US-12622331-B2 - Light emitting device for display and display apparatus having the same

US12622331B2US 12622331 B2US12622331 B2US 12622331B2US-12622331-B2

Abstract

A light emitting module including a circuit board and a lighting emitting device thereon and including first, second, and third LED stacks each including first and second conductivity type semiconductor layers, a first bonding layer between the second and third LED stacks, a second bonding layer between the first and second LED stacks, a first planarization layer between the second bonding layer and the third LED stack, a second planarization layer on the first LED stack, a lower conductive material extending along sides of the first planarization layer, the second LED stack, the first bonding layer, and electrically connected to the first conductivity type semiconductor layers of each LED stack, respectively, and an upper conductive material between the circuit board and the lower conductive material.

Inventors

Seom Geun LEE
Seong Kyu JANG
Yong Woo Ryu
Jong Hyeon Chae

Assignees

SEOUL VIOSYS CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20240711

Claims (20)

1 . A light emitting module, comprising: a circuit board; a first semiconductor stack, a second semiconductor stack, and a third semiconductor stack disposed between the first semiconductor stack and the second semiconductor stack, each of the first, second, and third semiconductor stacks including a first conductivity type semiconductor layer and a second conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer; at least one lower connector; a first bonding layer disposed between the third semiconductor stack and the circuit board; a second bonding layer disposed between the second semiconductor stack and the circuit board; a first electrode pad electrically connected to the first semiconductor stack; a second electrode pad electrically connected to the second semiconductor stack; a first planarization layer disposed between the first electrode pad and the first semiconductor stack; and a second planarization layer disposed between the second semiconductor stack and the second electrode pad, wherein a top surface of the first planarization layer is in contact with a bottom surface of the at least one lower connector.
2 . The light emitting module of claim 1 , wherein the third semiconductor stack further includes a substrate, and a light generated from the third semiconductor stack is emitted through the substrate.
3 . The light emitting module of claim 2 , wherein the light has a peak wavelength different from a peak wavelength of a light generated from the first semiconductor stack and a peak wavelength of a light generated from the second semiconductor stack.
4 . The light emitting module of claim 3 , wherein the first planarization layer includes a plurality of islands separated from each other.
5 . The light emitting module of claim 4 , wherein the second planarization layer includes a plurality of islands separated from each other.
6 . The light emitting module of claim 1 , further comprising: a first bump pad and an upper insulation layer, wherein the first bump pad is disposed between the circuit board and the first electrode pad, and the upper insulation layer is disposed between the first electrode pad and the first bump pad.
7 . The light emitting module of claim 5 , wherein the first bump pad covers a side surface of the upper insulation layer.
8 . The light emitting module of claim 1 , further comprising: a first transparent electrode disposed on the first semiconductor stack; a second transparent electrode disposed on the second semiconductor stack; and a third transparent electrode disposed on the third semiconductor stack, wherein a side surface of the second transparent electrode is recessed inwardly than that of the second semiconductor stack.
9 . The light emitting module of claim 7 , wherein a side surface of the third transparent electrode is recessed inwardly than that of the third semiconductor stack.
10 . The light emitting module of claim 7 , wherein a material of the first transparent electrode is same with a material of the second transparent electrode.
11 . A light emitting module, comprising: a circuit board; a first semiconductor stack, a second semiconductor stack, and a third semiconductor stack configured to operate independently, each of the first, second, and third semiconductor stacks including a first conductivity type semiconductor layer and a second conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer; at least one lower connector; a first bonding layer disposed between the third semiconductor stack and the circuit board; a second bonding layer disposed between the second semiconductor stack and the circuit board; a first electrode pad electrically connected to the first semiconductor stack; a second electrode pad electrically connected to the second semiconductor stack; a first planarization layer disposed between the first electrode pad and the first semiconductor stack; and a second planarization layer disposed between the second semiconductor stack and the second electrode pad, wherein a top surface of the first planarization layer is in contact with a bottom surface of the at least one lower connector.
12 . The light emitting module of claim 11 , wherein the third semiconductor stack further includes a substrate, and a light generated from the third semiconductor stack is emitted through the substrate.
13 . The light emitting module of claim 12 , wherein the light has a peak wavelength different from a peak wavelength of a light generated from the first semiconductor stack and a peak wavelength of a light generated from the second semiconductor stack.
14 . The light emitting module of claim 13 , wherein the first planarization layer includes a plurality of islands separated from each other.
15 . The light emitting module of claim 14 , wherein the second planarization layer includes a plurality of islands separated from each other.
16 . The light emitting module of claim 11 , further comprising: a first bump pad and; an upper insulation layer, wherein the first bump pad is disposed between the circuit board and the first electrode pad, and the upper insulation layer is disposed between the first electrode pad and the first bump pad.
17 . The light emitting module of claim 15 , wherein the first bump pad covers a side surface of the upper insulation layer.
18 . The light emitting module of claim 11 , further comprising: a first transparent electrode disposed on the first semiconductor stack; a second transparent electrode disposed on the second semiconductor stack; and a third transparent electrode disposed on the third semiconductor stack, wherein a side surface of the second transparent electrode is recessed inwardly than that of the second semiconductor stack.
19 . The light emitting module of claim 17 , wherein a side surface of the third transparent electrode is recessed inwardly than that of the third semiconductor stack.
20 . The light emitting module of claim 17 , wherein a material of the first transparent electrode is same with a material of the second transparent electrode.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a Continuation of U.S. patent application Ser. No. 18/226,779 filed Jul. 27, 2023, which is a Continuation of U.S. patent application Ser. No. 17/902,893 filed Sep. 4, 2022 (now U.S. Pat. No. 11,756,940), which is a Continuation of U.S. patent application Ser. No. 17/096,289 filed Nov. 12, 2020 (now U.S. Pat. No. 11,437,353), which claims priority from the benefit of U.S. Provisional Application No. 62/935,741 filed Nov. 15, 2019, each of which is incorporated herein in their entirety. BACKGROUND Field Exemplary embodiments of the invention relate generally to a light emitting device for a display and a display apparatus, and, more particularly, to a light emitting device having a stack structure of LEDs for a display and a display apparatus including the same. Discussion of the Background As an inorganic light source, light emitting diodes have been used in various fields including displays, vehicular lamps, general lighting, and the like. With various advantages of light emitting diodes over conventional light sources, such as longer lifespan, lower power consumption, and rapid response, light emitting diodes have been replacing conventional light sources. Light emitting diodes have been generally used as backlight light sources in display apparatuses. However, LED displays that directly display images using the light emitting diodes have been recently developed. In general, a display apparatus realizes various colors through mixture of blue, green, and red light. In order to display various images, the display apparatus includes a plurality of pixels each having sub-pixels corresponding to blue, green and red light, respectively. In this manner, a color of a certain pixel is determined based on the colors of the sub-pixels so that images can be displayed through combination of such pixels. Since LEDs can emit various colors depending upon materials thereof, a display apparatus may be provided by arranging individual LED chips emitting blue, green, and red light on a two-dimensional plane. However, when one LED chip is arranged in each sub-pixel, the number of LED chips may be increased, which may require excessive time for a mounting process during manufacture. Moreover, when the sub-pixels are arranged on a two-dimensional plane in the display apparatus, a relatively large area is occupied by one pixel that includes the sub-pixels for blue, green, and red light. Accordingly, an area of each LED chip may need to be reduced to arrange the sub-pixels in a restricted area. However, reduction in size of LED chips may cause difficulty in mounting the LED chips, as well as reducing luminous areas of the LED chips. The above information disclosed in this Background section is only for understanding of the background of the inventive concepts, and, therefore, it may contain information that does not constitute prior art. SUMMARY Light emitting devices for a display constructed according to exemplary embodiments of the invention are capable of increasing an area of each sub-pixel in a restricted pixel area and a display apparatus including the same. Exemplary embodiments also provide a light emitting device for a display that is capable of reducing a time for a mounting process and a display apparatus including the same. Exemplary embodiments also provide a light emitting device for a display and a display apparatus that is capable of increasing the production yield. Additional features of the inventive concepts will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the inventive concepts. A light emitting device according to an exemplary embodiment includes a first LED stack, a second LED stack disposed under the first LED stack, and a third LED stack disposed under the second LED stack, each of the first, second, and third LED stacks including a first conductivity type semiconductor layer and a second conductivity type semiconductor layer, a first bonding layer interposed between the second LED stack and the third LED stack, a second bonding layer interposed between the first LED stack and the second LED stack, a first planarization layer interposed between the second bonding layer and the second LED stack, a second planarization layer disposed on the first LED stack, lower buried vias passing through the first planarization layer, the second LED stack, and the first bonding layer and electrically connected to the first conductivity type semiconductor layer and the second conductivity type semiconductor layer of the third LED stack, respectively, and upper buried vias passing through the second planarization layer and the first LED stack, in which a width of an upper end of each of the lower buried vias and the upper buried vias is greater than a width of a corresponding through hole. The first, second, and third LED stacks may be configured to emit red light, blue light,