MICRO LED DISPLAY PANEL
A micro LED display panel includes a mesa array including a plurality of mesa structures; a top transparent conductive layer formed on a top surface of the mesa array; a reflective isolation layer filled in a space between the adjacent mesa structures, a bottom of the reflective isolation layer being lower than a bottom of the mesa structure; and an integrated circuit (IC) backplane formed at a bottom of the reflective isolation layer.
1 . A micro LED display panel, comprising:
a mesa array including a plurality of mesa structures;
a top transparent conductive layer formed on a top surface of the mesa array;
a reflective isolation layer filled in a space between adjacent mesa structures, a bottom of the reflective isolation layer being lower than a bottom of the mesa structure, wherein the reflective isolation layer is a non-metal layer;
an integrated circuit (IC) backplane formed at a bottom of the reflective isolation layer; and
a group of bottom connecting structures, one bottom connecting structure corresponding to one mesa structure, wherein the bottom connecting structure is provided at a bottom of the mesa structure and configured to bond the mesa structure with the IC backplane.
2 . The micro LED display panel according to claim 1 , wherein the reflective isolation layer comprises a dielectric distributed Bragg reflection (DBR) structure.
3 . The micro LED display panel according to claim 2 , wherein the DBR structure comprises a plurality of first layers and a plurality of second layers, the plurality of first layers and the plurality of second layers being alternately layered.
4 . The micro LED display panel according to claim 3 , wherein materials of the plurality of first layers and the plurality of second layers are SiO 2 and TiO 2 , respectively.
5 . The micro LED display panel according to claim 4 , wherein a thickness of the first layer or a thickness of the second layer is λ/4, wherein λ represents a wavelength of light emitted by the micro LED display panel.
6 . The micro LED display panel according to claim 5 , wherein a thickness of the reflective isolation layer is in a range of 0.3 μm to 5 μm.
7 . The micro LED display panel according to claim 1 , further comprising a plurality of top contacts, wherein each of the top contacts is formed on a surface of the top transparent conductive layer between adjacent ones of the plurality of mesa structures.
8 . The micro LED display panel according to claim 7 , wherein a material of the top contact is metal.
9 . The micro LED display panel according to claim 1 , further comprising:
a micro lens array corresponding to the mesa array, and formed on the top transparent conductive layer.
10 . The micro LED display panel according to claim 9 , wherein a material of the micro lens array is selected from one or more of SiO 2 , Si 3 N 4 , or Al 2 O 3 .
11 . The micro LED display panel according to claim 9 , wherein the micro lens array further comprises:
a bottom spacer formed on a top surface of the top transparent conductive layer; and
a plurality of micro lens structures formed on the bottom spacer.
12 . The micro LED display panel according to claim 11 , wherein the bottom spacer and the plurality of micro lens structures are an integrated structure.
13 . The micro LED display panel according to claim 1 , wherein the bottom connecting structure is a metal via.
14 . The micro LED display panel according to claim 13 , wherein a material of the metal via is TiCu or Cu.
15 . The micro LED display panel according to claim 13 , wherein the bottom connecting structure is connected with a bottom pad of the IC backplane.
16 . The micro LED display panel according to claim 1 , wherein the mesa structure comprises:
a first type epitaxial layer formed on a top surface of the bottom connecting structure;
a light emitting layer formed on the first type epitaxial layer; and
a second type epitaxial layer formed on the light emitting layer;
wherein the second type epitaxial layer comprises an extrusion portion formed on the reflective isolation layer and extending along a top surface of the reflective isolation layer.
17 . The micro LED display panel according to claim 16 , wherein the extrusion portion interconnects second type epitaxial layers of adjacent mesa structure of the mesa array; and a top surface of the second type epitaxial layer is continuously formed on the mesa array.
18 . The micro LED display panel according to claim 17 , wherein the top transparent conductive layer is continuously formed on the top surface of the second type epitaxial layer.
19 . The micro LED display panel according to claim 16 , further comprising:
a passivation layer formed on a sidewall surface of the mesa structure and on a bottom surface of the extrusion portion.
20 . The micro LED display panel according to claim 19 , wherein the passivation layer is further formed on a top surface of the reflective isolation layer, and the micro LED display panel further comprises:
an electrode pad formed on a top surface of the passivation layer and on a sidewall surface of the extrusion portion.
21 . The micro LED display panel according to claim 19 , further comprising:
one or more IO (Input/Output) vias, the IO via formed outside the mesa array and through the reflective isolation layer.
22 . The micro LED display panel according to claim 21 , further comprising:
one or more top connection pads corresponding to the one or more IO vias, wherein one top connection pad is formed on a top of one IO via;
a dielectric layer formed on the passivation layer and filled in a gap between the top connection pads; and
one or more bottom pads provided on the IC backplane corresponding the plurality of mesa structures, wherein a bottom of one IO via is bonded with one bottom pad.
23 . The micro LED display panel according to claim 19 , a top of the passivation layer is not higher than a top of an end of the top transparent conductive layer.
24 . The micro LED display panel according to claim 1 , further comprising:
an electrode pad formed on an edge of the mesa array, wherein the electrode pad is connected with the top transparent conductive layer.
25 . The micro LED display panel according to claim 24 , wherein the electrode pad is formed on a sidewall surface of the top transparent conductive layer.
26 . The micro LED display panel according to claim 25 , wherein a top of the electrode pad is higher than a top of the top transparent conductive layer.
27 . The micro LED display panel according to claim 24 , wherein an end of the top transparent conductive layer is formed on part of a top of the electrode pad and on a sidewall of the electrode pad.
28 . The micro LED display panel according to claim 1 , further comprising:
a passivation layer formed on a sidewall surface of the mesa structure.
29 . The micro LED display panel according to claim 28 , wherein a material of the passivation layer is selected from one or more of SiO 2 , Si 3 N 4 , or Al 2 O 3 .
30 . The micro LED display panel according to claim 16 , wherein a material of the first type epitaxial layer is selected from one or more of GaN, AlGaN, GaP, AlGaInP, or AlInP; a material of the second type epitaxial layer is selected from one or more of AlInP, AlGaInP, GaN, or AlGaN; and the light emitting layer is a quantum well layer.