US-12622328-B2 - Display apparatus

US12622328B2US 12622328 B2US12622328 B2US 12622328B2US-12622328-B2

Abstract

A display apparatus includes: a circuit board including a driving circuit; and a pixel array disposed on the circuit board and including pixels, each of the pixels having a plurality of sub-pixels. The pixel array includes: a semiconductor stack, a conductive partition structure and wavelength conversion portions. The semiconductor stack includes LED cells respectively constituting the plurality of sub-pixels. Each of the LED cells includes at least an active layer and a second conductivity-type semiconductor layer. The conductive partition structure is provided between sub-pixel spaces, respectively overlaps the LED cells on the semiconductor stack, and is provided as a first electrode. The wavelength conversion portions are respectively disposed on the sub-pixel spaces.

Inventors

Juyeon Jeong
MiHyun Kim
Sihan Kim
Hankyu SEONG
Jusong Eom
Jihye YEON

Assignees

SAMSUNG ELECTRONICS CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20230719
Priority Date: 20220719

Claims (20)

1 . A display apparatus comprising: a circuit board comprising a driving circuit; and a pixel array comprising a plurality of pixels provided on the circuit board, each of the plurality of pixels having a plurality of sub-pixels, wherein the pixel array comprises: a semiconductor stack comprising a first conductivity-type semiconductor layer having an upper surface provided as a light emission surface and light-emitting diode (LED) cells arranged on a lower surface of the first conductivity-type semiconductor layer, the LED cells respectively constituting the plurality of sub-pixels, and each of the LED cells comprising an active layer and a second conductivity-type semiconductor layer stacked sequentially on the lower surface of the first conductivity-type semiconductor layer; a conductive partition structure between sub-pixel spaces, respectively overlapping the LED cells, on the semiconductor stack, connected to the upper surface of the first conductivity-type semiconductor layer, and provided as a first electrode; wavelength conversion portions, respectively provided in the sub-pixel spaces; a common electrode provided on at least one side of an upper surface of the semiconductor stack and electrically connected to an edge region of the conductive partition structure and the driving circuit; second electrodes, respectively provided on lower surfaces of the LED cells and connected to the second conductivity-type semiconductor layer, each of the second electrodes being electrically connected to the driving circuit; and a pad electrode provided on an outer side of the common electrode and electrically connected to the driving circuit.
2 . The display apparatus of claim 1 , further comprising a transparent insulating layer provided on an upper surface and sidewalls of the conductive partition structure and on portions of the first conductivity-type semiconductor layer exposed by the sub-pixel spaces.
3 . The display apparatus of claim 2 , wherein each of the portions of the first conductivity-type semiconductor layer exposed by the sub-pixel spaces has a textured surface.
4 . The display apparatus of claim 2 , wherein the transparent insulating layer comprises an insulating material having a first refractive index lower than a second refractive index of the second conductivity-type semiconductor layer.
5 . The display apparatus of claim 1 , wherein the conductive partition structure comprises any one or any combination of Ag, Cr, Ni, Ti, Al, Rh, Ru.
6 . The display apparatus of claim 1 , wherein a portion of the first conductivity-type semiconductor layer between the LED cells has a thickness ranging from 0.1 micrometer (μm) to 2.0 μm.
7 . The display apparatus of claim 1 , wherein an upper surface of the common electrode has at least a partial region exposed from the at least one side of the upper surface of the semiconductor stack.
8 . The display apparatus of claim 7 , further comprising an interconnect portion provided on a region adjacent to the at least one side of the upper surface of the semiconductor stack and connecting the partial region of the common electrode and the edge region of the conductive partition structure to each other.
9 . The display apparatus of claim 8 , wherein the edge region of the conductive partition structure has a portion extending toward the at least one side of the upper surface of the semiconductor stack from an external sidewall of the conductive partition structure.
10 . The display apparatus of claim 9 , wherein the portion of the edge region of the conductive partition structure is provided along the external sidewall of the conductive partition structure.
11 . The display apparatus of claim 1 , further comprising: a passivation layer provided on the lower surfaces and side surfaces of the LED cells, and the lower surface of the first conductivity-type semiconductor layer, the passivation layer having a rounded edge around the lower surfaces of the LED cells; a reflective metal layer provided on the passivation layer and surrounding each of the LED cells; and a contact electrode layer provided on the reflective metal layer and connected to one region of each of the lower surfaces of the LED cells through the reflective metal layer.
