CN115483239A

CN115483239A - Display device and manufacturing method thereof

Info

Publication number: CN115483239A
Application number: CN202110591114.8A
Authority: CN
Inventors: 张廷斌; 林昌廷; 刘晓伟; 孙明晓
Original assignee: Hisense Visual Technology Co Ltd
Current assignee: Hisense Visual Technology Co Ltd
Priority date: 2021-05-28
Filing date: 2021-05-28
Publication date: 2022-12-16

Abstract

The invention discloses a display device and a manufacturing method thereof, wherein an epitaxial layer is formed on a substrate; forming a first electrode on one side of the epitaxial layer, which is far away from the substrate; forming a driving circuit layer on one side of the first electrode, which is far away from the epitaxial layer; stripping the substrate, and etching the epitaxial layer according to the position of the first electrode to form a plurality of epitaxial layer units; and forming a second electrode on one side of the epitaxial layer unit, which is far away from the driving line layer. Therefore, the Micro LED display unit capable of being actively driven can be directly formed, the step that the Micro LED is required to be massively transferred to be assembled when the driving substrate and the Micro LED are respectively manufactured is avoided, and the production yield and the production efficiency of the display device are improved.

Description

Display device and manufacturing method thereof

Technical Field

The invention relates to the technical field of display, in particular to a display device and a manufacturing method thereof.

Background

The Micro Light Emitting Diode (Micro LED) display technology refers to a display technology in which a Light Emitting chip is directly used as a Light Emitting unit. The Micro LED inherits the characteristics of high efficiency, high brightness, high reliability, quick response time and the like of the traditional light emitting diode, has the characteristic of self luminescence without a backlight source, and has the advantages of energy conservation, simple mechanism, small volume, thinness and the like.

The driving mode of the micro light emitting diode panel can be divided into an active mode and a passive mode, wherein the active driving mode has the advantages of low power consumption, crosstalk resistance, low driving cost and the like.

In the current active driving mode, a driving substrate and a Micro LED need to be manufactured respectively, and then the Micro LED and the driving substrate are paired in a massive transfer mode. However, the current bulk transfer process is complicated, the production yield is low, and the production efficiency needs to be improved.

Disclosure of Invention

In some embodiments of the present invention, the epitaxial layer is formed on the substrate; forming a first electrode on one side of the epitaxial layer, which is far away from the substrate; forming a driving circuit layer on one side of the first electrode, which is far away from the epitaxial layer; stripping the substrate, and etching the epitaxial layer according to the position of the first electrode to form a plurality of epitaxial layer units; and forming a second electrode on one side of the epitaxial layer unit, which is far away from the driving circuit layer. Therefore, the Micro LED display unit capable of being actively driven can be directly formed, the step that the Micro LED is required to be massively transferred to be assembled when the driving substrate and the Micro LED are respectively manufactured is avoided, and the production yield and the production efficiency of the display device are improved.

In some embodiments of the present invention, forming the epitaxial layer on the substrate includes sequentially forming an undoped layer, a first doped layer, a light emitting layer, and a second doped layer on the substrate. One of the first doping layer and the second doping layer is an N-type doping layer, the other one of the first doping layer and the second doping layer is a P-type doping layer, and the light emitting layer is a multi-quantum well layer.

In some embodiments of the present invention, after the forming the epitaxial layer, before the forming the driving seed layer, the method further includes: and forming a first electrode pattern on one side of the second doped layer, which is far away from the light-emitting layer. The first electrode is an ohmic contact layer matched with the work function of the second doped layer.

In some embodiments of the invention, the reflective layer is formed on the first electrode, so that the reflective layer is applied to a top-emission Micro LED display device, and the reflective layer is used for finally reflecting light emitted by the Micro LED to a light emitting side, thereby achieving the purpose of improving light efficiency.

In some embodiments of the present invention, the fabricating the driving circuit layer includes: the circuit comprises a first insulating layer, a conductive blocking layer, a second insulating layer, an active layer, a grid insulating layer, a grid metal layer, an interlayer insulating layer, a source drain metal layer, a third insulating layer, a capacitor electrode, a power signal line pattern and a passivation layer which are sequentially manufactured. The grid metal layer comprises a grid line, a grid and a pattern of one electrode of a capacitor; the source drain metal layer comprises a data line, a source electrode and a drain electrode; the active layer, the gate electrode, the source electrode and the drain electrode constitute a thin film transistor. The conductive barrier layer includes an opening exposing the first electrode, a gate electrode of the thin film transistor is electrically connected to the gate line, a source electrode is electrically connected to the data line, and a drain electrode is electrically connected to the first electrode through the opening of the conductive barrier layer. Thus, the Micro LED can be actively driven by a driving unit including a thin film transistor.

In some embodiments of the present invention, the power signal line is electrically connected to the conductive barrier layer through the annular through groove on the edge, thereby improving the problem of voltage drop.

In some embodiments of the present invention, after forming the driving line layer, the epitaxial layer on which the driving line layer is formed is transferred onto the temporary substrate and the driving line layer is bonded to the temporary substrate before peeling the substrate.

In some embodiments of the present invention, the substrate and the undoped layer are removed before the epitaxial layer is etched, and the first doped layer is thinned. The undoped layer is required to be removed because of its poor conductivity, and the entire thickness of the epitaxial layer affects the resistance of the device, and the first doped layer needs to be thinned in order to reduce the resistance.

In some embodiments of the present invention, etching the epitaxial layers requires etching all of the epitaxial layers through until the conductive barrier layer is exposed between the epitaxial layer cells. The conductive barrier layer can play a role in etching blocking, so that the driving circuit layer below the conductive barrier layer can not be damaged when the epitaxial layer is subjected to etching.

In some embodiments of the present invention, forming the second electrode on the surface of the epitaxial layer unit includes: and forming a fourth insulating layer on one side of the thinned first doping layer, which is far away from the driving circuit layer, and forming a second electrode on one side of the fourth insulating layer, which is far away from the driving circuit layer. The fourth insulating layer can cover the side wall of the epitaxial layer unit to prevent short circuit. The second electrode is an ohmic contact layer matched with the work function of the first doped layer, a signal provided by the power signal line can be loaded to the conductive barrier layer, and the signal loaded by the conductive barrier layer can be loaded to one side of the first doped layer through the second electrode.

In some embodiments of the present invention, the second electrode of the Micro LED is electrically connected to the conductive barrier layer to form a common electrode structure, and since an electrical signal of the common electrode is loaded onto the conductive barrier layer, only a small portion of the second electrode located on the sidewall of the Micro LED plays a role of conducting the electrical signal, a resistance of the common electrode depends on a resistance of the conductive barrier layer, and has a small correlation with a resistance of a material of the second electrode. The resistance of the conductive barrier layer can be effectively reduced by selecting a low-resistance conductive material to manufacture the conductive barrier layer or increasing the thickness of the conductive barrier layer, so that the problem of obvious voltage drop of the common electrode can be effectively solved.

In some embodiments of the present invention, the conductive barrier layer is made of a metal material or a transparent conductive material.

In some embodiments of the present invention, the conductive barrier layer has a thickness of 20nm to 1000nm.

In some embodiments of the present invention, after forming the Micro LED, further comprising: a light shielding layer is formed between the Micro LEDs, a flat layer is formed on one side, away from the driving line layer, of the light shielding layer and the Micro LEDs, and a protective layer is formed on one side, away from the Micro LEDs, of the flat layer.

