Semiconductor light-emitting element and light-emitting device

Abstract

The invention provides a semiconductor light-emitting element and a light-emitting device, which can be thinned, have high reliability and improve light output. A semiconductor light-emitting element is provided with: a flat translucent element substrate having two main surfaces facing each other; a light-emitting semiconductor layer formed on one main surface of the element substrate and formed by laminating an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer; an n electrode connected to the n-type semiconductor layer via at least one hole portion reaching the n-type semiconductor layer, and provided on the p-type semiconductor layer so as to be electrically separated from the p-type semiconductor layer by an insulating film; a first element electrode electrically connected to the n electrode and extending in a first direction; and a second element electrode electrically connected to the p-type semiconductor layer, spaced apart from the first element electrode and extending in the first direction, the element substrate having a thickness of 100 [mu] m or less.

Description

Technical Field

[0001] The present invention relates to a light emitting element and a light emitting device, and in particular to a semiconductor light emitting element such as a light emitting diode (LED) and a light emitting device equipped with the semiconductor light emitting element. Background Art

[0002] Light emitting devices equipped with semiconductor light emitting elements are used in various lighting and display devices, etc. In recent years, in particular, light emitting devices equipped with semiconductor light emitting elements are required to be thinner in order to achieve further space saving.

[0003] For example, Patent Document 1 discloses a light-emitting device comprising: a mounting substrate having a base material and a wiring layer for external connection; and a light-emitting element arranged on the upper surface of the mounting substrate and having two electrodes of a first conductivity type (negative) and a second conductivity type (positive).

[0004] [Prior art literature]

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2010-219324 Summary of the invention

[0007] Problems to be solved by the invention

[0008] However, in the following light-emitting device, for example, there is a reliability problem such as stress concentration between two electrodes, which may cause damage or degradation of the semiconductor light-emitting element. The light-emitting device comprises: a mounting substrate having a base material and a wiring layer for external connection; and a light-emitting element, which is arranged on the upper surface of the mounting substrate and has two electrodes of a first conductive type (negative) and a second conductive type (positive).

[0009] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a semiconductor light emitting element which can be reduced in thickness and has improved luminous flux when formed into a light emitting device, or a light emitting device which has high reliability and improved luminous flux.

[0010] Means for solving problems

[0011] A semiconductor light emitting device according to one embodiment of the present invention includes:

[0012] A flat-plate-shaped light-transmitting element substrate having two main surfaces facing each other;

[0013] A light-emitting semiconductor layer, which is formed on one main surface of the element substrate and is composed of a stack of an n-type semiconductor layer, a light-emitting layer and a p-type semiconductor layer;

[0014] an n-electrode connected to the n-type semiconductor layer via at least one hole reaching the n-type semiconductor layer and provided on the p-type semiconductor layer so as to be electrically separated from the p-type semiconductor layer by an insulating film;

[0015] a first element electrode electrically connected to the n-electrode and extending along a first direction; and

[0016] a second element electrode electrically connected to the p-type semiconductor layer, spaced apart from the first element electrode and extending along the first direction;

[0017] The element substrate has a thickness of 100 μm or less. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1A It is a plan view showing the upper surface of the semiconductor light emitting element of the present invention.

[0019] Figure 1B It is along Figure 1A A cross-sectional view of the semiconductor light emitting element taken along line AA is shown.

[0020] Figure 1C It is along Figure 1A A cross-sectional view of the semiconductor light emitting element taken along line BB is shown.

[0021] Figure 1D It is along Figure 1A A cross-sectional view of the semiconductor light emitting element taken along line CC is shown.

[0022] Figure 1E It is a plan view showing the lower surface of the semiconductor light emitting element of the present invention.

[0023] Figure 2A It is a plan view showing the upper surface of the light emitting device of the present invention.

[0024] Figure 2B It is along Figure 2A A cross-sectional view of the light emitting device taken along line DD is shown.

[0025] Figure 2C It is a plan view showing the lower surface of the light emitting device of the present invention.

[0026] Figure 2D It is a plan view showing the upper surface of the light emitting device of the present invention, and is a view showing a state through a cover member.

[0027] Figure 3 It is a plan view showing the upper surface of the device substrate of the present invention.

[0028] Figure 4 1 is a flowchart showing a method for manufacturing a light emitting device according to the present invention.

[0029] Figure 5A 1 is a plan view showing the upper surface of the light emitting device of the present invention in step S1 of manufacturing the light emitting device.

[0030] Figure 5B 1 is a plan view showing the upper surface of the light emitting device of the present invention in step S2 of manufacturing the light emitting device.

[0031] Figure 5C It is a plan view showing the upper surface of the light emitting device of the present invention in the manufacturing step S3.

[0032] Figure 5D It is a plan view showing the upper surface of the light emitting device of the present invention in the manufacturing step S4.

[0033] Figure 5E It is a plan view showing the upper surface of the light emitting device of the present invention in the manufacturing step S5.

[0034] Fig. 6A It is a plan view showing the upper surface of the light emitting device according to Embodiment 3, and is a view showing a state through a cover member.

[0035] Figure 6B 1 is a diagram showing a wiring pattern of a circuit board 60 on which a light emitting device according to a third embodiment is mounted.

[0036] Figure 6C This is a diagram showing a modified example of the wiring pattern of the circuit board 60 on which the light emitting device according to the third embodiment is mounted.

[0037] Figure 7 This is a plan view showing the upper surface of the device substrate of the light-emitting device according to Embodiment 3.

