Micro-led module and method for fabricating the same

Patent metadata

Field	Value
Publication number	US-2018182740-A1
Application number	US-201715814157-A
Country	US
Kind code	A1
Filing date	Nov 15, 2017
Priority date	Dec 23, 2016
Publication date	Jun 28, 2018
Grant date	—

Abstract

A micro-LED module is disclosed. The micro-LED module includes: a micro-LED including a plurality of LED cells, each of which includes a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; a submount substrate mounted with the micro-LED; a plurality of electrode pads formed on the micro-LED cells; a plurality of electrodes formed corresponding to the plurality of electrode pads on the submount substrate; a plurality of connection members through which the plurality of electrode pads are connected to the corresponding plurality of electrodes; and a gap fill layer formed in the gap between the micro-LED and the submount substrate and having a bonding strength to the micro-LED and the submount substrate.

First claim

What is claimed is:

1 . A micro-LED module comprising: a micro-LED comprising a plurality of LED cells, each of which comprises a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; a submount substrate mounted with the micro-LED; a plurality of electrode pads formed on the micro-LED cells; a plurality of electrodes formed corresponding to the plurality of electrode pads on the submount substrate; a plurality of connection members through which the plurality of electrode pads are connected to the corresponding plurality of electrodes; and a gap fill layer formed in the gap between the micro-LED and the submount substrate and having a bonding strength to the micro-LED and the submount substrate.

2 . The micro-LED module according to claim 1 , wherein the gap fill layer is formed between the micro-LED and the submount substrate to completely surround the plurality of connection members.

3 . The micro-LED module according to claim 1 , wherein the gap fill layer is formed by filling a gap filling material in the form of a liquid or gel between the micro-LED and the submount substrate and curing the gap filling material.

4 . The micro-LED module according to claim 1 , wherein the gap fill layer is formed by filling a gap filling material in the form of a powder between the micro-LED and the submount substrate, melting the gap filling material, and curing the molten gap filling material.

5 . The micro-LED module according to claim 1 , wherein the plurality of LED cells are arrayed in a matrix inside the micro-LED and an exposed area of the first conductive semiconductor layer is formed outside the micro-LED.

6 . The micro-LED module according to claim 5 , wherein the plurality of electrode pads comprise a plurality of individual electrode pads connected to the second conductive semiconductor layers of the plurality of LED cells and arrayed in a matrix and a peripheral common electrode pad connected to the first conductive semiconductor layer in the exposed area of the first conductive semiconductor layer; the plurality of electrodes comprise a plurality of first electrodes connected to the plurality of individual electrode pads and a second electrode connected to the common electrode pad; and the plurality of connection members comprise a plurality of inner connection members through which the plurality of individual electrode pads are connected to the plurality of first electrodes and a peripheral connection member through which the common electrode pad is connected to the second electrode.

7 . The micro-LED module according to claim 6 , wherein the gap fill layer comprises an inner filling portion occupying an inner area between the micro-LED and the submount substrate and surrounding the plurality of inner connection members and a peripheral filling portion occupying an outer area between the micro-LED and the submount substrate and surrounding the peripheral connection member.

8 . The micro-LED module according to claim 7 , wherein the gap fill layer further comprises a circumferential portion covering the peripheral sides of the micro-LED on a peripheral empty area of the submount substrate.

9 . The micro-LED module according to claim 1 , wherein each of the plurality of connection members comprises a metal pillar connected to one of the electrode pads and the electrodes and a solder formed on the metal pillar.

10 . The micro-LED module according to claim 1 , wherein each of the plurality of connection members comprises a conductive soft block disposed adjacent to one of the electrode pad and the electrode and a conductive insert rod inserted into and connected to the conductive soft block when a vertical force is applied thereto.

11 . The micro-LED module according to claim 1 , wherein the gap fill layer comprises an inner filling portion occupying an inner area between the micro-LED and the submount substrate where the plurality of micro-LED cells exist and a peripheral filling portion occupying a peripheral area between the micro-LED and the submount substrate where none of the plurality of micro-LED cells exist.

12 . The micro-LED module according to claim 1 , wherein the gap fill layer comprises a filling portion occupying an area between the micro-LED and the submount substrate and a circumferential portion covering the peripheral sides of the micro-LED on a peripheral empty area of the submount substrate.

13 . A method for fabricating a micro-LED module, comprising preparing a micro-LED provided with a plurality of electrode pads, preparing a submount substrate provided with a plurality of electrodes, mounting the micro-LED so as to face the submount substrate using a plurality of connection members connecting the plurality of electrode pads to the plurality of electrodes, and forming a gap fill layer having a bonding strength to the micro-LED and the submount substrate between the micro-LED and the submount substrate.

14 . The method according to claim 13 , wherein each of the plurality of connection members comprises a solder that is melted and cured to electrically connect the plurality of electrode pads to the plurality of electrodes and the gap fill layer is formed by filling a gap filling material in the form of a liquid, gel or powder between the micro-LED and the submount substrate after melting and curing of the solder.

15 . The method according to claim 13 , wherein each of the plurality of connection members comprises a solder that is melted and cured to electrically connect the plurality of electrode pads to the plurality of electrodes and the gap fill layer is formed by filling a gap filling material in the form of a liquid, gel or powder between the micro-LED and the submount substrate before melting of the solder.

16 . The method according to claim 13 , wherein the plurality of electrode pads comprise a plurality of individual electrode pads connected to second conductive semiconductor layers of the plurality of LED cells and arrayed in a matrix and a peripheral common electrode pad connected to the first conductive semiconductor layer in an exposed area of the first conductive semiconductor layer; the plurality of electrodes comprise a plurality of first electrodes connected to the plurality of individual electrode pads and a second electrode connected to the common electrode pad; and the plurality of connection members comprise a plurality of inner connection members through which the plurality of individual electrode pads are connected to the plurality of first electrodes and a peripheral connection member through which the common electrode pad is connected to the second electrode.

17 . The method according to claim 13 , wherein the micro-LED is mounted by connecting the electrode pads to the electrodes using the connection members comprising solders, and the submount substrate and an LED substrate of the micro-LED are controlled along different heating-cooling curves during melting of the solders by heating and curing of the solders by cooling.

Assignees

• Lumens Co Ltd

Inventors

• Kim Daewon
• Shin Eunsung
• Moon Myungji
• Chang Hanbeet
• Kim Yongpil
• Park Jaesoon

Classifications

• H10P14/40

  of conductive or resistive materials · CPC title

• H10W72/077

  Connecting of TAB connectors · CPC title

• H10W72/222

  Multilayered bumps, e.g. a coating on top and side surfaces of a bump core · CPC title

• H10W72/012

  of bump connectors, dummy bumps or thermal bumps · CPC title

• H10W90/00 Primary

  Package configurations · CPC title