JP2002033517A - Light emitting element and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emitting element which can obtain stable high luminous efficiency for a long period. SOLUTION: In this light emitting element, a semiconductor LED chip is provided in the recess of a package and the recess is filled up with a light- transmissive resin so as to cover the LED chip. A light scattering layer in which an inorganic material that scatters the light from a semiconductor LED and which has a glass layer in which the inorganic material is scattered and a resin layer formed on the glass layer is provided between the recess and the light-transmissive resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a light emitting device and a method for manufacturing the same.

[0002]

2. Description of the Related Art Light emitting diodes (LEDs) are widely used in various applications because they are semiconductor elements, have no breakage, and have excellent ON / OFF drive characteristics.

In recent years, chip-type LEDs that can be surface-mounted have been increasingly used.

In this chip type LED (chip type light emitting element), a semiconductor LED chip is die-bonded to a concave portion of a package made of, for example, a liquid crystal polymer in which electrode leads are embedded, and after wire bonding as necessary, the semiconductor LED chip is used. It is configured by filling a translucent resin in the recess so as to cover the semiconductor LED chip.

In general, a semiconductor LED chip has a G
The p semiconductor layer and the n semiconductor layer made of a compound semiconductor such as aN are directly joined to form a pn junction, or an active layer is interposed therebetween to form a double hetero junction, and the p semiconductor layer and the n semiconductor layer are formed. When a forward voltage is applied to the semiconductor layer, light is emitted from the pn junction or the active layer.

[0006] In the light emitting device configured as described above, the light emitted from the semiconductor LED chip is emitted forward through the translucent resin.

Recently, there has been a demand for a light-emitting element with lower power consumption and brighter light. The light-emitting element can enhance the light-emitting efficiency of the semiconductor LED chip and efficiently emit the light emitted from the semiconductor LED chip to the front. Studies have been made on a structure with a high take-out efficiency.

As an effective structure for improving the light extraction efficiency in a light emitting element, the present applicant firstly disperses a diffusing material made of an inorganic material such as titanium oxide in a resin and coats it on the wall surface of the concave portion of the package. (Japanese Patent Laid-Open No. 11-284234).
No.). According to the proposed structure, the light output from the semiconductor LED chip and incident on the wall surface can be scattered by the light scattering layer to increase the light emitted forward, and as a result, the light extraction efficiency can be improved. Can be improved.

As another method for improving the light extraction efficiency, in a chip type LED covered with a translucent resin, the refractive index of the semiconductor LED chip and the refractive index of the semiconductor LED chip are set between the semiconductor LED chip and the translucent resin. By providing an intermediate layer having a refractive index between the refractive index of the translucent resin,
It is conceivable to improve the light extraction efficiency.

On the other hand, in general, when an epoxy resin or the like having a higher refractive index than a silicone resin is used as a sealing resin,
Since the linear expansion coefficient of the epoxy resin is larger than that of the silicone resin, there is a problem that the conductive line electrically connecting the semiconductor LED chip and the base is cut or peeled off mainly at the junction between the conductive line and the base. Could occur.

Accordingly, the present applicant directly cuts off or peels off the conductive wire by directly surrounding the semiconductor LED chip and the conductive wire with a soft resin having a small coefficient of linear expansion such as silicone resin and then covering with an epoxy resin. We filed the invention (Japanese Patent Application Laid-Open No. 8-335720).

[0012]

However, a light-emitting device having a light-scattering layer in which titanium oxide is dispersed in a resin,
There is a problem that the resin constituting the light scattering layer is decomposed by active oxygen generated when the titanium oxide is irradiated with light.

As a result, the light scattering layer deteriorates due to problems such as peeling off of the interface between the light scattering layer and other elements and formation of voids in the light scattering layer itself, and high light extraction efficiency in the light emitting element. For a long period of time.

Light emitted at the pn junction or the active layer is emitted from the semiconductor layer or the sapphire substrate in the semiconductor LED chip to the light-transmitting resin, and then emitted from the light-transmitting resin into the air. Is used.

However, the refractive index of the material constituting the semiconductor LED chip (for example, the refractive index of GaN: about 2.2, the refractive index of GaP: about 3.3, the refractive index of sapphire: about 4.0) Since the refractive index of the translucent resin (for example, the refractive index of epoxy resin: about 1.5 to 1.6, the refractive index of silicone resin: about 1.4 to 1.5) is small, the pn junction Alternatively, the light emitted from the active layer is totally reflected at the interface between the semiconductor LED chip and the translucent resin, and it is difficult to obtain efficient light extraction efficiency (light returned to the semiconductor LED chip is May be absorbed by a semiconductor layer or the like).

