JP2003115611A - Light emitting device - Google Patents

Abstract

To provide a light-emitting device that has high luminance and can be manufactured at low cost and can be used as a surface-emitting light source or a display. A light-transmitting first substrate in which a semiconductor layer including an n-type semiconductor layer and a p-type semiconductor layer is formed on one surface, and a plurality of light-emitting elements are formed in the semiconductor layer, and a wiring A second substrate on which an electrode is formed, and each of the light emitting elements includes an n electrode formed on the n-type semiconductor layer and p
A p-electrode formed on the type semiconductor layer is provided on the same surface side, and the n-electrode and the p-electrode of the light-emitting element are bonded to the wiring electrode by bumps.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device having a plurality of light emitting elements.

[0002]

2. Description of the Related Art Conventionally, for example, in a light emitting device having a plurality of light emitting elements for a surface light source, a plurality of light emitting element chips are respectively die-bonded on a wiring board to provide a space between electrodes of each light emitting element and a terminal of the wiring board. For example, the electrodes are connected by wire bonding.

[0003]

However, in the conventional light emitting device constituted by die-bonding a plurality of light emitting element chips, there is a certain limit in mounting the light emitting element chips at a high density, and the brightness is reduced. It has been difficult to construct a high light emitting device. Further, since it is necessary to perform die bonding for each light emitting element chip and further connect the respective element chips and the like, productivity is poor and it is difficult to manufacture at low cost.

Therefore, an object of the present invention is to provide a light emitting device which has high brightness and can be manufactured at low cost and can be used as a surface emitting light source or a display.

[0005]

In order to achieve the above object, a light emitting device according to the present invention has a semiconductor layer including an n-type semiconductor layer and a p-type semiconductor layer formed on one surface thereof. A first substrate having a light-transmitting property in which a plurality of light emitting elements are formed in a layer and a second substrate in which a wiring electrode is formed, each of the light emitting elements being formed on the n-type semiconductor layer. An n-electrode and a p-electrode formed on the p-type semiconductor layer on the same surface side, and the n-electrode and the p-electrode of the light emitting element are bonded to each other by bumps so as to face the wiring electrode. It is characterized by

In the light emitting device configured as described above, a plurality of light emitting elements are integrally formed on the translucent substrate, so that each light emitting element is formed as an individual chip and then mounted. Light emitting elements can be formed with higher density than a light emitting device, and light emitted by each light emitting element can be output through the translucent substrate. Further, in the light emitting device of the present invention, a plurality of light emitting elements are integrally formed on the translucent substrate, and the p and n electrodes of each light emitting element are connected to the wiring electrodes by bumps. Can be connected with high productivity and can be manufactured at low cost as compared with the conventional connecting process of the light emitting device.

In the light emitting device according to the present invention, the plurality of light emitting elements may be connected in series or in parallel.

In the light emitting device of the present invention, the above n
The type semiconductor layer may be electrically separated for each light emitting element on the first substrate. In this way, either a serial or parallel connection method between the light emitting elements can be applied in accordance with the pattern of the wiring electrodes on the wiring board.

In the light emitting device of the present invention, when the plurality of light emitting elements are connected in series, the n-type semiconductor layer is electrically connected between the light emitting elements on the first substrate. May be connected to.

Further, in the light emitting device according to the present invention, the plurality of light emitting elements located between the first substrate and the second substrate are formed with resin around the first substrate. It can also be sealed. This makes it possible to provide a highly reliable light emitting device.

Further, in the light emitting device according to the present invention, the color conversion layer in which the fluorescent substance is dispersed in the translucent member can be formed on the other surface of the first substrate, whereby the light emitting element is formed. It is possible to emit light of a color (for example, white) different from the light generated by. In this case, the light emitting element may emit ultraviolet light and the fluorescent substance may absorb ultraviolet light and emit visible light. With this structure, light with little variation in emission color can be emitted.

Further, in the light emitting device according to the present invention, a mask having through holes formed corresponding to the light emitting elements is further provided on the other surface of the first substrate, and at least the color conversion layer is provided. It is preferable that each of the through holes be formed so as to be filled with a translucent member in which a fluorescent substance is dispersed.
By doing so, light diffusion can be prevented, and a clear and high-contrast light emitting device can be configured.

Further, in the light emitting device according to the present invention, a lens may be formed on the first substrate directly or through the color conversion layer in order to have directivity. Further, the above lens can be configured by a Fresnel lens, and thus a thin light emitting device can be realized.

Further, the light emitting device according to the present invention has the above-mentioned first aspect.
It is possible to provide a light guide plate on the substrate of (3) above, which makes it possible to improve the uniformity in the light emitting surface and to provide a light emitting device having excellent characteristics for a backlight. Also,
The light emitting device for a backlight configured in this way is not only excellent as a backlight for liquid crystal, for example, but also has high brightness and can emit light uniformly, so that there is strong light such as sunlight. Even when it is used outdoors, it is easy to confirm the light emission, and for example, it has excellent characteristics as a light source of a signal lamp.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION A light emitting device according to an embodiment of the present invention will be described below with reference to the drawings. Embodiment 1. As shown in the side view of FIG. 2, the light emitting device according to the first embodiment includes a light emitting element array 100 in which a plurality of light emitting elements are arranged on a transparent substrate, and a wiring board 200 having wiring electrodes formed thereon. And are joined as described later in detail.

