1. Field of the Invention
The present invention relates to a light-emitting diode (LED) package and a fabrication method thereof. More particularly, the present invention relates to a side-view light-emitting diode (LED) package with ultra-thin thickness and a fabrication method thereof.
2. Description of Related Art
Since the light-emitting diode (LED) has such advantages as long service life, small volume, high shock resistance, low heat output, and low power consumption, it has been widely utilized in indicators or light sources for household appliances and various instruments. In recent years, the LED has been developed towards multicolor and high brightness; therefore, its application scope has been expanded to large outdoor display boards, traffic signal lights, and the like. In the future, it may even become the main illumination light source with both power-saving and environment-protecting functions.
As a result of the development of small displays devices, the thickness of the illumination light source must become thinner and thinner. For example, a side-view LED package of about 0.6 millimeter in thickness had been produced.
Accordingly, the present invention is directed to a fabrication method of a side-view LED package so as to enhance yield rate.
The present invention is directed to a side-view LED package with an ultra-thin thickness.
As embodied and broadly described herein, the present invention provides a fabrication method of a side-view LED package. First, a chip carrier of lead frame substrate plus an opaque housing is provided. The opaque housing has a cavity for accommodating the light-emitting diode chip. Next, a chip-bonding process is performed for electrically connecting a light-emitting diode chip with the chip carrier. Then, a transparent encapsulant mixed with Phosphor, for example, is disposed in the cavity, wherein the transparent encapsulant has a side-view light output surface uncovered by the opaque housing and light emitted from the light-emitting diode chip is output via the side-view light output surface. Thereafter, a portion of the opaque housing and a portion of the transparent encapsulant are removed for reducing an overall thickness of the opaque housing such that a top surface of the transparent encapsulant is uncovered by the opaque housing beside the side-view light output surface. Then, an opaque protective layer is formed on the top surface of the transparent encapsulant and the opaque housing.
In one embodiment of the present invention, the above-mentioned chip carrier comprises a lead frame or a circuit board.
In one embodiment of the present invention, the above-mentioned chip-bonding process comprises a wire-bonding process or a flip-chip bonding process.
In one embodiment of the present invention, the method for forming the above-mentioned opaque housing comprises injection molding.
In one embodiment of the present invention, the method for forming the above-mentioned transparent encapsulant comprises dispensing or mold injection.
In one embodiment of the present invention, the method for forming the above-mentioned transparent encapsulant comprises providing a transparent compound having Phosphor material mixed therein and filling the transparent compound into the cavity.
In one embodiment of the present invention, the overall thickness of the above-mentioned opaque housing and the above-mentioned transparent encapsulant is about 0.5 millimeter to 0.8 millimeter before the portion of the opaque housing and the portion of the transparent encapsulant is removed.
In one embodiment of the present invention, the overall thickness of the above-mentioned opaque housing and the above-mentioned transparent encapsulant is about 0.35 millimeter to 0.45 millimeter after the portion of the opaque housing and the portion of the transparent encapsulant is removed.
In one embodiment of the present invention, the above-mentioned method of removing the portion of the opaque housing and the portion of the transparent encapsulant comprises cutting or grinding.
In one embodiment of the present invention, the above-mentioned method of forming the opaque protective layer comprises coating, screen printing, or sputtering. The material of the above-mentioned opaque protective layer, for example, comprises a polymer and a plurality of particles mixed therein. The polymer, for example, comprises Oligo-polymer, Silicon, Epoxy or Acrylic. The material of the particles, for example, comprises metal, Titanium Dioxide, Aluminum Oxide or Phosphor.
In one embodiment of the present invention, the thickness of the above-mentioned opaque protective layer is about 0.01 millimeter to 0.15 millimeter.
As embodied and broadly described herein, the present invention further provides a side-view LED package including a chip carrier, a light-emitting diode chip, an encapsulant and a protective opaque layer. The opaque housing is bonded with the chip carrier, wherein the opaque housing has a cavity for accommodating the light-emitting diode chip. The light-emitting diode chip is electrically connected with the chip carrier. The encapsulant comprises a transparent encapsulant. The transparent encapsulant is disposed in the cavity, wherein the transparent encapsulant has a side-view light output surface uncovered by the opaque housing, the transparent encapsulant has a top surface beside the side-view light output surface uncovered by the opaque housing, and light emitted from the light-emitting diode chip is output via the side-view light output surface. Additionally, an opaque protective layer is disposed on the removed surface of the transparent encapsulant and the opaque housing.
In one embodiment of the present invention, the above-mentioned chip carrier comprises a lead frame or a circuit board.
In one embodiment of the present invention, the overall thickness of the above-mentioned encapsulant and the above-mentioned opaque protective layer is about 0.5 millimeter to 0.8 millimeter.
In one embodiment of the present invention, the material of the above-mentioned opaque protective layer comprises a polymer and a plurality of particles mixed therein.
In one embodiment of the present invention, the above-mentioned polymer comprises Oligo-Polymer.
In one embodiment of the present invention, the material of the above-mentioned particles comprise metal, Titanium Dioxide, Aluminum Oxide or Phosphor.
In one embodiment of the present invention, the above-mentioned thickness of the above-mentioned opaque protective layer is about 0.01 millimeter to 0.15 millimeter.
In one embodiment of the present invention, the material of the above-mentioned transparent encapsulant comprises Silicon, Epoxy or Acrylic.
In one embodiment of the present invention, the material of the above-mentioned transparent encapsulant further comprises a Phosphor material.
In the present invention, since a portion of the opaque housing and a portion of the transparent encapsulant is removed for reducing the overall thickness of the side-view LED package, the mold used for fabricating the opaque housing is not necessary to be modified and the cost is decreased significantly. Additionally, the yield rate of the fabrication method of the side-view LED package is enhanced.
In order to the make the aforementioned and other objects, features, and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.
Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
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Particularly, the material of the opaque protective layer 260 comprises a polymer and a plurality of particles mixed in the polymer, wherein the polymer comprises Oligo-polymer, Silicon, Epoxy or Acrylic and the material of the particles comprises metal, Titanium Dioxide, Aluminum Oxide or Phosphor. The thickness d3 of the opaque protective layer 260 is about 0.01 millimeter to 0.15 millimeter. It is noticed that the opaque protective layer 260 is a thin film so the thickness d3 is much smaller than the difference between thickness d1 and thickness d2. Thus, the overall thickness d4 (i.e. d2+d3) of the side-view LED package 270 is significantly reduced as compared with the thickness d1 of the side-view LED package 250. Furthermore, the method of reducing the overall thickness of the side-view LED package 270 is simple and easy. In one word, the present embodiment provides a fabrication method of LED package with high yield rate. Certainly, in another embodiment, both the top and bottom sides beside the side-view light output surface 242 of the opaque housing 230 can further be removed and two opaque protective layers 260 are formed respectively on the top and bottom surface of the transparent encapsulant 240 and the opaque housing 230. Such that, the thickness d4 of the side-view LED package 270 can be much thinner.
The fabrication method of the present invention provides is compatible with current process and the opaque housing can be formed without modifying the mold used in mold injection process. Therefore, the fabrication method of a side-view LED package of the present invention is simple and easy and the yield rate of fabricating a thin side-view LED package of the present invention is high.
One or part or all of these and other features and advantages of the present invention will become readily apparent to those skilled in this art from the following description wherein there is shown and described a preferred embodiment of this invention, simply by way of illustration of one of the modes best suited to carry out the invention. As it will be realized, the invention is capable of different embodiments, and its several details are capable of modifications in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.