, the second partition wall 22 is preferably arranged in contact with the second electrode 16. The second partition wall 22 is preferably formed by the same process as the second external connection electrode 20 from the viewpoint of simplifying the manufacturing method. In this case, the second partition wall 22 and the second external connection electrode 20 are preferably made of the same material or the same material, and more preferably made of the same metal material.
When the second partition wall 22 is arranged, as shown in FIGS. 1A, 1B, and 1E, it is preferable that the second partition wall 22 is arranged inside the outer edge 15a of the light reflecting electrode 15 in a plan view. .. In other words, it is preferable that the second partition wall 22 is entirely arranged on the light reflecting electrode 15. Further, it is preferable that the bottom surface of the second partition wall 22 is arranged on the same light-reflecting electrode 15 or the same second electrode 16 arranged on the light-reflecting electrode 15. In a plan view, the distance between the second partition wall 22 (for example, the outer surface 22a of the second partition wall 22) and the outer edge 15a is in the range of several μm to several tens of μm, and is preferably in the range of 1 μm to 50 μm. , 20 μm to 30 μm is more preferable.
The distance between the first partition walls 21 and 41 and the outer edge 15a may be the same as the distance between the second partition wall 22 and the outer edge 15a, but may be different. For example, the distance between the first partition walls 21 and 41 and the outer edge 15a is preferably smaller than the distance between the second partition wall 22 and the outer edge 15a.

The planar shape and size of the first partition wall 21, 41 and the second partition wall 22 can be appropriately adjusted depending on their materials and the like. Examples of the planar shape of the first partition wall 21, 41 and the second partition wall 22 include an annular shape. The widths of the first partition wall 21, 41 and the second partition wall 22 are preferably smaller than, for example, the widths of the first external connection electrode 19 and the second external connection electrode 20, respectively. By reducing the widths of the first partition wall 21, 41 and the second partition wall 22 in this way, bonding can be performed with a load smaller than that of the first external connection electrode 19 and the second external connection electrode 20 at the time of mounting. Therefore, at the time of mounting, the first partition wall 21, 41 and the second partition wall 22 can suppress the hindrance of joining by the first external connection electrode 19 and the second external connection electrode 20, and the mountability can be ensured. The first partition wall 21 and the second partition wall 22 may have the same width in all parts or may have different widths in some parts. Specifically, in a plan view, the widths of the first partition wall 21 and the second partition wall 22 are in the range of 5 μm to 50 μm.
The thickness of the first partition wall 21, 41 and the second partition wall 22 includes, for example, a thickness in the range of 10 μm to 100 μm, and is preferably in the range of 10 μm to 30 μm. The thicknesses of the first partition wall 21, 41 and the second partition wall 22 may be the same as or different from those of the first external connection electrode 19 and the second external connection electrode 20, respectively. Above all, the thickness of the first partition walls 21 and 41 is preferably smaller than the thickness of the first external connection electrode 19. In this case, the thickness of the first partition walls 21 and 41 may be smaller in the range of 5% to 20% than the thickness of the first external connection electrode 19. Further, the thickness of the second partition wall 22 is preferably smaller than the thickness of the second external connection electrode 20. In this case, the thickness of the second partition wall 22 may be smaller in the range of 5% to 20% than the thickness of the second external connection electrode 20. It is preferable that the upper surfaces of the first partition walls 21, 41 and the second partition wall 22 are arranged at the same height from the surface of the second semiconductor layer 11p. The upper surfaces of the first partition wall 21 and the second partition wall 22 may be arranged at the same height as the upper surfaces of the first external connection electrode 19 and the second external connection electrode 20, respectively, from the surface of the second semiconductor layer 11p. , May be arranged at different heights. Among them, the upper surfaces of the first partition wall 21, 41 and the second partition wall 22 are lower than the upper surfaces of the first external connection electrode 19 and the second external connection electrode 20, respectively, from the surface of the second semiconductor layer 11p. That is, it is preferable that the second semiconductor layer is arranged on the 11p side. As a result, when the light emitting element is mounted on the wiring board, the first external connection electrode 19 and the second external connection electrode 20 come into contact with the wiring board before the first partition wall 21, 41 and / or the second partition wall 22. Therefore, the mountability of the light emitting element can be ensured. The thickness of the first external connection electrode 19 and the second external connection electrode 20 is reduced by being joined to the wiring board by crimping or the like. Then, the first partition wall 21, 41 and the second partition wall 22 formed to be smaller in thickness than the first external connection electrode 19 and the second external connection electrode 20 come into contact with the wiring board, or the first partition wall 21, 41 and the second partition wall are formed. The gap between 22 and the wiring board becomes smaller. Therefore, the first partition wall 21, 41 and the second partition wall 22 can function as members for damming the resin while ensuring the mountability of the light emitting element.
In particular, it is preferable that the first partition wall 21, 41 and the second partition wall 22 are formed by the same process containing or using the same material as the first external connection electrode 19 and the second external connection electrode 20.