In the first embodiment, in the light emitting element array 100, the light emitting elements 1 are arranged in a matrix (12 × 12) on one surface of the transparent substrate 11 made of, for example, sapphire.
It is formed in. Here, each light emitting element 1 has a structure shown in FIG.
As shown in (b), it has a structure in which a p-type semiconductor layer 14 made of a p-type gallium nitride compound semiconductor is stacked on an n-type semiconductor layer 12b made of an n-type gallium nitride compound semiconductor, N exposed by removing a part of the semiconductor layer
The n electrode 13 is formed on the type semiconductor layer 12b, and the p electrode 15 is formed on the p type semiconductor layer 14. In the present invention, an active layer made of, for example, a gallium nitride-based compound semiconductor may be provided between the n-type semiconductor layer 12b and the p-type semiconductor layer 14, and the n-type semiconductor layer 12b and the p-type semiconductor layer may be provided. Each of 14 may be composed of a plurality of gallium nitride-based compound semiconductor layers.

In addition, in the first embodiment, the wiring board 200 includes the p-electrodes of the light emitting elements in each column and the light emitting elements in each row of the light emitting element array 100 on the insulating substrate, as shown in FIGS. The positive electrode line 2 and the negative electrode line 3 are formed so as to correspond to the n-electrodes, respectively. Specifically, as shown in FIG. 4, 12 negative electrode lines 3 corresponding to each row of the light emitting element array 100 are formed in parallel on one surface of the insulating substrate, and the insulating film 4 is formed thereon. Is formed. Here, openings 4a are formed in the insulating film 4 at positions corresponding to the n-electrodes of the light-emitting element 1, and the surface of the negative electrode line 3 is exposed to connect with the n-electrodes. Further, the positive electrode line 2 is formed on the insulating layer 4 corresponding to the p-electrode of the light emitting element 1 in each column.

In the wiring board 200 configured as described above, as shown in FIG. 5, the solder bumps 2a are formed on the positive electrode lines 2 at the positions corresponding to the p electrodes of the respective light emitting elements 1, and the negative electrode lines 3 are formed. The solder bump 3a is formed on the portion exposed by the opening 4a. And the wiring board 2
No. 00 of the light emitting element array faces the surface of the light emitting element array on which the light emitting element is formed, and the solder bumps 2a of the positive electrode line 2 are in contact with the p electrodes of the respective light emitting elements so as to face each other, and the negative electrode The solder bumps 3a on the line 3 are aligned so that the n electrodes of the respective light emitting elements are in contact with and face each other, and the solder bumps 2a and 3a are melted and joined (FIG. 1).

Further, in the light emitting device of the first embodiment,
After bonding the light emitting element array 100 and the wiring board 200, a resin such as silicone is formed around the bonding portion (around the light emitting element array 100) to seal the light emitting element and the bonding portion. The light emitting device of the first embodiment is configured as described above.

Embodiment 1 configured as described above
This light emitting device can output the light emitted from each light emitting element through the translucent substrate 11. According to the light emitting device of the first embodiment configured in this way, a planar light emitting source having a relatively large light emitting area and high brightness can be realized by turning on all the light emitting elements at the same time. Also,
According to the light emitting device of the first embodiment, it is possible to realize a high-luminance and high-definition display by individually controlling the lighting of each light emitting element and turning on only the designated light emitting element.

Embodiment 2. Embodiment 2 according to the present invention
Is an illuminating device intended for use as a backlight (for example, a backlight of a liquid crystal display panel) that requires uniform surface emission characteristics. Specifically, in the light emitting device of the first embodiment, a light guide plate for diffusing (scattering) light is further provided on the light emitting surface of the transparent substrate 11, and light is emitted through the light guide plate. With this configuration, the uniformity of light intensity distribution in the light emitting surface (surface of the light guide plate) is improved. In the light emitting device of the second embodiment,
The parts other than the above are configured similarly to the light emitting device of the first embodiment.

In the present invention, the material forming the light guide plate is preferably excellent in light transmittance and moldability, and specific materials include acrylic resin, polycarbonate resin, non-crystalline polyolefin resin, polystyrene resin and the like. The organic member, the inorganic member such as glass, or the like can be used. In addition, the surface of the light guide plate has a surface roughness Ra of 25 μm (JIS) in order to improve the transmittance of light emitted from the light emitting element and to effectively reflect the light incident from the outside.
Standard) or less is preferable.

In the second embodiment, the light guide plate is opposed to and bonded to the light emitting surface of the transparent substrate 11. As the joining method of the light guide plates, various methods such as screwing, adhesion, welding, etc., which can be easily positioned and can obtain a predetermined joining strength, can be used, and they may be joined by fitting as follows. . For example, provide nails at several places on the end of the light guide plate,
The claw portion can be fixed by fitting it with the end of the bottom surface of the wiring board 200, and pins are provided at the end portion of the light guide plate or at several places in the vicinity thereof, and the pins are provided.
It can also be fixed by fitting it into the through hole formed in 0. The light emitting device for a backlight according to the second embodiment configured as described above has excellent uniformity of light emission intensity over the entire light emitting surface and can emit light with high brightness.

Embodiment 3. Embodiment 3 according to the present invention
Is a light emitting device including a plurality of blue light emitting elements having an emission wavelength of 460 nm, and has a color conversion layer 120 formed on the light emitting surface side as shown in FIG. In the light emitting device of the third embodiment, parts other than those described above are
It has the same structure as the light emitting device of the first embodiment. That is, in the light emitting device of the third embodiment, the color conversion layer 1 is formed on the surface of the translucent substrate 11 opposite to the surface on which the light emitting elements are formed.
Forming 20. The color conversion layer 120 is, for example, a SiO ₂ 75 wt% and the mean particle size of 16μm is filler with respect to the epoxy resin composition 100 wt% is translucent member _{(Y 0.9 Gd 0 .1) 2 .850} Al
_A color conversion layer material containing ₁₂ wt% of ₅ O ₁₂ : Ce _0.150 phosphor is formed on the surface of the translucent substrate by screen printing. When the light emitting device is formed in this manner, a white surface light source capable of uniformly emitting light is obtained.

