Patent Application
20080246397
1. Field of the Invention
The present invention generally relates to a light emitting diode (LED), in particular, to a manufacturing method of white light LEDs.
2. Description of Prior Art
In current market, white light LED is comprised of different colors of LED or fluorescent powders to emit various colors other than white color, then these colors are mixed again to generate white color. However, in terms of lighting lifetime, since its structurally packaging materials are mainly comprised of transparent chemical resin, which is capable of resisting vibration and impact, so its lifetime can exceed 10,000 hours, which is several times over that of traditional fluorescent lamp or tungsten-filament bulb. Another advantage of white light LED is that its power consumption is only about ⅓˜⅕ of common tungsten-filament bulb. In today, when energy's price is high, power saving is a notable incentive for comprehensively applying LED, so LED is currently regarded as a major light source for the future, while it has been comprehensively used in liquid crystal TV, cellular phone, PDA, GPS display panel, digital camera, and lightings of automobile, office, home.
The so-called “white light” is usually comprised of lights of multiple colors. That is, the white light commonly seen by human eyes includes at least two color lights of different wavelengths; for example blue light adding yellow light may become a white light resulted from two complementary wavelengths, or a white light of three complementary wavelengths may be comprised by blue light, green light, and red light. In our daily lives, no matter indoors or outdoors, where a light source is needed, it is always desired to get an irradiance of light source resembled to sun light. Therefore, white light LED is also requested to have similar optical spectrum, color rendering, and color temperature as those of sun light for satisfying the daily life requirement of illumination. Furthermore, under different requirements of illumination, the lightness, color rendering, color, and color temperature are also different, for example the illumination requirement among family, office, and factory being absolutely different, family needing warm white light of low color temperature similar to the light of tungsten-filament bulb, while factory and office building needing illumination of high color temperature. In addition, in terms of backlight source in liquid crystal display (LCD), the requiring specification for light source is the sufficiency of gamut. Therefore, the pursuit of multiple light sources is an urgent target for industry, academy, and research.
According to manufacture materials, the white light LED may be divided into organic LED and inorganic LED. Currently, there are two lighting mechanisms for white light source made of inorganic semiconductor:
1. A white light lighting module, which is comprised by LED crystal particles in colors of red, blue, and green, has the advantages of high lighting efficiency and high color rendering. In the meantime, according to different epitaxy materials, the color of crystal particle is also different, so is the voltage characteristics, making this method with expansive cost and complicatedly controlling wire design. In the meantime, it is difficult to achieve a white light by mixing three color lights, which is one of many problems needed to be solved in this method.
2. Blue light LED generates white light LED by means of exciting yellow YAG fluorescent powder, which is a mainstream in current market. In this method of manufacturing white light LED, optic glue mixed with yellow YAG fluorescent powders is filled around blue light LED chip, which is capable of emitting blue light with wavelength approximately 400-530 nm, this light generated from blue light LED chip making yellow fluorescent powder generate yellow light but, in the meantime, part of this blue light with appropriate percentage penetrates outwardly to match with yellow light emitted from fluorescent powder to generate white light resulted from two complementary wavelengths of blue and yellow colors.
However, there are several drawbacks in manufacturing this white light LED formed by the combination of blue light LED chip and yellow fluorescent powder:
1. Since blue light occupies most lighting spectrum, phenomena of higher color temperature and non-uniformity are occurred.
2. Since the lighting wavelengths of blue light LED will be changed following the raise of temperature, a light floating phenomenon of white light source is further created.
3. Furthermore, since the intensity of red color part in its lighting spectrum is weaker, a phenomenon of poor color rendering is created when a red color can not be completely shown during an object being illuminated.
So, regarding traditional drawbacks, the present invention is to provide an innovative LED capable of generating white light, the output power of which is notably large without the drawbacks of higher color temperature and non-uniformity, the occurrence of color floating of light source in generating white light, and the problem of poor color rendering.
The manufacturing method of white light LED and structure thereof according to the present invention, comprising:
First, a metallic substrate is prepared, which is formed as a holder consecutively connected by plural first electrodes and plural second electrodes, on both of which plural perforations are formed.
Second, fluorescent layer is constructed on the holder, wherein insulated fluorescent glue is coated on the first electrode to form a fluorescent layer.
Third, a chip capable of generating blue light is fixed on the fluorescent layer, after the chip being fixed, two conducting wires being welded onto the chip and respectively being electrically connected to first electrode and second electrode.
Fourth, glue is applied to encapsulate the holder, fluorescent layer, chip, and conducting wires, and thus a photic zone is formed, making part of first electrode and second electrode exposed to the outside of photic zone.
Finally, the photic zone is covered by a frame body, on which a window is formed and provided for making photic zone exposed and also making part of first electrode and second electrode exposed to the outside of frame body.
The features of the invention believed to be novel are set forth with particularity in the appended claims. The invention itself, however, may be best understood by reference to the following detailed description of the invention, which describes an exemplary embodiment of the invention, taken in conjunction with the accompanying drawings, in which:
In cooperation with attached drawings, the technical contents and detailed description of the present invention will be as follows.
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The dispersant, added to the silicone or EPOXY, excites the blue light and yellow light, both of which will be reflected and vibrated, such that they may be mixed uniformly to become white light. In the meantime, the lights will be concentrated longitudinally to make the output power promoted notably and the lightness enhanced significantly.
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The frame body 5 is provided for the reflection of the light source beside the LED, making the output power promoted notably and the lightness enhanced significantly.
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Aforementioned description is only preferable embodiment according to the present invention, being not used to limit its executing scope. Any equivalent variation and modification made according to appended claims is all covered by the claims claimed by the present invention.