In some embodiments of the present invention, the transient substrate is peeled off to bond the driver chip and the driver circuit layer.

In some embodiments of the invention, when the epitaxial layer is etched to form enough Micro LEDs, the driving chip can be directly bound to one side of the driving circuit layer, and then the packaging layer is formed on the surfaces of the driving circuit layer and the driving chip, thereby forming the Micro LED display device.

In some embodiments of the present invention, when the display device needs to be enlarged in size, a plurality of Micro LED display devices may be tiled to form a tiled display device, so as to implement super-large-size image display.

In some embodiments of the present invention, after the Micro LED display units are formed, if the display units only include one or several Micro LEDs, a plurality of display units may be integrated on the driving backplane, each display unit is connected to a circuit of the driving backplane by using a circuit connection method, and then each display unit is controlled to display an image by binding a driving chip on the driving backplane.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments of the present invention will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a flowchart of a method for manufacturing a display device according to an embodiment of the invention;

FIGS. 2 a-2 d are schematic cross-sectional views of the display device corresponding to the steps in FIG. 1;

fig. 3 is a schematic cross-sectional view of a display device according to an embodiment of the invention;

fig. 4 is a second schematic cross-sectional view illustrating a display device according to an embodiment of the invention;

fig. 5 is a third schematic cross-sectional view illustrating a display device according to an embodiment of the invention;

FIG. 6 is a fourth schematic cross-sectional view of a display device according to an embodiment of the present invention;

FIG. 7 is a fifth schematic cross-sectional view of a display device according to an embodiment of the present invention;

FIG. 8 is a sixth schematic cross-sectional view of a display device according to an embodiment of the present invention;

fig. 9 is a seventh schematic cross-sectional view of a display device according to an embodiment of the invention;

fig. 10 is an eighth schematic cross-sectional view of a display device according to an embodiment of the present invention;

fig. 11a is a schematic structural diagram of a display device according to an embodiment of the present invention;

fig. 11b is a second schematic structural diagram of a display device according to an embodiment of the present invention;

fig. 11c is a third schematic structural diagram of a display device according to an embodiment of the present invention.

10-substrate, 20-epitaxial layer, 30-driving circuit layer, 40-packaging protection layer, 50-packaging layer, 60-integrated backplane, 70-driving backplane, 200-micro light emitting diode, 201-undoped layer, 202-first doped layer, 203-light emitting layer, 204-second doped layer, 205-fourth insulating layer, 301-first insulating layer, 302-conductive barrier layer, 303-second insulating layer, 304-active layer, 305-gate insulating layer, 306-gate metal layer, 307-interlayer insulating layer, 308-source drain metal layer, 309-third insulating layer, 310-power signal line, 311-passivation layer, e 1-first electrode, e 2-second electrode, 101-transient substrate, 102-bonding layer, m-epitaxial layer unit, 401-light shielding layer, 402-flat layer, 403-protection layer, ic-driving chip.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, the present invention is further described with reference to the accompanying drawings and examples. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus, a repetitive description thereof will be omitted. The words expressing the position and direction described in the present invention are illustrated in the accompanying drawings, but may be changed as required and still be within the scope of the present invention. The drawings of the present invention are for illustrative purposes only and do not represent true scale.

Light Emitting Diodes (LEDs) have the advantages of low power consumption, long service life, no pollution, and the like. When forward bias is applied to the PN junction, electrons in the n-type region and holes in the p-type region move under the action of an external electric field, and energy generated after band-to-band recombination of the electrons and the holes is released in the form of photons, so that light is emitted. However, the light emitting efficiency of the LED with the homogeneous structure is low, and therefore, a multi-heterojunction structure is often introduced to manufacture the LED to improve the light emitting efficiency.

When the LED device with the multi-quantum well structure deflects in the forward direction, electrons and holes move to the multi-quantum well layer under the action of an external electric field, the coincidence rate of wave functions of the electrons and the holes is increased, and the composite luminous efficiency of the LED device is improved.

The Micro LED inherits the characteristics of high efficiency, high brightness, high reliability, quick response time and the like of the LED, has the characteristic of self luminescence without a backlight source, and has the advantages of energy conservation, simple mechanism, small volume, thinness and the like. The conventional Micro LED display device usually needs to separately manufacture a driving substrate and a Micro LED, and the Micro LED is transferred to the driving substrate to be assembled by adopting a massive transfer technology, so that the production yield is low, and the production efficiency needs to be improved.

The embodiment of the invention provides a display device and a manufacturing method thereof, which can combine an active driving circuit with a Micro LED, and can realize active driving display of the Micro LED without assembling the Micro LED with a driving substrate.

First, a method for manufacturing a display device is provided in an embodiment of the present invention, and fig. 1 is a flowchart of the method for manufacturing a display device provided in the embodiment of the present invention.

Referring to fig. 1, a method for manufacturing a display device according to an embodiment of the present invention includes:

s10, forming an epitaxial layer on a substrate;

s20, forming a first electrode on one side, away from the substrate, of the epitaxial layer; the first electrode has mutually discrete figures, and the first electrode and the corresponding epitaxial layer form a light-emitting unit;

s30, forming a driving circuit layer on one side of the first electrode, which is far away from the epitaxial layer; the driving circuit layer comprises a conductive barrier layer and a driving unit which are arranged in a whole layer;

s40, stripping the substrate, and etching the epitaxial layer according to the position of the first electrode to form a plurality of epitaxial layer units and exposed conductive barrier layers positioned on two sides of the epitaxial layer units; the epitaxial layer units correspond to the driving units one by one, and the first electrodes corresponding to the epitaxial layer units are electrically connected with the corresponding driving units through the via holes of the driving circuit layer;

s50, forming a second electrode on one side of each epitaxial layer unit, which is far away from the driving circuit layer; the second electrode is arranged in a whole layer and is electrically connected with the exposed conductive barrier layer;

the light-emitting diode comprises an epitaxial layer unit, a first electrode corresponding to the epitaxial layer unit and a second electrode corresponding to the epitaxial layer unit.

According to the manufacturing method of the display device, provided by the embodiment of the invention, the epitaxial layer is manufactured firstly, the driving circuit layer is formed on the epitaxial layer, and then the cutting and electrode deposition are carried out on the epitaxial layer, so that the Micro LED display unit capable of being actively driven can be directly formed, the step that the Micro LED needs to be subjected to a huge transfer to be paired when the driving substrate and the Micro LED are manufactured respectively is avoided, and the production yield and the production efficiency of the display device are improved.

Fig. 2a to 2d are schematic cross-sectional structural diagrams of the corresponding display device when the above steps are performed.

As shown in fig. 2a, an epitaxial layer 20 is first formed on a substrate 10, where the substrate 10 needs to be matched with the formed epitaxial layer, the epitaxial layer formed by the manufacturing method provided by the embodiment of the present invention is generally an epitaxial layer emitting light waves of a single color, and if full color display needs to be achieved, an image display needs to be performed after the manufacturing is completed by matching with a filter layer or a color conversion layer.

As shown in fig. 2b, after the epitaxial layer 20 is formed, a driving circuit layer 30 is formed on a side of the epitaxial layer facing away from the substrate 10, and a plurality of driving units for controlling the Micro LEDs to perform active driving are included in the driving circuit layer 30, and the driving units may generally include transistors, capacitors, resistors and other elements. Meanwhile, the embodiment of the present invention further forms a conductive barrier layer disposed in the entire layer in the driving line layer 30, and the conductive barrier layer may be used to connect one side electrode of each Micro LED to form a driving mode of a common electrode.

