The present invention relates to a light-emitting device and, particularly, to a semiconductor light emitting package and method of manufacturing the same.
Conventional materials used as the luminescent matrix include fluorescent powder, nano-crystals, glass, etc. Compared to the crystals and fluorescent powder, glass has received wide attention and is used in many applications, as it is transparent and rigid, has good chemical stability and good optical properties, and is easier to be made into products with various sizes or shapes, such as displays or light sources with various sizes or shapes. Therefore, glass is widely utilized.
This luminescent glass can be used in variety of luminescent device, such as LED (light-emitting diode) light sources, light sources, flat panel display, plasma display, etc. The LED device is increasingly being used in signal light, car light, huge display screen, and lighting area due to its advantages such as longer service life, energy-saving qualities, and quick start. Currently the white light LED emits white light by a LED chip and fluorescent glue excited by light emitted from the LED chip. In a typical manufacturing method of the white light LED, the LED chip is coated by fluorescent glue after welding process. The coated LED chip is baked. The method may be used to achieve the properties of the white light LED. The method is widely used for many manufacturers. The luminous efficiency of the commercial white light LED is 801 m/W.
However, the above mentioned method has some disadvantages. Firstly, high temperature and light will destroy the fluorescent powder and the organic device material. This method will cause the light degradation of the LED, and lead to shorten service life of the luminescent device. Secondly, the fluorescent powder is hard to be coated uniformly over the chip, and result in that the luminescent device has a bad uniformity of illumination, and come into being a “halo” phenomenon. Thirdly, white light LED has a glare because a very bright light in a small area. The manufacturing process of the white light LED has many processes. The baking operation of the glue wastes time and is costly.
What is needed, therefore, is a semiconductor light emitting package and method of manufacturing the same to overcome or at least alleviate the above-described problems.
The present invention provides a semiconductor light emitting package which will enlarge the light-emitting area, improves the uniformity of illumination of the LED, prevents the “halo” phenomenon, and has a long service life.
The present invention also relates to a method for manufacturing semiconductor light emitting package, which has a simple process and low production cost.
A semiconductor light emitting package includes a substrate, an encapsulating material, a semiconductor light emitting chip disposed on the substrate, wires; and an integrated glass-fluorescent powder compound light-emitting structure. The encapsulating material and the integrated glass-fluorescent powder compound light-emitting structure are packaged on the semiconductor light emitting chip, the integrated glass-fluorescent powder compound light-emitting structure is coated on the encapsulating material.
The present invention further provides a method for manufacturing semiconductor light emitting package, comprising:
forming an integrated glass-fluorescent powder compound light-emitting structure;
assembling a semiconductor light emitting chip on a substrate and at least one wire soldered; and
encapsulating the semiconductor light emitting chip by the integrated glass-fluorescent powder compound light-emitting structure cooperating with the encapsulating material to coat the encapsulating material with the integrated glass-fluorescent powder compound light-emitting structure for forming the semiconductor light emitting package.
Compared with the prior art, the glass-fluorescent powder compound light-emitting structure coated on the encapsulating material has a larger area than that of the typical fluorescent powder coated on the chip. The glass-fluorescent powder compound light-emitting structure will enlarge the light-emitting area, improve the uniformity of illumination of the LED, and prevent the “halo” phenomenon. The integrated glass-fluorescent powder compound light-emitting structure can prevent the fluorescent powder dispersed in the glass from water vapor in the air and direct contact between the fluorescent powder and the organic package material. The light emitting performance will not be degraded. The life of the semiconductor light emitting package can be prolonged. The integrated glass-fluorescent powder compound light-emitting structure is coated on the encapsulating material in package process for omitting a process of the chip coated by the fluorescent powder. This method will simplify the package method, improve efficiency, and reduce production cost.
Many aspects of the present semiconductor light emitting package and method of manufacturing the same can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present semiconductor light emitting package and method of manufacturing the same.
For further illustrating the purposes, technical solutions and advantages of the present invention, the invention will be described in more details with reference to the drawings and examples. It should be understood that the examples are provided for illustrating rather than limiting the present invention.
Referring to
Specifically, the semiconductor light emitting chip 201 can be a blue light LED chip capable of generating light with wavelength 420-490 nm. In alternative embodiments, the semiconductor light emitting chip 201 can be a purple light LED chip capable of generating light with wavelength 220-420 nm. In present embodiment, the semiconductor light emitting chip 201 is a blue light LED chip capable of generating light with wavelength 455 nm. The substrate 202 further includes a reflector cup 203. The semiconductor light emitting chip 201 is received in the reflector cup 203. The encapsulating material 204 is an organic transparent encapsulating material, such as a material selected from the group consisting of: epoxy resin, silicone, acrylics resin, thermoplastic material, and polyurethane material. The encapsulating material 204 is either coated or covered on the semiconductor light emitting chip 201 received in the reflector cup 203. The wires 205 are electrically connected to outer bonding pads on the substrate 202.
Referring to
A variety of suitable low-melting-point glass may be used the glass substrate 108, for example, but not limited to, borate glass, such as Na2O—ZnO—B2O3—SiO2. The appropriate melting point of the low melting point glass is 200-800° C., more preferably 200-600° C. In present embodiment, the glass substrate 108 is a sodium borosilicate glass.
In the present embodiment, the glass substrate 108 includes two pieces of glass layer 101a and 103a. The fluorescent powder embedded into the glass formed by the glass layers 101a and 103a will form a glass-fluorescent powder compound unit 102a. The fluorescent powder is approximately at center area of the glass layers 101a and 103a. The glass-fluorescent powder compound unit 102a includes glass and fluorescent powder dispersed in the glass.
In the present embodiment, the fluorescent powder can be made of a material selected from the group consisting of: red fluorescent material, green fluorescent material, and yellow fluorescent material. This fluorescent powder is stimulated by the light with wavelength of 420˜490 nm emitted by the blue light semiconductor light emitting chip. The red fluorescent material can be CaS:Eu, SrS:Eu or a rare-earth ion doped alkaline earth silicon nitride phosphor powder. The yellow fluorescent material can be a cerium doped yttrium aluminum garnet (YAG:Ce) phosphor powder, cerium doped terbium aluminum garnet (TAG:Ce) phosphor powder, rare-earth ion doped silicate phosphor powder or Eu2+-doped nitride/oxynitride phosphor powder. The green fluorescent material can be SrGa2S4:Eu, Ba2SiO4:Eu, etc. A portion of the blue light emitted by the semiconductor light emitting chip 201 stimulates the glass-fluorescent powder compound light-emitting material to generate fluorescent light. This combination of fluorescent light and the other portion of blue light produces is white light. In the present embodiment, the fluorescent powder is YAG:Ce phosphor powder. The fluorescent powder can be a commercial fluorescent powder (LMY-65-C produced by Dalian Luminglight Co., Ltd.).
In alternative embodiments, the fluorescent powder can be selected a material from the group consisting of: red fluorescent material, green fluorescent material, and yellow fluorescent material. This fluorescent powder is stimulated by the light with wavelength of 220˜420 nm emitted by the purple light semiconductor light emitting chip. The red fluorescent material can be Y2O3:Eu3+, Y2O2S:Eu3+ or a rare-earth ion doped tungstate, molybdate, gallate, silicate, aluminate, vanadate, and borate, etc. The yellow fluorescent material can be a cerium doped yttrium aluminum garnet (YAG:Ce) phosphor powder or cerium doped terbium aluminum garnet (TAG:Ce) phosphor powder. The green fluorescent material can be CaO.0.53SiO2.0.36Al2O3:Ce, Tb, ZnS:Cu,Al,Au, Y2SiO5:Ce,Tb, MgAl11O19:Ce,Tb, Ca8Mg(SiO4)Cl2:Eu2+, LaPO4:Ce,Tb, La2O3.0.2SiO2.0.9P2O5:Ce,Tb, GdMgB5O10:Ce,Tb,Mn2+, Y2O3.Al2O3:Tb, MgGa2O4:Mn2+, BaMg2Al16O27:Eu2+,Mn2+, (Ba,Sr,Ca)2SiO4:Eu2+ or Zn2SiO4:Mn2+, etc. The blue fluorescent material can be BaMg2Al16O27:Eu2+, BaMgAl10O17:Eu2+, ZnS:Ag, CaO.0.53 SiO2.0.36Al2O3:Ce, (Sr,Ca,Mg)10(PO4)6Cl2:Eu2+, Ca2B5O9Cl:Eu2+, Ba3MgSi2O8:Eu2+, (Sr,Ca)10(PO4)6.nB2O3:Eu2+, BaAl8O13:Eu2+, 2SrO.0.84P2O5.0.16B2O3:Eu2+, Sr2Si3O8.2SrCl2:Eu2+ or Y2SiO5:Ce, etc. In present embodiment, the fluorescent powder is a mixture of three kinds of fluorescent powder (BaMgAl10O17:Eu2+, CaO.0.53SiO2.0.36Al2O3:Ce,Tb and Y2O2S:Eu3+). The mass ratio of them is 0.7:16:40.