[0038] Explanation of symbols

[0039] 10: semiconductor light emitting element; 11: element substrate; 12: light emitting semiconductor layer; 13: n-type semiconductor layer; 14: light emitting layer; 15: p-type semiconductor layer; 16: n-electrode; 17: p-electrode; 18: insulating film; 19: first element electrode; 20: second element electrode; 30: light emitting device; 31: device substrate; 32: base; 33: first wiring electrode; 34: second wiring electrode; 35: first via hole; 36: second via hole; 37: first mounting electrode; 38: second mounting electrode; 39: protective element; 40: wire; 41: joining part; 42: adhesive part; 43: phosphor plate; 44: covering part; 45: frame; 46: cutting blade; 47: mounting electrode spacing band; 48: wiring electrode spacing band; 50: light emitting device; 60: circuit substrate. DETAILED DESCRIPTION

[0040] The preferred embodiments of the present invention are described below, but they can also be appropriately changed and combined. In addition, in the following description and drawings, substantially the same or equivalent parts are marked with the same reference numerals for description. In addition, the semiconductor light emitting element is first described, followed by the light emitting device.

[0041] [Implementation Method 1]

[0042] Embodiment 1 is a semiconductor light emitting element 10 used for a light emitting device 30 shown in FIG. 2 . Figure 1A 1 is a plan view showing the upper surface of the semiconductor light emitting element 10 of the present invention. Figure 1B It is along Figure 1A The cross-sectional view of the semiconductor light emitting element 10 taken along line AA is shown. Figure 1C It is along Figure 1A The cross-sectional view of the semiconductor light emitting element 10 taken along line BB shown in FIG. Figure 1D It is along Figure 1A The cross-sectional view of the semiconductor light emitting element 10 is shown along line CC. Figure 1E 1 is a plan view showing the lower surface of the semiconductor light emitting element 10 of the present invention.

[0043] In addition, Figure 1A In the figure, in order to clarify the arrangement relationship of the hole portions 12A included in the light emitting semiconductor layer 12 described later, the hole portions 12A are indicated by dotted lines.

[0044] In the description of the semiconductor light emitting element 10 , the direction in which the light emitting semiconductor layer 12 is provided with respect to the element substrate 11 is referred to as an upper direction, and the opposite direction is referred to as a lower direction.

[0045] like Figures 1A to 1E As shown, the semiconductor light emitting element 10 has a rectangular flat plate-shaped element substrate 11, and the element substrate 11 has two parallel main surfaces, and a light emitting semiconductor layer 12 stacked with semiconductor crystals is provided on the upper surface thereof. In addition, two electrodes, an n-electrode 16 and a p-electrode 17, which are partially insulated by an insulating film 18, are arranged on the upper surface of the light emitting semiconductor layer 12, and two electrodes are arranged in parallel on the upper surface of the two electrodes in a manner that substantially covers the upper surface of the semiconductor light emitting element 10 in one direction ( Figure 1A The first and second rectangular element electrodes 19 and 20 are substantially the same in size and extend in the left-right direction of the semiconductor substrate 11. That is, the main light emitting surface of the semiconductor light emitting element 10 of this embodiment is the lower surface 11B side of the element substrate 11.

[0046] (Component Substrate)

[0047] like Figure 1BAs shown in FIG. 1 , the element substrate 11 is a rectangular flat plate having an upper surface 11A as a first main surface and a lower surface (back surface) 11B as a second main surface that are parallel to each other. In addition, the element substrate 11 has light transmittance that allows light emitted from the light emitting semiconductor layer 12 to pass through. In addition, the element substrate 11 has a function as a main body (support body) of the semiconductor light emitting element 10.

[0048] As the element substrate 11, sapphire (A1 2 O 3 ) single crystal. The bending strength of sapphire single crystal is 690MPa, and it has high strength even when the element substrate 11 is thinned. In the present embodiment, the thickness of the entire semiconductor light emitting element 10 is reduced by thinning the thickness Tsub of the element substrate 11 to 100μm. However, if it is thinned too much, the function as the main body will be impaired, so the range of 40μm to 100μm is preferred. For example, when it is less than 40μm, the occurrence of abnormalities such as failure to light up during the manufacture or use of the semiconductor light emitting element 10 and the light emitting device 30 will increase. In addition, when it exceeds 100μm, although the strength of the main body can be improved, the light emitting device 30 cannot be thinned. In addition, as the element substrate 11, aluminum nitride (AlN) single crystal or silicon nitride (SiC) single crystal, gallium nitride (GaN) single crystal, etc. can also be used.

[0049] A rough surface layer for improving light extraction efficiency and an anti-reflection coating (AR coating) may be provided on the lower surface 11B of the element substrate 11 .

[0050] (Light-emitting semiconductor layer)

[0051] like Figure 1B As shown, the light-emitting semiconductor layer 12 is a stacked structure of semiconductor crystals with a total thickness Tepi of 3 μm to 5 μm, which is formed by sequentially stacking an n-type semiconductor layer 13 whose main conductive type is an n-type semiconductor layer, a light-emitting layer 14 including a quantum well layer structure, and a p-type semiconductor layer 15 whose main conductive type is a p-type semiconductor layer. In addition, the light-emitting semiconductor layer 12 is a crystal growth layer grown using the element substrate 11 as a growth substrate, and is supported by the element substrate 11 as an integral whole.

[0052] The n-type semiconductor layer 13 of the light emitting semiconductor layer 12 is of the same size as the element substrate 11 when viewed from above. In addition, the light emitting layer 14 and the p-type semiconductor layer 15 are slightly smaller than the n-type semiconductor layer 13. That is, the exposed portion of the n-type semiconductor layer 13 surrounds the light emitting layer 14 and the p-type semiconductor layer 15 in a frame shape over the entire circumference.

[0053] In addition, if Figure 1AAs shown, the light emitting semiconductor layer 12 has three holes 12A extending from the upper surface of the p-type semiconductor layer 15 to the n-type semiconductor layer 13. The three holes 12A are arranged in a straight line at equal intervals, and the central hole is arranged at the center X1 of the light emitting semiconductor layer 12. In addition, the three holes 12A are arranged in parallel with a set of parallel sides of the element substrate 11.

[0054] In the present embodiment, the number of the holes 12A is three, but the number may be one, two, or four or more. In addition, the holes 12A may be arranged in parallel in two rows.

