KR20050089490A - White color light emitting diode using violet light emitting diode - Google Patents

Abstract

The present invention relates to a white light emitting diode, and more particularly, to a white light emitting diode and a light emitting diode lamp using the same, wherein the color light emitting diode is combined with an α-SiAonON-based phosphor and a blue phosphor to obtain high color rendering and high luminous efficiency. .

Current methods for implementing white light using semiconductor light sources include low color rendering, low conversion efficiency of phosphors, and precise control of driving drivers. According to the present invention, a wavelength band (400-700 nm) in which an α-SiAion ON-based phosphor emits light is obtained by mixing the α-SiAionON-based phosphor with a violet light emitting diode (400-415 nm), which is known to have the highest external quantum efficiency. Since white light is used, high color rendering and high luminous efficiency can be obtained. It can also be applied to general epoxy lamps and surface mount packages.

Description

White light emitting diode using violet light emitting diode light source

The present invention relates to a white light emitting diode, and more particularly, to a white light emitting diode and a light emitting diode lamp using the same, wherein the color light emitting diode is combined with an α-SiAaion based phosphor and a blue phosphor to obtain high color rendering and high luminous efficiency. It is about.

The light emitting diode has a small size and can efficiently exhibit bright color light, and because it is a semiconductor device, there is little concern about disappearance, good initial driving characteristics and shock resistance, and strong resistance to on / off switching of the switch. Therefore, it is widely used as various indicators and various light sources. In addition, ultra high brightness, high efficiency red, green, and blue light emitting diodes have been developed, and light emitting diodes using the same have been used for large displays. Such a light emitting diode display is expected to be used in the future because it has excellent characteristics of being able to operate with low power and being light and having a long life.

 Recently, various attempts have been made to implement white light emission using light emitting diodes. Currently, a white light source using a semiconductor light source includes a white light emitting diode using a blue light emitting diode, a white light emitting diode using a yag-based yellow phosphor, a near ultraviolet light or a violet light emitting diode, and a white light emitting diode using a combination of red, green, and blue phosphors. And white light emitting diodes using green and blue light emitting diodes.

A white light emitting diode using a yag-based phosphor for a blue light emitting diode has low color rendering because it uses two wavelengths, blue and yellow.

1 shows a wavelength spectrum of a white light emitting diode manufactured using a blue light emitting diode and a yag phosphor.

2 shows the area of white light appearing on the CIE chart. In FIG. 2, B-LED represents a blue light emitting diode and Y-phosphor represents yellow in which some blue is wavelength-converted by a yag-based phosphor. White light moves along the connecting line between B-LED and Y-phosphor and is marked with W. With two wavelengths, blue and yellow, the color rendering properties are not suitable for general room lighting, such as 60-75.

White light-emitting diodes using red, green, and blue light whose wavelengths are converted by red, green, and blue phosphors from light emitted from the near-ultraviolet light-emitting diodes use three wavelengths, so that high color rendering properties can be obtained and various colors can be realized. have.

3 shows the wavelength spectrum of a three wavelength white light emitting diode wavelength-converted by ultraviolet light. The ultraviolet UV light emitting diode is used only as an excitation light source of the phosphor, and is wavelength-converted into blue, green, and red, respectively.

4 shows a white light emitting diode having a wavelength converted by ultraviolet rays on a CIE chart, wherein UV and V-LEDs represent ultraviolet or violet light emitting diodes, and R-phosphor, G-phorphor, and B-phosphor are ultraviolet rays, respectively. Or red, green, and blue light wavelength-converted by the purple light are shown. This method can realize a wide range of colors on a CIE chart.

However, in the current technology, the wavelength of the ultraviolet light emitting diode and the conversion efficiency of the phosphor are inversely proportional. UV light emitting diodes have wavelengths around 365nm ~ 400nm and violet light emitting diodes around 405nm. As the wavelength gets shorter, the light output decreases. Since the developed phosphors are manufactured for use in CRT or PDP, few phosphors have high conversion efficiency in the near ultraviolet region, and the shorter wavelength shows higher conversion efficiency. It is theoretically good to obtain white light using three wavelengths wavelength-converted through ultraviolet light, but in reality, intensive development is needed due to the low conversion efficiency of the phosphor.

