KR100649771B1 - RGB Light Emitting Diode Package with Improved Color Miscibility - Google Patents

Abstract

The present invention relates to an RGB LED package having improved color mixing.

An RGB light emitting diode package comprising: red, green, and blue light emitting diode chips disposed on a reflector on which a device is mounted or mounted, and an opal light mixture to help scatter light so that light emitted from each light emitting diode chip is evenly mixed. And a material and a resin filler, wherein the light mixture and the resin filler are mixed to cover the top surface of the diode chip, wherein the light mixture is uniformly dispersed in the resin filler. An RGB light emitting diode package having improved color mixing is provided.

While the conventional method has difficulty in designing a slim package due to the constraint that sufficient space for color mixing is provided, the RGB light emitting diode package of the present invention has excellent color mixing even in a relatively small space, resulting in a slim package design. This is possible.

 Light Emitting Diodes, Photomixers, Resins, Epoxy, Silicon

Description

RGB Light Emitting Diode Package with Improved Color Miscibility

1 schematically illustrates a conventional RGB light emitting diode package in which white light is arranged by arranging RGB chips.

Figure 2 shows an electron micrograph of the silicon resin light mixture material used in the present invention.

3 is an electron micrograph showing a state in which a silicon resin photomixer is mixed in a light emitting diode filler (a-surface photograph, b-cross section photograph).

Figure 4 schematically shows the RGB light emitting diode package of the present invention is improved color mixing by applying the light mixture on the RGB chip arrangement in accordance with the present invention.

FIG. 5 shows the results of investigating RGB light emitting diode color mixing in various cases through computer simulation in an embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

1-Ray 2-RGB LED Chip

3-reflector with light emitting element mounted or mounted 4-filler

5-Light Mixing Material (Scattering Agent)

The present invention relates to a red green blue light emitting diode (RGB LED) package, and more particularly, by applying a light mixing material in an RGB light emitting diode, excellent color mixing is possible in a relatively small space, and thus a slim package design is possible. An RGB light emitting diode package.

Light emitting diodes emit light of transparent color with high density and high efficiency. In addition, the light emitting diode is thermally free and is a semiconductor element, so it has excellent initial operating characteristics, high vibration resistance and durability to withstand repeated on / off operation. Light emitting diodes are therefore widely used as various indicators and light sources for such applications.

In recent years, the light emitting diode is being used as a luminaire and its use range is expanding. The light emitting diode is made of gallium arsenide (GaAs), gallium phosphite (GaP), gallium nitride (GaN), silicon carbide (SiC), etc., depending on the emission color, intensity of illuminance, and the like.Avalanche Breakdown Its PN junction can emit visible light at a relatively low voltage when biased in the) region. In the display device, power is applied by the multiplexing network to reduce power consumption, and the light emitting diodes provide light of different wavelengths by changing their structure. Such light emitting diodes are used individually or in a matrix structure.

Recently, light emitting diodes for RGB (red, green and blue) colors with ultra high luminous efficiency and high efficiency have been developed, and large screen LED displays using such light emitting diodes have emerged. These LED displays can be operated with less power and are expected to be used more widely in the future with excellent characteristics such as light weight and long life.

Various attempts have been made to generate a white light source using a light emitting diode. Since light emitting diodes have a favorable emission spectrum for producing monochromatic light, in order to generate a light source for white light, three light emitting components, R, G and B, are arranged in close proximity to each other and the light emitted by them is diffused and mixed. It is necessary to be. In the case of producing white light in this arrangement, they have a problem such that white light of a desired color tone is not generated due to changes in color tone, brightness and other factors of the light emitting components.

In addition, when the light emitting components are made of different materials, since the power required for operation is different for one light emitting component and another light emitting component, it is necessary to apply different voltages to the other light emitting components, which is complicated. There is an inconvenience in making the operation circuit. Furthermore, since the light emitting component is a semiconductor light emitting component, a color tone may change or an uneven color may be generated due to temperature characteristics, chronological changes, and differences in operating devices, which may result in a uniform mixing of light emitted by the light emitting component. You can prevent it from happening.

A method of implementing white in the conventional RGB light emitting diode is illustrated in FIG. 1. As shown in Fig. 1, in the conventional method, since the colors are mixed depending on the orientation angle of the chip itself, even color mixing is possible only over a certain distance. One application is to mount individual chips in the shape of a lens, but this also has a limitation in evenly mixing colors and hassle of complicated lens design.

