JP2003101074A - Light emitting device - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] To provide a light-emitting device that emits white light with good durability and has no color unevenness, and a method of manufacturing the same. A semiconductor light emitting layer includes a step of forming semiconductor light emitting layers on a light transmitting substrate, and a step of forming a p-type electrode and an n-type electrode on the semiconductor light emitting layer using a reflective material. LED chip 1 formed by the above method and a phosphor layer 22 in which a phosphor is dispersed at a high concentration in an inorganic binder.
Is bonded to the holding plate 21 having
Flip chip bonding is performed on the base 4 on which the substrate 6 is formed, and then resin sealing with a light-transmitting resin is performed.

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, and more particularly to a light emitting device incorporating a semiconductor light emitting element. More specifically, the present invention relates to a light emitting device that combines a semiconductor light emitting element such as a light emitting diode (hereinafter, referred to as an LED) and a fluorescent material, and that emits white light using emitted light from the fluorescent material.

[0002]

2. Description of the Related Art A light emitting device in which a semiconductor light emitting element such as an LED and a phosphor are combined is beginning to be widely used as a light emitting device having a long life. For example, a white light emitting LED is used as a liquid crystal backlight light source. It is expected to have various uses.

FIG. 7 is a cross-sectional view showing an example of a conventional white light emitting LED light emitting device.
An example of a so-called surface-mount type LED light emitting device on which the ED light emitting device is mounted is shown. As shown in FIG. 7A, the LED light emitting device 90 is a blue light emitting LE made of a GaN compound semiconductor or the like.
D chip 91 and recess 92 for mounting LED chip 91
A base portion 93 having a central portion and a translucent resin 94 filled in the concave portion 92. In addition, the translucent resin 94 includes
A phosphor 95 that absorbs part of the light emitted from the LED chip 91 and emits yellowish light is dispersed and mixed.
Further, a pair of external connection electrodes 96, 96 are provided on the outer peripheral surface of the base 93 and the inner surface of the recess 92, and are electrically connected to the LED chip 91 in the recess 92 by a metal wire. In the LED light emitting device 90, a part of the light emitted from the LED chip 91 is absorbed by the phosphor 95 dispersed in the translucent resin 94, and the phosphor 95 emits yellowish light. Accordingly, the blue light of the LED chip 91 and the yellow light of the phosphor 95 are simultaneously emitted from the light emitting device 90, and it is possible to obtain a white light emission color. A gallium nitride-based compound semiconductor that emits light in the ultraviolet region to the blue region is generally used as the LED chip, and an epoxy resin is used as the translucent resin.

When the phosphors are dispersed in the translucent resin 94, uneven distribution of the phosphors is likely to occur, which may cause color unevenness. Therefore, as shown in FIG. 7B, the LED chip 91 is sealed with a translucent resin 94 ′ that does not contain the phosphor 95, and a resin layer 97 containing the phosphor 95 is evenly formed thereon. It is also proposed that the color filter is formed to have a thickness so that color unevenness is less likely to occur. As a light emitting device capable of white light emission by color-converting the light emitted from the blue LED by the blue light emitting LED and the fluorescent substance, for example, Japanese Patent Laid-Open No. 5-152609,
JP-A-7-99345, JP-A-11-31845,
There is Japanese Patent Laid-Open No. 2000-156528.

[0005]

In the above-mentioned conventional technique, the light emitted from the LED chip 91 must pass through the transparent resin 94 before reaching the phosphor 95. However, since an epoxy resin is generally used as the translucent resin 94, the yellowing phenomenon that the translucent resin 94 is deteriorated by the ultraviolet light emitted from the LED chip and the transmittance is lowered with time. And so on.
Therefore, particularly in a light emitting device using a material that emits light in the ultraviolet region as the LED chip 91 and using an epoxy resin in the optical path, the white light emission output is reduced, and a light emitting device having excellent durability is obtained. There was a problem that it was difficult.

In addition, a fluorescent substance is provided by coating or the like in the recess 92 in which the LED chip 91 is mounted without using a transparent resin, and they are sealed with a transparent resin. Light emitting devices have also been proposed. However, in such a case, since the LED chip is embedded with the phosphor, it is difficult to adjust the thickness of the phosphor, which makes it difficult to adjust the color tone and brightness, and the reproducibility of the light emitting device with excellent color rendering properties is improved. There is a problem that it is difficult to get well.

In view of the above points, it is a main object of the present invention to provide a light emitting device that can obtain a light emitting device having excellent brightness and color uniformity and excellent durability, and a manufacturing method thereof. To do.