White light emitting diodes using three red, green, and blue light emitting diodes show the highest luminous efficiency due to no light loss, but precise control of the driving driver is required to achieve accurate white color. In addition, since the product is large and the temperature characteristics of the three light emitting diodes are different from each other, the optical properties and reliability of the product may be affected.

       SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide a light emitting device having a higher color rendering property and a high luminous efficiency and having extremely low emission luminous intensity or color change even for a long time use environment.

In order to achieve the above object, in a light emitting device having a light emitting element and a phosphor

(1) The light emitting element is capable of high luminance light emission, its light emission characteristics are stable against long time use,

(2) The phosphor is installed close to the above-described high-brightness light emitting device, and even when exposed to strong light emitted from the light emitting device for a long time, the phosphor is excellent in light resistance and heat resistance with little change in characteristics (a phosphor disposed close to the light emitting device It is known that it is exposed to light having an intensity of about 30 to 40 times that of sunlight, so the higher the brightness of the light emitting element is used, the more the light resistance required of the phosphor is very important.)

(3) The relationship between the light emitting element and the phosphor is that the phosphor efficiently absorbs light of a monochromatic peak wavelength having a spectral width from the light emitting element and at the same time efficiently emits a different light emitting wavelength. To

It aims to provide.

As a constituent means for achieving the above object, the present invention provides an α-SiAlON- based phosphor and a blue phosphor, which wavelength-converts the light of the violet light emitting diode and the violet light emitting diode having a wavelength of 400 to 415 nm, and an epoxy to mix them in an appropriate ratio. Or a mixed region of silicon gel or the like and further a lead frame or electrode wiring to connect the epoxy lens and the electrode to the outside.

Preferably has a peak wavelength of the light 400 ~ 415nm emitted from the purple light emitting diodes, the dominant wavelength is a light emitting diode having a wavelength of 415 ~ 435 nm, α-SiAlON fluorescent material using the at least one light-emitting diode as a light source and A white light emitting diode lamp, which emits white light by using light having a wavelength of 400 to 700 nm and is excited by mixing and exciting other phosphors, that is, emitted by violet and nitride-based phosphors of a light emitting diode and another phosphor. It is a white light emitting diode using a wavelength.

   The nitride-based phosphor is a nitride-based phosphor activated by a rare earth element, and the general formula is expressed as follows.

Me _x Si _{12- (m + n)} Al _{(m + n)} O _n N _16-n ; Re1 _Y Re2 _X

All or part of the metal Me in α-SiAlON solid solution, where Me is at least one metal selected from the group consisting of Ca, Mg, Y and lanthanide metals except La and Ce, where Re1 is Ce, Pr , At least one metal selected from the group consisting of Eu, Tb, Yb and Er), and two lanthanide metals Re1 and one auxiliary activator Re2, where Re2 is Dy Should be the central part of the. In the above-mentioned nitride-based phosphor activated by the rare earth element, when the metal Me is divalent, 0.6 <m <0.3 and 0 <n ≦ 1.5, and when Me is trivalent, 0.9 <m <4.5, 0 <n ≦ 1.5.

In the white light emitting diode using the light emitted by the violet light of the light emitting diode and the nitride-based phosphor and another phosphor, the other phosphor is Formula (Sr, Mg) ₅ (PO ₄ ) ₃ Cl; Eu ²⁺ It is a blue phosphor which can be used as, and preferably the violet light emitting diode has a peak wavelength of 400 ~ 415nm and the main wavelength is a light emitting diode having a wavelength of 415 ~ 435, the fundamental color of the violet light emitted from the light emitting diode, white It is used as part of the light.

