US-12622327-B2 - Micro light-emitting diode

US12622327B2US 12622327 B2US12622327 B2US 12622327B2US-12622327-B2

Abstract

The present invention provides a micro light-emitting diode (LED). A conductive layer is disposed on a substrate. A light-emitting assembly is disposed on the conductive layer. A first light-emitting semiconductor and a second light-emitting semiconductor of the light-emitting assembly are stacked vertically. A first conductive bump and a second conductive bump of a conductive bump set electrical conduct the first light-emitting semiconductor and the second light-emitting semiconductor. Thereby, the volume of the micro LED can be shrunk.

Inventors

Jr-Hau He
Chun-Wei Tsai
Zhi-Ting YE
Der-Hsien Lien
Yuk-Tong Cheng

Assignees

RAYLEIGH VISION LIMITED

Dates

Publication Date: 20260505
Application Date: 20230620

Claims (10)

1 . A micro light-emitting diode, comprising: a substrate; a conductive layer, including a first electrode and a second electrode disposed on said substrate apart; a light-emitting assembly, disposed on said conductive layer, said light-emitting assembly including: a first light-emitting semiconductor, including a first light-emitting element, a first n-type electrode, and a first p-type electrode, a side of said first light-emitting element disposed on said conductive layer, said first n-type electrode and said first p-type electrode disposed on another side of said first light-emitting element, said first light-emitting element including a first light-emitting layer, and said first light-emitting layer including a first area; and a second light-emitting semiconductor, disposed vertically on said first light-emitting semiconductor, including a second light-emitting element, a second n-type electrode, and a second p-type electrode, said second n-type electrode disposed on said first p-type electrode, said second p-type electrode disposed on said first n-type electrode, said second light-emitting element disposed on said second p-type electrode and said second n-type electrode, said second light-emitting element including a second light-emitting layer, said second light-emitting layer including a second area, and said first area greater than said second area; and a conductive bump set, including a first conductive bump and a second conductive bump, an end of said first conductive bump disposed on the said electrodes and extending to a side of said first n-type electrode and a side of said second p-type electrode, an end of said second conductive bump disposed on said second electrodes and extending to a side of said first p-type electrode and a side of said second n-type electrode; wherein during a persistence time of vision, any of said first electrode and said second electrode receives a control signal from said conductive layer for enabling an electrical conduction in one of said first light-emitting semiconductor and said second light-emitting semiconductor.
2 . The micro light-emitting diode of claim 1 , wherein said control signal includes a first electrical signal and a second electrical signal for enabling an electrical conduction in one of said first light-emitting semiconductor and said second light-emitting semiconductor sequentially.
3 . The micro light-emitting diode of claim 1 , wherein each wavelength of a light emitted from said first light-emitting element and said second light-emitting element is between 300 nanometers and 800 nanometers.
4 . The micro light-emitting diode of claim 1 , wherein a wavelength of a light emitted from said first light-emitting element is different from a wavelength of a light emitted from said second light-emitting element.
5 . The micro light-emitting diode of claim 1 , wherein an end of said first conductive bump is connected electrically to contacts of said first n-type semiconductor and said second p-type semiconductor; and another end of said first conductive bump is connected electrically to said first electrode.
6 . The micro light-emitting diode of claim 1 , wherein an end of said second conductive bump is connected electrically to contacts of said first p-type semiconductor and said second n-type semiconductor; and another end of said second conductive bump is connected electrically to said second electrode.
7 . The micro light-emitting diode of claim 2 , wherein said conductive layer further includes a third electrode and a fourth electrode; said third electrode is disposed on a side of said second electrode; and said fourth electrode is disposed on another side of said third electrode apart.
8 . The micro light-emitting diode of claim 7 , further comprising a third light-emitting semiconductor, including a third light-emitting element, a third n-type electrode, and a third p-type electrode, a side of said third light-emitting element disposed on an end of said third n-type electrode and an end of said third p-type electrode, another end of said third n-type electrode disposed on said fourth electrode, another end of said third p-type electrode disposed on said third electrode, said third electrode transmitting a third electrical signal of said control signal to said fourth electrode through said third light-emitting semiconductor for turning on said third light-emitting semiconductor continuously.
9 . The micro light-emitting diode of claim 8 , wherein a wavelength of a light emitted from said third light-emitting element is between 300 nanometers and 800 nanometers; and said wavelength of a light emitted from said third light-emitting element is different from a wavelength of said light emitted from said first light-emitting element and a wavelength of said light emitted from said second light-emitting element.
10 . The micro light-emitting diode of claim 8 , wherein said first light-emitting element, said second light-emitting element, and said third light-emitting element include an n-type semiconductor and a p-type semiconductor, respectively; said n-type semiconductors are disposed below said first light-emitting layer, said second light-emitting layer, and said third light-emitting layer, respectively; said p-type semiconductors are disposed on said first light-emitting layer, said second light-emitting layer, and said third light-emitting layer, respectively; and said n-type semiconductors are disposed on an insulating substrate.