[0008]

According to one aspect of the present invention, the above object is to provide a light emitting element having a semiconductor light emitting layer provided on a transparent substrate, and to absorb the emitted light of the light emitting element. In a light emitting device including a wavelength conversion member that emits light of different wavelengths and a translucent material that integrally seals these, in the light emitting element, a p-type electrode and an n-type electrode are provided on the light emitting layer surface side. It is made of a reflective material and has p on each surface.
The distance between the bonding pad for the n-type electrode mounting and the bonding pad for the n-type electrode mounting is the distance from the substrate surface on which the light emitting layer is formed to the outermost surface of the bonding pad for the p-type electrode mounting and the outermost surface of the bonding pad for the n-type electrode mounting. They are formed to be substantially the same, and are electrically connected to the electrodes for external connection via the bonding pads for mounting without using wires, and the wavelength conversion material member is on the opposite side of the light emitting layer of the substrate. And a size equal to or larger than that of the above-mentioned light-emitting element.

In this invention, most of the light emitted from the light emitting layer reaches the wavelength conversion member without entering the translucent resin, and the wavelength converted light is emitted to the outside. Therefore,
The translucent resin is not deteriorated by the light from the light emitting layer, and it is possible to obtain a light emitting device in which a decrease in light emission output is suppressed even after long-term use, and thus the above-described object is achieved.

According to another aspect of the present invention, a light emitting element having a semiconductor light emitting layer provided on a transparent substrate and a light emitting element that absorbs the emitted light and emits light of different wavelengths. A method of manufacturing a light-emitting device comprising a wavelength conversion member and a light-transmissive material that integrally seals these, wherein the step of forming a semiconductor light-emitting layer on the substrate, and the step of forming a semiconductor light-emitting layer on the substrate. A step of forming a p-type electrode and an n-type electrode by using a reflective material, and a bonding pad for mounting a p-type electrode and a bonding pad for mounting an n-type electrode on each surface of the p-type electrode and the bonding pad for mounting an n-type electrode from the substrate surface on which the light emitting layer is formed. A step of forming a light emitting element chip that sequentially performs a step of forming the distance to the outermost surface of the bonding pad for mounting and a distance to the outermost surface of the bonding pad for mounting the n-type electrode, and a light-transmitting property. A step of forming a phosphor film on at least one surface of the holding plate using a coating liquid in which a fluorescent material is dispersed in an inorganic binder, and a holding plate provided with the phosphor film on the stretchable sheet. After cutting, the wavelength conversion member manufacturing process including a step of dividing the wavelength conversion member by stretching the stretchable sheet after that, and the light emitting element chip manufacturing process for the pair of electrodes for external connection of the light emitting device are completed. A wavelength conversion member that has been subjected to the step of electrically connecting the bonding pad for mounting the p-type electrode and the bonding pad for mounting the n-type electrode, and the step of forming the wavelength conversion member on the surface of the substrate of the light emitting element opposite to the light emitting layer. And a step of mounting the light emitting element having a step of mounting, and a step of sealing the light emitting element, the wavelength conversion member and the electrode for external connection with a transparent material after the step of disposing the light emitting element. Method of manufacturing a light emitting device according to claim Rukoto, above object by is achieved.

According to the present invention, it is possible to easily obtain the wavelength conversion member controlled to have a uniform thickness, and it is possible to manufacture the light emitting device in which color unevenness is less likely to occur with good reproducibility, and to achieve the above-mentioned object. Can be able to.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. Figure 1
2 shows a first embodiment of a light emitting device according to the present invention. It should be noted that this embodiment is applied to a so-called surface mounting type or a chip component type LED light emitting device.

The surface-mounted LED light-emitting device 10 has a substantially rectangular parallelepiped shape, is mounted on a printed wiring board (not shown), and has a light ray L directed in a direction normal to the printed wiring board.
To irradiate. A concave portion 2 is formed in the central portion on the front surface side of the insulating substrate 4, an LED chip 1 is attached to the central portion of the concave portion 2, and a reflection frame 3 is formed in the periphery. In addition, the translucent sealing material 8 is filled in the recess 2. A first connection electrode and a second connection electrode are arranged on the back surface side of the base body 4, and the other end portion of each of them is provided with the recess 2
It is formed so as to wrap around inside and is electrically connected to the electrode of the LED chip 1.

