A display device and a manufacturing method thereof

Abstract

The present invention discloses a display device and a manufacturing method thereof, wherein an epitaxial layer is formed on a substrate; a first electrode is formed on the side of the epitaxial layer away from the substrate; a driving circuit layer is formed on the side of the first electrode away from the epitaxial layer; the substrate is peeled off, and the epitaxial layer is etched according to the position of the first electrode to form a plurality of epitaxial layer units; and a second electrode is formed on the side of the epitaxial layer unit away from the driving circuit layer. Thus, a Micro LED display unit that can be actively driven can be directly formed, avoiding the need to transfer and assemble the Micro LEDs in large quantities when separately manufacturing the driving substrate and the Micro LEDs, thereby improving the production yield and production efficiency of the display device.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a display device and a manufacturing method thereof. Background Art

[0002] Micro LED (Micro Light Emitting Diode) display technology refers to a display technology that uses light-emitting chips as direct light-emitting units. Micro LEDs inherit the high efficiency, high brightness, high reliability, and fast response time of traditional LEDs. They also feature self-luminescence, eliminating the need for a backlight. They offer advantages such as energy efficiency, simplified structure, small size, and thinness.

[0003] The driving modes of micro-LED panels can be divided into active and passive modes. The active driving mode has the advantages of low power consumption, anti-crosstalk, and low driving cost.

[0004] The current active drive method requires the driver substrate and Micro LEDs to be manufactured separately, and then assembled together through mass transfer. However, the current mass transfer process is relatively complex and has low production yields, leaving room for improvement in production efficiency. Summary of the Invention

[0005] In some embodiments of the present invention, an epitaxial layer is formed on a substrate; a first electrode is formed on the side of the epitaxial layer facing away from the substrate; a drive circuit layer is formed on the side of the first electrode facing away from the epitaxial layer; the substrate is peeled off, and the epitaxial layer is etched according to the location of the first electrode to form multiple epitaxial layer units; and a second electrode is formed on the side of the epitaxial layer unit facing away from the drive circuit layer. This allows the direct formation of actively driven Micro LED display units, avoiding the need for mass transfer and assembly of Micro LEDs required when separately manufacturing the drive substrate and Micro LEDs, thereby improving the production yield and efficiency of the display device.

[0006] In some embodiments of the present invention, forming an epitaxial layer on a 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 doped layer and the second doped layer is an N-type doped layer and the other is a P-type doped layer, and the light-emitting layer is a multi-quantum well layer.

[0007] In some embodiments of the present invention, after forming the epitaxial layer and before forming the driving circuit layer, the method further includes forming a first electrode pattern on a side of the second doped layer facing away from the light-emitting layer. The first electrode is an ohmic contact layer having a work function matching that of the second doped layer.

[0008] In some embodiments of the present invention, a reflective layer is formed on the first electrode, so as to be applied to a top-emitting MicroLED display device. The reflective layer is used to reflect the light emitted by the MicroLED toward the light-emitting side, thereby achieving the purpose of improving light efficiency.

[0009] In some embodiments of the present invention, the manufacturing of the driving circuit layer includes: a first insulating layer, a conductive barrier layer, a second insulating layer, an active layer, a gate insulating layer, a gate metal layer, an interlayer insulating layer, a source-drain metal layer, a third insulating layer, a pattern of capacitor electrodes and power signal lines, and a passivation layer, which are manufactured in sequence. Among them, the gate metal layer includes a pattern of a gate line, a gate, and one of the electrodes of the capacitor; the source-drain metal layer includes a pattern of a data line, a source electrode, and a drain electrode; the active layer, the gate, the source electrode, and the drain electrode constitute a thin film transistor. The conductive barrier layer includes an opening exposing the first electrode. The gate of the thin film transistor is electrically connected to the gate line, the source electrode is electrically connected to the data line, and the drain electrode is electrically connected to the first electrode through the opening of the conductive barrier layer. In this way, the Micro LED can be actively driven by a driving unit including a thin film transistor.

[0010] 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 voltage drop problem.

[0011] In some embodiments of the present invention, after forming the driving circuit layer and before stripping the substrate, the epitaxial layer formed with the driving circuit layer is transferred to a temporary substrate, and the driving circuit layer is bonded to the temporary substrate.

[0012] In some embodiments of the present invention, before etching the epitaxial layer, the substrate and undoped layer are removed, and the first doped layer is thinned. The undoped layer has poor conductivity, so it is necessary to remove the undoped layer. The overall thickness of the epitaxial layer affects the resistance of the device, so to reduce this resistance, the first doped layer needs to be thinned.

[0013] In some embodiments of the present invention, etching the epitaxial layer requires etching through the entire epitaxial layer until the conductive barrier layer is exposed between the epitaxial layer units. The conductive barrier layer can act as an etch stop, thus preventing damage to the drive circuit layer below the conductive barrier layer during etching of the epitaxial layer.

[0014] In some embodiments of the present invention, forming a second electrode on the surface of the epitaxial layer unit includes: forming a fourth insulating layer on a side of the thinned first doped layer facing away from the drive circuit layer, and forming the second electrode on a side of the fourth insulating layer facing away from the drive circuit layer. The fourth insulating layer can cover the sidewalls of the epitaxial layer unit to prevent short circuits. The second electrode is an ohmic contact layer that matches the work function of the first doped layer. Signals provided by the power signal line can be applied to the conductive barrier layer, and the signals applied to the conductive barrier layer can be applied to one side of the first doped layer via the second electrode.

[0015] In some embodiments of the present invention, the Micro LED second electrode is electrically connected to a conductive barrier layer to form a common electrode structure. Because the common electrode's electrical signal is applied to the conductive barrier layer, only a small portion of the second electrode located on the Micro LED sidewall functions to conduct the electrical signal. Therefore, the common electrode's resistance depends on the resistance of the conductive barrier layer and has little correlation with the material resistance of the second electrode. Therefore, selecting a low-impedance conductive material for the conductive barrier layer or increasing its thickness can effectively reduce its resistance, thereby effectively solving the problem of significant common electrode voltage drop.

[0016] In some embodiments of the present invention, the conductive barrier layer is made of metal material or transparent conductive material.

[0017] In some embodiments of the present invention, the thickness of the conductive barrier layer is 20 nm-1000 nm.

[0018] In some embodiments of the present invention, after forming the Micro LED, the further step includes: forming a light shielding layer between the Micro LEDs, forming a planarizing layer on the side of the light shielding layer and the Micro LED facing away from the driving circuit layer, and forming a protective layer on the side of the planarizing layer facing away from the Micro LED.

[0019] In some embodiments of the present invention, the temporary substrate is peeled off and the driving chip and the driving circuit layer are bonded together.

[0020] In some embodiments of the present invention, when the epitaxial layer is etched to form a sufficient number of Micro LEDs, a driver chip can be directly bonded to one side of the driver circuit layer, and then an encapsulation layer can be formed on the surface of the driver circuit layer and the driver chip to form a Micro LED display device.

[0021] In some embodiments of the present invention, when the size of a display device needs to be enlarged, multiple Micro LED display devices can be spliced ​​together to form a spliced ​​display device to achieve ultra-large image display.