As shown in
As shown in
In step S01, the integrated glass-fluorescent powder compound light-emitting structure is made.
In step S02, the semiconductor light emitting chip is fixed on the substrate. Then the wires are soldered.
In step S03, the semiconductor light emitting chip is packaged by the integrated glass-fluorescent powder compound light-emitting structure cooperating with the encapsulating material. The compound light-emitting structure is coated on the encapsulating material to form the semiconductor light emitting package.
In alternative embodiments, the order of the steps S01 through S03 can be changed, but ensure that the step S01 is stayed ahead the step S03
The compound light-emitting structure in the step S01 is formed by heating a glass containing the fluorescent powder to the softening point. As shown in
The fluorescent powder is formed on a first glass panel 101 to form a fluorescent powder layer 102.
A second glass 103 is positioned on the fluorescent powder layer 102 which has located on the first glass panel 101.
The first glass panel 101 and the second glass 103 are heated to the softening point to disperse the fluorescent powder in the first glass panel 101 and the second glass 103, and then solidified to form the integrated glass-fluorescent powder compound light-emitting structure 107.
As shown in
The fluorescent powder layer 102 is formed by coating process, deposition process or spraying process. For example, the fluorescent powder layer 102 is coated on the first glass panel 101 by screen printing technology. The compound light emitting structure made by the mature screen printing technology can be produced in mass production to increase productivity.
The first glass panel 101 can be under pre-process into a flat panel by some processes, such as cutting to a needed shape, grinding process, and polishing process. In alternative embodiments, the thickness of the first glass panel 101 is 0.5 mm, and the size is 3×3 cm2.
As shown in
The first glass panel 101 is disposed on a table such as a flat metal panel 104. At least one of spacers 105 are arranged around or disposed on the two opposite sides of the first glass panel 101 and the second glass 103. The thickness of the spacer 105 is adjustable. When the first glass panel 101 and the second glass 103 pressed by the pressing block 106 are heated to the softening point, the spacer 105 is used for ensuring that the thickness of the light-emitting structure 107 has a presetting final thickness. An integrated structure as seen in
In the above mentioned method of forming the compound light-emitting structure 107, the first glass panel 101 and the second glass 103 is used to prevent the fluorescent powder dispersed in the glass from water vapor in the air because the glass can be chosen flexibly, a high transparent performance, a good machinable performance, an air-tight and a chemical stability. The light emitting performance will not be degraded. The performance of the fluorescent powder will be degraded because the highest heat-resistant temperature of the fluorescent powder is higher than the softening point of the glass.
Moreover, the heating temperature of the above mentioned method is under the softening point of the glass, but not under a high melting temperature. The fluorescent powder will not be destroyed in the heating process so that it will improve the reliability and the stability of the light-emitting property of the compound light-emitting structure. The total produce process is simple and efficient because the process do not need complicated equipment and complicated parameter adjustment. The compound light-emitting structure 107 will have a longer life because the fluorescent powder do not suffer high temperature and be irradiated by light. The fluorescent powder can be uniformly dispersed in the glass to enhance light uniformity and light consistency and avoid “halo” phenomenon.
In typical device method, the fluorescent powder is mixed with resin. This typical device method will make the fluorescent powder agglomerate or nonuniformly disperse and affect light uniformity and light consistency of different batches of the products. In present embodiment, the fluorescent powder of the integrated glass-fluorescent powder compound light-emitting structure 107 is uniformly dispersed in the glass substrate. The uniformity of different batches of the products can be the same by controlling the coating amount of the fluorescent powder.
In step S02 of soldering wires, the LED semiconductor light emitting chip 201 is fixed on the reflector cup 203 disposed on the substrate 202. The semiconductor light emitting chip 201 is filled with the silicone (encapsulating material) 204 to encapsulate the semiconductor light emitting chip 201. The compound light-emitting structure 107 obtained from the above mentioned method is coated on the silicone 204. The silicone 204 is solidified. Specifically, the device structure packaged is placed into oven. The device structure is pre-solidified for 1-4 hours under 100-130° C. at first. A semiconductor light emitting package 100 is produced when the device structure is re-solidified for 1-8 hours under 140-170° C. to solidify the device structure absolutely. In present embodiment, the temperature of the pre-solidify process is 120° C., and the pre-solidify time is 2 hours. The temperature of the re-solidify process is 160° C., and the re-solidify time is 2 hours. The compound light-emitting structure 107 can be packaged again. The compound light-emitting structure 107 can be coated by the encapsulating material, such as silicone, epoxy, acrylics, thermoplastic material, and polyurethane material, etc.