On the other hand, an intermediate layer having a refractive index between the refractive index of the semiconductor LED chip and the refractive index of the translucent resin is provided between the semiconductor LED chip and the translucent resin. A high refractive index resin layer and a low refractive index resin layer (refractive index of low refractive index resin <
Refractive index of high refractive index resin <Refractive index of semiconductor LED chip)
In the method in which the low-melting glass is considered as a material of the high-refractive-index resin, when the low-melting glass is applied to the concave portion of the package, the package is melted at the curing temperature of the low-melting glass, that is, the melting point. I will. This is because, for example, the melting point of a low melting point glass having a refractive index of 2 is 400.
This is because the liquid crystal polymer having the highest heat resistance among thermoplastic resins has a heat resistance temperature of about 350 ° C., while the heat resistance is about 350 ° C.

Even if the low-melting glass is applied to a substrate other than the package, the low-melting glass is mainly composed of silica, which is an inorganic substance. When an organic epoxy resin layer is formed on the substrate, there is a problem that peeling or voids are generated at the interface.

Further, in the invention in which a semiconductor LED chip is directly surrounded by a soft resin such as a silicone resin and then covered with an epoxy resin to prevent the gold wire from being cut or peeled off, the silicone resin is hardened as in the prior art. After that, by forming an epoxy resin layer on the silicone resin, breakage or peeling of the gold wire can be prevented.

However, as the demand for LEDs increases, use under more severe conditions is conceivable. Under such special conditions, for example, the semiconductor LE
A first resin layer is formed on the D chip, and a second resin layer is further formed thereon.
In the case of an LED having a resin layer formed, peeling or voids may be generated at the interface between the first resin layer and the second resin layer.

On the other hand, comparing the high-refractive-index silicone resin with the generally used low-refractive-index silicone resin, the high-refractive-index silicone resin is softer and more vulnerable to an external impact. Therefore, when the surface of the light emitting element is made of a silicone resin having a high refractive index, there is a possibility that the sealing resin may be broken by a slight external impact.

Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide a light-emitting element capable of obtaining a high and stable light extraction efficiency for a long period of time.

[0022]

According to a first light emitting device of the present invention, a semiconductor LED is provided on a substrate to achieve the above object.
A semiconductor LED chip and the LED.
In a light-emitting element in which a light-transmitting resin is formed so as to cover at least a substrate around a chip, an inorganic material that scatters light from the semiconductor LED is dispersed between the substrate and the light-transmitting resin. A light scattering layer is provided, and the light scattering layer includes a glass layer in which the inorganic material is dispersed, and a resin layer formed on the glass layer.

With this arrangement, the inorganic material and the resin layer can be prevented from coming into direct contact with each other, so that deterioration of the resin due to the inorganic material can be prevented, and stable light scattering characteristics can be obtained over a long period of time.

Here, the glass referred to in the specification of the present application refers to an amorphous inorganic substance having a disordered structure in which constituent atoms are not arranged regularly.

According to a second light emitting device of the present invention, a semiconductor LED is provided in a recess of a package to achieve the above object.
In a chip-type light-emitting element in which a chip is provided and the concave portion is filled with a translucent resin so as to cover the semiconductor LED chip, light from the semiconductor LED is interposed between the concave portion and the translucent resin. A light scattering layer in which an inorganic material that scatters light is dispersed, and the light scattering layer has a glass layer in which the inorganic material is dispersed, and a resin layer formed on the glass layer. It is characterized by the following.

With the above configuration, light can be reflected by the wall surface of the concave portion and can be effectively emitted above the package, and the inorganic material and the resin layer do not come into direct contact with each other. Therefore, deterioration of the resin due to the inorganic material can be prevented, and stable light scattering characteristics can be obtained over a long period of time.

Further, in the first and second light emitting elements according to the present invention, between the glass layer and the resin layer, the glass material forming the glass layer is changed to the resin material forming the resin layer. It is preferable to have a composition gradient layer whose composition gradually changes.

In this case, the glass layer and the resin layer can be more firmly joined than when the glass layer and the resin layer are directly contacted.

In the first and second light emitting devices according to the present invention, the resin is preferably an epoxy resin or a silicone resin.

Further, in the first and second light emitting devices according to the present invention, the inorganic material may be titanium oxide.

In this configuration, the titanium oxide can be dispersed in the light scattering layer so as not to come into direct contact with the resin, so that deterioration of the resin can be prevented and stable light scattering characteristics can be obtained for a long period of time.

Further, in the method of manufacturing a light emitting device according to the present invention, a semiconductor LED chip is provided in a concave portion of a package, and the concave portion is filled with a translucent resin so as to cover the semiconductor LED chip. In the method for manufacturing a light emitting element, an inorganic coating agent is prepared by mixing an inorganic material that scatters light from the semiconductor LED with an inorganic sol having a skeleton of silica or siloxane, and Forming a gel-like inorganic coating layer by applying to a wall surface and drying, and forming a resin layer by coating a resin on the gel-like inorganic coating layer, forming the inorganic coating layer and the resin And curing the layer.

In this manner, the light scattering layer composed of the glass layer, the resin layer, and the composition gradient layer located between the glass layer and the resin layer can be easily formed on the bottom surface and the side wall surface of the concave portion 5c. Can be.

According to a seventh aspect of the present invention, there is provided a light emitting device, comprising:
A light-emitting element provided with a chip, wherein a light-transmitting resin is formed so as to cover the semiconductor LED chip and a substrate at least around the semiconductor LED chip, wherein the light-transmitting resin is formed at least on the substrate. A first resin layer and a second resin layer formed on the first resin layer, and a material constituting the first resin layer between the first resin layer and the second resin layer. A composition gradient layer in which the composition gradually changes from the material constituting the second resin layer to the material constituting the second resin layer.

In this case, compared with the case where the first resin layer and the second resin layer are sequentially formed on the base without providing the composition gradient layer, the first resin layer and the second resin layer are compared with each other. Can be bonded more firmly. In particular, when the main components of the first resin layer and the second resin layer are an organic substance and an inorganic substance or an inorganic substance and an organic substance, respectively, there is a possibility that the first resin layer and the second resin layer may occur at the interface between the first resin layer and the second resin layer. Peeling or generation of voids can be prevented. Further, the relationship of the refractive index of the second resin layer <the refractive index of the first resin layer <the refractive index of the semiconductor LED chip holds, and the semiconductor LE
When the D chip and the first resin layer are in contact with each other, the light of the light at the contact surface between the semiconductor LED chip and the first resin layer is smaller than when the semiconductor LED chip is directly covered with the second resin layer. Since total reflection is reduced, light extraction efficiency can be improved. Further, between the first resin layer and the second resin layer, a boundary where the refractive index changes discontinuously by providing a composition gradient layer between the first resin layer and the second resin layer. Does not exist, the composition gradient layer is not provided, and at least the first
As compared with the case where the resin layer and the second resin layer are formed, better light extraction efficiency can be obtained without reflecting light at the boundary. Further, at least one of the first resin layer and the second resin layer is made of a silicone resin or the like having a small linear expansion coefficient, and is used to cover at least a part of the conductive wire, so that the conductive wire generated at that part is cut off. Peeling can be prevented.

The light emitting device according to claim 8 of the present invention is the light emitting device according to claim 7, wherein the first resin layer is formed so as to cover the semiconductor LED chip. Features.

In this case, when the relationship of the refractive index of the second resin layer <the refractive index of the first resin layer <the refractive index of the semiconductor LED chip is satisfied, the semiconductor LED chip is directly covered with the second resin layer. Compared to the semiconductor LE
Since the total reflection of light at the contact surface between the D chip and the first resin layer is reduced, the light extraction efficiency can be more efficiently improved.

The light emitting device according to the ninth aspect of the present invention is the light emitting device according to the seventh to eighth aspects of the present invention.
The first resin layer and the second resin layer are both made of a silicone resin.

With this configuration, the conductive wire is covered with at least one of the first resin layer and the second resin layer, which are silicone resins having a small coefficient of linear expansion.
The conductive wire can be prevented from being cut or peeled off.

According to a tenth aspect of the present invention, in the light emitting element according to the seventh to eighth aspects of the present invention, the first resin layer and the second resin layer are made of a silicone resin and an epoxy resin, respectively. It is a resin.

According to this structure, since the surface of the light emitting element is made of epoxy resin, it is possible to prevent the light emitting element from adhering to the wall surface of the tray in the tie bar cutting process. Further, since the hardness of the epoxy resin is generally higher than that of the silicone resin, the epoxy resin is more resistant to external impact.

The light emitting device according to claim 11 of the present invention is the light emitting device according to claim 10 of the present invention,
At least the joint between the base and the conductive wire is covered with the silicone resin of the first resin layer.

With this configuration, at least the joint between the base and the conductive wire is covered with the silicone resin of the first resin layer, so that the conductive wire can be cut off at the portion of the first resin layer covered with the silicone resin. Peeling or the like can be prevented.

According to a twelfth aspect of the present invention, in the light emitting element according to the seventh or eighth aspects of the present invention, the first resin layer and the second resin layer are made of epoxy resin and silicone, respectively. It is a resin.

With this configuration, the refractive index of the epoxy resin is higher than the refractive index of most of the silicone resin. Therefore, in most cases, the refractive index of the second resin layer is smaller than the refractive index of the first resin layer.
The relationship of the refractive index of the resin layer <the refractive index of the semiconductor LED chip holds, and the semiconductor LED chip and the first resin layer are compared with the case where the semiconductor LED chip is directly covered with the second resin layer. Since total reflection of light at the contact surface is reduced, light extraction efficiency can be improved.

The light-emitting device according to claim 13 of the present invention is the light-emitting device according to claim 12 of the present invention,
At least the joint between the base and the conductive wire is covered with the silicone resin of the second resin layer.

According to this structure, at least the joint between the base and the conductive wire is covered with the silicone resin of the second resin layer. Peeling or the like can be prevented.

Further, according to a method of manufacturing a light emitting device according to the present invention, a light emitting device comprising a semiconductor LED chip provided on a base and a transparent resin filled on the base so as to cover the semiconductor LED chip. In the manufacturing method, a gel-like first resin layer is formed by applying a material constituting a first resin layer on at least a substrate, and a second resin layer is formed on the first resin layer in the gel state. Forming a second resin layer by applying a constituent material;
Curing the resin layer and the second resin layer at the same time.

In this manner, the first resin layer, the second resin layer, and the composition gradient layer located between the first resin layer and the second resin layer can be easily formed.

[0050]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment A chip type light emitting device according to a first embodiment of the present invention will be described below with reference to FIG.

The light emitting device according to the first embodiment of the present invention
The semiconductor LED chip 7 is provided inside the concave portion 5c of the package 5.
Is a chip type light emitting diode molded with the translucent resin 6 and capable of surface mounting, and is configured as follows.

In the light emitting device of the embodiment, the package 5 includes a pair of electrode terminals 5a and 5b, which are positive and negative terminals.
It is made of, for example, a liquid crystal polymer having a recess for accommodating a semiconductor LED chip.

The semiconductor LED chip 7 is formed, for example, by growing a gallium nitride-based semiconductor on a sapphire substrate, and is die-bonded to the bottom surface of the concave portion 5c of the package 5, and its positive and negative electrodes are respectively connected to the electrode terminals of the package 5. 5a and 5b are connected by wire bonding.

Then, the light scattering layer 10 is formed on the bottom surface and the side wall surface of the concave portion 5c of the package 5.

Here, in particular, in the light emitting device of the present embodiment, the light scattering layer 10 includes the glass layer 1 in which the TiO2 particles are dispersed and formed so as to be in contact with the bottom surface and the side wall surface of the concave portion 5c. It is characterized by comprising a resin layer 3 formed so as to be in contact with the conductive resin 6 and a composition gradient layer 2 located between the glass layer 1 and the resin layer 3.

In this embodiment, the composition gradient layer 2
The portion in contact with the glass layer 1 is mainly made of the glass material forming the glass layer 1, the portion in contact with the resin layer 3 is mainly made of the resin material forming the resin layer 3, and the portion in contact with the glass layer 1 is in contact with the resin layer 3. This is a layer whose composition gradually changes from a glass material to a resin material toward a portion.

In the light emitting device of the embodiment configured as described above, the light emitted from the semiconductor LED chip 7 is not only the light emitted upward (forward) but also the light scattering layer 10.
Is emitted by the light scattering layer 10 and emitted upward (forward).

Thus, the light emitted from the semiconductor LED chip 7 is efficiently emitted upward (forward).

In the light emitting device of the present embodiment, TiO 2 (titanium oxide) particles as scattering particles are dispersed in the glass layer 1 as an inorganic material in the light scattering layer 10 so that the resin material is in direct contact with the titanium oxide material. Because there is no, without deteriorating the resin by the oxidative decomposition action of titanium oxide,
Light scattering characteristics stable over a long period of time can be obtained.

Further, in the light emitting device of the present embodiment, since the composition gradient layer 2 is provided between the glass layer 1 and the resin layer 3, the contact between the titanium oxide particles and the resin can be more effectively prevented. In addition, the deterioration of the resin can be more effectively prevented as compared with the case where the composition gradient layer is not formed. That is, when the glass layer 1 and the resin layer 3 are brought into direct contact, the titanium oxide particles may come into contact with the resin at the boundary, and the resin may be deteriorated at the contact portion.

However, the present invention is not limited to the case where the composition gradient layer 2 is present, as long as it has at least a glass layer containing light scattering particles and a resin layer formed thereon. By separating into a glass layer and a resin layer, the deterioration of the resin can be significantly prevented compared to the conventional example.

Further, in the light emitting device of the present embodiment, since the composition gradient layer 2 is provided between the glass layer 1 and the resin layer 3, when the glass layer 1 and the resin layer 3 are brought into direct contact, In comparison, the glass layer 1 and the resin layer 3 can be more firmly joined.