[Light emitting device 30]
As shown in FIGS. 3A and 3B, the light emitting device 30 of the present embodiment includes a wiring board 32 having a wiring pattern 31 on the upper surface, a plurality of first external connection electrodes 19 and a plurality of second externals on the wiring pattern 31. It includes a light emitting element 10 connected by using the connection electrode 20, a covering member 33 that covers the light emitting element 10 and the outer surface 21a of the first partition wall 21.
With such a configuration, the first partition wall 21 in the light emitting element does not allow the covering member 33 to enter between the light emitting element and the wiring board 32, and the covering member 33 can be dammed outside the first partition wall 21. it can. Therefore, it is possible to effectively prevent the covering member 33 that has entered between the light emitting element and the wiring board 32 from floating or peeling off from the wiring board 32 of the light emitting element due to expansion due to the heat of the light emitting element.
Further, the light leakage from the light emitting element generated in the vicinity of the outer periphery of the light emitting element can be effectively suppressed by the covering member 33 arranged on the outside of the first partition wall 21. Further, the first partition wall 21 is arranged inside the outer edge 15a of the light-reflecting electrode 15 provided in the light-emitting element, and the light from the light-emitting element is transmitted to the light-reflecting electrode in the region where the covering member 33 does not enter. It has a structure that is reflected by 15. As a result, light leakage of the light emitting element can be reduced, and reliability can be improved while maintaining light extraction efficiency.

(Wiring board 32)
The wiring board 32 has a wiring pattern 31 on the upper surface.
Examples of the material of the wiring board 32 include an insulating member such as resin and ceramics, a metal member having an insulating member formed on the surface, and the like. Among them, the material of the substrate is preferably one using ceramics having high heat resistance and weather resistance. Examples of the ceramic material include alumina and aluminum nitride.
The wiring pattern 31 may be any as long as it can supply an electric current to the light emitting element, and is formed of a material, thickness, shape, or the like usually used in the art. Specifically, the wiring pattern 31 can be formed of, for example, a metal such as copper, aluminum, gold, silver, platinum, titanium, tungsten, palladium, iron, nickel, or an alloy containing these. In particular, a part of the outermost surface of the wiring pattern 31 arranged on the upper surface of the wiring board 32 may be covered with a material having high reflectance such as silver in order to efficiently take out the light from the light emitting element 10. preferable. The wiring pattern 31 is formed by electrolytic plating, electroless plating, thin film deposition, sputtering, or the like.
The first external connection electrode 19 and the second external connection electrode 20 in the light emitting element 10 and the wiring pattern 31 can be joined by, for example, an ultrasonic joining method. In addition, as joining members, bumps such as gold, silver and copper, metal powders such as silver, gold, copper, platinum, aluminum and palladium and metal pastes containing resin binders, tin-bismuth-based, tin-copper-based, tin- A silver-based solder, a gold-tin-based solder, a brazing material such as a low-melting metal may be used. For example, when the first external connection electrode 19 and the second external connection electrode 20 containing Au on the outermost surface are used for mounting the light emitting element on the wiring board 32, if Au is used on the outermost surface of the wiring pattern 31, the light emitting element and the light emitting element Bondability with the substrate can be improved.
The wiring pattern 31 preferably has a pair of positive and negative patterns on the upper surface of the wiring board 32. With such a wiring pattern 31, the first electrode 18 and the second electrode 16 in the light emitting element 10 can be connected via the first external connection electrode 19 and the second external connection electrode 20, respectively.