(Fluorescent substance) In the present invention, the color conversion layer may contain various fluorescent substances such as an inorganic fluorescent substance and an organic fluorescent substance. An example of this fluorescent substance is a fluorescent substance containing a rare earth element which is an inorganic fluorescent substance. More specifically, the rare earth element-containing fluorescent substance is a garnet (garnet) type fluorescent substance having at least one element selected from Y, Lu, Sc, La, Gd, and Sm. In the present invention, in particular, Ce
It is preferable to use the yttrium-aluminum oxide-based phosphor activated by the method described above.
b, Cu, Ag, Au, Fe, Cr, Nd, Dy, N
It is also possible to contain i, Ti, Eu, Pr and the like.

In the third embodiment, from the light emitting element array
Blue light and fluorescence that absorbs and converts part of that light
By mixing two wavelengths with yellowish light emitted by a substance
Although white light is synthesized, two kinds of fireflies are used in the present invention.
White light is synthesized by mixing three wavelengths using an optical material.
You can also For example, a light-emitting element that emits blue light
On the light emitting surface side of the array (main wavelength = 455 nm), the light emission is performed.
By the light of the shorter wavelength side than the main emission wavelength of the light of the element array
Excited (excitation light = 440 nm) green light (excitation light = 440 nm)
A YAG-based phosphor capable of emitting light of 530 nm)
Some Y_Three(Al _0.8Ga_0.2)₅O₁₂: Ce first
It has the same excitation light as the phosphor and its first phosphor
It is possible to emit color light (main wavelength = 650 nm)
Nitride Phosphor Sr_0.679Ca_0.291
Eu_0.03)_TwoSi₅N₈A second phosphor, and a color having
When the conversion layer 120 is formed, it is possible to mix these three wavelengths.
As a result, it is possible to obtain a warm-colored white light-emitting device having excellent color rendering properties.
The nitride-based fluorescent material is LXMYN
_{(2X / 3 + 4Y / 3)}: Z (L is II-valent Be, Mg,
Selected from the group consisting of Ca, Sr, Ba, Zn, Cd, Hg
At least one species, M is IV-valent C, Si, G
a small amount selected from the group consisting of e, Sn, Ti, Zr, and Hf
At least one kind, N is Eu, Cr, Mn, Pb, S
b, Ce, Tb, Pr, Sm, Tm, Ho, Er, Y
at least one selected from the group consisting of b and Nd
Z is a small number selected from the group consisting of Eu, Mn, and Ce.
At least one. ) Basic constituent elements represented by
g, Sr, Ba, Zn, B, Al, Cu, Mn, Cr,
At least one selected from the group consisting of O and Fe
It is a nitride phosphor containing the element and. Such a source
By having an element, the particle size is adjusted and the emission brightness is improved.
Can be made. In addition, B, Mg, Cr, Ni, A
l has the effect that afterglow can be suppressed
It

(Translucent Member) In the third embodiment, a transparent member is used.
Part of the light of the light emitting element is absorbed in the conductive member
Color conversion layer containing a fluorescent substance capable of emitting light
The translucent member is the luminescent element used.
Characteristics of the child (emission wavelength, emission intensity, etc.) and applications of the light emitting device
Have both organic and inorganic substances, depending on
You can Specific examples of translucent members suitably used in the present invention
Epoxy resin, acrylic resin, silicone
Transparent resin and SiO with excellent weather resistance_TwoInorganic such as
The thing etc. are mentioned. In addition, in the present invention, the
It may be possible to include pigments, fillers, etc. in the transparent member.
Yes. Also, as a translucent member, it is relatively deteriorated by ultraviolet rays.
By using a resin that is difficult to resist and glass that is an inorganic substance,
In the ultraviolet region shorter than 400 nm or short wave of visible light
It is also possible to use a light-emitting device whose main emission wavelength is in the long range.
It Color conversion using a light emitting device having a wavelength in the ultraviolet region
Type light emitting device emits light converted by a fluorescent material
Since the chromaticity is determined only by the color, the wavelength of the light emitting element, etc.
Variation is directly reflected in the emission color of the light emitting device.
I will not be told. Therefore, the light emitting device emits light and the fluorescent substance
The emission color is determined by the color mixture of the
Unlike a light-emitting device that uses a semiconductor light-emitting element that emits light,
It is possible to absorb variations such as the wavelength of the conductor light emitting element.
As a result, it is possible to reduce variations, resulting in a manufacturing step.
Since the retention can be improved, mass productivity is improved.
Can be made. As a light emitting device,
Emission capable of emitting ultraviolet rays whose main emission peak is in the short wavelength range
When using an element, the color conversion layer 120 is relatively resistant to ultraviolet rays.
It absorbs ultraviolet rays and emits visible light to a resin or glass.
It is preferable that the fluorescent substance is included. This
Such a firefly that can emit red, blue, and green light with short wavelength light
The following are examples of optical materials. For example red fluorescence
Y as the body _TwoO_TwoS: Eu, Sr as blue phosphor
₅(PO_Four)_ThreeCl: Eu, and as a green phosphor (S
rEu) O ・ Al_TwoO_ThreeIs mentioned. These fluorescents
A short-wavelength light-emitting element that contains quality in UV resistant resin.
By using it as a color conversion layer of a light emitting device using
Therefore, white light can be obtained. In addition to the above fluorescent substances, red
3.5MgO ・ 0.5MgF as color phosphor_Two・ GeO
_Two: Mn, Mg₆As_TwoO_{1 1}: Mn, Gd_TwoO_Two: E
u, LaO_TwoS: Eu, Re as blue phosphor₁₀(P
O_Four)₆Q_Two: Eu, Re₁₀(PO_Four)₆Q_Two: E
u, Mn (where Re is Sr, Ca, Ba, Mg, Zn
At least one selected from
At least one selected from F, Cl, Br, I),
BaMg_TwoAl₁₆O₂₇: Use Eu or the like suitably
You can By using the fluorescent substances listed above,
A white light emitting device that can emit light with high brightness can be obtained.

