TW573370B - Tri-color ZnSe white LED - Google Patents

Abstract

In the present manner for generating white light through the use of ZnSe substrate, blue color light emitting layer is grown on the yellow color ZnSe substrate. By using yellow blue complementary color to generate white light, because the generated white light lacks more in the part of green color wavelength, the generated white light color is prone to red color such that the real white light source can not be formed. The invented tri-color ZnSe white LED uses the conventional ZnSe white light LED chip as the light emitting source; and a layer of green-color fluorescent light body is coated on the LED, in which blue light emitted by ZnSe is used to excite the green-color fluorescent light body on its surface to generate green light for forming a tri-color white LED having distinct R, G, B colors.

Description

573370

The characteristics of Light Emitting Diode (LED), long life, power saving, fast response, high reliability, environmental protection, safety, etc. "With the advancement of technology, the brightness of LED has gradually increased, and in white light “LED” is currently regarded as the new main lighting source in the 21st century, especially the colorization of mobile phones and PDAs (Personal Mobile Assistants) in recent years. As a result, research units around the world are actively investing in white LEDs. Ranks. In the past, if you want to make white light LEDs, you need to use two or more different color light-emitting chips to package them together. It is more complicated to do solid-state bonding at the same time. Because of three different colors of red, blue, and green LED light-emitting crystals, Different granular materials require different driving voltages (Vf), so when designing a circuit, it is necessary to add different driving currents to each LED die to adjust the brightness and color as its disadvantages. At present, the more advanced method is to A single LED die is used to make white LEDs. The main manufacturing methods are the following two methods. One is to use LED die (such as GaN (gallium nitride) or SiC (silicon carbide), etc.) on the crystal. Adding fluorescent powder to the particles produces a mixed-wavelength method to produce white LEDs; the other method does not use fluorescent powder 'to directly generate white light such as Znse from the crystal grains, and uses the blue light emitted by the Znse blue light-emitting layer to irradiate the Znse substrate Generate yellow light and generate white light in a complementary way of yellow and blue. This is the first invention of Sumitomo Electric Industries. White LEDs generally made of ZnSe have the advantage that white light can be generated without the addition of fluorescent powder. The problem of powder precipitation or deterioration 'but the emission spectrum of white LEDs made with ZnSe is as shown in the first figure' From the first figure we can know that the current ZnSe type white LED lacks

573370 V. Description of the invention (2)-The lack of green wavelength light makes the overall LED color reddish. Due to the lack of green light, white LEDs cannot be used for LCD backlights or real lighting purposes. One of the major disadvantages of white LEDs. The inventors have many years of experience in the research and development of white LEDs, and have obtained a number of white LED patents at home and abroad. They have made further research on the lack of the above ZnSe type white LEDs, and proposed a new idea ~ "Three-wavelength ZnSe white "LED" is based on the existing ZnSe-type white LED crystal grains. A layer of green phosphor is used on the ZnSe white light crystal grains. The blue light emitted by the ZnSe blue light-emitting layer excites the green phosphor of the present invention to make it Generate green wavelength light ', so that the Z n S e type white light L £ d, which originally lacked a green wavelength, achieves the full-color effect of R, G, and B, and realizes true white light LEI). In the "three-wavelength ZnSe white light LED" of the present invention, the green phosphor used is: Y3 (GaxAlh) 502: Ce (0 < χ <1); or Ca8Mg (Si04) 4C12 ·· Eu, Mη; or Ca2MgSi2 07: Cl, Eu; or BaJMgxZivdS ^ O? · Eu; In the "three-wavelength ZnSe white light LED" of the present invention, the ZnSe-type white LED grain used in the blue light-emitting layer part can use blue light with a wavelength of 420 to 480 nm 'The peak wavelength of the yellow light generated by irradiation on the substrate is about 600 nm. After adding any one or more mixed phosphors of the three kinds of green phosphors of the present invention to this traditional ZnSe-type white LED, a true phosphor can be produced. Three-wavelength white LEDs can be used as backlight sources for color liquid crystal displays such as mobile phones and PDAs, so that the liquid crystal display can show more realistic colors.

573370 V. Description of the invention (3) As a real white light source. To sum up, the "three-wavelength ZnSe white LED" of the present invention proposes an innovative three-wavelength manufacturing method, which makes the application range of ZnSe-type white light LEDs wider. The manufacturing method of the present invention is also ZnSe-type white light LEDs provide another better option.

Page 6 573370 Brief description of the drawings The examples created in this case are illustrated with the illustrations as follows: The first figure is the emission spectrum of a traditional ZnSe white LED. The first picture is a traditional ZnSe-type white LED lamp type (Lamp) sound diagram. The second figure is a schematic diagram of a “three-wavelength ZnSe white LED” lamp type white LED according to the present invention. The fourth figure is a schematic diagram of a "three-wavelength" white light LED "front-emitting white light LED according to the present invention. The fifth figure is a schematic diagram of the surface-adhesive (SMD) white LED of the "three-wavelength white LED" die-casting method of the present invention. The sixth figure is a schematic diagram of a "three-wavelength ZnSe white LED" printed circuit board (PCB) type white light LED according to the present invention. The seventh figure is an excitation spectrum of the green phosphor Y3 (GaxA l1-x) 502: Ce (0 < χ < 1) in the "three-wavelength ZnSe white LED" of the present invention. The eighth figure is an emission spectrum chart of green phosphor Y, 3 (GaxA1i-x) 50i2: Ce (0 < χ < 1) in the "three-wavelength ZnSe white LED" of the present invention. The ninth figure is an excitation spectrum of the green phosphor Ca8Mg (Si〇4) 4cl2 ···, Mn in the "three-wavelength ZnSe white LED" of the present invention. The tenth figure is an emission spectrum chart of green phosphor Ca8Mg (Si〇4) 4Cl2: Eu, Mn in the "three-wavelength ZnSe white LED" of the present invention. The eleventh figure is an emission spectrum chart of ZnSe white light crystal grains and green phosphor powder of the "three-wavelength ZnSe white LED" of the present invention. Drawing number description: 1. ZnSe blue light-emitting layer