The LED chip 1 is a semiconductor light emitting element capable of exciting a fluorescent material, and preferably emits blue and / or ultraviolet light. Examples of such a semiconductor light emitting device include GaN, InGaN, InGaAlN,
A gallium nitride-based compound such as AlGaN, or a material in which diamond or the like is formed as a light emitting layer can be used.
For example, the LED chip 1 shown in FIG. 2 has an n-type semiconductor layer 12 (n-n) formed by MOCVD (metal organic chemical vapor deposition) on the surface of a substrate 11 such as sapphire that transmits ultraviolet light.
After forming GaN, the p-type semiconductor layer 13 (p
-GaN) to form a pn junction. Also,
An n-type ohmic electrode 16 and an n-electrode mounting bonding pad 18 are formed on the n-type semiconductor layer 12, and a p-type ohmic electrode 1 is formed on the p-type semiconductor layer 13.
4 and p electrode mounting bonding pads 17 are formed. Reference numeral 15 is an insulating film.

The wavelength conversion member 7 is made of a member containing a fluorescent material such as a phosphor that is excited by light emitted from the LED chip 1 to emit light, and is preferably equal to or larger than the size of the light emitting surface of the LED chip 1. Is the substrate 1 of the LED chip 1
A fluorescent material having a size larger than 1 is provided in close contact with the substrate 11 so as to be located on the LED chip 1 side. The wavelength conversion member 7 includes a phosphor layer 2 on a holding plate 21 such as glass that can transmit the irradiation light emitted from the light emitting device 10.
2 is formed by coating, and the phosphor layer 22 is coated by using an inorganic binder so as not to contain a resin component which is deteriorated by light. The fluorescent material contained in the phosphor layer 22 is the light emitted from the LED chip, which is an excitation light source, or the LED.
It is possible to appropriately select from various known fluorescent materials according to a desired emission color according to the use of the light emitting device. Specific fluorescent materials include yttrium-aluminum-garnet-based phosphors activated with cerium, yttrium-aluminum-garnet-based phosphors activated with cerium, and praseodymium-doped phosphors, and La for red conversion. ₂ O ₂ phosphor, 3Ba0.8A that converts to green
l ₂ O ₃ phosphor and blue-converting Sr ₁₀ (P
There are O ₄ ) ₆ C ₁₂ phosphors and mixed phosphors obtained by mixing these.

The translucent sealing material 8 is filled in the recess 2 and seals the LED chip 1 and the wavelength conversion member 7.
Further, a hemispherical lens or the like (not shown) may be formed on the concave portion 2. The LED chip 1 is used as the translucent sealing material 8.
It is preferable to use a material having a high transmissivity because it is easy to form a package that integrates the above and can electrically insulate the LED chip from the outside. It is more preferable to use a material that has excellent adhesion to the LED chip 1 and the like and also has excellent reliability such as heat resistance. Specific examples of the material include an epoxy resin, a polycarbonate resin, an acrylic resin, a silicone resin, and the like, which can be appropriately selected from various materials according to the application, and may have a laminated structure of a plurality of material layers.

Here, the LED light emitting device 1 of the present embodiment
A method of manufacturing 0 will be briefly described with reference to FIGS.

First, a manufacturing process of the LED chip 1 will be described. After cleaning the substrate 11 such as sapphire that transmits ultraviolet light, a buffer layer and an n-type semiconductor layer 12 (n-GaN) (not shown) are grown by MOCVD (metalorganic chemical vapor deposition), and p-type is formed thereon. Semiconductor layer 1
3 (p-GaN) is epitaxially grown to form a semiconductor light emitting layer.

A part of the n-type semiconductor layer 12 is exposed by liquid phase etching or vapor phase etching of a device wafer (not shown) provided with the light emitting layer in this way, and then Ni, Au, A p-type ohmic electrode 14 made of a metal such as Pt or Ph is provided. The p-type ohmic electrode 14 is preferably made of a material having a high reflectance for light emitted from a light emitting layer such as ultraviolet light, and is preferably formed so as to cover the entire surface of the p-type semiconductor layer 13. Examples of the p-type ohmic electrode 14 include platinum (Pt) 10 Å, silver (Ag) 3000 Å, and titanium (T) in order from the p-type semiconductor layer 13 side.
i) 1000 angstrom, platinum (Pt) 1000
A laminated electrode formed by sequentially depositing angstrom and gold (Au) 1000 angstrom is used. Platinum and silver are formed to make ohmic contact with the semiconductor layer and to increase the reflectance for emitted light, and the outermost gold layer is a surface layer that does not oxidize, and also has good contact with the bonding pad to be laminated later. It is stacked in order to do. The platinum layer in contact with the outermost gold layer is formed to prevent the diffusion of the gold layer, and the titanium layer in contact therewith is used to prevent the diffusion of the platinum layer.