[0055] The light-emitting semiconductor layer 12 is composed of a semiconductor of a gallium nitride (GaN) compound and emits blue light. In addition, in the p-type semiconductor layer 15 or the n-type semiconductor layer 13, in addition to the layer doped with impurities representing the main conductivity type, it can also include an undoped layer, an SLS (Strained-Layer Superlattice) layer, an EBL (electron blocking layer), a contact layer and other layers.

[0056] (n-electrode)

[0057] like Figure 1B As shown, the n-electrode 16 is provided on the upper surface of the left first p-electrode 17A separated by the linearly arranged holes 12A via the first insulating film 18A. In addition, a part of the n-electrode 16 is electrically connected to the n-type semiconductor layer 13 through the holes 12A whose walls are insulated by the first insulating film 18A.

[0058] The n-electrode 16 is formed by sequentially stacking titanium (Ti) and gold (Au). Hereinafter, the sequentially stacked layers are described as Ti / Au. As the n-electrode 16, Ti / aluminum (Al), Ti / Al / platinum (Pt) / Au, Ti / Pt / Au, Ti / rhodium (Rh) / Au, etc. can also be used.

[0059] (P electrode)

[0060] like Figure 1B As shown, the p-electrode 17 is composed of a first p-electrode 17A and a second p-electrode 17B. The first p-electrode 17A is provided on substantially the entire surface of the p-type semiconductor layer 15. The second p-electrode 17B is provided on the upper surface of the first p-electrode 17A on the right side separated by the holes 12A arranged in a straight line.

[0061] The first p-electrode 17A is formed by laminating nickel (Ni) / Au. ITO (Indium Tin Oxide), Ni / Pt / Au, Ni / palladium (Pd) / Au, Ni / silver (Ag) / Pt / Au, Ni / Pt / Al / Pt / Au, etc. may be used as the first p-electrode 17A.

[0062] The second P electrode 17B is formed by stacking Ti / Au. As the second P electrode 17B, similarly to the n-electrode 16, Ti / Al, Ti / Al / Pt / Au, Ti / Pt / Au, Ti / Rh / Au, or the like may be used.

[0063] (Insulating film)

[0064] like Figure 1B As shown, the insulating film 18 is composed of a first insulating film 18A and a second insulating film 18B.

[0065] First insulating film 18A covers and insulates n-type semiconductor layer 13, light emitting layer 14, and p-type semiconductor layer 15. In addition, first insulating film 18A covers and insulates a portion of the side surface and lower surface of first p electrode 17A in contact with p-type semiconductor layer 15.

[0066] The second insulating film 18B covers the first insulating film 18A and the n-electrode 16 and the second P-electrode 17B except for a part thereof for protection and insulation.

[0067] As the insulating film 18, silicon dioxide (SiO 2 ). In addition, titanium dioxide (TiO 2 ), hafnium oxide (HfO 2 ), aluminum oxide (Al 2 O 3 ) and other insulating metal oxides.

[0068] (Component Electrode)

[0069] like Figure 1A and Figure 1B As shown, the first element electrode 19 and the second element electrode 20 (hereinafter, referred to as element electrodes when the two are not distinguished) are arranged on the upper surface of the semiconductor light emitting element 10. The element electrodes 19, 20 are rectangles of approximately the same size with a pair of parallel long sides and another pair of parallel short sides, and are separated and arranged in parallel by three hole portions 12A arranged in a straight line. In addition, the element electrodes are separated from the outer periphery of the semiconductor light emitting element 10 and arranged on the inner side. The two element electrodes 19, 20 are bonding electrodes for electrically connecting the external wiring to the semiconductor light emitting element 10. Such a semiconductor light emitting element 10 is a flip chip connection type light emitting element that does not require wire connection.

[0070] The first element electrode 19 (cathode) is connected to the n-type semiconductor layer 13 via the n-electrode 16, and the second element electrode 20 (anode) is connected to the p-type semiconductor layer 15 via the p-electrode 17. Therefore, by applying voltage to the first element electrode 19 and the second element electrode 20, the light-emitting semiconductor layer 12 can be energized, and the semiconductor light-emitting element 10 can emit light.

[0071] As the element electrode, Ni / Au is used. As the element electrode, a metal having good conductivity such as Ti / Au or Ti / Ni / Au may also be used.

[0072] [Comparison method 1]

[0073] Next, Comparative Example 1 will be described. Comparative Example 1 is a semiconductor light emitting element in which the thickness Tsub of the element substrate 11 of Embodiment 1 is increased from 100 μm to 200 μm. Except for the thickness of the element substrate, the semiconductor light emitting element 10 of Embodiment 1 is the same as that of the semiconductor light emitting element 10 of Embodiment 1.

[0074] (Comparison of light output)

[0075] The semiconductor light emitting element 10 of Embodiment 1 and the semiconductor light emitting element of Comparative Embodiment 1 were bonded to a circuit board via a gold-tin bonding member, and each semiconductor light emitting element was energized to compare light outputs. As a result, when the light output of Comparative Embodiment 1 was set to 100%, the light output of Embodiment 1 was 98%. That is, the light output of the semiconductor light emitting element 10 of Embodiment 1 was 2% lower than the light output of the semiconductor light emitting element of Comparative Embodiment 1.

[0076] The reduction in light output is due to the reduction in the area of ​​the light emitting surface caused by thinning the element substrate 11. Therefore, as the element substrate 11 is thinned to 70 μm and 40 μm, the light output further decreases. In addition, the mechanical strength of the semiconductor light emitting element 10 is also reduced at the same time.

[0077] As described above, the semiconductor light emitting element 10 according to the first embodiment can be reduced in thickness while reducing light output and mechanical strength in the single-body stage.

[0078] (Method for manufacturing semiconductor light emitting element)

[0079] Next, a method for manufacturing the semiconductor light emitting element 10 according to the first embodiment will be described.