(Coating member 33)
The covering member 33 covers the light emitting element 10 and the outer surface 21a of the first partition wall 21. That is, the covering member 33 does not cover at least the first external connection electrode 19 between the light emitting element 10 and the wiring board 32 and / or the wiring pattern 31.
Further, as shown in FIG. 1C, when the second partition wall 22 surrounding the plurality of second external connection electrodes 20 is provided separately from the first partition wall 21, the light emitting element 10 and the first partition wall 21 It covers the outer side surface 21a and the outer surface 22a of the second partition wall 22. That is, the covering member 33 does not cover the first external connection electrode 19 and the second external connection electrode 20 between the light emitting element 10 and the wiring board 32 and / or the wiring pattern 31.
As a result, between the light emitting element 10 and the wiring board 32 and / or the wiring pattern 31, the covering member 33 does not exist, or even if it exists, it can cover an extremely small amount or a small area. Therefore, it is possible to reduce the stress load on the light emitting element 10 due to the thermal expansion of the covering member 33 due to the heat of the light emitting element 10. As a result, peeling of the light emitting element 10 from the wiring board 32 can be effectively suppressed.
As shown in FIG. 3B and the like, the covering member 33 preferably covers the outside of the first partition wall 21 of the light emitting element 10 and / or the outside of the second partition wall 22 and the side surface of the light emitting element 10. As will be described later, the side surface of the light emitting element may be partially covered with a translucent material such as an adhesive (35 in FIG. 3B). In this case, the side surface of the light emitting element is transparent. It is preferable to coat the surface of the light material.

As the covering member 33, a resin having light reflectivity, translucency, light shielding property and the like can be used. Specifically, as the covering member 33, a resin containing a light-reflecting substance in the resin can be used. As the resin, the light-reflecting substance, and the like constituting the covering member 33, any of those usually used in the art can be used.
For example, examples of the resin include a silicone resin, a modified silicone resin, an epoxy resin, a modified epoxy resin, a resin containing one or more of acrylic resins, a hybrid resin, and the like. Examples of the light-reflecting substance include titanium oxide, silicon oxide, zirconium oxide, potassium titanate, alumina, aluminum nitride, boron nitride, and mullite.
The coating member 33 preferably contains, for example, 20 wt% or more of a light-reflecting substance in the resin. The covering member 33 can be molded by, for example, injection molding, potting molding, resin printing method, transfer molding method, compression molding, or the like.

(Translucent member 34)
The light emitting device 30 preferably has a light transmitting member 34 on the light emitting element 10. For example, when the light emitting element 10 is flip-chip mounted on the wiring pattern 31 with the surface having the first electrode 18 and the second electrode 16 as the lower surface, the light emitting element 10 has the upper surface opposite to the lower surface as the main light extraction surface. As a result, the upper surface and the lower surface of the translucent member 34 are joined.
The light transmitting member 34 is a member that covers the upper surface of the light emitting element 10 and can transmit 50% or more or 60% or more, preferably 70% or more of the light emitted from the light emitting element 10 to the outside. Is. The light-transmitting member 34 can contain a light-reflecting substance and a phosphor capable of wavelength-converting at least a part of the light emitted from the light emitting element 10.
The lower surface of the light transmitting member 34 preferably has an area of about 80 to 150% of the area of the upper surface of the light emitting element 10. It is preferable that the outer edge of the lower surface of the light transmitting member 34 coincides with the outer edge of the upper surface of the light emitting element, or is located only inside or outside the outer edge of the upper surface. The thickness of the light transmitting member 34 may be, for example, in the range of 50 μm to 300 μm.

The translucent member 34 can be formed of, for example, resin, glass, or the like. Further, as the translucent member 34 containing a fluorescent substance, for example, a sintered body of the fluorescent substance, a resin or glass containing the fluorescent substance, and the like can be mentioned.

As the phosphor contained in the translucent member 34, for example, when a light emitting element that emits blue light or a light emitting element that emits ultraviolet light is used as the light emitting element 10, yttrium aluminum garnet-based fluorescence activated by cerium is used. Body (YAG: Ce), cerium-activated yttrium aluminum garnet-based phosphor (LAG: Ce), europium and / or chromium-activated nitrogen-containing calcium aluminum silicate-based phosphor (CaO-Al ₂ O ₃₎ −SiO ₂ : Eu), silicate-based phosphor activated with europium (for example, (Sr, Ba) 2SiO ₄ : Eu), β-sialon-based phosphor (for example, Si _6-z Al _z O _z N _8-z : Eu) (0 <Z <4.2)), nitride-based phosphors such as CASN-based phosphors and SCASN-based phosphors, KSF-based phosphors (K ₂ SiF ₆ : Mn), sulfide-based phosphors, quantum dot fluorescence The body etc. can be mentioned. By combining these phosphors with a light emitting element that emits blue light or a light emitting element that emits ultraviolet light, a light emitting device having a desired light emitting color (for example, a white light emitting device) can be obtained. When such a phosphor is contained in the translucent member 34, the concentration of the phosphor is preferably set to, for example, about 5 to 50%.