After the drive line layer 30 is formed, the epitaxial layer 20 and the drive line layer are transferred onto a temporary substrate (10'), while the substrate 10 of the epitaxial layer 20 is stripped, as shown in fig. 2 c. The epitaxial layer 20 is etched to form a plurality of epitaxial layer units, and a plurality of micro light emitting diodes 200 may be formed by covering electrodes on the epitaxial layer units.

Finally, as shown in fig. 2d, the Micro light emitting diodes 200 are packaged, and a packaging protection layer 40 is formed on the surface of each Micro LED, thereby completing the Micro LED display unit with the active driving unit.

Specifically, in the step S10, forming an epitaxial layer on a substrate specifically includes:

s101, forming an undoped layer on a substrate;

s102, forming a first doped layer on one side of the undoped layer, which is far away from the substrate;

s103, forming a light emitting layer on one side, away from the undoped layer, of the first doped layer;

and S104, forming a second doped layer on one side of the light emitting layer, which is far away from the first doped layer.

Fig. 3 is a schematic cross-sectional view of a display device according to an embodiment of the invention.

Referring to fig. 3, an undoped layer 201 is formed on a substrate 10, and the undoped layer 201 is formed entirely on the substrate 10. The undoped layer 201 may be grown directly from the epitaxial layer, for example, the undoped layer may be made from gallium oxide, and is not limited herein.

After the undoped layer 201 is formed, the first doped layer 202 is formed over the undoped layer 201, and the first doped layer 202 is entirely formed over the undoped layer 201. The first doped layer 202 may be doped N-type or P-type in the original material of the epitaxial layer so that the first doped layer 202 may provide electrons or holes.

After the first doping layer 202 is formed, the light emitting layer 203 is formed on the first doping layer 202, and the light emitting layer 203 may be formed entirely on the first doping layer 202. The light emitting layer 203 may employ a multiple quantum well layer to improve light emitting efficiency.

After the light emitting layer 203 is formed, the second doping layer 204 is formed over the light emitting layer 203, and the second doping layer 204 is entirely formed over the light emitting layer 203. The second doped layer 204 may be P-doped or N-doped in the native material of the epitaxial layer so that the second doped layer 204 may provide holes or electrons.

The first doping layer 202 and the second doping layer 204 are located on two sides of the light emitting layer 203, and doping types of the two doping layers are opposite, if the first doping layer 202 is doped in an N-type manner, the second doping layer 204 is doped in a P-type manner; if the first doped layer 202 is doped P-type, the second doped layer 204 is doped N-type. In practical applications, the above two structures can be applied, and are not limited herein.

Further, after the epitaxial layer 20 is formed, the driving circuit layer 30 may be directly formed on the epitaxial layer 20, and before that, in the step S20, the forming of the first electrode on the side of the epitaxial layer away from the substrate specifically includes:

s201, forming a first electrode layer on one side, away from the light emitting layer, of the second doping layer;

s202, patterning the first electrode layer to form a first electrode pattern;

and S203, forming a reflecting layer on one side of the first electrode, which is far away from the second doped layer.

Fig. 4 is a second schematic cross-sectional view of a display device according to an embodiment of the invention.

Referring to fig. 4, above the epitaxial layer 20 is formed, a first electrode layer may be formed on a surface of the second doping layer 204 of the epitaxial layer 20, and the first electrode layer may be entirely disposed, and then a plurality of first electrodes e1 separated from each other may be formed through a patterning process.

The first electrode e1 is an ohmic contact layer matching the work function of the second doped layer 204, and may be made of metal such as nickel or gold, or may be made of transparent conductive material such as Indium Tin Oxide (ITO), without being limited thereto.

In the embodiment of the invention, after the first electrode e1 is formed, a reflective layer (not shown in fig. 4) can be formed on the first electrode e1, and the reflective layer is used for reflecting light emitted by the Micro LED to a light emitting side finally, so that the purpose of improving the light efficiency is achieved.

The reflective layer may be the same as the image of the first electrode, and may be made of the above-described material such as nickel or gold, and in this case, the reflective layer and the first electrode e1 may share one layer. In addition, the reflective layer may be made of a metal material having high reflectivity such as silver and aluminum, but is not limited thereto.

After the first electrode e1 (and the reflective layer) are formed, the fabrication of the driving line layer 30 is continued.

Specifically, in step S30, forming a driving circuit layer on a side of the first electrode away from the epitaxial layer specifically includes:

s301, forming a first insulating layer on one side, away from the first electrode, of the reflecting layer;

s302, forming a conductive barrier layer on one side, away from the second doping layer, of the first insulating layer;

s303, forming a second insulating layer on one side of the conductive barrier layer, which is far away from the second doping layer;

s304, forming an active layer on one side of the second insulating layer, which is far away from the conductive barrier layer;

s305, forming a gate insulating layer on one side of the active layer, which is far away from the second insulating layer;

s306, forming a gate metal layer on one side of the gate insulating layer, which is far away from the active layer;

s307, forming an interlayer insulating layer on one side of the grid metal layer, which is far away from the grid insulating layer;

s308, forming a source drain metal layer on one side, away from the grid metal layer, of the interlayer insulating layer;

s309, forming a third insulating layer on one side, away from the interlayer insulating layer, of the source drain metal layer;

s310, forming a graph of the other electrode of the capacitor and the power signal line on one side, away from the source-drain metal layer, of the third insulating layer;

and S311, forming a passivation layer on one side, away from the source drain metal layer, of the third insulating layer.

The active layer, the grid electrode, the source electrode and the drain electrode form a thin film transistor, and the drain electrode of the thin film transistor is electrically connected with the first electrode through the first insulating layer, the second insulating layer, the grid electrode insulating layer and the through hole of the interlayer insulating layer; the power signal line is electrically connected to the conductive barrier layer through the annular through groove of the second insulating layer, the gate insulating layer, the interlayer insulating layer, and the third insulating layer.

With continued reference to fig. 4, after forming a reflective layer over the first electrode e1, a first insulating layer 301 may be formed over the reflective layer, the first insulating layer 301 being entirely disposed to insulate the first electrode e1, so that another conductive layer may be formed over the first insulating layer 301.

The first insulating layer 301 may be made of silicon oxide, silicon nitride, aluminum oxide, zirconium oxide, or the like, which is not limited herein.

After the first insulating layer 301 is formed, a conductive barrier layer 302 is formed over the first insulating layer 301. The conductive barrier layer may be formed on the first insulating layer 301 in a whole layer, and a plurality of openings may be formed through a patterning process, where the openings may expose the first electrode e1 and are fabricated for electrically connecting a circuit formed later with the first electrode e1.

In the embodiment of the present invention, the conductive barrier layer 302 is used as a common electrode, and therefore, it is required to be made of a conductive material, and at the same time, the conductive barrier layer 302 also has an etching barrier function, so that it may be made of a metal material such as platinum, titanium, and nickel, or may also be made of a transparent conductive material such as crystallized indium tin oxide (POLY ITO) or Indium Zinc Oxide (IZO), which is not limited herein.

In order to reduce the resistance of the conductive barrier layer 302, the thickness thereof may be set to be between 20nm and 1000nm, which is not limited herein.

After the conductive barrier layer 302 is formed, a second insulating layer 303 is formed over the conductive barrier layer 302, and the second insulating layer 303 is provided in layers to insulate the conductive barrier layer 302, so that other conductive layers can be formed over the second insulating layer 303.