In the light emitting device of this embodiment, since the composition gradient layer 2 is formed between the glass layer 1 and the resin layer 3, the glass layer 1 having a relatively large refractive index and the glass layer 1 having a relatively small refractive index are used. The refractive index with the resin layer 3 can be gradually changed. Accordingly, since there is no boundary between the glass layer 1 and the resin layer 3 where the refractive index changes discontinuously, reflection of light between the glass layer 1 and the resin layer 3 can be prevented.

Therefore, the light reflected and scattered by the titanium oxide particles can be emitted above the light emitting element via the light transmitting resin 6 without being reflected between the glass layer 1 and the resin layer 3. Light extraction efficiency (emission efficiency) can be further increased.

Next, a method for forming the light scattering layer 10 in the light emitting device of the present embodiment will be described. (1) First, an inorganic coating agent containing titanium oxide is produced by mixing titanium oxide with a sol containing silica or an inorganic sol having a siloxane skeleton as a binder. (2) Next, an inorganic coating agent containing titanium oxide is applied to the concave portion 5c of the package 5 on which the semiconductor LED chip is mounted.
By applying a predetermined thickness to the bottom and side walls of the
Form an inorganic coating layer. (3) Next, the applied inorganic coating layer is dried to a gel state, and an organic resin such as an epoxy resin or a silicone resin is coated thereon to form a resin layer. (4) Then, the inorganic coating layer and the resin layer are simultaneously cured at the curing temperature of the resin layer.

As described above, the light scattering layer 10 composed of the glass layer 1 in which the TiO 2 particles are dispersed, the resin layer 3, and the composition gradient layer 2 located between the glass layer 1 and the resin layer 3 is formed.
It can be formed on the bottom surface and the side wall surface of the concave portion 5c.

Here, in the present invention, the inorganic binder for forming the glass layer 1 can form a glass layer by heating at a low temperature or drying at room temperature. For example, a sol containing silica or an inorganic sol having a siloxane skeleton is used. Can be used.

In the present invention, the low-temperature heating refers to a curing temperature at which the resin constituting the resin layer 3 is cured or a temperature lower than the curing temperature.

In the above embodiment, titanium oxide having light scattering / diffusion has been described as an example. However, the present invention is not limited to this. The same operation and effect as those of the present invention can be obtained even when the inorganic material is used.

In the present invention, various inorganic materials such as barium titanate, aluminum oxide, silicon oxide and zinc oxide which have light scattering / diffusion properties and do not have a photocatalytic action can be used.

In the above embodiments, epoxy resin and silicone resin are mentioned as preferable examples of the material of the resin layer 3. However, the present invention is not limited to this, and other resins such as polyamide and UV curing resin may be used. You may.

In the above embodiment, an example was described in which the package 5 having the concave portion 5c was used. However, the present invention is not limited to this, and can be applied to a case where another substrate such as a substrate is used.

For example, in a light-emitting element in which a semiconductor LED chip is provided on a substrate and a light-transmitting resin is formed so as to cover the semiconductor LED chip and the substrate around the LED chip, an oxidizing element is formed so as to be in contact with the substrate. A glass layer in which an inorganic material such as titanium is dispersed may be formed, a resin layer may be formed on the glass layer, and a light-transmitting resin may be formed thereon. Even in the case described above, the same operation and effect as those of the light emitting element of Embodiment 1 can be obtained. [Second Embodiment] A chip type light emitting device according to a second embodiment of the present invention will be described below with reference to FIG.

The light emitting device according to the second embodiment of the present invention
A chip-type light emitting diode in which the semiconductor LED chip 7 described in the first embodiment is molded with a translucent resin, for example, inside the concave portion 15c of the package 15, and has the following configuration. Is done.

In the light emitting device of the second embodiment, the package 15 includes a pair of electrode terminals 15a, which are positive and negative terminals.
15b and a recess for accommodating a semiconductor LED chip, for example, a liquid crystal polymer or the like.

The semiconductor LED chip 7 is die-bonded to the bottom of the concave portion 15c of the package 15 via an adhesive 16, and its positive and negative electrodes are respectively connected to the electrodes of the package 15 via conductive wires 14 such as gold wires. Terminal 15a,
15b. Then, for example, the first resin layer 11 and the composition gradient layer 12 are sequentially formed on the semiconductor LED chip 7.
Then, the second resin layer 13 is formed.

Here, in particular, in the light emitting device of the present embodiment, the first resin layer 1 is formed on the semiconductor LED chip 7 in order.
1 and a second resin layer 13 formed on the first resin layer 11, and a composition gradient layer 12 located between the first resin layer 11 and the second resin layer 13. I have.

