Light emitting diode

1. Field of the Invention

The present invention relates to a light emitting diode, and more particularly to a light emitting diode having enhanced radiation effect and light-emitting efficiency.

2. Description of Related Prior Art

A conventional vertical-type light emitting diode, as shown in FIG. 1, includes a frame A 2 on which a bowl portion is formed for receiving a chip A 1 therein. The frame A 2 has two extended leads, at lower ends of which the frame A 2 is soldered onto a printed circuit board A 4 at soldering points A 3 . This type of conventional light emitting diode has relatively deep bowl portion that facilitates to enhanced light-emitting efficiency. However, it uses only one of the two leads to radiate heat and therefore has inferior radiation efficiency. It is theoretically known that the radiation effect is in proportion to the light-emitting efficiency. The poorer the radiation effect is, the poorer the light-emitting efficiency is. The vertical-type light emitting diode shown in FIG. 1 has poor radiation effect and therefore needs improvement.

FIG. 2 illustrates another conventional light emitting diode that includes a frame B 2 for holding a chip B 1 thereon. The frame B 2 has increased width and leads having increased diameter, compared with the frame A 2 shown in FIG. 1 . The leads are also soldered onto a printed circuit board B 4 at soldering points B 3 . In this type of conventional light emitting diode, the width-increased frame B 2 enables a reduced overall height of the light emitting diode, and both the two leads are used to radiate heat to provide an enhanced radiating capacity. However, the frame B 2 is thin in its thickness and the bowl portion on the frame B 2 has a relatively small depth of about 0.4 mm that is smaller than the bowl portion on the frame A 2 for the vertical-type light emitting diode of FIG. 1 . Since the depth of the bowl portion also has connection with the light-emitting efficiency, there is limitation in the light-emitting efficiency of the light emitting diode of FIG. 2 and an improvement on it is desired.

It is therefore tried by the inventor to develop a light emitting diode that has relatively deep bowl portion and increased radiation and light-emitting efficiency.

A primary object of the present invention is to provide a light emitting diode that has relatively deep bowl portion and increased radiation and light-emitting efficiency. To achieve the above and other objects, the light emitting diode of the present invention includes a frame having an increased thickness to enable the bowl portion formed thereon to have a depth more than 0.6 mm to provide enhanced light-emitting efficiency. The frame also includes leads downward extended from the frame and radiating blocks provided at or close to a bottom of the frame to increase the radiation efficiency. The light emitting diode of the present invention further includes a layer of radiation-enhancing material over bottoms of the frame and the radiating blocks to enhance the radiating capacity of the light emitting diode. In the present invention, the frame and the radiating blocks or the layer of radiation-enhancing material is connected to and in direct contact with the printed circuit board to further increase the radiating area of the light emitting diode.

The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein

FIG. 1 is a sectional view of a conventional vertical-type light emitting diode;

FIG. 2 is a sectional view of another conventional light emitting diode;

FIG. 3 is a perspective view of a light emitting diode according to a first embodiment of the present invention;

FIG. 4 is a sectional view of the light emitting diode of FIG. 3 being mounted on a printed circuit board;

FIG. 5 is a perspective view of a light emitting diode according to a second embodiment of the present invention; and

FIG. 6 is a perspective view of a light emitting diode according to a third embodiment of the present invention.

Please refer to FIGS. 3 and 4 that are perspective and sectional views, respectively, of a light emitting diode according to a first embodiment of the present invention. As shown, the light emitting diode includes a chip C 1 received in a bowl portion of a frame C 2 . The frame C 2 has a thickness relatively larger than that of the frame B 2 of the conventional light emitting diode shown in FIG. 2 . Accordingly, it is possible for the bowl portion of the frame C 2 to have a depth more than 0.6 mm that will largely upgrade a light-emitting efficiency of the light emitting diode. The frame C 2 also has an increased width and leads downward extended from two outer sides of the frame C 2 . The increased thickness and width of the frame C 2 enables the same to have increased radiating volume and enhanced radiation effect. Moreover, there are radiating blocks C 5 and a layer of radiation-enhancing material C 6 provided at a bottom of the frame C 2 . The frame C 2 is soldered onto a printed circuit board C 4 at soldering points C 3 , such that a large contact area exists between the frame C 2 and the printed circuit board C 4 . Alternatively, the frame C 2 may be connected to the printed circuit board C 4 by means of screws instead of being soldered onto the printed circuit board C 4 at soldering points C 3 . In this manner, the light emitting diode of the present invention may have relatively increased radiation efficiency and light-emitting efficiency in both theoretical basis and practical experimental basis. The light emitting diode of the present invention therefore has largely improved performance.

FIG. 5 shows a perspective view of another light emitting diode according to a second embodiment of the present invention. In the light emitting diode of this second embodiment, there are two bowl portions provided on the frame C 2 for respectively receiving a chip C 1 therein, so that the light emitting diode is able to emit two different color lights. When there are more than two bowl portions formed on the frame C 2 for each receiving a chip C 1 , the light emitting diode is able to emit multiple different color lights.

In conclusion, the light emitting diode of the present invention has bowl portion or portions having an increased depth more than 0.6 mm, increased radiating volume, and increased contact area between the frame and the printed circuit board, and therefore has improved radiation efficiency and enhanced light-emitting efficiency.

The present invention has been described with a preferred embodiment thereof and it is understood that many changes and modifications in the described embodiment can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims.