TW480747B - Light emitting device with a blue light emitting component and a covering member containing zinc selenide - Google Patents

Abstract

A light emitting device capable of emitting visually white light comprises a blue light emitting component and a covering member, which covers the light emitting component and contains zinc selenide phosphorescence material. The blue light emitting component, e.g., GaN based semiconductor light emitting component, is capable of emitting blue light in the visible frequency range. Part of the blue light emitted from the light emitting component is absorbed by the zinc selenide phosphorescence material and the absorbed blue light is then converted to phosphorescence light of a different wavelength (e.g., wideband phosphorescence light with center wavelength around 570 nm). The phosphorescence light of a different wavelength and the blue light not being absorbed is mixed to yield a visually white light.

Description

480747 V. Description of the Invention (1) [Application Field of the Invention] The present invention relates to a semiconductor light emitting device capable of emitting visual white light, and particularly to a light emitting device having a covering portion of a zinc selenide-containing fluorescent material. [Background of the Invention]

Light emitting diode (Light Emitting Diode) is a kind of light emitting element with small size and high luminous efficiency. It has been widely used in various indicators and various light sources. Since the light-emitting diode is a semiconductor light-emitting element, it has the advantages of being difficult to burn out, high shock resistance, and being able to withstand repeated repeated on / off operations (ο η / 〇 f f 〇 p e r a t i ο n s). In recent years, ultra-high illumination and high-efficiency red, green and blue light-emitting diodes have been successfully developed, and large-screen light-emitting diode displays (LEDDs) made of red-green-blue light-emitting diodes is ρ 1 ay) has also entered the practical stage. Since light emitting diode displays have the advantages of light weight and long life, they are expected to be used more widely in the future. Because light emitting diodes have many of the above advantages, the idea of using light emitting diodes as white light sources has also been tried by many parties in recent years. Because the light emitting diode has the characteristic of emitting monochromatic light, in order to manufacture a white light source, the three light emitting units of the three primary colors of red, green and blue must be closely arranged with each other. When the three colors of light are properly blended and uniformly mixed, a visual white light can be produced. However, since the light generated by three types of light-emitting units with different hue, luminous intensity, and other characteristics must be properly blended, it is not easy to blend the required hue of white light. In addition, different light-emitting units require different driving voltages, which complicates the design of the driving circuit of the light-emitting element, thereby increasing manufacturing costs. In addition,

Page 4 480747 V. Description of the invention (2)

Since the three light emitting units have different decay rates, this also causes the whiteness of the emitted white light to deteriorate over time. In order to solve the above problems, one of them is proposed by Sumitomo Electric (Republic of China Patent No. 406, 4 4 2). This method epitaxially grows a zinc selenide epitaxial layer on a single crystal substrate of zinc selenide. The zinc selenide substrate absorbs part of the blue light emitted by the stupid crystal layer and is excited to generate a wide-field fluorescence with a wave domain center close to the wavelength of yellow light, wherein the wide-field fluorescence is mixed with the blue light to generate white light. However, this method also has its shortcomings, that is, the selenide substrate is not easy to manufacture, and the growth of a blue light-emitting layer by stupid crystals on the zinc substrate also increases technical difficulty. Therefore, there is still a need to develop a new white light emitting element to solve the above problems. [Objective and Summary of the Invention] Accordingly, an object of the present invention is to provide a white light emitting element that has both high quality, easy production, and low cost. According to the above object, the light emitting element of the present invention forms a covering member on a blue light emitting unit (light emmiting component), and the covering unit cover covers the light emitting unit, and can be a fluorescent material containing smashed zinc Glue layer. The blue light -¾ A = r Ge Fan, / [列 士 口 GaN-based semiconductor light-emitting unit, read blue light in the spectrum. And with this zinc selenide fluorescent material. The difference is that the blue light emitted by Zaowu turns the absorbed blue light into long fluorescent light, for example, the center of the wave domain is close to the wavelength of yellow light, ^ ^ < unm