Referring to
The semiconductor light emitting package 300 of the second embodiment is similar to the semiconductor light emitting package 100 of the first embodiment, except for the encapsulating material 304, the compound light-emitting structure 307, and the semiconductor light emitting chip 301. In present embodiment, the encapsulating material 304 is an inert gas 304. The glass substrate of the compound light-emitting structure 307 is a Li—Zn—Si system glass. The fluorescent powder is coated though deposition coating method. The fluorescent powder is mixture of a yellow YAG:Ce fluorescent powder and a red CaS:Eu fluorescent powder. The mass ratio of them is 2:5.
A method of manufacturing the semiconductor light emitting package 300 of the second embodiment is similar to the method of manufacturing the semiconductor light emitting package 100 of the first embodiment, except for the steps S01 and S03.
Referring to
Referring to
The doping ratio, the thickness, and the transparent factory of the compound light emitting structure can be controlled through adjusting the coating thickness of the fluorescent powder and the number of the glass panel.
In the step S03 of the second embodiment, the compound light-emitting structure 307 is sealedly connected with the reflector cup 303 at first. The compound light-emitting structure 307 can be covered on the inner surface of the reflector cup 303. The compound light-emitting structure 307, the reflector cup 303, and the substrate 302 are used for enclosing a seal space. The seal space is filled with the inert gas 304 such as nitrogen, argon, etc to produce the semiconductor light emitting package 300. Solidification process is omitted because the semiconductor light emitting chip 301 is not packaged by the organic package material. The device method of the second embodiment can omit a process of the chip coated by the fluorescent powder and a process of the chip packaged by the organic package material. This method simplifies the package steps, improves efficiency, reduces production cost, prevents aging of the organic package material and the fluorescent powder, and has a longer life.
Referring to
The semiconductor light emitting package 400 of the third embodiment is similar to the semiconductor light emitting package 100 of the first embodiment, except for the following aspects. In present embodiment, the glass substrate of the compound light-emitting structure 407 is a sodium-boron-aluminum system glass. The fluorescent powder is coated though spraying coating method. The fluorescent powder is a yellow silicate fluorescent powder (LMS-560-B produced by Dalian Luminglight Co., Ltd.). The semiconductor light emitting chip is a 5×5 arrays blue light LED chips capable of generating light with wavelength of 420 nm. The encapsulating material 404 not only packages the chip 401, but also packages the compound light-emitting structure 407. The reflector cup 403 further includes a step structure 403a. The compound light-emitting structure 407 is disposed on the step structure 403a.
A method of manufacturing the semiconductor light emitting package 300 is similar to the method of manufacturing the semiconductor light emitting package 100 of the first embodiment, except for the number of the chip 401 packaged.
Referring to
The semiconductor light emitting package 500 of the fourth embodiment is similar to the semiconductor light emitting package 300 of the third embodiment, except for the following aspects. In present embodiment, the encapsulating material 506 is an inert gas. The glass substrate of the compound light-emitting structure 504 is a tellurate glass. The fluorescent powder is a mixture of three kinds of fluorescent powder (BaMgAl10O17:Eu2+, CaO.0.53SiO2.0.36Al2O3:Ce,Tb and Y2O2S:Eu3+). The mass ratio of them is 24.4:33.6:42. The semiconductor light emitting chip is a 5×5 arrays purple light LED chips capable of generating light with wavelength of 395 nm.
A method of manufacturing the semiconductor light emitting package 500 is similar to the method of manufacturing the semiconductor light emitting package 300 of the second embodiment, except for the number of the chip 501 packaged.
The glass-fluorescent powder compound light-emitting structure coated on the encapsulating material of the above-described embodiments has a larger area than that of the typical fluorescent powder coated on the chip. The glass-fluorescent powder compound light-emitting structure will enlarge the light-emitting area, improves the uniformity of illumination of the LED, and prevents the “halo” phenomenon. The integrated glass-fluorescent powder compound light-emitting structure can prevent the fluorescent powder dispersed in the glass from water vapor in the air and direct contact between the fluorescent powder and the organic package material. The light emitting performance will not be degraded. The life of the semiconductor light emitting package can be prolonged. The integrated glass-fluorescent powder compound light-emitting structure is coated on the encapsulating material in package process for omitting a process of the chip coated by the fluorescent powder. This method will simplify the package method, improve efficiency, and reduce production cost.
While the invention has been described in connection with what are presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/CN2009/074243 | 9/25/2009 | WO | 00 | 3/23/2012 |