Patent Application
20150029723
This application claims priority of Taiwan Patent Application No. 102126224, filed on Jul. 23, 2013, the entirety of which is incorporated by reference herein.
1. Technical Field
The present disclosure relates to a light-emitting diode, and in particular to a light-emitting diode (LED) package structure and a light-emitting diode (LED) light bulb.
2. Description of the Related Art
The light-emitting diode (LED) is a semiconductor device. The material of the light-emitting diode chip is primarily III-V group elements, such as compound semiconductors like GaP, or GaAs. The principle of emitting light from a light-emitting diode is to convert electrical energy into light. In other words, applying electric current to the compound semiconductor and emitting energy in form of light through the combination of electron and hole to achieve the purpose of light emission. Since the light-emitting diode does not emit light by heating or discharging, the lifetime of the light-emitting diode is more than 100,000 hours and the idling time does not exist. Besides, light-emitting diode has advantages such as fast response (about 10−9 seconds), small volume, electricity saving, low contamination, high reliability, and suitability for mass production. Therefore, light-emitting diode has been used as a household electric appliance or an indicator light or light source in various equipment.
A general colored light-emitting diode package structure utilizes various combinations or configurations of at least one light-emitting diode chip which could emit a primary color (such as red, blue, or green) to mix the primary color in order to produce light of a color. For example,
However, the conventional white light-emitting diode package structure 100 often suffers chromatic aberration problems or non-uniformity of light mixing as a result of different configurations of the light-emitting diode chips 120B, 120R1, and 120R2 or insufficient light mixing. For example, referring to
Thus, a light-emitting diode package structure which may uniformly mix the light emitted is needed.
The disclosure provides a light-emitting diode (LED) package structure, including: a lead frame; at least two light-emitting diode chips having different light-emitting wavelengths disposed on the lead frame; an encapsulant disposed over the lead frame and covering the light-emitting diode chips, wherein the encapsulant has a first concave portion; and an optical glue disposed in the first concave portion, wherein the optical glue has a plurality of scattering particles to uniformly mix the lights of different wavelengths emitted by the light-emitting diode chips.
The disclosure also provides a light-emitting diode (LED) light bulb, including: a lamp base; a light source module disposed over the lamp base, wherein the light source module includes a light-emitting diode (LED) package structure, including: a lead frame; at least two light-emitting diode chips having different light-emitting wavelengths disposed on the lead frame; an encapsulant disposed over the lead frame and covering the light-emitting diode chips, wherein the encapsulant has a first concave portion; and a first optical glue disposed in the first concave portion, wherein the first optical glue has a plurality of first scattering particles to uniformly mix the lights of different wavelengths emitted by the light-emitting diode chips; a driving circuit disposed in the lamp base and electrically connecting the light source module; and a lampshade disposed over the lamp base and covering the light source module.
A detailed description is given in the following embodiments with reference to the accompanying drawings.
The disclosure may be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing.
The light-emitting diode chips 220A, 220B1, and 220B2 are disposed over the lead frame 210 and electrically connect to the lead frame 210. It should be noted that although
The encapsulant 230 may further include a first concave portion 230a formed on the top surface of the encapsulant 230 and extending into the encapsulant 230. In some embodiments, the encapsulant 230 and the first concave portion 230a may be simultaneously formed by compression molding. Besides, in some other embodiments, the encapsulant 230 is formed first. Then, the first concave portion 230a is formed on the top surface of the encapsulant 230 through mechanical processing by other tools such as a drilling machine. Besides, In some embodiments of the present disclosure, the light-emitting diode package structure 200 may further include an optical glue 250 disposed in the first concave portion 230a, wherein the optical glue 250 contains a plurality of scattering particles 250a. The optical glue 250 may be epoxy, silicone, urea-formaldehyde resin, or a combination thereof. The optical glue 250 may be formed by, but is not limited to, an adhesive dripping process or any other suitable process. It should be noted that although the top surface of the optical glue 250 is coplanar with that of the encapsulant 230 in a flat-cup structure in
The scattering particle 250a may include, but is not limited to, TiO2, CrO2, Al2O3, or a combination thereof. The diameter of the scattering particle 250a is about 0.3˜6 μm. In one embodiment, a concentration of the scattering particle 250a is about 5 vol % to 60 vol %. The present disclosure designs the first concave portion 230a on the encapsulant 230 and fills the first concave portion 230a with the optical glue 250 containing the scattering particle 250a. The light with different wavelengths emitted by the light-emitting diode chips 220A, 220B1, and 220B2 may be mixed uniformly through the optical properties of the optical glue 250 and the scattering particle 250a to eliminate the chromatic aberration problems or the non-uniformity of light mixing of the light-emitting diode package structure 100.
