Micro-LED module and method for fabricating the same
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.
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 electrically connected to the micro-LED;
a plurality of electrode pads formed on the micro-LED;
a plurality of electrodes formed on the submount substrate to correspond to the plurality of electrode pads;
a plurality of connection members through which the plurality of electrode pads are connected to the corresponding plurality of electrodes;
a gap fill layer formed in a gap between the micro-LED and the submount substrate and having a bonding strength to the micro-LED and the submount substrate; and
a cell cover layer formed to cover exposed areas of the first conductive semiconductor layer and edge portions of the plurality of electrode pads and including pad exposure holes through which portions of each of the plurality of electrode pads are exposed,
wherein each of the plurality of exposed electrode pads is depressed to a predetermined depth from the surface of the cell cover layer, and
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.
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 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,
wherein 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
wherein 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.
6. The micro-LED module according to claim 5 , 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.
7. The micro-LED module according to claim 6 , 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.
8. 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.
9. 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.
10. 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.
11. 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 electrically connected to the micro-LED;
a plurality of electrode pads formed on the micro-LED and comprising a peripheral common electrode pad connected to the first conductive semiconductor layer in an exposed area of the first conductive semiconductor layer;
a plurality of electrodes formed on the submount substrate corresponding to the plurality of electrode pads;
a plurality of connection members through which the plurality of electrode pads are connected to the corresponding plurality of electrodes;
a gap fill layer formed in a gap between the micro-LED and the submount substrate and having a bonding strength to the micro-LED and the submount substrate; and
a cell cover layer formed to cover exposed areas of the first conductive semiconductor layer and edge portions of the plurality of electrode pads and including pad exposure holes through which portions of each of the plurality of electrode pads are exposed,
wherein the peripheral common electrode pad is in contact with the first semiconductor layer and not in contact with the second conductive layer and the active layer by the cell cover layer.
12. The micro-LED module according to claim 11 , wherein the gap fill layer is formed between the micro-LED and the submount substrate to completely surround the plurality of connection members.
13. The micro-LED module according to claim 11 , 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.
14. The micro-LED module according to claim 11 , 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.
15. The micro-LED module according to claim 11 , wherein the plurality of LED cells are arrayed in a matrix inside the micro-LED and the exposed area of the first conductive semiconductor layer is formed outside the micro-LED.
16. The micro-LED module according to claim 15 , 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,
wherein 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
wherein 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 micro-LED module according to claim 16 , 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.
18. The micro-LED module according to claim 17 , 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.
19. The micro-LED module according to claim 11 , 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.