Light-emitting diode
View Patent ↗The present invention relates to a light-emitting diode (LED). The LED comprises an LED die, one or more metal pads, and a fluorescent layer. The characteristics of the present invention include that the metals pads are left exposed for the convenience of subsequent wiring and packaging processes. In addition, the LED provided by the present invention is a single light-mixing chip, which can be packaged directly without the need of coating fluorescent powders on the packaging glue. Because the fluorescent layer and the packaging glue are not processed simultaneously and are of different materials, the stress problem in the packaged LED can be reduced effectively.
1. A light-emitting diode (LED), which is a positive light-emitting type light emitting diode, comprising:
an LED die;
at least two metal pads, set on said LED die, wherein the top surfaces of said metal pads set on the same plane essentially;
a fluorescent layer, set on a surface of said LED die and said metal pads;
said fluorescent layer located on the periphery of said metal pads and not covering said metal pads;
said metal pads being exposed;
said LED die comprising a first semiconductor layer; a second semiconductor layer, a light-emitting layer, a first electrode and a second electrode;
said light-emitting layer set on said first semiconductor layer;
said second semiconductor layer set on said light-emitting layer;
said second electrode being completely on top of said second semiconductor layer;
said first electrode being completely on top of said first semiconductor layer;
at least one of said metal pads set on said first electrode, and at least one of said metal pads set on said second electrode;
the thickness of the fluorescent layer is greater than 30 μm; and
at least part of light with a first wavelength produced by the LED die is converted to light with at least a second wavelength by the fluorescent layer.
2. The LED of claim 1 , wherein the materials of the fluorescent layer include fluorescent powders and an organic polymer material.
3. The LED of claim 2 , wherein the materials of said fluorescent powders are chosen from the group comprising red fluorescent powders, green fluorescent powders, blue fluorescent powders, and the combination of the fluorescent powders described above.
4. The LED of claim 1 , wherein said first semiconductor layer is N-type, and said second semiconductor is P-type.
5. The LED of claim 1 , wherein said first semiconductor layer is P-type, and said second semiconductor is N-type.
6. The LED of claim 1 , and further comprising a carrier, set on a side of the LED, and faced to the fluorescent layer.
7. The LED of claim 6 , and further comprising a packaging glue, set on the carrier, and covers the LED without coating of fluorescent powders, the metal pads and the fluorescent layer.
8. The LED of claim 7 , wherein the material of the packaging glue is organic polymer.
9. The LED of claim 7 , wherein the material of the packaging glue further comprising fluorescent powders.
10. The LED of claim 1 , and further comprising a dielectric layer, set between said LED die and said fluorescent layer.
11. The LED of claim 1 , wherein the shape of said fluorescent layer is trapezoidal or upside-down trapezoidal.
12. The LED of claim 1 , wherein a periphery of said fluorescent layer is aligned to a periphery of said LED die.