KR20120074734A - Wavelength converted light emitting diode chip and light emitting device having the same - Google Patents

Abstract

PURPOSE: A light emitting diode chip with wavelength conversion and a light emitting device including the same are provided to relieve deviation of a color according to a view angle by reducing influence on distribution of a fluorescent substance. CONSTITUTION: A light emitting diode chip(15) emits light of a first wavelength. A wavelength conversion layer(17) converts a part of the light of the first wavelength which is from the light emitting diode chip to light of a different wavelength band. The wavelength conversion layer includes transparent fluorescence resin(17b) and at least one kinds of fluorescence powder(17a). A nano particle(D) for light diffusion is spread into the wavelength conversion layer. Light(L1) from the light emitting diode chip is converted by the fluorescence powder.

Description

Wavelength converting light emitting diode chip and light emitting device having same {WAVELENGTH CONVERTED LIGHT EMITTING DIODE CHIP AND LIGHT EMITTING DEVICE HAVING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wavelength conversion type light emitting diode chip, and in particular, it is possible to finally emit white light by the mixing of secondary light by at least one phosphor excited by the original emission light of the LED chip and the emission light of a part thereof. The present invention relates to a wavelength conversion type light emitting diode chip and a wavelength conversion type light emitting device having the same.

Semiconductor light emitting diode (semiconductor light emitting diode) is known as a next-generation light source that has the advantages of long life, low power consumption, fast response speed, high output, etc., compared to the conventional light source, and has attracted great attention as a useful light source in various products. .

In the light emitting device using such a light emitting diode, a technique using a phosphor is widely applied to convert light emitted from a light emitting diode chip into light having a different wavelength. In particular, such wavelength conversion technology has been greatly demanded in light emitting devices for white light required in backlights of various types of lighting devices and display devices.

In such a wavelength converting light emitting device for white light, the phosphor is contained in a transparent resin for packaging the light emitting diode chip to convert a part of the original emitted light of the light emitting diode chip into secondary light of a different wavelength, and the unconverted original emitted light portion And secondary light may be mixed to achieve white color.

In this case, it is provided to surround the LED chip in a state in which phosphors are mixed in a transparent resin, in which case, the phosphor distribution provided for wavelength conversion can have a great influence on the luminance and spectral distribution of white light. In other words, when the phosphor is not uniformly distributed in the resin packaging, color reduction due to a decrease in luminous efficiency and a direction angle may occur. In addition, when using two or more phosphors (eg, selected combinations of yellow, green, and red phosphors) to improve color rendering (CRI), problems due to non-uniform distribution of phosphors will become more serious.

In particular, in a light emitting device having a high flux LED driven by applying a high current, the distribution of the phosphor having irregular and low reproducibility has a disadvantage of further accelerating the color conversion efficiency and reliability deterioration rate.

The present invention is to solve the problems of the prior art, an object of the present invention is to provide a wavelength conversion type light emitting diode chip that can ensure a high reproducibility while reducing the influence on the distribution of the phosphor to reduce the color deviation according to the orientation angle have.

Another object of the present invention is to provide a wavelength conversion type light emitting device capable of ensuring a high reproducibility while reducing the influence on the distribution of phosphors to mitigate color deviation according to a directivity angle.

In order to solve the above technical problem, an aspect of the present invention

A wavelength conversion comprising a light emitting diode chip emitting light of a first wavelength and a resin containing at least one phosphor powder converting a part of the light of the first wavelength emitted from the light emitting diode chip into light of another wavelength region Provided is a wavelength conversion type light emitting diode chip comprising a layer and light diffusion nanoparticles dispersed in the wavelength conversion layer so that the phosphor powder has a gentler distribution gradient than the distribution gradient in the thickness direction of the wavelength conversion layer.

Preferably, the light diffusion nanoparticles may be a porous material.

Preferably, a region from the top surface of the light emitting diode chip to an arbitrary point corresponding to 1/2 or less of the center height of the wavelength converting layer is defined as a lower region, and the other region of the wavelength converting layer is an upper region. In the definition, the phosphor powder may be mainly distributed in the lower region of the wavelength conversion layer rather than the upper region of the wavelength conversion layer.