[0080] First, an element substrate with a light-emitting semiconductor layer 12 is prepared as the element substrate 11. The light-emitting semiconductor layer 12 is formed by epitaxially growing a gallium nitride-based n-type semiconductor layer 13, a light-emitting layer 14 and a p-type semiconductor layer 15 on a single surface of a sapphire single crystal substrate (SD1).

[0081] A resist mask is formed on the portion of the element substrate 11 with the light-emitting semiconductor layer 12 that will become the light-emitting region, and etching is performed by RIE (Reactive Ion Etching) until the n-type semiconductor layer 13 is exposed outside the resist mask. Then, the resist mask is removed to form a light-emitting region (SD2) having a hole 12A.

[0082] A resist mask is formed on the upper surface of the p-type semiconductor layer 15 in the light emitting region to expose a portion to be the first p-electrode 17A, and Ni and Au are sequentially deposited as the first p-electrode 17A using an EB (electron beam) deposition device. The resist mask is then removed to form the first p-electrode 17A (SD3).

[0083] By using a sputtering device, SiO is formed on the entire surface of the element substrate on which the first p-electrode 17A is formed. 2 Next, a resist mask is formed on the bottom of the hole 12A and the portion other than the second P electrode 17B, and the insulating film on the bottom of the hole 12A and the second P electrode 17B forming portion is removed by etching with a hydrofluoric acid buffer solution to form a first insulating film 18A (SD4).

[0084] A resist mask is formed except for the portion to be the n-electrode 16 and the second P-electrode 17B, and Ti and Au are sequentially deposited by an EB deposition apparatus to form the n-electrode 16 and the second P-electrode 17B. Then, the resist mask is removed to form the n-electrode 16 and the second P-electrode 17B (SD5).

[0085] A SiO layer is formed on the entire surface of the element substrate on which the n-electrode 16 and the second P-electrode 17B are formed by a sputtering device. 2 Next, a resist mask is formed on the portion other than the first element electrode 19 and the second element electrode 20, and the insulating film of the portion where the n-electrode 16 and the second P-electrode 17B are formed is removed by etching with a hydrofluoric acid buffer solution to form a second insulating film 18B (SD6).

[0086] A resist mask is formed except for the portion to be the first element electrode 19 and the second element electrode 20, and Ti and Au are sequentially deposited as element electrodes using an EB deposition apparatus. Then, the resist mask is removed to form the first element electrode 19 and the second element electrode 20 (SD7).

[0087] Next, the sapphire single crystal substrate of the element substrate on which the first element electrode 19 and the second element electrode 20 are formed is thinned to 100 μm using a grinding and polishing device to form the element substrate 11 (SD8). In addition, in order to thin the element substrate 11 to 70 μm or 40 μm, etc., it is sufficient to increase the amount of grinding and polishing of the sapphire single crystal substrate in this step. In addition, in order to form the semiconductor light-emitting element of the comparative method 1 in which the sapphire substrate 11 is 200 μm, it is sufficient to reduce the amount of grinding and polishing.

[0088] Laser scribing is performed along the outer contour of each semiconductor light emitting element 10 from the surface side (back side) of the element substrate 11 to separate the semiconductor light emitting elements 10 into units, thereby forming semiconductor light emitting elements 10 (SD9).

[0089] [Implementation Method 2]

[0090] Next, the light emitting device 30 according to Embodiment 2 will be described. Figure 2A 1 is a plan view showing the upper surface of the light emitting device 30 of the present invention. Figure 2B It is along Figure 2A The cross-sectional view of the light emitting device 30 along the line DD shown, Figure 2C 1 is a plan view showing the lower surface of the light emitting device 30 of the present invention. Figure 2D 1 is a plan view showing the upper surface of the light emitting device 30 of the present invention, and is a view showing a state where the cover member 44 is transparent (a state where the cover member 44 is removed).

[0091] Figure 3 3 is a plan view showing the upper surface of the device substrate 31. Figure 2C In order to clarify the configuration relationship between the first element electrode 19 and the second element electrode 20 and the first through-hole 35 and the second through-hole 36, and the first mounting electrode 37 and the second mounting electrode 38 described later, the first through-hole 35 and the second through-hole 36, and the first element electrode 19 and the second element electrode 20 are indicated by dotted lines.

[0092] In order to clarify the arrangement relationship between the first element electrode 19 and the second element electrode 20 and the first mounting electrode 37 and the second mounting electrode 38, Figure 2D In FIG. 1 , the first mounting electrode 37 and the second mounting electrode 38 are shown by dotted lines. Figure 3 In FIG. 1 , the first element electrode 19 and the second element electrode 20 , and the first mounting electrode 37 and the second mounting electrode 38 are indicated by dotted lines.

[0093] In the description of the light emitting device 30, the direction in which the semiconductor light emitting element 10 is provided with respect to the device substrate 31 is referred to as upward, and the opposite direction is referred to as downward. In addition, XYZ coordinates are indicated in each figure.

[0094] like Figure 2A and Figure 2B As shown, the light emitting device 30 has the semiconductor light emitting element 10 and the protective element 39 bonded to the upper surface (+Z direction) of the rectangular flat plate-shaped device substrate 31 via a bonding member 41. In addition, a phosphor plate 43 is bonded to the upper surface of the semiconductor light emitting element 10 via a light-transmitting adhesive member 42. In addition, the upper surface 32A of the device substrate 31, and the side surfaces of the semiconductor light emitting element 10 and the phosphor plate 43 are covered by a light-shielding covering member 44. Therefore, the exposed upper surface of the phosphor plate 43 becomes the light emitting surface of the light emitting device 30.