Therefore, the light emitting diode is effective as a light emitting device for generating individual colors, but has not yet obtained a satisfactory light source capable of emitting white light using a light emitting component.

On the other hand, in recent years, a very thin RGB light emitting diode package using a high brightness LED chip tends to be preferred. However, such a thin RGB light emitting diode package has a limitation in even color mixing in the package due to space limitation.

Accordingly, an object of the present invention is to provide an RGB light emitting diode package that is excellent in color mixing in a relatively small space by applying a light mixture material in the RGB light emitting diode and thus enables a slim package design.

According to one aspect of the invention,

In an RGB (red, green, blue) light emitting diode package, red, green, and blue light emitting diode chips disposed on a reflector on which a device is mounted or mounted, and the light emitted from each light emitting diode chip are mixed evenly. It is provided with a light mixture and a resin filler to assist scattering, the light mixture and the resin filler is in a mixed form is arranged to cover the top surface of the diode chip in the package, wherein the light mixture is uniformly dispersed in the resin filler Provided is an RGB light emitting diode package characterized in that the present.

Hereinafter, the present invention will be described in more detail.

In the RGB light emitting diode package, the present invention can effectively scatter the light emitted from the light emitting diode when the resin-based or opal-based light mixture (also called 'scattering agent') is uniformly dispersed in the package together with the resin filler. Accordingly, it was found that uniform color mixing was possible even at a short distance, thereby completing the present invention.

Photomixers usable in the present invention include resin-based or opal-based photomixers. In particular, a resin-based light mixture is preferable. Opal-based photomixers cannot combine with filling resins, so they tend to stick together due to their high surface energy, and their specific gravity is also largely sinking, but resin-based photomixers are spherical chain structures and filling resins. Since the methyl group can form a linkage with the resin can easily be present in evenly dispersed form with the filling resin.

The resin-based photomixer useful in the present invention has a specific gravity similar to that of a conventional light emitting diode filler and has excellent dispersibility to help the light emitted from the RGB light emitting diode to be evenly emitted at a wide radiation angle.

Epoxy resin and / or silicone resin are particularly preferable as the resin-based light mixture.

Epoxy resins generally have a specific gravity of 1.230 to 1.189 and are known to be excellent in mechanical properties such as bending strength and firmness.

Silicon resin is also called silicon resin. The molecular structure of silicon resin is based on silicon in the form of siloxane bond (Si-O bond) in which silicon and oxygen are alternated, and methyl, phenyl, and hydroxy groups are added to silicon. Thermoplastic synthetic resin.

The resin-based light mixture includes a methyl group, such as silicone resin represented by the following formula (1).

[Formula 1]

Wherein R is a methyl group

Since the resin-based photomixer includes such a methyl group, the resin-based photomixer has excellent binding properties with the resin filler, and the specific gravity is similar to that of the resin filler, and thus may be dispersed evenly without precipitation.

In addition, an example of the silicone resin photomixer used in the present invention is shown in FIG. 2, and an electron micrograph showing a state in which the silicone resin photomixer is mixed in the LED filler is shown in FIG. , b-cross section picture).

As shown in Fig. 2, the silicone resin light-mixing material used in the present invention has a spherical bead or particle form, and when it is added to the filler in powder form, the shape of the arrow as shown by the arrow of Fig. 3 (b) indicates. Keep it.

In addition, according to the present invention is shown in Figure 4 the RGB light emitting diode to which the resin-based light mixture is applied.

As shown in FIG. 4, the resin-based light-mixing material dispersed evenly facilitates light scattering so that light is evenly emitted at a wide radiation angle, and the light paths emitted from each of the R, G, and B light emitting diodes. It serves to diversify. As a result, the resin-based photomixer helps to evenly mix the light emitted from each light emitting diode.

The photomixer is preferably used by uniformly mixing 1-20% by weight based on the total weight of the photomixer and the resin filler.

In addition, the photomixer preferably has a specific gravity similar to that of the filling resin so as to be evenly dispersed in the filler. The photomixer is preferably one having a specific gravity of 0.5-1.8.