573370 Brief description of the drawing 2. ZnSe substrate 3, lead wire 4, lamp holder 5, encapsulant 6, die electrode 7, green phosphor 8, front light-emitting package 9, front light-emitting internal electrode 1 0, front Light-emitting external electrode 11, metal support 12, printed circuit board 1 3. Printed circuit board electrode Example 1: Please refer to the third schematic diagram of the white LED lamp type, first select a traditional ZnSe white LED chip, the grain structure is mainly Divided into ZnSe blue light-emitting layer i and ZnSe substrate 2, of which ZnSe blue light-emitting layer! The light emitting wavelength is between 42 () ~ 48nm. This znSe white LED chip is fixed and passed through a process such as solid-state wire bonding and is conducted in the groove of the lamp bracket 4 and then in the groove of the ZnSe crystal. On the grains, the γ3 ((^ Α1ΐχ) 5〇ΐ2 · & (ouq) green fluorescent powder 7 of the present invention is directly or indirectly uniformly coated on the ZnSe white LED crystal by means of dispensing or coating, etc. On the chip, the encapsulation gel 5 is used to complete the lamp LED. The present invention (G ~ A1h): "(0 < χ < 1) green fluorescent powder 7 Blue-emitting

Figure 573370 is a simple illustration of 2 ::: Generates green light with an emission spectrum peak between 500 and 55 ° nm. The green wavelength is exactly the fluorescence that is lacking in traditional white checkers, so traditional ZnSe is used. The white light LED chip plus green ^ first becomes a three-wavelength ZnSe white light LED, and its spectrum is as shown in the twelfth figure / p. In the first embodiment, in addition to being packaged as a lamp-type LED, it can also be light / Γ 'as shown in the fourth figure; or it can be packaged as a mold-type package and packaged as Pfi; or it can be a printed circuit board (PCB) Not for the substrate. As shown in Figure 6, according to personal needs, it can be packaged into various green phosphors used in the present invention. In addition to h (Ga Alh) 5012: Ce (0 < X < 1) in Example 1, Ca8Mg (Si〇4 \ c3 x

The excitation and emission spectra of Eu and Mn green phosphors are shown in the ninth and tenth graphs. The emission wave is about 5 1 5 nm, and the other two green ordinary powders Ca2MgSl207: C1, Eu or Ba2 ( MgxZnh) Si207: Eu; can be excited by light to generate green wavelength light. β The green phosphor used in this month was pioneered by the inventor, and it has been researched for many years by Mingren. It is characterized by the fact that the phosphor can accept blue excitation: it produces green wavelength light and the composition of the phosphor Both of them have long oxidation stability and long life. Using the phosphor of the present invention with the traditional white…, LED grains can make up for the shortcomings of traditional ZnSe white LEDs that lack green light, and achieve three-wavelength white LEDs. The good color is also directly applied to the color liquid crystal display. White LEDs with three wavelengths of R, G, and B may become the mainstream products of white light in the future. Element 573370 illustration

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Claims (1)

573370 6. The scope of the patent application '' 1. A three-wavelength ZnSe white LED, including: a ZnSe white LED crystal grain, mainly including a ZnSe blue light-emitting layer and a znse substrate layer; a green phosphor, this phosphor can Excited by blue light wavelength to generate green wavelength light; 'a package substrate (or bracket); ZnSe white LED die is fixed on the package substrate or bracket via solid-state wire bonding process, and the green fluorescent powder is directly or indirectly It is attached to the LED die and then packaged. 2. According to the three wavelengths described in the scope of the patent application for white light LED, the green phosphor contains at least any of the following fluorescent substances: Y3 (GaxAlbu x) 5〇12: Ce (〇 < x & lt i) Ca8Mg (Si04) 4C12, Eu, Mn; Ca2MgSi207: Cl, Eu; Ba2 (MgxZn1.x) Si2 07: Eu; or a mixture of any two or more of the foregoing. Shen μ as described in the third wavelength white light of U Liwei 'wherein the light emission wavelength of the ZnSe blue light-emitting layer is between 42 and 480 nm 0 τ two Shen' as the three wavelengths described in the first patent scope 2—White light, the type of the middle package substrate (or bracket) can be metal, semiconducting, ceramic, plastic, printed circuit board (PCB) and other materials. Affirm the three-wavelength ZnSe white light as described in item 1 of the U-Range 573370 6. Scope of patent application LEDs, LEDs can be packaged into lamp type (Lamp), printed circuit board (PCB), front-emitting type, side-emitting type, surface-adhesive type (SMD), high-power type, etc. 6. As described in the application of the three-wavelength Z n S e white LED as described in item 1 of the scope of patent application, the number of ZnSe crystal grains may be singular or plural.