In this embodiment, the composition gradient layer 12
Is mainly composed of the resin material constituting the first resin layer 11 in a portion in contact with the first resin layer 11, and is mainly composed of the resin material constituting the second resin layer 13 in a portion in contact with the second resin layer 13. It is a layer whose composition gradually changes from a material forming the first resin layer 11 to a material forming the second resin layer 13 from a portion in contact with the resin layer 11 to a portion in contact with the second resin layer 13.

In the light emitting device of Embodiment 2 configured as described above, there is no discontinuous boundary where the refractive index changes at the interface between the first resin layer 11 and the second resin layer 13. Better light extraction efficiency can be obtained without reflecting light at the boundary. Further, since the first resin layer 11 and the second resin layer 13 can be more firmly joined, regardless of the materials of the first resin layer 11 and the second resin layer 13, The occurrence of peeling or voids at the interface with the resin layer 13 can be prevented.

Further, when the relationship of “refractive index of the second resin layer 13 <refractive index of the first resin layer 11 <refractive index of the semiconductor LED chip 7” is satisfied, the semiconductor LED chip 7 is formed only by the second resin layer 13. Light extraction efficiency can be improved as compared with the case of covering.

Further, by covering at least the joint between the conductive wire such as a gold wire and the electrode terminals 15a and 15b with a resin layer having a small linear expansion coefficient such as a silicone resin, the conductive wire is prevented from being cut at that portion. can do.

Next, in the light emitting device of the present embodiment,
A method for forming the composition gradient layer 12 will be described. (1) First, the first resin layer 11 is formed by applying a material of the first resin layer 11 to a predetermined thickness so as to cover the semiconductor LED chip 7 die-bonded to the bottom surface of the recess 15 c of the package 15. I do.

Here, by adjusting the amount of the material of the first resin layer 11 and the like, it is determined whether or not the joint between the conductive wire and the electrode terminals 15a and 15b is covered with the material of the first resin layer 11. be able to. (2) Next, the material of the second resin layer 13 is further applied on the first resin layer 11 without curing the first resin layer 11, that is, in a gel state, to form the second resin layer 13. . (3) Then, the first resin layer 11 and the second resin layer 13 are simultaneously cured at a temperature or time at which both layers are cured.

In this manner, the first resin layer 11, the second resin layer 13, and the composition gradient layer 12 located between the first resin layer 11 and the second resin layer 13 can be easily formed. Can be.

In the second embodiment, the first resin layer 11
As a material of the second resin layer 13, a resin such as an epoxy resin, a silicone resin, an amorphous polyamide, and a UV curable resin can be used.

In the second embodiment, the first resin layer 11
Is preferably a smooth convex shape as shown in FIG. 2, for example. This is because the first resin layer 11 and the second resin layer 1
This is because light incident on the interface with No. 3 has a small angle of incidence, and is easily emitted to the second resin layer 13 without being totally reflected. However, in the second embodiment, for example, the same effect is obtained even if the first resin layer 11 is provided in a shape parallel to the outer shape of the semiconductor LED chip 7.

The amounts of the first resin layer 11 and the second resin layer 13 are not particularly limited.

Further, in the second embodiment, the example in which the package 15 having the concave portion 15c is used has been described. However, the present invention is not limited to this, and can be applied to a case where another mounting substrate such as a base is used.

For example, as shown in FIG.
The semiconductor LED chip 7 described in 1 above is die-bonded to the base 21 with the adhesive 22 and is electrically connected to the electrode terminals 21 a and 21 b on the base 21 via the conductive wire 20. To
The first resin layer 17, the composition gradient layer 18, and the second resin layer 19 may be formed in this order. [Example 1] A nitride semiconductor layer having a double hetero structure was stacked on a sapphire substrate by MOCVD (metal organic chemical vapor deposition), and a p-electrode and an n-electrode were formed on the same surface side of the nitride semiconductor layer. A large number of formed blue (470 nm) LED chips are prepared.

Next, this LED chip is set on a die bonder, and face-up is performed on the concave portion of the package having the electrode terminals, and die bonding is performed. After die bonding, the package is transferred to a wire bonder, the n-electrode of the LED chip is wire-bonded to the corresponding electrode terminal of the package with a gold wire, and the p-electrode is wire-bonded to the other electrode terminal.

Next, a silica solution containing 50% by weight of titanium oxide mixed with vacuum degassed titanium oxide was transferred to a concave portion of the package by a pressure compensating dispenser. Is applied to a predetermined thickness on the bottom surface and side wall surfaces of the substrate.

Next, when the silica solution mixed with the titanium oxide is in a gel state before a curing reaction, a colorless and transparent silicone resin A is further poured into the gel state by a pressure compensating dispenser. The silicone resin A has a refractive index of 1.41, a hardness of 45 shore (A), and a viscosity of 400.
0 mPa · s.