[0022] In some embodiments of the present invention, after forming a Micro LED display unit, if the display unit only includes one or several Micro LEDs, then multiple display units can be integrated onto a driver backplane, and each display unit can be connected to the circuit of the driver backplane using a circuit connection method. Then, by binding a driver chip to the driver backplane, each display unit can be controlled to display an image. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings introduced below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 A flowchart of a method for manufacturing a display device provided by an embodiment of the present invention;

[0025] Figure 2a-2d for Figure 1 Schematic diagram of the cross-sectional structure of the display device corresponding to each step;

[0026] Figure 3 This is a schematic diagram of a cross-sectional structure of a display device provided by an embodiment of the present invention;

[0027] Figure 4 A second schematic cross-sectional structural diagram of a display device provided in an embodiment of the present invention;

[0028] Figure 5 The third schematic diagram of the cross-sectional structure of the display device provided by the embodiment of the present invention;

[0029] Figure 6 A fourth schematic cross-sectional structural diagram of a display device provided in an embodiment of the present invention;

[0030] Figure 7 A fifth schematic diagram of the cross-sectional structure of a display device provided in an embodiment of the present invention;

[0031] Figure 8 A sixth schematic diagram of the cross-sectional structure of a display device provided in an embodiment of the present invention;

[0032] Figure 9 The seventh schematic diagram of the cross-sectional structure of the display device provided by the embodiment of the present invention;

[0033] Figure 10 The eighth schematic diagram of the cross-sectional structure of the display device provided by the embodiment of the present invention;

[0034] Figure 11aThis is a schematic diagram of the structure of a display device provided by an embodiment of the present invention;

[0035] Figure 11b A second structural diagram of a display device provided in an embodiment of the present invention;

[0036] Figure 11c This is a third structural diagram of the display device provided in an embodiment of the present invention.

[0037] Among them, 10-substrate, 20-epitaxial layer, 30-driving circuit layer, 40-encapsulation protection layer, 50-encapsulation 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, 3 04-active layer, 305-gate insulating layer, 306-gate metal layer, 307-interlayer insulating layer, 308-source and drain metal layer, 309-third insulating layer, 310-power signal line, 311-passivation layer, e1-first electrode, e2-second electrode, 101-transient substrate, 102-bonding layer, m-epitaxial layer unit, 401-light shielding layer, 402-flat layer, 403-protective layer, ic-driver chip. DETAILED DESCRIPTION

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention will be further described below with reference to the accompanying drawings and examples. However, the example embodiments can be implemented in various forms and should not be understood as being limited to the embodiments described herein; on the contrary, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concepts of the example embodiments to those skilled in the art. The same figure marks in the figures represent the same or similar structures, and their repeated descriptions will be omitted. The words expressing position and direction described in the present invention are all explained with reference to the accompanying drawings as examples, but changes can be made as needed, and the changes made are all included in the scope of protection of the present invention. The drawings of the present invention are only used to illustrate the relative position relationship and do not represent the true proportion.

[0039] Light-emitting diodes (LEDs) offer advantages such as low power consumption, long life, and zero pollution. The core structure of an LED is a PN junction, which exhibits properties such as forward conduction and reflection cutoff. When a forward bias is applied to the PN junction, electrons in the n-type region and holes in the p-type region move under the influence of an applied electric field. The energy generated by interband recombination between the electrons and holes is released as photons, generating light. However, the luminous efficiency of LEDs with this homogeneous structure is low, so multi-heterojunction structures are often used to improve luminous efficiency.

[0040] When an LED device with a multi-quantum well structure is forward deflected, electrons and holes move to the multi-quantum well layer under the action of an external electric field, increasing the overlap rate of electron and hole wave functions and improving its composite luminescence efficiency.

[0041] Micro LEDs inherit the high efficiency, high brightness, high reliability, and fast response time of LEDs. Furthermore, they are self-luminous and require no backlight, offering advantages such as energy saving, simplified structure, small size, and thinness. Current Micro LED display devices typically require separate manufacturing of the driver substrate and Micro LEDs. Mass transfer technology is then used to transfer the Micro LEDs to the driver substrate for assembly, resulting in low production yields and potential for improved efficiency.

[0042] Embodiments of the present invention provide a display device and a manufacturing method thereof, which can combine an active driving circuit with a MicroLED, thereby realizing active driving display of the MicroLED without assembling the MicroLED with a driving substrate.

[0043] First, an embodiment of the present invention provides a method for manufacturing a display device. Figure 1 This is a flow chart of a method for manufacturing a display device provided by an embodiment of the present invention.

[0044] Reference Figure 1 , a method for manufacturing a display device provided by an embodiment of the present invention includes:

[0045] S10, forming an epitaxial layer on the substrate;

[0046] S20, forming a first electrode on a side of the epitaxial layer facing away from the substrate; the first electrode has separate patterns, and the first electrode and the corresponding epitaxial layer constitute a light-emitting unit;

[0047] S30, forming a driving circuit layer on a side of the first electrode facing away from the epitaxial layer; the driving circuit layer includes a conductive barrier layer and a driving unit arranged in an entire layer;

[0048] S40, peeling off the substrate, etching the epitaxial layer according to the location of the first electrode, forming a plurality of epitaxial layer units and exposed conductive barrier layers on both 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 to the corresponding driving units through via holes in the driving circuit layer;

[0049] S50, forming a second electrode on a side of each epitaxial layer unit away from the driving circuit layer; the second electrode is disposed throughout the entire layer, and the second electrode is electrically connected to the exposed conductive barrier layer;

[0050] Wherein, an epitaxial layer unit, a first electrode corresponding to the epitaxial layer unit and a second electrode corresponding to the epitaxial layer unit constitute a micro light emitting diode.

[0051] The manufacturing method of the above-mentioned display device provided by the embodiment of the present invention first manufactures an epitaxial layer, forms a driving circuit layer on the epitaxial layer, and then cuts the epitaxial layer and deposits electrodes. In this way, a Micro LED display unit that can be actively driven can be directly formed. This avoids the need to transfer and assemble Micro LEDs in large quantities when manufacturing the driving substrate and Micro LEDs separately, thereby improving the production yield and production efficiency of the display device.

[0052] Figure 2a-2d Schematic diagram of the cross-sectional structure of the display device corresponding to the execution of the above steps.

[0053] like Figure 2a As shown, an epitaxial layer 20 is first formed on a substrate 10. The substrate 10 needs to match the formed epitaxial layer. The epitaxial layer formed by the manufacturing method provided by the embodiment of the present invention is usually an epitaxial layer that emits a single color light wave. If full-color display is required, it is necessary to cooperate with a filter layer or a color conversion layer for image display after the manufacturing is completed.

[0054] like Figure 2b As shown in FIG. 1 , after forming the epitaxial layer 20, a drive circuit layer 30 is formed on the side of the epitaxial layer facing away from the substrate 10. The drive circuit layer 30 includes multiple drive units for controlling the active driving of the Micro LEDs. The drive units typically include components such as transistors, capacitors, and resistors. Simultaneously, embodiments of the present invention also form a conductive barrier layer throughout the drive circuit layer 30. This conductive barrier layer can be used to connect one side electrode of each Micro LED to form a common electrode drive mode.

[0055] like Figure 2c As shown, after forming the driving circuit layer 30, the epitaxial layer 20 and the driving circuit layer are transferred to a temporary substrate (10'), and the substrate 10 of the epitaxial layer 20 is peeled off. The epitaxial layer 20 is then etched to form a plurality of epitaxial layer units. After covering the epitaxial layer units with electrodes, a plurality of micro-LEDs 200 can be formed.

[0056] like Figure 2d As shown, finally, the micro light emitting diodes 200 are packaged, and a packaging protection layer 40 is formed on the surface of each Micro LED to complete the Micro LED display unit with an active driving unit.

[0057] Specifically, in the above-mentioned step S10, forming an epitaxial layer on the substrate specifically includes:

[0058] S101, forming an undoped layer on a substrate;

[0059] S102, forming a first doped layer on a side of the undoped layer facing away from the substrate;

[0060] S103, forming a light-emitting layer on a side of the first doped layer facing away from the undoped layer;

[0061] S104 , forming a second doping layer on a side of the light-emitting layer away from the first doping layer.

[0062] Figure 3 This is one of the schematic cross-sectional structural diagrams of a display device provided by an embodiment of the present invention.

[0063] Reference Figure 3 First, an undoped layer 201 is formed on the substrate 10. The undoped layer 201 is formed entirely on the substrate 10. The undoped layer 201 can be grown directly using the material of the epitaxial layer. For example, the undoped layer can be made of materials such as gallium oxide, which is not limited here.

[0064] After the undoped layer 201 is formed, a first doped layer 202 is formed on the undoped layer 201. The first doped layer 202 is entirely formed on the undoped layer 201. The first doped layer 202 can be N-type doped or P-type doped in the original material of the epitaxial layer so that the first doped layer 202 can provide electrons or holes.

[0065] After forming the first doping layer 202, the light emitting layer 203 is formed on the first doping layer 202. The light emitting layer 203 may be formed entirely on the first doping layer 202. The light emitting layer 203 may be a multi-quantum well layer to improve light emitting efficiency.

[0066] After the light-emitting layer 203 is formed, a second doped layer 204 is formed on the light-emitting layer 203. The second doped layer 204 is entirely formed on the light-emitting layer 203. The second doped layer 204 can be P-type doped or N-type doped in the original material of the epitaxial layer so that the second doped layer 204 can provide holes or electrons.

[0067] The first doping layer 202 and the second doping layer 204 are located on either side of the light-emitting layer 203, and the doping types of the two doping layers are opposite. If the first doping layer 202 is N-type doped, the second doping layer 204 is P-type doped; if the first doping layer 202 is P-type doped, the second doping layer 204 is N-type doped. In specific implementations, both of the above structures can be used and are not limited here.

[0068] Furthermore, after the epitaxial layer 20 is formed, the driving circuit layer 30 can be directly fabricated on the epitaxial layer 20. Prior to this, in the above-mentioned step S20, a first electrode is formed on the side of the epitaxial layer facing away from the substrate, specifically including:

[0069] S201, forming a first electrode layer on a side of the second doping layer facing away from the light-emitting layer;

[0070] S202, patterning the first electrode layer to form a pattern of the first electrode;

[0071] S203 , forming a reflective layer on a side of the first electrode facing away from the second doping layer.

[0072] Figure 4 This is a second schematic cross-sectional structural diagram of a display device provided in an embodiment of the present invention.

[0073] Reference Figure 4 After the epitaxial layer 20 is formed, a first electrode layer can be formed on the surface of the second doping layer 204 of the epitaxial layer 20. The first electrode layer can be provided as a whole layer, and then a plurality of mutually discrete first electrodes e1 are formed through a patterning process.

[0074] The first electrode e1 is an ohmic contact layer that matches the work function of the second doping layer 204 and can be made of metals such as nickel and gold, or transparent conductive materials such as indium tin oxide (ITO), which is not limited here.

[0075] In the embodiment of the present invention, after forming the first electrode e1, a reflective layer ( Figure 4 The reflective layer is used to reflect the light emitted by the Micro LED toward the light-emitting side, thereby improving the light efficiency.

[0076] The reflective layer can have the same pattern as the first electrode and can be made of the aforementioned materials such as nickel and gold. In this case, the reflective layer and the first electrode e1 can share a common layer. In addition, the reflective layer can also be made of high-reflectivity metal materials such as silver and aluminum, which are not limited here.

[0077] After the first electrode e1 (and the reflective layer) are formed, the driving circuit layer 30 is manufactured.

[0078] Specifically, in the above step S30, forming a driving circuit layer on a side of the first electrode away from the epitaxial layer specifically includes:

[0079] S301, forming a first insulating layer on a side of the reflective layer away from the first electrode;

[0080] S302, forming a conductive barrier layer on a side of the first insulating layer away from the second doping layer;

[0081] S303, forming a second insulating layer on a side of the conductive barrier layer away from the second doped layer;

[0082] S304, forming an active layer on a side of the second insulating layer away from the conductive barrier layer;

[0083] S305, forming a gate insulating layer on a side of the active layer away from the second insulating layer;

[0084] S306, forming a gate metal layer on a side of the gate insulating layer away from the active layer;

[0085] S307, forming an interlayer insulating layer on a side of the gate metal layer away from the gate insulating layer;

[0086] S308, forming a source and drain metal layer on a side of the interlayer insulating layer away from the gate metal layer;

[0087] S309, forming a third insulating layer on a side of the source / drain metal layer facing away from the interlayer insulating layer;

[0088] S310, forming another electrode of the capacitor and a pattern of a power signal line on a side of the third insulating layer away from the source / drain metal layer;

[0089] S311 , forming a passivation layer on a side of the third insulating layer away from the source / drain metal layer.

[0090] Among them, the active layer, gate, source and drain constitute a thin film transistor, and the drain 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 resistor and the insulating layer through the annular groove of the second insulating layer, the gate insulating layer, the interlayer insulating layer and the third insulating layer.

[0091] Continue to refer to Figure 4 After forming a reflective layer on the first electrode e1, a first insulating layer 301 can be formed on the reflective layer. The first insulating layer 301 is provided as a whole layer to insulate the first electrode e1, so that other conductive layers can be formed on the first insulating layer 301.

[0092] The first insulating layer 301 can be made of materials such as silicon oxide, silicon nitride, aluminum oxide, zirconium oxide, etc., which are not limited here.

[0093] After forming the first insulating layer 301, a conductive barrier layer 302 is formed on the first insulating layer 301. The conductive barrier layer can be formed entirely on the first insulating layer 301, and then a patterning process is performed to form a plurality of openings. These openings can expose the first electrode e1 and are formed to electrically connect subsequently formed circuits to the first electrode e1.

[0094] In the embodiment of the present invention, the conductive barrier layer 302 is used as a common electrode and therefore needs to be made of a conductive material. At the same time, the conductive barrier layer 302 also has the function of blocking etching, and thus can be made of metal materials such as platinum, titanium, nickel, or other transparent conductive materials such as crystallized indium tin oxide (POLY ITO) or indium zinc oxide (IZO), which are not limited here.

[0095] In order to reduce the resistance of the conductive barrier layer 302 , the thickness thereof may be set between 20 nm and 1000 nm, which is not limited here.

[0096] After the conductive barrier layer 302 is formed, a second insulating layer 303 is formed on the conductive barrier layer 302 . The second insulating layer 303 is provided as a whole layer to insulate the conductive barrier layer 302 , so that other conductive layers can be formed on the second insulating layer 303 .

[0097] The second insulating layer 303 can be made of silicon oxide, silicon nitride, aluminum oxide, zirconium oxide and other materials, which are not limited here.

[0098] After forming the second insulating layer 303, an active layer 304 is formed on 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 an undoped channel region.

[0099] The active layer 304 can be made of materials such as amorphous silicon, polycrystalline silicon, and metal oxides. Polycrystalline silicon can be formed by crystallizing amorphous silicon, which is not limited here.

[0100] After the active layer 304 is formed, a gate insulating layer 305 is formed on the active layer 304 . The gate insulating layer 305 is provided as a whole layer for insulating the active layer 304 , so that other conductive layers can be formed on the gate insulating layer 305 .

[0101] The gate insulating layer 305 can be made of materials such as silicon oxide, silicon nitride, aluminum oxide, zirconium oxide, etc., which are not limited here.

[0102] After the gate insulating layer 305 is formed, a gate metal layer 306 is formed on the gate insulating layer 305. A whole layer of gate metal layer 306 can be formed on the gate insulating layer 305, and then a pattern of a gate line, a gate, or one of the electrodes of the capacitor is formed through a patterning process.

[0103] The gate metal layer 306 can be made of a single layer or a stacked layer metal, which is not limited here.

[0104] After the gate metal layer 306 is formed, an interlayer insulating layer 307 is formed on the gate metal layer 306 . The interlayer insulating layer 307 is provided as a whole layer to insulate the gate metal layer 306 , so that other conductive layers can be formed on the interlayer insulating layer 307 .

[0105] The interlayer insulating layer 307 can be made of materials such as silicon oxide, silicon nitride, aluminum oxide, zirconium oxide, etc., which are not limited here.

[0106] After the interlayer insulating layer 307 is formed, a patterning process may be used to punch holes in the multiple insulating layers, thereby forming multiple vias that may be connected to the underlying conductive layer.

[0107] Then, a source-drain metal layer 308 is formed on the interlayer insulating layer 307. A whole source-drain metal layer 306 can be formed on the interlayer insulating layer 307, and then patterns of data lines, source electrodes, and drain electrodes are formed through a patterning process.

[0108] The source / drain metal layer 308 may be made of a single layer or a stacked layer metal, which is not limited here.

[0109] After the source / drain metal layer 308 is formed, a third insulating layer 309 is formed on the source / drain metal layer 308 . The third insulating layer 309 is provided as a whole layer to insulate the source / drain metal layer 308 , so that other conductive layers can be formed on the third insulating layer 309 .

[0110] The third insulating layer 309 can be made of materials such as silicon oxide, silicon nitride, aluminum oxide, zirconium oxide, etc., which are not limited here.

[0111] After forming the third insulating layer 309, a patterning process can be used to punch holes in the insulating layers to form multiple vias that can connect to the underlying conductive layer. At the same time, an annular through groove can be formed at the edge to expose the conductive barrier layer 302.

[0112] Then, a whole metal layer is formed on the third insulating layer 309 , and the metal layer is patterned to form another electrode of the capacitor and a pattern of the power signal line 310 .

[0113] The third insulating layer 309 is used as a dielectric layer between capacitors.

[0114] After the pattern of the power signal line is formed, a passivation layer 311 is formed on the third insulating layer 309. The passivation layer 311 is provided as a whole layer to insulate the underlying conductive layer and also protect the underlying film layer.

[0115] The passivation layer 311 can be made of materials such as silicon oxide, silicon nitride, aluminum oxide, zirconium oxide, etc., which are not limited here.

[0116] In an embodiment of the present invention, the active layer, the gate, the source and the drain constitute a thin film transistor, the gate of the thin film transistor is electrically connected to the gate line, the source of the thin film transistor is electrically connected to the data line, and the drain of the thin film transistor is electrically connected to the first electrode e1 through vias in the first insulating layer 301, the second insulating layer 303, the gate insulating layer 305 and the interlayer insulating layer 307.

[0117] One electrode of the capacitor located on the third insulating layer 309 is electrically connected to the gate of the thin film transistor through a via hole in the interlayer insulating layer 307 and the third insulating layer 309;

[0118] The power signal line 310 is electrically connected to the conductive barrier layer 302 through the annular grooves of the second insulating layer 303 , the gate insulating layer 305 , the interlayer insulating layer 307 and the third insulating layer 309 .

[0119] Thus, the driving circuit layer 30 is formed and the connection between the circuits is completed.

[0120] Furthermore, after forming the driving circuit layer on the side of the first electrode facing away from the epitaxial layer in the above step S30, and before peeling off the substrate in the above step S40, the method further includes:

[0121] S30 ′, transferring the epitaxial layer formed with the driving circuit layer onto a temporary substrate, and bonding the driving circuit layer and the temporary substrate.

[0122] Figure 5 This is a third schematic diagram of the cross-sectional structure of the display device provided in an embodiment of the present invention.

[0123] Reference Figure 5 On one side of the driving circuit layer 30 , a bonding layer 102 is used to bond the epitaxial layer 20 and the driving circuit layer 30 to the temporary substrate 101 .

[0124] The bonding layer 102 may be made of adhesive, or the driving circuit layer 30 and the temporary substrate 101 may be bonded by metal eutectic dissolution, which is not limited here.

[0125] The temporary substrate 101 may be a glass substrate or a resin substrate, which is not limited here.

[0126] After the epitaxial layer 20 and the driving circuit layer 30 are transferred, in the above-mentioned step S40, after the substrate is peeled off and before the epitaxial layer is etched according to the position of the first electrode, the following steps are further included:

[0127] S401, removing the substrate;

[0128] S402 , removing the undoped layer and thinning the first doped layer.

[0129] Continue to refer to Figure 5 After etching the epitaxial layer 20, the substrate on which the epitaxial layer 20 is formed needs to be removed. Specifically, the substrate 10 can be removed by laser lift-off (LLO) or chemical mechanical polishing (CMP).

[0130] After removing the substrate, the undoped layer 201 is removed and the first doped layer 302 is thinned. Because the undoped layer 201 has poor conductivity, it is necessary to remove it. The overall thickness of the epitaxial layer 20 affects the resistance of the device, so to reduce the resistance, the first doped layer 202 needs to be thinned.

[0131] Specifically, CMP or etching may be used to remove the undoped layer 201 and thin the first doped layer 202 , which is not limited here.

[0132] After the epitaxial layer 20 is subjected to the above-mentioned treatment, the epitaxial layer 20 may be etched.

[0133] Figure 6 This is a fourth schematic cross-sectional structural diagram of a display device provided in an embodiment of the present invention.

[0134] Reference Figure 6 In the embodiment of the present invention, when etching the epitaxial layer 20, it is necessary to etch the epitaxial layer 20 into a plurality of epitaxial layer units m according to the area where the first electrode e1 is located. One epitaxial layer unit m corresponds to one first electrode e1, and the area where the epitaxial layer unit m is located corresponds to one pixel area, in which a micro light emitting diode will be formed. Figure 6 , the orthographic projection of the epitaxial layer unit m on the temporary substrate completely covers the orthographic projection of the first electrode e1 on the temporary substrate.