When the color conversion layers 120 are mixed with the above-mentioned different types of fluorescent substances to form one color conversion layer, it is preferable that the different fluorescent substances have similar central particle diameters and particle shapes. As a result, the light emitted from various fluorescent substances is mixed well, and color unevenness can be suppressed. Alternatively, different color conversion thin film layers may be formed for each fluorescent substance, and they may be laminated. When the color conversion thin film layers each containing one type of fluorescent substance are laminated to form a color conversion multilayer, considering the ultraviolet light transmittance of each fluorescent substance, the ultraviolet transmittance of the fluorescent substance in each layer is the substrate side. It is preferable that the order is higher from the lower layer to the upper layer. Further, it is preferable that the median particle diameter of the fluorescent substance in each layer be smaller in order from the lower layer on the substrate side to the upper layer. As a result, it is possible to efficiently irradiate even the uppermost fluorescent material with ultraviolet rays and prevent leakage of ultraviolet rays to the outside. For example, when using the red fluorescent material, the green fluorescent material, and the blue fluorescent material listed above, it is preferable to stack the red fluorescent material layer, the green fluorescent material layer, and the blue fluorescent material layer in this order from the substrate side. It is preferable that the central particle diameter of the red phosphor material is red phosphor material> green phosphor material> blue phosphor material. In addition, each color conversion layer may be arranged on the element so as to have a stripe shape, a lattice shape, or a triangle shape. In this way, it is preferable that the layers are arranged with a space between them, because the color mixing property is good.

In the third embodiment, since the color conversion layer 120 is formed in contact with a transparent substrate (for example, a sapphire substrate) which is a flat surface, the thickness of the color conversion layer 120 should be uniform. Therefore, it is possible to minimize color unevenness that tends to occur when a fluorescent substance having a large particle size with high luminous efficiency is used. The particle diameter of the fluorescent substance used in the color conversion layer according to the present invention is preferably in the range of 6 μm to 50 μm, more preferably 15 μm to 30 μm, and the fluorescent substance having such a particle diameter absorbs light. The rate and conversion efficiency are high, and the width of the excitation wavelength is wide. Particle size is 6 μm
Smaller phosphors are more likely to form aggregates,
Since it is densely settled in the liquid resin and settles, the light transmission efficiency is reduced, and the light absorption rate and conversion efficiency are poor and the excitation wavelength range is narrow. Here, in the present invention,
The particle size of the fluorescent substance is a value obtained by a volume-based particle size distribution curve, and the volume-based particle size distribution curve is obtained by measuring the particle size distribution of the fluorescent substance by a laser diffraction / scattering method. Specifically, in an environment of a temperature of 25 ° C. and a humidity of 70%, a fluorescent substance is dispersed in an aqueous solution of sodium hexametaphosphate having a concentration of 0.05%, and a laser diffraction particle size distribution analyzer (SALD-2000A) is used.
It is obtained by measuring in a particle size range of 0.03 μm to 700 μm. In the present invention, the median particle size of the fluorescent substance means that the integrated value is 50 in the volume-based particle size distribution curve.
% Is the particle size value. It is preferable that the fluorescent substance having this median particle size value is frequently contained, and the frequency value is preferably 20% to 50%. By using the fluorescent substance having a small variation in particle size, a light emitting device capable of uniform light emission with suppressed color unevenness can be obtained.

The fluorescent substance used in the third embodiment is
After using an oxide or a compound that easily becomes an oxide at high temperature as a raw material of Y, Gd, Al, and Ce and sufficiently mixing them in a stoichiometric ratio to obtain a raw material, or Y, G
After mixing a coprecipitated oxide obtained by firing a solution obtained by coprecipitating a solution of rare earth elements of d and Ce in an acid at a stoichiometric ratio with oxalic acid, and aluminum oxide to obtain a mixed raw material ,
An appropriate amount of a fluoride such as barium fluoride or ammonium fluoride is mixed as a flux into this, packed in a crucible, and baked in the air at a temperature range of 1350 to 1450 ° C. for 2 to 5 hours to obtain a baked product, and then a baked product. Can be prepared by ball milling in water, washing, separating, drying and finally passing through a sieve.