[0095] (Device board)

[0096] like Figure 2B to Figure 2D and Figure 3 As shown, the device substrate 31 is a rectangular flat plate having a pair of long sides (sides in the X-axis direction) facing each other in parallel and another pair of short sides (sides in the Y-axis direction) facing each other in parallel and orthogonal to the pair of long sides in a plan view. The device substrate 31 has a base 32, and the base 32 has an upper surface 32A as a first main surface and a lower surface 32B as a second main surface facing each other. The first wiring electrode 33 and the second wiring electrode 34 are provided on the upper surface 32A of the base 32, and the first mounting electrode 37 and the second mounting electrode 38 are provided on the lower surface 32B. In addition, a first through hole 35 and a second through hole 36 are provided that penetrate the base 32 from top to bottom. Hereinafter, when the first wiring electrode 33 and the second wiring electrode 34 are not distinguished, they are described as wiring electrodes, when the first mounting electrode 37 and the second mounting electrode 38 are not distinguished, they are described as mounting electrodes, and when the first through hole 35 and the second through hole 36 are not distinguished, they are described as through holes.

[0097] As the base 32, an aluminum nitride (AlN) ceramic substrate with a thickness Tbase of 70 μm is used. Aluminum nitride (AlN) ceramics are insulating ceramics with a thermal conductivity of 180 to 220 W / mK and a bending strength of 300 to 350 MPa, and excellent thermal conductivity and bending strength. From the perspective of making the light emitting device 30 thinner, the thickness of the base 32 is preferably thinner. If the strength of the base is taken into consideration, the thickness is preferably 30 μm to 120 μm. In addition, silicon nitride (SiN) can also be used as the base 32. 3 N 4 ) are ceramics, etc.

[0098] like Figure 3 As shown, the first wiring electrode 33 (cathode) is provided on a surface ( Figure 3The first wiring electrode 33 has a first shoulder 33A and a first element mounting area 33B. The first element mounting area 33B is a rectangle including the element electrode 19 (cathode) of the semiconductor light emitting element 10, and is arranged in the center of the device substrate 31 in such a way that the long side is along the line segment LX2. In addition, the first shoulder 33A is arranged at the end of a surface separated from the first element mounting area 33B. In addition, the first element mounting area 33B and the first shoulder 33A are connected by a first band portion 33c parallel to the line segment LX2.

[0099] The second wiring electrode 34 (anode) is provided on the other surface ( x2 ) divided by a line segment LX2 passing through the midpoint X2 of the device substrate 31 and parallel to the long side of the device substrate 31. Figure 3 -Y direction of the surface). In addition, the second wiring electrode 34 has a second shoulder 34A, a second element loading area 34B and a protection element loading area 34C. The second element loading area 34B is a rectangle containing the element electrode 20 (anode) of the semiconductor light emitting element 10, and is arranged in the center of the device substrate 31 in such a way that the long side is along the line segment LX2. In addition, the second shoulder 34A is arranged at the end of the other surface that is not opposite to the first shoulder 33A. In addition, the protection element loading area 34C is arranged at the end of the other surface opposite to the first shoulder 33A. In addition, the second element loading area 34B, the second shoulder 34A and the protection element loading area 34C are connected by a second band portion 34D parallel to the line segment LX2.

[0100] The short sides of the first element mounting region 33B of the first wiring electrode 33 and the second element mounting region 34B of the second wiring electrode 34 are aligned when viewed from above (XY plane). In other words, the outer edge formed by combining the first element mounting region 33B and the second element mounting region 34B is rectangular and has a size that includes the semiconductor light emitting element 10.

[0101] The first mounting electrode 37 (cathode) is provided on a surface ( Figure 2C The first mounting electrode 37 is a rectangular shape that substantially covers one surface of the lower surface 32B of the base body 32, and a cathode mark (a missing corner portion) is provided at one corner.

[0102] The second mounting electrode 38 (anode) is provided on the other surface ( Figure 2C In addition, the second mounting electrode 38 is a rectangular shape that substantially covers the other surface of the lower surface 32B of the base body 32.

[0103] As described above, the first element mounting region 33B of the first wiring electrode 33 and the second element mounting region 34B of the second wiring electrode 34 are separated by the wiring electrode spacing band 48 along the line segment LX2. That is, the element electrodes 19 and 20 are arranged to be separated from each other in the extension direction (Y-axis direction) of the line segment LY2 orthogonal to the line segment LX2. In addition, the first mounting electrode 37 and the second mounting electrode 38 are separated by the mounting electrode spacing band 47 along the line segment LY2 orthogonal to the wiring electrode spacing band 48. That is, the first mounting electrode 37 and the second mounting electrode 38 are arranged to be separated from each other in the extension direction (X-axis direction) of the line segment LX2. In this way, by making the wiring electrode spacing band 48 of the element mounting regions 33B and 34B orthogonal to the mounting electrode spacing band 47 of the mounting electrodes 37 and 38, when the semiconductor light emitting element 10 is joined and the light emitting device 30 is mounted on the circuit substrate, it is possible to prevent the device substrate 31 from being bent even if the device substrate 31 is thinned.

[0104] The first via hole 35 (cathode) vertically penetrates the base body 32 between the first shoulder 33A of the first wiring electrode 33 and the first mounting electrode 37 to electrically connect the two.

[0105] The second via hole 36 (anode) vertically penetrates the base body 32 between the second shoulder 34A of the second wiring electrode 34 and the second mounting electrode 38 to electrically connect the two.

[0106] Since the surfaces of the wiring electrodes 33 and 34 and the mounting electrodes 37 and 38 connecting the via holes 35 and 36 are uneven and the smoothness of the electrode surfaces is impaired, the via holes 35 and 36 are provided in portions other than the first element mounting region 33B of the first wiring electrode 33 and the second element mounting region 34B of the second wiring electrode 34 .

[0107] The first wiring electrode 33, the second wiring electrode 34, the first mounting electrode 37, the second mounting electrode 38, the first via 35, and the second via 36 are metals mainly composed of copper (Cu). In addition, the wiring electrodes and the mounting electrodes are plated with a Ni / Au layer on their surfaces. In addition, tungsten (W) or the like may be used as the main metal of the wiring electrodes, the mounting electrodes, and the vias.