Page 5 480747 V. Description of invention (3)) Wide-field fluorescence. The fluorescent light of different wavelengths is mixed with the unabsorbed blue light to produce visual white light. The smashed zinc fluorescent material may be in the form of a powder, and the powder may be fine particles, flakes, or other irregular shapes, dispersed in the glue layer. The glue layer is used as a dispersion medium (d i s p er s i n g m e d i u m) of the sintered zinc fluorescent material, and may be transparent or nearly transparent. The adhesive layer can be directly printed on the semiconductor light emitting unit by printing or dispensing. The adhesive layer can also be formed on the semiconductor light emitting unit in a non-direct contact manner, and is separated from the semiconductor light emitting unit by an appropriate distance. The above-mentioned covering portion may also be a zinc selenide film directly deposited or grown on the light-emitting unit, or may also include the aforementioned adhesive layer covering the semiconductor light-emitting unit. In addition, the glue j can be divided into upper m, the lower layer contains zinc oxide fluorescent material with a higher volume concentration, and the upper layer contains a lower volume concentration of --------'--... ......-. ~ Shixihua zinc fluorescent material, so as to achieve better light diffusion effect. — — —--&Quot; — — …………… The semiconductor light emitting unit can be mounted on a circuit board by wire bonding or flip-chip bonding, or on a lead frame. In addition, the semiconductor light emitting unit may be covered with a molding material (mo 1 ding member), and the molding material may also contain the petrified zinc fluorescent material. As the zinc selenide fluorescent material can be a single crystal or polycrystalline powder or granule _________________________...—.......—------------------- -------------------------------------------------- --------------------—........ 'A ··, .. -... ... ..--.--Shape, special manufacturing and low cost. In order to have a clearer understanding of the features of the present invention described above, as well as other features and advantages of the present invention, it will be described in detail with reference to the drawings. However, it must be stated that the present invention may

480747 V. Description of the invention (4) Other embodiments, and the following figures are not necessarily drawn in full scale. [Detailed description of the embodiment] Please refer to "Fig. 1" for the first embodiment of a light-emitting element disclosed according to the present invention. A semiconductor light emitting unit 2 can emit blue light in the visible light frequency spectrum, and is structured on a circuit substrate 4 such as a printed circuit board by wire bonding. The semiconductor light emitting unit 2 may be, for example, a GaN-based light emitting unit, and is electrically connected to the circuit substrate 4 through a gold wire 3. A covering portion 5 containing a zinc selenide (ZnSe) fluorescent material 6 covers the semiconductor light emitting unit 2. The material of the covering portion 5 may be a transparent or nearly transparent resin glue layer as a dispersion medium of the fluorescent material. The zinc selenide fluorescent material 6 may be a single crystal or polycrystalline powder dispersed in the covering portion 5, and the powder may have a granular shape, a flake shape, or other irregular shapes. The zinc selenide fluorescent material 6 can absorb part of the blue light emitted by the semiconductor light emitting unit 2 and then emit fluorescent light of a wavelength different from the blue light. The fluorescent light of different wavelengths is, for example, a glare in a wide wave range. The center of the domain is about 570 nm (close to the wavelength of yellow light). By mixing the fluorescent light of different wavelengths with the remaining blue light, a visual white light can be generated. In this embodiment, the covering portion 5 is divided into an upper glue layer 7 and a lower glue layer 8, wherein the upper glue layer 7 has a lower volume concentration of zinc selenide fluorescent material, and the lower glue layer 8 has a higher The volume concentration of zinc selenide fluorescent material can make the light-emitting element obtain better light diffusion effect. However, the covering portion 6 is not limited to the structure of two adhesive layers, but can also be a single layer or other multilayer adhesive layers. structure. The upper glue layer 7 and the lower glue layer 8 can be directly applied by printing or dispensing.

480747 V. Description of the invention The semiconductor light emitting unit 2 is provided. The "factory map" shows another embodiment according to the present invention. The half leads to form a chip bonded to a circuit substrate 13 in a flip-chip configuration, and two contact surface-adhesive devices (SMD). Two of the semiconductor light-emitting unit 10 = f, 卜 12 are facing the circuit substrate 13 and are in direct contact with the semiconductor substrate ^ ^ connection ^ 1 4 and 15 to achieve electrical connection. You can use glue or printing to form a cover on the 10,4 bearing parts 10, and the material of the back cover part 16 can also be a transparent or nearly transparent tree: another: Γ, 营The light powder 17 is dispersed therein. On the covering portion 16 = or near the transparent victory layer 18 to protect the shell. In the known example, the glue layer i 8 and the candle glue layer 18 may also be blended with appropriate two as needed = 22, The material, of course, the reference to "Figure 3", is also another real spring according to the present invention. A wooden structure, & the light emitting element 20 is bonded to-the lead frame 2 1 at the top = a semiconductor light emitting unit Way, it is connected with the lead frame Η dia by wire bonding with gold wire 23. In the bearing cup 22, the point = sexual connection end can be used to achieve electrical conductivity containing fluorescent zinc powder 25. Or the feasible way is filled in the semiconductor light-emitting unit 20. In addition, while the fluorescent glue 24 covers the member 26, the carrier cup 22 and the grand fluorescent glue 24 are wrapped in the inside, wherein the mold dog Material, light unit 20, and the fluorescent powder 27. The molding material 26 can only be incorporated into petrochemicals, zinc selenide in the fluorescent glue 24, and the concentration of limulus can be less than The fruit. The material of the molding material 26 is the same as the better light diffusive effect. The material of 2 4 is the same, such as