After forming the p-type ohmic electrode 14,
SiNx, SiO _Two, Al_TwoO_ThreeTransparent in the ultraviolet range
The clear insulating film 15 is formed on the end face of the p-type semiconductor layer 13 and the p-type electrode.
P type oh except bonding pad 17 for pole mount
It is formed so as to cover the surface of the Mick electrode 14. This
The insulating film 15 is formed on the entire device wafer by electron beam evaporation.
Formed using deposition method, sputtering method, chemical vapor deposition method, etc.
However, it can be obtained by removing a part thereof.
Preventing pn short circuit by forming an insulating film
Can be used, but p-type ohmic electrodes are separated by an appropriate distance.
14 and the n-type ohmic electrode 16 are provided,
The insulating film 15 may be omitted.

After the insulating film 15 is formed, the n-type ohmic electrode 16 formed of Ag, Al, or the like having a high reflectance at the ultraviolet wavelength is formed on the exposed n-type semiconductor layer 12. The n-type ohmic electrode 16 is preferably made of a material having a high reflectance for light emitted from the LED chip such as ultraviolet light. As the n-type ohmic electrode 16, for example, n
A laminated electrode is formed by sequentially depositing titanium (Ti) 20 Å and aluminum (Al) 3000 Å from the type semiconductor layer 12 side. Such a metal material is formed to make ohmic contact with the n-type ohmic electrode 16 and to increase the reflectance with respect to the emitted light.

Subsequently, the p-type electrode mount bonding pad 17 and the n-type electrode mount bonding pad 18 are formed of a metal material such as Ti, Ni, or Au.
The n-type electrode mounting bonding pad 18 is made thicker than the p-type electrode mounting bonding pad 17 so that the distance from the surface of the substrate 11 is equal. The bonding pad 17 for mounting the p-type electrode is, for example, gold (A
u) 1000 angstrom, platinum (Pt) 1000
A laminated electrode formed by sequentially depositing angstrom and gold (Au) 2000 angstrom is used. The gold layer formed first is used for maintaining good connectivity with the p-type ohmic electrode 14, and the gold layer on the outermost surface is the LED chip 1.
And the first connection electrode 5 are stacked in order to improve the connectivity using the Au-Sn eutectic electrode 19. The platinum layer in contact with the outermost gold layer is formed to prevent its diffusion when the outermost gold layer is eutecticized.

The n-type electrode mounting bonding pad 18 is, for example, titanium (Ti) 1000 Å in order from the n-type semiconductor layer 12 side. Gold (Au) 100
A laminated electrode formed by sequentially depositing 0 angstrom, platinum (Pt) 1000 angstrom, and gold (Au) 2000 angstrom is used. The titanium layer is formed to improve the connectivity with the n-type ohmic electrode 16. The gold layer formed first is p from the surface of the substrate 11.
It is formed as a thickness adjusting layer for making the distance to the surface of the bonding pad 17 for die electrode mounting and the distance from the surface of the substrate 11 to the surface of the bonding pad 18 for n type electrode mounting substantially equal. The outermost gold layer is L
The platinum layer in contact with the gold layer on the outermost surface is the gold layer on the outermost surface because the connectivity between the ED chip 1 and the second connecting electrode 6 using the Au-Sn eutectic electrode 19 is good. It is the same as the p-type electrode mount bonding pad 17 in that it is formed to prevent its diffusion when it is eutectic. Therefore, both the n-type electrode mount bonding pad 18 and the p-type electrode mount bonding pad 17 can be simultaneously formed on the platinum layer and the gold layer. It should be noted that the reason why the materials having high reflectance are used as these electrode materials is to increase the amount of light extracted from the substrate 11 side by reflecting the light emitted toward the substrate side. Further, in the present specification, the high reflectance material is 5 with respect to the main peak wavelength of the light emitted from the light emitting layer.
A material that has a reflectance higher than 0%.
It means that the reflectance is at least%. For example, about 400 nm
The above-mentioned p-type electrode and n-type electrode both show a reflectance of about 70 to 80% with respect to the above wavelength, but a gold electrode has a reflectance of less than 50%.

On the other hand, Au—Sn is provided at a position in the recess 2 facing the p-type electrode mounting bonding pad 17 and the n-type electrode mounting bonding pad 18 of the first connection electrode 5 and the second connection electrode 6. A eutectic electrode 19 made of, for example, is formed in advance.