(Filler) The filler that can be used in the present invention is not limited to SiO _2, and various types of filler such as barium titanate, barium sulfate, titanium oxide, aluminum oxide, silicon oxide, light calcium carbonate, and heavy calcium carbonate can be used. Any thing can be used. In the present invention, the particle diameter of the filler is preferably such that the central particle diameter is 5 μm or more and 100 μm or less, and the filler having such a particle diameter is used in the color conversion layer 120.
In addition to improving the chromaticity variation of the light emitting device by the light scattering effect, it is possible to enhance the thermal shock resistance of the translucent resin. The filler preferably has a particle size and / or shape similar to that of the fluorescent substance. Here, in the present specification, the similar particle size refers to a case where the difference between the center particle sizes of the particles is less than 20%, and the similar shape refers to the degree of approximation of the perfect circle of each particle size. It refers to a case where the difference in the value of circularity (circularity = perimeter of a perfect circle equal to the projected area of a particle / perimeter of a projected particle) is less than 20%. By using such a filler, the fluorescent substance and the filler interact with each other, the dispersion of the fluorescent substance in the resin is improved, and color unevenness is suppressed. Furthermore, both the fluorescent substance and the filler preferably have a central particle diameter of 15 μm to 50 μm, more preferably 20 μm to 50 μm, and by adjusting the particle diameter in such a range, a preferable interval is provided between the respective particles. Can be placed. As a result, a light extraction path is secured, and it is possible to improve the directional characteristics while suppressing a decrease in luminous intensity due to the inclusion of filler. Also,
A color conversion layer is formed by screen printing by incorporating a fluorescent substance and a filler having such a particle size range into a translucent resin,
When the dicing step after curing is performed, the dresser effect of recovering the clogging of the dicing blade is obtained by these particles, and mass productivity is improved.

Fourth Embodiment Embodiment 4 according to the present invention
In the light emitting device of Embodiment 3, in the light emitting device of the third embodiment, an aluminum mask 122 is provided before forming the color conversion layer,
The light emitting device of the second embodiment has the same structure as that of the light emitting device of the second embodiment except that the color conversion layer is formed thereon. As shown in FIG. 13B, the mask 122 of the fourth embodiment has the light emitting array 10
12 × 12 through-holes 122 corresponding to each light emitting part of 0
It is a 2 mm thick aluminum mask 122 having a, and as shown in FIG. 13A, is provided on the surface of the translucent substrate opposite to the surface on which the light emitting element is formed, and the fluorescent substance The color conversion layer 123 made of a light-transmissive member including is formed. Here, the color conversion layer 123 is formed so as to cover the mask 122 and fill the through hole 122a as shown in the cross-sectional view of FIG. According to the fourth embodiment, by virtue of such a configuration, it is possible to obtain a display device (matrix die white display dot matrix unit) in which light diffusion is prevented and which is clear and has improved contrast.

As the mask 122, both a conductive member such as metal and an insulating member such as plastic can be used, and it is preferable to use a member having excellent thermal conductivity. This makes it possible to maintain good reliability even when the light emitting element array is turned on with a large current. As the mask 122, circular holes are formed in a matrix corresponding to each light emitting portion on a flat plate made of metal or the like by pressing or etching. Mask 1 using aluminum
In the case of forming No. 22, it is preferable to perform black alumite treatment to make the surface black, whereby good contrast can be obtained. When a mask layer is formed using a metal or resin other than aluminum, the same effect can be obtained by printing black ink on the main surface side. The mask 122 thus formed is placed on the surface of the translucent substrate made of, for example, a sapphire substrate opposite to the side where the semiconductor layers are laminated, and then the color conversion layer 12 is covered so as to cover the mask 122.
3 is applied to integrate the light emitting element array and the mask layer. Accordingly, the light emitting device can be manufactured with good workability. Alternatively, the color conversion layer may be formed in advance in the through-hole 122a of the mask layer and then fixed on the substrate with an adhesive or the like.

Fourth Embodiment Embodiment 4 according to the present invention
This light emitting device is the same as the light emitting device of the second embodiment except that the lens 130 is further formed on the color conversion layer 120. That is, in the second embodiment, the color conversion layer 12
After applying 0, the hemispherical lens 1 formed in a predetermined shape so as to cover the entire light emitting element array 100 on the upper surface thereof.
30 is placed and the color conversion layer 120 is cured to be structurally integrated. The light emitting device of the fourth embodiment configured as described above can satisfactorily collect the light emitted from each light emitting element, and a display device having excellent directional characteristics can be obtained.

In the present embodiment, the lens can be formed by directly potting as well as a method of separately fixing a lens previously molded of resin, plastic, glass or the like. In the former case, the lens shape can be arbitrarily determined as desired. Further, although the light emitting device of the fourth embodiment is configured by using the convex lens 130, the present invention is not limited to this, and may be configured by using another lens such as a Fresnel lens. In the light emitting device of the fourth embodiment, since the surface of the color conversion layer 120 is flat, it is easy to form a Fresnel lens on the surface of the color conversion layer 120, and the Fresnel lens is also used. Thus, a thin light emitting device can be provided.

In the above embodiment, an example of the light emitting device having (12 × 12) light emitting elements has been described.
The present invention is not limited to this. Hereinafter, various modifications of the present invention will be described. Modification 1. In the light emitting device of Modification 1, the translucent substrate 1 is obtained by separating only the p-type semiconductor layer for each light emitting element without separating the n-type semiconductor layer 12a for each light emitting element.
Light emitting element array 100 in which four light emitting elements are formed on one
a (FIG. 10A) is used. This light emitting device array 100a is configured in the same manner as the light emitting device array 100 of the embodiment except that the n-type semiconductor layer 12a is not separated for each light emitting device and that there are four light emitting devices.