         In the white light emitting diode using the violet light of the light emitting diode and the wavelength emitted by the nitride-based phosphor and other phosphors, the peak wavelength of the light emitted by using the violet light as the light source and the wavelength conversion by the phosphor is 400-700 nm. It is a white light emitting diode that uses wavelength converted light and its own color.

In addition, a purple light emitting diode is used as an excitation light source in a white light emitting diode using a violet light of a light emitting diode and a wavelength emitted by a nitride-based phosphor and another phosphor, and the blue phosphor is a Ca-α-Si _{12- (m + n)} Al. _{(m + n)} O _n N _16-n ; A white light emitting diode that produces white light by mixing a suitable ratio with Eu ²⁺ and Dy ³⁺ phosphors.

And Y-α- Si _{12- (m + n)} Al _{(m + n)} O _n N _16-n ; Eu ³⁺ It is a white light emitting diode that uses a purple light emitting diode as an excitation light source of a phosphor and a blue phosphor, and has a wavelength range of 400 to 700 nm for light emitted by wavelength conversion by the phosphor, and the wavelength converted light and its own color. .

In addition, in the white light emitting diode using the light emitted by the violet light and the nitride-based phosphor of the light emitting diode and other phosphors, when the white light emitting diode is manufactured, the phosphor is mixed with a certain amount of transparent epoxy to be distributed evenly, and the epoxy and the phosphor are manufactured in a liquid state. The white light emitting diode is manufactured by the method of coating on a purple light emitting diode chip by the dispensing method.

 In the white light emitting diode using the light emitted by the violet light and the nitride-based phosphor of the light emitting diode and other phosphors, when the white light emitting diode is manufactured, the phosphor is mixed with a certain amount of epoxy to be evenly distributed, and the epoxy and the phosphor are manufactured in a solid state. It is a white light emitting diode manufactured by the method of apply | coating on a purple light emitting diode chip by transfer molding.

In addition, the white light emitting diode using the light emitted by the violet light of the light emitting diode and the nitride-based phosphor and other phosphors is mixed evenly by mixing a phosphor with a certain amount of epoxy when manufacturing the white light emitting diode, and the epoxy and the phosphor are manufactured in a solid state. It is a white light emitting diode manufactured by the method of apply | coating on a light emitting diode chip by sputtering or vapor deposition.

In addition, it is a shell type white light emitting diode lamp that forms a white light by using a wavelength converted light by exciting the phosphor using the violet light of the violet light emitting diode and the violet light emitted from the violet light emitting diode.

In addition, it is a surface-mounted white light emitting diode lamp that forms a white light by using a wavelength-converted light by exciting the phosphor using the violet light of the violet light emitting diode and the violet light emitted from the violet light emitting diode.

In addition, the surface-mounted white light emitting diode lamp and the surface-mounted white light having an epoxy lens are used to excite the phosphor using the violet light of the violet light emitting diode and the violet light emitted from the violet light emitting diode to form white light using the wavelength-converted light. Light emitting diode lamp.

       The present invention relates to the fabrication of white light emitting diodes. According to various reports, purple light emitting diodes having a peak wavelength of 400 to 415 nm exhibit the highest quantum efficiency (up to 30%) as a semiconductor light source, and thus, a violet light emitting diode is used. . By using a purple light emitting diode light source having a peak wavelength range of 400 to 415 nm and a dominant wavelength of 415 to 435 nm, the above-described phosphor is mixed with other phosphors in an appropriate ratio with epoxy to emit purple (400 to 415 nm) light sources and phosphors. It is a method of manufacturing a white light emitting diode with a wavelength band of 400 ~ 700nm.

Here, as an example of another phosphor, a blue phosphor may be used. The chemical formula is (Sr, Mg) ₅ (PO ₄ ) ₃ Cl; Eu ²⁺ The excitation wavelength band is 250-500 nm and the emission wavelength is 400-500 nm.