Next, the LED chip 1 is arranged so that the substrate 11 side is the upper surface, the first connection electrode 5 and the p-type electrode mounting bonding pad 17 are connected, and the second connection electrode 6 and the n-type electrode mounting bonding are performed. The pads 18 are connected via eutectic electrodes 19, respectively, and heat-treated at about 300 ° C. to improve electrical and mechanical contact characteristics, so that the LED chip 1 is placed in the recess 2 in a so-called flip chip system. Install at.

Next, the wavelength conversion member manufacturing process will be described. FIG. 3 schematically shows the steps of manufacturing the wavelength conversion member in the order of steps. 21 is a holding plate, 22 is a phosphor layer, 2
Reference numeral 3 is a heat stretchable sheet. First, the holding plate 21 is prepared and washed (FIG. 3A). The holding plate 21 is made of a material such as glass that can transmit the irradiation light of the light emitting device 10, and has a thickness of about 50 to 100 μm. This is because if it is thicker than this, the light emitting device becomes large, and if it is thinner than this, handling work becomes difficult in the subsequent work. Further, it is preferable that the holding plate 21 is made of a material having a low transmittance of ultraviolet light. The light emitted from the LED chip 1 is the phosphor layer 2
After passing through 2, it passes through the holding plate 21 and reaches the translucent sealing material 8. Therefore, it is preferable to have the property of blocking as much as possible the ultraviolet rays that have passed through the phosphor layer 22 that may deteriorate the translucent sealing material 8. It is also possible to use a colored holding plate 21. This is because the color balance of the light emitting device can be adjusted by using the colored holding plate 21. For example, when the LED chip 1 which is an excitation light source emits ultraviolet light and the phosphor layer 22 is a so-called three-wavelength phosphor, the emission peaks of the phosphors for red emission are emitted by the phosphors for blue emission and green emission. If it is weaker than the peak, it is possible to adjust the white color tone by using a coloring material that absorbs light in the blue and green regions.

Next, the phosphor layer 22 is formed (FIG. 3).
(B)). The phosphor layer 22 is formed by coating a mixture of a phosphor in a high concentration in an inorganic binder mainly composed of silanol or water glass by a method such as a spin coating method, a blade coating method or a screen printing method. It can be formed by manufacturing. At this time, in order to increase the packing density of the phosphor, the phosphor is mixed with the inorganic binder 1 in a weight ratio of 3 to 5. Since viscosity is too high and it is difficult to apply it uniformly by simply mixing, it is preferable to appropriately adjust the viscosity by adding a viscosity modifier such as n-butyl acetate to the mixed solution to lower the viscosity. After application, heat treatment is performed at 150 ° C. to cure. At this time, it is preferable to use a material that volatilizes by heat treatment as the viscosity adjusting material. The phosphor having an average particle diameter of 3 to 20 μm is used, and the phosphor layer 22 has a thickness of 3
When a phosphor layer having a particle size of 0 to 100 μm, preferably a particle size of 8 to 15 μm and a thickness of 40 to 50 μm is used, a light emitting device having an excellent balance of brightness and efficiency can be obtained. This is because if the phosphor particles are small, the packing density can be increased, but the conversion efficiency is not preferable, and if they are too large, the uniformity tends to deteriorate. Also, if the thickness is thin, the conversion efficiency also deteriorates, and if it is thick, the brightness tends to decrease.

Next, the phosphor layer 22 side is provided with a heat expansion / contraction sheet 23.
It is attached to the top, the holding plate 21 is cut into a predetermined size by a scribing method or a dicing method (FIG. 3 (C)), and the thermal expansion / contraction sheet 23 is pulled to produce a plurality of wavelength conversion members 7 (FIG. 3 ( D)). The size of each wavelength conversion member 7 is LED
It is preferable that the length of the side of the chip 1 is equal to or longer than that of the side of the chip 1 so that the entire amount of light emitted from the LED chip 1 is incident. The size is preferably 1.2 to 3 times, and more preferably twice the side length of the LED chip 1.

Subsequently, as shown in FIG. 2, the phosphor layer 22 is formed.
The wavelength conversion member 7 is disposed on the LED chip 1 such that the LED is located on the substrate 11 of the LED chip 1. An inorganic adhesive is used to connect the two. Then, a translucent sealing material 8 such as an epoxy resin is filled in the recess 2 and cured.