Further, in the light emitting device of the modified example 1, the positive electrode 21 of the wiring board has two positive electrode branches (parallel to each other) corresponding to the p electrodes of the light emitting elements arranged in each row of the light emitting element array 100a. The negative electrode 31 is formed by connecting two negative electrode branches (parallel to each other) corresponding to the n electrodes of the light emitting elements arranged in each row of the light emitting element array 100a at one end. A solder bump 21a is formed on the positive electrode (positive electrode branch) 21 arranged as described above at a position corresponding to the p electrode of each light emitting element, and the n electrode of each light emitting element on the negative electrode (negative electrode branch) 31 is formed. A solder bump 31a is formed at a position corresponding to.

Then, the wiring electrode of the wiring board (the positive electrode 21
And the surface on which the negative electrode 31) is formed and the light emitting device array 100.
The positive electrode 2 is made to face the surface on which the light emitting element of a is formed.
The solder bumps 2a and 3a are aligned so that the p-electrodes of the respective light emitting elements are in contact with and face the solder bumps 21a of 1 and the n-electrodes of the respective light emitting elements are in contact with and face the solder bumps 31a of the negative electrode 31, respectively. It joins by melting (FIG. 1).

The light emitting device of the modified example 1 configured as described above has the same effects as those of the embodiment, and further has the following features. That is, since the number of light emitting elements is four, which is relatively small, as shown in FIG.
Since the positive electrode 21 and the negative electrode 31 can be arranged without crossing each other, it is not necessary to insulate them via the insulating layer 4 unlike the positive electrode line 2 and the negative electrode line 3 of the embodiment. Therefore, the wiring pattern (positive electrode 21 and negative electrode 31)
The step of forming an insulating layer when forming the wiring pattern is omitted, and the wiring patterns of the positive electrode 21 and the negative electrode 31 are formed at the same time (1
Since it can be manufactured in a single etching process), the manufacturing cost can be reduced.

Modification 2. Like the first modification, the light emitting device of the second modification uses the light emitting element array 100a in which four light emitting elements are formed on the translucent substrate 11 without separating the n-type semiconductor layer 12a. The pattern is as follows.

That is, in the light emitting device of the second modification,
As shown in FIGS. 7A and 7C, the negative electrode 32 of the wiring substrate is formed corresponding to only the n electrode of one light emitting element of the light emitting element array 100a, and the positive electrode 22 is the positive electrode 22.
It is formed so as to correspond to the p electrodes of the four light emitting elements 0a, respectively. Negative electrode 32 arranged as described above
Above, the solder bumps 32a are formed at the positions corresponding to the n electrodes of the one light emitting element, and the solder bumps 22a are formed at the positions on the positive electrode 22 corresponding to the p electrodes of the respective light emitting elements.

Then, the wiring electrode of the wiring board (the positive electrode 22
And the surface on which the negative electrode 32) is formed and the light emitting device array 100.
The negative electrode 3 is made to face the surface on which the light emitting element of a is formed.
The solder bumps 22a and 32a are aligned so that the n-electrode of the one light emitting element is in contact with and faces the solder bump 32a of No. 2 and the p-electrode of each light emitting element is in contact with and faces the solder bump 22a of the positive electrode 22, respectively. Are joined by melting (FIG. 1).

The light emitting device of the modified example 1 configured as described above has the same effects as those of the embodiment and the modified example 1. That is, in the light emitting device of Modification Example 2, since the negative electrode 32 and the positive electrode 22 can be arranged without intersecting each other, the step of forming the insulating layer when forming the wiring pattern of the wiring board is eliminated and the negative electrode is formed. Since the wiring patterns of 32 and the positive electrode 22 can be formed at the same time (in one etching step), the manufacturing cost can be reduced.

Modified Example 3. The light emitting device of the third modification includes a light emitting element array 10 in which four light emitting elements are formed on a transparent substrate 11 by separating the n-type semiconductor layer 12b for each light emitting element.
0b, the wiring pattern of the wiring board is as follows.

That is, in the light emitting device of Modification 3,
As shown in FIGS. 8A and 8C, the negative electrode 33 of the wiring substrate is formed so as to correspond to only the n electrode of one light emitting element (first light emitting element) of the light emitting element array 100b, and the positive electrode Reference numeral 23 is formed so as to correspond to the p electrode of the second light emitting element diagonally arranged with respect to the first light emitting element. On the wiring board, two other light emitting elements are connected in series between the second light emitting element whose electrode is connected to the positive electrode 23 and the first light emitting element whose n electrode is connected to the negative electrode 33. Connection electrodes 41, 42, 43 for connecting between the n electrode and the p electrode of two predetermined light emitting elements are formed so as to be connected to each other.

On the positive electrode 23, the negative electrode 33, and the connection electrodes 41, 42, 43 arranged as described above, solder bumps 23a, 33a, 41a, respectively at positions corresponding to the n electrode and the p electrode of each light emitting element. 42a and 43a are formed as shown in FIG. Then, the surface of the wiring board on which the wiring electrodes (the positive electrode 23 and the negative electrode 33) are formed and the surface of the light emitting element array 100b on which the light emitting elements are formed face each other, and the n-electrodes of the light emitting elements corresponding to the respective solder bumps. Alternatively, the p-electrodes are aligned so that they are in contact with each other and face each other, and the solder bumps are melted and joined (see FIG. 8).
(C)).

The light emitting device of the modified example 1 configured as described above has the same effects as those of the embodiment and the modified example 1.

Modification 4. The light emitting device of Modification 4 is similar to Modification 3 in that the n-type semiconductor layer 12 a is separated and four light emitting elements are formed on the transparent substrate 11 to form a light emitting element array 10.
In this modification 4, the wiring pattern of the wiring board is as follows.