Description

FIELD OF THE INVENTION The present application related to a structure, in particular to a micro light-emitting diode (LED). BACKGROUND OF THE INVENTION Owing to the continuous progress of technologies in recent years and the development in display technologies, the applications of light-emitting diodes (LEDs) become more extensive increasingly. LED lamps are the lamps adopting LEDs as the light sources and are generally made by semiconductor LEDs. A semiconductor is a semiconductor light source. When a current flows through a semiconductor LED, it emits light. Being a light-emitting semiconductor device enabled by electricity, when electrons and holes recombine therein, the energy will be released in the form of photons. The core part of an LED structure is the p-n junction with surrounding epoxy sealing the leads and frame for protecting the internal chips. When a forward current flows through the p-n junction, the visible or invisible radiation will be emitted. This radiation is a compound light source formed by trivalent and pentavalent elements. The lifetime and the light-emitting efficiency of an LED lamp are a multiple of those of an incandescent lamp and much higher than those of an integrated fluorescent lamp. The illuminance of a single LED is much lower a traditional incandescent lamp and an energy-saving light bulb. Thereby, a lamp normally will include multiple LEDs. In recent years, LED technologies have improved. High-power and high-luminance LEDs are developed successively, making them in the trend of replacing traditional light sources gradually. There have been vendors providing high-power LED chips for a single lamp. It requires only 100 watts of electrical power to convert to 7,527 lumens of luminous flux. In addition to the lamps designed specifically for LEDs, after adding conversion circuits and related stabilization devices, LEDs can be integrated with other light sources and installed in the lamps for traditional light sources. Unfortunately, according to the current LED technology, to use LEDs as the light sources in the light-emitting modules, the LEDs and the driving devices for LED should be connected electrically for lighting the LEDs. Since the wires of the LEDs and those of the driving devices in the light-emitting modules are not located on the same layer, it is required to drill holes in the substrate before the wires of the LEDs and the driving devices can be connected electrically. According to the prior art, to emit a certain amount of luminance, the light-emitting module must include a certain number of LEDs, which results in a vast number of wires and a large volume of optoelectronic diodes. In addition, the circuit layout inside the light-emitting modules will become quite complicated and the volume of the light-emitting modules will become large as well. Accordingly, how to fabricate micro optoelectronic diodes with decreased number of wires and overall size have become the major challenges in the field. SUMMARY OF THE INVENTION An objective of the present invention is to provide a micro LED, which shrinks the overall volume by vertically stacking a first light-emitting semiconductor and a second light-emitting semiconductor. Thanks to the vertically stacked structure, the number of wires is halved and thus achieving the purpose of reducing the wires. To achieve the above objective, the present invention provides a micro LED, which comprises a substrate, a conductive layer, a light-emitting assembly, and a conductive bump set. The conductive layer includes a first electrode and a second electrode disposed on the substrate apart. The light-emitting assembly is disposed on the conductive layer and includes a first light-emitting semiconductor and a second light-emitting semiconductor. The second light-emitting semiconductor is disposed vertically on the first light-emitting semiconductor. A first light-emitting element of the first light-emitting semiconductor includes a first light-emitting layer. The first light-emitting layer includes a first area. A second light-emitting element of the second light-emitting semiconductor includes a second light-emitting layer. The second light-emitting layer includes a second area. The second area is greater than the first area. The conductive bump set includes a first conductive bump and a second conductive bump. An end of the first conductive bump is disposed on the first electrodes and extending to a side of a first n-type electrode and a side of a second p-type electrode. An end of the second conductive bump is disposed on the second electrodes and extending to a side of a first p-type electrode and a side of a second n-type electrode. during a persistence of vision, any of said first electrode and said second electrode receives a control signal from said conductive layer for electrical conduction in one of said first light-emitting semiconductor and said second light-emitting semiconductor. According to an embodiment of the pre