If the specific gravity of the photomixture is too large, the amount of sinking may increase when mixing with the filler, which may interfere with light scattering. On the contrary, if the specific gravity is too small, the surface of the filler will be suspended when mixing with the filler. It can likewise interfere with the scattering of light. More preferably, the photomixer is one having a specific gravity of 0.9-1.8.

The light admixture and the resin filler are disposed to cover the top surface of the diode chip in a mixed form. If the light mixture material forms a layer on the light emitting diode chip at a predetermined interval, for example, when the light mixture material is not dispersed in the package and a layer of the light mixture material is formed on the package surface, the light mixture material is formed. The light emitted from each light-emitting diode may not be evenly mixed because it simply turns the light on only the package surface.

At this time, the light-mixed material is added in a powder form to a liquid filler in order to uniformly disperse in the form of beads or particles, and mixed by using a mixer at the time of mixing, and then added by removing the bubbles through a degassing process in a vacuum atmosphere. It is preferable to mix.

The added and mixed photomixed material is dispersed and present in the form of beads or particles. The size of the photomixed material dispersed in the form of beads or particles as described above preferably has a particle diameter of 0.1-30 μm.

In addition, the epoxy resin and the silicone resin may be used alone, respectively, and both may be mixed with each other when they are in powder form. When the mixture can be used, the mixing ratio is preferably 1: 1.

Resin fillers useful in the present invention are preferably, but not limited to, transparent epoxy resins or silicone resin fillers containing a reactor having a methyl group.

Hereinafter, the present invention will be described in more detail with reference to the following examples, which are merely illustrative of the present invention and do not limit the present invention to the following examples.

<Example>

Production Example  One

An RGB light emitting diode chip having an emission wavelength peak of 465 nm and a gallium nitride (GaN) semiconductor structure is used as an RGB light emitting diode. Silicone resin or epoxy resin is used as the photomixing material, which is uniformly mixed with 1-20% by weight based on the total weight of the photomixing material and the resin filler. At this time, the photomixing material is added and mixed by mixing the powdery photomixing material in a liquid resin filler in a uniform manner by mixing using a mixer. Then, bubbles are removed through a degassing process in a vacuum atmosphere and then dispersed and applied to the RGB LED package. The coating may be applied by a method such as dispensing, screen printing or dispersion. Thereafter, curing is performed under curing conditions appropriate for the resin. At this time, the curing is carried out for about 1 hour at 150 ℃ when the silicone resin is used as the light mixture material and 5 hours at 120-180 ℃ when the epoxy resin is used as the light mixture material.

Evaluation of color mixture by simulation 1

Under the following conditions, RGB light-emitting diode color mixing in various cases was investigated by computer simulation (Light Tools, Optical Research Associates).

1) When no photomixing material is contained,

2) When the light mixture material forms a layer on the light emitting diode chip at a predetermined interval (layer formation of the light mixture material on the package surface),

3) in the form of a mixture of a light mixture (added 3% by weight) and a resin filler, which is disposed directly on the side of the diode chip (the distribution of the light mixture in the package); and

4) in the form of a mixture of a light mixture (adding 10% by weight) and a resin filler, which is disposed directly on the top side of the diode chip (the distribution of the light mixture in the package);

RGB light emitting diode color mixing was investigated by ray tracing.

The number of RGB light beams was 20ea, and the directivity angle was 140 °. Since the actual size of the light mixed material (scattering agent) is very fine (less than 2㎛), it is impossible to implement. Therefore, it is assumed to be a small sphere, and the material is assumed to be a thermoplastic acrylic resin (PPMA (Polymethyl Methacrylate)). In order to investigate only the effect of the light mixture, it is assumed that the inside of the light emitting diode is air, and nothing is refracted or reflected from the surface. The ray tracing irradiation results are shown in FIG. 5.

As can be seen from FIG. 5, the light mixed material is distributed inside the package as compared with the case where no light mixed material is contained on the light emitting diode chip (a) and when the layer of the light mixed material is formed on the surface of the package (b). It can be seen that (c) and (d) can effectively disperse the direction of light, especially when the amount of the light mixture is increased (d) than when the amount of the light mixture is small (c). It can be seen that increases more. On the other hand, when the light mixture is present on the surface of the package simply plays a role of changing the direction of light on the surface of the package did not show a significant difference from the case that does not contain the light mixture.

