1. Field of the Invention
The invention refers to a light-emitting diode (LED), and particularly to a packaging structure of an LED for improving fabricating yield and avoiding short circuit of adjacent LED packaging structures due to contact of their conductive elements.
2. Description of the Prior Art
Reference is made to
In this case, the packaging structures of the LED are mass-manufactured by forming a plurality of LED packaging structures on a large-area substrate. To do this, a plurality of circle drills are formed on the large substrate, then the conductive pads, conductive strips and electrode pads are disposed on the upper and lower surfaces and the circle drill walls of the substrate by electroplating and etching; further, the light-emitting chips are disposed and electrically connected thereon, and then encapsulated by the protection unit on the substrate. Consequently, a plurality of interconnected LED packaging structures are formed. Finally the substrate is sliced along the direction of the aligned drills to separate the substrate into individual LED packaging structures with two opposite half-circle side walls. However, since the large-area substrate may be obliquely cut during the slicing process, this results in irregular half-circle side walls, thereby decreasing product yield.
Moreover, when a plurality of LED packaging structures are aligned in a matrix arrangement for use of display device, and two adjacent packaging structures are positioned close and thus may contact each other (as shown in
Accordingly, this invention is provided to improve the above disadvantages with a reasonable design.
It is a first object of the present invention to provide an LED packaging structure, in which two drills are formed on a substrate thereof and two conductors extend respectively through the two drills to connect electrically to the conductive elements on the upper and lower surfaces of the substrate, whereby the LED packaging structure is easily fabricated.
It is a second object of the present invention to provide an LED packaging structure, in which the conductors extend through the drills of a substrate thereof and the conductive elements on the upper and lower surfaces of the substrate are separated from the edges of the substrate by a certain interval, thereby avoiding short-circuits of adjacent LED packaging structures due to contact therebetween.
According to the above-mentioned objects, the present invention provides an LED packaging structure, comprising the following elements. A substrate has upper and lower surfaces, and a conductive pad and conductive strip are disposed on the upper surface of the substrate, while a first electrode pad and a second electrode pad are disposed on the lower surface of the substrate. A light-emitting chip is arranged on the conductive pad and is electrically connected to the conductive pad and the conductive strip. A protection colloid encapsulates the light-emitting chip on the upper surface of the substrate.
The substrate has two drills through the upper and lower surfaces, two conductors extending respectively along the two drills such that one of the conductors is electrically connected at both of its terminals to the conductive pad and the first electrode pad, respectively, and the other conductor is electrically connected at both of its terminals to the conductive strip and the second electrode pad, respectively. Therefore, fabrication thereof is easy, and short-circuits of adjacent LED packaging structures due to contact of conductive elements thereof can be avoided.
The foregoing aspects and many of the attendant advantages of this invention will be more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
With reference to FIGS. 3 to 5, this invention is directed to an LED packaging structure 10, in which two drills 21 are formed on a substrate 0.20 thereof, and two conductors 22 extends along the pair of drills 21, respectively, such that one of the conductors 22 is connected to a conductive pad 24 on the upper surface 23 of the substrate 20 and a first electrode pad 26 on the lower surface 25 of the substrate 20, and the other conductor 22 is connected to a conductive strip 27 on the upper surface 23 of the substrate 20 and a second electrode pad 29 on the lower surface 28 of the substrate 20 fabrication of the LED packaging structure 10 is thus easily performed and short-circuits between the adjacent LED packaging structures due to contact of conductive elements thereof can be avoided.
With reference to
The light-emitting chip 35 is, for example, a light-emitting diode (LED), arranged on the conductive pad 24. The light-emitting chip 35 has two electrodes 36, one of which is electrically connected to the conductive pad 24 and the other of which is electrically to the conductive strip 27 via a electro-conducting wire 40.
The protection colloid 45 is, for example, a transparent colloid, for encapsulating the light-emitting chip 35, the conductive pad 24 and the conductive strip 27 on the upper surface 23 of the substrate 20 to form an LED packaging structure 10.
With reference to
Therefore, the fabrication process is performed according to the following steps of fabricating LED packaging structures. A plurality of drills 21 are formed on a substrate 10. The upper and lower surfaces 23 and 25 of the substrate 20 and the walls of the drills 21 are further plated with conductive materials by electroplating. Undesired portions are removed by etching to form the conductive pad 24, the conductive strip 27, the first and second electrode pads 26 and 29, and the conductors 22. A plurality of light-emitting chips 35 aredisposed on the surface 23 of the substrate 20 and electrically connected to the conductive elements. The plurality of light-emitting chips 35 are encapsulated on the substrate 20 with a protection colloid 45 to form a plurality of interconnected LED packaging structures 10. Finally, the substrate 20 is sliced along the gaps between adjacent conductive elements to form a plurality of separate LED packaging structures 10, thereby increasing fabrication speed. Therefore, it is unnecessary to slice the walls of the drills across the drills, thus improving fabricating yield, speed and workability.
In conclusion, the LED packaging structure according to the invention is arranged to have two drills formed on a substrate and two conductors extending through the two drills respectively to connect electrically to the conductive elements on the upper and lower surfaces of the substrate. The structure is thus easy to fabricate. Moreover, the conductors extend through the drills of the substrate, and the conductive elements on the upper and lower surfaces of the substrate are separated from the edges of the substrate by a certain interval, so as to avoid short-circuits of adjacent LED packaging structures due to contact between conductive elements thereof. Fabrication processes and cost are thereby reduced.
Although possible embodiments of the invention have been described above, it is to be understood that the scope of the invention is not limited to these embodiments; in the same way, all equivalent structures and modifications as implemented in this specification and as illustrated in these drawings are covered within the scope of this invention, in order to protect the right of the inventor.