[0108] (Light-emitting element)

[0109] The semiconductor light emitting element 10 is a flip chip having a first element electrode 19 and a second element electrode 20 of approximately equal size and rectangular shape on a surface opposite to the element substrate 11 as a light emitting surface. In addition, in the semiconductor light emitting element 10, the first element electrode 19 and the second element electrode 20 are respectively connected to the first element mounting area 33B and the second element mounting area 34B via a bonding component 41. The semiconductor light emitting element 10 having such element electrodes 19 and 20 has excellent self-alignment to the element mounting areas 33B and 34B of the device substrate 31, and the residual stress of the bonding is also low. That is, even if the element substrate 11 or the device substrate 31 is thin, bonding can be performed with a high yield. The size of the semiconductor light emitting element 10 used in this embodiment is a quadrilateral with a side of about 1000μm and a thickness of about 100μm (the thickness of the semiconductor light emitting element 10 ≈ the thickness of the element substrate 11). In consideration of ease of handling in the manufacturing steps of the thin semiconductor light emitting element 10 , one side (line segment LX, line segment LY) is preferably 600 μm to 1600 μm.

[0110] (Protection element)

[0111] like Figure 2B and Figure 2D As shown, the protection element 39 is bonded to the protection element mounting region 34C of the device substrate 31 via a bonding member 41. In addition, the upper electrode of the protection element 39 is electrically connected to the first shoulder 33A via a conductive wire 40. The protection element 39 is connected in parallel with the semiconductor light emitting element 10 and with opposite polarity to prevent damage to the semiconductor light emitting element 10 caused by static electricity, etc. In addition, the top of the wire 40 of the protection element 39 is lower than the total height (thickness) of the semiconductor light emitting element 10 and the phosphor plate 43.

[0112] In addition, although the Zener diode is used as the protection element 39 in the present embodiment, a capacitor, a varistor, or the like may be used as the protection element 39 other than the Zener diode.

[0113] (Joint parts)

[0114] As the bonding component 41, a gold-tin (Au-20wt% Sn) alloy is used. Gold-tin paste solder is used to form the gold-tin alloy. The flux contained in the gold-tin paste solder evaporates when the semiconductor light-emitting element 10 and the protective element 39 are bonded to the device substrate 31. The surface of the element mounting areas 33B and 34B to which the semiconductor light-emitting element 10 is bonded is smooth, and the bonding component 41 is formed with a uniform thickness in the area where the element electrodes 19 and 20 of the semiconductor light-emitting element 10 overlap with the element mounting areas 33B and 34B. As a result, the stress during bonding acting on the thinned semiconductor light-emitting element 10 can be reduced, and damage to the semiconductor light-emitting element 10 can be prevented.

[0115] (Phosphor Plate)

[0116] The phosphor plate 43 as a wavelength conversion component is in the shape of a flat plate having substantially the same size as the light emitting surface of the semiconductor light emitting element 10 when viewed from above. The phosphor plate 43 is a ceramic phosphor containing cerium-activated yttrium aluminum garnet (YAG:Ce) phosphor particles in an alumina matrix. Figure 2B As shown, the phosphor plate 43 is bonded to the upper surface (+Z direction) of the element substrate 11 of the semiconductor light emitting element 10 via the adhesive member 42 of the translucent silicone resin. The phosphor plate 43 absorbs part or all of the blue light (primary light) emitted from the semiconductor light emitting element 10, and emits green light (secondary light) having a longer wavelength than the primary light. As a result, white light or greenish-yellow light, which is a mixture of blue light (primary light) and greenish-yellow light (secondary light), is emitted from the upper surface of the phosphor plate 43 of the light emitting device 30.

[0117] The phosphor plate 43 may be smaller or larger than the light-emitting surface of the semiconductor light-emitting element 10. In addition, a concave-convex structure for reducing reflectivity, a light-transmitting protective film for protecting the surface, a dielectric multilayer film for controlling directional characteristics, etc. may be provided on the light-incident surface (lower surface) or the light-emitting surface (upper surface) of the phosphor plate 43. In addition, a reflective dielectric multilayer film or a white ceramic film may be provided on the side.

[0118] As the base material of the phosphor plate 43, a light-transmitting ceramic or glass-type inorganic material, a light-transmitting resin material, etc. can be used. In addition, as the light conversion particles, it is not limited to cerium-activated yttrium aluminum garnet (YAG:Ce) phosphors, and cerium-activated lutetium aluminum garnet (LuAG:Ce) phosphors, europium or / and cerium-activated orthosilicate ((Ba, Sr, Ca)SiO 4 :Eu, Ce) phosphor, cerium-activated terbium aluminum garnet (TAG: Ce), europium-activated α-SiAlON phosphor (α-SiAlON: Eu), europium-activated β-SiAlON phosphor (β-SiAlON: Eu), manganese-activated potassium fluorosilicate (KFS: Mn), etc. Different types of light conversion particles can be appropriately selected and used according to the wavelength of the excitation light, the desired color tone, etc.

[0119] (covering parts)

[0120] like Figure 2A and Figure 2BAs shown, the covering member 44 starts from the outer peripheral edge of the upper surface of the phosphor plate 43, exposes the upper surface of the phosphor plate 43, and extends to the outside of the phosphor plate 43. In addition, the covering member 44 covers the upper surface of the device substrate 31, as well as the side surfaces of the bonding member 41, the semiconductor light emitting element 10, the adhesive member 42, and the phosphor plate 43. That is, the semiconductor light emitting element 10 and the protective element 39 are sealed by the covering member 44. In addition, the upper surface of the phosphor plate 43 becomes the light emitting surface of the light emitting device 30. In the present embodiment, since the element substrate 11 of the semiconductor light emitting element 10 is thinned, even if the device substrate 31 of the light emitting device 30 is thinned, the thickness of the covering member 44 is also thinned, so that the occurrence of warping of the light emitting device 30 caused by the expansion and contraction of the covering member 44 can also be suppressed.

[0121] As the cover member 44, a material in which reflective titanium oxide (TiO 2 ) particles. As the light-transmitting medium, epoxy resin, acrylic resin, polycarbonate resin, polystyrene resin, etc. can also be used. In addition, aluminum oxide (Al 2 O 3 ) and zirconium oxide (ZrO 2 ) mixed ceramic particles.

[0122] (Installation on a circuit board)

[0123] In the light emitting device 30 of the second embodiment, the first mounting electrode 37 and the second mounting electrode 38 are mounted on the circuit substrate via solder, respectively. The wiring electrode spacing band 48 of the first element mounting region 33B and the second element mounting region 34B of the light emitting device 30 is orthogonal to the mounting electrode spacing band 47 of the first mounting electrode 37 and the second mounting electrode 38. Therefore, when the light emitting device 30 is mounted on the circuit substrate, the stress that bends the straight line portion of the semiconductor light emitting element 10 where the three holes 12A are arranged can be suppressed. Thus, even if the element substrate 11 and the device substrate 31 are thin, it is possible to prevent the light emitting device 30 from being short-circuited or other undesirable situations, and the reliability of the light emitting device 30 can be improved.

[0124] [Comparison method 2]

[0125] Next, the light emitting device of Comparative Example 2 is described. The light emitting device of Comparative Example 2 is the same as Embodiment 2 except that the thickness of the element substrate 11 of the semiconductor light emitting element 10 of the light emitting device 30 of Embodiment 2 is changed from 100 μm to 200 μm.

[0126] (Comparison of light output of light emitting devices)

[0127] The light emitting device 30 of Embodiment 2 and the light emitting device of Comparative Embodiment 2 were soldered to a circuit board, and each light emitting device was energized to compare light output. As a result, when the light output of Comparative Embodiment 2 was set to 100%, the light output of Embodiment 2 was 108%. That is, the light output of the light emitting device 30 of Embodiment 2 increased by 8%. It is believed that this is because the contact area between the element substrate 11 of the semiconductor light emitting element 10 and the cover member 44 is reduced. Similarly, when the element substrate 11 is thinned to 70μm and 40μm, the light output increases. In this way, the semiconductor light emitting element 10 of Embodiment 1 used in the light emitting device 30 of Embodiment 2 has a tendency to reduce light output in a single body, but by forming it into the light emitting device 30 of Embodiment 2, a higher light output (luminous flux) characteristic is given as the light emitting device 30. In addition, by thinning the light emitting device 30, it is possible to suppress light leakage from the side of the light emitting device 30, and it is possible to increase the light output from the light emitting surface (the upper surface of the phosphor plate 43) of the light emitting device 30.

[0128] As described above, according to the present invention, it is possible to provide a semiconductor light emitting element 10 that is thinner and has improved luminous flux when formed into a light emitting device 30 or a light emitting device 30 that has high reliability and improved luminous flux.

[0129] (Method for manufacturing light emitting device)

[0130] Hereinafter, a method for manufacturing the light emitting device 30 according to Embodiment 2 will be described in detail with reference to flowcharts and drawings. Figure 4 is a flowchart showing a method for manufacturing the light emitting device 30. In addition, Figures 5A to 5E It is a top view showing each step.

[0131] (S1) Preparing a device substrate

[0132] As the device substrate 31, a substrate ( Figure 5A ). In the following description, the description of (S2) to (S4) is a description of the integrated substrate. In addition, an outer peripheral frame is provided on the outer periphery of the integrated substrate. In addition, the portion surrounded by the bold line in the figure is a unit device substrate 31.

[0133] (S2) Component installation steps

[0134] Au-Sn solder paste is applied as a bonding member 41 on the first wiring electrode 33 and the second wiring electrode 34 on which the semiconductor light emitting element 10 and the protection element 39 are mounted. Next, the semiconductor light emitting element 10 and the protection element 39 are placed on the Au-Sn solder paste.

[0135] Next, the gold-tin paste is heated to 300°C in a reflow furnace to melt and solidify, and the semiconductor light emitting element 10 is mounted on the first wiring electrode 33 and the second wiring electrode 34. At the same time, the protection element 39 is also mounted on the second wiring electrode 34. Then, the upper electrode of the protection element 39 is electrically connected to the first wiring electrode 33 through the wire 40 ( Figure 5B ).

[0136] (S3) Phosphor Plate Bonding Step

[0137] A silicone resin as a light-transmitting adhesive is applied to the upper surface of the semiconductor light-emitting element 10 as the adhesive member 42. Next, the phosphor plate 43 is placed on the semiconductor light-emitting element 10. The silicone resin is temporarily cured by heating at 170°C for 10 minutes, and the phosphor plate 43 is bonded to the semiconductor light-emitting element 10 ( Figure 5C ).

[0138] (S4) Covering member forming step

[0139] A frame 45 is formed around the outer periphery of the plurality of device substrates 31. A cover member 44 made of a silicone resin mixed with titanium oxide particles is filled inside the frame 45 until it contacts the outer periphery of the upper surface of the phosphor plate 43. Then, the silicone resin is cured by heating at 100°C for 30 minutes and at 150°C for 1 hour. At this time, the adhesive member 42 is also cured ( Figure 5D ).

[0140] (S5) Singulation Step

[0141] The light emitting device 30 is cut into individual pieces by a dicing blade 46. Figure 5E ).

[0142] [Implementation method 3]

[0143] Next, a light emitting device 50 according to Embodiment 3 will be described. Note that description of the same configuration as that of the light emitting device 30 according to Embodiment 2 of the present invention will be appropriately omitted. Fig. 6A 1 is a plan view showing the upper surface of the light emitting device 50 according to the third embodiment, and is a view showing a state where the cover member 44 is transparent (removed). Figure 6B 1 is a diagram showing a wiring pattern of a circuit substrate 60 on which a light emitting device 50 is mounted. Figure 6C 1 is a diagram showing a modified example of the wiring pattern of the circuit board 60 on which the light emitting device 50 is mounted.