The second insulating layer 303 may be made of silicon oxide, silicon nitride, aluminum oxide, zirconium oxide, or the like, which is not limited herein.

After the second insulating layer 303 is formed, an active layer 304 is formed over the second insulating layer 303. The active layer 304 includes a source region and a drain region formed by doping N-type impurity ions or P-type impurity ions. The region between the source region and the drain region is the channel region that is not doped.

The active layer 304 may be made of amorphous silicon, polysilicon, metal oxide, or the like, and the polysilicon may be formed by crystallization of the amorphous silicon, which is not limited herein.

After the active layer 304 is formed, a gate insulating layer 305 is formed over the active layer 304, and the gate insulating layer 305 is entirely provided for insulating the active layer 304, so that another conductive layer may be formed over the gate insulating layer 305.

The gate insulating layer 305 may be made of a material such as silicon oxide, silicon nitride, aluminum oxide, or zirconium oxide, but is not limited thereto.

After the gate insulating layer 305 is formed, a gate metal layer 306 is formed on the gate insulating layer 305, and the gate metal layer 306 may be formed on the gate insulating layer 305 in a complete layer, and then patterned to form one of a gate line, a gate electrode, and a capacitor through a patterning process.

The gate metal layer 306 may be made of a single layer or a stacked layer of metal, and is not limited herein.

After the gate metal layer 306 is formed, an interlayer insulating layer 307 is formed over the gate metal layer 306, and the interlayer insulating layer 307 is entirely provided for insulating the gate metal layer 306, so that another conductive layer can be formed over the interlayer insulating layer 307.

The interlayer insulating layer 307 may be made of a material such as silicon oxide, silicon nitride, aluminum oxide, or zirconium oxide, but is not limited thereto.

After the interlayer insulating layer 307 is formed, a patterning process may be used to punch holes through the insulating layers, thereby forming vias that may connect underlying conductive layers.

Then, a source/drain metal layer 308 is formed on the interlayer insulating layer 307, and a whole layer of the source/drain metal layer 306 may be formed on the interlayer edge insulating layer 307, and then a pattern of a data line, a source, and a drain is formed by a patterning process.

The source drain metal layer 308 may be formed by a single layer or a stacked layer of metal, and is not limited herein.

After the source-drain metal layer 308 is formed, a third insulating layer 309 is formed on the source-drain metal layer 308, and the third insulating layer 309 is entirely provided to insulate the source-drain metal layer 308, so that another conductive layer may be formed on the third insulating layer 309.

The third insulating layer 309 may be made of silicon oxide, silicon nitride, aluminum oxide, zirconium oxide, or the like, which is not limited herein.

After the third insulating layer 309 is formed, a patterning process may be used to perforate the insulating layers, thereby forming vias that may connect underlying conductive layers. Meanwhile, an annular through groove exposing the conductive barrier layer 302 may be formed at an edge position.

Then, an entire metal layer is formed over the third insulating layer 309, and the other electrode of the capacitor and the power signal line 310 are patterned by patterning the metal layer.

The third insulating layer 309 is used as a dielectric layer between capacitors.

After the power signal lines are patterned, a passivation layer 311 is formed over the third insulating layer 309, and the passivation layer 311 is entirely disposed to insulate the lower conductive layer and protect the lower film layer.

The passivation layer 311 may be made of silicon oxide, silicon nitride, aluminum oxide, zirconium oxide, or the like, which is not limited herein.

In the embodiment of the present invention, the active layer, the gate electrode, the source electrode, and the drain electrode constitute a thin film transistor, the gate electrode of the thin film transistor is electrically connected to the gate line, the source electrode of the thin film transistor is electrically connected to the data line, and the drain electrode of the thin film transistor is electrically connected to the first electrode e1 through the via holes of the first insulating layer 301, the second insulating layer 303, the gate insulating layer 305, and the interlayer insulating layer 307.

One pole of the capacitor located above the third insulating layer 309 is electrically connected to the gate of the thin film transistor through the via holes of the interlayer insulating layer 307 and the third insulating layer 309;

the power signal line 310 is electrically connected to the conductive barrier layer 302 through a circular through groove of the second insulating layer 303, the gate insulating layer 305, the interlayer insulating layer 307, and the third insulating layer 309.

Thereby forming the driving wiring layer 30 and completing the connection between the wirings.

Further, after forming the driving line layer on the side of the first electrode facing away from the epitaxial layer in step S30, before peeling the substrate in step S40, the method further includes:

s30', the epitaxial layer formed with the driving line layer is transferred onto the transient substrate, and the driving line layer and the transient substrate are bonded.

Fig. 5 is a third schematic cross-sectional view of a display device according to an embodiment of the invention.

Referring to fig. 5, epitaxial layers 20 and drive line layers 30 are bonded to a transient substrate 101 with a bonding layer 102 on one side of drive line layers 30.

The bonding layer 102 may be made of a rubber material, or may be formed by bonding the driving circuit layer 30 and the transient substrate 101 in a manner that metal eutectics are mutually soluble, which is not limited herein.

The transient substrate 101 may be a glass substrate or a resin material substrate, and is not limited herein.

After transferring the epitaxial layer 20 and the driving circuit layer 30, in the step S40, after peeling the substrate, before etching the epitaxial layer according to the position of the first electrode, the method further includes:

s401, removing the substrate;

s402, removing the undoped layer and thinning the first doped layer.

With continued reference to fig. 5, after the epitaxial layer 20 is etched, the substrate on which the epitaxial layer 20 is formed needs to be removed, and specifically, the substrate 10 may be removed by Laser-lift-Off (LLO) or Chemical Mechanical Polishing (CMP).

After the substrate is removed, the undoped layer 201 is removed and the first doped layer 302 is thinned. Since the undoped layer 201 has poor conductivity, the undoped layer 201 needs to be removed, and the overall thickness of the epitaxial layer 20 affects the resistance of the device, and the first doped layer 202 needs to be thinned to reduce the resistance.

Specifically, the undoped layer 201 and the first doped layer 202 may be removed by CMP or Etching (Etching), and the like, and the method is not limited herein.

After the epitaxial layer 20 is subjected to the above-described processing, the epitaxial layer 20 may be etched.

Fig. 6 is a fourth schematic cross-sectional view of a display device according to an embodiment of the present invention.

Referring to fig. 6, when the epitaxial layer 20 is etched, in the embodiment of the present invention, the epitaxial layer 20 needs to be etched into a plurality of epitaxial layer units m according to a region where the first electrode e1 is located, one epitaxial layer unit m corresponds to one first electrode e1, and a region where the epitaxial layer unit m is located corresponds to one pixel region, in which a micro light emitting diode is to be formed. Referring to fig. 6, the orthographic projection of the epitaxial layer unit m on the transient substrate completely covers the orthographic projection of the first electrode e1 on the transient substrate.

In etching, all of the epitaxial layer 20 needs to be etched through until the conductive barrier layer 302 is exposed between epitaxial layer cells. The conductive barrier layer 302 may function as an etch stop so that the drive line layer 30 below the conductive barrier layer 302 is not damaged when the epitaxial layer 20 is exposed.

After the epitaxial layer 20 is etched, a second electrode is formed on the side of each epitaxial layer unit, which is away from the driving circuit layer.