The surface-mounted LED light-emitting device 10 is configured as described above, and the light emitted from the LED chip 1 passes through the sapphire substrate 11 on which the LED light-emitting layer is grown and then directly becomes a wavelength conversion member. Incident. According to the present embodiment, most of the light emitted from the LED chip 1 travels in the main light emission direction L, and the light does not pass through a material such as an epoxy resin that easily causes photodegradation, and the fluorescent substance. To reach. Therefore, compared to the LED light emitting device 90 described in the conventional example, the problem of occurrence of photodegradation is less likely to occur. Further, the wavelength conversion member 7 having a uniform wavelength conversion function can be obtained relatively easily. Further, since the wavelength conversion member can be placed in close contact with the LED chip without the organic material layer interposed therebetween, color unevenness due to thickness can be reduced as compared with the case where light is taken out through the conventional fluorescent material-containing layer. Less affected and less likely to cause color unevenness.

A second embodiment will be described with reference to FIG. 4 and FIG. 5 which is a cross-sectional view of a main part.

The light emitting device 30 of the second embodiment is an LED lamp-shaped light emitting device provided with a cannonball type lens. The light emitting device 30 includes a pair of lead frames 31,
The LED chip 1 and the wavelength conversion member 7 placed in the recess 33 provided at one end of one lead frame 32, the metal wire 34 electrically connecting the lead frames 31, 32 and the LED chip, and these. And a cannonball-shaped lens 35 that covers the lens, and the wavelength of the light emitted from the LED chip 1 is converted while passing through the wavelength conversion member 7.
This light is supposed to be emitted in the main irradiation direction L.

The lead frames 31 and 32 are made of a metal material having excellent electrical conductivity and thermal conductivity, and a recess 33 is formed at one end of one lead frame 32. The recess 33 has a substantially mortar shape, and the flat portion 33
a and a reflection frame portion 33b around the flat portion 33a are provided to reflect light in the main irradiation direction L.

The lens 35 is formed of a translucent material, seals the LED chip 1 and the wavelength conversion member 7 and the like, and is formed into a bullet shape to have a lens function. The translucent material used for the lens 35 includes, for example, epoxy resin, polycarbonate resin, acrylic resin, silicone resin, etc., which can be appropriately selected from various materials depending on the application, and a plurality of material layers are laminated. Good structure.

LED chip 1 and wavelength conversion member 7
Although the same points as those in the previous embodiment are designated by the same reference numerals and detailed description thereof is omitted, the substrate of the LED chip 1 and the phosphor layer 22 of the wavelength conversion member 7 are laminated in close contact with each other.

Further, in the present embodiment, as shown in FIG. 5, after the LED chip 1 is mounted on the submount 36, these are mounted in the recess 33 of the lead frame 32. The submount 36 is made of, for example, a material having a high thermal conductivity and a thermal expansion coefficient similar to that of the semiconductor material of the LED chip 1, and the surface thereof has a bonding pad 17 for the p-type electrode mount and an n-type electrode mount for the LED chip 1. First connection electrode 37 and second connection electrode 3 which are respectively connected to the bonding pad 18
Have eight. In this embodiment, the submount is made of silicon (Si), and the first connection electrode 37 is provided on the surface of the submount through the insulating layer 39, and the second connection electrode 38 is formed so as to be electrically connected to the silicon material. is doing.

Here, the LED light emitting device 3 of the present embodiment
The manufacturing method of 0 will be briefly described. First, L until the bonding pad 17 for mounting the p-type electrode and the bonding pad 18 for mounting the n-type electrode are manufactured.
The manufacturing process of the ED chip 1 and the wavelength conversion member manufacturing process are performed in the same process as the previous embodiment. However,
The distance from the surface of the substrate 11 on which the light emitting layer is formed to the outermost surface of the bonding pad 17 for p-type electrode mounting and the outermost surface of the bonding pad 18 for n-type electrode mounting are substantially the same, but the bonding pad for p-type electrode mounting is used. The distance to 17 is formed to be shorter by the thickness of the insulating layer 39. Next, the manufactured LED chip 1 and the wavelength conversion member 7 are arranged so that the phosphor layer 22 is located on the substrate 11 of the LED chip 1 and the wavelength conversion member 7 is LE.
It is bonded and integrated on the D chip 1. Further, the insulating layer 3 having a predetermined shape having an opening is formed on the surface of the silicon wafer.
9 is formed. After that, the first connection electrode 37 and the second connection electrode 38 are formed on the insulating layer 39 and on the open silicon by appropriate means such as gold vapor deposition,
Pattern. After that, the eutectic electrode 19 made of Au—Sn or the like is formed on the first connection electrode 37 and the second connection electrode 38, and cut into substantially the same size as the wavelength conversion member to prepare the submount 36. .