In some embodiments of the present disclosure, the optical glue 250 may further include a wavelength-conversion material 250b according to the design requirements. The wavelength-conversion material 250b is used to further effectively transfer the light with different wavelengths emitted by the light-emitting diode chips 220A, 220B1, and 220B2 in the light-emitting diode package structure 100. The wavelength-conversion material 250b may be phosphor or any other suitable material.
Besides, the number of concave portions 230a and optical glues 250 may be increased according to the actual requirement. Referring to
The light-emitting diode package structure 400 may include a lead frame 210, at least two light-emitting diode chips 220A, 220B1, and 220B2 having different light-emitting wavelengths, and an encapsulant 230 with a first concave portion 230a, bonding wire 240, and an optical glue 250 containing scattering particles 250a. The light-emitting diode package structure 400 may further include a main body 460 disposed over the lead frame 210. The main body 460 has a cavity 460a which concaves inward or shrinks inward gradually. The cavity 460a exposes a portion of the top surface of the lead frame 210. The portion of the top surface of the lead frame 210 exposed in the cavity 460a is defined as a die-mount region A. As shown in the Figure, light-emitting diode chips 220A, 220B1, and 220B2 are fixed at the die-mount region A of the lead frame 210, and the encapsulant 230 is formed in the cavity 460a. In this embodiment, the encapsulant 230 may be formed in the cavity 460a by an adhesive dripping process, then the concave portion 230a is formed in the encapsulant 230 through mechanical processing. Alternatively, the encapsulant 230 and the concave portion 230a may be simultaneously formed in the cavity 460a by compression molding. The optical glue 250 of the light-emitting diode package structure 400 may further include a wavelength-conversion material 250b.
Referring to
The present disclosure designs at least one concave portion in the encapsulant 230 and fills the concave portion with the optical glue containing the scattering particle. The light with different wavelengths emitted by the light-emitting diode chips may be pre-mixed uniformly in the light-emitting diode package structure through the optical properties of the optical glue and the scattering particle to eliminate the chromatic aberration problems or the non-uniformity of light mixing. The present disclosure further adds the wavelength-conversion material into the optical glue to effectively transfer the light with different wavelengths emitted by the light-emitting diode chips in order to make the light emitted by the light-emitting diode package structure closer to the desired color without chromatic aberration.
Besides, the present disclosure also provides a light-emitting diode (LED) light bulb. Referring to
Besides, the lampshade 650 may further include a second concave portion 650a and a second optical glue 660 disposed in the second concave portion 650a. The second concave portion 650a is formed at a top portion of the lampshade 650 and extends from the top surface of the lampshade 650 into the lampshade 650. The second optical glue 660 contains a plurality of scattering particles 660a. The second optical glue 660 may be epoxy, silicone, urea-formaldehyde resin, or a combination thereof. The second optical glue 660 may be formed by, but is not limited to, an adhesive dripping process or any other suitable process. It should be noted that, although the top surface of the second optical glue 660 protrudes over that of the lampshade 650 in a protruding-cup structure in
The scattering particle 660a may include TiO2, CrO2, Al2O3, or a combination thereof. In one embodiment, the diameter of the scattering particle 660a is about 0.3˜6 μm, and a concentration of the scattering particle 660a is about 5 vol % to 60 vol %. The light with different wavelengths emitted by two different light-emitting diode (LED) package structures 640a may be pre-mixed uniformly in the lampshade 650 by the second optical glue 660 having the scattering particle 660a and the chromatic aberration problems of the light-emitting diode (LED) light bulb 600 may be eliminated.
The optical glue 660 may further include a wavelength-conversion material 660b according to the design requirement. The wavelength-conversion material 660b is used to provide more optical properties to the two different light-emitting diode (LED) package structures 640a in order to further effectively transfer the light with different wavelengths emitted by the two different light-emitting diode (LED) package structures 640a in the lampshade 650. The wavelength-conversion material 660b may be phosphor or any other suitable material.
It should be appreciated that although the lampshade 650 of the light-emitting diode (LED) light bulb 600 has only one second concave portion 650a in
The present disclosure designs at least one concave portion on the lampshade in the light-emitting diode (LED) light bulb and fills the concave portion with the optical glue containing the scattering particle. The light with different wavelengths emitted by the light-emitting diode (LED) package structures having different wavelength may be pre-mixed uniformly in the lampshade through the optical properties of the optical glue and the scattering particle to eliminate the chromatic aberration problems or the non-uniformity of light mixing. The present disclosure further adds the wavelength-conversion material into the optical glue to effectively transfer the light with different wavelengths emitted by the light-emitting diode chips in order to make the light emitted by the light-emitting diode (LED) light bulb closer to the desired color without chromatic aberration.
Although some embodiments of the present disclosure and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims. For example, it will be readily understood by those skilled in the art that many of the features, functions, processes, and materials described herein may be varied while remaining within the scope of the present disclosure. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present disclosure. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102126224 | Jul 2013 | TW | national |