In this case, the light diffusion nanoparticles distributed in the upper region of the wavelength conversion layer is preferably at least 30% of the weight of the light diffusion nanoparticles dispersed in the entire region of the wavelength conversion layer.

The phosphor powder distributed in the lower region of the wavelength conversion layer may be 90% or more relative to the weight of the phosphor powder dispersed in the entire region of the wavelength conversion layer.

In one embodiment, the light emitting diode chip may have a top surface having a convex meniscus shape. The boundary of the wavelength conversion layer may be defined by the top edge of the light emitting diode chip.

Preferably, the light diffusion nanoparticles may be a ceramic powder having a white.

For example, a material selected from Al ₂ O ₃ , TiO ₂ , SiO _2, and combinations thereof may be used as the light diffusing nanoparticles. It is preferable that the average particle size of the said light-diffusion nanoparticles is 20-200 nm.

The resin may be a silicone resin, an epoxy resin or a mixture thereof. The at least one kind of phosphor may be a plurality of kinds of phosphors for converting light emitted from the light emitting diode chip into different wavelength regions.

In a specific example, the peak wavelength of the emission light of the light emitting diode chip is in the range of 380 ~ 500nm, the plurality of phosphors may include a green phosphor and a red phosphor to convert to green light.

According to another aspect of the present invention, a mounting member having first and second lead structures, and mounted to the mounting member so as to be electrically connected to the first and second lead structures, emit light of the first wavelength. A wavelength conversion layer comprising a light emitting diode chip, a resin containing at least one phosphor powder for converting a part of light having a first wavelength emitted from the light emitting diode chip into light of another wavelength region, and the phosphor powder It provides a wavelength conversion light emitting device comprising a light diffusion nanoparticles dispersed in the wavelength conversion layer to have a gentler distribution gradient than the distribution gradient in the thickness direction of the wavelength conversion layer.

In one embodiment, the light emitting diode chip may have a top surface having a convex meniscus shape. The boundary of the wavelength conversion layer may be defined by the top edge of the light emitting diode chip.

In this case, the light emitting diode chip and at least one of the first and second lead structures may be electrically connected by wires. The maximum thickness of the wavelength conversion layer is preferably smaller than the height of the wire from the upper surface of the LED chip.

According to one embodiment of the present invention, in spite of the irregular distribution of the phosphor powder, by scattering the light-diffusing nanoparticles, not only the color deviation due to the orientation angle can be reduced, but also the color reproducibility can be improved.

In addition, the wavelength conversion layer on the upper surface of the light emitting diode chip may be provided to have a convex meniscus shape such as a dome structure. This shape can be controlled by selecting relatively factors such as optimizing the viscosity or thixotropy of the phosphor mixed resin.

1A and 1B are schematic cross-sectional views and a partially enlarged view of a wavelength conversion type light emitting diode chip according to an embodiment of the present invention, respectively.
2 is a graph illustrating a distribution gradient of phosphors and light diffusing nanoparticles in the thickness direction of the wavelength conversion layer of the wavelength conversion type light emitting diode chip according to the present invention.
3A and 3B are schematic cross-sectional views each showing an improvement example of the wavelength conversion type light emitting diode chip according to the present invention.
4A to 4C are cross-sectional views of main processes for explaining an example of a method of manufacturing a wavelength conversion light emitting device according to the present invention.
5 is a schematic cross-sectional view showing a wavelength conversion light emitting device according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described embodiments of the present invention;

1A is a schematic cross-sectional view of a wavelength conversion type light emitting diode chip according to an embodiment of the present invention.

The wavelength conversion type light emitting diode chip 10 shown in FIG. 1A includes an LED chip 15 and a wavelength conversion layer 17 formed on an upper surface thereof. The wavelength conversion layer 17 includes a transparent phosphor resin 17b and at least one phosphor powder 17a contained therein.

In the form for providing white light as final light, the emitted light of the LED chip 15 may have a wavelength range of 380 ~ 500nm. That is, the LED chip 15 may be a UV or blue LED chip.

As the phosphor 17a, at least one phosphor capable of converting the emitted light into light of another wavelength region may be used. That is, one kind of phosphor converted to yellow light may be used, but two or more kinds of phosphors may be used in combination.

For example, a combination of red and green phosphors, or a combination of red, yellow or green phosphors can be used. The larger the number of phosphors combined, the higher the color rendering can be expected.

As shown in FIG. 1, since the wavelength conversion layer 17 is provided only on the upper surface of the LED chip 15, it is possible to ensure a more uniform phosphor distribution than a shape formed to surround the entire area of the chip. In addition, since the upper surface of the LED chip 15 is provided as the main light emitting surface, even if the wavelength conversion layer 17 is formed only on the upper surface of the LED chip 15 can obtain a sufficient light conversion effect.

The wavelength conversion type light emitting diode chip 10 according to the present embodiment further includes light diffusing nanoparticles D dispersed in the wavelength conversion layer 17 in order to effectively alleviate the color deviation due to the orientation angle. Preferably, the light diffusion nanoparticles (D) may be a ceramic powder having a white. For example, a material selected from Al ₂ O ₃ , TiO ₂ , SiO _2, and combinations thereof may be used as the light diffusing nanoparticles (D). It is preferable that the average particle size of the said light-diffusion nanoparticles is 20-200 nm.

In order to alleviate the color variation with respect to the final light, the light diffusion nanoparticle (D) has a distribution gradient in which the phosphor powder 17a is gentler than the distribution gradient along the thickness direction of the wavelength conversion layer 17.

That is, in order to alleviate the color deviation with respect to the final light, the distribution of the phosphor powder 17a is light diffused so that the light diffusing nanoparticles D can scatter / diffuse light converted by the phosphor powder 17a effectively. It may be concentrated below the distribution of the molten nanoparticles (D).

For example, as illustrated in FIG. 1B, the main distribution of the phosphor powder 17a is concentrated in the lower portion close to the upper surface of the light emitting diode chip 15, while the light diffusing nanoparticles have relatively less precipitation. It can have a more uniform distribution in the whole area.

As described above, light L1 emitted from the light emitting diode chip is converted by the phosphor powder by being disposed in the order of the phosphor powder 17a and the nanoparticle D based on the relative particle distribution ratio along the light emission path. In order to increase the probability of meeting the converted light L2 with the light diffusing nanoparticles, scattering / diffusion L3 may be effectively performed.

Therefore, by using the distribution of the phosphor powder and nanoparticles shown in Figure 1b it can be expected to reduce the excellent color deviation by the nanoparticles.

Distribution gradient conditions of the above-described particles can be obtained by precipitating the phosphor powder 17a at a faster rate than the light diffusing nanoparticles D in the process of forming the wavelength conversion layer 17. By this precipitation rate, the phosphor powder 17a may be more concentrated in the lower portion than in the upper portion of the wavelength conversion layer 17 than the light diffusing nanoparticles D.

The precipitation rate control for the above-described distribution gradient can be realized by adjusting various conditions such as the density and particle size of the phosphor powder and the light diffusing nanoparticles, the viscosity of the resin of the wavelength conversion layer, the curing time, and the like.

Preferably, the distribution gradient required in this embodiment can be easily realized by selecting a material having a density lower than that of the phosphor powder for the light diffusing nanoparticles (D). In particular, in order to achieve a relatively slow precipitation of the light diffusion nanoparticles, it can be selected as a porous material. For example, a porous material selected from Al ₂ O ₃ , TiO ₂ , SiO _2, and a combination thereof may be used as the light diffusion nanoparticles (D).

In this way, the phosphor powder 17a is distributed closer to the upper surface of the LED chip than the light diffusing nanoparticles D, thereby reducing the probability that the converted light excited by the phosphor powder 17a meets the light diffusing nanoparticles D. In this case, even if the phosphor distribution is somewhat concentrated in one region of the wavelength conversion layer 17, color deviation due to the orientation angle may be effectively alleviated.