Thereafter, the silica solution and the silicone resin A were simultaneously cured at 150 ° C. for 4 hours.
LED.

Next, a light emitting device for comparison having the same structure as the light emitting device of Example 1 except that the light scattering layer was not provided and the LED chip was covered only with silicone resin A having a refractive index of 1.41. The light output ratio of the light emitting device of Example 1 was found to be 1.2 times based on the above. From this experimental result,
It became clear that the light output was surely improved by providing the light scattering layer. [Embodiment 2] First, the same blue color (470 n
m) A large number of LED chips are prepared, and the above-described LE is connected to a package having electrode terminals through a gold wire by the same operation as in the first embodiment.
D-die is die-bonded.

Next, it is transferred to a molding apparatus, and a colorless and transparent silicone resin B is applied to the concave portion of the package with a pressure-compensating dispenser so as to cover the entire LED chip and the gold wire.
Inject in a convex shape. Silicone resin B has a refractive index of 1.5
2. Hardness 25shore (A), viscosity 1800mPa.
s.

Next, when the silicone resin B is in a gel state before the curing reaction, a colorless and transparent silicone resin A having a refractive index of 1.41 is injected onto the silicone resin B by the same pressure compensating dispenser. Thereafter, this is cured at 150 ° C. for 4 hours to simultaneously cure each resin layer, thereby obtaining an LED of Example 2.

Next, the light output ratio of the light emitting device of Example 2 was determined to be 1.1 times based on the light emitting device for comparison shown in Example 1 as a reference. From this experimental result, it has been clarified that the light output is surely improved by configuring the light emitting device like the light emitting device of Example 2.

Further, 100 light emitting devices of Example 2 were manufactured and subjected to a thermal shock test. Thermal shock test at -40 ° C x 1
When 5 minutes and 100 ° C. × 15 minutes were performed under the conditions of 1040 cycles, no break or peeling of the gold wire occurred in all 100 pieces. [Example 3] The light emitting device in Example 3 was manufactured in the same manner as in Example 3, except that the first resin layer used was a silicone resin B having a refractive index of 1.52, and the second resin layer was an epoxy resin having a refractive index of 1.50. The configuration is the same as in Example 2. Here, in particular, in the light emitting device of the third embodiment, the entire gold wire is covered with the silicone resin B of the first resin layer without covering the gold wire with the epoxy resin of the second resin layer.

Next, the light output ratio of the light emitting device of Example 3 was found to be 1.2 times based on the light emitting device for comparison shown in Example 1 as a reference. From this experimental result, it has been clarified that the light output is surely improved by configuring the light emitting device like the light emitting device of Example 3.

Further, 100 light emitting devices of Example 3 were manufactured and subjected to the thermal shock test shown in Example 2.
No break or peeling of the gold wire occurred in all 0 pieces. Example 4 The light emitting device of Example 4 was manufactured in the same manner as in Example 4, except that the first resin layer was made of an epoxy resin having a refractive index of 1.60, and the second resin layer was made of a silicone resin A having a refractive index of 1.41. It has the same configuration as the light emitting element of Example 2. Here, in particular, in the light emitting element in Example 4, the bonding portion between the gold wire and the electrode terminal was not covered with the epoxy resin of the first resin layer,
The second resin layer is covered with a silicone resin A.

Next, the light output ratio of the light emitting element of Example 4 was calculated to be 1.1 times based on the light emitting element for comparison shown in Example 1 as a reference. From this experimental result, it has been clarified that the light output is surely improved by configuring the light emitting device like the light emitting device of Example 4.

Further, 100 light emitting devices of Example 3 were manufactured and subjected to a thermal shock test shown in Example 2.
No break or peeling of the gold wire occurred in all 0 pieces. [Example 5] The light emitting device of Example 5 is a light scattering layer of a silica solution mixed with 50 wt% of titanium oxide described in Example 1, and a silicone resin having a refractive index of 1.52 described in Example 2. Except that a first resin layer made of B and a second resin layer made of silicone resin A having a refractive index of 1.41 and a composition gradient layer formed at an interface between the first resin layer and the second resin layer Is configured similarly to the first embodiment.

Here, in particular, in the light emitting device of Example 5, the portion of the gold wire other than the portion covered with the light scattering layer is the first wire.
The resin layer is covered with silicone resin B.

Next, the light output ratio of the light emitting device of Example 5 was calculated to be 1.3 times based on the light emitting device for comparison shown in Example 1 as a reference. From this experimental result, it has been clarified that the light output is dramatically improved by configuring the light emitting device like the light emitting device of Example 5.