That is, in the light emitting device of Modification 4,
As shown in FIGS. 9A and 9C, four negative electrodes 34 of the wiring board are formed corresponding to the n-electrodes of the respective light-emitting elements.
Four positive electrodes 24 are formed so as to correspond to the p electrodes of each light emitting element. Solder bumps 24a and 34a are formed on the positive electrode 24 and the negative electrode 34 arranged as described above at positions corresponding to the p electrode of each light emitting element and the n electrode of each light emitting element.

Then, the wiring electrode (the positive electrode 24
And the surface on which the negative electrode 34) is formed and the light emitting device array 100.
The negative electrode 3 is made to face the surface on which the light emitting element of FIG.
The solder bumps 24a and 34a are melted by aligning so that the n electrode of each light emitting element is in contact with and faces the solder bump 34a of No. 4 and the p electrode of each light emitting element is in contact with and faces the solder bump 24a of the positive electrode 24. By doing so, they are joined (Fig. 9 (c)). The light emitting device of the modified example 4 configured as described above has the same effects as those of the embodiment and the modified example 1.

As described in the above embodiments and modifications 1 to 4, various connection methods such as serial connection, parallel connection, matrix connection and the like can be adopted depending on the application. Further, with the configuration of the present invention, it is possible to configure a light emitting device having an extremely large number of light emitting elements such as 128 × 128, and it is possible to expand the applicable range.

In the above embodiments and modifications, the example using the solder bumps has been described, but the present invention is not limited to this, and other bumps such as Au and Al may be used. . When a bump made of Au or the like is used, it may be formed either on the wiring electrode of the wiring board or on the positive electrode and the negative electrode of the light emitting element, or on the wiring electrode of the wiring board and the positive electrode of the light emitting element. It may be formed on both sides of the negative electrode. For Au bumps, for example, using a nail head bonding type bonder, the tip of the Au wire at the tip of the capillary is melted with an electric torch or hydrogen torch to form a ball, and the ball is placed on the electrode. It can be formed by cutting the wire at the neck of the ball after joining. When using the Au ball bumps, it is preferable that the formed ball bumps have the same height, and the ball bumps are pressed against a stage having high flatness, or after the ball bumps are formed, the capillaries have a predetermined height. It is preferable to perform a process for making the heights uniform by, for example, sliding the plates laterally. When using bumps such as Au, thermocompression bonding (Au-
Bonding can be performed by Au) or by eutectic alloy bonding by heat treatment (for example, Au-Sn).

Comparative Example FIG. 11 is a plan view showing the structure of a light emitting device of a comparative example. The light emitting device of the comparative example is a light emitting element array 1 including four light emitting elements on a base 70 made of a metal or an insulator.
00b is die-bonded with the light emitting element facing up, 4
One light emitting element is wire-bonded by the wires 52, 53, 54 so as to be connected in series as in the third modification, and the p electrode of the light emitting element located at one end is wire-bonded to the lead terminal 61 on the positive side. The n-electrode of the light emitting element at the end is wire-bonded to the lead terminal 62 on the negative side. In the light emitting device of the comparative example configured as described above, the light emitted from each light emitting element is output from the side where the p and n electrodes are formed.

Next, the effects obtained by the light emitting device according to the present invention will be described in comparison with the light emitting device of the comparative example. (1) According to the light emitting device of the present invention, a high brightness light emitting device can be realized. That is, like the light emitting device of the comparative example, when the light emitting elements and between the light emitting element and the lead terminal are connected by wire bonding and the emitted light is output from the side where the p and n electrodes are formed, Since the emitted light is blocked by the wire and thus the light extraction efficiency cannot be increased, in the configuration of the present invention, there is no such problem by performing flip chip bonding,
It is possible to emit light with high brightness. According to the study by the present inventors, when comparing the luminous intensity and power of the light emitting device of the comparative example and the light emitting device of the modified example 3 configured by the same wiring as that of the comparative example, the light emitting device of the modified example 3 is compared. The luminous intensity and power were 1.4 times higher than those of the comparative example.

(2) According to the configuration of the present invention, the manufacturing yield can be improved. That is, like the light emitting device of the comparative example, when the wire bonding method is used, the semiconductor layer may be damaged, such as making a dent in the light emitting region, but the structure of the present invention does not have such a problem, and the manufacturing yield Can be improved.

(3) According to the configuration of the present invention, the number of light emitting elements is not limited. That is, in the light emitting device configured by using the wire bonding method of the comparative example, it becomes difficult to connect the light emitting elements when the number of light emitting elements increases, and the number of light emitting elements is limited. There is no such limitation.

(4) According to the configuration of the present invention, it is possible to reduce the thickness. That is, in the light emitting device configured using the wire bonding method of the comparative example, it is necessary to form a resin on the surface of the light emitting element in order to protect the surface of the light emitting element. Therefore, it is necessary to form the resin to a certain thickness or more. However, in the configuration of the present application, the thickness of the light emitting device can be made approximately equal to the thickness of the light emitting element array and the thickness of the wiring substrate. Therefore, the thickness of each of the light transmitting substrate and the insulating substrate should be reduced. As a result, it becomes possible to reduce the thickness.

(5) According to the configuration of the present invention, productivity can be improved. That is, in the light emitting device of the comparative example, it is necessary to sequentially connect the wires. Therefore, when the number of light emitting elements increases, it takes time to perform bonding and the productivity decreases, but the configuration of the present invention does not have such a problem.