Specifically, in step S50, forming a second electrode on a side of each epitaxial layer unit facing away from the driving line layer specifically includes:

s501, forming a fourth insulating layer on one side, away from the driving circuit layer, of the thinned first doping layer;

and S502, forming a second electrode on one side of the fourth insulating layer, which is far away from the driving line layer.

Fig. 7 is a fifth schematic cross-sectional view of a display device according to an embodiment of the invention.

Referring to fig. 7, after the epitaxial layer 20 is etched to form a plurality of epitaxial layer units m separated from each other, a fourth insulating layer 205 may be formed on a surface of each epitaxial layer unit m. Specifically, the fourth insulating layer 205 may be formed on the exposed conductive barrier layer 302 and the thinned surface of the first doping layer 202, and then the fourth insulating layer 205 is patterned, so as to form openings that expose the surface m of each epitaxial layer unit and expose the conductive barrier layer 302 on both sides of each epitaxial layer unit.

The fourth insulating layer 205 may be made of silicon oxide, silicon nitride, aluminum oxide, zirconium oxide, or the like, which is not limited herein.

The fourth insulating layer may cover sidewalls of the epitaxial layer unit to prevent a short circuit from occurring.

Fig. 8 is a sixth schematic cross-sectional view of a display device according to an embodiment of the present invention.

Referring to fig. 8, after the fourth insulating layer 205 is patterned, a second electrode e2 is formed over the fourth insulating layer 205. Specifically, the second electrode e2 may be entirely formed over the exposed conductive barrier layer 302, the fourth insulating layer 205, and the exposed first doping layer 202.

The second electrode e2 is an ohmic contact layer matching the work function of the first doped layer 202, and may be made of metal such as nickel or gold, or may be made of transparent conductive material such as Indium Tin Oxide (ITO), without being limited thereto.

As shown in fig. 8, an epitaxial layer unit m and its corresponding first electrode e1 and second electrode e2 form a Micro LED. In this case, a signal provided by the power signal line 310 may be applied to the conductive blocking layer 302, and a signal applied to the conductive blocking layer 302 may be applied to one side of the first doped layer 202 through the second electrode e2. A signal supplied from the data line may be rounded to the first electrode e1 through the drain electrode of the thin film transistor, thereby being applied to one side of the second doped layer 204 through the first electrode e1. Therefore, each Micro LED can be actively driven in a common electrode mode.

The display device manufactured by the manufacturing method provided by the embodiment of the invention is a common electrode structure, because the electric signal of the common electrode is loaded on the conductive barrier layer 302, the second electrode e2 (the ohmic contact layer in contact with the first doped layer) only has a small area on the side wall of the Micro LED to play a role of conducting the electric signal, so that the resistance value of the common electrode depends on the resistance value of the conductive barrier layer 302, and the correlation with the material resistance value of the second electrode e2 is small. The resistance of the conductive barrier layer 302 can be effectively reduced by selecting a conductive material with low resistance or increasing the thickness of the conductive barrier layer 302, so that the problem of obvious voltage drop of the common electrode can be effectively solved.

After the second electrode e2 is formed, the manufacturing method provided by the embodiment of the invention may further include the following steps:

s60, forming a light shielding layer at the interval position between the micro light-emitting diodes on the side, away from the driving circuit layer, of the second electrode;

s70, forming a flat layer on the shading layer and one side of each micro light-emitting diode, which is far away from the driving circuit layer;

s80, forming a protective layer on one side of the flat layer, which is far away from the micro light-emitting diode;

and S90, stripping the transient substrate.

Fig. 9 is a seventh cross-sectional structural schematic diagram of a display device according to an embodiment of the present invention.

Referring to fig. 9, in order to avoid crosstalk between pixel units, after the second electrode e2 is formed, a light-shielding layer 401 may be formed at an interval between the micro light-emitting diodes at a side of the second electrode e2 facing away from the driving line layer 30.

The light-shielding layer 401 may be made of a black resin material, and the light-shielding layer 401 has a grid pattern that shields the spaced positions between the micro light-emitting diodes.

After the light-shielding layer 401 is formed, a planarization layer 402 may be further covered over the micro light-emitting diode and the light-shielding layer 401. The planarization layer 402 can be formed by a full-thickness overlay process, and the planarization layer 402 has a larger thickness to planarize the device surface. In an implementation, the planarization layer 402 may be made of a material, such as a glue, or an organic material, and is not limited herein.

After the formation of the planarization layer 402, a protective layer 403 may also be formed over the planarization layer 402. The flat layer 403 may be formed by covering the entire layer, and the protective layer 403 may play a role in protecting the micro light emitting diode device. In a specific implementation, the protective layer 403 may be formed by stacking an inorganic layer and an organic layer, which is not limited herein.

Fig. 10 is an eighth schematic cross-sectional view of a display device according to an embodiment of the present invention.

Referring to fig. 10, after the protective layer 403 is formed, the transient substrate 101 and the bonding layer 102 may be peeled off to expose the driving line layer 30 in preparation for the subsequent bonding work.

It should be noted that, in the manufacturing process, the transient substrate 101 may not be removed, and according to practical applications, if the transient substrate 101 is applied to a rigid display device, the transient substrate 101 may be made of a rigid material such as glass; if the present invention is applied to a flexible display device, the transient substrate 101 may be made of a flexible material such as Polyimide (PI), which is not limited herein.

The display device provided by the embodiment of the present invention may also be manufactured as a transparent display device, and in this case, the conductive barrier layer 302, the transient substrate 101, and the bonding layer 102 may be manufactured by using transparent materials. Meanwhile, the driving unit can be manufactured under the Micro LED, and the light shielding layer 401 is omitted, so that transparent display is achieved.

After the above manufacturing steps, a display unit structure as shown in fig. 10 may be formed, and the display unit may include only one Micro LED, or include a plurality of Micro LEDs to form a display unit, or a sufficient number of Micro LEDs may be directly formed to form a display device.

Fig. 11a is a schematic structural diagram of a display device according to an embodiment of the present invention.

Referring to fig. 11a, when the epitaxial layer 20 is etched to form a sufficient number of Micro LEDs, the driving chip ic may be directly bonded to one side of the driving circuit layer 30, and then the package layer 50 is formed on the surfaces of the driving circuit layer 30 and the driving chip ic, thereby forming the Micro LED display device.

Binding a driving chip ic at one side of the driving circuit layer 30, and punching the driving circuit layer 30, so that the driving chip ic is connected with a circuit in the driving circuit layer 30, the driving chip ic provides a driving signal for the display device, and the Micro LED is driven by adopting an active driving mode to perform image display.

The encapsulation layer 50 can encapsulate and protect the driving circuit layer by stacking an inorganic layer and an organic layer.

Fig. 11b is a second schematic structural diagram of a display device according to an embodiment of the present invention.

Referring to fig. 11b, when the display device needs to be enlarged in size, a plurality of Micro LED display devices as shown in fig. 11a may be tiled to form a tiled display device, so as to realize an oversized image display.

As shown in fig. 11b, for each display panel in the tiled display device, a driving chip ic may be bound to one side of the driving circuit layer 30, and after each display panel is packaged, the display panel is integrated on the integrated backplane 60, so as to form the tiled display device.

Referring to fig. 11c, after the display unit shown in fig. 10 is formed, if the display unit only includes one or several Micro LEDs, a plurality of display units may be integrated on the driving backplane 70, each display unit is connected to a circuit of the driving backplane 70 by using a circuit connection method, and then each display unit is controlled to display an image by binding a driving chip on the driving backplane 70.

