Inverted light emitting diode

Abstract

An inverted light emitting diode comprises a patterned substrate (100) and an epitaxial light emitting layer (200) on the substrate. The partial area of the substrate is exposed from the epitaxial light emitting layer. The projection (111) of a substrate exposed area is at least covered by an insulating protecting layer. The insulating protecting layer on the projection of the substrate exposed area has fluctuations. The peak height (h) of the fluctuation is 0-0.5 micrometer. Through reducing the fluctuation of the insulating protecting layer which is next to the epitaxial light emitting layer, insulating protecting layer break caused by stress change is prevented, thereby ensuring whole structure of the insulating protecting layer and further improving reliability of a chip.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to designing a patterned substrate structure for flip-chip light-emitting diodes. Background technique [0002] Light-emitting diodes are semiconductor devices that convert electrical energy into light energy, and become LED (Light Emitting Diode) chips. According to different packaging forms, light-emitting diodes can be simply divided into front-mounted light-emitting diodes, flip-chip light-emitting diodes and vertical light-emitting diodes. Among them, flip-chip light-emitting diodes have the advantages of no need for wire bonding, high current drive, and high reliability. Therefore, flip-chip light-emitting diodes have very good applications in general lighting, backlight, flash, display screens, and car lights. . [0003] In order to improve the light-emitting efficiency of light-emitting diodes, patterned substrates are widely used in the manufacture of flip-chip ligh...

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Problems solved by technology

[0005] refer to figure 2 When covering the insulating protective layer, the bumps will cause the insulating protective layer to be unevenly covered or the insulating protective layer is broken, causing solder paste to drill into the insulating protective layer from the gap (refer to the dark line in the wire frame area in the figure), causing a short circuit risk. During long-term burn-in, there is a risk of solder paste connecting to u-GaN (undoped gallium nitride at the bottom of the epitaxial layer) through the gap and causing a short circuit

Conventional size chips are larger than small or micro size chips, and this phenomenon will become more and more serious as the chip size continues to shrink, especially for Mini LED or Micro LED; on the other hand, due to the exposed The surface of the substrate has graphic protrusions, which are easy to absorb metal debris, dirt, etc. during the subsequent chip manufacturing process or packaging die-bonding process, resulting in solder paste remaining on the edge of the chip and causing abnormalities such as IR (high leakage current)

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