$ 8 pages 480747 V. Description of the invention (6) Transparent or nearly transparent resin. Of course, the molding material 26 does not need to be connected with a fluorescent material, but is shown in the "Figure 4". The upper surface of the semiconductor light-emitting unit 20 can be directly grown in advance to form a fluorescent film 28, or the zinc selenide fluorescent film 28 can be formed by a chemical vapor deposition method or other feasible methods. In this way, when the blue light emitted by the semiconductor light-emitting unit 20 passes through the zinc selenide fluorescent film 28, a part of the light is converted into a broad-wavelength fluorescence, and the center of the wave domain is about 5 7 0 nm (close to the wavelength of yellow light). The semiconductor light emitting unit in the above embodiment is not limited to a wire-type (w i r e b ο n d i n g) structure. According to a light-emitting element of the present invention, as shown in FIG. 5, a semiconductor light-emitting unit 31 is bonded to a submount 32 on a carrier cup 30 in a flip-chip manner. The two contact electrodes 3 3 and 3 4 of the semiconductor light-emitting unit 31 are facing the supporting base 32 and are directly connected to the two electrical connection pads 3 5 and 3 6 on the supporting base 32. The carrier cup 30 is filled with a photoresist 3 9 containing {Western chemical fluorescent powder 40, and the semiconductor light-emitting unit 31 is covered. In addition, the semiconductor light emitting unit 31 may also be coated with a fluorescent adhesive layer 37 in advance, as shown in "Figure 6". The fluorescent adhesive layer 37 contains a high volume concentration of zinc oxide fluorescent powder 38, so that a better light diffusion effect can be obtained in the same way. As shown in "Figure 7", it is yet another embodiment according to the present invention. A plurality of light emitting diode lamps 41 capable of emitting blue light are assembled on a printed circuit board 4 2 in a plug-in manner, wherein the light emitting diode lamps 41 are a blue light semiconductor light emitting unit 47 and a lead frame. Obtained by the construction. A fluorescent powder containing zinc selenide is formed on the plurality of light emitting diode lamps 41.

Page 9 480747 V. Description of the invention (7) The covering part 43 of the last 46 is covered on the plurality of light emitting diode lamps 41, wherein the covering part 43 and the light emitting diode lamp 41 and the inside thereof The semiconductor light emitting units 47 are not in direct contact, but are separated by an appropriate distance. The covering portion 4 3 may also be composed of a resin, including a glue layer 4 4 having a lower volume concentration of zinc selenide, and a glue layer 45 having a lower volume concentration of zinc selenide. The zinc selenide fluorescent powder 46 can also absorb part of the blue light emitted by the semiconductor light-emitting unit 47, and emit a broad-wavelength fluorescent light. The fluorescence-wavelength center of the wide-wavelength fluorescent domain is about 5700. n in (close to the wavelength of yellow light). This wide-wavelength fluorescence is mixed with the remaining blue light to produce visual white light. In this embodiment, although the light-emitting diode lamp 41 is taken as an example for description, the semiconductor light-emitting unit 47 can also be directly assembled by other feasible methods, such as wire bonding or flip-chip.于此 Printed circuit board 42. The above are only the preferred embodiments of the present invention, and are not intended to limit the scope of implementation of the present invention. Those skilled in the art can make appropriate modifications and retouches without departing from the spirit of the present invention, such as The zinc selenide fluorescent material may be added with I, Br, Cl, Ga, In, or A 1 as an active agent to obtain an appropriate fluorescence wavelength, and the zinc selenide fluorescent material is not limited to a single type. The powder can also be obtained by mixing a variety of different powders of zinc selenide series; therefore, all equal changes and modifications made in accordance with the scope of the patent application of the present invention are covered by the scope of the invention patent.

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I 480747 Brief description of the drawings [Simplified description of the drawings] FIG. 1 shows the structure of a light-emitting element according to the present invention. A semiconductor light-emitting unit is mounted on a circuit substrate in a wired manner, and has a zinc-containing fluorescent light. A glue layer of the material covers it. FIG. 2 illustrates a surface mount device (SMD) according to the present invention. Figure 3 is a drawing of a light-emitting element that is not a lead frame-type structure according to the present invention.