On the other hand, the embodiment of the invention also provides a display device manufactured by the manufacturing method. The structure of the display device can be seen in fig. 10.

As shown in fig. 10, the display device includes: a driving circuit layer 30 and a micro light emitting diode 200 on the driving circuit layer 30.

The driving circuit layer 30, the driving circuit layer 30 includes a conductive barrier layer 302 and a driving unit disposed in a whole layer.

The driving unit in the driving circuit layer 30 includes thin film transistors, capacitors, resistors, and the like.

The surface of the driving line seed layer 30 has a mesh pattern exposing the conductive barrier layer, and the exposed conductive barrier layer 302 partitions a pixel region.

At least one micro light emitting diode 200 is located in the pixel region of the driving circuit layer 30 on the side where the conductive barrier layer 302 is exposed.

In the embodiment of the invention, one pixel region corresponds to one micro light emitting diode 200, and the micro light emitting diodes 200 correspond to the driving units one by one. The micro light emitting diode 200 realizes active driving under the control of its corresponding driving unit.

Among them, the micro light emitting diode 200 includes: a first electrode e1, an epitaxial layer unit m and a second electrode e2.

The first electrode e1 is positioned on one side of the micro light-emitting diode 200 close to the driving circuit layer 30, and the orthographic projection of the micro light-emitting diode 200 on the driving circuit layer 30 covers the first electrode e1; the first electrode e1 is electrically connected to the corresponding driving unit through the via hole of the driving line layer 30.

The epitaxial layer unit m is obtained by etching the whole epitaxial layer 20, and one epitaxial layer unit m corresponds to one first electrode e1.

The second electrode e2 is positioned on one side of the micro light-emitting diodes 200 departing from the driving circuit layer 30, and the second electrode e2 of each micro light-emitting diode 200 is arranged in a whole layer; the second electrode e2 is electrically connected to the exposed conductive barrier layer 302.

The micro light emitting diode 200 emits light under the action of an electric field generated by loading an electric signal on the first electrode e1 and the second electrode e2, and the display device provided by the embodiment of the invention is formed by forming the epitaxial layer 20, forming the driving circuit layer 30 on the epitaxial layer 20, and etching the epitaxial layer 20 to form a plurality of micro light emitting diodes 200. Therefore, the driving circuit and the micro light emitting diode in the display panel are formed under a set of manufacturing process, and the driving circuit and the micro light emitting diode do not need to be assembled, so that the production yield and the production efficiency can be improved.

The first electrode e1 of the micro light emitting diode 200 is electrically connected to the corresponding driving unit, and the second electrode e2 is electrically connected to the conductive barrier layer 302 in a common electrode manner, so that each micro light emitting diode can load different image signals on the first electrode e1 through the corresponding driving unit to implement image display.

The conductive barrier layer 302 is located on one side of the driving circuit layer close to the micro light emitting diode 200, and the driving unit is located on one side of the conductive barrier layer 302 away from the micro light emitting diode 200. The conductive barrier layer 302 includes a plurality of openings during fabrication, and the driving unit may be electrically connected to the first electrode e1 of the corresponding micro light emitting diode through the openings of the conductive barrier layer 302.

Since the epitaxial layer 20 needs to be etched after the driving circuit layer 30 is formed, the conductive barrier layer 302 can block the etching action, thereby preventing the driving unit from being damaged by the etching step.

In a specific implementation, the material used for the conductive barrier layer 302 is a metal or a transparent conductive material. For example, the transparent conductive film may be made of a metal material such as platinum, titanium, or nickel, or may be made of a transparent conductive material such as crystallized indium tin oxide (POLY ITO) or Indium Zinc Oxide (IZO) when applied to a transparent display device, which is not limited herein.

Meanwhile, in order to reduce the resistance of the conductive barrier layer 302, the thickness of the conductive barrier layer 302 may be increased, and in an embodiment of the present invention, the thickness of the conductive barrier layer 302 may be set to be 20nm to 1000nm.

The driving unit is located below the conductive barrier layer 302, and the driving circuit layer further includes a plurality of gate lines and a plurality of data lines, the gate lines and the data lines are arranged to cross each other, and the gate lines and the data lines define a plurality of pixel units. In general, the driving unit includes a thin film transistor, a gate of the thin film transistor is electrically connected to a corresponding gate line, a source of the thin film transistor is electrically connected to a corresponding signal line, and a drain of the thin film transistor is electrically connected to the first electrode e1 of the corresponding Micro LED. When the gate line is scanned line by line and an effective level signal is loaded on the gate line, each data line corresponding to the gate line can load a data signal to each Micro LED corresponding to the gate line, so that the Micro LEDs are actively driven.

The driving line layer may further include power signal lines disposed to surround all the driving cells, and a circular through groove exposing the conductive barrier layer 302 may be formed at an edge position before the power signal lines are electrically formed, so that an electrical connection relationship between the power signal lines and the conductive barrier layer 302 may be formed when the power signal lines are formed, and the power signal lines may be disposed around the edge of the display device by one turn, or a voltage drop problem may be improved when the power signal is applied to the conductive barrier layer 302.

As shown in fig. 10, the display device further includes:

and the shading layer 401 is positioned at the interval position between the micro light-emitting diodes 200 on the side of the second electrode e2 away from the driving circuit layer 30.

The light shielding layer can prevent the light leakage problem of the Micro LED and realize higher contrast ratio during image display. In the transparent display device, the light-shielding layer 401 may be omitted.

And the flat layer 402 covers the light shielding layer 401 and one side of each micro light-emitting diode 200, which is far away from the driving circuit layer 30.

The planarization layer 402 typically has a large thickness for planarizing the surface of the display device while also having the function of protecting the Micro LEDs.

And the protective layer 403 is positioned on the side of the flat layer 402 facing away from the micro light-emitting diode 200.

The protective layer 403 is used for protecting the Micro LED, and may be formed by alternately stacking inorganic layers and organic layers, and the innermost and outermost film layers are inorganic layers, so as to block water and oxygen and prolong the service life of the Micro LED.

A driver chip or a driver backplane may be bound to the driver circuit layer 30 for different applications.

In some embodiments, as shown in fig. 11a, the display device further comprises:

and the driving chip ic is positioned on one side of the driving circuit layer 30, which is far away from the micro light-emitting diode 200, and the driving chip ic is electrically connected with the circuit in the driving circuit layer through the through hole of the driving circuit layer 30.

And the packaging layer 50 covers the surfaces of the driving chip ic and the driving circuit layer 300.

Therefore, the Micro LED display device is formed, under the condition, the epitaxial layer can be etched to form a sufficient number of Micro LEDs, and then an image display is realized by matching with a color film, an optical filter or a quantum dot film.

In some embodiments, as shown in fig. 11b, the display device further comprises:

and the driving chip ic is located on one side of the driving circuit layer 30, which is away from the micro light emitting diode 200, and the driving chip ic is electrically connected with the circuit in the driving circuit layer through the through hole of the driving circuit layer 30.

And an encapsulation layer 50 covering the surfaces of the driving chip ic and the driving circuit layer 30.

The driving circuit layer 30, the micro light emitting diodes 200 electrically connected to the driving circuit layer 30, and the driving chip ic electrically connected to the driving circuit layer 30 form a display panel unit, and at least two display panel units are disposed on the integrated backplane 60 to form a tiled display device.

In some embodiments, as shown in fig. 11c, the driving circuit layer 30 and each micro light emitting diode 200 electrically connected to the driving circuit layer 30 constitute a display unit; at least two display units are located on the driving backplane 70, and each display unit is electrically connected with the driving backplane. The display unit is an active display unit, so that active driving display can be realized after a plurality of display units and the driving backboard are integrated.

According to a first inventive concept, by forming an epitaxial layer on a substrate; forming a first electrode on one side of the epitaxial layer, which is far away from the substrate; forming a driving circuit layer on one side of the first electrode, which is far away from the epitaxial layer; stripping the substrate, and etching the epitaxial layer according to the position of the first electrode to form a plurality of epitaxial layer units; and forming a second electrode on one side of the epitaxial layer unit, which is far away from the driving circuit layer. Therefore, the Micro LED display unit capable of being actively driven can be directly formed, the step that the Micro LED is required to be massively transferred to be paired when the driving substrate and the Micro LED are respectively manufactured is avoided, and the production yield and the production efficiency of the display device are improved.

According to the second inventive concept, forming the epitaxial layer on the substrate includes sequentially forming an undoped layer, a first doped layer, a light emitting layer, and a second doped layer on the substrate. One of the first doping layer and the second doping layer is an N-type doping layer, the other one of the first doping layer and the second doping layer is a P-type doping layer, and the light emitting layer is a multi-quantum well layer.

According to the third inventive concept, after the epitaxial layer is formed, before the driving seed layer is formed, the method further includes: and forming a first electrode pattern on one side of the second doping layer, which is far away from the light-emitting layer. The first electrode is an ohmic contact layer matched with the work function of the second doped layer.

According to the fourth inventive concept, the reflecting layer is formed on the first electrode, so that the reflecting layer is applied to a top-emitting Micro LED display device, and the reflecting layer is used for reflecting light emitted by the Micro LED to the light emitting side finally, so that the purpose of improving the light efficiency is achieved.

According to a fifth inventive concept, the fabricating the driving line layer includes: the structure comprises a first insulating layer, a conductive blocking layer, a second insulating layer, an active layer, a grid insulating layer, a grid metal layer, an interlayer insulating layer, a source drain metal layer, a third insulating layer, a capacitor electrode, a power signal line pattern and a passivation layer which are sequentially manufactured. The grid metal layer comprises a grid line, a grid and a pattern of one electrode of a capacitor; the source drain metal layer comprises a data line, a source electrode and a drain electrode; the active layer, the gate electrode, the source electrode and the drain electrode constitute a thin film transistor. The conductive barrier layer includes an opening exposing the first electrode, a gate electrode of the thin film transistor is electrically connected to the gate line, a source electrode is electrically connected to the data line, and a drain electrode is electrically connected to the first electrode through the opening of the conductive barrier layer. The Micro LED may thus be actively driven by a driving unit including a thin film transistor.

According to the sixth inventive concept, the power signal line is electrically connected to the conductive barrier layer through the annular through groove of the edge, whereby the problem of voltage drop can be improved.

According to the seventh inventive concept, after the drive wiring layer is formed, the epitaxial layer on which the drive wiring layer is formed is transferred onto the temporary substrate and the drive wiring layer is bonded to the temporary substrate before the substrate is peeled.

According to the eighth inventive concept, the substrate and the undoped layer are removed and the first doped layer is thinned before the epitaxial layer is etched. The undoped layer is required to be removed because of its poor conductivity, and the entire thickness of the epitaxial layer affects the resistance of the device, and the first doped layer needs to be thinned in order to reduce the resistance.

According to the ninth inventive concept, etching the epitaxial layers requires etching all epitaxial layers through until the conductive barrier layer is exposed between the epitaxial layer units. The conductive barrier layer can play a role in etching blocking, so that the driving circuit layer below the conductive barrier layer can not be damaged when the epitaxial layer is subjected to etching.

According to the tenth inventive concept, forming the second electrode on the surface of the epitaxial-layer unit includes: and forming a fourth insulating layer on one side of the thinned first doping layer, which is far away from the driving circuit layer, and forming a second electrode on one side of the fourth insulating layer, which is far away from the driving circuit layer. The fourth insulating layer can cover the side wall of the epitaxial layer unit to prevent short circuit. The second electrode is an ohmic contact layer matched with the work function of the first doped layer, a signal provided by the power signal line can be loaded to the conductive barrier layer, and the signal loaded by the conductive barrier layer can be loaded to one side of the first doped layer through the second electrode.

According to the eleventh inventive concept, the second electrode of the Micro LED is electrically connected to the conductive barrier layer to form a common electrode structure, and since an electrical signal of the common electrode is loaded on the conductive barrier layer, only a small portion of the second electrode on the sidewall of the Micro LED plays a role in conducting the electrical signal, the resistance value of the common electrode depends on the resistance value of the conductive barrier layer, and has a small correlation with the material resistance value of the second electrode. The resistance of the conductive barrier layer can be effectively reduced by selecting a low-resistance conductive material to manufacture the conductive barrier layer or increasing the thickness of the conductive barrier layer, so that the problem of obvious voltage drop of the common electrode can be effectively solved.

According to the twelfth inventive concept, the conductive barrier layer is made of a metal material such as platinum, titanium, nickel, or the like, and when the conductive barrier layer is applied to a transparent display device, the conductive barrier layer may be made of a transparent conductive material such as crystallized indium tin oxide (POLY ITO) or Indium Zinc Oxide (IZO). The thickness of the conductive barrier layer is 20nm-1000nm.

According to the thirteenth inventive concept, after the forming of the Micro LED, further comprising: a light shielding layer is formed between the Micro LEDs, a flat layer is formed on one side, away from the driving line layer, of the light shielding layer and the Micro LEDs, and a protective layer is formed on one side, away from the Micro LEDs, of the flat layer.

According to the fourteenth inventive concept, the transient substrate is peeled off to bind the driving chip with the driving line layer.

According to the fifteenth inventive concept, when enough Micro LEDs are formed by etching the epitaxial layer, the driving chip can be directly bonded to one side of the driving circuit layer, and then the packaging layer is formed on the surfaces of the driving circuit layer and the driving chip, thereby forming the Micro LED display device.

According to the sixteenth inventive concept, when the display device needs to be enlarged in size, a plurality of Micro LED display devices can be tiled to form a tiled display device, so as to realize the display of an oversized image.

According to the seventeenth inventive concept, after the Micro LED display units are formed, if the display units only include one or several Micro LEDs, a plurality of display units may be integrated on the driving backplane, each display unit is connected with a circuit of the driving backplane by a circuit connection method, and then each display unit is controlled to display an image by binding a driving chip on the driving backplane.

According to the eighteenth inventive concept, the transient substrate may not be removed during the manufacturing process, and according to the practical application, if the transient substrate is applied to a rigid display device, the transient substrate may be made of a rigid material such as glass; if the transient substrate is applied to a flexible display device, the transient substrate may be made of a flexible material such as Polyimide (PI).

According to the nineteenth inventive concept, the display device may also be fabricated as a transparent display device, and in this case, the conductive barrier layer, the transient substrate, and the bonding layer may be fabricated by using transparent materials. Meanwhile, the driving unit can be manufactured under the Micro LED, and a shading layer is omitted, so that transparent display is realized.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A display device, comprising:

the driving circuit layer comprises a conductive barrier layer and a driving unit which are arranged in a whole layer, the surface of the driving circuit layer is provided with a grid pattern exposing the conductive barrier layer, and the exposed conductive barrier layer divides a pixel area;

at least one micro light emitting diode positioned in the pixel region on one side of the driving circuit layer, which is exposed out of the conductive barrier layer; the micro light-emitting diodes correspond to the driving units one by one;

the micro light emitting diode includes:

the first electrode is positioned on one side, close to the driving circuit layer, of the micro light-emitting diode, and the orthographic projection of the micro light-emitting diode on the driving circuit layer covers the first electrode; the first electrode is electrically connected with the corresponding driving unit through the via hole of the driving line layer;

the second electrode is positioned on one side of the micro light-emitting diodes, which is far away from the driving circuit layer, and the second electrode of each micro light-emitting diode is arranged in a whole layer; the second electrode is electrically connected with the exposed conductive barrier layer.

2. The display device according to claim 1, wherein the conductive barrier layer is located at the side close to the micro light emitting diode, and the driving unit is located at the side of the conductive barrier layer away from the micro light emitting diode;

the conductive barrier layer comprises a plurality of openings, and the driving unit is electrically connected with the corresponding micro light-emitting diode through the openings of the conductive barrier layer.

3. The display device of claim 1, further comprising:

the shading layer is positioned at the interval position between the micro light-emitting diodes on one side, away from the driving circuit layer, of the second electrode;

the flat layer covers the shading layer and one side of each micro light-emitting diode, which is far away from the driving circuit layer;

and the protective layer is positioned on one side of the flat layer, which is deviated from the micro light-emitting diode.

4. The display device according to claim 1, wherein the driving line layer further comprises:

a power supply signal line provided around each of the driving units; the power signal line is electrically connected with the conductive barrier layer through the annular through groove of the driving circuit layer.

5. The display device according to any one of claims 1 to 4, wherein the display device further comprises:

the driving chip is positioned on one side, away from the micro light-emitting diode, of the driving circuit layer and is electrically connected with the circuit in the driving circuit layer through the through hole in the driving circuit layer;

the packaging layer covers the surfaces of the driving chip and the driving circuit layer;

alternatively, the display device further includes:

the driving circuit layer, the micro light-emitting diodes electrically connected with the driving circuit layer and the driving chip electrically connected with the driving circuit layer form a display panel unit;

the display device further includes:

the integrated back plate is provided with at least two display panel units to form a spliced display device;

or the driving circuit layer and each micro light-emitting diode electrically connected with the driving circuit layer form a display unit; the display device further includes:

the display device comprises a driving back plate, at least two display units are positioned on the driving back plate, and each display unit is electrically connected with the driving back plate.

6. A method for manufacturing a display device, comprising:

forming an epitaxial layer on a substrate;

forming a first electrode on one side of the epitaxial layer, which is far away from the substrate; the first electrodes are provided with mutually discrete patterns, and the first electrodes and the corresponding epitaxial layers form a light-emitting unit;

forming a driving circuit layer on one side of the first electrode, which is far away from the epitaxial layer; the driving circuit layer comprises a conductive barrier layer and a driving unit which are arranged in a whole layer;

peeling off the substrate, and etching the epitaxial layer according to the position of the first electrode to form a plurality of epitaxial layer units and exposed conductive barrier layers positioned on two sides of the epitaxial layer units; the epitaxial layer units correspond to the driving units one by one, and the first electrodes corresponding to the epitaxial layer units are electrically connected with the corresponding driving units through the via holes of the driving circuit layer;

forming a second electrode on one side of each epitaxial layer unit, which is far away from the driving circuit layer; the second electrode is arranged in a whole layer mode and is electrically connected with the exposed conductive barrier layer;

the epitaxial layer unit, the first electrode corresponding to the epitaxial layer unit and the second electrode corresponding to the epitaxial layer unit form a micro light emitting diode.

7. The method of claim 6, wherein forming an epitaxial layer on a substrate comprises:

forming an undoped layer on the substrate;

forming a first doped layer on one side of the undoped layer, which is far away from the substrate;

forming a light emitting layer on one side of the first doped layer, which is far away from the undoped layer;

and forming a second doped layer on one side of the light emitting layer, which is far away from the first doped layer.

8. The method of manufacturing of claim 7, wherein said forming a first electrode on a side of said epitaxial layer facing away from said substrate comprises:

forming a first electrode layer on one side of the second doping layer, which is far away from the light emitting layer;

patterning the first electrode layer to form a pattern of the first electrode;

forming a reflecting layer on one side of the first electrode, which is far away from the second doped layer;

the forming of the driving circuit layer on the side of the first electrode, which is far away from the epitaxial layer, includes:

forming a first insulating layer on one side of the reflecting layer, which is far away from the first electrode;

forming a conductive barrier layer on one side of the first insulating layer, which is far away from the second doping layer; the conductive barrier layer includes an opening exposing the first electrode;

forming a second insulating layer on one side of the conductive barrier layer, which is far away from the second doping layer;

forming an active layer on one side, away from the conductive barrier layer, of the second insulating layer;

forming a gate insulating layer on one side of the active layer, which is far away from the second insulating layer;

forming a gate metal layer on one side of the gate insulating layer, which is far away from the active layer; the grid metal layer comprises a grid and a pattern of one electrode of the capacitor;

forming an interlayer insulating layer on one side of the grid metal layer, which is far away from the grid insulating layer;

forming a source drain metal layer on one side of the interlayer insulating layer, which is far away from the grid metal layer; the source drain metal layer comprises a source electrode pattern and a drain electrode pattern;

forming a third insulating layer on one side of the source drain metal layer, which is deviated from the interlayer insulating layer;

forming a pattern of the other electrode of the capacitor and a pattern of the power signal line on one side, away from the source-drain metal layer, of the third insulating layer;

wherein the active layer, the gate electrode, the source electrode and the drain electrode constitute a thin film transistor, and the drain electrode of the thin film transistor is electrically connected to the first electrode through the via holes of the first insulating layer, the second insulating layer, the gate insulating layer and the interlayer insulating layer; the power signal line is electrically connected to the conductive barrier layer through the annular through-groove of the second insulating layer, the gate insulating layer, the interlayer insulating layer, and the third insulating layer.

9. The method of manufacturing according to claim 8, wherein after forming the drive wiring layer on the side of the first electrode facing away from the epitaxial layer, before peeling the substrate, further comprising:

transferring the epitaxial layer formed with the driving line layer onto a transient substrate, and bonding the driving line layer and the transient substrate;

after the substrate is stripped, before the epitaxial layer is etched according to the position of the first electrode, the method further includes:

removing the substrate;

and removing the undoped layer and thinning the first doped layer.

10. The method of claim 9, wherein the forming a second electrode on a side of each epitaxial layer unit facing away from the driving line layer comprises:

forming a fourth insulating layer on one side of the thinned first doping layer, which is far away from the driving circuit layer; the fourth insulating layer is arranged in a whole layer and is provided with an opening which exposes the surface of each epitaxial layer unit and exposes the conductive barrier layers on two sides of each epitaxial layer unit;

forming a second electrode on one side of the fourth insulating layer, which is far away from the driving line layer;

the manufacturing method further comprises the following steps:

forming a light shielding layer at the interval position between the micro light-emitting diodes on the side, away from the driving circuit layer, of the second electrode;

forming a flat layer on the shading layer and one side of each micro light-emitting diode, which is far away from the driving circuit layer;

forming a protective layer on one side of the flat layer, which is far away from the micro light-emitting diode;

and peeling off the transient substrate.