TWI473305B - Light emitting diode structure - Google Patents

Description

Light-emitting diode structure

The present invention relates to a light-emitting diode structure, and more particularly to a light-emitting diode structure which can increase luminous efficiency and uniformly emit light.

Lighting equipment is indispensable for human life. With the development of technology, lighting tools with better illumination and more power saving have emerged. The most commonly used illumination source is the light-emitting diode. Light-Emitting Diode (LED) Compared with traditional light source, the light-emitting diode system has small volume, power saving, good luminous efficiency, long life, fast reaction speed, and no toxic substances such as heat radiation and mercury. Pollution and other advantages, so in recent years, the application of light-emitting diodes has been extremely extensive. In the past, the brightness of the light-emitting diodes could not replace the traditional illumination source. However, with the continuous improvement of the technical field, high-luminance LEDs (high-power LEDs) with high illumination brightness have been developed, which are sufficient to replace the traditional illumination sources. .

At present, the development of light-emitting diodes is dominated by white light-emitting diodes and high-power light-emitting diodes. In the era of environmental protection demand and high-priced energy, the white light-emitting diodes can be made into large-sized array light-emitting modules due to power saving, light and thin, and will become tomorrow's stars in the field of lighting. For example, high-power light-emitting diode light sources are increasingly used in automobiles, including automobile headlights, main brake lights, tail lights, directional lights, reverse lights, license plate lights, and the like. The traffic lights are also slowly changing to LED light sources, which not only increase the brightness, but also increase the safety and power saving.

Please refer to the first figure, which is a schematic structural diagram of a conventional light-emitting diode structure; As shown in the figure, a conventional light-emitting diode is generally provided with a light-emitting diode chip 10 in a reflector 5, and a phosphor powder layer 20 is disposed above the light-emitting diode chip 10. The phosphor powder layer 20 includes a firefly. For example, in the case of a white light emitting diode, a conventional white light emitting diode is combined with a yellow light yttrium aluminum garnet phosphor powder and a blue light emitting diode to produce a highly efficient white light emitting diode. . However, the light-emitting diode wafer 10 generates heat energy when it emits light, and heat energy is transmitted to the phosphor powder of the phosphor powder layer 20, so that the light conversion efficiency of the phosphor powder is lowered, so that the light-emitting diode wafer 10 emits light. The efficiency is also reduced, which also causes the light-emitting diode wafer 10 to emit less unevenly. If the influence of the thermal energy generated by the LED wafer 10 on the phosphor powder can be reduced, the luminous efficiency of the LED structure can be improved, and the LED structure can be uniformly illuminated.

Therefore, the present invention provides a light emitting diode structure which can reduce the heat energy generated by the light emitting diode wafer and affect the luminous efficiency of the fluorescent powder, thereby improving the luminous efficiency of the light emitting diode and making the light emitting diode structure Uniform illumination to solve the above problems.

The main purpose of the present invention is to provide a light-emitting diode structure which is disposed between a light-emitting diode wafer and a phosphor layer by a thermal barrier layer. The thickness of the thermal barrier layer is between 1 micrometer. Between 10 micrometers to reduce the influence of the thermal energy generated by the light-emitting diode wafer on the phosphor powder layer, so as to improve the conversion efficiency of the phosphor powder layer, so that the light-emitting diode structure can uniformly emit light, thereby improving the light-emitting diode The luminous efficiency of the body structure.

The light emitting diode structure of the present invention comprises a light emitting diode chip, a thermal barrier layer and a phosphor powder layer, wherein the thermal barrier layer is disposed above the light emitting diode wafer and the edge is aligned with the light emitting diode, and the fluorescent light The powder layer is disposed above the thermal barrier layer and the edge is aligned with the light-emitting layer The thickness of the phosphor layer is less than 20% of the thickness of the phosphor layer. The thermal barrier layer is used to reduce the influence of the thermal energy generated by the light-emitting diode wafer on the phosphor powder layer, so as to improve the conversion efficiency of the phosphor powder layer, so that the light-emitting diode structure can uniformly emit light, thereby improving the light-emitting diode. The luminous efficiency of the body structure.

5‧‧‧reflector

10‧‧‧Light Emitter Wafer

20‧‧‧Fluorescent powder layer

25‧‧‧reflector

30‧‧‧Light Emitter Wafer

40‧‧‧ Thermal barrier

50‧‧‧Flame powder layer

60‧‧‧Encapsulation layer

The first figure is a schematic structural view of a conventional light emitting diode structure; the second figure is a schematic structural view of a light emitting diode structure according to a preferred embodiment of the present invention; and the third figure is a light emitting light according to another preferred embodiment of the present invention. Schematic diagram of the structure of the diode structure.

In order to provide a better understanding and understanding of the structural features and efficacies of the present invention, the preferred embodiments and detailed descriptions are provided as follows:

Please refer to the second drawing, which is a schematic structural view of a light emitting diode structure according to a preferred embodiment of the present invention; as shown in the figure, the light emitting diode structure of the present invention is disposed in a reflective cover 25, and has a light emitting diode. The body structure comprises a light-emitting diode chip 30, a thermal barrier layer 40, a phosphor layer 50 and an encapsulation layer 60. The LED chip 30 is disposed in the reflector 25, and the thermal barrier layer 40 is disposed on the light-emitting layer The light-emitting diode is disposed above the edge of the polar body wafer 30, and the phosphor layer 50 is disposed above the thermal barrier layer 40 and the edge is aligned with the light-emitting diode. The package layer 60 fills the reflective cover 25, and the package layer 60 may be epoxy or silicon, wherein the thickness of the phosphor layer 50 is less than twenty percent of the thickness of the phosphor layer 50, and the thermal barrier layer 40 does not contain any phosphor, which is translucent. Polymer Materials. The present invention reduces the thickness of the light-emitting diode wafer 30 by the thermal barrier layer 40. The influence of the heat generated by the heat on the phosphor layer 50 is such that the conversion efficiency of the phosphor layer 50 is increased to uniformly illuminate the structure of the light-emitting diode, thereby improving the luminous efficiency of the structure of the light-emitting diode.

When the light-emitting diode wafer 30 of the present invention emits light, the light of the light-emitting diode wafer 30 is emitted to the thermal barrier layer 40 and transmitted to the phosphor powder layer 50 through the thermal barrier layer 40.

The light emitted by the LED chip 30 of the present invention is a visible light or an ultraviolet light, and the phosphor powder layer 50 has a single layer or a multi-layer structure, and the single or multiple layers of the phosphor powder layer 50 can be mixed. Colored light. The thickness of the phosphor layer 50 is less than 100 microns, and the width of the LED array 30 and the phosphor layer 50 is greater than 5 microns. The invention can use a single wafer with fluorescent powder to mix light, for example, a blue light emitting diode chip 30 plus yttrium aluminum garnet phosphor powder, or an ultraviolet light emitting diode chip 30 with red, blue and green color fires. Light mixing technology such as light powder.

The material of the thermal barrier layer 40 can be silicone or other materials; the silicone rubber is a granular porous ceria hydrate, and the thermal stability of the silicone can maintain stability between -100 and 250 ° C, for ozone and sunlight. It has good oxidation resistance, good elasticity and good electrical insulation. Therefore, the use of silicone as the thermal barrier layer 40 can effectively reduce the thermal energy of the LED wafer 30 to the phosphor layer 50.

The phosphor powder layer 50 has a plurality of phosphor powders, and the phosphor powder functions in light color recombination to form color light, and its characteristics mainly include particle size, shape, luminous efficiency, conversion efficiency, stability (heat and chemistry), etc. Luminous efficiency and conversion efficiency are key. As the temperature rises, the quantum efficiency of the phosphor powder decreases, the light emission decreases, and the radiation wavelength also changes, thereby causing a change in color temperature and chromaticity of the light-emitting diode structure. Higher temperatures also accelerate the aging of the phosphor. The reason is that the phosphor powder layer 50 is prepared by epoxy or silicone rubber and fluorescent powder, and has poor heat dissipation performance. When subjected to ultraviolet light or ultraviolet light radiation, temperature quenching and aging are liable to occur, and the luminous efficiency is lowered. In addition, the thermal stability of the potting compound and the phosphor powder at high temperatures is also problematic.

Therefore, if you want to avoid the influence of the fluorescent powder, you need to further protect the fluorescent powder. Therefore, the present invention uses the thermal barrier layer 40 to reduce the thermal energy of the light-emitting diode wafer 30 to the phosphor layer 50. Therefore, when the light of the LED chip 30 is emitted to the phosphor layer, the light excites the phosphor powder to emit light. When the LED chip 30 is in use, the LED film 30 generates thermal energy when converting electrical energy into light energy, and most of the heat energy will be conducted to the thermal barrier layer 40, and then will be less by the thermal barrier layer 40. Part of the thermal energy is conducted to the phosphor layer 50. The thickness of the thermal barrier layer 40 is between 1 micrometer and 10 micrometers, making the overall light-emitting diode wafer 30 uniform in illumination, and because heat is blocked to increase its efficiency. By reducing the heat energy absorbed by the phosphor powder, the light conversion efficiency of the phosphor powder can be improved, so that the phosphor powder emits more fluorescence. When the light conversion efficiency of the phosphor powder is increased, a part of the light of the LED chip 30 can be mixed with more fluorescent light, so that the uniformity of the illumination of the LED structure can be improved to improve the luminous efficiency.

The material of the phosphor layer 50 comprises a polymer material, a glass fiber material or a mixture of a polymer material and a glass fiber material. Fluorescent powder can be excited by visible or ultraviolet light to emit fluorescence. The structure of the phosphor powder is unstable and the center of the luminescence is easily oxidized. Therefore, the phosphor powder is easily aging due to exposure to heat or light, so that a protective layer can be coated in the process of the phosphor powder to protect The layer is for example alumina. This increases the life of the phosphor.

Please refer to the third figure, which is a schematic structural view of a light emitting diode structure according to another preferred embodiment of the present invention; as shown in the figure, this embodiment includes an encapsulation layer 60. It is disposed above the phosphor layer 50 and its shape can be differently designed to present different light shapes. In this embodiment, the encapsulating layer 60 allows a part of the light of the LED chip 30 to be uniformly diffused when it is mixed with the fluorescent light.

In summary, the LED structure of the present invention comprises a light-emitting diode chip, a thermal barrier layer and a phosphor layer, and the thermal barrier layer is disposed above the LED chip and the edge is aligned with the light-emitting diode. The polar body wafer, the phosphor powder layer is disposed above the thermal barrier layer and the edge is aligned with the light emitting diode chip, and the thickness of the phosphor powder layer is less than 20% of the thickness of the phosphor powder layer. The thickness of the thermal barrier layer is between 1 micrometer and 10 micrometer to reduce the influence of the thermal energy generated by the light-emitting diode wafer on the phosphor powder layer, so as to improve the conversion efficiency of the phosphor powder layer, so that the light-emitting layer The polar body structure uniformly emits light, thereby improving the luminous efficiency of the light emitting diode structure.

Therefore, the present invention is a novelty, progressive and available for industrial use. It should be in accordance with the patent application requirements stipulated in the Patent Law of China, and the invention patent application is filed according to law, and the prayer bureau will grant the patent as soon as possible. For prayer.

However, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and the shapes, structures, features, and spirits described in the claims are equivalently changed. Modifications are intended to be included in the scope of the patent application of the present invention.

25‧‧‧reflector

30‧‧‧Light Emitter Wafer

40‧‧‧ Thermal barrier

50‧‧‧Flame powder layer

60‧‧‧Encapsulation layer

Claims (9)

A light-emitting diode structure comprising: a light-emitting diode wafer; a thermal barrier layer disposed above the light-emitting diode wafer and having the edge of the thermal barrier layer aligned with the light-emitting diode wafer, the thermal barrier layer a thickness of between 1 micrometer and 10 micrometers; and at least one phosphor layer disposed above the thermal barrier layer and the edge of the phosphor powder layer is aligned with the light-emitting diode wafer, and the thickness of the phosphor powder layer is varied. Less than 20% of the thickness of the phosphor layer. The light emitting diode structure of claim 1, further comprising an encapsulation layer disposed above the phosphor powder layer. The light-emitting diode structure of claim 1, wherein the light emitted by the light-emitting diode chip is a visible light. The light-emitting diode structure of claim 1, wherein the light emitted by the light-emitting diode chip is an ultraviolet light. The luminescent diode structure of claim 1, wherein the thermal barrier layer does not comprise any phosphor powder. The light-emitting diode structure according to claim 1, wherein the thermal barrier layer is a transparent polymer material. The light-emitting diode structure according to claim 1, wherein the material of the phosphor powder layer comprises a polymer material, a glass fiber material or a mixture of a polymer material and a glass fiber material. The light-emitting diode structure of claim 1, wherein the phosphor powder layer has a thickness of less than 100 micrometers. The light emitting diode structure of claim 1, wherein the light emitting diode chip and the phosphor powder layer have a width greater than 5 micrometers.