     The method of obtaining white light by mixing red, green, and blue phosphors, which are widely known as a method of manufacturing white light emitting diodes using ultraviolet rays, to excite phosphors with a light source in the near ultraviolet region (380 to 410 nm) to obtain a visible light source has low efficiency. There is a difficulty in the manufacturing technology such as uniformity and reproducibility of the mixing ratio of the red, green, and blue phosphors during the production. The combination of the three phosphors can increase the degree of freedom in the fabrication, but it is not easy to achieve the desired color rendering or color temperature because the absorption and wavelength conversion of all the phosphors must be harmonized for the red, green and blue phosphors.

In the present invention, in order to solve this problem, since some of the light emitted from the purple light emitting diode is used and the remaining part of the wavelength is converted by the α-SiAlON- based phosphor and the blue phosphor, the composition of the mixing ratio can be easily controlled and uniformity. And improve reproducibility. In addition, the color rendering degree is more than 85 can be obtained similar to the color rendering value using the trichromatic phosphor.

      The color rendering property of the white light emitting diode using the yellow phosphor in the blue light emitting diode is 60-75 region, which is relatively smaller than the white light emitting diode using the near-ultraviolet light emitting diode. Therefore, the present invention implements a method of improving color rendering to 400 ~ 700 nm wavelength wavelength conversion by a violet light emitting diode light source and a phosphor having a peak wavelength of 400 ~ 415nm (wavelength 415 ~ 435nm). Color rendering was different depending on the mixing ratio of the resin and the phosphor, and a value of 85-90 was obtained.

The white light emitting diode uses a purple light source of 400 to 415 nm, and a thin coating of epoxy resin or silicone gel in which α- SiAlON- based phosphor is mixed with a blue phosphor, and a package of a lamp-type and surface-mounted packaged with an epoxy lens. Can be made.

5 shows a shell type white light emitting diode lamp using a purple light emitting diode. The purple light emitting diode 1 is made of an (Al) InGaN active layer, and the substrate may be a sapphire substrate or a silicon carbide (SiC) substrate. After die bonding the violet light emitting diode 1 to the lead frame 5, the gold wire 4 is bonded to connect the electrode to the outside. Gold wire bonding requires p- and n-type electrodes on the upper part of the device when sapphire substrate is used, and gold wire bonding must be performed respectively. When SiC conductive substrate is used, one gold wire bonding can be performed. After wire bonding, a region 2 in which epoxy and phosphors are mixed for white light emission is applied using a dispenser or a suitable coating method. After application, it should be cured at a certain temperature so as not to be disturbed After that, the epoxy lens 3 is formed by using a mold having a desired shape, and a white light emitting diode is manufactured by trimming and cutting the lead frame.

FIG. 6 is a graph illustrating the color temperature and the color rendering of a white light emitting diode using a yag-based phosphor for a blue light emitting diode and a white diode using green and red phosphors for a violet light emitting diode. The white light emitting diode using the blue light emitting diode increases the color rendering property as the color temperature is increased, and the apparent color rendering is not observed at a color temperature of more than 5500K and the value is about 75 to 78. However, white light emitting diodes using violet light emitting diodes show the opposite result and have much higher color rendering properties than white light emitting diodes using blue light emitting diodes.

Another type of package type may be manufactured. In particular, the package may be manufactured in a surface mount type (SMD, SMT), and is illustrated in FIG. 15 and FIG.

7 shows a surface mounted white light emitting diode lamp using a purple light emitting diode. Die bonding the violet light emitting diode 1 to the metal wire 7 of the PCB substrate 6 and bonding the p and n electrodes of the light emitting diode to the metal wire 7 with a gold wire 4 so as to be electrically connected to the outside. do. Thereafter, the phosphor 2a and the blue phosphor 2b are mixed with the appropriate amount of epoxy 2 and placed on the purple light emitting diode 1. The epoxy mixed with the phosphor may be molded in the form of a dispenser in a liquid form, and another method may be solidified and manufactured into a transfer mold.

8 is an epoxy lenticular surface mounted white light emitting diode lamp. The package is a PCB substrate or a ceramic substrate 6, the metal wire (7) is attached to the part to be an anode and the cathode (Cathode), the substrate 6 is separated by an insulator (9). The interior of the epoxy confinement region 8 consists of a reflective film coated with aluminum or silver, which serves to reflect upward the light emitted from the diode and to confine an appropriate amount of epoxy. The violet light emitting diode 1 is die-bonded in the form of a flip chip with a bonding material 3 such as a gold bumper or Au-Sn, and the epoxy or silicon gel 2 in which the phosphor is mixed at an appropriate mixing ratio is dispensed. Silicone gels can be used in high power light emitting diode packages. The silicone gel can transfer thermal stress directly to the chip, adversely affecting reliability or preventing short circuit of the gold wire due to heat shrinkage or expansion. In addition, by using a silicone gel having a refractive index higher than that of epoxy, it is possible to reduce the reflection at the interface of the light emitted from the diode, thereby improving luminance. The epoxy lens 3 is formed after coating the epoxy 2 mixed with phosphors. The epoxy lens 3 can vary in shape depending on the desired orientation angle.

The light emitting diode has a long lifespan with high reliability compared to a conventional lighting fixture, has a low maintenance cost, and contributes to energy saving because of low power consumption. In addition, the design's low fluidity and heat generation make it suitable for use as lighting.

The white light emitting diode of the present invention can also be used in lighting applications that require high color rendering since it can obtain a value similar to the color rendering value using trichromatic phosphors with a color rendering degree of 85 or more.

Since a light emitting device made of a nitride compound semiconductor capable of high luminance light emission is used, it can emit light at high luminance. The photoluminescence sensor used in the light emitting device is excellent in light resistance with very little fluorescence even when exposed to strong light for a long time. Therefore, deterioration can be reduced for long time use, not only strong light from the light emitting element, but also deterioration due to extraneous light (eg, sunlight including ultraviolet rays), such as during outdoor use, and extremely low in color change and luminance deterioration. Less light emitting devices can be provided.

The light emitting device uses some of the light emitted from the purple light emitting diode and converts the remaining part of the light by the α-SiAlON- based phosphor and the blue phosphor to easily control the composition of the mixing ratio and improve the uniformity and reproducibility. Can be provided.

While the invention has been shown and described with respect to particular embodiments, it will be understood that various changes and modifications can be made in the art without departing from the spirit or scope of the invention as set forth in the claims below. It will be appreciated that those skilled in the art can easily know.

It will contribute to the activation of related industries, such as related technologies, that is, light emitting diode manufacturing technology and phosphor manufacturing technology.

1 is a graph showing a wavelength spectrum distribution of a white light emitting diode by a blue light emitting diode + yag phosphor.

2 is a CIE chart of a white light emitting diode using a blue light emitting diode + yag phosphor.

3 is a graph showing wavelength spectrum distribution of white light emitting diodes wavelength-converted by red, green, and red phosphors in near ultraviolet and violet light emitting diodes.

FIG. 4 is a CIE chart of a white light emitting diode wavelength-converted by red, green, and red phosphors in a near ultraviolet and violet light emitting diode.

5 is an embodiment of a white light emitting diode lamp.

6 is a CIE chart of a wavelength-converted white light emitting diode by a purple light emitting diode and a green and red phosphor.

7 illustrates an embodiment of a surface mounted white light emitting diode lamp using a purple light emitting diode.

8 is an embodiment of an epoxy lenticular surface mount white light emitting diode lamp.

9 is a wavelength spectrum distribution of a white light emitting diode wavelength-converted by a violet light emitting diode and a phosphor.

10 is a CIE chart of a violet light emitting diode and a white light emitting diode wavelength-converted by green and red phosphors.

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

1: purple light emitting diode 2: epoxy

2a: α-SiAlON phosphor 2b: blue phosphor

3: epoxy lens 4: gold wire

5: lead frame 6: substrate

7: metal wire 8: frame required

9: insulator

Claims (11)

The light emitted from the violet light emitting diode has a peak wavelength of 400-415 nm and the main wavelength is a wavelength of 415-435 nm. The at least one light emitting diode is used as a light source to generate α-SiAlON phosphor and other phosphors. White light is formed by using light in the wavelength range of 400 to 700 nm that is mixed, excited, wavelength-converted to emit light, that is, the violet light of the light emitting diode and the wavelength emitted by the nitride-based phosphor and other phosphors. The nitride-based phosphor is a nitride-based phosphor represented by the following and activated by a rare earth element, Me _x Si _{12- (m + n)} Al _{(m + n)} O _n N _16-n ; Re1 _Y Re2 _X Here, all or part of the metal Me in α-SiAlON solid solution, where Me is at least one metal selected from the group consisting of Ca, Mg, Y and lanthanide metals except La and Ce, where Re1 is Ce , At least one metal selected from the group consisting of Pr, Eu, Tb, Yb and Er) and two lanthanide metals Re1 and one auxiliary activator Re2, where Re2 is Dy White light emitting diode, characterized in that the central portion of the light emission. According to claim 1, wherein the other phosphor is a blue phosphor having the chemical formula (Sr, Mg) ₅ (PO ₄ ) ₃ Cl; Eu ²⁺ is excited at a wavelength of 300 ~ 450 nm band and 400 ~ 500nm The wavelength of the band is converted, the violet light emitting diode has a peak wavelength of 400 ~ 415nm and the main wavelength is a light emitting diode having a wavelength of 415 ~ 435, characterized in that the use of the violet light emitted from the light emitting diode as part of the fundamental light of white White light source diode. The white light emitting diode according to claim 1, wherein the peak wavelength of the light emitted by using violet light as a light source and wavelength-converted by the phosphor is 400 to 700 nm, and the wavelength-converted light and its own color of the light emitting diode are used. The method of claim 1, wherein a purple light emitting diode is used as the excitation light source and the blue phosphor is Ca-α-Si _{12- (m + n)} Al _{(m + n)} O _n N _16-n ; Eu ²⁺ , Dy ^{3 +} White light-emitting diodes that produce white light, made by mixing phosphors with the right ratio. The compound of claim 1, wherein Y-α- Si _{12-(m + n)} Al _{(m + n)} O _n N _16-n ; Eu ³⁺ A white light emitting diode using a violet light emitting diode as an excitation light source of a phosphor and a blue phosphor, and having a wavelength range of 400 to 700 nm for the wavelength emitted by the wavelength conversion by the phosphor, and using the wavelength converted light and its own color. The white light emitting diode of claim 1, wherein the white light emitting diode is manufactured by mixing phosphors in a predetermined amount of epoxy to distribute the phosphors evenly and manufacturing the epoxy and the phosphor in a solid state and applying the same on a purple light emitting diode chip by transfer molding. . The white light emitting diode of claim 1, wherein the white light emitting diode is manufactured by mixing phosphors in a predetermined amount of epoxy to distribute the phosphors evenly and manufacturing the epoxy and the phosphor in a solid state and applying the same on a light emitting diode chip by sputtering or vapor deposition. . The method of claim 1, wherein when manufacturing a white light emitting diode, the phosphor is mixed with a certain amount of transparent epoxy to be evenly distributed, and the epoxy and the phosphor are prepared in a liquid state, and the white is manufactured by coating on a purple light emitting diode chip by a dispensing method. Light emitting diode. A shell-type white light emitting diode lamp which excites a phosphor using violet light of a violet light emitting diode and violet light emitted from the violet light emitting diode to form white light using wavelength converted light. A surface-mounted white light emitting diode lamp comprising white light by using wavelength converted light by exciting phosphors using purple light of purple light emitting diodes and purple light emitted from purple light emitting diodes. Surface-mounted white light emitting diodes with surface-mounted white light emitting diode lamps and epoxy lenses that excite phosphors using the violet light of the violet light emitting diodes and the violet light emitted from the violet light emitting diodes to form white light using wavelength converted light Diode lamp.