[0105]

As is apparent from the above description,
According to the light emitting element of the present invention, it is possible to provide a light emitting element capable of obtaining high light extraction efficiency that is stable for a long time.

Further, according to the method for manufacturing a light emitting device of the present invention, a light emitting device capable of obtaining a stable and high light extraction efficiency for a long time can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a light-emitting element according to Embodiment 1 of the present invention.

FIG. 2 is a cross-sectional view illustrating a configuration of a light emitting device according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a configuration of another light emitting device according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Glass layer 2, 12, 18 ... Gradient composition layer 3 ... Resin layer 5, 15 ... Package 5a, 5b, 15a, 15b, 21a, 21b ... Electrode terminal 5c, 15c ... Concave part 6 ... Translucent resin 7 ... Semiconductor LED chip 10 light scattering layer 11, 17 first resin layer 13, 19 second resin layer 14, 20 conductive wire 16, 22 adhesive 21 base

Claims (14)

[Claims] 1. A light emitting element comprising: a semiconductor LED chip provided on a base; and a light-transmitting resin formed so as to cover the semiconductor LED chip and at least a base surrounding the LED chip. A light scattering layer in which an inorganic material that scatters light from the semiconductor LED is dispersed between the light emitting resin and the light scattering layer, and the light scattering layer is a glass layer in which the inorganic material is dispersed, and a glass layer in which the inorganic material is dispersed. A light-emitting element comprising: a resin layer formed thereon. 2. A chip-type light emitting device in which a semiconductor LED chip is provided in a concave portion of a package, and the concave portion is filled with a translucent resin so as to cover the semiconductor LED chip. A resin is provided with a light scattering layer in which an inorganic material for scattering light from the semiconductor LED is dispersed between the resin and the resin, and the light scattering layer has a glass layer in which the inorganic material is dispersed and a glass layer on which the inorganic material is dispersed. A light-emitting element comprising: a formed resin layer. 3. A composition gradient layer between the glass layer and the resin layer, the composition gradient of which gradually changes from a glass material forming the glass layer to a resin material forming the resin layer. Or the light-emitting element according to 2. 4. The light emitting device according to claim 1, wherein the resin is an epoxy resin or a silicone resin. 5. The light emitting device according to claim 1, wherein the inorganic material is titanium oxide. 6. A method for manufacturing a chip-type light-emitting device, wherein a semiconductor LED chip is provided in a recess of a package, and the recess is filled with a translucent resin so as to cover the semiconductor LED chip. Preparing an inorganic coating agent by mixing an inorganic material that scatters light from the semiconductor LED into an inorganic sol serving as a skeleton; and applying the inorganic coating agent to the wall surface of the package and drying the gel. Forming a resin layer by coating a resin on the inorganic coating layer in the gel state, and curing the inorganic coating layer and the resin layer. Manufacturing method. 7. A light-emitting element comprising: a semiconductor LED chip provided on a base; and a light-transmitting resin formed to cover at least the semiconductor LED chip and the base surrounding the semiconductor LED chip. The resin is composed of at least a first resin layer formed on the base and a second resin layer formed on the first resin layer, and between the first resin layer and the second resin layer. A light-emitting element having a composition gradient layer in which a composition gradually changes from a material forming the first resin layer to a material forming the second resin layer. 8. The light emitting device according to claim 7, wherein the first resin layer is formed so as to cover the semiconductor LED chip. 9. The light emitting device according to claim 7, wherein both the first resin layer and the second resin layer are made of a silicone resin. 10. The first resin layer and the second resin layer are made of a silicone resin and an epoxy resin, respectively.
9. The light emitting device according to any one of items 1 to 8. 11. The light emitting device according to claim 10, wherein the base and the semiconductor LED chip are wire-bonded via a conductive wire, wherein the silicone resin of the first resin layer forms at least a joint between the base and the conductive wire. Light emitting element to cover. 12. The first resin layer and the second resin layer are made of an epoxy resin and a silicone resin, respectively.
9. The light emitting device according to any one of items 1 to 8. 13. The light emitting device according to claim 12, wherein the base and the semiconductor LED chip are wire-bonded via a conductive wire, wherein the silicone resin of the second resin layer forms at least a joint between the base and the conductive wire. Light emitting element to cover. 14. A method of manufacturing a light-emitting element, comprising: a semiconductor LED chip provided on a base; and a translucent resin filled on the base so as to cover the semiconductor LED chip. Forming a gel-like first resin layer by applying a material constituting a layer; and applying a material constituting a second resin layer on the first resin layer in the gel state, thereby forming a second resin. A method for manufacturing a light emitting device, comprising: forming a layer; and simultaneously curing the first resin layer and the second resin layer.