Then, p of the integrated LED chip 1 is
The type electrode mounting bonding pad 17, the n type electrode mounting bonding pad 18, the first connecting electrode 37 and the second connecting electrode 38 of the submount 36 are connected via the eutectic electrode 19, respectively, and electrical and mechanical In order to improve the dynamic contact characteristics, heat treatment is performed at about 300 ° C., and the integrated LED chip 1 is mounted on the submount 36 by a so-called flip chip method.

After that, the submount 36 on which the LED chip 1 and the wavelength conversion member 7 are mounted is fixed to the flat portion 33 a of the recess 33 using a conductive adhesive or the like, and the second submount 36 is manufactured. The connection electrode 38 and the lead frame 31 are connected by wire bonding. Finally, these are covered with a lens 35 made of epoxy resin by a transfer molding method.

The LED light emitting device 30 is configured as described above, and the light emitted from the LED chip 1 is LE
After passing through the sapphire substrate 11 on which the D light emitting layer is grown,
It directly enters the wavelength conversion member. Using a semiconductor light emitting element that emits ultraviolet light having a peak wavelength of 380 nm as an LED chip, the light emitting device 30 of this embodiment was manufactured and the life characteristics were examined. Yellowing was observed in less than 500 hours and the emission output was reduced, but it was 1150 in the continuous current test.
Even after the lapse of time, a high output of about 98% was maintained compared to the initial light emission output.

According to the present embodiment, most of the light emitted from the LED chip 1 travels in the main light emission direction, and the light does not pass through a material such as an epoxy resin that easily causes photodegradation. Reach the phosphor. Therefore, compared to the LED light emitting device 90 described in the conventional example, the problem of occurrence of photodegradation is less likely to occur. Further, the wavelength conversion member 7 having a uniform wavelength conversion function can be obtained relatively easily.
Furthermore, since it can be placed in close contact on the LED chip without the interposition of an organic material layer, it is less susceptible to color unevenness due to thickness, as compared with the case of extracting light through a conventional fluorescent material-containing layer. The uneven color is less likely to occur. Further, since the LED chip 1 and the like are mounted on the flat submount 36 and then mounted in the recess 33, the mounting work becomes easy.

Since the above-described embodiment is a preferred specific example of the present invention, various technically preferable limitations are attached, but the scope of the present invention is not limited to these aspects. . For example, as shown in FIG. 6, the light leaking from the end surface of the LED chip 1 is L converted so that the wavelength is surely converted.
The phosphor layer 42 may be provided on the end surface of the ED chip 1 by a method such as applying a coating liquid in which the phosphor 41 is highly mixed with an inorganic binder. In this case, the LED
The light emitted from the end surface of the chip 1 is also wavelength-converted, and a bright light emitting device can be obtained by the amount of the light.

Further, in the case where the lens has a bullet-shaped lens shape, but the lens has another shape, there are various cases such as the case where the LED chip mounted on the submount is arranged in the concave portion of the surface mount LED light emitting device. Modifications are naturally included in the present invention.

[0044]

As described above, according to the present invention, since the wavelength conversion member is bonded in close contact with the substrate of the LED chip, most of the light emitted by the LED chip is a transparent resin. Arrives at the wavelength conversion member without being incident on. Therefore, the light deterioration of the translucent resin with time is suppressed, so that the wavelength conversion light emitting device having excellent emission life characteristics can be obtained. In addition, since the wavelength conversion member having a uniform thickness is manufactured and is manufactured so as to be bonded to the substrate surface of the LED chip, the LED chip and the wavelength conversion member can be provided in close contact with each other. The translucent resin can be attached without interposing between them.
Therefore, suppressing the light deterioration of the translucent resin over time,
A wavelength conversion light emitting device having excellent emission life characteristics can be manufactured. Especially red phosphors with different characteristics as phosphors,
When using a mixed phosphor made by blending a green phosphor and a blue phosphor, it is possible to make the phosphor distribution uniform by drying the phosphor layer for a short time, and reproduce a light emitting device that does not cause color unevenness. It has a remarkable effect that it can be manufactured with good properties.

[Brief description of drawings]

FIG. 1 is a surface-mounted LED according to a first embodiment of the present invention.
It is a schematic sectional drawing of a light-emitting device.

FIG. 2 is an enlarged cross-sectional view showing a main part of the surface-mounted LED light emitting device of FIG.

FIG. 3 is a schematic cross-sectional view for sequentially explaining a manufacturing process of the wavelength conversion member according to the present invention.

FIG. 4 is an explanatory diagram showing an LED light emitting device of a second embodiment according to the present invention.

5 is an enlarged cross-sectional view showing a main part of the surface-mounted LED light emitting device of FIG.

FIG. 6 is an enlarged cross-sectional view showing a main part of a light emitting device according to another embodiment of the present invention.

FIG. 7 is a schematic cross-sectional view showing a conventional surface mount LED light emitting device.

[Explanation of symbols]

1 LED chip 2 recess 3 reflection frame 4 base 5 First connection electrode 6 Second connection electrode 7 Wavelength conversion member 8 Translucent sealing material 10,30 Light emitting device 11 board 12 n-type semiconductor layer 13 p-type semiconductor layer 14 p-type ohmic electrode 15 Insulating film 16 n-type ohmic electrode Bonding pad for 17 p electrode mount Bonding pad for 18 n-electrode mount 19 Eutectic electrode 21 holding plate 22 Phosphor layer 23 Thermal expansion sheet 31,32 Lead frame 33 recess 34 metal wire 35 lens 36 submount 37 First connection electrode 38 Second connection electrode 39 Insulation layer 41 Phosphor 90 Surface mount LED light emitting device 91 LED chip 92 recess 93 base 94 Translucent resin 95 phosphor 96 electrodes 97 Phosphor-containing resin layer

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5F041 AA05 AA11 AA44 CA40 CA46                       CA77 CA92 CA93 CB11 CB15                       DA09 DA18 DA20 DA44 DA57                       DB01 DB03 EE25

Claims (4)

[Claims] 1. A light emitting element having a semiconductor light emitting layer provided on a transparent substrate, a wavelength conversion member that absorbs emitted light of the light emitting element and emits light of different wavelengths, and these are integrally sealed. In the light-emitting device including a light-transmitting material that stops light emission, the light-emitting element includes a p-type electrode and an n-type electrode formed of a reflective material on the surface of the light emitting layer, and a p-type electrode and an n-type electrode on each surface of the light emitting layer.
The distance between the bonding pad for the n-type electrode mounting and the bonding pad for the n-type electrode mounting is the distance from the substrate surface on which the light emitting layer is formed to the outermost surface of the bonding pad for the p-type electrode mounting and the outermost surface of the bonding pad for the n-type electrode mounting. They are formed to be substantially the same, and are electrically connected to the electrodes for external connection via the bonding pads for mounting without using wires, and the wavelength conversion material member is on the opposite side of the light emitting layer of the substrate. A light emitting device, wherein the light emitting device is provided in close contact with the surface of the light emitting device and has a size equal to or larger than that of the light emitting element. 2. The light emitting device is mounted on the surface of the submount with the light emitting layer side facing the submount so that the mounting bonding pad of the device and the electrode provided on the submount are connected. The light emitting device according to claim 1, wherein an electrode for supplying power to the light emitting element is connected through the submount. 3. The light emitting device according to claim 1, wherein a phosphor layer is provided on an end surface of the light emitting layer of the light emitting element. 4. A light emitting element having a semiconductor light emitting layer provided on a transparent substrate, a wavelength conversion member that absorbs the emitted light of the light emitting element and emits light of different wavelengths, and these are integrally sealed. A method for manufacturing a light emitting device comprising a translucent material for stopping, comprising: forming a semiconductor light emitting layer on the substrate; and forming a p-type electrode and an n-type electrode on the semiconductor light emitting layer with a reflective material. The step of forming and the bonding pad for p-type electrode mounting and the bonding pad for n-type electrode mounting on each surface are formed from the substrate surface on which the light emitting layer is formed by p
A light emitting element chip manufacturing step of sequentially performing a step of forming the distance to the outermost surface of the bonding pad for die electrode mounting and a distance to the outermost surface of the bonding pad for n type electrode mounting, A step of forming a phosphor film on at least one surface of the holding plate using a coating liquid in which a fluorescent material is dispersed in an inorganic binder, and a holding plate provided with the phosphor film on an elastic sheet are placed. After that, the wavelength conversion member manufacturing step having a step of dividing the wavelength conversion member by stretching the elastic sheet after cutting, and the light emitting element chip manufacturing step for a pair of electrodes for external connection of the light emitting device are finished. A step of electrically connecting the bonding pad for mounting the p-type electrode and the bonding pad for mounting the n-type electrode, and the wavelength conversion unit on the surface of the substrate of the light-emitting element opposite to the light-emitting layer. After the manufacturing step, the step of placing the wavelength conversion member is placed, and after the step of providing the light emitting element, the light emitting element, the wavelength conversion member, and the external connection electrode are made of a translucent material. And a step of encapsulating. A method for manufacturing a light emitting device, comprising: