阅读说明：本技术 一种Micro LED背板及其制造方法 (Micro LED backboard and manufacturing method thereof ) 是由 黄安 于 2020-11-19 设计创作，主要内容包括：本发明提供一种Micro LED背板及其制造方法,Micro LED背板包括背板衬底、第一金属电极线、键合金属层、Micro LED、第一平坦绝缘层、第二金属电极线以及第二平坦绝缘层,Micro LED的顶部露出所述第二金属电极线和第二平坦绝缘层,其中所述第二金属电极线位于Micro LED之间的第一平坦绝缘层且连接相邻Micro LED的侧壁。本发明通过第二金属电极线位于Micro LED的侧壁且电性连接相邻Micro LED,省去了通过ITO电极连接相邻Micro LED,节省了开孔工艺,大大节约了工艺成本,并且没有ITO电极及ITO电极阻挡提升了Micro LED的显示亮度和提升了显示背板的分辨率PPI,N型氮化镓层的侧壁由第二金属电极线包裹使得N型氮化镓层不透光,可以起到防侧壁漏光的效果。(The invention provides a Micro LED backboard and a manufacturing method thereof. According to the invention, the second metal electrode wire is positioned on the side wall of the Micro LED and electrically connected with the adjacent Micro LED, so that the connection of the adjacent Micro LED through the ITO electrode is omitted, the hole opening process is saved, the process cost is greatly saved, the display brightness of the Micro LED is improved and the resolution PPI of the display back plate is improved without the ITO electrode and the ITO electrode barrier, the side wall of the N-type gallium nitride layer is wrapped by the second metal electrode wire, so that the N-type gallium nitride layer is light-proof, and the effect of preventing the side wall from light leakage can be achieved.)

1. A Micro LED backboard comprises a backboard substrate, first metal electrode wires, a bonding metal layer and a Micro LED, wherein the first metal electrode wires are located on the backboard substrate and are arranged in an array mode, the Micro LED is located on the bonding metal layer and is in bonding connection with the bonding metal layer, the Micro LED backboard is characterized by further comprising a first flat insulating layer, a second metal electrode wire and a second flat insulating layer, the first flat insulating layer is located on the backboard substrate and covers a part of the Micro LED, the second metal electrode wire is located on the first flat insulating layer and is located on the side wall of the Micro LED, the second flat insulating layer covers the second metal electrode wire, the second metal electrode wire and the second flat insulating layer are exposed from the top of the Micro LED, the second metal electrode wire is located on the first flat insulating layer between the Micro LEDs and is connected with the side wall of the adjacent Micro LED.

2. The Micro LED backplane according to claim 1, wherein the Micro LED comprises, from bottom to top, a bottom bonding metal layer, a P-type gallium nitride layer, a quantum well light-emitting layer and an N-type gallium nitride layer which are bonded to the bonding metal layer; the first flat insulating layer covers the area where the quantum well light-emitting layer is located.

3. The Micro LED backplane according to claim 2, wherein the second metal electrode lines are located on the first planar insulating layer between adjacent Micro LEDs and on sidewalls of the N-type gallium nitride layer.

4. A Micro LED backplane according to claim 2, wherein the first planarizing insulating layer is located on the first metal electrode lines at a height that exceeds a height of the quantum well light emitting layer of the Micro LED located on the first metal electrode lines.

5. A Micro LED backplane according to claim 1, wherein the width of the bonding metal layer is smaller than the width of the first metal electrode lines, and a projection of the bonding metal layer onto the first metal electrode lines is located inside the surface of the first metal electrode lines.

6. A manufacturing method of a Micro LED backboard is characterized by comprising the following steps:

s1: firstly, forming first metal electrode wires arranged in an array on a backboard substrate; then forming a bonding metal layer above the first metal electrode wire by a film forming and stripping process;

s2: the transfer head adsorbs the Micro LEDs and transfers the Micro LEDs to the upper part of the bonding metal layer of the back plate substrate to be in bonding connection with the corresponding bonding metal layer;

s3: firstly, depositing a first flat insulating layer covering the Micro LED, the bonding metal layer and the first metal electrode wire on a back plate substrate; then, the first flat insulating layer is etched comprehensively and leaks out of the N-type gallium nitride layer of the Micro LED, the etching depth of the first flat insulating layer is not more than that of a quantum well light-emitting layer of the Micro LED, and the first flat insulating layer becomes the first flat insulating layer with reduced thickness after being etched; laying a second metal electrode wire on the whole surface, wherein the second metal electrode wire covers the first flat insulating layer with the reduced thickness between the adjacent Micro LEDs, the surface of the N-type gallium nitride layer of the Micro LEDs and the side wall of the N-type gallium nitride layer of the Micro LEDs; then depositing a second flat insulating layer covering the second metal electrode wire; etching the second flat insulating layer to be below the top surface of the Micro LED and forming a second flat insulating layer with reduced thickness, wherein the thickness of the etched second metal electrode wire is not more than the height of the N-type gallium nitride layer of the Micro LED, and the second flat insulating layer with reduced thickness still covers part of the N-type gallium nitride layer; and finally, etching a second metal electrode wire at the top of the exposed Micro LED, wherein the second metal electrode wire forms a second metal electrode wire with a reduced height, and the Micro LED is electrically connected by utilizing the second metal electrode wire between the side walls of the adjacent N-type gallium nitride layers.

7. The method for manufacturing a Micro LED backplane according to claim 6, wherein in step S1, the width of the bonding metal layer is smaller than the width of the first metal electrode line, and the projection of the bonding metal layer on the first metal electrode line is located inside the surface of the first metal electrode line.

8. The method of manufacturing a Micro LED backplane according to claim 6, wherein the first planarizing, insulating layer is made of a light-resistant material.

Technical Field

The invention relates to the technical field of Micro LEDs, in particular to a Micro LED back plate and a manufacturing method thereof.

Background

With the vigorous development of the display industry, Micro LEDs have been on the stage of the era as a new generation of display technology, and compared with the existing OLED and LCD technologies, the Micro LEDs have higher brightness, lower power consumption, better light emitting efficiency and longer service life, and the existing Micro LEDs still have many problems to be solved, no matter the process technology, the inspection standard or the production and manufacturing cost, which are far away from mass production and commercial application.

The existing Micro LED backboard is provided with a first metal electrode wire formed on a backboard substrate, a second metal electrode wire and an insulating layer located between the first metal electrode wire and the second metal electrode wire, then the Micro LED is transferred, the insulating layer and an electrode layer are plated after the Micro LED is transferred, the insulating layer is required to be perforated at the top of the Micro LED and the second metal electrode wire, the process is complex, the cost is high, the electrode layer belongs to a semitransparent film, certain absorption can be carried out on the brightness of the Micro LED, the brightness of the Micro LED is weakened, and the resolution and PPI (pixel density) of the whole backboard can be influenced by the existence of the electrode layer.

Disclosure of Invention

The invention aims to provide a Micro LED backboard for improving resolution and preventing side wall light leakage and a manufacturing method thereof.

The invention provides a Micro LED backboard, which comprises a backboard substrate, first metal electrode wires, a bonding metal layer, a Micro LED, a first flat insulating layer, a second metal electrode wire and a second flat insulating layer, wherein the first metal electrode wires are positioned on the backboard substrate and are arranged in an array, the Micro LED is positioned on the bonding metal layer and is in bonding connection with the bonding metal layer, the first flat insulating layer is positioned on the backboard substrate and covers part of the Micro LED, the second metal electrode wire is positioned on the first flat insulating layer and is positioned on the side wall of the Micro LED, the second flat insulating layer is covered on the second metal electrode wire, the second metal electrode wire and the second flat insulating layer are exposed from the top of the Micro LED, and the second metal electrode wire is positioned on the first flat insulating layer between the Micro LEDs and is connected with the side wall of the adjacent Micro LED.

Further, the Micro LED is respectively provided with a bottom bonding metal layer, a P-type gallium nitride layer, a quantum well light emitting layer and an N-type gallium nitride layer from bottom to top, wherein the bottom bonding metal layer, the P-type gallium nitride layer, the quantum well light emitting layer and the N-type gallium nitride layer are in bonding connection with the bonding metal layer; the first flat insulating layer covers the area where the quantum well light-emitting layer is located.

Further, the second metal electrode wires are located on the first flat insulating layer between the adjacent Micro LEDs and on the side wall of the N-type gallium nitride layer.

Further, the height of the first planarization insulating layer on the first metal electrode line exceeds the height of the quantum well light emitting layer of the Micro LED on the first metal electrode line.

Further, the width of the bonding metal layer is smaller than that of the first metal electrode line, and the projection of the bonding metal layer on the first metal electrode line is located inside the surface of the first metal electrode line.

The invention also provides a manufacturing method of the Micro LED backboard, which comprises the following steps:

s1: firstly, forming first metal electrode wires arranged in an array on a backboard substrate; then forming a bonding metal layer above the first metal electrode wire by a film forming and stripping process;

s2: the transfer head adsorbs the Micro LEDs and transfers the Micro LEDs to the upper part of the bonding metal layer of the back plate substrate to be in bonding connection with the corresponding bonding metal layer;

s3: firstly, depositing a first flat insulating layer covering the Micro LED, the bonding metal layer and the first metal electrode wire on a back plate substrate; then, the first flat insulating layer is etched comprehensively and leaks out of the N-type gallium nitride layer of the Micro LED, the etching depth of the first flat insulating layer is not more than that of a quantum well light-emitting layer of the Micro LED, and the first flat insulating layer becomes the first flat insulating layer with reduced thickness after being etched; laying a second metal electrode wire on the whole surface, wherein the second metal electrode wire covers the first flat insulating layer with the reduced thickness between the adjacent Micro LEDs, the surface of the N-type gallium nitride layer of the Micro LEDs and the side wall of the N-type gallium nitride layer of the Micro LEDs; then depositing a second flat insulating layer covering the second metal electrode wire; etching the second flat insulating layer to be below the top surface of the Micro LED and forming a second flat insulating layer with reduced thickness, wherein the thickness of the etched second metal electrode wire is not more than the height of the N-type gallium nitride layer of the Micro LED, and the second flat insulating layer with reduced thickness still covers part of the N-type gallium nitride layer; finally, etching off a second metal electrode wire on the top of the exposed Micro LED, wherein the second metal electrode wire forms a second metal electrode wire with a reduced height, and the Micro LED is electrically connected by utilizing the second metal electrode wire between the side walls of the adjacent N-type gallium nitride layers

Further, in step S1, the width of the bonding metal layer is smaller than the width of the first metal electrode line, and a projection of the bonding metal layer on the first metal electrode line is located inside a surface of the first metal electrode line.

Further, the first planarization insulating layer is made of a light-shielding material.

According to the invention, the second metal electrode wire is positioned on the side wall of the Micro LED and electrically connected with the adjacent Micro LED, so that the connection of the adjacent Micro LED through the ITO electrode is omitted, the hole opening process is saved, the process cost is greatly saved, the display brightness of the Micro LED is improved and the resolution PPI of the display back plate is improved without the ITO electrode and the ITO electrode barrier, the side wall of the N-type gallium nitride layer is wrapped by the second metal electrode wire, so that the N-type gallium nitride layer is light-proof, and the effect of preventing the side wall from light leakage can be achieved.

Drawings

FIG. 1(a) is a schematic structural view of a Micro LED backplane according to the present invention;

FIG. 1(b) is a partial top view of the Micro LED backplane of FIG. 1 (a);

FIG. 1(c) is a cross-sectional view of the Micro LED backplane of FIG. 1 (b);

FIG. 1(d) is a schematic view of a Micro LED individual structure of a Micro LED backplane according to the present invention;

FIG. 1(e) is a partial schematic view of the Micro LED backplane of FIG. 1 (a);

FIG. 2(a) to FIG. 2(c) are schematic structural diagrams of one of the methods for manufacturing a Micro LED backplane according to the present invention;

FIGS. 3(a) and 3(b) are schematic structural views of a second method for manufacturing a Micro LED backplane according to the present invention;

fig. 4(a) to 4(f) are schematic structural views of a third method for manufacturing a Micro LED backplane according to the present invention.

Detailed Description

The present invention is further illustrated by the following figures and specific examples, which are to be understood as illustrative only and not as limiting the scope of the invention, which is to be given the full breadth of the appended claims and any and all equivalent modifications thereof which may occur to those skilled in the art upon reading the present specification.

For the sake of simplicity, the drawings only schematically show the parts relevant to the present invention, and they do not represent the actual structure as a product. In addition, in order to make the drawings concise and understandable, components having the same structure or function in some of the drawings are only schematically illustrated or only labeled. In this document, "one" means not only "only one" but also a case of "more than one".

The invention relates to a Micro LED backplane, which comprises a backplane substrate 100, first metal electrode lines 101 arranged on the backplane substrate 100 in an array manner, a bonding metal layer 102 arranged on the first metal electrode lines 101, Micro LEDs 103 arranged on the bonding metal layer 102 and connected with the bonding metal layer 102 in a bonding manner, a first flat insulating layer 104 arranged on the backplane substrate 100 and covering part of the Micro LEDs 103, second metal electrode lines 104 arranged on the first flat insulating layer 104 and arranged on the side walls of the Micro LEDs 103, and a second flat insulating layer 105 covering the second metal electrode lines 104, wherein the second metal electrode lines 104 are exposed from the tops of the Micro LEDs 103, and the second metal electrode lines 104 are arranged on the first flat insulating layer 104 between the Micro LEDs 103 and connected with the side walls of the adjacent Micro LEDs 103, as shown in FIGS. 1(a) to 1 (c).

The width of the bonding metal layer 102 is smaller than the width of the first metal electrode line 101, and a projection of the bonding metal layer 102 on the first metal electrode line 101 is located inside the surface of the first metal electrode line 101.

As shown in fig. 1(d), the Micro LED103 includes, from bottom to top, a bottom bonding metal layer 1031, a P-type gallium nitride layer 1032, a quantum well light emitting layer 1033, and an N-type gallium nitride layer 1034 bonded to the bonding metal layer 102.

The first flat insulating layer 104 covers more than the region where the quantum well light emitting layer 1033 is located; the second metal electrode lines 104 are located on the first flat insulating layer 104 between the adjacent Micro LEDs 103 and on the sidewall of the N-type gallium nitride layer 1034, and the adjacent Micro LEDs 103 are electrically connected through the second metal electrode lines 104.

As shown in fig. 1(d), the height H2 of the first planarization insulating layer 40 on the first metal electrode line 101 exceeds the height H1 of the quantum well light emitting layer 1033 of the Micro LED103 on the first metal electrode line 101, because the thickness of the N-type gallium nitride layer 1034 of the Micro LED is thick, for example, the thickness of the blue light epitaxial N-type gallium nitride layer is 3-3.2 um, the film forming range of the second metal electrode line 104 coated on the N-type gallium nitride layer 1034 is wide, the film forming is easy, in addition, the ITO film layer and the hole forming process are omitted, the process cost is greatly saved, and the display brightness of the Micro LED is improved and the resolution PPI of the display backplane is improved without the ITO film layer and the ITO film layer.

The invention discloses a manufacturing method of a Micro LED backboard, which comprises the following steps:

s1: as shown in fig. 2(a) and 2(b), first, a film-forming yellow light etching process is used to form first metal electrode lines 101 arranged in an array on a backplane substrate 100; as shown in fig. 2(c), a bonding metal layer 102 is then formed over the first metal electrode line 101 by a film-forming-Lift-Off (Lift-Off) process;

s2: as shown in fig. 3(a), the transfer head 200 adsorbs the Micro LEDs 103 and transfers the Micro LEDs 103 to the upper side of the bonding metal layer 102 of the backplane substrate 100, as shown in fig. 3(b), the Micro LEDs 103 are bonded and connected with the corresponding bonding metal layer 102;

s3: as shown in fig. 4(a), first, a first flat insulating layer 104 covering the Micro LEDs 103, the bonding metal layer 103 and the first metal electrode lines 101 is deposited on the backplane substrate 100 by a full-scale-bonding (Slit) or spin-coating process; as shown in fig. 4(b), the first flat insulating layer 104 is etched completely and leaks out of the N-type gallium nitride layer 1034 of the Micro LED103, the depth of etching the first flat insulating layer 104 is not more than the quantum well light emitting layer 1033 of the Micro LED103, and the first flat insulating layer 104 becomes the first flat insulating layer 104a with a reduced thickness after etching; as shown in fig. 4(c), a second metal electrode wire 105 is then laid on the whole surface by using a film forming process, and the second metal electrode wire 105 covers the first flat insulating layer 104a with a reduced thickness between the adjacent Micro LEDs 103, the surface of the N-type gallium nitride layer 1034 of the Micro LED103, and the side wall of the N-type gallium nitride layer 1034 of the Micro LED 103; as shown in fig. 4(d), a second flat insulating layer 106 covering the second metal electrode line 105 is deposited by a full-scale lamination (Slit) or spin coating process; as shown in fig. 4(e), the second flat insulating layer 105 is etched to a position below the top surface of the Micro LED103 and a second flat insulating layer 105a with a reduced thickness is formed, the thickness of the etched second metal electrode line does not exceed the height of the N-type gallium nitride layer 1034 of the Micro LED103, and the second flat insulating layer 105a with a reduced thickness still covers a part of the N-type gallium nitride layer 1034; as shown in fig. 4(f), the second metal electrode lines on the top of the exposed Micro LED103 are etched away by wet etching or the like, the second metal electrode lines form second metal electrode lines 105a with a reduced height, and the Micro LED103 is electrically connected by the second metal electrode lines 105a between the sidewalls of the adjacent N-type gallium nitride layers 1034 to realize display.

The Micro LED back plate is formed through the method.

In step S1, the width of the bonding metal layer 102 is smaller than the width of the first metal electrode line 101, and the projection of the bonding metal layer 102 on the first metal electrode line 101 is located inside the surface of the first metal electrode line 101.

The first planarization insulating layer is made of a light-shielding material and plays a role in preventing optical crosstalk.

According to the invention, the second metal electrode wire is positioned on the side wall of the Micro LED and electrically connected with the adjacent Micro LED, so that the connection of the adjacent Micro LED through the ITO electrode is omitted, the hole opening process is saved, the process cost is greatly saved, the display brightness of the Micro LED is improved and the resolution PPI of the display back plate is improved without the ITO electrode and the ITO electrode barrier, the side wall of the N-type gallium nitride layer is wrapped by the second metal electrode wire, so that the N-type gallium nitride layer is light-proof, and the effect of preventing the side wall from light leakage can be achieved.

Although the preferred embodiments of the present invention have been described in detail, the present invention is not limited to the details of the foregoing embodiments, and various equivalent changes (such as number, shape, position, etc.) may be made to the technical solution of the present invention within the technical spirit of the present invention, and these equivalent changes are all within the protection scope of the present invention.