In addition, in the manufacturing process, forming the light-mixing material as a layer on the surface of the package as shown in (b) requires generating a separate layer and injecting the light-mixing material therein. It is believed that dispersing the mixture into the package does not need to create a separate layer and can be produced by a much simpler process.

From the above results, when there is a light mixture in the package, the light direction can be effectively dispersed even in a small amount. If the amount of the light mixture is increased, the light dispersion can be increased, thereby effectively scattering the light. Therefore, it can be seen that uniform color mixing is possible at a short distance.

Production Example  2

An RGB light emitting diode chip having an emission wavelength peak of 465 nm and a gallium nitride (GaN) semiconductor structure is used as an RGB light emitting diode. Opal is used as the light mixture, which is uniformly mixed in an amount of 1-20% by weight based on the total weight of the light mixture and the silicone resin filler. At this time, the light mixed material is added and mixed by mixing the powdery light mixed material in the liquid silicone resin filler during mixing and uniformly mixing using a mixer. Then, bubbles are removed through a degassing process in a vacuum atmosphere and then dispersed and applied to the RGB LED package. The coating may be applied by a method such as dispensing, screen printing or dispersion. Thereafter, curing is performed at 150 ° C. for about 1 hour, which is appropriate for the silicone resin.

Evaluation of color mixture by simulation 2

Except that the RGB light emitting diode chip manufactured in Preparation Example 2 was used, color mixing evaluation was performed when opal was used as the light mixing material in the same manner as in the color mixing evaluation 1 according to the simulation.

The simulation test result showed the same result as the color mixture evaluation 1 by the simulation. That is, as shown in FIG. 5, the case where the light mixture is not contained on the light emitting diode chip (a) and when the layer of light mixture is formed on the surface of the package (b) when the light mixture is distributed inside the package It can be seen that (c and d) can effectively disperse the direction of light, especially when the amount of light mixture is increased (d) rather than when the amount of light mixture is small (c) It can be seen that the increase. On the other hand, when the light mixture is present on the surface of the package simply serves to turn the direction of light on the surface of the package did not show a significant difference from the case that does not contain the light mixture.

In addition, in the manufacturing process, forming the light-mixing material as a layer on the surface of the package as shown in (b) requires generating a separate layer and injecting the light-mixing material therein. It is believed that dispersing the mixture into the package does not need to create a separate layer and can be produced by a much simpler process.

From the above results, when there is a light mixture in the package, the light direction can be effectively dispersed even in a small amount. If the amount of the light mixture is increased, the light dispersion can be increased, thereby effectively scattering the light. Therefore, it can be seen that uniform color mixing is possible at a short distance.

While the conventional method has difficulty in designing a slim package due to the constraint that sufficient space for color mixing is provided, the RGB light emitting diode package of the present invention has excellent color mixing in a relatively small space and thus a slim package. Design is possible.

In the RGB light emitting diode of the present invention, there is no problem in that colors are locally different according to chip positions in the conventional method.

In addition, the RGB light emitting diode package of the present invention can widen the angle of emission of light is particularly advantageous for lighting design.

Claims (7)

In the RGB (red, green, blue) light emitting diode package, Red, green and blue light emitting diode chip disposed on the reflector on which the device is mounted or mounted, and opal light mixture and resin filler to help scatter the light so that the light emitted from each light emitting diode chip is evenly mixed. The opal light-mixing material and the resin filler are disposed to cover the top surface of the diode chip in a mixed form, wherein the opal light-mixing material is present in a uniformly dispersed form in the resin filler. Improved RGB light emitting diode package. The RGB light emitting diode package of claim 1, wherein the opal-based light mixture is added in an amount of 1-20% by weight based on the total weight of the light mixture and the resin filler. The RGB light emitting diode package of claim 1, wherein the opal light-mixing material has a specific gravity of 0.5-1.8. The method of claim 1, wherein the opal light-mixing material is added to the liquid filling resin in the form of a powder, mixed uniformly using a mixer, and then added and mixed in a manner of removing bubbles in a vacuum atmosphere. LED package. The RGB light emitting diode package of claim 1, wherein the opal light-mixing material is dispersed in the form of beads or particles. The RGB light emitting diode package of claim 5, wherein the opal light-mixing material having a bead or particle shape has a particle diameter of 0.1 to 30 µm. The RGB light emitting diode package of claim 1, wherein the resin filler is a transparent epoxy resin or a silicone resin filler.

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