[0059]

As described in detail above, in the light emitting device according to the present invention, a semiconductor layer including an n-type semiconductor layer and a p-type semiconductor layer is grown on one surface, and a plurality of light emitting layers are emitted in the semiconductor layer. A first substrate having a light-transmitting property in which an element is integrally formed;
The second substrate on which the wiring electrode is formed is configured by bonding the n electrode and the p electrode of the light emitting element to the wiring electrode by bumps. As a result, according to the present invention, it is possible to provide a light emitting device which has high brightness and can be manufactured at low cost, and which can be used as a surface emitting light source or a display.

[Brief description of drawings]

FIG. 1 is a plan view of a light emitting device according to an embodiment of the present invention.

FIG. 2 is a side view of the light emitting device of the embodiment.

FIG. 3 is a circuit diagram of an embodiment.

FIG. 4 is a plan view showing a wiring pattern of a wiring board used in the embodiment.

5 is a plan view in which solder bumps are formed on the wiring pattern of FIG.

FIG. 6 is a view showing a light emitting device of Modification 1 according to the present invention,
FIG. 2A is a plan view showing a wiring pattern of a wiring board, FIG. 3B is a plan view showing bumps formed on the wiring pattern, and FIG.

FIG. 7 is a diagram showing a light emitting device of Modification 2 according to the present invention,
FIG. 2A is a plan view showing a wiring pattern of a wiring board, FIG. 3B is a plan view showing bumps formed on the wiring pattern, and FIG.

FIG. 8 is a diagram showing a light emitting device of Modification 3 according to the present invention,
FIG. 2A is a plan view showing a wiring pattern of a wiring board, FIG. 3B is a plan view showing bumps formed on the wiring pattern, and FIG.

FIG. 9 is a view showing a light emitting device of Modification 4 according to the present invention.
FIG. 2A is a plan view showing a wiring pattern of a wiring board, FIG. 3B is a plan view showing bumps formed on the wiring pattern, and FIG.

FIG. 10 is a side view showing an example of a light emitting device array used in the present invention, FIG. 10A is a side view of a light emitting device array in which a plurality of light emitting devices are formed without separating an n-type semiconductor layer, FIG. 3B is a side view of a light emitting device array in which a plurality of light emitting devices are formed by separating the n-type semiconductor layer for each device.

FIG. 11 is a plan view of a light emitting device of a comparative example.

FIG. 12 is a side view of a second embodiment according to the present invention.

13A is a plan view of a mask 122 according to a fourth embodiment of the present invention, and FIG. 13B is a side view showing a mounting position of the mask 122 according to the fourth embodiment.

FIG. 14 is a sectional view of a light emitting device according to a fourth embodiment of the present invention.

FIG. 15 is a side view of a fourth embodiment according to the present invention.

[Explanation of symbols]

1 ... Light emitting element, 2 ... Positive electrode line, 2a, 3a, 21a, 22a, 23a, 24a, 31
a, 32a, 33a, 34a, 41a, 42a, 43a
... solder bumps, 3 ... negative electrode line, 4 ... insulating film, 4a ... opening, 11 ... translucent substrate, 12a, 12b ... n-type semiconductor layer, 13 ... n-electrode, 14 ... p-type semiconductor layer, 21, 22 , 23, 24 ... Positive electrode, 31, 32, 33, 34 ... Negative electrode, 41, 42, 43 ... Connection electrode, 100, 100a, 100b ... Light emitting element array, 120, 123 ... Color conversion layer, 121 ... Fluorescent substance , 122 ... Mask, 122a ... Through hole, 130 ... Lens, 200 ... Wiring board, 300 ... Resin layer.

Claims (12)

[Claims] 1. A translucent first substrate having a semiconductor layer including an n-type semiconductor layer and a p-type semiconductor layer formed on one surface, and a plurality of light-emitting elements being formed in the semiconductor layer,
A second substrate having a wiring electrode formed thereon, and the light emitting element has the n electrode formed on the n type semiconductor layer and the p electrode formed on the p type semiconductor layer on the same surface. A light-emitting device having the n-electrode and the p-electrode of the light-emitting element, which are provided on the side, and are bonded to each other by bumps so as to face the wiring electrodes. 2. The light emitting device according to claim 1, wherein the plurality of light emitting elements are connected in series. 3. The light emitting device according to claim 1, wherein the plurality of light emitting elements are connected in parallel. 4. The light emitting device according to claim 1, wherein the n-type semiconductor layer is electrically separated for each light emitting element on the first substrate. 5. The light emitting device according to claim 3, wherein the n-type semiconductor layer is connected on the first substrate so as to be electrically connected between the light emitting elements. 6. The method according to claim 1, wherein the plurality of light emitting elements located between the first substrate and the second substrate are sealed by forming a resin around the first substrate. The light-emitting device according to any one of the above. 7. The light emitting device according to claim 1, further comprising a color conversion layer formed by dispersing a fluorescent material in a translucent member on the other surface of the first substrate. . 8. The light emitting device according to claim 7, wherein the light emitting element emits ultraviolet light, and the fluorescent material absorbs ultraviolet light to emit visible light. 9. A mask is further provided on the other surface of the first substrate, and the mask has through holes corresponding to the light emitting elements, and the color conversion layer has at least the through holes. 9. The light emitting device according to claim 7, which is formed so as to be filled with a translucent member in which a fluorescent substance is dispersed. 10. The light-emitting device according to claim 1, wherein a lens is formed on the first substrate directly or via the color conversion layer. 11. The light emitting device according to claim 10, wherein the lens is a Fresnel lens. 12. The light emitting device according to claim 1, further comprising a light guide plate on the first substrate.