FIG. 4 shows another light-emitting device in a lead frame structure according to the present invention, in which a zinc selenide fluorescent film is formed on the upper surface of a semiconductor light-emitting unit. FIG. 5 shows a semiconductor light-emitting unit bonded to a carrier on a carrier cup in a flip-chip manner. FIG. 6 shows a fluorescent adhesive layer formed in advance on a semiconductor device with a flip-chip structure in a carrier cup. FIG. 7 shows a covering portion of a zinc selenide-containing fluorescent material, which is formed on a plurality of semiconductor light emitting units in a non-contact manner. [Symbol description] 2 Semiconductor light-emitting unit 3 Gold wire 4 Circuit board 5 Covering part 6 {西化 语 营 光 粉 7 Upper glue layer 8 Lower glue layer

Page 11 480747 Brief description of the drawings 10 Semiconductor light-emitting unit 1 bu 12 Contact electrode 13 Circuit board 14, 15 Electrical connection pad 16 Cover 17 Stone chemical conversion fluorescent powder 18 Adhesive layer 20 Semiconductor light emitting σ mouth early element 21 Lead frame 22 Carrying cup 23 Gold wire 24 Fluorescent glue 25 Fluorochemical zinc powder 26 Moulding material 27 Fluorescent zinc powder 28 Fluorescent zinc film 30 Fluorescent film 31 Fluorescence unit 32 Semiconductor base 32 Socket 33 ^ 34 Contact electrode 35 ^ 36 Electrical connection pad 37 Fluorescent adhesive layer 38 Fluorescent zinc powder 39 Fluorescent adhesive

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480747 Brief description of the diagram 40 Shixihua Zinc Fluorescent powder 41 Luminescent diode lamp 42 Printed circuit board 43 Covering part 44 Upper glue layer 45 Lower glue layer 46 Shixihua Zinc fluorescent powder powder 47 Semiconductor light emitting unit

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Claims (1)

480747 6. Scope of patent application 1. A light-emitting element including at least: a semiconductor light-emitting unit capable of emitting blue light; and a covering portion containing a zinc selenide fluorescent material covering the light-emitting element, the zinc selenide fluorescent material can Absorbs part of the blue light emitted by the light emitting element and emits light of a different wavelength from the blue light, wherein the light of different wavelengths is mixed with the blue light to generate visual white light. 2. The light-emitting element according to item 1 of the scope of patent application, wherein the covering portion is an adhesive layer covering the semiconductor light-emitting unit. 3. The light-emitting element according to item 2 of the scope of patent application, wherein the zinc selenide fluorescent material is dispersed in the adhesive layer in a powder form. 4. The light-emitting element according to item 3 of the scope of the patent application, wherein the adhesive layer comprises: a lower adhesive layer containing a higher volume zinc concentration; and an upper adhesive layer containing a lower volume zinc concentration . 5. The light-emitting element according to item 2 of the scope of patent application, wherein the covering portion is in direct contact with the semiconductor light-emitting unit. 6. The light-emitting element according to item 5 of the scope of patent application, wherein the covering portion is formed on the semiconductor light-emitting unit by printing. 7. The light-emitting element according to item 5 of the scope of patent application, wherein the covering portion is formed on the semiconductor light-emitting unit by a dispensing method. 8. The light-emitting element according to item 2 of the scope of patent application, wherein the covering portion is spaced from the semiconductor light-emitting unit by an appropriate distance. 9. The light-emitting element according to item 1 of the scope of patent application, wherein the covering portion Page 14 480747 6. Scope of patent application: Zinc selenide film directly grown on the semiconductor light-emitting unit. 10. The light-emitting element according to item 1 of the scope of patent application, wherein the covering portion is a zinc selenide film formed on the semiconductor light-emitting unit by a deposition method. 1 1. The light-emitting element according to item 1 of the scope of patent application, wherein the semiconductor light-emitting unit is a light-emitting unit of a gallium nitride series. 12. The light-emitting element according to item 1 of the scope of patent application, wherein the zinc selenide fluorescent material is added with a group selected from the group consisting of I, B r, C 1, G a, I η, or A 1 Any one of them acts as an active agent. 1 3. The light-emitting element according to item 1 of the scope of patent application, wherein the covering portion is a molding material that surrounds the semiconductor light-emitting unit. Page 15