[0135] During etching, all epitaxial layers 20 need to be etched through until the conductive barrier layer 302 is exposed between the epitaxial layer units. The conductive barrier layer 302 can act as an etch stop, so that the drive circuit layer 30 below the conductive barrier layer 302 is not damaged when etching the epitaxial layer 20.

[0136] After etching the epitaxial layer 20 , a second electrode is formed on a side of each epitaxial layer unit away from the driving circuit layer.

[0137] Specifically, in the above step S50, forming a second electrode on a side of each epitaxial layer unit away from the driving circuit layer specifically includes:

[0138] S501, forming a fourth insulating layer on a side of the thinned first doped layer away from the driving circuit layer;

[0139] S502 , forming a second electrode on a side of the fourth insulating layer away from the driving circuit layer.

[0140] Figure 7 This is the fifth schematic diagram of the cross-sectional structure of the display device provided in an embodiment of the present invention.

[0141] Reference Figure 7 After etching the epitaxial layer 20 to form a plurality of mutually discrete epitaxial layer units m, a fourth insulating layer 205 can be formed on the surface of each epitaxial layer unit m. Specifically, the fourth insulating layer 205 can be formed entirely on the surface of the exposed conductive barrier layer 302 and the thinned first doped layer 202. The fourth insulating layer 205 is then patterned to form openings that expose the surface of each epitaxial layer unit m and the conductive barrier layer 302 on both sides of each epitaxial layer unit.

[0142] The fourth insulating layer 205 can be made of materials such as silicon oxide, silicon nitride, aluminum oxide, zirconium oxide, etc., which are not limited here.

[0143] The fourth insulating layer can cover the sidewalls of the epitaxial layer unit to prevent short circuit.

[0144] Figure 8 This is the sixth schematic diagram of the cross-sectional structure of the display device provided in an embodiment of the present invention.

[0145] Reference Figure 8 After forming the pattern of the fourth insulating layer 205, the second electrode e2 is formed on the fourth insulating layer 205. Specifically, the second electrode e2 can be formed entirely on the exposed conductive barrier layer 302, the fourth insulating layer 205, and the exposed first doped layer 202.

[0146] The second electrode e2 is an ohmic contact layer that matches the work function of the first doped layer 202 and can be generally made of metals such as nickel and gold, or can also be made of transparent conductive materials such as indium tin oxide (ITO), which is not limited here.

[0147] like Figure 8 As shown, an epitaxial layer unit m and its corresponding first electrode e1 and second electrode e2 constitute a Micro LED. The signal provided by the power signal line 310 can be applied to the conductive barrier layer 302. The signal applied to the conductive barrier layer 302 can be applied to one side of the first doped layer 202 via the second electrode e2. The signal provided by the data line can pass through the drain electrode of the thin-film transistor to the first electrode e1, and then be applied to one side of the second doped layer 204 via the first electrode e1. This allows each Micro LED to be actively driven using a common electrode.

[0148] The display device fabricated using the manufacturing method provided by the embodiments of the present invention has a common electrode structure. Since the common electrode's electrical signal is applied to the conductive barrier layer 302, only a small area of ​​the second electrode e2 (the ohmic contact layer in contact with the first doped layer) located on the Micro LED sidewall functions to conduct the electrical signal. Therefore, the common electrode's resistance depends on the resistance of the conductive barrier layer 302 and has little correlation with the material resistance of the second electrode e2. Therefore, selecting a low-impedance conductive material for the conductive barrier layer 302 or increasing its thickness can effectively reduce its resistance, thereby effectively solving the problem of significant common electrode voltage drop.

[0149] After forming the second electrode e2, the manufacturing method provided by the embodiment of the present invention may further include the following steps:

[0150] S60, forming a light shielding layer at intervals between the micro-LEDs on a side of the second electrode facing away from the driving circuit layer;

[0151] S70, forming a flat layer on the side of the light shielding layer and each micro-LED facing away from the driving circuit layer;

[0152] S80, forming a protective layer on a side of the flat layer facing away from the micro light emitting diode;

[0153] S90, peeling off the temporary substrate.

[0154] Figure 9 This is the seventh schematic diagram of the cross-sectional structure of the display device provided in an embodiment of the present invention.

[0155] Reference Figure 9 In order to avoid crosstalk between pixel units, after the second electrode e2 is formed, a light shielding layer 401 can be formed at the intervals between the micro-LEDs on the side of the second electrode e2 away from the driving circuit layer 30.

[0156] The light shielding layer 401 can be made of black resin material, and has a grid-like pattern that shields the intervals between the micro-LEDs.

[0157] After forming the light-shielding layer 401, a planarization layer 402 can be applied over the micro-LEDs and light-shielding layer 401. Planarization layer 402 can be fabricated by covering the entire device and has a relatively large thickness to flatten the device surface. In practice, planarization layer 402 can be fabricated using a plastic or organic material, without limitation.

[0158] After forming the planar layer 402, a protective layer 403 may be formed over the planar layer 402. The planar layer 403 may be formed by providing a full-layer coverage, and the protective layer 403 may serve to encapsulate and protect the micro-LED 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 here.

[0159] Figure 10 This is the eighth schematic diagram of the cross-sectional structure of the display device provided by an embodiment of the present invention.

[0160] Reference Figure 10 After the protective layer 403 is formed, the temporary substrate 101 and the bonding layer 102 can be peeled off to expose the driving circuit layer 30 in preparation for subsequent binding work.

[0161] It should be noted that the temporary substrate 101 may not be removed during the manufacturing process. Depending on the actual application, if it is applied to a rigid display device, the temporary substrate 101 can be made of a rigid material such as glass; if it is applied to a flexible display device, the temporary substrate 101 can be made of a flexible material such as polyimide (PI), and there is no limitation here.

[0162] The display device provided in the embodiments of the present invention can also be fabricated as a transparent display device. In this case, the conductive barrier layer 302, the transient substrate 101, and the bonding layer 102 can be made of transparent materials. Furthermore, the driving unit can be fabricated directly below the Micro LED, omitting the light shielding layer 401, thereby achieving a transparent display.

[0163] After the above steps, the Figure 10 In the display unit structure shown, the display unit may include only one Micro LED, or may include multiple Micro LEDs to form a display unit, or may directly form a sufficient number of Micro LEDs to form a display device.

[0164] Figure 11a This is one of the structural schematic diagrams of the display device provided by an embodiment of the present invention.

[0165] Reference Figure 11a When the epitaxial layer 20 is etched to form enough Micro LEDs, a driver chip IC can be directly bonded to one side of the driver circuit layer 30, and then an encapsulation layer 50 is formed on the surface of the driver circuit layer 30 and the driver chip IC to form a Micro LED display device.

[0166] A driver chip IC is bound to one side of the driving circuit layer 30, and the driving circuit layer 30 needs to be punched so that the driver chip IC is connected to the circuit in the driving circuit layer 30. The driver chip IC provides a driving signal to the display device, and uses an active driving method to drive the Micro LED to display images.

[0167] The encapsulation layer 50 may be configured by stacking an inorganic layer and an organic layer to encapsulate and protect the driving circuit layer.

[0168] Figure 11b This is a second structural diagram of the display device provided in an embodiment of the present invention.