In this aspect, a preferable distribution gradient condition of the phosphor powder 17a and the light diffusing nanoparticles D in the wavelength conversion layer 17 can be proposed as the distribution ratio for each region.

2, there is shown a graph for explaining the preferred distribution gradient. In this graph, the x axis represents "H", which is the height of the center portion of the wavelength conversion layer 17 from the top surface of the LED chip 15, the y axis represents the distribution density of particles, and "P" and "D" represent phosphor powder and The distribution along the thickness direction of the light diffusion nanoparticles is shown.

When the area from the wavelength conversion layer 17 to any point corresponding to 1/2 or less of the height H is defined as the lower area, and the other area of the wavelength conversion layer 17 is defined as the upper area. The phosphor powder may be distributed in the lower region of the wavelength conversion layer 17 rather than the upper region of the wavelength conversion layer 17.

In this case, the light diffusing nanoparticles distributed in the upper region of the wavelength conversion layer 17 is 30% of the weight of the light diffusing nanoparticles (D) dispersed in the entire region of the wavelength conversion layer 17. It is preferable that it is above. In particular, the phosphor powder 17a distributed in the lower region of the wavelength conversion layer 17 may be 90% or more relative to the weight of the phosphor powder dispersed in the entire region of the wavelength conversion layer 17.

This distribution gradient is mainly because light diffusing nanoparticles (D) are distributed in the upper region compared to the phosphor powder, and phosphor powder (17a) is dominantly distributed in the lower region than the upper region, the light by the phosphor powder (17a) The conversion is mainly performed in the lower region, and meets the light diffusing nanoparticles (D) in the path through which the converted light travels to mitigate color deviation in the overall directivity angle.

As shown in FIG. 1A, the wavelength conversion layer 17 formed on the upper surface of the LED chip 15 may have a convex meniscus upper surface M. Referring to FIG.

The convex meniscus structure can provide advantageous advantages in terms of the directivity angle and color distribution of light emitted from the wavelength conversion layer 17. The convex meniscus structure employed in the present embodiment can be obtained using the surface tension of the liquid resin in which the phosphor powder 17a is contained in advance.

In addition, the convex menisker structure may be adjusted using conditions such as viscosity or thixotropy of the phosphor-containing liquid resin. In particular, in the process of forming the wavelength conversion layer using a liquid resin, the boundary of the structure having a convex meniscus shape for the wavelength conversion layer 17 may be defined by the top edge of the LED chip 15.

In this case, the wavelength conversion layer 17 can be formed to have high structural reproducibility in a desired region (top surface of the chip).

The meniscus shape employed as the structure of the wavelength conversion layer 17 in the present invention may be easily deformed by adjusting some process factors in consideration of desired orientation angle characteristics and chromaticity distribution. In particular, as a simple method for obtaining a desired meniscus shape, a method of adjusting the viscosity or thixotropy of the phosphor-containing liquid resin can be used.

The viscosity or thixotropy of the phosphor-containing liquid resin can be controlled not only by the viscosity itself of the transparent resin used, but also by the content and / or particle size of the phosphor. In addition, the viscosity control of the phosphor-containing liquid resin may be realized using additional additives. This will be described in more detail with reference to FIG. 4.

On the other hand, in addition to the restructuring scheme of the wavelength conversion layer described above, it is possible to form a desired convex meniscus structure on the chip upper surface to ensure a stable and high reproducibility using another approach.

As such an approach, for example, a method of changing the surface state of the upper surface of the LED chip may be used. This will be described in detail with reference to FIGS. 3A and 3B.

The wavelength conversion type light emitting diode chip 20 shown in FIG. 3A includes an LED chip 25 and a surface modification layer 26 formed on an upper surface thereof. The wavelength conversion layer 27 is formed on the surface modification layer 26. The wavelength conversion layer 27 includes a transparent phosphor resin 27b and at least one phosphor powder 27a contained therein.

The wavelength conversion layer 27 further includes light diffusing nanoparticles D in addition to the phosphor powder 27a.

As illustrated in FIGS. 1B and 2, the light diffusing nanoparticles D have a distribution gradient that is slower than that of the phosphor powder 27a in the thickness direction of the wavelength conversion layer 27. In the present embodiment, most of the phosphor powder 27a is deposited on the upper surface of the LED chip 25, and is shown in a state in which a relatively large amount of light diffusing nanoparticles D are suspended.

In this way, the phosphor powder 27a is distributed closer to the upper surface of the LED chip than the light diffusing nanoparticles D, thereby reducing the probability that the converted light excited by the phosphor powder 27a meets the light diffusing nanoparticles D. It can increase. Even if the phosphor distribution is somewhat concentrated in one region of the wavelength conversion layer 27, color deviation due to the directivity angle may be effectively alleviated.

The light diffusion nanoparticles (D) may be a ceramic powder having a white color. For example, the light diffusion nanoparticles (D), Al ₂ O ₃ , TiO ₂ , SiO ₂ And combinations thereof. It is preferable that the average particle size (D) of the light-diffusion nanoparticles is 20 to 200 nm.

In the present embodiment, the surface modification layer 26 is selected as a material having the same physical properties as the liquid resin for the wavelength conversion layer 27 of hydrophobicity and hydrophilicity.

For example, when the resin for the wavelength conversion layer 27 is a hydrophobic liquid resin such as a silicone resin, a hydrophobic material such as a silicon nitride film (SiN _x ) may be formed of an LED chip ( 25) It is formed in advance on the upper surface.

The surface modification layer 26 may provide a meniscus shape to have a relatively high contact angle θ _c by lowering the wettability of the phosphor-containing resin on the top surface of the LED chip 25. As such, the surface modification layer 26 employed in the present embodiment serves to help maintain the convex meniscus shape of the wavelength conversion layer 27 well.

In addition, when the surface modification layer 26 is a material having electrical insulation, it may be provided as a passivation layer including the LED chip 25. In this case, the surface modification layer 26 may be additionally formed in another region in addition to the top surface of the LED chip 25.

In the embodiment shown in FIG. 3A, a method of forming an additional layer is introduced. Alternatively, the upper surface of the LED chip 25 on which the wavelength conversion layer 27 is to be formed is the same as the phosphor-containing resin by surface treatment. It may be implemented in a physical (hydrophobic or hydrophilic) manner.

3B, the wavelength conversion type LED chip 30 includes an LED chip 35 having an upper surface on which the unevenness 35a is formed, and a wavelength conversion layer 37 formed on the upper surface thereof. The wavelength conversion layer 37 includes a transparent phosphor resin 37b and at least one phosphor 37a contained therein.

The wavelength conversion layer 37 is similar to the embodiment described with reference to FIG. 3A, wherein the phosphor powder 37a has a distribution gradient that is gentler than a distribution gradient along the thickness direction of the wavelength conversion layer 37. It further comprises a nanoparticle (D).

In this example, the contact area of the surface on which the wavelength conversion layer 37 is to be formed may be increased by using unevenness. Therefore, by delaying the flow of the liquid resin on the upper surface of the LED chip 35, not only helps to form a convex meniscus structure, but also improves adhesive strength with the wavelength conversion layer 37.

The unevenness 35a employable in the present embodiment is not limited thereto, but may be irregular unevenness by wet etching.

4A to 4C are cross-sectional views of main processes for explaining an example of a method of manufacturing a wavelength conversion light emitting device according to the present invention.

As shown in FIG. 4A, the method of manufacturing the wavelength conversion type light emitting device includes mounting a light emitting diode (LED) chip 55 emitting light of ultraviolet (UV) light or blue wavelength region on the mounting member 51. Begins with.

The mounting member 51 includes first and second lead structures 52 capable of providing external connection terminals. The mounted LED chip 55 may be electrically connected to the first and second lead structures 52 to be driven. Unlike the present embodiment, wire bonding may be applied only to the electrical connection of one electrode according to the electrode structure of the LED chip, or all electrical connections may be implemented by flip chip bonding without wire bonding.

As in the present embodiment, when wire bonding is applied, it is preferable to appropriately set the connection form and height h of the wire so that the wire 53 is not adversely affected in forming the wavelength conversion layer in a subsequent step. Do. Here, when the height h of the wire is defined as the height of the uppermost end of the wire 53 from the top surface of the mounted LED chip 55, the height h of the wire, that is, the thickness of the wavelength conversion layer to be formed in a subsequent process, namely It is preferable to set larger than the height H of the center part.

Next, as shown in FIG. 4B, a mixed liquid resin 57 for forming a wavelength conversion layer is provided, and then the mixed liquid resin 57 is provided on the LED chip 55 to form a desired convex meniscus shape. To form a structure 57 " having a top surface thereof.

The mixed liquid resin 57 is a transparent liquid resin containing nanoparticles for light diffusion together with at least one phosphor powder 57a for converting light emitted from the LED chip 55 into light of a different wavelength region ( 57b).

The mixed liquid resin 57 may be provided on an upper surface of the LED chip 55. The present process may be a known process such as dispensing, screen printing, spray coating and the like. In particular, the dispensing process has an advantage in that the desired meniscus curved surface can be easily implemented using the surface tension of the liquid resin.

The process example shown in FIG. 4B is an example employing a dispensing process. As shown in Fig. 4B, the droplet 57 'provided on the upper surface of the LED chip 55 using the nozzle N is spread on the upper surface of the chip, and the desired convex meniscus structure 57 " It can have

At this time, the viscosity of the liquid resin can be adjusted together with the amount of droplets to be added to provide a desired convex meniscus structure 57 ″ only on the upper surface of the chip. (55) By changing the convex meniscus structure formed on the upper surface, it is possible to control the orientation angle characteristic and chromaticity distribution.

The viscosity of the phosphor-containing resin can be controlled by the content and / or particle size of the phosphor as well as the viscosity itself of the transparent resin used. For example, the higher the content of the phosphor and the smaller the particle size of the phosphor, the higher the viscosity and thixotropy of the phosphor-containing resin, and consequently, the greater the surface tension will increase the curvature of the meniscus shape. On the contrary, a meniscus wavelength conversion layer having a small curvature or a contact angle can be obtained.

In addition, it is preferable to adjust the shape and height of the wire 53 so that the injected droplets do not flow out of the upper surface of the chip 55 and have a desired convex meniscus structure. In the step of FIG. 4A in advance, it is preferable to form the wire 53 to have a height h greater than the height of the meniscus structure 57 'for the wavelength conversion layer. In addition, it is preferable that the wire extraction angle θ _w is formed to be about 45 ° or more based on the surface of the meniscus structure in contact with the wire.

On the other hand, the distribution gradient of the light diffusion nanoparticles is implemented to be more gentle than the distribution gradient of the phosphor powder. Preferably, the light diffusion nanoparticles (D) in the upper region is mainly distributed compared to the phosphor powder, while the phosphor powder may be dominantly distributed in the lower region than the upper region. In order to obtain such a distribution it can be controlled to occur the difference in the settling rate of the two powders.

For example, it can be realized by adjusting various conditions such as the density and particle size of the phosphor powder 57a and the light diffusing nanoparticles (D), the viscosity of the resin of the wavelength conversion layer, the curing time, and the like. In particular, the particle size conditions of the phosphor powder 17a and the light-diffusion nanoparticles (D) can be appropriately selected to easily realize the distribution gradient required in the present embodiment.

Next, as shown in FIG. 4C, the mixed liquid resin 57 ″ including the phosphor powder 57a, the light diffusion nanoparticles D, and the transparent liquid resin 57b is cured to maintain the meniscus structure. As a result, the wavelength conversion layer 67 may be formed on the upper surface of the LED chip.

Before this curing process, as shown in Fig. 4B, the mixed liquid resin 57 'provided on the upper surface of the chip 55 is deformed to have a convex meniscus structure 57 ". At this time, the convex menis At the boundary of the curse structure 57 ", the edge of the upper surface of the chip 55 is reached, and the structural change of the liquid resin on the upper surface of the chip is significantly slowed down, and the change can be almost finished by adjusting the viscosity of the resin droplet.

As such, the boundary of the convex meniscus structure may be defined using the edges of the upper surface of the LED chip 55, and the wavelength conversion layer defined by the upper surface of the chip 55 is applied as shown in FIG. 4C by applying a curing process. Not only can 67 be provided, but also the reproducibility of the structure of the wavelength conversion layer 67 can be improved.

In the finally obtained wavelength conversion layer 67, the distribution gradient of the light diffusion nanoparticles appears more gentle than the distribution gradient of the phosphor powder. As shown, the light diffusing nanoparticles D are mainly distributed in the upper region compared to the phosphor powder 57a, whereas the phosphor powder 57a may be dominantly distributed in the lower region than the upper region.

5 is a schematic cross-sectional view showing a wavelength conversion light emitting device 130 according to an embodiment of the present invention.

Referring to FIG. 5, the wavelength conversion type light emitting device 130 according to the present embodiment includes a main body 131 having a cavity C having an inclined sidewall and an LED chip 135 mounted in a cavity of the main body 131. ).

The LED chip 135 may be electrically connected to the lead structure 132 of the substrate 131 using a wire 133. As shown, the height of the wire, i.e., the height of the top of the wire 53 from the top surface of the mounted LED chip 55, in order to prevent the resin from flowing down during the formation of the wavelength conversion layer by the wire 133. Is set to be larger than the height of the wavelength conversion layer 137.

The wavelength conversion layer 137 having a convex meniscus upper surface is formed on the upper surface of the LED chip 135. The wavelength conversion layer 137 further includes light diffusing nanoparticles D together with the phosphor powder 137a.

The light diffusing nanoparticles D have a distribution gradient in which the phosphor powder 137a is gentler than a distribution gradient in the thickness direction of the wavelength conversion layer 137. In the present embodiment, most of the phosphor powder 137a is deposited on the upper surface of the LED chip 135 and is shown in a state in which a relatively large amount of light diffusing nanoparticles D are suspended.

As described above, the phosphor light 137a is distributed closer to the upper surface of the LED chip 135 than the light diffusing nanoparticles D so that the converted light excited by the phosphor powder 137a is applied to the light diffusing nanoparticles D. You can increase your chances of meeting. Although the phosphor distribution is somewhat concentrated in one region of the wavelength conversion layer 137, color deviation due to the directivity angle may be effectively alleviated.

The light diffusion nanoparticles (D) may be a ceramic powder having a white color. For example, the light diffusion nanoparticles (D) may be a material selected from Al ₂ O ₃ , TiO ₂ , SiO _2, and combinations thereof. In particular, a porous material may be preferably used for delaying the settling rate. In consideration of the particle size of a conventional phosphor powder, the average particle size of the light diffusion nanoparticles is preferably 20 to 200 nm.

It is intended that the invention not be limited by the foregoing embodiments and the accompanying drawings, but rather by the claims appended hereto. It will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. something to do.

Claims (22)

A light emitting diode chip emitting light of a first wavelength;
A wavelength conversion layer made of a resin containing at least one phosphor powder for converting a part of light having a first wavelength emitted from the light emitting diode chip into light having a different wavelength region; And
And a light diffusion nanoparticle dispersed in the wavelength conversion layer such that the phosphor powder has a gentler distribution gradient than the distribution gradient in the thickness direction of the wavelength conversion layer.
The method of claim 1,
The light diffusing nanoparticle is a light emitting diode chip, characterized in that the porous material.
The method of claim 1,
In the wavelength conversion layer, an area from an upper surface of the light emitting diode chip to an arbitrary point corresponding to 1/2 or less of the center height thereof is defined as a lower area, and another area of the wavelength conversion layer is defined as an upper area. ,
The phosphor powder is mainly distributed in the lower region of the wavelength conversion layer than the upper region of the wavelength conversion layer LED chip.
The method of claim 3,
The light diffusing nanoparticles distributed in the upper region of the wavelength conversion layer is a wavelength conversion light emitting diode chip, characterized in that more than 30% of the weight of the light diffusion nanoparticles dispersed in the entire area of the wavelength conversion layer.
The method of claim 3,
The phosphor powder distributed in the lower region of the wavelength conversion layer is a wavelength conversion light emitting diode chip, characterized in that more than 90% of the weight of the phosphor powder dispersed in the entire region of the wavelength conversion layer.
The method according to any one of claims 1 to 5,
A wavelength conversion type light emitting diode chip formed on the upper surface of the light emitting diode chip and has a convex meniscus top surface.
The method of claim 6,
The boundary of the wavelength conversion layer is a wavelength conversion type light emitting diode chip, characterized in that defined by the top edge of the light emitting diode chip.
The method according to any one of claims 1 to 5,
The light diffusion nanoparticles wavelength conversion type light emitting diode chip, characterized in that the ceramic powder having a white.
The method of claim 8,
The light diffusion nanoparticles are wavelength conversion type light emitting diode chip, characterized in that made of a material selected from Al ₂ O ₃ , TiO ₂ , SiO ₂ and combinations thereof.
The method of claim 8,
The wavelength conversion type light emitting diode chip, characterized in that the average particle size of the light diffusion nanoparticles is 20 ~ 200nm.
The method according to any one of claims 1 to 5,
The resin is a silicon resin, epoxy resin or a mixture thereof wavelength converting light emitting diode chip.
The method according to any one of claims 1 to 5,
And said at least one kind of phosphor is a plurality of kinds of phosphors for converting light emitted from said light emitting diode chip into different wavelength ranges.
The method of claim 12,
The peak wavelength of the emission light of the light emitting diode chip is in the range of 380 ~ 500nm,
And said plurality of phosphors comprises a green phosphor and a red phosphor converting green light.
A mounting member having first and second lead structures;
A light emitting diode chip mounted on the mounting member to be electrically connected to the first and second lead structures, the light emitting diode chip emitting light of the first wavelength;
A wavelength conversion layer made of a resin containing at least one phosphor powder for converting a part of light having a first wavelength emitted from the light emitting diode chip into light having a different wavelength region; And
And a light diffusion nanoparticle dispersed in the wavelength conversion layer such that the phosphor powder has a gentler distribution gradient than the distribution gradient along the thickness direction of the wavelength conversion layer.
The method of claim 14,
The light diffusion nanoparticles wavelength conversion type light emitting device, characterized in that the porous material.
The method of claim 14,
In the wavelength conversion layer, an area from an upper surface of the light emitting diode chip to an arbitrary point corresponding to 1/2 or less of the center height thereof is defined as a lower area, and another area of the wavelength conversion layer is defined as an upper area. ,
The phosphor powder is mainly distributed in the lower region of the wavelength conversion layer than the upper region of the wavelength conversion layer light emitting device.
The method of claim 16,
The light diffusing nanoparticles distributed in the upper region of the wavelength conversion layer is a wavelength conversion light emitting device, characterized in that more than 30% of the weight of the light diffusion nanoparticles dispersed in the entire region of the wavelength conversion layer.
The method of claim 16,
And the phosphor powder distributed in the lower region of the wavelength conversion layer is 90% or more relative to the weight of the phosphor powder dispersed in the entire region of the wavelength conversion layer.
The method according to any one of claims 14 to 18,
And a convex meniscus upper surface formed on the upper surface of the light emitting diode chip.
20. The method of claim 19,
The boundary of the wavelength conversion layer is a wavelength conversion light emitting device, characterized in that defined by the top edge of the light emitting diode chip.
20. The method of claim 19,
And at least one of the light emitting diode chip and the first and second lead structures is electrically connected by a wire.
The method of claim 21,
And the maximum thickness of the wavelength conversion layer is smaller than a height of the wire from an upper surface of the light emitting diode chip.

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