12 . The display apparatus of claim 11 , wherein the passivation layer comprises: a first insulating layer provided on the lower surfaces and the side surfaces of the LED cells, and the lower surface of the first conductivity-type semiconductor layer; and a second insulating layer provided on the first insulating layer, having a thickness, greater than a thickness of the first insulating layer, and having the rounded edge around the lower surfaces of the LED cells.
13 . The display apparatus of claim 12 , wherein the first insulating layer comprises a silicon nitride, an aluminum oxide, or an aluminum nitride, and the second insulating layer comprises a silicon oxide.
14 . The display apparatus of claim 12 , wherein the reflective metal layer comprises any one or any combination of Ag, Ni, Al, Rh and Ru, the contact electrode layer comprises any one or any combination of Ti and Cr.
15 . The display apparatus of claim 1 , wherein the plurality of sub-pixels are arranged in a diamond structure.
16 . A display apparatus comprising: a circuit board comprising a driving circuit; and a pixel array comprising a plurality of pixels provided on the circuit board, each of the plurality of pixels having a plurality of sub-pixels, wherein the pixel array comprises: a semiconductor stack comprising a first conductivity-type semiconductor layer having an upper surface provided as a light emission surface and light-emitting diode (LED) cells arranged on a lower surface of the first conductivity-type semiconductor layer, the LED cells respectively constituting the plurality of sub-pixels, and each of the LED cells comprising an active layer and a second conductivity-type semiconductor layer stacked sequentially on the lower surface of the first conductivity-type semiconductor layer; a conductive partition structure between sub-pixel spaces, respectively overlapping the LED cells, on the semiconductor stack, connected to the upper surface of the first conductivity-type semiconductor layer, and provided as a first electrode, wherein textured regions of the first conductivity-type semiconductor layer, respectively exposed by the sub-pixel spaces, have textured surfaces; a transparent insulating layer provided on an upper surface and sidewalls of the conductive partition structure and in the textured regions of the first conductivity-type semiconductor layer exposed by the sub-pixel spaces; wavelength conversion portions, respectively provided in the sub-pixel spaces; a common electrode provided on at least one side of an upper surface of the semiconductor stack and electrically connected to an edge region of the conductive partition structure and the driving circuit; second electrodes, respectively provided on lower surfaces of the LED cells and connected to the second conductivity-type semiconductor layer, each of the second electrodes being electrically connected to the driving circuit; and a pad electrode provided on an outer side of the common electrode and electrically connected to the driving circuit.
17 . The display apparatus of claim 16 , wherein each of the LED cells has a width, greater than a width of the wavelength conversion portions.
18 . The display apparatus of claim 16 , wherein a height of the wavelength conversion portions is at least twice a width of the wavelength conversion portions.
19 . The display apparatus of claim 16 , further comprising: a passivation layer provided on the lower surfaces and side surfaces of the LED cells, and the lower surface of the first conductivity-type semiconductor layer; a reflective metal layer provided on the passivation layer and surrounding each of the LED cells; and a contact electrode layer provided on the reflective metal layer and connected to one region of each of the lower surfaces of the LED cells through the reflective metal layer.
20 . A display apparatus comprising: a circuit board comprising a driving circuit, a lower bonding insulating layer covering the driving circuit, and a first lower bonding electrode, second lower bonding electrodes, and a third lower bonding electrode, each penetrating through the lower bonding insulating layer and electrically connected to the driving circuit; and a pixel array comprising a plurality of pixels provided on the circuit board, each of the plurality of pixels having a plurality of sub-pixels, wherein the pixel array comprises: a semiconductor stack comprising a first conductivity-type semiconductor layer having an upper surface provided as a light emission surface and light-emitting diode (LED) cells arranged on a lower surface of the first conductivity-type semiconductor layer, the LED cells respectively constituting the plurality of sub-pixels, and each of the LED cells comprising at least an active layer and a second conductivity-type semiconductor layer stacked sequentially on the lower surface of the first conductivity-type semiconductor layer; a conductive partition structure between sub-pixel spaces, respectively overlapping the LED cells, on the semiconductor stack, connected to the upper surface of the first conductivity-type semiconductor layer, and provided as a first electrode; wavelength conversion portions, respectively provided in the sub-pixel spaces; a common electrode provided on at least one side of an upper surface of the semiconductor stack and electrically connected to an edge region of the conductive partition structure and the driving circuit; a pad electrode provided on the same level as the common electrode; a wiring insulating layer provided on a lower surface of the semiconductor stack to cover the LED cells; second electrodes, respectively provided on lower surfaces of the LED cells and connected to the second conductivity-type semiconductor layer; an upper bonding insulating layer provided on the wiring insulating layer and contacting the lower bonding insulating layer; a first upper bonding electrode connected to the common electrode through the upper bonding insulating layer and the wiring insulating layer, and connected to the first lower bonding electrode; second upper bonding electrodes, respectively connected to the second electrodes through the upper bonding insulating layer and the wiring insulating layer, and respectively connected to the second lower bonding electrodes; and a third upper bonding electrode connected to the pad electrode through the upper bonding insulating layer and the wiring insulating layer and connected to the third lower bonding electrode.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to Korean Patent Application No. 10-2022-0088761, filed on Jul. 19, 2022, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety. BACKGROUND The present disclosure relates to a display apparatus including a micro-LED. Semiconductor light-emitting diodes (LEDs) have been used as light sources for lighting devices, and other electronic products. For example, semiconductor LEDs have widely been used as light sources for various display apparatuses such as televisions (TVs), mobile phones, personal computers (PCs), laptop computers, personal digital assistants (PDAs), or the like. Display apparatuses according to the related art include display panels, such as liquid crystal display (LCD) panels, and backlight units. Some display apparatuses use LEDs as pixels and do not require separate backlight units. Such a display apparatus may have a compact size, and may be implemented as a high-luminance display apparatus having improved optical efficiency, as compared with LCDs. SUMMARY Example embodiments provide a display apparatus having improved uniform light emission over an entire region. According to an example embodiment, a display apparatus includes: a circuit board including a driving circuit; and a pixel array including a plurality of pixels provided on the circuit board, each of the plurality of pixels having a plurality of sub-pixels. The pixel array includes: a semiconductor stack including a first conductivity-type semiconductor layer having an upper surface provided as a light emission surface and LED cells arranged on a lower surface of the first conductivity-type semiconductor layer, the LED cells respectively constituting the plurality of sub-pixels, and each of the LED cells including an active layer and a second conductivity-type semiconductor layer stacked sequentially on the lower surface of the first conductivity-type semiconductor layer; a conductive partition structure between sub-pixel spaces, respectively overlapping the LED cells, on the semiconductor stack, connected to an upper surface of the first conductivity-type semiconductor layer, and provided as a first electrode; wavelength conversion portions, respectively provided in the sub-pixel spaces; a common electrode provided on at least one side of an upper surface of the semiconductor stack and electrically connected to an edge region of the conductive partition structure and the driving circuit; second electrodes, respectively provided on lower surfaces of the LED cells and connected to the second conductivity-type semiconductor layer, each of the second electrodes being electrically connected to the driving circuit; and a pad electrode provided on an outer side of the common electrode and electrically connected to the driving circuit. According to an example embodiment, a display apparatus includes: a circuit board including a driving circuit; and a pixel array including a plurality of pixels provided on the circuit board, each of the plurality of pixels having a plurality of sub-pixels. The pixel array includes: a semiconductor stack including a first conductivity-type semiconductor layer having an upper surface provided as a light emission surface and LED cells arranged on a lower surface of the first conductivity-type semiconductor layer, the LED cells respectively constituting the plurality of sub-pixels, and each of the LED cells including an active layer and a second conductivity-type semiconductor layer stacked sequentially on the lower surface of the first conductivity-type semiconductor layer; a conductive partition structure between sub-pixel spaces, respectively overlapping the LED cells, on the semiconductor stack, connected to an upper surface of the first conductivity-type semiconductor layer, and provided as a first electrode, wherein textured regions of the first conductivity-type semiconductor layer, respectively exposed by the sub-pixel spaces, have textured surfaces; a transparent insulating layer provided on an upper surface and sidewalls of the conductive partition structure and in the textured regions of the first conductivity-type semiconductor layer exposed by the sub-pixel spaces; wavelength conversion portions, respectively provided in the sub-pixel spaces; a common electrode provided on at least one side of an upper surface of the semiconductor stack and electrically connected to an edge region of the conductive partition structure and the driving circuit; second electrodes, respectively provided on lower surfaces of the LED cells and connected to the second conductivity-type semiconductor layer, each of the second electrodes being electrically connected to the driving circuit; and a pad electrode provided on an outer side of the common electrode and electrically connected to the driving circuit. According to an example embodiment, a display apparatus includes: a circuit bo