[0169] Reference Figure 11b When the display device needs to be enlarged, multiple Figure 11a The Micro LED display devices shown are spliced ​​to form a spliced ​​display device to achieve ultra-large-size image display.

[0170] like Figure 11b As shown, for each display panel in the spliced ​​display device, a driver chip IC can be bound to one side of the driving circuit layer 30. After each display panel is packaged, it is integrated onto the integrated backplane 60 to form a spliced ​​display device.

[0171] Figure 11c This is a third structural diagram of the display device provided in an embodiment of the present invention.

[0172] Reference Figure 11c , in the formation Figure 10 After the display unit shown, if the display unit only includes one or several Micro LEDs, then multiple display units can be integrated onto the driving backplane 70, and each display unit can be connected to the circuit of the driving backplane 70 by circuit connection. Then, by binding the driving chip to the driving backplane 70, each display unit can be controlled to display an image.

[0173] On the other hand, an embodiment of the present invention further provides a display device manufactured using the above manufacturing method. The structure of the display device can be seen in FIG. Figure 10 .

[0174] like Figure 10 As shown, the display device includes a driving circuit layer 30 and a micro light emitting diode 200 located on the driving circuit layer 30 .

[0175] The driving circuit layer 30 includes a conductive barrier layer 302 and a driving unit.

[0176] The driving unit in the driving circuit layer 30 includes components such as thin film transistors, capacitors, and resistors.

[0177] The surface of the driving line seed layer 30 has a grid pattern with exposed conductive resistors and barrier layers. The exposed conductive resistors and barrier layers 302 divide pixel areas.

[0178] At least one micro-LED 200 is located in the pixel region on the side of the driving circuit layer 30 that exposes the conductive barrier layer 302 .

[0179] In the embodiment of the present invention, one pixel region corresponds to one micro-LED 200, and each micro-LED 200 corresponds to a driving unit on a one-to-one basis. The micro-LED 200 is actively driven under the control of its corresponding driving unit.

[0180] The micro light emitting diode 200 includes a first electrode e1, an epitaxial layer unit m and a second electrode e2.

[0181] The first electrode e1 is located on one side of the micro-LED 200 close to the driving circuit layer 30 . The orthographic projection of the micro-LED 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 circuit layer 30 .

[0182] The epitaxial layer unit m is obtained by etching the entire epitaxial layer 20 , and one epitaxial layer unit m corresponds to one first electrode e1 .

[0183] The second electrode e2 is located on a side of the micro-LED 200 away from the driving circuit layer 30 . The second electrode e2 of each micro-LED 200 is disposed throughout the entire layer. The second electrode e2 is electrically connected to the exposed conductive barrier layer 302 .

[0184] The micro-LEDs 200 emit light under the influence of the electric field generated by the electrical signals applied to the first and second electrodes e1 and e2. The display device provided in this embodiment of the present invention is manufactured by first forming an epitaxial layer 20, then forming a drive circuit layer 30 on the epitaxial layer 20, and then etching the epitaxial layer 20 to form the plurality of micro-LEDs 200. Therefore, the drive circuits and micro-LEDs in the display panel are formed using a single manufacturing process, eliminating the need to align the drive circuits and micro-LEDs, thereby improving production yield and efficiency.

[0185] The first electrode e1 of the micro-LED 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. Then, each micro-LED can load different image signals to the first electrode e1 through the corresponding driving unit to realize image display.

[0186] The conductive barrier layer 302 is located on the side of the driving circuit layer close to the micro-LED 200, and the driving unit is located on the side of the conductive barrier layer 302 facing away from the micro-LED 200. The conductive barrier layer 302 includes multiple openings during fabrication, and the driving unit can be electrically connected to the first electrode e1 of the corresponding micro-LED through the openings of the conductive barrier layer 302.

[0187] 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 effect, thereby preventing the driving unit from being damaged by the etching step.

[0188] In a specific implementation, the conductive barrier layer 302 is made of a metal or a transparent conductive material. For example, it can be made of metal materials such as platinum, titanium, and nickel. When used in a transparent display device, it can also be made of transparent conductive materials such as crystallized indium tin oxide (POLY ITO) or indium zinc oxide (IZO), without limitation.

[0189] At the same time, in order to reduce the resistance of the conductive barrier layer 302 , the thickness of the conductive barrier layer 302 may be increased. In the embodiment of the present invention, the thickness of the conductive barrier layer 302 may be set to 20 nm-1000 nm.

[0190] The drive unit is located below the conductive barrier layer 302. The drive circuit layer also includes multiple gate lines and multiple data lines. The gate lines and data lines are arranged to intersect with each other and divide the multiple pixel units. Typically, the drive unit includes a thin-film transistor, the gate of the thin-film transistor is electrically connected to the corresponding gate line, the source is electrically connected to the corresponding signal line, and the drain is electrically connected to the first electrode e1 of the corresponding Micro LED. Then, when the gate lines are scanned row by row, when the gate lines are loaded with an effective level signal, the data lines corresponding to the gate lines can load the data signals to the corresponding Micro LEDs, thereby achieving active driving of the Micro LEDs.

[0191] The driving circuit layer also includes power signal lines that surround all driving units. Before the power signal lines are formed, an annular through-groove can be formed at the edge to expose the conductive barrier layer 302. This allows an electrical connection to be established between the power signal lines and the conductive barrier layer 302 when the power signal lines are formed. The power signal lines are arranged around the edge of the display device to reduce voltage drop when a power signal is applied to the conductive barrier layer 302.

[0192] like Figure 10 As shown, the display device further includes:

[0193] The light shielding layer 401 is located between the micro-LEDs 200 on the side of the second electrode e2 facing away from the driving circuit layer 30 .

[0194] The light shielding layer can prevent light leakage from the Micro LED and achieve higher contrast when displaying images. In a transparent display device, the light shielding layer 401 can be omitted.

[0195] The planar layer 402 covers the light shielding layer 401 and the side of each micro-LED 200 facing away from the driving circuit layer 30 .

[0196] The planarization layer 402 is generally thick and is used to planarize the surface of the display device while also protecting the Micro LEDs.

[0197] The protection layer 403 is located on a side of the planar layer 402 facing away from the micro-LED 200 .

[0198] The protective layer 403 is used to encapsulate and protect the Micro LED. It can usually be arranged by alternating inorganic and organic layers. The innermost and outermost film layers are both inorganic layers, which can block water and oxygen and extend the service life of the Micro LED.

[0199] A driving chip or a driving backplane can be bonded to one side of the driving circuit layer 30 for application in different scenarios.

[0200] In some embodiments, as Figure 11a As shown, the display device further includes:

[0201] The driving chip IC is located on a side of the driving circuit layer 30 away from the micro-LED 200 . The driving chip IC is electrically connected to the circuits in the driving circuit layer through the through holes of the driving circuit layer 30 .

[0202] The encapsulation layer 50 covers the surfaces of the driver chip IC and the driver circuit layer 300 .

[0203] This forms a Micro LED display device. In this case, the epitaxial layer can be etched to form a sufficient number of Micro LEDs, which are then combined with color filters, filters or quantum dot films to realize image display.

[0204] In some embodiments, as Figure 11b As shown, the display device further includes:

[0205] The driving chip IC is located on a side of the driving circuit layer 30 away from the micro-LED 200 . The driving chip IC is electrically connected to the circuits in the driving circuit layer through the through holes of the driving circuit layer 30 .

[0206] The packaging layer 50 covers the surfaces of the driver chip IC and the driver circuit layer 30 .

[0207] Among them, 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 constitute a display panel unit, and at least two display panel units are arranged on the integrated backplane 60 to form a spliced ​​display device.

[0208] In some embodiments, as Figure 11c As shown, the driving circuit layer 30 and the micro-LEDs 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 to the driving backplane. The above-mentioned display units are active display units, so after integrating multiple display units with the driving backplane, an active drive display can be achieved.

[0209] According to the first inventive concept, an epitaxial layer is formed on a substrate; a first electrode is formed on the side of the epitaxial layer facing away from the substrate; a drive circuit layer is formed on the side of the first electrode facing away from the epitaxial layer; the substrate is peeled off, and the epitaxial layer is etched according to the location of the first electrode to form multiple epitaxial layer units; and a second electrode is formed on the side of the epitaxial layer unit facing away from the drive circuit layer. This allows the direct formation of an actively driven Micro LED display unit, avoiding the need for mass transfer and assembly of Micro LEDs when separately manufacturing the drive substrate and Micro LEDs, thereby improving the production yield and efficiency of the display device.

[0210] According to the second inventive concept, forming an epitaxial layer on a 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 doped layer and the second doped layer is an N-type doped layer and the other is a P-type doped layer, and the light-emitting layer is a multi-quantum well layer.

[0211] According to the third inventive concept, after forming the epitaxial layer and before forming the driving circuit layer, the method further includes forming a first electrode pattern on the side of the second doped layer away from the light emitting layer. The first electrode is an ohmic contact layer having a work function matching that of the second doped layer.

[0212] According to the fourth inventive concept, a reflective layer is formed on the first electrode, so as to be applied to a top-emitting Micro LED display device. The reflective layer is used to reflect the light emitted by the Micro LED to the light-emitting side, thereby achieving the purpose of improving the light efficiency.

[0213] According to the fifth inventive concept, the manufacturing of the driving circuit layer includes: a first insulating layer, a conductive barrier layer, a second insulating layer, an active layer, a gate insulating layer, a gate metal layer, an interlayer insulating layer, a source-drain metal layer, a third insulating layer, a pattern of capacitor electrodes and power signal lines, and a passivation layer, which are manufactured in sequence. Among them, the gate metal layer includes a pattern of a gate line, a gate, and one of the electrodes of the capacitor; the source-drain metal layer includes a pattern of a data line, a source electrode, and a drain electrode; the active layer, the gate, the source electrode, and the drain electrode constitute a thin film transistor. The conductive barrier layer includes an opening exposing the first electrode. The gate of the thin film transistor is electrically connected to the gate line, the source electrode is electrically connected to the data line, and the drain electrode is electrically connected to the first electrode through the opening of the conductive barrier layer. In this way, the Micro LED can be actively driven by a driving unit including a thin film transistor.

[0214] According to the sixth inventive concept, the power signal line is electrically connected to the conductive barrier layer through the annular through groove at the edge, thereby improving the voltage drop problem.

[0215] According to the seventh inventive concept, after forming the driving circuit layer and before peeling off the substrate, the epitaxial layer formed with the driving circuit layer is transferred onto a temporary substrate, and the driving circuit layer is bonded to the temporary substrate.

[0216] According to the eighth inventive concept, before etching the epitaxial layer, the substrate and undoped layer are removed, and the first doped layer is thinned. The undoped layer has poor conductivity, so it is necessary to remove the undoped layer. The overall thickness of the epitaxial layer affects the resistance of the device, so to reduce the resistance, the first doped layer needs to be thinned.

[0217] According to the ninth inventive concept, etching the epitaxial layer requires etching through the entire epitaxial layer until the conductive barrier layer is exposed between the epitaxial layer units. The conductive barrier layer can act as an etch stop, so that the drive circuit layer below the conductive barrier layer is not damaged during etching of the epitaxial layer.

[0218] According to the tenth inventive concept, forming a second electrode on the surface of the epitaxial layer unit includes: forming a fourth insulating layer on a side of the thinned first doped layer facing away from the drive circuit layer, and forming a second electrode on a side of the fourth insulating layer facing away from the drive circuit layer. The fourth insulating layer can cover the sidewalls of the epitaxial layer unit to prevent short circuits. The second electrode is an ohmic contact layer that matches the work function of the first doped layer. The signal provided by the power signal line can be applied to the conductive barrier layer, and the signal applied to the conductive barrier layer can be applied to one side of the first doped layer via the second electrode.

[0219] According to the eleventh inventive concept, the Micro LED second electrode is electrically connected to the conductive barrier layer to form a common electrode structure. Since the common electrode's electrical signal is applied to the conductive barrier layer, only a small area of ​​the second electrode located on the Micro LED sidewall functions to conduct the electrical signal. Therefore, the resistance of the common electrode depends on the resistance of the conductive barrier layer and has little correlation with the material resistance of the second electrode. Therefore, by selecting a low-impedance conductive material for the conductive barrier layer or increasing the thickness of the conductive barrier layer, its resistance can be effectively reduced, thereby effectively solving the problem of significant common electrode voltage drop.

[0220] According to the twelfth inventive concept, the conductive barrier layer is made of a metal material such as platinum, titanium, or nickel. When used in a transparent display device, it can also 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 20 nm to 1000 nm.

[0221] According to the thirteenth inventive concept, after forming the Micro LED, it also includes: forming a light shielding layer between the Micro LEDs, forming a flat layer on the side of the light shielding layer and the Micro LED away from the driving circuit layer, and forming a protective layer on the side of the flat layer away from the Micro LED.

[0222] According to the fourteenth inventive concept, the temporary substrate is peeled off and the driving chip and the driving circuit layer are bound together.

[0223] According to the fifteenth inventive concept, when the epitaxial layer is etched to form a sufficient number of Micro LEDs, a driver chip can be directly bound to one side of the driver circuit layer, and then a packaging layer can be formed on the surface of the driver circuit layer and the driver chip to form a Micro LED display device.

[0224] According to the sixteenth inventive concept, when the display device needs to be enlarged in size, multiple Micro LED display devices can be spliced ​​together to form a spliced ​​display device to achieve ultra-large-size image display.

[0225] According to the seventeenth inventive concept, after forming a Micro LED display unit, if the display unit includes only one or several Micro LEDs, then multiple display units can be integrated onto a driving backplane, and each display unit can be connected to the circuit of the driving backplane by using a circuit connection method, and then by binding a driving chip to the driving backplane, each display unit can be controlled to display an image.

[0226] According to the eighteenth inventive concept, the temporary substrate may not be removed during the manufacturing process. Then, depending on the actual application, if it is applied to a rigid display device, the temporary substrate may be made of a rigid material such as glass; if it is applied to a flexible display device, the temporary substrate may be made of a flexible material such as polyimide (PI).

[0227] According to the nineteenth inventive concept, the display device can also be fabricated as a transparent display device. In this case, the conductive barrier layer, transient substrate, and bonding layer can be made of transparent materials. Furthermore, the driving unit can be fabricated directly below the Micro LED, eliminating the need for a light shielding layer, thereby achieving a transparent display.

[0228] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0229] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A display device, characterized in that: include: A driving circuit layer, wherein the driving circuit layer includes a conductive resistor and a driving unit arranged in an entire layer, and a surface of the driving circuit layer has a grid pattern exposing the conductive resistor and the insulating layer, and the exposed conductive resistor and insulating layer divide the pixel area; At least one micro light emitting diode is located in the pixel region of the driving circuit layer on a side of the conductive barrier layer exposed; The micro light emitting diodes correspond to the driving units one by one; The micro light emitting diode comprises: A first electrode is located on a side of the micro-LED close to the driving circuit layer, and the orthographic projection of the micro-LED on the driving circuit layer covers the first electrode; the first electrode is electrically connected to the corresponding driving unit through a via hole in the driving circuit layer; The second electrode is located at a side of the micro-LED away from the driving circuit layer, and the second electrode of each micro-LED is arranged as a whole layer; the second electrode is electrically connected to the exposed conductive barrier layer.

2. The display device according to claim 1, wherein: The conductive resistor barrier layer is located on the side close to the micro-light emitting diode, and the driving unit is located on the side of the conductive resistor barrier layer away from the micro-light emitting diode; The conductive resistor barrier layer includes a plurality of openings, and the driving unit is electrically connected to the corresponding micro light emitting diodes through the openings of the conductive resistor barrier layer.

3. The display device according to claim 1, wherein: Also includes: A light shielding layer, located at an interval between the micro light emitting diodes on a side of the second electrode away from the driving circuit layer; A flat layer, covering the light shielding layer and a side of each of the micro-LEDs away from the driving circuit layer; The protection layer is located on a side of the flat layer away from the micro light emitting diode.

4. The display device according to claim 1, wherein: The driving circuit layer also includes: A power signal line is arranged around each of the driving units; the power signal line is electrically connected to 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, characterized in that: The display device further includes: A driving chip is located on a side of the driving circuit layer away from the micro-light emitting diode, and the driving chip is electrically connected to the circuit in the driving circuit layer through the through hole of the driving circuit layer; A packaging layer, covering the surfaces of the driving chip and the driving circuit layer; Alternatively, the display device further includes: A driving chip is located on a side of the driving circuit layer away from the micro-light emitting diode, and the driving chip is electrically connected to the circuit in the driving circuit layer through the through hole of the driving circuit layer; A packaging layer, covering the surfaces of the driving chip and the driving circuit layer; The driving circuit layer, the micro-LEDs electrically connected to the driving circuit layer, and the driving chip electrically connected to the driving circuit layer constitute a display panel unit; The display device further includes: An integrated backplane, on which at least two display panel units are arranged to form a spliced ​​display device; Alternatively, the driving circuit layer and each of the micro-LEDs electrically connected to the driving circuit layer constitute a display unit; and the display device further comprises: A driving backplane, at least two of the display units are located on the driving backplane, and each of the display units is electrically connected to the driving backplane.

6. A method for manufacturing a display device, characterized in that: include: forming an epitaxial layer on a substrate; forming a first electrode on a side of the epitaxial layer facing away from the substrate; The first electrodes have mutually separate patterns, and the first electrodes and the corresponding epitaxial layers constitute a light-emitting unit; A driving circuit layer is formed on a side of the first electrode away from the epitaxial layer; the driving circuit layer includes a conductive barrier layer and a driving unit arranged in an integral layer; The substrate is peeled off, and the epitaxial layer is etched according to the position of the first electrode to form a plurality of epitaxial layer units and exposed conductive barrier layers located on both 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 to the corresponding driving units through the via holes of the driving circuit layer; A second electrode is formed on a side of each epitaxial layer unit away from the driving circuit layer; the second electrode is disposed throughout the entire layer, and the second electrode is electrically connected to the exposed conductive barrier layer; Among them, one epitaxial layer unit, the first electrode corresponding to the epitaxial layer unit and the second electrode corresponding to the epitaxial layer unit constitute a micro light emitting diode.

7. The method according to claim 6, characterized in that: The step of forming an epitaxial layer on a substrate comprises: forming an undoped layer on the substrate; forming a first doped layer on a side of the undoped layer facing away from the substrate; forming a light-emitting layer on a side of the first doped layer away from the undoped layer; A second doping layer is formed on a side of the light emitting layer away from the first doping layer.

8. The method according to claim 7, characterized in that: The step of forming a first electrode on a side of the epitaxial layer away from the substrate comprises: forming a first electrode layer on a side of the second doped layer away from the light emitting layer; Patterning the first electrode layer to form a pattern of the first electrode; forming a reflective layer on a side of the first electrode facing away from the second doping layer; The step of forming a driving circuit layer on a side of the first electrode facing away from the epitaxial layer comprises: forming a first insulating layer on a side of the reflective layer away from the first electrode; forming a conductive barrier layer on a side of the first insulating layer away from the second doping layer; the conductive barrier layer comprises an opening exposing the first electrode; forming a second insulating layer on a side of the conductive barrier layer away from the second doped layer; forming an active layer on a side of the second insulating layer away from the conductive barrier layer; forming a gate insulating layer on a side of the active layer away from the second insulating layer; A gate metal layer is formed on a side of the gate insulating layer away from the active layer; the gate metal layer includes a pattern of a gate and one of the electrodes of a capacitor; forming an interlayer insulating layer on a side of the gate metal layer away from the gate insulating layer; A source-drain metal layer is formed on a side of the interlayer insulating layer away from the gate metal layer; the source-drain metal layer includes patterns of source and drain electrodes; forming a third insulating layer on a side of the source / drain metal layer away from the interlayer insulating layer; Forming another electrode of the capacitor and a pattern of a power signal line on a side of the third insulating layer away from the source-drain metal layer; Among them, the active layer, the gate, the source and the drain constitute a thin film transistor, and the drain 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 resistor and the insulating layer through the annular grooves of the second insulating layer, the gate insulating layer, the interlayer insulating layer and the third insulating layer.

9. The method of claim 8, wherein: After forming a driving circuit layer on a side of the first electrode away from the epitaxial layer and before peeling off the substrate, the method further includes: Transferring the epitaxial layer formed with the driving circuit layer onto a temporary substrate, and bonding the driving circuit layer and the temporary substrate; After the substrate is peeled off and before the epitaxial layer is etched according to the position of the first electrode, the method further includes: removing the substrate; The undoped layer is removed, and the first doped layer is thinned.

10. The manufacturing method according to claim 9, characterized in that: The forming of a second electrode on a side of each epitaxial layer unit away from the driving circuit layer comprises: A fourth insulating layer is formed on a side of the first doped layer after thinning away from the driving circuit layer; the fourth insulating layer is provided as a whole layer, and the fourth insulating layer has openings exposing the surface of each epitaxial layer unit and the conductive and resistive barrier layers on both sides of each epitaxial layer unit; forming a second electrode on a side of the fourth insulating layer away from the driving circuit layer; The production method further comprises: forming a light shielding layer at intervals between the micro-LEDs on a side of the second electrode away from the driving circuit layer; forming a flat layer on the side of the light shielding layer and each of the micro-LEDs away from the driving circuit layer; forming a protective layer on a side of the flat layer facing away from the micro-light emitting diode; The temporary substrate is peeled off.

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