[0144] Figure 73 is a plan view showing the upper surface of the device substrate 31 of the light emitting device 50 according to Embodiment 3. Fig. 6A In order to clarify the arrangement relationship between the first and second via holes 35 and 36 and the first and second mounting electrodes 37 and 38, the first and second via holes 35 and 36 and the first and second mounting electrodes 37 and 38 are shown by dotted lines. Figure 7 In order to clarify the configuration relationship between the first element electrode 19 and the second element electrode 20 and the first through-hole 35 and the second through-hole 36, and the first mounting electrode 37 and the second mounting electrode 38, the first through-hole 35 and the second through-hole 36, and the first mounting electrode 37 and the second mounting electrode 38 are indicated by dotted lines.

[0145] like Fig. 6A As shown, the light emitting device 50 of the third embodiment is a multi-unit type (here, two units) light emitting device having two light emitting devices 30 adjacent to each other. The light emitting device 50 is a light emitting device 30 of the second embodiment in which two units are connected in parallel on the device substrate 31. Therefore, if Figure 6B By setting the wiring pattern of the circuit board 60 in this way, each light emitting element (light emitting area) of the light emitting device 50 can be driven independently.

[0146] Thus, by setting the two light emitting devices 30 to be driven in parallel, the semiconductor light emitting elements 10 of each light emitting device 30 can be individually lit. Therefore, for example, by setting the wavelength conversion characteristics of the phosphor plates 43 of the light emitting devices 30 to different characteristics, a single light emitting device can emit light of multiple colors.

[0147] [Variation of Implementation Example 3]

[0148] Next, in a modified example of the light emitting device 50 of Embodiment 3, the wiring pattern of the circuit substrate 60 is as follows: Figure 6C As shown, a set of anodes and cathodes are connected in series. Thus, by setting the two light emitting devices 30 to be driven in series, the semiconductor light emitting elements 10 of each light emitting device 30 can be lit at the same time. Therefore, the luminous flux of the light emitting device can be further improved.

[0149] In addition, in this embodiment, the number of light emitting devices 30 included in the multi-unit light emitting device 50 is two, but it may be three or more. Fig. 6A As shown, in the present embodiment, the two light emitting devices 30 include the phosphor plate 43 for each semiconductor light emitting element 10 , but one phosphor plate 43 may be provided for a plurality of semiconductor light emitting elements 10 .

[0150] As described above, according to the present invention, it is possible to provide a semiconductor light emitting element or a light emitting device that is thinner, has high reliability, and has improved luminous flux.

Claims

1. A semiconductor light emitting element, comprising: A flat-plate-shaped light-transmitting element substrate having two main surfaces facing each other; A light-emitting semiconductor layer, which is formed on one main surface of the element substrate and is composed of a stack of an n-type semiconductor layer, a light-emitting layer and a p-type semiconductor layer; an n-electrode connected to the n-type semiconductor layer via at least one hole reaching the n-type semiconductor layer and provided on the p-type semiconductor layer so as to be electrically separated from the p-type semiconductor layer by an insulating film; A first element electrode, which is electrically connected to the n-electrode and extends along a first direction; as well as a second element electrode electrically connected to the p-type semiconductor layer, spaced apart from the first element electrode and extending along the first direction; The thickness of the element substrate is 100 μm or less.

2. The semiconductor light emitting element according to claim 1, wherein The thickness of the element substrate is 40 μm or more.

3. The semiconductor light emitting element according to claim 1, wherein The thickness of the light emitting semiconductor layer is 3-5 μm.

4. The semiconductor light emitting element according to claim 1, wherein The light emitting semiconductor layer has three or more holes. The plurality of holes are arranged at equal intervals in a straight line.

5. A light emitting device comprising: The semiconductor light emitting element according to any one of claims 1 to 4; and A device substrate, comprising a flat-plate-shaped substrate having two planes facing each other, a first wiring electrode and a second wiring electrode provided on one of the planes, a first mounting electrode provided on the other plane and connected to the first wiring electrode via a first via hole penetrating the substrate, and a second mounting electrode provided on the other plane and connected to the second wiring electrode via a second via hole penetrating the substrate, wherein the semiconductor light emitting element is bonded to the first wiring electrode and the second wiring electrode via a bonding member, The first element electrode and the second element electrode are arranged to be spaced apart from each other along a second direction orthogonal to the first direction. The first implementation electrode and the second implementation electrode are arranged to be spaced apart from each other along the first direction.

6. The light emitting device according to claim 5, wherein: The first element electrode and the second element electrode are arranged to be spaced apart from each other along the second direction from the midpoint of the device substrate. The first implementation electrode and the second implementation electrode are arranged to be spaced apart from each other along the first direction from a midpoint of the device substrate.

7. The light emitting device according to claim 5, wherein: The first wiring electrode includes a first element mounting region on which the first element electrode is mounted and a first shoulder on which the first via hole is arranged. The second wiring electrode includes a second element mounting region on which the second element electrode is mounted and a second shoulder on which the second via hole is arranged. The first shoulder and the second shoulder are disposed so as to be spaced apart from the first component mounting region and the second component mounting region, respectively, along the first direction.

8. The light emitting device according to claim 5, wherein: The element substrate is formed of sapphire single crystal, The base of the device substrate is formed of aluminum nitride-based ceramics.

9. The light emitting device according to claim 5, wherein: The thickness of the substrate is 30 μm to 120 μm.

10. A multi-unit light emitting device, wherein: The light-emitting device comprises a plurality of light-emitting devices according to claim 5, The plurality of light emitting devices are disposed adjacent to each other and are electrically connected in series or in parallel.

11. The light emitting device according to claim 10, wherein: The light emitting device comprises a phosphor plate bonded to the plurality of semiconductor light emitting elements via an adhesive member. The phosphor plate is formed as one body.

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