Light emitting diode structure

Abstract

A light-emitting diode structure has: a substrate; a light-emitting semiconductor stack on the substrate, wherein the light-emitting semiconductor stack comprises a first semiconductor layer, a second semiconductor layer with electrical polarity different from that of the first semiconductor layer, and a light-emitting layer between the first semiconductor layer and the second semiconductor layer; a first electrode electrically connected to the first semiconductor layer; and a second electrode electrically connected to the second semiconductor layer, wherein the first electrode comprises a contact area and an extension area, and the contact area has a first surface corresponding to the first semiconductor layer and the extension area has a second surface corresponding to the first semiconductor layer, wherein a roughness of the first surface is different from that of the second surface, and the reflectivity of the first surface is smaller than that of the second surface.

Description

technical field [0001] The invention relates to a high brightness light emitting diode structure. Background technique [0002] The principle and structure of light-emitting diodes (LEDs) are different from traditional light sources. It is easy to make extremely small or arrayed components according to the application requirements. Some products have been widely used in the market, such as the backlight of the display, and the general lighting part is gradually growing. [0003] The performance-price ratio of current light-emitting diodes (LEDs) is becoming more and more stringent with the wider application, and the brightness requirements per unit area are getting higher and higher. Therefore, it will be achieved by increasing the size of a single light-emitting diode (LED) chip, but After enlarging the area, there will be problems of uneven current distribution, so as Figure 1A As shown, this light emitting diode (LED) includes a first semiconductor layer 22, a second se...

AI Technical Summary

Problems solved by technology

However, when the proportion of the first extension portion 4b on the chip area is higher, the light-shielding or light-absorbing phenomenon of the electrode becomes more serious, which affects the luminous efficiency.

Therefore, if Figure 1B displayed Figure 1A The cross-sectional view of the dotted line AA', under the first contact region 4a, the first extension part 4b and the second electrode 5, three contact surfaces of the flat first surface 43, the second surface 46 and the third surface 53 are respectively formed , and set high reflectivity layers 41, 45, and 51 to reduce the light-shielding or light-absorbing phenomenon at the bottom of the metal pad and the finger electrode, but this flat contact surface is prone to peeling off of the metal pad during the subsequent packaging and bonding process Phenomenon, resulting in a decline in the quality of the wire

Images