When the translucent member 34 is arranged so as to cover the upper surface of the light emitting element 10, it can be joined via the adhesive 35. As the adhesive, a well-known translucent resin such as epoxy or silicone can be used. In this case, the adhesive 35 may cover not only between the lower surface of the light transmitting member 34 and the light emitting element 10 but also the side surface of the light emitting element 10. Further, for the bonding between the translucent member 34 and the light emitting element 10, a bonding method by crimping or sintering, or a direct bonding method by surface activation bonding, atomic diffusion bonding or hydroxyl group bonding may be used.
The light emitting device 30 may optionally have another element such as a protective element 36, an electronic component, or the like. For example, as shown in FIG. 3B, the protective element 36 is preferably embedded in the covering member 33 and / or the second covering member 37 described later.

(Second covering member 37)
When the light emitting device 30 has the translucent member 34, it is preferable that the light emitting device 30 further includes a second covering member 37 that covers a part or all of the side surface of the translucent member 34. The upper surface of the second covering member 37 is preferably arranged flush with or substantially flush with the upper surface of the translucent member 34, for example. Further, the second covering member 37 can form a part of the outer shape of the light emitting device 30.
The second covering member 37 can be formed by using the same material as the covering member 33.

[Light emitting device 50]
As shown in FIG. 2, the light emitting device 50 uses a light emitting element 40 provided with a first partition wall 41 that surrounds not only the plurality of first external connection electrodes 19 but also the plurality of second external connection electrodes 20. As shown in FIG. 4, a wiring board 52 having a wiring pattern 51 on the upper surface is used, and a light emitting element 40 is mounted on the wiring pattern 51 by a plurality of first external connection electrodes 19 and a plurality of second external connection electrodes 20. To do.
In the wiring board 52 used here, the wiring pattern 51 is not arranged in the portion of the light emitting element 40 facing the first partition wall 41, or even if the wiring pattern 51 is arranged, a part thereof is embedded in the wiring board 52. By using such a wiring board 52, even when the first partition wall 41 is connected to the first electrode 18 or the second electrode 16 of the light emitting element 40, the continuity between the first partition wall 41 and the wiring pattern 51 can be achieved. Since it is prevented, a short circuit can be prevented.
Other configurations are substantially the same as those of the light emitting device 30.
Even when such a wiring board 52 is used, the first external connection electrode 19 and the second external connection electrode 20 are attached to the covering member 33 between the light emitting element 40 and the wiring board 52 and / or the wiring pattern 51. Not covered. That is, the covering member 33 covers the outer surface 41a of the first partition wall 41 and is arranged outside the first partition wall 41, thereby exerting an effect of suppressing light leakage that occurs in the vicinity of the outer periphery of the light emitting element.

[Light emitting device 60]
In the light emitting device 60, the light emitting element 40 shown in FIG. 2 is used in the same manner as the light emitting device 50 described above. As shown in FIG. 5, a wiring board 62 having a wiring pattern 61 on the upper surface is used, and a light emitting element 40 is mounted on the wiring pattern 61 by a plurality of first external connection electrodes 19 and a plurality of second external connection electrodes 20. To do.
In the wiring board 62 used here, the coating layer 63 is arranged on the wiring pattern 61 on which the first partition wall 41 of the light emitting element 40 faces. The coating layer 63 is made of an insulating material. By using such a wiring board 62, even when the first partition wall 41 is connected to the electrode of the light emitting element, the conduction between the first partition wall 41 and the wiring pattern 61 is prevented, so that a short circuit is prevented. be able to.
Other configurations are substantially the same as those of the light emitting device 30.
Even when such a wiring board 62 is used, the first external connection electrode 19 and the second external connection electrode 20 are attached to the covering member 33 between the light emitting element 40 and the wiring board 62 and / or the wiring pattern 61. Not covered. That is, the covering member 33 covers the outer surface 41a of the first partition wall 41 and is arranged outside the first partition wall 41, thereby exerting an effect of suppressing light leakage that occurs in the vicinity of the outer periphery of the light emitting element.

The light emitting element of the present invention can be used for various light sources such as lighting light sources, various indicator light sources, in-vehicle light sources, display light sources, liquid crystal backlight light sources, sensor light sources, traffic lights, in-vehicle parts, and signage channel letters. Can be used.

10 Light emitting element 11 Semiconductor laminate 11a Light emitting layer 11b Exposed part 11n First semiconductor layer 11p Second semiconductor layer 11c Outer edge 12 Insulating film 12a Opening 13 Substrate 15 Light reflective electrode 15a Outer edge 16 Second electrode 17 Protective layer 18 First Electrode 19 1st external connection electrode 20 2nd external connection electrode 21, 41 1st partition 21a, 41a Outer side surface 22 2nd partition 22a Outer side surface 30, 50, 60 Light emitting device 31, 51, 61 Wiring pattern 32, 52, 62 Wiring board 33 Coating member 34 Translucent member 35 Adhesive material 36 Protective element 63 Coating layer

Claims (13)

A semiconductor laminate having a first semiconductor layer, a light emitting layer, and a second semiconductor layer in this order, in which the first semiconductor layer is exposed from the second semiconductor layer on the upper surface side of the second semiconductor layer. A semiconductor laminate having a plurality of exposed parts and
A light-reflecting electrode provided on the second semiconductor layer and connected to the second semiconductor layer,
A second electrode provided on the light-reflecting electrode and
An insulating film that covers the semiconductor laminate and the light-reflecting electrode and has an opening above the plurality of exposed portions.
A first electrode connected to the first semiconductor layer at the opening and partially arranged on the second semiconductor layer via the insulating film.
A plurality of first external connection electrodes arranged on the first electrode,
A plurality of second external connection electrodes arranged on the second electrode,
A first partition wall arranged on the first electrode and surrounding the plurality of first external connection electrodes in a plan view is provided.
The outer edge of the light-reflecting electrode is arranged inside the outer edge of the second semiconductor layer in a plan view.
The first partition wall is a light emitting element arranged inside the outer edge of the light reflecting electrode in a plan view. Further, a second partition wall surrounding the plurality of second external connection electrodes is arranged.
The light emitting element according to claim 1, wherein the outer edge of the second partition wall is arranged inside the outer edge of the light reflecting electrode in a plan view. The light emitting element according to claim 1, wherein the first partition wall surrounds the plurality of first external connection electrodes and the plurality of second external connection electrodes. In a plan view, the first external connection electrode is arranged on both sides of the second external connection electrode.
The light emitting element according to claim 1 or 2, wherein the first partition wall includes two first partition walls that surround the plurality of first external connection electrodes on both sides of the second external connection electrode. The light emitting element according to any one of claims 1 to 4, wherein the first external connection electrode is arranged apart from the exposed portion in a plan view. The light emitting element according to any one of claims 1 to 5, wherein the first electrode integrally covers the plurality of exposed portions. The light emitting element according to any one of claims 1 to 6, wherein the second electrode is connected to the second semiconductor layer via the light reflecting electrode. The light emitting element according to any one of claims 1 to 7, wherein the thickness of the first partition wall is smaller than the thickness of the first external connection electrode. The light emitting element according to any one of claims 1 to 8, wherein the width of the first partition wall is smaller than the width of the first external connection electrode. The light emitting element according to any one of claims 1 to 9, wherein the first external connection electrode and the first partition wall are made of the same metal material. A wiring board with a wiring pattern on the top surface,
The light emitting element according to any one of claims 1 to 10, which is mounted on the wiring pattern by the plurality of first external connection electrodes and the plurality of second external connection electrodes.
A light emitting device including the light emitting element and a covering member that covers the outer surface of the first partition wall. The second partition wall surrounding the plurality of second external connection electrodes,
In plan view, both sides of the second bulkhead include two first bulkheads surrounding the plurality of first external connection electrodes, respectively.
The light emitting device according to claim 11, wherein the covering member covers the outer surface of the first partition wall and the outer surface of the second partition wall. The light emitting device according to claim 11 or 12, wherein the covering member contains a light-reflecting substance.

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